Index: lib/Sema/SemaDecl.cpp =================================================================== --- lib/Sema/SemaDecl.cpp +++ lib/Sema/SemaDecl.cpp @@ -5966,8 +5966,15 @@ if (const InheritableAttr *Attr = getDLLAttr(&ND)) { // dll attributes require external linkage. Static locals may have external // linkage but still cannot be explicitly imported or exported. + // Initialized variables in an anonymous spaces are exported. auto *VD = dyn_cast(&ND); - if (!ND.isExternallyVisible() || (VD && VD->isStaticLocal())) { + NamespaceDecl *NS = NULL; + if (VD) + NS = dyn_cast(VD->getDeclContext()); + int isAnonymousNS = NS && NS->getDeclName().isEmpty(); + if ((!ND.isExternallyVisible() && + (!isAnonymousNS || !(VD && VD->hasInit()))) || + (VD && VD->isStaticLocal())) { S.Diag(ND.getLocation(), diag::err_attribute_dll_not_extern) << &ND << Attr; ND.setInvalidDecl(); @@ -11371,6 +11378,16 @@ !isTemplateInstantiation(VDecl->getTemplateSpecializationKind())) Diag(VDecl->getLocation(), diag::warn_extern_init); + // In Microsoft C++ mode, a const variable defined in namespace scope has + // external linkage by default if the variable is declared with + // __declspec(dllexport). + if (Context.getTargetInfo().getCXXABI().isMicrosoft() && + getLangOpts().CPlusPlus && + VDecl->getType().isConstQualified() && + VDecl->hasAttr() && + VDecl->getDefinition()) + VDecl->setStorageClass(SC_Extern); + // C99 6.7.8p4. All file scoped initializers need to be constant. if (!getLangOpts().CPlusPlus && !VDecl->isInvalidDecl()) CheckForConstantInitializer(Init, DclT); Index: mypatch.patch =================================================================== --- /dev/null +++ mypatch.patch @@ -0,0 +1,17468 @@ +commit 8109b43483e5213654bfe6c8af660f75e2a695bc +Author: Zahira Ammarguellat +Date: Sat Feb 23 06:52:35 2019 -0500 + + Fix for CMPLRS-41049. + + Change-Id: I7efb6c0dcb27b4c2edee36e66e4c8cb41ab2dd05 + +diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp +index d6e44af0eb..fe8e9f147a 100644 +--- a/lib/Sema/SemaDecl.cpp ++++ b/lib/Sema/SemaDecl.cpp +@@ -1,17382 +1,17399 @@ + //===--- SemaDecl.cpp - Semantic Analysis for 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 declarations. + // + //===----------------------------------------------------------------------===// + + #include "TypeLocBuilder.h" + #include "clang/AST/ASTConsumer.h" + #include "clang/AST/ASTContext.h" + #include "clang/AST/ASTLambda.h" + #include "clang/AST/CXXInheritance.h" + #include "clang/AST/CharUnits.h" + #include "clang/AST/CommentDiagnostic.h" + #include "clang/AST/DeclCXX.h" + #include "clang/AST/DeclObjC.h" + #include "clang/AST/DeclTemplate.h" + #include "clang/AST/EvaluatedExprVisitor.h" + #include "clang/AST/ExprCXX.h" + #include "clang/AST/StmtCXX.h" + #include "clang/Basic/Builtins.h" + #include "clang/Basic/PartialDiagnostic.h" + #include "clang/Basic/SourceManager.h" + #include "clang/Basic/TargetInfo.h" + #include "clang/Lex/HeaderSearch.h" // TODO: Sema shouldn't depend on Lex + #include "clang/Lex/Lexer.h" // TODO: Extract static functions to fix layering. + #include "clang/Lex/ModuleLoader.h" // TODO: Sema shouldn't depend on Lex + #include "clang/Lex/Preprocessor.h" // Included for isCodeCompletionEnabled() + #include "clang/Sema/CXXFieldCollector.h" + #include "clang/Sema/DeclSpec.h" + #include "clang/Sema/DelayedDiagnostic.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/SmallString.h" + #include "llvm/ADT/Triple.h" + #include + #include + #include + + using namespace clang; + using namespace sema; + + Sema::DeclGroupPtrTy Sema::ConvertDeclToDeclGroup(Decl *Ptr, Decl *OwnedType) { + if (OwnedType) { + Decl *Group[2] = { OwnedType, Ptr }; + return DeclGroupPtrTy::make(DeclGroupRef::Create(Context, Group, 2)); + } + + return DeclGroupPtrTy::make(DeclGroupRef(Ptr)); + } + + namespace { + + class TypeNameValidatorCCC : public CorrectionCandidateCallback { + public: + TypeNameValidatorCCC(bool AllowInvalid, bool WantClass = false, + bool AllowTemplates = false, + bool AllowNonTemplates = true) + : AllowInvalidDecl(AllowInvalid), WantClassName(WantClass), + AllowTemplates(AllowTemplates), AllowNonTemplates(AllowNonTemplates) { + WantExpressionKeywords = false; + WantCXXNamedCasts = false; + WantRemainingKeywords = false; + } + + bool ValidateCandidate(const TypoCorrection &candidate) override { + if (NamedDecl *ND = candidate.getCorrectionDecl()) { + if (!AllowInvalidDecl && ND->isInvalidDecl()) + return false; + + if (getAsTypeTemplateDecl(ND)) + return AllowTemplates; + + bool IsType = isa(ND) || isa(ND); + if (!IsType) + return false; + + if (AllowNonTemplates) + return true; + + // An injected-class-name of a class template (specialization) is valid + // as a template or as a non-template. + if (AllowTemplates) { + auto *RD = dyn_cast(ND); + if (!RD || !RD->isInjectedClassName()) + return false; + RD = cast(RD->getDeclContext()); + return RD->getDescribedClassTemplate() || + isa(RD); + } + + return false; + } + + return !WantClassName && candidate.isKeyword(); + } + + private: + bool AllowInvalidDecl; + bool WantClassName; + bool AllowTemplates; + bool AllowNonTemplates; + }; + + } // end anonymous namespace + + /// Determine whether the token kind starts a simple-type-specifier. + bool Sema::isSimpleTypeSpecifier(tok::TokenKind Kind) const { + switch (Kind) { + // FIXME: Take into account the current language when deciding whether a + // token kind is a valid type specifier + case tok::kw_short: + case tok::kw_long: + case tok::kw___int64: + case tok::kw___int128: + case tok::kw_signed: + case tok::kw_unsigned: + case tok::kw_void: + case tok::kw_char: + case tok::kw_int: + case tok::kw_half: + case tok::kw_float: + case tok::kw_double: + case tok::kw__Float16: + case tok::kw___float128: + case tok::kw_wchar_t: + case tok::kw_bool: + case tok::kw___underlying_type: + case tok::kw___auto_type: + return true; + + case tok::annot_typename: + case tok::kw_char16_t: + case tok::kw_char32_t: + case tok::kw_typeof: + case tok::annot_decltype: + case tok::kw_decltype: + return getLangOpts().CPlusPlus; + + case tok::kw_char8_t: + return getLangOpts().Char8; + + default: + break; + } + + return false; + } + + namespace { + enum class UnqualifiedTypeNameLookupResult { + NotFound, + FoundNonType, + FoundType + }; + } // end anonymous namespace + + /// Tries to perform unqualified lookup of the type decls in bases for + /// dependent class. + /// \return \a NotFound if no any decls is found, \a FoundNotType if found not a + /// type decl, \a FoundType if only type decls are found. + static UnqualifiedTypeNameLookupResult + lookupUnqualifiedTypeNameInBase(Sema &S, const IdentifierInfo &II, + SourceLocation NameLoc, + const CXXRecordDecl *RD) { + if (!RD->hasDefinition()) + return UnqualifiedTypeNameLookupResult::NotFound; + // Look for type decls in base classes. + UnqualifiedTypeNameLookupResult FoundTypeDecl = + UnqualifiedTypeNameLookupResult::NotFound; + for (const auto &Base : RD->bases()) { + const CXXRecordDecl *BaseRD = nullptr; + if (auto *BaseTT = Base.getType()->getAs()) + BaseRD = BaseTT->getAsCXXRecordDecl(); + else if (auto *TST = Base.getType()->getAs()) { + // Look for type decls in dependent base classes that have known primary + // templates. + if (!TST || !TST->isDependentType()) + continue; + auto *TD = TST->getTemplateName().getAsTemplateDecl(); + if (!TD) + continue; + if (auto *BasePrimaryTemplate = + dyn_cast_or_null(TD->getTemplatedDecl())) { + if (BasePrimaryTemplate->getCanonicalDecl() != RD->getCanonicalDecl()) + BaseRD = BasePrimaryTemplate; + else if (auto *CTD = dyn_cast(TD)) { + if (const ClassTemplatePartialSpecializationDecl *PS = + CTD->findPartialSpecialization(Base.getType())) + if (PS->getCanonicalDecl() != RD->getCanonicalDecl()) + BaseRD = PS; + } + } + } + if (BaseRD) { + for (NamedDecl *ND : BaseRD->lookup(&II)) { + if (!isa(ND)) + return UnqualifiedTypeNameLookupResult::FoundNonType; + FoundTypeDecl = UnqualifiedTypeNameLookupResult::FoundType; + } + if (FoundTypeDecl == UnqualifiedTypeNameLookupResult::NotFound) { + switch (lookupUnqualifiedTypeNameInBase(S, II, NameLoc, BaseRD)) { + case UnqualifiedTypeNameLookupResult::FoundNonType: + return UnqualifiedTypeNameLookupResult::FoundNonType; + case UnqualifiedTypeNameLookupResult::FoundType: + FoundTypeDecl = UnqualifiedTypeNameLookupResult::FoundType; + break; + case UnqualifiedTypeNameLookupResult::NotFound: + break; + } + } + } + } + + return FoundTypeDecl; + } + + static ParsedType recoverFromTypeInKnownDependentBase(Sema &S, + const IdentifierInfo &II, + SourceLocation NameLoc) { + // Lookup in the parent class template context, if any. + const CXXRecordDecl *RD = nullptr; + UnqualifiedTypeNameLookupResult FoundTypeDecl = + UnqualifiedTypeNameLookupResult::NotFound; + for (DeclContext *DC = S.CurContext; + DC && FoundTypeDecl == UnqualifiedTypeNameLookupResult::NotFound; + DC = DC->getParent()) { + // Look for type decls in dependent base classes that have known primary + // templates. + RD = dyn_cast(DC); + if (RD && RD->getDescribedClassTemplate()) + FoundTypeDecl = lookupUnqualifiedTypeNameInBase(S, II, NameLoc, RD); + } + if (FoundTypeDecl != UnqualifiedTypeNameLookupResult::FoundType) + return nullptr; + + // We found some types in dependent base classes. Recover as if the user + // wrote 'typename MyClass::II' instead of 'II'. We'll fully resolve the + // lookup during template instantiation. + S.Diag(NameLoc, diag::ext_found_via_dependent_bases_lookup) << &II; + + ASTContext &Context = S.Context; + auto *NNS = NestedNameSpecifier::Create(Context, nullptr, false, + cast(Context.getRecordType(RD))); + QualType T = Context.getDependentNameType(ETK_Typename, NNS, &II); + + CXXScopeSpec SS; + SS.MakeTrivial(Context, NNS, SourceRange(NameLoc)); + + TypeLocBuilder Builder; + DependentNameTypeLoc DepTL = Builder.push(T); + DepTL.setNameLoc(NameLoc); + DepTL.setElaboratedKeywordLoc(SourceLocation()); + DepTL.setQualifierLoc(SS.getWithLocInContext(Context)); + return S.CreateParsedType(T, Builder.getTypeSourceInfo(Context, T)); + } + + /// If the identifier refers to a type name within this scope, + /// return the declaration of that type. + /// + /// This routine performs ordinary name lookup of the identifier II + /// within the given scope, with optional C++ scope specifier SS, to + /// determine whether the name refers to a type. If so, returns an + /// opaque pointer (actually a QualType) corresponding to that + /// type. Otherwise, returns NULL. + ParsedType Sema::getTypeName(const IdentifierInfo &II, SourceLocation NameLoc, + Scope *S, CXXScopeSpec *SS, + bool isClassName, bool HasTrailingDot, + ParsedType ObjectTypePtr, + bool IsCtorOrDtorName, + bool WantNontrivialTypeSourceInfo, + bool IsClassTemplateDeductionContext, + IdentifierInfo **CorrectedII) { + // FIXME: Consider allowing this outside C++1z mode as an extension. + bool AllowDeducedTemplate = IsClassTemplateDeductionContext && + getLangOpts().CPlusPlus17 && !IsCtorOrDtorName && + !isClassName && !HasTrailingDot; + + // Determine where we will perform name lookup. + DeclContext *LookupCtx = nullptr; + if (ObjectTypePtr) { + QualType ObjectType = ObjectTypePtr.get(); + if (ObjectType->isRecordType()) + LookupCtx = computeDeclContext(ObjectType); + } else if (SS && SS->isNotEmpty()) { + LookupCtx = computeDeclContext(*SS, false); + + if (!LookupCtx) { + if (isDependentScopeSpecifier(*SS)) { + // C++ [temp.res]p3: + // A qualified-id that refers to a type and in which the + // nested-name-specifier depends on a template-parameter (14.6.2) + // shall be prefixed by the keyword typename to indicate that the + // qualified-id denotes a type, forming an + // elaborated-type-specifier (7.1.5.3). + // + // We therefore do not perform any name lookup if the result would + // refer to a member of an unknown specialization. + if (!isClassName && !IsCtorOrDtorName) + return nullptr; + + // We know from the grammar that this name refers to a type, + // so build a dependent node to describe the type. + if (WantNontrivialTypeSourceInfo) + return ActOnTypenameType(S, SourceLocation(), *SS, II, NameLoc).get(); + + NestedNameSpecifierLoc QualifierLoc = SS->getWithLocInContext(Context); + QualType T = CheckTypenameType(ETK_None, SourceLocation(), QualifierLoc, + II, NameLoc); + return ParsedType::make(T); + } + + return nullptr; + } + + if (!LookupCtx->isDependentContext() && + RequireCompleteDeclContext(*SS, LookupCtx)) + return nullptr; + } + + // FIXME: LookupNestedNameSpecifierName isn't the right kind of + // lookup for class-names. + LookupNameKind Kind = isClassName ? LookupNestedNameSpecifierName : + LookupOrdinaryName; + LookupResult Result(*this, &II, NameLoc, Kind); + if (LookupCtx) { + // Perform "qualified" name lookup into the declaration context we + // computed, which is either the type of the base of a member access + // expression or the declaration context associated with a prior + // nested-name-specifier. + LookupQualifiedName(Result, LookupCtx); + + if (ObjectTypePtr && Result.empty()) { + // C++ [basic.lookup.classref]p3: + // If the unqualified-id is ~type-name, the type-name is looked up + // in the context of the entire postfix-expression. If the type T of + // the object expression is of a class type C, the type-name is also + // looked up in the scope of class C. At least one of the lookups shall + // find a name that refers to (possibly cv-qualified) T. + LookupName(Result, S); + } + } else { + // Perform unqualified name lookup. + LookupName(Result, S); + + // For unqualified lookup in a class template in MSVC mode, look into + // dependent base classes where the primary class template is known. + if (Result.empty() && getLangOpts().MSVCCompat && (!SS || SS->isEmpty())) { + if (ParsedType TypeInBase = + recoverFromTypeInKnownDependentBase(*this, II, NameLoc)) + return TypeInBase; + } + } + + NamedDecl *IIDecl = nullptr; + switch (Result.getResultKind()) { + case LookupResult::NotFound: + case LookupResult::NotFoundInCurrentInstantiation: + if (CorrectedII) { + TypoCorrection Correction = + CorrectTypo(Result.getLookupNameInfo(), Kind, S, SS, + llvm::make_unique( + true, isClassName, AllowDeducedTemplate), + CTK_ErrorRecovery); + IdentifierInfo *NewII = Correction.getCorrectionAsIdentifierInfo(); + TemplateTy Template; + bool MemberOfUnknownSpecialization; + UnqualifiedId TemplateName; + TemplateName.setIdentifier(NewII, NameLoc); + NestedNameSpecifier *NNS = Correction.getCorrectionSpecifier(); + CXXScopeSpec NewSS, *NewSSPtr = SS; + if (SS && NNS) { + NewSS.MakeTrivial(Context, NNS, SourceRange(NameLoc)); + NewSSPtr = &NewSS; + } + if (Correction && (NNS || NewII != &II) && + // Ignore a correction to a template type as the to-be-corrected + // identifier is not a template (typo correction for template names + // is handled elsewhere). + !(getLangOpts().CPlusPlus && NewSSPtr && + isTemplateName(S, *NewSSPtr, false, TemplateName, nullptr, false, + Template, MemberOfUnknownSpecialization))) { + ParsedType Ty = getTypeName(*NewII, NameLoc, S, NewSSPtr, + isClassName, HasTrailingDot, ObjectTypePtr, + IsCtorOrDtorName, + WantNontrivialTypeSourceInfo, + IsClassTemplateDeductionContext); + if (Ty) { + diagnoseTypo(Correction, + PDiag(diag::err_unknown_type_or_class_name_suggest) + << Result.getLookupName() << isClassName); + if (SS && NNS) + SS->MakeTrivial(Context, NNS, SourceRange(NameLoc)); + *CorrectedII = NewII; + return Ty; + } + } + } + // If typo correction failed or was not performed, fall through + LLVM_FALLTHROUGH; + case LookupResult::FoundOverloaded: + case LookupResult::FoundUnresolvedValue: + Result.suppressDiagnostics(); + return nullptr; + + case LookupResult::Ambiguous: + // Recover from type-hiding ambiguities by hiding the type. We'll + // do the lookup again when looking for an object, and we can + // diagnose the error then. If we don't do this, then the error + // about hiding the type will be immediately followed by an error + // that only makes sense if the identifier was treated like a type. + if (Result.getAmbiguityKind() == LookupResult::AmbiguousTagHiding) { + Result.suppressDiagnostics(); + return nullptr; + } + + // Look to see if we have a type anywhere in the list of results. + for (LookupResult::iterator Res = Result.begin(), ResEnd = Result.end(); + Res != ResEnd; ++Res) { + if (isa(*Res) || isa(*Res) || + (AllowDeducedTemplate && getAsTypeTemplateDecl(*Res))) { + if (!IIDecl || + (*Res)->getLocation().getRawEncoding() < + IIDecl->getLocation().getRawEncoding()) + IIDecl = *Res; + } + } + + if (!IIDecl) { + // None of the entities we found is a type, so there is no way + // to even assume that the result is a type. In this case, don't + // complain about the ambiguity. The parser will either try to + // perform this lookup again (e.g., as an object name), which + // will produce the ambiguity, or will complain that it expected + // a type name. + Result.suppressDiagnostics(); + return nullptr; + } + + // We found a type within the ambiguous lookup; diagnose the + // ambiguity and then return that type. This might be the right + // answer, or it might not be, but it suppresses any attempt to + // perform the name lookup again. + break; + + case LookupResult::Found: + IIDecl = Result.getFoundDecl(); + break; + } + + assert(IIDecl && "Didn't find decl"); + + QualType T; + if (TypeDecl *TD = dyn_cast(IIDecl)) { + // C++ [class.qual]p2: A lookup that would find the injected-class-name + // instead names the constructors of the class, except when naming a class. + // This is ill-formed when we're not actually forming a ctor or dtor name. + auto *LookupRD = dyn_cast_or_null(LookupCtx); + auto *FoundRD = dyn_cast(TD); + if (!isClassName && !IsCtorOrDtorName && LookupRD && FoundRD && + FoundRD->isInjectedClassName() && + declaresSameEntity(LookupRD, cast(FoundRD->getParent()))) + Diag(NameLoc, diag::err_out_of_line_qualified_id_type_names_constructor) + << &II << /*Type*/1; + + DiagnoseUseOfDecl(IIDecl, NameLoc); + + T = Context.getTypeDeclType(TD); + MarkAnyDeclReferenced(TD->getLocation(), TD, /*OdrUse=*/false); + } else if (ObjCInterfaceDecl *IDecl = dyn_cast(IIDecl)) { + (void)DiagnoseUseOfDecl(IDecl, NameLoc); + if (!HasTrailingDot) + T = Context.getObjCInterfaceType(IDecl); + } else if (AllowDeducedTemplate) { + if (auto *TD = getAsTypeTemplateDecl(IIDecl)) + T = Context.getDeducedTemplateSpecializationType(TemplateName(TD), + QualType(), false); + } + + if (T.isNull()) { + // If it's not plausibly a type, suppress diagnostics. + Result.suppressDiagnostics(); + return nullptr; + } + + // NOTE: avoid constructing an ElaboratedType(Loc) if this is a + // constructor or destructor name (in such a case, the scope specifier + // will be attached to the enclosing Expr or Decl node). + if (SS && SS->isNotEmpty() && !IsCtorOrDtorName && + !isa(IIDecl)) { + if (WantNontrivialTypeSourceInfo) { + // Construct a type with type-source information. + TypeLocBuilder Builder; + Builder.pushTypeSpec(T).setNameLoc(NameLoc); + + T = getElaboratedType(ETK_None, *SS, T); + ElaboratedTypeLoc ElabTL = Builder.push(T); + ElabTL.setElaboratedKeywordLoc(SourceLocation()); + ElabTL.setQualifierLoc(SS->getWithLocInContext(Context)); + return CreateParsedType(T, Builder.getTypeSourceInfo(Context, T)); + } else { + T = getElaboratedType(ETK_None, *SS, T); + } + } + + return ParsedType::make(T); + } + + // Builds a fake NNS for the given decl context. + static NestedNameSpecifier * + synthesizeCurrentNestedNameSpecifier(ASTContext &Context, DeclContext *DC) { + for (;; DC = DC->getLookupParent()) { + DC = DC->getPrimaryContext(); + auto *ND = dyn_cast(DC); + if (ND && !ND->isInline() && !ND->isAnonymousNamespace()) + return NestedNameSpecifier::Create(Context, nullptr, ND); + else if (auto *RD = dyn_cast(DC)) + return NestedNameSpecifier::Create(Context, nullptr, RD->isTemplateDecl(), + RD->getTypeForDecl()); + else if (isa(DC)) + return NestedNameSpecifier::GlobalSpecifier(Context); + } + llvm_unreachable("something isn't in TU scope?"); + } + + /// Find the parent class with dependent bases of the innermost enclosing method + /// context. Do not look for enclosing CXXRecordDecls directly, or we will end + /// up allowing unqualified dependent type names at class-level, which MSVC + /// correctly rejects. + static const CXXRecordDecl * + findRecordWithDependentBasesOfEnclosingMethod(const DeclContext *DC) { + for (; DC && DC->isDependentContext(); DC = DC->getLookupParent()) { + DC = DC->getPrimaryContext(); + if (const auto *MD = dyn_cast(DC)) + if (MD->getParent()->hasAnyDependentBases()) + return MD->getParent(); + } + return nullptr; + } + + ParsedType Sema::ActOnMSVCUnknownTypeName(const IdentifierInfo &II, + SourceLocation NameLoc, + bool IsTemplateTypeArg) { + assert(getLangOpts().MSVCCompat && "shouldn't be called in non-MSVC mode"); + + NestedNameSpecifier *NNS = nullptr; + if (IsTemplateTypeArg && getCurScope()->isTemplateParamScope()) { + // If we weren't able to parse a default template argument, delay lookup + // until instantiation time by making a non-dependent DependentTypeName. We + // pretend we saw a NestedNameSpecifier referring to the current scope, and + // lookup is retried. + // FIXME: This hurts our diagnostic quality, since we get errors like "no + // type named 'Foo' in 'current_namespace'" when the user didn't write any + // name specifiers. + NNS = synthesizeCurrentNestedNameSpecifier(Context, CurContext); + Diag(NameLoc, diag::ext_ms_delayed_template_argument) << &II; + } else if (const CXXRecordDecl *RD = + findRecordWithDependentBasesOfEnclosingMethod(CurContext)) { + // Build a DependentNameType that will perform lookup into RD at + // instantiation time. + NNS = NestedNameSpecifier::Create(Context, nullptr, RD->isTemplateDecl(), + RD->getTypeForDecl()); + + // Diagnose that this identifier was undeclared, and retry the lookup during + // template instantiation. + Diag(NameLoc, diag::ext_undeclared_unqual_id_with_dependent_base) << &II + << RD; + } else { + // This is not a situation that we should recover from. + return ParsedType(); + } + + QualType T = Context.getDependentNameType(ETK_None, NNS, &II); + + // Build type location information. We synthesized the qualifier, so we have + // to build a fake NestedNameSpecifierLoc. + NestedNameSpecifierLocBuilder NNSLocBuilder; + NNSLocBuilder.MakeTrivial(Context, NNS, SourceRange(NameLoc)); + NestedNameSpecifierLoc QualifierLoc = NNSLocBuilder.getWithLocInContext(Context); + + TypeLocBuilder Builder; + DependentNameTypeLoc DepTL = Builder.push(T); + DepTL.setNameLoc(NameLoc); + DepTL.setElaboratedKeywordLoc(SourceLocation()); + DepTL.setQualifierLoc(QualifierLoc); + return CreateParsedType(T, Builder.getTypeSourceInfo(Context, T)); + } + + /// isTagName() - This method is called *for error recovery purposes only* + /// to determine if the specified name is a valid tag name ("struct foo"). If + /// so, this returns the TST for the tag corresponding to it (TST_enum, + /// TST_union, TST_struct, TST_interface, TST_class). This is used to diagnose + /// cases in C where the user forgot to specify the tag. + DeclSpec::TST Sema::isTagName(IdentifierInfo &II, Scope *S) { + // Do a tag name lookup in this scope. + LookupResult R(*this, &II, SourceLocation(), LookupTagName); + LookupName(R, S, false); + R.suppressDiagnostics(); + if (R.getResultKind() == LookupResult::Found) + if (const TagDecl *TD = R.getAsSingle()) { + switch (TD->getTagKind()) { + case TTK_Struct: return DeclSpec::TST_struct; + case TTK_Interface: return DeclSpec::TST_interface; + case TTK_Union: return DeclSpec::TST_union; + case TTK_Class: return DeclSpec::TST_class; + case TTK_Enum: return DeclSpec::TST_enum; + } + } + + return DeclSpec::TST_unspecified; + } + + /// isMicrosoftMissingTypename - In Microsoft mode, within class scope, + /// if a CXXScopeSpec's type is equal to the type of one of the base classes + /// then downgrade the missing typename error to a warning. + /// This is needed for MSVC compatibility; Example: + /// @code + /// template class A { + /// public: + /// typedef int TYPE; + /// }; + /// template class B : public A { + /// public: + /// A::TYPE a; // no typename required because A is a base class. + /// }; + /// @endcode + bool Sema::isMicrosoftMissingTypename(const CXXScopeSpec *SS, Scope *S) { + if (CurContext->isRecord()) { + if (SS->getScopeRep()->getKind() == NestedNameSpecifier::Super) + return true; + + const Type *Ty = SS->getScopeRep()->getAsType(); + + CXXRecordDecl *RD = cast(CurContext); + for (const auto &Base : RD->bases()) + if (Ty && Context.hasSameUnqualifiedType(QualType(Ty, 1), Base.getType())) + return true; + return S->isFunctionPrototypeScope(); + } + return CurContext->isFunctionOrMethod() || S->isFunctionPrototypeScope(); + } + + void Sema::DiagnoseUnknownTypeName(IdentifierInfo *&II, + SourceLocation IILoc, + Scope *S, + CXXScopeSpec *SS, + ParsedType &SuggestedType, + bool IsTemplateName) { + // Don't report typename errors for editor placeholders. + if (II->isEditorPlaceholder()) + return; + // We don't have anything to suggest (yet). + SuggestedType = nullptr; + + // There may have been a typo in the name of the type. Look up typo + // results, in case we have something that we can suggest. + if (TypoCorrection Corrected = + CorrectTypo(DeclarationNameInfo(II, IILoc), LookupOrdinaryName, S, SS, + llvm::make_unique( + false, false, IsTemplateName, !IsTemplateName), + CTK_ErrorRecovery)) { + // FIXME: Support error recovery for the template-name case. + bool CanRecover = !IsTemplateName; + if (Corrected.isKeyword()) { + // We corrected to a keyword. + diagnoseTypo(Corrected, + PDiag(IsTemplateName ? diag::err_no_template_suggest + : diag::err_unknown_typename_suggest) + << II); + II = Corrected.getCorrectionAsIdentifierInfo(); + } else { + // We found a similarly-named type or interface; suggest that. + if (!SS || !SS->isSet()) { + diagnoseTypo(Corrected, + PDiag(IsTemplateName ? diag::err_no_template_suggest + : diag::err_unknown_typename_suggest) + << II, CanRecover); + } else if (DeclContext *DC = computeDeclContext(*SS, false)) { + std::string CorrectedStr(Corrected.getAsString(getLangOpts())); + bool DroppedSpecifier = Corrected.WillReplaceSpecifier() && + II->getName().equals(CorrectedStr); + diagnoseTypo(Corrected, + PDiag(IsTemplateName + ? diag::err_no_member_template_suggest + : diag::err_unknown_nested_typename_suggest) + << II << DC << DroppedSpecifier << SS->getRange(), + CanRecover); + } else { + llvm_unreachable("could not have corrected a typo here"); + } + + if (!CanRecover) + return; + + CXXScopeSpec tmpSS; + if (Corrected.getCorrectionSpecifier()) + tmpSS.MakeTrivial(Context, Corrected.getCorrectionSpecifier(), + SourceRange(IILoc)); + // FIXME: Support class template argument deduction here. + SuggestedType = + getTypeName(*Corrected.getCorrectionAsIdentifierInfo(), IILoc, S, + tmpSS.isSet() ? &tmpSS : SS, false, false, nullptr, + /*IsCtorOrDtorName=*/false, + /*NonTrivialTypeSourceInfo=*/true); + } + return; + } + + if (getLangOpts().CPlusPlus && !IsTemplateName) { + // See if II is a class template that the user forgot to pass arguments to. + UnqualifiedId Name; + Name.setIdentifier(II, IILoc); + CXXScopeSpec EmptySS; + TemplateTy TemplateResult; + bool MemberOfUnknownSpecialization; + if (isTemplateName(S, SS ? *SS : EmptySS, /*hasTemplateKeyword=*/false, + Name, nullptr, true, TemplateResult, + MemberOfUnknownSpecialization) == TNK_Type_template) { + diagnoseMissingTemplateArguments(TemplateResult.get(), IILoc); + return; + } + } + + // FIXME: Should we move the logic that tries to recover from a missing tag + // (struct, union, enum) from Parser::ParseImplicitInt here, instead? + + if (!SS || (!SS->isSet() && !SS->isInvalid())) + Diag(IILoc, IsTemplateName ? diag::err_no_template + : diag::err_unknown_typename) + << II; + else if (DeclContext *DC = computeDeclContext(*SS, false)) + Diag(IILoc, IsTemplateName ? diag::err_no_member_template + : diag::err_typename_nested_not_found) + << II << DC << SS->getRange(); + else if (isDependentScopeSpecifier(*SS)) { + unsigned DiagID = diag::err_typename_missing; + if (getLangOpts().MSVCCompat && isMicrosoftMissingTypename(SS, S)) + DiagID = diag::ext_typename_missing; + + Diag(SS->getRange().getBegin(), DiagID) + << SS->getScopeRep() << II->getName() + << SourceRange(SS->getRange().getBegin(), IILoc) + << FixItHint::CreateInsertion(SS->getRange().getBegin(), "typename "); + SuggestedType = ActOnTypenameType(S, SourceLocation(), + *SS, *II, IILoc).get(); + } else { + assert(SS && SS->isInvalid() && + "Invalid scope specifier has already been diagnosed"); + } + } + + /// Determine whether the given result set contains either a type name + /// or + static bool isResultTypeOrTemplate(LookupResult &R, const Token &NextToken) { + bool CheckTemplate = R.getSema().getLangOpts().CPlusPlus && + NextToken.is(tok::less); + + for (LookupResult::iterator I = R.begin(), IEnd = R.end(); I != IEnd; ++I) { + if (isa(*I) || isa(*I)) + return true; + + if (CheckTemplate && isa(*I)) + return true; + } + + return false; + } + + static bool isTagTypeWithMissingTag(Sema &SemaRef, LookupResult &Result, + Scope *S, CXXScopeSpec &SS, + IdentifierInfo *&Name, + SourceLocation NameLoc) { + LookupResult R(SemaRef, Name, NameLoc, Sema::LookupTagName); + SemaRef.LookupParsedName(R, S, &SS); + if (TagDecl *Tag = R.getAsSingle()) { + StringRef FixItTagName; + switch (Tag->getTagKind()) { + case TTK_Class: + FixItTagName = "class "; + break; + + case TTK_Enum: + FixItTagName = "enum "; + break; + + case TTK_Struct: + FixItTagName = "struct "; + break; + + case TTK_Interface: + FixItTagName = "__interface "; + break; + + case TTK_Union: + FixItTagName = "union "; + break; + } + + StringRef TagName = FixItTagName.drop_back(); + SemaRef.Diag(NameLoc, diag::err_use_of_tag_name_without_tag) + << Name << TagName << SemaRef.getLangOpts().CPlusPlus + << FixItHint::CreateInsertion(NameLoc, FixItTagName); + + for (LookupResult::iterator I = Result.begin(), IEnd = Result.end(); + I != IEnd; ++I) + SemaRef.Diag((*I)->getLocation(), diag::note_decl_hiding_tag_type) + << Name << TagName; + + // Replace lookup results with just the tag decl. + Result.clear(Sema::LookupTagName); + SemaRef.LookupParsedName(Result, S, &SS); + return true; + } + + return false; + } + + /// Build a ParsedType for a simple-type-specifier with a nested-name-specifier. + static ParsedType buildNestedType(Sema &S, CXXScopeSpec &SS, + QualType T, SourceLocation NameLoc) { + ASTContext &Context = S.Context; + + TypeLocBuilder Builder; + Builder.pushTypeSpec(T).setNameLoc(NameLoc); + + T = S.getElaboratedType(ETK_None, SS, T); + ElaboratedTypeLoc ElabTL = Builder.push(T); + ElabTL.setElaboratedKeywordLoc(SourceLocation()); + ElabTL.setQualifierLoc(SS.getWithLocInContext(Context)); + return S.CreateParsedType(T, Builder.getTypeSourceInfo(Context, T)); + } + + Sema::NameClassification + Sema::ClassifyName(Scope *S, CXXScopeSpec &SS, IdentifierInfo *&Name, + SourceLocation NameLoc, const Token &NextToken, + bool IsAddressOfOperand, + std::unique_ptr CCC) { + DeclarationNameInfo NameInfo(Name, NameLoc); + ObjCMethodDecl *CurMethod = getCurMethodDecl(); + + if (NextToken.is(tok::coloncolon)) { + NestedNameSpecInfo IdInfo(Name, NameLoc, NextToken.getLocation()); + BuildCXXNestedNameSpecifier(S, IdInfo, false, SS, nullptr, false); + } else if (getLangOpts().CPlusPlus && SS.isSet() && + isCurrentClassName(*Name, S, &SS)) { + // Per [class.qual]p2, this names the constructors of SS, not the + // injected-class-name. We don't have a classification for that. + // There's not much point caching this result, since the parser + // will reject it later. + return NameClassification::Unknown(); + } + + LookupResult Result(*this, Name, NameLoc, LookupOrdinaryName); + LookupParsedName(Result, S, &SS, !CurMethod); + + // For unqualified lookup in a class template in MSVC mode, look into + // dependent base classes where the primary class template is known. + if (Result.empty() && SS.isEmpty() && getLangOpts().MSVCCompat) { + if (ParsedType TypeInBase = + recoverFromTypeInKnownDependentBase(*this, *Name, NameLoc)) + return TypeInBase; + } + + // Perform lookup for Objective-C instance variables (including automatically + // synthesized instance variables), if we're in an Objective-C method. + // FIXME: This lookup really, really needs to be folded in to the normal + // unqualified lookup mechanism. + if (!SS.isSet() && CurMethod && !isResultTypeOrTemplate(Result, NextToken)) { + ExprResult E = LookupInObjCMethod(Result, S, Name, true); + if (E.get() || E.isInvalid()) + return E; + } + + bool SecondTry = false; + bool IsFilteredTemplateName = false; + + Corrected: + switch (Result.getResultKind()) { + case LookupResult::NotFound: + // If an unqualified-id is followed by a '(', then we have a function + // call. + if (!SS.isSet() && NextToken.is(tok::l_paren)) { + // In C++, this is an ADL-only call. + // FIXME: Reference? + if (getLangOpts().CPlusPlus) + return BuildDeclarationNameExpr(SS, Result, /*ADL=*/true); + + // C90 6.3.2.2: + // If the expression that precedes the parenthesized argument list in a + // function call consists solely of an identifier, and if no + // declaration is visible for this identifier, the identifier is + // implicitly declared exactly as if, in the innermost block containing + // the function call, the declaration + // + // extern int identifier (); + // + // appeared. + // + // We also allow this in C99 as an extension. + if (NamedDecl *D = ImplicitlyDefineFunction(NameLoc, *Name, S)) { + Result.addDecl(D); + Result.resolveKind(); + return BuildDeclarationNameExpr(SS, Result, /*ADL=*/false); + } + } + + // In C, we first see whether there is a tag type by the same name, in + // which case it's likely that the user just forgot to write "enum", + // "struct", or "union". + if (!getLangOpts().CPlusPlus && !SecondTry && + isTagTypeWithMissingTag(*this, Result, S, SS, Name, NameLoc)) { + break; + } + + // Perform typo correction to determine if there is another name that is + // close to this name. + if (!SecondTry && CCC) { + SecondTry = true; + if (TypoCorrection Corrected = CorrectTypo(Result.getLookupNameInfo(), + Result.getLookupKind(), S, + &SS, std::move(CCC), + CTK_ErrorRecovery)) { + unsigned UnqualifiedDiag = diag::err_undeclared_var_use_suggest; + unsigned QualifiedDiag = diag::err_no_member_suggest; + + NamedDecl *FirstDecl = Corrected.getFoundDecl(); + NamedDecl *UnderlyingFirstDecl = Corrected.getCorrectionDecl(); + if (getLangOpts().CPlusPlus && NextToken.is(tok::less) && + UnderlyingFirstDecl && isa(UnderlyingFirstDecl)) { + UnqualifiedDiag = diag::err_no_template_suggest; + QualifiedDiag = diag::err_no_member_template_suggest; + } else if (UnderlyingFirstDecl && + (isa(UnderlyingFirstDecl) || + isa(UnderlyingFirstDecl) || + isa(UnderlyingFirstDecl))) { + UnqualifiedDiag = diag::err_unknown_typename_suggest; + QualifiedDiag = diag::err_unknown_nested_typename_suggest; + } + + if (SS.isEmpty()) { + diagnoseTypo(Corrected, PDiag(UnqualifiedDiag) << Name); + } else {// FIXME: is this even reachable? Test it. + std::string CorrectedStr(Corrected.getAsString(getLangOpts())); + bool DroppedSpecifier = Corrected.WillReplaceSpecifier() && + Name->getName().equals(CorrectedStr); + diagnoseTypo(Corrected, PDiag(QualifiedDiag) + << Name << computeDeclContext(SS, false) + << DroppedSpecifier << SS.getRange()); + } + + // Update the name, so that the caller has the new name. + Name = Corrected.getCorrectionAsIdentifierInfo(); + + // Typo correction corrected to a keyword. + if (Corrected.isKeyword()) + return Name; + + // Also update the LookupResult... + // FIXME: This should probably go away at some point + Result.clear(); + Result.setLookupName(Corrected.getCorrection()); + if (FirstDecl) + Result.addDecl(FirstDecl); + + // If we found an Objective-C instance variable, let + // LookupInObjCMethod build the appropriate expression to + // reference the ivar. + // FIXME: This is a gross hack. + if (ObjCIvarDecl *Ivar = Result.getAsSingle()) { + Result.clear(); + ExprResult E(LookupInObjCMethod(Result, S, Ivar->getIdentifier())); + return E; + } + + goto Corrected; + } + } + + // We failed to correct; just fall through and let the parser deal with it. + Result.suppressDiagnostics(); + return NameClassification::Unknown(); + + case LookupResult::NotFoundInCurrentInstantiation: { + // We performed name lookup into the current instantiation, and there were + // dependent bases, so we treat this result the same way as any other + // dependent nested-name-specifier. + + // C++ [temp.res]p2: + // A name used in a template declaration or definition and that is + // dependent on a template-parameter is assumed not to name a type + // unless the applicable name lookup finds a type name or the name is + // qualified by the keyword typename. + // + // FIXME: If the next token is '<', we might want to ask the parser to + // perform some heroics to see if we actually have a + // template-argument-list, which would indicate a missing 'template' + // keyword here. + return ActOnDependentIdExpression(SS, /*TemplateKWLoc=*/SourceLocation(), + NameInfo, IsAddressOfOperand, + /*TemplateArgs=*/nullptr); + } + + case LookupResult::Found: + case LookupResult::FoundOverloaded: + case LookupResult::FoundUnresolvedValue: + break; + + case LookupResult::Ambiguous: + if (getLangOpts().CPlusPlus && NextToken.is(tok::less) && + hasAnyAcceptableTemplateNames(Result, /*AllowFunctionTemplates=*/true, + /*AllowDependent=*/false)) { + // C++ [temp.local]p3: + // A lookup that finds an injected-class-name (10.2) can result in an + // ambiguity in certain cases (for example, if it is found in more than + // one base class). If all of the injected-class-names that are found + // refer to specializations of the same class template, and if the name + // is followed by a template-argument-list, the reference refers to the + // class template itself and not a specialization thereof, and is not + // ambiguous. + // + // This filtering can make an ambiguous result into an unambiguous one, + // so try again after filtering out template names. + FilterAcceptableTemplateNames(Result); + if (!Result.isAmbiguous()) { + IsFilteredTemplateName = true; + break; + } + } + + // Diagnose the ambiguity and return an error. + return NameClassification::Error(); + } + + if (getLangOpts().CPlusPlus && NextToken.is(tok::less) && + (IsFilteredTemplateName || + hasAnyAcceptableTemplateNames(Result, /*AllowFunctionTemplates=*/true, + /*AllowDependent=*/false))) { + // C++ [temp.names]p3: + // After name lookup (3.4) finds that a name is a template-name or that + // an operator-function-id or a literal- operator-id refers to a set of + // overloaded functions any member of which is a function template if + // this is followed by a <, the < is always taken as the delimiter of a + // template-argument-list and never as the less-than operator. + if (!IsFilteredTemplateName) + FilterAcceptableTemplateNames(Result); + + if (!Result.empty()) { + bool IsFunctionTemplate; + bool IsVarTemplate; + TemplateName Template; + if (Result.end() - Result.begin() > 1) { + IsFunctionTemplate = true; + Template = Context.getOverloadedTemplateName(Result.begin(), + Result.end()); + } else { + auto *TD = cast(getAsTemplateNameDecl( + *Result.begin(), /*AllowFunctionTemplates=*/true, + /*AllowDependent=*/false)); + IsFunctionTemplate = isa(TD); + IsVarTemplate = isa(TD); + + if (SS.isSet() && !SS.isInvalid()) + Template = + Context.getQualifiedTemplateName(SS.getScopeRep(), + /*TemplateKeyword=*/false, TD); + else + Template = TemplateName(TD); + } + + if (IsFunctionTemplate) { + // Function templates always go through overload resolution, at which + // point we'll perform the various checks (e.g., accessibility) we need + // to based on which function we selected. + Result.suppressDiagnostics(); + + return NameClassification::FunctionTemplate(Template); + } + + return IsVarTemplate ? NameClassification::VarTemplate(Template) + : NameClassification::TypeTemplate(Template); + } + } + + NamedDecl *FirstDecl = (*Result.begin())->getUnderlyingDecl(); + if (TypeDecl *Type = dyn_cast(FirstDecl)) { + DiagnoseUseOfDecl(Type, NameLoc); + MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false); + QualType T = Context.getTypeDeclType(Type); + if (SS.isNotEmpty()) + return buildNestedType(*this, SS, T, NameLoc); + return ParsedType::make(T); + } + + ObjCInterfaceDecl *Class = dyn_cast(FirstDecl); + if (!Class) { + // FIXME: It's unfortunate that we don't have a Type node for handling this. + if (ObjCCompatibleAliasDecl *Alias = + dyn_cast(FirstDecl)) + Class = Alias->getClassInterface(); + } + + if (Class) { + DiagnoseUseOfDecl(Class, NameLoc); + + if (NextToken.is(tok::period)) { + // Interface. is parsed as a property reference expression. + // Just return "unknown" as a fall-through for now. + Result.suppressDiagnostics(); + return NameClassification::Unknown(); + } + + QualType T = Context.getObjCInterfaceType(Class); + return ParsedType::make(T); + } + + // We can have a type template here if we're classifying a template argument. + if (isa(FirstDecl) && !isa(FirstDecl) && + !isa(FirstDecl)) + return NameClassification::TypeTemplate( + TemplateName(cast(FirstDecl))); + + // Check for a tag type hidden by a non-type decl in a few cases where it + // seems likely a type is wanted instead of the non-type that was found. + bool NextIsOp = NextToken.isOneOf(tok::amp, tok::star); + if ((NextToken.is(tok::identifier) || + (NextIsOp && + FirstDecl->getUnderlyingDecl()->isFunctionOrFunctionTemplate())) && + isTagTypeWithMissingTag(*this, Result, S, SS, Name, NameLoc)) { + TypeDecl *Type = Result.getAsSingle(); + DiagnoseUseOfDecl(Type, NameLoc); + QualType T = Context.getTypeDeclType(Type); + if (SS.isNotEmpty()) + return buildNestedType(*this, SS, T, NameLoc); + return ParsedType::make(T); + } + + if (FirstDecl->isCXXClassMember()) + return BuildPossibleImplicitMemberExpr(SS, SourceLocation(), Result, + nullptr, S); + + bool ADL = UseArgumentDependentLookup(SS, Result, NextToken.is(tok::l_paren)); + return BuildDeclarationNameExpr(SS, Result, ADL); + } + + Sema::TemplateNameKindForDiagnostics + Sema::getTemplateNameKindForDiagnostics(TemplateName Name) { + auto *TD = Name.getAsTemplateDecl(); + if (!TD) + return TemplateNameKindForDiagnostics::DependentTemplate; + if (isa(TD)) + return TemplateNameKindForDiagnostics::ClassTemplate; + if (isa(TD)) + return TemplateNameKindForDiagnostics::FunctionTemplate; + if (isa(TD)) + return TemplateNameKindForDiagnostics::VarTemplate; + if (isa(TD)) + return TemplateNameKindForDiagnostics::AliasTemplate; + if (isa(TD)) + return TemplateNameKindForDiagnostics::TemplateTemplateParam; + return TemplateNameKindForDiagnostics::DependentTemplate; + } + + // Determines the context to return to after temporarily entering a + // context. This depends in an unnecessarily complicated way on the + // exact ordering of callbacks from the parser. + DeclContext *Sema::getContainingDC(DeclContext *DC) { + + // Functions defined inline within classes aren't parsed until we've + // finished parsing the top-level class, so the top-level class is + // the context we'll need to return to. + // A Lambda call operator whose parent is a class must not be treated + // as an inline member function. A Lambda can be used legally + // either as an in-class member initializer or a default argument. These + // are parsed once the class has been marked complete and so the containing + // context would be the nested class (when the lambda is defined in one); + // If the class is not complete, then the lambda is being used in an + // ill-formed fashion (such as to specify the width of a bit-field, or + // in an array-bound) - in which case we still want to return the + // lexically containing DC (which could be a nested class). + if (isa(DC) && !isLambdaCallOperator(DC)) { + DC = DC->getLexicalParent(); + + // A function not defined within a class will always return to its + // lexical context. + if (!isa(DC)) + return DC; + + // A C++ inline method/friend is parsed *after* the topmost class + // it was declared in is fully parsed ("complete"); the topmost + // class is the context we need to return to. + while (CXXRecordDecl *RD = dyn_cast(DC->getLexicalParent())) + DC = RD; + + // Return the declaration context of the topmost class the inline method is + // declared in. + return DC; + } + + return DC->getLexicalParent(); + } + + void Sema::PushDeclContext(Scope *S, DeclContext *DC) { + assert(getContainingDC(DC) == CurContext && + "The next DeclContext should be lexically contained in the current one."); + CurContext = DC; + S->setEntity(DC); + } + + void Sema::PopDeclContext() { + assert(CurContext && "DeclContext imbalance!"); + + CurContext = getContainingDC(CurContext); + assert(CurContext && "Popped translation unit!"); + } + + Sema::SkippedDefinitionContext Sema::ActOnTagStartSkippedDefinition(Scope *S, + Decl *D) { + // Unlike PushDeclContext, the context to which we return is not necessarily + // the containing DC of TD, because the new context will be some pre-existing + // TagDecl definition instead of a fresh one. + auto Result = static_cast(CurContext); + CurContext = cast(D)->getDefinition(); + assert(CurContext && "skipping definition of undefined tag"); + // Start lookups from the parent of the current context; we don't want to look + // into the pre-existing complete definition. + S->setEntity(CurContext->getLookupParent()); + return Result; + } + + void Sema::ActOnTagFinishSkippedDefinition(SkippedDefinitionContext Context) { + CurContext = static_cast(Context); + } + + /// EnterDeclaratorContext - Used when we must lookup names in the context + /// of a declarator's nested name specifier. + /// + void Sema::EnterDeclaratorContext(Scope *S, DeclContext *DC) { + // C++0x [basic.lookup.unqual]p13: + // A name used in the definition of a static data member of class + // X (after the qualified-id of the static member) is looked up as + // if the name was used in a member function of X. + // C++0x [basic.lookup.unqual]p14: + // If a variable member of a namespace is defined outside of the + // scope of its namespace then any name used in the definition of + // the variable member (after the declarator-id) is looked up as + // if the definition of the variable member occurred in its + // namespace. + // Both of these imply that we should push a scope whose context + // is the semantic context of the declaration. We can't use + // PushDeclContext here because that context is not necessarily + // lexically contained in the current context. Fortunately, + // the containing scope should have the appropriate information. + + assert(!S->getEntity() && "scope already has entity"); + + #ifndef NDEBUG + Scope *Ancestor = S->getParent(); + while (!Ancestor->getEntity()) Ancestor = Ancestor->getParent(); + assert(Ancestor->getEntity() == CurContext && "ancestor context mismatch"); + #endif + + CurContext = DC; + S->setEntity(DC); + } + + void Sema::ExitDeclaratorContext(Scope *S) { + assert(S->getEntity() == CurContext && "Context imbalance!"); + + // Switch back to the lexical context. The safety of this is + // enforced by an assert in EnterDeclaratorContext. + Scope *Ancestor = S->getParent(); + while (!Ancestor->getEntity()) Ancestor = Ancestor->getParent(); + CurContext = Ancestor->getEntity(); + + // We don't need to do anything with the scope, which is going to + // disappear. + } + + void Sema::ActOnReenterFunctionContext(Scope* S, Decl *D) { + // We assume that the caller has already called + // ActOnReenterTemplateScope so getTemplatedDecl() works. + FunctionDecl *FD = D->getAsFunction(); + if (!FD) + return; + + // Same implementation as PushDeclContext, but enters the context + // from the lexical parent, rather than the top-level class. + assert(CurContext == FD->getLexicalParent() && + "The next DeclContext should be lexically contained in the current one."); + CurContext = FD; + S->setEntity(CurContext); + + for (unsigned P = 0, NumParams = FD->getNumParams(); P < NumParams; ++P) { + ParmVarDecl *Param = FD->getParamDecl(P); + // If the parameter has an identifier, then add it to the scope + if (Param->getIdentifier()) { + S->AddDecl(Param); + IdResolver.AddDecl(Param); + } + } + } + + void Sema::ActOnExitFunctionContext() { + // Same implementation as PopDeclContext, but returns to the lexical parent, + // rather than the top-level class. + assert(CurContext && "DeclContext imbalance!"); + CurContext = CurContext->getLexicalParent(); + assert(CurContext && "Popped translation unit!"); + } + + /// Determine whether we allow overloading of the function + /// PrevDecl with another declaration. + /// + /// This routine determines whether overloading is possible, not + /// whether some new function is actually an overload. It will return + /// true in C++ (where we can always provide overloads) or, as an + /// extension, in C when the previous function is already an + /// overloaded function declaration or has the "overloadable" + /// attribute. + static bool AllowOverloadingOfFunction(LookupResult &Previous, + ASTContext &Context, + const FunctionDecl *New) { + if (Context.getLangOpts().CPlusPlus) + return true; + + if (Previous.getResultKind() == LookupResult::FoundOverloaded) + return true; + + return Previous.getResultKind() == LookupResult::Found && + (Previous.getFoundDecl()->hasAttr() || + New->hasAttr()); + } + + /// Add this decl to the scope shadowed decl chains. + void Sema::PushOnScopeChains(NamedDecl *D, Scope *S, bool AddToContext) { + // Move up the scope chain until we find the nearest enclosing + // non-transparent context. The declaration will be introduced into this + // scope. + while (S->getEntity() && S->getEntity()->isTransparentContext()) + S = S->getParent(); + + // Add scoped declarations into their context, so that they can be + // found later. Declarations without a context won't be inserted + // into any context. + if (AddToContext) + CurContext->addDecl(D); + + // Out-of-line definitions shouldn't be pushed into scope in C++, unless they + // are function-local declarations. + if (getLangOpts().CPlusPlus && D->isOutOfLine() && + !D->getDeclContext()->getRedeclContext()->Equals( + D->getLexicalDeclContext()->getRedeclContext()) && + !D->getLexicalDeclContext()->isFunctionOrMethod()) + return; + + // Template instantiations should also not be pushed into scope. + if (isa(D) && + cast(D)->isFunctionTemplateSpecialization()) + return; + + // If this replaces anything in the current scope, + IdentifierResolver::iterator I = IdResolver.begin(D->getDeclName()), + IEnd = IdResolver.end(); + for (; I != IEnd; ++I) { + if (S->isDeclScope(*I) && D->declarationReplaces(*I)) { + S->RemoveDecl(*I); + IdResolver.RemoveDecl(*I); + + // Should only need to replace one decl. + break; + } + } + + S->AddDecl(D); + + if (isa(D) && !cast(D)->isGnuLocal()) { + // Implicitly-generated labels may end up getting generated in an order that + // isn't strictly lexical, which breaks name lookup. Be careful to insert + // the label at the appropriate place in the identifier chain. + for (I = IdResolver.begin(D->getDeclName()); I != IEnd; ++I) { + DeclContext *IDC = (*I)->getLexicalDeclContext()->getRedeclContext(); + if (IDC == CurContext) { + if (!S->isDeclScope(*I)) + continue; + } else if (IDC->Encloses(CurContext)) + break; + } + + IdResolver.InsertDeclAfter(I, D); + } else { + IdResolver.AddDecl(D); + } + } + + void Sema::pushExternalDeclIntoScope(NamedDecl *D, DeclarationName Name) { + if (IdResolver.tryAddTopLevelDecl(D, Name) && TUScope) + TUScope->AddDecl(D); + } + + bool Sema::isDeclInScope(NamedDecl *D, DeclContext *Ctx, Scope *S, + bool