Index: flang/lib/Semantics/check-call.cpp =================================================================== --- flang/lib/Semantics/check-call.cpp +++ flang/lib/Semantics/check-call.cpp @@ -207,16 +207,18 @@ dummy.attrs.test(characteristics::DummyDataObject::Attr::Pointer)}; bool dummyIsAllocatableOrPointer{dummyIsAllocatable || dummyIsPointer}; allowActualArgumentConversions &= !dummyIsAllocatableOrPointer; - if (allowActualArgumentConversions) { - ConvertIntegerActual(actual, dummy.type, actualType, messages); - } - bool typesCompatible{ + bool typesCompatibleWithIgnoreTKR{ (dummy.ignoreTKR.test(common::IgnoreTKR::Type) && (dummy.type.type().category() == TypeCategory::Derived || actualType.type().category() == TypeCategory::Derived || dummy.type.type().category() != actualType.type().category())) || (dummy.ignoreTKR.test(common::IgnoreTKR::Kind) && - dummy.type.type().category() == actualType.type().category()) || + dummy.type.type().category() == actualType.type().category())}; + allowActualArgumentConversions &= !typesCompatibleWithIgnoreTKR; + if (allowActualArgumentConversions) { + ConvertIntegerActual(actual, dummy.type, actualType, messages); + } + bool typesCompatible{typesCompatibleWithIgnoreTKR || dummy.type.type().IsTkCompatibleWith(actualType.type())}; if (!typesCompatible && dummy.type.Rank() == 0 && allowActualArgumentConversions) { Index: flang/test/Semantics/ignore_tkr02.f90 =================================================================== --- flang/test/Semantics/ignore_tkr02.f90 +++ flang/test/Semantics/ignore_tkr02.f90 @@ -17,21 +17,21 @@ !dir$ ignore_tkr(kr) k end end interface -!CHECK: CALL sub1(1_1,int(1_1,kind=4)) +!CHECK: CALL sub1(1_1,1_1) call generic(1_1,1_1) -!CHECK: CALL sub1(1_1,int(1_2,kind=4)) +!CHECK: CALL sub1(1_1,1_2) call generic(1_1,1_2) !CHECK: CALL sub1(1_1,[INTEGER(1)::1_1]) call generic(1_1,[1_1]) -!CHECK: CALL sub2(1_2,int(1_1,kind=4)) +!CHECK: CALL sub2(1_2,1_1) call generic(1_2,1_1) -!CHECK: CALL sub2(1_2,int(1_2,kind=4)) +!CHECK: CALL sub2(1_2,1_2) call generic(1_2,1_2) !CHECK: CALL sub2(1_2,[INTEGER(1)::1_1]) call generic(1_2,[1_1]) -!CHECK: CALL sub4(1_4,int(1_1,kind=4)) +!CHECK: CALL sub4(1_4,1_1) call generic(1_4,1_1) -!CHECK: CALL sub4(1_4,int(1_2,kind=4)) +!CHECK: CALL sub4(1_4,1_2) call generic(1_4,1_2) !CHECK: CALL sub4(1_4,[INTEGER(1)::1_1]) call generic(1_4,[1_1]) Index: mypatch.patch =================================================================== --- /dev/null +++ mypatch.patch @@ -0,0 +1,20058 @@ +diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp +index cbe4229b05d0..65122c04c4b3 100644 +--- a/clang/lib/Sema/SemaDeclCXX.cpp ++++ b/clang/lib/Sema/SemaDeclCXX.cpp +@@ -1,18644 +1,18644 @@ + //===------ SemaDeclCXX.cpp - Semantic Analysis for C++ Declarations ------===// + // + // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. + // See https://llvm.org/LICENSE.txt for license information. + // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception + // + //===----------------------------------------------------------------------===// + // + // This file implements semantic analysis for C++ declarations. + // + //===----------------------------------------------------------------------===// + + #include "clang/AST/ASTConsumer.h" + #include "clang/AST/ASTContext.h" + #include "clang/AST/ASTLambda.h" + #include "clang/AST/ASTMutationListener.h" + #include "clang/AST/CXXInheritance.h" + #include "clang/AST/CharUnits.h" + #include "clang/AST/ComparisonCategories.h" + #include "clang/AST/DeclCXX.h" + #include "clang/AST/DeclTemplate.h" + #include "clang/AST/EvaluatedExprVisitor.h" + #include "clang/AST/ExprCXX.h" + #include "clang/AST/RecordLayout.h" + #include "clang/AST/RecursiveASTVisitor.h" + #include "clang/AST/StmtVisitor.h" + #include "clang/AST/TypeLoc.h" + #include "clang/AST/TypeOrdering.h" + #include "clang/Basic/AttributeCommonInfo.h" + #include "clang/Basic/PartialDiagnostic.h" + #include "clang/Basic/Specifiers.h" + #include "clang/Basic/TargetInfo.h" + #include "clang/Lex/LiteralSupport.h" + #include "clang/Lex/Preprocessor.h" + #include "clang/Sema/CXXFieldCollector.h" + #include "clang/Sema/DeclSpec.h" + #include "clang/Sema/EnterExpressionEvaluationContext.h" + #include "clang/Sema/Initialization.h" + #include "clang/Sema/Lookup.h" + #include "clang/Sema/ParsedTemplate.h" + #include "clang/Sema/Scope.h" + #include "clang/Sema/ScopeInfo.h" + #include "clang/Sema/SemaInternal.h" + #include "clang/Sema/Template.h" + #include "llvm/ADT/STLExtras.h" + #include "llvm/ADT/ScopeExit.h" + #include "llvm/ADT/SmallString.h" + #include "llvm/ADT/StringExtras.h" + #include + #include + #include + + using namespace clang; + + //===----------------------------------------------------------------------===// + // CheckDefaultArgumentVisitor + //===----------------------------------------------------------------------===// + + namespace { + /// CheckDefaultArgumentVisitor - C++ [dcl.fct.default] Traverses + /// the default argument of a parameter to determine whether it + /// contains any ill-formed subexpressions. For example, this will + /// diagnose the use of local variables or parameters within the + /// default argument expression. + class CheckDefaultArgumentVisitor + : public ConstStmtVisitor { + Sema &S; + const Expr *DefaultArg; + + public: + CheckDefaultArgumentVisitor(Sema &S, const Expr *DefaultArg) + : S(S), DefaultArg(DefaultArg) {} + + bool VisitExpr(const Expr *Node); + bool VisitDeclRefExpr(const DeclRefExpr *DRE); + bool VisitCXXThisExpr(const CXXThisExpr *ThisE); + bool VisitLambdaExpr(const LambdaExpr *Lambda); + bool VisitPseudoObjectExpr(const PseudoObjectExpr *POE); + }; + + /// VisitExpr - Visit all of the children of this expression. + bool CheckDefaultArgumentVisitor::VisitExpr(const Expr *Node) { + bool IsInvalid = false; + for (const Stmt *SubStmt : Node->children()) + IsInvalid |= Visit(SubStmt); + return IsInvalid; + } + + /// VisitDeclRefExpr - Visit a reference to a declaration, to + /// determine whether this declaration can be used in the default + /// argument expression. + bool CheckDefaultArgumentVisitor::VisitDeclRefExpr(const DeclRefExpr *DRE) { + const ValueDecl *Decl = dyn_cast(DRE->getDecl()); + + if (!isa(Decl)) + return false; + + if (const auto *Param = dyn_cast(Decl)) { + // C++ [dcl.fct.default]p9: + // [...] parameters of a function shall not be used in default + // argument expressions, even if they are not evaluated. [...] + // + // C++17 [dcl.fct.default]p9 (by CWG 2082): + // [...] A parameter shall not appear as a potentially-evaluated + // expression in a default argument. [...] + // + if (DRE->isNonOdrUse() != NOUR_Unevaluated) + return S.Diag(DRE->getBeginLoc(), + diag::err_param_default_argument_references_param) + << Param->getDeclName() << DefaultArg->getSourceRange(); + } else if (auto *VD = Decl->getPotentiallyDecomposedVarDecl()) { + // C++ [dcl.fct.default]p7: + // Local variables shall not be used in default argument + // expressions. + // + // C++17 [dcl.fct.default]p7 (by CWG 2082): + // A local variable shall not appear as a potentially-evaluated + // expression in a default argument. + // + // C++20 [dcl.fct.default]p7 (DR as part of P0588R1, see also CWG 2346): + // Note: A local variable cannot be odr-used (6.3) in a default + // argument. + // + if (VD->isLocalVarDecl() && !DRE->isNonOdrUse()) + return S.Diag(DRE->getBeginLoc(), + diag::err_param_default_argument_references_local) + << Decl << DefaultArg->getSourceRange(); + } + return false; + } + + /// VisitCXXThisExpr - Visit a C++ "this" expression. + bool CheckDefaultArgumentVisitor::VisitCXXThisExpr(const CXXThisExpr *ThisE) { + // C++ [dcl.fct.default]p8: + // The keyword this shall not be used in a default argument of a + // member function. + return S.Diag(ThisE->getBeginLoc(), + diag::err_param_default_argument_references_this) + << ThisE->getSourceRange(); + } + + bool CheckDefaultArgumentVisitor::VisitPseudoObjectExpr( + const PseudoObjectExpr *POE) { + bool Invalid = false; + for (const Expr *E : POE->semantics()) { + // Look through bindings. + if (const auto *OVE = dyn_cast(E)) { + E = OVE->getSourceExpr(); + assert(E && "pseudo-object binding without source expression?"); + } + + Invalid |= Visit(E); + } + return Invalid; + } + + bool CheckDefaultArgumentVisitor::VisitLambdaExpr(const LambdaExpr *Lambda) { + // [expr.prim.lambda.capture]p9 + // a lambda-expression appearing in a default argument cannot implicitly or + // explicitly capture any local entity. Such a lambda-expression can still + // have an init-capture if any full-expression in its initializer satisfies + // the constraints of an expression appearing in a default argument. + bool Invalid = false; + for (const LambdaCapture &LC : Lambda->captures()) { + if (!Lambda->isInitCapture(&LC)) + return S.Diag(LC.getLocation(), diag::err_lambda_capture_default_arg); + // Init captures are always VarDecl. + auto *D = cast(LC.getCapturedVar()); + Invalid |= Visit(D->getInit()); + } + return Invalid; + } + } // namespace + + void + Sema::ImplicitExceptionSpecification::CalledDecl(SourceLocation CallLoc, + const CXXMethodDecl *Method) { + // If we have an MSAny spec already, don't bother. + if (!Method || ComputedEST == EST_MSAny) + return; + + const FunctionProtoType *Proto + = Method->getType()->getAs(); + Proto = Self->ResolveExceptionSpec(CallLoc, Proto); + if (!Proto) + return; + + ExceptionSpecificationType EST = Proto->getExceptionSpecType(); + + // If we have a throw-all spec at this point, ignore the function. + if (ComputedEST == EST_None) + return; + + if (EST == EST_None && Method->hasAttr()) + EST = EST_BasicNoexcept; + + switch (EST) { + case EST_Unparsed: + case EST_Uninstantiated: + case EST_Unevaluated: + llvm_unreachable("should not see unresolved exception specs here"); + + // If this function can throw any exceptions, make a note of that. + case EST_MSAny: + case EST_None: + // FIXME: Whichever we see last of MSAny and None determines our result. + // We should make a consistent, order-independent choice here. + ClearExceptions(); + ComputedEST = EST; + return; + case EST_NoexceptFalse: + ClearExceptions(); + ComputedEST = EST_None; + return; + // FIXME: If the call to this decl is using any of its default arguments, we + // need to search them for potentially-throwing calls. + // If this function has a basic noexcept, it doesn't affect the outcome. + case EST_BasicNoexcept: + case EST_NoexceptTrue: + case EST_NoThrow: + return; + // If we're still at noexcept(true) and there's a throw() callee, + // change to that specification. + case EST_DynamicNone: + if (ComputedEST == EST_BasicNoexcept) + ComputedEST = EST_DynamicNone; + return; + case EST_DependentNoexcept: + llvm_unreachable( + "should not generate implicit declarations for dependent cases"); + case EST_Dynamic: + break; + } + assert(EST == EST_Dynamic && "EST case not considered earlier."); + assert(ComputedEST != EST_None && + "Shouldn't collect exceptions when throw-all is guaranteed."); + ComputedEST = EST_Dynamic; + // Record the exceptions in this function's exception specification. + for (const auto &E : Proto->exceptions()) + if (ExceptionsSeen.insert(Self->Context.getCanonicalType(E)).second) + Exceptions.push_back(E); + } + + void Sema::ImplicitExceptionSpecification::CalledStmt(Stmt *S) { + if (!S || ComputedEST == EST_MSAny) + return; + + // FIXME: + // + // C++0x [except.spec]p14: + // [An] implicit exception-specification specifies the type-id T if and + // only if T is allowed by the exception-specification of a function directly + // invoked by f's implicit definition; f shall allow all exceptions if any + // function it directly invokes allows all exceptions, and f shall allow no + // exceptions if every function it directly invokes allows no exceptions. + // + // Note in particular that if an implicit exception-specification is generated + // for a function containing a throw-expression, that specification can still + // be noexcept(true). + // + // Note also that 'directly invoked' is not defined in the standard, and there + // is no indication that we should only consider potentially-evaluated calls. + // + // Ultimately we should implement the intent of the standard: the exception + // specification should be the set of exceptions which can be thrown by the + // implicit definition. For now, we assume that any non-nothrow expression can + // throw any exception. + + if (Self->canThrow(S)) + ComputedEST = EST_None; + } + + ExprResult Sema::ConvertParamDefaultArgument(ParmVarDecl *Param, Expr *Arg, + SourceLocation EqualLoc) { + if (RequireCompleteType(Param->getLocation(), Param->getType(), + diag::err_typecheck_decl_incomplete_type)) + return true; + + // C++ [dcl.fct.default]p5 + // A default argument expression is implicitly converted (clause + // 4) to the parameter type. The default argument expression has + // the same semantic constraints as the initializer expression in + // a declaration of a variable of the parameter type, using the + // copy-initialization semantics (8.5). + InitializedEntity Entity = InitializedEntity::InitializeParameter(Context, + Param); + InitializationKind Kind = InitializationKind::CreateCopy(Param->getLocation(), + EqualLoc); + InitializationSequence InitSeq(*this, Entity, Kind, Arg); + ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Arg); + if (Result.isInvalid()) + return true; + Arg = Result.getAs(); + + CheckCompletedExpr(Arg, EqualLoc); + Arg = MaybeCreateExprWithCleanups(Arg); + + return Arg; + } + + void Sema::SetParamDefaultArgument(ParmVarDecl *Param, Expr *Arg, + SourceLocation EqualLoc) { + // Add the default argument to the parameter + Param->setDefaultArg(Arg); + + // We have already instantiated this parameter; provide each of the + // instantiations with the uninstantiated default argument. + UnparsedDefaultArgInstantiationsMap::iterator InstPos + = UnparsedDefaultArgInstantiations.find(Param); + if (InstPos != UnparsedDefaultArgInstantiations.end()) { + for (unsigned I = 0, N = InstPos->second.size(); I != N; ++I) + InstPos->second[I]->setUninstantiatedDefaultArg(Arg); + + // We're done tracking this parameter's instantiations. + UnparsedDefaultArgInstantiations.erase(InstPos); + } + } + + /// ActOnParamDefaultArgument - Check whether the default argument + /// provided for a function parameter is well-formed. If so, attach it + /// to the parameter declaration. + void + Sema::ActOnParamDefaultArgument(Decl *param, SourceLocation EqualLoc, + Expr *DefaultArg) { + if (!param || !DefaultArg) + return; + + ParmVarDecl *Param = cast(param); + UnparsedDefaultArgLocs.erase(Param); + + auto Fail = [&] { + Param->setInvalidDecl(); + Param->setDefaultArg(new (Context) OpaqueValueExpr( + EqualLoc, Param->getType().getNonReferenceType(), VK_PRValue)); + }; + + // Default arguments are only permitted in C++ + if (!getLangOpts().CPlusPlus) { + Diag(EqualLoc, diag::err_param_default_argument) + << DefaultArg->getSourceRange(); + return Fail(); + } + + // Check for unexpanded parameter packs. + if (DiagnoseUnexpandedParameterPack(DefaultArg, UPPC_DefaultArgument)) { + return Fail(); + } + + // C++11 [dcl.fct.default]p3 + // A default argument expression [...] shall not be specified for a + // parameter pack. + if (Param->isParameterPack()) { + Diag(EqualLoc, diag::err_param_default_argument_on_parameter_pack) + << DefaultArg->getSourceRange(); + // Recover by discarding the default argument. + Param->setDefaultArg(nullptr); + return; + } + + ExprResult Result = ConvertParamDefaultArgument(Param, DefaultArg, EqualLoc); + if (Result.isInvalid()) + return Fail(); + + DefaultArg = Result.getAs(); + + // Check that the default argument is well-formed + CheckDefaultArgumentVisitor DefaultArgChecker(*this, DefaultArg); + if (DefaultArgChecker.Visit(DefaultArg)) + return Fail(); + + SetParamDefaultArgument(Param, DefaultArg, EqualLoc); + } + + /// ActOnParamUnparsedDefaultArgument - We've seen a default + /// argument for a function parameter, but we can't parse it yet + /// because we're inside a class definition. Note that this default + /// argument will be parsed later. + void Sema::ActOnParamUnparsedDefaultArgument(Decl *param, + SourceLocation EqualLoc, + SourceLocation ArgLoc) { + if (!param) + return; + + ParmVarDecl *Param = cast(param); + Param->setUnparsedDefaultArg(); + UnparsedDefaultArgLocs[Param] = ArgLoc; + } + + /// ActOnParamDefaultArgumentError - Parsing or semantic analysis of + /// the default argument for the parameter param failed. + void Sema::ActOnParamDefaultArgumentError(Decl *param, + SourceLocation EqualLoc) { + if (!param) + return; + + ParmVarDecl *Param = cast(param); + Param->setInvalidDecl(); + UnparsedDefaultArgLocs.erase(Param); + Param->setDefaultArg(new (Context) OpaqueValueExpr( + EqualLoc, Param->getType().getNonReferenceType(), VK_PRValue)); + } + + /// CheckExtraCXXDefaultArguments - Check for any extra default + /// arguments in the declarator, which is not a function declaration + /// or definition and therefore is not permitted to have default + /// arguments. This routine should be invoked for every declarator + /// that is not a function declaration or definition. + void Sema::CheckExtraCXXDefaultArguments(Declarator &D) { + // C++ [dcl.fct.default]p3 + // A default argument expression shall be specified only in the + // parameter-declaration-clause of a function declaration or in a + // template-parameter (14.1). It shall not be specified for a + // parameter pack. If it is specified in a + // parameter-declaration-clause, it shall not occur within a + // declarator or abstract-declarator of a parameter-declaration. + bool MightBeFunction = D.isFunctionDeclarationContext(); + for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) { + DeclaratorChunk &chunk = D.getTypeObject(i); + if (chunk.Kind == DeclaratorChunk::Function) { + if (MightBeFunction) { + // This is a function declaration. It can have default arguments, but + // keep looking in case its return type is a function type with default + // arguments. + MightBeFunction = false; + continue; + } + for (unsigned argIdx = 0, e = chunk.Fun.NumParams; argIdx != e; + ++argIdx) { + ParmVarDecl *Param = cast(chunk.Fun.Params[argIdx].Param); + if (Param->hasUnparsedDefaultArg()) { + std::unique_ptr Toks = + std::move(chunk.Fun.Params[argIdx].DefaultArgTokens); + SourceRange SR; + if (Toks->size() > 1) + SR = SourceRange((*Toks)[1].getLocation(), + Toks->back().getLocation()); + else + SR = UnparsedDefaultArgLocs[Param]; + Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc) + << SR; + } else if (Param->getDefaultArg()) { + Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc) + << Param->getDefaultArg()->getSourceRange(); + Param->setDefaultArg(nullptr); + } + } + } else if (chunk.Kind != DeclaratorChunk::Paren) { + MightBeFunction = false; + } + } + } + + static bool functionDeclHasDefaultArgument(const FunctionDecl *FD) { + return llvm::any_of(FD->parameters(), [](ParmVarDecl *P) { + return P->hasDefaultArg() && !P->hasInheritedDefaultArg(); + }); + } + + /// MergeCXXFunctionDecl - Merge two declarations of the same C++ + /// function, once we already know that they have the same + /// type. Subroutine of MergeFunctionDecl. Returns true if there was an + /// error, false otherwise. + bool Sema::MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old, + Scope *S) { + bool Invalid = false; + + // The declaration context corresponding to the scope is the semantic + // parent, unless this is a local function declaration, in which case + // it is that surrounding function. + DeclContext *ScopeDC = New->isLocalExternDecl() + ? New->getLexicalDeclContext() + : New->getDeclContext(); + + // Find the previous declaration for the purpose of default arguments. + FunctionDecl *PrevForDefaultArgs = Old; + for (/**/; PrevForDefaultArgs; + // Don't bother looking back past the latest decl if this is a local + // extern declaration; nothing else could work. + PrevForDefaultArgs = New->isLocalExternDecl() + ? nullptr + : PrevForDefaultArgs->getPreviousDecl()) { + // Ignore hidden declarations. + if (!LookupResult::isVisible(*this, PrevForDefaultArgs)) + continue; + + if (S && !isDeclInScope(PrevForDefaultArgs, ScopeDC, S) && + !New->isCXXClassMember()) { + // Ignore default arguments of old decl if they are not in + // the same scope and this is not an out-of-line definition of + // a member function. + continue; + } + + if (PrevForDefaultArgs->isLocalExternDecl() != New->isLocalExternDecl()) { + // If only one of these is a local function declaration, then they are + // declared in different scopes, even though isDeclInScope may think + // they're in the same scope. (If both are local, the scope check is + // sufficient, and if neither is local, then they are in the same scope.) + continue; + } + + // We found the right previous declaration. + break; + } + + // C++ [dcl.fct.default]p4: + // For non-template functions, default arguments can be added in + // later declarations of a function in the same + // scope. Declarations in different scopes have completely + // distinct sets of default arguments. That is, declarations in + // inner scopes do not acquire default arguments from + // declarations in outer scopes, and vice versa. In a given + // function declaration, all parameters subsequent to a + // parameter with a default argument shall have default + // arguments supplied in this or previous declarations. A + // default argument shall not be redefined by a later + // declaration (not even to the same value). + // + // C++ [dcl.fct.default]p6: + // Except for member functions of class templates, the default arguments + // in a member function definition that appears outside of the class + // definition are added to the set of default arguments provided by the + // member function declaration in the class definition. + for (unsigned p = 0, NumParams = PrevForDefaultArgs + ? PrevForDefaultArgs->getNumParams() + : 0; + p < NumParams; ++p) { + ParmVarDecl *OldParam = PrevForDefaultArgs->getParamDecl(p); + ParmVarDecl *NewParam = New->getParamDecl(p); + + bool OldParamHasDfl = OldParam ? OldParam->hasDefaultArg() : false; + bool NewParamHasDfl = NewParam->hasDefaultArg(); + + if (OldParamHasDfl && NewParamHasDfl) { + unsigned DiagDefaultParamID = + diag::err_param_default_argument_redefinition; + + // MSVC accepts that default parameters be redefined for member functions + // of template class. The new default parameter's value is ignored. + Invalid = true; + if (getLangOpts().MicrosoftExt) { + CXXMethodDecl *MD = dyn_cast(New); + if (MD && MD->getParent()->getDescribedClassTemplate()) { + // Merge the old default argument into the new parameter. + NewParam->setHasInheritedDefaultArg(); + if (OldParam->hasUninstantiatedDefaultArg()) + NewParam->setUninstantiatedDefaultArg( + OldParam->getUninstantiatedDefaultArg()); + else + NewParam->setDefaultArg(OldParam->getInit()); + DiagDefaultParamID = diag::ext_param_default_argument_redefinition; + Invalid = false; + } + } + + // FIXME: If we knew where the '=' was, we could easily provide a fix-it + // hint here. Alternatively, we could walk the type-source information + // for NewParam to find the last source location in the type... but it + // isn't worth the effort right now. This is the kind of test case that + // is hard to get right: + // int f(int); + // void g(int (*fp)(int) = f); + // void g(int (*fp)(int) = &f); + Diag(NewParam->getLocation(), DiagDefaultParamID) + << NewParam->getDefaultArgRange(); + + // Look for the function declaration where the default argument was + // actually written, which may be a declaration prior to Old. + for (auto Older = PrevForDefaultArgs; + OldParam->hasInheritedDefaultArg(); /**/) { + Older = Older->getPreviousDecl(); + OldParam = Older->getParamDecl(p); + } + + Diag(OldParam->getLocation(), diag::note_previous_definition) + << OldParam->getDefaultArgRange(); + } else if (OldParamHasDfl) { + // Merge the old default argument into the new parameter unless the new + // function is a friend declaration in a template class. In the latter + // case the default arguments will be inherited when the friend + // declaration will be instantiated. + if (New->getFriendObjectKind() == Decl::FOK_None || + !New->getLexicalDeclContext()->isDependentContext()) { + // It's important to use getInit() here; getDefaultArg() + // strips off any top-level ExprWithCleanups. + NewParam->setHasInheritedDefaultArg(); + if (OldParam->hasUnparsedDefaultArg()) + NewParam->setUnparsedDefaultArg(); + else if (OldParam->hasUninstantiatedDefaultArg()) + NewParam->setUninstantiatedDefaultArg( + OldParam->getUninstantiatedDefaultArg()); + else + NewParam->setDefaultArg(OldParam->getInit()); + } + } else if (NewParamHasDfl) { + if (New->getDescribedFunctionTemplate()) { + // Paragraph 4, quoted above, only applies to non-template functions. + Diag(NewParam->getLocation(), + diag::err_param_default_argument_template_redecl) + << NewParam->getDefaultArgRange(); + Diag(PrevForDefaultArgs->getLocation(), + diag::note_template_prev_declaration) + << false; + } else if (New->getTemplateSpecializationKind() + != TSK_ImplicitInstantiation && + New->getTemplateSpecializationKind() != TSK_Undeclared) { + // C++ [temp.expr.spec]p21: + // Default function arguments shall not be specified in a declaration + // or a definition for one of the following explicit specializations: + // - the explicit specialization of a function template; + // - the explicit specialization of a member function template; + // - the explicit specialization of a member function of a class + // template where the class template specialization to which the + // member function specialization belongs is implicitly + // instantiated. + Diag(NewParam->getLocation(), diag::err_template_spec_default_arg) + << (New->getTemplateSpecializationKind() ==TSK_ExplicitSpecialization) + << New->getDeclName() + << NewParam->getDefaultArgRange(); + } else if (New->getDeclContext()->isDependentContext()) { + // C++ [dcl.fct.default]p6 (DR217): + // Default arguments for a member function of a class template shall + // be specified on the initial declaration of the member function + // within the class template. + // + // Reading the tea leaves a bit in DR217 and its reference to DR205 + // leads me to the conclusion that one cannot add default function + // arguments for an out-of-line definition of a member function of a + // dependent type. + int WhichKind = 2; + if (CXXRecordDecl *Record + = dyn_cast(New->getDeclContext())) { + if (Record->getDescribedClassTemplate()) + WhichKind = 0; + else if (isa(Record)) + WhichKind = 1; + else + WhichKind = 2; + } + + Diag(NewParam->getLocation(), + diag::err_param_default_argument_member_template_redecl) + << WhichKind + << NewParam->getDefaultArgRange(); + } + } + } + + // DR1344: If a default argument is added outside a class definition and that + // default argument makes the function a special member function, the program + // is ill-formed. This can only happen for constructors. + if (isa(New) && + New->getMinRequiredArguments() < Old->getMinRequiredArguments()) { + CXXSpecialMember NewSM = getSpecialMember(cast(New)), + OldSM = getSpecialMember(cast(Old)); + if (NewSM != OldSM) { + ParmVarDecl *NewParam = New->getParamDecl(New->getMinRequiredArguments()); + assert(NewParam->hasDefaultArg()); + Diag(NewParam->getLocation(), diag::err_default_arg_makes_ctor_special) + << NewParam->getDefaultArgRange() << NewSM; + Diag(Old->getLocation(), diag::note_previous_declaration); + } + } + + const FunctionDecl *Def; + // C++11 [dcl.constexpr]p1: If any declaration of a function or function + // template has a constexpr specifier then all its declarations shall + // contain the constexpr specifier. + if (New->getConstexprKind() != Old->getConstexprKind()) { + Diag(New->getLocation(), diag::err_constexpr_redecl_mismatch) + << New << static_cast(New->getConstexprKind()) + << static_cast(Old->getConstexprKind()); + Diag(Old->getLocation(), diag::note_previous_declaration); + Invalid = true; + } else if (!Old->getMostRecentDecl()->isInlined() && New->isInlined() && + Old->isDefined(Def) && + // If a friend function is inlined but does not have 'inline' + // specifier, it is a definition. Do not report attribute conflict + // in this case, redefinition will be diagnosed later. + (New->isInlineSpecified() || + New->getFriendObjectKind() == Decl::FOK_None)) { + // C++11 [dcl.fcn.spec]p4: + // If the definition of a function appears in a translation unit before its + // first declaration as inline, the program is ill-formed. + Diag(New->getLocation(), diag::err_inline_decl_follows_def) << New; + Diag(Def->getLocation(), diag::note_previous_definition); + Invalid = true; + } + + // C++17 [temp.deduct.guide]p3: + // Two deduction guide declarations in the same translation unit + // for the same class template shall not have equivalent + // parameter-declaration-clauses. + if (isa(New) && + !New->isFunctionTemplateSpecialization() && isVisible(Old)) { + Diag(New->getLocation(), diag::err_deduction_guide_redeclared); + Diag(Old->getLocation(), diag::note_previous_declaration); + } + + // C++11 [dcl.fct.default]p4: If a friend declaration specifies a default + // argument expression, that declaration shall be a definition and shall be + // the only declaration of the function or function template in the + // translation unit. + if (Old->getFriendObjectKind() == Decl::FOK_Undeclared && + functionDeclHasDefaultArgument(Old)) { + Diag(New->getLocation(), diag::err_friend_decl_with_def_arg_redeclared); + Diag(Old->getLocation(), diag::note_previous_declaration); + Invalid = true; + } + + // C++11 [temp.friend]p4 (DR329): + // When a function is defined in a friend function declaration in a class + // template, the function is instantiated when the function is odr-used. + // The same restrictions on multiple declarations and definitions that + // apply to non-template function declarations and definitions also apply + // to these implicit definitions. + const FunctionDecl *OldDefinition = nullptr; + if (New->isThisDeclarationInstantiatedFromAFriendDefinition() && + Old->isDefined(OldDefinition, true)) + CheckForFunctionRedefinition(New, OldDefinition); + + return Invalid; + } + + NamedDecl * + Sema::ActOnDecompositionDeclarator(Scope *S, Declarator &D, + MultiTemplateParamsArg TemplateParamLists) { + assert(D.isDecompositionDeclarator()); + const DecompositionDeclarator &Decomp = D.getDecompositionDeclarator(); + + // The syntax only allows a decomposition declarator as a simple-declaration, + // a for-range-declaration, or a condition in Clang, but we parse it in more + // cases than that. + if (!D.mayHaveDecompositionDeclarator()) { + Diag(Decomp.getLSquareLoc(), diag::err_decomp_decl_context) + << Decomp.getSourceRange(); + return nullptr; + } + + if (!TemplateParamLists.empty()) { + // FIXME: There's no rule against this, but there are also no rules that + // would actually make it usable, so we reject it for now. + Diag(TemplateParamLists.front()->getTemplateLoc(), + diag::err_decomp_decl_template); + return nullptr; + } + + Diag(Decomp.getLSquareLoc(), + !getLangOpts().CPlusPlus17 + ? diag::ext_decomp_decl + : D.getContext() == DeclaratorContext::Condition + ? diag::ext_decomp_decl_cond + : diag::warn_cxx14_compat_decomp_decl) + << Decomp.getSourceRange(); + + // The semantic context is always just the current context. + DeclContext *const DC = CurContext; + + // C++17 [dcl.dcl]/8: + // The decl-specifier-seq shall contain only the type-specifier auto + // and cv-qualifiers. + // C++20 [dcl.dcl]/8: + // If decl-specifier-seq contains any decl-specifier other than static, + // thread_local, auto, or cv-qualifiers, the program is ill-formed. + // C++23 [dcl.pre]/6: + // Each decl-specifier in the decl-specifier-seq shall be static, + // thread_local, auto (9.2.9.6 [dcl.spec.auto]), or a cv-qualifier. + auto &DS = D.getDeclSpec(); + { + // Note: While constrained-auto needs to be checked, we do so separately so + // we can emit a better diagnostic. + SmallVector BadSpecifiers; + SmallVector BadSpecifierLocs; + SmallVector CPlusPlus20Specifiers; + SmallVector CPlusPlus20SpecifierLocs; + if (auto SCS = DS.getStorageClassSpec()) { + if (SCS == DeclSpec::SCS_static) { + CPlusPlus20Specifiers.push_back(DeclSpec::getSpecifierName(SCS)); + CPlusPlus20SpecifierLocs.push_back(DS.getStorageClassSpecLoc()); + } else { + BadSpecifiers.push_back(DeclSpec::getSpecifierName(SCS)); + BadSpecifierLocs.push_back(DS.getStorageClassSpecLoc()); + } + } + if (auto TSCS = DS.getThreadStorageClassSpec()) { + CPlusPlus20Specifiers.push_back(DeclSpec::getSpecifierName(TSCS)); + CPlusPlus20SpecifierLocs.push_back(DS.getThreadStorageClassSpecLoc()); + } + if (DS.hasConstexprSpecifier()) { + BadSpecifiers.push_back( + DeclSpec::getSpecifierName(DS.getConstexprSpecifier())); + BadSpecifierLocs.push_back(DS.getConstexprSpecLoc()); + } + if (DS.isInlineSpecified()) { + BadSpecifiers.push_back("inline"); + BadSpecifierLocs.push_back(DS.getInlineSpecLoc()); + } + + if (!BadSpecifiers.empty()) { + auto &&Err = Diag(BadSpecifierLocs.front(), diag::err_decomp_decl_spec); + Err << (int)BadSpecifiers.size() + << llvm::join(BadSpecifiers.begin(), BadSpecifiers.end(), " "); + // Don't add FixItHints to remove the specifiers; we do still respect + // them when building the underlying variable. + for (auto Loc : BadSpecifierLocs) + Err << SourceRange(Loc, Loc); + } else if (!CPlusPlus20Specifiers.empty()) { + auto &&Warn = Diag(CPlusPlus20SpecifierLocs.front(), + getLangOpts().CPlusPlus20 + ? diag::warn_cxx17_compat_decomp_decl_spec + : diag::ext_decomp_decl_spec); + Warn << (int)CPlusPlus20Specifiers.size() + << llvm::join(CPlusPlus20Specifiers.begin(), + CPlusPlus20Specifiers.end(), " "); + for (auto Loc : CPlusPlus20SpecifierLocs) + Warn << SourceRange(Loc, Loc); + } + // We can't recover from it being declared as a typedef. + if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef) + return nullptr; + } + + // C++2a [dcl.struct.bind]p1: + // A cv that includes volatile is deprecated + if ((DS.getTypeQualifiers() & DeclSpec::TQ_volatile) && + getLangOpts().CPlusPlus20) + Diag(DS.getVolatileSpecLoc(), + diag::warn_deprecated_volatile_structured_binding); + + TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S); + QualType R = TInfo->getType(); + + if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo, + UPPC_DeclarationType)) + D.setInvalidType(); + + // The syntax only allows a single ref-qualifier prior to the decomposition + // declarator. No other declarator chunks are permitted. Also check the type + // specifier here. + if (DS.getTypeSpecType() != DeclSpec::TST_auto || + D.hasGroupingParens() || D.getNumTypeObjects() > 1 || + (D.getNumTypeObjects() == 1 && + D.getTypeObject(0).Kind != DeclaratorChunk::Reference)) { + Diag(Decomp.getLSquareLoc(), + (D.hasGroupingParens() || + (D.getNumTypeObjects() && + D.getTypeObject(0).Kind == DeclaratorChunk::Paren)) + ? diag::err_decomp_decl_parens + : diag::err_decomp_decl_type) + << R; + + // In most cases, there's no actual problem with an explicitly-specified + // type, but a function type won't work here, and ActOnVariableDeclarator + // shouldn't be called for such a type. + if (R->isFunctionType()) + D.setInvalidType(); + } + + // Constrained auto is prohibited by [decl.pre]p6, so check that here. + if (DS.isConstrainedAuto()) { + TemplateIdAnnotation *TemplRep = DS.getRepAsTemplateId(); + assert(TemplRep->Kind == TNK_Concept_template && + "No other template kind should be possible for a constrained auto"); + + SourceRange TemplRange{TemplRep->TemplateNameLoc, + TemplRep->RAngleLoc.isValid() + ? TemplRep->RAngleLoc + : TemplRep->TemplateNameLoc}; + Diag(TemplRep->TemplateNameLoc, diag::err_decomp_decl_constraint) + << TemplRange << FixItHint::CreateRemoval(TemplRange); + } + + // Build the BindingDecls. + SmallVector Bindings; + + // Build the BindingDecls. + for (auto &B : D.getDecompositionDeclarator().bindings()) { + // Check for name conflicts. + DeclarationNameInfo NameInfo(B.Name, B.NameLoc); + LookupResult Previous(*this, NameInfo, LookupOrdinaryName, + ForVisibleRedeclaration); + LookupName(Previous, S, + /*CreateBuiltins*/DC->getRedeclContext()->isTranslationUnit()); + + // It's not permitted to shadow a template parameter name. + if (Previous.isSingleResult() && + Previous.getFoundDecl()->isTemplateParameter()) { + DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), + Previous.getFoundDecl()); + Previous.clear(); + } + + auto *BD = BindingDecl::Create(Context, DC, B.NameLoc, B.Name); + + // Find the shadowed declaration before filtering for scope. + NamedDecl *ShadowedDecl = D.getCXXScopeSpec().isEmpty() + ? getShadowedDeclaration(BD, Previous) + : nullptr; + + bool ConsiderLinkage = DC->isFunctionOrMethod() && + DS.getStorageClassSpec() == DeclSpec::SCS_extern; + FilterLookupForScope(Previous, DC, S, ConsiderLinkage, + /*AllowInlineNamespace*/false); + + if (!Previous.empty()) { + auto *Old = Previous.getRepresentativeDecl(); + Diag(B.NameLoc, diag::err_redefinition) << B.Name; + Diag(Old->getLocation(), diag::note_previous_definition); + } else if (ShadowedDecl && !D.isRedeclaration()) { + CheckShadow(BD, ShadowedDecl, Previous); + } + PushOnScopeChains(BD, S, true); + Bindings.push_back(BD); + ParsingInitForAutoVars.insert(BD); + } + + // There are no prior lookup results for the variable itself, because it + // is unnamed. + DeclarationNameInfo NameInfo((IdentifierInfo *)nullptr, + Decomp.getLSquareLoc()); + LookupResult Previous(*this, NameInfo, LookupOrdinaryName, + ForVisibleRedeclaration); + + // Build the variable that holds the non-decomposed object. + bool AddToScope = true; + NamedDecl *New = + ActOnVariableDeclarator(S, D, DC, TInfo, Previous, + MultiTemplateParamsArg(), AddToScope, Bindings); + if (AddToScope) { + S->AddDecl(New); + CurContext->addHiddenDecl(New); + } + + if (isInOpenMPDeclareTargetContext()) + checkDeclIsAllowedInOpenMPTarget(nullptr, New); + + return New; + } + + static bool checkSimpleDecomposition( + Sema &S, ArrayRef Bindings, ValueDecl *Src, + QualType DecompType, const llvm::APSInt &NumElems, QualType ElemType, + llvm::function_ref GetInit) { + if ((int64_t)Bindings.size() != NumElems) { + S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings) + << DecompType << (unsigned)Bindings.size() + << (unsigned)NumElems.getLimitedValue(UINT_MAX) + << toString(NumElems, 10) << (NumElems < Bindings.size()); + return true; + } + + unsigned I = 0; + for (auto *B : Bindings) { + SourceLocation Loc = B->getLocation(); + ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc); + if (E.isInvalid()) + return true; + E = GetInit(Loc, E.get(), I++); + if (E.isInvalid()) + return true; + B->setBinding(ElemType, E.get()); + } + + return false; + } + + static bool checkArrayLikeDecomposition(Sema &S, + ArrayRef Bindings, + ValueDecl *Src, QualType DecompType, + const llvm::APSInt &NumElems, + QualType ElemType) { + return checkSimpleDecomposition( + S, Bindings, Src, DecompType, NumElems, ElemType, + [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult { + ExprResult E = S.ActOnIntegerConstant(Loc, I); + if (E.isInvalid()) + return ExprError(); + return S.CreateBuiltinArraySubscriptExpr(Base, Loc, E.get(), Loc); + }); + } + + static bool checkArrayDecomposition(Sema &S, ArrayRef Bindings, + ValueDecl *Src, QualType DecompType, + const ConstantArrayType *CAT) { + return checkArrayLikeDecomposition(S, Bindings, Src, DecompType, + llvm::APSInt(CAT->getSize()), + CAT->getElementType()); + } + + static bool checkVectorDecomposition(Sema &S, ArrayRef Bindings, + ValueDecl *Src, QualType DecompType, + const VectorType *VT) { + return checkArrayLikeDecomposition( + S, Bindings, Src, DecompType, llvm::APSInt::get(VT->getNumElements()), + S.Context.getQualifiedType(VT->getElementType(), + DecompType.getQualifiers())); + } + + static bool checkComplexDecomposition(Sema &S, + ArrayRef Bindings, + ValueDecl *Src, QualType DecompType, + const ComplexType *CT) { + return checkSimpleDecomposition( + S, Bindings, Src, DecompType, llvm::APSInt::get(2), + S.Context.getQualifiedType(CT->getElementType(), + DecompType.getQualifiers()), + [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult { + return S.CreateBuiltinUnaryOp(Loc, I ? UO_Imag : UO_Real, Base); + }); + } + + static std::string printTemplateArgs(const PrintingPolicy &PrintingPolicy, + TemplateArgumentListInfo &Args, + const TemplateParameterList *Params) { + SmallString<128> SS; + llvm::raw_svector_ostream OS(SS); + bool First = true; + unsigned I = 0; + for (auto &Arg : Args.arguments()) { + if (!First) + OS << ", "; + Arg.getArgument().print(PrintingPolicy, OS, + TemplateParameterList::shouldIncludeTypeForArgument( + PrintingPolicy, Params, I)); + First = false; + I++; + } + return std::string(OS.str()); + } + + static bool lookupStdTypeTraitMember(Sema &S, LookupResult &TraitMemberLookup, + SourceLocation Loc, StringRef Trait, + TemplateArgumentListInfo &Args, + unsigned DiagID) { + auto DiagnoseMissing = [&] { + if (DiagID) + S.Diag(Loc, DiagID) << printTemplateArgs(S.Context.getPrintingPolicy(), + Args, /*Params*/ nullptr); + return true; + }; + + // FIXME: Factor out duplication with lookupPromiseType in SemaCoroutine. + NamespaceDecl *Std = S.getStdNamespace(); + if (!Std) + return DiagnoseMissing(); + + // Look up the trait itself, within namespace std. We can diagnose various + // problems with this lookup even if we've been asked to not diagnose a + // missing specialization, because this can only fail if the user has been + // declaring their own names in namespace std or we don't support the + // standard library implementation in use. + LookupResult Result(S, &S.PP.getIdentifierTable().get(Trait), + Loc, Sema::LookupOrdinaryName); + if (!S.LookupQualifiedName(Result, Std)) + return DiagnoseMissing(); + if (Result.isAmbiguous()) + return true; + + ClassTemplateDecl *TraitTD = Result.getAsSingle(); + if (!TraitTD) { + Result.suppressDiagnostics(); + NamedDecl *Found = *Result.begin(); + S.Diag(Loc, diag::err_std_type_trait_not_class_template) << Trait; + S.Diag(Found->getLocation(), diag::note_declared_at); + return true; + } + + // Build the template-id. + QualType TraitTy = S.CheckTemplateIdType(TemplateName(TraitTD), Loc, Args); + if (TraitTy.isNull()) + return true; + if (!S.isCompleteType(Loc, TraitTy)) { + if (DiagID) + S.RequireCompleteType( + Loc, TraitTy, DiagID, + printTemplateArgs(S.Context.getPrintingPolicy(), Args, + TraitTD->getTemplateParameters())); + return true; + } + + CXXRecordDecl *RD = TraitTy->getAsCXXRecordDecl(); + assert(RD && "specialization of class template is not a class?"); + + // Look up the member of the trait type. + S.LookupQualifiedName(TraitMemberLookup, RD); + return TraitMemberLookup.isAmbiguous(); + } + + static TemplateArgumentLoc + getTrivialIntegralTemplateArgument(Sema &S, SourceLocation Loc, QualType T, + uint64_t I) { + TemplateArgument Arg(S.Context, S.Context.MakeIntValue(I, T), T); + return S.getTrivialTemplateArgumentLoc(Arg, T, Loc); + } + + static TemplateArgumentLoc + getTrivialTypeTemplateArgument(Sema &S, SourceLocation Loc, QualType T) { + return S.getTrivialTemplateArgumentLoc(TemplateArgument(T), QualType(), Loc); + } + + namespace { enum class IsTupleLike { TupleLike, NotTupleLike, Error }; } + + static IsTupleLike isTupleLike(Sema &S, SourceLocation Loc, QualType T, + llvm::APSInt &Size) { + EnterExpressionEvaluationContext ContextRAII( + S, Sema::ExpressionEvaluationContext::ConstantEvaluated); + + DeclarationName Value = S.PP.getIdentifierInfo("value"); + LookupResult R(S, Value, Loc, Sema::LookupOrdinaryName); + + // Form template argument list for tuple_size. + TemplateArgumentListInfo Args(Loc, Loc); + Args.addArgument(getTrivialTypeTemplateArgument(S, Loc, T)); + + // If there's no tuple_size specialization or the lookup of 'value' is empty, + // it's not tuple-like. + if (lookupStdTypeTraitMember(S, R, Loc, "tuple_size", Args, /*DiagID*/ 0) || + R.empty()) + return IsTupleLike::NotTupleLike; + + // If we get this far, we've committed to the tuple interpretation, but + // we can still fail if there actually isn't a usable ::value. + + struct ICEDiagnoser : Sema::VerifyICEDiagnoser { + LookupResult &R; + TemplateArgumentListInfo &Args; + ICEDiagnoser(LookupResult &R, TemplateArgumentListInfo &Args) + : R(R), Args(Args) {} + Sema::SemaDiagnosticBuilder diagnoseNotICE(Sema &S, + SourceLocation Loc) override { + return S.Diag(Loc, diag::err_decomp_decl_std_tuple_size_not_constant) + << printTemplateArgs(S.Context.getPrintingPolicy(), Args, + /*Params*/ nullptr); + } + } Diagnoser(R, Args); + + ExprResult E = + S.BuildDeclarationNameExpr(CXXScopeSpec(), R, /*NeedsADL*/false); + if (E.isInvalid()) + return IsTupleLike::Error; + + E = S.VerifyIntegerConstantExpression(E.get(), &Size, Diagnoser); + if (E.isInvalid()) + return IsTupleLike::Error; + + return IsTupleLike::TupleLike; + } + + /// \return std::tuple_element::type. + static QualType getTupleLikeElementType(Sema &S, SourceLocation Loc, + unsigned I, QualType T) { + // Form template argument list for tuple_element. + TemplateArgumentListInfo Args(Loc, Loc); + Args.addArgument( + getTrivialIntegralTemplateArgument(S, Loc, S.Context.getSizeType(), I)); + Args.addArgument(getTrivialTypeTemplateArgument(S, Loc, T)); + + DeclarationName TypeDN = S.PP.getIdentifierInfo("type"); + LookupResult R(S, TypeDN, Loc, Sema::LookupOrdinaryName); + if (lookupStdTypeTraitMember( + S, R, Loc, "tuple_element", Args, + diag::err_decomp_decl_std_tuple_element_not_specialized)) + return QualType(); + + auto *TD = R.getAsSingle(); + if (!TD) { + R.suppressDiagnostics(); + S.Diag(Loc, diag::err_decomp_decl_std_tuple_element_not_specialized) + << printTemplateArgs(S.Context.getPrintingPolicy(), Args, + /*Params*/ nullptr); + if (!R.empty()) + S.Diag(R.getRepresentativeDecl()->getLocation(), diag::note_declared_at); + return QualType(); + } + + return S.Context.getTypeDeclType(TD); + } + + namespace { + struct InitializingBinding { + Sema &S; + InitializingBinding(Sema &S, BindingDecl *BD) : S(S) { + Sema::CodeSynthesisContext Ctx; + Ctx.Kind = Sema::CodeSynthesisContext::InitializingStructuredBinding; + Ctx.PointOfInstantiation = BD->getLocation(); + Ctx.Entity = BD; + S.pushCodeSynthesisContext(Ctx); + } + ~InitializingBinding() { + S.popCodeSynthesisContext(); + } + }; + } + + static bool checkTupleLikeDecomposition(Sema &S, + ArrayRef Bindings, + VarDecl *Src, QualType DecompType, + const llvm::APSInt &TupleSize) { + if ((int64_t)Bindings.size() != TupleSize) { + S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings) + << DecompType << (unsigned)Bindings.size() + << (unsigned)TupleSize.getLimitedValue(UINT_MAX) + << toString(TupleSize, 10) << (TupleSize < Bindings.size()); + return true; + } + + if (Bindings.empty()) + return false; + + DeclarationName GetDN = S.PP.getIdentifierInfo("get"); + + // [dcl.decomp]p3: + // The unqualified-id get is looked up in the scope of E by class member + // access lookup ... + LookupResult MemberGet(S, GetDN, Src->getLocation(), Sema::LookupMemberName); + bool UseMemberGet = false; + if (S.isCompleteType(Src->getLocation(), DecompType)) { + if (auto *RD = DecompType->getAsCXXRecordDecl()) + S.LookupQualifiedName(MemberGet, RD); + if (MemberGet.isAmbiguous()) + return true; + // ... and if that finds at least one declaration that is a function + // template whose first template parameter is a non-type parameter ... + for (NamedDecl *D : MemberGet) { + if (FunctionTemplateDecl *FTD = + dyn_cast(D->getUnderlyingDecl())) { + TemplateParameterList *TPL = FTD->getTemplateParameters(); + if (TPL->size() != 0 && + isa(TPL->getParam(0))) { + // ... the initializer is e.get(). + UseMemberGet = true; + break; + } + } + } + } + + unsigned I = 0; + for (auto *B : Bindings) { + InitializingBinding InitContext(S, B); + SourceLocation Loc = B->getLocation(); + + ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc); + if (E.isInvalid()) + return true; + + // e is an lvalue if the type of the entity is an lvalue reference and + // an xvalue otherwise + if (!Src->getType()->isLValueReferenceType()) + E = ImplicitCastExpr::Create(S.Context, E.get()->getType(), CK_NoOp, + E.get(), nullptr, VK_XValue, + FPOptionsOverride()); + + TemplateArgumentListInfo Args(Loc, Loc); + Args.addArgument( + getTrivialIntegralTemplateArgument(S, Loc, S.Context.getSizeType(), I)); + + if (UseMemberGet) { + // if [lookup of member get] finds at least one declaration, the + // initializer is e.get(). + E = S.BuildMemberReferenceExpr(E.get(), DecompType, Loc, false, + CXXScopeSpec(), SourceLocation(), nullptr, + MemberGet, &Args, nullptr); + if (E.isInvalid()) + return true; + + E = S.BuildCallExpr(nullptr, E.get(), Loc, std::nullopt, Loc); + } else { + // Otherwise, the initializer is get(e), where get is looked up + // in the associated namespaces. + Expr *Get = UnresolvedLookupExpr::Create( + S.Context, nullptr, NestedNameSpecifierLoc(), SourceLocation(), + DeclarationNameInfo(GetDN, Loc), /*RequiresADL*/true, &Args, + UnresolvedSetIterator(), UnresolvedSetIterator()); + + Expr *Arg = E.get(); + E = S.BuildCallExpr(nullptr, Get, Loc, Arg, Loc); + } + if (E.isInvalid()) + return true; + Expr *Init = E.get(); + + // Given the type T designated by std::tuple_element::type, + QualType T = getTupleLikeElementType(S, Loc, I, DecompType); + if (T.isNull()) + return true; + + // each vi is a variable of type "reference to T" initialized with the + // initializer, where the reference is an lvalue reference if the + // initializer is an lvalue and an rvalue reference otherwise + QualType RefType = + S.BuildReferenceType(T, E.get()->isLValue(), Loc, B->getDeclName()); + if (RefType.isNull()) + return true; + auto *RefVD = VarDecl::Create( + S.Context, Src->getDeclContext(), Loc, Loc, + B->getDeclName().getAsIdentifierInfo(), RefType, + S.Context.getTrivialTypeSourceInfo(T, Loc), Src->getStorageClass()); + RefVD->setLexicalDeclContext(Src->getLexicalDeclContext()); + RefVD->setTSCSpec(Src->getTSCSpec()); + RefVD->setImplicit(); + if (Src->isInlineSpecified()) + RefVD->setInlineSpecified(); + RefVD->getLexicalDeclContext()->addHiddenDecl(RefVD); + + InitializedEntity Entity = InitializedEntity::InitializeBinding(RefVD); + InitializationKind Kind = InitializationKind::CreateCopy(Loc, Loc); + InitializationSequence Seq(S, Entity, Kind, Init); + E = Seq.Perform(S, Entity, Kind, Init); + if (E.isInvalid()) + return true; + E = S.ActOnFinishFullExpr(E.get(), Loc, /*DiscardedValue*/ false); + if (E.isInvalid()) + return true; + RefVD->setInit(E.get()); + S.CheckCompleteVariableDeclaration(RefVD); + + E = S.BuildDeclarationNameExpr(CXXScopeSpec(), + DeclarationNameInfo(B->getDeclName(), Loc), + RefVD); + if (E.isInvalid()) + return true; + + B->setBinding(T, E.get()); + I++; + } + + return false; + } + + /// Find the base class to decompose in a built-in decomposition of a class type. + /// This base class search is, unfortunately, not quite like any other that we + /// perform anywhere else in C++. + static DeclAccessPair findDecomposableBaseClass(Sema &S, SourceLocation Loc, + const CXXRecordDecl *RD, + CXXCastPath &BasePath) { + auto BaseHasFields = [](const CXXBaseSpecifier *Specifier, + CXXBasePath &Path) { + return Specifier->getType()->getAsCXXRecordDecl()->hasDirectFields(); + }; + + const CXXRecordDecl *ClassWithFields = nullptr; + AccessSpecifier AS = AS_public; + if (RD->hasDirectFields()) + // [dcl.decomp]p4: + // Otherwise, all of E's non-static data members shall be public direct + // members of E ... + ClassWithFields = RD; + else { + // ... or of ... + CXXBasePaths Paths; + Paths.setOrigin(const_cast(RD)); + if (!RD->lookupInBases(BaseHasFields, Paths)) { + // If no classes have fields, just decompose RD itself. (This will work + // if and only if zero bindings were provided.) + return DeclAccessPair::make(const_cast(RD), AS_public); + } + + CXXBasePath *BestPath = nullptr; + for (auto &P : Paths) { + if (!BestPath) + BestPath = &P; + else if (!S.Context.hasSameType(P.back().Base->getType(), + BestPath->back().Base->getType())) { + // ... the same ... + S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members) + << false << RD << BestPath->back().Base->getType() + << P.back().Base->getType(); + return DeclAccessPair(); + } else if (P.Access < BestPath->Access) { + BestPath = &P; + } + } + + // ... unambiguous ... + QualType BaseType = BestPath->back().Base->getType(); + if (Paths.isAmbiguous(S.Context.getCanonicalType(BaseType))) { + S.Diag(Loc, diag::err_decomp_decl_ambiguous_base) + << RD << BaseType << S.getAmbiguousPathsDisplayString(Paths); + return DeclAccessPair(); + } + + // ... [accessible, implied by other rules] base class of E. + S.CheckBaseClassAccess(Loc, BaseType, S.Context.getRecordType(RD), + *BestPath, diag::err_decomp_decl_inaccessible_base); + AS = BestPath->Access; + + ClassWithFields = BaseType->getAsCXXRecordDecl(); + S.BuildBasePathArray(Paths, BasePath); + } + + // The above search did not check whether the selected class itself has base + // classes with fields, so check that now. + CXXBasePaths Paths; + if (ClassWithFields->lookupInBases(BaseHasFields, Paths)) { + S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members) + << (ClassWithFields == RD) << RD << ClassWithFields + << Paths.front().back().Base->getType(); + return DeclAccessPair(); + } + + return DeclAccessPair::make(const_cast(ClassWithFields), AS); + } + + static bool checkMemberDecomposition(Sema &S, ArrayRef Bindings, + ValueDecl *Src, QualType DecompType, + const CXXRecordDecl *OrigRD) { + if (S.RequireCompleteType(Src->getLocation(), DecompType, + diag::err_incomplete_type)) + return true; + + CXXCastPath BasePath; + DeclAccessPair BasePair = + findDecomposableBaseClass(S, Src->getLocation(), OrigRD, BasePath); + const CXXRecordDecl *RD = cast_or_null(BasePair.getDecl()); + if (!RD) + return true; + QualType BaseType = S.Context.getQualifiedType(S.Context.getRecordType(RD), + DecompType.getQualifiers()); + + auto DiagnoseBadNumberOfBindings = [&]() -> bool { + unsigned NumFields = llvm::count_if( + RD->fields(), [](FieldDecl *FD) { return !FD->isUnnamedBitfield(); }); + assert(Bindings.size() != NumFields); + S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings) + << DecompType << (unsigned)Bindings.size() << NumFields << NumFields + << (NumFields < Bindings.size()); + return true; + }; + + // all of E's non-static data members shall be [...] well-formed + // when named as e.name in the context of the structured binding, + // E shall not have an anonymous union member, ... + unsigned I = 0; + for (auto *FD : RD->fields()) { + if (FD->isUnnamedBitfield()) + continue; + + // All the non-static data members are required to be nameable, so they + // must all have names. + if (!FD->getDeclName()) { + if (RD->isLambda()) { + S.Diag(Src->getLocation(), diag::err_decomp_decl_lambda); + S.Diag(RD->getLocation(), diag::note_lambda_decl); + return true; + } + + if (FD->isAnonymousStructOrUnion()) { + S.Diag(Src->getLocation(), diag::err_decomp_decl_anon_union_member) + << DecompType << FD->getType()->isUnionType(); + S.Diag(FD->getLocation(), diag::note_declared_at); + return true; + } + + // FIXME: Are there any other ways we could have an anonymous member? + } + + // We have a real field to bind. + if (I >= Bindings.size()) + return DiagnoseBadNumberOfBindings(); + auto *B = Bindings[I++]; + SourceLocation Loc = B->getLocation(); + + // The field must be accessible in the context of the structured binding. + // We already checked that the base class is accessible. + // FIXME: Add 'const' to AccessedEntity's classes so we can remove the + // const_cast here. + S.CheckStructuredBindingMemberAccess( + Loc, const_cast(OrigRD), + DeclAccessPair::make(FD, CXXRecordDecl::MergeAccess( + BasePair.getAccess(), FD->getAccess()))); + + // Initialize the binding to Src.FD. + ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc); + if (E.isInvalid()) + return true; + E = S.ImpCastExprToType(E.get(), BaseType, CK_UncheckedDerivedToBase, + VK_LValue, &BasePath); + if (E.isInvalid()) + return true; + E = S.BuildFieldReferenceExpr(E.get(), /*IsArrow*/ false, Loc, + CXXScopeSpec(), FD, + DeclAccessPair::make(FD, FD->getAccess()), + DeclarationNameInfo(FD->getDeclName(), Loc)); + if (E.isInvalid()) + return true; + + // If the type of the member is T, the referenced type is cv T, where cv is + // the cv-qualification of the decomposition expression. + // + // FIXME: We resolve a defect here: if the field is mutable, we do not add + // 'const' to the type of the field. + Qualifiers Q = DecompType.getQualifiers(); + if (FD->isMutable()) + Q.removeConst(); + B->setBinding(S.BuildQualifiedType(FD->getType(), Loc, Q), E.get()); + } + + if (I != Bindings.size()) + return DiagnoseBadNumberOfBindings(); + + return false; + } + + void Sema::CheckCompleteDecompositionDeclaration(DecompositionDecl *DD) { + QualType DecompType = DD->getType(); + + // If the type of the decomposition is dependent, then so is the type of + // each binding. + if (DecompType->isDependentType()) { + for (auto *B : DD->bindings()) + B->setType(Context.DependentTy); + return; + } + + DecompType = DecompType.getNonReferenceType(); + ArrayRef Bindings = DD->bindings(); + + // C++1z [dcl.decomp]/2: + // If E is an array type [...] + // As an extension, we also support decomposition of built-in complex and + // vector types. + if (auto *CAT = Context.getAsConstantArrayType(DecompType)) { + if (checkArrayDecomposition(*this, Bindings, DD, DecompType, CAT)) + DD->setInvalidDecl(); + return; + } + if (auto *VT = DecompType->getAs()) { + if (checkVectorDecomposition(*this, Bindings, DD, DecompType, VT)) + DD->setInvalidDecl(); + return; + } + if (auto *CT = DecompType->getAs()) { + if (checkComplexDecomposition(*this, Bindings, DD, DecompType, CT)) + DD->setInvalidDecl(); + return; + } + + // C++1z [dcl.decomp]/3: + // if the expression std::tuple_size::value is a well-formed integral + // constant expression, [...] + llvm::APSInt TupleSize(32); + switch (isTupleLike(*this, DD->getLocation(), DecompType, TupleSize)) { + case IsTupleLike::Error: + DD->setInvalidDecl(); + return; + + case IsTupleLike::TupleLike: + if (checkTupleLikeDecomposition(*this, Bindings, DD, DecompType, TupleSize)) + DD->setInvalidDecl(); + return; + + case IsTupleLike::NotTupleLike: + break; + } + + // C++1z [dcl.dcl]/8: + // [E shall be of array or non-union class type] + CXXRecordDecl *RD = DecompType->getAsCXXRecordDecl(); + if (!RD || RD->isUnion()) { + Diag(DD->getLocation(), diag::err_decomp_decl_unbindable_type) + << DD << !RD << DecompType; + DD->setInvalidDecl(); + return; + } + + // C++1z [dcl.decomp]/4: + // all of E's non-static data members shall be [...] direct members of + // E or of the same unambiguous public base class of E, ... + if (checkMemberDecomposition(*this, Bindings, DD, DecompType, RD)) + DD->setInvalidDecl(); + } + + /// Merge the exception specifications of two variable declarations. + /// + /// This is called when there's a redeclaration of a VarDecl. The function + /// checks if the redeclaration might have an exception specification and + /// validates compatibility and merges the specs if necessary. + void Sema::MergeVarDeclExceptionSpecs(VarDecl *New, VarDecl *Old) { + // Shortcut if exceptions are disabled. + if (!getLangOpts().CXXExceptions) + return; + + assert(Context.hasSameType(New->getType(), Old->getType()) && + "Should only be called if types are otherwise the same."); + + QualType NewType = New->getType(); + QualType OldType = Old->getType(); + + // We're only interested in pointers and references to functions, as well + // as pointers to member functions. + if (const ReferenceType *R = NewType->getAs()) { + NewType = R->getPointeeType(); + OldType = OldType->castAs()->getPointeeType(); + } else if (const PointerType *P = NewType->getAs()) { + NewType = P->getPointeeType(); + OldType = OldType->castAs()->getPointeeType(); + } else if (const MemberPointerType *M = NewType->getAs()) { + NewType = M->getPointeeType(); + OldType = OldType->castAs()->getPointeeType(); + } + + if (!NewType->isFunctionProtoType()) + return; + + // There's lots of special cases for functions. For function pointers, system + // libraries are hopefully not as broken so that we don't need these + // workarounds. + if (CheckEquivalentExceptionSpec( + OldType->getAs(), Old->getLocation(), + NewType->getAs(), New->getLocation())) { + New->setInvalidDecl(); + } + } + + /// CheckCXXDefaultArguments - Verify that the default arguments for a + /// function declaration are well-formed according to C++ + /// [dcl.fct.default]. + void Sema::CheckCXXDefaultArguments(FunctionDecl *FD) { + unsigned NumParams = FD->getNumParams(); + unsigned ParamIdx = 0; + + // This checking doesn't make sense for explicit specializations; their + // default arguments are determined by the declaration we're specializing, + // not by FD. + if (FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization) + return; + if (auto *FTD = FD->getDescribedFunctionTemplate()) + if (FTD->isMemberSpecialization()) + return; + + // Find first parameter with a default argument + for (; ParamIdx < NumParams; ++ParamIdx) { + ParmVarDecl *Param = FD->getParamDecl(ParamIdx); + if (Param->hasDefaultArg()) + break; + } + + // C++20 [dcl.fct.default]p4: + // In a given function declaration, each parameter subsequent to a parameter + // with a default argument shall have a default argument supplied in this or + // a previous declaration, unless the parameter was expanded from a + // parameter pack, or shall be a function parameter pack. + for (; ParamIdx < NumParams; ++ParamIdx) { + ParmVarDecl *Param = FD->getParamDecl(ParamIdx); + if (!Param->hasDefaultArg() && !Param->isParameterPack() && + !(CurrentInstantiationScope && + CurrentInstantiationScope->isLocalPackExpansion(Param))) { + if (Param->isInvalidDecl()) + /* We already complained about this parameter. */; + else if (Param->getIdentifier()) + Diag(Param->getLocation(), + diag::err_param_default_argument_missing_name) + << Param->getIdentifier(); + else + Diag(Param->getLocation(), + diag::err_param_default_argument_missing); + } + } + } + + /// Check that the given type is a literal type. Issue a diagnostic if not, + /// if Kind is Diagnose. + /// \return \c true if a problem has been found (and optionally diagnosed). + template + static bool CheckLiteralType(Sema &SemaRef, Sema::CheckConstexprKind Kind, + SourceLocation Loc, QualType T, unsigned DiagID, + Ts &&...DiagArgs) { + if (T->isDependentType()) + return false; + + switch (Kind) { + case Sema::CheckConstexprKind::Diagnose: + return SemaRef.RequireLiteralType(Loc, T, DiagID, + std::forward(DiagArgs)...); + + case Sema::CheckConstexprKind::CheckValid: + return !T->isLiteralType(SemaRef.Context); + } + + llvm_unreachable("unknown CheckConstexprKind"); + } + + /// Determine whether a destructor cannot be constexpr due to + static bool CheckConstexprDestructorSubobjects(Sema &SemaRef, + const CXXDestructorDecl *DD, + Sema::CheckConstexprKind Kind) { + auto Check = [&](SourceLocation Loc, QualType T, const FieldDecl *FD) { + const CXXRecordDecl *RD = + T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl(); + if (!RD || RD->hasConstexprDestructor()) + return true; + + if (Kind == Sema::CheckConstexprKind::Diagnose) { + SemaRef.Diag(DD->getLocation(), diag::err_constexpr_dtor_subobject) + << static_cast(DD->getConstexprKind()) << !FD + << (FD ? FD->getDeclName() : DeclarationName()) << T; + SemaRef.Diag(Loc, diag::note_constexpr_dtor_subobject) + << !FD << (FD ? FD->getDeclName() : DeclarationName()) << T; + } + return false; + }; + + const CXXRecordDecl *RD = DD->getParent(); + for (const CXXBaseSpecifier &B : RD->bases()) + if (!Check(B.getBaseTypeLoc(), B.getType(), nullptr)) + return false; + for (const FieldDecl *FD : RD->fields()) + if (!Check(FD->getLocation(), FD->getType(), FD)) + return false; + return true; + } + + /// Check whether a function's parameter types are all literal types. If so, + /// return true. If not, produce a suitable diagnostic and return false. + static bool CheckConstexprParameterTypes(Sema &SemaRef, + const FunctionDecl *FD, + Sema::CheckConstexprKind Kind) { + unsigned ArgIndex = 0; + const auto *FT = FD->getType()->castAs(); + for (FunctionProtoType::param_type_iterator i = FT->param_type_begin(), + e = FT->param_type_end(); + i != e; ++i, ++ArgIndex) { + const ParmVarDecl *PD = FD->getParamDecl(ArgIndex); + assert(PD && "null in a parameter list"); + SourceLocation ParamLoc = PD->getLocation(); + if (CheckLiteralType(SemaRef, Kind, ParamLoc, *i, + diag::err_constexpr_non_literal_param, ArgIndex + 1, + PD->getSourceRange(), isa(FD), + FD->isConsteval())) + return false; + } + return true; + } + + /// Check whether a function's return type is a literal type. If so, return + /// true. If not, produce a suitable diagnostic and return false. + static bool CheckConstexprReturnType(Sema &SemaRef, const FunctionDecl *FD, + Sema::CheckConstexprKind Kind) { + if (CheckLiteralType(SemaRef, Kind, FD->getLocation(), FD->getReturnType(), + diag::err_constexpr_non_literal_return, + FD->isConsteval())) + return false; + return true; + } + + /// Get diagnostic %select index for tag kind for + /// record diagnostic message. + /// WARNING: Indexes apply to particular diagnostics only! + /// + /// \returns diagnostic %select index. + static unsigned getRecordDiagFromTagKind(TagTypeKind Tag) { + switch (Tag) { + case TTK_Struct: return 0; + case TTK_Interface: return 1; + case TTK_Class: return 2; + default: llvm_unreachable("Invalid tag kind for record diagnostic!"); + } + } + + static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl, + Stmt *Body, + Sema::CheckConstexprKind Kind); + + // Check whether a function declaration satisfies the requirements of a + // constexpr function definition or a constexpr constructor definition. If so, + // return true. If not, produce appropriate diagnostics (unless asked not to by + // Kind) and return false. + // + // This implements C++11 [dcl.constexpr]p3,4, as amended by DR1360. + bool Sema::CheckConstexprFunctionDefinition(const FunctionDecl *NewFD, + CheckConstexprKind Kind) { + const CXXMethodDecl *MD = dyn_cast(NewFD); + if (MD && MD->isInstance()) { + // C++11 [dcl.constexpr]p4: + // The definition of a constexpr constructor shall satisfy the following + // constraints: + // - the class shall not have any virtual base classes; + // + // FIXME: This only applies to constructors and destructors, not arbitrary + // member functions. + const CXXRecordDecl *RD = MD->getParent(); + if (RD->getNumVBases()) { + if (Kind == CheckConstexprKind::CheckValid) + return false; + + Diag(NewFD->getLocation(), diag::err_constexpr_virtual_base) + << isa(NewFD) + << getRecordDiagFromTagKind(RD->getTagKind()) << RD->getNumVBases(); + for (const auto &I : RD->vbases()) + Diag(I.getBeginLoc(), diag::note_constexpr_virtual_base_here) + << I.getSourceRange(); + return false; + } + } + + if (!isa(NewFD)) { + // C++11 [dcl.constexpr]p3: + // The definition of a constexpr function shall satisfy the following + // constraints: + // - it shall not be virtual; (removed in C++20) + const CXXMethodDecl *Method = dyn_cast(NewFD); + if (Method && Method->isVirtual()) { + if (getLangOpts().CPlusPlus20) { + if (Kind == CheckConstexprKind::Diagnose) + Diag(Method->getLocation(), diag::warn_cxx17_compat_constexpr_virtual); + } else { + if (Kind == CheckConstexprKind::CheckValid) + return false; + + Method = Method->getCanonicalDecl(); + Diag(Method->getLocation(), diag::err_constexpr_virtual); + + // If it's not obvious why this function is virtual, find an overridden + // function which uses the 'virtual' keyword. + const CXXMethodDecl *WrittenVirtual = Method; + while (!WrittenVirtual->isVirtualAsWritten()) + WrittenVirtual = *WrittenVirtual->begin_overridden_methods(); + if (WrittenVirtual != Method) + Diag(WrittenVirtual->getLocation(), + diag::note_overridden_virtual_function); + return false; + } + } + + // - its return type shall be a literal type; + if (!CheckConstexprReturnType(*this, NewFD, Kind)) + return false; + } + + if (auto *Dtor = dyn_cast(NewFD)) { + // A destructor can be constexpr only if the defaulted destructor could be; + // we don't need to check the members and bases if we already know they all + // have constexpr destructors. + if (!Dtor->getParent()->defaultedDestructorIsConstexpr()) { + if (Kind == CheckConstexprKind::CheckValid) + return false; + if (!CheckConstexprDestructorSubobjects(*this, Dtor, Kind)) + return false; + } + } + + // - each of its parameter types shall be a literal type; + if (!CheckConstexprParameterTypes(*this, NewFD, Kind)) + return false; + + Stmt *Body = NewFD->getBody(); + assert(Body && + "CheckConstexprFunctionDefinition called on function with no body"); + return CheckConstexprFunctionBody(*this, NewFD, Body, Kind); + } + + /// Check the given declaration statement is legal within a constexpr function + /// body. C++11 [dcl.constexpr]p3,p4, and C++1y [dcl.constexpr]p3. + /// + /// \return true if the body is OK (maybe only as an extension), false if we + /// have diagnosed a problem. + static bool CheckConstexprDeclStmt(Sema &SemaRef, const FunctionDecl *Dcl, + DeclStmt *DS, SourceLocation &Cxx1yLoc, + Sema::CheckConstexprKind Kind) { + // C++11 [dcl.constexpr]p3 and p4: + // The definition of a constexpr function(p3) or constructor(p4) [...] shall + // contain only + for (const auto *DclIt : DS->decls()) { + switch (DclIt->getKind()) { + case Decl::StaticAssert: + case Decl::Using: + case Decl::UsingShadow: + case Decl::UsingDirective: + case Decl::UnresolvedUsingTypename: + case Decl::UnresolvedUsingValue: + case Decl::UsingEnum: + // - static_assert-declarations + // - using-declarations, + // - using-directives, + // - using-enum-declaration + continue; + + case Decl::Typedef: + case Decl::TypeAlias: { + // - typedef declarations and alias-declarations that do not define + // classes or enumerations, + const auto *TN = cast(DclIt); + if (TN->getUnderlyingType()->isVariablyModifiedType()) { + // Don't allow variably-modified types in constexpr functions. + if (Kind == Sema::CheckConstexprKind::Diagnose) { + TypeLoc TL = TN->getTypeSourceInfo()->getTypeLoc(); + SemaRef.Diag(TL.getBeginLoc(), diag::err_constexpr_vla) + << TL.getSourceRange() << TL.getType() + << isa(Dcl); + } + return false; + } + continue; + } + + case Decl::Enum: + case Decl::CXXRecord: + // C++1y allows types to be defined, not just declared. + if (cast(DclIt)->isThisDeclarationADefinition()) { + if (Kind == Sema::CheckConstexprKind::Diagnose) { + SemaRef.Diag(DS->getBeginLoc(), + SemaRef.getLangOpts().CPlusPlus14 + ? diag::warn_cxx11_compat_constexpr_type_definition + : diag::ext_constexpr_type_definition) + << isa(Dcl); + } else if (!SemaRef.getLangOpts().CPlusPlus14) { + return false; + } + } + continue; + + case Decl::EnumConstant: + case Decl::IndirectField: + case Decl::ParmVar: + // These can only appear with other declarations which are banned in + // C++11 and permitted in C++1y, so ignore them. + continue; + + case Decl::Var: + case Decl::Decomposition: { + // C++1y [dcl.constexpr]p3 allows anything except: + // a definition of a variable of non-literal type or of static or + // thread storage duration or [before C++2a] for which no + // initialization is performed. + const auto *VD = cast(DclIt); + if (VD->isThisDeclarationADefinition()) { + if (VD->isStaticLocal()) { + if (Kind == Sema::CheckConstexprKind::Diagnose) { + SemaRef.Diag(VD->getLocation(), + SemaRef.getLangOpts().CPlusPlus23 + ? diag::warn_cxx20_compat_constexpr_var + : diag::ext_constexpr_static_var) + << isa(Dcl) + << (VD->getTLSKind() == VarDecl::TLS_Dynamic); + } else if (!SemaRef.getLangOpts().CPlusPlus23) { + return false; + } + } + if (SemaRef.LangOpts.CPlusPlus23) { + CheckLiteralType(SemaRef, Kind, VD->getLocation(), VD->getType(), + diag::warn_cxx20_compat_constexpr_var, + isa(Dcl), + /*variable of non-literal type*/ 2); + } else if (CheckLiteralType( + SemaRef, Kind, VD->getLocation(), VD->getType(), + diag::err_constexpr_local_var_non_literal_type, + isa(Dcl))) { + return false; + } + if (!VD->getType()->isDependentType() && + !VD->hasInit() && !VD->isCXXForRangeDecl()) { + if (Kind == Sema::CheckConstexprKind::Diagnose) { + SemaRef.Diag( + VD->getLocation(), + SemaRef.getLangOpts().CPlusPlus20 + ? diag::warn_cxx17_compat_constexpr_local_var_no_init + : diag::ext_constexpr_local_var_no_init) + << isa(Dcl); + } else if (!SemaRef.getLangOpts().CPlusPlus20) { + return false; + } + continue; + } + } + if (Kind == Sema::CheckConstexprKind::Diagnose) { + SemaRef.Diag(VD->getLocation(), + SemaRef.getLangOpts().CPlusPlus14 + ? diag::warn_cxx11_compat_constexpr_local_var + : diag::ext_constexpr_local_var) + << isa(Dcl); + } else if (!SemaRef.getLangOpts().CPlusPlus14) { + return false; + } + continue; + } + + case Decl::NamespaceAlias: + case Decl::Function: + // These are disallowed in C++11 and permitted in C++1y. Allow them + // everywhere as an extension. + if (!Cxx1yLoc.isValid()) + Cxx1yLoc = DS->getBeginLoc(); + continue; + + default: + if (Kind == Sema::CheckConstexprKind::Diagnose) { + SemaRef.Diag(DS->getBeginLoc(), diag::err_constexpr_body_invalid_stmt) + << isa(Dcl) << Dcl->isConsteval(); + } + return false; + } + } + + return true; + } + + /// Check that the given field is initialized within a constexpr constructor. + /// + /// \param Dcl The constexpr constructor being checked. + /// \param Field The field being checked. This may be a member of an anonymous + /// struct or union nested within the class being checked. + /// \param Inits All declarations, including anonymous struct/union members and + /// indirect members, for which any initialization was provided. + /// \param Diagnosed Whether we've emitted the error message yet. Used to attach + /// multiple notes for different members to the same error. + /// \param Kind Whether we're diagnosing a constructor as written or determining + /// whether the formal requirements are satisfied. + /// \return \c false if we're checking for validity and the constructor does + /// not satisfy the requirements on a constexpr constructor. + static bool CheckConstexprCtorInitializer(Sema &SemaRef, + const FunctionDecl *Dcl, + FieldDecl *Field, + llvm::SmallSet &Inits, + bool &Diagnosed, + Sema::CheckConstexprKind Kind) { + // In C++20 onwards, there's nothing to check for validity. + if (Kind == Sema::CheckConstexprKind::CheckValid && + SemaRef.getLangOpts().CPlusPlus20) + return true; + + if (Field->isInvalidDecl()) + return true; + + if (Field->isUnnamedBitfield()) + return true; + + // Anonymous unions with no variant members and empty anonymous structs do not + // need to be explicitly initialized. FIXME: Anonymous structs that contain no + // indirect fields don't need initializing. + if (Field->isAnonymousStructOrUnion() && + (Field->getType()->isUnionType() + ? !Field->getType()->getAsCXXRecordDecl()->hasVariantMembers() + : Field->getType()->getAsCXXRecordDecl()->isEmpty())) + return true; + + if (!Inits.count(Field)) { + if (Kind == Sema::CheckConstexprKind::Diagnose) { + if (!Diagnosed) { + SemaRef.Diag(Dcl->getLocation(), + SemaRef.getLangOpts().CPlusPlus20 + ? diag::warn_cxx17_compat_constexpr_ctor_missing_init + : diag::ext_constexpr_ctor_missing_init); + Diagnosed = true; + } + SemaRef.Diag(Field->getLocation(), + diag::note_constexpr_ctor_missing_init); + } else if (!SemaRef.getLangOpts().CPlusPlus20) { + return false; + } + } else if (Field->isAnonymousStructOrUnion()) { + const RecordDecl *RD = Field->getType()->castAs()->getDecl(); + for (auto *I : RD->fields()) + // If an anonymous union contains an anonymous struct of which any member + // is initialized, all members must be initialized. + if (!RD->isUnion() || Inits.count(I)) + if (!CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed, + Kind)) + return false; + } + return true; + } + + /// Check the provided statement is allowed in a constexpr function + /// definition. + static bool + CheckConstexprFunctionStmt(Sema &SemaRef, const FunctionDecl *Dcl, Stmt *S, + SmallVectorImpl &ReturnStmts, + SourceLocation &Cxx1yLoc, SourceLocation &Cxx2aLoc, + SourceLocation &Cxx2bLoc, + Sema::CheckConstexprKind Kind) { + // - its function-body shall be [...] a compound-statement that contains only + switch (S->getStmtClass()) { + case Stmt::NullStmtClass: + // - null statements, + return true; + + case Stmt::DeclStmtClass: + // - static_assert-declarations + // - using-declarations, + // - using-directives, + // - typedef declarations and alias-declarations that do not define + // classes or enumerations, + if (!CheckConstexprDeclStmt(SemaRef, Dcl, cast(S), Cxx1yLoc, Kind)) + return false; + return true; + + case Stmt::ReturnStmtClass: + // - and exactly one return statement; + if (isa(Dcl)) { + // C++1y allows return statements in constexpr constructors. + if (!Cxx1yLoc.isValid()) + Cxx1yLoc = S->getBeginLoc(); + return true; + } + + ReturnStmts.push_back(S->getBeginLoc()); + return true; + + case Stmt::AttributedStmtClass: + // Attributes on a statement don't affect its formal kind and hence don't + // affect its validity in a constexpr function. + return CheckConstexprFunctionStmt( + SemaRef, Dcl, cast(S)->getSubStmt(), ReturnStmts, + Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind); + + case Stmt::CompoundStmtClass: { + // C++1y allows compound-statements. + if (!Cxx1yLoc.isValid()) + Cxx1yLoc = S->getBeginLoc(); + + CompoundStmt *CompStmt = cast(S); + for (auto *BodyIt : CompStmt->body()) { + if (!CheckConstexprFunctionStmt(SemaRef, Dcl, BodyIt, ReturnStmts, + Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind)) + return false; + } + return true; + } + + case Stmt::IfStmtClass: { + // C++1y allows if-statements. + if (!Cxx1yLoc.isValid()) + Cxx1yLoc = S->getBeginLoc(); + + IfStmt *If = cast(S); + if (!CheckConstexprFunctionStmt(SemaRef, Dcl, If->getThen(), ReturnStmts, + Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind)) + return false; + if (If->getElse() && + !CheckConstexprFunctionStmt(SemaRef, Dcl, If->getElse(), ReturnStmts, + Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind)) + return false; + return true; + } + + case Stmt::WhileStmtClass: + case Stmt::DoStmtClass: + case Stmt::ForStmtClass: + case Stmt::CXXForRangeStmtClass: + case Stmt::ContinueStmtClass: + // C++1y allows all of these. We don't allow them as extensions in C++11, + // because they don't make sense without variable mutation. + if (!SemaRef.getLangOpts().CPlusPlus14) + break; + if (!Cxx1yLoc.isValid()) + Cxx1yLoc = S->getBeginLoc(); + for (Stmt *SubStmt : S->children()) { + if (SubStmt && + !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts, + Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind)) + return false; + } + return true; + + case Stmt::SwitchStmtClass: + case Stmt::CaseStmtClass: + case Stmt::DefaultStmtClass: + case Stmt::BreakStmtClass: + // C++1y allows switch-statements, and since they don't need variable + // mutation, we can reasonably allow them in C++11 as an extension. + if (!Cxx1yLoc.isValid()) + Cxx1yLoc = S->getBeginLoc(); + for (Stmt *SubStmt : S->children()) { + if (SubStmt && + !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts, + Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind)) + return false; + } + return true; + + case Stmt::LabelStmtClass: + case Stmt::GotoStmtClass: + if (Cxx2bLoc.isInvalid()) + Cxx2bLoc = S->getBeginLoc(); + for (Stmt *SubStmt : S->children()) { + if (SubStmt && + !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts, + Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind)) + return false; + } + return true; + + case Stmt::GCCAsmStmtClass: + case Stmt::MSAsmStmtClass: + // C++2a allows inline assembly statements. + case Stmt::CXXTryStmtClass: + if (Cxx2aLoc.isInvalid()) + Cxx2aLoc = S->getBeginLoc(); + for (Stmt *SubStmt : S->children()) { + if (SubStmt && + !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts, + Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind)) + return false; + } + return true; + + case Stmt::CXXCatchStmtClass: + // Do not bother checking the language mode (already covered by the + // try block check). + if (!CheckConstexprFunctionStmt( + SemaRef, Dcl, cast(S)->getHandlerBlock(), ReturnStmts, + Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind)) + return false; + return true; + + default: + if (!isa(S)) + break; + + // C++1y allows expression-statements. + if (!Cxx1yLoc.isValid()) + Cxx1yLoc = S->getBeginLoc(); + return true; + } + + if (Kind == Sema::CheckConstexprKind::Diagnose) { + SemaRef.Diag(S->getBeginLoc(), diag::err_constexpr_body_invalid_stmt) + << isa(Dcl) << Dcl->isConsteval(); + } + return false; + } + + /// Check the body for the given constexpr function declaration only contains + /// the permitted types of statement. C++11 [dcl.constexpr]p3,p4. + /// + /// \return true if the body is OK, false if we have found or diagnosed a + /// problem. + static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl, + Stmt *Body, + Sema::CheckConstexprKind Kind) { + SmallVector ReturnStmts; + + if (isa(Body)) { + // C++11 [dcl.constexpr]p3: + // The definition of a constexpr function shall satisfy the following + // constraints: [...] + // - its function-body shall be = delete, = default, or a + // compound-statement + // + // C++11 [dcl.constexpr]p4: + // In the definition of a constexpr constructor, [...] + // - its function-body shall not be a function-try-block; + // + // This restriction is lifted in C++2a, as long as inner statements also + // apply the general constexpr rules. + switch (Kind) { + case Sema::CheckConstexprKind::CheckValid: + if (!SemaRef.getLangOpts().CPlusPlus20) + return false; + break; + + case Sema::CheckConstexprKind::Diagnose: + SemaRef.Diag(Body->getBeginLoc(), + !SemaRef.getLangOpts().CPlusPlus20 + ? diag::ext_constexpr_function_try_block_cxx20 + : diag::warn_cxx17_compat_constexpr_function_try_block) + << isa(Dcl); + break; + } + } + + // - its function-body shall be [...] a compound-statement that contains only + // [... list of cases ...] + // + // Note that walking the children here is enough to properly check for + // CompoundStmt and CXXTryStmt body. + SourceLocation Cxx1yLoc, Cxx2aLoc, Cxx2bLoc; + for (Stmt *SubStmt : Body->children()) { + if (SubStmt && + !