AllowInlineNamespace) { + return IdResolver.isDeclInScope(D, Ctx, S, AllowInlineNamespace); + } + + Scope *Sema::getScopeForDeclContext(Scope *S, DeclContext *DC) { + DeclContext *TargetDC = DC->getPrimaryContext(); + do { + if (DeclContext *ScopeDC = S->getEntity()) + if (ScopeDC->getPrimaryContext() == TargetDC) + return S; + } while ((S = S->getParent())); + + return nullptr; + } + + static bool isOutOfScopePreviousDeclaration(NamedDecl *, + DeclContext*, + ASTContext&); + + /// Filters out lookup results that don't fall within the given scope + /// as determined by isDeclInScope. + void Sema::FilterLookupForScope(LookupResult &R, DeclContext *Ctx, Scope *S, + bool ConsiderLinkage, + bool AllowInlineNamespace) { + LookupResult::Filter F = R.makeFilter(); + while (F.hasNext()) { + NamedDecl *D = F.next(); + + if (isDeclInScope(D, Ctx, S, AllowInlineNamespace)) + continue; + + if (ConsiderLinkage && isOutOfScopePreviousDeclaration(D, Ctx, Context)) + continue; + + F.erase(); + } + + F.done(); + } + + /// We've determined that \p New is a redeclaration of \p Old. Check that they + /// have compatible owning modules. + bool Sema::CheckRedeclarationModuleOwnership(NamedDecl *New, NamedDecl *Old) { + // FIXME: The Modules TS is not clear about how friend declarations are + // to be treated. It's not meaningful to have different owning modules for + // linkage in redeclarations of the same entity, so for now allow the + // redeclaration and change the owning modules to match. + if (New->getFriendObjectKind() && + Old->getOwningModuleForLinkage() != New->getOwningModuleForLinkage()) { + New->setLocalOwningModule(Old->getOwningModule()); + makeMergedDefinitionVisible(New); + return false; + } + + Module *NewM = New->getOwningModule(); + Module *OldM = Old->getOwningModule(); + if (NewM == OldM) + return false; + + // FIXME: Check proclaimed-ownership-declarations here too. + bool NewIsModuleInterface = NewM && NewM->Kind == Module::ModuleInterfaceUnit; + bool OldIsModuleInterface = OldM && OldM->Kind == Module::ModuleInterfaceUnit; + if (NewIsModuleInterface || OldIsModuleInterface) { + // C++ Modules TS [basic.def.odr] 6.2/6.7 [sic]: + // if a declaration of D [...] appears in the purview of a module, all + // other such declarations shall appear in the purview of the same module + Diag(New->getLocation(), diag::err_mismatched_owning_module) + << New + << NewIsModuleInterface + << (NewIsModuleInterface ? NewM->getFullModuleName() : "") + << OldIsModuleInterface + << (OldIsModuleInterface ? OldM->getFullModuleName() : ""); + Diag(Old->getLocation(), diag::note_previous_declaration); + New->setInvalidDecl(); + return true; + } + + return false; + } + + static bool isUsingDecl(NamedDecl *D) { + return isa(D) || + isa(D) || + isa(D); + } + + /// Removes using shadow declarations from the lookup results. + static void RemoveUsingDecls(LookupResult &R) { + LookupResult::Filter F = R.makeFilter(); + while (F.hasNext()) + if (isUsingDecl(F.next())) + F.erase(); + + F.done(); + } + + /// Check for this common pattern: + /// @code + /// class S { + /// S(const S&); // DO NOT IMPLEMENT + /// void operator=(const S&); // DO NOT IMPLEMENT + /// }; + /// @endcode + static bool IsDisallowedCopyOrAssign(const CXXMethodDecl *D) { + // FIXME: Should check for private access too but access is set after we get + // the decl here. + if (D->doesThisDeclarationHaveABody()) + return false; + + if (const CXXConstructorDecl *CD = dyn_cast(D)) + return CD->isCopyConstructor(); + return D->isCopyAssignmentOperator(); + } + + // We need this to handle + // + // typedef struct { + // void *foo() { return 0; } + // } A; + // + // When we see foo we don't know if after the typedef we will get 'A' or '*A' + // for example. If 'A', foo will have external linkage. If we have '*A', + // foo will have no linkage. Since we can't know until we get to the end + // of the typedef, this function finds out if D might have non-external linkage. + // Callers should verify at the end of the TU if it D has external linkage or + // not. + bool Sema::mightHaveNonExternalLinkage(const DeclaratorDecl *D) { + const DeclContext *DC = D->getDeclContext(); + while (!DC->isTranslationUnit()) { + if (const RecordDecl *RD = dyn_cast(DC)){ + if (!RD->hasNameForLinkage()) + return true; + } + DC = DC->getParent(); + } + + return !D->isExternallyVisible(); + } + + // FIXME: This needs to be refactored; some other isInMainFile users want + // these semantics. + static bool isMainFileLoc(const Sema &S, SourceLocation Loc) { + if (S.TUKind != TU_Complete) + return false; + return S.SourceMgr.isInMainFile(Loc); + } + + bool Sema::ShouldWarnIfUnusedFileScopedDecl(const DeclaratorDecl *D) const { + assert(D); + + if (D->isInvalidDecl() || D->isUsed() || D->hasAttr()) + return false; + + // Ignore all entities declared within templates, and out-of-line definitions + // of members of class templates. + if (D->getDeclContext()->isDependentContext() || + D->getLexicalDeclContext()->isDependentContext()) + return false; + + if (const FunctionDecl *FD = dyn_cast(D)) { + if (FD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation) + return false; + // A non-out-of-line declaration of a member specialization was implicitly + // instantiated; it's the out-of-line declaration that we're interested in. + if (FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization && + FD->getMemberSpecializationInfo() && !FD->isOutOfLine()) + return false; + + if (const CXXMethodDecl *MD = dyn_cast(FD)) { + if (MD->isVirtual() || IsDisallowedCopyOrAssign(MD)) + return false; + } else { + // 'static inline' functions are defined in headers; don't warn. + if (FD->isInlined() && !isMainFileLoc(*this, FD->getLocation())) + return false; + } + + if (FD->doesThisDeclarationHaveABody() && + Context.DeclMustBeEmitted(FD)) + return false; + } else if (const VarDecl *VD = dyn_cast(D)) { + // Constants and utility variables are defined in headers with internal + // linkage; don't warn. (Unlike functions, there isn't a convenient marker + // like "inline".) + if (!isMainFileLoc(*this, VD->getLocation())) + return false; + + if (Context.DeclMustBeEmitted(VD)) + return false; + + if (VD->isStaticDataMember() && + VD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation) + return false; + if (VD->isStaticDataMember() && + VD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization && + VD->getMemberSpecializationInfo() && !VD->isOutOfLine()) + return false; + + if (VD->isInline() && !isMainFileLoc(*this, VD->getLocation())) + return false; + } else { + return false; + } + + // Only warn for unused decls internal to the translation unit. + // FIXME: This seems like a bogus check; it suppresses -Wunused-function + // for inline functions defined in the main source file, for instance. + return mightHaveNonExternalLinkage(D); + } + + void Sema::MarkUnusedFileScopedDecl(const DeclaratorDecl *D) { + if (!D) + return; + + if (const FunctionDecl *FD = dyn_cast(D)) { + const FunctionDecl *First = FD->getFirstDecl(); + if (FD != First && ShouldWarnIfUnusedFileScopedDecl(First)) + return; // First should already be in the vector. + } + + if (const VarDecl *VD = dyn_cast(D)) { + const VarDecl *First = VD->getFirstDecl(); + if (VD != First && ShouldWarnIfUnusedFileScopedDecl(First)) + return; // First should already be in the vector. + } + + if (ShouldWarnIfUnusedFileScopedDecl(D)) + UnusedFileScopedDecls.push_back(D); + } + + static bool ShouldDiagnoseUnusedDecl(const NamedDecl *D) { + if (D->isInvalidDecl()) + return false; + + bool Referenced = false; + if (auto *DD = dyn_cast(D)) { + // For a decomposition declaration, warn if none of the bindings are + // referenced, instead of if the variable itself is referenced (which + // it is, by the bindings' expressions). + for (auto *BD : DD->bindings()) { + if (BD->isReferenced()) { + Referenced = true; + break; + } + } + } else if (!D->getDeclName()) { + return false; + } else if (D->isReferenced() || D->isUsed()) { + Referenced = true; + } + + if (Referenced || D->hasAttr() || + D->hasAttr()) + return false; + + if (isa(D)) + return true; + + // Except for labels, we only care about unused decls that are local to + // functions. + bool WithinFunction = D->getDeclContext()->isFunctionOrMethod(); + if (const auto *R = dyn_cast(D->getDeclContext())) + // For dependent types, the diagnostic is deferred. + WithinFunction = + WithinFunction || (R->isLocalClass() && !R->isDependentType()); + if (!WithinFunction) + return false; + + if (isa(D)) + return true; + + // White-list anything that isn't a local variable. + if (!isa(D) || isa(D) || isa(D)) + return false; + + // Types of valid local variables should be complete, so this should succeed. + if (const VarDecl *VD = dyn_cast(D)) { + + // White-list anything with an __attribute__((unused)) type. + const auto *Ty = VD->getType().getTypePtr(); + + // Only look at the outermost level of typedef. + if (const TypedefType *TT = Ty->getAs()) { + if (TT->getDecl()->hasAttr()) + return false; + } + + // If we failed to complete the type for some reason, or if the type is + // dependent, don't diagnose the variable. + if (Ty->isIncompleteType() || Ty->isDependentType()) + return false; + + // Look at the element type to ensure that the warning behaviour is + // consistent for both scalars and arrays. + Ty = Ty->getBaseElementTypeUnsafe(); + + if (const TagType *TT = Ty->getAs()) { + const TagDecl *Tag = TT->getDecl(); + if (Tag->hasAttr()) + return false; + + if (const CXXRecordDecl *RD = dyn_cast(Tag)) { + if (!RD->hasTrivialDestructor() && !RD->hasAttr()) + return false; + + if (const Expr *Init = VD->getInit()) { + if (const ExprWithCleanups *Cleanups = + dyn_cast(Init)) + Init = Cleanups->getSubExpr(); + const CXXConstructExpr *Construct = + dyn_cast(Init); + if (Construct && !Construct->isElidable()) { + CXXConstructorDecl *CD = Construct->getConstructor(); + if (!CD->isTrivial() && !RD->hasAttr() && + (VD->getInit()->isValueDependent() || !VD->evaluateValue())) + return false; + } + } + } + } + + // TODO: __attribute__((unused)) templates? + } + + return true; + } + + static void GenerateFixForUnusedDecl(const NamedDecl *D, ASTContext &Ctx, + FixItHint &Hint) { + if (isa(D)) { + SourceLocation AfterColon = Lexer::findLocationAfterToken( + D->getEndLoc(), tok::colon, Ctx.getSourceManager(), Ctx.getLangOpts(), + true); + if (AfterColon.isInvalid()) + return; + Hint = FixItHint::CreateRemoval( + CharSourceRange::getCharRange(D->getBeginLoc(), AfterColon)); + } + } + + void Sema::DiagnoseUnusedNestedTypedefs(const RecordDecl *D) { + if (D->getTypeForDecl()->isDependentType()) + return; + + for (auto *TmpD : D->decls()) { + if (const auto *T = dyn_cast(TmpD)) + DiagnoseUnusedDecl(T); + else if(const auto *R = dyn_cast(TmpD)) + DiagnoseUnusedNestedTypedefs(R); + } + } + + /// DiagnoseUnusedDecl - Emit warnings about declarations that are not used + /// unless they are marked attr(unused). + void Sema::DiagnoseUnusedDecl(const NamedDecl *D) { + if (!ShouldDiagnoseUnusedDecl(D)) + return; + + if (auto *TD = dyn_cast(D)) { + // typedefs can be referenced later on, so the diagnostics are emitted + // at end-of-translation-unit. + UnusedLocalTypedefNameCandidates.insert(TD); + return; + } + + FixItHint Hint; + GenerateFixForUnusedDecl(D, Context, Hint); + + unsigned DiagID; + if (isa(D) && cast(D)->isExceptionVariable()) + DiagID = diag::warn_unused_exception_param; + else if (isa(D)) + DiagID = diag::warn_unused_label; + else + DiagID = diag::warn_unused_variable; + + Diag(D->getLocation(), DiagID) << D << Hint; + } + + static void CheckPoppedLabel(LabelDecl *L, Sema &S) { + // Verify that we have no forward references left. If so, there was a goto + // or address of a label taken, but no definition of it. Label fwd + // definitions are indicated with a null substmt which is also not a resolved + // MS inline assembly label name. + bool Diagnose = false; + if (L->isMSAsmLabel()) + Diagnose = !L->isResolvedMSAsmLabel(); + else + Diagnose = L->getStmt() == nullptr; + if (Diagnose) + S.Diag(L->getLocation(), diag::err_undeclared_label_use) <getDeclName(); + } + + void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) { + S->mergeNRVOIntoParent(); + + if (S->decl_empty()) return; + assert((S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) && + "Scope shouldn't contain decls!"); + + for (auto *TmpD : S->decls()) { + assert(TmpD && "This decl didn't get pushed??"); + + assert(isa(TmpD) && "Decl isn't NamedDecl?"); + NamedDecl *D = cast(TmpD); + + // Diagnose unused variables in this scope. + if (!S->hasUnrecoverableErrorOccurred()) { + DiagnoseUnusedDecl(D); + if (const auto *RD = dyn_cast(D)) + DiagnoseUnusedNestedTypedefs(RD); + } + + if (!D->getDeclName()) continue; + + // If this was a forward reference to a label, verify it was defined. + if (LabelDecl *LD = dyn_cast(D)) + CheckPoppedLabel(LD, *this); + + // Remove this name from our lexical scope, and warn on it if we haven't + // already. + IdResolver.RemoveDecl(D); + auto ShadowI = ShadowingDecls.find(D); + if (ShadowI != ShadowingDecls.end()) { + if (const auto *FD = dyn_cast(ShadowI->second)) { + Diag(D->getLocation(), diag::warn_ctor_parm_shadows_field) + << D << FD << FD->getParent(); + Diag(FD->getLocation(), diag::note_previous_declaration); + } + ShadowingDecls.erase(ShadowI); + } + } + } + + /// Look for an Objective-C class in the translation unit. + /// + /// \param Id The name of the Objective-C class we're looking for. If + /// typo-correction fixes this name, the Id will be updated + /// to the fixed name. + /// + /// \param IdLoc The location of the name in the translation unit. + /// + /// \param DoTypoCorrection If true, this routine will attempt typo correction + /// if there is no class with the given name. + /// + /// \returns The declaration of the named Objective-C class, or NULL if the + /// class could not be found. + ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *&Id, + SourceLocation IdLoc, + bool DoTypoCorrection) { + // The third "scope" argument is 0 since we aren't enabling lazy built-in + // creation from this context. + NamedDecl *IDecl = LookupSingleName(TUScope, Id, IdLoc, LookupOrdinaryName); + + if (!IDecl && DoTypoCorrection) { + // Perform typo correction at the given location, but only if we + // find an Objective-C class name. + if (TypoCorrection C = CorrectTypo( + DeclarationNameInfo(Id, IdLoc), LookupOrdinaryName, TUScope, nullptr, + llvm::make_unique>(), + CTK_ErrorRecovery)) { + diagnoseTypo(C, PDiag(diag::err_undef_interface_suggest) << Id); + IDecl = C.getCorrectionDeclAs(); + Id = IDecl->getIdentifier(); + } + } + ObjCInterfaceDecl *Def = dyn_cast_or_null(IDecl); + // This routine must always return a class definition, if any. + if (Def && Def->getDefinition()) + Def = Def->getDefinition(); + return Def; + } + + /// getNonFieldDeclScope - Retrieves the innermost scope, starting + /// from S, where a non-field would be declared. This routine copes + /// with the difference between C and C++ scoping rules in structs and + /// unions. For example, the following code is well-formed in C but + /// ill-formed in C++: + /// @code + /// struct S6 { + /// enum { BAR } e; + /// }; + /// + /// void test_S6() { + /// struct S6 a; + /// a.e = BAR; + /// } + /// @endcode + /// For the declaration of BAR, this routine will return a different + /// scope. The scope S will be the scope of the unnamed enumeration + /// within S6. In C++, this routine will return the scope associated + /// with S6, because the enumeration's scope is a transparent + /// context but structures can contain non-field names. In C, this + /// routine will return the translation unit scope, since the + /// enumeration's scope is a transparent context and structures cannot + /// contain non-field names. + Scope *Sema::getNonFieldDeclScope(Scope *S) { + while (((S->getFlags() & Scope::DeclScope) == 0) || + (S->getEntity() && S->getEntity()->isTransparentContext()) || + (S->isClassScope() && !getLangOpts().CPlusPlus)) + S = S->getParent(); + return S; + } + + /// Looks up the declaration of "struct objc_super" and + /// saves it for later use in building builtin declaration of + /// objc_msgSendSuper and objc_msgSendSuper_stret. If no such + /// pre-existing declaration exists no action takes place. + static void LookupPredefedObjCSuperType(Sema &ThisSema, Scope *S, + IdentifierInfo *II) { + if (!II->isStr("objc_msgSendSuper")) + return; + ASTContext &Context = ThisSema.Context; + + LookupResult Result(ThisSema, &Context.Idents.get("objc_super"), + SourceLocation(), Sema::LookupTagName); + ThisSema.LookupName(Result, S); + if (Result.getResultKind() == LookupResult::Found) + if (const TagDecl *TD = Result.getAsSingle()) + Context.setObjCSuperType(Context.getTagDeclType(TD)); + } + + static StringRef getHeaderName(Builtin::Context &BuiltinInfo, unsigned ID, + ASTContext::GetBuiltinTypeError Error) { + switch (Error) { + case ASTContext::GE_None: + return ""; + case ASTContext::GE_Missing_type: + return BuiltinInfo.getHeaderName(ID); + case ASTContext::GE_Missing_stdio: + return "stdio.h"; + case ASTContext::GE_Missing_setjmp: + return "setjmp.h"; + case ASTContext::GE_Missing_ucontext: + return "ucontext.h"; + } + llvm_unreachable("unhandled error kind"); + } + + /// LazilyCreateBuiltin - The specified Builtin-ID was first used at + /// file scope. lazily create a decl for it. ForRedeclaration is true + /// if we're creating this built-in in anticipation of redeclaring the + /// built-in. + NamedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned ID, + Scope *S, bool ForRedeclaration, + SourceLocation Loc) { + LookupPredefedObjCSuperType(*this, S, II); + + ASTContext::GetBuiltinTypeError Error; + QualType R = Context.GetBuiltinType(ID, Error); + if (Error) { + if (ForRedeclaration) + Diag(Loc, diag::warn_implicit_decl_requires_sysheader) + << getHeaderName(Context.BuiltinInfo, ID, Error) + << Context.BuiltinInfo.getName(ID); + return nullptr; + } + + if (!ForRedeclaration && + (Context.BuiltinInfo.isPredefinedLibFunction(ID) || + Context.BuiltinInfo.isHeaderDependentFunction(ID))) { + Diag(Loc, diag::ext_implicit_lib_function_decl) + << Context.BuiltinInfo.getName(ID) << R; + if (Context.BuiltinInfo.getHeaderName(ID) && + !Diags.isIgnored(diag::ext_implicit_lib_function_decl, Loc)) + Diag(Loc, diag::note_include_header_or_declare) + << Context.BuiltinInfo.getHeaderName(ID) + << Context.BuiltinInfo.getName(ID); + } + + if (R.isNull()) + return nullptr; + + DeclContext *Parent = Context.getTranslationUnitDecl(); + if (getLangOpts().CPlusPlus) { + LinkageSpecDecl *CLinkageDecl = + LinkageSpecDecl::Create(Context, Parent, Loc, Loc, + LinkageSpecDecl::lang_c, false); + CLinkageDecl->setImplicit(); + Parent->addDecl(CLinkageDecl); + Parent = CLinkageDecl; + } + + FunctionDecl *New = FunctionDecl::Create(Context, + Parent, + Loc, Loc, II, R, /*TInfo=*/nullptr, + SC_Extern, + false, + R->isFunctionProtoType()); + New->setImplicit(); + + // Create Decl objects for each parameter, adding them to the + // FunctionDecl. + if (const FunctionProtoType *FT = dyn_cast(R)) { + SmallVector Params; + for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) { + ParmVarDecl *parm = + ParmVarDecl::Create(Context, New, SourceLocation(), SourceLocation(), + nullptr, FT->getParamType(i), /*TInfo=*/nullptr, + SC_None, nullptr); + parm->setScopeInfo(0, i); + Params.push_back(parm); + } + New->setParams(Params); + } + + AddKnownFunctionAttributes(New); + RegisterLocallyScopedExternCDecl(New, S); + + // TUScope is the translation-unit scope to insert this function into. + // FIXME: This is hideous. We need to teach PushOnScopeChains to + // relate Scopes to DeclContexts, and probably eliminate CurContext + // entirely, but we're not there yet. + DeclContext *SavedContext = CurContext; + CurContext = Parent; + PushOnScopeChains(New, TUScope); + CurContext = SavedContext; + return New; + } + + /// Typedef declarations don't have linkage, but they still denote the same + /// entity if their types are the same. + /// FIXME: This is notionally doing the same thing as ASTReaderDecl's + /// isSameEntity. + static void filterNonConflictingPreviousTypedefDecls(Sema &S, + TypedefNameDecl *Decl, + LookupResult &Previous) { + // This is only interesting when modules are enabled. + if (!S.getLangOpts().Modules && !S.getLangOpts().ModulesLocalVisibility) + return; + + // Empty sets are uninteresting. + if (Previous.empty()) + return; + + LookupResult::Filter Filter = Previous.makeFilter(); + while (Filter.hasNext()) { + NamedDecl *Old = Filter.next(); + + // Non-hidden declarations are never ignored. + if (S.isVisible(Old)) + continue; + + // Declarations of the same entity are not ignored, even if they have + // different linkages. + if (auto *OldTD = dyn_cast(Old)) { + if (S.Context.hasSameType(OldTD->getUnderlyingType(), + Decl->getUnderlyingType())) + continue; + + // If both declarations give a tag declaration a typedef name for linkage + // purposes, then they declare the same entity. + if (OldTD->getAnonDeclWithTypedefName(/*AnyRedecl*/true) && + Decl->getAnonDeclWithTypedefName()) + continue; + } + + Filter.erase(); + } + + Filter.done(); + } + + bool Sema::isIncompatibleTypedef(TypeDecl *Old, TypedefNameDecl *New) { + QualType OldType; + if (TypedefNameDecl *OldTypedef = dyn_cast(Old)) + OldType = OldTypedef->getUnderlyingType(); + else + OldType = Context.getTypeDeclType(Old); + QualType NewType = New->getUnderlyingType(); + + if (NewType->isVariablyModifiedType()) { + // Must not redefine a typedef with a variably-modified type. + int Kind = isa(Old) ? 1 : 0; + Diag(New->getLocation(), diag::err_redefinition_variably_modified_typedef) + << Kind << NewType; + if (Old->getLocation().isValid()) + notePreviousDefinition(Old, New->getLocation()); + New->setInvalidDecl(); + return true; + } + + if (OldType != NewType && + !OldType->isDependentType() && + !NewType->isDependentType() && + !Context.hasSameType(OldType, NewType)) { + int Kind = isa(Old) ? 