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts, + Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind)) + return false; + } + + if (Kind == Sema::CheckConstexprKind::CheckValid) { + // If this is only valid as an extension, report that we don't satisfy the + // constraints of the current language. + if ((Cxx2bLoc.isValid() && !SemaRef.getLangOpts().CPlusPlus23) || + (Cxx2aLoc.isValid() && !SemaRef.getLangOpts().CPlusPlus20) || + (Cxx1yLoc.isValid() && !SemaRef.getLangOpts().CPlusPlus17)) + return false; + } else if (Cxx2bLoc.isValid()) { + SemaRef.Diag(Cxx2bLoc, + SemaRef.getLangOpts().CPlusPlus23 + ? diag::warn_cxx20_compat_constexpr_body_invalid_stmt + : diag::ext_constexpr_body_invalid_stmt_cxx23) + << isa(Dcl); + } else if (Cxx2aLoc.isValid()) { + SemaRef.Diag(Cxx2aLoc, + SemaRef.getLangOpts().CPlusPlus20 + ? diag::warn_cxx17_compat_constexpr_body_invalid_stmt + : diag::ext_constexpr_body_invalid_stmt_cxx20) + << isa(Dcl); + } else if (Cxx1yLoc.isValid()) { + SemaRef.Diag(Cxx1yLoc, + SemaRef.getLangOpts().CPlusPlus14 + ? diag::warn_cxx11_compat_constexpr_body_invalid_stmt + : diag::ext_constexpr_body_invalid_stmt) + << isa(Dcl); + } + + if (const CXXConstructorDecl *Constructor + = dyn_cast(Dcl)) { + const CXXRecordDecl *RD = Constructor->getParent(); + // DR1359: + // - every non-variant non-static data member and base class sub-object + // shall be initialized; + // DR1460: + // - if the class is a union having variant members, exactly one of them + // shall be initialized; + if (RD->isUnion()) { + if (Constructor->getNumCtorInitializers() == 0 && + RD->hasVariantMembers()) { + if (Kind == Sema::CheckConstexprKind::Diagnose) { + SemaRef.Diag( + Dcl->getLocation(), + SemaRef.getLangOpts().CPlusPlus20 + ? diag::warn_cxx17_compat_constexpr_union_ctor_no_init + : diag::ext_constexpr_union_ctor_no_init); + } else if (!SemaRef.getLangOpts().CPlusPlus20) { + return false; + } + } + } else if (!Constructor->isDependentContext() && + !Constructor->isDelegatingConstructor()) { + assert(RD->getNumVBases() == 0 && "constexpr ctor with virtual bases"); + + // Skip detailed checking if we have enough initializers, and we would + // allow at most one initializer per member. + bool AnyAnonStructUnionMembers = false; + unsigned Fields = 0; + for (CXXRecordDecl::field_iterator I = RD->field_begin(), + E = RD->field_end(); I != E; ++I, ++Fields) { + if (I->isAnonymousStructOrUnion()) { + AnyAnonStructUnionMembers = true; + break; + } + } + // DR1460: + // - if the class is a union-like class, but is not a union, for each of + // its anonymous union members having variant members, exactly one of + // them shall be initialized; + if (AnyAnonStructUnionMembers || + Constructor->getNumCtorInitializers() != RD->getNumBases() + Fields) { + // Check initialization of non-static data members. Base classes are + // always initialized so do not need to be checked. Dependent bases + // might not have initializers in the member initializer list. + llvm::SmallSet Inits; + for (const auto *I: Constructor->inits()) { + if (FieldDecl *FD = I->getMember()) + Inits.insert(FD); + else if (IndirectFieldDecl *ID = I->getIndirectMember()) + Inits.insert(ID->chain_begin(), ID->chain_end()); + } + + bool Diagnosed = false; + for (auto *I : RD->fields()) + if (!CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed, + Kind)) + return false; + } + } + } else { + if (ReturnStmts.empty()) { + // C++1y doesn't require constexpr functions to contain a 'return' + // statement. We still do, unless the return type might be void, because + // otherwise if there's no return statement, the function cannot + // be used in a core constant expression. + bool OK = SemaRef.getLangOpts().CPlusPlus14 && + (Dcl->getReturnType()->isVoidType() || + Dcl->getReturnType()->isDependentType()); + switch (Kind) { + case Sema::CheckConstexprKind::Diagnose: + SemaRef.Diag(Dcl->getLocation(), + OK ? diag::warn_cxx11_compat_constexpr_body_no_return + : diag::err_constexpr_body_no_return) + << Dcl->isConsteval(); + if (!OK) + return false; + break; + + case Sema::CheckConstexprKind::CheckValid: + // The formal requirements don't include this rule in C++14, even + // though the "must be able to produce a constant expression" rules + // still imply it in some cases. + if (!SemaRef.getLangOpts().CPlusPlus14) + return false; + break; + } + } else if (ReturnStmts.size() > 1) { + switch (Kind) { + case Sema::CheckConstexprKind::Diagnose: + SemaRef.Diag( + ReturnStmts.back(), + SemaRef.getLangOpts().CPlusPlus14 + ? diag::warn_cxx11_compat_constexpr_body_multiple_return + : diag::ext_constexpr_body_multiple_return); + for (unsigned I = 0; I < ReturnStmts.size() - 1; ++I) + SemaRef.Diag(ReturnStmts[I], + diag::note_constexpr_body_previous_return); + break; + + case Sema::CheckConstexprKind::CheckValid: + if (!SemaRef.getLangOpts().CPlusPlus14) + return false; + break; + } + } + } + + // C++11 [dcl.constexpr]p5: + // if no function argument values exist such that the function invocation + // substitution would produce a constant expression, the program is + // ill-formed; no diagnostic required. + // C++11 [dcl.constexpr]p3: + // - every constructor call and implicit conversion used in initializing the + // return value shall be one of those allowed in a constant expression. + // C++11 [dcl.constexpr]p4: + // - every constructor involved in initializing non-static data members and + // base class sub-objects shall be a constexpr constructor. + // + // Note that this rule is distinct from the "requirements for a constexpr + // function", so is not checked in CheckValid mode. + SmallVector Diags; + if (Kind == Sema::CheckConstexprKind::Diagnose && + !Expr::isPotentialConstantExpr(Dcl, Diags)) { + SemaRef.Diag(Dcl->getLocation(), + diag::ext_constexpr_function_never_constant_expr) + << isa(Dcl) << Dcl->isConsteval(); + for (size_t I = 0, N = Diags.size(); I != N; ++I) + SemaRef.Diag(Diags[I].first, Diags[I].second); + // Don't return false here: we allow this for compatibility in + // system headers. + } + + return true; + } + + /// Get the class that is directly named by the current context. This is the + /// class for which an unqualified-id in this scope could name a constructor + /// or destructor. + /// + /// If the scope specifier denotes a class, this will be that class. + /// If the scope specifier is empty, this will be the class whose + /// member-specification we are currently within. Otherwise, there + /// is no such class. + CXXRecordDecl *Sema::getCurrentClass(Scope *, const CXXScopeSpec *SS) { + assert(getLangOpts().CPlusPlus && "No class names in C!"); + + if (SS && SS->isInvalid()) + return nullptr; + + if (SS && SS->isNotEmpty()) { + DeclContext *DC = computeDeclContext(*SS, true); + return dyn_cast_or_null(DC); + } + + return dyn_cast_or_null(CurContext); + } + + /// isCurrentClassName - Determine whether the identifier II is the + /// name of the class type currently being defined. In the case of + /// nested classes, this will only return true if II is the name of + /// the innermost class. + bool Sema::isCurrentClassName(const IdentifierInfo &II, Scope *S, + const CXXScopeSpec *SS) { + CXXRecordDecl *CurDecl = getCurrentClass(S, SS); + return CurDecl && &II == CurDecl->getIdentifier(); + } + + /// Determine whether the identifier II is a typo for the name of + /// the class type currently being defined. If so, update it to the identifier + /// that should have been used. + bool Sema::isCurrentClassNameTypo(IdentifierInfo *&II, const CXXScopeSpec *SS) { + assert(getLangOpts().CPlusPlus && "No class names in C!"); + + if (!getLangOpts().SpellChecking) + return false; + + CXXRecordDecl *CurDecl; + if (SS && SS->isSet() && !SS->isInvalid()) { + DeclContext *DC = computeDeclContext(*SS, true); + CurDecl = dyn_cast_or_null(DC); + } else + CurDecl = dyn_cast_or_null(CurContext); + + if (CurDecl && CurDecl->getIdentifier() && II != CurDecl->getIdentifier() && + 3 * II->getName().edit_distance(CurDecl->getIdentifier()->getName()) + < II->getLength()) { + II = CurDecl->getIdentifier(); + return true; + } + + return false; + } + + /// Determine whether the given class is a base class of the given + /// class, including looking at dependent bases. + static bool findCircularInheritance(const CXXRecordDecl *Class, + const CXXRecordDecl *Current) { + SmallVector Queue; + + Class = Class->getCanonicalDecl(); + while (true) { + for (const auto &I : Current->bases()) { + CXXRecordDecl *Base = I.getType()->getAsCXXRecordDecl(); + if (!Base) + continue; + + Base = Base->getDefinition(); + if (!Base) + continue; + + if (Base->getCanonicalDecl() == Class) + return true; + + Queue.push_back(Base); + } + + if (Queue.empty()) + return false; + + Current = Queue.pop_back_val(); + } + + return false; + } + + /// Check the validity of a C++ base class specifier. + /// + /// \returns a new CXXBaseSpecifier if well-formed, emits diagnostics + /// and returns NULL otherwise. + CXXBaseSpecifier * + Sema::CheckBaseSpecifier(CXXRecordDecl *Class, + SourceRange SpecifierRange, + bool Virtual, AccessSpecifier Access, + TypeSourceInfo *TInfo, + SourceLocation EllipsisLoc) { + // In HLSL, unspecified class access is public rather than private. + if (getLangOpts().HLSL && Class->getTagKind() == TTK_Class && + Access == AS_none) + Access = AS_public; + + QualType BaseType = TInfo->getType(); + if (BaseType->containsErrors()) { + // Already emitted a diagnostic when parsing the error type. + return nullptr; + } + // C++ [class.union]p1: + // A union shall not have base classes. + if (Class->isUnion()) { + Diag(Class->getLocation(), diag::err_base_clause_on_union) + << SpecifierRange; + return nullptr; + } + + if (EllipsisLoc.isValid() && + !TInfo->getType()->containsUnexpandedParameterPack()) { + Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs) + << TInfo->getTypeLoc().getSourceRange(); + EllipsisLoc = SourceLocation(); + } + + SourceLocation BaseLoc = TInfo->getTypeLoc().getBeginLoc(); + + if (BaseType->isDependentType()) { + // Make sure that we don't have circular inheritance among our dependent + // bases. For non-dependent bases, the check for completeness below handles + // this. + if (CXXRecordDecl *BaseDecl = BaseType->getAsCXXRecordDecl()) { + if (BaseDecl->getCanonicalDecl() == Class->getCanonicalDecl() || + ((BaseDecl = BaseDecl->getDefinition()) && + findCircularInheritance(Class, BaseDecl))) { + Diag(BaseLoc, diag::err_circular_inheritance) + << BaseType << Context.getTypeDeclType(Class); + + if (BaseDecl->getCanonicalDecl() != Class->getCanonicalDecl()) + Diag(BaseDecl->getLocation(), diag::note_previous_decl) + << BaseType; + + return nullptr; + } + } + + // Make sure that we don't make an ill-formed AST where the type of the + // Class is non-dependent and its attached base class specifier is an + // dependent type, which violates invariants in many clang code paths (e.g. + // constexpr evaluator). If this case happens (in errory-recovery mode), we + // explicitly mark the Class decl invalid. The diagnostic was already + // emitted. + if (!Class->getTypeForDecl()->isDependentType()) + Class->setInvalidDecl(); + return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual, + Class->getTagKind() == TTK_Class, + Access, TInfo, EllipsisLoc); + } + + // Base specifiers must be record types. + if (!BaseType->isRecordType()) { + Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange; + return nullptr; + } + + // C++ [class.union]p1: + // A union shall not be used as a base class. + if (BaseType->isUnionType()) { + Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange; + return nullptr; + } + + // For the MS ABI, propagate DLL attributes to base class templates. + if (Context.getTargetInfo().getCXXABI().isMicrosoft() || + Context.getTargetInfo().getTriple().isPS()) { + if (Attr *ClassAttr = getDLLAttr(Class)) { + if (auto *BaseTemplate = dyn_cast_or_null( + BaseType->getAsCXXRecordDecl())) { + propagateDLLAttrToBaseClassTemplate(Class, ClassAttr, BaseTemplate, + BaseLoc); + } + } + } + + // C++ [class.derived]p2: + // The class-name in a base-specifier shall not be an incompletely + // defined class. + if (RequireCompleteType(BaseLoc, BaseType, + diag::err_incomplete_base_class, SpecifierRange)) { + Class->setInvalidDecl(); + return nullptr; + } + + // If the base class is polymorphic or isn't empty, the new one is/isn't, too. + RecordDecl *BaseDecl = BaseType->castAs()->getDecl(); + assert(BaseDecl && "Record type has no declaration"); + BaseDecl = BaseDecl->getDefinition(); + assert(BaseDecl && "Base type is not incomplete, but has no definition"); + CXXRecordDecl *CXXBaseDecl = cast(BaseDecl); + assert(CXXBaseDecl && "Base type is not a C++ type"); + + // Microsoft docs say: + // "If a base-class has a code_seg attribute, derived classes must have the + // same attribute." + const auto *BaseCSA = CXXBaseDecl->getAttr(); + const auto *DerivedCSA = Class->getAttr(); + if ((DerivedCSA || BaseCSA) && + (!BaseCSA || !DerivedCSA || BaseCSA->getName() != DerivedCSA->getName())) { + Diag(Class->getLocation(), diag::err_mismatched_code_seg_base); + Diag(CXXBaseDecl->getLocation(), diag::note_base_class_specified_here) + << CXXBaseDecl; + return nullptr; + } + + // A class which contains a flexible array member is not suitable for use as a + // base class: + // - If the layout determines that a base comes before another base, + // the flexible array member would index into the subsequent base. + // - If the layout determines that base comes before the derived class, + // the flexible array member would index into the derived class. + if (CXXBaseDecl->hasFlexibleArrayMember()) { + Diag(BaseLoc, diag::err_base_class_has_flexible_array_member) + << CXXBaseDecl->getDeclName(); + return nullptr; + } + + // C++ [class]p3: + // If a class is marked final and it appears as a base-type-specifier in + // base-clause, the program is ill-formed. + if (FinalAttr *FA = CXXBaseDecl->getAttr()) { + Diag(BaseLoc, diag::err_class_marked_final_used_as_base) + << CXXBaseDecl->getDeclName() + << FA->isSpelledAsSealed(); + Diag(CXXBaseDecl->getLocation(), diag::note_entity_declared_at) + << CXXBaseDecl->getDeclName() << FA->getRange(); + return nullptr; + } + + if (BaseDecl->isInvalidDecl()) + Class->setInvalidDecl(); + + // Create the base specifier. + return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual, + Class->getTagKind() == TTK_Class, + Access, TInfo, EllipsisLoc); + } + + /// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is + /// one entry in the base class list of a class specifier, for + /// example: + /// class foo : public bar, virtual private baz { + /// 'public bar' and 'virtual private baz' are each base-specifiers. + BaseResult Sema::ActOnBaseSpecifier(Decl *classdecl, SourceRange SpecifierRange, + const ParsedAttributesView &Attributes, + bool Virtual, AccessSpecifier Access, + ParsedType basetype, SourceLocation BaseLoc, + SourceLocation EllipsisLoc) { + if (!classdecl) + return true; + + AdjustDeclIfTemplate(classdecl); + CXXRecordDecl *Class = dyn_cast(classdecl); + if (!Class) + return true; + + // We haven't yet attached the base specifiers. + Class->setIsParsingBaseSpecifiers(); + + // We do not support any C++11 attributes on base-specifiers yet. + // Diagnose any attributes we see. + for (const ParsedAttr &AL : Attributes) { + if (AL.isInvalid() || AL.getKind() == ParsedAttr::IgnoredAttribute) + continue; + Diag(AL.getLoc(), AL.getKind() == ParsedAttr::UnknownAttribute + ? (unsigned)diag::warn_unknown_attribute_ignored + : (unsigned)diag::err_base_specifier_attribute) + << AL << AL.getRange(); + } + + TypeSourceInfo *TInfo = nullptr; + GetTypeFromParser(basetype, &TInfo); + + if (EllipsisLoc.isInvalid() && + DiagnoseUnexpandedParameterPack(SpecifierRange.getBegin(), TInfo, + UPPC_BaseType)) + return true; + + if (CXXBaseSpecifier *BaseSpec = CheckBaseSpecifier(Class, SpecifierRange, + Virtual, Access, TInfo, + EllipsisLoc)) + return BaseSpec; + else + Class->setInvalidDecl(); + + return true; + } + + /// Use small set to collect indirect bases. As this is only used + /// locally, there's no need to abstract the small size parameter. + typedef llvm::SmallPtrSet IndirectBaseSet; + + /// Recursively add the bases of Type. Don't add Type itself. + static void + NoteIndirectBases(ASTContext &Context, IndirectBaseSet &Set, + const QualType &Type) + { + // Even though the incoming type is a base, it might not be + // a class -- it could be a template parm, for instance. + if (auto Rec = Type->getAs()) { + auto Decl = Rec->getAsCXXRecordDecl(); + + // Iterate over its bases. + for (const auto &BaseSpec : Decl->bases()) { + QualType Base = Context.getCanonicalType(BaseSpec.getType()) + .getUnqualifiedType(); + if (Set.insert(Base).second) + // If we've not already seen it, recurse. + NoteIndirectBases(Context, Set, Base); + } + } + } + + /// Performs the actual work of attaching the given base class + /// specifiers to a C++ class. + bool Sema::AttachBaseSpecifiers(CXXRecordDecl *Class, + MutableArrayRef Bases) { + if (Bases.empty()) + return false; + + // Used to keep track of which base types we have already seen, so + // that we can properly diagnose redundant direct base types. Note + // that the key is always the unqualified canonical type of the base + // class. + std::map KnownBaseTypes; + + // Used to track indirect bases so we can see if a direct base is + // ambiguous. + IndirectBaseSet IndirectBaseTypes; + + // Copy non-redundant base specifiers into permanent storage. + unsigned NumGoodBases = 0; + bool Invalid = false; + for (unsigned idx = 0; idx < Bases.size(); ++idx) { + QualType NewBaseType + = Context.getCanonicalType(Bases[idx]->getType()); + NewBaseType = NewBaseType.getLocalUnqualifiedType(); + + CXXBaseSpecifier *&KnownBase = KnownBaseTypes[NewBaseType]; + if (KnownBase) { + // C++ [class.mi]p3: + // A class shall not be specified as a direct base class of a + // derived class more than once. + Diag(Bases[idx]->getBeginLoc(), diag::err_duplicate_base_class) + << KnownBase->getType() << Bases[idx]->getSourceRange(); + + // Delete the duplicate base class specifier; we're going to + // overwrite its pointer later. + Context.Deallocate(Bases[idx]); + + Invalid = true; + } else { + // Okay, add this new base class. + KnownBase = Bases[idx]; + Bases[NumGoodBases++] = Bases[idx]; + + if (NewBaseType->isDependentType()) + continue; + // Note this base's direct & indirect bases, if there could be ambiguity. + if (Bases.size() > 1) + NoteIndirectBases(Context, IndirectBaseTypes, NewBaseType); + + if (const RecordType *Record = NewBaseType->getAs()) { + const CXXRecordDecl *RD = cast(Record->getDecl()); + if (Class->isInterface() && + (!RD->isInterfaceLike() || + KnownBase->getAccessSpecifier() != AS_public)) { + // The Microsoft extension __interface does not permit bases that + // are not themselves public interfaces. + Diag(KnownBase->getBeginLoc(), diag::err_invalid_base_in_interface) + << getRecordDiagFromTagKind(RD->getTagKind()) << RD + << RD->getSourceRange(); + Invalid = true; + } + if (RD->hasAttr()) + Class->addAttr(WeakAttr::CreateImplicit(Context)); + } + } + } + + // Attach the remaining base class specifiers to the derived class. + Class->setBases(Bases.data(), NumGoodBases); + + // Check that the only base classes that are duplicate are virtual. + for (unsigned idx = 0; idx < NumGoodBases; ++idx) { + // Check whether this direct base is inaccessible due to ambiguity. + QualType BaseType = Bases[idx]->getType(); + + // Skip all dependent types in templates being used as base specifiers. + // Checks below assume that the base specifier is a CXXRecord. + if (BaseType->isDependentType()) + continue; + + CanQualType CanonicalBase = Context.getCanonicalType(BaseType) + .getUnqualifiedType(); + + if (IndirectBaseTypes.count(CanonicalBase)) { + CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, + /*DetectVirtual=*/true); + bool found + = Class->isDerivedFrom(CanonicalBase->getAsCXXRecordDecl(), Paths); + assert(found); + (void)found; + + if (Paths.isAmbiguous(CanonicalBase)) + Diag(Bases[idx]->getBeginLoc(), diag::warn_inaccessible_base_class) + << BaseType << getAmbiguousPathsDisplayString(Paths) + << Bases[idx]->getSourceRange(); + else + assert(Bases[idx]->isVirtual()); + } + + // Delete the base class specifier, since its data has been copied + // into the CXXRecordDecl. + Context.Deallocate(Bases[idx]); + } + + return Invalid; + } + + /// ActOnBaseSpecifiers - Attach the given base specifiers to the + /// class, after checking whether there are any duplicate base + /// classes. + void Sema::ActOnBaseSpecifiers(Decl *ClassDecl, + MutableArrayRef Bases) { + if (!ClassDecl || Bases.empty()) + return; + + AdjustDeclIfTemplate(ClassDecl); + AttachBaseSpecifiers(cast(ClassDecl), Bases); + } + + /// Determine whether the type \p Derived is a C++ class that is + /// derived from the type \p Base. + bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base) { + if (!getLangOpts().CPlusPlus) + return false; + + CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl(); + if (!DerivedRD) + return false; + + CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl(); + if (!BaseRD) + return false; + + // If either the base or the derived type is invalid, don't try to + // check whether one is derived from the other. + if (BaseRD->isInvalidDecl() || DerivedRD->isInvalidDecl()) + return false; + + // FIXME: In a modules build, do we need the entire path to be visible for us + // to be able to use the inheritance relationship? + if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined()) + return false; + + return DerivedRD->isDerivedFrom(BaseRD); + } + + /// Determine whether the type \p Derived is a C++ class that is + /// derived from the type \p Base. + bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base, + CXXBasePaths &Paths) { + if (!getLangOpts().CPlusPlus) + return false; + + CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl(); + if (!DerivedRD) + return false; + + CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl(); + if (!BaseRD) + return false; + + if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined()) + return false; + + return DerivedRD->isDerivedFrom(BaseRD, Paths); + } + + static void BuildBasePathArray(const CXXBasePath &Path, + CXXCastPath &BasePathArray) { + // We first go backward and check if we have a virtual base. + // FIXME: It would be better if CXXBasePath had the base specifier for + // the nearest virtual base. + unsigned Start = 0; + for (unsigned I = Path.size(); I != 0; --I) { + if (Path[I - 1].Base->isVirtual()) { + Start = I - 1; + break; + } + } + + // Now add all bases. + for (unsigned I = Start, E = Path.size(); I != E; ++I) + BasePathArray.push_back(const_cast(Path[I].Base)); + } + + + void Sema::BuildBasePathArray(const CXXBasePaths &Paths, + CXXCastPath &BasePathArray) { + assert(BasePathArray.empty() && "Base path array must be empty!"); + assert(Paths.isRecordingPaths() && "Must record paths!"); + return ::BuildBasePathArray(Paths.front(), BasePathArray); + } + /// CheckDerivedToBaseConversion - Check whether the Derived-to-Base + /// conversion (where Derived and Base are class types) is + /// well-formed, meaning that the conversion is unambiguous (and + /// that all of the base classes are accessible). Returns true + /// and emits a diagnostic if the code is ill-formed, returns false + /// otherwise. Loc is the location where this routine should point to + /// if there is an error, and Range is the source range to highlight + /// if there is an error. + /// + /// If either InaccessibleBaseID or AmbiguousBaseConvID are 0, then the + /// diagnostic for the respective type of error will be suppressed, but the + /// check for ill-formed code will still be performed. + bool + Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base, + unsigned InaccessibleBaseID, + unsigned AmbiguousBaseConvID, + SourceLocation Loc, SourceRange Range, + DeclarationName Name, + CXXCastPath *BasePath, + bool IgnoreAccess) { + // First, determine whether the path from Derived to Base is + // ambiguous. This is slightly more expensive than checking whether + // the Derived to Base conversion exists, because here we need to + // explore multiple paths to determine if there is an ambiguity. + CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, + /*DetectVirtual=*/false); + bool DerivationOkay = IsDerivedFrom(Loc, Derived, Base, Paths); + if (!DerivationOkay) + return true; + + const CXXBasePath *Path = nullptr; + if (!Paths.isAmbiguous(Context.getCanonicalType(Base).getUnqualifiedType())) + Path = &Paths.front(); + + // For MSVC compatibility, check if Derived directly inherits from Base. Clang + // warns about this hierarchy under -Winaccessible-base, but MSVC allows the + // user to access such bases. + if (!Path && getLangOpts().MSVCCompat) { + for (const CXXBasePath &PossiblePath : Paths) { + if (PossiblePath.size() == 1) { + Path = &PossiblePath; + if (AmbiguousBaseConvID) + Diag(Loc, diag::ext_ms_ambiguous_direct_base) + << Base << Derived << Range; + break; + } + } + } + + if (Path) { + if (!IgnoreAccess) { + // Check that the base class can be accessed. + switch ( + CheckBaseClassAccess(Loc, Base, Derived, *Path, InaccessibleBaseID)) { + case AR_inaccessible: + return true; + case AR_accessible: + case AR_dependent: + case AR_delayed: + break; + } + } + + // Build a base path if necessary. + if (BasePath) + ::BuildBasePathArray(*Path, *BasePath); + return false; + } + + if (AmbiguousBaseConvID) { + // We know that the derived-to-base conversion is ambiguous, and + // we're going to produce a diagnostic. Perform the derived-to-base + // search just one more time to compute all of the possible paths so + // that we can print them out. This is more expensive than any of + // the previous derived-to-base checks we've done, but at this point + // performance isn't as much of an issue. + Paths.clear(); + Paths.setRecordingPaths(true); + bool StillOkay = IsDerivedFrom(Loc, Derived, Base, Paths); + assert(StillOkay && "Can only be used with a derived-to-base conversion"); + (void)StillOkay; + + // Build up a textual representation of the ambiguous paths, e.g., + // D -> B -> A, that will be used to illustrate the ambiguous + // conversions in the diagnostic. We only print one of the paths + // to each base class subobject. + std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); + + Diag(Loc, AmbiguousBaseConvID) + << Derived << Base << PathDisplayStr << Range << Name; + } + return true; + } + + bool + Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base, + SourceLocation Loc, SourceRange Range, + CXXCastPath *BasePath, + bool IgnoreAccess) { + return CheckDerivedToBaseConversion( + Derived, Base, diag::err_upcast_to_inaccessible_base, + diag::err_ambiguous_derived_to_base_conv, Loc, Range, DeclarationName(), + BasePath, IgnoreAccess); + } + + + /// Builds a string representing ambiguous paths from a + /// specific derived class to different subobjects of the same base + /// class. + /// + /// This function builds a string that can be used in error messages + /// to show the different paths that one can take through the + /// inheritance hierarchy to go from the derived class to different + /// subobjects of a base class. The result looks something like this: + /// @code + /// struct D -> struct B -> struct A + /// struct D -> struct C -> struct A + /// @endcode + std::string Sema::getAmbiguousPathsDisplayString(CXXBasePaths &Paths) { + std::string PathDisplayStr; + std::set DisplayedPaths; + for (CXXBasePaths::paths_iterator Path = Paths.begin(); + Path != Paths.end(); ++Path) { + if (DisplayedPaths.insert(Path->back().SubobjectNumber).second) { + // We haven't displayed a path to this particular base + // class subobject yet. + PathDisplayStr += "\n "; + PathDisplayStr += Context.getTypeDeclType(Paths.getOrigin()).getAsString(); + for (CXXBasePath::const_iterator Element = Path->begin(); + Element != Path->end(); ++Element) + PathDisplayStr += " -> " + Element->Base->getType().getAsString(); + } + } + + return PathDisplayStr; + } + + //===----------------------------------------------------------------------===// + // C++ class member Handling + //===----------------------------------------------------------------------===// + + /// ActOnAccessSpecifier - Parsed an access specifier followed by a colon. + bool Sema::ActOnAccessSpecifier(AccessSpecifier Access, SourceLocation ASLoc, + SourceLocation ColonLoc, + const ParsedAttributesView &Attrs) { + assert(Access != AS_none && "Invalid kind for syntactic access specifier!"); + AccessSpecDecl *ASDecl = AccessSpecDecl::Create(Context, Access, CurContext, + ASLoc, ColonLoc); + CurContext->addHiddenDecl(ASDecl); + return ProcessAccessDeclAttributeList(ASDecl, Attrs); + } + + /// CheckOverrideControl - Check C++11 override control semantics. + void Sema::CheckOverrideControl(NamedDecl *D) { + if (D->isInvalidDecl()) + return; + + // We only care about "override" and "final" declarations. + if (!D->hasAttr() && !D->hasAttr()) + return; + + CXXMethodDecl *MD = dyn_cast(D); + + // We can't check dependent instance methods. + if (MD && MD->isInstance() && + (MD->getParent()->hasAnyDependentBases() || + MD->getType()->isDependentType())) + return; + + if (MD && !MD->isVirtual()) { + // If we have a non-virtual method, check if it hides a virtual method. + // (In that case, it's most likely the method has the wrong type.) + SmallVector OverloadedMethods; + FindHiddenVirtualMethods(MD, OverloadedMethods); + + if (!OverloadedMethods.empty()) { + if (OverrideAttr *OA = D->getAttr()) { + Diag(OA->getLocation(), + diag::override_keyword_hides_virtual_member_function) + << "override" << (OverloadedMethods.size() > 1); + } else if (FinalAttr *FA = D->getAttr()) { + Diag(FA->getLocation(), + diag::override_keyword_hides_virtual_member_function) + << (FA->isSpelledAsSealed() ? "sealed" : "final") + << (OverloadedMethods.size() > 1); + } + NoteHiddenVirtualMethods(MD, OverloadedMethods); + MD->setInvalidDecl(); + return; + } + // Fall through into the general case diagnostic. + // FIXME: We might want to attempt typo correction here. + } + + if (!MD || !MD->isVirtual()) { + if (OverrideAttr *OA = D->getAttr()) { + Diag(OA->getLocation(), + diag::override_keyword_only_allowed_on_virtual_member_functions) + << "override" << FixItHint::CreateRemoval(OA->getLocation()); + D->dropAttr(); + } + if (FinalAttr *FA = D->getAttr()) { + Diag(FA->getLocation(), + diag::override_keyword_only_allowed_on_virtual_member_functions) + << (FA->isSpelledAsSealed() ? "sealed" : "final") + << FixItHint::CreateRemoval(FA->getLocation()); + D->dropAttr(); + } + return; + } + + // C++11 [class.virtual]p5: + // If a function is marked with the virt-specifier override and + // does not override a member function of a base class, the program is + // ill-formed. + bool HasOverriddenMethods = MD->size_overridden_methods() != 0; + if (MD->hasAttr() && !HasOverriddenMethods) + Diag(MD->getLocation(), diag::err_function_marked_override_not_overriding) + << MD->getDeclName(); + } + + void Sema::DiagnoseAbsenceOfOverrideControl(NamedDecl *D, bool Inconsistent) { + if (D->isInvalidDecl() || D->hasAttr()) + return; + CXXMethodDecl *MD = dyn_cast(D); + if (!MD || MD->isImplicit() || MD->hasAttr()) + return; + + SourceLocation Loc = MD->getLocation(); + SourceLocation SpellingLoc = Loc; + if (getSourceManager().isMacroArgExpansion(Loc)) + SpellingLoc = getSourceManager().getImmediateExpansionRange(Loc).getBegin(); + SpellingLoc = getSourceManager().getSpellingLoc(SpellingLoc); + if (SpellingLoc.isValid() && getSourceManager().isInSystemHeader(SpellingLoc)) + return; + + if (MD->size_overridden_methods() > 0) { + auto EmitDiag = [&](unsigned DiagInconsistent, unsigned DiagSuggest) { + unsigned DiagID = + Inconsistent && !Diags.isIgnored(DiagInconsistent, MD->getLocation()) + ? DiagInconsistent + : DiagSuggest; + Diag(MD->getLocation(), DiagID) << MD->getDeclName(); + const CXXMethodDecl *OMD = *MD->begin_overridden_methods(); + Diag(OMD->getLocation(), diag::note_overridden_virtual_function); + }; + if (isa(MD)) + EmitDiag( + diag::warn_inconsistent_destructor_marked_not_override_overriding, + diag::warn_suggest_destructor_marked_not_override_overriding); + else + EmitDiag(diag::warn_inconsistent_function_marked_not_override_overriding, + diag::warn_suggest_function_marked_not_override_overriding); + } + } + + /// CheckIfOverriddenFunctionIsMarkedFinal - Checks whether a virtual member + /// function overrides a virtual member function marked 'final', according to + /// C++11 [class.virtual]p4. + bool Sema::CheckIfOverriddenFunctionIsMarkedFinal(const CXXMethodDecl *New, + const CXXMethodDecl *Old) { + FinalAttr *FA = Old->getAttr(); + if (!FA) + return false; + + Diag(New->getLocation(), diag::err_final_function_overridden) + << New->getDeclName() + << FA->isSpelledAsSealed(); + Diag(Old->getLocation(), diag::note_overridden_virtual_function); + return true; + } + + static bool InitializationHasSideEffects(const FieldDecl &FD) { + const Type *T = FD.getType()->getBaseElementTypeUnsafe(); + // FIXME: Destruction of ObjC lifetime types has side-effects. + if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) + return !RD->isCompleteDefinition() || + !RD->hasTrivialDefaultConstructor() || + !RD->hasTrivialDestructor(); + return false; + } + + // Check if there is a field shadowing. + void Sema::CheckShadowInheritedFields(const SourceLocation &Loc, + DeclarationName FieldName, + const CXXRecordDecl *RD, + bool DeclIsField) { + if (Diags.isIgnored(diag::warn_shadow_field, Loc)) + return; + + // To record a shadowed field in a base + std::map Bases; + auto FieldShadowed = [&](const CXXBaseSpecifier *Specifier, + CXXBasePath &Path) { + const auto Base = Specifier->getType()->getAsCXXRecordDecl(); + // Record an ambiguous path directly + if (Bases.find(Base) != Bases.end()) + return true; + for (const auto Field : Base->lookup(FieldName)) { + if ((isa(Field) || isa(Field)) && + Field->getAccess() != AS_private) { + assert(Field->getAccess() != AS_none); + assert(Bases.find(Base) == Bases.end()); + Bases[Base] = Field; + return true; + } + } + return false; + }; + + CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, + /*DetectVirtual=*/true); + if (!RD->lookupInBases(FieldShadowed, Paths)) + return; + + for (const auto &P : Paths) { + auto Base = P.back().Base->getType()->getAsCXXRecordDecl(); + auto It = Bases.find(Base); + // Skip duplicated bases + if (It == Bases.end()) + continue; + auto BaseField = It->second; + assert(BaseField->getAccess() != AS_private); + if (AS_none != + CXXRecordDecl::MergeAccess(P.Access, BaseField->getAccess())) { + Diag(Loc, diag::warn_shadow_field) + << FieldName << RD << Base << DeclIsField; + Diag(BaseField->getLocation(), diag::note_shadow_field); + Bases.erase(It); + } + } + } + + /// ActOnCXXMemberDeclarator - This is invoked when a C++ class member + /// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the + /// bitfield width if there is one, 'InitExpr' specifies the initializer if + /// one has been parsed, and 'InitStyle' is set if an in-class initializer is + /// present (but parsing it has been deferred). + NamedDecl * + Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D, + MultiTemplateParamsArg TemplateParameterLists, + Expr *BW, const VirtSpecifiers &VS, + InClassInitStyle InitStyle) { + const DeclSpec &DS = D.getDeclSpec(); + DeclarationNameInfo NameInfo = GetNameForDeclarator(D); + DeclarationName Name = NameInfo.getName(); + SourceLocation Loc = NameInfo.getLoc(); + + // For anonymous bitfields, the location should point to the type. + if (Loc.isInvalid()) + Loc = D.getBeginLoc(); + + Expr *BitWidth = static_cast(BW); + + assert(isa(CurContext)); + assert(!DS.isFriendSpecified()); + + bool isFunc = D.isDeclarationOfFunction(); + const ParsedAttr *MSPropertyAttr = + D.getDeclSpec().getAttributes().getMSPropertyAttr(); + + if (cast(CurContext)->isInterface()) { + // The Microsoft extension __interface only permits public member functions + // and prohibits constructors, destructors, operators, non-public member + // functions, static methods and data members. + unsigned InvalidDecl; + bool ShowDeclName = true; + if (!isFunc && + (DS.getStorageClassSpec() == DeclSpec::SCS_typedef || MSPropertyAttr)) + InvalidDecl = 0; + else if (!isFunc) + InvalidDecl = 1; + else if (AS != AS_public) + InvalidDecl = 2; + else if (DS.getStorageClassSpec() == DeclSpec::SCS_static) + InvalidDecl = 3; + else switch (Name.getNameKind()) { + case DeclarationName::CXXConstructorName: + InvalidDecl = 4; + ShowDeclName = false; + break; + + case DeclarationName::CXXDestructorName: + InvalidDecl = 5; + ShowDeclName = false; + break; + + case DeclarationName::CXXOperatorName: + case DeclarationName::CXXConversionFunctionName: + InvalidDecl = 6; + break; + + default: + InvalidDecl = 0; + break; + } + + if (InvalidDecl) { + if (ShowDeclName) + Diag(Loc, diag::err_invalid_member_in_interface) + << (InvalidDecl-1) << Name; + else + Diag(Loc, diag::err_invalid_member_in_interface) + << (InvalidDecl-1) << ""; + return nullptr; + } + } + + // C++ 9.2p6: A member shall not be declared to have automatic storage + // duration (auto, register) or with the extern storage-class-specifier. + // C++ 7.1.1p8: The mutable specifier can be applied only to names of class + // data members and cannot be applied to names declared const or static, + // and cannot be applied to reference members. + switch (DS.getStorageClassSpec()) { + case DeclSpec::SCS_unspecified: + case DeclSpec::SCS_typedef: + case DeclSpec::SCS_static: + break; + case DeclSpec::SCS_mutable: + if (isFunc) { + Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function); + + // FIXME: It would be nicer if the keyword was ignored only for this + // declarator. Otherwise we could get follow-up errors. + D.getMutableDeclSpec().ClearStorageClassSpecs(); + } + break; + default: + Diag(DS.getStorageClassSpecLoc(), + diag::err_storageclass_invalid_for_member); + D.getMutableDeclSpec().ClearStorageClassSpecs(); + break; + } + + bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified || + DS.getStorageClassSpec() == DeclSpec::SCS_mutable) && + !isFunc); + + if (DS.hasConstexprSpecifier() && isInstField) { + SemaDiagnosticBuilder B = + Diag(DS.getConstexprSpecLoc(), diag::err_invalid_constexpr_member); + SourceLocation ConstexprLoc = DS.getConstexprSpecLoc(); + if (InitStyle == ICIS_NoInit) { + B << 0 << 0; + if (D.getDeclSpec().getTypeQualifiers() & DeclSpec::TQ_const) + B << FixItHint::CreateRemoval(ConstexprLoc); + else { + B << FixItHint::CreateReplacement(ConstexprLoc, "const"); + D.getMutableDeclSpec().ClearConstexprSpec(); + const char *PrevSpec; + unsigned DiagID; + bool Failed = D.getMutableDeclSpec().SetTypeQual( + DeclSpec::TQ_const, ConstexprLoc, PrevSpec, DiagID, getLangOpts()); + (void)Failed; + assert(!Failed && "Making a constexpr member const shouldn't fail"); + } + } else { + B << 1; + const char *PrevSpec; + unsigned DiagID; + if (D.getMutableDeclSpec().SetStorageClassSpec( + *this, DeclSpec::SCS_static, ConstexprLoc, PrevSpec, DiagID, + Context.getPrintingPolicy())) { + assert(DS.getStorageClassSpec() == DeclSpec::SCS_mutable && + "This is the only DeclSpec that should fail to be applied"); + B << 1; + } else { + B << 0 << FixItHint::CreateInsertion(ConstexprLoc, "static "); + isInstField = false; + } + } + } + + NamedDecl *Member; + if (isInstField) { + CXXScopeSpec &SS = D.getCXXScopeSpec(); + + // Data members must have identifiers for names. + if (!Name.isIdentifier()) { + Diag(Loc, diag::err_bad_variable_name) + << Name; + return nullptr; + } + + IdentifierInfo *II = Name.getAsIdentifierInfo(); + + // Member field could not be with "template" keyword. + // So TemplateParameterLists should be empty in this case. + if (TemplateParameterLists.size()) { + TemplateParameterList* TemplateParams = TemplateParameterLists[0]; + if (TemplateParams->size()) { + // There is no such thing as a member field template. + Diag(D.getIdentifierLoc(), diag::err_template_member) + << II + << SourceRange(TemplateParams->getTemplateLoc(), + TemplateParams->getRAngleLoc()); + } else { + // There is an extraneous 'template<>' for this member. + Diag(TemplateParams->getTemplateLoc(), + diag::err_template_member_noparams) + << II + << SourceRange(TemplateParams->getTemplateLoc(), + TemplateParams->getRAngleLoc()); + } + return nullptr; + } + + if (D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId) { + Diag(D.getIdentifierLoc(), diag::err_member_with_template_arguments) + << II + << SourceRange(D.getName().TemplateId->LAngleLoc, + D.getName().TemplateId->RAngleLoc) + << D.getName().TemplateId->LAngleLoc; + D.SetIdentifier(II, Loc); + } + + if (SS.isSet() && !SS.isInvalid()) { + // The user provided a superfluous scope specifier inside a class + // definition: + // + // class X { + // int X::member; + // }; + if (DeclContext *DC = computeDeclContext(SS, false)) + diagnoseQualifiedDeclaration(SS, DC, Name, D.getIdentifierLoc(), + D.getName().getKind() == + UnqualifiedIdKind::IK_TemplateId); + else + Diag(D.getIdentifierLoc(), diag::err_member_qualification) + << Name << SS.getRange(); + + SS.clear(); + } + + if (MSPropertyAttr) { + Member = HandleMSProperty(S, cast(CurContext), Loc, D, + BitWidth, InitStyle, AS, *MSPropertyAttr); + if (!Member) + return nullptr; + isInstField = false; + } else { + Member = HandleField(S, cast(CurContext), Loc, D, + BitWidth, InitStyle, AS); + if (!Member) + return nullptr; + } + + CheckShadowInheritedFields(Loc, Name, cast(CurContext)); + } else { + Member = HandleDeclarator(S, D, TemplateParameterLists); + if (!Member) + return nullptr; + + // Non-instance-fields can't have a bitfield. + if (BitWidth) { + if (Member->isInvalidDecl()) { + // don't emit another diagnostic. + } else if (isa(Member) || isa(Member)) { + // C++ 9.6p3: A bit-field shall not be a static member. + // "static member 'A' cannot be a bit-field" + Diag(Loc, diag::err_static_not_bitfield) + << Name << BitWidth->getSourceRange(); + } else if (isa(Member)) { + // "typedef member 'x' cannot be a bit-field" + Diag(Loc, diag::err_typedef_not_bitfield) + << Name << BitWidth->getSourceRange(); + } else { + // A function typedef ("typedef int f(); f a;"). + // C++ 9.6p3: A bit-field shall have integral or enumeration type. + Diag(Loc, diag::err_not_integral_type_bitfield) + << Name << cast(Member)->getType() + << BitWidth->getSourceRange(); + } + + BitWidth = nullptr; + Member->setInvalidDecl(); + } + + NamedDecl *NonTemplateMember = Member; + if (FunctionTemplateDecl *FunTmpl = dyn_cast(Member)) + NonTemplateMember = FunTmpl->getTemplatedDecl(); + else if (VarTemplateDecl *VarTmpl = dyn_cast(Member)) + NonTemplateMember = VarTmpl->getTemplatedDecl(); + + Member->setAccess(AS); + + // If we have declared a member function template or static data member + // template, set the access of the templated declaration as well. + if (NonTemplateMember != Member) + NonTemplateMember->setAccess(AS); + + // C++ [temp.deduct.guide]p3: + // A deduction guide [...] for a member class template [shall be + // declared] with the same access [as the template]. + if (auto *DG = dyn_cast(NonTemplateMember)) { + auto *TD = DG->getDeducedTemplate(); + // Access specifiers are only meaningful if both the template and the + // deduction guide are from the same scope. + if (AS != TD->getAccess() && + TD->getDeclContext()->getRedeclContext()->Equals( + DG->getDeclContext()->getRedeclContext())) { + Diag(DG->getBeginLoc(), diag::err_deduction_guide_wrong_access); + Diag(TD->getBeginLoc(), diag::note_deduction_guide_template_access) + << TD->getAccess(); + const AccessSpecDecl *LastAccessSpec = nullptr; + for (const auto *D : cast(CurContext)->decls()) { + if (const auto *AccessSpec = dyn_cast(D)) + LastAccessSpec = AccessSpec; + } + assert(LastAccessSpec && "differing access with no access specifier"); + Diag(LastAccessSpec->getBeginLoc(), diag::note_deduction_guide_access) + << AS; + } + } + } + + if (VS.isOverrideSpecified()) + Member->addAttr(OverrideAttr::Create(Context, VS.getOverrideLoc())); + if (VS.isFinalSpecified()) + Member->addAttr(FinalAttr::Create(Context, VS.getFinalLoc(), + VS.isFinalSpelledSealed() + ? FinalAttr::Keyword_sealed + : FinalAttr::Keyword_final)); + + if (VS.getLastLocation().isValid()) { + // Update the end location of a method that has a virt-specifiers. + if (CXXMethodDecl *MD = dyn_cast_or_null(Member)) + MD->setRangeEnd(VS.getLastLocation()); + } + + CheckOverrideControl(Member); + + assert((Name || isInstField) && "No identifier for non-field ?"); + + if (isInstField) { + FieldDecl *FD = cast(Member); + FieldCollector->Add(FD); + + if (!Diags.isIgnored(diag::warn_unused_private_field, FD->getLocation())) { + // Remember all explicit private FieldDecls that have a name, no side + // effects and are not part of a dependent type declaration. + if (!FD->isImplicit() && FD->getDeclName() && + FD->getAccess() == AS_private && + !FD->hasAttr() && + !FD->getParent()->isDependentContext() && + !InitializationHasSideEffects(*FD)) + UnusedPrivateFields.insert(FD); + } + } + + return Member; + } + + namespace { + class UninitializedFieldVisitor + : public EvaluatedExprVisitor { + Sema &S; + // List of Decls to generate a warning on. Also remove Decls that become + // initialized. + llvm::SmallPtrSetImpl &Decls; + // List of base classes of the record. Classes are removed after their + // initializers. + llvm::SmallPtrSetImpl &BaseClasses; + // Vector of decls to be removed from the Decl set prior to visiting the + // nodes. These Decls may have been initialized in the prior initializer. + llvm::SmallVector DeclsToRemove; + // If non-null, add a note to the warning pointing back to the constructor. + const CXXConstructorDecl *Constructor; + // Variables to hold state when processing an initializer list. When + // InitList is true, special case initialization of FieldDecls matching + // InitListFieldDecl. + bool InitList; + FieldDecl *InitListFieldDecl; + llvm::SmallVector InitFieldIndex; + + public: + typedef EvaluatedExprVisitor Inherited; + UninitializedFieldVisitor(Sema &S, + llvm::SmallPtrSetImpl &Decls, + llvm::SmallPtrSetImpl &BaseClasses) + : Inherited(S.Context), S(S), Decls(Decls), BaseClasses(BaseClasses), + Constructor(nullptr), InitList(false), InitListFieldDecl(nullptr) {} + + // Returns true if the use of ME is not an uninitialized use. + bool IsInitListMemberExprInitialized(MemberExpr *ME, + bool CheckReferenceOnly) { + llvm::SmallVector Fields; + bool ReferenceField = false; + while (ME) { + FieldDecl *FD = dyn_cast(ME->getMemberDecl()); + if (!FD) + return false; + Fields.push_back(FD); + if (FD->getType()->isReferenceType()) + ReferenceField = true; + ME = dyn_cast(ME->getBase()->IgnoreParenImpCasts()); + } + + // Binding a reference to an uninitialized field is not an + // uninitialized use. + if (CheckReferenceOnly && !ReferenceField) + return true; + + llvm::SmallVector UsedFieldIndex; + // Discard the first field since it is the field decl that is being + // initialized. + for (const FieldDecl *FD : llvm::drop_begin(llvm::reverse(Fields))) + UsedFieldIndex.push_back(FD->getFieldIndex()); + + for (auto UsedIter = UsedFieldIndex.begin(), + UsedEnd = UsedFieldIndex.end(), + OrigIter = InitFieldIndex.begin(), + OrigEnd = InitFieldIndex.end(); + UsedIter != UsedEnd && OrigIter != OrigEnd; ++UsedIter, ++OrigIter) { + if (*UsedIter < *OrigIter) + return true; + if (*UsedIter > *OrigIter) + break; + } + + return false; + } + + void HandleMemberExpr(MemberExpr *ME, bool CheckReferenceOnly, + bool AddressOf) { + if (isa(ME->getMemberDecl())) + return; + + // FieldME is the inner-most MemberExpr that is not an anonymous struct + // or union. + MemberExpr *FieldME = ME; + + bool AllPODFields = FieldME->getType().isPODType(S.Context); + + Expr *Base = ME; + while (MemberExpr *SubME = + dyn_cast(Base->IgnoreParenImpCasts())) { + + if (isa(SubME->getMemberDecl())) + return; + + if (FieldDecl *FD = dyn_cast(SubME->getMemberDecl())) + if (!FD->isAnonymousStructOrUnion()) + FieldME = SubME; + + if (!FieldME->getType().isPODType(S.Context)) + AllPODFields = false; + + Base = SubME->getBase(); + } + + if (!isa(Base->IgnoreParenImpCasts())) { + Visit(Base); + return; + } + + if (AddressOf && AllPODFields) + return; + + ValueDecl* FoundVD = FieldME->getMemberDecl(); + + if (ImplicitCastExpr *BaseCast = dyn_cast(Base)) { + while (isa(BaseCast->getSubExpr())) { + BaseCast = cast(BaseCast->getSubExpr()); + } + + if (BaseCast->getCastKind() == CK_UncheckedDerivedToBase) { + QualType T = BaseCast->getType(); + if (T->isPointerType() && + BaseClasses.count(T->getPointeeType())) { + S.Diag(FieldME->getExprLoc(), diag::warn_base_class_is_uninit) + << T->getPointeeType() << FoundVD; + } + } + } + + if (!Decls.count(FoundVD)) + return; + + const bool IsReference = FoundVD->getType()->isReferenceType(); + + if (InitList && !AddressOf && FoundVD == InitListFieldDecl) { + // Special checking for initializer lists. + if (IsInitListMemberExprInitialized(ME, CheckReferenceOnly)) { + return; + } + } else { + // Prevent double warnings on use of unbounded references. + if (CheckReferenceOnly && !IsReference) + return; + } + + unsigned diag = IsReference + ? diag::warn_reference_field_is_uninit + : diag::warn_field_is_uninit; + S.Diag(FieldME->getExprLoc(), diag) << FoundVD; + if (Constructor) + S.Diag(Constructor->getLocation(), + diag::note_uninit_in_this_constructor) + << (Constructor->isDefaultConstructor() && Constructor->isImplicit()); + + } + + void HandleValue(Expr *E, bool AddressOf) { + E = E->IgnoreParens(); + + if (MemberExpr *ME = dyn_cast(E)) { + HandleMemberExpr(ME, false /*CheckReferenceOnly*/, + AddressOf /*AddressOf*/); + return; + } + + if (ConditionalOperator *CO = dyn_cast(E)) { + Visit(CO->getCond()); + HandleValue(CO->getTrueExpr(), AddressOf); + HandleValue(CO->getFalseExpr(), AddressOf); + return; + } + + if (BinaryConditionalOperator *BCO = + dyn_cast(E)) { + Visit(BCO->getCond()); + HandleValue(BCO->getFalseExpr(), AddressOf); + return; + } + + if (OpaqueValueExpr *OVE = dyn_cast(E)) { + HandleValue(OVE->getSourceExpr(), AddressOf); + return; + } + + if (BinaryOperator *BO = dyn_cast(E)) { + switch (BO->getOpcode()) { + default: + break; + case(BO_PtrMemD): + case(BO_PtrMemI): + HandleValue(BO->getLHS(), AddressOf); + Visit(BO->getRHS()); + return; + case(BO_Comma): + Visit(BO->getLHS()); + HandleValue(BO->getRHS(), AddressOf); + return; + } + } + + Visit(E); + } + + void CheckInitListExpr(InitListExpr *ILE) { + InitFieldIndex.push_back(0); + for (auto *Child : ILE->children()) { + if (InitListExpr *SubList = dyn_cast(Child)) { + CheckInitListExpr(SubList); + } else { + Visit(Child); + } + ++InitFieldIndex.back(); + } + InitFieldIndex.pop_back(); + } + + void CheckInitializer(Expr *E, const CXXConstructorDecl *FieldConstructor, + FieldDecl *Field, const Type *BaseClass) { + // Remove Decls that may have been initialized in the previous + // initializer. + for (ValueDecl* VD : DeclsToRemove) + Decls.erase(VD); + DeclsToRemove.clear(); + + Constructor = FieldConstructor; + InitListExpr *ILE = dyn_cast(E); + + if (ILE && Field) { + InitList = true; + InitListFieldDecl = Field; + InitFieldIndex.clear(); + CheckInitListExpr(ILE); + } else { + InitList = false; + Visit(E); + } + + if (Field) + Decls.erase(Field); + if (BaseClass) + BaseClasses.erase(BaseClass->getCanonicalTypeInternal()); + } + + void VisitMemberExpr(MemberExpr *ME) { + // All uses of unbounded reference fields will warn. + HandleMemberExpr(ME, true /*CheckReferenceOnly*/, false /*AddressOf*/); + } + + void VisitImplicitCastExpr(ImplicitCastExpr *E) { + if (E->getCastKind() == CK_LValueToRValue) { + HandleValue(E->getSubExpr(), false /*AddressOf*/); + return; + } + + Inherited::VisitImplicitCastExpr(E); + } + + void VisitCXXConstructExpr(CXXConstructExpr *E) { + if (E->getConstructor()->isCopyConstructor()) { + Expr *ArgExpr = E->getArg(0); + if (InitListExpr *ILE = dyn_cast(ArgExpr)) + if (ILE->getNumInits() == 1) + ArgExpr = ILE->getInit(0); + if (ImplicitCastExpr *ICE = dyn_cast(ArgExpr)) + if (ICE->getCastKind() == CK_NoOp) + ArgExpr = ICE->getSubExpr(); + HandleValue(ArgExpr, false /*AddressOf*/); + return; + } + Inherited::VisitCXXConstructExpr(E); + } + + void VisitCXXMemberCallExpr(CXXMemberCallExpr *E) { + Expr *Callee = E->getCallee(); + if (isa(Callee)) { + HandleValue(Callee, false /*AddressOf*/); + for (auto *Arg : E->arguments()) + Visit(Arg); + return; + } + + Inherited::VisitCXXMemberCallExpr(E); + } + + void VisitCallExpr(CallExpr *E) { + // Treat std::move as a use. + if (E->isCallToStdMove()) { + HandleValue(E->getArg(0), /*AddressOf=*/false); + return; + } + + Inherited::VisitCallExpr(E); + } + + void VisitCXXOperatorCallExpr(CXXOperatorCallExpr *E) { + Expr *Callee = E->getCallee(); + + if (isa(Callee)) + return Inherited::VisitCXXOperatorCallExpr(E); + + Visit(Callee); + for (auto *Arg : E->arguments()) + HandleValue(Arg->IgnoreParenImpCasts(), false /*AddressOf*/); + } + + void VisitBinaryOperator(BinaryOperator *E) { + // If a field assignment is detected, remove the field from the + // uninitiailized field set. + if (E->getOpcode() == BO_Assign) + if (MemberExpr *ME = dyn_cast(E->getLHS())) + if (FieldDecl *FD = dyn_cast(ME->getMemberDecl())) + if (!FD->getType()->isReferenceType()) + DeclsToRemove.push_back(FD); + + if (E->isCompoundAssignmentOp()) { + HandleValue(E->getLHS(), false /*AddressOf*/); + Visit(E->getRHS()); + return; + } + + Inherited::VisitBinaryOperator(E); + } + + void VisitUnaryOperator(UnaryOperator *E) { + if (E->isIncrementDecrementOp()) { + HandleValue(E->getSubExpr(), false /*AddressOf*/); + return; + } + if (E->getOpcode() == UO_AddrOf) { + if (MemberExpr *ME = dyn_cast(E->getSubExpr())) { + HandleValue(ME->getBase(), true /*AddressOf*/); + return; + } + } + + Inherited::VisitUnaryOperator(E); + } + }; + + // Diagnose value-uses of fields to initialize themselves, e.g. + // foo(foo) + // where foo is not also a parameter to the constructor. + // Also diagnose across field uninitialized use such as + // x(y), y(x) + // TODO: implement -Wuninitialized and fold this into that framework. + static void DiagnoseUninitializedFields( + Sema &SemaRef, const CXXConstructorDecl *Constructor) { + + if (SemaRef.getDiagnostics().isIgnored(diag::warn_field_is_uninit, + Constructor->getLocation())) { + return; + } + + if (Constructor->isInvalidDecl()) + return; + + const CXXRecordDecl *RD = Constructor->getParent(); + + if (RD->isDependentContext()) + return; + + // Holds fields that are uninitialized. + llvm::SmallPtrSet UninitializedFields; + + // At the beginning, all fields are uninitialized. + for (auto *I : RD->decls()) { + if (auto *FD = dyn_cast(I)) { + UninitializedFields.insert(FD); + } else if (auto *IFD = dyn_cast(I)) { + UninitializedFields.insert(IFD->getAnonField()); + } + } + + llvm::SmallPtrSet UninitializedBaseClasses; + for (const auto &I : RD->bases()) + UninitializedBaseClasses.insert(I.getType().getCanonicalType()); + + if (UninitializedFields.empty() && UninitializedBaseClasses.empty()) + return; + + UninitializedFieldVisitor UninitializedChecker(SemaRef, + UninitializedFields, + UninitializedBaseClasses); + + for (const auto *FieldInit : Constructor->inits()) { + if (UninitializedFields.empty() && UninitializedBaseClasses.empty()) + break; + + Expr *InitExpr = FieldInit->getInit(); + if (!InitExpr) + continue; + + if (CXXDefaultInitExpr *Default = + dyn_cast(InitExpr)) { + InitExpr = Default->getExpr(); + if (!InitExpr) + continue; + // In class initializers will point to the constructor. + UninitializedChecker.CheckInitializer(InitExpr, Constructor, + FieldInit->getAnyMember(), + FieldInit->getBaseClass()); + } else { + UninitializedChecker.CheckInitializer(InitExpr, nullptr, + FieldInit->getAnyMember(), + FieldInit->getBaseClass()); + } + } + } + } // namespace + + /// Enter a new C++ default initializer scope. After calling this, the + /// caller must call \ref ActOnFinishCXXInClassMemberInitializer, even if + /// parsing or instantiating the initializer failed. + void Sema::ActOnStartCXXInClassMemberInitializer() { + // Create a synthetic function scope to represent the call to the constructor + // that notionally surrounds a use of this initializer. + PushFunctionScope(); + } + + void Sema::ActOnStartTrailingRequiresClause(Scope *S, Declarator &D) { + if (!D.isFunctionDeclarator()) + return; + auto &FTI = D.getFunctionTypeInfo(); + if (!FTI.Params) + return; + for (auto &Param : ArrayRef(FTI.Params, + FTI.NumParams)) { + auto *ParamDecl = cast(Param.Param); + if (ParamDecl->getDeclName()) + PushOnScopeChains(ParamDecl, S, /*AddToContext=*/false); + } + } + + ExprResult Sema::ActOnFinishTrailingRequiresClause(ExprResult ConstraintExpr) { + return ActOnRequiresClause(ConstraintExpr); + } + + ExprResult Sema::ActOnRequiresClause(ExprResult ConstraintExpr) { + if (ConstraintExpr.isInvalid()) + return ExprError(); + + ConstraintExpr = CorrectDelayedTyposInExpr(ConstraintExpr); + if (ConstraintExpr.isInvalid()) + return ExprError(); + + if (DiagnoseUnexpandedParameterPack(ConstraintExpr.get(), + UPPC_RequiresClause)) + return ExprError(); + + return ConstraintExpr; + } + + ExprResult Sema::ConvertMemberDefaultInitExpression(FieldDecl *FD, + Expr *InitExpr, + SourceLocation InitLoc) { + InitializedEntity Entity = + InitializedEntity::InitializeMemberFromDefaultMemberInitializer(FD); + InitializationKind Kind = + FD->getInClassInitStyle() == ICIS_ListInit + ? InitializationKind::CreateDirectList(InitExpr->getBeginLoc(), + InitExpr->getBeginLoc(), + InitExpr->getEndLoc()) + : InitializationKind::CreateCopy(InitExpr->getBeginLoc(), InitLoc); + InitializationSequence Seq(*this, Entity, Kind, InitExpr); + return Seq.Perform(*this, Entity, Kind, InitExpr); + } + + /// This is invoked after parsing an in-class initializer for a + /// non-static C++ class member, and after instantiating an in-class initializer + /// in a class template. Such actions are deferred until the class is complete. + void Sema::ActOnFinishCXXInClassMemberInitializer(Decl *D, + SourceLocation InitLoc, + Expr *InitExpr) { + // Pop the notional constructor scope we created earlier. + PopFunctionScopeInfo(nullptr, D); + + FieldDecl *FD = dyn_cast(D); + assert((isa(D) || FD->getInClassInitStyle() != ICIS_NoInit) && + "must set init style when field is created"); + + if (!InitExpr) { + D->setInvalidDecl(); + if (FD) + FD->removeInClassInitializer(); + return; + } + + if (DiagnoseUnexpandedParameterPack(InitExpr, UPPC_Initializer)) { + FD->setInvalidDecl(); + FD->removeInClassInitializer(); + return; + } + + ExprResult Init = CorrectDelayedTyposInExpr(InitExpr, /*InitDecl=*/nullptr, + /*RecoverUncorrectedTypos=*/true); + assert(Init.isUsable() && "Init should at least have a RecoveryExpr"); + if (!FD->getType()->isDependentType() && !Init.get()->isTypeDependent()) { + Init = ConvertMemberDefaultInitExpression(FD, Init.get(), InitLoc); + // C++11 [class.base.init]p7: + // The initialization of each base and member constitutes a + // full-expression. + if (!Init.isInvalid()) + Init = ActOnFinishFullExpr(Init.get(), /*DiscarededValue=*/false); + if (Init.isInvalid()) { + FD->setInvalidDecl(); + return; + } + } + + FD->setInClassInitializer(Init.get()); + } + + /// Find the direct and/or virtual base specifiers that + /// correspond to the given base type, for use in base initialization + /// within a constructor. + static bool FindBaseInitializer(Sema &SemaRef, + CXXRecordDecl *ClassDecl, + QualType BaseType, + const CXXBaseSpecifier *&DirectBaseSpec, + const CXXBaseSpecifier *&VirtualBaseSpec) { + // First, check for a direct base class. + DirectBaseSpec = nullptr; + for (const auto &Base : ClassDecl->bases()) { + if (SemaRef.Context.hasSameUnqualifiedType(BaseType, Base.getType())) { + // We found a direct base of this type. That's what we're + // initializing. + DirectBaseSpec = &Base; + break; + } + } + + // Check for a virtual base class. + // FIXME: We might be able to short-circuit this if we know in advance that + // there are no virtual bases. + VirtualBaseSpec = nullptr; + if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) { + // We haven't found a base yet; search the class hierarchy for a + // virtual base class. + CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, + /*DetectVirtual=*/false); + if (SemaRef.IsDerivedFrom(ClassDecl->getLocation(), + SemaRef.Context.getTypeDeclType(ClassDecl), + BaseType, Paths)) { + for (CXXBasePaths::paths_iterator Path = Paths.begin(); + Path != Paths.end(); ++Path) { + if (Path->back().Base->isVirtual()) { + VirtualBaseSpec = Path->back().Base; + break; + } + } + } + } + + return DirectBaseSpec || VirtualBaseSpec; + } + + /// Handle a C++ member initializer using braced-init-list syntax. + MemInitResult + Sema::ActOnMemInitializer(Decl *ConstructorD, + Scope *S, + CXXScopeSpec &SS, + IdentifierInfo *MemberOrBase, + ParsedType TemplateTypeTy, + const DeclSpec &DS, + SourceLocation IdLoc, + Expr *InitList, + SourceLocation EllipsisLoc) { + return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy, + DS, IdLoc, InitList, + EllipsisLoc); + } + + /// Handle a C++ member initializer using parentheses syntax. + MemInitResult + Sema::ActOnMemInitializer(Decl *ConstructorD, + Scope *S, + CXXScopeSpec &SS, + IdentifierInfo *MemberOrBase, + ParsedType TemplateTypeTy, + const DeclSpec &DS, + SourceLocation IdLoc, + SourceLocation LParenLoc, + ArrayRef Args, + SourceLocation RParenLoc, + SourceLocation EllipsisLoc) { + Expr *List = ParenListExpr::Create(Context, LParenLoc, Args, RParenLoc); + return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy, + DS, IdLoc, List, EllipsisLoc); + } + + namespace { + + // Callback to only accept typo corrections that can be a valid C++ member + // initializer: either a non-static field member or a base class. + class MemInitializerValidatorCCC final : public CorrectionCandidateCallback { + public: + explicit MemInitializerValidatorCCC(CXXRecordDecl *ClassDecl) + : ClassDecl(ClassDecl) {} + + bool ValidateCandidate(const TypoCorrection &candidate) override { + if (NamedDecl *ND = candidate.getCorrectionDecl()) { + if (FieldDecl *Member = dyn_cast(ND)) + return Member->getDeclContext()->getRedeclContext()->Equals(ClassDecl); + return isa(ND); + } + return false; + } + + std::unique_ptr clone() override { + return std::make_unique(*this); + } + + private: + CXXRecordDecl *ClassDecl; + }; + + } + + ValueDecl *Sema::tryLookupCtorInitMemberDecl(CXXRecordDecl *ClassDecl, + CXXScopeSpec &SS, + ParsedType TemplateTypeTy, + IdentifierInfo *MemberOrBase) { + if (SS.getScopeRep() || TemplateTypeTy) + return nullptr; + for (auto *D : ClassDecl->lookup(MemberOrBase)) + if (isa(D) || isa(D)) + return cast(D); + return nullptr; + } + + /// Handle a C++ member initializer. + MemInitResult + Sema::BuildMemInitializer(Decl *ConstructorD, + Scope *S, + CXXScopeSpec &SS, + IdentifierInfo *MemberOrBase, + ParsedType TemplateTypeTy, + const DeclSpec &DS, + SourceLocation IdLoc, + Expr *Init, + SourceLocation EllipsisLoc) { + ExprResult Res = CorrectDelayedTyposInExpr(Init, /*InitDecl=*/nullptr, + /*RecoverUncorrectedTypos=*/true); + if (!Res.isUsable()) + return true; + Init = Res.get(); + + if (!ConstructorD) + return true; + + AdjustDeclIfTemplate(ConstructorD); + + CXXConstructorDecl *Constructor + = dyn_cast(ConstructorD); + if (!Constructor) { + // The user wrote a constructor initializer on a function that is + // not a C++ constructor. Ignore the error for now, because we may + // have more member initializers coming; we'll diagnose it just + // once in ActOnMemInitializers. + return true; + } + + CXXRecordDecl *ClassDecl = Constructor->getParent(); + + // C++ [class.base.init]p2: + // Names in a mem-initializer-id are looked up in the scope of the + // constructor's class and, if not found in that scope, are looked + // up in the scope containing the constructor's definition. + // [Note: if the constructor's class contains a member with the + // same name as a direct or virtual base class of the class, a + // mem-initializer-id naming the member or base class and composed + // of a single identifier refers to the class member. A + // mem-initializer-id for the hidden base class may be specified + // using a qualified name. ] + + // Look for a member, first. + if (ValueDecl *Member = tryLookupCtorInitMemberDecl( + ClassDecl, SS, TemplateTypeTy, MemberOrBase)) { + if (EllipsisLoc.isValid()) + Diag(EllipsisLoc, diag::err_pack_expansion_member_init) + << MemberOrBase + << SourceRange(IdLoc, Init->getSourceRange().getEnd()); + + return BuildMemberInitializer(Member, Init, IdLoc); + } + // It didn't name a member, so see if it names a class. + QualType BaseType; + TypeSourceInfo *TInfo = nullptr; + + if (TemplateTypeTy) { + BaseType = GetTypeFromParser(TemplateTypeTy, &TInfo); + if (BaseType.isNull()) + return true; + } else if (DS.getTypeSpecType() == TST_decltype) { + BaseType = BuildDecltypeType(DS.getRepAsExpr()); + } else if (DS.getTypeSpecType() == TST_decltype_auto) { + Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid); + return true; + } else { + LookupResult R(*this, MemberOrBase, IdLoc, LookupOrdinaryName); + LookupParsedName(R, S, &SS); + + TypeDecl *TyD = R.getAsSingle(); + if (!TyD) { + if (R.isAmbiguous()) return true; + + // We don't want access-control diagnostics here. + R.suppressDiagnostics(); + + if (SS.isSet() && isDependentScopeSpecifier(SS)) { + bool NotUnknownSpecialization = false; + DeclContext *DC = computeDeclContext(SS, false); + if (CXXRecordDecl *Record = dyn_cast_or_null(DC)) + NotUnknownSpecialization = !Record->hasAnyDependentBases(); + + if (!NotUnknownSpecialization) { + // When the scope specifier can refer to a member of an unknown + // specialization, we take it as a type name. + BaseType = CheckTypenameType(ETK_None, SourceLocation(), + SS.getWithLocInContext(Context), + *MemberOrBase, IdLoc); + if (BaseType.isNull()) + return true; + + TInfo = Context.CreateTypeSourceInfo(BaseType); + DependentNameTypeLoc TL = + TInfo->getTypeLoc().castAs(); + if (!TL.isNull()) { + TL.setNameLoc(IdLoc); + TL.setElaboratedKeywordLoc(SourceLocation()); + TL.setQualifierLoc(SS.getWithLocInContext(Context)); + } + + R.clear(); + R.setLookupName(MemberOrBase); + } + } + + if (getLangOpts().MSVCCompat && !getLangOpts().CPlusPlus20) { + if (auto UnqualifiedBase = R.getAsSingle()) { + auto *TempSpec = cast( + UnqualifiedBase->getInjectedClassNameSpecialization()); + TemplateName TN = TempSpec->getTemplateName(); + for (auto const &Base : ClassDecl->bases()) { + auto BaseTemplate = + Base.getType()->getAs(); + if (BaseTemplate && Context.hasSameTemplateName( + BaseTemplate->getTemplateName(), TN)) { + Diag(IdLoc, diag::ext_unqualified_base_class) + << SourceRange(IdLoc, Init->getSourceRange().getEnd()); + BaseType = Base.getType(); + break; + } + } + } + } + + // If no results were found, try to correct typos. + TypoCorrection Corr; + MemInitializerValidatorCCC CCC(ClassDecl); + if (R.empty() && BaseType.isNull() && + (Corr = CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS, + CCC, CTK_ErrorRecovery, ClassDecl))) { + if (FieldDecl *Member = Corr.getCorrectionDeclAs()) { + // We have found a non-static data member with a similar + // name to what was typed; complain and initialize that + // member. + diagnoseTypo(Corr, + PDiag(diag::err_mem_init_not_member_or_class_suggest) + << MemberOrBase << true); + return BuildMemberInitializer(Member, Init, IdLoc); + } else if (TypeDecl *Type = Corr.getCorrectionDeclAs()) { + const CXXBaseSpecifier *DirectBaseSpec; + const CXXBaseSpecifier *VirtualBaseSpec; + if (FindBaseInitializer(*this, ClassDecl, + Context.getTypeDeclType(Type), + DirectBaseSpec, VirtualBaseSpec)) { + // We have found a direct or virtual base class with a + // similar name to what was typed; complain and initialize + // that base class. + diagnoseTypo(Corr, + PDiag(diag::err_mem_init_not_member_or_class_suggest) + << MemberOrBase << false, + PDiag() /*Suppress note, we provide our own.*/); + + const CXXBaseSpecifier *BaseSpec = DirectBaseSpec ? DirectBaseSpec + : VirtualBaseSpec; + Diag(BaseSpec->getBeginLoc(), diag::note_base_class_specified_here) + << BaseSpec->getType() << BaseSpec->getSourceRange(); + + TyD = Type; + } + } + } + + if (!TyD && BaseType.isNull()) { + Diag(IdLoc, diag::err_mem_init_not_member_or_class) + << MemberOrBase << SourceRange(IdLoc,Init->getSourceRange().getEnd()); + return true; + } + } + + if (BaseType.isNull()) { + BaseType = getElaboratedType(ETK_None, SS, Context.getTypeDeclType(TyD)); + MarkAnyDeclReferenced(TyD->getLocation(), TyD, /*OdrUse=*/false); + TInfo = Context.CreateTypeSourceInfo(BaseType); + ElaboratedTypeLoc TL = TInfo->getTypeLoc().castAs(); + TL.getNamedTypeLoc().castAs().setNameLoc(IdLoc); + TL.setElaboratedKeywordLoc(SourceLocation()); + TL.setQualifierLoc(SS.getWithLocInContext(Context)); + } + } + + if (!TInfo) + TInfo = Context.getTrivialTypeSourceInfo(BaseType, IdLoc); + + return BuildBaseInitializer(BaseType, TInfo, Init, ClassDecl, EllipsisLoc); + } + + MemInitResult + Sema::BuildMemberInitializer(ValueDecl *Member, Expr *Init, + SourceLocation IdLoc) { + FieldDecl *DirectMember = dyn_cast(Member); + IndirectFieldDecl *IndirectMember = dyn_cast(Member); + assert((DirectMember || IndirectMember) && + "Member must be a FieldDecl or IndirectFieldDecl"); + + if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer)) + return true; + + if (Member->isInvalidDecl()) + return true; + + MultiExprArg Args; + if (ParenListExpr *ParenList = dyn_cast(Init)) { + Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs()); + } else if (InitListExpr *InitList = dyn_cast(Init)) { + Args = MultiExprArg(InitList->getInits(), InitList->getNumInits()); + } else { + // Template instantiation doesn't reconstruct ParenListExprs for us. + Args = Init; + } + + SourceRange InitRange = Init->getSourceRange(); + + if (Member->getType()->isDependentType() || Init->isTypeDependent()) { + // Can't check initialization for a member of dependent type or when + // any of the arguments are type-dependent expressions. + DiscardCleanupsInEvaluationContext(); + } else { + bool InitList = false; + if (isa(Init)) { + InitList = true; + Args = Init; + } + + // Initialize the member. + InitializedEntity MemberEntity = + DirectMember ? InitializedEntity::InitializeMember(DirectMember, nullptr) + : InitializedEntity::InitializeMember(IndirectMember, + nullptr); + InitializationKind Kind = + InitList ? InitializationKind::CreateDirectList( + IdLoc, Init->getBeginLoc(), Init->getEndLoc()) + : InitializationKind::CreateDirect(IdLoc, InitRange.getBegin(), + InitRange.getEnd()); + + InitializationSequence InitSeq(*this, MemberEntity, Kind, Args); + ExprResult MemberInit = InitSeq.Perform(*this, MemberEntity, Kind, Args, + nullptr); + if (!MemberInit.isInvalid()) { + // C++11 [class.base.init]p7: + // The initialization of each base and member constitutes a + // full-expression. + MemberInit = ActOnFinishFullExpr(MemberInit.get(), InitRange.getBegin(), + /*DiscardedValue*/ false); + } + + if (MemberInit.isInvalid()) { + // Args were sensible expressions but we couldn't initialize the member + // from them. Preserve them in a RecoveryExpr instead. + Init = CreateRecoveryExpr(InitRange.getBegin(), InitRange.getEnd(), Args, + Member->getType()) + .get(); + if (!Init) + return true; + } else { + Init = MemberInit.get(); + } + } + + if (DirectMember) { + return new (Context) CXXCtorInitializer(Context, DirectMember, IdLoc, + InitRange.getBegin(), Init, + InitRange.getEnd()); + } else { + return new (Context) CXXCtorInitializer(Context, IndirectMember, IdLoc, + InitRange.getBegin(), Init, + InitRange.getEnd()); + } + } + + MemInitResult + Sema::BuildDelegatingInitializer(TypeSourceInfo *TInfo, Expr *Init, + CXXRecordDecl *ClassDecl) { + SourceLocation NameLoc = TInfo->getTypeLoc().getSourceRange().getBegin(); + if (!LangOpts.CPlusPlus11) + return Diag(NameLoc, diag::err_delegating_ctor) + << TInfo->getTypeLoc().getSourceRange(); + Diag(NameLoc, diag::warn_cxx98_compat_delegating_ctor); + + bool InitList = true; + MultiExprArg Args = Init; + if (ParenListExpr *ParenList = dyn_cast(Init)) { + InitList = false; + Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs()); + } + + SourceRange InitRange = Init->getSourceRange(); + // Initialize the object. + InitializedEntity DelegationEntity = InitializedEntity::InitializeDelegation( + QualType(ClassDecl->getTypeForDecl(), 0)); + InitializationKind Kind = + InitList ? InitializationKind::CreateDirectList( + NameLoc, Init->getBeginLoc(), Init->getEndLoc()) + : InitializationKind::CreateDirect(NameLoc, InitRange.getBegin(), + InitRange.getEnd()); + InitializationSequence InitSeq(*this, DelegationEntity, Kind, Args); + ExprResult DelegationInit = InitSeq.Perform(*this, DelegationEntity, Kind, + Args, nullptr); + if (!DelegationInit.isInvalid()) { + assert((DelegationInit.get()->containsErrors() || + cast(DelegationInit.get())->getConstructor()) && + "Delegating constructor with no target?"); + + // C++11 [class.base.init]p7: + // The initialization of each base and member constitutes a + // full-expression. + DelegationInit = ActOnFinishFullExpr( + DelegationInit.get(), InitRange.getBegin(), /*DiscardedValue*/ false); + } + + if (DelegationInit.isInvalid()) { + DelegationInit = + CreateRecoveryExpr(InitRange.getBegin(), InitRange.getEnd(), Args, + QualType(ClassDecl->getTypeForDecl(), 0)); + if (DelegationInit.isInvalid()) + return true; + } else { + // If we are in a dependent context, template instantiation will + // perform this type-checking again. Just save the arguments that we + // received in a ParenListExpr. + // FIXME: This isn't quite ideal, since our ASTs don't capture all + // of the information that we have about the base + // initializer. However, deconstructing the ASTs is a dicey process, + // and this approach is far more likely to get the corner cases right. + if (CurContext->isDependentContext()) + DelegationInit = Init; + } + + return new (Context) CXXCtorInitializer(Context, TInfo, InitRange.getBegin(), + DelegationInit.getAs(), + InitRange.getEnd()); + } + + MemInitResult + Sema::BuildBaseInitializer(QualType BaseType, TypeSourceInfo *BaseTInfo, + Expr *Init, CXXRecordDecl *ClassDecl, + SourceLocation EllipsisLoc) { + SourceLocation BaseLoc = BaseTInfo->getTypeLoc().getBeginLoc(); + + if (!BaseType->isDependentType() && !BaseType->isRecordType()) + return Diag(BaseLoc, diag::err_base_init_does_not_name_class) + << BaseType << BaseTInfo->getTypeLoc().getSourceRange(); + + // C++ [class.base.init]p2: + // [...] Unless the mem-initializer-id names a nonstatic data + // member of the constructor's class or a direct or virtual base + // of that class, the mem-initializer is ill-formed. A + // mem-initializer-list can initialize a base class using any + // name that denotes that base class type. + + // We can store the initializers in "as-written" form and delay analysis until + // instantiation if the constructor is dependent. But not for dependent + // (broken) code in a non-template! SetCtorInitializers does not expect this. + bool Dependent = CurContext->isDependentContext() && + (BaseType->isDependentType() || Init->isTypeDependent()); + + SourceRange InitRange = Init->getSourceRange(); + if (EllipsisLoc.isValid()) { + // This is a pack expansion. + if (!BaseType->containsUnexpandedParameterPack()) { + Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs) + << SourceRange(BaseLoc, InitRange.getEnd()); + + EllipsisLoc = SourceLocation(); + } + } else { + // Check for any unexpanded parameter packs. + if (DiagnoseUnexpandedParameterPack(BaseLoc, BaseTInfo, UPPC_Initializer)) + return true; + + if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer)) + return true; + } + + // Check for direct and virtual base classes. + const CXXBaseSpecifier *DirectBaseSpec = nullptr; + const CXXBaseSpecifier *VirtualBaseSpec = nullptr; + if (!Dependent) { + if (Context.hasSameUnqualifiedType(QualType(ClassDecl->getTypeForDecl(),0), + BaseType)) + return BuildDelegatingInitializer(BaseTInfo, Init, ClassDecl); + + FindBaseInitializer(*this, ClassDecl, BaseType, DirectBaseSpec, + VirtualBaseSpec); + + // C++ [base.class.init]p2: + // Unless the mem-initializer-id names a nonstatic data member of the + // constructor's class or a direct or virtual base of that class, the + // mem-initializer is ill-formed. + if (!DirectBaseSpec && !VirtualBaseSpec) { + // If the class has any dependent bases, then it's possible that + // one of those types will resolve to the same type as + // BaseType. Therefore, just treat this as a dependent base + // class initialization. FIXME: Should we try to check the + // initialization anyway? It seems odd. + if (ClassDecl->hasAnyDependentBases()) + Dependent = true; + else + return Diag(BaseLoc, diag::err_not_direct_base_or_virtual) + << BaseType << Context.getTypeDeclType(ClassDecl) + << BaseTInfo->getTypeLoc().getSourceRange(); + } + } + + if (Dependent) { + DiscardCleanupsInEvaluationContext(); + + return new (Context) CXXCtorInitializer(Context, BaseTInfo, + /*IsVirtual=*/false, + InitRange.getBegin(), Init, + InitRange.getEnd(), EllipsisLoc); + } + + // C++ [base.class.init]p2: + // If a mem-initializer-id is ambiguous because it designates both + // a direct non-virtual base class and an inherited virtual base + // class, the mem-initializer is ill-formed. + if (DirectBaseSpec && VirtualBaseSpec) + return Diag(BaseLoc, diag::err_base_init_direct_and_virtual) + << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange(); + + const CXXBaseSpecifier *BaseSpec = DirectBaseSpec; + if (!BaseSpec) + BaseSpec = VirtualBaseSpec; + + // Initialize the base. + bool InitList = true; + MultiExprArg Args = Init; + if (ParenListExpr *ParenList = dyn_cast(Init)) { + InitList = false; + Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs()); + } + + InitializedEntity BaseEntity = + InitializedEntity::InitializeBase(Context, BaseSpec, VirtualBaseSpec); + InitializationKind Kind = + InitList ? InitializationKind::CreateDirectList(BaseLoc) + : InitializationKind::CreateDirect(BaseLoc, InitRange.getBegin(), + InitRange.getEnd()); + InitializationSequence InitSeq(*this, BaseEntity, Kind, Args); + ExprResult BaseInit = InitSeq.Perform(*this, BaseEntity, Kind, Args, nullptr); + if (!BaseInit.isInvalid()) { + // C++11 [class.base.init]p7: + // The initialization of each base and member constitutes a + // full-expression. + BaseInit = ActOnFinishFullExpr(BaseInit.get(), InitRange.getBegin(), + /*DiscardedValue*/ false); + } + + if (BaseInit.isInvalid()) { + BaseInit = CreateRecoveryExpr(InitRange.getBegin(), InitRange.getEnd(), + Args, BaseType); + if (BaseInit.isInvalid()) + return true; + } else { + // If we are in a dependent context, template instantiation will + // perform this type-checking again. Just save the arguments that we + // received in a ParenListExpr. + // FIXME: This isn't quite ideal, since our ASTs don't capture all + // of the information that we have about the base + // initializer. However, deconstructing the ASTs is a dicey process, + // and this approach is far more likely to get the corner cases right. + if (CurContext->isDependentContext()) + BaseInit = Init; + } + + return new (Context) CXXCtorInitializer(Context, BaseTInfo, + BaseSpec->isVirtual(), + InitRange.getBegin(), + BaseInit.getAs(), + InitRange.getEnd(), EllipsisLoc); + } + + // Create a static_cast\(expr). + static Expr *CastForMoving(Sema &SemaRef, Expr *E) { + QualType TargetType = + SemaRef.BuildReferenceType(E->getType(), /*SpelledAsLValue*/ false, + SourceLocation(), DeclarationName()); + SourceLocation ExprLoc = E->getBeginLoc(); + TypeSourceInfo *TargetLoc = SemaRef.Context.getTrivialTypeSourceInfo( + TargetType, ExprLoc); + + return SemaRef.BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E, + SourceRange(ExprLoc, ExprLoc), + E->getSourceRange()).get(); + } + + /// ImplicitInitializerKind - How an implicit base or member initializer should + /// initialize its base or member. + enum ImplicitInitializerKind { + IIK_Default, + IIK_Copy, + IIK_Move, + IIK_Inherit + }; + + static bool + BuildImplicitBaseInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor, + ImplicitInitializerKind ImplicitInitKind, + CXXBaseSpecifier *BaseSpec, + bool IsInheritedVirtualBase, + CXXCtorInitializer *&CXXBaseInit) { + InitializedEntity InitEntity + = InitializedEntity::InitializeBase(SemaRef.Context, BaseSpec, + IsInheritedVirtualBase); + + ExprResult BaseInit; + + switch (ImplicitInitKind) { + case IIK_Inherit: + case IIK_Default: { + InitializationKind InitKind + = InitializationKind::CreateDefault(Constructor->getLocation()); + InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, std::nullopt); + BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, std::nullopt); + break; + } + + case IIK_Move: + case IIK_Copy: { + bool Moving = ImplicitInitKind == IIK_Move; + ParmVarDecl *Param = Constructor->getParamDecl(0); + QualType ParamType = Param->getType().getNonReferenceType(); + + Expr *CopyCtorArg = + DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(), + SourceLocation(), Param, false, + Constructor->getLocation(), ParamType, + VK_LValue, nullptr); + + SemaRef.MarkDeclRefReferenced(cast(CopyCtorArg)); + + // Cast to the base class to avoid ambiguities. + QualType ArgTy = + SemaRef.Context.getQualifiedType(BaseSpec->getType().getUnqualifiedType(), + ParamType.getQualifiers()); + + if (Moving) { + CopyCtorArg = CastForMoving(SemaRef, CopyCtorArg); + } + + CXXCastPath BasePath; + BasePath.push_back(BaseSpec); + CopyCtorArg = SemaRef.ImpCastExprToType(CopyCtorArg, ArgTy, + CK_UncheckedDerivedToBase, + Moving ? VK_XValue : VK_LValue, + &BasePath).get(); + + InitializationKind InitKind + = InitializationKind::CreateDirect(Constructor->getLocation(), + SourceLocation(), SourceLocation()); + InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, CopyCtorArg); + BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, CopyCtorArg); + break; + } + } + + BaseInit = SemaRef.MaybeCreateExprWithCleanups(BaseInit); + if (BaseInit.isInvalid()) + return true; + + CXXBaseInit = + new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, + SemaRef.Context.getTrivialTypeSourceInfo(BaseSpec->getType(), + SourceLocation()), + BaseSpec->isVirtual(), + SourceLocation(), + BaseInit.getAs(), + SourceLocation(), + SourceLocation()); + + return false; + } + + static bool RefersToRValueRef(Expr *MemRef) { + ValueDecl *Referenced = cast(MemRef)->getMemberDecl(); + return Referenced->getType()->isRValueReferenceType(); + } + + static bool + BuildImplicitMemberInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor, + ImplicitInitializerKind ImplicitInitKind, + FieldDecl *Field, IndirectFieldDecl *Indirect, + CXXCtorInitializer *&CXXMemberInit) { + if (Field->isInvalidDecl()) + return true; + + SourceLocation Loc = Constructor->getLocation(); + + if (ImplicitInitKind == IIK_Copy || ImplicitInitKind == IIK_Move) { + bool Moving = ImplicitInitKind == IIK_Move; + ParmVarDecl *Param = Constructor->getParamDecl(0); + QualType ParamType = Param->getType().getNonReferenceType(); + + // Suppress copying zero-width bitfields. + if (Field->isZeroLengthBitField(SemaRef.Context)) + return false; + + Expr *MemberExprBase = + DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(), + SourceLocation(), Param, false, + Loc, ParamType, VK_LValue, nullptr); + + SemaRef.MarkDeclRefReferenced(cast(MemberExprBase)); + + if (Moving) { + MemberExprBase = CastForMoving(SemaRef, MemberExprBase); + } + + // Build a reference to this field within the parameter. + CXXScopeSpec SS; + LookupResult MemberLookup(SemaRef, Field->getDeclName(), Loc, + Sema::LookupMemberName); + MemberLookup.addDecl(Indirect ? cast(Indirect) + : cast(Field), AS_public); + MemberLookup.resolveKind(); + ExprResult CtorArg + = SemaRef.BuildMemberReferenceExpr(MemberExprBase, + ParamType, Loc, + /*IsArrow=*/false, + SS, + /*TemplateKWLoc=*/SourceLocation(), + /*FirstQualifierInScope=*/nullptr, + MemberLookup, + /*TemplateArgs=*/nullptr, + /*S*/nullptr); + if (CtorArg.isInvalid()) + return true; + + // C++11 [class.copy]p15: + // - if a member m has rvalue reference type T&&, it is direct-initialized + // with static_cast(x.m); + if (RefersToRValueRef(CtorArg.get())) { + CtorArg = CastForMoving(SemaRef, CtorArg.get()); + } + + InitializedEntity Entity = + Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr, + /*Implicit*/ true) + : InitializedEntity::InitializeMember(Field, nullptr, + /*Implicit*/ true); + + // Direct-initialize to use the copy constructor. + InitializationKind InitKind = + InitializationKind::CreateDirect(Loc, SourceLocation(), SourceLocation()); + + Expr *CtorArgE = CtorArg.getAs(); + InitializationSequence InitSeq(SemaRef, Entity, InitKind, CtorArgE); + ExprResult MemberInit = + InitSeq.Perform(SemaRef, Entity, InitKind, MultiExprArg(&CtorArgE, 1)); + MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit); + if (MemberInit.isInvalid()) + return true; + + if (Indirect) + CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer( + SemaRef.Context, Indirect, Loc, Loc, MemberInit.getAs(), Loc); + else + CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer( + SemaRef.Context, Field, Loc, Loc, MemberInit.getAs(), Loc); + return false; + } + + assert((ImplicitInitKind == IIK_Default || ImplicitInitKind == IIK_Inherit) && + "Unhandled implicit init kind!"); + + QualType FieldBaseElementType = + SemaRef.Context.getBaseElementType(Field->getType()); + + if (FieldBaseElementType->isRecordType()) { + InitializedEntity InitEntity = + Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr, + /*Implicit*/ true) + : InitializedEntity::InitializeMember(Field, nullptr, + /*Implicit*/ true); + InitializationKind InitKind = + InitializationKind::CreateDefault(Loc); + + InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, std::nullopt); + ExprResult MemberInit = + InitSeq.Perform(SemaRef, InitEntity, InitKind, std::nullopt); + + MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit); + if (MemberInit.isInvalid()) + return true; + + if (Indirect) + CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, + Indirect, Loc, + Loc, + MemberInit.get(), + Loc); + else + CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, + Field, Loc, Loc, + MemberInit.get(), + Loc); + return false; + } + + if (!Field->getParent()->isUnion()) { + if (FieldBaseElementType->isReferenceType()) { + SemaRef.Diag(Constructor->getLocation(), + diag::err_uninitialized_member_in_ctor) + << (int)Constructor->isImplicit() + << SemaRef.Context.getTagDeclType(Constructor->getParent()) + << 0 << Field->getDeclName(); + SemaRef.Diag(Field->getLocation(), diag::note_declared_at); + return true; + } + + if (FieldBaseElementType.isConstQualified()) { + SemaRef.Diag(Constructor->getLocation(), + diag::err_uninitialized_member_in_ctor) + << (int)Constructor->isImplicit() + << SemaRef.Context.getTagDeclType(Constructor->getParent()) + << 1 << Field->getDeclName(); + SemaRef.Diag(Field->getLocation(), diag::note_declared_at); + return true; + } + } + + if (FieldBaseElementType.hasNonTrivialObjCLifetime()) { + // ARC and Weak: + // Default-initialize Objective-C pointers to NULL. + CXXMemberInit + = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Field, + Loc, Loc, + new (SemaRef.Context) ImplicitValueInitExpr(Field->getType()), + Loc); + return false; + } + + // Nothing to initialize. + CXXMemberInit = nullptr; + return false; + } + + namespace { + struct BaseAndFieldInfo { + Sema &S; + CXXConstructorDecl *Ctor; + bool AnyErrorsInInits; + ImplicitInitializerKind IIK; + llvm::DenseMap AllBaseFields; + SmallVector AllToInit; + llvm::DenseMap ActiveUnionMember; + + BaseAndFieldInfo(Sema &S, CXXConstructorDecl *Ctor, bool ErrorsInInits) + : S(S), Ctor(Ctor), AnyErrorsInInits(ErrorsInInits) { + bool Generated = Ctor->isImplicit() || Ctor->isDefaulted(); + if (Ctor->getInheritedConstructor()) + IIK = IIK_Inherit; + else if (Generated && Ctor->isCopyConstructor()) + IIK = IIK_Copy; + else if (Generated && Ctor->isMoveConstructor()) + IIK = IIK_Move; + else + IIK = IIK_Default; + } + + bool isImplicitCopyOrMove() const { + switch (IIK) { + case IIK_Copy: + case IIK_Move: + return true; + + case IIK_Default: + case IIK_Inherit: + return false; + } + + llvm_unreachable("Invalid ImplicitInitializerKind!"); + } + + bool addFieldInitializer(CXXCtorInitializer *Init) { + AllToInit.push_back(Init); + + // Check whether this initializer makes the field "used". + if (Init->getInit()->HasSideEffects(S.Context)) + S.UnusedPrivateFields.remove(Init->getAnyMember()); + + return false; + } + + bool isInactiveUnionMember(FieldDecl *Field) { + RecordDecl *Record = Field->getParent(); + if (!Record->isUnion()) + return false; + + if (FieldDecl *Active = + ActiveUnionMember.lookup(Record->getCanonicalDecl())) + return Active != Field->getCanonicalDecl(); + + // In an implicit copy or move constructor, ignore any in-class initializer. + if (isImplicitCopyOrMove()) + return true; + + // If there's no explicit initialization, the field is active only if it + // has an in-class initializer... + if (Field->hasInClassInitializer()) + return false; + // ... or it's an anonymous struct or union whose class has an in-class + // initializer. + if (!Field->isAnonymousStructOrUnion()) + return true; + CXXRecordDecl *FieldRD = Field->getType()->getAsCXXRecordDecl(); + return !FieldRD->hasInClassInitializer(); + } + + /// Determine whether the given field is, or is within, a union member + /// that is inactive (because there was an initializer given for a different + /// member of the union, or because the union was not initialized at all). + bool isWithinInactiveUnionMember(FieldDecl *Field, + IndirectFieldDecl *Indirect) { + if (!Indirect) + return isInactiveUnionMember(Field); + + for (auto *C : Indirect->chain()) { + FieldDecl *Field = dyn_cast(C); + if (Field && isInactiveUnionMember(Field)) + return true; + } + return false; + } + }; + } + + /// Determine whether the given type is an incomplete or zero-lenfgth + /// array type. + static bool isIncompleteOrZeroLengthArrayType(ASTContext &Context, QualType T) { + if (T->isIncompleteArrayType()) + return true; + + while (const ConstantArrayType *ArrayT = Context.getAsConstantArrayType(T)) { + if (!ArrayT->getSize()) + return true; + + T = ArrayT->getElementType(); + } + + return false; + } + + static bool CollectFieldInitializer(Sema &SemaRef, BaseAndFieldInfo &Info, + FieldDecl *Field, + IndirectFieldDecl *Indirect = nullptr) { + if (Field->isInvalidDecl()) + return false; + + // Overwhelmingly common case: we have a direct initializer for this field. + if (CXXCtorInitializer *Init = + Info.AllBaseFields.lookup(Field->getCanonicalDecl())) + return Info.addFieldInitializer(Init); + + // C++11 [class.base.init]p8: + // if the entity is a non-static data member that has a + // brace-or-equal-initializer and either + // -- the constructor's class is a union and no other variant member of that + // union is designated by a mem-initializer-id