1 : 0; + Diag(New->getLocation(), diag::err_redefinition_different_typedef) + << Kind << NewType << OldType; + if (Old->getLocation().isValid()) + notePreviousDefinition(Old, New->getLocation()); + New->setInvalidDecl(); + return true; + } + return false; + } + + /// MergeTypedefNameDecl - We just parsed a typedef 'New' which has the + /// same name and scope as a previous declaration 'Old'. Figure out + /// how to resolve this situation, merging decls or emitting + /// diagnostics as appropriate. If there was an error, set New to be invalid. + /// + void Sema::MergeTypedefNameDecl(Scope *S, TypedefNameDecl *New, + LookupResult &OldDecls) { + // If the new decl is known invalid already, don't bother doing any + // merging checks. + if (New->isInvalidDecl()) return; + + // Allow multiple definitions for ObjC built-in typedefs. + // FIXME: Verify the underlying types are equivalent! + if (getLangOpts().ObjC) { + const IdentifierInfo *TypeID = New->getIdentifier(); + switch (TypeID->getLength()) { + default: break; + case 2: + { + if (!TypeID->isStr("id")) + break; + QualType T = New->getUnderlyingType(); + if (!T->isPointerType()) + break; + if (!T->isVoidPointerType()) { + QualType PT = T->getAs()->getPointeeType(); + if (!PT->isStructureType()) + break; + } + Context.setObjCIdRedefinitionType(T); + // Install the built-in type for 'id', ignoring the current definition. + New->setTypeForDecl(Context.getObjCIdType().getTypePtr()); + return; + } + case 5: + if (!TypeID->isStr("Class")) + break; + Context.setObjCClassRedefinitionType(New->getUnderlyingType()); + // Install the built-in type for 'Class', ignoring the current definition. + New->setTypeForDecl(Context.getObjCClassType().getTypePtr()); + return; + case 3: + if (!TypeID->isStr("SEL")) + break; + Context.setObjCSelRedefinitionType(New->getUnderlyingType()); + // Install the built-in type for 'SEL', ignoring the current definition. + New->setTypeForDecl(Context.getObjCSelType().getTypePtr()); + return; + } + // Fall through - the typedef name was not a builtin type. + } + + // Verify the old decl was also a type. + TypeDecl *Old = OldDecls.getAsSingle(); + if (!Old) { + Diag(New->getLocation(), diag::err_redefinition_different_kind) + << New->getDeclName(); + + NamedDecl *OldD = OldDecls.getRepresentativeDecl(); + if (OldD->getLocation().isValid()) + notePreviousDefinition(OldD, New->getLocation()); + + return New->setInvalidDecl(); + } + + // If the old declaration is invalid, just give up here. + if (Old->isInvalidDecl()) + return New->setInvalidDecl(); + + if (auto *OldTD = dyn_cast(Old)) { + auto *OldTag = OldTD->getAnonDeclWithTypedefName(/*AnyRedecl*/true); + auto *NewTag = New->getAnonDeclWithTypedefName(); + NamedDecl *Hidden = nullptr; + if (OldTag && NewTag && + OldTag->getCanonicalDecl() != NewTag->getCanonicalDecl() && + !hasVisibleDefinition(OldTag, &Hidden)) { + // There is a definition of this tag, but it is not visible. Use it + // instead of our tag. + New->setTypeForDecl(OldTD->getTypeForDecl()); + if (OldTD->isModed()) + New->setModedTypeSourceInfo(OldTD->getTypeSourceInfo(), + OldTD->getUnderlyingType()); + else + New->setTypeSourceInfo(OldTD->getTypeSourceInfo()); + + // Make the old tag definition visible. + makeMergedDefinitionVisible(Hidden); + + // If this was an unscoped enumeration, yank all of its enumerators + // out of the scope. + if (isa(NewTag)) { + Scope *EnumScope = getNonFieldDeclScope(S); + for (auto *D : NewTag->decls()) { + auto *ED = cast(D); + assert(EnumScope->isDeclScope(ED)); + EnumScope->RemoveDecl(ED); + IdResolver.RemoveDecl(ED); + ED->getLexicalDeclContext()->removeDecl(ED); + } + } + } + } + + // If the typedef types are not identical, reject them in all languages and + // with any extensions enabled. + if (isIncompatibleTypedef(Old, New)) + return; + + // The types match. Link up the redeclaration chain and merge attributes if + // the old declaration was a typedef. + if (TypedefNameDecl *Typedef = dyn_cast(Old)) { + New->setPreviousDecl(Typedef); + mergeDeclAttributes(New, Old); + } + + if (getLangOpts().MicrosoftExt) + return; + + if (getLangOpts().CPlusPlus) { + // C++ [dcl.typedef]p2: + // In a given non-class scope, a typedef specifier can be used to + // redefine the name of any type declared in that scope to refer + // to the type to which it already refers. + if (!isa(CurContext)) + return; + + // C++0x [dcl.typedef]p4: + // In a given class scope, a typedef specifier can be used to redefine + // any class-name declared in that scope that is not also a typedef-name + // to refer to the type to which it already refers. + // + // This wording came in via DR424, which was a correction to the + // wording in DR56, which accidentally banned code like: + // + // struct S { + // typedef struct A { } A; + // }; + // + // in the C++03 standard. We implement the C++0x semantics, which + // allow the above but disallow + // + // struct S { + // typedef int I; + // typedef int I; + // }; + // + // since that was the intent of DR56. + if (!isa(Old)) + return; + + Diag(New->getLocation(), diag::err_redefinition) + << New->getDeclName(); + notePreviousDefinition(Old, New->getLocation()); + return New->setInvalidDecl(); + } + + // Modules always permit redefinition of typedefs, as does C11. + if (getLangOpts().Modules || getLangOpts().C11) + return; + + // If we have a redefinition of a typedef in C, emit a warning. This warning + // is normally mapped to an error, but can be controlled with + // -Wtypedef-redefinition. If either the original or the redefinition is + // in a system header, don't emit this for compatibility with GCC. + if (getDiagnostics().getSuppressSystemWarnings() && + // Some standard types are defined implicitly in Clang (e.g. OpenCL). + (Old->isImplicit() || + Context.getSourceManager().isInSystemHeader(Old->getLocation()) || + Context.getSourceManager().isInSystemHeader(New->getLocation()))) + return; + + Diag(New->getLocation(), diag::ext_redefinition_of_typedef) + << New->getDeclName(); + notePreviousDefinition(Old, New->getLocation()); + } + + /// DeclhasAttr - returns true if decl Declaration already has the target + /// attribute. + static bool DeclHasAttr(const Decl *D, const Attr *A) { + const OwnershipAttr *OA = dyn_cast(A); + const AnnotateAttr *Ann = dyn_cast(A); + for (const auto *i : D->attrs()) + if (i->getKind() == A->getKind()) { + if (Ann) { + if (Ann->getAnnotation() == cast(i)->getAnnotation()) + return true; + continue; + } + // FIXME: Don't hardcode this check + if (OA && isa(i)) + return OA->getOwnKind() == cast(i)->getOwnKind(); + return true; + } + + return false; + } + + static bool isAttributeTargetADefinition(Decl *D) { + if (VarDecl *VD = dyn_cast(D)) + return VD->isThisDeclarationADefinition(); + if (TagDecl *TD = dyn_cast(D)) + return TD->isCompleteDefinition() || TD->isBeingDefined(); + return true; + } + + /// Merge alignment attributes from \p Old to \p New, taking into account the + /// special semantics of C11's _Alignas specifier and C++11's alignas attribute. + /// + /// \return \c true if any attributes were added to \p New. + static bool mergeAlignedAttrs(Sema &S, NamedDecl *New, Decl *Old) { + // Look for alignas attributes on Old, and pick out whichever attribute + // specifies the strictest alignment requirement. + AlignedAttr *OldAlignasAttr = nullptr; + AlignedAttr *OldStrictestAlignAttr = nullptr; + unsigned OldAlign = 0; + for (auto *I : Old->specific_attrs()) { + // FIXME: We have no way of representing inherited dependent alignments + // in a case like: + // template struct alignas(A) X; + // template struct alignas(B) X {}; + // For now, we just ignore any alignas attributes which are not on the + // definition in such a case. + if (I->isAlignmentDependent()) + return false; + + if (I->isAlignas()) + OldAlignasAttr = I; + + unsigned Align = I->getAlignment(S.Context); + if (Align > OldAlign) { + OldAlign = Align; + OldStrictestAlignAttr = I; + } + } + + // Look for alignas attributes on New. + AlignedAttr *NewAlignasAttr = nullptr; + unsigned NewAlign = 0; + for (auto *I : New->specific_attrs()) { + if (I->isAlignmentDependent()) + return false; + + if (I->isAlignas()) + NewAlignasAttr = I; + + unsigned Align = I->getAlignment(S.Context); + if (Align > NewAlign) + NewAlign = Align; + } + + if (OldAlignasAttr && NewAlignasAttr && OldAlign != NewAlign) { + // Both declarations have 'alignas' attributes. We require them to match. + // C++11 [dcl.align]p6 and C11 6.7.5/7 both come close to saying this, but + // fall short. (If two declarations both have alignas, they must both match + // every definition, and so must match each other if there is a definition.) + + // If either declaration only contains 'alignas(0)' specifiers, then it + // specifies the natural alignment for the type. + if (OldAlign == 0 || NewAlign == 0) { + QualType Ty; + if (ValueDecl *VD = dyn_cast(New)) + Ty = VD->getType(); + else + Ty = S.Context.getTagDeclType(cast(New)); + + if (OldAlign == 0) + OldAlign = S.Context.getTypeAlign(Ty); + if (NewAlign == 0) + NewAlign = S.Context.getTypeAlign(Ty); + } + + if (OldAlign != NewAlign) { + S.Diag(NewAlignasAttr->getLocation(), diag::err_alignas_mismatch) + << (unsigned)S.Context.toCharUnitsFromBits(OldAlign).getQuantity() + << (unsigned)S.Context.toCharUnitsFromBits(NewAlign).getQuantity(); + S.Diag(OldAlignasAttr->getLocation(), diag::note_previous_declaration); + } + } + + if (OldAlignasAttr && !NewAlignasAttr && isAttributeTargetADefinition(New)) { + // C++11 [dcl.align]p6: + // if any declaration of an entity has an alignment-specifier, + // every defining declaration of that entity shall specify an + // equivalent alignment. + // C11 6.7.5/7: + // If the definition of an object does not have an alignment + // specifier, any other declaration of that object shall also + // have no alignment specifier. + S.Diag(New->getLocation(), diag::err_alignas_missing_on_definition) + << OldAlignasAttr; + S.Diag(OldAlignasAttr->getLocation(), diag::note_alignas_on_declaration) + << OldAlignasAttr; + } + + bool AnyAdded = false; + + // Ensure we have an attribute representing the strictest alignment. + if (OldAlign > NewAlign) { + AlignedAttr *Clone = OldStrictestAlignAttr->clone(S.Context); + Clone->setInherited(true); + New->addAttr(Clone); + AnyAdded = true; + } + + // Ensure we have an alignas attribute if the old declaration had one. + if (OldAlignasAttr && !NewAlignasAttr && + !(AnyAdded && OldStrictestAlignAttr->isAlignas())) { + AlignedAttr *Clone = OldAlignasAttr->clone(S.Context); + Clone->setInherited(true); + New->addAttr(Clone); + AnyAdded = true; + } + + return AnyAdded; + } + + static bool mergeDeclAttribute(Sema &S, NamedDecl *D, + const InheritableAttr *Attr, + Sema::AvailabilityMergeKind AMK) { + // This function copies an attribute Attr from a previous declaration to the + // new declaration D if the new declaration doesn't itself have that attribute + // yet or if that attribute allows duplicates. + // If you're adding a new attribute that requires logic different from + // "use explicit attribute on decl if present, else use attribute from + // previous decl", for example if the attribute needs to be consistent + // between redeclarations, you need to call a custom merge function here. + InheritableAttr *NewAttr = nullptr; + unsigned AttrSpellingListIndex = Attr->getSpellingListIndex(); + if (const auto *AA = dyn_cast(Attr)) + NewAttr = S.mergeAvailabilityAttr( + D, AA->getRange(), AA->getPlatform(), AA->isImplicit(), + AA->getIntroduced(), AA->getDeprecated(), AA->getObsoleted(), + AA->getUnavailable(), AA->getMessage(), AA->getStrict(), + AA->getReplacement(), AMK, AA->getPriority(), AttrSpellingListIndex); + else if (const auto *VA = dyn_cast(Attr)) + NewAttr = S.mergeVisibilityAttr(D, VA->getRange(), VA->getVisibility(), + AttrSpellingListIndex); + else if (const auto *VA = dyn_cast(Attr)) + NewAttr = S.mergeTypeVisibilityAttr(D, VA->getRange(), VA->getVisibility(), + AttrSpellingListIndex); + else if (const auto *ImportA = dyn_cast(Attr)) + NewAttr = S.mergeDLLImportAttr(D, ImportA->getRange(), + AttrSpellingListIndex); + else if (const auto *ExportA = dyn_cast(Attr)) + NewAttr = S.mergeDLLExportAttr(D, ExportA->getRange(), + AttrSpellingListIndex); + else if (const auto *FA = dyn_cast(Attr)) + NewAttr = S.mergeFormatAttr(D, FA->getRange(), FA->getType(), + FA->getFormatIdx(), FA->getFirstArg(), + AttrSpellingListIndex); + else if (const auto *SA = dyn_cast(Attr)) + NewAttr = S.mergeSectionAttr(D, SA->getRange(), SA->getName(), + AttrSpellingListIndex); + else if (const auto *CSA = dyn_cast(Attr)) + NewAttr = S.mergeCodeSegAttr(D, CSA->getRange(), CSA->getName(), + AttrSpellingListIndex); + else if (const auto *IA = dyn_cast(Attr)) + NewAttr = S.mergeMSInheritanceAttr(D, IA->getRange(), IA->getBestCase(), + AttrSpellingListIndex, + IA->getSemanticSpelling()); + else if (const auto *AA = dyn_cast(Attr)) + NewAttr = S.mergeAlwaysInlineAttr(D, AA->getRange(), + &S.Context.Idents.get(AA->getSpelling()), + AttrSpellingListIndex); + else if (S.getLangOpts().CUDA && isa(D) && + (isa(Attr) || isa(Attr) || + isa(Attr))) { + // CUDA target attributes are part of function signature for + // overloading purposes and must not be merged. + return false; + } else if (const auto *MA = dyn_cast(Attr)) + NewAttr = S.mergeMinSizeAttr(D, MA->getRange(), AttrSpellingListIndex); + else if (const auto *OA = dyn_cast(Attr)) + NewAttr = S.mergeOptimizeNoneAttr(D, OA->getRange(), AttrSpellingListIndex); + else if (const auto *InternalLinkageA = dyn_cast(Attr)) + NewAttr = S.mergeInternalLinkageAttr(D, *InternalLinkageA); + else if (const auto *CommonA = dyn_cast(Attr)) + NewAttr = S.mergeCommonAttr(D, *CommonA); + else if (isa(Attr)) + // AlignedAttrs are handled separately, because we need to handle all + // such attributes on a declaration at the same time. + NewAttr = nullptr; + else if ((isa(Attr) || isa(Attr)) && + (AMK == Sema::AMK_Override || + AMK == Sema::AMK_ProtocolImplementation)) + NewAttr = nullptr; + else if (const auto *UA = dyn_cast(Attr)) + NewAttr = S.mergeUuidAttr(D, UA->getRange(), AttrSpellingListIndex, + UA->getGuid()); + else if (const auto *SLHA = dyn_cast(Attr)) + NewAttr = S.mergeSpeculativeLoadHardeningAttr(D, *SLHA); + else if (const auto *SLHA = dyn_cast(Attr)) + NewAttr = S.mergeNoSpeculativeLoadHardeningAttr(D, *SLHA); + else if (Attr->shouldInheritEvenIfAlreadyPresent() || !DeclHasAttr(D, Attr)) + NewAttr = cast(Attr->clone(S.Context)); + + if (NewAttr) { + NewAttr->setInherited(true); + D->addAttr(NewAttr); + if (isa(NewAttr)) + S.Consumer.AssignInheritanceModel(cast(D)); + return true; + } + + return false; + } + + static const NamedDecl *getDefinition(const Decl *D) { + if (const TagDecl *TD = dyn_cast(D)) + return TD->getDefinition(); + if (const VarDecl *VD = dyn_cast(D)) { + const VarDecl *Def = VD->getDefinition(); + if (Def) + return Def; + return VD->getActingDefinition(); + } + if (const FunctionDecl *FD = dyn_cast(D)) + return FD->getDefinition(); + return nullptr; + } + + static bool hasAttribute(const Decl *D, attr::Kind Kind) { + for (const auto *Attribute : D->attrs()) + if (Attribute->getKind() == Kind) + return true; + return false; + } + + /// checkNewAttributesAfterDef - If we already have a definition, check that + /// there are no new attributes in this declaration. + static void checkNewAttributesAfterDef(Sema &S, Decl *New, const Decl *Old) { + if (!New->hasAttrs()) + return; + + const NamedDecl *Def = getDefinition(Old); + if (!Def || Def == New) + return; + + AttrVec &NewAttributes = New->getAttrs(); + for (unsigned I = 0, E = NewAttributes.size(); I != E;) { + const Attr *NewAttribute = NewAttributes[I]; + + if (isa(NewAttribute) || isa(NewAttribute)) { + if (FunctionDecl *FD = dyn_cast(New)) { + Sema::SkipBodyInfo SkipBody; + S.CheckForFunctionRedefinition(FD, cast(Def), &SkipBody); + + // If we're skipping this definition, drop the "alias" attribute. + if (SkipBody.ShouldSkip) { + NewAttributes.erase(NewAttributes.begin() + I); + --E; + continue; + } + } else { + VarDecl *VD = cast(New); + unsigned Diag = cast(Def)->isThisDeclarationADefinition() == + VarDecl::TentativeDefinition + ? diag::err_alias_after_tentative + : diag::err_redefinition; + S.Diag(VD->getLocation(), Diag) << VD->getDeclName(); + if (Diag == diag::err_redefinition) + S.notePreviousDefinition(Def, VD->getLocation()); + else + S.Diag(Def->getLocation(), diag::note_previous_definition); + VD->setInvalidDecl(); + } + ++I; + continue; + } + + if (const VarDecl *VD = dyn_cast(Def)) { + // Tentative definitions are only interesting for the alias check above. + if (VD->isThisDeclarationADefinition() != VarDecl::Definition) { + ++I; + continue; + } + } + + if (hasAttribute(Def, NewAttribute->getKind())) { + ++I; + continue; // regular attr merging will take care of validating this. + } + + if (isa(NewAttribute)) { + // C's _Noreturn is allowed to be added to a function after it is defined. + ++I; + continue; + } else if (const AlignedAttr *AA = dyn_cast(NewAttribute)) { + if (AA->isAlignas()) { + // C++11 [dcl.align]p6: + // if any declaration of an entity has an alignment-specifier, + // every defining declaration of that entity shall specify an + // equivalent alignment. + // C11 6.7.5/7: + // If the definition of an object does not have an alignment + // specifier, any other declaration of that object shall also + // have no alignment specifier. + S.Diag(Def->getLocation(), diag::err_alignas_missing_on_definition) + << AA; + S.Diag(NewAttribute->getLocation(), diag::note_alignas_on_declaration) + << AA; + NewAttributes.erase(NewAttributes.begin() + I); + --E; + continue; + } + } + + S.Diag(NewAttribute->getLocation(), + diag::warn_attribute_precede_definition); + S.Diag(Def->getLocation(), diag::note_previous_definition); + NewAttributes.erase(NewAttributes.begin() + I); + --E; + } + } + + /// mergeDeclAttributes - Copy attributes from the Old decl to the New one. + void Sema::mergeDeclAttributes(NamedDecl *New, Decl *Old, + AvailabilityMergeKind AMK) { + if (UsedAttr *OldAttr = Old->getMostRecentDecl()->getAttr()) { + UsedAttr *NewAttr = OldAttr->clone(Context); + NewAttr->setInherited(true); + New->addAttr(NewAttr); + } + + if (!Old->hasAttrs() && !New->hasAttrs()) + return; + + // Attributes declared post-definition are currently ignored. + checkNewAttributesAfterDef(*this, New, Old); + + if (AsmLabelAttr *NewA = New->getAttr()) { + if (AsmLabelAttr *OldA = Old->getAttr()) { + if (OldA->getLabel() != NewA->getLabel()) { + // This redeclaration changes __asm__ label. + Diag(New->getLocation(), diag::err_different_asm_label); + Diag(OldA->getLocation(), diag::note_previous_declaration); + } + } else if (Old->isUsed()) { + // This redeclaration adds an __asm__ label to a declaration that has + // already been ODR-used. + Diag(New->getLocation(), diag::err_late_asm_label_name) + << isa(Old) << New->getAttr()->getRange(); + } + } + + // Re-declaration cannot add abi_tag's. + if (const auto *NewAbiTagAttr = New->getAttr()) { + if (const auto *OldAbiTagAttr = Old->getAttr()) { + for (const auto &NewTag : NewAbiTagAttr->tags()) { + if (std::find(OldAbiTagAttr->tags_begin(), OldAbiTagAttr->tags_end(), + NewTag) == OldAbiTagAttr->tags_end()) { + Diag(NewAbiTagAttr->getLocation(), + diag::err_new_abi_tag_on_redeclaration) + << NewTag; + Diag(OldAbiTagAttr->getLocation(), diag::note_previous_declaration); + } + } + } else { + Diag(NewAbiTagAttr->getLocation(), diag::err_abi_tag_on_redeclaration); + Diag(Old->getLocation(), diag::note_previous_declaration); + } + } + + // This redeclaration adds a section attribute. + if (New->hasAttr() && !Old->hasAttr()) { + if (auto *VD = dyn_cast(New)) { + if (VD->isThisDeclarationADefinition() == VarDecl::DeclarationOnly) { + Diag(New->getLocation(), diag::warn_attribute_section_on_redeclaration); + Diag(Old->getLocation(), diag::note_previous_declaration); + } + } + } + + // Redeclaration adds code-seg attribute. + const auto *NewCSA = New->getAttr(); + if (NewCSA && !Old->hasAttr() && + !NewCSA->isImplicit() && isa(New)) { + Diag(New->getLocation(), diag::warn_mismatched_section) + << 0 /*codeseg*/; + Diag(Old->getLocation(), diag::note_previous_declaration); + } + + if (!Old->hasAttrs()) + return; + + bool foundAny = New->hasAttrs(); + + // Ensure that any moving of objects within the allocated map is done before + // we process them. + if (!foundAny) New->setAttrs(AttrVec()); + + for (auto *I : Old->specific_attrs()) { + // Ignore deprecated/unavailable/availability attributes if requested. + AvailabilityMergeKind LocalAMK = AMK_None; + if (isa(I) || + isa(I) || + isa(I)) { + switch (AMK) { + case AMK_None: + continue; + + case AMK_Redeclaration: + case AMK_Override: + case AMK_ProtocolImplementation: + LocalAMK = AMK; + break; + } + } + + // Already handled. + if (isa(I)) + continue; + + if (mergeDeclAttribute(*this, New, I, LocalAMK)) + foundAny = true; + } + + if (mergeAlignedAttrs(*this, New, Old)) + foundAny = true; + + if (!foundAny) New->dropAttrs(); + } + + /// mergeParamDeclAttributes - Copy attributes from the old parameter + /// to the new one. + static void mergeParamDeclAttributes(ParmVarDecl *newDecl, + const ParmVarDecl *oldDecl, + Sema &S) { + // C++11 [dcl.attr.depend]p2: + // The first declaration of a function shall specify the + // carries_dependency attribute for its declarator-id if any declaration + // of the function specifies the carries_dependency attribute. + const CarriesDependencyAttr *CDA = newDecl->getAttr(); + if (CDA && !oldDecl->hasAttr()) { + S.Diag(CDA->getLocation(), + diag::err_carries_dependency_missing_on_first_decl) << 1/*Param*/; + // Find the first declaration of the parameter. + // FIXME: Should we build redeclaration chains for function parameters? + const FunctionDecl *FirstFD = + cast(oldDecl->getDeclContext())->getFirstDecl(); + const ParmVarDecl *FirstVD = + FirstFD->getParamDecl(oldDecl->getFunctionScopeIndex()); + S.Diag(FirstVD->getLocation(), + diag::note_carries_dependency_missing_first_decl) << 1/*Param*/; + } + + if (!oldDecl->hasAttrs()) + return; + + bool foundAny = newDecl->hasAttrs(); + + // Ensure that any moving of objects within the allocated map is + // done before we process them. + if (!foundAny) newDecl->setAttrs(AttrVec()); + + for (const auto *I : oldDecl->specific_attrs()) { + if (!DeclHasAttr(newDecl, I)) { + InheritableAttr *newAttr = + cast(I->clone(S.Context)); + newAttr->setInherited(true); + newDecl->addAttr(newAttr); + foundAny = true; + } + } + + if (!foundAny) newDecl->dropAttrs(); + } + + static void mergeParamDeclTypes(ParmVarDecl *NewParam, + const ParmVarDecl *OldParam, + Sema &S) { + if (auto Oldnullability = OldParam->getType()->getNullability(S.Context)) { + if (auto Newnullability = NewParam->getType()->getNullability(S.Context)) { + if (*Oldnullability != *Newnullability) { + S.Diag(NewParam->getLocation(), diag::warn_mismatched_nullability_attr) + << DiagNullabilityKind( + *Newnullability, + ((NewParam->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability) + != 0)) + << DiagNullabilityKind( + *Oldnullability, + ((OldParam->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability) + != 0)); + S.Diag(OldParam->getLocation(), diag::note_previous_declaration); + } + } else { + QualType NewT = NewParam->getType(); + NewT = S.Context.getAttributedType( + AttributedType::getNullabilityAttrKind(*Oldnullability), + NewT, NewT); + NewParam->setType(NewT); + } + } + } + + namespace { + + /// Used in MergeFunctionDecl to keep track of function parameters in + /// C. + struct GNUCompatibleParamWarning { + ParmVarDecl *OldParm; + ParmVarDecl *NewParm; + QualType PromotedType; + }; + + } // end anonymous namespace + + /// getSpecialMember - get the special member enum for a method. + Sema::CXXSpecialMember Sema::getSpecialMember(const CXXMethodDecl *MD) { + if (const CXXConstructorDecl *Ctor = dyn_cast(MD)) { + if (Ctor->isDefaultConstructor()) + return Sema::CXXDefaultConstructor; + + if (Ctor->isCopyConstructor()) + return Sema::CXXCopyConstructor; + + if (Ctor->isMoveConstructor()) + return Sema::CXXMoveConstructor; + } else if (isa(MD)) { + return Sema::CXXDestructor; + } else if (MD->isCopyAssignmentOperator()) { + return Sema::CXXCopyAssignment; + } else if (MD->isMoveAssignmentOperator()) { + return Sema::CXXMoveAssignment; + } + + return Sema::CXXInvalid; + } + + // Determine whether the previous declaration was a definition, implicit + // declaration, or a declaration. + template + static std::pair + getNoteDiagForInvalidRedeclaration(const T *Old, const T *New) { + diag::kind PrevDiag; + SourceLocation OldLocation = Old->getLocation(); + if (Old->isThisDeclarationADefinition()) + PrevDiag = diag::note_previous_definition; + else if (Old->isImplicit()) { + PrevDiag = diag::note_previous_implicit_declaration; + if (OldLocation.isInvalid()) + OldLocation = New->getLocation(); + } else + PrevDiag = diag::note_previous_declaration; + return std::make_pair(PrevDiag, OldLocation); + } + + /// canRedefineFunction - checks if a function can be redefined. Currently, + /// only extern inline functions can be redefined, and even then only in + /// GNU89 mode. + static bool canRedefineFunction(const FunctionDecl *FD, + const LangOptions& LangOpts) { + return ((FD->hasAttr() || LangOpts.GNUInline) && + !LangOpts.CPlusPlus && + FD->isInlineSpecified() && + FD->getStorageClass() == SC_Extern); + } + + const AttributedType *Sema::getCallingConvAttributedType(QualType T) const { + const AttributedType *AT = T->getAs(); + while (AT && !AT->isCallingConv()) + AT = AT->getModifiedType()->getAs(); + return AT; + } + + template + static bool haveIncompatibleLanguageLinkages(const T *Old, const T *New) { + const DeclContext *DC = Old->getDeclContext(); + if (DC->isRecord()) + return false; + + LanguageLinkage OldLinkage = Old->getLanguageLinkage(); + if (OldLinkage == CXXLanguageLinkage && New->isInExternCContext()) + return true; + if (OldLinkage == CLanguageLinkage && New->isInExternCXXContext()) + return true; + return false; + } + + template static bool isExternC(T *D) { return D->isExternC(); } + static bool isExternC(VarTemplateDecl *) { return false; } + + /// Check whether a redeclaration of an entity introduced by a + /// using-declaration is valid, given that we know it's not an overload + /// (nor a hidden tag declaration). + template + static bool checkUsingShadowRedecl(Sema &S, UsingShadowDecl *OldS, + ExpectedDecl *New) { + // C++11 [basic.scope.declarative]p4: + // Given a set of declarations in a single declarative region, each of + // which specifies the same unqualified name, + // -- they shall all refer to the same entity, or all refer to functions + // and function templates; or + // -- exactly one declaration shall declare a class name or enumeration + // name that is not a typedef name and the other declarations shall all + // refer to the same variable or enumerator, or all refer to functions + // and function templates; in this case the class name or enumeration + // name is hidden (3.3.10). + + // C++11 [namespace.udecl]p14: + // If a function declaration in namespace scope or block scope has the + // same name and the same parameter-type-list as a function introduced + // by a using-declaration, and the declarations do not declare the same + // function, the program is ill-formed. + + auto *Old = dyn_cast(OldS->getTargetDecl()); + if (Old && + !Old->getDeclContext()->getRedeclContext()->Equals( + New->getDeclContext()->getRedeclContext()) && + !