or + // -- the constructor's class is not a union, and, if the entity is a member + // of an anonymous union, no other member of that union is designated by + // a mem-initializer-id, + // the entity is initialized as specified in [dcl.init]. + // + // We also apply the same rules to handle anonymous structs within anonymous + // unions. + if (Info.isWithinInactiveUnionMember(Field, Indirect)) + return false; + + if (Field->hasInClassInitializer() && !Info.isImplicitCopyOrMove()) { + ExprResult DIE = + SemaRef.BuildCXXDefaultInitExpr(Info.Ctor->getLocation(), Field); + if (DIE.isInvalid()) + return true; + + auto Entity = InitializedEntity::InitializeMember(Field, nullptr, true); + SemaRef.checkInitializerLifetime(Entity, DIE.get()); + + CXXCtorInitializer *Init; + if (Indirect) + Init = new (SemaRef.Context) + CXXCtorInitializer(SemaRef.Context, Indirect, SourceLocation(), + SourceLocation(), DIE.get(), SourceLocation()); + else + Init = new (SemaRef.Context) + CXXCtorInitializer(SemaRef.Context, Field, SourceLocation(), + SourceLocation(), DIE.get(), SourceLocation()); + return Info.addFieldInitializer(Init); + } + + // Don't initialize incomplete or zero-length arrays. + if (isIncompleteOrZeroLengthArrayType(SemaRef.Context, Field->getType())) + return false; + + // Don't try to build an implicit initializer if there were semantic + // errors in any of the initializers (and therefore we might be + // missing some that the user actually wrote). + if (Info.AnyErrorsInInits) + return false; + + CXXCtorInitializer *Init = nullptr; + if (BuildImplicitMemberInitializer(Info.S, Info.Ctor, Info.IIK, Field, + Indirect, Init)) + return true; + + if (!Init) + return false; + + return Info.addFieldInitializer(Init); + } + + bool + Sema::SetDelegatingInitializer(CXXConstructorDecl *Constructor, + CXXCtorInitializer *Initializer) { + assert(Initializer->isDelegatingInitializer()); + Constructor->setNumCtorInitializers(1); + CXXCtorInitializer **initializer = + new (Context) CXXCtorInitializer*[1]; + memcpy(initializer, &Initializer, sizeof (CXXCtorInitializer*)); + Constructor->setCtorInitializers(initializer); + + if (CXXDestructorDecl *Dtor = LookupDestructor(Constructor->getParent())) { + MarkFunctionReferenced(Initializer->getSourceLocation(), Dtor); + DiagnoseUseOfDecl(Dtor, Initializer->getSourceLocation()); + } + + DelegatingCtorDecls.push_back(Constructor); + + DiagnoseUninitializedFields(*this, Constructor); + + return false; + } + + bool Sema::SetCtorInitializers(CXXConstructorDecl *Constructor, bool AnyErrors, + ArrayRef Initializers) { + if (Constructor->isDependentContext()) { + // Just store the initializers as written, they will be checked during + // instantiation. + if (!Initializers.empty()) { + Constructor->setNumCtorInitializers(Initializers.size()); + CXXCtorInitializer **baseOrMemberInitializers = + new (Context) CXXCtorInitializer*[Initializers.size()]; + memcpy(baseOrMemberInitializers, Initializers.data(), + Initializers.size() * sizeof(CXXCtorInitializer*)); + Constructor->setCtorInitializers(baseOrMemberInitializers); + } + + // Let template instantiation know whether we had errors. + if (AnyErrors) + Constructor->setInvalidDecl(); + + return false; + } + + BaseAndFieldInfo Info(*this, Constructor, AnyErrors); + + // We need to build the initializer AST according to order of construction + // and not what user specified in the Initializers list. + CXXRecordDecl *ClassDecl = Constructor->getParent()->getDefinition(); + if (!ClassDecl) + return true; + + bool HadError = false; + + for (unsigned i = 0; i < Initializers.size(); i++) { + CXXCtorInitializer *Member = Initializers[i]; + + if (Member->isBaseInitializer()) + Info.AllBaseFields[Member->getBaseClass()->getAs()] = Member; + else { + Info.AllBaseFields[Member->getAnyMember()->getCanonicalDecl()] = Member; + + if (IndirectFieldDecl *F = Member->getIndirectMember()) { + for (auto *C : F->chain()) { + FieldDecl *FD = dyn_cast(C); + if (FD && FD->getParent()->isUnion()) + Info.ActiveUnionMember.insert(std::make_pair( + FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl())); + } + } else if (FieldDecl *FD = Member->getMember()) { + if (FD->getParent()->isUnion()) + Info.ActiveUnionMember.insert(std::make_pair( + FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl())); + } + } + } + + // Keep track of the direct virtual bases. + llvm::SmallPtrSet DirectVBases; + for (auto &I : ClassDecl->bases()) { + if (I.isVirtual()) + DirectVBases.insert(&I); + } + + // Push virtual bases before others. + for (auto &VBase : ClassDecl->vbases()) { + if (CXXCtorInitializer *Value + = Info.AllBaseFields.lookup(VBase.getType()->getAs())) { + // [class.base.init]p7, per DR257: + // A mem-initializer where the mem-initializer-id names a virtual base + // class is ignored during execution of a constructor of any class that + // is not the most derived class. + if (ClassDecl->isAbstract()) { + // FIXME: Provide a fixit to remove the base specifier. This requires + // tracking the location of the associated comma for a base specifier. + Diag(Value->getSourceLocation(), diag::warn_abstract_vbase_init_ignored) + << VBase.getType() << ClassDecl; + DiagnoseAbstractType(ClassDecl); + } + + Info.AllToInit.push_back(Value); + } else if (!AnyErrors && !ClassDecl->isAbstract()) { + // [class.base.init]p8, per DR257: + // If a given [...] base class is not named by a mem-initializer-id + // [...] and the entity is not a virtual base class of an abstract + // class, then [...] the entity is default-initialized. + bool IsInheritedVirtualBase = !DirectVBases.count(&VBase); + CXXCtorInitializer *CXXBaseInit; + if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK, + &VBase, IsInheritedVirtualBase, + CXXBaseInit)) { + HadError = true; + continue; + } + + Info.AllToInit.push_back(CXXBaseInit); + } + } + + // Non-virtual bases. + for (auto &Base : ClassDecl->bases()) { + // Virtuals are in the virtual base list and already constructed. + if (Base.isVirtual()) + continue; + + if (CXXCtorInitializer *Value + = Info.AllBaseFields.lookup(Base.getType()->getAs())) { + Info.AllToInit.push_back(Value); + } else if (!AnyErrors) { + CXXCtorInitializer *CXXBaseInit; + if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK, + &Base, /*IsInheritedVirtualBase=*/false, + CXXBaseInit)) { + HadError = true; + continue; + } + + Info.AllToInit.push_back(CXXBaseInit); + } + } + + // Fields. + for (auto *Mem : ClassDecl->decls()) { + if (auto *F = dyn_cast(Mem)) { + // C++ [class.bit]p2: + // A declaration for a bit-field that omits the identifier declares an + // unnamed bit-field. Unnamed bit-fields are not members and cannot be + // initialized. + if (F->isUnnamedBitfield()) + continue; + + // If we're not generating the implicit copy/move constructor, then we'll + // handle anonymous struct/union fields based on their individual + // indirect fields. + if (F->isAnonymousStructOrUnion() && !Info.isImplicitCopyOrMove()) + continue; + + if (CollectFieldInitializer(*this, Info, F)) + HadError = true; + continue; + } + + // Beyond this point, we only consider default initialization. + if (Info.isImplicitCopyOrMove()) + continue; + + if (auto *F = dyn_cast(Mem)) { + if (F->getType()->isIncompleteArrayType()) { + assert(ClassDecl->hasFlexibleArrayMember() && + "Incomplete array type is not valid"); + continue; + } + + // Initialize each field of an anonymous struct individually. + if (CollectFieldInitializer(*this, Info, F->getAnonField(), F)) + HadError = true; + + continue; + } + } + + unsigned NumInitializers = Info.AllToInit.size(); + if (NumInitializers > 0) { + Constructor->setNumCtorInitializers(NumInitializers); + CXXCtorInitializer **baseOrMemberInitializers = + new (Context) CXXCtorInitializer*[NumInitializers]; + memcpy(baseOrMemberInitializers, Info.AllToInit.data(), + NumInitializers * sizeof(CXXCtorInitializer*)); + Constructor->setCtorInitializers(baseOrMemberInitializers); + + // Constructors implicitly reference the base and member + // destructors. + MarkBaseAndMemberDestructorsReferenced(Constructor->getLocation(), + Constructor->getParent()); + } + + return HadError; + } + + static void PopulateKeysForFields(FieldDecl *Field, SmallVectorImpl &IdealInits) { + if (const RecordType *RT = Field->getType()->getAs()) { + const RecordDecl *RD = RT->getDecl(); + if (RD->isAnonymousStructOrUnion()) { + for (auto *Field : RD->fields()) + PopulateKeysForFields(Field, IdealInits); + return; + } + } + IdealInits.push_back(Field->getCanonicalDecl()); + } + + static const void *GetKeyForBase(ASTContext &Context, QualType BaseType) { + return Context.getCanonicalType(BaseType).getTypePtr(); + } + + static const void *GetKeyForMember(ASTContext &Context, + CXXCtorInitializer *Member) { + if (!Member->isAnyMemberInitializer()) + return GetKeyForBase(Context, QualType(Member->getBaseClass(), 0)); + + return Member->getAnyMember()->getCanonicalDecl(); + } + + static void AddInitializerToDiag(const Sema::SemaDiagnosticBuilder &Diag, + const CXXCtorInitializer *Previous, + const CXXCtorInitializer *Current) { + if (Previous->isAnyMemberInitializer()) + Diag << 0 << Previous->getAnyMember(); + else + Diag << 1 << Previous->getTypeSourceInfo()->getType(); + + if (Current->isAnyMemberInitializer()) + Diag << 0 << Current->getAnyMember(); + else + Diag << 1 << Current->getTypeSourceInfo()->getType(); + } + + static void DiagnoseBaseOrMemInitializerOrder( + Sema &SemaRef, const CXXConstructorDecl *Constructor, + ArrayRef Inits) { + if (Constructor->getDeclContext()->isDependentContext()) + return; + + // Don't check initializers order unless the warning is enabled at the + // location of at least one initializer. + bool ShouldCheckOrder = false; + for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) { + CXXCtorInitializer *Init = Inits[InitIndex]; + if (!SemaRef.Diags.isIgnored(diag::warn_initializer_out_of_order, + Init->getSourceLocation())) { + ShouldCheckOrder = true; + break; + } + } + if (!ShouldCheckOrder) + return; + + // Build the list of bases and members in the order that they'll + // actually be initialized. The explicit initializers should be in + // this same order but may be missing things. + SmallVector IdealInitKeys; + + const CXXRecordDecl *ClassDecl = Constructor->getParent(); + + // 1. Virtual bases. + for (const auto &VBase : ClassDecl->vbases()) + IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, VBase.getType())); + + // 2. Non-virtual bases. + for (const auto &Base : ClassDecl->bases()) { + if (Base.isVirtual()) + continue; + IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, Base.getType())); + } + + // 3. Direct fields. + for (auto *Field : ClassDecl->fields()) { + if (Field->isUnnamedBitfield()) + continue; + + PopulateKeysForFields(Field, IdealInitKeys); + } + + unsigned NumIdealInits = IdealInitKeys.size(); + unsigned IdealIndex = 0; + + // Track initializers that are in an incorrect order for either a warning or + // note if multiple ones occur. + SmallVector WarnIndexes; + // Correlates the index of an initializer in the init-list to the index of + // the field/base in the class. + SmallVector, 32> CorrelatedInitOrder; + + for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) { + const void *InitKey = GetKeyForMember(SemaRef.Context, Inits[InitIndex]); + + // Scan forward to try to find this initializer in the idealized + // initializers list. + for (; IdealIndex != NumIdealInits; ++IdealIndex) + if (InitKey == IdealInitKeys[IdealIndex]) + break; + + // If we didn't find this initializer, it must be because we + // scanned past it on a previous iteration. That can only + // happen if we're out of order; emit a warning. + if (IdealIndex == NumIdealInits && InitIndex) { + WarnIndexes.push_back(InitIndex); + + // Move back to the initializer's location in the ideal list. + for (IdealIndex = 0; IdealIndex != NumIdealInits; ++IdealIndex) + if (InitKey == IdealInitKeys[IdealIndex]) + break; + + assert(IdealIndex < NumIdealInits && + "initializer not found in initializer list"); + } + CorrelatedInitOrder.emplace_back(IdealIndex, InitIndex); + } + + if (WarnIndexes.empty()) + return; + + // Sort based on the ideal order, first in the pair. + llvm::sort(CorrelatedInitOrder, llvm::less_first()); + + // Introduce a new scope as SemaDiagnosticBuilder needs to be destroyed to + // emit the diagnostic before we can try adding notes. + { + Sema::SemaDiagnosticBuilder D = SemaRef.Diag( + Inits[WarnIndexes.front() - 1]->getSourceLocation(), + WarnIndexes.size() == 1 ? diag::warn_initializer_out_of_order + : diag::warn_some_initializers_out_of_order); + + for (unsigned I = 0; I < CorrelatedInitOrder.size(); ++I) { + if (CorrelatedInitOrder[I].second == I) + continue; + // Ideally we would be using InsertFromRange here, but clang doesn't + // appear to handle InsertFromRange correctly when the source range is + // modified by another fix-it. + D << FixItHint::CreateReplacement( + Inits[I]->getSourceRange(), + Lexer::getSourceText( + CharSourceRange::getTokenRange( + Inits[CorrelatedInitOrder[I].second]->getSourceRange()), + SemaRef.getSourceManager(), SemaRef.getLangOpts())); + } + + // If there is only 1 item out of order, the warning expects the name and + // type of each being added to it. + if (WarnIndexes.size() == 1) { + AddInitializerToDiag(D, Inits[WarnIndexes.front() - 1], + Inits[WarnIndexes.front()]); + return; + } + } + // More than 1 item to warn, create notes letting the user know which ones + // are bad. + for (unsigned WarnIndex : WarnIndexes) { + const clang::CXXCtorInitializer *PrevInit = Inits[WarnIndex - 1]; + auto D = SemaRef.Diag(PrevInit->getSourceLocation(), + diag::note_initializer_out_of_order); + AddInitializerToDiag(D, PrevInit, Inits[WarnIndex]); + D << PrevInit->getSourceRange(); + } + } + + namespace { + bool CheckRedundantInit(Sema &S, + CXXCtorInitializer *Init, + CXXCtorInitializer *&PrevInit) { + if (!PrevInit) { + PrevInit = Init; + return false; + } + + if (FieldDecl *Field = Init->getAnyMember()) + S.Diag(Init->getSourceLocation(), + diag::err_multiple_mem_initialization) + << Field->getDeclName() + << Init->getSourceRange(); + else { + const Type *BaseClass = Init->getBaseClass(); + assert(BaseClass && "neither field nor base"); + S.Diag(Init->getSourceLocation(), + diag::err_multiple_base_initialization) + << QualType(BaseClass, 0) + << Init->getSourceRange(); + } + S.Diag(PrevInit->getSourceLocation(), diag::note_previous_initializer) + << 0 << PrevInit->getSourceRange(); + + return true; + } + + typedef std::pair UnionEntry; + typedef llvm::DenseMap RedundantUnionMap; + + bool CheckRedundantUnionInit(Sema &S, + CXXCtorInitializer *Init, + RedundantUnionMap &Unions) { + FieldDecl *Field = Init->getAnyMember(); + RecordDecl *Parent = Field->getParent(); + NamedDecl *Child = Field; + + while (Parent->isAnonymousStructOrUnion() || Parent->isUnion()) { + if (Parent->isUnion()) { + UnionEntry &En = Unions[Parent]; + if (En.first && En.first != Child) { + S.Diag(Init->getSourceLocation(), + diag::err_multiple_mem_union_initialization) + << Field->getDeclName() + << Init->getSourceRange(); + S.Diag(En.second->getSourceLocation(), diag::note_previous_initializer) + << 0 << En.second->getSourceRange(); + return true; + } + if (!En.first) { + En.first = Child; + En.second = Init; + } + if (!Parent->isAnonymousStructOrUnion()) + return false; + } + + Child = Parent; + Parent = cast(Parent->getDeclContext()); + } + + return false; + } + } // namespace + + /// ActOnMemInitializers - Handle the member initializers for a constructor. + void Sema::ActOnMemInitializers(Decl *ConstructorDecl, + SourceLocation ColonLoc, + ArrayRef MemInits, + bool AnyErrors) { + if (!ConstructorDecl) + return; + + AdjustDeclIfTemplate(ConstructorDecl); + + CXXConstructorDecl *Constructor + = dyn_cast(ConstructorDecl); + + if (!Constructor) { + Diag(ColonLoc, diag::err_only_constructors_take_base_inits); + return; + } + + // Mapping for the duplicate initializers check. + // For member initializers, this is keyed with a FieldDecl*. + // For base initializers, this is keyed with a Type*. + llvm::DenseMap Members; + + // Mapping for the inconsistent anonymous-union initializers check. + RedundantUnionMap MemberUnions; + + bool HadError = false; + for (unsigned i = 0; i < MemInits.size(); i++) { + CXXCtorInitializer *Init = MemInits[i]; + + // Set the source order index. + Init->setSourceOrder(i); + + if (Init->isAnyMemberInitializer()) { + const void *Key = GetKeyForMember(Context, Init); + if (CheckRedundantInit(*this, Init, Members[Key]) || + CheckRedundantUnionInit(*this, Init, MemberUnions)) + HadError = true; + } else if (Init->isBaseInitializer()) { + const void *Key = GetKeyForMember(Context, Init); + if (CheckRedundantInit(*this, Init, Members[Key])) + HadError = true; + } else { + assert(Init->isDelegatingInitializer()); + // This must be the only initializer + if (MemInits.size() != 1) { + Diag(Init->getSourceLocation(), + diag::err_delegating_initializer_alone) + << Init->getSourceRange() << MemInits[i ? 0 : 1]->getSourceRange(); + // We will treat this as being the only initializer. + } + SetDelegatingInitializer(Constructor, MemInits[i]); + // Return immediately as the initializer is set. + return; + } + } + + if (HadError) + return; + + DiagnoseBaseOrMemInitializerOrder(*this, Constructor, MemInits); + + SetCtorInitializers(Constructor, AnyErrors, MemInits); + + DiagnoseUninitializedFields(*this, Constructor); + } + + void + Sema::MarkBaseAndMemberDestructorsReferenced(SourceLocation Location, + CXXRecordDecl *ClassDecl) { + // Ignore dependent contexts. Also ignore unions, since their members never + // have destructors implicitly called. + if (ClassDecl->isDependentContext() || ClassDecl->isUnion()) + return; + + // FIXME: all the access-control diagnostics are positioned on the + // field/base declaration. That's probably good; that said, the + // user might reasonably want to know why the destructor is being + // emitted, and we currently don't say. + + // Non-static data members. + for (auto *Field : ClassDecl->fields()) { + if (Field->isInvalidDecl()) + continue; + + // Don't destroy incomplete or zero-length arrays. + if (isIncompleteOrZeroLengthArrayType(Context, Field->getType())) + continue; + + QualType FieldType = Context.getBaseElementType(Field->getType()); + + const RecordType* RT = FieldType->getAs(); + if (!RT) + continue; + + CXXRecordDecl *FieldClassDecl = cast(RT->getDecl()); + if (FieldClassDecl->isInvalidDecl()) + continue; + if (FieldClassDecl->hasIrrelevantDestructor()) + continue; + // The destructor for an implicit anonymous union member is never invoked. + if (FieldClassDecl->isUnion() && FieldClassDecl->isAnonymousStructOrUnion()) + continue; + + CXXDestructorDecl *Dtor = LookupDestructor(FieldClassDecl); + // Dtor might still be missing, e.g because it's invalid. + if (!Dtor) + continue; + CheckDestructorAccess(Field->getLocation(), Dtor, + PDiag(diag::err_access_dtor_field) + << Field->getDeclName() + << FieldType); + + MarkFunctionReferenced(Location, Dtor); + DiagnoseUseOfDecl(Dtor, Location); + } + + // We only potentially invoke the destructors of potentially constructed + // subobjects. + bool VisitVirtualBases = !ClassDecl->isAbstract(); + + // If the destructor exists and has already been marked used in the MS ABI, + // then virtual base destructors have already been checked and marked used. + // Skip checking them again to avoid duplicate diagnostics. + if (Context.getTargetInfo().getCXXABI().isMicrosoft()) { + CXXDestructorDecl *Dtor = ClassDecl->getDestructor(); + if (Dtor && Dtor->isUsed()) + VisitVirtualBases = false; + } + + llvm::SmallPtrSet DirectVirtualBases; + + // Bases. + for (const auto &Base : ClassDecl->bases()) { + const RecordType *RT = Base.getType()->getAs(); + if (!RT) + continue; + + // Remember direct virtual bases. + if (Base.isVirtual()) { + if (!VisitVirtualBases) + continue; + DirectVirtualBases.insert(RT); + } + + CXXRecordDecl *BaseClassDecl = cast(RT->getDecl()); + // If our base class is invalid, we probably can't get its dtor anyway. + if (BaseClassDecl->isInvalidDecl()) + continue; + if (BaseClassDecl->hasIrrelevantDestructor()) + continue; + + CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl); + // Dtor might still be missing, e.g because it's invalid. + if (!Dtor) + continue; + + // FIXME: caret should be on the start of the class name + CheckDestructorAccess(Base.getBeginLoc(), Dtor, + PDiag(diag::err_access_dtor_base) + << Base.getType() << Base.getSourceRange(), + Context.getTypeDeclType(ClassDecl)); + + MarkFunctionReferenced(Location, Dtor); + DiagnoseUseOfDecl(Dtor, Location); + } + + if (VisitVirtualBases) + MarkVirtualBaseDestructorsReferenced(Location, ClassDecl, + &DirectVirtualBases); + } + + void Sema::MarkVirtualBaseDestructorsReferenced( + SourceLocation Location, CXXRecordDecl *ClassDecl, + llvm::SmallPtrSetImpl *DirectVirtualBases) { + // Virtual bases. + for (const auto &VBase : ClassDecl->vbases()) { + // Bases are always records in a well-formed non-dependent class. + const RecordType *RT = VBase.getType()->castAs(); + + // Ignore already visited direct virtual bases. + if (DirectVirtualBases && DirectVirtualBases->count(RT)) + continue; + + CXXRecordDecl *BaseClassDecl = cast(RT->getDecl()); + // If our base class is invalid, we probably can't get its dtor anyway. + if (BaseClassDecl->isInvalidDecl()) + continue; + if (BaseClassDecl->hasIrrelevantDestructor()) + continue; + + CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl); + // Dtor might still be missing, e.g because it's invalid. + if (!Dtor) + continue; + if (CheckDestructorAccess( + ClassDecl->getLocation(), Dtor, + PDiag(diag::err_access_dtor_vbase) + << Context.getTypeDeclType(ClassDecl) << VBase.getType(), + Context.getTypeDeclType(ClassDecl)) == + AR_accessible) { + CheckDerivedToBaseConversion( + Context.getTypeDeclType(ClassDecl), VBase.getType(), + diag::err_access_dtor_vbase, 0, ClassDecl->getLocation(), + SourceRange(), DeclarationName(), nullptr); + } + + MarkFunctionReferenced(Location, Dtor); + DiagnoseUseOfDecl(Dtor, Location); + } + } + + void Sema::ActOnDefaultCtorInitializers(Decl *CDtorDecl) { + if (!CDtorDecl) + return; + + if (CXXConstructorDecl *Constructor + = dyn_cast(CDtorDecl)) { + SetCtorInitializers(Constructor, /*AnyErrors=*/false); + DiagnoseUninitializedFields(*this, Constructor); + } + } + + bool Sema::isAbstractType(SourceLocation Loc, QualType T) { + if (!getLangOpts().CPlusPlus) + return false; + + const auto *RD = Context.getBaseElementType(T)->getAsCXXRecordDecl(); + if (!RD) + return false; + + // FIXME: Per [temp.inst]p1, we are supposed to trigger instantiation of a + // class template specialization here, but doing so breaks a lot of code. + + // We can't answer whether something is abstract until it has a + // definition. If it's currently being defined, we'll walk back + // over all the declarations when we have a full definition. + const CXXRecordDecl *Def = RD->getDefinition(); + if (!Def || Def->isBeingDefined()) + return false; + + return RD->isAbstract(); + } + + bool Sema::RequireNonAbstractType(SourceLocation Loc, QualType T, + TypeDiagnoser &Diagnoser) { + if (!isAbstractType(Loc, T)) + return false; + + T = Context.getBaseElementType(T); + Diagnoser.diagnose(*this, Loc, T); + DiagnoseAbstractType(T->getAsCXXRecordDecl()); + return true; + } + + void Sema::DiagnoseAbstractType(const CXXRecordDecl *RD) { + // Check if we've already emitted the list of pure virtual functions + // for this class. + if (PureVirtualClassDiagSet && PureVirtualClassDiagSet->count(RD)) + return; + + // If the diagnostic is suppressed, don't emit the notes. We're only + // going to emit them once, so try to attach them to a diagnostic we're + // actually going to show. + if (Diags.isLastDiagnosticIgnored()) + return; + + CXXFinalOverriderMap FinalOverriders; + RD->getFinalOverriders(FinalOverriders); + + // Keep a set of seen pure methods so we won't diagnose the same method + // more than once. + llvm::SmallPtrSet SeenPureMethods; + + for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(), + MEnd = FinalOverriders.end(); + M != MEnd; + ++M) { + for (OverridingMethods::iterator SO = M->second.begin(), + SOEnd = M->second.end(); + SO != SOEnd; ++SO) { + // C++ [class.abstract]p4: + // A class is abstract if it contains or inherits at least one + // pure virtual function for which the final overrider is pure + // virtual. + + // + if (SO->second.size() != 1) + continue; + + if (!SO->second.front().Method->isPure()) + continue; + + if (!SeenPureMethods.insert(SO->second.front().Method).second) + continue; + + Diag(SO->second.front().Method->getLocation(), + diag::note_pure_virtual_function) + << SO->second.front().Method->getDeclName() << RD->getDeclName(); + } + } + + if (!PureVirtualClassDiagSet) + PureVirtualClassDiagSet.reset(new RecordDeclSetTy); + PureVirtualClassDiagSet->insert(RD); + } + + namespace { + struct AbstractUsageInfo { + Sema &S; + CXXRecordDecl *Record; + CanQualType AbstractType; + bool Invalid; + + AbstractUsageInfo(Sema &S, CXXRecordDecl *Record) + : S(S), Record(Record), + AbstractType(S.Context.getCanonicalType( + S.Context.getTypeDeclType(Record))), + Invalid(false) {} + + void DiagnoseAbstractType() { + if (Invalid) return; + S.DiagnoseAbstractType(Record); + Invalid = true; + } + + void CheckType(const NamedDecl *D, TypeLoc TL, Sema::AbstractDiagSelID Sel); + }; + + struct CheckAbstractUsage { + AbstractUsageInfo &Info; + const NamedDecl *Ctx; + + CheckAbstractUsage(AbstractUsageInfo &Info, const NamedDecl *Ctx) + : Info(Info), Ctx(Ctx) {} + + void Visit(TypeLoc TL, Sema::AbstractDiagSelID Sel) { + switch (TL.getTypeLocClass()) { + #define ABSTRACT_TYPELOC(CLASS, PARENT) + #define TYPELOC(CLASS, PARENT) \ + case TypeLoc::CLASS: Check(TL.castAs(), Sel); break; + #include "clang/AST/TypeLocNodes.def" + } + } + + void Check(FunctionProtoTypeLoc TL, Sema::AbstractDiagSelID Sel) { + Visit(TL.getReturnLoc(), Sema::AbstractReturnType); + for (unsigned I = 0, E = TL.getNumParams(); I != E; ++I) { + if (!TL.getParam(I)) + continue; + + TypeSourceInfo *TSI = TL.getParam(I)->getTypeSourceInfo(); + if (TSI) Visit(TSI->getTypeLoc(), Sema::AbstractParamType); + } + } + + void Check(ArrayTypeLoc TL, Sema::AbstractDiagSelID Sel) { + Visit(TL.getElementLoc(), Sema::AbstractArrayType); + } + + void Check(TemplateSpecializationTypeLoc TL, Sema::AbstractDiagSelID Sel) { + // Visit the type parameters from a permissive context. + for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) { + TemplateArgumentLoc TAL = TL.getArgLoc(I); + if (TAL.getArgument().getKind() == TemplateArgument::Type) + if (TypeSourceInfo *TSI = TAL.getTypeSourceInfo()) + Visit(TSI->getTypeLoc(), Sema::AbstractNone); + // TODO: other template argument types? + } + } + + // Visit pointee types from a permissive context. + #define CheckPolymorphic(Type) \ + void Check(Type TL, Sema::AbstractDiagSelID Sel) { \ + Visit(TL.getNextTypeLoc(), Sema::AbstractNone); \ + } + CheckPolymorphic(PointerTypeLoc) + CheckPolymorphic(ReferenceTypeLoc) + CheckPolymorphic(MemberPointerTypeLoc) + CheckPolymorphic(BlockPointerTypeLoc) + CheckPolymorphic(AtomicTypeLoc) + + /// Handle all the types we haven't given a more specific + /// implementation for above. + void Check(TypeLoc TL, Sema::AbstractDiagSelID Sel) { + // Every other kind of type that we haven't called out already + // that has an inner type is either (1) sugar or (2) contains that + // inner type in some way as a subobject. + if (TypeLoc Next = TL.getNextTypeLoc()) + return Visit(Next, Sel); + + // If there's no inner type and we're in a permissive context, + // don't diagnose. + if (Sel == Sema::AbstractNone) return; + + // Check whether the type matches the abstract type. + QualType T = TL.getType(); + if (T->isArrayType()) { + Sel = Sema::AbstractArrayType; + T = Info.S.Context.getBaseElementType(T); + } + CanQualType CT = T->getCanonicalTypeUnqualified().getUnqualifiedType(); + if (CT != Info.AbstractType) return; + + // It matched; do some magic. + // FIXME: These should be at most warnings. See P0929R2, CWG1640, CWG1646. + if (Sel == Sema::AbstractArrayType) { + Info.S.Diag(Ctx->getLocation(), diag::err_array_of_abstract_type) + << T << TL.getSourceRange(); + } else { + Info.S.Diag(Ctx->getLocation(), diag::err_abstract_type_in_decl) + << Sel << T << TL.getSourceRange(); + } + Info.DiagnoseAbstractType(); + } + }; + + void AbstractUsageInfo::CheckType(const NamedDecl *D, TypeLoc TL, + Sema::AbstractDiagSelID Sel) { + CheckAbstractUsage(*this, D).Visit(TL, Sel); + } + + } + + /// Check for invalid uses of an abstract type in a function declaration. + static void CheckAbstractClassUsage(AbstractUsageInfo &Info, + FunctionDecl *FD) { + // No need to do the check on definitions, which require that + // the return/param types be complete. + if (FD->doesThisDeclarationHaveABody()) + return; + + // For safety's sake, just ignore it if we don't have type source + // information. This should never happen for non-implicit methods, + // but... + if (TypeSourceInfo *TSI = FD->getTypeSourceInfo()) + Info.CheckType(FD, TSI->getTypeLoc(), Sema::AbstractNone); + } + + /// Check for invalid uses of an abstract type in a variable0 declaration. + static void CheckAbstractClassUsage(AbstractUsageInfo &Info, + VarDecl *VD) { + // No need to do the check on definitions, which require that + // the type is complete. + if (VD->isThisDeclarationADefinition()) + return; + + Info.CheckType(VD, VD->getTypeSourceInfo()->getTypeLoc(), + Sema::AbstractVariableType); + } + + /// Check for invalid uses of an abstract type within a class definition. + static void CheckAbstractClassUsage(AbstractUsageInfo &Info, + CXXRecordDecl *RD) { + for (auto *D : RD->decls()) { + if (D->isImplicit()) continue; + + // Step through friends to the befriended declaration. + if (auto *FD = dyn_cast(D)) { + D = FD->getFriendDecl(); + if (!D) continue; + } + + // Functions and function templates. + if (auto *FD = dyn_cast(D)) { + CheckAbstractClassUsage(Info, FD); + } else if (auto *FTD = dyn_cast(D)) { + CheckAbstractClassUsage(Info, FTD->getTemplatedDecl()); + + // Fields and static variables. + } else if (auto *FD = dyn_cast(D)) { + if (TypeSourceInfo *TSI = FD->getTypeSourceInfo()) + Info.CheckType(FD, TSI->getTypeLoc(), Sema::AbstractFieldType); + } else if (auto *VD = dyn_cast(D)) { + CheckAbstractClassUsage(Info, VD); + } else if (auto *VTD = dyn_cast(D)) { + CheckAbstractClassUsage(Info, VTD->getTemplatedDecl()); + + // Nested classes and class templates. + } else if (auto *RD = dyn_cast(D)) { + CheckAbstractClassUsage(Info, RD); + } else if (auto *CTD = dyn_cast(D)) { + CheckAbstractClassUsage(Info, CTD->getTemplatedDecl()); + } + } + } + + static void ReferenceDllExportedMembers(Sema &S, CXXRecordDecl *Class) { + Attr *ClassAttr = getDLLAttr(Class); + if (!ClassAttr) + return; + + assert(ClassAttr->getKind() == attr::DLLExport); + + TemplateSpecializationKind TSK = Class->getTemplateSpecializationKind(); + + if (TSK == TSK_ExplicitInstantiationDeclaration) + // Don't go any further if this is just an explicit instantiation + // declaration. + return; + + // Add a context note to explain how we got to any diagnostics produced below. + struct MarkingClassDllexported { + Sema &S; + MarkingClassDllexported(Sema &S, CXXRecordDecl *Class, + SourceLocation AttrLoc) + : S(S) { + Sema::CodeSynthesisContext Ctx; + Ctx.Kind = Sema::CodeSynthesisContext::MarkingClassDllexported; + Ctx.PointOfInstantiation = AttrLoc; + Ctx.Entity = Class; + S.pushCodeSynthesisContext(Ctx); + } + ~MarkingClassDllexported() { + S.popCodeSynthesisContext(); + } + } MarkingDllexportedContext(S, Class, ClassAttr->getLocation()); + + if (S.Context.getTargetInfo().getTriple().isWindowsGNUEnvironment()) + S.MarkVTableUsed(Class->getLocation(), Class, true); + + for (Decl *Member : Class->decls()) { + // Skip members that were not marked exported. + if (!Member->hasAttr()) + continue; + + // Defined static variables that are members of an exported base + // class must be marked export too. + auto *VD = dyn_cast(Member); + if (VD && VD->getStorageClass() == SC_Static && + TSK == TSK_ImplicitInstantiation) + S.MarkVariableReferenced(VD->getLocation(), VD); + + auto *MD = dyn_cast(Member); + if (!MD) + continue; + + if (MD->isUserProvided()) { + // Instantiate non-default class member functions ... + + // .. except for certain kinds of template specializations. + if (TSK == TSK_ImplicitInstantiation && !ClassAttr->isInherited()) + continue; + + // If this is an MS ABI dllexport default constructor, instantiate any + // default arguments. + if (S.Context.getTargetInfo().getCXXABI().isMicrosoft()) { + auto *CD = dyn_cast(MD); + if (CD && CD->isDefaultConstructor() && TSK == TSK_Undeclared) { + S.InstantiateDefaultCtorDefaultArgs(CD); + } + } + + S.MarkFunctionReferenced(Class->getLocation(), MD); + + // The function will be passed to the consumer when its definition is + // encountered. + } else if (MD->isExplicitlyDefaulted()) { + // Synthesize and instantiate explicitly defaulted methods. + S.MarkFunctionReferenced(Class->getLocation(), MD); + + if (TSK != TSK_ExplicitInstantiationDefinition) { + // Except for explicit instantiation defs, we will not see the + // definition again later, so pass it to the consumer now. + S.Consumer.HandleTopLevelDecl(DeclGroupRef(MD)); + } + } else if (!MD->isTrivial() || + MD->isCopyAssignmentOperator() || + MD->isMoveAssignmentOperator()) { + // Synthesize and instantiate non-trivial implicit methods, and the copy + // and move assignment operators. The latter are exported even if they + // are trivial, because the address of an operator can be taken and + // should compare equal across libraries. + S.MarkFunctionReferenced(Class->getLocation(), MD); + + // There is no later point when we will see the definition of this + // function, so pass it to the consumer now. + S.Consumer.HandleTopLevelDecl(DeclGroupRef(MD)); + } + } + } + + static void checkForMultipleExportedDefaultConstructors(Sema &S, + CXXRecordDecl *Class) { + // Only the MS ABI has default constructor closures, so we don't need to do + // this semantic checking anywhere else. + if (!S.Context.getTargetInfo().getCXXABI().isMicrosoft()) + return; + + CXXConstructorDecl *LastExportedDefaultCtor = nullptr; + for (Decl *Member : Class->decls()) { + // Look for exported default constructors. + auto *CD = dyn_cast(Member); + if (!CD || !CD->isDefaultConstructor()) + continue; + auto *Attr = CD->getAttr(); + if (!Attr) + continue; + + // If the class is non-dependent, mark the default arguments as ODR-used so + // that we can properly codegen the constructor closure. + if (!Class->isDependentContext()) { + for (ParmVarDecl *PD : CD->parameters()) { + (void)S.CheckCXXDefaultArgExpr(Attr->getLocation(), CD, PD); + S.DiscardCleanupsInEvaluationContext(); + } + } + + if (LastExportedDefaultCtor) { + S.Diag(LastExportedDefaultCtor->getLocation(), + diag::err_attribute_dll_ambiguous_default_ctor) + << Class; + S.Diag(CD->getLocation(), diag::note_entity_declared_at) + << CD->getDeclName(); + return; + } + LastExportedDefaultCtor = CD; + } + } + + static void checkCUDADeviceBuiltinSurfaceClassTemplate(Sema &S, + CXXRecordDecl *Class) { + bool ErrorReported = false; + auto reportIllegalClassTemplate = [&ErrorReported](Sema &S, + ClassTemplateDecl *TD) { + if (ErrorReported) + return; + S.Diag(TD->getLocation(), + diag::err_cuda_device_builtin_surftex_cls_template) + << /*surface*/ 0 << TD; + ErrorReported = true; + }; + + ClassTemplateDecl *TD = Class->getDescribedClassTemplate(); + if (!TD) { + auto *SD = dyn_cast(Class); + if (!SD) { + S.Diag(Class->getLocation(), + diag::err_cuda_device_builtin_surftex_ref_decl) + << /*surface*/ 0 << Class; + S.Diag(Class->getLocation(), + diag::note_cuda_device_builtin_surftex_should_be_template_class) + << Class; + return; + } + TD = SD->getSpecializedTemplate(); + } + + TemplateParameterList *Params = TD->getTemplateParameters(); + unsigned N = Params->size(); + + if (N != 2) { + reportIllegalClassTemplate(S, TD); + S.Diag(TD->getLocation(), + diag::note_cuda_device_builtin_surftex_cls_should_have_n_args) + << TD << 2; + } + if (N > 0 && !isa(Params->getParam(0))) { + reportIllegalClassTemplate(S, TD); + S.Diag(TD->getLocation(), + diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg) + << TD << /*1st*/ 0 << /*type*/ 0; + } + if (N > 1) { + auto *NTTP = dyn_cast(Params->getParam(1)); + if (!NTTP || !NTTP->getType()->isIntegralOrEnumerationType()) { + reportIllegalClassTemplate(S, TD); + S.Diag(TD->getLocation(), + diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg) + << TD << /*2nd*/ 1 << /*integer*/ 1; + } + } + } + + static void checkCUDADeviceBuiltinTextureClassTemplate(Sema &S, + CXXRecordDecl *Class) { + bool ErrorReported = false; + auto reportIllegalClassTemplate = [&ErrorReported](Sema &S, + ClassTemplateDecl *TD) { + if (ErrorReported) + return; + S.Diag(TD->getLocation(), + diag::err_cuda_device_builtin_surftex_cls_template) + << /*texture*/ 1 << TD; + ErrorReported = true; + }; + + ClassTemplateDecl *TD = Class->getDescribedClassTemplate(); + if (!TD) { + auto *SD = dyn_cast(Class); + if (!SD) { + S.Diag(Class->getLocation(), + diag::err_cuda_device_builtin_surftex_ref_decl) + << /*texture*/ 1 << Class; + S.Diag(Class->getLocation(), + diag::note_cuda_device_builtin_surftex_should_be_template_class) + << Class; + return; + } + TD = SD->getSpecializedTemplate(); + } + + TemplateParameterList *Params = TD->getTemplateParameters(); + unsigned N = Params->size(); + + if (N != 3) { + reportIllegalClassTemplate(S, TD); + S.Diag(TD->getLocation(), + diag::note_cuda_device_builtin_surftex_cls_should_have_n_args) + << TD << 3; + } + if (N > 0 && !isa(Params->getParam(0))) { + reportIllegalClassTemplate(S, TD); + S.Diag(TD->getLocation(), + diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg) + << TD << /*1st*/ 0 << /*type*/ 0; + } + if (N > 1) { + auto *NTTP = dyn_cast(Params->getParam(1)); + if (!NTTP || !NTTP->getType()->isIntegralOrEnumerationType()) { + reportIllegalClassTemplate(S, TD); + S.Diag(TD->getLocation(), + diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg) + << TD << /*2nd*/ 1 << /*integer*/ 1; + } + } + if (N > 2) { + auto *NTTP = dyn_cast(Params->getParam(2)); + if (!NTTP || !NTTP->getType()->isIntegralOrEnumerationType()) { + reportIllegalClassTemplate(S, TD); + S.Diag(TD->getLocation(), + diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg) + << TD << /*3rd*/ 2 << /*integer*/ 1; + } + } + } + + void Sema::checkClassLevelCodeSegAttribute(CXXRecordDecl *Class) { + // Mark any compiler-generated routines with the implicit code_seg attribute. + for (auto *Method : Class->methods()) { + if (Method->isUserProvided()) + continue; + if (Attr *A = getImplicitCodeSegOrSectionAttrForFunction(Method, /*IsDefinition=*/true)) + Method->addAttr(A); + } + } + + /// Check class-level dllimport/dllexport attribute. + void Sema::checkClassLevelDLLAttribute(CXXRecordDecl *Class) { + Attr *ClassAttr = getDLLAttr(Class); + + // MSVC inherits DLL attributes to partial class template specializations. + if (Context.getTargetInfo().shouldDLLImportComdatSymbols() && !ClassAttr) { + if (auto *Spec = dyn_cast(Class)) { + if (Attr *TemplateAttr = + getDLLAttr(Spec->getSpecializedTemplate()->getTemplatedDecl())) { + auto *A = cast(TemplateAttr->clone(getASTContext())); + A->setInherited(true); + ClassAttr = A; + } + } + } + + if (!ClassAttr) + return; + + // MSVC allows imported or exported template classes that have UniqueExternal + // linkage. This occurs when the template class has been instantiated with + // a template parameter which itself has internal linkage. + // We drop the attribute to avoid exporting or importing any members. + if ((Context.getTargetInfo().getCXXABI().isMicrosoft() || + Context.getTargetInfo().getTriple().isPS()) && + (!Class->isExternallyVisible() && Class->hasExternalFormalLinkage())) { + Class->dropAttr(); + Class->dropAttr(); + return; + } + + if (!Class->isExternallyVisible()) { + Diag(Class->getLocation(), diag::err_attribute_dll_not_extern) + << Class << ClassAttr; + return; + } + + if (Context.getTargetInfo().shouldDLLImportComdatSymbols() && + !ClassAttr->isInherited()) { + // Diagnose dll attributes on members of class with dll attribute. + for (Decl *Member : Class->decls()) { + if (!isa(Member) && !isa(Member)) + continue; + InheritableAttr *MemberAttr = getDLLAttr(Member); + if (!MemberAttr || MemberAttr->isInherited() || Member->isInvalidDecl()) + continue; + + Diag(MemberAttr->getLocation(), + diag::err_attribute_dll_member_of_dll_class) + << MemberAttr << ClassAttr; + Diag(ClassAttr->getLocation(), diag::note_previous_attribute); + Member->setInvalidDecl(); + } + } + + if (Class->getDescribedClassTemplate()) + // Don't inherit dll attribute until the template is instantiated. + return; + + // The class is either imported or exported. + const bool ClassExported = ClassAttr->getKind() == attr::DLLExport; + + // Check if this was a dllimport attribute propagated from a derived class to + // a base class template specialization. We don't apply these attributes to + // static data members. + const bool PropagatedImport = + !ClassExported && + cast(ClassAttr)->wasPropagatedToBaseTemplate(); + + TemplateSpecializationKind TSK = Class->getTemplateSpecializationKind(); + + // Ignore explicit dllexport on explicit class template instantiation + // declarations, except in MinGW mode. + if (ClassExported && !ClassAttr->isInherited() && + TSK == TSK_ExplicitInstantiationDeclaration && + !Context.getTargetInfo().getTriple().isWindowsGNUEnvironment()) { + Class->dropAttr(); + return; + } + + // Force declaration of implicit members so they can inherit the attribute. + ForceDeclarationOfImplicitMembers(Class); + + // FIXME: MSVC's docs say all bases must be exportable, but this doesn't + // seem to be true in practice? + + for (Decl *Member : Class->decls()) { + VarDecl *VD = dyn_cast(Member); + CXXMethodDecl *MD = dyn_cast(Member); + + // Only methods and static fields inherit the attributes. + if (!VD && !MD) + continue; + + if (MD) { + // Don't process deleted methods. + if (MD->isDeleted()) + continue; + + if (MD->isInlined()) { + // MinGW does not import or export inline methods. But do it for + // template instantiations. + if (!Context.getTargetInfo().shouldDLLImportComdatSymbols() && + TSK != TSK_ExplicitInstantiationDeclaration && + TSK != TSK_ExplicitInstantiationDefinition) + continue; + + // MSVC versions before 2015 don't export the move assignment operators + // and move constructor, so don't attempt to import/export them if + // we have a definition. + auto *Ctor = dyn_cast(MD); + if ((MD->isMoveAssignmentOperator() || + (Ctor && Ctor->isMoveConstructor())) && + !getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015)) + continue; + + // MSVC2015 doesn't export trivial defaulted x-tor but copy assign + // operator is exported anyway. + if (getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) && + (Ctor || isa(MD)) && MD->isTrivial()) + continue; + } + } + + // Don't apply dllimport attributes to static data members of class template + // instantiations when the attribute is propagated from a derived class. + if (VD && PropagatedImport) + continue; + + if (!cast(Member)->isExternallyVisible()) + continue; + + if (!getDLLAttr(Member)) { + InheritableAttr *NewAttr = nullptr; + + // Do not export/import inline function when -fno-dllexport-inlines is + // passed. But add attribute for later local static var check. + if (!getLangOpts().DllExportInlines && MD && MD->isInlined() && + TSK != TSK_ExplicitInstantiationDeclaration && + TSK != TSK_ExplicitInstantiationDefinition) { + if (ClassExported) { + NewAttr = ::new (getASTContext()) + DLLExportStaticLocalAttr(getASTContext(), *ClassAttr); + } else { + NewAttr = ::new (getASTContext()) + DLLImportStaticLocalAttr(getASTContext(), *ClassAttr); + } + } else { + NewAttr = cast(ClassAttr->clone(getASTContext())); + } + + NewAttr->setInherited(true); + Member->addAttr(NewAttr); + + if (MD) { + // Propagate DLLAttr to friend re-declarations of MD that have already + // been constructed. + for (FunctionDecl *FD = MD->getMostRecentDecl(); FD; + FD = FD->getPreviousDecl()) { + if (FD->getFriendObjectKind() == Decl::FOK_None) + continue; + assert(!getDLLAttr(FD) && + "friend re-decl should not already have a DLLAttr"); + NewAttr = cast(ClassAttr->clone(getASTContext())); + NewAttr->setInherited(true); + FD->addAttr(NewAttr); + } + } + } + } + + if (ClassExported) + DelayedDllExportClasses.push_back(Class); + } + + /// Perform propagation of DLL attributes from a derived class to a + /// templated base class for MS compatibility. + void Sema::propagateDLLAttrToBaseClassTemplate( + CXXRecordDecl *Class, Attr *ClassAttr, + ClassTemplateSpecializationDecl *BaseTemplateSpec, SourceLocation BaseLoc) { + if (getDLLAttr( + BaseTemplateSpec->getSpecializedTemplate()->getTemplatedDecl())) { + // If the base class template has a DLL attribute, don't try to change it. + return; + } + + auto TSK = BaseTemplateSpec->getSpecializationKind(); + if (!getDLLAttr(BaseTemplateSpec) && + (TSK == TSK_Undeclared || TSK == TSK_ExplicitInstantiationDeclaration || + TSK == TSK_ImplicitInstantiation)) { + // The template hasn't been instantiated yet (or it has, but only as an + // explicit instantiation declaration or implicit instantiation, which means + // we haven't codegenned any members yet), so propagate the attribute. + auto *NewAttr = cast(ClassAttr->clone(getASTContext())); + NewAttr->setInherited(true); + BaseTemplateSpec->addAttr(NewAttr); + + // If this was an import, mark that we propagated it from a derived class to + // a base class template specialization. + if (auto *ImportAttr = dyn_cast(NewAttr)) + ImportAttr->setPropagatedToBaseTemplate(); + + // If the template is already instantiated, checkDLLAttributeRedeclaration() + // needs to be run again to work see the new attribute. Otherwise this will + // get run whenever the template is instantiated. + if (TSK != TSK_Undeclared) + checkClassLevelDLLAttribute(BaseTemplateSpec); + + return; + } + + if (getDLLAttr(BaseTemplateSpec)) { + // The template has already been specialized or instantiated with an + // attribute, explicitly or through propagation. We should not try to change + // it. + return; + } + + // The template was previously instantiated or explicitly specialized without + // a dll attribute, It's too late for us to add an attribute, so warn that + // this is unsupported. + Diag(BaseLoc, diag::warn_attribute_dll_instantiated_base_class) + << BaseTemplateSpec->isExplicitSpecialization(); + Diag(ClassAttr->getLocation(), diag::note_attribute); + if (BaseTemplateSpec->isExplicitSpecialization()) { + Diag(BaseTemplateSpec->getLocation(), + diag::note_template_class_explicit_specialization_was_here) + << BaseTemplateSpec; + } else { + Diag(BaseTemplateSpec->getPointOfInstantiation(), + diag::note_template_class_instantiation_was_here) + << BaseTemplateSpec; + } + } + + /// Determine the kind of defaulting that would be done for a given function. + /// + /// If the function is both a default constructor and a copy / move constructor + /// (due to having a default argument for the first parameter), this picks + /// CXXDefaultConstructor. + /// + /// FIXME: Check that case is properly handled by all callers. + Sema::DefaultedFunctionKind + Sema::getDefaultedFunctionKind(const FunctionDecl *FD) { + if (auto *MD = dyn_cast(FD)) { + if (const CXXConstructorDecl *Ctor = dyn_cast(FD)) { + if (Ctor->isDefaultConstructor()) + return Sema::CXXDefaultConstructor; + + if (Ctor->isCopyConstructor()) + return Sema::CXXCopyConstructor; + + if (Ctor->isMoveConstructor()) + return Sema::CXXMoveConstructor; + } + + if (MD->isCopyAssignmentOperator()) + return Sema::CXXCopyAssignment; + + if (MD->isMoveAssignmentOperator()) + return Sema::CXXMoveAssignment; + + if (isa(FD)) + return Sema::CXXDestructor; + } + + switch (FD->getDeclName().getCXXOverloadedOperator()) { + case OO_EqualEqual: + return DefaultedComparisonKind::Equal; + + case OO_ExclaimEqual: + return DefaultedComparisonKind::NotEqual; + + case OO_Spaceship: + // No point allowing this if <=> doesn't exist in the current language mode. + if (!getLangOpts().CPlusPlus20) + break; + return DefaultedComparisonKind::ThreeWay; + + case OO_Less: + case OO_LessEqual: + case OO_Greater: + case OO_GreaterEqual: + // No point allowing this if <=> doesn't exist in the current language mode. + if (!getLangOpts().CPlusPlus20) + break; + return DefaultedComparisonKind::Relational; + + default: + break; + } + + // Not defaultable. + return DefaultedFunctionKind(); + } + + static void DefineDefaultedFunction(Sema &S, FunctionDecl *FD, + SourceLocation DefaultLoc) { + Sema::DefaultedFunctionKind DFK = S.getDefaultedFunctionKind(FD); + if (DFK.isComparison()) + return S.DefineDefaultedComparison(DefaultLoc, FD, DFK.asComparison()); + + switch (DFK.asSpecialMember()) { + case Sema::CXXDefaultConstructor: + S.DefineImplicitDefaultConstructor(DefaultLoc, + cast(FD)); + break; + case Sema::CXXCopyConstructor: + S.DefineImplicitCopyConstructor(DefaultLoc, cast(FD)); + break; + case Sema::CXXCopyAssignment: + S.DefineImplicitCopyAssignment(DefaultLoc, cast(FD)); + break; + case Sema::CXXDestructor: + S.DefineImplicitDestructor(DefaultLoc, cast(FD)); + break; + case Sema::CXXMoveConstructor: + S.DefineImplicitMoveConstructor(DefaultLoc, cast(FD)); + break; + case Sema::CXXMoveAssignment: + S.DefineImplicitMoveAssignment(DefaultLoc, cast(FD)); + break; + case Sema::CXXInvalid: + llvm_unreachable("Invalid special member."); + } + } + + /// Determine whether a type is permitted to be passed or returned in + /// registers, per C++ [class.temporary]p3. + static bool canPassInRegisters(Sema &S, CXXRecordDecl *D, + TargetInfo::CallingConvKind CCK) { + if (D->isDependentType() || D->isInvalidDecl()) + return false; + + // Clang <= 4 used the pre-C++11 rule, which ignores move operations. + // The PS4 platform ABI follows the behavior of Clang 3.2. + if (CCK == TargetInfo::CCK_ClangABI4OrPS4) + return !D->hasNonTrivialDestructorForCall() && + !D->hasNonTrivialCopyConstructorForCall(); + + if (CCK == TargetInfo::CCK_MicrosoftWin64) { + bool CopyCtorIsTrivial = false, CopyCtorIsTrivialForCall = false; + bool DtorIsTrivialForCall = false; + + // If a class has at least one eligible, trivial copy constructor, it + // is passed according to the C ABI. Otherwise, it is passed indirectly. + // + // Note: This permits classes with non-trivial copy or move ctors to be + // passed in registers, so long as they *also* have a trivial copy ctor, + // which is non-conforming. + if (D->needsImplicitCopyConstructor()) { + if (!D->defaultedCopyConstructorIsDeleted()) { + if (D->hasTrivialCopyConstructor()) + CopyCtorIsTrivial = true; + if (D->hasTrivialCopyConstructorForCall()) + CopyCtorIsTrivialForCall = true; + } + } else { + for (const CXXConstructorDecl *CD : D->ctors()) { + if (CD->isCopyConstructor() && !CD->isDeleted() && + !CD->isIneligibleOrNotSelected()) { + if (CD->isTrivial()) + CopyCtorIsTrivial = true; + if (CD->isTrivialForCall()) + CopyCtorIsTrivialForCall = true; + } + } + } + + if (D->needsImplicitDestructor()) { + if (!D->defaultedDestructorIsDeleted() && + D->hasTrivialDestructorForCall()) + DtorIsTrivialForCall = true; + } else if (const auto *DD = D->getDestructor()) { + if (!DD->isDeleted() && DD->isTrivialForCall()) + DtorIsTrivialForCall = true; + } + + // If the copy ctor and dtor are both trivial-for-calls, pass direct. + if (CopyCtorIsTrivialForCall && DtorIsTrivialForCall) + return true; + + // If a class has a destructor, we'd really like to pass it indirectly + // because it allows us to elide copies. Unfortunately, MSVC makes that + // impossible for small types, which it will pass in a single register or + // stack slot. Most objects with dtors are large-ish, so handle that early. + // We can't call out all large objects as being indirect because there are + // multiple x64 calling conventions and the C++ ABI code shouldn't dictate + // how we pass large POD types. + + // Note: This permits small classes with nontrivial destructors to be + // passed in registers, which is non-conforming. + bool isAArch64 = S.Context.getTargetInfo().getTriple().isAArch64(); + uint64_t TypeSize = isAArch64 ? 128 : 64; + + if (CopyCtorIsTrivial && + S.getASTContext().getTypeSize(D->getTypeForDecl()) <= TypeSize) + return true; + return false; + } + + // Per C++ [class.temporary]p3, the relevant condition is: + // each copy constructor, move constructor, and destructor of X is + // either trivial or deleted, and X has at least one non-deleted copy + // or move constructor + bool HasNonDeletedCopyOrMove = false; + + if (D->needsImplicitCopyConstructor() && + !D->defaultedCopyConstructorIsDeleted()) { + if (!D->hasTrivialCopyConstructorForCall()) + return false; + HasNonDeletedCopyOrMove = true; + } + + if (S.getLangOpts().CPlusPlus11 && D->needsImplicitMoveConstructor() && + !D->defaultedMoveConstructorIsDeleted()) { + if (!D->hasTrivialMoveConstructorForCall()) + return false; + HasNonDeletedCopyOrMove = true; + } + + if (D->needsImplicitDestructor() && !D->defaultedDestructorIsDeleted() && + !D->hasTrivialDestructorForCall()) + return false; + + for (const CXXMethodDecl *MD : D->methods()) { + if (MD->isDeleted() || MD->isIneligibleOrNotSelected()) + continue; + + auto *CD = dyn_cast(MD); + if (CD && CD->isCopyOrMoveConstructor()) + HasNonDeletedCopyOrMove = true; + else if (!isa(MD)) + continue; + + if (!MD->isTrivialForCall()) + return false; + } + + return HasNonDeletedCopyOrMove; + } + + /// Report an error regarding overriding, along with any relevant + /// overridden methods. + /// + /// \param DiagID the primary error to report. + /// \param MD the overriding method. + static bool + ReportOverrides(Sema &S, unsigned DiagID, const CXXMethodDecl *MD, + llvm::function_ref Report) { + bool IssuedDiagnostic = false; + for (const CXXMethodDecl *O : MD->overridden_methods()) { + if (Report(O)) { + if (!IssuedDiagnostic) { + S.Diag(MD->getLocation(), DiagID) << MD->getDeclName(); + IssuedDiagnostic = true; + } + S.Diag(O->getLocation(), diag::note_overridden_virtual_function); + } + } + return IssuedDiagnostic; + } + + /// Perform semantic checks on a class definition that has been + /// completing, introducing implicitly-declared members, checking for + /// abstract types, etc. + /// + /// \param S The scope in which the class was parsed. Null if we didn't just + /// parse a class definition. + /// \param Record The completed class. + void Sema::CheckCompletedCXXClass(Scope *S, CXXRecordDecl *Record) { + if (!Record) + return; + + if (Record->isAbstract() && !Record->isInvalidDecl()) { + AbstractUsageInfo Info(*this, Record); + CheckAbstractClassUsage(Info, Record); + } + + // If this is not an aggregate type and has no user-declared constructor, + // complain about any non-static data members of reference or const scalar + // type, since they will never get initializers. + if (!Record->isInvalidDecl() && !Record->isDependentType() && + !Record->isAggregate() && !Record->hasUserDeclaredConstructor() && + !Record->isLambda()) { + bool Complained = false; + for (const auto *F : Record->fields()) { + if (F->hasInClassInitializer() || F->isUnnamedBitfield()) + continue; + + if (F->getType()->isReferenceType() || + (F->getType().isConstQualified() && F->getType()->isScalarType())) { + if (!Complained) { + Diag(Record->getLocation(), diag::warn_no_constructor_for_refconst) + << Record->getTagKind() << Record; + Complained = true; + } + + Diag(F->getLocation(), diag::note_refconst_member_not_initialized) + << F->getType()->isReferenceType() + << F->getDeclName(); + } + } + } + + if (Record->getIdentifier()) { + // C++ [class.mem]p13: + // If T is the name of a class, then each of the following shall have a + // name different from T: + // - every member of every anonymous union that is a member of class T. + // + // C++ [class.mem]p14: + // In addition, if class T has a user-declared constructor (12.1), every + // non-static data member of class T shall have a name different from T. + DeclContext::lookup_result R = Record->lookup(Record->getDeclName()); + for (DeclContext::lookup_iterator I = R.begin(), E = R.end(); I != E; + ++I) { + NamedDecl *D = (*I)->getUnderlyingDecl(); + if (((isa(D) || isa(D)) && + Record->hasUserDeclaredConstructor()) || + isa(D)) { + Diag((*I)->getLocation(), diag::err_member_name_of_class) + << D->getDeclName(); + break; + } + } + } + + // Warn if the class has virtual methods but non-virtual public destructor. + if (Record->isPolymorphic() && !Record->isDependentType()) { + CXXDestructorDecl *dtor = Record->getDestructor(); + if ((!dtor || (!dtor->isVirtual() && dtor->getAccess() == AS_public)) && + !Record->hasAttr()) + Diag(dtor ? dtor->getLocation() : Record->getLocation(), + diag::warn_non_virtual_dtor) << Context.getRecordType(Record); + } + + if (Record->isAbstract()) { + if (FinalAttr *FA = Record->getAttr()) { + Diag(Record->getLocation(), diag::warn_abstract_final_class) + << FA->isSpelledAsSealed(); + DiagnoseAbstractType(Record); + } + } + + // Warn if the class has a final destructor but is not itself marked final. + if (!Record->hasAttr()) { + if (const CXXDestructorDecl *dtor = Record->getDestructor()) { + if (const FinalAttr *FA = dtor->getAttr()) { + Diag(FA->getLocation(), diag::warn_final_dtor_non_final_class) + << FA->isSpelledAsSealed() + << FixItHint::CreateInsertion( + getLocForEndOfToken(Record->getLocation()), + (FA->isSpelledAsSealed() ? " sealed" : " final")); + Diag(Record->getLocation(), + diag::note_final_dtor_non_final_class_silence) + << Context.getRecordType(Record) << FA->isSpelledAsSealed(); + } + } + } + + // See if trivial_abi has to be dropped. + if (Record->hasAttr()) + checkIllFormedTrivialABIStruct(*Record); + + // Set HasTrivialSpecialMemberForCall if the record has attribute + // "trivial_abi". + bool HasTrivialABI = Record->hasAttr(); + + if (HasTrivialABI) + Record->setHasTrivialSpecialMemberForCall(); + + // Explicitly-defaulted secondary comparison functions (!=, <, <=, >, >=). + // We check these last because they can depend on the properties of the + // primary comparison functions (==, <=>). + llvm::SmallVector DefaultedSecondaryComparisons; + + // Perform checks that can't be done until we know all the properties of a + // member function (whether it's defaulted, deleted, virtual, overriding, + // ...). + auto CheckCompletedMemberFunction = [&](CXXMethodDecl *MD) { + // A static function cannot override anything. + if (MD->getStorageClass() == SC_Static) { + if (ReportOverrides(*this, diag::err_static_overrides_virtual, MD, + [](const CXXMethodDecl *) { return true; })) + return; + } + + // A deleted function cannot override a non-deleted function and vice + // versa. + if (ReportOverrides(*this, + MD->isDeleted() ? diag::err_deleted_override + : diag::err_non_deleted_override, + MD, [&](const CXXMethodDecl *V) { + return MD->isDeleted() != V->isDeleted(); + })) { + if (MD->isDefaulted() && MD->isDeleted()) + // Explain why this defaulted function was deleted. + DiagnoseDeletedDefaultedFunction(MD); + return; + } + + // A consteval function cannot override a non-consteval function and vice + // versa. + if (ReportOverrides(*this, + MD->isConsteval() ? diag::err_consteval_override + : diag::err_non_consteval_override, + MD, [&](const CXXMethodDecl *V) { + return MD->isConsteval() != V->isConsteval(); + })) { + if (MD->isDefaulted() && MD->isDeleted()) + // Explain why this defaulted function was deleted. + DiagnoseDeletedDefaultedFunction(MD); + return; + } + }; + + auto CheckForDefaultedFunction = [&](FunctionDecl *FD) -> bool { + if (!FD || FD->isInvalidDecl() || !FD->isExplicitlyDefaulted()) + return false; + + DefaultedFunctionKind DFK = getDefaultedFunctionKind(FD); + if (DFK.asComparison() == DefaultedComparisonKind::NotEqual || + DFK.asComparison() == DefaultedComparisonKind::Relational) { + DefaultedSecondaryComparisons.push_back(FD); + return true; + } + + CheckExplicitlyDefaultedFunction(S, FD); + return false; + }; + + auto CompleteMemberFunction = [&](CXXMethodDecl *M) { + // Check whether the explicitly-defaulted members are valid. + bool Incomplete = CheckForDefaultedFunction(M); + + // Skip the rest of the checks for a member of a dependent class. + if (Record->isDependentType()) + return; + + // For an explicitly defaulted or deleted special member, we defer + // determining triviality until the class is complete. That time is now! + CXXSpecialMember CSM = getSpecialMember(M); + if (!M->isImplicit() && !M->isUserProvided()) { + if (CSM != CXXInvalid) { + M->setTrivial(SpecialMemberIsTrivial(M, CSM)); + // Inform the class that we've finished declaring this member. + Record->finishedDefaultedOrDeletedMember(M); + M->setTrivialForCall( + HasTrivialABI || + SpecialMemberIsTrivial(M, CSM, TAH_ConsiderTrivialABI)); + Record->setTrivialForCallFlags(M); + } + } + + // Set triviality for the purpose of calls if this is a user-provided + // copy/move constructor or destructor. + if ((CSM == CXXCopyConstructor || CSM == CXXMoveConstructor || + CSM == CXXDestructor) && M->isUserProvided()) { + M->setTrivialForCall(HasTrivialABI); + Record->setTrivialForCallFlags(M); + } + + if (!M->isInvalidDecl() && M->isExplicitlyDefaulted() && + M->hasAttr()) { + if (getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) && + M->isTrivial() && + (CSM == CXXDefaultConstructor || CSM == CXXCopyConstructor || + CSM == CXXDestructor)) + M->dropAttr(); + + if (M->hasAttr()) { + // Define after any fields with in-class initializers have been parsed. + DelayedDllExportMemberFunctions.push_back(M); + } + } + + // Define defaulted constexpr virtual functions that override a base class + // function right away. + // FIXME: We can defer doing this until the vtable is marked as used. + if (CSM != CXXInvalid && !M->isDeleted() && M->isDefaulted() && + M->isConstexpr() && M->size_overridden_methods()) + DefineDefaultedFunction(*this, M, M->getLocation()); + + if (!Incomplete) + CheckCompletedMemberFunction(M); + }; + + // Check the destructor before any other member function. We need to + // determine whether it's trivial in order to determine whether the claas + // type is a literal type, which is a prerequisite for determining whether + // other special member functions are valid and whether they're implicitly + // 'constexpr'. + if (CXXDestructorDecl *Dtor = Record->getDestructor()) + CompleteMemberFunction(Dtor); + + bool HasMethodWithOverrideControl = false, + HasOverridingMethodWithoutOverrideControl = false; + for (auto *D : Record->decls()) { + if (auto *M = dyn_cast(D)) { + // FIXME: We could do this check for dependent types with non-dependent + // bases. + if (!Record->isDependentType()) { + // See if a method overloads virtual methods in a base + // class without overriding any. + if (!M->isStatic()) + DiagnoseHiddenVirtualMethods(M); + if (M->hasAttr()) + HasMethodWithOverrideControl = true; + else if (M->size_overridden_methods() > 0) + HasOverridingMethodWithoutOverrideControl = true; + } + + if (!isa(M)) + CompleteMemberFunction(M); + } else if (auto *F = dyn_cast(D)) { + CheckForDefaultedFunction( + dyn_cast_or_null(F->getFriendDecl())); + } + } + + if (HasOverridingMethodWithoutOverrideControl) { + bool HasInconsistentOverrideControl = HasMethodWithOverrideControl; + for (auto *M : Record->methods()) + DiagnoseAbsenceOfOverrideControl(M, HasInconsistentOverrideControl); + } + + // Check the defaulted secondary comparisons after any other member functions. + for (FunctionDecl *FD : DefaultedSecondaryComparisons) { + CheckExplicitlyDefaultedFunction(S, FD); + + // If this is a member function, we deferred checking it until now. + if (auto *MD = dyn_cast(FD)) + CheckCompletedMemberFunction(MD); + } + + // ms_struct is a request to use the same ABI rules as MSVC. Check + // whether this class uses any C++ features that are implemented + // completely differently in MSVC, and if so, emit a diagnostic. + // That diagnostic defaults to an error, but we allow projects to + // map it down to a warning (or ignore it). It's a fairly common + // practice among users of the ms_struct pragma to mass-annotate + // headers, sweeping up a bunch of types that the project doesn't + // really rely on MSVC-compatible layout for. We must therefore + // support "ms_struct except for C++ stuff" as a secondary ABI. + // Don't emit this diagnostic if the feature was enabled as a + // language option (as opposed to via a pragma or attribute), as + // the option -mms-bitfields otherwise essentially makes it impossible + // to build C++ code, unless this diagnostic is turned off. + if (Record->isMsStruct(Context) && !Context.getLangOpts().MSBitfields && + (Record->isPolymorphic() || Record->getNumBases())) { + Diag(Record->getLocation(), diag::warn_cxx_ms_struct); + } + + checkClassLevelDLLAttribute(Record); + checkClassLevelCodeSegAttribute(Record); + + bool ClangABICompat4 = + Context.getLangOpts().getClangABICompat() <= LangOptions::ClangABI::Ver4; + TargetInfo::CallingConvKind CCK = + Context.getTargetInfo().getCallingConvKind(ClangABICompat4); + bool CanPass = canPassInRegisters(*this, Record, CCK); + + // Do not change ArgPassingRestrictions if it has already been set to + // APK_CanNeverPassInRegs. + if (Record->getArgPassingRestrictions() != RecordDecl::APK_CanNeverPassInRegs) + Record->setArgPassingRestrictions(CanPass + ? RecordDecl::APK_CanPassInRegs + : RecordDecl::APK_CannotPassInRegs); + + // If canPassInRegisters returns true despite the record having a non-trivial + // destructor, the record is destructed in the callee. This happens only when + // the record or one of its subobjects has a field annotated with trivial_abi + // or a field qualified with ObjC __strong/__weak. + if (Context.getTargetInfo().getCXXABI().areArgsDestroyedLeftToRightInCallee()) + Record->setParamDestroyedInCallee(true); + else if (Record->hasNonTrivialDestructor()) + Record->setParamDestroyedInCallee(CanPass); + + if (getLangOpts().ForceEmitVTables) { + // If we want to emit all the vtables, we need to mark it as used. This + // is especially required for cases like vtable assumption loads. + MarkVTableUsed(Record->getInnerLocStart(), Record); + } + + if (getLangOpts().CUDA) { + if (Record->hasAttr()) + checkCUDADeviceBuiltinSurfaceClassTemplate(*this, Record); + else if (Record->hasAttr()) + checkCUDADeviceBuiltinTextureClassTemplate(*this, Record); + } + } + + /// Look up the special member function that would be called by a special + /// member function for a subobject of class type. + /// + /// \param Class The class type of the subobject. + /// \param CSM The kind of special member function. + /// \param FieldQuals If the subobject is a field, its cv-qualifiers. + /// \param ConstRHS True if this is a copy operation with a const object + /// on its RHS, that is, if the argument to the outer special member + /// function is 'const' and this is not a field marked 'mutable'. + static Sema::SpecialMemberOverloadResult lookupCallFromSpecialMember( + Sema &S, CXXRecordDecl *Class, Sema::CXXSpecialMember CSM, + unsigned FieldQuals, bool ConstRHS) { + unsigned LHSQuals = 0; + if (CSM == Sema::CXXCopyAssignment || CSM == Sema::CXXMoveAssignment) + LHSQuals = FieldQuals; + + unsigned RHSQuals = FieldQuals; + if (CSM == Sema::CXXDefaultConstructor || CSM == Sema::CXXDestructor) + RHSQuals = 0; + else if (ConstRHS) + RHSQuals |= Qualifiers::Const; + + return S.LookupSpecialMember(Class, CSM, + RHSQuals & Qualifiers::Const, + RHSQuals & Qualifiers::Volatile, + false, + LHSQuals & Qualifiers::Const, + LHSQuals & Qualifiers::Volatile); + } + + class Sema::InheritedConstructorInfo { + Sema &S; + SourceLocation UseLoc; + + /// A mapping from the base classes through which the constructor was + /// inherited to the using shadow declaration in that base class (or a null + /// pointer if the constructor was declared in that base class). + llvm::DenseMap + InheritedFromBases; + + public: + InheritedConstructorInfo(Sema &S, SourceLocation UseLoc, + ConstructorUsingShadowDecl *Shadow) + : S(S), UseLoc(UseLoc) { + bool DiagnosedMultipleConstructedBases = false; + CXXRecordDecl *ConstructedBase = nullptr; + BaseUsingDecl *ConstructedBaseIntroducer = nullptr; + + // Find the set of such base class subobjects and check that there's a + // unique constructed subobject. + for (auto *D : Shadow->redecls()) { + auto *DShadow = cast(D); + auto *DNominatedBase = DShadow->getNominatedBaseClass(); + auto *DConstructedBase = DShadow->getConstructedBaseClass(); + + InheritedFromBases.insert( + std::make_pair(DNominatedBase->getCanonicalDecl(), + DShadow->getNominatedBaseClassShadowDecl())); + if (DShadow->constructsVirtualBase()) + InheritedFromBases.insert( + std::make_pair(DConstructedBase->getCanonicalDecl(), + DShadow->getConstructedBaseClassShadowDecl())); + else + assert(DNominatedBase == DConstructedBase); + + // [class.inhctor.init]p2: + // If the constructor was inherited from multiple base class subobjects + // of type B, the program is ill-formed. + if (!ConstructedBase) { + ConstructedBase = DConstructedBase; + ConstructedBaseIntroducer = D->getIntroducer(); + } else if (ConstructedBase != DConstructedBase && + !Shadow->isInvalidDecl()) { + if (!DiagnosedMultipleConstructedBases) { + S.Diag(UseLoc, diag::err_ambiguous_inherited_constructor) + << Shadow->getTargetDecl(); + S.Diag(ConstructedBaseIntroducer->getLocation(), + diag::note_ambiguous_inherited_constructor_using) + << ConstructedBase; + DiagnosedMultipleConstructedBases = true; + } + S.Diag(D->getIntroducer()->getLocation(), + diag::note_ambiguous_inherited_constructor_using) + << DConstructedBase; + } + } + + if (DiagnosedMultipleConstructedBases) + Shadow->setInvalidDecl(); + } + + /// Find the constructor to use for inherited construction of a base class, + /// and whether that base class constructor inherits the constructor from a + /// virtual base class (in which case it won't actually invoke it). + std::pair + findConstructorForBase(CXXRecordDecl *Base, CXXConstructorDecl *Ctor) const { + auto It = InheritedFromBases.find(Base->getCanonicalDecl()); + if (It == InheritedFromBases.end()) + return std::make_pair(nullptr, false); + + // This is an intermediary class. + if (It->second) + return std::make_pair( + S.findInheritingConstructor(UseLoc, Ctor, It->second), + It->second->constructsVirtualBase()); + + // This is the base class from which the constructor was inherited. + return std::make_pair(Ctor, false); + } + }; + + /// Is the special member function which would be selected to perform the + /// specified operation on the specified class type a constexpr constructor? + static bool + specialMemberIsConstexpr(Sema &S, CXXRecordDecl *ClassDecl, + Sema::CXXSpecialMember CSM, unsigned Quals, + bool ConstRHS, + CXXConstructorDecl *InheritedCtor = nullptr, + Sema::InheritedConstructorInfo *Inherited = nullptr) { + // Suppress duplicate constraint checking here, in case a constraint check + // caused us to decide to do this. Any truely recursive checks will get + // caught during these checks anyway. + Sema::SatisfactionStackResetRAII SSRAII{S}; + + // If we're inheriting a constructor, see if we need to call it for this base + // class. + if (InheritedCtor) { + assert(CSM == Sema::CXXDefaultConstructor); + auto BaseCtor = + Inherited->findConstructorForBase(ClassDecl, InheritedCtor).first; + if (BaseCtor) + return BaseCtor->isConstexpr(); + } + + if (CSM == Sema::CXXDefaultConstructor) + return ClassDecl->hasConstexprDefaultConstructor(); + if (CSM == Sema::CXXDestructor) + return ClassDecl->hasConstexprDestructor(); + + Sema::SpecialMemberOverloadResult SMOR = + lookupCallFromSpecialMember(S, ClassDecl, CSM, Quals, ConstRHS); + if (!SMOR.getMethod()) + // A constructor we wouldn't select can't be "involved in initializing" + // anything. + return true; + return SMOR.getMethod()->isConstexpr(); + } + + /// Determine whether the specified special member function would be constexpr + /// if it were implicitly defined. + static bool defaultedSpecialMemberIsConstexpr( + Sema &S, CXXRecordDecl *ClassDecl, Sema::CXXSpecialMember CSM, + bool ConstArg, CXXConstructorDecl *InheritedCtor = nullptr, + Sema::InheritedConstructorInfo *Inherited = nullptr) { + if (!S.getLangOpts().CPlusPlus11) + return false; + + // C++11 [dcl.constexpr]p4: + // In the definition of a constexpr constructor [...] + bool Ctor = true; + switch (CSM) { + case Sema::CXXDefaultConstructor: + if (Inherited) + break; + // Since default constructor lookup is essentially trivial (and cannot + // involve, for instance, template instantiation), we compute whether a + // defaulted default constructor is constexpr directly within CXXRecordDecl. + // + // This is important for performance; we need to know whether the default + // constructor is constexpr to determine whether the type is a literal type. + return ClassDecl->defaultedDefaultConstructorIsConstexpr(); + + case Sema::CXXCopyConstructor: + case Sema::CXXMoveConstructor: + // For copy or move constructors, we need to perform overload resolution. + break; + + case Sema::CXXCopyAssignment: + case Sema::CXXMoveAssignment: + if (!S.getLangOpts().CPlusPlus14) + return false; + // In C++1y, we need to perform overload resolution. + Ctor = false; + break; + + case Sema::CXXDestructor: + return ClassDecl->defaultedDestructorIsConstexpr(); + + case Sema::CXXInvalid: + return false; + } + + // -- if the class is a non-empty union, or for each non-empty anonymous + // union member of a non-union class, exactly one non-static data member + // shall be initialized; [DR1359] + // + // If we squint, this is guaranteed, since exactly one non-static data member + // will be initialized (if the constructor isn't deleted), we just don't know + // which one. + if (Ctor && ClassDecl->isUnion()) + return CSM == Sema::CXXDefaultConstructor + ? ClassDecl->hasInClassInitializer() || + !ClassDecl->hasVariantMembers() + : true; + + // -- the class shall not have any virtual base classes; + if (Ctor && ClassDecl->getNumVBases()) + return false; + + // C++1y [class.copy]p26: + // -- [the class] is a literal type, and + if (!Ctor && !ClassDecl->isLiteral()) + return false; + + // -- every constructor involved in initializing [...] base class + // sub-objects shall be a constexpr constructor; + // -- the assignment operator selected to copy/move each direct base + // class is a constexpr function, and + for (const auto &B : ClassDecl->bases()) { + const RecordType *BaseType = B.getType()->getAs(); + if (!BaseType) + continue; + CXXRecordDecl *BaseClassDecl = cast(BaseType->getDecl()); + if (!specialMemberIsConstexpr(S, BaseClassDecl, CSM, 0, ConstArg, + InheritedCtor, Inherited)) + return false; + } + + // -- every constructor involved in initializing non-static data members + // [...] shall be a constexpr constructor; + // -- every non-static data member and base class sub-object shall be + // initialized + // -- for each non-static data member of X that is of class type (or array + // thereof), the assignment operator selected to copy/move that member is + // a constexpr function + for (const auto *F : ClassDecl->fields()) { + if (F->isInvalidDecl()) + continue; + if (CSM == Sema::CXXDefaultConstructor && F->hasInClassInitializer()) + continue; + QualType BaseType = S.Context.getBaseElementType(F->getType()); + if (const RecordType *RecordTy = BaseType->getAs()) { + CXXRecordDecl *FieldRecDecl = cast(RecordTy->getDecl()); + if (!specialMemberIsConstexpr(S, FieldRecDecl, CSM, + BaseType.getCVRQualifiers(), + ConstArg && !F->isMutable())) + return false; + } else if (CSM == Sema::CXXDefaultConstructor) { + return false; + } + } + + // All OK, it's constexpr! + return true; + } + + namespace { + /// RAII object to register a defaulted function as having its exception + /// specification computed. + struct ComputingExceptionSpec { + Sema &S; + + ComputingExceptionSpec(Sema &S, FunctionDecl *FD, SourceLocation Loc) + : S(S) { + Sema::CodeSynthesisContext Ctx; + Ctx.Kind = Sema::CodeSynthesisContext::ExceptionSpecEvaluation; + Ctx.PointOfInstantiation = Loc; + Ctx.Entity = FD; + S.pushCodeSynthesisContext(Ctx); + } + ~ComputingExceptionSpec() { + S.popCodeSynthesisContext(); + } + }; + } + + static Sema::ImplicitExceptionSpecification + ComputeDefaultedSpecialMemberExceptionSpec( + Sema &S, SourceLocation Loc, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM, + Sema::InheritedConstructorInfo *ICI); + + static Sema::ImplicitExceptionSpecification + ComputeDefaultedComparisonExceptionSpec(Sema &S, SourceLocation Loc, + FunctionDecl *FD, + Sema::DefaultedComparisonKind DCK); + + static Sema::ImplicitExceptionSpecification + computeImplicitExceptionSpec(Sema &S, SourceLocation Loc, FunctionDecl *FD) { + auto DFK = S.getDefaultedFunctionKind(FD); + if (DFK.isSpecialMember()) + return ComputeDefaultedSpecialMemberExceptionSpec( + S, Loc, cast(FD), DFK.asSpecialMember(), nullptr); + if (DFK.isComparison()) + return ComputeDefaultedComparisonExceptionSpec(S, Loc, FD, + DFK.asComparison()); + + auto *CD = cast(FD); + assert(CD->getInheritedConstructor() && + "only defaulted functions and inherited constructors have implicit " + "exception specs"); + Sema::InheritedConstructorInfo ICI( + S, Loc, CD->getInheritedConstructor().getShadowDecl()); + return ComputeDefaultedSpecialMemberExceptionSpec( + S, Loc, CD, Sema::CXXDefaultConstructor, &ICI); + } + + static FunctionProtoType::ExtProtoInfo getImplicitMethodEPI(Sema &S, + CXXMethodDecl *MD) { + FunctionProtoType::ExtProtoInfo EPI; + + // Build an exception specification pointing back at this member. + EPI.ExceptionSpec.Type = EST_Unevaluated; + EPI.ExceptionSpec.SourceDecl = MD; + + // Set the calling convention to the default for C++ instance methods. + EPI.ExtInfo = EPI.ExtInfo.withCallingConv( + S.Context.getDefaultCallingConvention(/*IsVariadic=*/false, + /*IsCXXMethod=*/true)); + return EPI; + } + + void Sema::EvaluateImplicitExceptionSpec(SourceLocation Loc, FunctionDecl *FD) { + const FunctionProtoType *FPT = FD->getType()->castAs(); + if (FPT->getExceptionSpecType() != EST_Unevaluated) + return; + + // Evaluate the exception specification. + auto IES = computeImplicitExceptionSpec(*this, Loc, FD); + auto ESI = IES.getExceptionSpec(); + + // Update the type of the special member to use it. + UpdateExceptionSpec(FD, ESI); + } + + void Sema::CheckExplicitlyDefaultedFunction(Scope *S, FunctionDecl *FD) { + assert(FD->isExplicitlyDefaulted() && "not explicitly-defaulted"); + + DefaultedFunctionKind DefKind = getDefaultedFunctionKind(FD); + if (!DefKind) { + assert(FD->getDeclContext()->isDependentContext()); + return; + } + + if (DefKind.isComparison()) + UnusedPrivateFields.clear(); + + if (DefKind.isSpecialMember() + ? CheckExplicitlyDefaultedSpecialMember(cast(FD), + DefKind.asSpecialMember(), + FD->getDefaultLoc()) + : CheckExplicitlyDefaultedComparison(S, FD, DefKind.asComparison())) + FD->setInvalidDecl(); + } + + bool Sema::CheckExplicitlyDefaultedSpecialMember(CXXMethodDecl *MD, + CXXSpecialMember CSM, + SourceLocation DefaultLoc) { + CXXRecordDecl *RD = MD->getParent(); + + assert(MD->isExplicitlyDefaulted() && CSM != CXXInvalid && + "not an explicitly-defaulted special member"); + + // Defer all checking for special members of a dependent type. + if (RD->isDependentType()) + return false; + + // Whether this was the first-declared instance of the constructor. + // This affects whether we implicitly add an exception spec and constexpr. + bool First = MD == MD->getCanonicalDecl(); + + bool HadError = false; + + // C++11 [dcl.fct.def.default]p1: + // A function that is explicitly defaulted shall + // -- be a special member function [...] (checked elsewhere), + // -- have the same type (except for ref-qualifiers, and except that a + // copy operation can take a non-const reference) as an implicit + // declaration, and + // -- not have default arguments. + // C++2a changes the second bullet to instead delete the function if it's + // defaulted on its first declaration, unless it's "an assignment operator, + // and its return type differs or its parameter type is not a reference". + bool DeleteOnTypeMismatch = getLangOpts().CPlusPlus20 && First; + bool ShouldDeleteForTypeMismatch = false; + unsigned ExpectedParams = 1; + if (CSM == CXXDefaultConstructor || CSM == CXXDestructor) + ExpectedParams = 0; + if (MD->getNumParams() != ExpectedParams) { + // This checks for default arguments: a copy or move constructor with a + // default argument is classified as a default constructor, and assignment + // operations and destructors can't have default arguments. + Diag(MD->getLocation(), diag::err_defaulted_special_member_params) + << CSM << MD->getSourceRange(); + HadError = true; + } else if (MD->isVariadic()) { + if (DeleteOnTypeMismatch) + ShouldDeleteForTypeMismatch = true; + else { + Diag(MD->getLocation(), diag::err_defaulted_special_member_variadic) + << CSM << MD->getSourceRange(); + HadError = true; + } + } + +- const FunctionProtoType *Type = MD->getType()->getAs(); ++ const FunctionProtoType *Type = MD->getType()->castAs(); + + bool CanHaveConstParam = false; + if (CSM == CXXCopyConstructor) + CanHaveConstParam = RD->implicitCopyConstructorHasConstParam(); + else if (CSM == CXXCopyAssignment) + CanHaveConstParam = RD->implicitCopyAssignmentHasConstParam(); + + QualType ReturnType = Context.VoidTy; + if (CSM == CXXCopyAssignment || CSM == CXXMoveAssignment) { + // Check for return type matching. + ReturnType = Type->getReturnType(); + + QualType DeclType = Context.getTypeDeclType(RD); + DeclType = Context.getElaboratedType(ETK_None, nullptr, DeclType, nullptr); + DeclType = Context.getAddrSpaceQualType(DeclType, MD->getMethodQualifiers().getAddressSpace()); + QualType ExpectedReturnType = Context.getLValueReferenceType(DeclType); + + if (!Context.hasSameType(ReturnType, ExpectedReturnType)) { + Diag(MD->getLocation(), diag::err_defaulted_special_member_return_type) + << (CSM == CXXMoveAssignment) << ExpectedReturnType; + HadError = true; + } + + // A defaulted special member cannot have cv-qualifiers. + if (Type->getMethodQuals().hasConst() || Type->getMethodQuals().hasVolatile()) { + if (DeleteOnTypeMismatch) + ShouldDeleteForTypeMismatch = true; + else { + Diag(MD->getLocation(), diag::err_defaulted_special_member_quals) + << (CSM == CXXMoveAssignment) << getLangOpts().CPlusPlus14; + HadError = true; + } + } + } + + // Check for parameter type matching. + QualType ArgType = ExpectedParams ? Type->getParamType(0) : QualType(); + bool HasConstParam = false; + if (ExpectedParams && ArgType->isReferenceType()) { + // Argument must be reference to possibly-const T. + QualType ReferentType = ArgType->getPointeeType(); + HasConstParam = ReferentType.isConstQualified(); + + if (ReferentType.isVolatileQualified()) { + if (DeleteOnTypeMismatch) + ShouldDeleteForTypeMismatch = true; + else { + Diag(MD->getLocation(), + diag::err_defaulted_special_member_volatile_param) << CSM; + HadError = true; + } + } + + if (HasConstParam && !CanHaveConstParam) { + if (DeleteOnTypeMismatch) + ShouldDeleteForTypeMismatch = true; + else if (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment) { + Diag(MD->getLocation(), + diag::err_defaulted_special_member_copy_const_param) + << (CSM == CXXCopyAssignment); + // FIXME: Explain why this special member can't be const. + HadError = true; + } else { + Diag(MD->getLocation(), + diag::err_defaulted_special_member_move_const_param) + << (CSM == CXXMoveAssignment); + HadError = true; + } + } + } else if (ExpectedParams) { + // A copy assignment operator can take its argument by value, but a + // defaulted one cannot. + assert(CSM == CXXCopyAssignment && "unexpected non-ref argument"); + Diag(MD->getLocation(), diag::err_defaulted_copy_assign_not_ref); + HadError = true; + } + + // C++11 [dcl.fct.def.default]p2: + // An explicitly-defaulted function may be declared constexpr only if it + // would have been implicitly declared as constexpr, + // Do not apply this rule to members of class templates, since core issue 1358 + // makes such functions always instantiate to constexpr functions. For + // functions which cannot be constexpr (for non-constructors in C++11 and for + // destructors in C++14 and C++17), this is checked elsewhere. + // + // FIXME: This should not apply if the member is deleted. + bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, RD, CSM, + HasConstParam); + + // C++14 [dcl.constexpr]p6 (CWG DR647/CWG DR1358): + // If the instantiated template specialization of a constexpr function + // template or member function of a class template would fail to satisfy + // the requirements for a constexpr function or constexpr constructor, that + // specialization is still a constexpr function or constexpr constructor, + // even though a call to such a function cannot appear in a constant + // expression. + if (MD->isTemplateInstantiation() && MD->isConstexpr()) + Constexpr = true; + + if ((getLangOpts().CPlusPlus20 || + (getLangOpts().CPlusPlus14 ? !isa(MD) + : isa(MD))) && + MD->isConstexpr() && !Constexpr && + MD->getTemplatedKind() == FunctionDecl::TK_NonTemplate) { + Diag(MD->getBeginLoc(), MD->isConsteval() + ? diag::err_incorrect_defaulted_consteval + : diag::err_incorrect_defaulted_constexpr) + << CSM; + // FIXME: Explain why the special member can't be constexpr. + HadError = true; + } + + if (First) { + // C++2a [dcl.fct.def.default]p3: + // If a function is explicitly defaulted on its first declaration, it is + // implicitly considered to be constexpr if the implicit declaration + // would be. + MD->setConstexprKind(Constexpr ? (MD->isConsteval() + ? ConstexprSpecKind::Consteval + : ConstexprSpecKind::Constexpr) + : ConstexprSpecKind::Unspecified); + + if (!Type->hasExceptionSpec()) { + // C++2a [except.spec]p3: + // If a declaration of a function does not have a noexcept-specifier + // [and] is defaulted on its first declaration, [...] the exception + // specification is as specified below + FunctionProtoType::ExtProtoInfo EPI = Type->getExtProtoInfo(); + EPI.ExceptionSpec.Type = EST_Unevaluated; + EPI.ExceptionSpec.SourceDecl = MD; + MD->setType(Context.getFunctionType( + ReturnType, llvm::ArrayRef(&ArgType, ExpectedParams), EPI)); + } + } + + if (ShouldDeleteForTypeMismatch || ShouldDeleteSpecialMember(MD, CSM)) { + if (First) { + SetDeclDeleted(MD, MD->getLocation()); + if (!inTemplateInstantiation() && !HadError) { + Diag(MD->getLocation(), diag::warn_defaulted_method_deleted) << CSM; + if (ShouldDeleteForTypeMismatch) { + Diag(MD->getLocation(), diag::note_deleted_type_mismatch) << CSM; + } else if (ShouldDeleteSpecialMember(MD, CSM, nullptr, + /*Diagnose*/ true) && + DefaultLoc.isValid()) { + Diag(DefaultLoc, diag::note_replace_equals_default_to_delete) + << FixItHint::CreateReplacement(DefaultLoc, "delete"); + } + } + if (ShouldDeleteForTypeMismatch && !HadError) { + Diag(MD->getLocation(), + diag::warn_cxx17_compat_defaulted_method_type_mismatch) << CSM; + } + } else { + // C++11 [dcl.fct.def.default]p4: + // [For a] user-provided explicitly-defaulted function [...] if such a + // function is implicitly defined as deleted, the program is ill-formed. + Diag(MD->getLocation(), diag::err_out_of_line_default_deletes) << CSM; + assert(!ShouldDeleteForTypeMismatch && "deleted non-first decl"); + ShouldDeleteSpecialMember(MD, CSM, nullptr, /*Diagnose*/true); + HadError = true; + } + } + + return HadError; + } + + namespace { + /// Helper class for building and checking a defaulted comparison. + /// + /// Defaulted functions are built in two phases: + /// + /// * First, the set of operations that the function will perform are + /// identified, and some of them are checked. If any of the checked + /// operations is invalid in certain ways, the comparison function is + /// defined as deleted and no body is built. + /// * Then, if the function is not defined as deleted, the body is built. + /// + /// This is accomplished by performing two visitation steps over the eventual + /// body of the function. + template + class DefaultedComparisonVisitor { + public: + using DefaultedComparisonKind = Sema::DefaultedComparisonKind; + + DefaultedComparisonVisitor(Sema &S, CXXRecordDecl *RD, FunctionDecl *FD, + DefaultedComparisonKind DCK) + : S(S), RD(RD), FD(FD), DCK(DCK) { + if (auto *Info = FD->getDefaultedFunctionInfo()) { + // FIXME: Change CreateOverloadedBinOp to take an ArrayRef instead of an + // UnresolvedSet to avoid this copy. + Fns.assign(Info->getUnqualifiedLookups().begin(), + Info->getUnqualifiedLookups().end()); + } + } + + ResultList visit() { + // The type of an lvalue naming a parameter of this function. + QualType ParamLvalType = + FD->getParamDecl(0)->getType().getNonReferenceType(); + + ResultList Results; + + switch (DCK) { + case DefaultedComparisonKind::None: + llvm_unreachable("not a defaulted comparison"); + + case DefaultedComparisonKind::Equal: + case DefaultedComparisonKind::ThreeWay: + getDerived().visitSubobjects(Results, RD, ParamLvalType.getQualifiers()); + return Results; + + case DefaultedComparisonKind::NotEqual: + case DefaultedComparisonKind::Relational: + Results.add(getDerived().visitExpandedSubobject( + ParamLvalType, getDerived().getCompleteObject())); + return Results; + } + llvm_unreachable(""); + } + + protected: + Derived &getDerived() { return static_cast(*this); } + + /// Visit the expanded list of subobjects of the given type, as specified in + /// C++2a [class.compare.default]. + /// + /// \return \c true if the ResultList object said we're done, \c false if not. + bool visitSubobjects(ResultList &Results, CXXRecordDecl *Record, + Qualifiers Quals) { + // C++2a [class.compare.default]p4: + // The direct base class subobjects of C + for (CXXBaseSpecifier &Base : Record->bases()) + if (Results.add(getDerived().visitSubobject( + S.Context.getQualifiedType(Base.getType(), Quals), + getDerived().getBase(&Base)))) + return true; + + // followed by the non-static data members of C + for (FieldDecl *Field : Record->fields()) { + // C++23 [class.bit]p2: + // Unnamed bit-fields are not members ... + if (Field->isUnnamedBitfield()) + continue; + // Recursively expand anonymous structs. + if (Field->isAnonymousStructOrUnion()) { + if (visitSubobjects(Results, Field->getType()->getAsCXXRecordDecl(), + Quals)) + return true; + continue; + } + + // Figure out the type of an lvalue denoting this field. + Qualifiers FieldQuals = Quals; + if (Field->isMutable()) + FieldQuals.removeConst(); + QualType FieldType = + S.Context.getQualifiedType(Field->getType(), FieldQuals); + + if (Results.add(getDerived().visitSubobject( + FieldType, getDerived().getField(Field)))) + return true; + } + + // form a list of subobjects. + return false; + } + + Result visitSubobject(QualType Type, Subobject Subobj) { + // In that list, any subobject of array type is recursively expanded + const ArrayType *AT = S.Context.getAsArrayType(Type); + if (auto *CAT = dyn_cast_or_null(AT)) + return getDerived().visitSubobjectArray(CAT->getElementType(), + CAT->getSize(), Subobj); + return getDerived().visitExpandedSubobject(Type, Subobj); + } + + Result visitSubobjectArray(QualType Type, const llvm::APInt &Size, + Subobject Subobj) { + return getDerived().visitSubobject(Type, Subobj); + } + + protected: + Sema &S; + CXXRecordDecl *RD; + FunctionDecl *FD; + DefaultedComparisonKind DCK; + UnresolvedSet<16> Fns; + }; + + /// Information about a defaulted comparison, as determined by + /// DefaultedComparisonAnalyzer. + struct DefaultedComparisonInfo { + bool Deleted = false; + bool Constexpr = true; + ComparisonCategoryType Category = ComparisonCategoryType::StrongOrdering; + + static DefaultedComparisonInfo deleted() { + DefaultedComparisonInfo Deleted; + Deleted.Deleted = true; + return Deleted; + } + + bool add(const DefaultedComparisonInfo &R) { + Deleted |= R.Deleted; + Constexpr &= R.Constexpr; + Category = commonComparisonType(Category, R.Category); + return Deleted; + } + }; + + /// An element in the expanded list of subobjects of a defaulted comparison, as + /// specified in C++2a [class.compare.default]p4. + struct DefaultedComparisonSubobject { + enum { CompleteObject, Member, Base } Kind; + NamedDecl *Decl; + SourceLocation Loc; + }; + + /// A visitor over the notional body of a defaulted comparison that determines + /// whether that body would be deleted or constexpr. + class DefaultedComparisonAnalyzer + : public DefaultedComparisonVisitor { + public: + enum DiagnosticKind { NoDiagnostics, ExplainDeleted, ExplainConstexpr }; + + private: + DiagnosticKind Diagnose; + + public: + using Base = DefaultedComparisonVisitor; + using Result = DefaultedComparisonInfo; + using Subobject = DefaultedComparisonSubobject; + + friend Base; + + DefaultedComparisonAnalyzer(Sema &S, CXXRecordDecl *RD, FunctionDecl *FD, + DefaultedComparisonKind DCK, + DiagnosticKind Diagnose = NoDiagnostics) + : Base(S, RD, FD, DCK), Diagnose(Diagnose) {} + + Result visit() { + if ((DCK == DefaultedComparisonKind::Equal || + DCK == DefaultedComparisonKind::ThreeWay) && + RD->hasVariantMembers()) { + // C++2a [class.compare.default]p2 [P2002R0]: + // A defaulted comparison operator function for class C is defined as + // deleted if [...] C has variant members. + if (Diagnose == ExplainDeleted) { + S.Diag(FD->getLocation(), diag::note_defaulted_comparison_union) + << FD << RD->isUnion() << RD; + } + return Result::deleted(); + } + + return Base::visit(); + } + + private: + Subobject getCompleteObject() { + return Subobject{Subobject::CompleteObject, RD, FD->getLocation()}; + } + + Subobject getBase(CXXBaseSpecifier *Base) { + return Subobject{Subobject::Base, Base->getType()->getAsCXXRecordDecl(), + Base->getBaseTypeLoc()}; + } + + Subobject getField(FieldDecl *Field) { + return Subobject{Subobject::Member, Field, Field->getLocation()}; + } + + Result visitExpandedSubobject(QualType Type, Subobject Subobj) { + // C++2a [class.compare.default]p2 [P2002R0]: + // A defaulted <=> or == operator function for class C is defined as + // deleted if any non-static data member of C is of reference type + if (Type->isReferenceType()) { + if (Diagnose == ExplainDeleted) { + S.Diag(Subobj.Loc, diag::note_defaulted_comparison_reference_member) + << FD << RD; + } + return Result::deleted(); + } + + // [...] Let xi be an lvalue denoting the ith element [...] + OpaqueValueExpr Xi(FD->getLocation(), Type, VK_LValue); + Expr *Args[] = {&Xi, &Xi}; + + // All operators start by trying to apply that same operator recursively. + OverloadedOperatorKind OO = FD->getOverloadedOperator(); + assert(OO != OO_None && "not an overloaded operator!"); + return visitBinaryOperator(OO, Args, Subobj); + } + + Result + visitBinaryOperator(OverloadedOperatorKind OO, ArrayRef Args, + Subobject Subobj, + OverloadCandidateSet *SpaceshipCandidates = nullptr) { + // Note that there is no need to consider rewritten candidates here if + // we've already found there is no viable 'operator<=>' candidate (and are + // considering synthesizing a '<=>' from '==' and '<'). + OverloadCandidateSet CandidateSet( + FD->getLocation(), OverloadCandidateSet::CSK_Operator, + OverloadCandidateSet::OperatorRewriteInfo( + OO, FD->getLocation(), + /*AllowRewrittenCandidates=*/!SpaceshipCandidates)); + + /// C++2a [class.compare.default]p1 [P2002R0]: + /// [...] the defaulted function itself is never a candidate for overload + /// resolution [...] + CandidateSet.exclude(FD); + + if (Args[0]->getType()->isOverloadableType()) + S.LookupOverloadedBinOp(CandidateSet, OO, Fns, Args); + else + // FIXME: We determine whether this is a valid expression by checking to + // see if there's a viable builtin operator candidate for it. That isn't + // really what the rules ask us to do, but should give the right results. + S.AddBuiltinOperatorCandidates(OO, FD->getLocation(), Args, CandidateSet); + + Result R; + + OverloadCandidateSet::iterator Best; + switch (CandidateSet.BestViableFunction(S, FD->getLocation(), Best)) { + case OR_Success: { + // C++2a [class.compare.secondary]p2 [P2002R0]: + // The operator function [...] is defined as deleted if [...] the + // candidate selected by overload resolution is not a rewritten + // candidate. + if ((DCK == DefaultedComparisonKind::NotEqual || + DCK == DefaultedComparisonKind::Relational) && + !Best->RewriteKind) { + if (Diagnose == ExplainDeleted) { + if (Best->Function) { + S.Diag(Best->Function->getLocation(), + diag::note_defaulted_comparison_not_rewritten_callee) + << FD; + } else { + assert(Best->Conversions.size() == 2 && + Best->Conversions[0].isUserDefined() && + "non-user-defined conversion from class to built-in " + "comparison"); + S.Diag(Best->Conversions[0] + .UserDefined.FoundConversionFunction.getDecl() + ->getLocation(), + diag::note_defaulted_comparison_not_rewritten_conversion) + << FD; + } + } + return Result::deleted(); + } + + // Throughout C++2a [class.compare]: if overload resolution does not + // result in a usable function, the candidate function is defined as + // deleted. This requires that we selected an accessible function. + // + // Note that this only considers the access of the function when named + // within the type of the subobject, and not the access path for any + // derived-to-base conversion. + CXXRecordDecl *ArgClass = Args[0]->getType()->getAsCXXRecordDecl(); + if (ArgClass && Best->FoundDecl.getDecl() && + Best->FoundDecl.getDecl()->isCXXClassMember()) { + QualType ObjectType = Subobj.Kind == Subobject::Member + ? Args[0]->getType() + : S.Context.getRecordType(RD); + if (!S.isMemberAccessibleForDeletion( + ArgClass, Best->FoundDecl, ObjectType, Subobj.Loc, + Diagnose == ExplainDeleted + ? S.PDiag(diag::note_defaulted_comparison_inaccessible) + << FD << Subobj.Kind << Subobj.Decl + : S.PDiag())) + return Result::deleted(); + } + + bool NeedsDeducing = + OO == OO_Spaceship && FD->getReturnType()->isUndeducedAutoType(); + + if (FunctionDecl *BestFD = Best->Function) { + // C++2a [class.compare.default]p3 [P2002R0]: + // A defaulted comparison function is constexpr-compatible if + // [...] no overlod resolution performed [...] results in a + // non-constexpr function. + assert(!BestFD->isDeleted() && "wrong overload resolution result"); + // If it's not constexpr, explain why not. + if (Diagnose == ExplainConstexpr && !BestFD->isConstexpr()) { + if (Subobj.Kind != Subobject::CompleteObject) + S.Diag(Subobj.Loc, diag::note_defaulted_comparison_not_constexpr) + << Subobj.Kind << Subobj.Decl; + S.Diag(BestFD->getLocation(), + diag::note_defaulted_comparison_not_constexpr_here); + // Bail out after explaining; we don't want any more notes. + return Result::deleted(); + } + R.Constexpr &= BestFD->isConstexpr(); + + if (NeedsDeducing) { + // If any callee has an undeduced return type, deduce it now. + // FIXME: It's not clear how a failure here should be handled. For + // now, we produce an eager diagnostic, because that is forward + // compatible with most (all?) other reasonable options. + if (BestFD->getReturnType()->isUndeducedType() && + S.DeduceReturnType(BestFD, FD->getLocation(), + /*Diagnose=*/false)) { + // Don't produce a duplicate error when asked to explain why the + // comparison is deleted: we diagnosed that when initially checking + // the defaulted operator. + if (Diagnose == NoDiagnostics) { + S.Diag( + FD->getLocation(), + diag::err_defaulted_comparison_cannot_deduce_undeduced_auto) + << Subobj.Kind << Subobj.Decl; + S.Diag( + Subobj.Loc, + diag::note_defaulted_comparison_cannot_deduce_undeduced_auto) + << Subobj.Kind << Subobj.Decl; + S.Diag(BestFD->getLocation(), + diag::note_defaulted_comparison_cannot_deduce_callee) + << Subobj.Kind << Subobj.Decl; + } + return Result::deleted(); + } + auto *Info = S.Context.CompCategories.lookupInfoForType( + BestFD->getCallResultType()); + if (!Info) { + if (Diagnose == ExplainDeleted) { + S.Diag(Subobj.Loc, diag::note_defaulted_comparison_cannot_deduce) + << Subobj.Kind << Subobj.Decl + << BestFD->getCallResultType().withoutLocalFastQualifiers(); + S.Diag(BestFD->getLocation(), + diag::note_defaulted_comparison_cannot_deduce_callee) + << Subobj.Kind << Subobj.Decl; + } + return Result::deleted(); + } + R.Category = Info->Kind; + } + } else { + QualType T = Best->BuiltinParamTypes[0]; + assert(T == Best->BuiltinParamTypes[1] && + "builtin comparison for different types?"); + assert(Best->BuiltinParamTypes[2].isNull() && + "invalid builtin comparison"); + + if (NeedsDeducing) { + std::optional Cat = + getComparisonCategoryForBuiltinCmp(T); + assert(Cat && "no category for builtin comparison?"); + R.Category = *Cat; + } + } + + // Note that we might be rewriting to a different operator. That call is + // not considered until we come to actually build the comparison function. + break; + } + + case OR_Ambiguous: + if (Diagnose == ExplainDeleted) { + unsigned Kind = 0; + if (FD->getOverloadedOperator() == OO_Spaceship && OO != OO_Spaceship) + Kind = OO == OO_EqualEqual ? 1 : 2; + CandidateSet.NoteCandidates( + PartialDiagnosticAt( + Subobj.Loc, S.PDiag(diag::note_defaulted_comparison_ambiguous) + << FD << Kind << Subobj.Kind << Subobj.Decl), + S, OCD_AmbiguousCandidates, Args); + } + R = Result::deleted(); + break; + + case OR_Deleted: + if (Diagnose == ExplainDeleted) { + if ((DCK == DefaultedComparisonKind::NotEqual || + DCK == DefaultedComparisonKind::Relational) && + !Best->RewriteKind) { + S.Diag(Best->Function->getLocation(), + diag::note_defaulted_comparison_not_rewritten_callee) + << FD; + } else { + S.Diag(Subobj.Loc, + diag::note_defaulted_comparison_calls_deleted) + << FD << Subobj.Kind << Subobj.Decl; + S.NoteDeletedFunction(Best->Function); + } + } + R = Result::deleted(); + break; + + case OR_No_Viable_Function: + // If there's no usable candidate, we're done unless we can rewrite a + // '<=>' in terms of '==' and '<'. + if (OO == OO_Spaceship && + S.Context.CompCategories.lookupInfoForType(FD->getReturnType())) { + // For any kind of comparison category return type, we need a usable + // '==' and a usable '<'. + if (!R.add(visitBinaryOperator(OO_EqualEqual, Args, Subobj, + &CandidateSet))) + R.add(visitBinaryOperator(OO_Less, Args, Subobj, &CandidateSet)); + break; + } + + if (Diagnose == ExplainDeleted) { + S.Diag(Subobj.Loc, diag::note_defaulted_comparison_no_viable_function) + << FD << (OO == OO_ExclaimEqual) << Subobj.Kind << Subobj.Decl; + + // For a three-way comparison, list both the candidates for the + // original operator and the candidates for the synthesized operator. + if (SpaceshipCandidates) { + SpaceshipCandidates->NoteCandidates( + S, Args, + SpaceshipCandidates->CompleteCandidates(S, OCD_AllCandidates, + Args, FD->getLocation())); + S.Diag(Subobj.Loc, + diag::note_defaulted_comparison_no_viable_function_synthesized) + << (OO == OO_EqualEqual ? 0 : 1); + } + + CandidateSet.NoteCandidates( + S, Args, + CandidateSet.CompleteCandidates(S, OCD_AllCandidates, Args, + FD->getLocation())); + } + R = Result::deleted(); + break; + } + + return R; + } + }; + + /// A list of statements. + struct StmtListResult { + bool IsInvalid = false; + llvm::SmallVector Stmts; + + bool add(const StmtResult &S) { + IsInvalid |= S.isInvalid(); + if (IsInvalid) + return true; + Stmts.push_back(S.get()); + return false; + } + }; + + /// A visitor over the notional body of a defaulted comparison that synthesizes + /// the actual body. + class DefaultedComparisonSynthesizer + : public DefaultedComparisonVisitor> { + SourceLocation Loc; + unsigned ArrayDepth = 0; + + public: + using Base = DefaultedComparisonVisitor; + using ExprPair = std::pair; + + friend Base; + + DefaultedComparisonSynthesizer(Sema &S, CXXRecordDecl *RD, FunctionDecl *FD, + DefaultedComparisonKind DCK, + SourceLocation BodyLoc) + : Base(S, RD, FD, DCK), Loc(BodyLoc) {} + + /// Build a suitable function body for this defaulted comparison operator. + StmtResult build() { + Sema::CompoundScopeRAII CompoundScope(S); + + StmtListResult Stmts = visit(); + if (Stmts.IsInvalid) + return StmtError(); + + ExprResult RetVal; + switch (DCK) { + case DefaultedComparisonKind::None: + llvm_unreachable("not a defaulted comparison"); + + case DefaultedComparisonKind::Equal: { + // C++2a [class.eq]p3: + // [...] compar[e] the corresponding elements [...] until the first + // index i where xi == yi yields [...] false. If no such index exists, + // V is true. Otherwise, V is false. + // + // Join the comparisons with '&&'s and return the result. Use a right + // fold (traversing the conditions right-to-left), because that + // short-circuits more naturally. + auto OldStmts = std::move(Stmts.Stmts); + Stmts.Stmts.clear(); + ExprResult CmpSoFar; + // Finish a particular comparison chain. + auto FinishCmp = [&] { + if (Expr *Prior = CmpSoFar.get()) { + // Convert the last expression to 'return ...;' + if (RetVal.isUnset() && Stmts.Stmts.empty()) + RetVal = CmpSoFar; + // Convert any prior comparison to 'if (!(...)) return false;' + else if (Stmts.add(buildIfNotCondReturnFalse(Prior))) + return true; + CmpSoFar = ExprResult(); + } + return false; + }; + for (Stmt *EAsStmt : llvm::reverse(OldStmts)) { + Expr *E = dyn_cast(EAsStmt); + if (!E) { + // Found an array comparison. + if (FinishCmp() || Stmts.add(EAsStmt)) + return StmtError(); + continue; + } + + if (CmpSoFar.isUnset()) { + CmpSoFar = E; + continue; + } + CmpSoFar = S.CreateBuiltinBinOp(Loc, BO_LAnd, E, CmpSoFar.get()); + if (CmpSoFar.isInvalid()) + return StmtError(); + } + if (FinishCmp()) + return StmtError(); + std::reverse(Stmts.Stmts.begin(), Stmts.Stmts.end()); + // If no such index exists, V is true. + if (RetVal.isUnset()) + RetVal = S.ActOnCXXBoolLiteral(Loc, tok::kw_true); + break; + } + + case DefaultedComparisonKind::ThreeWay: { + // Per C++2a [class.spaceship]p3, as a fallback add: + // return static_cast(std::strong_ordering::equal); + QualType StrongOrdering = S.CheckComparisonCategoryType( + ComparisonCategoryType::StrongOrdering, Loc, + Sema::ComparisonCategoryUsage::DefaultedOperator); + if (StrongOrdering.isNull()) + return StmtError(); + VarDecl *EqualVD = S.Context.CompCategories.getInfoForType(StrongOrdering) + .getValueInfo(ComparisonCategoryResult::Equal) + ->VD; + RetVal = getDecl(EqualVD); + if (RetVal.isInvalid()) + return StmtError(); + RetVal = buildStaticCastToR(RetVal.get()); + break; + } + + case DefaultedComparisonKind::NotEqual: + case DefaultedComparisonKind::Relational: + RetVal = cast(Stmts.Stmts.pop_back_val()); + break; + } + + // Build the final return statement. + if (RetVal.isInvalid()) + return StmtError(); + StmtResult ReturnStmt = S.BuildReturnStmt(Loc, RetVal.get()); + if (ReturnStmt.isInvalid()) + return StmtError(); + Stmts.Stmts.push_back(ReturnStmt.get()); + + return S.ActOnCompoundStmt(Loc, Loc, Stmts.Stmts, /*IsStmtExpr=*/false); + } + + private: + ExprResult getDecl(ValueDecl *VD) { + return S.BuildDeclarationNameExpr( + CXXScopeSpec(), DeclarationNameInfo(VD->getDeclName(), Loc), VD); + } + + ExprResult getParam(unsigned I) { + ParmVarDecl *PD = FD->getParamDecl(I); + return getDecl(PD); + } + + ExprPair getCompleteObject() { + unsigned Param = 0; + ExprResult LHS; + if (isa(FD)) { + // LHS is '*this'. + LHS = S.ActOnCXXThis(Loc); + if (!LHS.isInvalid()) + LHS = S.CreateBuiltinUnaryOp(Loc, UO_Deref, LHS.get()); + } else { + LHS = getParam(Param++); + } + ExprResult RHS = getParam(Param++); + assert(Param == FD->getNumParams()); + return {LHS, RHS}; + } + + ExprPair getBase(CXXBaseSpecifier *Base) { + ExprPair Obj = getCompleteObject(); + if (Obj.first.isInvalid() || Obj.second.isInvalid()) + return {ExprError(), ExprError()}; + CXXCastPath Path = {Base}; + return {S.ImpCastExprToType(Obj.first.get(), Base->getType(), + CK_DerivedToBase, VK_LValue, &Path), + S.ImpCastExprToType(Obj.second.get(), Base->getType(), + CK_DerivedToBase, VK_LValue, &Path)}; + } + + ExprPair getField(FieldDecl *Field) { + ExprPair Obj = getCompleteObject(); + if (Obj.first.isInvalid() || Obj.second.isInvalid()) + return {ExprError(), ExprError()}; + + DeclAccessPair Found = DeclAccessPair::make(Field, Field->getAccess()); + DeclarationNameInfo NameInfo(Field->getDeclName(), Loc); + return {S.BuildFieldReferenceExpr(Obj.first.get(), /*IsArrow=*/false, Loc, + CXXScopeSpec(), Field, Found, NameInfo), + S.BuildFieldReferenceExpr(Obj.second.get(), /*IsArrow=*/false, Loc, + CXXScopeSpec(), Field, Found, NameInfo)}; + } + + // FIXME: When expanding a subobject, register a note in the code synthesis + // stack to say which subobject we're comparing. + + StmtResult buildIfNotCondReturnFalse(ExprResult Cond) { + if (Cond.isInvalid()) + return StmtError(); + + ExprResult NotCond = S.CreateBuiltinUnaryOp(Loc, UO_LNot, Cond.get()); + if (NotCond.isInvalid()) + return StmtError(); + + ExprResult False = S.ActOnCXXBoolLiteral(Loc, tok::kw_false); + assert(!False.isInvalid() && "should never fail"); + StmtResult ReturnFalse = S.BuildReturnStmt(Loc, False.get()); + if (ReturnFalse.isInvalid()) + return StmtError(); + + return S.ActOnIfStmt(Loc, IfStatementKind::Ordinary, Loc, nullptr, + S.ActOnCondition(nullptr, Loc, NotCond.get(), + Sema::ConditionKind::Boolean), + Loc, ReturnFalse.get(), SourceLocation(), nullptr); + } + + StmtResult visitSubobjectArray(QualType Type, llvm::APInt Size, + ExprPair Subobj) { + QualType SizeType = S.Context.getSizeType(); + Size = Size.zextOrTrunc(S.Context.getTypeSize(SizeType)); + + // Build 'size_t i$n = 0'. + IdentifierInfo *IterationVarName = nullptr; + { + SmallString<8> Str; + llvm::raw_svector_ostream OS(Str); + OS << "i" << ArrayDepth; + IterationVarName = &S.Context.Idents.get(OS.str()); + } + VarDecl *IterationVar = VarDecl::Create( + S.Context, S.CurContext, Loc, Loc, IterationVarName, SizeType, + S.Context.getTrivialTypeSourceInfo(SizeType, Loc), SC_None); + llvm::APInt Zero(S.Context.getTypeSize(SizeType), 0); + IterationVar->setInit( + IntegerLiteral::Create(S.Context, Zero, SizeType, Loc)); + Stmt *Init = new (S.Context) DeclStmt(DeclGroupRef(IterationVar), Loc, Loc); + + auto IterRef = [&] { + ExprResult Ref = S.BuildDeclarationNameExpr( + CXXScopeSpec(), DeclarationNameInfo(IterationVarName, Loc), + IterationVar); + assert(!Ref.isInvalid() && "can't reference our own variable?"); + return Ref.get(); + }; + + // Build 'i$n != Size'. + ExprResult Cond = S.CreateBuiltinBinOp( + Loc, BO_NE, IterRef(), + IntegerLiteral::Create(S.Context, Size, SizeType, Loc)); + assert(!Cond.isInvalid() && "should never fail"); + + // Build '++i$n'. + ExprResult Inc = S.CreateBuiltinUnaryOp(Loc, UO_PreInc, IterRef()); + assert(!Inc.isInvalid() && "should never fail"); + + // Build 'a[i$n]' and 'b[i$n]'. + auto Index = [&](ExprResult E) { + if (E.isInvalid()) + return ExprError(); + return S.CreateBuiltinArraySubscriptExpr(E.get(), Loc, IterRef(), Loc); + }; + Subobj.first = Index(Subobj.first); + Subobj.second = Index(Subobj.second); + + // Compare the array elements. + ++ArrayDepth; + StmtResult Substmt = visitSubobject(Type, Subobj); + --ArrayDepth; + + if (Substmt.isInvalid()) + return StmtError(); + + // For the inner level of an 'operator==', build 'if (!cmp) return false;'. + // For outer levels or for an 'operator<=>' we already have a suitable + // statement that returns as necessary. + if (Expr *ElemCmp = dyn_cast(Substmt.get())) { + assert(DCK == DefaultedComparisonKind::Equal && + "should have non-expression statement"); + Substmt = buildIfNotCondReturnFalse(ElemCmp); + if (Substmt.isInvalid()) + return StmtError(); + } + + // Build 'for (...) ...' + return S.ActOnForStmt(Loc, Loc, Init, + S.ActOnCondition(nullptr, Loc, Cond.get(), + Sema::ConditionKind::Boolean), + S.MakeFullDiscardedValueExpr(Inc.get()), Loc, + Substmt.get()); + } + + StmtResult visitExpandedSubobject(QualType Type, ExprPair Obj) { + if (Obj.first.isInvalid() || Obj.second.isInvalid()) + return StmtError(); + + OverloadedOperatorKind OO = FD->getOverloadedOperator(); + BinaryOperatorKind Opc = BinaryOperator::getOverloadedOpcode(OO); + ExprResult Op; + if (Type->isOverloadableType()) + Op = S.CreateOverloadedBinOp(Loc, Opc, Fns, Obj.first.get(), + Obj.second.get(), /*PerformADL=*/true, + /*AllowRewrittenCandidates=*/true, FD); + else + Op = S.CreateBuiltinBinOp(Loc, Opc, Obj.first.get(), Obj.second.get()); + if (Op.isInvalid()) + return StmtError(); + + switch (DCK) { + case DefaultedComparisonKind::None: + llvm_unreachable("not a defaulted comparison"); + + case DefaultedComparisonKind::Equal: + // Per C++2a [class.eq]p2, each comparison is individually contextually + // converted to bool. + Op = S.PerformContextuallyConvertToBool(Op.get()); + if (Op.isInvalid()) + return StmtError(); + return Op.get(); + + case DefaultedComparisonKind::ThreeWay: { + // Per C++2a [class.spaceship]p3, form: + // if (R cmp = static_cast(op); cmp != 0) + // return cmp; + QualType R = FD->getReturnType(); + Op = buildStaticCastToR(Op.get()); + if (Op.isInvalid()) + return StmtError(); + + // R cmp = ...; + IdentifierInfo *Name = &S.Context.Idents.get("cmp"); + VarDecl *VD = + VarDecl::Create(S.Context, S.CurContext, Loc, Loc, Name, R, + S.Context.getTrivialTypeSourceInfo(R, Loc), SC_None); + S.AddInitializerToDecl(VD, Op.get(), /*DirectInit=*/false); + Stmt *InitStmt = new (S.Context) DeclStmt(DeclGroupRef(VD), Loc, Loc); + + // cmp != 0 + ExprResult VDRef = getDecl(VD); + if (VDRef.isInvalid()) + return StmtError(); + llvm::APInt ZeroVal(S.Context.getIntWidth(S.Context.IntTy), 0); + Expr *Zero = + IntegerLiteral::Create(S.Context, ZeroVal, S.Context.IntTy, Loc); + ExprResult Comp; + if (VDRef.get()->getType()->isOverloadableType()) + Comp = S.CreateOverloadedBinOp(Loc, BO_NE, Fns, VDRef.get(), Zero, true, + true, FD); + else + Comp = S.CreateBuiltinBinOp(Loc, BO_NE, VDRef.get(), Zero); + if (Comp.isInvalid()) + return StmtError(); + Sema::ConditionResult Cond = S.ActOnCondition( + nullptr, Loc, Comp.get(), Sema::ConditionKind::Boolean); + if (Cond.isInvalid()) + return StmtError(); + + // return cmp; + VDRef = getDecl(VD); + if (VDRef.isInvalid()) + return StmtError(); + StmtResult ReturnStmt = S.BuildReturnStmt(Loc, VDRef.get()); + if (ReturnStmt.isInvalid()) + return StmtError(); + + // if (...) + return S.ActOnIfStmt(Loc, IfStatementKind::Ordinary, Loc, InitStmt, Cond, + Loc, ReturnStmt.get(), + /*ElseLoc=*/SourceLocation(), /*Else=*/nullptr); + } + + case DefaultedComparisonKind::NotEqual: + case DefaultedComparisonKind::Relational: + // C++2a [class.compare.secondary]p2: + // Otherwise, the operator function yields x @ y. + return Op.get(); + } + llvm_unreachable(""); + } + + /// Build "static_cast(E)". + ExprResult buildStaticCastToR(Expr *E) { + QualType R = FD->getReturnType(); + assert(!R->isUndeducedType() && "type should have been deduced already"); + + // Don't bother forming a no-op cast in the common case. + if (E->isPRValue() && S.Context.hasSameType(E->getType(), R)) + return E; + return S.BuildCXXNamedCast(Loc, tok::kw_static_cast, + S.Context.getTrivialTypeSourceInfo(R, Loc), E, + SourceRange(Loc, Loc), SourceRange(Loc, Loc)); + } + }; + } + + /// Perform the unqualified lookups that might be needed to form a defaulted + /// comparison function for the given operator. + static void lookupOperatorsForDefaultedComparison(Sema &Self, Scope *S, + UnresolvedSetImpl &Operators, + OverloadedOperatorKind Op) { + auto Lookup = [&](OverloadedOperatorKind OO) { + Self.LookupOverloadedOperatorName(OO, S, Operators); + }; + + // Every defaulted operator looks up itself. + Lookup(Op); + // ... and the rewritten form of itself, if any. + if (OverloadedOperatorKind ExtraOp = getRewrittenOverloadedOperator(Op)) + Lookup(ExtraOp); + + // For 'operator<=>', we also form a 'cmp != 0' expression, and might + // synthesize a three-way comparison from '<' and '=='. In a dependent + // context, we also need to look up '==' in case we implicitly declare a + // defaulted 'operator=='. + if (Op == OO_Spaceship) { + Lookup(OO_ExclaimEqual); + Lookup(OO_Less); + Lookup(OO_EqualEqual); + } + } + + bool Sema::CheckExplicitlyDefaultedComparison(Scope *S, FunctionDecl *FD, + DefaultedComparisonKind DCK) { + assert(DCK != DefaultedComparisonKind::None && "not a defaulted comparison"); + + // Perform any unqualified lookups we're going to need to default this + // function. + if (S) { + UnresolvedSet<32> Operators; + lookupOperatorsForDefaultedComparison(*this, S, Operators, + FD->getOverloadedOperator()); + FD->setDefaultedFunctionInfo(FunctionDecl::DefaultedFunctionInfo::Create( + Context, Operators.pairs())); + } + + // C++2a [class.compare.default]p1: + // A defaulted comparison operator function for some class C shall be a + // non-template function declared in the member-specification of C that is + // -- a non-static const member of C having one parameter of type + // const C&, or + // -- a friend of C having two parameters of type const C& or two + // parameters of type C. + + CXXRecordDecl *RD = dyn_cast(FD->getLexicalDeclContext()); + bool IsMethod = isa(FD); + if (IsMethod) { + auto *MD = cast(FD); + assert(!MD->isStatic() && "comparison function cannot be a static member"); + + // If we're out-of-class, this is the class we're comparing. + if (!RD) + RD = MD->getParent(); + + if (!MD->isConst()) { + SourceLocation InsertLoc; + if (FunctionTypeLoc Loc = MD->getFunctionTypeLoc()) + InsertLoc = getLocForEndOfToken(Loc.getRParenLoc()); + // Don't diagnose an implicit 'operator=='; we will have diagnosed the + // corresponding defaulted 'operator<=>' already. + if (!MD->isImplicit()) { + Diag(MD->getLocation(), diag::err_defaulted_comparison_non_const) + << (int)DCK << FixItHint::CreateInsertion(InsertLoc, " const"); + } + + // Add the 'const' to the type to recover. + const auto *FPT = MD->getType()->castAs(); + FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo(); + EPI.TypeQuals.addConst(); + MD->setType(Context.getFunctionType(FPT->getReturnType(), + FPT->getParamTypes(), EPI)); + } + } + + if (FD->getNumParams() != (IsMethod ? 1 : 2)) { + // Let's not worry about using a variadic template pack here -- who would do + // such a thing? + Diag(FD->getLocation(), diag::err_defaulted_comparison_num_args) + << int(IsMethod) << int(DCK); + return true; + } + + const ParmVarDecl *KnownParm = nullptr; + for (const ParmVarDecl *Param : FD->parameters()) { + QualType ParmTy = Param->getType(); + + if (!KnownParm) { + auto CTy = ParmTy; + // Is it `T const &`? + bool Ok = !IsMethod; + QualType ExpectedTy; + if (RD) + ExpectedTy = Context.getRecordType(RD); + if (auto *Ref = CTy->getAs()) { + CTy = Ref->getPointeeType(); + if (RD) + ExpectedTy.addConst(); + Ok = true; + } + + // Is T a class? + if (!Ok) { + } else if (RD) { + if (!RD->isDependentType() && !Context.hasSameType(CTy, ExpectedTy)) + Ok = false; + } else if (auto *CRD = CTy->getAsRecordDecl()) { + RD = cast(CRD); + } else { + Ok = false; + } + + if (Ok) { + KnownParm = Param; + } else { + // Don't diagnose an implicit 'operator=='; we will have diagnosed the + // corresponding defaulted 'operator<=>' already. + if (!FD->isImplicit()) { + if (RD) { + QualType PlainTy = Context.getRecordType(RD); + QualType RefTy = + Context.getLValueReferenceType(PlainTy.withConst()); + Diag(FD->getLocation(), diag::err_defaulted_comparison_param) + << int(DCK) << ParmTy << RefTy << int(!IsMethod) << PlainTy + << Param->getSourceRange(); + } else { + assert(!IsMethod && "should know expected type for method"); + Diag(FD->getLocation(), + diag::err_defaulted_comparison_param_unknown) + << int(DCK) << ParmTy << Param->getSourceRange(); + } + } + return true; + } + } else if (!Context.hasSameType(KnownParm->getType(), ParmTy)) { + Diag(FD->getLocation(), diag::err_defaulted_comparison_param_mismatch) + << int(DCK) << KnownParm->getType() << KnownParm->getSourceRange() + << ParmTy << Param->getSourceRange(); + return true; + } + } + + assert(RD && "must have determined class"); + if (IsMethod) { + } else if (isa(FD->getLexicalDeclContext())) { + // In-class, must be a friend decl. + assert(FD->getFriendObjectKind() && "expected a friend declaration"); + } else { + // Out of class, require the defaulted comparison to be a friend (of a + // complete type). + if (RequireCompleteType(FD->getLocation(), Context.getRecordType(RD), + diag::err_defaulted_comparison_not_friend, int(DCK), + int(1))) + return true; + + if (llvm::none_of(RD->friends(), [&](const FriendDecl *F) { + return FD->getCanonicalDecl() == + F->getFriendDecl()->getCanonicalDecl(); + })) { + Diag(FD->getLocation(), diag::err_defaulted_comparison_not_friend) + << int(DCK) << int(0) << RD; + Diag(RD->getCanonicalDecl()->getLocation(), diag::note_declared_at); + return true; + } + } + + // C++2a [class.eq]p1, [class.rel]p1: + // A [defaulted comparison other than <=>] shall have a declared return + // type bool. + if (DCK != DefaultedComparisonKind::ThreeWay && + !FD->getDeclaredReturnType()->isDependentType() && + !Context.hasSameType(FD->getDeclaredReturnType(), Context.BoolTy)) { + Diag(FD->getLocation(), diag::err_defaulted_comparison_return_type_not_bool) + << (int)DCK << FD->getDeclaredReturnType() << Context.BoolTy + << FD->getReturnTypeSourceRange(); + return true; + } + // C++2a [class.spaceship]p2 [P2002R0]: + // Let R be the declared return type [...]. If R is auto, [...]. Otherwise, + // R shall not contain a placeholder type. + if (QualType RT = FD->getDeclaredReturnType(); + DCK == DefaultedComparisonKind::ThreeWay && + RT->getContainedDeducedType() && + (!Context.hasSameType(RT, Context.getAutoDeductType()) || + RT->getContainedAutoType()->isConstrained())) { + Diag(FD->getLocation(), + diag::err_defaulted_comparison_deduced_return_type_not_auto) + << (int)DCK << FD->getDeclaredReturnType() << Context.AutoDeductTy + << FD->getReturnTypeSourceRange(); + return true; + } + + // For a defaulted function in a dependent class, defer all remaining checks + // until instantiation. + if (RD->isDependentType()) + return false; + + // Determine whether the function should be defined as deleted. + DefaultedComparisonInfo Info = + DefaultedComparisonAnalyzer(*this, RD, FD, DCK).visit(); + + bool First = FD == FD->getCanonicalDecl(); + + if (!First) { + if (Info.Deleted) { + // C++11 [dcl.fct.def.default]p4: + // [For a] user-provided explicitly-defaulted function [...] if such a + // function is implicitly defined as deleted, the program is ill-formed. + // + // This is really just a consequence of the general rule that you can + // only delete a function on its first declaration. + Diag(FD->getLocation(), diag::err_non_first_default_compare_deletes) + << FD->isImplicit() << (int)DCK; + DefaultedComparisonAnalyzer(*this, RD, FD, DCK, + DefaultedComparisonAnalyzer::ExplainDeleted) + .visit(); + return true; + } + if (isa(FD->getLexicalDeclContext())) { + // C++20 [class.compare.default]p1: + // [...] A definition of a comparison operator as defaulted that appears + // in a class shall be the first declaration of that function. + Diag(FD->getLocation(), diag::err_non_first_default_compare_in_class) + << (int)DCK; + Diag(FD->getCanonicalDecl()->getLocation(), + diag::note_previous_declaration); + return true; + } + } + + // If we want to delete the function, then do so; there's nothing else to + // check in that case. + if (Info.Deleted) { + SetDeclDeleted(FD, FD->getLocation()); + if (!inTemplateInstantiation() && !FD->isImplicit()) { + Diag(FD->getLocation(), diag::warn_defaulted_comparison_deleted) + << (int)DCK; + DefaultedComparisonAnalyzer(*this, RD, FD, DCK, + DefaultedComparisonAnalyzer::ExplainDeleted) + .visit(); + if (FD->getDefaultLoc().isValid()) + Diag(FD->getDefaultLoc(), diag::note_replace_equals_default_to_delete) + << FixItHint::CreateReplacement(FD->getDefaultLoc(), "delete"); + } + return false; + } + + // C++2a [class.spaceship]p2: + // The return type is deduced as the common comparison type of R0, R1, ... + if (DCK == DefaultedComparisonKind::ThreeWay && + FD->getDeclaredReturnType()->isUndeducedAutoType()) { + SourceLocation RetLoc = FD->getReturnTypeSourceRange().getBegin(); + if (RetLoc.isInvalid()) + RetLoc = FD->getBeginLoc(); + // FIXME: Should we really care whether we have the complete type and the + // 'enumerator' constants here? A forward declaration seems sufficient. + QualType Cat = CheckComparisonCategoryType( + Info.Category, RetLoc, ComparisonCategoryUsage::DefaultedOperator); + if (Cat.isNull()) + return true; + Context.adjustDeducedFunctionResultType( + FD, SubstAutoType(FD->getDeclaredReturnType(), Cat)); + } + + // C++2a [dcl.fct.def.default]p3 [P2002R0]: + // An explicitly-defaulted function that is not defined as deleted may be + // declared constexpr or consteval only if it is constexpr-compatible. + // C++2a [class.compare.default]p3 [P2002R0]: + // A defaulted comparison function is constexpr-compatible if it satisfies + // the requirements for a constexpr function [...] + // The only relevant requirements are that the parameter and return types are + // literal types. The remaining conditions are checked by the analyzer. + // + // We support P2448R2 in language modes earlier than C++23 as an extension. + // The concept of constexpr-compatible was removed. + // C++23 [dcl.fct.def.default]p3 [P2448R2] + // A function explicitly defaulted on its first declaration is implicitly + // inline, and is implicitly constexpr if it is constexpr-suitable. + // C++23 [dcl.constexpr]p3 + // A function is constexpr-suitable if + // - it is not a coroutine, and + // - if the function is a constructor or destructor, its class does not + // have any virtual base classes. + if (FD->isConstexpr()) { + if (CheckConstexprReturnType(*this, FD, CheckConstexprKind::Diagnose) && + CheckConstexprParameterTypes(*this, FD, CheckConstexprKind::Diagnose) && + !Info.Constexpr) { + Diag(FD->getBeginLoc(), + getLangOpts().CPlusPlus23 + ? diag::warn_cxx23_compat_defaulted_comparison_constexpr_mismatch + : diag::ext_defaulted_comparison_constexpr_mismatch) + << FD->isImplicit() << (int)DCK << FD->isConsteval(); + DefaultedComparisonAnalyzer(*this, RD, FD, DCK, + DefaultedComparisonAnalyzer::ExplainConstexpr) + .visit(); + } + } + + // C++2a [dcl.fct.def.default]p3 [P2002R0]: + // If a constexpr-compatible function is explicitly defaulted on its first + // declaration, it is implicitly considered to be constexpr. + // FIXME: Only applying this to the first declaration seems problematic, as + // simple reorderings can affect the meaning of the program. + if (First && !FD->isConstexpr() && Info.Constexpr) + FD->setConstexprKind(ConstexprSpecKind::Constexpr); + + // C++2a [except.spec]p3: + // If a declaration of a function does not have a noexcept-specifier + // [and] is defaulted on its first declaration, [...] the exception + // specification is as specified below + if (FD->getExceptionSpecType() == EST_None) { + auto *FPT = FD->getType()->castAs(); + FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo(); + EPI.ExceptionSpec.Type = EST_Unevaluated; + EPI.ExceptionSpec.SourceDecl = FD; + FD->setType(Context.getFunctionType(FPT->getReturnType(), + FPT->getParamTypes(), EPI)); + } + + return false; + } + + void Sema::DeclareImplicitEqualityComparison(CXXRecordDecl *RD, + FunctionDecl *Spaceship) { + Sema::CodeSynthesisContext Ctx; + Ctx.Kind = Sema::CodeSynthesisContext::DeclaringImplicitEqualityComparison; + Ctx.PointOfInstantiation = Spaceship->getEndLoc(); + Ctx.Entity = Spaceship; + pushCodeSynthesisContext(Ctx); + + if (FunctionDecl *EqualEqual = SubstSpaceshipAsEqualEqual(RD, Spaceship)) + EqualEqual->setImplicit(); + + popCodeSynthesisContext(); + } + + void Sema::DefineDefaultedComparison(SourceLocation UseLoc, FunctionDecl *FD, + DefaultedComparisonKind DCK) { + assert(FD->isDefaulted() && !FD->isDeleted() && + !FD->doesThisDeclarationHaveABody()); + if (FD->willHaveBody() || FD->isInvalidDecl()) + return; + + SynthesizedFunctionScope Scope(*this, FD); + + // Add a context note for diagnostics produced after this point. + Scope.addContextNote(UseLoc); + + { + // Build and set up the function body. + // The first parameter has type maybe-ref-to maybe-const T, use that to get + // the type of the class being compared. + auto PT = FD->getParamDecl(0)->getType(); + CXXRecordDecl *RD = PT.getNonReferenceType()->getAsCXXRecordDecl(); + SourceLocation BodyLoc = + FD->getEndLoc().isValid() ? FD->getEndLoc() : FD->getLocation(); + StmtResult Body = + DefaultedComparisonSynthesizer(*this, RD, FD, DCK, BodyLoc).build(); + if (Body.isInvalid()) { + FD->setInvalidDecl(); + return; + } + FD->setBody(Body.get()); + FD->markUsed(Context); + } + + // The exception specification is needed because we are defining the + // function. Note that this will reuse the body we just built. + ResolveExceptionSpec(UseLoc, FD->getType()->castAs()); + + if (ASTMutationListener *L = getASTMutationListener()) + L->CompletedImplicitDefinition(FD); + } + + static Sema::ImplicitExceptionSpecification + ComputeDefaultedComparisonExceptionSpec(Sema &S, SourceLocation Loc, + FunctionDecl *FD, + Sema::DefaultedComparisonKind DCK) { + ComputingExceptionSpec CES(S, FD, Loc); + Sema::ImplicitExceptionSpecification ExceptSpec(S); + + if (FD->isInvalidDecl()) + return ExceptSpec; + + // The common case is that we just defined the comparison function. In that + // case, just look at whether the body can throw. + if (FD->hasBody()) { + ExceptSpec.CalledStmt(FD->getBody()); + } else { + // Otherwise, build a body so we can check it. This should ideally only + // happen when we're not actually marking the function referenced. (This is + // only really important for efficiency: we don't want to build and throw + // away bodies for comparison functions more than we strictly need to.) + + // Pretend to synthesize the function body in an unevaluated context. + // Note that we can't actually just go ahead and define the function here: + // we are not permitted to mark its callees as referenced. + Sema::SynthesizedFunctionScope Scope(S, FD); + EnterExpressionEvaluationContext Context( + S, Sema::ExpressionEvaluationContext::Unevaluated); + + CXXRecordDecl *RD = cast(FD->getLexicalParent()); + SourceLocation BodyLoc = + FD->getEndLoc().isValid() ? FD->getEndLoc() : FD->getLocation(); + StmtResult Body = + DefaultedComparisonSynthesizer(S, RD, FD, DCK, BodyLoc).build(); + if (!Body.isInvalid()) + ExceptSpec.CalledStmt(Body.get()); + + // FIXME: Can we hold onto this body and just transform it to potentially + // evaluated when we're asked to define the function rather than rebuilding + // it? Either that, or we should only build the bits of the body that we + // need (the expressions, not the statements). + } + + return ExceptSpec; + } + + void Sema::CheckDelayedMemberExceptionSpecs() { + decltype(DelayedOverridingExceptionSpecChecks) Overriding; + decltype(DelayedEquivalentExceptionSpecChecks) Equivalent; + + std::swap(Overriding, DelayedOverridingExceptionSpecChecks); + std::swap(Equivalent, DelayedEquivalentExceptionSpecChecks); + + // Perform any deferred checking of exception specifications for virtual + // destructors. + for (auto &Check : Overriding) + CheckOverridingFunctionExceptionSpec(Check.first, Check.second); + + // Perform any deferred checking of exception specifications for befriended + // special members. + for (auto &Check : Equivalent) + CheckEquivalentExceptionSpec(Check.second, Check.first); + } + + namespace { + /// CRTP base class for visiting operations performed by a special member + /// function (or inherited constructor). + template + struct SpecialMemberVisitor { + Sema &S; + CXXMethodDecl *MD; + Sema::CXXSpecialMember CSM; + Sema::InheritedConstructorInfo *ICI; + + // Properties of the special member, computed for convenience. + bool IsConstructor = false, IsAssignment = false, ConstArg = false; + + SpecialMemberVisitor(Sema &S, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM, + Sema::InheritedConstructorInfo *ICI) + : S(S), MD(MD), CSM(CSM), ICI(ICI) { + switch (CSM) { + case Sema::CXXDefaultConstructor: + case Sema::CXXCopyConstructor: + case Sema::CXXMoveConstructor: + IsConstructor = true; + break; + case Sema::CXXCopyAssignment: + case Sema::CXXMoveAssignment: + IsAssignment = true; + break; + case Sema::CXXDestructor: + break; + case Sema::CXXInvalid: + llvm_unreachable("invalid special member kind"); + } + + if (MD->getNumParams()) { + if (const ReferenceType *RT = + MD->getParamDecl(0)->getType()->getAs()) + ConstArg = RT->getPointeeType().isConstQualified(); + } + } + + Derived &getDerived() { return static_cast(*this); } + + /// Is this a "move" special member? + bool isMove() const { + return CSM == Sema::CXXMoveConstructor || CSM == Sema::CXXMoveAssignment; + } + + /// Look up the corresponding special member in the given class. + Sema::SpecialMemberOverloadResult lookupIn(CXXRecordDecl *Class, + unsigned Quals, bool IsMutable) { + return lookupCallFromSpecialMember(S, Class, CSM, Quals, + ConstArg && !IsMutable); + } + + /// Look up the constructor for the specified base class to see if it's + /// overridden due to this being an inherited constructor. + Sema::SpecialMemberOverloadResult lookupInheritedCtor(CXXRecordDecl *Class) { + if (!ICI) + return {}; + assert(CSM == Sema::CXXDefaultConstructor); + auto *BaseCtor = + cast(MD)->getInheritedConstructor().getConstructor(); + if (auto *MD = ICI->findConstructorForBase(Class, BaseCtor).first) + return MD; + return {}; + } + + /// A base or member subobject. + typedef llvm::PointerUnion Subobject; + + /// Get the location to use for a subobject in diagnostics. + static SourceLocation getSubobjectLoc(Subobject Subobj) { + // FIXME: For an indirect virtual base, the direct base leading to + // the indirect virtual base would be a more useful choice. + if (auto *B = Subobj.dyn_cast()) + return B->getBaseTypeLoc(); + else + return Subobj.get()->getLocation(); + } + + enum BasesToVisit { + /// Visit all non-virtual (direct) bases. + VisitNonVirtualBases, + /// Visit all direct bases, virtual or not. + VisitDirectBases, + /// Visit all non-virtual bases, and all virtual bases if the class + /// is not abstract. + VisitPotentiallyConstructedBases, + /// Visit all direct or virtual bases. + VisitAllBases + }; + + // Visit the bases and members of the class. + bool visit(BasesToVisit Bases) { + CXXRecordDecl *RD = MD->getParent(); + + if (Bases == VisitPotentiallyConstructedBases) + Bases = RD->isAbstract() ? VisitNonVirtualBases : VisitAllBases; + + for (auto &B : RD->bases()) + if ((Bases == VisitDirectBases || !B.isVirtual()) && + getDerived().visitBase(&B)) + return true; + + if (Bases == VisitAllBases) + for (auto &B : RD->vbases()) + if (getDerived().visitBase(&B)) + return true; + + for (auto *F : RD->fields()) + if (!F->isInvalidDecl() && !F->isUnnamedBitfield() && + getDerived().visitField(F)) + return true; + + return false; + } + }; + } + + namespace { + struct SpecialMemberDeletionInfo + : SpecialMemberVisitor { + bool Diagnose; + + SourceLocation Loc; + + bool AllFieldsAreConst; + + SpecialMemberDeletionInfo(Sema &S, CXXMethodDecl *MD, + Sema::CXXSpecialMember CSM, + Sema::InheritedConstructorInfo *ICI, bool Diagnose) + : SpecialMemberVisitor(S, MD, CSM, ICI), Diagnose(Diagnose), + Loc(MD->getLocation()), AllFieldsAreConst(true) {} + + bool inUnion() const { return MD->getParent()->isUnion(); } + + Sema::CXXSpecialMember getEffectiveCSM() { + return ICI ? Sema::CXXInvalid : CSM; + } + + bool shouldDeleteForVariantObjCPtrMember(FieldDecl *FD, QualType FieldType); + + bool visitBase(CXXBaseSpecifier *Base) { return shouldDeleteForBase(Base); } + bool visitField(FieldDecl *Field) { return shouldDeleteForField(Field); } + + bool shouldDeleteForBase(CXXBaseSpecifier *Base); + bool shouldDeleteForField(FieldDecl *FD); + bool shouldDeleteForAllConstMembers(); + + bool shouldDeleteForClassSubobject(CXXRecordDecl *Class, Subobject Subobj, + unsigned Quals); + bool shouldDeleteForSubobjectCall(Subobject Subobj, + Sema::SpecialMemberOverloadResult SMOR, + bool IsDtorCallInCtor); + + bool isAccessible(Subobject Subobj, CXXMethodDecl *D); + }; + } + + /// Is the given special member inaccessible when used on the given + /// sub-object. + bool SpecialMemberDeletionInfo::isAccessible(Subobject Subobj, + CXXMethodDecl *target) { + /// If we're operating on a base class, the object type is the + /// type of this special member. + QualType objectTy; + AccessSpecifier access = target->getAccess(); + if (CXXBaseSpecifier *base = Subobj.dyn_cast()) { + objectTy = S.Context.getTypeDeclType(MD->getParent()); + access = CXXRecordDecl::MergeAccess(base->getAccessSpecifier(), access); + + // If we're operating on a field, the object type is the type of the field. + } else { + objectTy = S.Context.getTypeDeclType(target->getParent()); + } + + return S.isMemberAccessibleForDeletion( + target->getParent(), DeclAccessPair::make(target, access), objectTy); + } + + /// Check whether we should delete a special member due to the implicit + /// definition containing a call to a special member of a subobject. + bool SpecialMemberDeletionInfo::shouldDeleteForSubobjectCall( + Subobject Subobj, Sema::SpecialMemberOverloadResult SMOR, + bool IsDtorCallInCtor) { + CXXMethodDecl *Decl = SMOR.getMethod(); + FieldDecl *Field = Subobj.dyn_cast(); + + int DiagKind = -1; + + if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::NoMemberOrDeleted) + DiagKind = !Decl ? 0 : 1; + else if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::Ambiguous) + DiagKind = 2; + else if (!isAccessible(Subobj, Decl)) + DiagKind = 3; + else if (!IsDtorCallInCtor && Field && Field->getParent()->isUnion() && + !Decl->isTrivial()) { + // A member of a union must have a trivial corresponding special member. + // As a weird special case, a destructor call from a union's constructor + // must be accessible and non-deleted, but need not be trivial. Such a + // destructor is never actually called, but is semantically checked as + // if it were. + if (CSM == Sema::CXXDefaultConstructor) { + // [class.default.ctor]p2: + // A defaulted default constructor for class X is defined as deleted if + // - X is a union that has a variant member with a non-trivial default + // constructor and no variant member of X has a default member + // initializer + const auto *RD = cast(Field->getParent()); + if (!RD->hasInClassInitializer()) + DiagKind = 4; + } else { + DiagKind = 4; + } + } + + if (DiagKind == -1) + return false; + + if (Diagnose) { + if (Field) { + S.Diag(Field->getLocation(), + diag::note_deleted_special_member_class_subobject) + << getEffectiveCSM() << MD->getParent() << /*IsField*/true + << Field << DiagKind << IsDtorCallInCtor << /*IsObjCPtr*/false; + } else { + CXXBaseSpecifier *Base = Subobj.get(); + S.Diag(Base->getBeginLoc(), + diag::note_deleted_special_member_class_subobject) + << getEffectiveCSM() << MD->getParent() << /*IsField*/ false + << Base->getType() << DiagKind << IsDtorCallInCtor + << /*IsObjCPtr*/false; + } + + if (DiagKind == 1) + S.NoteDeletedFunction(Decl); + // FIXME: Explain inaccessibility if DiagKind == 3. + } + + return true; + } + + /// Check whether we should delete a special member function due to having a + /// direct or virtual base class or non-static data member of class type M. + bool SpecialMemberDeletionInfo::shouldDeleteForClassSubobject( + CXXRecordDecl *Class, Subobject Subobj, unsigned Quals) { + FieldDecl *Field = Subobj.dyn_cast(); + bool IsMutable = Field && Field->isMutable(); + + // C++11 [class.ctor]p5: + // -- any direct or virtual base class, or non-static data member with no + // brace-or-equal-initializer, has class type M (or array thereof) and + // either M has no default constructor or overload resolution as applied + // to M's default constructor results in an ambiguity or in a function + // that is deleted or inaccessible + // C++11 [class.copy]p11, C++11 [class.copy]p23: + // -- a direct or virtual base class B that cannot be copied/moved because + // overload resolution, as applied to B's corresponding special member, + // results in an ambiguity or a function that is deleted or inaccessible + // from the defaulted special member + // C++11 [class.dtor]p5: + // -- any direct or virtual base class [...] has a type with a destructor + // that is deleted or inaccessible + if (!(CSM == Sema::CXXDefaultConstructor && + Field && Field->hasInClassInitializer()) && + shouldDeleteForSubobjectCall(Subobj, lookupIn(Class, Quals, IsMutable), + false)) + return true; + + // C++11 [class.ctor]p5, C++11 [class.copy]p11: + // -- any direct or virtual base class or non-static data member has a + // type with a destructor that is deleted or inaccessible + if (IsConstructor) { + Sema::SpecialMemberOverloadResult SMOR = + S.LookupSpecialMember(Class, Sema::CXXDestructor, + false, false, false, false, false); + if (shouldDeleteForSubobjectCall(Subobj, SMOR, true)) + return true; + } + + return false; + } + + bool SpecialMemberDeletionInfo::shouldDeleteForVariantObjCPtrMember( + FieldDecl *FD, QualType FieldType) { + // The defaulted special functions are defined as deleted if this is a variant + // member with a non-trivial ownership type, e.g., ObjC __strong or __weak + // type under ARC. + if (!FieldType.hasNonTrivialObjCLifetime()) + return false; + + // Don't make the defaulted default constructor defined as deleted if the + // member has an in-class initializer. + if (CSM == Sema::CXXDefaultConstructor && FD->hasInClassInitializer()) + return false; + + if (Diagnose) { + auto *ParentClass = cast(FD->getParent()); + S.Diag(FD->getLocation(), + diag::note_deleted_special_member_class_subobject) + << getEffectiveCSM() << ParentClass << /*IsField*/true + << FD << 4 << /*IsDtorCallInCtor*/false << /*IsObjCPtr*/true; + } + + return true; + } + + /// Check whether we should delete a special member function due to the class + /// having a particular direct or virtual base class. + bool SpecialMemberDeletionInfo::shouldDeleteForBase(CXXBaseSpecifier *Base) { + CXXRecordDecl *BaseClass = Base->getType()->getAsCXXRecordDecl(); + // If program is correct, BaseClass cannot be null, but if it is, the error + // must be reported elsewhere. + if (!BaseClass) + return false; + // If we have an inheriting constructor, check whether we're calling an + // inherited constructor instead of a default constructor. + Sema::SpecialMemberOverloadResult SMOR = lookupInheritedCtor(BaseClass); + if (auto *BaseCtor = SMOR.getMethod()) { + // Note that we do not check access along this path; other than that, + // this is the same as shouldDeleteForSubobjectCall(Base, BaseCtor, false); + // FIXME: Check that the base has a usable destructor! Sink this into + // shouldDeleteForClassSubobject. + if (BaseCtor->isDeleted() && Diagnose) { + S.Diag(Base->getBeginLoc(), + diag::note_deleted_special_member_class_subobject) + << getEffectiveCSM() << MD->getParent() << /*IsField*/ false + << Base->getType() << /*Deleted*/ 1 << /*IsDtorCallInCtor*/ false + << /*IsObjCPtr*/false; + S.NoteDeletedFunction(BaseCtor); + } + return BaseCtor->isDeleted(); + } + return shouldDeleteForClassSubobject(BaseClass, Base, 0); + } + + /// Check whether we should delete a special member function due to the class + /// having a particular non-static data member. + bool SpecialMemberDeletionInfo::shouldDeleteForField(FieldDecl *FD) { + QualType FieldType = S.Context.getBaseElementType(FD->getType()); + CXXRecordDecl *FieldRecord = FieldType->getAsCXXRecordDecl(); + + if (inUnion() && shouldDeleteForVariantObjCPtrMember(FD, FieldType)) + return true; + + if (CSM == Sema::CXXDefaultConstructor) { + // For a default constructor, all references must be initialized in-class + // and, if a union, it must have a non-const member. + if (FieldType->isReferenceType() && !FD->hasInClassInitializer()) { + if (Diagnose) + S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field) + << !!ICI << MD->getParent() << FD << FieldType << /*Reference*/0; + return true; + } + // C++11 [class.ctor]p5 (modified by DR2394): any non-variant non-static + // data member of const-qualified type (or array thereof) with no + // brace-or-equal-initializer is not const-default-constructible. + if (!inUnion() && FieldType.isConstQualified() && + !FD->hasInClassInitializer() && + (!FieldRecord || !FieldRecord->allowConstDefaultInit())) { + if (Diagnose) + S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field) + << !!ICI << MD->getParent() << FD << FD->getType() << /*Const*/1; + return true; + } + + if (inUnion() && !FieldType.isConstQualified()) + AllFieldsAreConst = false; + } else if (CSM == Sema::CXXCopyConstructor) { + // For a copy constructor, data members must not be of rvalue reference + // type. + if (FieldType->isRValueReferenceType()) { + if (Diagnose) + S.Diag(FD->getLocation(), diag::note_deleted_copy_ctor_rvalue_reference) + << MD->getParent() << FD << FieldType; + return true; + } + } else if (IsAssignment) { + // For an assignment operator, data members must not be of reference type. + if (FieldType->isReferenceType()) { + if (Diagnose) + S.Diag(FD->getLocation(), diag::note_deleted_assign_field) + << isMove() << MD->getParent() << FD << FieldType << /*Reference*/0; + return true; + } + if (!FieldRecord && FieldType.isConstQualified()) { + // C++11 [class.copy]p23: + // -- a non-static data member of const non-class type (or array thereof) + if (Diagnose) + S.Diag(FD->getLocation(), diag::note_deleted_assign_field) + << isMove() << MD->getParent() << FD << FD->getType() << /*Const*/1; + return true; + } + } + + if (FieldRecord) { + // Some additional restrictions exist on the variant members. + if (!inUnion() && FieldRecord->isUnion() && + FieldRecord->isAnonymousStructOrUnion()) { + bool AllVariantFieldsAreConst = true; + + // FIXME: Handle anonymous unions declared within anonymous unions. + for (auto *UI : FieldRecord->fields()) { + QualType UnionFieldType = S.Context.getBaseElementType(UI->getType()); + + if (shouldDeleteForVariantObjCPtrMember(&*UI, UnionFieldType)) + return true; + + if (!UnionFieldType.isConstQualified()) + AllVariantFieldsAreConst = false; + + CXXRecordDecl *UnionFieldRecord = UnionFieldType->getAsCXXRecordDecl(); + if (UnionFieldRecord && + shouldDeleteForClassSubobject(UnionFieldRecord, UI, + UnionFieldType.getCVRQualifiers())) + return true; + } + + // At least one member in each anonymous union must be non-const + if (CSM == Sema::CXXDefaultConstructor && AllVariantFieldsAreConst && + !FieldRecord->field_empty()) { + if (Diagnose) + S.Diag(FieldRecord->getLocation(), + diag::note_deleted_default_ctor_all_const) + << !!ICI << MD->getParent() << /*anonymous union*/1; + return true; + } + + // Don't check the implicit member of the anonymous union type. + // This is technically non-conformant but supported, and we have a + // diagnostic for this elsewhere. + return false; + } + + if (shouldDeleteForClassSubobject(FieldRecord, FD, + FieldType.getCVRQualifiers())) + return true; + } + + return false; + } + + /// C++11 [class.ctor] p5: + /// A defaulted default constructor for a class X is defined as deleted if + /// X is a union and all of its variant members are of const-qualified type. + bool SpecialMemberDeletionInfo::shouldDeleteForAllConstMembers() { + // This is a silly definition, because it gives an empty union a deleted + // default constructor. Don't do that. + if (CSM == Sema::CXXDefaultConstructor && inUnion() && AllFieldsAreConst) { + bool AnyFields = false; + for (auto *F : MD->getParent()->fields()) + if ((AnyFields = !F->isUnnamedBitfield())) + break; + if (!AnyFields) + return false; + if (Diagnose) + S.Diag(MD->getParent()->getLocation(), + diag::note_deleted_default_ctor_all_const) + << !!ICI << MD->getParent() << /*not anonymous union*/0; + return true; + } + return false; + } + + /// Determine whether a defaulted special member function should be defined as + /// deleted, as specified in C++11 [class.ctor]p5, C++11 [class.copy]p11, + /// C++11 [class.copy]p23, and C++11 [class.dtor]p5. + bool Sema::ShouldDeleteSpecialMember(CXXMethodDecl *MD, CXXSpecialMember CSM, + InheritedConstructorInfo *ICI, + bool Diagnose) { + if (MD->isInvalidDecl()) + return false; + CXXRecordDecl *RD = MD->getParent(); + assert(!RD->isDependentType() && "do deletion after instantiation"); + if (!LangOpts.CPlusPlus11 || RD->isInvalidDecl()) + return false; + + // C++11 [expr.lambda.prim]p19: + // The closure type associated with a lambda-expression has a + // deleted (8.4.3) default constructor and a deleted copy + // assignment operator. + // C++2a adds back these operators if the lambda has no lambda-capture. + if (RD->isLambda() && !RD->lambdaIsDefaultConstructibleAndAssignable() && + (CSM == CXXDefaultConstructor || CSM == CXXCopyAssignment)) { + if (Diagnose) + Diag(RD->getLocation(), diag::note_lambda_decl); + return true; + } + + // For an anonymous struct or union, the copy and assignment special members + // will never be used, so skip the check. For an anonymous union declared at + // namespace scope, the constructor and destructor are used. + if (CSM != CXXDefaultConstructor && CSM != CXXDestructor && + RD->isAnonymousStructOrUnion()) + return false; + + // C++11 [class.copy]p7, p18: + // If the class definition declares a move constructor or move assignment + // operator, an implicitly declared copy constructor or copy assignment + // operator is defined as deleted. + if (MD->isImplicit() && + (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment)) { + CXXMethodDecl *UserDeclaredMove = nullptr; + + // In Microsoft mode up to MSVC 2013, a user-declared move only causes the + // deletion of the corresponding copy operation, not both copy operations. + // MSVC 2015 has adopted the standards conforming behavior. + bool DeletesOnlyMatchingCopy = + getLangOpts().MSVCCompat && + !getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015); + + if (RD->hasUserDeclaredMoveConstructor() && + (!DeletesOnlyMatchingCopy || CSM == CXXCopyConstructor)) { + if (!Diagnose) return true; + + // Find any user-declared move constructor. + for (auto *I : RD->ctors()) { + if (I->isMoveConstructor()) { + UserDeclaredMove = I; + break; + } + } + assert(UserDeclaredMove); + } else if (RD->hasUserDeclaredMoveAssignment() && + (!DeletesOnlyMatchingCopy || CSM == CXXCopyAssignment)) { + if (!Diagnose) return true; + + // Find any user-declared move assignment operator. + for (auto *I : RD->methods()) { + if (I->isMoveAssignmentOperator()) { + UserDeclaredMove = I; + break; + } + } + assert(UserDeclaredMove); + } + + if (UserDeclaredMove) { + Diag(UserDeclaredMove->getLocation(), + diag::note_deleted_copy_user_declared_move) + << (CSM == CXXCopyAssignment) << RD + << UserDeclaredMove->isMoveAssignmentOperator(); + return true; + } + } + + // Do access control from the special member function + ContextRAII MethodContext(*this, MD); + + // C++11 [class.dtor]p5: + // -- for a virtual destructor, lookup of the non-array deallocation function + // results in an ambiguity or in a function that is deleted or inaccessible + if (CSM == CXXDestructor && MD->isVirtual()) { + FunctionDecl *OperatorDelete = nullptr; + DeclarationName Name = + Context.DeclarationNames.getCXXOperatorName(OO_Delete); + if (FindDeallocationFunction(MD->getLocation(), MD->getParent(), Name, + OperatorDelete, /*Diagnose*/false)) { + if (Diagnose) + Diag(RD->getLocation(), diag::note_deleted_dtor_no_operator_delete); + return true; + } + } + + SpecialMemberDeletionInfo SMI(*this, MD, CSM, ICI, Diagnose); + + // Per DR1611, do not consider virtual bases of constructors of abstract + // classes, since we are not going to construct them. + // Per DR1658, do not consider virtual bases of destructors of abstract + // classes either. + // Per DR2180, for assignment operators we only assign (and thus only + // consider) direct bases. + if (SMI.visit(SMI.IsAssignment ? SMI.VisitDirectBases + : SMI.VisitPotentiallyConstructedBases)) + return true; + + if (SMI.shouldDeleteForAllConstMembers()) + return true; + + if (getLangOpts().CUDA) { + // We should delete the special member in CUDA mode if target inference + // failed. + // For inherited constructors (non-null ICI), CSM may be passed so that MD + // is treated as certain special member, which may not reflect what special + // member MD really is. However inferCUDATargetForImplicitSpecialMember + // expects CSM to match MD, therefore recalculate CSM. + assert(ICI || CSM == getSpecialMember(MD)); + auto RealCSM = CSM; + if (ICI) + RealCSM = getSpecialMember(MD); + + return inferCUDATargetForImplicitSpecialMember(RD, RealCSM, MD, + SMI.ConstArg, Diagnose); + } + + return false; + } + + void Sema::DiagnoseDeletedDefaultedFunction(FunctionDecl *FD) { + DefaultedFunctionKind DFK = getDefaultedFunctionKind(FD); + assert(DFK && "not a defaultable function"); + assert(FD->isDefaulted() && FD->isDeleted() && "not defaulted and deleted"); + + if (DFK.isSpecialMember()) { + ShouldDeleteSpecialMember(cast(FD), DFK.asSpecialMember(), + nullptr, /*Diagnose=*/true); + } else { + DefaultedComparisonAnalyzer( + *this, cast(FD->getLexicalDeclContext()), FD, + DFK.asComparison(), DefaultedComparisonAnalyzer::ExplainDeleted) + .visit(); + } + } + + /// Perform lookup for a special member of the specified kind, and determine + /// whether it is trivial. If the triviality can be determined without the + /// lookup, skip it. This is intended for use when determining whether a + /// special member of a containing object is trivial, and thus does not ever + /// perform overload resolution for default constructors. + /// + /// If \p Selected is not \c NULL, \c *Selected will be filled in with the + /// member that was most likely to be intended to be trivial, if any. + /// + /// If \p ForCall is true, look at CXXRecord::HasTrivialSpecialMembersForCall to + /// determine whether the special member is trivial. + static bool findTrivialSpecialMember(Sema &S, CXXRecordDecl *RD, + Sema::CXXSpecialMember CSM, unsigned Quals, + bool ConstRHS, + Sema::TrivialABIHandling TAH, + CXXMethodDecl **Selected) { + if (Selected) + *Selected = nullptr; + + switch (CSM) { + case Sema::CXXInvalid: + llvm_unreachable("not a special member"); + + case Sema::CXXDefaultConstructor: + // C++11 [class.ctor]p5: + // A default constructor is trivial if: + // - all the [direct subobjects] have trivial default constructors + // + // Note, no overload resolution is performed in this case. + if (RD->hasTrivialDefaultConstructor()) + return true; + + if (Selected) { + // If there's a default constructor which could have been trivial, dig it + // out. Otherwise, if there's any user-provided default constructor, point + // to that as an example of why there's not a trivial one. + CXXConstructorDecl *DefCtor = nullptr; + if (RD->needsImplicitDefaultConstructor()) + S.DeclareImplicitDefaultConstructor(RD); + for (auto *CI : RD->ctors()) { + if (!CI->isDefaultConstructor()) + continue; + DefCtor = CI; + if (!DefCtor->isUserProvided()) + break; + } + + *Selected = DefCtor; + } + + return false; + + case Sema::CXXDestructor: + // C++11 [class.dtor]p5: + // A destructor is trivial if: + // - all the direct [subobjects] have trivial destructors + if (RD->hasTrivialDestructor() || + (TAH == Sema::TAH_ConsiderTrivialABI && + RD->hasTrivialDestructorForCall())) + return true; + + if (Selected) { + if (RD->needsImplicitDestructor()) + S.DeclareImplicitDestructor(RD); + *Selected = RD->getDestructor(); + } + + return false; + + case Sema::CXXCopyConstructor: + // C++11 [class.copy]p12: + // A copy constructor is trivial if: + // - the constructor selected to copy each direct [subobject] is trivial + if (RD->hasTrivialCopyConstructor() || + (TAH == Sema::TAH_ConsiderTrivialABI && + RD->hasTrivialCopyConstructorForCall())) { + if (Quals == Qualifiers::Const) + // We must either select the trivial copy constructor or reach an + // ambiguity; no need to actually perform overload resolution. + return true; + } else if (!Selected) { + return false; + } + // In C++98, we are not supposed to perform overload resolution here, but we + // treat that as a language defect, as suggested on cxx-abi-dev, to treat + // cases like B as having a non-trivial copy constructor: + // struct A { template A(T&); }; + // struct B { mutable A a; }; + goto NeedOverloadResolution; + + case Sema::CXXCopyAssignment: + // C++11 [class.copy]p25: + // A copy assignment operator is trivial if: + // - the assignment operator selected to copy each direct [subobject] is + // trivial + if (RD->hasTrivialCopyAssignment()) { + if (Quals == Qualifiers::Const) + return true; + } else if (!Selected) { + return false; + } + // In C++98, we are not supposed to perform overload resolution here, but we + // treat that as a language defect. + goto NeedOverloadResolution; + + case Sema::CXXMoveConstructor: + case Sema::CXXMoveAssignment: + NeedOverloadResolution: + Sema::SpecialMemberOverloadResult SMOR = + lookupCallFromSpecialMember(S, RD, CSM, Quals, ConstRHS); + + // The standard doesn't describe how to behave if the lookup is ambiguous. + // We treat it as not making the member non-trivial, just like the standard + // mandates for the default constructor. This should rarely matter, because + // the member will also be deleted. + if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::Ambiguous) + return true; + + if (!SMOR.getMethod()) { + assert(SMOR.getKind() == + Sema::SpecialMemberOverloadResult::NoMemberOrDeleted); + return false; + } + + // We deliberately don't check if we found a deleted special member. We're + // not supposed to! + if (Selected) + *Selected = SMOR.getMethod(); + + if (TAH == Sema::TAH_ConsiderTrivialABI && + (CSM == Sema::CXXCopyConstructor || CSM == Sema::CXXMoveConstructor)) + return SMOR.getMethod()->isTrivialForCall(); + return SMOR.getMethod()->isTrivial(); + } + + llvm_unreachable("unknown special method kind"); + } + + static CXXConstructorDecl *findUserDeclaredCtor(CXXRecordDecl *RD) { + for (auto *CI : RD->ctors()) + if (!CI->isImplicit()) + return CI; + + // Look for constructor templates. + typedef CXXRecordDecl::specific_decl_iterator tmpl_iter; + for (tmpl_iter TI(RD->decls_begin()), TE(RD->decls_end()); TI != TE; ++TI) { + if (CXXConstructorDecl *CD = + dyn_cast(TI->getTemplatedDecl())) + return CD; + } + + return nullptr; + } + + /// The kind of subobject we are checking for triviality. The values of this + /// enumeration are used in diagnostics. + enum TrivialSubobjectKind { + /// The subobject is a base class. + TSK_BaseClass, + /// The subobject is a non-static data member. + TSK_Field, + /// The object is actually the complete object. + TSK_CompleteObject + }; + + /// Check whether the special member selected for a given type would be trivial. + static bool checkTrivialSubobjectCall(Sema &S, SourceLocation SubobjLoc, + QualType SubType, bool ConstRHS, + Sema::CXXSpecialMember CSM, + TrivialSubobjectKind Kind, + Sema::TrivialABIHandling TAH, bool Diagnose) { + CXXRecordDecl *SubRD = SubType->getAsCXXRecordDecl(); + if (!SubRD) + return true; + + CXXMethodDecl *Selected; + if (findTrivialSpecialMember(S, SubRD, CSM, SubType.getCVRQualifiers(), + ConstRHS, TAH, Diagnose ? &Selected : nullptr)) + return true; + + if (Diagnose) { + if (ConstRHS) + SubType.addConst(); + + if (!Selected && CSM == Sema::CXXDefaultConstructor) { + S.Diag(SubobjLoc, diag::note_nontrivial_no_def_ctor) + << Kind << SubType.getUnqualifiedType(); + if (CXXConstructorDecl *CD = findUserDeclaredCtor(SubRD)) + S.Diag(CD->getLocation(), diag::note_user_declared_ctor); + } else if (!Selected) + S.Diag(SubobjLoc, diag::note_nontrivial_no_copy) + << Kind << SubType.getUnqualifiedType() << CSM << SubType; + else if (Selected->isUserProvided()) { + if (Kind == TSK_CompleteObject) + S.Diag(Selected->getLocation(), diag::note_nontrivial_user_provided) + << Kind << SubType.getUnqualifiedType() << CSM; + else { + S.Diag(SubobjLoc, diag::note_nontrivial_user_provided) + << Kind << SubType.getUnqualifiedType() << CSM; + S.Diag(Selected->getLocation(), diag::note_declared_at); + } + } else { + if (Kind != TSK_CompleteObject) + S.Diag(SubobjLoc, diag::note_nontrivial_subobject) + << Kind << SubType.getUnqualifiedType() << CSM; + + // Explain why the defaulted or deleted special member isn't trivial. + S.SpecialMemberIsTrivial(Selected, CSM, Sema::TAH_IgnoreTrivialABI, + Diagnose); + } + } + + return false; + } + + /// Check whether the members of a class type allow a special member to be + /// trivial. + static bool checkTrivialClassMembers(Sema &S, CXXRecordDecl *RD, + Sema::CXXSpecialMember CSM, + bool ConstArg, + Sema::TrivialABIHandling TAH, + bool Diagnose) { + for (const auto *FI : RD->fields()) { + if (FI->isInvalidDecl() || FI->isUnnamedBitfield()) + continue; + + QualType FieldType = S.Context.getBaseElementType(FI->getType()); + + // Pretend anonymous struct or union members are members of this class. + if (FI->isAnonymousStructOrUnion()) { + if (!checkTrivialClassMembers(S, FieldType->getAsCXXRecordDecl(), + CSM, ConstArg, TAH, Diagnose)) + return false; + continue; + } + + // C++11 [class.ctor]p5: + // A default constructor is trivial if [...] + // -- no non-static data member of its class has a + // brace-or-equal-initializer + if (CSM == Sema::CXXDefaultConstructor && FI->hasInClassInitializer()) { + if (Diagnose) + S.Diag(FI->getLocation(), diag::note_nontrivial_default_member_init) + << FI; + return false; + } + + // Objective C ARC 4.3.5: + // [...] nontrivally ownership-qualified types are [...] not trivially + // default constructible, copy constructible, move constructible, copy + // assignable, move assignable, or destructible [...] + if (FieldType.hasNonTrivialObjCLifetime()) { + if (Diagnose) + S.Diag(FI->getLocation(), diag::note_nontrivial_objc_ownership) + << RD << FieldType.getObjCLifetime(); + return false; + } + + bool ConstRHS = ConstArg && !FI->isMutable(); + if (!checkTrivialSubobjectCall(S, FI->getLocation(), FieldType, ConstRHS, + CSM, TSK_Field, TAH, Diagnose)) + return false; + } + + return true; + } + + /// Diagnose why the specified class does not have a trivial special member of + /// the given kind. + void Sema::DiagnoseNontrivial(const CXXRecordDecl *RD, CXXSpecialMember CSM) { + QualType Ty = Context.getRecordType(RD); + + bool ConstArg = (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment); + checkTrivialSubobjectCall(*this, RD->getLocation(), Ty, ConstArg, CSM, + TSK_CompleteObject, TAH_IgnoreTrivialABI, + /*Diagnose*/true); + } + + /// Determine whether a defaulted or deleted special member function is trivial, + /// as specified in C++11 [class.ctor]p5, C++11 [class.copy]p12, + /// C++11 [class.copy]p25, and C++11 [class.dtor]p5. + bool Sema::SpecialMemberIsTrivial(CXXMethodDecl *MD, CXXSpecialMember CSM, + TrivialABIHandling TAH, bool Diagnose) { + assert(!MD->isUserProvided() && CSM != CXXInvalid && "not special enough"); + + CXXRecordDecl *RD = MD->getParent(); + + bool ConstArg = false; + + // C++11 [class.copy]p12, p25: [DR1593] + // A [special member] is trivial if [...] its parameter-type-list is + // equivalent to the parameter-type-list of an implicit declaration [...] + switch (CSM) { + case CXXDefaultConstructor: + case CXXDestructor: + // Trivial default constructors and destructors cannot have parameters. + break; + + case CXXCopyConstructor: + case CXXCopyAssignment: { + const ParmVarDecl *Param0 = MD->getParamDecl(0); + const ReferenceType *RT = Param0->getType()->getAs(); + + // When ClangABICompat14 is true, CXX copy constructors will only be trivial + // if they are not user-provided and their parameter-type-list is equivalent + // to the parameter-type-list of an implicit declaration. This maintains the + // behavior before dr2171 was implemented. + // + // Otherwise, if ClangABICompat14 is false, All copy constructors can be + // trivial, if they are not user-provided, regardless of the qualifiers on + // the reference type. + const bool ClangABICompat14 = Context.getLangOpts().getClangABICompat() <= + LangOptions::ClangABI::Ver14; + if (!RT || + ((RT->getPointeeType().getCVRQualifiers() != Qualifiers::Const) && + ClangABICompat14)) { + if (Diagnose) + Diag(Param0->getLocation(), diag::note_nontrivial_param_type) + << Param0->getSourceRange() << Param0->getType() + << Context.getLValueReferenceType( + Context.getRecordType(RD).withConst()); + return false; + } + + ConstArg = RT->getPointeeType().isConstQualified(); + break; + } + + case CXXMoveConstructor: + case CXXMoveAssignment: { + // Trivial move operations always have non-cv-qualified parameters. + const ParmVarDecl *Param0 = MD->getParamDecl(0); + const RValueReferenceType *RT = + Param0->getType()->getAs(); + if (!RT || RT->getPointeeType().getCVRQualifiers()) { + if (Diagnose) + Diag(Param0->getLocation(), diag::note_nontrivial_param_type) + << Param0->getSourceRange() << Param0->getType() + << Context.getRValueReferenceType(Context.getRecordType(RD)); + return false; + } + break; + } + + case CXXInvalid: + llvm_unreachable("not a special member"); + } + + if (MD->getMinRequiredArguments() < MD->getNumParams()) { + if (Diagnose) + Diag(MD->getParamDecl(MD->getMinRequiredArguments())->getLocation(), + diag::note_nontrivial_default_arg) + << MD->getParamDecl(MD->getMinRequiredArguments())->getSourceRange(); + return false; + } + if (MD->isVariadic()) { + if (Diagnose) + Diag(MD->getLocation(), diag::note_nontrivial_variadic); + return false; + } + + // C++11 [class.ctor]p5, C++11 [class.dtor]p5: + // A copy/move [constructor or assignment operator] is trivial if + // -- the [member] selected to copy/move each direct base class subobject + // is trivial + // + // C++11 [class.copy]p12, C++11 [class.copy]p25: + // A [default constructor or destructor] is trivial if + // -- all the direct base classes have trivial [default constructors or + // destructors] + for (const auto &BI : RD->bases()) + if (!checkTrivialSubobjectCall(*this, BI.getBeginLoc(), BI.getType(), + ConstArg, CSM, TSK_BaseClass, TAH, Diagnose)) + return false; + + // C++11 [class.ctor]p5, C++11 [class.dtor]p5: + // A copy/move [constructor or assignment operator] for a class X is + // trivial if + // -- for each non-static data member of X that is of class type (or array + // thereof), the constructor selected to copy/move that member is + // trivial + // + // C++11 [class.copy]p12, C++11 [class.copy]p25: + // A [default constructor or destructor] is trivial if + // -- for all of the non-static data members of its class that are of class + // type (or array thereof), each such class has a trivial [default + // constructor or destructor] + if (!checkTrivialClassMembers(*this, RD, CSM, ConstArg, TAH, Diagnose)) + return false; + + // C++11 [class.dtor]p5: + // A destructor is trivial if [...] + // -- the destructor is not virtual + if (CSM == CXXDestructor && MD->isVirtual()) { + if (Diagnose) + Diag(MD->getLocation(), diag::note_nontrivial_virtual_dtor) << RD; + return false; + } + + // C++11 [class.ctor]p5, C++11 [class.copy]p12, C++11 [class.copy]p25: + // A [special member] for class X is trivial if [...] + // -- class X has no virtual functions and no virtual base classes + if (CSM != CXXDestructor && MD->getParent()->isDynamicClass()) { + if (!Diagnose) + return false; + + if (RD->getNumVBases()) { + // Check for virtual bases. We already know that the corresponding + // member in all bases is trivial, so vbases must all be direct. + CXXBaseSpecifier &BS = *RD->vbases_begin(); + assert(BS.isVirtual()); + Diag(BS.getBeginLoc(), diag::note_nontrivial_has_virtual) << RD << 1; + return false; + } + + // Must have a virtual method. + for (const auto *MI : RD->methods()) { + if (MI->isVirtual()) { + SourceLocation MLoc = MI->getBeginLoc(); + Diag(MLoc, diag::note_nontrivial_has_virtual) << RD << 0; + return false; + } + } + + llvm_unreachable("dynamic class with no vbases and no virtual functions"); + } + + // Looks like it's trivial! + return true; + } + + namespace { + struct FindHiddenVirtualMethod { + Sema *S; + CXXMethodDecl *Method; + llvm::SmallPtrSet OverridenAndUsingBaseMethods; + SmallVector OverloadedMethods; + + private: + /// Check whether any most overridden method from MD in Methods + static bool CheckMostOverridenMethods( + const CXXMethodDecl *MD, + const llvm::SmallPtrSetImpl &Methods) { + if (MD->size_overridden_methods() == 0) + return Methods.count(MD->getCanonicalDecl()); + for (const CXXMethodDecl *O : MD->overridden_methods()) + if (CheckMostOverridenMethods(O, Methods)) + return true; + return false; + } + + public: + /// Member lookup function that determines whether a given C++ + /// method overloads virtual methods in a base class without overriding any, + /// to be used with CXXRecordDecl::lookupInBases(). + bool operator()(const CXXBaseSpecifier *Specifier, CXXBasePath &Path) { + RecordDecl *BaseRecord = + Specifier->getType()->castAs()->getDecl(); + + DeclarationName Name = Method->getDeclName(); + assert(Name.getNameKind() == DeclarationName::Identifier); + + bool foundSameNameMethod = false; + SmallVector overloadedMethods; + for (Path.Decls = BaseRecord->lookup(Name).begin(); + Path.Decls != DeclContext::lookup_iterator(); ++Path.Decls) { + NamedDecl *D = *Path.Decls; + if (CXXMethodDecl *MD = dyn_cast(D)) { + MD = MD->getCanonicalDecl(); + foundSameNameMethod = true; + // Interested only in hidden virtual methods. + if (!MD->isVirtual()) + continue; + // If the method we are checking overrides a method from its base + // don't warn about the other overloaded methods. Clang deviates from + // GCC by only diagnosing overloads of inherited virtual functions that + // do not override any other virtual functions in the base. GCC's + // -Woverloaded-virtual diagnoses any derived function hiding a virtual + // function from a base class. These cases may be better served by a + // warning (not specific to virtual functions) on call sites when the + // call would select a different function from the base class, were it + // visible. + // See FIXME in test/SemaCXX/warn-overload-virtual.cpp for an example. + if (!S->IsOverload(Method, MD, false)) + return true; + // Collect the overload only if its hidden. + if (!CheckMostOverridenMethods(MD, OverridenAndUsingBaseMethods)) + overloadedMethods.push_back(MD); + } + } + + if (foundSameNameMethod) + OverloadedMethods.append(overloadedMethods.begin(), + overloadedMethods.end()); + return foundSameNameMethod; + } + }; + } // end anonymous namespace + + /// Add the most overridden methods from MD to Methods + static void AddMostOverridenMethods(const CXXMethodDecl *MD, + llvm::SmallPtrSetImpl& Methods) { + if (MD->size_overridden_methods() == 0) + Methods.insert(MD->getCanonicalDecl()); + else + for (const CXXMethodDecl *O : MD->overridden_methods()) + AddMostOverridenMethods(O, Methods); + } + + /// Check if a method overloads virtual methods in a base class without + /// overriding any. + void Sema::FindHiddenVirtualMethods(CXXMethodDecl *MD, + SmallVectorImpl &OverloadedMethods) { + if (!MD->getDeclName().isIdentifier()) + return; + + CXXBasePaths Paths(/*FindAmbiguities=*/true, // true to look in all bases. + /*bool RecordPaths=*/false, + /*bool DetectVirtual=*/false); + FindHiddenVirtualMethod FHVM; + FHVM.Method = MD; + FHVM.S = this; + + // Keep the base methods that were overridden or introduced in the subclass + // by 'using' in a set. A base method not in this set is hidden. + CXXRecordDecl *DC = MD->getParent(); + DeclContext::lookup_result R = DC->lookup(MD->getDeclName()); + for (DeclContext::lookup_iterator I = R.begin(), E = R.end(); I != E; ++I) { + NamedDecl *ND = *I; + if (UsingShadowDecl *shad = dyn_cast(*I)) + ND = shad->getTargetDecl(); + if (CXXMethodDecl *MD = dyn_cast(ND)) + AddMostOverridenMethods(MD, FHVM.OverridenAndUsingBaseMethods); + } + + if (DC->lookupInBases(FHVM, Paths)) + OverloadedMethods = FHVM.OverloadedMethods; + } + + void Sema::NoteHiddenVirtualMethods(CXXMethodDecl *MD, + SmallVectorImpl &OverloadedMethods) { + for (unsigned i = 0, e = OverloadedMethods.size(); i != e; ++i) { + CXXMethodDecl *overloadedMD = OverloadedMethods[i]; + PartialDiagnostic PD = PDiag( + diag::note_hidden_overloaded_virtual_declared_here) << overloadedMD; + HandleFunctionTypeMismatch(PD, MD->getType(), overloadedMD->getType()); + Diag(overloadedMD->getLocation(), PD); + } + } + + /// Diagnose methods which overload virtual methods in a base class + /// without overriding any. + void Sema::DiagnoseHiddenVirtualMethods(CXXMethodDecl *MD) { + if (MD->isInvalidDecl()) + return; + + if (Diags.isIgnored(diag::warn_overloaded_virtual, MD->getLocation())) + return; + + SmallVector OverloadedMethods; + FindHiddenVirtualMethods(MD, OverloadedMethods); + if (!OverloadedMethods.empty()) { + Diag(MD->getLocation(), diag::warn_overloaded_virtual) + << MD << (OverloadedMethods.size() > 1); + + NoteHiddenVirtualMethods(MD, OverloadedMethods); + } + } + + void Sema::checkIllFormedTrivialABIStruct(CXXRecordDecl &RD) { + auto PrintDiagAndRemoveAttr = [&](unsigned N) { + // No diagnostics if this is a template instantiation. + if (!isTemplateInstantiation(RD.getTemplateSpecializationKind())) { + Diag(RD.getAttr()->getLocation(), + diag::ext_cannot_use_trivial_abi) << &RD; + Diag(RD.getAttr()->getLocation(), + diag::note_cannot_use_trivial_abi_reason) << &RD << N; + } + RD.dropAttr(); + }; + + // Ill-formed if the copy and move constructors are deleted. + auto HasNonDeletedCopyOrMoveConstructor = [&]() { + // If the type is dependent, then assume it might have + // implicit copy or move ctor because we won't know yet at this point. + if (RD.isDependentType()) + return true; + if (RD.needsImplicitCopyConstructor() && + !RD.defaultedCopyConstructorIsDeleted()) + return true; + if (RD.needsImplicitMoveConstructor() && + !RD.defaultedMoveConstructorIsDeleted()) + return true; + for (const CXXConstructorDecl *CD : RD.ctors()) + if (CD->isCopyOrMoveConstructor() && !CD->isDeleted()) + return true; + return false; + }; + + if (!HasNonDeletedCopyOrMoveConstructor()) { + PrintDiagAndRemoveAttr(0); + return; + } + + // Ill-formed if the struct has virtual functions. + if (RD.isPolymorphic()) { + PrintDiagAndRemoveAttr(1); + return; + } + + for (const auto &B : RD.bases()) { + // Ill-formed if the base class is non-trivial for the purpose of calls or a + // virtual base. + if (!B.getType()->isDependentType() && + !B.getType()->getAsCXXRecordDecl()->canPassInRegisters()) { + PrintDiagAndRemoveAttr(2); + return; + } + + if (B.isVirtual()) { + PrintDiagAndRemoveAttr(3); + return; + } + } + + for (const auto *FD : RD.fields()) { + // Ill-formed if the field is an ObjectiveC pointer or of a type that is + // non-trivial for the purpose of calls. + QualType FT = FD->getType(); + if (FT.getObjCLifetime() == Qualifiers::OCL_Weak) { + PrintDiagAndRemoveAttr(4); + return; + } + + if (const auto *RT = FT->getBaseElementTypeUnsafe()->getAs()) + if (!RT->isDependentType() && + !cast(RT->getDecl())->canPassInRegisters()) { + PrintDiagAndRemoveAttr(5); + return; + } + } + } + + void Sema::ActOnFinishCXXMemberSpecification( + Scope *S, SourceLocation RLoc, Decl *TagDecl, SourceLocation LBrac, + SourceLocation RBrac, const ParsedAttributesView &AttrList) { + if (!TagDecl) + return; + + AdjustDeclIfTemplate(TagDecl); + + for (const ParsedAttr &AL : AttrList) { + if (AL.getKind() != ParsedAttr::AT_Visibility) + continue; + AL.setInvalid(); + Diag(AL.getLoc(), diag::warn_attribute_after_definition_ignored) << AL; + } + + ActOnFields(S, RLoc, TagDecl, + llvm::ArrayRef( + // strict aliasing violation! + reinterpret_cast(FieldCollector->getCurFields()), + FieldCollector->getCurNumFields()), + LBrac, RBrac, AttrList); + + CheckCompletedCXXClass(S, cast(TagDecl)); + } + + /// Find the equality comparison functions that should be implicitly declared + /// in a given class definition, per C++2a [class.compare.default]p3. + static void findImplicitlyDeclaredEqualityComparisons( + ASTContext &Ctx, CXXRecordDecl *RD, + llvm::SmallVectorImpl &Spaceships) { + DeclarationName EqEq = Ctx.DeclarationNames.getCXXOperatorName(OO_EqualEqual); + if (!RD->lookup(EqEq).empty()) + // Member operator== explicitly declared: no implicit operator==s. + return; + + // Traverse friends looking for an '==' or a '<=>'. + for (FriendDecl *Friend : RD->friends()) { + FunctionDecl *FD = dyn_cast_or_null(Friend->getFriendDecl()); + if (!FD) continue; + + if (FD->getOverloadedOperator() == OO_EqualEqual) { + // Friend operator== explicitly declared: no implicit operator==s. + Spaceships.clear(); + return; + } + + if (FD->getOverloadedOperator() == OO_Spaceship && + FD->isExplicitlyDefaulted()) + Spaceships.push_back(FD); + } + + // Look for members named 'operator<=>'. + DeclarationName Cmp = Ctx.DeclarationNames.getCXXOperatorName(OO_Spaceship); + for (NamedDecl *ND : RD->lookup(Cmp)) { + // Note that we could find a non-function here (either a function template + // or a using-declaration). Neither case results in an implicit + // 'operator=='. + if (auto *FD = dyn_cast(ND)) + if (FD->isExplicitlyDefaulted()) + Spaceships.push_back(FD); + } + } + + /// AddImplicitlyDeclaredMembersToClass - Adds any implicitly-declared + /// special functions, such as the default constructor, copy + /// constructor, or destructor, to the given C++ class (C++ + /// [special]p1). This routine can only be executed just before the + /// definition of the class is complete. + void Sema::AddImplicitlyDeclaredMembersToClass(CXXRecordDecl *ClassDecl) { + // Don't add implicit special members to templated classes. + // FIXME: This means unqualified lookups for 'operator=' within a class + // template don't work properly. + if (!ClassDecl->isDependentType()) { + if (ClassDecl->needsImplicitDefaultConstructor()) { + ++getASTContext().NumImplicitDefaultConstructors; + + if (ClassDecl->hasInheritedConstructor()) + DeclareImplicitDefaultConstructor(ClassDecl); + } + + if (ClassDecl->needsImplicitCopyConstructor()) { + ++getASTContext().NumImplicitCopyConstructors; + + // If the properties or semantics of the copy constructor couldn't be + // determined while the class was being declared, force a declaration + // of it now. + if (ClassDecl->needsOverloadResolutionForCopyConstructor() || + ClassDecl->hasInheritedConstructor()) + DeclareImplicitCopyConstructor(ClassDecl); + // For the MS ABI we need to know whether the copy ctor is deleted. A + // prerequisite for deleting the implicit copy ctor is that the class has + // a move ctor or move assignment that is either user-declared or whose + // semantics are inherited from a subobject. FIXME: We should provide a + // more direct way for CodeGen to ask whether the constructor was deleted. + else if (Context.getTargetInfo().getCXXABI().isMicrosoft() && + (ClassDecl->hasUserDeclaredMoveConstructor() || + ClassDecl->needsOverloadResolutionForMoveConstructor() || + ClassDecl->hasUserDeclaredMoveAssignment() || + ClassDecl->needsOverloadResolutionForMoveAssignment())) + DeclareImplicitCopyConstructor(ClassDecl); + } + + if (getLangOpts().CPlusPlus11 && + ClassDecl->needsImplicitMoveConstructor()) { + ++getASTContext().NumImplicitMoveConstructors; + + if (ClassDecl->needsOverloadResolutionForMoveConstructor() || + ClassDecl->hasInheritedConstructor()) + DeclareImplicitMoveConstructor(ClassDecl); + } + + if (ClassDecl->needsImplicitCopyAssignment()) { + ++getASTContext().NumImplicitCopyAssignmentOperators; + + // If we have a dynamic class, then the copy assignment operator may be + // virtual, so we have to declare it immediately. This ensures that, e.g., + // it shows up in the right place in the vtable and that we diagnose + // problems with the implicit exception specification. + if (ClassDecl->isDynamicClass() || + ClassDecl->needsOverloadResolutionForCopyAssignment() || + ClassDecl->hasInheritedAssignment()) + DeclareImplicitCopyAssignment(ClassDecl); + } + + if (getLangOpts().CPlusPlus11 && ClassDecl->needsImplicitMoveAssignment()) { + ++getASTContext().NumImplicitMoveAssignmentOperators; + + // Likewise for the move assignment operator. + if (ClassDecl->isDynamicClass() || + ClassDecl->needsOverloadResolutionForMoveAssignment() || + ClassDecl->hasInheritedAssignment()) + DeclareImplicitMoveAssignment(ClassDecl); + } + + if (ClassDecl->needsImplicitDestructor()) { + ++getASTContext().NumImplicitDestructors; + + // If we have a dynamic class, then the destructor may be virtual, so we + // have to declare the destructor immediately. This ensures that, e.g., it + // shows up in the right place in the vtable and that we diagnose problems + // with the implicit exception specification. + if (ClassDecl->isDynamicClass() || + ClassDecl->needsOverloadResolutionForDestructor()) + DeclareImplicitDestructor(ClassDecl); + } + } + + // C++2a [class.compare.default]p3: + // If the member-specification does not explicitly declare any member or + // friend named operator==, an == operator function is declared implicitly + // for each defaulted three-way comparison operator function defined in + // the member-specification + // FIXME: Consider doing this lazily. + // We do this during the initial parse for a class template, not during + // instantiation, so that we can handle unqualified lookups for 'operator==' + // when parsing the template. + if (getLangOpts().CPlusPlus20 && !inTemplateInstantiation()) { + llvm::SmallVector DefaultedSpaceships; + findImplicitlyDeclaredEqualityComparisons(Context, ClassDecl, + DefaultedSpaceships); + for (auto *FD : DefaultedSpaceships) + DeclareImplicitEqualityComparison(ClassDecl, FD); + } + } + + unsigned + Sema::ActOnReenterTemplateScope(Decl *D, + llvm::function_ref EnterScope) { + if (!D) + return 0; + AdjustDeclIfTemplate(D); + + // In order to get name lookup right, reenter template scopes in order from + // outermost to innermost. + SmallVector ParameterLists; + DeclContext *LookupDC = dyn_cast(D); + + if (DeclaratorDecl *DD = dyn_cast(D)) { + for (unsigned i = 0; i < DD->getNumTemplateParameterLists(); ++i) + ParameterLists.push_back(DD->getTemplateParameterList(i)); + + if (FunctionDecl *FD = dyn_cast(D)) { + if (FunctionTemplateDecl *FTD = FD->getDescribedFunctionTemplate()) + ParameterLists.push_back(FTD->getTemplateParameters()); + } else if (VarDecl *VD = dyn_cast(D)) { + LookupDC = VD->getDeclContext(); + + if (VarTemplateDecl *VTD = VD->getDescribedVarTemplate()) + ParameterLists.push_back(VTD->getTemplateParameters()); + else if (auto *PSD = dyn_cast(D)) + ParameterLists.push_back(PSD->getTemplateParameters()); + } + } else if (TagDecl *TD = dyn_cast(D)) { + for (unsigned i = 0; i < TD->getNumTemplateParameterLists(); ++i) + ParameterLists.push_back(TD->getTemplateParameterList(i)); + + if (CXXRecordDecl *RD = dyn_cast(TD)) { + if (ClassTemplateDecl *CTD = RD->getDescribedClassTemplate()) + ParameterLists.push_back(CTD->getTemplateParameters()); + else if (auto *PSD = dyn_cast(D)) + ParameterLists.push_back(PSD->getTemplateParameters()); + } + } + // FIXME: Alias declarations and concepts. + + unsigned Count = 0; + Scope *InnermostTemplateScope = nullptr; + for (TemplateParameterList *Params : ParameterLists) { + // Ignore explicit specializations; they don't contribute to the template + // depth. + if (Params->size() == 0) + continue; + + InnermostTemplateScope = EnterScope(); + for (NamedDecl *Param : *Params) { + if (Param->getDeclName()) { + InnermostTemplateScope->AddDecl(Param); + IdResolver.AddDecl(Param); + } + } + ++Count; + } + + // Associate the new template scopes with the corresponding entities. + if (InnermostTemplateScope) { + assert(LookupDC && "no enclosing DeclContext for template lookup"); + EnterTemplatedContext(InnermostTemplateScope, LookupDC); + } + + return Count; + } + + void Sema::ActOnStartDelayedMemberDeclarations(Scope *S, Decl *RecordD) { + if (!RecordD) return; + AdjustDeclIfTemplate(RecordD); + CXXRecordDecl *Record = cast(RecordD); + PushDeclContext(S, Record); + } + + void Sema::ActOnFinishDelayedMemberDeclarations(Scope *S, Decl *RecordD) { + if (!RecordD) return; + PopDeclContext(); + } + + /// This is used to implement the constant expression evaluation part of the + /// attribute enable_if extension. There is nothing in standard C++ which would + /// require reentering parameters. + void Sema::ActOnReenterCXXMethodParameter(Scope *S, ParmVarDecl *Param) { + if (!Param) + return; + + S->AddDecl(Param); + if (Param->getDeclName()) + IdResolver.AddDecl(Param); + } + + /// ActOnStartDelayedCXXMethodDeclaration - We have completed + /// parsing a top-level (non-nested) C++ class, and we are now + /// parsing those parts of the given Method declaration that could + /// not be parsed earlier (C++ [class.mem]p2), such as default + /// arguments. This action should enter the scope of the given + /// Method declaration as if we had just parsed the qualified method + /// name. However, it should not bring the parameters into scope; + /// that will be performed by ActOnDelayedCXXMethodParameter. + void Sema::ActOnStartDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) { + } + + /// ActOnDelayedCXXMethodParameter - We've already started a delayed + /// C++ method declaration. We're (re-)introducing the given + /// function parameter into scope for use in parsing later parts of + /// the method declaration. For example, we could see an + /// ActOnParamDefaultArgument event for this parameter. + void Sema::ActOnDelayedCXXMethodParameter(Scope *S, Decl *ParamD) { + if (!ParamD) + return; + + ParmVarDecl *Param = cast(ParamD); + + S->AddDecl(Param); + if (Param->getDeclName()) + IdResolver.AddDecl(Param); + } + + /// ActOnFinishDelayedCXXMethodDeclaration - We have finished + /// processing the delayed method declaration for Method. The method + /// declaration is now considered finished. There may be a separate + /// ActOnStartOfFunctionDef action later (not necessarily + /// immediately!) for this method, if it was also defined inside the + /// class body. + void Sema::ActOnFinishDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) { + if (!MethodD) + return; + + AdjustDeclIfTemplate(MethodD); + + FunctionDecl *Method = cast(MethodD); + + // Now that we have our default arguments, check the constructor + // again. It could produce additional diagnostics or affect whether + // the class has implicitly-declared destructors, among other + // things. + if (CXXConstructorDecl *Constructor = dyn_cast(Method)) + CheckConstructor(Constructor); + + // Check the default arguments, which we may have added. + if (!Method->isInvalidDecl()) + CheckCXXDefaultArguments(Method); + } + + // Emit the given diagnostic for each non-address-space qualifier. + // Common part of CheckConstructorDeclarator and CheckDestructorDeclarator. + static void checkMethodTypeQualifiers(Sema &S, Declarator &D, unsigned DiagID) { + const DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo(); + if (FTI.hasMethodTypeQualifiers() && !D.isInvalidType()) { + bool DiagOccured = false; + FTI.MethodQualifiers->forEachQualifier( + [DiagID, &S, &DiagOccured](DeclSpec::TQ, StringRef QualName, + SourceLocation SL) { + // This diagnostic should be emitted on any qualifier except an addr + // space qualifier. However, forEachQualifier currently doesn't visit + // addr space qualifiers, so there's no way to write this condition + // right now; we just diagnose on everything. + S.Diag(SL, DiagID) << QualName << SourceRange(SL); + DiagOccured = true; + }); + if (DiagOccured) + D.setInvalidType(); + } + } + + /// CheckConstructorDeclarator - Called by ActOnDeclarator to check + /// the well-formedness of the constructor declarator @p D with type @p + /// R. If there are any errors in the declarator, this routine will + /// emit diagnostics and set the invalid bit to true. In any case, the type + /// will be updated to reflect a well-formed type for the constructor and + /// returned. + QualType Sema::CheckConstructorDeclarator(Declarator &D, QualType R, + StorageClass &SC) { + bool isVirtual = D.getDeclSpec().isVirtualSpecified(); + + // C++ [class.ctor]p3: + // A constructor shall not be virtual (10.3) or static (9.4). A + // constructor can be invoked for a const, volatile or const + // volatile object. A constructor shall not be declared const, + // volatile, or const volatile (9.3.2). + if (isVirtual) { + if (!D.isInvalidType()) + Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be) + << "virtual" << SourceRange(D.getDeclSpec().getVirtualSpecLoc()) + << SourceRange(D.getIdentifierLoc()); + D.setInvalidType(); + } + if (SC == SC_Static) { + if (!D.isInvalidType()) + Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be) + << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc()) + << SourceRange(D.getIdentifierLoc()); + D.setInvalidType(); + SC = SC_None; + } + + if (unsigned TypeQuals = D.getDeclSpec().getTypeQualifiers()) { + diagnoseIgnoredQualifiers( + diag::err_constructor_return_type, TypeQuals, SourceLocation(), + D.getDeclSpec().getConstSpecLoc(), D.getDeclSpec().getVolatileSpecLoc(), + D.getDeclSpec().getRestrictSpecLoc(), + D.getDeclSpec().getAtomicSpecLoc()); + D.setInvalidType(); + } + + checkMethodTypeQualifiers(*this, D, diag::err_invalid_qualified_constructor); + + // C++0x [class.ctor]p4: + // A constructor shall not be declared with a ref-qualifier. + DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo(); + if (FTI.hasRefQualifier()) { + Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_constructor) + << FTI.RefQualifierIsLValueRef + << FixItHint::CreateRemoval(FTI.getRefQualifierLoc()); + D.setInvalidType(); + } + + // Rebuild the function type "R" without any type qualifiers (in + // case any of the errors above fired) and with "void" as the + // return type, since constructors don't have return types. + const FunctionProtoType *Proto = R->castAs(); + if (Proto->getReturnType() == Context.VoidTy && !D.isInvalidType()) + return R; + + FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo(); + EPI.TypeQuals = Qualifiers(); + EPI.RefQualifier = RQ_None; + + return Context.getFunctionType(Context.VoidTy, Proto->getParamTypes(), EPI); + } + + /// CheckConstructor - Checks a fully-formed constructor for + /// well-formedness, issuing any diagnostics required. Returns true if + /// the constructor declarator is invalid. + void Sema::CheckConstructor(CXXConstructorDecl *Constructor) { + CXXRecordDecl *ClassDecl + = dyn_cast(Constructor->getDeclContext()); + if (!ClassDecl) + return Constructor->setInvalidDecl(); + + // C++ [class.copy]p3: + // A declaration of a constructor for a class X is ill-formed if + // its first parameter is of type (optionally cv-qualified) X and + // either there are no other parameters or else all other + // parameters have default arguments. + if (!Constructor->isInvalidDecl() && + Constructor->hasOneParamOrDefaultArgs() && + Constructor->getTemplateSpecializationKind() != + TSK_ImplicitInstantiation) { + QualType ParamType = Constructor->getParamDecl(0)->getType(); + QualType ClassTy = Context.getTagDeclType(ClassDecl); + if (Context.getCanonicalType(ParamType).getUnqualifiedType() == ClassTy) { + SourceLocation ParamLoc = Constructor->getParamDecl(0)->getLocation(); + const char *ConstRef + = Constructor->getParamDecl(0)->getIdentifier() ? "const &" + : " const &"; + Diag(ParamLoc, diag::err_constructor_byvalue_arg) + << FixItHint::CreateInsertion(ParamLoc, ConstRef); + + // FIXME: Rather that making the constructor invalid, we should endeavor + // to fix the type. + Constructor->setInvalidDecl(); + } + } + } + + /// CheckDestructor - Checks a fully-formed destructor definition for + /// well-formedness, issuing any diagnostics required. Returns true + /// on error. + bool Sema::CheckDestructor(CXXDestructorDecl *Destructor) { + CXXRecordDecl *RD = Destructor->getParent(); + + if (!Destructor->getOperatorDelete() && Destructor->isVirtual()) { + SourceLocation Loc; + + if (!Destructor->isImplicit()) + Loc = Destructor->getLocation(); + else + Loc = RD->getLocation(); + + // If we have a virtual destructor, look up the deallocation function + if (FunctionDecl *OperatorDelete = + FindDeallocationFunctionForDestructor(Loc, RD)) { + Expr *ThisArg = nullptr; + + // If the notional 'delete this' expression requires a non-trivial + // conversion from 'this' to the type of a destroying operator delete's + // first parameter, perform that conversion now. + if (OperatorDelete->isDestroyingOperatorDelete()) { + QualType ParamType = OperatorDelete->getParamDecl(0)->getType(); + if (!declaresSameEntity(ParamType->getAsCXXRecordDecl(), RD)) { + // C++ [class.dtor]p13: + // ... as if for the expression 'delete this' appearing in a + // non-virtual destructor of the destructor's class. + ContextRAII SwitchContext(*this, Destructor); + ExprResult This = + ActOnCXXThis(OperatorDelete->getParamDecl(0)->getLocation()); + assert(!This.isInvalid() && "couldn't form 'this' expr in dtor?"); + This = PerformImplicitConversion(This.get(), ParamType, AA_Passing); + if (This.isInvalid()) { + // FIXME: Register this as a context note so that it comes out + // in the right order. + Diag(Loc, diag::note_implicit_delete_this_in_destructor_here); + return true; + } + ThisArg = This.get(); + } + } + + DiagnoseUseOfDecl(OperatorDelete, Loc); + MarkFunctionReferenced(Loc, OperatorDelete); + Destructor->setOperatorDelete(OperatorDelete, ThisArg); + } + } + + return false; + } + + /// CheckDestructorDeclarator - Called by ActOnDeclarator to check + /// the well-formednes of the destructor declarator @p D with type @p + /// R. If there are any errors in the declarator, this routine will + /// emit diagnostics and set the declarator to invalid. Even if this happens, + /// will be updated to reflect a well-formed type for the destructor and + /// returned. + QualType Sema::CheckDestructorDeclarator(Declarator &D, QualType R, + StorageClass& SC) { + // C++ [class.dtor]p1: + // [...] A typedef-name that names a class is a class-name + // (7.1.3); however, a typedef-name that names a class shall not + // be used as the identifier in the declarator for a destructor + // declaration. + QualType DeclaratorType = GetTypeFromParser(D.getName().DestructorName); + if (const TypedefType *TT = DeclaratorType->getAs()) + Diag(D.getIdentifierLoc(), diag::ext_destructor_typedef_name) + << DeclaratorType << isa(TT->getDecl()); + else if (const TemplateSpecializationType *TST = + DeclaratorType->getAs()) + if (TST->isTypeAlias()) + Diag(D.getIdentifierLoc(), diag::ext_destructor_typedef_name) + << DeclaratorType << 1; + + // C++ [class.dtor]p2: + // A destructor is used to destroy objects of its class type. A + // destructor takes no parameters, and no return type can be + // specified for it (not even void). The address of a destructor + // shall not be taken. A destructor shall not be static. A + // destructor can be invoked for a const, volatile or const + // volatile object. A destructor shall not be declared const, + // volatile or const volatile (9.3.2). + if (SC == SC_Static) { + if (!D.isInvalidType()) + Diag(D.getIdentifierLoc(), diag::err_destructor_cannot_be) + << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc()) + << SourceRange(D.getIdentifierLoc()) + << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc()); + + SC = SC_None; + } + if (!D.isInvalidType()) { + // Destructors don't have return types, but the parser will + // happily parse something like: + // + // class X { + // float ~X(); + // }; + // + // The return type will be eliminated later. + if (D.getDeclSpec().hasTypeSpecifier()) + Diag(D.getIdentifierLoc(), diag::err_destructor_return_type) + << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc()) + << SourceRange(D.getIdentifierLoc()); + else if (unsigned TypeQuals = D.getDeclSpec().getTypeQualifiers()) { + diagnoseIgnoredQualifiers(diag::err_destructor_return_type, TypeQuals, + SourceLocation(), + D.getDeclSpec().getConstSpecLoc(), + D.getDeclSpec().getVolatileSpecLoc(), + D.getDeclSpec().getRestrictSpecLoc(), + D.getDeclSpec().getAtomicSpecLoc()); + D.setInvalidType(); + } + } + + checkMethodTypeQualifiers(*this, D, diag::err_invalid_qualified_destructor); + + // C++0x [class.dtor]p2: + // A destructor shall not be declared with a ref-qualifier. + DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo(); + if (FTI.hasRefQualifier()) { + Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_destructor) + << FTI.RefQualifierIsLValueRef + << FixItHint::CreateRemoval(FTI.getRefQualifierLoc()); + D.setInvalidType(); + } + + // Make sure we don't have any parameters. + if (FTIHasNonVoidParameters(FTI)) { + Diag(D.getIdentifierLoc(), diag::err_destructor_with_params); + + // Delete the parameters. + FTI.freeParams(); + D.setInvalidType(); + } + + // Make sure the destructor isn't variadic. + if (FTI.isVariadic) { + Diag(D.getIdentifierLoc(), diag::err_destructor_variadic); + D.setInvalidType(); + } + + // Rebuild the function type "R" without any type qualifiers or + // parameters (in case any of the errors above fired) and with + // "void" as the return type, since destructors don't have return + // types. + if (!D.isInvalidType()) + return R; + + const FunctionProtoType *Proto = R->castAs(); + FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo(); + EPI.Variadic = false; + EPI.TypeQuals = Qualifiers(); + EPI.RefQualifier = RQ_None; + return Context.getFunctionType(Context.VoidTy, std::nullopt, EPI); + } + + static void extendLeft(SourceRange &R, SourceRange Before) { + if (Before.isInvalid()) + return; + R.setBegin(Before.getBegin()); + if (R.getEnd().isInvalid()) + R.setEnd(Before.getEnd()); + } + + static void extendRight(SourceRange &R, SourceRange After) { + if (After.isInvalid()) + return; + if (R.getBegin().isInvalid()) + R.setBegin(After.getBegin()); + R.setEnd(After.getEnd()); + } + + /// CheckConversionDeclarator - Called by ActOnDeclarator to check the + /// well-formednes of the conversion function declarator @p D with + /// type @p R. If there are any errors in the declarator, this routine + /// will emit diagnostics and return true. Otherwise, it will return + /// false. Either way, the type @p R will be updated to reflect a + /// well-formed type for the conversion operator. + void Sema::CheckConversionDeclarator(Declarator &D, QualType &R, + StorageClass& SC) { + // C++ [class.conv.fct]p1: + // Neither parameter types nor return type can be specified. The + // type of a conversion function (8.3.5) is "function taking no + // parameter returning conversion-type-id." + if (SC == SC_Static) { + if (!D.isInvalidType()) + Diag(D.getIdentifierLoc(), diag::err_conv_function_not_member) + << SourceRange(D.getDeclSpec().getStorageClassSpecLoc()) + << D.getName().getSourceRange(); + D.setInvalidType(); + SC = SC_None; + } + + TypeSourceInfo *ConvTSI = nullptr; + QualType ConvType = + GetTypeFromParser(D.getName().ConversionFunctionId, &ConvTSI); + + const DeclSpec &DS = D.getDeclSpec(); + if (DS.hasTypeSpecifier() && !D.isInvalidType()) { + // Conversion functions don't have return types, but the parser will + // happily parse something like: + // + // class X { + // float operator bool(); + // }; + // + // The return type will be changed later anyway. + Diag(D.getIdentifierLoc(), diag::err_conv_function_return_type) + << SourceRange(DS.getTypeSpecTypeLoc()) + << SourceRange(D.getIdentifierLoc()); + D.setInvalidType(); + } else if (DS.getTypeQualifiers() && !D.isInvalidType()) { + // It's also plausible that the user writes type qualifiers in the wrong + // place, such as: + // struct S { const operator int(); }; + // FIXME: we could provide a fixit to move the qualifiers onto the + // conversion type. + Diag(D.getIdentifierLoc(), diag::err_conv_function_with_complex_decl) + << SourceRange(D.getIdentifierLoc()) << 0; + D.setInvalidType(); + } + + const auto *Proto = R->castAs(); + + // Make sure we don't have any parameters. + if (Proto->getNumParams() > 0) { + Diag(D.getIdentifierLoc(), diag::err_conv_function_with_params); + + // Delete the parameters. + D.getFunctionTypeInfo().freeParams(); + D.setInvalidType(); + } else if (Proto->isVariadic()) { + Diag(D.getIdentifierLoc(), diag::err_conv_function_variadic); + D.setInvalidType(); + } + + // Diagnose "&operator bool()" and other such nonsense. This + // is actually a gcc extension which we don't support. + if (Proto->getReturnType() != ConvType) { + bool NeedsTypedef = false; + SourceRange Before, After; + + // Walk the chunks and extract information on them for our diagnostic. + bool PastFunctionChunk = false; + for (auto &Chunk : D.type_objects()) { + switch (Chunk.Kind) { + case DeclaratorChunk::Function: + if (!PastFunctionChunk) { + if (Chunk.Fun.HasTrailingReturnType) { + TypeSourceInfo *TRT = nullptr; + GetTypeFromParser(Chunk.Fun.getTrailingReturnType(), &TRT); + if (TRT) extendRight(After, TRT->getTypeLoc().getSourceRange()); + } + PastFunctionChunk = true; + break; + } + [[fallthrough]]; + case DeclaratorChunk::Array: + NeedsTypedef = true; + extendRight(After, Chunk.getSourceRange()); + break; + + case DeclaratorChunk::Pointer: + case DeclaratorChunk::BlockPointer: + case DeclaratorChunk::Reference: + case DeclaratorChunk::MemberPointer: + case DeclaratorChunk::Pipe: + extendLeft(Before, Chunk.getSourceRange()); + break; + + case DeclaratorChunk::Paren: + extendLeft(Before, Chunk.Loc); + extendRight(After, Chunk.EndLoc); + break; + } + } + + SourceLocation Loc = Before.isValid() ? Before.getBegin() : + After.isValid() ? After.getBegin() : + D.getIdentifierLoc(); + auto &&DB = Diag(Loc, diag::err_conv_function_with_complex_decl); + DB << Before << After; + + if (!NeedsTypedef) { + DB << /*don't need a typedef*/0; + + // If we can provide a correct fix-it hint, do so. + if (After.isInvalid() && ConvTSI) { + SourceLocation InsertLoc = + getLocForEndOfToken(ConvTSI->getTypeLoc().getEndLoc()); + DB << FixItHint::CreateInsertion(InsertLoc, " ") + << FixItHint::CreateInsertionFromRange( + InsertLoc, CharSourceRange::getTokenRange(Before)) + << FixItHint::CreateRemoval(Before); + } + } else if (!Proto->getReturnType()->isDependentType()) { + DB << /*typedef*/1 << Proto->getReturnType(); + } else if (getLangOpts().CPlusPlus11) { + DB << /*alias template*/2 << Proto->getReturnType(); + } else { + DB << /*might not be fixable*/3; + } + + // Recover by incorporating the other type chunks into the result type. + // Note, this does *not* change the name of the function. This is compatible + // with the GCC extension: + // struct S { &operator int(); } s; + // int &r = s.operator int(); // ok in GCC + // S::operator int&() {} // error in GCC, function name is 'operator int'. + ConvType = Proto->getReturnType(); + } + + // C++ [class.conv.fct]p4: + // The conversion-type-id shall not represent a function type nor + // an array type. + if (ConvType->isArrayType()) { + Diag(D.getIdentifierLoc(), diag::err_conv_function_to_array); + ConvType = Context.getPointerType(ConvType); + D.setInvalidType(); + } else if (ConvType->isFunctionType()) { + Diag(D.getIdentifierLoc(), diag::err_conv_function_to_function); + ConvType = Context.getPointerType(ConvType); + D.setInvalidType(); + } + + // Rebuild the function type "R" without any parameters (in case any + // of the errors above fired) and with the conversion type as the + // return type. + if (D.isInvalidType()) + R = Context.getFunctionType(ConvType, std::nullopt, + Proto->getExtProtoInfo()); + + // C++0x explicit conversion operators. + if (DS.hasExplicitSpecifier() && !getLangOpts().CPlusPlus20) + Diag(DS.getExplicitSpecLoc(), + getLangOpts().CPlusPlus11 + ? diag::warn_cxx98_compat_explicit_conversion_functions + : diag::ext_explicit_conversion_functions) + << SourceRange(DS.getExplicitSpecRange()); + } + + /// ActOnConversionDeclarator - Called by ActOnDeclarator to complete + /// the declaration of the given C++ conversion function. This routine + /// is responsible for recording the conversion function in the C++ + /// class, if possible. + Decl *Sema::ActOnConversionDeclarator(CXXConversionDecl *Conversion) { + assert(Conversion && "Expected to receive a conversion function declaration"); + + CXXRecordDecl *ClassDecl = cast(Conversion->getDeclContext()); + + // Make sure we aren't redeclaring the conversion function. + QualType ConvType = Context.getCanonicalType(Conversion->getConversionType()); + // C++ [class.conv.fct]p1: + // [...] A conversion function is never used to convert a + // (possibly cv-qualified) object to the (possibly cv-qualified) + // same object type (or a reference to it), to a (possibly + // cv-qualified) base class of that type (or a reference to it), + // or to (possibly cv-qualified) void. + QualType ClassType + = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl)); + if (const ReferenceType *ConvTypeRef = ConvType->getAs()) + ConvType = ConvTypeRef->getPointeeType(); + if (Conversion->getTemplateSpecializationKind() != TSK_Undeclared && + Conversion->getTemplateSpecializationKind() != TSK_ExplicitSpecialization) + /* Suppress diagnostics for instantiations. */; + else if (Conversion->size_overridden_methods() != 0) + /* Suppress diagnostics for overriding virtual function in a base class. */; + else if (ConvType->isRecordType()) { + ConvType = Context.getCanonicalType(ConvType).getUnqualifiedType(); + if (ConvType == ClassType) + Diag(Conversion->getLocation(), diag::warn_conv_to_self_not_used) + << ClassType; + else if (IsDerivedFrom(Conversion->getLocation(), ClassType, ConvType)) + Diag(Conversion->getLocation(), diag::warn_conv_to_base_not_used) + << ClassType << ConvType; + } else if (ConvType->isVoidType()) { + Diag(Conversion->getLocation(), diag::warn_conv_to_void_not_used) + << ClassType << ConvType; + } + + if (FunctionTemplateDecl *ConversionTemplate + = Conversion->getDescribedFunctionTemplate()) + return ConversionTemplate; + + return Conversion; + } + + namespace { + /// Utility class to accumulate and print a diagnostic listing the invalid + /// specifier(s) on a declaration. + struct BadSpecifierDiagnoser { + BadSpecifierDiagnoser(Sema &S, SourceLocation Loc, unsigned DiagID) + : S(S), Diagnostic(S.Diag(Loc, DiagID)) {} + ~BadSpecifierDiagnoser() { + Diagnostic << Specifiers; + } + + template void check(SourceLocation SpecLoc, T Spec) { + return check(SpecLoc, DeclSpec::getSpecifierName(Spec)); + } + void check(SourceLocation SpecLoc, DeclSpec::TST Spec) { + return check(SpecLoc, + DeclSpec::getSpecifierName(Spec, S.getPrintingPolicy())); + } + void check(SourceLocation SpecLoc, const char *Spec) { + if (SpecLoc.isInvalid()) return; + Diagnostic << SourceRange(SpecLoc, SpecLoc); + if (!Specifiers.empty()) Specifiers += " "; + Specifiers += Spec; + } + + Sema &S; + Sema::SemaDiagnosticBuilder Diagnostic; + std::string Specifiers; + }; + } + + /// Check the validity of a declarator that we parsed for a deduction-guide. + /// These aren't actually declarators in the grammar, so we need to check that + /// the user didn't specify any pieces that are not part of the deduction-guide + /// grammar. Return true on invalid deduction-guide. + bool Sema::CheckDeductionGuideDeclarator(Declarator &D, QualType &R, + StorageClass &SC) { + TemplateName GuidedTemplate = D.getName().TemplateName.get().get(); + TemplateDecl *GuidedTemplateDecl = GuidedTemplate.getAsTemplateDecl(); + assert(GuidedTemplateDecl && "missing template decl for deduction guide"); + + // C++ [temp.deduct.guide]p3: + // A deduction-gide shall be declared in the same scope as the + // corresponding class template. + if (!CurContext->getRedeclContext()->Equals( + GuidedTemplateDecl->getDeclContext()->getRedeclContext())) { + Diag(D.getIdentifierLoc(), diag::err_deduction_guide_wrong_scope) + << GuidedTemplateDecl; + Diag(GuidedTemplateDecl->getLocation(), diag::note_template_decl_here); + } + + auto &DS = D.getMutableDeclSpec(); + // We leave 'friend' and 'virtual' to be rejected in the normal way. + if (DS.hasTypeSpecifier() || DS.getTypeQualifiers() || + DS.getStorageClassSpecLoc().isValid() || DS.isInlineSpecified() || + DS.isNoreturnSpecified() || DS.hasConstexprSpecifier()) { + BadSpecifierDiagnoser Diagnoser( + *this, D.getIdentifierLoc(), + diag::err_deduction_guide_invalid_specifier); + + Diagnoser.check(DS.getStorageClassSpecLoc(), DS.getStorageClassSpec()); + DS.ClearStorageClassSpecs(); + SC = SC_None; + + // 'explicit' is permitted. + Diagnoser.check(DS.getInlineSpecLoc(), "inline"); + Diagnoser.check(DS.getNoreturnSpecLoc(), "_Noreturn"); + Diagnoser.check(DS.getConstexprSpecLoc(), "constexpr"); + DS.ClearConstexprSpec(); + + Diagnoser.check(DS.getConstSpecLoc(), "const"); + Diagnoser.check(DS.getRestrictSpecLoc(), "__restrict"); + Diagnoser.check(DS.getVolatileSpecLoc(), "volatile"); + Diagnoser.check(DS.getAtomicSpecLoc(), "_Atomic"); + Diagnoser.check(DS.getUnalignedSpecLoc(), "__unaligned"); + DS.ClearTypeQualifiers(); + + Diagnoser.check(DS.getTypeSpecComplexLoc(), DS.getTypeSpecComplex()); + Diagnoser.check(DS.getTypeSpecSignLoc(), DS.getTypeSpecSign()); + Diagnoser.check(DS.getTypeSpecWidthLoc(), DS.getTypeSpecWidth()); + Diagnoser.check(DS.getTypeSpecTypeLoc(), DS.getTypeSpecType()); + DS.ClearTypeSpecType(); + } + + if (D.isInvalidType()) + return true; + + // Check the declarator is simple enough. + bool FoundFunction = false; + for (const DeclaratorChunk &Chunk : llvm::reverse(D.type_objects())) { + if (Chunk.Kind == DeclaratorChunk::Paren) + continue; + if (Chunk.Kind != DeclaratorChunk::Function || FoundFunction) { + Diag(D.getDeclSpec().getBeginLoc(), + diag::err_deduction_guide_with_complex_decl) + << D.getSourceRange(); + break; + } + if (!Chunk.Fun.hasTrailingReturnType()) + return Diag(D.getName().getBeginLoc(), + diag::err_deduction_guide_no_trailing_return_type); + + // Check that the return type is written as a specialization of + // the template specified as the deduction-guide's name. + // The template name may not be qualified. [temp.deduct.guide] + ParsedType TrailingReturnType = Chunk.Fun.getTrailingReturnType(); + TypeSourceInfo *TSI = nullptr; + QualType RetTy = GetTypeFromParser(TrailingReturnType, &TSI); + assert(TSI && "deduction guide has valid type but invalid return type?"); + bool AcceptableReturnType = false; + bool MightInstantiateToSpecialization = false; + if (auto RetTST = + TSI->getTypeLoc().getAsAdjusted()) { + TemplateName SpecifiedName = RetTST.getTypePtr()->getTemplateName(); + bool TemplateMatches = + Context.hasSameTemplateName(SpecifiedName, GuidedTemplate); + auto TKind = SpecifiedName.getKind(); + // A Using TemplateName can't actually be valid (either it's qualified, or + // we're in the wrong scope). But we have diagnosed these problems + // already. + bool SimplyWritten = TKind == TemplateName::Template || + TKind == TemplateName::UsingTemplate; + if (SimplyWritten && TemplateMatches) + AcceptableReturnType = true; + else { + // This could still instantiate to the right type, unless we know it + // names the wrong class template. + auto *TD = SpecifiedName.getAsTemplateDecl(); + MightInstantiateToSpecialization = !(TD && isa(TD) && + !TemplateMatches); + } + } else if (!RetTy.hasQualifiers() && RetTy->isDependentType()) { + MightInstantiateToSpecialization = true; + } + + if (!AcceptableReturnType) + return Diag(TSI->getTypeLoc().getBeginLoc(), + diag::err_deduction_guide_bad_trailing_return_type) + << GuidedTemplate << TSI->getType() + << MightInstantiateToSpecialization + << TSI->getTypeLoc().getSourceRange(); + + // Keep going to check that we don't have any inner declarator pieces (we + // could still have a function returning a pointer to a function). + FoundFunction = true; + } + + if (D.isFunctionDefinition()) + // we can still create a valid deduction guide here. + Diag(D.getIdentifierLoc(), diag::err_deduction_guide_defines_function); + return false; + } + + //===----------------------------------------------------------------------===// + // Namespace Handling + //===----------------------------------------------------------------------===// + + /// Diagnose a mismatch in 'inline' qualifiers when a namespace is + /// reopened. + static void DiagnoseNamespaceInlineMismatch(Sema &S, SourceLocation KeywordLoc, + SourceLocation Loc, + IdentifierInfo *II, bool *IsInline, + NamespaceDecl *PrevNS) { + assert(*IsInline != PrevNS->isInline()); + + // 'inline' must appear on the original definition, but not necessarily + // on all extension definitions, so the note should point to the first + // definition to avoid confusion. + PrevNS = PrevNS->getFirstDecl(); + + if (PrevNS->isInline()) + // The user probably just forgot the 'inline', so suggest that it + // be added back. + S.Diag(Loc, diag::warn_inline_namespace_reopened_noninline) + << FixItHint::CreateInsertion(KeywordLoc, "inline "); + else + S.Diag(Loc, diag::err_inline_namespace_mismatch); + + S.Diag(PrevNS->getLocation(), diag::note_previous_definition); + *IsInline = PrevNS->isInline(); + } + + /// ActOnStartNamespaceDef - This is called at the start of a namespace + /// definition. + Decl *Sema::ActOnStartNamespaceDef(Scope *NamespcScope, + SourceLocation InlineLoc, + SourceLocation NamespaceLoc, + SourceLocation IdentLoc, IdentifierInfo *II, + SourceLocation LBrace, + const ParsedAttributesView &AttrList, + UsingDirectiveDecl *&UD, bool IsNested) { + SourceLocation StartLoc = InlineLoc.isValid() ? InlineLoc : NamespaceLoc; + // For anonymous namespace, take the location of the left brace. + SourceLocation Loc = II ? IdentLoc : LBrace; + bool IsInline = InlineLoc.isValid(); + bool IsInvalid = false; + bool IsStd = false; + bool AddToKnown = false; + Scope *DeclRegionScope = NamespcScope->getParent(); + + NamespaceDecl *PrevNS = nullptr; + if (II) { + // C++ [namespace.def]p2: + // The identifier in an original-namespace-definition shall not + // have been previously defined in the declarative region in + // which the original-namespace-definition appears. The + // identifier in an original-namespace-definition is the name of + // the namespace. Subsequently in that declarative region, it is + // treated as an original-namespace-name. + // + // Since namespace names are unique in their scope, and we don't + // look through using directives, just look for any ordinary names + // as if by qualified name lookup. + LookupResult R(*this, II, IdentLoc, LookupOrdinaryName, + ForExternalRedeclaration); + LookupQualifiedName(R, CurContext->getRedeclContext()); + NamedDecl *PrevDecl = + R.isSingleResult() ? R.getRepresentativeDecl() : nullptr; + PrevNS = dyn_cast_or_null(PrevDecl); + + if (PrevNS) { + // This is an extended namespace definition. + if (IsInline != PrevNS->isInline()) + DiagnoseNamespaceInlineMismatch(*this, NamespaceLoc, Loc, II, + &IsInline, PrevNS); + } else if (PrevDecl) { + // This is an invalid name redefinition. + Diag(Loc, diag::err_redefinition_different_kind) + << II; + Diag(PrevDecl->getLocation(), diag::note_previous_definition); + IsInvalid = true; + // Continue on to push Namespc as current DeclContext and return it. + } else if (II->isStr("std") && + CurContext->getRedeclContext()->isTranslationUnit()) { + // This is the first "real" definition of the namespace "std", so update + // our cache of the "std" namespace to point at this definition. + PrevNS = getStdNamespace(); + IsStd = true; + AddToKnown = !IsInline; + } else { + // We've seen this namespace for the first time. + AddToKnown = !IsInline; + } + } else { + // Anonymous namespaces. + + // Determine whether the parent already has an anonymous namespace. + DeclContext *Parent = CurContext->getRedeclContext(); + if (TranslationUnitDecl *TU = dyn_cast(Parent)) { + PrevNS = TU->getAnonymousNamespace(); + } else { + NamespaceDecl *ND = cast(Parent); + PrevNS = ND->getAnonymousNamespace(); + } + + if (PrevNS && IsInline != PrevNS->isInline()) + DiagnoseNamespaceInlineMismatch(*this, NamespaceLoc, NamespaceLoc, II, + &IsInline, PrevNS); + } + + NamespaceDecl *Namespc = NamespaceDecl::Create( + Context, CurContext, IsInline, StartLoc, Loc, II, PrevNS, IsNested); + if (IsInvalid) + Namespc->setInvalidDecl(); + + ProcessDeclAttributeList(DeclRegionScope, Namespc, AttrList); + AddPragmaAttributes(DeclRegionScope, Namespc); + + // FIXME: Should we be merging attributes? + if (const VisibilityAttr *Attr = Namespc->getAttr()) + PushNamespaceVisibilityAttr(Attr, Loc); + + if (IsStd) + StdNamespace = Namespc; + if (AddToKnown) + KnownNamespaces[Namespc] = false; + + if (II) { + PushOnScopeChains(Namespc, DeclRegionScope); + } else { + // Link the anonymous namespace into its parent. + DeclContext *Parent = CurContext->getRedeclContext(); + if (TranslationUnitDecl *TU = dyn_cast(Parent)) { + TU->setAnonymousNamespace(Namespc); + } else { + cast(Parent)->setAnonymousNamespace(Namespc); + } + + CurContext->addDecl(Namespc); + + // C++ [namespace.unnamed]p1. An unnamed-namespace-definition + // behaves as if it were replaced by + // namespace unique { /* empty body */ } + // using namespace unique; + // namespace unique { namespace-body } + // where all occurrences of 'unique' in a translation unit are + // replaced by the same identifier and this identifier differs + // from all other identifiers in the entire program. + + // We just create the namespace with an empty name and then add an + // implicit using declaration, just like the standard suggests. + // + // CodeGen enforces the "universally unique" aspect by giving all + // declarations semantically contained within an anonymous + // namespace internal linkage. + + if (!PrevNS) { + UD = UsingDirectiveDecl::Create(Context, Parent, + /* 'using' */ LBrace, + /* 'namespace' */ SourceLocation(), + /* qualifier */ NestedNameSpecifierLoc(), + /* identifier */ SourceLocation(), + Namespc, + /* Ancestor */ Parent); + UD->setImplicit(); + Parent->addDecl(UD); + } + } + + ActOnDocumentableDecl(Namespc); + + // Although we could have an invalid decl (i.e. the namespace name is a + // redefinition), push it as current DeclContext and try to continue parsing. + // FIXME: We should be able to push Namespc here, so that the each DeclContext + // for the namespace has the declarations that showed up in that particular + // namespace definition. + PushDeclContext(NamespcScope, Namespc); + return Namespc; + } + + /// getNamespaceDecl - Returns the namespace a decl represents. If the decl + /// is a namespace alias, returns the namespace it points to. + static inline NamespaceDecl *getNamespaceDecl(NamedDecl *D) { + if (NamespaceAliasDecl *AD = dyn_cast_or_null(D)) + return AD->getNamespace(); + return dyn_cast_or_null(D); + } + + /// ActOnFinishNamespaceDef - This callback is called after a namespace is + /// exited. Decl is the DeclTy returned by ActOnStartNamespaceDef. + void Sema::ActOnFinishNamespaceDef(Decl *Dcl, SourceLocation RBrace) { + NamespaceDecl *Namespc = dyn_cast_or_null(Dcl); + assert(Namespc && "Invalid parameter, expected NamespaceDecl"); + Namespc->setRBraceLoc(RBrace); + PopDeclContext(); + if (Namespc->hasAttr()) + PopPragmaVisibility(true, RBrace); + // If this namespace contains an export-declaration, export it now. + if (DeferredExportedNamespaces.erase(Namespc)) + Dcl->setModuleOwnershipKind(Decl::ModuleOwnershipKind::VisibleWhenImported); + } + + CXXRecordDecl *Sema::getStdBadAlloc() const { + return cast_or_null( + StdBadAlloc.get(Context.getExternalSource())); + } + + EnumDecl *Sema::getStdAlignValT() const { + return cast_or_null(StdAlignValT.get(Context.getExternalSource())); + } + + NamespaceDecl *Sema::getStdNamespace() const { + return cast_or_null( + StdNamespace.get(Context.getExternalSource())); + } + namespace { + + enum UnsupportedSTLSelect { + USS_InvalidMember, + USS_MissingMember, + USS_NonTrivial, + USS_Other + }; + + struct InvalidSTLDiagnoser { + Sema &S; + SourceLocation Loc; + QualType TyForDiags; + + QualType operator()(UnsupportedSTLSelect Sel = USS_Other, StringRef Name = "", + const VarDecl *VD = nullptr) { + { + auto D = S.Diag(Loc, diag::err_std_compare_type_not_supported) + << TyForDiags << ((int)Sel); + if (Sel == USS_InvalidMember || Sel == USS_MissingMember) { + assert(!Name.empty()); + D << Name; + } + } + if (Sel == USS_InvalidMember) { + S.Diag(VD->getLocation(), diag::note_var_declared_here) + << VD << VD->getSourceRange(); + } + return QualType(); + } + }; + } // namespace + + QualType Sema::CheckComparisonCategoryType(ComparisonCategoryType Kind, + SourceLocation Loc, + ComparisonCategoryUsage Usage) { + assert(getLangOpts().CPlusPlus && + "Looking for comparison category type outside of C++."); + + // Use an elaborated type for diagnostics which has a name containing the + // prepended 'std' namespace but not any inline namespace names. + auto TyForDiags = [&](ComparisonCategoryInfo *Info) { + auto *NNS = + NestedNameSpecifier::Create(Context, nullptr, getStdNamespace()); + return Context.getElaboratedType(ETK_None, NNS, Info->getType()); + }; + + // Check if we've already successfully checked the comparison category type + // before. If so, skip checking it again. + ComparisonCategoryInfo *Info = Context.CompCategories.lookupInfo(Kind); + if (Info && FullyCheckedComparisonCategories[static_cast(Kind)]) { + // The only thing we need to check is that the type has a reachable + // definition in the current context. + if (RequireCompleteType(Loc, TyForDiags(Info), diag::err_incomplete_type)) + return QualType(); + + return Info->getType(); + } + + // If lookup failed + if (!Info) { + std::string NameForDiags = "std::"; + NameForDiags += ComparisonCategories::getCategoryString(Kind); + Diag(Loc, diag::err_implied_comparison_category_type_not_found) + << NameForDiags << (int)Usage; + return QualType(); + } + + assert(Info->Kind == Kind); + assert(Info->Record); + + // Update the Record decl in case we encountered a forward declaration on our + // first pass. FIXME: This is a bit of a hack. + if (Info->Record->hasDefinition()) + Info->Record = Info->Record->getDefinition(); + + if (RequireCompleteType(Loc, TyForDiags(Info), diag::err_incomplete_type)) + return QualType(); + + InvalidSTLDiagnoser UnsupportedSTLError{*this, Loc, TyForDiags(Info)}; + + if (!Info->Record->isTriviallyCopyable()) + return UnsupportedSTLError(USS_NonTrivial); + + for (const CXXBaseSpecifier &BaseSpec : Info->Record->bases()) { + CXXRecordDecl *Base = BaseSpec.getType()->getAsCXXRecordDecl(); + // Tolerate empty base classes. + if (Base->isEmpty()) + continue; + // Reject STL implementations which have at least one non-empty base. + return UnsupportedSTLError(); + } + + // Check that the STL has implemented the types using a single integer field. + // This expectation allows better codegen for builtin operators. We require: + // (1) The class has exactly one field. + // (2) The field is an integral or enumeration type. + auto FIt = Info->Record->field_begin(), FEnd = Info->Record->field_end(); + if (std::distance(FIt, FEnd) != 1 || + !FIt->getType()->isIntegralOrEnumerationType()) { + return UnsupportedSTLError(); + } + + // Build each of the require values and store them in Info. + for (ComparisonCategoryResult CCR : + ComparisonCategories::getPossibleResultsForType(Kind)) { + StringRef MemName = ComparisonCategories::getResultString(CCR); + ComparisonCategoryInfo::ValueInfo *ValInfo = Info->lookupValueInfo(CCR); + + if (!ValInfo) + return UnsupportedSTLError(USS_MissingMember, MemName); + + VarDecl *VD = ValInfo->VD; + assert(VD && "should not be null!"); + + // Attempt to diagnose reasons why the STL definition of this type + // might be foobar, including it failing to be a constant expression. + // TODO Handle more ways the lookup or result can be invalid. + if (!VD->isStaticDataMember() || + !VD->isUsableInConstantExpressions(Context)) + return UnsupportedSTLError(USS_InvalidMember, MemName, VD); + + // Attempt to evaluate the var decl as a constant expression and extract + // the value of its first field as a ICE. If this fails, the STL + // implementation is not supported. + if (!ValInfo->hasValidIntValue()) + return UnsupportedSTLError(); + + MarkVariableReferenced(Loc, VD); + } + + // We've successfully built the required types and expressions. Update + // the cache and return the newly cached value. + FullyCheckedComparisonCategories[static_cast(Kind)] = true; + return Info->getType(); + } + + /// Retrieve the special "std" namespace, which may require us to + /// implicitly define the namespace. + NamespaceDecl *Sema::getOrCreateStdNamespace() { + if (!StdNamespace) { + // The "std" namespace has not yet been defined, so build one implicitly. + StdNamespace = NamespaceDecl::Create( + Context, Context.getTranslationUnitDecl(), + /*Inline=*/false, SourceLocation(), SourceLocation(), + &PP.getIdentifierTable().get("std"), + /*PrevDecl=*/nullptr, /*Nested=*/false); + getStdNamespace()->setImplicit(true); + // We want the created NamespaceDecl to be available for redeclaration + // lookups, but not for regular name lookups. + Context.getTranslationUnitDecl()->addDecl(getStdNamespace()); + getStdNamespace()->clearIdentifierNamespace(); + } + + return getStdNamespace(); + } + + bool Sema::isStdInitializerList(QualType Ty, QualType *Element) { + assert(getLangOpts().CPlusPlus && + "Looking for std::initializer_list outside of C++."); + + // We're looking for implicit instantiations of + // template class std::initializer_list. + + if (!StdNamespace) // If we haven't seen namespace std yet, this can't be it. + return false; + + ClassTemplateDecl *Template = nullptr; + const TemplateArgument *Arguments = nullptr; + + if (const RecordType *RT = Ty->getAs()) { + + ClassTemplateSpecializationDecl *Specialization = + dyn_cast(RT->getDecl()); + if (!Specialization) + return false; + + Template = Specialization->getSpecializedTemplate(); + Arguments = Specialization->getTemplateArgs().data(); + } else if (const TemplateSpecializationType *TST = + Ty->getAs()) { + Template = dyn_cast_or_null( + TST->getTemplateName().getAsTemplateDecl()); + Arguments = TST->template_arguments().begin(); + } + if (!Template) + return false; + + if (!StdInitializerList) { + // Haven't recognized std::initializer_list yet, maybe this is it. + CXXRecordDecl *TemplateClass = Template->getTemplatedDecl(); + if (TemplateClass->getIdentifier() != + &PP.getIdentifierTable().get("initializer_list") || + !getStdNamespace()->InEnclosingNamespaceSetOf( + TemplateClass->getDeclContext())) + return false; + // This is a template called std::initializer_list, but is it the right + // template? + TemplateParameterList *Params = Template->getTemplateParameters(); + if (Params->getMinRequiredArguments() != 1) + return false; + if (!isa(Params->getParam(0))) + return false; + + // It's the right template. + StdInitializerList = Template; + } + + if (Template->getCanonicalDecl() != StdInitializerList->getCanonicalDecl()) + return false; + + // This is an instance of std::initializer_list. Find the argument type. + if (Element) + *Element = Arguments[0].getAsType(); + return true; + } + + static ClassTemplateDecl *LookupStdInitializerList(Sema &S, SourceLocation Loc){ + NamespaceDecl *Std = S.getStdNamespace(); + if (!Std) { + S.Diag(Loc, diag::err_implied_std_initializer_list_not_found); + return nullptr; + } + + LookupResult Result(S, &S.PP.getIdentifierTable().get("initializer_list"), + Loc, Sema::LookupOrdinaryName); + if (!S.LookupQualifiedName(Result, Std)) { + S.Diag(Loc, diag::err_implied_std_initializer_list_not_found); + return nullptr; + } + ClassTemplateDecl *Template = Result.getAsSingle(); + if (!Template) { + Result.suppressDiagnostics(); + // We found something weird. Complain about the first thing we found. + NamedDecl *Found = *Result.begin(); + S.Diag(Found->getLocation(), diag::err_malformed_std_initializer_list); + return nullptr; + } + + // We found some template called std::initializer_list. Now verify that it's + // correct. + TemplateParameterList *Params = Template->getTemplateParameters(); + if (Params->getMinRequiredArguments() != 1 || + !isa(Params->getParam(0))) { + S.Diag(Template->getLocation(), diag::err_malformed_std_initializer_list); + return nullptr; + } + + return Template; + } + + QualType Sema::BuildStdInitializerList(QualType Element, SourceLocation Loc) { + if (!StdInitializerList) { + StdInitializerList = LookupStdInitializerList(*this, Loc); + if (!StdInitializerList) + return QualType(); + } + + TemplateArgumentListInfo Args(Loc, Loc); + Args.addArgument(TemplateArgumentLoc(TemplateArgument(Element), + Context.getTrivialTypeSourceInfo(Element, + Loc))); + return Context.getElaboratedType( + ElaboratedTypeKeyword::ETK_None, + NestedNameSpecifier::Create(Context, nullptr, getStdNamespace()), + CheckTemplateIdType(TemplateName(StdInitializerList), Loc, Args)); + } + + bool Sema::isInitListConstructor(const FunctionDecl *Ctor) { + // C++ [dcl.init.list]p2: + // A constructor is an initializer-list constructor if its first parameter + // is of type std::initializer_list or reference to possibly cv-qualified + // std::initializer_list for some type E, and either there are no other + // parameters or else all other parameters have default arguments. + if (!Ctor->hasOneParamOrDefaultArgs()) + return false; + + QualType ArgType = Ctor->getParamDecl(0)->getType(); + if (const ReferenceType *RT = ArgType->getAs()) + ArgType = RT->getPointeeType().getUnqualifiedType(); + + return isStdInitializerList(ArgType, nullptr); + } + + /// Determine whether a using statement is in a context where it will be + /// apply in all contexts. + static bool IsUsingDirectiveInToplevelContext(DeclContext *CurContext) { + switch (CurContext->getDeclKind()) { + case Decl::TranslationUnit: + return true; + case Decl::LinkageSpec: + return IsUsingDirectiveInToplevelContext(CurContext->getParent()); + default: + return false; + } + } + + namespace { + + // Callback to only accept typo corrections that are namespaces. + class NamespaceValidatorCCC final : public CorrectionCandidateCallback { + public: + bool ValidateCandidate(const TypoCorrection &candidate) override { + if (NamedDecl *ND = candidate.getCorrectionDecl()) + return isa(ND) || isa(ND); + return false; + } + + std::unique_ptr clone() override { + return std::make_unique(*this); + } + }; + + } + + static bool TryNamespaceTypoCorrection(Sema &S, LookupResult &R, Scope *Sc, + CXXScopeSpec &SS, + SourceLocation IdentLoc, + IdentifierInfo *Ident) { + R.clear(); + NamespaceValidatorCCC CCC{}; + if (TypoCorrection Corrected = + S.CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), Sc, &SS, CCC, + Sema::CTK_ErrorRecovery)) { + if (DeclContext *DC = S.computeDeclContext(SS, false)) { + std::string CorrectedStr(Corrected.getAsString(S.getLangOpts())); + bool DroppedSpecifier = Corrected.WillReplaceSpecifier() && + Ident->getName().equals(CorrectedStr); + S.diagnoseTypo(Corrected, + S.PDiag(diag::err_using_directive_member_suggest) + << Ident << DC << DroppedSpecifier << SS.getRange(), + S.PDiag(diag::note_namespace_defined_here)); + } else { + S.diagnoseTypo(Corrected, + S.PDiag(diag::err_using_directive_suggest) << Ident, + S.PDiag(diag::note_namespace_defined_here)); + } + R.addDecl(Corrected.getFoundDecl()); + return true; + } + return false; + } + + Decl *Sema::ActOnUsingDirective(Scope *S, SourceLocation UsingLoc, + SourceLocation NamespcLoc, CXXScopeSpec &SS, + SourceLocation IdentLoc, + IdentifierInfo *NamespcName, + const ParsedAttributesView &AttrList) { + assert(!SS.isInvalid() && "Invalid CXXScopeSpec."); + assert(NamespcName && "Invalid NamespcName."); + assert(IdentLoc.isValid() && "Invalid NamespceName location."); + + // This can only happen along a recovery path. + while (S->isTemplateParamScope()) + S = S->getParent(); + assert(S->getFlags() & Scope::DeclScope && "Invalid Scope."); + + UsingDirectiveDecl *UDir = nullptr; + NestedNameSpecifier *Qualifier = nullptr; + if (SS.isSet()) + Qualifier = SS.getScopeRep(); + + // Lookup namespace name. + LookupResult R(*this, NamespcName, IdentLoc, LookupNamespaceName); + LookupParsedName(R, S, &SS); + if (R.isAmbiguous()) + return nullptr; + + if (R.empty()) { + R.clear(); + // Allow "using namespace std;" or "using namespace ::std;" even if + // "std" hasn't been defined yet, for GCC compatibility. + if ((!Qualifier || Qualifier->getKind() == NestedNameSpecifier::Global) && + NamespcName->isStr("std")) { + Diag(IdentLoc, diag::ext_using_undefined_std); + R.addDecl(getOrCreateStdNamespace()); + R.resolveKind(); + } + // Otherwise, attempt typo correction. + else TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, NamespcName); + } + + if (!R.empty()) { + NamedDecl *Named = R.getRepresentativeDecl(); + NamespaceDecl *NS = R.getAsSingle(); + assert(NS && "expected namespace decl"); + + // The use of a nested name specifier may trigger deprecation warnings. + DiagnoseUseOfDecl(Named, IdentLoc); + + // C++ [namespace.udir]p1: + // A using-directive specifies that the names in the nominated + // namespace can be used in the scope in which the + // using-directive appears after the using-directive. During + // unqualified name lookup (3.4.1), the names appear as if they + // were declared in the nearest enclosing namespace which + // contains both the using-directive and the nominated + // namespace. [Note: in this context, "contains" means "contains + // directly or indirectly". ] + + // Find enclosing context containing both using-directive and + // nominated namespace. + DeclContext *CommonAncestor = NS; + while (CommonAncestor && !CommonAncestor->Encloses(CurContext)) + CommonAncestor = CommonAncestor->getParent(); + + UDir = UsingDirectiveDecl::Create(Context, CurContext, UsingLoc, NamespcLoc, + SS.getWithLocInContext(Context), + IdentLoc, Named, CommonAncestor); + + if (IsUsingDirectiveInToplevelContext(CurContext) && + !SourceMgr.isInMainFile(SourceMgr.getExpansionLoc(IdentLoc))) { + Diag(IdentLoc, diag::warn_using_directive_in_header); + } + + PushUsingDirective(S, UDir); + } else { + Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange(); + } + + if (UDir) + ProcessDeclAttributeList(S, UDir, AttrList); + + return UDir; + } + + void Sema::PushUsingDirective(Scope *S, UsingDirectiveDecl *UDir) { + // If the scope has an associated entity and the using directive is at + // namespace or translation unit scope, add the UsingDirectiveDecl into + // its lookup structure so qualified name lookup can find it. + DeclContext *Ctx = S->getEntity(); + if (Ctx && !Ctx->isFunctionOrMethod()) + Ctx->addDecl(UDir); + else + // Otherwise, it is at block scope. The using-directives will affect lookup + // only to the end of the scope. + S->PushUsingDirective(UDir); + } + + Decl *Sema::ActOnUsingDeclaration(Scope *S, AccessSpecifier AS, + SourceLocation UsingLoc, + SourceLocation TypenameLoc, CXXScopeSpec &SS, + UnqualifiedId &Name, + SourceLocation EllipsisLoc, + const ParsedAttributesView &AttrList) { + assert(S->getFlags() & Scope::DeclScope && "Invalid Scope."); + + if (SS.isEmpty()) { + Diag(Name.getBeginLoc(), diag::err_using_requires_qualname); + return nullptr; + } + + switch (Name.getKind()) { + case UnqualifiedIdKind::IK_ImplicitSelfParam: + case UnqualifiedIdKind::IK_Identifier: + case UnqualifiedIdKind::IK_OperatorFunctionId: + case UnqualifiedIdKind::IK_LiteralOperatorId: + case UnqualifiedIdKind::IK_ConversionFunctionId: + break; + + case UnqualifiedIdKind::IK_ConstructorName: + case UnqualifiedIdKind::IK_ConstructorTemplateId: + // C++11 inheriting constructors. + Diag(Name.getBeginLoc(), + getLangOpts().CPlusPlus11 + ? diag::warn_cxx98_compat_using_decl_constructor + : diag::err_using_decl_constructor) + << SS.getRange(); + + if (getLangOpts().CPlusPlus11) break; + + return nullptr; + + case UnqualifiedIdKind::IK_DestructorName: + Diag(Name.getBeginLoc(), diag::err_using_decl_destructor) << SS.getRange(); + return nullptr; + + case UnqualifiedIdKind::IK_TemplateId: + Diag(Name.getBeginLoc(), diag::err_using_decl_template_id) + << SourceRange(Name.TemplateId->LAngleLoc, Name.TemplateId->RAngleLoc); + return nullptr; + + case UnqualifiedIdKind::IK_DeductionGuideName: + llvm_unreachable("cannot parse qualified deduction guide name"); + } + + DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name); + DeclarationName TargetName = TargetNameInfo.getName(); + if (!TargetName) + return nullptr; + + // Warn about access declarations. + if (UsingLoc.isInvalid()) { + Diag(Name.getBeginLoc(), getLangOpts().CPlusPlus11 + ? diag::err_access_decl + : diag::warn_access_decl_deprecated) + << FixItHint::CreateInsertion(SS.getRange().getBegin(), "using "); + } + + if (EllipsisLoc.isInvalid()) { + if (DiagnoseUnexpandedParameterPack(SS, UPPC_UsingDeclaration) || + DiagnoseUnexpandedParameterPack(TargetNameInfo, UPPC_UsingDeclaration)) + return nullptr; + } else { + if (!SS.getScopeRep()->containsUnexpandedParameterPack() && + !TargetNameInfo.containsUnexpandedParameterPack()) { + Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs) + << SourceRange(SS.getBeginLoc(), TargetNameInfo.getEndLoc()); + EllipsisLoc = SourceLocation(); + } + } + + NamedDecl *UD = + BuildUsingDeclaration(S, AS, UsingLoc, TypenameLoc.isValid(), TypenameLoc, + SS, TargetNameInfo, EllipsisLoc, AttrList, + /*IsInstantiation*/ false, + AttrList.hasAttribute(ParsedAttr::AT_UsingIfExists)); + if (UD) + PushOnScopeChains(UD, S, /*AddToContext*/ false); + + return UD; + } + + Decl *Sema::ActOnUsingEnumDeclaration(Scope *S, AccessSpecifier AS, + SourceLocation UsingLoc, + SourceLocation EnumLoc, + SourceLocation IdentLoc, + IdentifierInfo &II, CXXScopeSpec *SS) { + assert(!SS->isInvalid() && "ScopeSpec is invalid"); + TypeSourceInfo *TSI = nullptr; + QualType EnumTy = GetTypeFromParser( + getTypeName(II, IdentLoc, S, SS, /*isClassName=*/false, + /*HasTrailingDot=*/false, + /*ObjectType=*/nullptr, /*IsCtorOrDtorName=*/false, + /*WantNontrivialTypeSourceInfo=*/true), + &TSI); + if (EnumTy.isNull()) { + Diag(IdentLoc, SS && isDependentScopeSpecifier(*SS) + ? diag::err_using_enum_is_dependent + : diag::err_unknown_typename) + << II.getName() + << SourceRange(SS ? SS->getBeginLoc() : IdentLoc, IdentLoc); + return nullptr; + } + + auto *Enum = dyn_cast_if_present(EnumTy->getAsTagDecl()); + if (!Enum) { + Diag(IdentLoc, diag::err_using_enum_not_enum) << EnumTy; + return nullptr; + } + + if (auto *Def = Enum->getDefinition()) + Enum = Def; + + if (TSI == nullptr) + TSI = Context.getTrivialTypeSourceInfo(EnumTy, IdentLoc); + + auto *UD = + BuildUsingEnumDeclaration(S, AS, UsingLoc, EnumLoc, IdentLoc, TSI, Enum); + + if (UD) + PushOnScopeChains(UD, S, /*AddToContext*/ false); + + return UD; + } + + /// Determine whether a using declaration considers the given + /// declarations as "equivalent", e.g., if they are redeclarations of + /// the same entity or are both typedefs of the same type. + static bool + IsEquivalentForUsingDecl(ASTContext &Context, NamedDecl *D1, NamedDecl *D2) { + if (D1->getCanonicalDecl() == D2->getCanonicalDecl()) + return true; + + if (TypedefNameDecl *TD1 = dyn_cast(D1)) + if (TypedefNameDecl *TD2 = dyn_cast(D2)) + return Context.hasSameType(TD1->getUnderlyingType(), + TD2->getUnderlyingType()); + + // Two using_if_exists using-declarations are equivalent if both are + // unresolved. + if (isa(D1) && + isa(D2)) + return true; + + return false; + } + + + /// Determines whether to create a using shadow decl for a particular + /// decl, given the set of decls existing prior to this using lookup. + bool Sema::CheckUsingShadowDecl(BaseUsingDecl *BUD, NamedDecl *Orig, + const LookupResult &Previous, + UsingShadowDecl *&PrevShadow) { + // Diagnose finding a decl which is not from a base class of the + // current class. We do this now because there are cases where this + // function will silently decide not to build a shadow decl, which + // will pre-empt further diagnostics. + // + // We don't need to do this in C++11 because we do the check once on + // the qualifier. + // + // FIXME: diagnose the following if we care enough: + // struct A { int foo; }; + // struct B : A { using A::foo; }; + // template struct C : A {}; + // template struct D : C { using B::foo; } // <--- + // This is invalid (during instantiation) in C++03 because B::foo + // resolves to the using decl in B, which is not a base class of D. + // We can't diagnose it immediately because C is an unknown + // specialization. The UsingShadowDecl in D then points directly + // to A::foo, which will look well-formed when we instantiate. + // The right solution is to not collapse the shadow-decl chain. + if (!getLangOpts().CPlusPlus11 && CurContext->isRecord()) + if (auto *Using = dyn_cast(BUD)) { + DeclContext *OrigDC = Orig->getDeclContext(); + + // Handle enums and anonymous structs. + if (isa(OrigDC)) + OrigDC = OrigDC->getParent(); + CXXRecordDecl *OrigRec = cast(OrigDC); + while (OrigRec->isAnonymousStructOrUnion()) + OrigRec = cast(OrigRec->getDeclContext()); + + if (cast(CurContext)->isProvablyNotDerivedFrom(OrigRec)) { + if (OrigDC == CurContext) { + Diag(Using->getLocation(), + diag::err_using_decl_nested_name_specifier_is_current_class) + << Using->getQualifierLoc().getSourceRange(); + Diag(Orig->getLocation(), diag::note_using_decl_target); + Using->setInvalidDecl(); + return true; + } + + Diag(Using->getQualifierLoc().getBeginLoc(), + diag::err_using_decl_nested_name_specifier_is_not_base_class) + << Using->getQualifier() << cast(CurContext) + << Using->getQualifierLoc().getSourceRange(); + Diag(Orig->getLocation(), diag::note_using_decl_target); + Using->setInvalidDecl(); + return true; + } + } + + if (Previous.empty()) return false; + + NamedDecl *Target = Orig; + if (isa(Target)) + Target = cast(Target)->getTargetDecl(); + + // If the target happens to be one of the previous declarations, we + // don't have a conflict. + // + // FIXME: but we might be increasing its access, in which case we + // should redeclare it. + NamedDecl *NonTag = nullptr, *Tag = nullptr; + bool FoundEquivalentDecl = false; + for (LookupResult::iterator I = Previous.begin(), E = Previous.end(); + I != E; ++I) { + NamedDecl *D = (*I)->getUnderlyingDecl(); + // We can have UsingDecls in our Previous results because we use the same + // LookupResult for checking whether the UsingDecl itself is a valid + // redeclaration. + if (isa(D) || isa(D) || isa(D)) + continue; + + if (auto *RD = dyn_cast(D)) { + // C++ [class.mem]p19: + // If T is the name of a class, then [every named member other than + // a non-static data member] shall have a name different from T + if (RD->isInjectedClassName() && !isa(Target) && + !isa(Target) && + !isa(Target) && + DiagnoseClassNameShadow( + CurContext, + DeclarationNameInfo(BUD->getDeclName(), BUD->getLocation()))) + return true; + } + + if (IsEquivalentForUsingDecl(Context, D, Target)) { + if (UsingShadowDecl *Shadow = dyn_cast(*I)) + PrevShadow = Shadow; + FoundEquivalentDecl = true; + } else if (isEquivalentInternalLinkageDeclaration(D, Target)) { + // We don't conflict with an existing using shadow decl of an equivalent + // declaration, but we're not a redeclaration of it. + FoundEquivalentDecl = true; + } + + if (isVisible(D)) + (isa(D) ? Tag : NonTag) = D; + } + + if (FoundEquivalentDecl) + return false; + + // Always emit a diagnostic for a mismatch between an unresolved + // using_if_exists and a resolved using declaration in either direction. + if (isa(Target) != + (isa_and_nonnull(NonTag))) { + if (!NonTag && !Tag) + return false; + Diag(BUD->getLocation(), diag::err_using_decl_conflict); + Diag(Target->getLocation(), diag::note_using_decl_target); + Diag((NonTag ? NonTag : Tag)->getLocation(), + diag::note_using_decl_conflict); + BUD->setInvalidDecl(); + return true; + } + + if (FunctionDecl *FD = Target->getAsFunction()) { + NamedDecl *OldDecl = nullptr; + switch (CheckOverload(nullptr, FD, Previous, OldDecl, + /*IsForUsingDecl*/ true)) { + case Ovl_Overload: + return false; + + case Ovl_NonFunction: + Diag(BUD->getLocation(), diag::err_using_decl_conflict); + break; + + // We found a decl with the exact signature. + case Ovl_Match: + // If we're in a record, we want to hide the target, so we + // return true (without a diagnostic) to tell the caller not to + // build a shadow decl. + if (CurContext->isRecord()) + return true; + + // If we're not in a record, this is an error. + Diag(BUD->getLocation(), diag::err_using_decl_conflict); + break; + } + + Diag(Target->getLocation(), diag::note_using_decl_target); + Diag(OldDecl->getLocation(), diag::note_using_decl_conflict); + BUD->setInvalidDecl(); + return true; + } + + // Target is not a function. + + if (isa(Target)) { + // No conflict between a tag and a non-tag. + if (!Tag) return false; + + Diag(BUD->getLocation(), diag::err_using_decl_conflict); + Diag(Target->getLocation(), diag::note_using_decl_target); + Diag(Tag->getLocation(), diag::note_using_decl_conflict); + BUD->setInvalidDecl(); + return true; + } + + // No conflict between a tag and a non-tag. + if (!NonTag) return false; + + Diag(BUD->getLocation(), diag::err_using_decl_conflict); + Diag(Target->getLocation(), diag::note_using_decl_target); + Diag(NonTag->getLocation(), diag::note_using_decl_conflict); + BUD->setInvalidDecl(); + return true; + } + + /// Determine whether a direct base class is a virtual base class. + static bool isVirtualDirectBase(CXXRecordDecl *Derived, CXXRecordDecl *Base) { + if (!Derived->getNumVBases()) + return false; + for (auto &B : Derived->bases()) + if (B.getType()->getAsCXXRecordDecl() == Base) + return B.isVirtual(); + llvm_unreachable("not a direct base class"); + } + + /// Builds a shadow declaration corresponding to a 'using' declaration. + UsingShadowDecl *Sema::BuildUsingShadowDecl(Scope *S, BaseUsingDecl *BUD, + NamedDecl *Orig, + UsingShadowDecl *PrevDecl) { + // If we resolved to another shadow declaration, just coalesce them. + NamedDecl *Target = Orig; + if (isa(Target)) { + Target = cast(Target)->getTargetDecl(); + assert(!isa(Target) && "nested shadow declaration"); + } + + NamedDecl *NonTemplateTarget = Target; + if (auto *TargetTD = dyn_cast(Target)) + NonTemplateTarget = TargetTD->getTemplatedDecl(); + + UsingShadowDecl *Shadow; + if (NonTemplateTarget && isa(NonTemplateTarget)) { + UsingDecl *Using = cast(BUD); + bool IsVirtualBase = + isVirtualDirectBase(cast(CurContext), + Using->getQualifier()->getAsRecordDecl()); + Shadow = ConstructorUsingShadowDecl::Create( + Context, CurContext, Using->getLocation(), Using, Orig, IsVirtualBase); + } else { + Shadow = UsingShadowDecl::Create(Context, CurContext, BUD->getLocation(), + Target->getDeclName(), BUD, Target); + } + BUD->addShadowDecl(Shadow); + + Shadow->setAccess(BUD->getAccess()); + if (Orig->isInvalidDecl() || BUD->isInvalidDecl()) + Shadow->setInvalidDecl(); + + Shadow->setPreviousDecl(PrevDecl); + + if (S) + PushOnScopeChains(Shadow, S); + else + CurContext->addDecl(Shadow); + + + return Shadow; + } + + /// Hides a using shadow declaration. This is required by the current + /// using-decl implementation when a resolvable using declaration in a + /// class is followed by a declaration which would hide or override + /// one or more of the using decl's targets; for example: + /// + /// struct Base { void foo(int); }; + /// struct Derived : Base { + /// using Base::foo; + /// void foo(int); + /// }; + /// + /// The governing language is C++03 [namespace.udecl]p12: + /// + /// When a using-declaration brings names from a base class into a + /// derived class scope, member functions in the derived class + /// override and/or hide member functions with the same name and + /// parameter types in a base class (rather than conflicting). + /// + /// There are two ways to implement this: + /// (1) optimistically create shadow decls when they're not hidden + /// by existing declarations, or + /// (2) don't create any shadow decls (or at least don't make them + /// visible) until we've fully parsed/instantiated the class. + /// The problem with (1) is that we might have to retroactively remove + /// a shadow decl, which requires several O(n) operations because the + /// decl structures are (very reasonably) not designed for removal. + /// (2) avoids this but is very fiddly and phase-dependent. + void Sema::HideUsingShadowDecl(Scope *S, UsingShadowDecl *Shadow) { + if (Shadow->getDeclName().getNameKind() == + DeclarationName::CXXConversionFunctionName) + cast(Shadow->getDeclContext())->removeConversion(Shadow); + + // Remove it from the DeclContext... + Shadow->getDeclContext()->removeDecl(Shadow); + + // ...and the scope, if applicable... + if (S) { + S->RemoveDecl(Shadow); + IdResolver.RemoveDecl(Shadow); + } + + // ...and the using decl. + Shadow->getIntroducer()->removeShadowDecl(Shadow); + + // TODO: complain somehow if Shadow was used. It shouldn't + // be possible for this to happen, because...? + } + + /// Find the base specifier for a base class with the given type. + static CXXBaseSpecifier *findDirectBaseWithType(CXXRecordDecl *Derived, + QualType DesiredBase, + bool &AnyDependentBases) { + // Check whether the named type is a direct base class. + CanQualType CanonicalDesiredBase = DesiredBase->getCanonicalTypeUnqualified() + .getUnqualifiedType(); + for (auto &Base : Derived->bases()) { + CanQualType BaseType = Base.getType()->getCanonicalTypeUnqualified(); + if (CanonicalDesiredBase == BaseType) + return &Base; + if (BaseType->isDependentType()) + AnyDependentBases = true; + } + return nullptr; + } + + namespace { + class UsingValidatorCCC final : public CorrectionCandidateCallback { + public: + UsingValidatorCCC(bool HasTypenameKeyword, bool IsInstantiation, + NestedNameSpecifier *NNS, CXXRecordDecl *RequireMemberOf) + : HasTypenameKeyword(HasTypenameKeyword), + IsInstantiation(IsInstantiation), OldNNS(NNS), + RequireMemberOf(RequireMemberOf) {} + + bool ValidateCandidate(const TypoCorrection &Candidate) override { + NamedDecl *ND = Candidate.getCorrectionDecl(); + + // Keywords are not valid here. + if (!ND || isa(ND)) + return false; + + // Completely unqualified names are invalid for a 'using' declaration. + if (Candidate.WillReplaceSpecifier() && !Candidate.getCorrectionSpecifier()) + return false; + + // FIXME: Don't correct to a name that CheckUsingDeclRedeclaration would + // reject. + + if (RequireMemberOf) { + auto *FoundRecord = dyn_cast(ND); + if (FoundRecord && FoundRecord->isInjectedClassName()) { + // No-one ever wants a using-declaration to name an injected-class-name + // of a base class, unless they're declaring an inheriting constructor. + ASTContext &Ctx = ND->getASTContext(); + if (!Ctx.getLangOpts().CPlusPlus11) + return false; + QualType FoundType = Ctx.getRecordType(FoundRecord); + + // Check that the injected-class-name is named as a member of its own + // type; we don't want to suggest 'using Derived::Base;', since that + // means something else. + NestedNameSpecifier *Specifier = + Candidate.WillReplaceSpecifier() + ? Candidate.getCorrectionSpecifier() + : OldNNS; + if (!Specifier->getAsType() || + !Ctx.hasSameType(QualType(Specifier->getAsType(), 0), FoundType)) + return false; + + // Check that this inheriting constructor declaration actually names a + // direct base class of the current class. + bool AnyDependentBases = false; + if (!findDirectBaseWithType(RequireMemberOf, + Ctx.getRecordType(FoundRecord), + AnyDependentBases) && + !AnyDependentBases) + return false; + } else { + auto *RD = dyn_cast(ND->getDeclContext()); + if (!RD || RequireMemberOf->isProvablyNotDerivedFrom(RD)) + return false; + + // FIXME: Check that the base class member is accessible? + } + } else { + auto *FoundRecord = dyn_cast(ND); + if (FoundRecord && FoundRecord->isInjectedClassName()) + return false; + } + + if (isa(ND)) + return HasTypenameKeyword || !IsInstantiation; + + return !HasTypenameKeyword; + } + + std::unique_ptr clone() override { + return std::make_unique(*this); + } + + private: + bool HasTypenameKeyword; + bool IsInstantiation; + NestedNameSpecifier *OldNNS; + CXXRecordDecl *RequireMemberOf; + }; + } // end anonymous namespace + + /// Remove decls we can't actually see from a lookup being used to declare + /// shadow using decls. + /// + /// \param S - The scope of the potential shadow decl + /// \param Previous - The lookup of a potential shadow decl's name. + void Sema::FilterUsingLookup(Scope *S, LookupResult &Previous) { + // It is really dumb that we have to do this. + LookupResult::Filter F = Previous.makeFilter(); + while (F.hasNext()) { + NamedDecl *D = F.next(); + if (!isDeclInScope(D, CurContext, S)) + F.erase(); + // If we found a local extern declaration that's not ordinarily visible, + // and this declaration is being added to a non-block scope, ignore it. + // We're only checking for scope conflicts here, not also for violations + // of the linkage rules. + else if (!CurContext->isFunctionOrMethod() && D->isLocalExternDecl() && + !(D->getIdentifierNamespace() & Decl::IDNS_Ordinary)) + F.erase(); + } + F.done(); + } + + /// Builds a using declaration. + /// + /// \param IsInstantiation - Whether this call arises from an + /// instantiation of an unresolved using declaration. We treat + /// the lookup differently for these declarations. + NamedDecl *Sema::BuildUsingDeclaration( + Scope *S, AccessSpecifier AS, SourceLocation UsingLoc, + bool HasTypenameKeyword, SourceLocation TypenameLoc, CXXScopeSpec &SS, + DeclarationNameInfo NameInfo, SourceLocation EllipsisLoc, + const ParsedAttributesView &AttrList, bool IsInstantiation, + bool IsUsingIfExists) { + assert(!SS.isInvalid() && "Invalid CXXScopeSpec."); + SourceLocation IdentLoc = NameInfo.getLoc(); + assert(IdentLoc.isValid() && "Invalid TargetName location."); + + // FIXME: We ignore attributes for now. + + // For an inheriting constructor declaration, the name of the using + // declaration is the name of a constructor in this class, not in the + // base class. + DeclarationNameInfo UsingName = NameInfo; + if (UsingName.getName().getNameKind() == DeclarationName::CXXConstructorName) + if (auto *RD = dyn_cast(CurContext)) + UsingName.setName(Context.DeclarationNames.getCXXConstructorName( + Context.getCanonicalType(Context.getRecordType(RD)))); + + // Do the redeclaration lookup in the current scope. + LookupResult Previous(*this, UsingName, LookupUsingDeclName, + ForVisibleRedeclaration); + Previous.setHideTags(false); + if (S) { + LookupName(Previous, S); + + FilterUsingLookup(S, Previous); + } else { + assert(IsInstantiation && "no scope in non-instantiation"); + if (CurContext->isRecord()) + LookupQualifiedName(Previous, CurContext); + else { + // No redeclaration check is needed here; in non-member contexts we + // diagnosed all possible conflicts with other using-declarations when + // building the template: + // + // For a dependent non-type using declaration, the only valid case is + // if we instantiate to a single enumerator. We check for conflicts + // between shadow declarations we introduce, and we check in the template + // definition for conflicts between a non-type using declaration and any + // other declaration, which together covers all cases. + // + // A dependent typename using declaration will never successfully + // instantiate, since it will always name a class member, so we reject + // that in the template definition. + } + } + + // Check for invalid redeclarations. + if (CheckUsingDeclRedeclaration(UsingLoc, HasTypenameKeyword, + SS, IdentLoc, Previous)) + return nullptr; + + // 'using_if_exists' doesn't make sense on an inherited constructor. + if (IsUsingIfExists && UsingName.getName().getNameKind() == + DeclarationName::CXXConstructorName) { + Diag(UsingLoc, diag::err_using_if_exists_on_ctor); + return nullptr; + } + + DeclContext *LookupContext = computeDeclContext(SS); + NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context); + if (!LookupContext || EllipsisLoc.isValid()) { + NamedDecl *D; + // Dependent scope, or an unexpanded pack + if (!LookupContext && CheckUsingDeclQualifier(UsingLoc, HasTypenameKeyword, + SS, NameInfo, IdentLoc)) + return nullptr; + + if (HasTypenameKeyword) { + // FIXME: not all declaration name kinds are legal here + D = UnresolvedUsingTypenameDecl::Create(Context, CurContext, + UsingLoc, TypenameLoc, + QualifierLoc, + IdentLoc, NameInfo.getName(), + EllipsisLoc); + } else { + D = UnresolvedUsingValueDecl::Create(Context, CurContext, UsingLoc, + QualifierLoc, NameInfo, EllipsisLoc); + } + D->setAccess(AS); + CurContext->addDecl(D); + ProcessDeclAttributeList(S, D, AttrList); + return D; + } + + auto Build = [&](bool Invalid) { + UsingDecl *UD = + UsingDecl::Create(Context, CurContext, UsingLoc, QualifierLoc, + UsingName, HasTypenameKeyword); + UD->setAccess(AS); + CurContext->addDecl(UD); + ProcessDeclAttributeList(S, UD, AttrList); + UD->setInvalidDecl(Invalid); + return UD; + }; + auto BuildInvalid = [&]{ return Build(true); }; + auto BuildValid = [&]{ return Build(false); }; + + if (RequireCompleteDeclContext(SS, LookupContext)) + return BuildInvalid(); + + // Look up the target name. + LookupResult R(*this, NameInfo, LookupOrdinaryName); + + // Unlike most lookups, we don't always want to hide tag + // declarations: tag names are visible through the using declaration + // even if hidden by ordinary names, *except* in a dependent context + // where they may be used by two-phase lookup. + if (!IsInstantiation) + R.setHideTags(false); + + // For the purposes of this lookup, we have a base object type + // equal to that of the current context. + if (CurContext->isRecord()) { + R.setBaseObjectType( + Context.getTypeDeclType(cast(CurContext))); + } + + LookupQualifiedName(R, LookupContext); + + // Validate the context, now we have a lookup + if (CheckUsingDeclQualifier(UsingLoc, HasTypenameKeyword, SS, NameInfo, + IdentLoc, &R)) + return nullptr; + + if (R.empty() && IsUsingIfExists) + R.addDecl(UnresolvedUsingIfExistsDecl::Create(Context, CurContext, UsingLoc, + UsingName.getName()), + AS_public); + + // Try to correct typos if possible. If constructor name lookup finds no + // results, that means the named class has no explicit constructors, and we + // suppressed declaring implicit ones (probably because it's dependent or + // invalid). + if (R.empty() && + NameInfo.getName().getNameKind() != DeclarationName::CXXConstructorName) { + // HACK 2017-01-08: Work around an issue with libstdc++'s detection of + // ::gets. Sometimes it believes that glibc provides a ::gets in cases where + // it does not. The issue was fixed in libstdc++ 6.3 (2016-12-21) and later. + auto *II = NameInfo.getName().getAsIdentifierInfo(); + if (getLangOpts().CPlusPlus14 && II && II->isStr("gets") && + CurContext->isStdNamespace() && + isa(LookupContext) && + getSourceManager().isInSystemHeader(UsingLoc)) + return nullptr; + UsingValidatorCCC CCC(HasTypenameKeyword, IsInstantiation, SS.getScopeRep(), + dyn_cast(CurContext)); + if (TypoCorrection Corrected = + CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS, CCC, + CTK_ErrorRecovery)) { + // We reject candidates where DroppedSpecifier == true, hence the + // literal '0' below. + diagnoseTypo(Corrected, PDiag(diag::err_no_member_suggest) + << NameInfo.getName() << LookupContext << 0 + << SS.getRange()); + + // If we picked a correction with no attached Decl we can't do anything + // useful with it, bail out. + NamedDecl *ND = Corrected.getCorrectionDecl(); + if (!ND) + return BuildInvalid(); + + // If we corrected to an inheriting constructor, handle it as one. + auto *RD = dyn_cast(ND); + if (RD && RD->isInjectedClassName()) { + // The parent of the injected class name is the class itself. + RD = cast(RD->getParent()); + + // Fix up the information we'll use to build the using declaration. + if (Corrected.WillReplaceSpecifier()) { + NestedNameSpecifierLocBuilder Builder; + Builder.MakeTrivial(Context, Corrected.getCorrectionSpecifier(), + QualifierLoc.getSourceRange()); + QualifierLoc = Builder.getWithLocInContext(Context); + } + + // In this case, the name we introduce is the name of a derived class + // constructor. + auto *CurClass = cast(CurContext); + UsingName.setName(Context.DeclarationNames.getCXXConstructorName( + Context.getCanonicalType(Context.getRecordType(CurClass)))); + UsingName.setNamedTypeInfo(nullptr); + for (auto *Ctor : LookupConstructors(RD)) + R.addDecl(Ctor); + R.resolveKind(); + } else { + // FIXME: Pick up all the declarations if we found an overloaded + // function. + UsingName.setName(ND->getDeclName()); + R.addDecl(ND); + } + } else { + Diag(IdentLoc, diag::err_no_member) + << NameInfo.getName() << LookupContext << SS.getRange(); + return BuildInvalid(); + } + } + + if (R.isAmbiguous()) + return BuildInvalid(); + + if (HasTypenameKeyword) { + // If we asked for a typename and got a non-type decl, error out. + if (!R.getAsSingle() && + !R.getAsSingle()) { + Diag(IdentLoc, diag::err_using_typename_non_type); + for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) + Diag((*I)->getUnderlyingDecl()->getLocation(), + diag::note_using_decl_target); + return BuildInvalid(); + } + } else { + // If we asked for a non-typename and we got a type, error out, + // but only if this is an instantiation of an unresolved using + // decl. Otherwise just silently find the type name. + if (IsInstantiation && R.getAsSingle()) { + Diag(IdentLoc, diag::err_using_dependent_value_is_type); + Diag(R.getFoundDecl()->getLocation(), diag::note_using_decl_target); + return BuildInvalid(); + } + } + + // C++14 [namespace.udecl]p6: + // A using-declaration shall not name a namespace. + if (R.getAsSingle()) { + Diag(IdentLoc, diag::err_using_decl_can_not_refer_to_namespace) + << SS.getRange(); + return BuildInvalid(); + } + + UsingDecl *UD = BuildValid(); + + // Some additional rules apply to inheriting constructors. + if (UsingName.getName().getNameKind() == + DeclarationName::CXXConstructorName) { + // Suppress access diagnostics; the access check is instead performed at the + // point of use for an inheriting constructor. + R.suppressDiagnostics(); + if (CheckInheritingConstructorUsingDecl(UD)) + return UD; + } + + for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { + UsingShadowDecl *PrevDecl = nullptr; + if (!CheckUsingShadowDecl(UD, *I, Previous, PrevDecl)) + BuildUsingShadowDecl(S, UD, *I, PrevDecl); + } + + return UD; + } + + NamedDecl *Sema::BuildUsingEnumDeclaration(Scope *S, AccessSpecifier AS, + SourceLocation UsingLoc, + SourceLocation EnumLoc, + SourceLocation NameLoc, + TypeSourceInfo *EnumType, + EnumDecl *ED) { + bool Invalid = false; + + if (CurContext->getRedeclContext()->isRecord()) { + /// In class scope, check if this is a duplicate, for better a diagnostic. + DeclarationNameInfo UsingEnumName(ED->getDeclName(), NameLoc); + LookupResult Previous(*this, UsingEnumName, LookupUsingDeclName, + ForVisibleRedeclaration); + + LookupName(Previous, S); + + for (NamedDecl *D : Previous) + if (UsingEnumDecl *UED = dyn_cast(D)) + if (UED->getEnumDecl() == ED) { + Diag(UsingLoc, diag::err_using_enum_decl_redeclaration) + << SourceRange(EnumLoc, NameLoc); + Diag(D->getLocation(), diag::note_using_enum_decl) << 1; + Invalid = true; + break; + } + } + + if (RequireCompleteEnumDecl(ED, NameLoc)) + Invalid = true; + + UsingEnumDecl *UD = UsingEnumDecl::Create(Context, CurContext, UsingLoc, + EnumLoc, NameLoc, EnumType); + UD->setAccess(AS); + CurContext->addDecl(UD); + + if (Invalid) { + UD->setInvalidDecl(); + return UD; + } + + // Create the shadow decls for each enumerator + for (EnumConstantDecl *EC : ED->enumerators()) { + UsingShadowDecl *PrevDecl = nullptr; + DeclarationNameInfo DNI(EC->getDeclName(), EC->getLocation()); + LookupResult Previous(*this, DNI, LookupOrdinaryName, + ForVisibleRedeclaration); + LookupName(Previous, S); + FilterUsingLookup(S, Previous); + + if (!CheckUsingShadowDecl(UD, EC, Previous, PrevDecl)) + BuildUsingShadowDecl(S, UD, EC, PrevDecl); + } + + return UD; + } + + NamedDecl *Sema::BuildUsingPackDecl(NamedDecl *InstantiatedFrom, + ArrayRef Expansions) { + assert(isa(InstantiatedFrom) || + isa(InstantiatedFrom) || + isa(InstantiatedFrom)); + + auto *UPD = + UsingPackDecl::Create(Context, CurContext, InstantiatedFrom, Expansions); + UPD->setAccess(InstantiatedFrom->getAccess()); + CurContext->addDecl(UPD); + return UPD; + } + + /// Additional checks for a using declaration referring to a constructor name. + bool Sema::CheckInheritingConstructorUsingDecl(UsingDecl *UD) { + assert(!UD->hasTypename() && "expecting a constructor name"); + + const Type *SourceType = UD->getQualifier()->getAsType(); + assert(SourceType && + "Using decl naming constructor doesn't have type in scope spec."); + CXXRecordDecl *TargetClass = cast(CurContext); + + // Check whether the named type is a direct base class. + bool AnyDependentBases = false; + auto *Base = findDirectBaseWithType(TargetClass, QualType(SourceType, 0), + AnyDependentBases); + if (!Base && !AnyDependentBases) { + Diag(UD->getUsingLoc(), + diag::err_using_decl_constructor_not_in_direct_base) + << UD->getNameInfo().getSourceRange() + << QualType(SourceType, 0) << TargetClass; + UD->setInvalidDecl(); + return true; + } + + if (Base) + Base->setInheritConstructors(); + + return false; + } + + /// Checks that the given using declaration is not an invalid + /// redeclaration. Note that this is checking only for the using decl + /// itself, not for any ill-formedness among the UsingShadowDecls. + bool Sema::CheckUsingDeclRedeclaration(SourceLocation UsingLoc, + bool HasTypenameKeyword, + const CXXScopeSpec &SS, + SourceLocation NameLoc, + const LookupResult &Prev) { + NestedNameSpecifier *Qual = SS.getScopeRep(); + + // C++03 [namespace.udecl]p8: + // C++0x [namespace.udecl]p10: + // A using-declaration is a declaration and can therefore be used + // repeatedly where (and only where) multiple declarations are + // allowed. + // + // That's in non-member contexts. + if (!CurContext->getRedeclContext()->isRecord()) { + // A dependent qualifier outside a class can only ever resolve to an + // enumeration type. Therefore it conflicts with any other non-type + // declaration in the same scope. + // FIXME: How should we check for dependent type-type conflicts at block + // scope? + if (Qual->isDependent() && !HasTypenameKeyword) { + for (auto *D : Prev) { + if (!isa(D) && !isa(D) && !isa(D)) { + bool OldCouldBeEnumerator = + isa(D) || isa(D); + Diag(NameLoc, + OldCouldBeEnumerator ? diag::err_redefinition + : diag::err_redefinition_different_kind) + << Prev.getLookupName(); + Diag(D->getLocation(), diag::note_previous_definition); + return true; + } + } + } + return false; + } + + const NestedNameSpecifier *CNNS = + Context.getCanonicalNestedNameSpecifier(Qual); + for (LookupResult::iterator I = Prev.begin(), E = Prev.end(); I != E; ++I) { + NamedDecl *D = *I; + + bool DTypename; + NestedNameSpecifier *DQual; + if (UsingDecl *UD = dyn_cast(D)) { + DTypename = UD->hasTypename(); + DQual = UD->getQualifier(); + } else if (UnresolvedUsingValueDecl *UD + = dyn_cast(D)) { + DTypename = false; + DQual = UD->getQualifier(); + } else if (UnresolvedUsingTypenameDecl *UD + = dyn_cast(D)) { + DTypename = true; + DQual = UD->getQualifier(); + } else continue; + + // using decls differ if one says 'typename' and the other doesn't. + // FIXME: non-dependent using decls? + if (HasTypenameKeyword != DTypename) continue; + + // using decls differ if they name different scopes (but note that + // template instantiation can cause this check to trigger when it + // didn't before instantiation). + if (CNNS != Context.getCanonicalNestedNameSpecifier(DQual)) + continue; + + Diag(NameLoc, diag::err_using_decl_redeclaration) << SS.getRange(); + Diag(D->getLocation(), diag::note_using_decl) << 1; + return true; + } + + return false; + } + + /// Checks that the given nested-name qualifier used in a using decl + /// in the current context is appropriately related to the current + /// scope. If an error is found, diagnoses it and returns true. + /// R is nullptr, if the caller has not (yet) done a lookup, otherwise it's the + /// result of that lookup. UD is likewise nullptr, except when we have an + /// already-populated UsingDecl whose shadow decls contain the same information + /// (i.e. we're instantiating a UsingDecl with non-dependent scope). + bool Sema::CheckUsingDeclQualifier(SourceLocation UsingLoc, bool HasTypename, + const CXXScopeSpec &SS, + const DeclarationNameInfo &NameInfo, + SourceLocation NameLoc, + const LookupResult *R, const UsingDecl *UD) { + DeclContext *NamedContext = computeDeclContext(SS); + assert(bool(NamedContext) == (R || UD) && !