(isExternC(Old) && isExternC(New))) + Old = nullptr; + + if (!Old) { + S.Diag(New->getLocation(), diag::err_using_decl_conflict_reverse); + S.Diag(OldS->getTargetDecl()->getLocation(), diag::note_using_decl_target); + S.Diag(OldS->getUsingDecl()->getLocation(), diag::note_using_decl) << 0; + return true; + } + return false; + } + + static bool hasIdenticalPassObjectSizeAttrs(const FunctionDecl *A, + const FunctionDecl *B) { + assert(A->getNumParams() == B->getNumParams()); + + auto AttrEq = [](const ParmVarDecl *A, const ParmVarDecl *B) { + const auto *AttrA = A->getAttr(); + const auto *AttrB = B->getAttr(); + if (AttrA == AttrB) + return true; + return AttrA && AttrB && AttrA->getType() == AttrB->getType(); + }; + + return std::equal(A->param_begin(), A->param_end(), B->param_begin(), AttrEq); + } + + /// If necessary, adjust the semantic declaration context for a qualified + /// declaration to name the correct inline namespace within the qualifier. + static void adjustDeclContextForDeclaratorDecl(DeclaratorDecl *NewD, + DeclaratorDecl *OldD) { + // The only case where we need to update the DeclContext is when + // redeclaration lookup for a qualified name finds a declaration + // in an inline namespace within the context named by the qualifier: + // + // inline namespace N { int f(); } + // int ::f(); // Sema DC needs adjusting from :: to N::. + // + // For unqualified declarations, the semantic context *can* change + // along the redeclaration chain (for local extern declarations, + // extern "C" declarations, and friend declarations in particular). + if (!NewD->getQualifier()) + return; + + // NewD is probably already in the right context. + auto *NamedDC = NewD->getDeclContext()->getRedeclContext(); + auto *SemaDC = OldD->getDeclContext()->getRedeclContext(); + if (NamedDC->Equals(SemaDC)) + return; + + assert((NamedDC->InEnclosingNamespaceSetOf(SemaDC) || + NewD->isInvalidDecl() || OldD->isInvalidDecl()) && + "unexpected context for redeclaration"); + + auto *LexDC = NewD->getLexicalDeclContext(); + auto FixSemaDC = [=](NamedDecl *D) { + if (!D) + return; + D->setDeclContext(SemaDC); + D->setLexicalDeclContext(LexDC); + }; + + FixSemaDC(NewD); + if (auto *FD = dyn_cast(NewD)) + FixSemaDC(FD->getDescribedFunctionTemplate()); + else if (auto *VD = dyn_cast(NewD)) + FixSemaDC(VD->getDescribedVarTemplate()); + } + + /// MergeFunctionDecl - We just parsed a function 'New' from + /// declarator D which has the same name and scope as a previous + /// declaration 'Old'. Figure out how to resolve this situation, + /// merging decls or emitting diagnostics as appropriate. + /// + /// In C++, New and Old must be declarations that are not + /// overloaded. Use IsOverload to determine whether New and Old are + /// overloaded, and to select the Old declaration that New should be + /// merged with. + /// + /// Returns true if there was an error, false otherwise. + bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD, + Scope *S, bool MergeTypeWithOld) { + // Verify the old decl was also a function. + FunctionDecl *Old = OldD->getAsFunction(); + if (!Old) { + if (UsingShadowDecl *Shadow = dyn_cast(OldD)) { + if (New->getFriendObjectKind()) { + Diag(New->getLocation(), diag::err_using_decl_friend); + Diag(Shadow->getTargetDecl()->getLocation(), + diag::note_using_decl_target); + Diag(Shadow->getUsingDecl()->getLocation(), + diag::note_using_decl) << 0; + return true; + } + + // Check whether the two declarations might declare the same function. + if (checkUsingShadowRedecl(*this, Shadow, New)) + return true; + OldD = Old = cast(Shadow->getTargetDecl()); + } else { + Diag(New->getLocation(), diag::err_redefinition_different_kind) + << New->getDeclName(); + notePreviousDefinition(OldD, New->getLocation()); + return true; + } + } + + // If the old declaration is invalid, just give up here. + if (Old->isInvalidDecl()) + return true; + + // Disallow redeclaration of some builtins. + if (!getASTContext().canBuiltinBeRedeclared(Old)) { + Diag(New->getLocation(), diag::err_builtin_redeclare) << Old->getDeclName(); + Diag(Old->getLocation(), diag::note_previous_builtin_declaration) + << Old << Old->getType(); + return true; + } + + diag::kind PrevDiag; + SourceLocation OldLocation; + std::tie(PrevDiag, OldLocation) = + getNoteDiagForInvalidRedeclaration(Old, New); + + // Don't complain about this if we're in GNU89 mode and the old function + // is an extern inline function. + // Don't complain about specializations. They are not supposed to have + // storage classes. + if (!isa(New) && !isa(Old) && + New->getStorageClass() == SC_Static && + Old->hasExternalFormalLinkage() && + !New->getTemplateSpecializationInfo() && + !canRedefineFunction(Old, getLangOpts())) { + if (getLangOpts().MicrosoftExt) { + Diag(New->getLocation(), diag::ext_static_non_static) << New; + Diag(OldLocation, PrevDiag); + } else { + Diag(New->getLocation(), diag::err_static_non_static) << New; + Diag(OldLocation, PrevDiag); + return true; + } + } + + if (New->hasAttr() && + !Old->hasAttr()) { + Diag(New->getLocation(), diag::err_internal_linkage_redeclaration) + << New->getDeclName(); + notePreviousDefinition(Old, New->getLocation()); + New->dropAttr(); + } + + if (CheckRedeclarationModuleOwnership(New, Old)) + return true; + + if (!getLangOpts().CPlusPlus) { + bool OldOvl = Old->hasAttr(); + if (OldOvl != New->hasAttr() && !Old->isImplicit()) { + Diag(New->getLocation(), diag::err_attribute_overloadable_mismatch) + << New << OldOvl; + + // Try our best to find a decl that actually has the overloadable + // attribute for the note. In most cases (e.g. programs with only one + // broken declaration/definition), this won't matter. + // + // FIXME: We could do this if we juggled some extra state in + // OverloadableAttr, rather than just removing it. + const Decl *DiagOld = Old; + if (OldOvl) { + auto OldIter = llvm::find_if(Old->redecls(), [](const Decl *D) { + const auto *A = D->getAttr(); + return A && !A->isImplicit(); + }); + // If we've implicitly added *all* of the overloadable attrs to this + // chain, emitting a "previous redecl" note is pointless. + DiagOld = OldIter == Old->redecls_end() ? nullptr : *OldIter; + } + + if (DiagOld) + Diag(DiagOld->getLocation(), + diag::note_attribute_overloadable_prev_overload) + << OldOvl; + + if (OldOvl) + New->addAttr(OverloadableAttr::CreateImplicit(Context)); + else + New->dropAttr(); + } + } + + // If a function is first declared with a calling convention, but is later + // declared or defined without one, all following decls assume the calling + // convention of the first. + // + // It's OK if a function is first declared without a calling convention, + // but is later declared or defined with the default calling convention. + // + // To test if either decl has an explicit calling convention, we look for + // AttributedType sugar nodes on the type as written. If they are missing or + // were canonicalized away, we assume the calling convention was implicit. + // + // Note also that we DO NOT return at this point, because we still have + // other tests to run. + QualType OldQType = Context.getCanonicalType(Old->getType()); + QualType NewQType = Context.getCanonicalType(New->getType()); + const FunctionType *OldType = cast(OldQType); + const FunctionType *NewType = cast(NewQType); + FunctionType::ExtInfo OldTypeInfo = OldType->getExtInfo(); + FunctionType::ExtInfo NewTypeInfo = NewType->getExtInfo(); + bool RequiresAdjustment = false; + + if (OldTypeInfo.getCC() != NewTypeInfo.getCC()) { + FunctionDecl *First = Old->getFirstDecl(); + const FunctionType *FT = + First->getType().getCanonicalType()->castAs(); + FunctionType::ExtInfo FI = FT->getExtInfo(); + bool NewCCExplicit = getCallingConvAttributedType(New->getType()); + if (!NewCCExplicit) { + // Inherit the CC from the previous declaration if it was specified + // there but not here. + NewTypeInfo = NewTypeInfo.withCallingConv(OldTypeInfo.getCC()); + RequiresAdjustment = true; + } else { + // Calling conventions aren't compatible, so complain. + bool FirstCCExplicit = getCallingConvAttributedType(First->getType()); + Diag(New->getLocation(), diag::err_cconv_change) + << FunctionType::getNameForCallConv(NewTypeInfo.getCC()) + << !FirstCCExplicit + << (!FirstCCExplicit ? "" : + FunctionType::getNameForCallConv(FI.getCC())); + + // Put the note on the first decl, since it is the one that matters. + Diag(First->getLocation(), diag::note_previous_declaration); + return true; + } + } + + // FIXME: diagnose the other way around? + if (OldTypeInfo.getNoReturn() && !NewTypeInfo.getNoReturn()) { + NewTypeInfo = NewTypeInfo.withNoReturn(true); + RequiresAdjustment = true; + } + + // Merge regparm attribute. + if (OldTypeInfo.getHasRegParm() != NewTypeInfo.getHasRegParm() || + OldTypeInfo.getRegParm() != NewTypeInfo.getRegParm()) { + if (NewTypeInfo.getHasRegParm()) { + Diag(New->getLocation(), diag::err_regparm_mismatch) + << NewType->getRegParmType() + << OldType->getRegParmType(); + Diag(OldLocation, diag::note_previous_declaration); + return true; + } + + NewTypeInfo = NewTypeInfo.withRegParm(OldTypeInfo.getRegParm()); + RequiresAdjustment = true; + } + + // Merge ns_returns_retained attribute. + if (OldTypeInfo.getProducesResult() != NewTypeInfo.getProducesResult()) { + if (NewTypeInfo.getProducesResult()) { + Diag(New->getLocation(), diag::err_function_attribute_mismatch) + << "'ns_returns_retained'"; + Diag(OldLocation, diag::note_previous_declaration); + return true; + } + + NewTypeInfo = NewTypeInfo.withProducesResult(true); + RequiresAdjustment = true; + } + + if (OldTypeInfo.getNoCallerSavedRegs() != + NewTypeInfo.getNoCallerSavedRegs()) { + if (NewTypeInfo.getNoCallerSavedRegs()) { + AnyX86NoCallerSavedRegistersAttr *Attr = + New->getAttr(); + Diag(New->getLocation(), diag::err_function_attribute_mismatch) << Attr; + Diag(OldLocation, diag::note_previous_declaration); + return true; + } + + NewTypeInfo = NewTypeInfo.withNoCallerSavedRegs(true); + RequiresAdjustment = true; + } + + if (RequiresAdjustment) { + const FunctionType *AdjustedType = New->getType()->getAs(); + AdjustedType = Context.adjustFunctionType(AdjustedType, NewTypeInfo); + New->setType(QualType(AdjustedType, 0)); + NewQType = Context.getCanonicalType(New->getType()); + NewType = cast(NewQType); + } + + // If this redeclaration makes the function inline, we may need to add it to + // UndefinedButUsed. + if (!Old->isInlined() && New->isInlined() && + !New->hasAttr() && + !getLangOpts().GNUInline && + Old->isUsed(false) && + !Old->isDefined() && !New->isThisDeclarationADefinition()) + UndefinedButUsed.insert(std::make_pair(Old->getCanonicalDecl(), + SourceLocation())); + + // If this redeclaration makes it newly gnu_inline, we don't want to warn + // about it. + if (New->hasAttr() && + Old->isInlined() && !Old->hasAttr()) { + UndefinedButUsed.erase(Old->getCanonicalDecl()); + } + + // If pass_object_size params don't match up perfectly, this isn't a valid + // redeclaration. + if (Old->getNumParams() > 0 && Old->getNumParams() == New->getNumParams() && + !hasIdenticalPassObjectSizeAttrs(Old, New)) { + Diag(New->getLocation(), diag::err_different_pass_object_size_params) + << New->getDeclName(); + Diag(OldLocation, PrevDiag) << Old << Old->getType(); + return true; + } + + if (getLangOpts().CPlusPlus) { + // C++1z [over.load]p2 + // Certain function declarations cannot be overloaded: + // -- Function declarations that differ only in the return type, + // the exception specification, or both cannot be overloaded. + + // Check the exception specifications match. This may recompute the type of + // both Old and New if it resolved exception specifications, so grab the + // types again after this. Because this updates the type, we do this before + // any of the other checks below, which may update the "de facto" NewQType + // but do not necessarily update the type of New. + if (CheckEquivalentExceptionSpec(Old, New)) + return true; + OldQType = Context.getCanonicalType(Old->getType()); + NewQType = Context.getCanonicalType(New->getType()); + + // Go back to the type source info to compare the declared return types, + // per C++1y [dcl.type.auto]p13: + // Redeclarations or specializations of a function or function template + // with a declared return type that uses a placeholder type shall also + // use that placeholder, not a deduced type. + QualType OldDeclaredReturnType = Old->getDeclaredReturnType(); + QualType NewDeclaredReturnType = New->getDeclaredReturnType(); + if (!Context.hasSameType(OldDeclaredReturnType, NewDeclaredReturnType) && + canFullyTypeCheckRedeclaration(New, Old, NewDeclaredReturnType, + OldDeclaredReturnType)) { + QualType ResQT; + if (NewDeclaredReturnType->isObjCObjectPointerType() && + OldDeclaredReturnType->isObjCObjectPointerType()) + // FIXME: This does the wrong thing for a deduced return type. + ResQT = Context.mergeObjCGCQualifiers(NewQType, OldQType); + if (ResQT.isNull()) { + if (New->isCXXClassMember() && New->isOutOfLine()) + Diag(New->getLocation(), diag::err_member_def_does_not_match_ret_type) + << New << New->getReturnTypeSourceRange(); + else + Diag(New->getLocation(), diag::err_ovl_diff_return_type) + << New->getReturnTypeSourceRange(); + Diag(OldLocation, PrevDiag) << Old << Old->getType() + << Old->getReturnTypeSourceRange(); + return true; + } + else + NewQType = ResQT; + } + + QualType OldReturnType = OldType->getReturnType(); + QualType NewReturnType = cast(NewQType)->getReturnType(); + if (OldReturnType != NewReturnType) { + // If this function has a deduced return type and has already been + // defined, copy the deduced value from the old declaration. + AutoType *OldAT = Old->getReturnType()->getContainedAutoType(); + if (OldAT && OldAT->isDeduced()) { + New->setType( + SubstAutoType(New->getType(), + OldAT->isDependentType() ? Context.DependentTy + : OldAT->getDeducedType())); + NewQType = Context.getCanonicalType( + SubstAutoType(NewQType, + OldAT->isDependentType() ? Context.DependentTy + : OldAT->getDeducedType())); + } + } + + const CXXMethodDecl *OldMethod = dyn_cast(Old); + CXXMethodDecl *NewMethod = dyn_cast(New); + if (OldMethod && NewMethod) { + // Preserve triviality. + NewMethod->setTrivial(OldMethod->isTrivial()); + + // MSVC allows explicit template specialization at class scope: + // 2 CXXMethodDecls referring to the same function will be injected. + // We don't want a redeclaration error. + bool IsClassScopeExplicitSpecialization = + OldMethod->isFunctionTemplateSpecialization() && + NewMethod->isFunctionTemplateSpecialization(); + bool isFriend = NewMethod->getFriendObjectKind(); + + if (!isFriend && NewMethod->getLexicalDeclContext()->isRecord() && + !IsClassScopeExplicitSpecialization) { + // -- Member function declarations with the same name and the + // same parameter types cannot be overloaded if any of them + // is a static member function declaration. + if (OldMethod->isStatic() != NewMethod->isStatic()) { + Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member); + Diag(OldLocation, PrevDiag) << Old << Old->getType(); + return true; + } + + // C++ [class.mem]p1: + // [...] A member shall not be declared twice in the + // member-specification, except that a nested class or member + // class template can be declared and then later defined. + if (!inTemplateInstantiation()) { + unsigned NewDiag; + if (isa(OldMethod)) + NewDiag = diag::err_constructor_redeclared; + else if (isa(NewMethod)) + NewDiag = diag::err_destructor_redeclared; + else if (isa(NewMethod)) + NewDiag = diag::err_conv_function_redeclared; + else + NewDiag = diag::err_member_redeclared; + + Diag(New->getLocation(), NewDiag); + } else { + Diag(New->getLocation(), diag::err_member_redeclared_in_instantiation) + << New << New->getType(); + } + Diag(OldLocation, PrevDiag) << Old << Old->getType(); + return true; + + // Complain if this is an explicit declaration of a special + // member that was initially declared implicitly. + // + // As an exception, it's okay to befriend such methods in order + // to permit the implicit constructor/destructor/operator calls. + } else if (OldMethod->isImplicit()) { + if (isFriend) { + NewMethod->setImplicit(); + } else { + Diag(NewMethod->getLocation(), + diag::err_definition_of_implicitly_declared_member) + << New << getSpecialMember(OldMethod); + return true; + } + } else if (OldMethod->getFirstDecl()->isExplicitlyDefaulted() && !isFriend) { + Diag(NewMethod->getLocation(), + diag::err_definition_of_explicitly_defaulted_member) + << getSpecialMember(OldMethod); + return true; + } + } + + // C++11 [dcl.attr.noreturn]p1: + // The first declaration of a function shall specify the noreturn + // attribute if any declaration of that function specifies the noreturn + // attribute. + const CXX11NoReturnAttr *NRA = New->getAttr(); + if (NRA && !Old->hasAttr()) { + Diag(NRA->getLocation(), diag::err_noreturn_missing_on_first_decl); + Diag(Old->getFirstDecl()->getLocation(), + diag::note_noreturn_missing_first_decl); + } + + // C++11 [dcl.attr.depend]p2: + // The first declaration of a function shall specify the + // carries_dependency attribute for its declarator-id if any declaration + // of the function specifies the carries_dependency attribute. + const CarriesDependencyAttr *CDA = New->getAttr(); + if (CDA && !Old->hasAttr()) { + Diag(CDA->getLocation(), + diag::err_carries_dependency_missing_on_first_decl) << 0/*Function*/; + Diag(Old->getFirstDecl()->getLocation(), + diag::note_carries_dependency_missing_first_decl) << 0/*Function*/; + } + + // (C++98 8.3.5p3): + // All declarations for a function shall agree exactly in both the + // return type and the parameter-type-list. + // We also want to respect all the extended bits except noreturn. + + // noreturn should now match unless the old type info didn't have it. + QualType OldQTypeForComparison = OldQType; + if (!OldTypeInfo.getNoReturn() && NewTypeInfo.getNoReturn()) { + auto *OldType = OldQType->castAs(); + const FunctionType *OldTypeForComparison + = Context.adjustFunctionType(OldType, OldTypeInfo.withNoReturn(true)); + OldQTypeForComparison = QualType(OldTypeForComparison, 0); + assert(OldQTypeForComparison.isCanonical()); + } + + if (haveIncompatibleLanguageLinkages(Old, New)) { + // As a special case, retain the language linkage from previous + // declarations of a friend function as an extension. + // + // This liberal interpretation of C++ [class.friend]p3 matches GCC/MSVC + // and is useful because there's otherwise no way to specify language + // linkage within class scope. + // + // Check cautiously as the friend object kind isn't yet complete. + if (New->getFriendObjectKind() != Decl::FOK_None) { + Diag(New->getLocation(), diag::ext_retained_language_linkage) << New; + Diag(OldLocation, PrevDiag); + } else { + Diag(New->getLocation(), diag::err_different_language_linkage) << New; + Diag(OldLocation, PrevDiag); + return true; + } + } + + if (OldQTypeForComparison == NewQType) + return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld); + + // If the types are imprecise (due to dependent constructs in friends or + // local extern declarations), it's OK if they differ. We'll check again + // during instantiation. + if (!canFullyTypeCheckRedeclaration(New, Old, NewQType, OldQType)) + return false; + + // Fall through for conflicting redeclarations and redefinitions. + } + + // C: Function types need to be compatible, not identical. This handles + // duplicate function decls like "void f(int); void f(enum X);" properly. + if (!getLangOpts().CPlusPlus && + Context.typesAreCompatible(OldQType, NewQType)) { + const FunctionType *OldFuncType = OldQType->getAs(); + const FunctionType *NewFuncType = NewQType->getAs(); + const FunctionProtoType *OldProto = nullptr; + if (MergeTypeWithOld && isa(NewFuncType) && + (OldProto = dyn_cast(OldFuncType))) { + // The old declaration provided a function prototype, but the + // new declaration does not. Merge in the prototype. + assert(!OldProto->hasExceptionSpec() && "Exception spec in C"); + SmallVector ParamTypes(OldProto->param_types()); + NewQType = + Context.getFunctionType(NewFuncType->getReturnType(), ParamTypes, + OldProto->getExtProtoInfo()); + New->setType(NewQType); + New->setHasInheritedPrototype(); + + // Synthesize parameters with the same types. + SmallVector Params; + for (const auto &ParamType : OldProto->param_types()) { + ParmVarDecl *Param = ParmVarDecl::Create(Context, New, SourceLocation(), + SourceLocation(), nullptr, + ParamType, /*TInfo=*/nullptr, + SC_None, nullptr); + Param->setScopeInfo(0, Params.size()); + Param->setImplicit(); + Params.push_back(Param); + } + + New->setParams(Params); + } + + return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld); + } + + // GNU C permits a K&R definition to follow a prototype declaration + // if the declared types of the parameters in the K&R definition + // match the types in the prototype declaration, even when the + // promoted types of the parameters from the K&R definition differ + // from the types in the prototype. GCC then keeps the types from + // the prototype. + // + // If a variadic prototype is followed by a non-variadic K&R definition, + // the K&R definition becomes variadic. This is sort of an edge case, but + // it's legal per the standard depending on how you read C99 6.7.5.3p15 and + // C99 6.9.1p8. + if (!getLangOpts().CPlusPlus && + Old->hasPrototype() && !New->hasPrototype() && + New->getType()->getAs() && + Old->getNumParams() == New->getNumParams()) { + SmallVector ArgTypes; + SmallVector Warnings; + const FunctionProtoType *OldProto + = Old->getType()->getAs(); + const FunctionProtoType *NewProto + = New->getType()->getAs(); + + // Determine whether this is the GNU C extension. + QualType MergedReturn = Context.mergeTypes(OldProto->getReturnType(), + NewProto->getReturnType()); + bool LooseCompatible = !MergedReturn.isNull(); + for (unsigned Idx = 0, End = Old->getNumParams(); + LooseCompatible && Idx != End; ++Idx) { + ParmVarDecl *OldParm = Old->getParamDecl(Idx); + ParmVarDecl *NewParm = New->getParamDecl(Idx); + if (Context.typesAreCompatible(OldParm->getType(), + NewProto->getParamType(Idx))) { + ArgTypes.push_back(NewParm->getType()); + } else if (Context.typesAreCompatible(OldParm->getType(), + NewParm->getType(), + /*CompareUnqualified=*/true)) { + GNUCompatibleParamWarning Warn = { OldParm, NewParm, + NewProto->getParamType(Idx) }; + Warnings.push_back(Warn); + ArgTypes.push_back(NewParm->getType()); + } else + LooseCompatible = false; + } + + if (LooseCompatible) { + for (unsigned Warn = 0; Warn < Warnings.size(); ++Warn) { + Diag(Warnings[Warn].NewParm->getLocation(), + diag::ext_param_promoted_not_compatible_with_prototype) + << Warnings[Warn].PromotedType + << Warnings[Warn].OldParm->getType(); + if (Warnings[Warn].OldParm->getLocation().isValid()) + Diag(Warnings[Warn].OldParm->getLocation(), + diag::note_previous_declaration); + } + + if (MergeTypeWithOld) + New->setType(Context.getFunctionType(MergedReturn, ArgTypes, + OldProto->getExtProtoInfo())); + return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld); + } + + // Fall through to diagnose conflicting types. + } + + // A function that has already been declared has been redeclared or + // defined with a different type; show an appropriate diagnostic. + + // If the previous declaration was an implicitly-generated builtin + // declaration, then at the very least we should use a specialized note. + unsigned BuiltinID; + if (Old->isImplicit() && (BuiltinID = Old->getBuiltinID())) { + // If it's actually a library-defined builtin function like 'malloc' + // or 'printf', just warn about the incompatible redeclaration. + if (Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) { + Diag(New->getLocation(), diag::warn_redecl_library_builtin) << New; + Diag(OldLocation, diag::note_previous_builtin_declaration) + << Old << Old->getType(); + + // If this is a global redeclaration, just forget hereafter + // about the "builtin-ness" of the function. + // + // Doing this for local extern declarations is problematic. If + // the builtin declaration remains visible, a second invalid + // local declaration will produce a hard error; if it doesn't + // remain visible, a single bogus local redeclaration (which is + // actually only a warning) could break all the downstream code. + if (!New->getLexicalDeclContext()->isFunctionOrMethod()) + New->getIdentifier()->revertBuiltin(); + + return false; + } + + PrevDiag = diag::note_previous_builtin_declaration; + } + + Diag(New->getLocation(), diag::err_conflicting_types) << New->getDeclName(); + Diag(OldLocation, PrevDiag) << Old << Old->getType(); + return true; + } + + /// Completes the merge of two function declarations that are + /// known to be compatible. + /// + /// This routine handles the merging of attributes and other + /// properties of function declarations from the old declaration to + /// the new declaration, once we know that New is in fact a + /// redeclaration of Old. + /// + /// \returns false + bool Sema::MergeCompatibleFunctionDecls(FunctionDecl *New, FunctionDecl *Old, + Scope *S, bool MergeTypeWithOld) { + // Merge the attributes + mergeDeclAttributes(New, Old); + + // Merge "pure" flag. + if (Old->isPure()) + New->setPure(); + + // Merge "used" flag. + if (Old->getMostRecentDecl()->isUsed(false)) + New->setIsUsed(); + + // Merge attributes from the parameters. These can mismatch with K&R + // declarations. + if (New->getNumParams() == Old->getNumParams()) + for (unsigned i = 0, e = New->getNumParams(); i != e; ++i) { + ParmVarDecl *NewParam = New->getParamDecl(i); + ParmVarDecl *OldParam = Old->getParamDecl(i); + mergeParamDeclAttributes(NewParam, OldParam, *this); + mergeParamDeclTypes(NewParam, OldParam, *this); + } + + if (getLangOpts().CPlusPlus) + return MergeCXXFunctionDecl(New, Old, S); + + // Merge the function types so the we get the composite types for the return + // and argument types. Per C11 6.2.7/4, only update the type if the old decl + // was visible. + QualType Merged = Context.mergeTypes(Old->getType(), New->getType()); + if (!Merged.isNull() && MergeTypeWithOld) + New->setType(Merged); + + return false; + } + + void Sema::mergeObjCMethodDecls(ObjCMethodDecl *newMethod, + ObjCMethodDecl *oldMethod) { + // Merge the attributes, including deprecated/unavailable + AvailabilityMergeKind MergeKind = + isa(oldMethod->getDeclContext()) + ? AMK_ProtocolImplementation + : isa(newMethod->getDeclContext()) ? AMK_Redeclaration + : AMK_Override; + + mergeDeclAttributes(newMethod, oldMethod, MergeKind); + + // Merge attributes from the parameters. + ObjCMethodDecl::param_const_iterator oi = oldMethod->param_begin(), + oe = oldMethod->param_end(); + for (ObjCMethodDecl::param_iterator + ni = newMethod->param_begin(), ne = newMethod->param_end(); + ni != ne && oi != oe; ++ni, ++oi) + mergeParamDeclAttributes(*ni, *oi, *this); + + CheckObjCMethodOverride(newMethod, oldMethod); + } + + static void diagnoseVarDeclTypeMismatch(Sema &S, VarDecl *New, VarDecl* Old) { + assert(!S.Context.hasSameType(New->getType(), Old->getType())); + + S.Diag(New->getLocation(), New->isThisDeclarationADefinition() + ? diag::err_redefinition_different_type + : diag::err_redeclaration_different_type) + << New->getDeclName() << New->getType() << Old->getType(); + + diag::kind PrevDiag; + SourceLocation OldLocation; + std::tie(PrevDiag, OldLocation) + = getNoteDiagForInvalidRedeclaration(Old, New); + S.Diag(OldLocation, PrevDiag); + New->setInvalidDecl(); + } + + /// MergeVarDeclTypes - We parsed a variable 'New' which has the same name and + /// scope as a previous declaration 'Old'. Figure out how to merge their types, + /// emitting diagnostics as appropriate. + /// + /// Declarations using the auto type specifier (C++ [decl.spec.auto]) call back + /// to here in AddInitializerToDecl. We can't check them before the initializer + /// is attached. + void Sema::MergeVarDeclTypes(VarDecl *New, VarDecl *Old, + bool MergeTypeWithOld) { + if (New->isInvalidDecl() || Old->isInvalidDecl()) + return; + + QualType MergedT; + if (getLangOpts().CPlusPlus) { + if (New->getType()->isUndeducedType()) { + // We don't know what the new type is until the initializer is attached. + return; + } else if (Context.hasSameType(New->getType(), Old->getType())) { + // These could still be something that needs exception specs checked. + return MergeVarDeclExceptionSpecs(New, Old); + } + // C++ [basic.link]p10: + // [...] the types specified by all declarations referring to a given + // object or function shall be identical, except that declarations for an + // array object can specify array types that differ by the presence or + // absence of a major array bound (8.3.4). + else if (Old->getType()->isArrayType() && New->getType()->isArrayType()) { + const ArrayType *OldArray = Context.getAsArrayType(Old->getType()); + const ArrayType *NewArray = Context.getAsArrayType(New->getType()); + + // We are merging a variable declaration New into Old. If it has an array + // bound, and that bound differs from Old's bound, we should diagnose the + // mismatch. + if (!NewArray->isIncompleteArrayType() && !NewArray->isDependentType()) { + for (VarDecl *PrevVD = Old->getMostRecentDecl(); PrevVD; + PrevVD = PrevVD->getPreviousDecl()) { + const ArrayType *PrevVDTy = Context.getAsArrayType(PrevVD->getType()); + if (PrevVDTy->isIncompleteArrayType() || PrevVDTy->isDependentType()) + continue; + + if (!Context.hasSameType(NewArray, PrevVDTy)) + return diagnoseVarDeclTypeMismatch(*this, New, PrevVD); + } + } + + if (OldArray->isIncompleteArrayType() && NewArray->isArrayType()) { + if (Context.hasSameType(OldArray->getElementType(), + NewArray->getElementType())) + MergedT = New->getType(); + } + // FIXME: Check visibility. New is hidden but has a complete type. If New + // has no array bound, it should not inherit one from Old, if Old is not + // visible. + else if (OldArray->isArrayType() && NewArray->isIncompleteArrayType()) { + if (Context.hasSameType(OldArray->getElementType(), + NewArray->getElementType())) + MergedT = Old->getType(); + } + } + else if (New->getType()->isObjCObjectPointerType() && + Old->getType()->isObjCObjectPointerType()) { + MergedT = Context.mergeObjCGCQualifiers(New->getType(), + Old->getType()); + } + } else { + // C 6.2.7p2: + // All declarations that refer to the same object or function shall have + // compatible type. + MergedT = Context.mergeTypes(New->getType(), Old->getType()); + } + if (MergedT.isNull()) { + // It's OK if we couldn't merge types if either type is dependent, for a + // block-scope variable. In other cases (static data members of class + // templates, variable templates, ...), we require the types to be + // equivalent. + // FIXME: The C++ standard doesn't say anything about this. + if ((New->getType()->isDependentType() || + Old->getType()->isDependentType()) && New->isLocalVarDecl()) { + // If the old type was dependent, we can't merge with it, so the new type + // becomes dependent for now. We'll reproduce the original type when we + // instantiate the TypeSourceInfo for the variable. + if (!New->getType()->isDependentType() && MergeTypeWithOld) + New->setType(Context.DependentTy); + return; + } + return diagnoseVarDeclTypeMismatch(*this, New, Old); + } + + // Don't actually update the type on the new declaration if the old + // declaration was an extern declaration in a different scope. + if (MergeTypeWithOld) + New->setType(MergedT); + } + + static bool mergeTypeWithPrevious(Sema &S, VarDecl *NewVD, VarDecl *OldVD, + LookupResult &Previous) { + // C11 6.2.7p4: + // For an identifier with internal or external linkage declared + // in a scope in which a prior declaration of that identifier is + // visible, if the prior declaration specifies internal or + // external linkage, the type of the identifier at the later + // declaration becomes the composite type. + // + // If the variable isn't visible, we do not merge with its type. + if (Previous.isShadowed()) + return false; + + if (S.getLangOpts().CPlusPlus) { + // C++11 [dcl.array]p3: + // If there is a preceding declaration of the entity in the same + // scope in which the bound was specified, an omitted array bound + // is taken to be the same as in that earlier declaration. + return NewVD->isPreviousDeclInSameBlockScope() || + (!OldVD->getLexicalDeclContext()->isFunctionOrMethod() && + !NewVD->getLexicalDeclContext()->isFunctionOrMethod()); + } else { + // If the old declaration was function-local, don't merge with its + // type unless we're in the same function. + return !OldVD->getLexicalDeclContext()->isFunctionOrMethod() || + OldVD->getLexicalDeclContext() == NewVD->getLexicalDeclContext(); + } + } + + /// MergeVarDecl - We just parsed a variable 'New' which has the same name + /// and scope as a previous declaration 'Old'. Figure out how to resolve this + /// situation, merging decls or emitting diagnostics as appropriate. + /// + /// Tentative definition rules (C99 6.9.2p2) are checked by + /// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative + /// definitions here, since the initializer hasn't been attached. + /// + void Sema::MergeVarDecl(VarDecl *New, LookupResult &Previous) { + // If the new decl is already invalid, don't do any other checking. + if (New->isInvalidDecl()) + return; + + if (!shouldLinkPossiblyHiddenDecl(Previous, New)) + return; + + VarTemplateDecl *NewTemplate = New->getDescribedVarTemplate(); + + // Verify the old decl was also a variable or variable template. + VarDecl *Old = nullptr; + VarTemplateDecl *OldTemplate = nullptr; + if (Previous.isSingleResult()) { + if (NewTemplate) { + OldTemplate = dyn_cast(Previous.getFoundDecl()); + Old = OldTemplate ? OldTemplate->getTemplatedDecl() : nullptr; + + if (auto *Shadow = + dyn_cast(Previous.getRepresentativeDecl())) + if (checkUsingShadowRedecl(*this, Shadow, NewTemplate)) + return New->setInvalidDecl(); + } else { + Old = dyn_cast(Previous.getFoundDecl()); + + if (auto *Shadow = + dyn_cast(Previous.getRepresentativeDecl())) + if (checkUsingShadowRedecl(*this, Shadow, New)) + return New->setInvalidDecl(); + } + } + if (!Old) { + Diag(New->getLocation(), diag::err_redefinition_different_kind) + << New->getDeclName(); + notePreviousDefinition(Previous.getRepresentativeDecl(), + New->getLocation()); + return New->setInvalidDecl(); + } + + // Ensure the template parameters are compatible. + if (NewTemplate && + !TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), + OldTemplate->getTemplateParameters(), + /*Complain=*/true, TPL_TemplateMatch)) + return New->setInvalidDecl(); + + // C++ [class.mem]p1: + // A member shall not be declared twice in the member-specification [...] + // + // Here, we need only consider static data members. + if (Old->isStaticDataMember() && !New->isOutOfLine()) { + Diag(New->getLocation(), diag::err_duplicate_member) + << New->getIdentifier(); + Diag(Old->getLocation(), diag::note_previous_declaration); + New->setInvalidDecl(); + } + + mergeDeclAttributes(New, Old); + // Warn if an already-declared variable is made a weak_import in a subsequent + // declaration + if (New->hasAttr() && + Old->getStorageClass() == SC_None && + !Old->hasAttr()) { + Diag(New->getLocation(), diag::warn_weak_import) << New->getDeclName(); + notePreviousDefinition(Old, New->getLocation()); + // Remove weak_import attribute on new declaration. + New->dropAttr(); + } + + if (New->hasAttr() && + !Old->hasAttr()) { + Diag(New->getLocation(), diag::err_internal_linkage_redeclaration) + << New->getDeclName(); + notePreviousDefinition(Old, New->getLocation()); + New->dropAttr(); + } + + // Merge the types. + VarDecl *MostRecent = Old->getMostRecentDecl(); + if (MostRecent != Old) { + MergeVarDeclTypes(New, MostRecent, + mergeTypeWithPrevious(*this, New, MostRecent, Previous)); + if (New->isInvalidDecl()) + return; + } + + MergeVarDeclTypes(New, Old, mergeTypeWithPrevious(*this, New, Old, Previous)); + if (New->isInvalidDecl()) + return; + + diag::kind PrevDiag; + SourceLocation OldLocation; + std::tie(PrevDiag, OldLocation) = + getNoteDiagForInvalidRedeclaration(Old, New); + + // [dcl.stc]p8: Check if we have a non-static decl followed by a static. + if (New->getStorageClass() == SC_Static && + !New->isStaticDataMember() && + Old->hasExternalFormalLinkage()) { + if (getLangOpts().MicrosoftExt) { + Diag(New->getLocation(), diag::ext_static_non_static) + << New->getDeclName(); + Diag(OldLocation, PrevDiag); + } else { + Diag(New->getLocation(), diag::err_static_non_static) + << New->getDeclName(); + Diag(OldLocation, PrevDiag); + return New->setInvalidDecl(); + } + } + // C99 6.2.2p4: + // For an identifier declared with the storage-class specifier + // extern in a scope in which a prior declaration of that + // identifier is visible,23) if the prior declaration specifies + // internal or external linkage, the linkage of the identifier at + // the later declaration is the same as the linkage specified at + // the prior declaration. If no prior declaration is visible, or + // if the prior declaration specifies no linkage, then the + // identifier has external linkage. + if (New->hasExternalStorage() && Old->hasLinkage()) + /* Okay */; + else if (New->getCanonicalDecl()->getStorageClass() != SC_Static && + !New->isStaticDataMember() && + Old->getCanonicalDecl()->getStorageClass() == SC_Static) { + Diag(New->getLocation(), diag::err_non_static_static) << New->getDeclName(); + Diag(OldLocation, PrevDiag); + return New->setInvalidDecl(); + } + + // Check if extern is followed by non-extern and vice-versa. + if (New->hasExternalStorage() && + !Old->hasLinkage() && Old->isLocalVarDeclOrParm()) { + Diag(New->getLocation(), diag::err_extern_non_extern) << New->getDeclName(); + Diag(OldLocation, PrevDiag); + return New->setInvalidDecl(); + } + if (Old->hasLinkage() && New->isLocalVarDeclOrParm() && + !New->hasExternalStorage()) { + Diag(New->getLocation(), diag::err_non_extern_extern) << New->getDeclName(); + Diag(OldLocation, PrevDiag); + return New->setInvalidDecl(); + } + + if (CheckRedeclarationModuleOwnership(New, Old)) + return; + + // Variables with external linkage are analyzed in FinalizeDeclaratorGroup. + + // FIXME: The test for external storage here seems wrong? We still + // need to check for mismatches. + if (!New->hasExternalStorage() && !New->isFileVarDecl() && + // Don't complain about out-of-line definitions of static members. + !(Old->getLexicalDeclContext()->isRecord() && + !New->getLexicalDeclContext()->isRecord())) { + Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName(); + Diag(OldLocation, PrevDiag); + return New->setInvalidDecl(); + } + + if (New->isInline() && !Old->getMostRecentDecl()->isInline()) { + if (VarDecl *Def = Old->getDefinition()) { + // C++1z [dcl.fcn.spec]p4: + // If the definition of a variable 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); + } + } + + // If this redeclaration makes the variable inline, we may need to add it to + // UndefinedButUsed. + if (!Old->isInline() && New->isInline() && Old->isUsed(false) && + !Old->getDefinition() && !New->isThisDeclarationADefinition()) + UndefinedButUsed.insert(std::make_pair(Old->getCanonicalDecl(), + SourceLocation())); + + if (New->getTLSKind() != Old->getTLSKind()) { + if (!Old->getTLSKind()) { + Diag(New->getLocation(), diag::err_thread_non_thread) << New->getDeclName(); + Diag(OldLocation, PrevDiag); + } else if (!New->getTLSKind()) { + Diag(New->getLocation(), diag::err_non_thread_thread) << New->getDeclName(); + Diag(OldLocation, PrevDiag); + } else { + // Do not allow redeclaration to change the variable between requiring + // static and dynamic initialization. + // FIXME: GCC allows this, but uses the TLS keyword on the first + // declaration to determine the kind. Do we need to be compatible here? + Diag(New->getLocation(), diag::err_thread_thread_different_kind) + << New->getDeclName() << (New->getTLSKind() == VarDecl::TLS_Dynamic); + Diag(OldLocation, PrevDiag); + } + } + + // C++ doesn't have tentative definitions, so go right ahead and check here. + if (getLangOpts().CPlusPlus && + New->isThisDeclarationADefinition() == VarDecl::Definition) { + if (Old->isStaticDataMember() && Old->getCanonicalDecl()->isInline() && + Old->getCanonicalDecl()->isConstexpr()) { + // This definition won't be a definition any more once it's been merged. + Diag(New->getLocation(), + diag::warn_deprecated_redundant_constexpr_static_def); + } else if (VarDecl *Def = Old->getDefinition()) { + if (checkVarDeclRedefinition(Def, New)) + return; + } + } + + if (haveIncompatibleLanguageLinkages(Old, New)) { + Diag(New->getLocation(), diag::err_different_language_linkage) << New; + Diag(OldLocation, PrevDiag); + New->setInvalidDecl(); + return; + } + + // Merge "used" flag. + if (Old->getMostRecentDecl()->isUsed(false)) + New->setIsUsed(); + + // Keep a chain of previous declarations. + New->setPreviousDecl(Old); + if (NewTemplate) + NewTemplate->setPreviousDecl(OldTemplate); + adjustDeclContextForDeclaratorDecl(New, Old); + + // Inherit access appropriately. + New->setAccess(Old->getAccess()); + if (NewTemplate) + NewTemplate->setAccess(New->getAccess()); + + if (Old->isInline()) + New->setImplicitlyInline(); + } + + void Sema::notePreviousDefinition(const NamedDecl *Old, SourceLocation New) { + SourceManager &SrcMgr = getSourceManager(); + auto FNewDecLoc = SrcMgr.getDecomposedLoc(New); + auto FOldDecLoc = SrcMgr.getDecomposedLoc(Old->getLocation()); + auto *FNew = SrcMgr.getFileEntryForID(FNewDecLoc.first); + auto *FOld = SrcMgr.getFileEntryForID(FOldDecLoc.first); + auto &HSI = PP.getHeaderSearchInfo(); + StringRef HdrFilename = + SrcMgr.getFilename(SrcMgr.getSpellingLoc(Old->getLocation())); + + auto noteFromModuleOrInclude = [&](Module *Mod, + SourceLocation IncLoc) -> bool { + // Redefinition errors with modules are common with non modular mapped + // headers, example: a non-modular header H in module A that also gets + // included directly in a TU. Pointing twice to the same header/definition + // is confusing, try to get better diagnostics when modules is on. + if (IncLoc.isValid()) { + if (Mod) { + Diag(IncLoc, diag::note_redefinition_modules_same_file) + << HdrFilename.str() << Mod->getFullModuleName(); + if (!Mod->DefinitionLoc.isInvalid()) + Diag(Mod->DefinitionLoc, diag::note_defined_here) + << Mod->getFullModuleName(); + } else { + Diag(IncLoc, diag::note_redefinition_include_same_file) + << HdrFilename.str(); + } + return true; + } + + return false; + }; + + // Is it the same file and same offset? Provide more information on why + // this leads to a redefinition error. + bool EmittedDiag = false; + if (FNew == FOld && FNewDecLoc.second == FOldDecLoc.second) { + SourceLocation OldIncLoc = SrcMgr.getIncludeLoc(FOldDecLoc.first); + SourceLocation NewIncLoc = SrcMgr.getIncludeLoc(FNewDecLoc.first); + EmittedDiag = noteFromModuleOrInclude(Old->getOwningModule(), OldIncLoc); + EmittedDiag |= noteFromModuleOrInclude(getCurrentModule(), NewIncLoc); + + // If the header has no guards, emit a note suggesting one. + if (FOld && !HSI.isFileMultipleIncludeGuarded(FOld)) + Diag(Old->getLocation(), diag::note_use_ifdef_guards); + + if (EmittedDiag) + return; + } + + // Redefinition coming from different files or couldn't do better above. + if (Old->getLocation().isValid()) + Diag(Old->getLocation(), diag::note_previous_definition); + } + + /// We've just determined that \p Old and \p New both appear to be definitions + /// of the same variable. Either diagnose or fix the problem. + bool Sema::checkVarDeclRedefinition(VarDecl *Old, VarDecl *New) { + if (!hasVisibleDefinition(Old) && + (New->getFormalLinkage() == InternalLinkage || + New->isInline() || + New->getDescribedVarTemplate() || + New->getNumTemplateParameterLists() || + New->getDeclContext()->isDependentContext())) { + // The previous definition is hidden, and multiple definitions are + // permitted (in separate TUs). Demote this to a declaration. + New->demoteThisDefinitionToDeclaration(); + + // Make the canonical definition visible. + if (auto *OldTD = Old->getDescribedVarTemplate()) + makeMergedDefinitionVisible(OldTD); + makeMergedDefinitionVisible(Old); + return false; + } else { + Diag(New->getLocation(), diag::err_redefinition) << New; + notePreviousDefinition(Old, New->getLocation()); + New->setInvalidDecl(); + return true; + } + } + + /// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with + /// no declarator (e.g. "struct foo;") is parsed. + Decl * + Sema::ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS, DeclSpec &DS, + RecordDecl *&AnonRecord) { + return ParsedFreeStandingDeclSpec(S, AS, DS, MultiTemplateParamsArg(), false, + AnonRecord); + } + + // The MS ABI changed between VS2013 and VS2015 with regard to numbers used to + // disambiguate entities defined in different scopes. + // While the VS2015 ABI fixes potential miscompiles, it is also breaks + // compatibility. + // We will pick our mangling number depending on which version of MSVC is being + // targeted. + static unsigned getMSManglingNumber(const LangOptions &LO, Scope *S) { + return LO.isCompatibleWithMSVC(LangOptions::MSVC2015) + ? S->getMSCurManglingNumber() + : S->getMSLastManglingNumber(); + } + + void Sema::handleTagNumbering(const TagDecl *Tag, Scope *TagScope) { + if (!Context.getLangOpts().CPlusPlus) + return; + + if (isa(Tag->getParent())) { + // If this tag is the direct child of a class, number it if + // it is anonymous. + if (!Tag->getName().empty() || Tag->getTypedefNameForAnonDecl()) + return; + MangleNumberingContext &MCtx = + Context.getManglingNumberContext(Tag->getParent()); + Context.setManglingNumber( + Tag, MCtx.getManglingNumber( + Tag, getMSManglingNumber(getLangOpts(), TagScope))); + return; + } + + // If this tag isn't a direct child of a class, number it if it is local. + Decl *ManglingContextDecl; + if (MangleNumberingContext *MCtx = getCurrentMangleNumberContext( + Tag->getDeclContext(), ManglingContextDecl)) { + Context.setManglingNumber( + Tag, MCtx->getManglingNumber( + Tag, getMSManglingNumber(getLangOpts(), TagScope))); + } + } + + void Sema::setTagNameForLinkagePurposes(TagDecl *TagFromDeclSpec, + TypedefNameDecl *NewTD) { + if (TagFromDeclSpec->isInvalidDecl()) + return; + + // Do nothing if the tag already has a name for linkage purposes. + if (TagFromDeclSpec->hasNameForLinkage()) + return; + + // A well-formed anonymous tag must always be a TUK_Definition. + assert(TagFromDeclSpec->isThisDeclarationADefinition()); + + // The type must match the tag exactly; no qualifiers allowed. + if (!Context.hasSameType(NewTD->getUnderlyingType(), + Context.getTagDeclType(TagFromDeclSpec))) { + if (getLangOpts().CPlusPlus) + Context.addTypedefNameForUnnamedTagDecl(TagFromDeclSpec, NewTD); + return; + } + + // If we've already computed linkage for the anonymous tag, then + // adding a typedef name for the anonymous decl can change that + // linkage, which might be a serious problem. Diagnose this as + // unsupported and ignore the typedef name. TODO: we should + // pursue this as a language defect and establish a formal rule + // for how to handle it. + if (TagFromDeclSpec->hasLinkageBeenComputed()) { + Diag(NewTD->getLocation(), diag::err_typedef_changes_linkage); + + SourceLocation tagLoc = TagFromDeclSpec->getInnerLocStart(); + tagLoc = getLocForEndOfToken(tagLoc); + + llvm::SmallString<40> textToInsert; + textToInsert += ' '; + textToInsert += NewTD->getIdentifier()->getName(); + Diag(tagLoc, diag::note_typedef_changes_linkage) + << FixItHint::CreateInsertion(tagLoc, textToInsert); + return; + } + + // Otherwise, set this is the anon-decl typedef for the tag. + TagFromDeclSpec->setTypedefNameForAnonDecl(NewTD); + } + + static unsigned GetDiagnosticTypeSpecifierID(DeclSpec::TST T) { + switch (T) { + case DeclSpec::TST_class: + return 0; + case DeclSpec::TST_struct: + return 1; + case DeclSpec::TST_interface: + return 2; + case DeclSpec::TST_union: + return 3; + case DeclSpec::TST_enum: + return 4; + default: + llvm_unreachable("unexpected type specifier"); + } + } + + /// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with + /// no declarator (e.g. "struct foo;") is parsed. It also accepts template + /// parameters to cope with template friend declarations. + Decl * + Sema::ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS, DeclSpec &DS, + MultiTemplateParamsArg TemplateParams, + bool IsExplicitInstantiation, + RecordDecl *&AnonRecord) { + Decl *TagD = nullptr; + TagDecl *Tag = nullptr; + if (DS.getTypeSpecType() == DeclSpec::TST_class || + DS.getTypeSpecType() == DeclSpec::TST_struct || + DS.getTypeSpecType() == DeclSpec::TST_interface || + DS.getTypeSpecType() == DeclSpec::TST_union || + DS.getTypeSpecType() == DeclSpec::TST_enum) { + TagD = DS.getRepAsDecl(); + + if (!TagD) // We probably had an error + return nullptr; + + // Note that the above type specs guarantee that the + // type rep is a Decl, whereas in many of the others + // it's a Type. + if (isa(TagD)) + Tag = cast(TagD); + else if (ClassTemplateDecl *CTD = dyn_cast(TagD)) + Tag = CTD->getTemplatedDecl(); + } + + if (Tag) { + handleTagNumbering(Tag, S); + Tag->setFreeStanding(); + if (Tag->isInvalidDecl()) + return Tag; + } + + if (unsigned TypeQuals = DS.getTypeQualifiers()) { + // Enforce C99 6.7.3p2: "Types other than pointer types derived from object + // or incomplete types shall not be restrict-qualified." + if (TypeQuals & DeclSpec::TQ_restrict) + Diag(DS.getRestrictSpecLoc(), + diag::err_typecheck_invalid_restrict_not_pointer_noarg) + << DS.getSourceRange(); + } + + if (DS.isInlineSpecified()) + Diag(DS.getInlineSpecLoc(), diag::err_inline_non_function) + << getLangOpts().CPlusPlus17; + + if (DS.isConstexprSpecified()) { + // C++0x [dcl.constexpr]p1: constexpr can only be applied to declarations + // and definitions of functions and variables. + if (Tag) + Diag(DS.getConstexprSpecLoc(), diag::err_constexpr_tag) + << GetDiagnosticTypeSpecifierID(DS.getTypeSpecType()); + else + Diag(DS.getConstexprSpecLoc(), diag::err_constexpr_no_declarators); + // Don't emit warnings after this error. + return TagD; + } + + DiagnoseFunctionSpecifiers(DS); + + if (DS.isFriendSpecified()) { + // If we're dealing with a decl but not a TagDecl, assume that + // whatever routines created it handled the friendship aspect. + if (TagD && !Tag) + return nullptr; + return ActOnFriendTypeDecl(S, DS, TemplateParams); + } + + const CXXScopeSpec &SS = DS.getTypeSpecScope(); + bool IsExplicitSpecialization = + !TemplateParams.empty() && TemplateParams.back()->size() == 0; + if (Tag && SS.isNotEmpty() && !Tag->isCompleteDefinition() && + !IsExplicitInstantiation && !IsExplicitSpecialization && + !isa(Tag)) { + // Per C++ [dcl.type.elab]p1, a class declaration cannot have a + // nested-name-specifier unless it is an explicit instantiation + // or an explicit specialization. + // + // FIXME: We allow class template partial specializations here too, per the + // obvious intent of DR1819. + // + // Per C++ [dcl.enum]p1, an opaque-enum-declaration can't either. + Diag(SS.getBeginLoc(), diag::err_standalone_class_nested_name_specifier) + << GetDiagnosticTypeSpecifierID(DS.getTypeSpecType()) << SS.getRange(); + return nullptr; + } + + // Track whether this decl-specifier declares anything. + bool DeclaresAnything = true; + + // Handle anonymous struct definitions. + if (RecordDecl *Record = dyn_cast_or_null(Tag)) { + if (!Record->getDeclName() && Record->isCompleteDefinition() && + DS.getStorageClassSpec() != DeclSpec::SCS_typedef) { + if (getLangOpts().CPlusPlus || + Record->getDeclContext()->isRecord()) { + // If CurContext is a DeclContext that can contain statements, + // RecursiveASTVisitor won't visit the decls that + // BuildAnonymousStructOrUnion() will put into CurContext. + // Also store them here so that they can be part of the + // DeclStmt that gets created in this case. + // FIXME: Also return the IndirectFieldDecls created by + // BuildAnonymousStructOr union, for the same reason? + if (CurContext->isFunctionOrMethod()) + AnonRecord = Record; + return BuildAnonymousStructOrUnion(S, DS, AS, Record, + Context.getPrintingPolicy()); + } + + DeclaresAnything = false; + } + } + + // C11 6.7.2.1p2: + // A struct-declaration that does not declare an anonymous structure or + // anonymous union shall contain a struct-declarator-list. + // + // This rule also existed in C89 and C99; the grammar for struct-declaration + // did not permit a struct-declaration without a struct-declarator-list. + if (!getLangOpts().CPlusPlus && CurContext->isRecord() && + DS.getStorageClassSpec() == DeclSpec::SCS_unspecified) { + // Check for Microsoft C extension: anonymous struct/union member. + // Handle 2 kinds of anonymous struct/union: + // struct STRUCT; + // union UNION; + // and + // STRUCT_TYPE; <- where STRUCT_TYPE is a typedef struct. + // UNION_TYPE; <- where UNION_TYPE is a typedef union. + if ((Tag && Tag->getDeclName()) || + DS.getTypeSpecType() == DeclSpec::TST_typename) { + RecordDecl *Record = nullptr; + if (Tag) + Record = dyn_cast(Tag); + else if (const RecordType *RT = + DS.getRepAsType().get()->getAsStructureType()) + Record = RT->getDecl(); + else if (const RecordType *UT = DS.getRepAsType().get()->getAsUnionType()) + Record = UT->getDecl(); + + if (Record && getLangOpts().MicrosoftExt) { + Diag(DS.getBeginLoc(), diag::ext_ms_anonymous_record) + << Record->isUnion() << DS.getSourceRange(); + return BuildMicrosoftCAnonymousStruct(S, DS, Record); + } + + DeclaresAnything = false; + } + } + + // Skip all the checks below if we have a type error. + if (DS.getTypeSpecType() == DeclSpec::TST_error || + (TagD && TagD->isInvalidDecl())) + return TagD; + + if (getLangOpts().CPlusPlus && + DS.getStorageClassSpec() != DeclSpec::SCS_typedef) + if (EnumDecl *Enum = dyn_cast_or_null(Tag)) + if (Enum->enumerator_begin() == Enum->enumerator_end() && + !Enum->getIdentifier() && !Enum->isInvalidDecl()) + DeclaresAnything = false; + + if (!DS.isMissingDeclaratorOk()) { + // Customize diagnostic for a typedef missing a name. + if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef) + Diag(DS.getBeginLoc(), diag::ext_typedef_without_a_name) + << DS.getSourceRange(); + else + DeclaresAnything = false; + } + + if (DS.isModulePrivateSpecified() && + Tag && Tag->getDeclContext()->isFunctionOrMethod()) + Diag(DS.getModulePrivateSpecLoc(), diag::err_module_private_local_class) + << Tag->getTagKind() + << FixItHint::CreateRemoval(DS.getModulePrivateSpecLoc()); + + ActOnDocumentableDecl(TagD); + + // C 6.7/2: + // A declaration [...] shall declare at least a declarator [...], a tag, + // or the members of an enumeration. + // C++ [dcl.dcl]p3: + // [If there are no declarators], and except for the declaration of an + // unnamed bit-field, the decl-specifier-seq shall introduce one or more + // names into the program, or shall redeclare a name introduced by a + // previous declaration. + if (!DeclaresAnything) { + // In C, we allow this as a (popular) extension / bug. Don't bother + // producing further diagnostics for redundant qualifiers after this. + Diag(DS.getBeginLoc(), diag::ext_no_declarators) << DS.getSourceRange(); + return TagD; + } + + // C++ [dcl.stc]p1: + // If a storage-class-specifier appears in a decl-specifier-seq, [...] the + // init-declarator-list of the declaration shall not be empty. + // C++ [dcl.fct.spec]p1: + // If a cv-qualifier appears in a decl-specifier-seq, the + // init-declarator-list of the declaration shall not be empty. + // + // Spurious qualifiers here appear to be valid in C. + unsigned DiagID = diag::warn_standalone_specifier; + if (getLangOpts().CPlusPlus) + DiagID = diag::ext_standalone_specifier; + + // Note that a linkage-specification sets a storage class, but + // 'extern "C" struct foo;' is actually valid and not theoretically + // useless. + if (DeclSpec::SCS SCS = DS.getStorageClassSpec()) { + if (SCS == DeclSpec::SCS_mutable) + // Since mutable is not a viable storage class specifier in C, there is + // no reason to treat it as an extension. Instead, diagnose as an error. + Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_nonmember); + else if (!DS.isExternInLinkageSpec() && SCS != DeclSpec::SCS_typedef) + Diag(DS.getStorageClassSpecLoc(), DiagID) + << DeclSpec::getSpecifierName(SCS); + } + + if (DeclSpec::TSCS TSCS = DS.getThreadStorageClassSpec()) + Diag(DS.getThreadStorageClassSpecLoc(), DiagID) + << DeclSpec::getSpecifierName(TSCS); + if (DS.getTypeQualifiers()) { + if (DS.getTypeQualifiers() & DeclSpec::TQ_const) + Diag(DS.getConstSpecLoc(), DiagID) << "const"; + if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile) + Diag(DS.getConstSpecLoc(), DiagID) << "volatile"; + // Restrict is covered above. + if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic) + Diag(DS.getAtomicSpecLoc(), DiagID) << "_Atomic"; + if (DS.getTypeQualifiers() & DeclSpec::TQ_unaligned) + Diag(DS.getUnalignedSpecLoc(), DiagID) << "__unaligned"; + } + + // Warn about ignored type attributes, for example: + // __attribute__((aligned)) struct A; + // Attributes should be placed after tag to apply to type declaration. + if (!DS.getAttributes().empty()) { + DeclSpec::TST TypeSpecType = DS.getTypeSpecType(); + if (TypeSpecType == DeclSpec::TST_class || + TypeSpecType == DeclSpec::TST_struct || + TypeSpecType == DeclSpec::TST_interface || + TypeSpecType == DeclSpec::TST_union || + TypeSpecType == DeclSpec::TST_enum) { + for (const ParsedAttr &AL : DS.getAttributes()) + Diag(AL.getLoc(), diag::warn_declspec_attribute_ignored) + << AL.getName() << GetDiagnosticTypeSpecifierID(TypeSpecType); + } + } + + return TagD; + } + + /// We are trying to inject an anonymous member into the given scope; + /// check if there's an existing declaration that can't be overloaded. + /// + /// \return true if this is a forbidden redeclaration + static bool CheckAnonMemberRedeclaration(Sema &SemaRef, + Scope *S, + DeclContext *Owner, + DeclarationName Name, + SourceLocation NameLoc, + bool IsUnion) { + LookupResult R(SemaRef, Name, NameLoc, Sema::LookupMemberName, + Sema::ForVisibleRedeclaration); + if (!SemaRef.LookupName(R, S)) return false; + + // Pick a representative declaration. + NamedDecl *PrevDecl = R.getRepresentativeDecl()->getUnderlyingDecl(); + assert(PrevDecl && "Expected a non-null Decl"); + + if (!SemaRef.isDeclInScope(PrevDecl, Owner, S)) + return false; + + SemaRef.Diag(NameLoc, diag::err_anonymous_record_member_redecl) + << IsUnion << Name; + SemaRef.Diag(PrevDecl->getLocation(), diag::note_previous_declaration); + + return true; + } + + /// InjectAnonymousStructOrUnionMembers - Inject the members of the + /// anonymous struct or union AnonRecord into the owning context Owner + /// and scope S. This routine will be invoked just after we realize + /// that an unnamed union or struct is actually an anonymous union or + /// struct, e.g., + /// + /// @code + /// union { + /// int i; + /// float f; + /// }; // InjectAnonymousStructOrUnionMembers called here to inject i and + /// // f into the surrounding scope.x + /// @endcode + /// + /// This routine is recursive, injecting the names of nested anonymous + /// structs/unions into the owning context and scope as well. + static bool + InjectAnonymousStructOrUnionMembers(Sema &SemaRef, Scope *S, DeclContext *Owner, + RecordDecl *AnonRecord, AccessSpecifier AS, + SmallVectorImpl &Chaining) { + bool Invalid = false; + + // Look every FieldDecl and IndirectFieldDecl with a name. + for (auto *D : AnonRecord->decls()) { + if ((isa(D) || isa(D)) && + cast(D)->getDeclName()) { + ValueDecl *VD = cast(D); + if (CheckAnonMemberRedeclaration(SemaRef, S, Owner, VD->getDeclName(), + VD->getLocation(), + AnonRecord->isUnion())) { + // C++ [class.union]p2: + // The names of the members of an anonymous union shall be + // distinct from the names of any other entity in the + // scope in which the anonymous union is declared. + Invalid = true; + } else { + // C++ [class.union]p2: + // For the purpose of name lookup, after the anonymous union + // definition, the members of the anonymous union are + // considered to have been defined in the scope in which the + // anonymous union is declared. + unsigned OldChainingSize = Chaining.size(); + if (IndirectFieldDecl *IF = dyn_cast(VD)) + Chaining.append(IF->chain_begin(), IF->chain_end()); + else + Chaining.push_back(VD); + + assert(Chaining.size() >= 2); + NamedDecl **NamedChain = + new (SemaRef.Context)NamedDecl*[Chaining.size()]; + for (unsigned i = 0; i < Chaining.size(); i++) + NamedChain[i] = Chaining[i]; + + IndirectFieldDecl *IndirectField = IndirectFieldDecl::Create( + SemaRef.Context, Owner, VD->getLocation(), VD->getIdentifier(), + VD->getType(), {NamedChain, Chaining.size()}); + + for (const auto *Attr : VD->attrs()) + IndirectField->addAttr(Attr->clone(SemaRef.Context)); + + IndirectField->setAccess(AS); + IndirectField->setImplicit(); + SemaRef.PushOnScopeChains(IndirectField, S); + + // That includes picking up the appropriate access specifier. + if (AS != AS_none) IndirectField->setAccess(AS); + + Chaining.resize(OldChainingSize); + } + } + } + + return Invalid; + } + + /// StorageClassSpecToVarDeclStorageClass - Maps a DeclSpec::SCS to + /// a VarDecl::StorageClass. Any error reporting is up to the caller: + /// illegal input values are mapped to SC_None. + static StorageClass + StorageClassSpecToVarDeclStorageClass(const DeclSpec &DS) { + DeclSpec::SCS StorageClassSpec = DS.getStorageClassSpec(); + assert(StorageClassSpec != DeclSpec::SCS_typedef && + "Parser allowed 'typedef' as storage class VarDecl."); + switch (StorageClassSpec) { + case DeclSpec::SCS_unspecified: return SC_None; + case DeclSpec::SCS_extern: + if (DS.isExternInLinkageSpec()) + return SC_None; + return SC_Extern; + case DeclSpec::SCS_static: return SC_Static; + case DeclSpec::SCS_auto: return SC_Auto; + case DeclSpec::SCS_register: return SC_Register; + case DeclSpec::SCS_private_extern: return SC_PrivateExtern; + // Illegal SCSs map to None: error reporting is up to the caller. + case DeclSpec::SCS_mutable: // Fall through. + case DeclSpec::SCS_typedef: return SC_None; + } + llvm_unreachable("unknown storage class specifier"); + } + + static SourceLocation findDefaultInitializer(const CXXRecordDecl *Record) { + assert(Record->hasInClassInitializer()); + + for (const auto *I : Record->decls()) { + const auto *FD = dyn_cast(I); + if (const auto *IFD = dyn_cast(I)) + FD = IFD->getAnonField(); + if (FD && FD->hasInClassInitializer()) + return FD->getLocation(); + } + + llvm_unreachable("couldn't find in-class initializer"); + } + + static void checkDuplicateDefaultInit(Sema &S, CXXRecordDecl *Parent, + SourceLocation DefaultInitLoc) { + if (!Parent->isUnion() || !Parent->hasInClassInitializer()) + return; + + S.Diag(DefaultInitLoc, diag::err_multiple_mem_union_initialization); + S.Diag(findDefaultInitializer(Parent), diag::note_previous_initializer) << 0; + } + + static void checkDuplicateDefaultInit(Sema &S, CXXRecordDecl *Parent, + CXXRecordDecl *AnonUnion) { + if (!Parent->isUnion() || !Parent->hasInClassInitializer()) + return; + + checkDuplicateDefaultInit(S, Parent, findDefaultInitializer(AnonUnion)); + } + + /// BuildAnonymousStructOrUnion - Handle the declaration of an + /// anonymous structure or union. Anonymous unions are a C++ feature + /// (C++ [class.union]) and a C11 feature; anonymous structures + /// are a C11 feature and GNU C++ extension. + Decl *Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS, + AccessSpecifier AS, + RecordDecl *Record, + const PrintingPolicy &Policy) { + DeclContext *Owner = Record->getDeclContext(); + + // Diagnose whether this anonymous struct/union is an extension. + if (Record->isUnion() && !getLangOpts().CPlusPlus && !getLangOpts().C11) + Diag(Record->getLocation(), diag::ext_anonymous_union); + else if (!Record->isUnion() && getLangOpts().CPlusPlus) + Diag(Record->getLocation(), diag::ext_gnu_anonymous_struct); + else if (!Record->isUnion() && !getLangOpts().C11) + Diag(Record->getLocation(), diag::ext_c11_anonymous_struct); + + // C and C++ require different kinds of checks for anonymous + // structs/unions. + bool Invalid = false; + if (getLangOpts().CPlusPlus) { + const char *PrevSpec = nullptr; + unsigned DiagID; + if (Record->isUnion()) { + // C++ [class.union]p6: + // C++17 [class.union.anon]p2: + // Anonymous unions declared in a named namespace or in the + // global namespace shall be declared static. + DeclContext *OwnerScope = Owner->getRedeclContext(); + if (DS.getStorageClassSpec() != DeclSpec::SCS_static && + (OwnerScope->isTranslationUnit() || + (OwnerScope->isNamespace() && + !cast(OwnerScope)->isAnonymousNamespace()))) { + Diag(Record->getLocation(), diag::err_anonymous_union_not_static) + << FixItHint::CreateInsertion(Record->getLocation(), "static "); + + // Recover by adding 'static'. + DS.SetStorageClassSpec(*this, DeclSpec::SCS_static, SourceLocation(), + PrevSpec, DiagID, Policy); + } + // C++ [class.union]p6: + // A storage class is not allowed in a declaration of an + // anonymous union in a class scope. + else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified && + isa(Owner)) { + Diag(DS.getStorageClassSpecLoc(), + diag::err_anonymous_union_with_storage_spec) + << FixItHint::CreateRemoval(DS.getStorageClassSpecLoc()); + + // Recover by removing the storage specifier. + DS.SetStorageClassSpec(*this, DeclSpec::SCS_unspecified, + SourceLocation(), + PrevSpec, DiagID, Context.getPrintingPolicy()); + } + } + + // Ignore const/volatile/restrict qualifiers. + if (DS.getTypeQualifiers()) { + if (DS.getTypeQualifiers() & DeclSpec::TQ_const) + Diag(DS.getConstSpecLoc(), diag::ext_anonymous_struct_union_qualified) + << Record->isUnion() << "const" + << FixItHint::CreateRemoval(DS.getConstSpecLoc()); + if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile) + Diag(DS.getVolatileSpecLoc(), + diag::ext_anonymous_struct_union_qualified) + << Record->isUnion() << "volatile" + << FixItHint::CreateRemoval(DS.getVolatileSpecLoc()); + if (DS.getTypeQualifiers() & DeclSpec::TQ_restrict) + Diag(DS.getRestrictSpecLoc(), + diag::ext_anonymous_struct_union_qualified) + << Record->isUnion() << "restrict" + << FixItHint::CreateRemoval(DS.getRestrictSpecLoc()); + if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic) + Diag(DS.getAtomicSpecLoc(), + diag::ext_anonymous_struct_union_qualified) + << Record->isUnion() << "_Atomic" + << FixItHint::CreateRemoval(DS.getAtomicSpecLoc()); + if (DS.getTypeQualifiers() & DeclSpec::TQ_unaligned) + Diag(DS.getUnalignedSpecLoc(), + diag::ext_anonymous_struct_union_qualified) + << Record->isUnion() << "__unaligned" + << FixItHint::CreateRemoval(DS.getUnalignedSpecLoc()); + + DS.ClearTypeQualifiers(); + } + + // C++ [class.union]p2: + // The member-specification of an anonymous union shall only + // define non-static data members. [Note: nested types and + // functions cannot be declared within an anonymous union. ] + for (auto *Mem : Record->decls()) { + if (auto *FD = dyn_cast(Mem)) { + // C++ [class.union]p3: + // An anonymous union shall not have private or protected + // members (clause 11). + assert(FD->getAccess() != AS_none); + if (FD->getAccess() != AS_public) { + Diag(FD->getLocation(), diag::err_anonymous_record_nonpublic_member) + << Record->isUnion() << (FD->getAccess() == AS_protected); + Invalid = true; + } + + // C++ [class.union]p1 + // An object of a class with a non-trivial constructor, a non-trivial + // copy constructor, a non-trivial destructor, or a non-trivial copy + // assignment operator cannot be a member of a union, nor can an + // array of such objects. + if (CheckNontrivialField(FD)) + Invalid = true; + } else if (Mem->isImplicit()) { + // Any implicit members are fine. + } else if (isa(Mem) && Mem->getDeclContext() != Record) { + // This is a type that showed up in an + // elaborated-type-specifier inside the anonymous struct or + // union, but which actually declares a type outside of the + // anonymous struct or union. It's okay. + } else if (auto *MemRecord = dyn_cast(Mem)) { + if (!MemRecord->isAnonymousStructOrUnion() && + MemRecord->getDeclName()) { + // Visual C++ allows type definition in anonymous struct or union. + if (getLangOpts().MicrosoftExt) + Diag(MemRecord->getLocation(), diag::ext_anonymous_record_with_type) + << Record->isUnion(); + else { + // This is a nested type declaration. + Diag(MemRecord->getLocation(), diag::err_anonymous_record_with_type) + << Record->isUnion(); + Invalid = true; + } + } else { + // This is an anonymous type definition within another anonymous type. + // This is a popular extension, provided by Plan9, MSVC and GCC, but + // not part of standard C++. + Diag(MemRecord->getLocation(), + diag::ext_anonymous_record_with_anonymous_type) + << Record->isUnion(); + } + } else if (isa(Mem)) { + // Any access specifier is fine. + } else if (isa(Mem)) { + // In C++1z, static_assert declarations are also fine. + } else { + // We have something that isn't a non-static data + // member. Complain about it. + unsigned DK = diag::err_anonymous_record_bad_member; + if (isa(Mem)) + DK = diag::err_anonymous_record_with_type; + else if (isa(Mem)) + DK = diag::err_anonymous_record_with_function; + else if (isa(Mem)) + DK = diag::err_anonymous_record_with_static; + + // Visual C++ allows type definition in anonymous struct or union. + if (getLangOpts().MicrosoftExt && + DK == diag::err_anonymous_record_with_type) + Diag(Mem->getLocation(), diag::ext_anonymous_record_with_type) + << Record->isUnion(); + else { + Diag(Mem->getLocation(), DK) << Record->isUnion(); + Invalid = true; + } + } + } + + // C++11 [class.union]p8 (DR1460): + // At most one variant member of a union may have a + // brace-or-equal-initializer. + if (cast(Record)->hasInClassInitializer() && + Owner->isRecord()) + checkDuplicateDefaultInit(*this, cast(Owner), + cast(Record)); + } + + if (!Record->isUnion() && !Owner->isRecord()) { + Diag(Record->getLocation(), diag::err_anonymous_struct_not_member) + << getLangOpts().CPlusPlus; + Invalid = true; + } + + // Mock up a declarator. + Declarator Dc(DS, DeclaratorContext::MemberContext); + TypeSourceInfo *TInfo = GetTypeForDeclarator(Dc, S); + assert(TInfo && "couldn't build declarator info for anonymous struct/union"); + + // Create a declaration for this anonymous struct/union. + NamedDecl *Anon = nullptr; + if (RecordDecl *OwningClass = dyn_cast(Owner)) { + Anon = FieldDecl::Create( + Context, OwningClass, DS.getBeginLoc(), Record->getLocation(), + /*IdentifierInfo=*/nullptr, Context.getTypeDeclType(Record), TInfo, + /*BitWidth=*/nullptr, /*Mutable=*/false, + /*InitStyle=*/ICIS_NoInit); + Anon->setAccess(AS); + if (getLangOpts().CPlusPlus) + FieldCollector->Add(cast(Anon)); + } else { + DeclSpec::SCS SCSpec = DS.getStorageClassSpec(); + StorageClass SC = StorageClassSpecToVarDeclStorageClass(DS); + if (SCSpec == DeclSpec::SCS_mutable) { + // mutable can only appear on non-static class members, so it's always + // an error here + Diag(Record->getLocation(), diag::err_mutable_nonmember); + Invalid = true; + SC = SC_None; + } + + Anon = VarDecl::Create(Context, Owner, DS.getBeginLoc(), + Record->getLocation(), /*IdentifierInfo=*/nullptr, + Context.getTypeDeclType(Record), TInfo, SC); + + // Default-initialize the implicit variable. This initialization will be + // trivial in almost all cases, except if a union member has an in-class + // initializer: + // union { int n = 0; }; + ActOnUninitializedDecl(Anon); + } + Anon->setImplicit(); + + // Mark this as an anonymous struct/union type. + Record->setAnonymousStructOrUnion(true); + + // Add the anonymous struct/union object to the current + // context. We'll be referencing this object when we refer to one of + // its members. + Owner->addDecl(Anon); + + // Inject the members of the anonymous struct/union into the owning + // context and into the identifier resolver chain for name lookup + // purposes. + SmallVector Chain; + Chain.push_back(Anon); + + if (InjectAnonymousStructOrUnionMembers(*this, S, Owner, Record, AS, Chain)) + Invalid = true; + + if (VarDecl *NewVD = dyn_cast(Anon)) { + if (getLangOpts().CPlusPlus && NewVD->isStaticLocal()) { + Decl *ManglingContextDecl; + if (MangleNumberingContext *MCtx = getCurrentMangleNumberContext( + NewVD->getDeclContext(), ManglingContextDecl)) { + Context.setManglingNumber( + NewVD, MCtx->getManglingNumber( + NewVD, getMSManglingNumber(getLangOpts(), S))); + Context.setStaticLocalNumber(NewVD, MCtx->getStaticLocalNumber(NewVD)); + } + } + } + + if (Invalid) + Anon->setInvalidDecl(); + + return Anon; + } + + /// BuildMicrosoftCAnonymousStruct - Handle the declaration of an + /// Microsoft C anonymous structure. + /// Ref: http://msdn.microsoft.com/en-us/library/z2cx9y4f.aspx + /// Example: + /// + /// struct A { int a; }; + /// struct B { struct A; int b; }; + /// + /// void foo() { + /// B var; + /// var.a = 3; + /// } + /// + Decl *Sema::BuildMicrosoftCAnonymousStruct(Scope *S, DeclSpec &DS, + RecordDecl *Record) { + assert(Record && "expected a record!"); + + // Mock up a declarator. + Declarator Dc(DS, DeclaratorContext::TypeNameContext); + TypeSourceInfo *TInfo = GetTypeForDeclarator(Dc, S); + assert(TInfo && "couldn't build declarator info for anonymous struct"); + + auto *ParentDecl = cast(CurContext); + QualType RecTy = Context.getTypeDeclType(Record); + + // Create a declaration for this anonymous struct. + NamedDecl *Anon = + FieldDecl::Create(Context, ParentDecl, DS.getBeginLoc(), DS.getBeginLoc(), + /*IdentifierInfo=*/nullptr, RecTy, TInfo, + /*BitWidth=*/nullptr, /*Mutable=*/false, + /*InitStyle=*/ICIS_NoInit); + Anon->setImplicit(); + + // Add the anonymous struct object to the current context. + CurContext->addDecl(Anon); + + // Inject the members of the anonymous struct into the current + // context and into the identifier resolver chain for name lookup + // purposes. + SmallVector Chain; + Chain.push_back(Anon); + + RecordDecl *RecordDef = Record->getDefinition(); + if (RequireCompleteType(Anon->getLocation(), RecTy, + diag::err_field_incomplete) || + InjectAnonymousStructOrUnionMembers(*this, S, CurContext, RecordDef, + AS_none, Chain)) { + Anon->setInvalidDecl(); + ParentDecl->setInvalidDecl(); + } + + return Anon; + } + + /// GetNameForDeclarator - Determine the full declaration name for the + /// given Declarator. + DeclarationNameInfo Sema::GetNameForDeclarator(Declarator &D) { + return GetNameFromUnqualifiedId(D.getName()); + } + + /// Retrieves the declaration name from a parsed unqualified-id. + DeclarationNameInfo + Sema::GetNameFromUnqualifiedId(const UnqualifiedId &Name) { + DeclarationNameInfo NameInfo; + NameInfo.setLoc(Name.StartLocation); + + switch (Name.getKind()) { + + case UnqualifiedIdKind::IK_ImplicitSelfParam: + case UnqualifiedIdKind::IK_Identifier: + NameInfo.setName(Name.Identifier); + return NameInfo; + + case UnqualifiedIdKind::IK_DeductionGuideName: { + // C++ [temp.deduct.guide]p3: + // The simple-template-id shall name a class template specialization. + // The template-name shall be the same identifier as the template-name + // of the simple-template-id. + // These together intend to imply that the template-name shall name a + // class template. + // FIXME: template struct X {}; + // template using Y = X; + // Y(int) -> Y; + // satisfies these rules but does not name a class template. + TemplateName TN = Name.TemplateName.get().get(); + auto *Template = TN.getAsTemplateDecl(); + if (!Template || !isa(Template)) { + Diag(Name.StartLocation, + diag::err_deduction_guide_name_not_class_template) + << (int)getTemplateNameKindForDiagnostics(TN) << TN; + if (Template) + Diag(Template->getLocation(), diag::note_template_decl_here); + return DeclarationNameInfo(); + } + + NameInfo.setName( + Context.DeclarationNames.getCXXDeductionGuideName(Template)); + return NameInfo; + } + + case UnqualifiedIdKind::IK_OperatorFunctionId: + NameInfo.setName(Context.DeclarationNames.getCXXOperatorName( + Name.OperatorFunctionId.Operator)); + NameInfo.getInfo().CXXOperatorName.BeginOpNameLoc + = Name.OperatorFunctionId.SymbolLocations[0]; + NameInfo.getInfo().CXXOperatorName.EndOpNameLoc + = Name.EndLocation.getRawEncoding(); + return NameInfo; + + case UnqualifiedIdKind::IK_LiteralOperatorId: + NameInfo.setName(Context.DeclarationNames.getCXXLiteralOperatorName( + Name.Identifier)); + NameInfo.setCXXLiteralOperatorNameLoc(Name.EndLocation); + return NameInfo; + + case UnqualifiedIdKind::IK_ConversionFunctionId: { + TypeSourceInfo *TInfo; + QualType Ty = GetTypeFromParser(Name.ConversionFunctionId, &TInfo); + if (Ty.isNull()) + return DeclarationNameInfo(); + NameInfo.setName(Context.DeclarationNames.getCXXConversionFunctionName( + Context.getCanonicalType(Ty))); + NameInfo.setNamedTypeInfo(TInfo); + return NameInfo; + } + + case UnqualifiedIdKind::IK_ConstructorName: { + TypeSourceInfo *TInfo; + QualType Ty = GetTypeFromParser(Name.ConstructorName, &TInfo); + if (Ty.isNull()) + return DeclarationNameInfo(); + NameInfo.setName(Context.DeclarationNames.getCXXConstructorName( + Context.getCanonicalType(Ty))); + NameInfo.setNamedTypeInfo(TInfo); + return NameInfo; + } + + case UnqualifiedIdKind::IK_ConstructorTemplateId: { + // In well-formed code, we can only have a constructor + // template-id that refers to the current context, so go there + // to find the actual type being constructed. + CXXRecordDecl *CurClass = dyn_cast(CurContext); + if (!CurClass || CurClass->getIdentifier() != Name.TemplateId->Name) + return DeclarationNameInfo(); + + // Determine the type of the class being constructed. + QualType CurClassType = Context.getTypeDeclType(CurClass); + + // FIXME: Check two things: that the template-id names the same type as + // CurClassType, and that the template-id does not occur when the name + // was qualified. + + NameInfo.setName(Context.DeclarationNames.getCXXConstructorName( + Context.getCanonicalType(CurClassType))); + // FIXME: should we retrieve TypeSourceInfo? + NameInfo.setNamedTypeInfo(nullptr); + return NameInfo; + } + + case UnqualifiedIdKind::IK_DestructorName: { + TypeSourceInfo *TInfo; + QualType Ty = GetTypeFromParser(Name.DestructorName, &TInfo); + if (Ty.isNull()) + return DeclarationNameInfo(); + NameInfo.setName(Context.DeclarationNames.getCXXDestructorName( + Context.getCanonicalType(Ty))); + NameInfo.setNamedTypeInfo(TInfo); + return NameInfo; + } + + case UnqualifiedIdKind::IK_TemplateId: { + TemplateName TName = Name.TemplateId->Template.get(); + SourceLocation TNameLoc = Name.TemplateId->TemplateNameLoc; + return Context.getNameForTemplate(TName, TNameLoc); + } + + } // switch (Name.getKind()) + + llvm_unreachable("Unknown name kind"); + } + + static QualType getCoreType(QualType Ty) { + do { + if (Ty->isPointerType() || Ty->isReferenceType()) + Ty = Ty->getPointeeType(); + else if (Ty->isArrayType()) + Ty = Ty->castAsArrayTypeUnsafe()->getElementType(); + else + return Ty.withoutLocalFastQualifiers(); + } while (true); + } + + /// hasSimilarParameters - Determine whether the C++ functions Declaration + /// and Definition have "nearly" matching parameters. This heuristic is + /// used to improve diagnostics in the case where an out-of-line function + /// definition doesn't match any declaration within the class or namespace. + /// Also sets Params to the list of indices to the parameters that differ + /// between the declaration and the definition. If hasSimilarParameters + /// returns true and Params is empty, then all of the parameters match. + static bool hasSimilarParameters(ASTContext &Context, + FunctionDecl *Declaration, + FunctionDecl *Definition, + SmallVectorImpl &Params) { + Params.clear(); + if (Declaration->param_size() != Definition->param_size()) + return false; + for (unsigned Idx = 0; Idx < Declaration->param_size(); ++Idx) { + QualType DeclParamTy = Declaration->getParamDecl(Idx)->getType(); + QualType