(R && UD) && + "resolvable context must have exactly one set of decls"); + + // C++ 20 permits using an enumerator that does not have a class-hierarchy + // relationship. + bool Cxx20Enumerator = false; + if (NamedContext) { + EnumConstantDecl *EC = nullptr; + if (R) + EC = R->getAsSingle(); + else if (UD && UD->shadow_size() == 1) + EC = dyn_cast(UD->shadow_begin()->getTargetDecl()); + if (EC) + Cxx20Enumerator = getLangOpts().CPlusPlus20; + + if (auto *ED = dyn_cast(NamedContext)) { + // C++14 [namespace.udecl]p7: + // A using-declaration shall not name a scoped enumerator. + // C++20 p1099 permits enumerators. + if (EC && R && ED->isScoped()) + Diag(SS.getBeginLoc(), + getLangOpts().CPlusPlus20 + ? diag::warn_cxx17_compat_using_decl_scoped_enumerator + : diag::ext_using_decl_scoped_enumerator) + << SS.getRange(); + + // We want to consider the scope of the enumerator + NamedContext = ED->getDeclContext(); + } + } + + if (!CurContext->isRecord()) { + // C++03 [namespace.udecl]p3: + // C++0x [namespace.udecl]p8: + // A using-declaration for a class member shall be a member-declaration. + // C++20 [namespace.udecl]p7 + // ... other than an enumerator ... + + // If we weren't able to compute a valid scope, it might validly be a + // dependent class or enumeration scope. If we have a 'typename' keyword, + // the scope must resolve to a class type. + if (NamedContext ? !NamedContext->getRedeclContext()->isRecord() + : !HasTypename) + return false; // OK + + Diag(NameLoc, + Cxx20Enumerator + ? diag::warn_cxx17_compat_using_decl_class_member_enumerator + : diag::err_using_decl_can_not_refer_to_class_member) + << SS.getRange(); + + if (Cxx20Enumerator) + return false; // OK + + auto *RD = NamedContext + ? cast(NamedContext->getRedeclContext()) + : nullptr; + if (RD && !RequireCompleteDeclContext(const_cast(SS), RD)) { + // See if there's a helpful fixit + + if (!R) { + // We will have already diagnosed the problem on the template + // definition, Maybe we should do so again? + } else if (R->getAsSingle()) { + if (getLangOpts().CPlusPlus11) { + // Convert 'using X::Y;' to 'using Y = X::Y;'. + Diag(SS.getBeginLoc(), diag::note_using_decl_class_member_workaround) + << 0 // alias declaration + << FixItHint::CreateInsertion(SS.getBeginLoc(), + NameInfo.getName().getAsString() + + " = "); + } else { + // Convert 'using X::Y;' to 'typedef X::Y Y;'. + SourceLocation InsertLoc = getLocForEndOfToken(NameInfo.getEndLoc()); + Diag(InsertLoc, diag::note_using_decl_class_member_workaround) + << 1 // typedef declaration + << FixItHint::CreateReplacement(UsingLoc, "typedef") + << FixItHint::CreateInsertion( + InsertLoc, " " + NameInfo.getName().getAsString()); + } + } else if (R->getAsSingle()) { + // Don't provide a fixit outside C++11 mode; we don't want to suggest + // repeating the type of the static data member here. + FixItHint FixIt; + if (getLangOpts().CPlusPlus11) { + // Convert 'using X::Y;' to 'auto &Y = X::Y;'. + FixIt = FixItHint::CreateReplacement( + UsingLoc, "auto &" + NameInfo.getName().getAsString() + " = "); + } + + Diag(UsingLoc, diag::note_using_decl_class_member_workaround) + << 2 // reference declaration + << FixIt; + } else if (R->getAsSingle()) { + // Don't provide a fixit outside C++11 mode; we don't want to suggest + // repeating the type of the enumeration here, and we can't do so if + // the type is anonymous. + FixItHint FixIt; + if (getLangOpts().CPlusPlus11) { + // Convert 'using X::Y;' to 'auto &Y = X::Y;'. + FixIt = FixItHint::CreateReplacement( + UsingLoc, + "constexpr auto " + NameInfo.getName().getAsString() + " = "); + } + + Diag(UsingLoc, diag::note_using_decl_class_member_workaround) + << (getLangOpts().CPlusPlus11 ? 4 : 3) // const[expr] variable + << FixIt; + } + } + + return true; // Fail + } + + // If the named context is dependent, we can't decide much. + if (!NamedContext) { + // FIXME: in C++0x, we can diagnose if we can prove that the + // nested-name-specifier does not refer to a base class, which is + // still possible in some cases. + + // Otherwise we have to conservatively report that things might be + // okay. + return false; + } + + // The current scope is a record. + if (!NamedContext->isRecord()) { + // Ideally this would point at the last name in the specifier, + // but we don't have that level of source info. + Diag(SS.getBeginLoc(), + Cxx20Enumerator + ? diag::warn_cxx17_compat_using_decl_non_member_enumerator + : diag::err_using_decl_nested_name_specifier_is_not_class) + << SS.getScopeRep() << SS.getRange(); + + if (Cxx20Enumerator) + return false; // OK + + return true; + } + + if (!NamedContext->isDependentContext() && + RequireCompleteDeclContext(const_cast(SS), NamedContext)) + return true; + + if (getLangOpts().CPlusPlus11) { + // C++11 [namespace.udecl]p3: + // In a using-declaration used as a member-declaration, the + // nested-name-specifier shall name a base class of the class + // being defined. + + if (cast(CurContext)->isProvablyNotDerivedFrom( + cast(NamedContext))) { + + if (Cxx20Enumerator) { + Diag(NameLoc, diag::warn_cxx17_compat_using_decl_non_member_enumerator) + << SS.getRange(); + return false; + } + + if (CurContext == NamedContext) { + Diag(SS.getBeginLoc(), + diag::err_using_decl_nested_name_specifier_is_current_class) + << SS.getRange(); + return !getLangOpts().CPlusPlus20; + } + + if (!cast(NamedContext)->isInvalidDecl()) { + Diag(SS.getBeginLoc(), + diag::err_using_decl_nested_name_specifier_is_not_base_class) + << SS.getScopeRep() << cast(CurContext) + << SS.getRange(); + } + return true; + } + + return false; + } + + // C++03 [namespace.udecl]p4: + // A using-declaration used as a member-declaration shall refer + // to a member of a base class of the class being defined [etc.]. + + // Salient point: SS doesn't have to name a base class as long as + // lookup only finds members from base classes. Therefore we can + // diagnose here only if we can prove that can't happen, + // i.e. if the class hierarchies provably don't intersect. + + // TODO: it would be nice if "definitely valid" results were cached + // in the UsingDecl and UsingShadowDecl so that these checks didn't + // need to be repeated. + + llvm::SmallPtrSet Bases; + auto Collect = [&Bases](const CXXRecordDecl *Base) { + Bases.insert(Base); + return true; + }; + + // Collect all bases. Return false if we find a dependent base. + if (!cast(CurContext)->forallBases(Collect)) + return false; + + // Returns true if the base is dependent or is one of the accumulated base + // classes. + auto IsNotBase = [&Bases](const CXXRecordDecl *Base) { + return !Bases.count(Base); + }; + + // Return false if the class has a dependent base or if it or one + // of its bases is present in the base set of the current context. + if (Bases.count(cast(NamedContext)) || + !cast(NamedContext)->forallBases(IsNotBase)) + return false; + + Diag(SS.getRange().getBegin(), + diag::err_using_decl_nested_name_specifier_is_not_base_class) + << SS.getScopeRep() + << cast(CurContext) + << SS.getRange(); + + return true; + } + + Decl *Sema::ActOnAliasDeclaration(Scope *S, AccessSpecifier AS, + MultiTemplateParamsArg TemplateParamLists, + SourceLocation UsingLoc, UnqualifiedId &Name, + const ParsedAttributesView &AttrList, + TypeResult Type, Decl *DeclFromDeclSpec) { + // Skip up to the relevant declaration scope. + while (S->isTemplateParamScope()) + S = S->getParent(); + assert((S->getFlags() & Scope::DeclScope) && + "got alias-declaration outside of declaration scope"); + + if (Type.isInvalid()) + return nullptr; + + bool Invalid = false; + DeclarationNameInfo NameInfo = GetNameFromUnqualifiedId(Name); + TypeSourceInfo *TInfo = nullptr; + GetTypeFromParser(Type.get(), &TInfo); + + if (DiagnoseClassNameShadow(CurContext, NameInfo)) + return nullptr; + + if (DiagnoseUnexpandedParameterPack(Name.StartLocation, TInfo, + UPPC_DeclarationType)) { + Invalid = true; + TInfo = Context.getTrivialTypeSourceInfo(Context.IntTy, + TInfo->getTypeLoc().getBeginLoc()); + } + + LookupResult Previous(*this, NameInfo, LookupOrdinaryName, + TemplateParamLists.size() + ? forRedeclarationInCurContext() + : ForVisibleRedeclaration); + LookupName(Previous, S); + + // Warn about shadowing the name of a template parameter. + if (Previous.isSingleResult() && + Previous.getFoundDecl()->isTemplateParameter()) { + DiagnoseTemplateParameterShadow(Name.StartLocation,Previous.getFoundDecl()); + Previous.clear(); + } + + assert(Name.getKind() == UnqualifiedIdKind::IK_Identifier && + "name in alias declaration must be an identifier"); + TypeAliasDecl *NewTD = TypeAliasDecl::Create(Context, CurContext, UsingLoc, + Name.StartLocation, + Name.Identifier, TInfo); + + NewTD->setAccess(AS); + + if (Invalid) + NewTD->setInvalidDecl(); + + ProcessDeclAttributeList(S, NewTD, AttrList); + AddPragmaAttributes(S, NewTD); + + CheckTypedefForVariablyModifiedType(S, NewTD); + Invalid |= NewTD->isInvalidDecl(); + + bool Redeclaration = false; + + NamedDecl *NewND; + if (TemplateParamLists.size()) { + TypeAliasTemplateDecl *OldDecl = nullptr; + TemplateParameterList *OldTemplateParams = nullptr; + + if (TemplateParamLists.size() != 1) { + Diag(UsingLoc, diag::err_alias_template_extra_headers) + << SourceRange(TemplateParamLists[1]->getTemplateLoc(), + TemplateParamLists[TemplateParamLists.size()-1]->getRAngleLoc()); + } + TemplateParameterList *TemplateParams = TemplateParamLists[0]; + + // Check that we can declare a template here. + if (CheckTemplateDeclScope(S, TemplateParams)) + return nullptr; + + // Only consider previous declarations in the same scope. + FilterLookupForScope(Previous, CurContext, S, /*ConsiderLinkage*/false, + /*ExplicitInstantiationOrSpecialization*/false); + if (!Previous.empty()) { + Redeclaration = true; + + OldDecl = Previous.getAsSingle(); + if (!OldDecl && !Invalid) { + Diag(UsingLoc, diag::err_redefinition_different_kind) + << Name.Identifier; + + NamedDecl *OldD = Previous.getRepresentativeDecl(); + if (OldD->getLocation().isValid()) + Diag(OldD->getLocation(), diag::note_previous_definition); + + Invalid = true; + } + + if (!Invalid && OldDecl && !OldDecl->isInvalidDecl()) { + if (TemplateParameterListsAreEqual(TemplateParams, + OldDecl->getTemplateParameters(), + /*Complain=*/true, + TPL_TemplateMatch)) + OldTemplateParams = + OldDecl->getMostRecentDecl()->getTemplateParameters(); + else + Invalid = true; + + TypeAliasDecl *OldTD = OldDecl->getTemplatedDecl(); + if (!Invalid && + !Context.hasSameType(OldTD->getUnderlyingType(), + NewTD->getUnderlyingType())) { + // FIXME: The C++0x standard does not clearly say this is ill-formed, + // but we can't reasonably accept it. + Diag(NewTD->getLocation(), diag::err_redefinition_different_typedef) + << 2 << NewTD->getUnderlyingType() << OldTD->getUnderlyingType(); + if (OldTD->getLocation().isValid()) + Diag(OldTD->getLocation(), diag::note_previous_definition); + Invalid = true; + } + } + } + + // Merge any previous default template arguments into our parameters, + // and check the parameter list. + if (CheckTemplateParameterList(TemplateParams, OldTemplateParams, + TPC_TypeAliasTemplate)) + return nullptr; + + TypeAliasTemplateDecl *NewDecl = + TypeAliasTemplateDecl::Create(Context, CurContext, UsingLoc, + Name.Identifier, TemplateParams, + NewTD); + NewTD->setDescribedAliasTemplate(NewDecl); + + NewDecl->setAccess(AS); + + if (Invalid) + NewDecl->setInvalidDecl(); + else if (OldDecl) { + NewDecl->setPreviousDecl(OldDecl); + CheckRedeclarationInModule(NewDecl, OldDecl); + } + + NewND = NewDecl; + } else { + if (auto *TD = dyn_cast_or_null(DeclFromDeclSpec)) { + setTagNameForLinkagePurposes(TD, NewTD); + handleTagNumbering(TD, S); + } + ActOnTypedefNameDecl(S, CurContext, NewTD, Previous, Redeclaration); + NewND = NewTD; + } + + PushOnScopeChains(NewND, S); + ActOnDocumentableDecl(NewND); + return NewND; + } + + Decl *Sema::ActOnNamespaceAliasDef(Scope *S, SourceLocation NamespaceLoc, + SourceLocation AliasLoc, + IdentifierInfo *Alias, CXXScopeSpec &SS, + SourceLocation IdentLoc, + IdentifierInfo *Ident) { + + // Lookup the namespace name. + LookupResult R(*this, Ident, IdentLoc, LookupNamespaceName); + LookupParsedName(R, S, &SS); + + if (R.isAmbiguous()) + return nullptr; + + if (R.empty()) { + if (!TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, Ident)) { + Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange(); + return nullptr; + } + } + assert(!R.isAmbiguous() && !R.empty()); + NamedDecl *ND = R.getRepresentativeDecl(); + + // Check if we have a previous declaration with the same name. + LookupResult PrevR(*this, Alias, AliasLoc, LookupOrdinaryName, + ForVisibleRedeclaration); + LookupName(PrevR, S); + + // Check we're not shadowing a template parameter. + if (PrevR.isSingleResult() && PrevR.getFoundDecl()->isTemplateParameter()) { + DiagnoseTemplateParameterShadow(AliasLoc, PrevR.getFoundDecl()); + PrevR.clear(); + } + + // Filter out any other lookup result from an enclosing scope. + FilterLookupForScope(PrevR, CurContext, S, /*ConsiderLinkage*/false, + /*AllowInlineNamespace*/false); + + // Find the previous declaration and check that we can redeclare it. + NamespaceAliasDecl *Prev = nullptr; + if (PrevR.isSingleResult()) { + NamedDecl *PrevDecl = PrevR.getRepresentativeDecl(); + if (NamespaceAliasDecl *AD = dyn_cast(PrevDecl)) { + // We already have an alias with the same name that points to the same + // namespace; check that it matches. + if (AD->getNamespace()->Equals(getNamespaceDecl(ND))) { + Prev = AD; + } else if (isVisible(PrevDecl)) { + Diag(AliasLoc, diag::err_redefinition_different_namespace_alias) + << Alias; + Diag(AD->getLocation(), diag::note_previous_namespace_alias) + << AD->getNamespace(); + return nullptr; + } + } else if (isVisible(PrevDecl)) { + unsigned DiagID = isa(PrevDecl->getUnderlyingDecl()) + ? diag::err_redefinition + : diag::err_redefinition_different_kind; + Diag(AliasLoc, DiagID) << Alias; + Diag(PrevDecl->getLocation(), diag::note_previous_definition); + return nullptr; + } + } + + // The use of a nested name specifier may trigger deprecation warnings. + DiagnoseUseOfDecl(ND, IdentLoc); + + NamespaceAliasDecl *AliasDecl = + NamespaceAliasDecl::Create(Context, CurContext, NamespaceLoc, AliasLoc, + Alias, SS.getWithLocInContext(Context), + IdentLoc, ND); + if (Prev) + AliasDecl->setPreviousDecl(Prev); + + PushOnScopeChains(AliasDecl, S); + return AliasDecl; + } + + namespace { + struct SpecialMemberExceptionSpecInfo + : SpecialMemberVisitor { + SourceLocation Loc; + Sema::ImplicitExceptionSpecification ExceptSpec; + + SpecialMemberExceptionSpecInfo(Sema &S, CXXMethodDecl *MD, + Sema::CXXSpecialMember CSM, + Sema::InheritedConstructorInfo *ICI, + SourceLocation Loc) + : SpecialMemberVisitor(S, MD, CSM, ICI), Loc(Loc), ExceptSpec(S) {} + + bool visitBase(CXXBaseSpecifier *Base); + bool visitField(FieldDecl *FD); + + void visitClassSubobject(CXXRecordDecl *Class, Subobject Subobj, + unsigned Quals); + + void visitSubobjectCall(Subobject Subobj, + Sema::SpecialMemberOverloadResult SMOR); + }; + } + + bool SpecialMemberExceptionSpecInfo::visitBase(CXXBaseSpecifier *Base) { + auto *RT = Base->getType()->getAs(); + if (!RT) + return false; + + auto *BaseClass = cast(RT->getDecl()); + Sema::SpecialMemberOverloadResult SMOR = lookupInheritedCtor(BaseClass); + if (auto *BaseCtor = SMOR.getMethod()) { + visitSubobjectCall(Base, BaseCtor); + return false; + } + + visitClassSubobject(BaseClass, Base, 0); + return false; + } + + bool SpecialMemberExceptionSpecInfo::visitField(FieldDecl *FD) { + if (CSM == Sema::CXXDefaultConstructor && FD->hasInClassInitializer()) { + Expr *E = FD->getInClassInitializer(); + if (!E) + // FIXME: It's a little wasteful to build and throw away a + // CXXDefaultInitExpr here. + // FIXME: We should have a single context note pointing at Loc, and + // this location should be MD->getLocation() instead, since that's + // the location where we actually use the default init expression. + E = S.BuildCXXDefaultInitExpr(Loc, FD).get(); + if (E) + ExceptSpec.CalledExpr(E); + } else if (auto *RT = S.Context.getBaseElementType(FD->getType()) + ->getAs()) { + visitClassSubobject(cast(RT->getDecl()), FD, + FD->getType().getCVRQualifiers()); + } + return false; + } + + void SpecialMemberExceptionSpecInfo::visitClassSubobject(CXXRecordDecl *Class, + Subobject Subobj, + unsigned Quals) { + FieldDecl *Field = Subobj.dyn_cast(); + bool IsMutable = Field && Field->isMutable(); + visitSubobjectCall(Subobj, lookupIn(Class, Quals, IsMutable)); + } + + void SpecialMemberExceptionSpecInfo::visitSubobjectCall( + Subobject Subobj, Sema::SpecialMemberOverloadResult SMOR) { + // Note, if lookup fails, it doesn't matter what exception specification we + // choose because the special member will be deleted. + if (CXXMethodDecl *MD = SMOR.getMethod()) + ExceptSpec.CalledDecl(getSubobjectLoc(Subobj), MD); + } + + bool Sema::tryResolveExplicitSpecifier(ExplicitSpecifier &ExplicitSpec) { + llvm::APSInt Result; + ExprResult Converted = CheckConvertedConstantExpression( + ExplicitSpec.getExpr(), Context.BoolTy, Result, CCEK_ExplicitBool); + ExplicitSpec.setExpr(Converted.get()); + if (Converted.isUsable() && !Converted.get()->isValueDependent()) { + ExplicitSpec.setKind(Result.getBoolValue() + ? ExplicitSpecKind::ResolvedTrue + : ExplicitSpecKind::ResolvedFalse); + return true; + } + ExplicitSpec.setKind(ExplicitSpecKind::Unresolved); + return false; + } + + ExplicitSpecifier Sema::ActOnExplicitBoolSpecifier(Expr *ExplicitExpr) { + ExplicitSpecifier ES(ExplicitExpr, ExplicitSpecKind::Unresolved); + if (!ExplicitExpr->isTypeDependent()) + tryResolveExplicitSpecifier(ES); + return ES; + } + + static Sema::ImplicitExceptionSpecification + ComputeDefaultedSpecialMemberExceptionSpec( + Sema &S, SourceLocation Loc, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM, + Sema::InheritedConstructorInfo *ICI) { + ComputingExceptionSpec CES(S, MD, Loc); + + CXXRecordDecl *ClassDecl = MD->getParent(); + + // C++ [except.spec]p14: + // An implicitly declared special member function (Clause 12) shall have an + // exception-specification. [...] + SpecialMemberExceptionSpecInfo Info(S, MD, CSM, ICI, MD->getLocation()); + if (ClassDecl->isInvalidDecl()) + return Info.ExceptSpec; + + // FIXME: If this diagnostic fires, we're probably missing a check for + // attempting to resolve an exception specification before it's known + // at a higher level. + if (S.RequireCompleteType(MD->getLocation(), + S.Context.getRecordType(ClassDecl), + diag::err_exception_spec_incomplete_type)) + return Info.ExceptSpec; + + // C++1z [except.spec]p7: + // [Look for exceptions thrown by] a constructor selected [...] to + // initialize a potentially constructed subobject, + // C++1z [except.spec]p8: + // The exception specification for an implicitly-declared destructor, or a + // destructor without a noexcept-specifier, is potentially-throwing if and + // only if any of the destructors for any of its potentially constructed + // subojects is potentially throwing. + // FIXME: We respect the first rule but ignore the "potentially constructed" + // in the second rule to resolve a core issue (no number yet) that would have + // us reject: + // struct A { virtual void f() = 0; virtual ~A() noexcept(false) = 0; }; + // struct B : A {}; + // struct C : B { void f(); }; + // ... due to giving B::~B() a non-throwing exception specification. + Info.visit(Info.IsConstructor ? Info.VisitPotentiallyConstructedBases + : Info.VisitAllBases); + + return Info.ExceptSpec; + } + + namespace { + /// RAII object to register a special member as being currently declared. + struct DeclaringSpecialMember { + Sema &S; + Sema::SpecialMemberDecl D; + Sema::ContextRAII SavedContext; + bool WasAlreadyBeingDeclared; + + DeclaringSpecialMember(Sema &S, CXXRecordDecl *RD, Sema::CXXSpecialMember CSM) + : S(S), D(RD, CSM), SavedContext(S, RD) { + WasAlreadyBeingDeclared = !S.SpecialMembersBeingDeclared.insert(D).second; + if (WasAlreadyBeingDeclared) + // This almost never happens, but if it does, ensure that our cache + // doesn't contain a stale result. + S.SpecialMemberCache.clear(); + else { + // Register a note to be produced if we encounter an error while + // declaring the special member. + Sema::CodeSynthesisContext Ctx; + Ctx.Kind = Sema::CodeSynthesisContext::DeclaringSpecialMember; + // FIXME: We don't have a location to use here. Using the class's + // location maintains the fiction that we declare all special members + // with the class, but (1) it's not clear that lying about that helps our + // users understand what's going on, and (2) there may be outer contexts + // on the stack (some of which are relevant) and printing them exposes + // our lies. + Ctx.PointOfInstantiation = RD->getLocation(); + Ctx.Entity = RD; + Ctx.SpecialMember = CSM; + S.pushCodeSynthesisContext(Ctx); + } + } + ~DeclaringSpecialMember() { + if (!WasAlreadyBeingDeclared) { + S.SpecialMembersBeingDeclared.erase(D); + S.popCodeSynthesisContext(); + } + } + + /// Are we already trying to declare this special member? + bool isAlreadyBeingDeclared() const { + return WasAlreadyBeingDeclared; + } + }; + } + + void Sema::CheckImplicitSpecialMemberDeclaration(Scope *S, FunctionDecl *FD) { + // Look up any existing declarations, but don't trigger declaration of all + // implicit special members with this name. + DeclarationName Name = FD->getDeclName(); + LookupResult R(*this, Name, SourceLocation(), LookupOrdinaryName, + ForExternalRedeclaration); + for (auto *D : FD->getParent()->lookup(Name)) + if (auto *Acceptable = R.getAcceptableDecl(D)) + R.addDecl(Acceptable); + R.resolveKind(); + R.suppressDiagnostics(); + + CheckFunctionDeclaration(S, FD, R, /*IsMemberSpecialization*/ false, + FD->isThisDeclarationADefinition()); + } + + void Sema::setupImplicitSpecialMemberType(CXXMethodDecl *SpecialMem, + QualType ResultTy, + ArrayRef Args) { + // Build an exception specification pointing back at this constructor. + FunctionProtoType::ExtProtoInfo EPI = getImplicitMethodEPI(*this, SpecialMem); + + LangAS AS = getDefaultCXXMethodAddrSpace(); + if (AS != LangAS::Default) { + EPI.TypeQuals.addAddressSpace(AS); + } + + auto QT = Context.getFunctionType(ResultTy, Args, EPI); + SpecialMem->setType(QT); + + // During template instantiation of implicit special member functions we need + // a reliable TypeSourceInfo for the function prototype in order to allow + // functions to be substituted. + if (inTemplateInstantiation() && + cast(SpecialMem->getParent())->isLambda()) { + TypeSourceInfo *TSI = + Context.getTrivialTypeSourceInfo(SpecialMem->getType()); + SpecialMem->setTypeSourceInfo(TSI); + } + } + + CXXConstructorDecl *Sema::DeclareImplicitDefaultConstructor( + CXXRecordDecl *ClassDecl) { + // C++ [class.ctor]p5: + // A default constructor for a class X is a constructor of class X + // that can be called without an argument. If there is no + // user-declared constructor for class X, a default constructor is + // implicitly declared. An implicitly-declared default constructor + // is an inline public member of its class. + assert(ClassDecl->needsImplicitDefaultConstructor() && + "Should not build implicit default constructor!"); + + DeclaringSpecialMember DSM(*this, ClassDecl, CXXDefaultConstructor); + if (DSM.isAlreadyBeingDeclared()) + return nullptr; + + bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl, + CXXDefaultConstructor, + false); + + // Create the actual constructor declaration. + CanQualType ClassType + = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl)); + SourceLocation ClassLoc = ClassDecl->getLocation(); + DeclarationName Name + = Context.DeclarationNames.getCXXConstructorName(ClassType); + DeclarationNameInfo NameInfo(Name, ClassLoc); + CXXConstructorDecl *DefaultCon = CXXConstructorDecl::Create( + Context, ClassDecl, ClassLoc, NameInfo, /*Type*/ QualType(), + /*TInfo=*/nullptr, ExplicitSpecifier(), + getCurFPFeatures().isFPConstrained(), + /*isInline=*/true, /*isImplicitlyDeclared=*/true, + Constexpr ? ConstexprSpecKind::Constexpr + : ConstexprSpecKind::Unspecified); + DefaultCon->setAccess(AS_public); + DefaultCon->setDefaulted(); + + setupImplicitSpecialMemberType(DefaultCon, Context.VoidTy, std::nullopt); + + if (getLangOpts().CUDA) + inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXDefaultConstructor, + DefaultCon, + /* ConstRHS */ false, + /* Diagnose */ false); + + // We don't need to use SpecialMemberIsTrivial here; triviality for default + // constructors is easy to compute. + DefaultCon->setTrivial(ClassDecl->hasTrivialDefaultConstructor()); + + // Note that we have declared this constructor. + ++getASTContext().NumImplicitDefaultConstructorsDeclared; + + Scope *S = getScopeForContext(ClassDecl); + CheckImplicitSpecialMemberDeclaration(S, DefaultCon); + + if (ShouldDeleteSpecialMember(DefaultCon, CXXDefaultConstructor)) + SetDeclDeleted(DefaultCon, ClassLoc); + + if (S) + PushOnScopeChains(DefaultCon, S, false); + ClassDecl->addDecl(DefaultCon); + + return DefaultCon; + } + + void Sema::DefineImplicitDefaultConstructor(SourceLocation CurrentLocation, + CXXConstructorDecl *Constructor) { + assert((Constructor->isDefaulted() && Constructor->isDefaultConstructor() && + !Constructor->doesThisDeclarationHaveABody() && + !Constructor->isDeleted()) && + "DefineImplicitDefaultConstructor - call it for implicit default ctor"); + if (Constructor->willHaveBody() || Constructor->isInvalidDecl()) + return; + + CXXRecordDecl *ClassDecl = Constructor->getParent(); + assert(ClassDecl && "DefineImplicitDefaultConstructor - invalid constructor"); + + SynthesizedFunctionScope Scope(*this, Constructor); + + // The exception specification is needed because we are defining the + // function. + ResolveExceptionSpec(CurrentLocation, + Constructor->getType()->castAs()); + MarkVTableUsed(CurrentLocation, ClassDecl); + + // Add a context note for diagnostics produced after this point. + Scope.addContextNote(CurrentLocation); + + if (SetCtorInitializers(Constructor, /*AnyErrors=*/false)) { + Constructor->setInvalidDecl(); + return; + } + + SourceLocation Loc = Constructor->getEndLoc().isValid() + ? Constructor->getEndLoc() + : Constructor->getLocation(); + Constructor->setBody(new (Context) CompoundStmt(Loc)); + Constructor->markUsed(Context); + + if (ASTMutationListener *L = getASTMutationListener()) { + L->CompletedImplicitDefinition(Constructor); + } + + DiagnoseUninitializedFields(*this, Constructor); + } + + void Sema::ActOnFinishDelayedMemberInitializers(Decl *D) { + // Perform any delayed checks on exception specifications. + CheckDelayedMemberExceptionSpecs(); + } + + /// Find or create the fake constructor we synthesize to model constructing an + /// object of a derived class via a constructor of a base class. + CXXConstructorDecl * + Sema::findInheritingConstructor(SourceLocation Loc, + CXXConstructorDecl *BaseCtor, + ConstructorUsingShadowDecl *Shadow) { + CXXRecordDecl *Derived = Shadow->getParent(); + SourceLocation UsingLoc = Shadow->getLocation(); + + // FIXME: Add a new kind of DeclarationName for an inherited constructor. + // For now we use the name of the base class constructor as a member of the + // derived class to indicate a (fake) inherited constructor name. + DeclarationName Name = BaseCtor->getDeclName(); + + // Check to see if we already have a fake constructor for this inherited + // constructor call. + for (NamedDecl *Ctor : Derived->lookup(Name)) + if (declaresSameEntity(cast(Ctor) + ->getInheritedConstructor() + .getConstructor(), + BaseCtor)) + return cast(Ctor); + + DeclarationNameInfo NameInfo(Name, UsingLoc); + TypeSourceInfo *TInfo = + Context.getTrivialTypeSourceInfo(BaseCtor->getType(), UsingLoc); + FunctionProtoTypeLoc ProtoLoc = + TInfo->getTypeLoc().IgnoreParens().castAs(); + + // Check the inherited constructor is valid and find the list of base classes + // from which it was inherited. + InheritedConstructorInfo ICI(*this, Loc, Shadow); + + bool Constexpr = + BaseCtor->isConstexpr() && + defaultedSpecialMemberIsConstexpr(*this, Derived, CXXDefaultConstructor, + false, BaseCtor, &ICI); + + CXXConstructorDecl *DerivedCtor = CXXConstructorDecl::Create( + Context, Derived, UsingLoc, NameInfo, TInfo->getType(), TInfo, + BaseCtor->getExplicitSpecifier(), getCurFPFeatures().isFPConstrained(), + /*isInline=*/true, + /*isImplicitlyDeclared=*/true, + Constexpr ? BaseCtor->getConstexprKind() : ConstexprSpecKind::Unspecified, + InheritedConstructor(Shadow, BaseCtor), + BaseCtor->getTrailingRequiresClause()); + if (Shadow->isInvalidDecl()) + DerivedCtor->setInvalidDecl(); + + // Build an unevaluated exception specification for this fake constructor. + const FunctionProtoType *FPT = TInfo->getType()->castAs(); + FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo(); + EPI.ExceptionSpec.Type = EST_Unevaluated; + EPI.ExceptionSpec.SourceDecl = DerivedCtor; + DerivedCtor->setType(Context.getFunctionType(FPT->getReturnType(), + FPT->getParamTypes(), EPI)); + + // Build the parameter declarations. + SmallVector ParamDecls; + for (unsigned I = 0, N = FPT->getNumParams(); I != N; ++I) { + TypeSourceInfo *TInfo = + Context.getTrivialTypeSourceInfo(FPT->getParamType(I), UsingLoc); + ParmVarDecl *PD = ParmVarDecl::Create( + Context, DerivedCtor, UsingLoc, UsingLoc, /*IdentifierInfo=*/nullptr, + FPT->getParamType(I), TInfo, SC_None, /*DefArg=*/nullptr); + PD->setScopeInfo(0, I); + PD->setImplicit(); + // Ensure attributes are propagated onto parameters (this matters for + // format, pass_object_size, ...). + mergeDeclAttributes(PD, BaseCtor->getParamDecl(I)); + ParamDecls.push_back(PD); + ProtoLoc.setParam(I, PD); + } + + // Set up the new constructor. + assert(!BaseCtor->isDeleted() && "should not use deleted constructor"); + DerivedCtor->setAccess(BaseCtor->getAccess()); + DerivedCtor->setParams(ParamDecls); + Derived->addDecl(DerivedCtor); + + if (ShouldDeleteSpecialMember(DerivedCtor, CXXDefaultConstructor, &ICI)) + SetDeclDeleted(DerivedCtor, UsingLoc); + + return DerivedCtor; + } + + void Sema::NoteDeletedInheritingConstructor(CXXConstructorDecl *Ctor) { + InheritedConstructorInfo ICI(*this, Ctor->getLocation(), + Ctor->getInheritedConstructor().getShadowDecl()); + ShouldDeleteSpecialMember(Ctor, CXXDefaultConstructor, &ICI, + /*Diagnose*/true); + } + + void Sema::DefineInheritingConstructor(SourceLocation CurrentLocation, + CXXConstructorDecl *Constructor) { + CXXRecordDecl *ClassDecl = Constructor->getParent(); + assert(Constructor->getInheritedConstructor() && + !Constructor->doesThisDeclarationHaveABody() && + !Constructor->isDeleted()); + if (Constructor->willHaveBody() || Constructor->isInvalidDecl()) + return; + + // Initializations are performed "as if by a defaulted default constructor", + // so enter the appropriate scope. + SynthesizedFunctionScope Scope(*this, Constructor); + + // The exception specification is needed because we are defining the + // function. + ResolveExceptionSpec(CurrentLocation, + Constructor->getType()->castAs()); + MarkVTableUsed(CurrentLocation, ClassDecl); + + // Add a context note for diagnostics produced after this point. + Scope.addContextNote(CurrentLocation); + + ConstructorUsingShadowDecl *Shadow = + Constructor->getInheritedConstructor().getShadowDecl(); + CXXConstructorDecl *InheritedCtor = + Constructor->getInheritedConstructor().getConstructor(); + + // [class.inhctor.init]p1: + // initialization proceeds as if a defaulted default constructor is used to + // initialize the D object and each base class subobject from which the + // constructor was inherited + + InheritedConstructorInfo ICI(*this, CurrentLocation, Shadow); + CXXRecordDecl *RD = Shadow->getParent(); + SourceLocation InitLoc = Shadow->getLocation(); + + // Build explicit initializers for all base classes from which the + // constructor was inherited. + SmallVector Inits; + for (bool VBase : {false, true}) { + for (CXXBaseSpecifier &B : VBase ? RD->vbases() : RD->bases()) { + if (B.isVirtual() != VBase) + continue; + + auto *BaseRD = B.getType()->getAsCXXRecordDecl(); + if (!BaseRD) + continue; + + auto BaseCtor = ICI.findConstructorForBase(BaseRD, InheritedCtor); + if (!BaseCtor.first) + continue; + + MarkFunctionReferenced(CurrentLocation, BaseCtor.first); + ExprResult Init = new (Context) CXXInheritedCtorInitExpr( + InitLoc, B.getType(), BaseCtor.first, VBase, BaseCtor.second); + + auto *TInfo = Context.getTrivialTypeSourceInfo(B.getType(), InitLoc); + Inits.push_back(new (Context) CXXCtorInitializer( + Context, TInfo, VBase, InitLoc, Init.get(), InitLoc, + SourceLocation())); + } + } + + // We now proceed as if for a defaulted default constructor, with the relevant + // initializers replaced. + + if (SetCtorInitializers(Constructor, /*AnyErrors*/false, Inits)) { + Constructor->setInvalidDecl(); + return; + } + + Constructor->setBody(new (Context) CompoundStmt(InitLoc)); + Constructor->markUsed(Context); + + if (ASTMutationListener *L = getASTMutationListener()) { + L->CompletedImplicitDefinition(Constructor); + } + + DiagnoseUninitializedFields(*this, Constructor); + } + + CXXDestructorDecl *Sema::DeclareImplicitDestructor(CXXRecordDecl *ClassDecl) { + // C++ [class.dtor]p2: + // If a class has no user-declared destructor, a destructor is + // declared implicitly. An implicitly-declared destructor is an + // inline public member of its class. + assert(ClassDecl->needsImplicitDestructor()); + + DeclaringSpecialMember DSM(*this, ClassDecl, CXXDestructor); + if (DSM.isAlreadyBeingDeclared()) + return nullptr; + + bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl, + CXXDestructor, + false); + + // Create the actual destructor declaration. + CanQualType ClassType + = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl)); + SourceLocation ClassLoc = ClassDecl->getLocation(); + DeclarationName Name + = Context.DeclarationNames.getCXXDestructorName(ClassType); + DeclarationNameInfo NameInfo(Name, ClassLoc); + CXXDestructorDecl *Destructor = CXXDestructorDecl::Create( + Context, ClassDecl, ClassLoc, NameInfo, QualType(), nullptr, + getCurFPFeatures().isFPConstrained(), + /*isInline=*/true, + /*isImplicitlyDeclared=*/true, + Constexpr ? ConstexprSpecKind::Constexpr + : ConstexprSpecKind::Unspecified); + Destructor->setAccess(AS_public); + Destructor->setDefaulted(); + + setupImplicitSpecialMemberType(Destructor, Context.VoidTy, std::nullopt); + + if (getLangOpts().CUDA) + inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXDestructor, + Destructor, + /* ConstRHS */ false, + /* Diagnose */ false); + + // We don't need to use SpecialMemberIsTrivial here; triviality for + // destructors is easy to compute. + Destructor->setTrivial(ClassDecl->hasTrivialDestructor()); + Destructor->setTrivialForCall(ClassDecl->hasAttr() || + ClassDecl->hasTrivialDestructorForCall()); + + // Note that we have declared this destructor. + ++getASTContext().NumImplicitDestructorsDeclared; + + Scope *S = getScopeForContext(ClassDecl); + CheckImplicitSpecialMemberDeclaration(S, Destructor); + + // We can't check whether an implicit destructor is deleted before we complete + // the definition of the class, because its validity depends on the alignment + // of the class. We'll check this from ActOnFields once the class is complete. + if (ClassDecl->isCompleteDefinition() && + ShouldDeleteSpecialMember(Destructor, CXXDestructor)) + SetDeclDeleted(Destructor, ClassLoc); + + // Introduce this destructor into its scope. + if (S) + PushOnScopeChains(Destructor, S, false); + ClassDecl->addDecl(Destructor); + + return Destructor; + } + + void Sema::DefineImplicitDestructor(SourceLocation CurrentLocation, + CXXDestructorDecl *Destructor) { + assert((Destructor->isDefaulted() && + !Destructor->doesThisDeclarationHaveABody() && + !Destructor->isDeleted()) && + "DefineImplicitDestructor - call it for implicit default dtor"); + if (Destructor->willHaveBody() || Destructor->isInvalidDecl()) + return; + + CXXRecordDecl *ClassDecl = Destructor->getParent(); + assert(ClassDecl && "DefineImplicitDestructor - invalid destructor"); + + SynthesizedFunctionScope Scope(*this, Destructor); + + // The exception specification is needed because we are defining the + // function. + ResolveExceptionSpec(CurrentLocation, + Destructor->getType()->castAs()); + MarkVTableUsed(CurrentLocation, ClassDecl); + + // Add a context note for diagnostics produced after this point. + Scope.addContextNote(CurrentLocation); + + MarkBaseAndMemberDestructorsReferenced(Destructor->getLocation(), + Destructor->getParent()); + + if (CheckDestructor(Destructor)) { + Destructor->setInvalidDecl(); + return; + } + + SourceLocation Loc = Destructor->getEndLoc().isValid() + ? Destructor->getEndLoc() + : Destructor->getLocation(); + Destructor->setBody(new (Context) CompoundStmt(Loc)); + Destructor->markUsed(Context); + + if (ASTMutationListener *L = getASTMutationListener()) { + L->CompletedImplicitDefinition(Destructor); + } + } + + void Sema::CheckCompleteDestructorVariant(SourceLocation CurrentLocation, + CXXDestructorDecl *Destructor) { + if (Destructor->isInvalidDecl()) + return; + + CXXRecordDecl *ClassDecl = Destructor->getParent(); + assert(Context.getTargetInfo().getCXXABI().isMicrosoft() && + "implicit complete dtors unneeded outside MS ABI"); + assert(ClassDecl->getNumVBases() > 0 && + "complete dtor only exists for classes with vbases"); + + SynthesizedFunctionScope Scope(*this, Destructor); + + // Add a context note for diagnostics produced after this point. + Scope.addContextNote(CurrentLocation); + + MarkVirtualBaseDestructorsReferenced(Destructor->getLocation(), ClassDecl); + } + + /// Perform any semantic analysis which needs to be delayed until all + /// pending class member declarations have been parsed. + void Sema::ActOnFinishCXXMemberDecls() { + // If the context is an invalid C++ class, just suppress these checks. + if (CXXRecordDecl *Record = dyn_cast(CurContext)) { + if (Record->isInvalidDecl()) { + DelayedOverridingExceptionSpecChecks.clear(); + DelayedEquivalentExceptionSpecChecks.clear(); + return; + } + checkForMultipleExportedDefaultConstructors(*this, Record); + } + } + + void Sema::ActOnFinishCXXNonNestedClass() { + referenceDLLExportedClassMethods(); + + if (!DelayedDllExportMemberFunctions.empty()) { + SmallVector WorkList; + std::swap(DelayedDllExportMemberFunctions, WorkList); + for (CXXMethodDecl *M : WorkList) { + DefineDefaultedFunction(*this, M, M->getLocation()); + + // Pass the method to the consumer to get emitted. This is not necessary + // for explicit instantiation definitions, as they will get emitted + // anyway. + if (M->getParent()->getTemplateSpecializationKind() != + TSK_ExplicitInstantiationDefinition) + ActOnFinishInlineFunctionDef(M); + } + } + } + + void Sema::referenceDLLExportedClassMethods() { + if (!DelayedDllExportClasses.empty()) { + // Calling ReferenceDllExportedMembers might cause the current function to + // be called again, so use a local copy of DelayedDllExportClasses. + SmallVector WorkList; + std::swap(DelayedDllExportClasses, WorkList); + for (CXXRecordDecl *Class : WorkList) + ReferenceDllExportedMembers(*this, Class); + } + } + + void Sema::AdjustDestructorExceptionSpec(CXXDestructorDecl *Destructor) { + assert(getLangOpts().CPlusPlus11 && + "adjusting dtor exception specs was introduced in c++11"); + + if (Destructor->isDependentContext()) + return; + + // C++11 [class.dtor]p3: + // A declaration of a destructor that does not have an exception- + // specification is implicitly considered to have the same exception- + // specification as an implicit declaration. + const auto *DtorType = Destructor->getType()->castAs(); + if (DtorType->hasExceptionSpec()) + return; + + // Replace the destructor's type, building off the existing one. Fortunately, + // the only thing of interest in the destructor type is its extended info. + // The return and arguments are fixed. + FunctionProtoType::ExtProtoInfo EPI = DtorType->getExtProtoInfo(); + EPI.ExceptionSpec.Type = EST_Unevaluated; + EPI.ExceptionSpec.SourceDecl = Destructor; + Destructor->setType( + Context.getFunctionType(Context.VoidTy, std::nullopt, EPI)); + + // FIXME: If the destructor has a body that could throw, and the newly created + // spec doesn't allow exceptions, we should emit a warning, because this + // change in behavior can break conforming C++03 programs at runtime. + // However, we don't have a body or an exception specification yet, so it + // needs to be done somewhere else. + } + + namespace { + /// An abstract base class for all helper classes used in building the + // copy/move operators. These classes serve as factory functions and help us + // avoid using the same Expr* in the AST twice. + class ExprBuilder { + ExprBuilder(const ExprBuilder&) = delete; + ExprBuilder &operator=(const ExprBuilder&) = delete; + + protected: + static Expr *assertNotNull(Expr *E) { + assert(E && "Expression construction must not fail."); + return E; + } + + public: + ExprBuilder() {} + virtual ~ExprBuilder() {} + + virtual Expr *build(Sema &S, SourceLocation Loc) const = 0; + }; + + class RefBuilder: public ExprBuilder { + VarDecl *Var; + QualType VarType; + + public: + Expr *build(Sema &S, SourceLocation Loc) const override { + return assertNotNull(S.BuildDeclRefExpr(Var, VarType, VK_LValue, Loc)); + } + + RefBuilder(VarDecl *Var, QualType VarType) + : Var(Var), VarType(VarType) {} + }; + + class ThisBuilder: public ExprBuilder { + public: + Expr *build(Sema &S, SourceLocation Loc) const override { + return assertNotNull(S.ActOnCXXThis(Loc).getAs()); + } + }; + + class CastBuilder: public ExprBuilder { + const ExprBuilder &Builder; + QualType Type; + ExprValueKind Kind; + const CXXCastPath &Path; + + public: + Expr *build(Sema &S, SourceLocation Loc) const override { + return assertNotNull(S.ImpCastExprToType(Builder.build(S, Loc), Type, + CK_UncheckedDerivedToBase, Kind, + &Path).get()); + } + + CastBuilder(const ExprBuilder &Builder, QualType Type, ExprValueKind Kind, + const CXXCastPath &Path) + : Builder(Builder), Type(Type), Kind(Kind), Path(Path) {} + }; + + class DerefBuilder: public ExprBuilder { + const ExprBuilder &Builder; + + public: + Expr *build(Sema &S, SourceLocation Loc) const override { + return assertNotNull( + S.CreateBuiltinUnaryOp(Loc, UO_Deref, Builder.build(S, Loc)).get()); + } + + DerefBuilder(const ExprBuilder &Builder) : Builder(Builder) {} + }; + + class MemberBuilder: public ExprBuilder { + const ExprBuilder &Builder; + QualType Type; + CXXScopeSpec SS; + bool IsArrow; + LookupResult &MemberLookup; + + public: + Expr *build(Sema &S, SourceLocation Loc) const override { + return assertNotNull(S.BuildMemberReferenceExpr( + Builder.build(S, Loc), Type, Loc, IsArrow, SS, SourceLocation(), + nullptr, MemberLookup, nullptr, nullptr).get()); + } + + MemberBuilder(const ExprBuilder &Builder, QualType Type, bool IsArrow, + LookupResult &MemberLookup) + : Builder(Builder), Type(Type), IsArrow(IsArrow), + MemberLookup(MemberLookup) {} + }; + + class MoveCastBuilder: public ExprBuilder { + const ExprBuilder &Builder; + + public: + Expr *build(Sema &S, SourceLocation Loc) const override { + return assertNotNull(CastForMoving(S, Builder.build(S, Loc))); + } + + MoveCastBuilder(const ExprBuilder &Builder) : Builder(Builder) {} + }; + + class LvalueConvBuilder: public ExprBuilder { + const ExprBuilder &Builder; + + public: + Expr *build(Sema &S, SourceLocation Loc) const override { + return assertNotNull( + S.DefaultLvalueConversion(Builder.build(S, Loc)).get()); + } + + LvalueConvBuilder(const ExprBuilder &Builder) : Builder(Builder) {} + }; + + class SubscriptBuilder: public ExprBuilder { + const ExprBuilder &Base; + const ExprBuilder &Index; + + public: + Expr *build(Sema &S, SourceLocation Loc) const override { + return assertNotNull(S.CreateBuiltinArraySubscriptExpr( + Base.build(S, Loc), Loc, Index.build(S, Loc), Loc).get()); + } + + SubscriptBuilder(const ExprBuilder &Base, const ExprBuilder &Index) + : Base(Base), Index(Index) {} + }; + + } // end anonymous namespace + + /// When generating a defaulted copy or move assignment operator, if a field + /// should be copied with __builtin_memcpy rather than via explicit assignments, + /// do so. This optimization only applies for arrays of scalars, and for arrays + /// of class type where the selected copy/move-assignment operator is trivial. + static StmtResult + buildMemcpyForAssignmentOp(Sema &S, SourceLocation Loc, QualType T, + const ExprBuilder &ToB, const ExprBuilder &FromB) { + // Compute the size of the memory buffer to be copied. + QualType SizeType = S.Context.getSizeType(); + llvm::APInt Size(S.Context.getTypeSize(SizeType), + S.Context.getTypeSizeInChars(T).getQuantity()); + + // Take the address of the field references for "from" and "to". We + // directly construct UnaryOperators here because semantic analysis + // does not permit us to take the address of an xvalue. + Expr *From = FromB.build(S, Loc); + From = UnaryOperator::Create( + S.Context, From, UO_AddrOf, S.Context.getPointerType(From->getType()), + VK_PRValue, OK_Ordinary, Loc, false, S.CurFPFeatureOverrides()); + Expr *To = ToB.build(S, Loc); + To = UnaryOperator::Create( + S.Context, To, UO_AddrOf, S.Context.getPointerType(To->getType()), + VK_PRValue, OK_Ordinary, Loc, false, S.CurFPFeatureOverrides()); + + const Type *E = T->getBaseElementTypeUnsafe(); + bool NeedsCollectableMemCpy = + E->isRecordType() && + E->castAs()->getDecl()->hasObjectMember(); + + // Create a reference to the __builtin_objc_memmove_collectable function + StringRef MemCpyName = NeedsCollectableMemCpy ? + "__builtin_objc_memmove_collectable" : + "__builtin_memcpy"; + LookupResult R(S, &S.Context.Idents.get(MemCpyName), Loc, + Sema::LookupOrdinaryName); + S.LookupName(R, S.TUScope, true); + + FunctionDecl *MemCpy = R.getAsSingle(); + if (!MemCpy) + // Something went horribly wrong earlier, and we will have complained + // about it. + return StmtError(); + + ExprResult MemCpyRef = S.BuildDeclRefExpr(MemCpy, S.Context.BuiltinFnTy, + VK_PRValue, Loc, nullptr); + assert(MemCpyRef.isUsable() && "Builtin reference cannot fail"); + + Expr *CallArgs[] = { + To, From, IntegerLiteral::Create(S.Context, Size, SizeType, Loc) + }; + ExprResult Call = S.BuildCallExpr(/*Scope=*/nullptr, MemCpyRef.get(), + Loc, CallArgs, Loc); + + assert(!Call.isInvalid() && "Call to __builtin_memcpy cannot fail!"); + return Call.getAs(); + } + + /// Builds a statement that copies/moves the given entity from \p From to + /// \c To. + /// + /// This routine is used to copy/move the members of a class with an + /// implicitly-declared copy/move assignment operator. When the entities being + /// copied are arrays, this routine builds for loops to copy them. + /// + /// \param S The Sema object used for type-checking. + /// + /// \param Loc The location where the implicit copy/move is being generated. + /// + /// \param T The type of the expressions being copied/moved. Both expressions + /// must have this type. + /// + /// \param To The expression we are copying/moving to. + /// + /// \param From The expression we are copying/moving from. + /// + /// \param CopyingBaseSubobject Whether we're copying/moving a base subobject. + /// Otherwise, it's a non-static member subobject. + /// + /// \param Copying Whether we're copying or moving. + /// + /// \param Depth Internal parameter recording the depth of the recursion. + /// + /// \returns A statement or a loop that copies the expressions, or StmtResult(0) + /// if a memcpy should be used instead. + static StmtResult + buildSingleCopyAssignRecursively(Sema &S, SourceLocation Loc, QualType T, + const ExprBuilder &To, const ExprBuilder &From, + bool CopyingBaseSubobject, bool Copying, + unsigned Depth = 0) { + // C++11 [class.copy]p28: + // Each subobject is assigned in the manner appropriate to its type: + // + // - if the subobject is of class type, as if by a call to operator= with + // the subobject as the object expression and the corresponding + // subobject of x as a single function argument (as if by explicit + // qualification; that is, ignoring any possible virtual overriding + // functions in more derived classes); + // + // C++03 [class.copy]p13: + // - if the subobject is of class type, the copy assignment operator for + // the class is used (as if by explicit qualification; that is, + // ignoring any possible virtual overriding functions in more derived + // classes); + if (const RecordType *RecordTy = T->getAs()) { + CXXRecordDecl *ClassDecl = cast(RecordTy->getDecl()); + + // Look for operator=. + DeclarationName Name + = S.Context.DeclarationNames.getCXXOperatorName(OO_Equal); + LookupResult OpLookup(S, Name, Loc, Sema::LookupOrdinaryName); + S.LookupQualifiedName(OpLookup, ClassDecl, false); + + // Prior to C++11, filter out any result that isn't a copy/move-assignment + // operator. + if (!S.getLangOpts().CPlusPlus11) { + LookupResult::Filter F = OpLookup.makeFilter(); + while (F.hasNext()) { + NamedDecl *D = F.next(); + if (CXXMethodDecl *Method = dyn_cast(D)) + if (Method->isCopyAssignmentOperator() || + (!Copying && Method->isMoveAssignmentOperator())) + continue; + + F.erase(); + } + F.done(); + } + + // Suppress the protected check (C++ [class.protected]) for each of the + // assignment operators we found. This strange dance is required when + // we're assigning via a base classes's copy-assignment operator. To + // ensure that we're getting the right base class subobject (without + // ambiguities), we need to cast "this" to that subobject type; to + // ensure that we don't go through the virtual call mechanism, we need + // to qualify the operator= name with the base class (see below). However, + // this means that if the base class has a protected copy assignment + // operator, the protected member access check will fail. So, we + // rewrite "protected" access to "public" access in this case, since we + // know by construction that we're calling from a derived class. + if (CopyingBaseSubobject) { + for (LookupResult::iterator L = OpLookup.begin(), LEnd = OpLookup.end(); + L != LEnd; ++L) { + if (L.getAccess() == AS_protected) + L.setAccess(AS_public); + } + } + + // Create the nested-name-specifier that will be used to qualify the + // reference to operator=; this is required to suppress the virtual + // call mechanism. + CXXScopeSpec SS; + const Type *CanonicalT = S.Context.getCanonicalType(T.getTypePtr()); + SS.MakeTrivial(S.Context, + NestedNameSpecifier::Create(S.Context, nullptr, false, + CanonicalT), + Loc); + + // Create the reference to operator=. + ExprResult OpEqualRef + = S.BuildMemberReferenceExpr(To.build(S, Loc), T, Loc, /*IsArrow=*/false, + SS, /*TemplateKWLoc=*/SourceLocation(), + /*FirstQualifierInScope=*/nullptr, + OpLookup, + /*TemplateArgs=*/nullptr, /*S*/nullptr, + /*SuppressQualifierCheck=*/true); + if (OpEqualRef.isInvalid()) + return StmtError(); + + // Build the call to the assignment operator. + + Expr *FromInst = From.build(S, Loc); + ExprResult Call = S.BuildCallToMemberFunction(/*Scope=*/nullptr, + OpEqualRef.getAs(), + Loc, FromInst, Loc); + if (Call.isInvalid()) + return StmtError(); + + // If we built a call to a trivial 'operator=' while copying an array, + // bail out. We'll replace the whole shebang with a memcpy. + CXXMemberCallExpr *CE = dyn_cast(Call.get()); + if (CE && CE->getMethodDecl()->isTrivial() && Depth) + return StmtResult((Stmt*)nullptr); + + // Convert to an expression-statement, and clean up any produced + // temporaries. + return S.ActOnExprStmt(Call); + } + + // - if the subobject is of scalar type, the built-in assignment + // operator is used. + const ConstantArrayType *ArrayTy = S.Context.getAsConstantArrayType(T); + if (!ArrayTy) { + ExprResult Assignment = S.CreateBuiltinBinOp( + Loc, BO_Assign, To.build(S, Loc), From.build(S, Loc)); + if (Assignment.isInvalid()) + return StmtError(); + return S.ActOnExprStmt(Assignment); + } + + // - if the subobject is an array, each element is assigned, in the + // manner appropriate to the element type; + + // Construct a loop over the array bounds, e.g., + // + // for (__SIZE_TYPE__ i0 = 0; i0 != array-size; ++i0) + // + // that will copy each of the array elements. + QualType SizeType = S.Context.getSizeType(); + + // Create the iteration variable. + IdentifierInfo *IterationVarName = nullptr; + { + SmallString<8> Str; + llvm::raw_svector_ostream OS(Str); + OS << "__i" << Depth; + IterationVarName = &S.Context.Idents.get(OS.str()); + } + VarDecl *IterationVar = VarDecl::Create(S.Context, S.CurContext, Loc, Loc, + IterationVarName, SizeType, + S.Context.getTrivialTypeSourceInfo(SizeType, Loc), + SC_None); + + // Initialize the iteration variable to zero. + llvm::APInt Zero(S.Context.getTypeSize(SizeType), 0); + IterationVar->setInit(IntegerLiteral::Create(S.Context, Zero, SizeType, Loc)); + + // Creates a reference to the iteration variable. + RefBuilder IterationVarRef(IterationVar, SizeType); + LvalueConvBuilder IterationVarRefRVal(IterationVarRef); + + // Create the DeclStmt that holds the iteration variable. + Stmt *InitStmt = new (S.Context) DeclStmt(DeclGroupRef(IterationVar),Loc,Loc); + + // Subscript the "from" and "to" expressions with the iteration variable. + SubscriptBuilder FromIndexCopy(From, IterationVarRefRVal); + MoveCastBuilder FromIndexMove(FromIndexCopy); + const ExprBuilder *FromIndex; + if (Copying) + FromIndex = &FromIndexCopy; + else + FromIndex = &FromIndexMove; + + SubscriptBuilder ToIndex(To, IterationVarRefRVal); + + // Build the copy/move for an individual element of the array. + StmtResult Copy = + buildSingleCopyAssignRecursively(S, Loc, ArrayTy->getElementType(), + ToIndex, *FromIndex, CopyingBaseSubobject, + Copying, Depth + 1); + // Bail out if copying fails or if we determined that we should use memcpy. + if (Copy.isInvalid() || !Copy.get()) + return Copy; + + // Create the comparison against the array bound. + llvm::APInt Upper + = ArrayTy->getSize().zextOrTrunc(S.Context.getTypeSize(SizeType)); + Expr *Comparison = BinaryOperator::Create( + S.Context, IterationVarRefRVal.build(S, Loc), + IntegerLiteral::Create(S.Context, Upper, SizeType, Loc), BO_NE, + S.Context.BoolTy, VK_PRValue, OK_Ordinary, Loc, + S.CurFPFeatureOverrides()); + + // Create the pre-increment of the iteration variable. We can determine + // whether the increment will overflow based on the value of the array + // bound. + Expr *Increment = UnaryOperator::Create( + S.Context, IterationVarRef.build(S, Loc), UO_PreInc, SizeType, VK_LValue, + OK_Ordinary, Loc, Upper.isMaxValue(), S.CurFPFeatureOverrides()); + + // Construct the loop that copies all elements of this array. + return S.ActOnForStmt( + Loc, Loc, InitStmt, + S.ActOnCondition(nullptr, Loc, Comparison, Sema::ConditionKind::Boolean), + S.MakeFullDiscardedValueExpr(Increment), Loc, Copy.get()); + } + + static StmtResult + buildSingleCopyAssign(Sema &S, SourceLocation Loc, QualType T, + const ExprBuilder &To, const ExprBuilder &From, + bool CopyingBaseSubobject, bool Copying) { + // Maybe we should use a memcpy? + if (T->isArrayType() && !T.isConstQualified() && !T.isVolatileQualified() && + T.isTriviallyCopyableType(S.Context)) + return buildMemcpyForAssignmentOp(S, Loc, T, To, From); + + StmtResult Result(buildSingleCopyAssignRecursively(S, Loc, T, To, From, + CopyingBaseSubobject, + Copying, 0)); + + // If we ended up picking a trivial assignment operator for an array of a + // non-trivially-copyable class type, just emit a memcpy. + if (!Result.isInvalid() && !Result.get()) + return buildMemcpyForAssignmentOp(S, Loc, T, To, From); + + return Result; + } + + CXXMethodDecl *Sema::DeclareImplicitCopyAssignment(CXXRecordDecl *ClassDecl) { + // Note: The following rules are largely analoguous to the copy + // constructor rules. Note that virtual bases are not taken into account + // for determining the argument type of the operator. Note also that + // operators taking an object instead of a reference are allowed. + assert(ClassDecl->needsImplicitCopyAssignment()); + + DeclaringSpecialMember DSM(*this, ClassDecl, CXXCopyAssignment); + if (DSM.isAlreadyBeingDeclared()) + return nullptr; + + QualType ArgType = Context.getTypeDeclType(ClassDecl); + ArgType = Context.getElaboratedType(ETK_None, nullptr, ArgType, nullptr); + LangAS AS = getDefaultCXXMethodAddrSpace(); + if (AS != LangAS::Default) + ArgType = Context.getAddrSpaceQualType(ArgType, AS); + QualType RetType = Context.getLValueReferenceType(ArgType); + bool Const = ClassDecl->implicitCopyAssignmentHasConstParam(); + if (Const) + ArgType = ArgType.withConst(); + + ArgType = Context.getLValueReferenceType(ArgType); + + bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl, + CXXCopyAssignment, + Const); + + // An implicitly-declared copy assignment operator is an inline public + // member of its class. + DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal); + SourceLocation ClassLoc = ClassDecl->getLocation(); + DeclarationNameInfo NameInfo(Name, ClassLoc); + CXXMethodDecl *CopyAssignment = CXXMethodDecl::Create( + Context, ClassDecl, ClassLoc, NameInfo, QualType(), + /*TInfo=*/nullptr, /*StorageClass=*/SC_None, + getCurFPFeatures().isFPConstrained(), + /*isInline=*/true, + Constexpr ? ConstexprSpecKind::Constexpr : ConstexprSpecKind::Unspecified, + SourceLocation()); + CopyAssignment->setAccess(AS_public); + CopyAssignment->setDefaulted(); + CopyAssignment->setImplicit(); + + setupImplicitSpecialMemberType(CopyAssignment, RetType, ArgType); + + if (getLangOpts().CUDA) + inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXCopyAssignment, + CopyAssignment, + /* ConstRHS */ Const, + /* Diagnose */ false); + + // Add the parameter to the operator. + ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyAssignment, + ClassLoc, ClassLoc, + /*Id=*/nullptr, ArgType, + /*TInfo=*/nullptr, SC_None, + nullptr); + CopyAssignment->setParams(FromParam); + + CopyAssignment->setTrivial( + ClassDecl->needsOverloadResolutionForCopyAssignment() + ? SpecialMemberIsTrivial(CopyAssignment, CXXCopyAssignment) + : ClassDecl->hasTrivialCopyAssignment()); + + // Note that we have added this copy-assignment operator. + ++getASTContext().NumImplicitCopyAssignmentOperatorsDeclared; + + Scope *S = getScopeForContext(ClassDecl); + CheckImplicitSpecialMemberDeclaration(S, CopyAssignment); + + if (ShouldDeleteSpecialMember(CopyAssignment, CXXCopyAssignment)) { + ClassDecl->setImplicitCopyAssignmentIsDeleted(); + SetDeclDeleted(CopyAssignment, ClassLoc); + } + + if (S) + PushOnScopeChains(CopyAssignment, S, false); + ClassDecl->addDecl(CopyAssignment); + + return CopyAssignment; + } + + /// Diagnose an implicit copy operation for a class which is odr-used, but + /// which is deprecated because the class has a user-declared copy constructor, + /// copy assignment operator, or destructor. + static void diagnoseDeprecatedCopyOperation(Sema &S, CXXMethodDecl *CopyOp) { + assert(CopyOp->isImplicit()); + + CXXRecordDecl *RD = CopyOp->getParent(); + CXXMethodDecl *UserDeclaredOperation = nullptr; + + if (RD->hasUserDeclaredDestructor()) { + UserDeclaredOperation = RD->getDestructor(); + } else if (!isa(CopyOp) && + RD->hasUserDeclaredCopyConstructor()) { + // Find any user-declared copy constructor. + for (auto *I : RD->ctors()) { + if (I->isCopyConstructor()) { + UserDeclaredOperation = I; + break; + } + } + assert(UserDeclaredOperation); + } else if (isa(CopyOp) && + RD->hasUserDeclaredCopyAssignment()) { + // Find any user-declared move assignment operator. + for (auto *I : RD->methods()) { + if (I->isCopyAssignmentOperator()) { + UserDeclaredOperation = I; + break; + } + } + assert(UserDeclaredOperation); + } + + if (UserDeclaredOperation) { + bool UDOIsUserProvided = UserDeclaredOperation->isUserProvided(); + bool UDOIsDestructor = isa(UserDeclaredOperation); + bool IsCopyAssignment = !isa(CopyOp); + unsigned DiagID = + (UDOIsUserProvided && UDOIsDestructor) + ? diag::warn_deprecated_copy_with_user_provided_dtor + : (UDOIsUserProvided && !UDOIsDestructor) + ? diag::warn_deprecated_copy_with_user_provided_copy + : (!UDOIsUserProvided && UDOIsDestructor) + ? diag::warn_deprecated_copy_with_dtor + : diag::warn_deprecated_copy; + S.Diag(UserDeclaredOperation->getLocation(), DiagID) + << RD << IsCopyAssignment; + } + } + + void Sema::DefineImplicitCopyAssignment(SourceLocation CurrentLocation, + CXXMethodDecl *CopyAssignOperator) { + assert((CopyAssignOperator->isDefaulted() && + CopyAssignOperator->isOverloadedOperator() && + CopyAssignOperator->getOverloadedOperator() == OO_Equal && + !CopyAssignOperator->doesThisDeclarationHaveABody() && + !CopyAssignOperator->isDeleted()) && + "DefineImplicitCopyAssignment called for wrong function"); + if (CopyAssignOperator->willHaveBody() || CopyAssignOperator->isInvalidDecl()) + return; + + CXXRecordDecl *ClassDecl = CopyAssignOperator->getParent(); + if (ClassDecl->isInvalidDecl()) { + CopyAssignOperator->setInvalidDecl(); + return; + } + + SynthesizedFunctionScope Scope(*this, CopyAssignOperator); + + // The exception specification is needed because we are defining the + // function. + ResolveExceptionSpec(CurrentLocation, + CopyAssignOperator->getType()->castAs()); + + // Add a context note for diagnostics produced after this point. + Scope.addContextNote(CurrentLocation); + + // C++11 [class.copy]p18: + // The [definition of an implicitly declared copy assignment operator] is + // deprecated if the class has a user-declared copy constructor or a + // user-declared destructor. + if (getLangOpts().CPlusPlus11 && CopyAssignOperator->isImplicit()) + diagnoseDeprecatedCopyOperation(*this, CopyAssignOperator); + + // C++0x [class.copy]p30: + // The implicitly-defined or explicitly-defaulted copy assignment operator + // for a non-union class X performs memberwise copy assignment of its + // subobjects. The direct base classes of X are assigned first, in the + // order of their declaration in the base-specifier-list, and then the + // immediate non-static data members of X are assigned, in the order in + // which they were declared in the class definition. + + // The statements that form the synthesized function body. + SmallVector Statements; + + // The parameter for the "other" object, which we are copying from. + ParmVarDecl *Other = CopyAssignOperator->getParamDecl(0); + Qualifiers OtherQuals = Other->getType().getQualifiers(); + QualType OtherRefType = Other->getType(); + if (const LValueReferenceType *OtherRef + = OtherRefType->getAs()) { + OtherRefType = OtherRef->getPointeeType(); + OtherQuals = OtherRefType.getQualifiers(); + } + + // Our location for everything implicitly-generated. + SourceLocation Loc = CopyAssignOperator->getEndLoc().isValid() + ? CopyAssignOperator->getEndLoc() + : CopyAssignOperator->getLocation(); + + // Builds a DeclRefExpr for the "other" object. + RefBuilder OtherRef(Other, OtherRefType); + + // Builds the "this" pointer. + ThisBuilder This; + + // Assign base classes. + bool Invalid = false; + for (auto &Base : ClassDecl->bases()) { + // Form the assignment: + // static_cast(this)->Base::operator=(static_cast(other)); + QualType BaseType = Base.getType().getUnqualifiedType(); + if (!BaseType->isRecordType()) { + Invalid = true; + continue; + } + + CXXCastPath BasePath; + BasePath.push_back(&Base); + + // Construct the "from" expression, which is an implicit cast to the + // appropriately-qualified base type. + CastBuilder From(OtherRef, Context.getQualifiedType(BaseType, OtherQuals), + VK_LValue, BasePath); + + // Dereference "this". + DerefBuilder DerefThis(This); + CastBuilder To(DerefThis, + Context.getQualifiedType( + BaseType, CopyAssignOperator->getMethodQualifiers()), + VK_LValue, BasePath); + + // Build the copy. + StmtResult Copy = buildSingleCopyAssign(*this, Loc, BaseType, + To, From, + /*CopyingBaseSubobject=*/true, + /*Copying=*/true); + if (Copy.isInvalid()) { + CopyAssignOperator->setInvalidDecl(); + return; + } + + // Success! Record the copy. + Statements.push_back(Copy.getAs()); + } + + // Assign non-static members. + for (auto *Field : ClassDecl->fields()) { + // FIXME: We should form some kind of AST representation for the implied + // memcpy in a union copy operation. + if (Field->isUnnamedBitfield() || Field->getParent()->isUnion()) + continue; + + if (Field->isInvalidDecl()) { + Invalid = true; + continue; + } + + // Check for members of reference type; we can't copy those. + if (Field->getType()->isReferenceType()) { + Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign) + << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName(); + Diag(Field->getLocation(), diag::note_declared_at); + Invalid = true; + continue; + } + + // Check for members of const-qualified, non-class type. + QualType BaseType = Context.getBaseElementType(Field->getType()); + if (!BaseType->getAs() && BaseType.isConstQualified()) { + Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign) + << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName(); + Diag(Field->getLocation(), diag::note_declared_at); + Invalid = true; + continue; + } + + // Suppress assigning zero-width bitfields. + if (Field->isZeroLengthBitField(Context)) + continue; + + QualType FieldType = Field->getType().getNonReferenceType(); + if (FieldType->isIncompleteArrayType()) { + assert(ClassDecl->hasFlexibleArrayMember() && + "Incomplete array type is not valid"); + continue; + } + + // Build references to the field in the object we're copying from and to. + CXXScopeSpec SS; // Intentionally empty + LookupResult MemberLookup(*this, Field->getDeclName(), Loc, + LookupMemberName); + MemberLookup.addDecl(Field); + MemberLookup.resolveKind(); + + MemberBuilder From(OtherRef, OtherRefType, /*IsArrow=*/false, MemberLookup); + + MemberBuilder To(This, getCurrentThisType(), /*IsArrow=*/!LangOpts.HLSL, + MemberLookup); + + // Build the copy of this field. + StmtResult Copy = buildSingleCopyAssign(*this, Loc, FieldType, + To, From, + /*CopyingBaseSubobject=*/false, + /*Copying=*/true); + if (Copy.isInvalid()) { + CopyAssignOperator->setInvalidDecl(); + return; + } + + // Success! Record the copy. + Statements.push_back(Copy.getAs()); + } + + if (!Invalid) { + // Add a "return *this;" + Expr *ThisExpr = nullptr; + if (!LangOpts.HLSL) { + ExprResult ThisObj = + CreateBuiltinUnaryOp(Loc, UO_Deref, This.build(*this, Loc)); + ThisExpr = ThisObj.get(); + } else { + ThisExpr = This.build(*this, Loc); + } + + StmtResult Return = BuildReturnStmt(Loc, ThisExpr); + if (Return.isInvalid()) + Invalid = true; + else + Statements.push_back(Return.getAs()); + } + + if (Invalid) { + CopyAssignOperator->setInvalidDecl(); + return; + } + + StmtResult Body; + { + CompoundScopeRAII CompoundScope(*this); + Body = ActOnCompoundStmt(Loc, Loc, Statements, + /*isStmtExpr=*/false); + assert(!Body.isInvalid() && "Compound statement creation cannot fail"); + } + CopyAssignOperator->setBody(Body.getAs()); + CopyAssignOperator->markUsed(Context); + + if (ASTMutationListener *L = getASTMutationListener()) { + L->CompletedImplicitDefinition(CopyAssignOperator); + } + } + + CXXMethodDecl *Sema::DeclareImplicitMoveAssignment(CXXRecordDecl *ClassDecl) { + assert(ClassDecl->needsImplicitMoveAssignment()); + + DeclaringSpecialMember DSM(*this, ClassDecl, CXXMoveAssignment); + if (DSM.isAlreadyBeingDeclared()) + return nullptr; + + // Note: The following rules are largely analoguous to the move + // constructor rules. + + QualType ArgType = Context.getTypeDeclType(ClassDecl); + ArgType = Context.getElaboratedType(ETK_None, nullptr, ArgType, nullptr); + LangAS AS = getDefaultCXXMethodAddrSpace(); + if (AS != LangAS::Default) + ArgType = Context.getAddrSpaceQualType(ArgType, AS); + QualType RetType = Context.getLValueReferenceType(ArgType); + ArgType = Context.getRValueReferenceType(ArgType); + + bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl, + CXXMoveAssignment, + false); + + // An implicitly-declared move assignment operator is an inline public + // member of its class. + DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal); + SourceLocation ClassLoc = ClassDecl->getLocation(); + DeclarationNameInfo NameInfo(Name, ClassLoc); + CXXMethodDecl *MoveAssignment = CXXMethodDecl::Create( + Context, ClassDecl, ClassLoc, NameInfo, QualType(), + /*TInfo=*/nullptr, /*StorageClass=*/SC_None, + getCurFPFeatures().isFPConstrained(), + /*isInline=*/true, + Constexpr ? ConstexprSpecKind::Constexpr : ConstexprSpecKind::Unspecified, + SourceLocation()); + MoveAssignment->setAccess(AS_public); + MoveAssignment->setDefaulted(); + MoveAssignment->setImplicit(); + + setupImplicitSpecialMemberType(MoveAssignment, RetType, ArgType); + + if (getLangOpts().CUDA) + inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXMoveAssignment, + MoveAssignment, + /* ConstRHS */ false, + /* Diagnose */ false); + + // Add the parameter to the operator. + ParmVarDecl *FromParam = ParmVarDecl::Create(Context, MoveAssignment, + ClassLoc, ClassLoc, + /*Id=*/nullptr, ArgType, + /*TInfo=*/nullptr, SC_None, + nullptr); + MoveAssignment->setParams(FromParam); + + MoveAssignment->setTrivial( + ClassDecl->needsOverloadResolutionForMoveAssignment() + ? SpecialMemberIsTrivial(MoveAssignment, CXXMoveAssignment) + : ClassDecl->hasTrivialMoveAssignment()); + + // Note that we have added this copy-assignment operator. + ++getASTContext().NumImplicitMoveAssignmentOperatorsDeclared; + + Scope *S = getScopeForContext(ClassDecl); + CheckImplicitSpecialMemberDeclaration(S, MoveAssignment); + + if (ShouldDeleteSpecialMember(MoveAssignment, CXXMoveAssignment)) { + ClassDecl->setImplicitMoveAssignmentIsDeleted(); + SetDeclDeleted(MoveAssignment, ClassLoc); + } + + if (S) + PushOnScopeChains(MoveAssignment, S, false); + ClassDecl->addDecl(MoveAssignment); + + return MoveAssignment; + } + + /// Check if we're implicitly defining a move assignment operator for a class + /// with virtual bases. Such a move assignment might move-assign the virtual + /// base multiple times. + static void checkMoveAssignmentForRepeatedMove(Sema &S, CXXRecordDecl *Class, + SourceLocation CurrentLocation) { + assert(!Class->isDependentContext() && "should not define dependent move"); + + // Only a virtual base could get implicitly move-assigned multiple times. + // Only a non-trivial move assignment can observe this. We only want to + // diagnose if we implicitly define an assignment operator that assigns + // two base classes, both of which move-assign the same virtual base. + if (Class->getNumVBases() == 0 || Class->hasTrivialMoveAssignment() || + Class->getNumBases() < 2) + return; + + llvm::SmallVector Worklist; + typedef llvm::DenseMap VBaseMap; + VBaseMap VBases; + + for (auto &BI : Class->bases()) { + Worklist.push_back(&BI); + while (!Worklist.empty()) { + CXXBaseSpecifier *BaseSpec = Worklist.pop_back_val(); + CXXRecordDecl *Base = BaseSpec->getType()->getAsCXXRecordDecl(); + + // If the base has no non-trivial move assignment operators, + // we don't care about moves from it. + if (!Base->hasNonTrivialMoveAssignment()) + continue; + + // If there's nothing virtual here, skip it. + if (!BaseSpec->isVirtual() && !Base->getNumVBases()) + continue; + + // If we're not actually going to call a move assignment for this base, + // or the selected move assignment is trivial, skip it. + Sema::SpecialMemberOverloadResult SMOR = + S.LookupSpecialMember(Base, Sema::CXXMoveAssignment, + /*ConstArg*/false, /*VolatileArg*/false, + /*RValueThis*/true, /*ConstThis*/false, + /*VolatileThis*/false); + if (!SMOR.getMethod() || SMOR.getMethod()->isTrivial() || + !SMOR.getMethod()->isMoveAssignmentOperator()) + continue; + + if (BaseSpec->isVirtual()) { + // We're going to move-assign this virtual base, and its move + // assignment operator is not trivial. If this can happen for + // multiple distinct direct bases of Class, diagnose it. (If it + // only happens in one base, we'll diagnose it when synthesizing + // that base class's move assignment operator.) + CXXBaseSpecifier *&Existing = + VBases.insert(std::make_pair(Base->getCanonicalDecl(), &BI)) + .first->second; + if (Existing && Existing != &BI) { + S.Diag(CurrentLocation, diag::warn_vbase_moved_multiple_times) + << Class << Base; + S.Diag(Existing->getBeginLoc(), diag::note_vbase_moved_here) + << (Base->getCanonicalDecl() == + Existing->getType()->getAsCXXRecordDecl()->getCanonicalDecl()) + << Base << Existing->getType() << Existing->getSourceRange(); + S.Diag(BI.getBeginLoc(), diag::note_vbase_moved_here) + << (Base->getCanonicalDecl() == + BI.getType()->getAsCXXRecordDecl()->getCanonicalDecl()) + << Base << BI.getType() << BaseSpec->getSourceRange(); + + // Only diagnose each vbase once. + Existing = nullptr; + } + } else { + // Only walk over bases that have defaulted move assignment operators. + // We assume that any user-provided move assignment operator handles + // the multiple-moves-of-vbase case itself somehow. + if (!SMOR.getMethod()->isDefaulted()) + continue; + + // We're going to move the base classes of Base. Add them to the list. + llvm::append_range(Worklist, llvm::make_pointer_range(Base->bases())); + } + } + } + } + + void Sema::DefineImplicitMoveAssignment(SourceLocation CurrentLocation, + CXXMethodDecl *MoveAssignOperator) { + assert((MoveAssignOperator->isDefaulted() && + MoveAssignOperator->isOverloadedOperator() && + MoveAssignOperator->getOverloadedOperator() == OO_Equal && + !MoveAssignOperator->doesThisDeclarationHaveABody() && + !MoveAssignOperator->isDeleted()) && + "DefineImplicitMoveAssignment called for wrong function"); + if (MoveAssignOperator->willHaveBody() || MoveAssignOperator->isInvalidDecl()) + return; + + CXXRecordDecl *ClassDecl = MoveAssignOperator->getParent(); + if (ClassDecl->isInvalidDecl()) { + MoveAssignOperator->setInvalidDecl(); + return; + } + + // C++0x [class.copy]p28: + // The implicitly-defined or move assignment operator for a non-union class + // X performs memberwise move assignment of its subobjects. The direct base + // classes of X are assigned first, in the order of their declaration in the + // base-specifier-list, and then the immediate non-static data members of X + // are assigned, in the order in which they were declared in the class + // definition. + + // Issue a warning if our implicit move assignment operator will move + // from a virtual base more than once. + checkMoveAssignmentForRepeatedMove(*this, ClassDecl, CurrentLocation); + + SynthesizedFunctionScope Scope(*this, MoveAssignOperator); + + // The exception specification is needed because we are defining the + // function. + ResolveExceptionSpec(CurrentLocation, + MoveAssignOperator->getType()->castAs()); + + // Add a context note for diagnostics produced after this point. + Scope.addContextNote(CurrentLocation); + + // The statements that form the synthesized function body. + SmallVector Statements; + + // The parameter for the "other" object, which we are move from. + ParmVarDecl *Other = MoveAssignOperator->getParamDecl(0); + QualType OtherRefType = + Other->getType()->castAs()->getPointeeType(); + + // Our location for everything implicitly-generated. + SourceLocation Loc = MoveAssignOperator->getEndLoc().isValid() + ? MoveAssignOperator->getEndLoc() + : MoveAssignOperator->getLocation(); + + // Builds a reference to the "other" object. + RefBuilder OtherRef(Other, OtherRefType); + // Cast to rvalue. + MoveCastBuilder MoveOther(OtherRef); + + // Builds the "this" pointer. + ThisBuilder This; + + // Assign base classes. + bool Invalid = false; + for (auto &Base : ClassDecl->bases()) { + // C++11 [class.copy]p28: + // It is unspecified whether subobjects representing virtual base classes + // are assigned more than once by the implicitly-defined copy assignment + // operator. + // FIXME: Do not assign to a vbase that will be assigned by some other base + // class. For a move-assignment, this can result in the vbase being moved + // multiple times. + + // Form the assignment: + // static_cast(this)->Base::operator=(static_cast(other)); + QualType BaseType = Base.getType().getUnqualifiedType(); + if (!BaseType->isRecordType()) { + Invalid = true; + continue; + } + + CXXCastPath BasePath; + BasePath.push_back(&Base); + + // Construct the "from" expression, which is an implicit cast to the + // appropriately-qualified base type. + CastBuilder From(OtherRef, BaseType, VK_XValue, BasePath); + + // Dereference "this". + DerefBuilder DerefThis(This); + + // Implicitly cast "this" to the appropriately-qualified base type. + CastBuilder To(DerefThis, + Context.getQualifiedType( + BaseType, MoveAssignOperator->getMethodQualifiers()), + VK_LValue, BasePath); + + // Build the move. + StmtResult Move = buildSingleCopyAssign(*this, Loc, BaseType, + To, From, + /*CopyingBaseSubobject=*/true, + /*Copying=*/false); + if (Move.isInvalid()) { + MoveAssignOperator->setInvalidDecl(); + return; + } + + // Success! Record the move. + Statements.push_back(Move.getAs()); + } + + // Assign non-static members. + for (auto *Field : ClassDecl->fields()) { + // FIXME: We should form some kind of AST representation for the implied + // memcpy in a union copy operation. + if (Field->isUnnamedBitfield() || Field->getParent()->isUnion()) + continue; + + if (Field->isInvalidDecl()) { + Invalid = true; + continue; + } + + // Check for members of reference type; we can't move those. + if (Field->getType()->isReferenceType()) { + Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign) + << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName(); + Diag(Field->getLocation(), diag::note_declared_at); + Invalid = true; + continue; + } + + // Check for members of const-qualified, non-class type. + QualType BaseType = Context.getBaseElementType(Field->getType()); + if (!BaseType->getAs() && BaseType.isConstQualified()) { + Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign) + << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName(); + Diag(Field->getLocation(), diag::note_declared_at); + Invalid = true; + continue; + } + + // Suppress assigning zero-width bitfields. + if (Field->isZeroLengthBitField(Context)) + continue; + + QualType FieldType = Field->getType().getNonReferenceType(); + if (FieldType->isIncompleteArrayType()) { + assert(ClassDecl->hasFlexibleArrayMember() && + "Incomplete array type is not valid"); + continue; + } + + // Build references to the field in the object we're copying from and to. + LookupResult MemberLookup(*this, Field->getDeclName(), Loc, + LookupMemberName); + MemberLookup.addDecl(Field); + MemberLookup.resolveKind(); + MemberBuilder From(MoveOther, OtherRefType, + /*IsArrow=*/false, MemberLookup); + MemberBuilder To(This, getCurrentThisType(), + /*IsArrow=*/true, MemberLookup); + + assert(!From.build(*this, Loc)->isLValue() && // could be xvalue or prvalue + "Member reference with rvalue base must be rvalue except for reference " + "members, which aren't allowed for move assignment."); + + // Build the move of this field. + StmtResult Move = buildSingleCopyAssign(*this, Loc, FieldType, + To, From, + /*CopyingBaseSubobject=*/false, + /*Copying=*/false); + if (Move.isInvalid()) { + MoveAssignOperator->setInvalidDecl(); + return; + } + + // Success! Record the copy. + Statements.push_back(Move.getAs()); + } + + if (!Invalid) { + // Add a "return *this;" + ExprResult ThisObj = + CreateBuiltinUnaryOp(Loc, UO_Deref, This.build(*this, Loc)); + + StmtResult Return = BuildReturnStmt(Loc, ThisObj.get()); + if (Return.isInvalid()) + Invalid = true; + else + Statements.push_back(Return.getAs()); + } + + if (Invalid) { + MoveAssignOperator->setInvalidDecl(); + return; + } + + StmtResult Body; + { + CompoundScopeRAII CompoundScope(*this); + Body = ActOnCompoundStmt(Loc, Loc, Statements, + /*isStmtExpr=*/false); + assert(!Body.isInvalid() && "Compound statement creation cannot fail"); + } + MoveAssignOperator->setBody(Body.getAs()); + MoveAssignOperator->markUsed(Context); + + if (ASTMutationListener *L = getASTMutationListener()) { + L->CompletedImplicitDefinition(MoveAssignOperator); + } + } + + CXXConstructorDecl *Sema::DeclareImplicitCopyConstructor( + CXXRecordDecl *ClassDecl) { + // C++ [class.copy]p4: + // If the class definition does not explicitly declare a copy + // constructor, one is declared implicitly. + assert(ClassDecl->needsImplicitCopyConstructor()); + + DeclaringSpecialMember DSM(*this, ClassDecl, CXXCopyConstructor); + if (DSM.isAlreadyBeingDeclared()) + return nullptr; + + QualType ClassType = Context.getTypeDeclType(ClassDecl); + QualType ArgType = ClassType; + ArgType = Context.getElaboratedType(ETK_None, nullptr, ArgType, nullptr); + bool Const = ClassDecl->implicitCopyConstructorHasConstParam(); + if (Const) + ArgType = ArgType.withConst(); + + LangAS AS = getDefaultCXXMethodAddrSpace(); + if (AS != LangAS::Default) + ArgType = Context.getAddrSpaceQualType(ArgType, AS); + + ArgType = Context.getLValueReferenceType(ArgType); + + bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl, + CXXCopyConstructor, + Const); + + DeclarationName Name + = Context.DeclarationNames.getCXXConstructorName( + Context.getCanonicalType(ClassType)); + SourceLocation ClassLoc = ClassDecl->getLocation(); + DeclarationNameInfo NameInfo(Name, ClassLoc); + + // An implicitly-declared copy constructor is an inline public + // member of its class. + CXXConstructorDecl *CopyConstructor = CXXConstructorDecl::Create( + Context, ClassDecl, ClassLoc, NameInfo, QualType(), /*TInfo=*/nullptr, + ExplicitSpecifier(), getCurFPFeatures().isFPConstrained(), + /*isInline=*/true, + /*isImplicitlyDeclared=*/true, + Constexpr ? ConstexprSpecKind::Constexpr + : ConstexprSpecKind::Unspecified); + CopyConstructor->setAccess(AS_public); + CopyConstructor->setDefaulted(); + + setupImplicitSpecialMemberType(CopyConstructor, Context.VoidTy, ArgType); + + if (getLangOpts().CUDA) + inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXCopyConstructor, + CopyConstructor, + /* ConstRHS */ Const, + /* Diagnose */ false); + + // During template instantiation of special member functions we need a + // reliable TypeSourceInfo for the parameter types in order to allow functions + // to be substituted. + TypeSourceInfo *TSI = nullptr; + if (inTemplateInstantiation() && ClassDecl->isLambda()) + TSI = Context.getTrivialTypeSourceInfo(ArgType); + + // Add the parameter to the constructor. + ParmVarDecl *FromParam = + ParmVarDecl::Create(Context, CopyConstructor, ClassLoc, ClassLoc, + /*IdentifierInfo=*/nullptr, ArgType, + /*TInfo=*/TSI, SC_None, nullptr); + CopyConstructor->setParams(FromParam); + + CopyConstructor->setTrivial( + ClassDecl->needsOverloadResolutionForCopyConstructor() + ? SpecialMemberIsTrivial(CopyConstructor, CXXCopyConstructor) + : ClassDecl->hasTrivialCopyConstructor()); + + CopyConstructor->setTrivialForCall( + ClassDecl->hasAttr() || + (ClassDecl->needsOverloadResolutionForCopyConstructor() + ? SpecialMemberIsTrivial(CopyConstructor, CXXCopyConstructor, + TAH_ConsiderTrivialABI) + : ClassDecl->hasTrivialCopyConstructorForCall())); + + // Note that we have declared this constructor. + ++getASTContext().NumImplicitCopyConstructorsDeclared; + + Scope *S = getScopeForContext(ClassDecl); + CheckImplicitSpecialMemberDeclaration(S, CopyConstructor); + + if (ShouldDeleteSpecialMember(CopyConstructor, CXXCopyConstructor)) { + ClassDecl->setImplicitCopyConstructorIsDeleted(); + SetDeclDeleted(CopyConstructor, ClassLoc); + } + + if (S) + PushOnScopeChains(CopyConstructor, S, false); + ClassDecl->addDecl(CopyConstructor); + + return CopyConstructor; + } + + void Sema::DefineImplicitCopyConstructor(SourceLocation CurrentLocation, + CXXConstructorDecl *CopyConstructor) { + assert((CopyConstructor->isDefaulted() && + CopyConstructor->isCopyConstructor() && + !CopyConstructor->doesThisDeclarationHaveABody() && + !CopyConstructor->isDeleted()) && + "DefineImplicitCopyConstructor - call it for implicit copy ctor"); + if (CopyConstructor->willHaveBody() || CopyConstructor->isInvalidDecl()) + return; + + CXXRecordDecl *ClassDecl = CopyConstructor->getParent(); + assert(ClassDecl && "DefineImplicitCopyConstructor - invalid constructor"); + + SynthesizedFunctionScope Scope(*this, CopyConstructor); + + // The exception specification is needed because we are defining the + // function. + ResolveExceptionSpec(CurrentLocation, + CopyConstructor->getType()->castAs()); + MarkVTableUsed(CurrentLocation, ClassDecl); + + // Add a context note for diagnostics produced after this point. + Scope.addContextNote(CurrentLocation); + + // C++11 [class.copy]p7: + // The [definition of an implicitly declared copy constructor] is + // deprecated if the class has a user-declared copy assignment operator + // or a user-declared destructor. + if (getLangOpts().CPlusPlus11 && CopyConstructor->isImplicit()) + diagnoseDeprecatedCopyOperation(*this, CopyConstructor); + + if (SetCtorInitializers(CopyConstructor, /*AnyErrors=*/false)) { + CopyConstructor->setInvalidDecl(); + } else { + SourceLocation Loc = CopyConstructor->getEndLoc().isValid() + ? CopyConstructor->getEndLoc() + : CopyConstructor->getLocation(); + Sema::CompoundScopeRAII CompoundScope(*this); + CopyConstructor->setBody( + ActOnCompoundStmt(Loc, Loc, std::nullopt, /*isStmtExpr=*/false) + .getAs()); + CopyConstructor->markUsed(Context); + } + + if (ASTMutationListener *L = getASTMutationListener()) { + L->CompletedImplicitDefinition(CopyConstructor); + } + } + + CXXConstructorDecl *Sema::DeclareImplicitMoveConstructor( + CXXRecordDecl *ClassDecl) { + assert(ClassDecl->needsImplicitMoveConstructor()); + + DeclaringSpecialMember DSM(*this, ClassDecl, CXXMoveConstructor); + if (DSM.isAlreadyBeingDeclared()) + return nullptr; + + QualType ClassType = Context.getTypeDeclType(ClassDecl); + + QualType ArgType = ClassType; + ArgType = Context.getElaboratedType(ETK_None, nullptr, ArgType, nullptr); + LangAS AS = getDefaultCXXMethodAddrSpace(); + if (AS != LangAS::Default) + ArgType = Context.getAddrSpaceQualType(ClassType, AS); + ArgType = Context.getRValueReferenceType(ArgType); + + bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl, + CXXMoveConstructor, + false); + + DeclarationName Name + = Context.DeclarationNames.getCXXConstructorName( + Context.getCanonicalType(ClassType)); + SourceLocation ClassLoc = ClassDecl->getLocation(); + DeclarationNameInfo NameInfo(Name, ClassLoc); + + // C++11 [class.copy]p11: + // An implicitly-declared copy/move constructor is an inline public + // member of its class. + CXXConstructorDecl *MoveConstructor = CXXConstructorDecl::Create( + Context, ClassDecl, ClassLoc, NameInfo, QualType(), /*TInfo=*/nullptr, + ExplicitSpecifier(), getCurFPFeatures().isFPConstrained(), + /*isInline=*/true, + /*isImplicitlyDeclared=*/true, + Constexpr ? ConstexprSpecKind::Constexpr + : ConstexprSpecKind::Unspecified); + MoveConstructor->setAccess(AS_public); + MoveConstructor->setDefaulted(); + + setupImplicitSpecialMemberType(MoveConstructor, Context.VoidTy, ArgType); + + if (getLangOpts().CUDA) + inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXMoveConstructor, + MoveConstructor, + /* ConstRHS */ false, + /* Diagnose */ false); + + // Add the parameter to the constructor. + ParmVarDecl *FromParam = ParmVarDecl::Create(Context, MoveConstructor, + ClassLoc, ClassLoc, + /*IdentifierInfo=*/nullptr, + ArgType, /*TInfo=*/nullptr, + SC_None, nullptr); + MoveConstructor->setParams(FromParam); + + MoveConstructor->setTrivial( + ClassDecl->needsOverloadResolutionForMoveConstructor() + ? SpecialMemberIsTrivial(MoveConstructor, CXXMoveConstructor) + : ClassDecl->hasTrivialMoveConstructor()); + + MoveConstructor->setTrivialForCall( + ClassDecl->hasAttr() || + (ClassDecl->needsOverloadResolutionForMoveConstructor() + ? SpecialMemberIsTrivial(MoveConstructor, CXXMoveConstructor, + TAH_ConsiderTrivialABI) + : ClassDecl->hasTrivialMoveConstructorForCall())); + + // Note that we have declared this constructor. + ++getASTContext().NumImplicitMoveConstructorsDeclared; + + Scope *S = getScopeForContext(ClassDecl); + CheckImplicitSpecialMemberDeclaration(S, MoveConstructor); + + if (ShouldDeleteSpecialMember(MoveConstructor, CXXMoveConstructor)) { + ClassDecl->setImplicitMoveConstructorIsDeleted(); + SetDeclDeleted(MoveConstructor, ClassLoc); + } + + if (S) + PushOnScopeChains(MoveConstructor, S, false); + ClassDecl->addDecl(MoveConstructor); + + return MoveConstructor; + } + + void Sema::DefineImplicitMoveConstructor(SourceLocation CurrentLocation, + CXXConstructorDecl *MoveConstructor) { + assert((MoveConstructor->isDefaulted() && + MoveConstructor->isMoveConstructor() && + !MoveConstructor->doesThisDeclarationHaveABody() && + !MoveConstructor->isDeleted()) && + "DefineImplicitMoveConstructor - call it for implicit move ctor"); + if (MoveConstructor->willHaveBody() || MoveConstructor->isInvalidDecl()) + return; + + CXXRecordDecl *ClassDecl = MoveConstructor->getParent(); + assert(ClassDecl && "DefineImplicitMoveConstructor - invalid constructor"); + + SynthesizedFunctionScope Scope(*this, MoveConstructor); + + // The exception specification is needed because we are defining the + // function. + ResolveExceptionSpec(CurrentLocation, + MoveConstructor->getType()->castAs()); + MarkVTableUsed(CurrentLocation, ClassDecl); + + // Add a context note for diagnostics produced after this point. + Scope.addContextNote(CurrentLocation); + + if (SetCtorInitializers(MoveConstructor, /*AnyErrors=*/false)) { + MoveConstructor->setInvalidDecl(); + } else { + SourceLocation Loc = MoveConstructor->getEndLoc().isValid() + ? MoveConstructor->getEndLoc() + : MoveConstructor->getLocation(); + Sema::CompoundScopeRAII CompoundScope(*this); + MoveConstructor->setBody( + ActOnCompoundStmt(Loc, Loc, std::nullopt, /*isStmtExpr=*/false) + .getAs()); + MoveConstructor->markUsed(Context); + } + + if (ASTMutationListener *L = getASTMutationListener()) { + L->CompletedImplicitDefinition(MoveConstructor); + } + } + + bool Sema::isImplicitlyDeleted(FunctionDecl *FD) { + return FD->isDeleted() && FD->isDefaulted() && isa(FD); + } + + void Sema::DefineImplicitLambdaToFunctionPointerConversion( + SourceLocation CurrentLocation, + CXXConversionDecl *Conv) { + SynthesizedFunctionScope Scope(*this, Conv); + assert(!Conv->getReturnType()->isUndeducedType()); + + QualType ConvRT = Conv->getType()->castAs()->getReturnType(); + CallingConv CC = + ConvRT->getPointeeType()->castAs()->getCallConv(); + + CXXRecordDecl *Lambda = Conv->getParent(); + FunctionDecl *CallOp = Lambda->getLambdaCallOperator(); + FunctionDecl *Invoker = + CallOp->isStatic() ? CallOp : Lambda->getLambdaStaticInvoker(CC); + + if (auto *TemplateArgs = Conv->getTemplateSpecializationArgs()) { + CallOp = InstantiateFunctionDeclaration( + CallOp->getDescribedFunctionTemplate(), TemplateArgs, CurrentLocation); + if (!CallOp) + return; + + if (CallOp != Invoker) { + Invoker = InstantiateFunctionDeclaration( + Invoker->getDescribedFunctionTemplate(), TemplateArgs, + CurrentLocation); + if (!Invoker) + return; + } + } + + if (CallOp->isInvalidDecl()) + return; + + // Mark the call operator referenced (and add to pending instantiations + // if necessary). + // For both the conversion and static-invoker template specializations + // we construct their body's in this function, so no need to add them + // to the PendingInstantiations. + MarkFunctionReferenced(CurrentLocation, CallOp); + + if (Invoker != CallOp) { + // Fill in the __invoke function with a dummy implementation. IR generation + // will fill in the actual details. Update its type in case it contained + // an 'auto'. + Invoker->markUsed(Context); + Invoker->setReferenced(); + Invoker->setType(Conv->getReturnType()->getPointeeType()); + Invoker->setBody(new (Context) CompoundStmt(Conv->getLocation())); + } + + // Construct the body of the conversion function { return __invoke; }. + Expr *FunctionRef = BuildDeclRefExpr(Invoker, Invoker->getType(), VK_LValue, + Conv->getLocation()); + assert(FunctionRef && "Can't refer to __invoke function?"); + Stmt *Return = BuildReturnStmt(Conv->getLocation(), FunctionRef).get(); + Conv->setBody(CompoundStmt::Create(Context, Return, FPOptionsOverride(), + Conv->getLocation(), Conv->getLocation())); + Conv->markUsed(Context); + Conv->setReferenced(); + + if (ASTMutationListener *L = getASTMutationListener()) { + L->CompletedImplicitDefinition(Conv); + if (Invoker != CallOp) + L->CompletedImplicitDefinition(Invoker); + } + } + + void Sema::DefineImplicitLambdaToBlockPointerConversion( + SourceLocation CurrentLocation, CXXConversionDecl *Conv) { + assert(!Conv->getParent()->isGenericLambda()); + + SynthesizedFunctionScope Scope(*this, Conv); + + // Copy-initialize the lambda object as needed to capture it. + Expr *This = ActOnCXXThis(CurrentLocation).get(); + Expr *DerefThis =CreateBuiltinUnaryOp(CurrentLocation, UO_Deref, This).get(); + + ExprResult BuildBlock = BuildBlockForLambdaConversion(CurrentLocation, + Conv->getLocation(), + Conv, DerefThis); + + // If we're not under ARC, make sure we still get the _Block_copy/autorelease + // behavior. Note that only the general conversion function does this + // (since it's unusable otherwise); in the case where we inline the + // block literal, it has block literal lifetime semantics. + if (!BuildBlock.isInvalid() && !getLangOpts().ObjCAutoRefCount) + BuildBlock = ImplicitCastExpr::Create( + Context, BuildBlock.get()->getType(), CK_CopyAndAutoreleaseBlockObject, + BuildBlock.get(), nullptr, VK_PRValue, FPOptionsOverride()); + + if (BuildBlock.isInvalid()) { + Diag(CurrentLocation, diag::note_lambda_to_block_conv); + Conv->setInvalidDecl(); + return; + } + + // Create the return statement that returns the block from the conversion + // function. + StmtResult Return = BuildReturnStmt(Conv->getLocation(), BuildBlock.get()); + if (Return.isInvalid()) { + Diag(CurrentLocation, diag::note_lambda_to_block_conv); + Conv->setInvalidDecl(); + return; + } + + // Set the body of the conversion function. + Stmt *ReturnS = Return.get(); + Conv->setBody(CompoundStmt::Create(Context, ReturnS, FPOptionsOverride(), + Conv->getLocation(), Conv->getLocation())); + Conv->markUsed(Context); + + // We're done; notify the mutation listener, if any. + if (ASTMutationListener *L = getASTMutationListener()) { + L->CompletedImplicitDefinition(Conv); + } + } + + /// Determine whether the given list arguments contains exactly one + /// "real" (non-default) argument. + static bool hasOneRealArgument(MultiExprArg Args) { + switch (Args.size()) { + case 0: + return false; + + default: + if (!Args[1]->isDefaultArgument()) + return false; + + [[fallthrough]]; + case 1: + return !Args[0]->isDefaultArgument(); + } + + return false; + } + + ExprResult + Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType, + NamedDecl *FoundDecl, + CXXConstructorDecl *Constructor, + MultiExprArg ExprArgs, + bool HadMultipleCandidates, + bool IsListInitialization, + bool IsStdInitListInitialization, + bool RequiresZeroInit, + unsigned ConstructKind, + SourceRange ParenRange) { + bool Elidable = false; + + // C++0x [class.copy]p34: + // When certain criteria are met, an implementation is allowed to + // omit the copy/move construction of a class object, even if the + // copy/move constructor and/or destructor for the object have + // side effects. [...] + // - when a temporary class object that has not been bound to a + // reference (12.2) would be copied/moved to a class object + // with the same cv-unqualified type, the copy/move operation + // can be omitted by constructing the temporary object + // directly into the target of the omitted copy/move + if (ConstructKind == CXXConstructExpr::CK_Complete && Constructor && + // FIXME: Converting constructors should also be accepted. + // But to fix this, the logic that digs down into a CXXConstructExpr + // to find the source object needs to handle it. + // Right now it assumes the source object is passed directly as the + // first argument. + Constructor->isCopyOrMoveConstructor() && hasOneRealArgument(ExprArgs)) { + Expr *SubExpr = ExprArgs[0]; + // FIXME: Per above, this is also incorrect if we want to accept + // converting constructors, as isTemporaryObject will + // reject temporaries with different type from the + // CXXRecord itself. + Elidable = SubExpr->isTemporaryObject( + Context, cast(FoundDecl->getDeclContext())); + } + + return BuildCXXConstructExpr(ConstructLoc, DeclInitType, + FoundDecl, Constructor, + Elidable, ExprArgs, HadMultipleCandidates, + IsListInitialization, + IsStdInitListInitialization, RequiresZeroInit, + ConstructKind, ParenRange); + } + + ExprResult + Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType, + NamedDecl *FoundDecl, + CXXConstructorDecl *Constructor, + bool Elidable, + MultiExprArg ExprArgs, + bool HadMultipleCandidates, + bool IsListInitialization, + bool IsStdInitListInitialization, + bool RequiresZeroInit, + unsigned ConstructKind, + SourceRange ParenRange) { + if (auto *Shadow = dyn_cast(FoundDecl)) { + Constructor = findInheritingConstructor(ConstructLoc, Constructor, Shadow); + // The only way to get here is if we did overlaod resolution to find the + // shadow decl, so we don't need to worry about re-checking the trailing + // requires clause. + if (DiagnoseUseOfOverloadedDecl(Constructor, ConstructLoc)) + return ExprError(); + } + + return BuildCXXConstructExpr( + ConstructLoc, DeclInitType, Constructor, Elidable, ExprArgs, + HadMultipleCandidates, IsListInitialization, IsStdInitListInitialization, + RequiresZeroInit, ConstructKind, ParenRange); + } + + /// BuildCXXConstructExpr - Creates a complete call to a constructor, + /// including handling of its default argument expressions. + ExprResult + Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType, + CXXConstructorDecl *Constructor, + bool Elidable, + MultiExprArg ExprArgs, + bool HadMultipleCandidates, + bool IsListInitialization, + bool IsStdInitListInitialization, + bool RequiresZeroInit, + unsigned ConstructKind, + SourceRange ParenRange) { + assert(declaresSameEntity( + Constructor->getParent(), + DeclInitType->getBaseElementTypeUnsafe()->getAsCXXRecordDecl()) && + "given constructor for wrong type"); + MarkFunctionReferenced(ConstructLoc, Constructor); + if (getLangOpts().CUDA && !CheckCUDACall(ConstructLoc, Constructor)) + return ExprError(); + + return CheckForImmediateInvocation( + CXXConstructExpr::Create( + Context, DeclInitType, ConstructLoc, Constructor, Elidable, ExprArgs, + HadMultipleCandidates, IsListInitialization, + IsStdInitListInitialization, RequiresZeroInit, + static_cast(ConstructKind), + ParenRange), + Constructor); + } + + void Sema::FinalizeVarWithDestructor(VarDecl *VD, const RecordType *Record) { + if (VD->isInvalidDecl()) return; + // If initializing the variable failed, don't also diagnose problems with + // the destructor, they're likely related. + if (VD->getInit() && VD->getInit()->containsErrors()) + return; + + CXXRecordDecl *ClassDecl = cast(Record->getDecl()); + if (ClassDecl->isInvalidDecl()) return; + if (ClassDecl->hasIrrelevantDestructor()) return; + if (ClassDecl->isDependentContext()) return; + + if (VD->isNoDestroy(getASTContext())) + return; + + CXXDestructorDecl *Destructor = LookupDestructor(ClassDecl); + + // If this is an array, we'll require the destructor during initialization, so + // we can skip over this. We still want to emit exit-time destructor warnings + // though. + if (!VD->getType()->isArrayType()) { + MarkFunctionReferenced(VD->getLocation(), Destructor); + CheckDestructorAccess(VD->getLocation(), Destructor, + PDiag(diag::err_access_dtor_var) + << VD->getDeclName() << VD->getType()); + DiagnoseUseOfDecl(Destructor, VD->getLocation()); + } + + if (Destructor->isTrivial()) return; + + // If the destructor is constexpr, check whether the variable has constant + // destruction now. + if (Destructor->isConstexpr()) { + bool HasConstantInit = false; + if (VD->getInit() && !VD->getInit()->isValueDependent()) + HasConstantInit = VD->evaluateValue(); + SmallVector Notes; + if (!VD->evaluateDestruction(Notes) && VD->isConstexpr() && + HasConstantInit) { + Diag(VD->getLocation(), + diag::err_constexpr_var_requires_const_destruction) << VD; + for (unsigned I = 0, N = Notes.size(); I != N; ++I) + Diag(Notes[I].first, Notes[I].second); + } + } + + if (!VD->hasGlobalStorage() || !VD->needsDestruction(Context)) + return; + + // Emit warning for non-trivial dtor in global scope (a real global, + // class-static, function-static). + Diag(VD->getLocation(), diag::warn_exit_time_destructor); + + // TODO: this should be re-enabled for static locals by !CXAAtExit + if (!VD->isStaticLocal()) + Diag(VD->getLocation(), diag::warn_global_destructor); + } + + /// Given a constructor and the set of arguments provided for the + /// constructor, convert the arguments and add any required default arguments + /// to form a proper call to this constructor. + /// + /// \returns true if an error occurred, false otherwise. + bool Sema::CompleteConstructorCall(CXXConstructorDecl *Constructor, + QualType DeclInitType, MultiExprArg ArgsPtr, + SourceLocation Loc, + SmallVectorImpl &ConvertedArgs, + bool AllowExplicit, + bool IsListInitialization) { + // FIXME: This duplicates a lot of code from Sema::ConvertArgumentsForCall. + unsigned NumArgs = ArgsPtr.size(); + Expr **Args = ArgsPtr.data(); + + const auto *Proto = Constructor->getType()->castAs(); + unsigned NumParams = Proto->getNumParams(); + + // If too few arguments are available, we'll fill in the rest with defaults. + if (NumArgs < NumParams) + ConvertedArgs.reserve(NumParams); + else + ConvertedArgs.reserve(NumArgs); + + VariadicCallType CallType = + Proto->isVariadic() ? VariadicConstructor : VariadicDoesNotApply; + SmallVector AllArgs; + bool Invalid = GatherArgumentsForCall( + Loc, Constructor, Proto, 0, llvm::ArrayRef(Args, NumArgs), AllArgs, + CallType, AllowExplicit, IsListInitialization); + ConvertedArgs.append(AllArgs.begin(), AllArgs.end()); + + DiagnoseSentinelCalls(Constructor, Loc, AllArgs); + + CheckConstructorCall(Constructor, DeclInitType, + llvm::ArrayRef(AllArgs.data(), AllArgs.size()), Proto, + Loc); + + return Invalid; + } + + static inline bool + CheckOperatorNewDeleteDeclarationScope(Sema &SemaRef, + const FunctionDecl *FnDecl) { + const DeclContext *DC = FnDecl->getDeclContext()->getRedeclContext(); + if (isa(DC)) { + return SemaRef.Diag(FnDecl->getLocation(), + diag::err_operator_new_delete_declared_in_namespace) + << FnDecl->getDeclName(); + } + + if (isa(DC) && + FnDecl->getStorageClass() == SC_Static) { + return SemaRef.Diag(FnDecl->getLocation(), + diag::err_operator_new_delete_declared_static) + << FnDecl->getDeclName(); + } + + return false; + } + + static CanQualType RemoveAddressSpaceFromPtr(Sema &SemaRef, + const PointerType *PtrTy) { + auto &Ctx = SemaRef.Context; + Qualifiers PtrQuals = PtrTy->getPointeeType().getQualifiers(); + PtrQuals.removeAddressSpace(); + return Ctx.getPointerType(Ctx.getCanonicalType(Ctx.getQualifiedType( + PtrTy->getPointeeType().getUnqualifiedType(), PtrQuals))); + } + + static inline bool + CheckOperatorNewDeleteTypes(Sema &SemaRef, const FunctionDecl *FnDecl, + CanQualType ExpectedResultType, + CanQualType ExpectedFirstParamType, + unsigned DependentParamTypeDiag, + unsigned InvalidParamTypeDiag) { + QualType ResultType = + FnDecl->getType()->castAs()->getReturnType(); + + if (SemaRef.getLangOpts().OpenCLCPlusPlus) { + // The operator is valid on any address space for OpenCL. + // Drop address space from actual and expected result types. + if (const auto *PtrTy = ResultType->getAs()) + ResultType = RemoveAddressSpaceFromPtr(SemaRef, PtrTy); + + if (auto ExpectedPtrTy = ExpectedResultType->getAs()) + ExpectedResultType = RemoveAddressSpaceFromPtr(SemaRef, ExpectedPtrTy); + } + + // Check that the result type is what we expect. + if (SemaRef.Context.getCanonicalType(ResultType) != ExpectedResultType) { + // Reject even if the type is dependent; an operator delete function is + // required to have a non-dependent result type. + return SemaRef.Diag( + FnDecl->getLocation(), + ResultType->isDependentType() + ? diag::err_operator_new_delete_dependent_result_type + : diag::err_operator_new_delete_invalid_result_type) + << FnDecl->getDeclName() << ExpectedResultType; + } + + // A function template must have at least 2 parameters. + if (FnDecl->getDescribedFunctionTemplate() && FnDecl->getNumParams() < 2) + return SemaRef.Diag(FnDecl->getLocation(), + diag::err_operator_new_delete_template_too_few_parameters) + << FnDecl->getDeclName(); + + // The function decl must have at least 1 parameter. + if (FnDecl->getNumParams() == 0) + return SemaRef.Diag(FnDecl->getLocation(), + diag::err_operator_new_delete_too_few_parameters) + << FnDecl->getDeclName(); + + QualType FirstParamType = FnDecl->getParamDecl(0)->getType(); + if (SemaRef.getLangOpts().OpenCLCPlusPlus) { + // The operator is valid on any address space for OpenCL. + // Drop address space from actual and expected first parameter types. + if (const auto *PtrTy = + FnDecl->getParamDecl(0)->getType()->getAs()) + FirstParamType = RemoveAddressSpaceFromPtr(SemaRef, PtrTy); + + if (auto ExpectedPtrTy = ExpectedFirstParamType->getAs()) + ExpectedFirstParamType = + RemoveAddressSpaceFromPtr(SemaRef, ExpectedPtrTy); + } + + // Check that the first parameter type is what we expect. + if (SemaRef.Context.getCanonicalType(FirstParamType).getUnqualifiedType() != + ExpectedFirstParamType) { + // The first parameter type is not allowed to be dependent. As a tentative + // DR resolution, we allow a dependent parameter type if it is the right + // type anyway, to allow destroying operator delete in class templates. + return SemaRef.Diag(FnDecl->getLocation(), FirstParamType->isDependentType() + ? DependentParamTypeDiag + : InvalidParamTypeDiag) + << FnDecl->getDeclName() << ExpectedFirstParamType; + } + + return false; + } + + static bool + CheckOperatorNewDeclaration(Sema &SemaRef, const FunctionDecl *FnDecl) { + // C++ [basic.stc.dynamic.allocation]p1: + // A program is ill-formed if an allocation function is declared in a + // namespace scope other than global scope or declared static in global + // scope. + if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl)) + return true; + + CanQualType SizeTy = + SemaRef.Context.getCanonicalType(SemaRef.Context.getSizeType()); + + // C++ [basic.stc.dynamic.allocation]p1: + // The return type shall be void*. The first parameter shall have type + // std::size_t. + if (CheckOperatorNewDeleteTypes(SemaRef, FnDecl, SemaRef.Context.VoidPtrTy, + SizeTy, + diag::err_operator_new_dependent_param_type, + diag::err_operator_new_param_type)) + return true; + + // C++ [basic.stc.dynamic.allocation]p1: + // The first parameter shall not have an associated default argument. + if (FnDecl->getParamDecl(0)->hasDefaultArg()) + return SemaRef.Diag(FnDecl->getLocation(), + diag::err_operator_new_default_arg) + << FnDecl->getDeclName() << FnDecl->getParamDecl(0)->getDefaultArgRange(); + + return false; + } + + static bool + CheckOperatorDeleteDeclaration(Sema &SemaRef, FunctionDecl *FnDecl) { + // C++ [basic.stc.dynamic.deallocation]p1: + // A program is ill-formed if deallocation functions are declared in a + // namespace scope other than global scope or declared static in global + // scope. + if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl)) + return true; + + auto *MD = dyn_cast(FnDecl); + + // C++ P0722: + // Within a class C, the first parameter of a destroying operator delete + // shall be of type C *. The first parameter of any other deallocation + // function shall be of type void *. + CanQualType ExpectedFirstParamType = + MD && MD->isDestroyingOperatorDelete() + ? SemaRef.Context.getCanonicalType(SemaRef.Context.getPointerType( + SemaRef.Context.getRecordType(MD->getParent()))) + : SemaRef.Context.VoidPtrTy; + + // C++ [basic.stc.dynamic.deallocation]p2: + // Each deallocation function shall return void + if (CheckOperatorNewDeleteTypes( + SemaRef, FnDecl, SemaRef.Context.VoidTy, ExpectedFirstParamType, + diag::err_operator_delete_dependent_param_type, + diag::err_operator_delete_param_type)) + return true; + + // C++ P0722: + // A destroying operator delete shall be a usual deallocation function. + if (MD && !MD->getParent()->isDependentContext() && + MD->isDestroyingOperatorDelete() && + !SemaRef.isUsualDeallocationFunction(MD)) { + SemaRef.Diag(MD->getLocation(), + diag::err_destroying_operator_delete_not_usual); + return true; + } + + return false; + } + + /// CheckOverloadedOperatorDeclaration - Check whether the declaration + /// of this overloaded operator is well-formed. If so, returns false; + /// otherwise, emits appropriate diagnostics and returns true. + bool Sema::CheckOverloadedOperatorDeclaration(FunctionDecl *FnDecl) { + assert(FnDecl && FnDecl->isOverloadedOperator() && + "Expected an overloaded operator declaration"); + + OverloadedOperatorKind Op = FnDecl->getOverloadedOperator(); + + // C++ [over.oper]p5: + // The allocation and deallocation functions, operator new, + // operator new[], operator delete and operator delete[], are + // described completely in 3.7.3. The attributes and restrictions + // found in the rest of this subclause do not apply to them unless + // explicitly stated in 3.7.3. + if (Op == OO_Delete || Op == OO_Array_Delete) + return CheckOperatorDeleteDeclaration(*this, FnDecl); + + if (Op == OO_New || Op == OO_Array_New) + return CheckOperatorNewDeclaration(*this, FnDecl); + + // C++ [over.oper]p7: + // An operator function shall either be a member function or + // be a non-member function and have at least one parameter + // whose type is a class, a reference to a class, an enumeration, + // or a reference to an enumeration. + // Note: Before C++23, a member function could not be static. The only member + // function allowed to be static is the call operator function. + if (CXXMethodDecl *MethodDecl = dyn_cast(FnDecl)) { + if (MethodDecl->isStatic()) { + if (Op == OO_Call || Op == OO_Subscript) + Diag(FnDecl->getLocation(), + (LangOpts.CPlusPlus23 + ? diag::warn_cxx20_compat_operator_overload_static + : diag::ext_operator_overload_static)) + << FnDecl; + else + return Diag(FnDecl->getLocation(), diag::err_operator_overload_static) + << FnDecl; + } + } else { + bool ClassOrEnumParam = false; + for (auto *Param : FnDecl->parameters()) { + QualType ParamType = Param->getType().getNonReferenceType(); + if (ParamType->isDependentType() || ParamType->isRecordType() || + ParamType->isEnumeralType()) { + ClassOrEnumParam = true; + break; + } + } + + if (!ClassOrEnumParam) + return Diag(FnDecl->getLocation(), + diag::err_operator_overload_needs_class_or_enum) + << FnDecl->getDeclName(); + } + + // C++ [over.oper]p8: + // An operator function cannot have default arguments (8.3.6), + // except where explicitly stated below. + // + // Only the function-call operator (C++ [over.call]p1) and the subscript + // operator (CWG2507) allow default arguments. + if (Op != OO_Call) { + ParmVarDecl *FirstDefaultedParam = nullptr; + for (auto *Param : FnDecl->parameters()) { + if (Param->hasDefaultArg()) { + FirstDefaultedParam = Param; + break; + } + } + if (FirstDefaultedParam) { + if (Op == OO_Subscript) { + Diag(FnDecl->getLocation(), LangOpts.CPlusPlus23 + ? diag::ext_subscript_overload + : diag::error_subscript_overload) + << FnDecl->getDeclName() << 1 + << FirstDefaultedParam->getDefaultArgRange(); + } else { + return Diag(FirstDefaultedParam->getLocation(), + diag::err_operator_overload_default_arg) + << FnDecl->getDeclName() + << FirstDefaultedParam->getDefaultArgRange(); + } + } + } + + static const bool OperatorUses[NUM_OVERLOADED_OPERATORS][3] = { + { false, false, false } + #define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \ + , { Unary, Binary, MemberOnly } + #include "clang/Basic/OperatorKinds.def" + }; + + bool CanBeUnaryOperator = OperatorUses[Op][0]; + bool CanBeBinaryOperator = OperatorUses[Op][1]; + bool MustBeMemberOperator = OperatorUses[Op][2]; + + // C++ [over.oper]p8: + // [...] Operator functions cannot have more or fewer parameters + // than the number required for the corresponding operator, as + // described in the rest of this subclause. + unsigned NumParams = FnDecl->getNumParams() + + (isa(FnDecl)? 1 : 0); + if (Op != OO_Call && Op != OO_Subscript && + ((NumParams == 1 && !CanBeUnaryOperator) || + (NumParams == 2 && !CanBeBinaryOperator) || (NumParams < 1) || + (NumParams > 2))) { + // We have the wrong number of parameters. + unsigned ErrorKind; + if (CanBeUnaryOperator && CanBeBinaryOperator) { + ErrorKind = 2; // 2 -> unary or binary. + } else if (CanBeUnaryOperator) { + ErrorKind = 0; // 0 -> unary + } else { + assert(CanBeBinaryOperator && + "All non-call overloaded operators are unary or binary!"); + ErrorKind = 1; // 1 -> binary + } + return Diag(FnDecl->getLocation(), diag::err_operator_overload_must_be) + << FnDecl->getDeclName() << NumParams << ErrorKind; + } + + if (Op == OO_Subscript && NumParams != 2) { + Diag(FnDecl->getLocation(), LangOpts.CPlusPlus23 + ? diag::ext_subscript_overload + : diag::error_subscript_overload) + << FnDecl->getDeclName() << (NumParams == 1 ? 0 : 2); + } + + // Overloaded operators other than operator() and operator[] cannot be + // variadic. + if (Op != OO_Call && + FnDecl->getType()->castAs()->isVariadic()) { + return Diag(FnDecl->getLocation(), diag::err_operator_overload_variadic) + << FnDecl->getDeclName(); + } + + // Some operators must be member functions. + if (MustBeMemberOperator && !isa(FnDecl)) { + return Diag(FnDecl->getLocation(), + diag::err_operator_overload_must_be_member) + << FnDecl->getDeclName(); + } + + // C++ [over.inc]p1: + // The user-defined function called operator++ implements the + // prefix and postfix ++ operator. If this function is a member + // function with no parameters, or a non-member function with one + // parameter of class or enumeration type, it defines the prefix + // increment operator ++ for objects of that type. If the function + // is a member function with one parameter (which shall be of type + // int) or a non-member function with two parameters (the second + // of which shall be of type int), it defines the postfix + // increment operator ++ for objects of that type. + if ((Op == OO_PlusPlus || Op == OO_MinusMinus) && NumParams == 2) { + ParmVarDecl *LastParam = FnDecl->getParamDecl(FnDecl->getNumParams() - 1); + QualType ParamType = LastParam->getType(); + + if (!ParamType->isSpecificBuiltinType(BuiltinType::Int) && + !ParamType->isDependentType()) + return Diag(LastParam->getLocation(), + diag::err_operator_overload_post_incdec_must_be_int) + << LastParam->getType() << (Op == OO_MinusMinus); + } + + return false; + } + + static bool + checkLiteralOperatorTemplateParameterList(Sema &SemaRef, + FunctionTemplateDecl *TpDecl) { + TemplateParameterList *TemplateParams = TpDecl->getTemplateParameters(); + + // Must have one or two template parameters. + if (TemplateParams->size() == 1) { + NonTypeTemplateParmDecl *PmDecl = + dyn_cast(TemplateParams->getParam(0)); + + // The template parameter must be a char parameter pack. + if (PmDecl && PmDecl->isTemplateParameterPack() && + SemaRef.Context.hasSameType(PmDecl->getType(), SemaRef.Context.CharTy)) + return false; + + // C++20 [over.literal]p5: + // A string literal operator template is a literal operator template + // whose template-parameter-list comprises a single non-type + // template-parameter of class type. + // + // As a DR resolution, we also allow placeholders for deduced class + // template specializations. + if (SemaRef.getLangOpts().CPlusPlus20 && PmDecl && + !PmDecl->isTemplateParameterPack() && + (PmDecl->getType()->isRecordType() || + PmDecl->getType()->getAs())) + return false; + } else if (TemplateParams->size() == 2) { + TemplateTypeParmDecl *PmType = + dyn_cast(TemplateParams->getParam(0)); + NonTypeTemplateParmDecl *PmArgs = + dyn_cast(TemplateParams->getParam(1)); + + // The second template parameter must be a parameter pack with the + // first template parameter as its type. + if (PmType && PmArgs && !PmType->isTemplateParameterPack() && + PmArgs->isTemplateParameterPack()) { + const TemplateTypeParmType *TArgs = + PmArgs->getType()->getAs(); + if (TArgs && TArgs->getDepth() == PmType->getDepth() && + TArgs->getIndex() == PmType->getIndex()) { + if (!SemaRef.inTemplateInstantiation()) + SemaRef.Diag(TpDecl->getLocation(), + diag::ext_string_literal_operator_template); + return false; + } + } + } + + SemaRef.Diag(TpDecl->getTemplateParameters()->getSourceRange().getBegin(), + diag::err_literal_operator_template) + << TpDecl->getTemplateParameters()->getSourceRange(); + return true; + } + + /// CheckLiteralOperatorDeclaration - Check whether the declaration + /// of this literal operator function is well-formed. If so, returns + /// false; otherwise, emits appropriate diagnostics and returns true. + bool Sema::CheckLiteralOperatorDeclaration(FunctionDecl *FnDecl) { + if (isa(FnDecl)) { + Diag(FnDecl->getLocation(), diag::err_literal_operator_outside_namespace) + << FnDecl->getDeclName(); + return true; + } + + if (FnDecl->isExternC()) { + Diag(FnDecl->getLocation(), diag::err_literal_operator_extern_c); + if (const LinkageSpecDecl *LSD = + FnDecl->getDeclContext()->getExternCContext()) + Diag(LSD->getExternLoc(), diag::note_extern_c_begins_here); + return true; + } + + // This might be the definition of a literal operator template. + FunctionTemplateDecl *TpDecl = FnDecl->getDescribedFunctionTemplate(); + + // This might be a specialization of a literal operator template. + if (!TpDecl) + TpDecl = FnDecl->getPrimaryTemplate(); + + // template type operator "" name() and + // template type operator "" name() are the only valid + // template signatures, and the only valid signatures with no parameters. + // + // C++20 also allows template type operator "" name(). + if (TpDecl) { + if (FnDecl->param_size() != 0) { + Diag(FnDecl->getLocation(), + diag::err_literal_operator_template_with_params); + return true; + } + + if (checkLiteralOperatorTemplateParameterList(*this, TpDecl)) + return true; + + } else if (FnDecl->param_size() == 1) { + const ParmVarDecl *Param = FnDecl->getParamDecl(0); + + QualType ParamType = Param->getType().getUnqualifiedType(); + + // Only unsigned long long int, long double, any character type, and const + // char * are allowed as the only parameters. + if (ParamType->isSpecificBuiltinType(BuiltinType::ULongLong) || + ParamType->isSpecificBuiltinType(BuiltinType::LongDouble) || + Context.hasSameType(ParamType, Context.CharTy) || + Context.hasSameType(ParamType, Context.WideCharTy) || + Context.hasSameType(ParamType, Context.Char8Ty) || + Context.hasSameType(ParamType, Context.Char16Ty) || + Context.hasSameType(ParamType, Context.Char32Ty)) { + } else if (const PointerType *Ptr = ParamType->getAs()) { + QualType InnerType = Ptr->getPointeeType(); + + // Pointer parameter must be a const char *. + if (!(Context.hasSameType(InnerType.getUnqualifiedType(), + Context.CharTy) && + InnerType.isConstQualified() && !InnerType.isVolatileQualified())) { + Diag(Param->getSourceRange().getBegin(), + diag::err_literal_operator_param) + << ParamType << "'const char *'" << Param->getSourceRange(); + return true; + } + + } else if (ParamType->isRealFloatingType()) { + Diag(Param->getSourceRange().getBegin(), diag::err_literal_operator_param) + << ParamType << Context.LongDoubleTy << Param->getSourceRange(); + return true; + + } else if (ParamType->isIntegerType()) { + Diag(Param->getSourceRange().getBegin(), diag::err_literal_operator_param) + << ParamType << Context.UnsignedLongLongTy << Param->getSourceRange(); + return true; + + } else { + Diag(Param->getSourceRange().getBegin(), + diag::err_literal_operator_invalid_param) + << ParamType << Param->getSourceRange(); + return true; + } + + } else if (FnDecl->param_size() == 2) { + FunctionDecl::param_iterator Param = FnDecl->param_begin(); + + // First, verify that the first parameter is correct. + + QualType FirstParamType = (*Param)->getType().getUnqualifiedType(); + + // Two parameter function must have a pointer to const as a + // first parameter; let's strip those qualifiers. + const PointerType *PT = FirstParamType->getAs(); + + if (!PT) { + Diag((*Param)->getSourceRange().getBegin(), + diag::err_literal_operator_param) + << FirstParamType << "'const char *'" << (*Param)->getSourceRange(); + return true; + } + + QualType PointeeType = PT->getPointeeType(); + // First parameter must be const + if (!PointeeType.isConstQualified() || PointeeType.isVolatileQualified()) { + Diag((*Param)->getSourceRange().getBegin(), + diag::err_literal_operator_param) + << FirstParamType << "'const char *'" << (*Param)->getSourceRange(); + return true; + } + + QualType InnerType = PointeeType.getUnqualifiedType(); + // Only const char *, const wchar_t*, const char8_t*, const char16_t*, and + // const char32_t* are allowed as the first parameter to a two-parameter + // function + if (!(Context.hasSameType(InnerType, Context.CharTy) || + Context.hasSameType(InnerType, Context.WideCharTy) || + Context.hasSameType(InnerType, Context.Char8Ty) || + Context.hasSameType(InnerType, Context.Char16Ty) || + Context.hasSameType(InnerType, Context.Char32Ty))) { + Diag((*Param)->getSourceRange().getBegin(), + diag::err_literal_operator_param) + << FirstParamType << "'const char *'" << (*Param)->getSourceRange(); + return true; + } + + // Move on to the second and final parameter. + ++Param; + + // The second parameter must be a std::size_t. + QualType SecondParamType = (*Param)->getType().getUnqualifiedType(); + if (!Context.hasSameType(SecondParamType, Context.getSizeType())) { + Diag((*Param)->getSourceRange().getBegin(), + diag::err_literal_operator_param) + << SecondParamType << Context.getSizeType() + << (*Param)->getSourceRange(); + return true; + } + } else { + Diag(FnDecl->getLocation(), diag::err_literal_operator_bad_param_count); + return true; + } + + // Parameters are good. + + // A parameter-declaration-clause containing a default argument is not + // equivalent to any of the permitted forms. + for (auto *Param : FnDecl->parameters()) { + if (Param->hasDefaultArg()) { + Diag(Param->getDefaultArgRange().getBegin(), + diag::err_literal_operator_default_argument) + << Param->getDefaultArgRange(); + break; + } + } + + StringRef LiteralName + = FnDecl->getDeclName().getCXXLiteralIdentifier()->getName(); + if (LiteralName[0] != '_' && + !getSourceManager().isInSystemHeader(FnDecl->getLocation())) { + // C++11 [usrlit.suffix]p1: + // Literal suffix identifiers that do not start with an underscore + // are reserved for future standardization. + Diag(FnDecl->getLocation(), diag::warn_user_literal_reserved) + << StringLiteralParser::isValidUDSuffix(getLangOpts(), LiteralName); + } + + return false; + } + + /// ActOnStartLinkageSpecification - Parsed the beginning of a C++ + /// linkage specification, including the language and (if present) + /// the '{'. ExternLoc is the location of the 'extern', Lang is the + /// language string literal. LBraceLoc, if valid, provides the location of + /// the '{' brace. Otherwise, this linkage specification does not + /// have any braces. + Decl *Sema::ActOnStartLinkageSpecification(Scope *S, SourceLocation ExternLoc, + Expr *LangStr, + SourceLocation LBraceLoc) { + StringLiteral *Lit = cast(LangStr); + if (!Lit->isOrdinary()) { + Diag(LangStr->getExprLoc(), diag::err_language_linkage_spec_not_ascii) + << LangStr->getSourceRange(); + return nullptr; + } + + StringRef Lang = Lit->getString(); + LinkageSpecDecl::LanguageIDs Language; + if (Lang == "C") + Language = LinkageSpecDecl::lang_c; + else if (Lang == "C++") + Language = LinkageSpecDecl::lang_cxx; + else { + Diag(LangStr->getExprLoc(), diag::err_language_linkage_spec_unknown) + << LangStr->getSourceRange(); + return nullptr; + } + + // FIXME: Add all the various semantics of linkage specifications + + LinkageSpecDecl *D = LinkageSpecDecl::Create(Context, CurContext, ExternLoc, + LangStr->getExprLoc(), Language, + LBraceLoc.isValid()); + + /// C++ [module.unit]p7.2.3 + /// - Otherwise, if the declaration + /// - ... + /// - ... + /// - appears within a linkage-specification, + /// it is attached to the global module. + /// + /// If the declaration is already in global module fragment, we don't + /// need to attach it again. + if (getLangOpts().CPlusPlusModules && isCurrentModulePurview()) { + Module *GlobalModule = PushImplicitGlobalModuleFragment( + ExternLoc, /*IsExported=*/D->isInExportDeclContext()); + D->setLocalOwningModule(GlobalModule); + } + + CurContext->addDecl(D); + PushDeclContext(S, D); + return D; + } + + /// ActOnFinishLinkageSpecification - Complete the definition of + /// the C++ linkage specification LinkageSpec. If RBraceLoc is + /// valid, it's the position of the closing '}' brace in a linkage + /// specification that uses braces. + Decl *Sema::ActOnFinishLinkageSpecification(Scope *S, + Decl *LinkageSpec, + SourceLocation RBraceLoc) { + if (RBraceLoc.isValid()) { + LinkageSpecDecl* LSDecl = cast(LinkageSpec); + LSDecl->setRBraceLoc(RBraceLoc); + } + + // If the current module doesn't has Parent, it implies that the + // LinkageSpec isn't in the module created by itself. So we don't + // need to pop it. + if (getLangOpts().CPlusPlusModules && getCurrentModule() && + getCurrentModule()->isImplicitGlobalModule() && + getCurrentModule()->Parent) + PopImplicitGlobalModuleFragment(); + + PopDeclContext(); + return LinkageSpec; + } + + Decl *Sema::ActOnEmptyDeclaration(Scope *S, + const ParsedAttributesView &AttrList, + SourceLocation SemiLoc) { + Decl *ED = EmptyDecl::Create(Context, CurContext, SemiLoc); + // Attribute declarations appertain to empty declaration so we handle + // them here. + ProcessDeclAttributeList(S, ED, AttrList); + + CurContext->addDecl(ED); + return ED; + } + + /// Perform semantic analysis for the variable declaration that + /// occurs within a C++ catch clause, returning the newly-created + /// variable. + VarDecl *Sema::BuildExceptionDeclaration(Scope *S, + TypeSourceInfo *TInfo, + SourceLocation StartLoc, + SourceLocation Loc, + IdentifierInfo *Name) { + bool Invalid = false; + QualType ExDeclType = TInfo->getType(); + + // Arrays and functions decay. + if (ExDeclType->isArrayType()) + ExDeclType = Context.getArrayDecayedType(ExDeclType); + else if (ExDeclType->isFunctionType()) + ExDeclType = Context.getPointerType(ExDeclType); + + // C++ 15.3p1: The exception-declaration shall not denote an incomplete type. + // The exception-declaration shall not denote a pointer or reference to an + // incomplete type, other than [cv] void*. + // N2844 forbids rvalue references. + if (!ExDeclType->isDependentType() && ExDeclType->isRValueReferenceType()) { + Diag(Loc, diag::err_catch_rvalue_ref); + Invalid = true; + } + + if (ExDeclType->isVariablyModifiedType()) { + Diag(Loc, diag::err_catch_variably_modified) << ExDeclType; + Invalid = true; + } + + QualType BaseType = ExDeclType; + int Mode = 0; // 0 for direct type, 1 for pointer, 2 for reference + unsigned DK = diag::err_catch_incomplete; + if (const PointerType *Ptr = BaseType->getAs()) { + BaseType = Ptr->getPointeeType(); + Mode = 1; + DK = diag::err_catch_incomplete_ptr; + } else if (const ReferenceType *Ref = BaseType->getAs()) { + // For the purpose of error recovery, we treat rvalue refs like lvalue refs. + BaseType = Ref->getPointeeType(); + Mode = 2; + DK = diag::err_catch_incomplete_ref; + } + if (!Invalid && (Mode == 0 || !BaseType->isVoidType()) && + !BaseType->isDependentType() && RequireCompleteType(Loc, BaseType, DK)) + Invalid = true; + + if (!Invalid && Mode != 1 && BaseType->isSizelessType()) { + Diag(Loc, diag::err_catch_sizeless) << (Mode == 2 ? 1 : 0) << BaseType; + Invalid = true; + } + + if (!Invalid && !ExDeclType->isDependentType() && + RequireNonAbstractType(Loc, ExDeclType, + diag::err_abstract_type_in_decl, + AbstractVariableType)) + Invalid = true; + + // Only the non-fragile NeXT runtime currently supports C++ catches + // of ObjC types, and no runtime supports catching ObjC types by value. + if (!Invalid && getLangOpts().ObjC) { + QualType T = ExDeclType; + if (const ReferenceType *RT = T->getAs()) + T = RT->getPointeeType(); + + if (T->isObjCObjectType()) { + Diag(Loc, diag::err_objc_object_catch); + Invalid = true; + } else if (T->isObjCObjectPointerType()) { + // FIXME: should this be a test for macosx-fragile specifically? + if (getLangOpts().ObjCRuntime.isFragile()) + Diag(Loc, diag::warn_objc_pointer_cxx_catch_fragile); + } + } + + VarDecl *ExDecl = VarDecl::Create(Context, CurContext, StartLoc, Loc, Name, + ExDeclType, TInfo, SC_None); + ExDecl->setExceptionVariable(true); + + // In ARC, infer 'retaining' for variables of retainable type. + if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(ExDecl)) + Invalid = true; + + if (!Invalid && !ExDeclType->isDependentType()) { + if (const RecordType *recordType = ExDeclType->getAs()) { + // Insulate this from anything else we might currently be parsing. + EnterExpressionEvaluationContext scope( + *this, ExpressionEvaluationContext::PotentiallyEvaluated); + + // C++ [except.handle]p16: + // The object declared in an exception-declaration or, if the + // exception-declaration does not specify a name, a temporary (12.2) is + // copy-initialized (8.5) from the exception object. [...] + // The object is destroyed when the handler exits, after the destruction + // of any automatic objects initialized within the handler. + // + // We just pretend to initialize the object with itself, then make sure + // it can be destroyed later. + QualType initType = Context.getExceptionObjectType(ExDeclType); + + InitializedEntity entity = + InitializedEntity::InitializeVariable(ExDecl); + InitializationKind initKind = + InitializationKind::CreateCopy(Loc, SourceLocation()); + + Expr *opaqueValue = + new (Context) OpaqueValueExpr(Loc, initType, VK_LValue, OK_Ordinary); + InitializationSequence sequence(*this, entity, initKind, opaqueValue); + ExprResult result = sequence.Perform(*this, entity, initKind, opaqueValue); + if (result.isInvalid()) + Invalid = true; + else { + // If the constructor used was non-trivial, set this as the + // "initializer". + CXXConstructExpr *construct = result.getAs(); + if (!construct->getConstructor()->isTrivial()) { + Expr *init = MaybeCreateExprWithCleanups(construct); + ExDecl->setInit(init); + } + + // And make sure it's destructable. + FinalizeVarWithDestructor(ExDecl, recordType); + } + } + } + + if (Invalid) + ExDecl->setInvalidDecl(); + + return ExDecl; + } + + /// ActOnExceptionDeclarator - Parsed the exception-declarator in a C++ catch + /// handler. + Decl *Sema::ActOnExceptionDeclarator(Scope *S, Declarator &D) { + TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S); + bool Invalid = D.isInvalidType(); + + // Check for unexpanded parameter packs. + if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo, + UPPC_ExceptionType)) { + TInfo = Context.getTrivialTypeSourceInfo(Context.IntTy, + D.getIdentifierLoc()); + Invalid = true; + } + + IdentifierInfo *II = D.getIdentifier(); + if (NamedDecl *PrevDecl = LookupSingleName(S, II, D.getIdentifierLoc(), + LookupOrdinaryName, + ForVisibleRedeclaration)) { + // The scope should be freshly made just for us. There is just no way + // it contains any previous declaration, except for function parameters in + // a function-try-block's catch statement. + assert(!S->isDeclScope(PrevDecl)); + if (isDeclInScope(PrevDecl, CurContext, S)) { + Diag(D.getIdentifierLoc(), diag::err_redefinition) + << D.getIdentifier(); + Diag(PrevDecl->getLocation(), diag::note_previous_definition); + Invalid = true; + } else if (PrevDecl->isTemplateParameter()) + // Maybe we will complain about the shadowed template parameter. + DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); + } + + if (D.getCXXScopeSpec().isSet() && !Invalid) { + Diag(D.getIdentifierLoc(), diag::err_qualified_catch_declarator) + << D.getCXXScopeSpec().getRange(); + Invalid = true; + } + + VarDecl *ExDecl = BuildExceptionDeclaration( + S, TInfo, D.getBeginLoc(), D.getIdentifierLoc(), D.getIdentifier()); + if (Invalid) + ExDecl->setInvalidDecl(); + + // Add the exception declaration into this scope. + if (II) + PushOnScopeChains(ExDecl, S); + else + CurContext->addDecl(ExDecl); + + ProcessDeclAttributes(S, ExDecl, D); + return ExDecl; + } + + Decl *Sema::ActOnStaticAssertDeclaration(SourceLocation StaticAssertLoc, + Expr *AssertExpr, + Expr *AssertMessageExpr, + SourceLocation RParenLoc) { + StringLiteral *AssertMessage = + AssertMessageExpr ? cast(AssertMessageExpr) : nullptr; + + if (DiagnoseUnexpandedParameterPack(AssertExpr, UPPC_StaticAssertExpression)) + return nullptr; + + return BuildStaticAssertDeclaration(StaticAssertLoc, AssertExpr, + AssertMessage, RParenLoc, false); + } + + /// Convert \V to a string we can present to the user in a diagnostic + /// \T is the type of the expression that has been evaluated into \V + static bool ConvertAPValueToString(const APValue &V, QualType T, + SmallVectorImpl &Str) { + if (!V.hasValue()) + return false; + + switch (V.getKind()) { + case APValue::ValueKind::Int: + if (T->isBooleanType()) { + // Bools are reduced to ints during evaluation, but for + // diagnostic purposes we want to print them as + // true or false. + int64_t BoolValue = V.getInt().getExtValue(); + assert((BoolValue == 0 || BoolValue == 1) && + "Bool type, but value is not 0 or 1"); + llvm::raw_svector_ostream OS(Str); + OS << (BoolValue ? "true" : "false"); + } else if (T->isCharType()) { + // Same is true for chars. + Str.push_back('\''); + Str.push_back(V.getInt().getExtValue()); + Str.push_back('\''); + } else + V.getInt().toString(Str); + + break; + + case APValue::ValueKind::Float: + V.getFloat().toString(Str); + break; + + case APValue::ValueKind::LValue: + if (V.isNullPointer()) { + llvm::raw_svector_ostream OS(Str); + OS << "nullptr"; + } else + return false; + break; + + case APValue::ValueKind::ComplexFloat: { + llvm::raw_svector_ostream OS(Str); + OS << '('; + V.getComplexFloatReal().toString(Str); + OS << " + "; + V.getComplexFloatImag().toString(Str); + OS << "i)"; + } break; + + case APValue::ValueKind::ComplexInt: { + llvm::raw_svector_ostream OS(Str); + OS << '('; + V.getComplexIntReal().toString(Str); + OS << " + "; + V.getComplexIntImag().toString(Str); + OS << "i)"; + } break; + + default: + return false; + } + + return true; + } + + /// Some Expression types are not useful to print notes about, + /// e.g. literals and values that have already been expanded + /// before such as int-valued template parameters. + static bool UsefulToPrintExpr(const Expr *E) { + E = E->IgnoreParenImpCasts(); + // Literals are pretty easy for humans to understand. + if (isa(E)) + return false; + + // These have been substituted from template parameters + // and appear as literals in the static assert error. + if (isa(E)) + return false; + + // -5 is also simple to understand. + if (const auto *UnaryOp = dyn_cast(E)) + return UsefulToPrintExpr(UnaryOp->getSubExpr()); + + // Ignore nested binary operators. This could be a FIXME for improvements + // to the diagnostics in the future. + if (isa(E)) + return false; + + return true; + } + + /// Try to print more useful information about a failed static_assert + /// with expression \E + void Sema::DiagnoseStaticAssertDetails(const Expr *E) { + if (const auto *Op = dyn_cast(E); + Op && Op->getOpcode() != BO_LOr) { + const Expr *LHS = Op->getLHS()->IgnoreParenImpCasts(); + const Expr *RHS = Op->getRHS()->IgnoreParenImpCasts(); + + // Ignore comparisons of boolean expressions with a boolean literal. + if ((isa(LHS) && RHS->getType()->isBooleanType()) || + (isa(RHS) && LHS->getType()->isBooleanType())) + return; + + // Don't print obvious expressions. + if (!UsefulToPrintExpr(LHS) && !UsefulToPrintExpr(RHS)) + return; + + struct { + const clang::Expr *Cond; + Expr::EvalResult Result; + SmallString<12> ValueString; + bool Print; + } DiagSide[2] = {{LHS, Expr::EvalResult(), {}, false}, + {RHS, Expr::EvalResult(), {}, false}}; + for (unsigned I = 0; I < 2; I++) { + const Expr *Side = DiagSide[I].Cond; + + Side->EvaluateAsRValue(DiagSide[I].Result, Context, true); + + DiagSide[I].Print = ConvertAPValueToString( + DiagSide[I].Result.Val, Side->getType(), DiagSide[I].ValueString); + } + if (DiagSide[0].Print && DiagSide[1].Print) { + Diag(Op->getExprLoc(), diag::note_expr_evaluates_to) + << DiagSide[0].ValueString << Op->getOpcodeStr() + << DiagSide[1].ValueString << Op->getSourceRange(); + } + } + } + + Decl *Sema::BuildStaticAssertDeclaration(SourceLocation StaticAssertLoc, + Expr *AssertExpr, + StringLiteral *AssertMessage, + SourceLocation RParenLoc, + bool Failed) { + assert(AssertExpr != nullptr && "Expected non-null condition"); + if (!AssertExpr->isTypeDependent() && !AssertExpr->isValueDependent() && + !Failed) { + // In a static_assert-declaration, the constant-expression shall be a + // constant expression that can be contextually converted to bool. + ExprResult Converted = PerformContextuallyConvertToBool(AssertExpr); + if (Converted.isInvalid()) + Failed = true; + + ExprResult FullAssertExpr = + ActOnFinishFullExpr(Converted.get(), StaticAssertLoc, + /*DiscardedValue*/ false, + /*IsConstexpr*/ true); + if (FullAssertExpr.isInvalid()) + Failed = true; + else + AssertExpr = FullAssertExpr.get(); + + llvm::APSInt Cond; + Expr *BaseExpr = AssertExpr; + AllowFoldKind FoldKind = NoFold; + + if (!getLangOpts().CPlusPlus) { + // In C mode, allow folding as an extension for better compatibility with + // C++ in terms of expressions like static_assert("test") or + // static_assert(nullptr). + FoldKind = AllowFold; + } + + if (!Failed && VerifyIntegerConstantExpression( + BaseExpr, &Cond, + diag::err_static_assert_expression_is_not_constant, + FoldKind).isInvalid()) + Failed = true; + + // CWG2518 + // [dcl.pre]/p10 If [...] the expression is evaluated in the context of a + // template definition, the declaration has no effect. + bool InTemplateDefinition = + getLangOpts().CPlusPlus && CurContext->isDependentContext(); + + if (!Failed && !Cond && !InTemplateDefinition) { + + SmallString<256> MsgBuffer; + llvm::raw_svector_ostream Msg(MsgBuffer); + if (AssertMessage) { + const auto *MsgStr = cast(AssertMessage); + if (MsgStr->isOrdinary()) + Msg << MsgStr->getString(); + else + MsgStr->printPretty(Msg, nullptr, getPrintingPolicy()); + } + + Expr *InnerCond = nullptr; + std::string InnerCondDescription; + std::tie(InnerCond, InnerCondDescription) = + findFailedBooleanCondition(Converted.get()); + if (InnerCond && isa(InnerCond)) { + // Drill down into concept specialization expressions to see why they + // weren't satisfied. + Diag(AssertExpr->getBeginLoc(), diag::err_static_assert_failed) + << !AssertMessage << Msg.str() << AssertExpr->getSourceRange(); + ConstraintSatisfaction Satisfaction; + if (!CheckConstraintSatisfaction(InnerCond, Satisfaction)) + DiagnoseUnsatisfiedConstraint(Satisfaction); + } else if (InnerCond && !isa(InnerCond) + && !isa(InnerCond)) { + Diag(InnerCond->getBeginLoc(), + diag::err_static_assert_requirement_failed) + << InnerCondDescription << !AssertMessage << Msg.str() + << InnerCond->getSourceRange(); + DiagnoseStaticAssertDetails(InnerCond); + } else { + Diag(AssertExpr->getBeginLoc(), diag::err_static_assert_failed) + << !AssertMessage << Msg.str() << AssertExpr->getSourceRange(); + PrintContextStack(); + } + Failed = true; + } + } else { + ExprResult FullAssertExpr = ActOnFinishFullExpr(AssertExpr, StaticAssertLoc, + /*DiscardedValue*/false, + /*IsConstexpr*/true); + if (FullAssertExpr.isInvalid()) + Failed = true; + else + AssertExpr = FullAssertExpr.get(); + } + + Decl *Decl = StaticAssertDecl::Create(Context, CurContext, StaticAssertLoc, + AssertExpr, AssertMessage, RParenLoc, + Failed); + + CurContext->addDecl(Decl); + return Decl; + } + + /// Perform semantic analysis of the given friend type declaration. + /// + /// \returns A friend declaration that. + FriendDecl *Sema::CheckFriendTypeDecl(SourceLocation LocStart, + SourceLocation FriendLoc, + TypeSourceInfo *TSInfo) { + assert(TSInfo && "NULL TypeSourceInfo for friend type declaration"); + + QualType T = TSInfo->getType(); + SourceRange TypeRange = TSInfo->getTypeLoc().getSourceRange(); + + // C++03 [class.friend]p2: + // An elaborated-type-specifier shall be used in a friend declaration + // for a class.* + // + // * The class-key of the elaborated-type-specifier is required. + if (!CodeSynthesisContexts.empty()) { + // Do not complain about the form of friend template types during any kind + // of code synthesis. For template instantiation, we will have complained + // when the template was defined. + } else { + if (!T->isElaboratedTypeSpecifier()) { + // If we evaluated the type to a record type, suggest putting + // a tag in front. + if (const RecordType *RT = T->getAs()) { + RecordDecl *RD = RT->getDecl(); + + SmallString<16> InsertionText(" "); + InsertionText += RD->getKindName(); + + Diag(TypeRange.getBegin(), + getLangOpts().CPlusPlus11 ? + diag::warn_cxx98_compat_unelaborated_friend_type : + diag::ext_unelaborated_friend_type) + << (unsigned) RD->getTagKind() + << T + << FixItHint::CreateInsertion(getLocForEndOfToken(FriendLoc), + InsertionText); + } else { + Diag(FriendLoc, + getLangOpts().CPlusPlus11 ? + diag::warn_cxx98_compat_nonclass_type_friend : + diag::ext_nonclass_type_friend) + << T + << TypeRange; + } + } else if (T->getAs()) { + Diag(FriendLoc, + getLangOpts().CPlusPlus11 ? + diag::warn_cxx98_compat_enum_friend : + diag::ext_enum_friend) + << T + << TypeRange; + } + + // C++11 [class.friend]p3: + // A friend declaration that does not declare a function shall have one + // of the following forms: + // friend elaborated-type-specifier ; + // friend simple-type-specifier ; + // friend typename-specifier ; + if (getLangOpts().CPlusPlus11 && LocStart != FriendLoc) + Diag(FriendLoc, diag::err_friend_not_first_in_declaration) << T; + } + + // If the type specifier in a friend declaration designates a (possibly + // cv-qualified) class type, that class is declared as a friend; otherwise, + // the friend declaration is ignored. + return FriendDecl::Create(Context, CurContext, + TSInfo->getTypeLoc().getBeginLoc(), TSInfo, + FriendLoc); + } + + /// Handle a friend tag declaration where the scope specifier was + /// templated. + DeclResult Sema::ActOnTemplatedFriendTag( + Scope *S, SourceLocation FriendLoc, unsigned TagSpec, SourceLocation TagLoc, + CXXScopeSpec &SS, IdentifierInfo *Name, SourceLocation NameLoc, + const ParsedAttributesView &Attr, MultiTemplateParamsArg TempParamLists) { + TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); + + bool IsMemberSpecialization = false; + bool Invalid = false; + + if (TemplateParameterList *TemplateParams = + MatchTemplateParametersToScopeSpecifier( + TagLoc, NameLoc, SS, nullptr, TempParamLists, /*friend*/ true, + IsMemberSpecialization, Invalid)) { + if (TemplateParams->size() > 0) { + // This is a declaration of a class template. + if (Invalid) + return true; + + return CheckClassTemplate(S, TagSpec, TUK_Friend, TagLoc, SS, Name, + NameLoc, Attr, TemplateParams, AS_public, + /*ModulePrivateLoc=*/SourceLocation(), + FriendLoc, TempParamLists.size() - 1, + TempParamLists.data()).get(); + } else { + // The "template<>" header is extraneous. + Diag(TemplateParams->getTemplateLoc(), diag::err_template_tag_noparams) + << TypeWithKeyword::getTagTypeKindName(Kind) << Name; + IsMemberSpecialization = true; + } + } + + if (Invalid) return true; + + bool isAllExplicitSpecializations = true; + for (unsigned I = TempParamLists.size(); I-- > 0; ) { + if (TempParamLists[I]->size()) { + isAllExplicitSpecializations = false; + break; + } + } + + // FIXME: don't ignore attributes. + + // If it's explicit specializations all the way down, just forget + // about the template header and build an appropriate non-templated + // friend. TODO: for source fidelity, remember the headers. + if (isAllExplicitSpecializations) { + if (SS.isEmpty()) { + bool Owned = false; + bool IsDependent = false; + return ActOnTag(S, TagSpec, TUK_Friend, TagLoc, SS, Name, NameLoc, Attr, + AS_public, + /*ModulePrivateLoc=*/SourceLocation(), + MultiTemplateParamsArg(), Owned, IsDependent, + /*ScopedEnumKWLoc=*/SourceLocation(), + /*ScopedEnumUsesClassTag=*/false, + /*UnderlyingType=*/TypeResult(), + /*IsTypeSpecifier=*/false, + /*IsTemplateParamOrArg=*/false, /*OOK=*/OOK_Outside); + } + + NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context); + ElaboratedTypeKeyword Keyword + = TypeWithKeyword::getKeywordForTagTypeKind(Kind); + QualType T = CheckTypenameType(Keyword, TagLoc, QualifierLoc, + *Name, NameLoc); + if (T.isNull()) + return true; + + TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T); + if (isa(T)) { + DependentNameTypeLoc TL = + TSI->getTypeLoc().castAs(); + TL.setElaboratedKeywordLoc(TagLoc); + TL.setQualifierLoc(QualifierLoc); + TL.setNameLoc(NameLoc); + } else { + ElaboratedTypeLoc TL = TSI->getTypeLoc().castAs(); + TL.setElaboratedKeywordLoc(TagLoc); + TL.setQualifierLoc(QualifierLoc); + TL.getNamedTypeLoc().castAs().setNameLoc(NameLoc); + } + + FriendDecl *Friend = FriendDecl::Create(Context, CurContext, NameLoc, + TSI, FriendLoc, TempParamLists); + Friend->setAccess(AS_public); + CurContext->addDecl(Friend); + return Friend; + } + + assert(SS.isNotEmpty() && "valid templated tag with no SS and no direct?"); + + + + // Handle the case of a templated-scope friend class. e.g. + // template class A::B; + // FIXME: we don't support these right now. + Diag(NameLoc, diag::warn_template_qualified_friend_unsupported) + << SS.getScopeRep() << SS.getRange() << cast(CurContext); + ElaboratedTypeKeyword ETK = TypeWithKeyword::getKeywordForTagTypeKind(Kind); + QualType T = Context.getDependentNameType(ETK, SS.getScopeRep(), Name); + TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T); + DependentNameTypeLoc TL = TSI->getTypeLoc().castAs(); + TL.setElaboratedKeywordLoc(TagLoc); + TL.setQualifierLoc(SS.getWithLocInContext(Context)); + TL.setNameLoc(NameLoc); + + FriendDecl *Friend = FriendDecl::Create(Context, CurContext, NameLoc, + TSI, FriendLoc, TempParamLists); + Friend->setAccess(AS_public); + Friend->setUnsupportedFriend(true); + CurContext->addDecl(Friend); + return Friend; + } + + /// Handle a friend type declaration. This works in tandem with + /// ActOnTag. + /// + /// Notes on friend class templates: + /// + /// We generally treat friend class declarations as if they were + /// declaring a class. So, for example, the elaborated type specifier + /// in a friend declaration is required to obey the restrictions of a + /// class-head (i.e. no typedefs in the scope chain), template + /// parameters are required to match up with simple template-ids, &c. + /// However, unlike when declaring a template specialization, it's + /// okay to refer to a template specialization without an empty + /// template parameter declaration, e.g. + /// friend class A::B; + /// We permit this as a special case; if there are any template + /// parameters present at all, require proper matching, i.e. + /// template <> template \ friend class A::B; + Decl *Sema::ActOnFriendTypeDecl(Scope *S, const DeclSpec &DS, + MultiTemplateParamsArg TempParams) { + SourceLocation Loc = DS.getBeginLoc(); + + assert(DS.isFriendSpecified()); + assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified); + + // C++ [class.friend]p3: + // A friend declaration that does not declare a function shall have one of + // the following forms: + // friend elaborated-type-specifier ; + // friend simple-type-specifier ; + // friend typename-specifier ; + // + // Any declaration with a type qualifier does not have that form. (It's + // legal to specify a qualified type as a friend, you just can't write the + // keywords.) + if (DS.getTypeQualifiers()) { + if (DS.getTypeQualifiers() & DeclSpec::TQ_const) + Diag(DS.getConstSpecLoc(), diag::err_friend_decl_spec) << "const"; + if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile) + Diag(DS.getVolatileSpecLoc(), diag::err_friend_decl_spec) << "volatile"; + if (DS.getTypeQualifiers() & DeclSpec::TQ_restrict) + Diag(DS.getRestrictSpecLoc(), diag::err_friend_decl_spec) << "restrict"; + if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic) + Diag(DS.getAtomicSpecLoc(), diag::err_friend_decl_spec) << "_Atomic"; + if (DS.getTypeQualifiers() & DeclSpec::TQ_unaligned) + Diag(DS.getUnalignedSpecLoc(), diag::err_friend_decl_spec) << "__unaligned"; + } + + // Try to convert the decl specifier to a type. This works for + // friend templates because ActOnTag never produces a ClassTemplateDecl + // for a TUK_Friend. + Declarator TheDeclarator(DS, ParsedAttributesView::none(), + DeclaratorContext::Member); + TypeSourceInfo *TSI = GetTypeForDeclarator(TheDeclarator, S); + QualType T = TSI->getType(); + if (TheDeclarator.isInvalidType()) + return nullptr; + + if (DiagnoseUnexpandedParameterPack(Loc, TSI, UPPC_FriendDeclaration)) + return nullptr; + + // This is definitely an error in C++98. It's probably meant to + // be forbidden in C++0x, too, but the specification is just + // poorly written. + // + // The problem is with declarations like the following: + // template friend A::foo; + // where deciding whether a class C is a friend or not now hinges + // on whether there exists an instantiation of A that causes + // 'foo' to equal C. There are restrictions on class-heads + // (which we declare (by fiat) elaborated friend declarations to + // be) that makes this tractable. + // + // FIXME: handle "template <> friend class A;", which + // is possibly well-formed? Who even knows? + if (TempParams.size() && !T->isElaboratedTypeSpecifier()) { + Diag(Loc, diag::err_tagless_friend_type_template) + << DS.getSourceRange(); + return nullptr; + } + + // C++98 [class.friend]p1: A friend of a class is a function + // or class that is not a member of the class . . . + // This is fixed in DR77, which just barely didn't make the C++03 + // deadline. It's also a very silly restriction that seriously + // affects inner classes and which nobody else seems to implement; + // thus we never diagnose it, not even in -pedantic. + // + // But note that we could warn about it: it's always useless to + // friend one of your own members (it's not, however, worthless to + // friend a member of an arbitrary specialization of your template). + + Decl *D; + if (!TempParams.empty()) + D = FriendTemplateDecl::Create(Context, CurContext, Loc, + TempParams, + TSI, + DS.getFriendSpecLoc()); + else + D = CheckFriendTypeDecl(Loc, DS.getFriendSpecLoc(), TSI); + + if (!D) + return nullptr; + + D->setAccess(AS_public); + CurContext->addDecl(D); + + return D; + } + + NamedDecl *Sema::ActOnFriendFunctionDecl(Scope *S, Declarator &D, + MultiTemplateParamsArg TemplateParams) { + const DeclSpec &DS = D.getDeclSpec(); + + assert(DS.isFriendSpecified()); + assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified); + + SourceLocation Loc = D.getIdentifierLoc(); + TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S); + + // C++ [class.friend]p1 + // A friend of a class is a function or class.... + // Note that this sees through typedefs, which is intended. + // It *doesn't* see through dependent types, which is correct + // according to [temp.arg.type]p3: + // If a declaration acquires a function type through a + // type dependent on a template-parameter and this causes + // a declaration that does not use the syntactic form of a + // function declarator to have a function type, the program + // is ill-formed. + if (!TInfo->getType()->isFunctionType()) { + Diag(Loc, diag::err_unexpected_friend); + + // It might be worthwhile to try to recover by creating an + // appropriate declaration. + return nullptr; + } + + // C++ [namespace.memdef]p3 + // - If a friend declaration in a non-local class first declares a + // class or function, the friend class or function is a member + // of the innermost enclosing namespace. + // - The name of the friend is not found by simple name lookup + // until a matching declaration is provided in that namespace + // scope (either before or after the class declaration granting + // friendship). + // - If a friend function is called, its name may be found by the + // name lookup that considers functions from namespaces and + // classes associated with the types of the function arguments. + // - When looking for a prior declaration of a class or a function + // declared as a friend, scopes outside the innermost enclosing + // namespace scope are not considered. + + CXXScopeSpec &SS = D.getCXXScopeSpec(); + DeclarationNameInfo NameInfo = GetNameForDeclarator(D); + assert(NameInfo.getName()); + + // Check for unexpanded parameter packs. + if (DiagnoseUnexpandedParameterPack(Loc, TInfo, UPPC_FriendDeclaration) || + DiagnoseUnexpandedParameterPack(NameInfo, UPPC_FriendDeclaration) || + DiagnoseUnexpandedParameterPack(SS, UPPC_FriendDeclaration)) + return nullptr; + + // The context we found the declaration in, or in which we should + // create the declaration. + DeclContext *DC; + Scope *DCScope = S; + LookupResult Previous(*this, NameInfo, LookupOrdinaryName, + ForExternalRedeclaration); + + // There are five cases here. + // - There's no scope specifier and we're in a local class. Only look + // for functions declared in the immediately-enclosing block scope. + // We recover from invalid scope qualifiers as if they just weren't there. + FunctionDecl *FunctionContainingLocalClass = nullptr; + if ((SS.isInvalid() || !SS.isSet()) && + (FunctionContainingLocalClass = + cast(CurContext)->isLocalClass())) { + // C++11 [class.friend]p11: + // If a friend declaration appears in a local class and the name + // specified is an unqualified name, a prior declaration is + // looked up without considering scopes that are outside the + // innermost enclosing non-class scope. For a friend function + // declaration, if there is no prior declaration, the program is + // ill-formed. + + // Find the innermost enclosing non-class scope. This is the block + // scope containing the local class definition (or for a nested class, + // the outer local class). + DCScope = S->getFnParent(); + + // Look up the function name in the scope. + Previous.clear(LookupLocalFriendName); + LookupName(Previous, S, /*AllowBuiltinCreation*/false); + + if (!Previous.empty()) { + // All possible previous declarations must have the same context: + // either they were declared at block scope or they are members of + // one of the enclosing local classes. + DC = Previous.getRepresentativeDecl()->getDeclContext(); + } else { + // This is ill-formed, but provide the context that we would have + // declared the function in, if we were permitted to, for error recovery. + DC = FunctionContainingLocalClass; + } + adjustContextForLocalExternDecl(DC); + + // C++ [class.friend]p6: + // A function can be defined in a friend declaration of a class if and + // only if the class is a non-local class (9.8), the function name is + // unqualified, and the function has namespace scope. + if (D.isFunctionDefinition()) { + Diag(NameInfo.getBeginLoc(), diag::err_friend_def_in_local_class); + } + + // - There's no scope specifier, in which case we just go to the + // appropriate scope and look for a function or function template + // there as appropriate. + } else if (SS.isInvalid() || !SS.isSet()) { + // C++11 [namespace.memdef]p3: + // If the name in a friend declaration is neither qualified nor + // a template-id and the declaration is a function or an + // elaborated-type-specifier, the lookup to determine whether + // the entity has been previously declared shall not consider + // any scopes outside the innermost enclosing namespace. + bool isTemplateId = + D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId; + + // Find the appropriate context according to the above. + DC = CurContext; + + // Skip class contexts. If someone can cite chapter and verse + // for this behavior, that would be nice --- it's what GCC and + // EDG do, and it seems like a reasonable intent, but the spec + // really only says that checks for unqualified existing + // declarations should stop at the nearest enclosing namespace, + // not that they should only consider the nearest enclosing + // namespace. + while (DC->isRecord()) + DC = DC->getParent(); + + DeclContext *LookupDC = DC->getNonTransparentContext(); + while (true) { + LookupQualifiedName(Previous, LookupDC); + + if (!Previous.empty()) { + DC = LookupDC; + break; + } + + if (isTemplateId) { + if (isa(LookupDC)) break; + } else { + if (LookupDC->isFileContext()) break; + } + LookupDC = LookupDC->getParent(); + } + + DCScope = getScopeForDeclContext(S, DC); + + // - There's a non-dependent scope specifier, in which case we + // compute it and do a previous lookup there for a function + // or function template. + } else if (!SS.getScopeRep()->isDependent()) { + DC = computeDeclContext(SS); + if (!DC) return nullptr; + + if (RequireCompleteDeclContext(SS, DC)) return nullptr; + + LookupQualifiedName(Previous, DC); + + // C++ [class.friend]p1: A friend of a class is a function or + // class that is not a member of the class . . . + if (DC->Equals(CurContext)) + Diag(DS.getFriendSpecLoc(), + getLangOpts().CPlusPlus11 ? + diag::warn_cxx98_compat_friend_is_member : + diag::err_friend_is_member); + + if (D.isFunctionDefinition()) { + // C++ [class.friend]p6: + // A function can be defined in a friend declaration of a class if and + // only if the class is a non-local class (9.8), the function name is + // unqualified, and the function has namespace scope. + // + // FIXME: We should only do this if the scope specifier names the + // innermost enclosing namespace; otherwise the fixit changes the + // meaning of the code. + SemaDiagnosticBuilder DB + = Diag(SS.getRange().getBegin(), diag::err_qualified_friend_def); + + DB << SS.getScopeRep(); + if (DC->isFileContext()) + DB << FixItHint::CreateRemoval(SS.getRange()); + SS.clear(); + } + + // - There's a scope specifier that does not match any template + // parameter lists, in which case we use some arbitrary context, + // create a method or method template, and wait for instantiation. + // - There's a scope specifier that does match some template + // parameter lists, which we don't handle right now. + } else { + if (D.isFunctionDefinition()) { + // C++ [class.friend]p6: + // A function can be defined in a friend declaration of a class if and + // only if the class is a non-local class (9.8), the function name is + // unqualified, and the function has namespace scope. + Diag(SS.getRange().getBegin(), diag::err_qualified_friend_def) + << SS.getScopeRep(); + } + + DC = CurContext; + assert(isa(DC) && "friend declaration not in class?"); + } + + if (!DC->isRecord()) { + int DiagArg = -1; + switch (D.getName().getKind()) { + case UnqualifiedIdKind::IK_ConstructorTemplateId: + case UnqualifiedIdKind::IK_ConstructorName: + DiagArg = 0; + break; + case UnqualifiedIdKind::IK_DestructorName: + DiagArg = 1; + break; + case UnqualifiedIdKind::IK_ConversionFunctionId: + DiagArg = 2; + break; + case UnqualifiedIdKind::IK_DeductionGuideName: + DiagArg = 3; + break; + case UnqualifiedIdKind::IK_Identifier: + case UnqualifiedIdKind::IK_ImplicitSelfParam: + case UnqualifiedIdKind::IK_LiteralOperatorId: + case UnqualifiedIdKind::IK_OperatorFunctionId: + case UnqualifiedIdKind::IK_TemplateId: + break; + } + // This implies that it has to be an operator or function. + if (DiagArg >= 0) { + Diag(Loc, diag::err_introducing_special_friend) << DiagArg; + return nullptr; + } + } + + // FIXME: This is an egregious hack to cope with cases where the scope stack + // does not contain the declaration context, i.e., in an out-of-line + // definition of a class. + Scope FakeDCScope(S, Scope::DeclScope, Diags); + if (!DCScope) { + FakeDCScope.setEntity(DC); + DCScope = &FakeDCScope; + } + + bool AddToScope = true; + NamedDecl *ND = ActOnFunctionDeclarator(DCScope, D, DC, TInfo, Previous, + TemplateParams, AddToScope); + if (!ND) return nullptr; + + assert(ND->getLexicalDeclContext() == CurContext); + + // If we performed typo correction, we might have added a scope specifier + // and changed the decl context. + DC = ND->getDeclContext(); + + // Add the function declaration to the appropriate lookup tables, + // adjusting the redeclarations list as necessary. We don't + // want to do this yet if the friending class is dependent. + // + // Also update the scope-based lookup if the target context's + // lookup context is in lexical scope. + if (!CurContext->isDependentContext()) { + DC = DC->getRedeclContext(); + DC->makeDeclVisibleInContext(ND); + if (Scope *EnclosingScope = getScopeForDeclContext(S, DC)) + PushOnScopeChains(ND, EnclosingScope, /*AddToContext=*/ false); + } + + FriendDecl *FrD = FriendDecl::Create(Context, CurContext, + D.getIdentifierLoc(), ND, + DS.getFriendSpecLoc()); + FrD->setAccess(AS_public); + CurContext->addDecl(FrD); + + if (ND->isInvalidDecl()) { + FrD->setInvalidDecl(); + } else { + if (DC->isRecord()) CheckFriendAccess(ND); + + FunctionDecl *FD; + if (FunctionTemplateDecl *FTD = dyn_cast(ND)) + FD = FTD->getTemplatedDecl(); + else + FD = cast(ND); + + // C++11 [dcl.fct.default]p4: If a friend declaration specifies a + // default argument expression, that declaration shall be a definition + // and shall be the only declaration of the function or function + // template in the translation unit. + if (functionDeclHasDefaultArgument(FD)) { + // We can't look at FD->getPreviousDecl() because it may not have been set + // if we're in a dependent context. If the function is known to be a + // redeclaration, we will have narrowed Previous down to the right decl. + if (D.isRedeclaration()) { + Diag(FD->getLocation(), diag::err_friend_decl_with_def_arg_redeclared); + Diag(Previous.getRepresentativeDecl()->getLocation(), + diag::note_previous_declaration); + } else if (!D.isFunctionDefinition()) + Diag(FD->getLocation(), diag::err_friend_decl_with_def_arg_must_be_def); + } + + // Mark templated-scope function declarations as unsupported. + if (FD->getNumTemplateParameterLists() && SS.isValid()) { + Diag(FD->getLocation(), diag::warn_template_qualified_friend_unsupported) + << SS.getScopeRep() << SS.getRange() + << cast(CurContext); + FrD->setUnsupportedFriend(true); + } + } + + warnOnReservedIdentifier(ND); + + return ND; + } + + void Sema::SetDeclDeleted(Decl *Dcl, SourceLocation DelLoc) { + AdjustDeclIfTemplate(Dcl); + + FunctionDecl *Fn = dyn_cast_or_null(Dcl); + if (!Fn) { + Diag(DelLoc, diag::err_deleted_non_function); + return; + } + + // Deleted function does not have a body. + Fn->setWillHaveBody(false); + + if (const FunctionDecl *Prev = Fn->getPreviousDecl()) { + // Don't consider the implicit declaration we generate for explicit + // specializations. FIXME: Do not generate these implicit declarations. + if ((Prev->getTemplateSpecializationKind() != TSK_ExplicitSpecialization || + Prev->getPreviousDecl()) && + !Prev->isDefined()) { + Diag(DelLoc, diag::err_deleted_decl_not_first); + Diag(Prev->getLocation().isInvalid() ? DelLoc : Prev->getLocation(), + Prev->isImplicit() ? diag::note_previous_implicit_declaration + : diag::note_previous_declaration); + // We can't recover from this; the declaration might have already + // been used. + Fn->setInvalidDecl(); + return; + } + + // To maintain the invariant that functions are only deleted on their first + // declaration, mark the implicitly-instantiated declaration of the + // explicitly-specialized function as deleted instead of marking the + // instantiated redeclaration. + Fn = Fn->getCanonicalDecl(); + } + + // dllimport/dllexport cannot be deleted. + if (const InheritableAttr *DLLAttr = getDLLAttr(Fn)) { + Diag(Fn->getLocation(), diag::err_attribute_dll_deleted) << DLLAttr; + Fn->setInvalidDecl(); + } + + // C++11 [basic.start.main]p3: + // A program that defines main as deleted [...] is ill-formed. + if (Fn->isMain()) + Diag(DelLoc, diag::err_deleted_main); + + // C++11 [dcl.fct.def.delete]p4: + // A deleted function is implicitly inline. + Fn->setImplicitlyInline(); + Fn->setDeletedAsWritten(); + } + + void Sema::SetDeclDefaulted(Decl *Dcl, SourceLocation DefaultLoc) { + if (!Dcl || Dcl->isInvalidDecl()) + return; + + auto *FD = dyn_cast(Dcl); + if (!FD) { + if (auto *FTD = dyn_cast(Dcl)) { + if (getDefaultedFunctionKind(FTD->getTemplatedDecl()).isComparison()) { + Diag(DefaultLoc, diag::err_defaulted_comparison_template); + return; + } + } + + Diag(DefaultLoc, diag::err_default_special_members) + << getLangOpts().CPlusPlus20; + return; + } + + // Reject if this can't possibly be a defaultable function. + DefaultedFunctionKind DefKind = getDefaultedFunctionKind(FD); + if (!DefKind && + // A dependent function that doesn't locally look defaultable can + // still instantiate to a defaultable function if it's a constructor + // or assignment operator. + (!FD->isDependentContext() || + (!isa(FD) && + FD->getDeclName().getCXXOverloadedOperator() != OO_Equal))) { + Diag(DefaultLoc, diag::err_default_special_members) + << getLangOpts().CPlusPlus20; + return; + } + + // Issue compatibility warning. We already warned if the operator is + // 'operator<=>' when parsing the '<=>' token. + if (DefKind.isComparison() && + DefKind.asComparison() != DefaultedComparisonKind::ThreeWay) { + Diag(DefaultLoc, getLangOpts().CPlusPlus20 + ? diag::warn_cxx17_compat_defaulted_comparison + : diag::ext_defaulted_comparison); + } + + FD->setDefaulted(); + FD->setExplicitlyDefaulted(); + FD->setDefaultLoc(DefaultLoc); + + // Defer checking functions that are defaulted in a dependent context. + if (FD->isDependentContext()) + return; + + // Unset that we will have a body for this function. We might not, + // if it turns out to be trivial, and we don't need this marking now + // that we've marked it as defaulted. + FD->setWillHaveBody(false); + + if (DefKind.isComparison()) { + // If this comparison's defaulting occurs within the definition of its + // lexical class context, we have to do the checking when complete. + if (auto const *RD = dyn_cast(FD->getLexicalDeclContext())) + if (!RD->isCompleteDefinition()) + return; + } + + // If this member fn was defaulted on its first declaration, we will have + // already performed the checking in CheckCompletedCXXClass. Such a + // declaration doesn't trigger an implicit definition. + if (isa(FD)) { + const FunctionDecl *Primary = FD; + if (const FunctionDecl *Pattern = FD->getTemplateInstantiationPattern()) + // Ask the template instantiation pattern that actually had the + // '= default' on it. + Primary = Pattern; + if (Primary->getCanonicalDecl()->isDefaulted()) + return; + } + + if (DefKind.isComparison()) { + if (CheckExplicitlyDefaultedComparison(nullptr, FD, DefKind.asComparison())) + FD->setInvalidDecl(); + else + DefineDefaultedComparison(DefaultLoc, FD, DefKind.asComparison()); + } else { + auto *MD = cast(FD); + + if (CheckExplicitlyDefaultedSpecialMember(MD, DefKind.asSpecialMember(), + DefaultLoc)) + MD->setInvalidDecl(); + else + DefineDefaultedFunction(*this, MD, DefaultLoc); + } + } + + static void SearchForReturnInStmt(Sema &Self, Stmt *S) { + for (Stmt *SubStmt : S->children()) { + if (!SubStmt) + continue; + if (isa(SubStmt)) + Self.Diag(SubStmt->getBeginLoc(), + diag::err_return_in_constructor_handler); + if (!isa(SubStmt)) + SearchForReturnInStmt(Self, SubStmt); + } + } + + void Sema::DiagnoseReturnInConstructorExceptionHandler(CXXTryStmt *TryBlock) { + for (unsigned I = 0, E = TryBlock->getNumHandlers(); I != E; ++I) { + CXXCatchStmt *Handler = TryBlock->getHandler(I); + SearchForReturnInStmt(*this, Handler); + } + } + + void Sema::SetFunctionBodyKind(Decl *D, SourceLocation Loc, + FnBodyKind BodyKind) { + switch (BodyKind) { + case FnBodyKind::Delete: + SetDeclDeleted(D, Loc); + break; + case FnBodyKind::Default: + SetDeclDefaulted(D, Loc); + break; + case FnBodyKind::Other: + llvm_unreachable( + "Parsed function body should be '= delete;' or '= default;'"); + } + } + + bool Sema::CheckOverridingFunctionAttributes(const CXXMethodDecl *New, + const CXXMethodDecl *Old) { + const auto *NewFT = New->getType()->castAs(); + const auto *OldFT = Old->getType()->castAs(); + + if (OldFT->hasExtParameterInfos()) { + for (unsigned I = 0, E = OldFT->getNumParams(); I != E; ++I) + // A parameter of the overriding method should be annotated with noescape + // if the corresponding parameter of the overridden method is annotated. + if (OldFT->getExtParameterInfo(I).isNoEscape() && + !NewFT->getExtParameterInfo(I).isNoEscape()) { + Diag(New->getParamDecl(I)->getLocation(), + diag::warn_overriding_method_missing_noescape); + Diag(Old->getParamDecl(I)->getLocation(), + diag::note_overridden_marked_noescape); + } + } + + // Virtual overrides must have the same code_seg. + const auto *OldCSA = Old->getAttr(); + const auto *NewCSA = New->getAttr(); + if ((NewCSA || OldCSA) && + (!OldCSA || !NewCSA || NewCSA->getName() != OldCSA->getName())) { + Diag(New->getLocation(), diag::err_mismatched_code_seg_override); + Diag(Old->getLocation(), diag::note_previous_declaration); + return true; + } + + CallingConv NewCC = NewFT->getCallConv(), OldCC = OldFT->getCallConv(); + + // If the calling conventions match, everything is fine + if (NewCC == OldCC) + return false; + + // If the calling conventions mismatch because the new function is static, + // suppress the calling convention mismatch error; the error about static + // function override (err_static_overrides_virtual from + // Sema::CheckFunctionDeclaration) is more clear. + if (New->getStorageClass() == SC_Static) + return false; + + Diag(New->getLocation(), + diag::err_conflicting_overriding_cc_attributes) + << New->getDeclName() << New->getType() << Old->getType(); + Diag(Old->getLocation(), diag::note_overridden_virtual_function); + return true; + } + + bool Sema::CheckOverridingFunctionReturnType(const CXXMethodDecl *New, + const CXXMethodDecl *Old) { + QualType NewTy = New->getType()->castAs()->getReturnType(); + QualType OldTy = Old->getType()->castAs()->getReturnType(); + + if (Context.hasSameType(NewTy, OldTy) || + NewTy->isDependentType() || OldTy->isDependentType()) + return false; + + // Check if the return types are covariant + QualType NewClassTy, OldClassTy; + + /// Both types must be pointers or references to classes. + if (const PointerType *NewPT = NewTy->getAs()) { + if (const PointerType *OldPT = OldTy->getAs()) { + NewClassTy = NewPT->getPointeeType(); + OldClassTy = OldPT->getPointeeType(); + } + } else if (const ReferenceType *NewRT = NewTy->getAs()) { + if (const ReferenceType *OldRT = OldTy->getAs()) { + if (NewRT->getTypeClass() == OldRT->getTypeClass()) { + NewClassTy = NewRT->getPointeeType(); + OldClassTy = OldRT->getPointeeType(); + } + } + } + + // The return types aren't either both pointers or references to a class type. + if (NewClassTy.isNull()) { + Diag(New->getLocation(), + diag::err_different_return_type_for_overriding_virtual_function) + << New->getDeclName() << NewTy << OldTy + << New->getReturnTypeSourceRange(); + Diag(Old->getLocation(), diag::note_overridden_virtual_function) + << Old->getReturnTypeSourceRange(); + + return true; + } + + if (!Context.hasSameUnqualifiedType(NewClassTy, OldClassTy)) { + // C++14 [class.virtual]p8: + // If the class type in the covariant return type of D::f differs from + // that of B::f, the class type in the return type of D::f shall be + // complete at the point of declaration of D::f or shall be the class + // type D. + if (const RecordType *RT = NewClassTy->getAs()) { + if (!RT->isBeingDefined() && + RequireCompleteType(New->getLocation(), NewClassTy, + diag::err_covariant_return_incomplete, + New->getDeclName())) + return true; + } + + // Check if the new class derives from the old class. + if (!IsDerivedFrom(New->getLocation(), NewClassTy, OldClassTy)) { + Diag(New->getLocation(), diag::err_covariant_return_not_derived) + << New->getDeclName() << NewTy << OldTy + << New->getReturnTypeSourceRange(); + Diag(Old->getLocation(), diag::note_overridden_virtual_function) + << Old->getReturnTypeSourceRange(); + return true; + } + + // Check if we the conversion from derived to base is valid. + if (CheckDerivedToBaseConversion( + NewClassTy, OldClassTy, + diag::err_covariant_return_inaccessible_base, + diag::err_covariant_return_ambiguous_derived_to_base_conv, + New->getLocation(), New->getReturnTypeSourceRange(), + New->getDeclName(), nullptr)) { + // FIXME: this note won't trigger for delayed access control + // diagnostics, and it's impossible to get an undelayed error + // here from access control during the original parse because + // the ParsingDeclSpec/ParsingDeclarator are still in scope. + Diag(Old->getLocation(), diag::note_overridden_virtual_function) + << Old->getReturnTypeSourceRange(); + return true; + } + } + + // The qualifiers of the return types must be the same. + if (NewTy.getLocalCVRQualifiers() != OldTy.getLocalCVRQualifiers()) { + Diag(New->getLocation(), + diag::err_covariant_return_type_different_qualifications) + << New->getDeclName() << NewTy << OldTy + << New->getReturnTypeSourceRange(); + Diag(Old->getLocation(), diag::note_overridden_virtual_function) + << Old->getReturnTypeSourceRange(); + return true; + } + + + // The new class type must have the same or less qualifiers as the old type. + if (NewClassTy.isMoreQualifiedThan(OldClassTy)) { + Diag(New->getLocation(), + diag::err_covariant_return_type_class_type_more_qualified) + << New->getDeclName() << NewTy << OldTy + << New->getReturnTypeSourceRange(); + Diag(Old->getLocation(), diag::note_overridden_virtual_function) + << Old->getReturnTypeSourceRange(); + return true; + } + + return false; + } + + /// Mark the given method pure. + /// + /// \param Method the method to be marked pure. + /// + /// \param InitRange the source range that covers the "0" initializer. + bool Sema::CheckPureMethod(CXXMethodDecl *Method, SourceRange InitRange) { + SourceLocation EndLoc = InitRange.getEnd(); + if (EndLoc.isValid()) + Method->setRangeEnd(EndLoc); + + if (Method->isVirtual() || Method->getParent()->isDependentContext()) { + Method->setPure(); + return false; + } + + if (!Method->isInvalidDecl()) + Diag(Method->getLocation(), diag::err_non_virtual_pure) + << Method->getDeclName() << InitRange; + return true; + } + + void Sema::ActOnPureSpecifier(Decl *D, SourceLocation ZeroLoc) { + if (D->getFriendObjectKind()) + Diag(D->getLocation(), diag::err_pure_friend); + else if (auto *M = dyn_cast(D)) + CheckPureMethod(M, ZeroLoc); + else + Diag(D->getLocation(), diag::err_illegal_initializer); + } + + /// Determine whether the given declaration is a global variable or + /// static data member. + static bool isNonlocalVariable(const Decl *D) { + if (const VarDecl *Var = dyn_cast_or_null(D)) + return Var->hasGlobalStorage(); + + return false; + } + + /// Invoked when we are about to parse an initializer for the declaration + /// 'Dcl'. + /// + /// After this method is called, according to [C++ 3.4.1p13], if 'Dcl' is a + /// static data member of class X, names should be looked up in the scope of + /// class X. If the declaration had a scope specifier, a scope will have + /// been created and passed in for this purpose. Otherwise, S will be null. + void Sema::ActOnCXXEnterDeclInitializer(Scope *S, Decl *D) { + // If there is no declaration, there was an error parsing it. + if (!D || D->isInvalidDecl()) + return; + + // We will always have a nested name specifier here, but this declaration + // might not be out of line if the specifier names the current namespace: + // extern int n; + // int ::n = 0; + if (S && D->isOutOfLine()) + EnterDeclaratorContext(S, D->getDeclContext()); + + // If we are parsing the initializer for a static data member, push a + // new expression evaluation context that is associated with this static + // data member. + if (isNonlocalVariable(D)) + PushExpressionEvaluationContext( + ExpressionEvaluationContext::PotentiallyEvaluated, D); + } + + /// Invoked after we are finished parsing an initializer for the declaration D. + void Sema::ActOnCXXExitDeclInitializer(Scope *S, Decl *D) { + // If there is no declaration, there was an error parsing it. + if (!D || D->isInvalidDecl()) + return; + + if (isNonlocalVariable(D)) + PopExpressionEvaluationContext(); + + if (S && D->isOutOfLine()) + ExitDeclaratorContext(S); + } + + /// ActOnCXXConditionDeclarationExpr - Parsed a condition declaration of a + /// C++ if/switch/while/for statement. + /// e.g: "if (int x = f()) {...}" + DeclResult Sema::ActOnCXXConditionDeclaration(Scope *S, Declarator &D) { + // C++ 6.4p2: + // The declarator shall not specify a function or an array. + // The type-specifier-seq shall not contain typedef and shall not declare a + // new class or enumeration. + assert(D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef && + "Parser allowed 'typedef' as storage class of condition decl."); + + Decl *Dcl = ActOnDeclarator(S, D); + if (!Dcl) + return true; + + if (isa(Dcl)) { // The declarator shall not specify a function. + Diag(Dcl->getLocation(), diag::err_invalid_use_of_function_type) + << D.getSourceRange(); + return true; + } + + return Dcl; + } + + void Sema::LoadExternalVTableUses() { + if (!ExternalSource) + return; + + SmallVector VTables; + ExternalSource->ReadUsedVTables(VTables); + SmallVector NewUses; + for (unsigned I = 0, N = VTables.size(); I != N; ++I) { + llvm::DenseMap::iterator Pos + = VTablesUsed.find(VTables[I].Record); + // Even if a definition wasn't required before, it may be required now. + if (Pos != VTablesUsed.end()) { + if (!Pos->second && VTables[I].DefinitionRequired) + Pos->second = true; + continue; + } + + VTablesUsed[VTables[I].Record] = VTables[I].DefinitionRequired; + NewUses.push_back(VTableUse(VTables[I].Record, VTables[I].Location)); + } + + VTableUses.insert(VTableUses.begin(), NewUses.begin(), NewUses.end()); + } + + void Sema::MarkVTableUsed(SourceLocation Loc, CXXRecordDecl *Class, + bool DefinitionRequired) { + // Ignore any vtable uses in unevaluated operands or for classes that do + // not have a vtable. + if (!Class->isDynamicClass() || Class->isDependentContext() || + CurContext->isDependentContext() || isUnevaluatedContext()) + return; + // Do not mark as used if compiling for the device outside of the target + // region. + if (TUKind != TU_Prefix && LangOpts.OpenMP && LangOpts.OpenMPIsDevice && + !isInOpenMPDeclareTargetContext() && + !isInOpenMPTargetExecutionDirective()) { + if (!DefinitionRequired) + MarkVirtualMembersReferenced(Loc, Class); + return; + } + + // Try to insert this class into the map. + LoadExternalVTableUses(); + Class = Class->getCanonicalDecl(); + std::pair::iterator, bool> + Pos = VTablesUsed.insert(std::make_pair(Class, DefinitionRequired)); + if (!Pos.second) { + // If we already had an entry, check to see if we are promoting this vtable + // to require a definition. If so, we need to reappend to the VTableUses + // list, since we may have already processed the first entry. + if (DefinitionRequired && !Pos.first->second) { + Pos.first->second = true; + } else { + // Otherwise, we can early exit. + return; + } + } else { + // The Microsoft ABI requires that we perform the destructor body + // checks (i.e. operator delete() lookup) when the vtable is marked used, as + // the deleting destructor is emitted with the vtable, not with the + // destructor definition as in the Itanium ABI. + if (Context.getTargetInfo().getCXXABI().isMicrosoft()) { + CXXDestructorDecl *DD = Class->getDestructor(); + if (DD && DD->isVirtual() && !DD->isDeleted()) { + if (Class->hasUserDeclaredDestructor() && !DD->isDefined()) { + // If this is an out-of-line declaration, marking it referenced will + // not do anything. Manually call CheckDestructor to look up operator + // delete(). + ContextRAII SavedContext(*this, DD); + CheckDestructor(DD); + } else { + MarkFunctionReferenced(Loc, Class->getDestructor()); + } + } + } + } + + // Local classes need to have their virtual members marked + // immediately. For all other classes, we mark their virtual members + // at the end of the translation unit. + if (Class->isLocalClass()) + MarkVirtualMembersReferenced(Loc, Class->getDefinition()); + else + VTableUses.push_back(std::make_pair(Class, Loc)); + } + + bool Sema::DefineUsedVTables() { + LoadExternalVTableUses(); + if (VTableUses.empty()) + return false; + + // Note: The VTableUses vector could grow as a result of marking + // the members of a class as "used", so we check the size each + // time through the loop and prefer indices (which are stable) to + // iterators (which are not). + bool DefinedAnything = false; + for (unsigned I = 0; I != VTableUses.size(); ++I) { + CXXRecordDecl *Class = VTableUses[I].first->getDefinition(); + if (!Class) + continue; + TemplateSpecializationKind ClassTSK = + Class->getTemplateSpecializationKind(); + + SourceLocation Loc = VTableUses[I].second; + + bool DefineVTable = true; + + // If this class has a key function, but that key function is + // defined in another translation unit, we don't need to emit the + // vtable even though we're using it. + const CXXMethodDecl *KeyFunction = Context.getCurrentKeyFunction(Class); + if (KeyFunction && !KeyFunction->hasBody()) { + // The key function is in another translation unit. + DefineVTable = false; + TemplateSpecializationKind TSK = + KeyFunction->getTemplateSpecializationKind(); + assert(TSK != TSK_ExplicitInstantiationDefinition && + TSK != TSK_ImplicitInstantiation && + "Instantiations don't have key functions"); + (void)TSK; + } else if (!KeyFunction) { + // If we have a class with no key function that is the subject + // of an explicit instantiation declaration, suppress the + // vtable; it will live with the explicit instantiation + // definition. + bool IsExplicitInstantiationDeclaration = + ClassTSK == TSK_ExplicitInstantiationDeclaration; + for (auto *R : Class->redecls()) { + TemplateSpecializationKind TSK + = cast(R)->getTemplateSpecializationKind(); + if (TSK == TSK_ExplicitInstantiationDeclaration) + IsExplicitInstantiationDeclaration = true; + else if (TSK == TSK_ExplicitInstantiationDefinition) { + IsExplicitInstantiationDeclaration = false; + break; + } + } + + if (IsExplicitInstantiationDeclaration) + DefineVTable = false; + } + + // The exception specifications for all virtual members may be needed even + // if we are not providing an authoritative form of the vtable in this TU. + // We may choose to emit it available_externally anyway. + if (!DefineVTable) { + MarkVirtualMemberExceptionSpecsNeeded(Loc, Class); + continue; + } + + // Mark all of the virtual members of this class as referenced, so + // that we can build a vtable. Then, tell the AST consumer that a + // vtable for this class is required. + DefinedAnything = true; + MarkVirtualMembersReferenced(Loc, Class); + CXXRecordDecl *Canonical = Class->getCanonicalDecl(); + if (VTablesUsed[Canonical]) + Consumer.HandleVTable(Class); + + // Warn if we're emitting a weak vtable. The vtable will be weak if there is + // no key function or the key function is inlined. Don't warn in C++ ABIs + // that lack key functions, since the user won't be able to make one. + if (Context.getTargetInfo().getCXXABI().hasKeyFunctions() && + Class->isExternallyVisible() && ClassTSK != TSK_ImplicitInstantiation && + ClassTSK != TSK_ExplicitInstantiationDefinition) { + const FunctionDecl *KeyFunctionDef = nullptr; + if (!KeyFunction || (KeyFunction->hasBody(KeyFunctionDef) && + KeyFunctionDef->isInlined())) + Diag(Class->getLocation(), diag::warn_weak_vtable) << Class; + } + } + VTableUses.clear(); + + return DefinedAnything; + } + + void Sema::MarkVirtualMemberExceptionSpecsNeeded(SourceLocation Loc, + const CXXRecordDecl *RD) { + for (const auto *I : RD->methods()) + if (I->isVirtual() && !I->isPure()) + ResolveExceptionSpec(Loc, I->getType()->castAs()); + } + + void Sema::MarkVirtualMembersReferenced(SourceLocation Loc, + const CXXRecordDecl *RD, + bool ConstexprOnly) { + // Mark all functions which will appear in RD's vtable as used. + CXXFinalOverriderMap FinalOverriders; + RD->getFinalOverriders(FinalOverriders); + for (CXXFinalOverriderMap::const_iterator I = FinalOverriders.begin(), + E = FinalOverriders.end(); + I != E; ++I) { + for (OverridingMethods::const_iterator OI = I->second.begin(), + OE = I->second.end(); + OI != OE; ++OI) { + assert(OI->second.size() > 0 && "no final overrider"); + CXXMethodDecl *Overrider = OI->second.front().Method; + + // C++ [basic.def.odr]p2: + // [...] A virtual member function is used if it is not pure. [...] + if (!Overrider->isPure() && (!ConstexprOnly || Overrider->isConstexpr())) + MarkFunctionReferenced(Loc, Overrider); + } + } + + // Only classes that have virtual bases need a VTT. + if (RD->getNumVBases() == 0) + return; + + for (const auto &I : RD->bases()) { + const auto *Base = + cast(I.getType()->castAs()->getDecl()); + if (Base->getNumVBases() == 0) + continue; + MarkVirtualMembersReferenced(Loc, Base); + } + } + + /// SetIvarInitializers - This routine builds initialization ASTs for the + /// Objective-C implementation whose ivars need be initialized. + void Sema::SetIvarInitializers(ObjCImplementationDecl *ObjCImplementation) { + if (!getLangOpts().CPlusPlus) + return; + if (ObjCInterfaceDecl *OID = ObjCImplementation->getClassInterface()) { + SmallVector ivars; + CollectIvarsToConstructOrDestruct(OID, ivars); + if (ivars.empty()) + return; + SmallVector AllToInit; + for (unsigned i = 0; i < ivars.size(); i++) { + FieldDecl *Field = ivars[i]; + if (Field->isInvalidDecl()) + continue; + + CXXCtorInitializer *Member; + InitializedEntity InitEntity = InitializedEntity::InitializeMember(Field); + InitializationKind InitKind = + InitializationKind::CreateDefault(ObjCImplementation->getLocation()); + + InitializationSequence InitSeq(*this, InitEntity, InitKind, std::nullopt); + ExprResult MemberInit = + InitSeq.Perform(*this, InitEntity, InitKind, std::nullopt); + MemberInit = MaybeCreateExprWithCleanups(MemberInit); + // Note, MemberInit could actually come back empty if no initialization + // is required (e.g., because it would call a trivial default constructor) + if (!MemberInit.get() || MemberInit.isInvalid()) + continue; + + Member = + new (Context) CXXCtorInitializer(Context, Field, SourceLocation(), + SourceLocation(), + MemberInit.getAs(), + SourceLocation()); + AllToInit.push_back(Member); + + // Be sure that the destructor is accessible and is marked as referenced. + if (const RecordType *RecordTy = + Context.getBaseElementType(Field->getType()) + ->getAs()) { + CXXRecordDecl *RD = cast(RecordTy->getDecl()); + if (CXXDestructorDecl *Destructor = LookupDestructor(RD)) { + MarkFunctionReferenced(Field->getLocation(), Destructor); + CheckDestructorAccess(Field->getLocation(), Destructor, + PDiag(diag::err_access_dtor_ivar) + << Context.getBaseElementType(Field->getType())); + } + } + } + ObjCImplementation->setIvarInitializers(Context, + AllToInit.data(), AllToInit.size()); + } + } + + static + void DelegatingCycleHelper(CXXConstructorDecl* Ctor, + llvm::SmallPtrSet &Valid, + llvm::SmallPtrSet &Invalid, + llvm::SmallPtrSet &Current, + Sema &S) { + if (Ctor->isInvalidDecl()) + return; + + CXXConstructorDecl *Target = Ctor->getTargetConstructor(); + + // Target may not be determinable yet, for instance if this is a dependent + // call in an uninstantiated template. + if (Target) { + const FunctionDecl *FNTarget = nullptr; + (void)Target->hasBody(FNTarget); + Target = const_cast( + cast_or_null(FNTarget)); + } + + CXXConstructorDecl *Canonical = Ctor->getCanonicalDecl(), + // Avoid dereferencing a null pointer here. + *TCanonical = Target? Target->getCanonicalDecl() : nullptr; + + if (!Current.insert(Canonical).second) + return; + + // We know that beyond here, we aren't chaining into a cycle. + if (!Target || !Target->isDelegatingConstructor() || + Target->isInvalidDecl() || Valid.count(TCanonical)) { + Valid.insert(Current.begin(), Current.end()); + Current.clear(); + // We've hit a cycle. + } else if (TCanonical == Canonical || Invalid.count(TCanonical) || + Current.count(TCanonical)) { + // If we haven't diagnosed this cycle yet, do so now. + if (!Invalid.count(TCanonical)) { + S.Diag((*Ctor->init_begin())->getSourceLocation(), + diag::warn_delegating_ctor_cycle) + << Ctor; + + // Don't add a note for a function delegating directly to itself. + if (TCanonical != Canonical) + S.Diag(Target->getLocation(), diag::note_it_delegates_to); + + CXXConstructorDecl *C = Target; + while (C->getCanonicalDecl() != Canonical) { + const FunctionDecl *FNTarget = nullptr; + (void)C->getTargetConstructor()->hasBody(FNTarget); + assert(FNTarget && "Ctor cycle through bodiless function"); + + C = const_cast( + cast(FNTarget)); + S.Diag(C->getLocation(), diag::note_which_delegates_to); + } + } + + Invalid.insert(Current.begin(), Current.end()); + Current.clear(); + } else { + DelegatingCycleHelper(Target, Valid, Invalid, Current, S); + } + } + + + void Sema::CheckDelegatingCtorCycles() { + llvm::SmallPtrSet Valid, Invalid, Current; + + for (DelegatingCtorDeclsType::iterator + I = DelegatingCtorDecls.begin(ExternalSource.get()), + E = DelegatingCtorDecls.end(); + I != E; ++I) + DelegatingCycleHelper(*I, Valid, Invalid, Current, *this); + + for (auto CI = Invalid.begin(), CE = Invalid.end(); CI != CE; ++CI) + (*CI)->setInvalidDecl(); + } + + namespace { + /// AST visitor that finds references to the 'this' expression. + class FindCXXThisExpr : public RecursiveASTVisitor { + Sema &S; + + public: + explicit FindCXXThisExpr(Sema &S) : S(S) { } + + bool VisitCXXThisExpr(CXXThisExpr *E) { + S.Diag(E->getLocation(), diag::err_this_static_member_func) + << E->isImplicit(); + return false; + } + }; + } + + bool Sema::checkThisInStaticMemberFunctionType(CXXMethodDecl *Method) { + TypeSourceInfo *TSInfo = Method->getTypeSourceInfo(); + if (!TSInfo) + return false; + + TypeLoc TL = TSInfo->getTypeLoc(); + FunctionProtoTypeLoc ProtoTL = TL.getAs(); + if (!ProtoTL) + return false; + + // C++11 [expr.prim.general]p3: + // [The expression this] shall not appear before the optional + // cv-qualifier-seq and it shall not appear within the declaration of a + // static member function (although its type and value category are defined + // within a static member function as they are within a non-static member + // function). [ Note: this is because declaration matching does not occur + // until the complete declarator is known. - end note ] + const FunctionProtoType *Proto = ProtoTL.getTypePtr(); + FindCXXThisExpr Finder(*this); + + // If the return type came after the cv-qualifier-seq, check it now. + if (Proto->hasTrailingReturn() && + !Finder.TraverseTypeLoc(ProtoTL.getReturnLoc())) + return true; + + // Check the exception specification. + if (checkThisInStaticMemberFunctionExceptionSpec(Method)) + return true; + + // Check the trailing requires clause + if (Expr *E = Method->getTrailingRequiresClause()) + if (!Finder.TraverseStmt(E)) + return true; + + return checkThisInStaticMemberFunctionAttributes(Method); + } + + bool Sema::checkThisInStaticMemberFunctionExceptionSpec(CXXMethodDecl *Method) { + TypeSourceInfo *TSInfo = Method->getTypeSourceInfo(); + if (!TSInfo) + return false; + + TypeLoc TL = TSInfo->getTypeLoc(); + FunctionProtoTypeLoc ProtoTL = TL.getAs(); + if (!ProtoTL) + return false; + + const FunctionProtoType *Proto = ProtoTL.getTypePtr(); + FindCXXThisExpr Finder(*this); + + switch (Proto->getExceptionSpecType()) { + case EST_Unparsed: + case EST_Uninstantiated: + case EST_Unevaluated: + case EST_BasicNoexcept: + case EST_NoThrow: + case EST_DynamicNone: + case EST_MSAny: + case EST_None: + break; + + case EST_DependentNoexcept: + case EST_NoexceptFalse: + case EST_NoexceptTrue: + if (!Finder.TraverseStmt(Proto->getNoexceptExpr())) + return true; + [[fallthrough]]; + + case EST_Dynamic: + for (const auto &E : Proto->exceptions()) { + if (!Finder.TraverseType(E)) + return true; + } + break; + } + + return false; + } + + bool Sema::checkThisInStaticMemberFunctionAttributes(CXXMethodDecl *Method) { + FindCXXThisExpr Finder(*this); + + // Check attributes. + for (const auto *A : Method->attrs()) { + // FIXME: This should be emitted by tblgen. + Expr *Arg = nullptr; + ArrayRef Args; + if (const auto *G = dyn_cast(A)) + Arg = G->getArg(); + else if (const auto *G = dyn_cast(A)) + Arg = G->getArg(); + else if (const auto *AA = dyn_cast(A)) + Args = llvm::ArrayRef(AA->args_begin(), AA->args_size()); + else if (const auto *AB = dyn_cast(A)) + Args = llvm::ArrayRef(AB->args_begin(), AB->args_size()); + else if (const auto *ETLF = dyn_cast(A)) { + Arg = ETLF->getSuccessValue(); + Args = llvm::ArrayRef(ETLF->args_begin(), ETLF->args_size()); + } else if (const auto *STLF = dyn_cast(A)) { + Arg = STLF->getSuccessValue(); + Args = llvm::ArrayRef(STLF->args_begin(), STLF->args_size()); + } else if (const auto *LR = dyn_cast(A)) + Arg = LR->getArg(); + else if (const auto *LE = dyn_cast(A)) + Args = llvm::ArrayRef(LE->args_begin(), LE->args_size()); + else if (const auto *RC = dyn_cast(A)) + Args = llvm::ArrayRef(RC->args_begin(), RC->args_size()); + else if (const auto *AC = dyn_cast(A)) + Args = llvm::ArrayRef(AC->args_begin(), AC->args_size()); + else if (const auto *AC = dyn_cast(A)) + Args = llvm::ArrayRef(AC->args_begin(), AC->args_size()); + else if (const auto *RC = dyn_cast(A)) + Args = llvm::ArrayRef(RC->args_begin(), RC->args_size()); + + if (Arg && !Finder.TraverseStmt(Arg)) + return true; + + for (unsigned I = 0, N = Args.size(); I != N; ++I) { + if (!Finder.TraverseStmt(Args[I])) + return true; + } + } + + return false; + } + + void Sema::checkExceptionSpecification( + bool IsTopLevel, ExceptionSpecificationType EST, + ArrayRef DynamicExceptions, + ArrayRef DynamicExceptionRanges, Expr *NoexceptExpr, + SmallVectorImpl &Exceptions, + FunctionProtoType::ExceptionSpecInfo &ESI) { + Exceptions.clear(); + ESI.Type = EST; + if (EST == EST_Dynamic) { + Exceptions.reserve(DynamicExceptions.size()); + for (unsigned ei = 0, ee = DynamicExceptions.size(); ei != ee; ++ei) { + // FIXME: Preserve type source info. + QualType ET = GetTypeFromParser(DynamicExceptions[ei]); + + if (IsTopLevel) { + SmallVector Unexpanded; + collectUnexpandedParameterPacks(ET, Unexpanded); + if (!Unexpanded.empty()) { + DiagnoseUnexpandedParameterPacks( + DynamicExceptionRanges[ei].getBegin(), UPPC_ExceptionType, + Unexpanded); + continue; + } + } + + // Check that the type is valid for an exception spec, and + // drop it if not. + if (!CheckSpecifiedExceptionType(ET, DynamicExceptionRanges[ei])) + Exceptions.push_back(ET); + } + ESI.Exceptions = Exceptions; + return; + } + + if (isComputedNoexcept(EST)) { + assert((NoexceptExpr->isTypeDependent() || + NoexceptExpr->getType()->getCanonicalTypeUnqualified() == + Context.BoolTy) && + "Parser should have made sure that the expression is boolean"); + if (IsTopLevel && DiagnoseUnexpandedParameterPack(NoexceptExpr)) { + ESI.Type = EST_BasicNoexcept; + return; + } + + ESI.NoexceptExpr = NoexceptExpr; + return; + } + } + + void Sema::actOnDelayedExceptionSpecification(Decl *MethodD, + ExceptionSpecificationType EST, + SourceRange SpecificationRange, + ArrayRef DynamicExceptions, + ArrayRef DynamicExceptionRanges, + Expr *NoexceptExpr) { + if (!MethodD) + return; + + // Dig out the method we're referring to. + if (FunctionTemplateDecl *FunTmpl = dyn_cast(MethodD)) + MethodD = FunTmpl->getTemplatedDecl(); + + CXXMethodDecl *Method = dyn_cast(MethodD); + if (!Method) + return; + + // Check the exception specification. + llvm::SmallVector Exceptions; + FunctionProtoType::ExceptionSpecInfo ESI; + checkExceptionSpecification(/*IsTopLevel*/true, EST, DynamicExceptions, + DynamicExceptionRanges, NoexceptExpr, Exceptions, + ESI); + + // Update the exception specification on the function type. + Context.adjustExceptionSpec(Method, ESI, /*AsWritten*/true); + + if (Method->isStatic()) + checkThisInStaticMemberFunctionExceptionSpec(Method); + + if (Method->isVirtual()) { + // Check overrides, which we previously had to delay. + for (const CXXMethodDecl *O : Method->overridden_methods()) + CheckOverridingFunctionExceptionSpec(Method, O); + } + } + + /// HandleMSProperty - Analyze a __delcspec(property) field of a C++ class. + /// + MSPropertyDecl *Sema::HandleMSProperty(Scope *S, RecordDecl *Record, + SourceLocation DeclStart, Declarator &D, + Expr *BitWidth, + InClassInitStyle InitStyle, + AccessSpecifier AS, + const ParsedAttr &MSPropertyAttr) { + IdentifierInfo *II = D.getIdentifier(); + if (!II) { + Diag(DeclStart, diag::err_anonymous_property); + return nullptr; + } + SourceLocation Loc = D.getIdentifierLoc(); + + TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S); + QualType T = TInfo->getType(); + if (getLangOpts().CPlusPlus) { + CheckExtraCXXDefaultArguments(D); + + if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo, + UPPC_DataMemberType)) { + D.setInvalidType(); + T = Context.IntTy; + TInfo = Context.getTrivialTypeSourceInfo(T, Loc); + } + } + + DiagnoseFunctionSpecifiers(D.getDeclSpec()); + + if (D.getDeclSpec().isInlineSpecified()) + Diag(D.getDeclSpec().getInlineSpecLoc(), diag::err_inline_non_function) + << getLangOpts().CPlusPlus17; + if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec()) + Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(), + diag::err_invalid_thread) + << DeclSpec::getSpecifierName(TSCS); + + // Check to see if this name was declared as a member previously + NamedDecl *PrevDecl = nullptr; + LookupResult Previous(*this, II, Loc, LookupMemberName, + ForVisibleRedeclaration); + LookupName(Previous, S); + switch (Previous.getResultKind()) { + case LookupResult::Found: + case LookupResult::FoundUnresolvedValue: + PrevDecl = Previous.getAsSingle(); + break; + + case LookupResult::FoundOverloaded: + PrevDecl = Previous.getRepresentativeDecl(); + break; + + case LookupResult::NotFound: + case LookupResult::NotFoundInCurrentInstantiation: + case LookupResult::Ambiguous: + break; + } + + if (PrevDecl && PrevDecl->isTemplateParameter()) { + // Maybe we will complain about the shadowed template parameter. + DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); + // Just pretend that we didn't see the previous declaration. + PrevDecl = nullptr; + } + + if (PrevDecl && !isDeclInScope(PrevDecl, Record, S)) + PrevDecl = nullptr; + + SourceLocation TSSL = D.getBeginLoc(); + MSPropertyDecl *NewPD = + MSPropertyDecl::Create(Context, Record, Loc, II, T, TInfo, TSSL, + MSPropertyAttr.getPropertyDataGetter(), + MSPropertyAttr.getPropertyDataSetter()); + ProcessDeclAttributes(TUScope, NewPD, D); + NewPD->setAccess(AS); + + if (NewPD->isInvalidDecl()) + Record->setInvalidDecl(); + + if (D.getDeclSpec().isModulePrivateSpecified()) + NewPD->setModulePrivate(); + + if (NewPD->isInvalidDecl() && PrevDecl) { + // Don't introduce NewFD into scope; there's already something + // with the same name in the same scope. + } else if (II) { + PushOnScopeChains(NewPD, S); + } else + Record->addDecl(NewPD); + + return NewPD; + } + + void Sema::ActOnStartFunctionDeclarationDeclarator( + Declarator &Declarator, unsigned TemplateParameterDepth) { + auto &Info = InventedParameterInfos.emplace_back(); + TemplateParameterList *ExplicitParams = nullptr; + ArrayRef ExplicitLists = + Declarator.getTemplateParameterLists(); + if (!ExplicitLists.empty()) { + bool IsMemberSpecialization, IsInvalid; + ExplicitParams = MatchTemplateParametersToScopeSpecifier( + Declarator.getBeginLoc(), Declarator.getIdentifierLoc(), + Declarator.getCXXScopeSpec(), /*TemplateId=*/nullptr, + ExplicitLists, /*IsFriend=*/false, IsMemberSpecialization, IsInvalid, + /*SuppressDiagnostic=*/true); + } + if (ExplicitParams) { + Info.AutoTemplateParameterDepth = ExplicitParams->getDepth(); + llvm::append_range(Info.TemplateParams, *ExplicitParams); + Info.NumExplicitTemplateParams = ExplicitParams->size(); + } else { + Info.AutoTemplateParameterDepth = TemplateParameterDepth; + Info.NumExplicitTemplateParams = 0; + } + } + + void Sema::ActOnFinishFunctionDeclarationDeclarator(Declarator &Declarator) { + auto &FSI = InventedParameterInfos.back(); + if (FSI.TemplateParams.size() > FSI.NumExplicitTemplateParams) { + if (FSI.NumExplicitTemplateParams != 0) { + TemplateParameterList *ExplicitParams = + Declarator.getTemplateParameterLists().back(); + Declarator.setInventedTemplateParameterList( + TemplateParameterList::Create( + Context, ExplicitParams->getTemplateLoc(), + ExplicitParams->getLAngleLoc(), FSI.TemplateParams, + ExplicitParams->getRAngleLoc(), + ExplicitParams->getRequiresClause())); + } else { + Declarator.setInventedTemplateParameterList( + TemplateParameterList::Create( + Context, SourceLocation(), SourceLocation(), FSI.TemplateParams, + SourceLocation(), /*RequiresClause=*/nullptr)); + } + } + InventedParameterInfos.pop_back(); + } +diff --git a/flang/lib/Semantics/check-call.cpp b/flang/lib/Semantics/check-call.cpp +index fc07b8d26ace..00766715ef53 100644 +--- a/flang/lib/Semantics/check-call.cpp ++++ b/flang/lib/Semantics/check-call.cpp +@@ -1,1350 +1,1351 @@ + //===-- lib/Semantics/check-call.cpp --------------------------------------===// + // + // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. + // See https://llvm.org/LICENSE.txt for license information. + // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception + // + //===----------------------------------------------------------------------===// + + #include "check-call.h" + #include "definable.h" + #include "pointer-assignment.h" + #include "flang/Evaluate/characteristics.h" + #include "flang/Evaluate/check-expression.h" + #include "flang/Evaluate/shape.h" + #include "flang/Evaluate/tools.h" + #include "flang/Parser/characters.h" + #include "flang/Parser/message.h" + #include "flang/Semantics/scope.h" + #include "flang/Semantics/tools.h" + #include + #include + + using namespace Fortran::parser::literals; + namespace characteristics = Fortran::evaluate::characteristics; + + namespace Fortran::semantics { + + static void CheckImplicitInterfaceArg(evaluate::ActualArgument &arg, + parser::ContextualMessages &messages, evaluate::FoldingContext &context) { + auto restorer{ + messages.SetLocation(arg.sourceLocation().value_or(messages.at()))}; + if (auto kw{arg.keyword()}) { + messages.Say(*kw, + "Keyword '%s=' may not appear in a reference to a procedure with an implicit interface"_err_en_US, + *kw); + } + if (auto type{arg.GetType()}) { + if (type->IsAssumedType()) { + messages.Say( + "Assumed type argument requires an explicit interface"_err_en_US); + } else if (type->IsPolymorphic()) { + messages.Say( + "Polymorphic argument requires an explicit interface"_err_en_US); + } else if (const DerivedTypeSpec * derived{GetDerivedTypeSpec(type)}) { + if (!derived->parameters().empty()) { + messages.Say( + "Parameterized derived type argument requires an explicit interface"_err_en_US); + } + } + } + if (const auto *expr{arg.UnwrapExpr()}) { + if (IsBOZLiteral(*expr)) { + messages.Say("BOZ argument requires an explicit interface"_err_en_US); + } else if (evaluate::IsNullPointer(*expr)) { + messages.Say( + "Null pointer argument requires an explicit interface"_err_en_US); + } else if (auto named{evaluate::ExtractNamedEntity(*expr)}) { + const Symbol &symbol{named->GetLastSymbol()}; + if (symbol.Corank() > 0) { + messages.Say( + "Coarray argument requires an explicit interface"_err_en_US); + } + if (const auto *details{symbol.detailsIf()}) { + if (details->IsAssumedRank()) { + messages.Say( + "Assumed rank argument requires an explicit interface"_err_en_US); + } + } + if (symbol.attrs().test(Attr::ASYNCHRONOUS)) { + messages.Say( + "ASYNCHRONOUS argument requires an explicit interface"_err_en_US); + } + if (symbol.attrs().test(Attr::VOLATILE)) { + messages.Say( + "VOLATILE argument requires an explicit interface"_err_en_US); + } + } else if (auto argChars{characteristics::DummyArgument::FromActual( + "actual argument", *expr, context)}) { + const auto *argProcDesignator{ + std::get_if(&expr->u)}; + if (const auto *argProcSymbol{ + argProcDesignator ? argProcDesignator->GetSymbol() : nullptr}) { + if (!argChars->IsTypelessIntrinsicDummy() && argProcDesignator && + argProcDesignator->IsElemental()) { // C1533 + evaluate::SayWithDeclaration(messages, *argProcSymbol, + "Non-intrinsic ELEMENTAL procedure '%s' may not be passed as an actual argument"_err_en_US, + argProcSymbol->name()); + } else if (const auto *subp{argProcSymbol->GetUltimate() + .detailsIf()}) { + if (subp->stmtFunction()) { + evaluate::SayWithDeclaration(messages, *argProcSymbol, + "Statement function '%s' may not be passed as an actual argument"_err_en_US, + argProcSymbol->name()); + } + } + } + } + } + } + + // When a CHARACTER actual argument is known to be short, + // we extend it on the right with spaces and a warning if + // possible. When it is long, and not required to be equal, + // the usage conforms to the standard and no warning is needed. + static void CheckCharacterActual(evaluate::Expr &actual, + const characteristics::DummyDataObject &dummy, + characteristics::TypeAndShape &actualType, SemanticsContext &context, + parser::ContextualMessages &messages) { + if (dummy.type.type().category() == TypeCategory::Character && + actualType.type().category() == TypeCategory::Character && + dummy.type.type().kind() == actualType.type().kind()) { + if (dummy.type.LEN() && actualType.LEN()) { + evaluate::FoldingContext &foldingContext{context.foldingContext()}; + auto dummyLength{ + ToInt64(Fold(foldingContext, common::Clone(*dummy.type.LEN())))}; + auto actualLength{ + ToInt64(Fold(foldingContext, common::Clone(*actualType.LEN())))}; + if (dummyLength && actualLength && *actualLength != *dummyLength) { + if (dummy.attrs.test( + characteristics::DummyDataObject::Attr::Allocatable) || + dummy.attrs.test(characteristics::DummyDataObject::Attr::Pointer) || + dummy.type.attrs().test( + characteristics::TypeAndShape::Attr::AssumedRank) || + dummy.type.attrs().test( + characteristics::TypeAndShape::Attr::AssumedShape)) { + // See 15.5.2.4 paragraph 4., 15.5.2.5. + messages.Say( + "Actual argument variable length '%jd' does not match the expected length '%jd'"_err_en_US, + *actualLength, *dummyLength); + } else if (*actualLength < *dummyLength) { + bool isVariable{evaluate::IsVariable(actual)}; + if (context.ShouldWarn(common::UsageWarning::ShortCharacterActual)) { + if (isVariable) { + messages.Say( + "Actual argument variable length '%jd' is less than expected length '%jd'"_warn_en_US, + *actualLength, *dummyLength); + } else { + messages.Say( + "Actual argument expression length '%jd' is less than expected length '%jd'"_warn_en_US, + *actualLength, *dummyLength); + } + } + if (!isVariable) { + auto converted{ConvertToType(dummy.type.type(), std::move(actual))}; + CHECK(converted); + actual = std::move(*converted); + actualType.set_LEN(SubscriptIntExpr{*dummyLength}); + } + } + } + } + } + } + + // Automatic conversion of different-kind INTEGER scalar actual + // argument expressions (not variables) to INTEGER scalar dummies. + // We return nonstandard INTEGER(8) results from intrinsic functions + // like SIZE() by default in order to facilitate the use of large + // arrays. Emit a warning when downconverting. + static void ConvertIntegerActual(evaluate::Expr &actual, + const characteristics::TypeAndShape &dummyType, + characteristics::TypeAndShape &actualType, + parser::ContextualMessages &messages) { + if (dummyType.type().category() == TypeCategory::Integer && + actualType.type().category() == TypeCategory::Integer && + dummyType.type().kind() != actualType.type().kind() && + GetRank(dummyType.shape()) == 0 && GetRank(actualType.shape()) == 0 && + !evaluate::IsVariable(actual)) { + auto converted{ + evaluate::ConvertToType(dummyType.type(), std::move(actual))}; + CHECK(converted); + actual = std::move(*converted); + if (dummyType.type().kind() < actualType.type().kind()) { + messages.Say( + "Actual argument scalar expression of type INTEGER(%d) was converted to smaller dummy argument type INTEGER(%d)"_port_en_US, + actualType.type().kind(), dummyType.type().kind()); + } + actualType = dummyType; + } + } + + static bool DefersSameTypeParameters( + const DerivedTypeSpec &actual, const DerivedTypeSpec &dummy) { + for (const auto &pair : actual.parameters()) { + const ParamValue &actualValue{pair.second}; + const ParamValue *dummyValue{dummy.FindParameter(pair.first)}; + if (!dummyValue || (actualValue.isDeferred() != dummyValue->isDeferred())) { + return false; + } + } + return true; + } + + static void CheckExplicitDataArg(const characteristics::DummyDataObject &dummy, + const std::string &dummyName, evaluate::Expr &actual, + characteristics::TypeAndShape &actualType, bool isElemental, + SemanticsContext &context, evaluate::FoldingContext &foldingContext, + const Scope *scope, const evaluate::SpecificIntrinsic *intrinsic, + bool allowActualArgumentConversions) { + + // Basic type & rank checking + parser::ContextualMessages &messages{foldingContext.messages()}; + CheckCharacterActual(actual, dummy, actualType, context, messages); + bool dummyIsAllocatable{ + dummy.attrs.test(characteristics::DummyDataObject::Attr::Allocatable)}; + bool dummyIsPointer{ + dummy.attrs.test(characteristics::DummyDataObject::Attr::Pointer)}; + bool dummyIsAllocatableOrPointer{dummyIsAllocatable || dummyIsPointer}; + allowActualArgumentConversions &= !dummyIsAllocatableOrPointer; +- if (allowActualArgumentConversions) { +- ConvertIntegerActual(actual, dummy.type, actualType, messages); +- } + bool typesCompatible{ + (dummy.ignoreTKR.test(common::IgnoreTKR::Type) && + (dummy.type.type().category() == TypeCategory::Derived || + actualType.type().category() == TypeCategory::Derived || + dummy.type.type().category() != actualType.type().category())) || + (dummy.ignoreTKR.test(common::IgnoreTKR::Kind) && + dummy.type.type().category() == actualType.type().category()) || + dummy.type.type().IsTkCompatibleWith(actualType.type())}; ++ allowActualArgumentConversions &= !typesCompatible; ++ if (allowActualArgumentConversions) { ++ ConvertIntegerActual(actual, dummy.type, actualType, messages); ++ } + if (!typesCompatible && dummy.type.Rank() == 0 && + allowActualArgumentConversions) { + // Extension: pass Hollerith literal to scalar as if it had been BOZ + if (auto converted{evaluate::HollerithToBOZ( + foldingContext, actual, dummy.type.type())}) { + messages.Say( + "passing Hollerith or character literal as if it were BOZ"_port_en_US); + actual = *converted; + actualType.type() = dummy.type.type(); + typesCompatible = true; + } + } + if (typesCompatible) { + if (isElemental) { + } else if (dummy.type.attrs().test( + characteristics::TypeAndShape::Attr::AssumedRank)) { + } else if (dummy.ignoreTKR.test(common::IgnoreTKR::Rank)) { + } else if (dummy.type.Rank() > 0 && !dummyIsAllocatableOrPointer && + !dummy.type.attrs().test( + characteristics::TypeAndShape::Attr::AssumedShape) && + !dummy.type.attrs().test( + characteristics::TypeAndShape::Attr::DeferredShape) && + (actualType.Rank() > 0 || IsArrayElement(actual))) { + // Sequence association (15.5.2.11) applies -- rank need not match + // if the actual argument is an array or array element designator, + // and the dummy is an array, but not assumed-shape or an INTENT(IN) + // pointer that's standing in for an assumed-shape dummy. + } else { + // Let CheckConformance accept actual scalars; storage association + // cases are checked here below. + CheckConformance(messages, dummy.type.shape(), actualType.shape(), + dummyIsAllocatableOrPointer + ? evaluate::CheckConformanceFlags::None + : evaluate::CheckConformanceFlags::RightScalarExpandable, + "dummy argument", "actual argument"); + } + } else { + const auto &len{actualType.LEN()}; + messages.Say( + "Actual argument type '%s' is not compatible with dummy argument type '%s'"_err_en_US, + actualType.type().AsFortran(len ? len->AsFortran() : ""), + dummy.type.type().AsFortran()); + } + + bool actualIsPolymorphic{actualType.type().IsPolymorphic()}; + bool dummyIsPolymorphic{dummy.type.type().IsPolymorphic()}; + bool actualIsCoindexed{ExtractCoarrayRef(actual).has_value()}; + bool actualIsAssumedSize{actualType.attrs().test( + characteristics::TypeAndShape::Attr::AssumedSize)}; + bool dummyIsAssumedSize{dummy.type.attrs().test( + characteristics::TypeAndShape::Attr::AssumedSize)}; + bool dummyIsAsynchronous{ + dummy.attrs.test(characteristics::DummyDataObject::Attr::Asynchronous)}; + bool dummyIsVolatile{ + dummy.attrs.test(characteristics::DummyDataObject::Attr::Volatile)}; + bool dummyIsValue{ + dummy.attrs.test(characteristics::DummyDataObject::Attr::Value)}; + + if (actualIsPolymorphic && dummyIsPolymorphic && + actualIsCoindexed) { // 15.5.2.4(2) + messages.Say( + "Coindexed polymorphic object may not be associated with a polymorphic %s"_err_en_US, + dummyName); + } + if (actualIsPolymorphic && !dummyIsPolymorphic && + actualIsAssumedSize) { // 15.5.2.4(2) + messages.Say( + "Assumed-size polymorphic array may not be associated with a monomorphic %s"_err_en_US, + dummyName); + } + + // Derived type actual argument checks + const Symbol *actualFirstSymbol{evaluate::GetFirstSymbol(actual)}; + bool actualIsAsynchronous{ + actualFirstSymbol && actualFirstSymbol->attrs().test(Attr::ASYNCHRONOUS)}; + bool actualIsVolatile{ + actualFirstSymbol && actualFirstSymbol->attrs().test(Attr::VOLATILE)}; + if (const auto *derived{evaluate::GetDerivedTypeSpec(actualType.type())}) { + if (dummy.type.type().IsAssumedType()) { + if (!derived->parameters().empty()) { // 15.5.2.4(2) + messages.Say( + "Actual argument associated with TYPE(*) %s may not have a parameterized derived type"_err_en_US, + dummyName); + } + if (const Symbol * + tbp{FindImmediateComponent(*derived, [](const Symbol &symbol) { + return symbol.has(); + })}) { // 15.5.2.4(2) + evaluate::SayWithDeclaration(messages, *tbp, + "Actual argument associated with TYPE(*) %s may not have type-bound procedure '%s'"_err_en_US, + dummyName, tbp->name()); + } + auto finals{FinalsForDerivedTypeInstantiation(*derived)}; + if (!finals.empty()) { // 15.5.2.4(2) + SourceName name{finals.front()->name()}; + if (auto *msg{messages.Say( + "Actual argument associated with TYPE(*) %s may not have derived type '%s' with FINAL subroutine '%s'"_err_en_US, + dummyName, derived->typeSymbol().name(), name)}) { + msg->Attach(name, "FINAL subroutine '%s' in derived type '%s'"_en_US, + name, derived->typeSymbol().name()); + } + } + } + if (actualIsCoindexed) { + if (dummy.intent != common::Intent::In && !dummyIsValue) { + if (auto bad{ + FindAllocatableUltimateComponent(*derived)}) { // 15.5.2.4(6) + evaluate::SayWithDeclaration(messages, *bad, + "Coindexed actual argument with ALLOCATABLE ultimate component '%s' must be associated with a %s with VALUE or INTENT(IN) attributes"_err_en_US, + bad.BuildResultDesignatorName(), dummyName); + } + } + if (auto coarrayRef{evaluate::ExtractCoarrayRef(actual)}) { // C1537 + const Symbol &coarray{coarrayRef->GetLastSymbol()}; + if (const DeclTypeSpec * type{coarray.GetType()}) { + if (const DerivedTypeSpec * derived{type->AsDerived()}) { + if (auto bad{semantics::FindPointerUltimateComponent(*derived)}) { + evaluate::SayWithDeclaration(messages, coarray, + "Coindexed object '%s' with POINTER ultimate component '%s' cannot be associated with %s"_err_en_US, + coarray.name(), bad.BuildResultDesignatorName(), dummyName); + } + } + } + } + } + if (actualIsVolatile != dummyIsVolatile) { // 15.5.2.4(22) + if (auto bad{semantics::FindCoarrayUltimateComponent(*derived)}) { + evaluate::SayWithDeclaration(messages, *bad, + "VOLATILE attribute must match for %s when actual argument has a coarray ultimate component '%s'"_err_en_US, + dummyName, bad.BuildResultDesignatorName()); + } + } + } + + // Rank and shape checks + const auto *actualLastSymbol{evaluate::GetLastSymbol(actual)}; + if (actualLastSymbol) { + actualLastSymbol = &ResolveAssociations(*actualLastSymbol); + } + const ObjectEntityDetails *actualLastObject{actualLastSymbol + ? actualLastSymbol->detailsIf() + : nullptr}; + int actualRank{evaluate::GetRank(actualType.shape())}; + bool actualIsPointer{evaluate::IsObjectPointer(actual, foldingContext)}; + bool dummyIsAssumedRank{dummy.type.attrs().test( + characteristics::TypeAndShape::Attr::AssumedRank)}; + if (dummy.type.attrs().test( + characteristics::TypeAndShape::Attr::AssumedShape)) { + // 15.5.2.4(16) + if (actualRank == 0) { + messages.Say( + "Scalar actual argument may not be associated with assumed-shape %s"_err_en_US, + dummyName); + } + if (actualIsAssumedSize && actualLastSymbol) { + evaluate::SayWithDeclaration(messages, *actualLastSymbol, + "Assumed-size array may not be associated with assumed-shape %s"_err_en_US, + dummyName); + } + } else if (actualRank == 0 && dummy.type.Rank() > 0 && + !dummyIsAllocatableOrPointer) { + // Actual is scalar, dummy is an array. 15.5.2.4(14), 15.5.2.11 + if (actualIsCoindexed) { + messages.Say( + "Coindexed scalar actual argument must be associated with a scalar %s"_err_en_US, + dummyName); + } + bool actualIsArrayElement{IsArrayElement(actual)}; + bool actualIsCKindCharacter{ + actualType.type().category() == TypeCategory::Character && + actualType.type().kind() == 1}; + if (!actualIsCKindCharacter) { + if (!actualIsArrayElement && + !(dummy.type.type().IsAssumedType() && dummyIsAssumedSize) && + !dummyIsAssumedRank && + !dummy.ignoreTKR.test(common::IgnoreTKR::Rank)) { + messages.Say( + "Whole scalar actual argument may not be associated with a %s array"_err_en_US, + dummyName); + } + if (actualIsPolymorphic) { + messages.Say( + "Polymorphic scalar may not be associated with a %s array"_err_en_US, + dummyName); + } + if (actualIsArrayElement && actualLastSymbol && + IsPointer(*actualLastSymbol)) { + messages.Say( + "Element of pointer array may not be associated with a %s array"_err_en_US, + dummyName); + } + if (actualLastSymbol && IsAssumedShape(*actualLastSymbol)) { + messages.Say( + "Element of assumed-shape array may not be associated with a %s array"_err_en_US, + dummyName); + } + } + } + if (actualLastObject && actualLastObject->IsCoarray() && + IsAllocatable(*actualLastSymbol) && dummy.intent == common::Intent::Out && + !(intrinsic && + evaluate::AcceptsIntentOutAllocatableCoarray( + intrinsic->name))) { // C846 + messages.Say( + "ALLOCATABLE coarray '%s' may not be associated with INTENT(OUT) %s"_err_en_US, + actualLastSymbol->name(), dummyName); + } + + // Definability + const char *reason{nullptr}; + if (dummy.intent == common::Intent::Out) { + reason = "INTENT(OUT)"; + } else if (dummy.intent == common::Intent::InOut) { + reason = "INTENT(IN OUT)"; + } + if (reason && scope) { + // Problems with polymorphism are caught in the callee's definition. + DefinabilityFlags flags{DefinabilityFlag::PolymorphicOkInPure}; + if (isElemental || dummyIsValue) { // 15.5.2.4(21) + flags.set(DefinabilityFlag::VectorSubscriptIsOk); + } + if (actualIsPointer && dummyIsPointer) { // 19.6.8 + flags.set(DefinabilityFlag::PointerDefinition); + } + if (auto whyNot{WhyNotDefinable(messages.at(), *scope, flags, actual)}) { + if (auto *msg{messages.Say( + "Actual argument associated with %s %s is not definable"_err_en_US, + reason, dummyName)}) { + msg->Attach(std::move(*whyNot)); + } + } + } + + // technically legal but worth emitting a warning + // llvm-project issue #58973: constant actual argument passed in where dummy + // argument is marked volatile + bool actualIsVariable{evaluate::IsVariable(actual)}; + if (dummyIsVolatile && !actualIsVariable && + context.ShouldWarn(common::UsageWarning::ExprPassedToVolatile)) { + messages.Say( + "actual argument associated with VOLATILE %s is not a variable"_warn_en_US, + dummyName); + } + + // Cases when temporaries might be needed but must not be permitted. + bool actualIsContiguous{IsSimplyContiguous(actual, foldingContext)}; + bool dummyIsAssumedShape{dummy.type.attrs().test( + characteristics::TypeAndShape::Attr::AssumedShape)}; + bool dummyIsContiguous{ + dummy.attrs.test(characteristics::DummyDataObject::Attr::Contiguous)}; + if ((actualIsAsynchronous || actualIsVolatile) && + (dummyIsAsynchronous || dummyIsVolatile) && !dummyIsValue) { + if (actualIsCoindexed) { // C1538 + messages.Say( + "Coindexed ASYNCHRONOUS or VOLATILE actual argument may not be associated with %s with ASYNCHRONOUS or VOLATILE attributes unless VALUE"_err_en_US, + dummyName); + } + if (actualRank > 0 && !actualIsContiguous) { + if (dummyIsContiguous || + !(dummyIsAssumedShape || dummyIsAssumedRank || + (actualIsPointer && dummyIsPointer))) { // C1539 & C1540 + messages.Say( + "ASYNCHRONOUS or VOLATILE actual argument that is not simply contiguous may not be associated with a contiguous %s"_err_en_US, + dummyName); + } + } + } + + // 15.5.2.6 -- dummy is ALLOCATABLE + bool actualIsAllocatable{evaluate::IsAllocatableDesignator(actual)}; + if (dummyIsAllocatable) { + if (!actualIsAllocatable) { + messages.Say( + "ALLOCATABLE %s must be associated with an ALLOCATABLE actual argument"_err_en_US, + dummyName); + } + if (actualIsAllocatable && actualIsCoindexed && + dummy.intent != common::Intent::In) { + messages.Say( + "ALLOCATABLE %s must have INTENT(IN) to be associated with a coindexed actual argument"_err_en_US, + dummyName); + } + if (!actualIsCoindexed && actualLastSymbol && + actualLastSymbol->Corank() != dummy.type.corank()) { + messages.Say( + "ALLOCATABLE %s has corank %d but actual argument has corank %d"_err_en_US, + dummyName, dummy.type.corank(), actualLastSymbol->Corank()); + } + } + + // 15.5.2.7 -- dummy is POINTER + if (dummyIsPointer) { + if (actualIsPointer || dummy.intent == common::Intent::In) { + if (scope) { + semantics::CheckPointerAssignment( + context, messages.at(), dummyName, dummy, actual, *scope); + } + } else if (!actualIsPointer) { + messages.Say( + "Actual argument associated with POINTER %s must also be POINTER unless INTENT(IN)"_err_en_US, + dummyName); + } + } + + // 15.5.2.5 -- actual & dummy are both POINTER or both ALLOCATABLE + if ((actualIsPointer && dummyIsPointer) || + (actualIsAllocatable && dummyIsAllocatable)) { + bool actualIsUnlimited{actualType.type().IsUnlimitedPolymorphic()}; + bool dummyIsUnlimited{dummy.type.type().IsUnlimitedPolymorphic()}; + if (actualIsUnlimited != dummyIsUnlimited) { + if (typesCompatible) { + messages.Say( + "If a POINTER or ALLOCATABLE dummy or actual argument is unlimited polymorphic, both must be so"_err_en_US); + } + } else if (dummyIsPolymorphic != actualIsPolymorphic) { + if (dummy.intent == common::Intent::In && typesCompatible) { + // extension: allow with warning, rule is only relevant for definables + messages.Say( + "If a POINTER or ALLOCATABLE dummy or actual argument is polymorphic, both should be so"_port_en_US); + } else { + messages.Say( + "If a POINTER or ALLOCATABLE dummy or actual argument is polymorphic, both must be so"_err_en_US); + } + } else if (!actualIsUnlimited && typesCompatible) { + if (!actualType.type().IsTkCompatibleWith(dummy.type.type())) { + if (dummy.intent == common::Intent::In) { + // extension: allow with warning, rule is only relevant for definables + messages.Say( + "POINTER or ALLOCATABLE dummy and actual arguments should have the same declared type and kind"_port_en_US); + } else { + messages.Say( + "POINTER or ALLOCATABLE dummy and actual arguments must have the same declared type and kind"_err_en_US); + } + } + // 15.5.2.5(4) + const auto *derived{evaluate::GetDerivedTypeSpec(actualType.type())}; + if ((derived && + !DefersSameTypeParameters(*derived, + *evaluate::GetDerivedTypeSpec(dummy.type.type()))) || + dummy.type.type().HasDeferredTypeParameter() != + actualType.type().HasDeferredTypeParameter()) { + messages.Say( + "Dummy and actual arguments must defer the same type parameters when POINTER or ALLOCATABLE"_err_en_US); + } + } + } + + // 15.5.2.8 -- coarray dummy arguments + if (dummy.type.corank() > 0) { + if (actualType.corank() == 0) { + messages.Say( + "Actual argument associated with coarray %s must be a coarray"_err_en_US, + dummyName); + } + if (dummyIsVolatile) { + if (!actualIsVolatile) { + messages.Say( + "non-VOLATILE coarray may not be associated with VOLATILE coarray %s"_err_en_US, + dummyName); + } + } else { + if (actualIsVolatile) { + messages.Say( + "VOLATILE coarray may not be associated with non-VOLATILE coarray %s"_err_en_US, + dummyName); + } + } + if (actualRank == dummy.type.Rank() && !actualIsContiguous) { + if (dummyIsContiguous) { + messages.Say( + "Actual argument associated with a CONTIGUOUS coarray %s must be simply contiguous"_err_en_US, + dummyName); + } else if (!dummyIsAssumedShape && !dummyIsAssumedRank) { + messages.Say( + "Actual argument associated with coarray %s (not assumed shape or rank) must be simply contiguous"_err_en_US, + dummyName); + } + } + } + + // NULL(MOLD=) checking for non-intrinsic procedures + bool dummyIsOptional{ + dummy.attrs.test(characteristics::DummyDataObject::Attr::Optional)}; + bool actualIsNull{evaluate::IsNullPointer(actual)}; + if (!intrinsic && !dummyIsPointer && !dummyIsOptional && actualIsNull) { + messages.Say( + "Actual argument associated with %s may not be null pointer %s"_err_en_US, + dummyName, actual.AsFortran()); + } + + // Warn about dubious actual argument association with a TARGET dummy argument + if (dummy.attrs.test(characteristics::DummyDataObject::Attr::Target) && + context.ShouldWarn(common::UsageWarning::NonTargetPassedToTarget)) { + bool actualIsTemp{!actualIsVariable || HasVectorSubscript(actual) || + evaluate::ExtractCoarrayRef(actual)}; + if (actualIsTemp) { + messages.Say( + "Any pointer associated with TARGET %s during this call will not be associated with the value of '%s' afterwards"_warn_en_US, + dummyName, actual.AsFortran()); + } else { + auto actualSymbolVector{GetSymbolVector(actual)}; + if (!evaluate::GetLastTarget(actualSymbolVector)) { + messages.Say( + "Any pointer associated with TARGET %s during this call must not be used afterwards, as '%s' is not a target"_warn_en_US, + dummyName, actual.AsFortran()); + } + } + } + } + + static void CheckProcedureArg(evaluate::ActualArgument &arg, + const characteristics::Procedure &proc, + const characteristics::DummyProcedure &dummy, const std::string &dummyName, + SemanticsContext &context) { + evaluate::FoldingContext &foldingContext{context.foldingContext()}; + parser::ContextualMessages &messages{foldingContext.messages()}; + auto restorer{ + messages.SetLocation(arg.sourceLocation().value_or(messages.at()))}; + const characteristics::Procedure &interface { dummy.procedure.value() }; + if (const auto *expr{arg.UnwrapExpr()}) { + bool dummyIsPointer{ + dummy.attrs.test(characteristics::DummyProcedure::Attr::Pointer)}; + const auto *argProcDesignator{ + std::get_if(&expr->u)}; + const auto *argProcSymbol{ + argProcDesignator ? argProcDesignator->GetSymbol() : nullptr}; + if (argProcSymbol) { + if (const auto *subp{ + argProcSymbol->GetUltimate().detailsIf()}) { + if (subp->stmtFunction()) { + evaluate::SayWithDeclaration(messages, *argProcSymbol, + "Statement function '%s' may not be passed as an actual argument"_err_en_US, + argProcSymbol->name()); + return; + } + } else if (argProcSymbol->has()) { + evaluate::SayWithDeclaration(messages, *argProcSymbol, + "Procedure binding '%s' passed as an actual argument"_port_en_US, + argProcSymbol->name()); + } + } + if (auto argChars{characteristics::DummyArgument::FromActual( + "actual argument", *expr, foldingContext)}) { + if (!argChars->IsTypelessIntrinsicDummy()) { + if (auto *argProc{ + std::get_if(&argChars->u)}) { + characteristics::Procedure &argInterface{argProc->procedure.value()}; + argInterface.attrs.reset( + characteristics::Procedure::Attr::NullPointer); + if (!argProcSymbol || argProcSymbol->attrs().test(Attr::INTRINSIC)) { + // It's ok to pass ELEMENTAL unrestricted intrinsic functions. + argInterface.attrs.reset( + characteristics::Procedure::Attr::Elemental); + } else if (argInterface.attrs.test( + characteristics::Procedure::Attr::Elemental)) { + if (argProcSymbol) { // C1533 + evaluate::SayWithDeclaration(messages, *argProcSymbol, + "Non-intrinsic ELEMENTAL procedure '%s' may not be passed as an actual argument"_err_en_US, + argProcSymbol->name()); + return; // avoid piling on with checks below + } else { + argInterface.attrs.reset( + characteristics::Procedure::Attr::NullPointer); + } + } + if (interface.HasExplicitInterface()) { + std::string whyNot; + if (!interface.IsCompatibleWith(argInterface, &whyNot)) { + // 15.5.2.9(1): Explicit interfaces must match + if (argInterface.HasExplicitInterface()) { + messages.Say( + "Actual procedure argument has interface incompatible with %s: %s"_err_en_US, + dummyName, whyNot); + return; + } else if (proc.IsPure()) { + messages.Say( + "Actual procedure argument for %s of a PURE procedure must have an explicit interface"_err_en_US, + dummyName); + } else if (context.ShouldWarn( + common::UsageWarning::ImplicitInterfaceActual)) { + messages.Say( + "Actual procedure argument has an implicit interface which is not known to be compatible with %s which has an explicit interface"_warn_en_US, + dummyName); + } + } + } else { // 15.5.2.9(2,3) + if (interface.IsSubroutine() && argInterface.IsFunction()) { + messages.Say( + "Actual argument associated with procedure %s is a function but must be a subroutine"_err_en_US, + dummyName); + } else if (interface.IsFunction()) { + if (argInterface.IsFunction()) { + std::string whyNot; + if (!interface.functionResult->IsCompatibleWith( + *argInterface.functionResult, &whyNot)) { + messages.Say( + "Actual argument function associated with procedure %s is not compatible: %s"_err_en_US, + dummyName, whyNot); + } + } else if (argInterface.IsSubroutine()) { + messages.Say( + "Actual argument associated with procedure %s is a subroutine but must be a function"_err_en_US, + dummyName); + } + } + } + } else { + messages.Say( + "Actual argument associated with procedure %s is not a procedure"_err_en_US, + dummyName); + } + } else if (IsNullPointer(*expr)) { + if (!dummyIsPointer && + !dummy.attrs.test( + characteristics::DummyProcedure::Attr::Optional)) { + messages.Say( + "Actual argument associated with procedure %s is a null pointer"_err_en_US, + dummyName); + } + } else { + messages.Say( + "Actual argument associated with procedure %s is typeless"_err_en_US, + dummyName); + } + } + if (dummyIsPointer && dummy.intent != common::Intent::In) { + const Symbol *last{GetLastSymbol(*expr)}; + if (last && IsProcedurePointer(*last)) { + if (dummy.intent != common::Intent::Default && + IsIntentIn(last->GetUltimate())) { // 19.6.8 + messages.Say( + "Actual argument associated with procedure pointer %s may not be INTENT(IN)"_err_en_US, + dummyName); + } + } else if (!(dummy.intent == common::Intent::Default && + IsNullProcedurePointer(*expr))) { + // 15.5.2.9(5) -- dummy procedure POINTER + // Interface compatibility has already been checked above + messages.Say( + "Actual argument associated with procedure pointer %s must be a POINTER unless INTENT(IN)"_err_en_US, + dummyName); + } + } + } else { + messages.Say( + "Assumed-type argument may not be forwarded as procedure %s"_err_en_US, + dummyName); + } + } + + // Allow BOZ literal actual arguments when they can be converted to a known + // dummy argument type + static void ConvertBOZLiteralArg( + evaluate::ActualArgument &arg, const evaluate::DynamicType &type) { + if (auto *expr{arg.UnwrapExpr()}) { + if (IsBOZLiteral(*expr)) { + if (auto converted{evaluate::ConvertToType(type, SomeExpr{*expr})}) { + arg = std::move(*converted); + } + } + } + } + + static void CheckExplicitInterfaceArg(evaluate::ActualArgument &arg, + const characteristics::DummyArgument &dummy, + const characteristics::Procedure &proc, SemanticsContext &context, + const Scope *scope, const evaluate::SpecificIntrinsic *intrinsic, + bool allowActualArgumentConversions) { + evaluate::FoldingContext &foldingContext{context.foldingContext()}; + auto &messages{foldingContext.messages()}; + std::string dummyName{"dummy argument"}; + if (!dummy.name.empty()) { + dummyName += " '"s + parser::ToLowerCaseLetters(dummy.name) + "='"; + } + auto restorer{ + messages.SetLocation(arg.sourceLocation().value_or(messages.at()))}; + auto checkActualArgForLabel = [&](evaluate::ActualArgument &arg) { + if (arg.isAlternateReturn()) { + messages.Say( + "Alternate return label '%d' cannot be associated with %s"_err_en_US, + arg.GetLabel(), dummyName); + return true; + } else { + return false; + } + }; + common::visit( + common::visitors{ + [&](const characteristics::DummyDataObject &object) { + if (!checkActualArgForLabel(arg)) { + ConvertBOZLiteralArg(arg, object.type.type()); + if (auto *expr{arg.UnwrapExpr()}) { + if (auto type{characteristics::TypeAndShape::Characterize( + *expr, foldingContext)}) { + arg.set_dummyIntent(object.intent); + bool isElemental{ + object.type.Rank() == 0 && proc.IsElemental()}; + CheckExplicitDataArg(object, dummyName, *expr, *type, + isElemental, context, foldingContext, scope, intrinsic, + allowActualArgumentConversions); + } else if (object.type.type().IsTypelessIntrinsicArgument() && + IsBOZLiteral(*expr)) { + // ok + } else if (object.type.type().IsTypelessIntrinsicArgument() && + evaluate::IsNullObjectPointer(*expr)) { + // ok, ASSOCIATED(NULL()) + } else if ((object.attrs.test(characteristics::DummyDataObject:: + Attr::Pointer) || + object.attrs.test(characteristics:: + DummyDataObject::Attr::Optional)) && + evaluate::IsNullObjectPointer(*expr)) { + // ok, FOO(NULL()) + } else if (object.attrs.test(characteristics::DummyDataObject:: + Attr::Allocatable) && + evaluate::IsNullPointer(*expr)) { + // Unsupported extension that more or less naturally falls + // out of other Fortran implementations that pass separate + // base address and descriptor address physical arguments + messages.Say( + "Null actual argument '%s' may not be associated with allocatable %s"_err_en_US, + expr->AsFortran(), dummyName); + } else { + messages.Say( + "Actual argument '%s' associated with %s is not a variable or typed expression"_err_en_US, + expr->AsFortran(), dummyName); + } + } else { + const Symbol &assumed{DEREF(arg.GetAssumedTypeDummy())}; + if (!object.type.type().IsAssumedType()) { + messages.Say( + "Assumed-type '%s' may be associated only with an assumed-type %s"_err_en_US, + assumed.name(), dummyName); + } else if (object.type.attrs().test(evaluate::characteristics:: + TypeAndShape::Attr::AssumedRank) && + !IsAssumedShape(assumed) && + !evaluate::IsAssumedRank(assumed)) { + messages.Say( // C711 + "Assumed-type '%s' must be either assumed shape or assumed rank to be associated with assumed rank %s"_err_en_US, + assumed.name(), dummyName); + } + } + } + }, + [&](const characteristics::DummyProcedure &dummy) { + if (!checkActualArgForLabel(arg)) { + CheckProcedureArg(arg, proc, dummy, dummyName, context); + } + }, + [&](const characteristics::AlternateReturn &) { + // All semantic checking is done elsewhere + }, + }, + dummy.u); + } + + static void RearrangeArguments(const characteristics::Procedure &proc, + evaluate::ActualArguments &actuals, parser::ContextualMessages &messages) { + CHECK(proc.HasExplicitInterface()); + if (actuals.size() < proc.dummyArguments.size()) { + actuals.resize(proc.dummyArguments.size()); + } else if (actuals.size() > proc.dummyArguments.size()) { + messages.Say( + "Too many actual arguments (%zd) passed to procedure that expects only %zd"_err_en_US, + actuals.size(), proc.dummyArguments.size()); + } + std::map kwArgs; + bool anyKeyword{false}; + int which{1}; + for (auto &x : actuals) { + if (!x) { + } else if (x->keyword()) { + auto emplaced{ + kwArgs.try_emplace(x->keyword()->ToString(), std::move(*x))}; + if (!emplaced.second) { + messages.Say(*x->keyword(), + "Argument keyword '%s=' appears on more than one effective argument in this procedure reference"_err_en_US, + *x->keyword()); + } + x.reset(); + anyKeyword = true; + } else if (anyKeyword) { + messages.Say(x ? x->sourceLocation() : std::nullopt, + "Actual argument #%d without a keyword may not follow any actual argument with a keyword"_err_en_US, + which); + } + ++which; + } + if (!kwArgs.empty()) { + int index{0}; + for (const auto &dummy : proc.dummyArguments) { + if (!dummy.name.empty()) { + auto iter{kwArgs.find(dummy.name)}; + if (iter != kwArgs.end()) { + evaluate::ActualArgument &x{iter->second}; + if (actuals[index]) { + messages.Say(*x.keyword(), + "Keyword argument '%s=' has already been specified positionally (#%d) in this procedure reference"_err_en_US, + *x.keyword(), index + 1); + } else { + actuals[index] = std::move(x); + } + kwArgs.erase(iter); + } + } + ++index; + } + for (auto &bad : kwArgs) { + evaluate::ActualArgument &x{bad.second}; + messages.Say(*x.keyword(), + "Argument keyword '%s=' is not recognized for this procedure reference"_err_en_US, + *x.keyword()); + } + } + } + + // 15.8.1(3) -- In a reference to an elemental procedure, if any argument is an + // array, each actual argument that corresponds to an INTENT(OUT) or + // INTENT(INOUT) dummy argument shall be an array. The actual argument to an + // ELEMENTAL procedure must conform. + static bool CheckElementalConformance(parser::ContextualMessages &messages, + const characteristics::Procedure &proc, evaluate::ActualArguments &actuals, + evaluate::FoldingContext &context) { + std::optional shape; + std::string shapeName; + int index{0}; + bool hasArrayArg{false}; + for (const auto &arg : actuals) { + if (arg && !arg->isAlternateReturn() && arg->Rank() > 0) { + hasArrayArg = true; + break; + } + } + for (const auto &arg : actuals) { + const auto &dummy{proc.dummyArguments.at(index++)}; + if (arg) { + if (const auto *expr{arg->UnwrapExpr()}) { + if (auto argShape{evaluate::GetShape(context, *expr)}) { + if (GetRank(*argShape) > 0) { + std::string argName{"actual argument ("s + expr->AsFortran() + + ") corresponding to dummy argument #" + std::to_string(index) + + " ('" + dummy.name + "')"}; + if (shape) { + auto tristate{evaluate::CheckConformance(messages, *shape, + *argShape, evaluate::CheckConformanceFlags::None, + shapeName.c_str(), argName.c_str())}; + if (tristate && !*tristate) { + return false; + } + } else { + shape = std::move(argShape); + shapeName = argName; + } + } else if ((dummy.GetIntent() == common::Intent::Out || + dummy.GetIntent() == common::Intent::InOut) && + hasArrayArg) { + messages.Say( + "In an elemental procedure reference with at least one array argument, actual argument %s that corresponds to an INTENT(OUT) or INTENT(INOUT) dummy argument must be an array"_err_en_US, + expr->AsFortran()); + } + } + } + } + } + return true; + } + + // ASSOCIATED (16.9.16) + static void CheckAssociated(evaluate::ActualArguments &arguments, + evaluate::FoldingContext &context, const Scope *scope) { + bool ok{true}; + if (arguments.size() < 2) { + return; + } + if (const auto &pointerArg{arguments[0]}) { + if (const auto *pointerExpr{pointerArg->UnwrapExpr()}) { + const Symbol *pointerSymbol{GetLastSymbol(*pointerExpr)}; + if (pointerSymbol && !IsPointer(*pointerSymbol)) { + evaluate::AttachDeclaration( + context.messages().Say(pointerArg->sourceLocation(), + "POINTER= argument of ASSOCIATED() must be a POINTER"_err_en_US), + *pointerSymbol); + return; + } + if (const auto &targetArg{arguments[1]}) { + // The standard requires that the POINTER= argument be a valid LHS for + // a pointer assignment when the TARGET= argument is present. This, + // perhaps unintentionally, excludes function results, including NULL(), + // from being used there, as well as INTENT(IN) dummy pointers. + // Allow this usage as a benign extension with a portability warning. + if (!evaluate::ExtractDataRef(*pointerExpr) && + !evaluate::IsProcedurePointer(*pointerExpr)) { + context.messages().Say(pointerArg->sourceLocation(), + "POINTER= argument of ASSOCIATED() should be a pointer"_port_en_US); + } else if (scope) { + if (auto whyNot{WhyNotDefinable(pointerArg->sourceLocation().value_or( + context.messages().at()), + *scope, + DefinabilityFlags{DefinabilityFlag::PointerDefinition}, + *pointerExpr)}) { + if (auto *msg{context.messages().Say(pointerArg->sourceLocation(), + "POINTER= argument of ASSOCIATED() would not be a valid left-hand side of a pointer assignment statement"_port_en_US)}) { + msg->Attach(std::move(*whyNot)); + } + } + } + const auto *targetExpr{targetArg->UnwrapExpr()}; + if (targetExpr && pointerSymbol) { + std::optional pointerProc, targetProc; + const auto *targetProcDesignator{ + evaluate::UnwrapExpr(*targetExpr)}; + const Symbol *targetSymbol{GetLastSymbol(*targetExpr)}; + bool isCall{false}; + std::string targetName; + if (const auto *targetProcRef{// target is a function call + std::get_if(&targetExpr->u)}) { + if (auto targetRefedChars{characteristics::Procedure::Characterize( + *targetProcRef, context)}) { + targetProc = *targetRefedChars; + targetName = targetProcRef->proc().GetName() + "()"; + isCall = true; + } + } else if (targetProcDesignator) { + targetProc = characteristics::Procedure::Characterize( + *targetProcDesignator, context); + targetName = targetProcDesignator->GetName(); + } else if (targetSymbol) { + if (IsProcedure(*targetSymbol)) { + // proc that's not a call + targetProc = characteristics::Procedure::Characterize( + *targetSymbol, context); + } + targetName = targetSymbol->name().ToString(); + } + if (pointerSymbol && IsProcedure(*pointerSymbol)) { + pointerProc = characteristics::Procedure::Characterize( + *pointerSymbol, context); + } + if (pointerProc) { + if (targetProc) { + // procedure pointer and procedure target + std::string whyNot; + const evaluate::SpecificIntrinsic *specificIntrinsic{nullptr}; + if (targetProcDesignator) { + specificIntrinsic = + targetProcDesignator->GetSpecificIntrinsic(); + } + if (std::optional msg{ + CheckProcCompatibility(isCall, pointerProc, &*targetProc, + specificIntrinsic, whyNot)}) { + msg->set_severity(parser::Severity::Warning); + evaluate::AttachDeclaration( + context.messages().Say(std::move(*msg), + "pointer '" + pointerSymbol->name().ToString() + "'", + targetName, whyNot), + *pointerSymbol); + } + } else if (!IsNullProcedurePointer(*targetExpr)) { + // procedure pointer and object target + evaluate::AttachDeclaration( + context.messages().Say( + "POINTER= argument '%s' is a procedure pointer but the TARGET= argument '%s' is not a procedure or procedure pointer"_err_en_US, + pointerSymbol->name(), targetName), + *pointerSymbol); + } + } else if (targetProc) { + // object pointer and procedure target + evaluate::AttachDeclaration( + context.messages().Say( + "POINTER= argument '%s' is an object pointer but the TARGET= argument '%s' is a procedure designator"_err_en_US, + pointerSymbol->name(), targetName), + *pointerSymbol); + } else if (targetSymbol) { + // object pointer and target + SymbolVector symbols{GetSymbolVector(*targetExpr)}; + CHECK(!symbols.empty()); + if (!evaluate::GetLastTarget(symbols)) { + parser::Message *msg{context.messages().Say( + targetArg->sourceLocation(), + "TARGET= argument '%s' must have either the POINTER or the TARGET attribute"_err_en_US, + targetExpr->AsFortran())}; + for (SymbolRef ref : symbols) { + msg = evaluate::AttachDeclaration(msg, *ref); + } + } else if (HasVectorSubscript(*targetExpr) || + ExtractCoarrayRef(*targetExpr)) { + context.messages().Say(targetArg->sourceLocation(), + "TARGET= argument '%s' may not have a vector subscript or coindexing"_err_en_US, + targetExpr->AsFortran()); + } + if (const auto pointerType{pointerArg->GetType()}) { + if (const auto targetType{targetArg->GetType()}) { + ok = pointerType->IsTkCompatibleWith(*targetType); + } + } + } + } + } + } + } else { + // No arguments to ASSOCIATED() + ok = false; + } + if (!ok) { + context.messages().Say( + "Arguments of ASSOCIATED() must be a POINTER and an optional valid target"_err_en_US); + } + } + + // TRANSFER (16.9.193) + static void CheckTransferOperandType(SemanticsContext &context, + const evaluate::DynamicType &type, const char *which) { + if (type.IsPolymorphic() && + context.ShouldWarn(common::UsageWarning::PolymorphicTransferArg)) { + context.foldingContext().messages().Say( + "%s of TRANSFER is polymorphic"_warn_en_US, which); + } else if (!type.IsUnlimitedPolymorphic() && + type.category() == TypeCategory::Derived && + context.ShouldWarn(common::UsageWarning::PointerComponentTransferArg)) { + DirectComponentIterator directs{type.GetDerivedTypeSpec()}; + if (auto bad{std::find_if(directs.begin(), directs.end(), IsDescriptor)}; + bad != directs.end()) { + evaluate::SayWithDeclaration(context.foldingContext().messages(), *bad, + "%s of TRANSFER contains allocatable or pointer component %s"_warn_en_US, + which, bad.BuildResultDesignatorName()); + } + } + } + + static void CheckTransfer(evaluate::ActualArguments &arguments, + SemanticsContext &context, const Scope *scope) { + evaluate::FoldingContext &foldingContext{context.foldingContext()}; + parser::ContextualMessages &messages{foldingContext.messages()}; + if (arguments.size() >= 2) { + if (auto source{characteristics::TypeAndShape::Characterize( + arguments[0], foldingContext)}) { + CheckTransferOperandType(context, source->type(), "Source"); + if (auto mold{characteristics::TypeAndShape::Characterize( + arguments[1], foldingContext)}) { + CheckTransferOperandType(context, mold->type(), "Mold"); + if (mold->Rank() > 0 && + evaluate::ToInt64( + evaluate::Fold(foldingContext, + mold->MeasureElementSizeInBytes(foldingContext, false))) + .value_or(1) == 0) { + if (auto sourceSize{evaluate::ToInt64(evaluate::Fold(foldingContext, + source->MeasureSizeInBytes(foldingContext)))}) { + if (*sourceSize > 0) { + messages.Say( + "Element size of MOLD= array may not be zero when SOURCE= is not empty"_err_en_US); + } + } else { + messages.Say( + "Element size of MOLD= array may not be zero unless SOURCE= is empty"_warn_en_US); + } + } + } + } + if (arguments.size() > 2) { // SIZE= + if (const Symbol * + whole{UnwrapWholeSymbolOrComponentDataRef(arguments[2])}) { + if (IsOptional(*whole)) { + messages.Say( + "SIZE= argument may not be the optional dummy argument '%s'"_err_en_US, + whole->name()); + } else if (context.ShouldWarn( + common::UsageWarning::TransferSizePresence) && + IsAllocatableOrPointer(*whole)) { + messages.Say( + "SIZE= argument that is allocatable or pointer must be present at execution; parenthesize to silence this warning"_warn_en_US); + } + } + } + } + } + + static void CheckSpecificIntrinsic(evaluate::ActualArguments &arguments, + SemanticsContext &context, const Scope *scope, + const evaluate::SpecificIntrinsic &intrinsic) { + if (intrinsic.name == "associated") { + CheckAssociated(arguments, context.foldingContext(), scope); + } else if (intrinsic.name == "transfer") { + CheckTransfer(arguments, context, scope); + } + } + + static parser::Messages CheckExplicitInterface( + const characteristics::Procedure &proc, evaluate::ActualArguments &actuals, + SemanticsContext &context, const Scope *scope, + const evaluate::SpecificIntrinsic *intrinsic, + bool allowActualArgumentConversions) { + evaluate::FoldingContext &foldingContext{context.foldingContext()}; + parser::ContextualMessages &messages{foldingContext.messages()}; + parser::Messages buffer; + auto restorer{messages.SetMessages(buffer)}; + RearrangeArguments(proc, actuals, messages); + if (!buffer.empty()) { + return buffer; + } + int index{0}; + for (auto &actual : actuals) { + const auto &dummy{proc.dummyArguments.at(index++)}; + if (actual) { + CheckExplicitInterfaceArg(*actual, dummy, proc, context, scope, intrinsic, + allowActualArgumentConversions); + } else if (!dummy.IsOptional()) { + if (dummy.name.empty()) { + messages.Say( + "Dummy argument #%d is not OPTIONAL and is not associated with " + "an actual argument in this procedure reference"_err_en_US, + index); + } else { + messages.Say("Dummy argument '%s=' (#%d) is not OPTIONAL and is not " + "associated with an actual argument in this procedure " + "reference"_err_en_US, + dummy.name, index); + } + } + } + if (proc.IsElemental() && !buffer.AnyFatalError()) { + CheckElementalConformance(messages, proc, actuals, foldingContext); + } + if (intrinsic) { + CheckSpecificIntrinsic(actuals, context, scope, *intrinsic); + } + return buffer; + } + + bool CheckInterfaceForGeneric(const characteristics::Procedure &proc, + evaluate::ActualArguments &actuals, SemanticsContext &context, + bool allowActualArgumentConversions) { + return proc.HasExplicitInterface() && + !CheckExplicitInterface(proc, actuals, context, nullptr, nullptr, + allowActualArgumentConversions) + .AnyFatalError(); + } + + bool CheckArgumentIsConstantExprInRange( + const evaluate::ActualArguments &actuals, int index, int lowerBound, + int upperBound, parser::ContextualMessages &messages) { + CHECK(index >= 0 && static_cast(index) < actuals.size()); + + const std::optional &argOptional{actuals[index]}; + if (!argOptional) { + DIE("Actual argument should have value"); + return false; + } + + const evaluate::ActualArgument &arg{argOptional.value()}; + const evaluate::Expr *argExpr{arg.UnwrapExpr()}; + CHECK(argExpr != nullptr); + + if (!IsConstantExpr(*argExpr)) { + messages.Say("Actual argument #%d must be a constant expression"_err_en_US, + index + 1); + return false; + } + + // This does not imply that the kind of the argument is 8. The kind + // for the intrinsic's argument should have been check prior. This is just + // a conversion so that we can read the constant value. + auto scalarValue{evaluate::ToInt64(argExpr)}; + CHECK(scalarValue.has_value()); + + if (*scalarValue < lowerBound || *scalarValue > upperBound) { + messages.Say( + "Argument #%d must be a constant expression in range %d-%d"_err_en_US, + index + 1, lowerBound, upperBound); + return false; + } + return true; + } + + bool CheckPPCIntrinsic(const Symbol &generic, const Symbol &specific, + const evaluate::ActualArguments &actuals, + evaluate::FoldingContext &context) { + parser::ContextualMessages &messages{context.messages()}; + + if (specific.name() == "__ppc_mtfsf") { + return CheckArgumentIsConstantExprInRange(actuals, 0, 0, 7, messages); + } + if (specific.name() == "__ppc_mtfsfi") { + return CheckArgumentIsConstantExprInRange(actuals, 0, 0, 7, messages) && + CheckArgumentIsConstantExprInRange(actuals, 1, 0, 15, messages); + } + return false; + } + + bool CheckArguments(const characteristics::Procedure &proc, + evaluate::ActualArguments &actuals, SemanticsContext &context, + const Scope &scope, bool treatingExternalAsImplicit, + const evaluate::SpecificIntrinsic *intrinsic) { + bool explicitInterface{proc.HasExplicitInterface()}; + evaluate::FoldingContext foldingContext{context.foldingContext()}; + parser::ContextualMessages &messages{foldingContext.messages()}; + if (!explicitInterface || treatingExternalAsImplicit) { + parser::Messages buffer; + { + auto restorer{messages.SetMessages(buffer)}; + for (auto &actual : actuals) { + if (actual) { + CheckImplicitInterfaceArg(*actual, messages, foldingContext); + } + } + } + if (!buffer.empty()) { + if (auto *msgs{messages.messages()}) { + msgs->Annex(std::move(buffer)); + } + return false; // don't pile on + } + } + if (explicitInterface) { + auto buffer{CheckExplicitInterface( + proc, actuals, context, &scope, intrinsic, true)}; + if (!buffer.empty()) { + if (treatingExternalAsImplicit) { + if (auto *msg{messages.Say( + "If the procedure's interface were explicit, this reference would be in error"_warn_en_US)}) { + buffer.AttachTo(*msg, parser::Severity::Because); + } + } + if (auto *msgs{messages.messages()}) { + msgs->Annex(std::move(buffer)); + } + return false; + } + } + return true; + } + } // namespace Fortran::semantics +diff --git a/flang/test/Semantics/ignore_tkr02.f90 b/flang/test/Semantics/ignore_tkr02.f90 +index a56b92d6613a..b7cb7233c0a4 100644 +--- a/flang/test/Semantics/ignore_tkr02.f90 ++++ b/flang/test/Semantics/ignore_tkr02.f90 +@@ -1,38 +1,38 @@ + ! RUN: %flang_fc1 -fdebug-unparse %s 2>&1 | FileCheck %s + program main + interface generic + subroutine sub1(j, k) + integer(1) j + integer k + !dir$ ignore_tkr(kr) k + end + subroutine sub2(j, k) + integer(2) j + integer k + !dir$ ignore_tkr(kr) k + end + subroutine sub4(j, k) + integer(4) j + integer k + !dir$ ignore_tkr(kr) k + end + end interface +-!CHECK: CALL sub1(1_1,int(1_1,kind=4)) ++!CHECK: CALL sub1(1_1,1_1) + call generic(1_1,1_1) +-!CHECK: CALL sub1(1_1,int(1_2,kind=4)) ++!CHECK: CALL sub1(1_1,1_2) + call generic(1_1,1_2) + !CHECK: CALL sub1(1_1,[INTEGER(1)::1_1]) + call generic(1_1,[1_1]) +-!CHECK: CALL sub2(1_2,int(1_1,kind=4)) ++!CHECK: CALL sub2(1_2,1_1) + call generic(1_2,1_1) +-!CHECK: CALL sub2(1_2,int(1_2,kind=4)) ++!CHECK: CALL sub2(1_2,1_2) + call generic(1_2,1_2) + !CHECK: CALL sub2(1_2,[INTEGER(1)::1_1]) + call generic(1_2,[1_1]) +-!CHECK: CALL sub4(1_4,int(1_1,kind=4)) ++!CHECK: CALL sub4(1_4,1_1) + call generic(1_4,1_1) +-!CHECK: CALL sub4(1_4,int(1_2,kind=4)) ++!CHECK: CALL sub4(1_4,1_2) + call generic(1_4,1_2) + !CHECK: CALL sub4(1_4,[INTEGER(1)::1_1]) + call generic(1_4,[1_1]) + end