DefParamTy = Definition->getParamDecl(Idx)->getType(); + + // The parameter types are identical + if (Context.hasSameUnqualifiedType(DefParamTy, DeclParamTy)) + continue; + + QualType DeclParamBaseTy = getCoreType(DeclParamTy); + QualType DefParamBaseTy = getCoreType(DefParamTy); + const IdentifierInfo *DeclTyName = DeclParamBaseTy.getBaseTypeIdentifier(); + const IdentifierInfo *DefTyName = DefParamBaseTy.getBaseTypeIdentifier(); + + if (Context.hasSameUnqualifiedType(DeclParamBaseTy, DefParamBaseTy) || + (DeclTyName && DeclTyName == DefTyName)) + Params.push_back(Idx); + else // The two parameters aren't even close + return false; + } + + return true; + } + + /// NeedsRebuildingInCurrentInstantiation - Checks whether the given + /// declarator needs to be rebuilt in the current instantiation. + /// Any bits of declarator which appear before the name are valid for + /// consideration here. That's specifically the type in the decl spec + /// and the base type in any member-pointer chunks. + static bool RebuildDeclaratorInCurrentInstantiation(Sema &S, Declarator &D, + DeclarationName Name) { + // The types we specifically need to rebuild are: + // - typenames, typeofs, and decltypes + // - types which will become injected class names + // Of course, we also need to rebuild any type referencing such a + // type. It's safest to just say "dependent", but we call out a + // few cases here. + + DeclSpec &DS = D.getMutableDeclSpec(); + switch (DS.getTypeSpecType()) { + case DeclSpec::TST_typename: + case DeclSpec::TST_typeofType: + case DeclSpec::TST_underlyingType: + case DeclSpec::TST_atomic: { + // Grab the type from the parser. + TypeSourceInfo *TSI = nullptr; + QualType T = S.GetTypeFromParser(DS.getRepAsType(), &TSI); + if (T.isNull() || !T->isDependentType()) break; + + // Make sure there's a type source info. This isn't really much + // of a waste; most dependent types should have type source info + // attached already. + if (!TSI) + TSI = S.Context.getTrivialTypeSourceInfo(T, DS.getTypeSpecTypeLoc()); + + // Rebuild the type in the current instantiation. + TSI = S.RebuildTypeInCurrentInstantiation(TSI, D.getIdentifierLoc(), Name); + if (!TSI) return true; + + // Store the new type back in the decl spec. + ParsedType LocType = S.CreateParsedType(TSI->getType(), TSI); + DS.UpdateTypeRep(LocType); + break; + } + + case DeclSpec::TST_decltype: + case DeclSpec::TST_typeofExpr: { + Expr *E = DS.getRepAsExpr(); + ExprResult Result = S.RebuildExprInCurrentInstantiation(E); + if (Result.isInvalid()) return true; + DS.UpdateExprRep(Result.get()); + break; + } + + default: + // Nothing to do for these decl specs. + break; + } + + // It doesn't matter what order we do this in. + for (unsigned I = 0, E = D.getNumTypeObjects(); I != E; ++I) { + DeclaratorChunk &Chunk = D.getTypeObject(I); + + // The only type information in the declarator which can come + // before the declaration name is the base type of a member + // pointer. + if (Chunk.Kind != DeclaratorChunk::MemberPointer) + continue; + + // Rebuild the scope specifier in-place. + CXXScopeSpec &SS = Chunk.Mem.Scope(); + if (S.RebuildNestedNameSpecifierInCurrentInstantiation(SS)) + return true; + } + + return false; + } + + Decl *Sema::ActOnDeclarator(Scope *S, Declarator &D) { + D.setFunctionDefinitionKind(FDK_Declaration); + Decl *Dcl = HandleDeclarator(S, D, MultiTemplateParamsArg()); + + if (OriginalLexicalContext && OriginalLexicalContext->isObjCContainer() && + Dcl && Dcl->getDeclContext()->isFileContext()) + Dcl->setTopLevelDeclInObjCContainer(); + + if (getLangOpts().OpenCL) + setCurrentOpenCLExtensionForDecl(Dcl); + + return Dcl; + } + + /// DiagnoseClassNameShadow - Implement 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 static data member of class T; + /// - every member function of class T + /// - every member of class T that is itself a type; + /// \returns true if the declaration name violates these rules. + bool Sema::DiagnoseClassNameShadow(DeclContext *DC, + DeclarationNameInfo NameInfo) { + DeclarationName Name = NameInfo.getName(); + + CXXRecordDecl *Record = dyn_cast(DC); + while (Record && Record->isAnonymousStructOrUnion()) + Record = dyn_cast(Record->getParent()); + if (Record && Record->getIdentifier() && Record->getDeclName() == Name) { + Diag(NameInfo.getLoc(), diag::err_member_name_of_class) << Name; + return true; + } + + return false; + } + + /// Diagnose a declaration whose declarator-id has the given + /// nested-name-specifier. + /// + /// \param SS The nested-name-specifier of the declarator-id. + /// + /// \param DC The declaration context to which the nested-name-specifier + /// resolves. + /// + /// \param Name The name of the entity being declared. + /// + /// \param Loc The location of the name of the entity being declared. + /// + /// \param IsTemplateId Whether the name is a (simple-)template-id, and thus + /// we're declaring an explicit / partial specialization / instantiation. + /// + /// \returns true if we cannot safely recover from this error, false otherwise. + bool Sema::diagnoseQualifiedDeclaration(CXXScopeSpec &SS, DeclContext *DC, + DeclarationName Name, + SourceLocation Loc, bool IsTemplateId) { + DeclContext *Cur = CurContext; + while (isa(Cur) || isa(Cur)) + Cur = Cur->getParent(); + + // If the user provided a superfluous scope specifier that refers back to the + // class in which the entity is already declared, diagnose and ignore it. + // + // class X { + // void X::f(); + // }; + // + // Note, it was once ill-formed to give redundant qualification in all + // contexts, but that rule was removed by DR482. + if (Cur->Equals(DC)) { + if (Cur->isRecord()) { + Diag(Loc, LangOpts.MicrosoftExt ? diag::warn_member_extra_qualification + : diag::err_member_extra_qualification) + << Name << FixItHint::CreateRemoval(SS.getRange()); + SS.clear(); + } else { + Diag(Loc, diag::warn_namespace_member_extra_qualification) << Name; + } + return false; + } + + // Check whether the qualifying scope encloses the scope of the original + // declaration. For a template-id, we perform the checks in + // CheckTemplateSpecializationScope. + if (!Cur->Encloses(DC) && !IsTemplateId) { + if (Cur->isRecord()) + Diag(Loc, diag::err_member_qualification) + << Name << SS.getRange(); + else if (isa(DC)) + Diag(Loc, diag::err_invalid_declarator_global_scope) + << Name << SS.getRange(); + else if (isa(Cur)) + Diag(Loc, diag::err_invalid_declarator_in_function) + << Name << SS.getRange(); + else if (isa(Cur)) + Diag(Loc, diag::err_invalid_declarator_in_block) + << Name << SS.getRange(); + else + Diag(Loc, diag::err_invalid_declarator_scope) + << Name << cast(Cur) << cast(DC) << SS.getRange(); + + return true; + } + + if (Cur->isRecord()) { + // Cannot qualify members within a class. + Diag(Loc, diag::err_member_qualification) + << Name << SS.getRange(); + SS.clear(); + + // C++ constructors and destructors with incorrect scopes can break + // our AST invariants by having the wrong underlying types. If + // that's the case, then drop this declaration entirely. + if ((Name.getNameKind() == DeclarationName::CXXConstructorName || + Name.getNameKind() == DeclarationName::CXXDestructorName) && + !Context.hasSameType(Name.getCXXNameType(), + Context.getTypeDeclType(cast(Cur)))) + return true; + + return false; + } + + // C++11 [dcl.meaning]p1: + // [...] "The nested-name-specifier of the qualified declarator-id shall + // not begin with a decltype-specifer" + NestedNameSpecifierLoc SpecLoc(SS.getScopeRep(), SS.location_data()); + while (SpecLoc.getPrefix()) + SpecLoc = SpecLoc.getPrefix(); + if (dyn_cast_or_null( + SpecLoc.getNestedNameSpecifier()->getAsType())) + Diag(Loc, diag::err_decltype_in_declarator) + << SpecLoc.getTypeLoc().getSourceRange(); + + return false; + } + + NamedDecl *Sema::HandleDeclarator(Scope *S, Declarator &D, + MultiTemplateParamsArg TemplateParamLists) { + // TODO: consider using NameInfo for diagnostic. + DeclarationNameInfo NameInfo = GetNameForDeclarator(D); + DeclarationName Name = NameInfo.getName(); + + // All of these full declarators require an identifier. If it doesn't have + // one, the ParsedFreeStandingDeclSpec action should be used. + if (D.isDecompositionDeclarator()) { + return ActOnDecompositionDeclarator(S, D, TemplateParamLists); + } else if (!Name) { + if (!D.isInvalidType()) // Reject this if we think it is valid. + Diag(D.getDeclSpec().getBeginLoc(), diag::err_declarator_need_ident) + << D.getDeclSpec().getSourceRange() << D.getSourceRange(); + return nullptr; + } else if (DiagnoseUnexpandedParameterPack(NameInfo, UPPC_DeclarationType)) + return nullptr; + + // The scope passed in may not be a decl scope. Zip up the scope tree until + // we find one that is. + while ((S->getFlags() & Scope::DeclScope) == 0 || + (S->getFlags() & Scope::TemplateParamScope) != 0) + S = S->getParent(); + + DeclContext *DC = CurContext; + if (D.getCXXScopeSpec().isInvalid()) + D.setInvalidType(); + else if (D.getCXXScopeSpec().isSet()) { + if (DiagnoseUnexpandedParameterPack(D.getCXXScopeSpec(), + UPPC_DeclarationQualifier)) + return nullptr; + + bool EnteringContext = !D.getDeclSpec().isFriendSpecified(); + DC = computeDeclContext(D.getCXXScopeSpec(), EnteringContext); + if (!DC || isa(DC)) { + // If we could not compute the declaration context, it's because the + // declaration context is dependent but does not refer to a class, + // class template, or class template partial specialization. Complain + // and return early, to avoid the coming semantic disaster. + Diag(D.getIdentifierLoc(), + diag::err_template_qualified_declarator_no_match) + << D.getCXXScopeSpec().getScopeRep() + << D.getCXXScopeSpec().getRange(); + return nullptr; + } + bool IsDependentContext = DC->isDependentContext(); + + if (!IsDependentContext && + RequireCompleteDeclContext(D.getCXXScopeSpec(), DC)) + return nullptr; + + // If a class is incomplete, do not parse entities inside it. + if (isa(DC) && !cast(DC)->hasDefinition()) { + Diag(D.getIdentifierLoc(), + diag::err_member_def_undefined_record) + << Name << DC << D.getCXXScopeSpec().getRange(); + return nullptr; + } + if (!D.getDeclSpec().isFriendSpecified()) { + if (diagnoseQualifiedDeclaration( + D.getCXXScopeSpec(), DC, Name, D.getIdentifierLoc(), + D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId)) { + if (DC->isRecord()) + return nullptr; + + D.setInvalidType(); + } + } + + // Check whether we need to rebuild the type of the given + // declaration in the current instantiation. + if (EnteringContext && IsDependentContext && + TemplateParamLists.size() != 0) { + ContextRAII SavedContext(*this, DC); + if (RebuildDeclaratorInCurrentInstantiation(*this, D, Name)) + D.setInvalidType(); + } + } + + TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S); + QualType R = TInfo->getType(); + + if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo, + UPPC_DeclarationType)) + D.setInvalidType(); + + LookupResult Previous(*this, NameInfo, LookupOrdinaryName, + forRedeclarationInCurContext()); + + // See if this is a redefinition of a variable in the same scope. + if (!D.getCXXScopeSpec().isSet()) { + bool IsLinkageLookup = false; + bool CreateBuiltins = false; + + // If the declaration we're planning to build will be a function + // or object with linkage, then look for another declaration with + // linkage (C99 6.2.2p4-5 and C++ [basic.link]p6). + // + // If the declaration we're planning to build will be declared with + // external linkage in the translation unit, create any builtin with + // the same name. + if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) + /* Do nothing*/; + else if (CurContext->isFunctionOrMethod() && + (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_extern || + R->isFunctionType())) { + IsLinkageLookup = true; + CreateBuiltins = + CurContext->getEnclosingNamespaceContext()->isTranslationUnit(); + } else if (CurContext->getRedeclContext()->isTranslationUnit() && + D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_static) + CreateBuiltins = true; + + if (IsLinkageLookup) { + Previous.clear(LookupRedeclarationWithLinkage); + Previous.setRedeclarationKind(ForExternalRedeclaration); + } + + LookupName(Previous, S, CreateBuiltins); + } else { // Something like "int foo::x;" + LookupQualifiedName(Previous, DC); + + // C++ [dcl.meaning]p1: + // When the declarator-id is qualified, the declaration shall refer to a + // previously declared member of the class or namespace to which the + // qualifier refers (or, in the case of a namespace, of an element of the + // inline namespace set of that namespace (7.3.1)) or to a specialization + // thereof; [...] + // + // Note that we already checked the context above, and that we do not have + // enough information to make sure that Previous contains the declaration + // we want to match. For example, given: + // + // class X { + // void f(); + // void f(float); + // }; + // + // void X::f(int) { } // ill-formed + // + // In this case, Previous will point to the overload set + // containing the two f's declared in X, but neither of them + // matches. + + // C++ [dcl.meaning]p1: + // [...] the member shall not merely have been introduced by a + // using-declaration in the scope of the class or namespace nominated by + // the nested-name-specifier of the declarator-id. + RemoveUsingDecls(Previous); + } + + if (Previous.isSingleResult() && + Previous.getFoundDecl()->isTemplateParameter()) { + // Maybe we will complain about the shadowed template parameter. + if (!D.isInvalidType()) + DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), + Previous.getFoundDecl()); + + // Just pretend that we didn't see the previous declaration. + Previous.clear(); + } + + if (!R->isFunctionType() && DiagnoseClassNameShadow(DC, NameInfo)) + // Forget that the previous declaration is the injected-class-name. + Previous.clear(); + + // In C++, the previous declaration we find might be a tag type + // (class or enum). In this case, the new declaration will hide the + // tag type. Note that this applies to functions, function templates, and + // variables, but not to typedefs (C++ [dcl.typedef]p4) or variable templates. + if (Previous.isSingleTagDecl() && + D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef && + (TemplateParamLists.size() == 0 || R->isFunctionType())) + Previous.clear(); + + // Check that there are no default arguments other than in the parameters + // of a function declaration (C++ only). + if (getLangOpts().CPlusPlus) + CheckExtraCXXDefaultArguments(D); + + NamedDecl *New; + + bool AddToScope = true; + if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) { + if (TemplateParamLists.size()) { + Diag(D.getIdentifierLoc(), diag::err_template_typedef); + return nullptr; + } + + New = ActOnTypedefDeclarator(S, D, DC, TInfo, Previous); + } else if (R->isFunctionType()) { + New = ActOnFunctionDeclarator(S, D, DC, TInfo, Previous, + TemplateParamLists, + AddToScope); + } else { + New = ActOnVariableDeclarator(S, D, DC, TInfo, Previous, TemplateParamLists, + AddToScope); + } + + if (!New) + return nullptr; + + // If this has an identifier and is not a function template specialization, + // add it to the scope stack. + if (New->getDeclName() && AddToScope) + PushOnScopeChains(New, S); + + if (isInOpenMPDeclareTargetContext()) + checkDeclIsAllowedInOpenMPTarget(nullptr, New); + + return New; + } + + /// Helper method to turn variable array types into constant array + /// types in certain situations which would otherwise be errors (for + /// GCC compatibility). + static QualType TryToFixInvalidVariablyModifiedType(QualType T, + ASTContext &Context, + bool &SizeIsNegative, + llvm::APSInt &Oversized) { + // This method tries to turn a variable array into a constant + // array even when the size isn't an ICE. This is necessary + // for compatibility with code that depends on gcc's buggy + // constant expression folding, like struct {char x[(int)(char*)2];} + SizeIsNegative = false; + Oversized = 0; + + if (T->isDependentType()) + return QualType(); + + QualifierCollector Qs; + const Type *Ty = Qs.strip(T); + + if (const PointerType* PTy = dyn_cast(Ty)) { + QualType Pointee = PTy->getPointeeType(); + QualType FixedType = + TryToFixInvalidVariablyModifiedType(Pointee, Context, SizeIsNegative, + Oversized); + if (FixedType.isNull()) return FixedType; + FixedType = Context.getPointerType(FixedType); + return Qs.apply(Context, FixedType); + } + if (const ParenType* PTy = dyn_cast(Ty)) { + QualType Inner = PTy->getInnerType(); + QualType FixedType = + TryToFixInvalidVariablyModifiedType(Inner, Context, SizeIsNegative, + Oversized); + if (FixedType.isNull()) return FixedType; + FixedType = Context.getParenType(FixedType); + return Qs.apply(Context, FixedType); + } + + const VariableArrayType* VLATy = dyn_cast(T); + if (!VLATy) + return QualType(); + // FIXME: We should probably handle this case + if (VLATy->getElementType()->isVariablyModifiedType()) + return QualType(); + + Expr::EvalResult Result; + if (!VLATy->getSizeExpr() || + !VLATy->getSizeExpr()->EvaluateAsInt(Result, Context)) + return QualType(); + + llvm::APSInt Res = Result.Val.getInt(); + + // Check whether the array size is negative. + if (Res.isSigned() && Res.isNegative()) { + SizeIsNegative = true; + return QualType(); + } + + // Check whether the array is too large to be addressed. + unsigned ActiveSizeBits + = ConstantArrayType::getNumAddressingBits(Context, VLATy->getElementType(), + Res); + if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context)) { + Oversized = Res; + return QualType(); + } + + return Context.getConstantArrayType(VLATy->getElementType(), + Res, ArrayType::Normal, 0); + } + + static void + FixInvalidVariablyModifiedTypeLoc(TypeLoc SrcTL, TypeLoc DstTL) { + SrcTL = SrcTL.getUnqualifiedLoc(); + DstTL = DstTL.getUnqualifiedLoc(); + if (PointerTypeLoc SrcPTL = SrcTL.getAs()) { + PointerTypeLoc DstPTL = DstTL.castAs(); + FixInvalidVariablyModifiedTypeLoc(SrcPTL.getPointeeLoc(), + DstPTL.getPointeeLoc()); + DstPTL.setStarLoc(SrcPTL.getStarLoc()); + return; + } + if (ParenTypeLoc SrcPTL = SrcTL.getAs()) { + ParenTypeLoc DstPTL = DstTL.castAs(); + FixInvalidVariablyModifiedTypeLoc(SrcPTL.getInnerLoc(), + DstPTL.getInnerLoc()); + DstPTL.setLParenLoc(SrcPTL.getLParenLoc()); + DstPTL.setRParenLoc(SrcPTL.getRParenLoc()); + return; + } + ArrayTypeLoc SrcATL = SrcTL.castAs(); + ArrayTypeLoc DstATL = DstTL.castAs(); + TypeLoc SrcElemTL = SrcATL.getElementLoc(); + TypeLoc DstElemTL = DstATL.getElementLoc(); + DstElemTL.initializeFullCopy(SrcElemTL); + DstATL.setLBracketLoc(SrcATL.getLBracketLoc()); + DstATL.setSizeExpr(SrcATL.getSizeExpr()); + DstATL.setRBracketLoc(SrcATL.getRBracketLoc()); + } + + /// Helper method to turn variable array types into constant array + /// types in certain situations which would otherwise be errors (for + /// GCC compatibility). + static TypeSourceInfo* + TryToFixInvalidVariablyModifiedTypeSourceInfo(TypeSourceInfo *TInfo, + ASTContext &Context, + bool &SizeIsNegative, + llvm::APSInt &Oversized) { + QualType FixedTy + = TryToFixInvalidVariablyModifiedType(TInfo->getType(), Context, + SizeIsNegative, Oversized); + if (FixedTy.isNull()) + return nullptr; + TypeSourceInfo *FixedTInfo = Context.getTrivialTypeSourceInfo(FixedTy); + FixInvalidVariablyModifiedTypeLoc(TInfo->getTypeLoc(), + FixedTInfo->getTypeLoc()); + return FixedTInfo; + } + + /// Register the given locally-scoped extern "C" declaration so + /// that it can be found later for redeclarations. We include any extern "C" + /// declaration that is not visible in the translation unit here, not just + /// function-scope declarations. + void + Sema::RegisterLocallyScopedExternCDecl(NamedDecl *ND, Scope *S) { + if (!getLangOpts().CPlusPlus && + ND->getLexicalDeclContext()->getRedeclContext()->isTranslationUnit()) + // Don't need to track declarations in the TU in C. + return; + + // Note that we have a locally-scoped external with this name. + Context.getExternCContextDecl()->makeDeclVisibleInContext(ND); + } + + NamedDecl *Sema::findLocallyScopedExternCDecl(DeclarationName Name) { + // FIXME: We can have multiple results via __attribute__((overloadable)). + auto Result = Context.getExternCContextDecl()->lookup(Name); + return Result.empty() ? nullptr : *Result.begin(); + } + + /// Diagnose function specifiers on a declaration of an identifier that + /// does not identify a function. + void Sema::DiagnoseFunctionSpecifiers(const DeclSpec &DS) { + // FIXME: We should probably indicate the identifier in question to avoid + // confusion for constructs like "virtual int a(), b;" + if (DS.isVirtualSpecified()) + Diag(DS.getVirtualSpecLoc(), + diag::err_virtual_non_function); + + if (DS.isExplicitSpecified()) + Diag(DS.getExplicitSpecLoc(), + diag::err_explicit_non_function); + + if (DS.isNoreturnSpecified()) + Diag(DS.getNoreturnSpecLoc(), + diag::err_noreturn_non_function); + } + + NamedDecl* + Sema::ActOnTypedefDeclarator(Scope* S, Declarator& D, DeclContext* DC, + TypeSourceInfo *TInfo, LookupResult &Previous) { + // Typedef declarators cannot be qualified (C++ [dcl.meaning]p1). + if (D.getCXXScopeSpec().isSet()) { + Diag(D.getIdentifierLoc(), diag::err_qualified_typedef_declarator) + << D.getCXXScopeSpec().getRange(); + D.setInvalidType(); + // Pretend we didn't see the scope specifier. + DC = CurContext; + Previous.clear(); + } + + DiagnoseFunctionSpecifiers(D.getDeclSpec()); + + if (D.getDeclSpec().isInlineSpecified()) + Diag(D.getDeclSpec().getInlineSpecLoc(), diag::err_inline_non_function) + << getLangOpts().CPlusPlus17; + if (D.getDeclSpec().isConstexprSpecified()) + Diag(D.getDeclSpec().getConstexprSpecLoc(), diag::err_invalid_constexpr) + << 1; + + if (D.getName().Kind != UnqualifiedIdKind::IK_Identifier) { + if (D.getName().Kind == UnqualifiedIdKind::IK_DeductionGuideName) + Diag(D.getName().StartLocation, + diag::err_deduction_guide_invalid_specifier) + << "typedef"; + else + Diag(D.getName().StartLocation, diag::err_typedef_not_identifier) + << D.getName().getSourceRange(); + return nullptr; + } + + TypedefDecl *NewTD = ParseTypedefDecl(S, D, TInfo->getType(), TInfo); + if (!NewTD) return nullptr; + + // Handle attributes prior to checking for duplicates in MergeVarDecl + ProcessDeclAttributes(S, NewTD, D); + + CheckTypedefForVariablyModifiedType(S, NewTD); + + bool Redeclaration = D.isRedeclaration(); + NamedDecl *ND = ActOnTypedefNameDecl(S, DC, NewTD, Previous, Redeclaration); + D.setRedeclaration(Redeclaration); + return ND; + } + + void + Sema::CheckTypedefForVariablyModifiedType(Scope *S, TypedefNameDecl *NewTD) { + // C99 6.7.7p2: If a typedef name specifies a variably modified type + // then it shall have block scope. + // Note that variably modified types must be fixed before merging the decl so + // that redeclarations will match. + TypeSourceInfo *TInfo = NewTD->getTypeSourceInfo(); + QualType T = TInfo->getType(); + if (T->isVariablyModifiedType()) { + setFunctionHasBranchProtectedScope(); + + if (S->getFnParent() == nullptr) { + bool SizeIsNegative; + llvm::APSInt Oversized; + TypeSourceInfo *FixedTInfo = + TryToFixInvalidVariablyModifiedTypeSourceInfo(TInfo, Context, + SizeIsNegative, + Oversized); + if (FixedTInfo) { + Diag(NewTD->getLocation(), diag::warn_illegal_constant_array_size); + NewTD->setTypeSourceInfo(FixedTInfo); + } else { + if (SizeIsNegative) + Diag(NewTD->getLocation(), diag::err_typecheck_negative_array_size); + else if (T->isVariableArrayType()) + Diag(NewTD->getLocation(), diag::err_vla_decl_in_file_scope); + else if (Oversized.getBoolValue()) + Diag(NewTD->getLocation(), diag::err_array_too_large) + << Oversized.toString(10); + else + Diag(NewTD->getLocation(), diag::err_vm_decl_in_file_scope); + NewTD->setInvalidDecl(); + } + } + } + } + + /// ActOnTypedefNameDecl - Perform semantic checking for a declaration which + /// declares a typedef-name, either using the 'typedef' type specifier or via + /// a C++0x [dcl.typedef]p2 alias-declaration: 'using T = A;'. + NamedDecl* + Sema::ActOnTypedefNameDecl(Scope *S, DeclContext *DC, TypedefNameDecl *NewTD, + LookupResult &Previous, bool &Redeclaration) { + + // Find the shadowed declaration before filtering for scope. + NamedDecl *ShadowedDecl = getShadowedDeclaration(NewTD, Previous); + + // Merge the decl with the existing one if appropriate. If the decl is + // in an outer scope, it isn't the same thing. + FilterLookupForScope(Previous, DC, S, /*ConsiderLinkage*/false, + /*AllowInlineNamespace*/false); + filterNonConflictingPreviousTypedefDecls(*this, NewTD, Previous); + if (!Previous.empty()) { + Redeclaration = true; + MergeTypedefNameDecl(S, NewTD, Previous); + } + + if (ShadowedDecl && !Redeclaration) + CheckShadow(NewTD, ShadowedDecl, Previous); + + // If this is the C FILE type, notify the AST context. + if (IdentifierInfo *II = NewTD->getIdentifier()) + if (!NewTD->isInvalidDecl() && + NewTD->getDeclContext()->getRedeclContext()->isTranslationUnit()) { + if (II->isStr("FILE")) + Context.setFILEDecl(NewTD); + else if (II->isStr("jmp_buf")) + Context.setjmp_bufDecl(NewTD); + else if (II->isStr("sigjmp_buf")) + Context.setsigjmp_bufDecl(NewTD); + else if (II->isStr("ucontext_t")) + Context.setucontext_tDecl(NewTD); + } + + return NewTD; + } + + /// Determines whether the given declaration is an out-of-scope + /// previous declaration. + /// + /// This routine should be invoked when name lookup has found a + /// previous declaration (PrevDecl) that is not in the scope where a + /// new declaration by the same name is being introduced. If the new + /// declaration occurs in a local scope, previous declarations with + /// linkage may still be considered previous declarations (C99 + /// 6.2.2p4-5, C++ [basic.link]p6). + /// + /// \param PrevDecl the previous declaration found by name + /// lookup + /// + /// \param DC the context in which the new declaration is being + /// declared. + /// + /// \returns true if PrevDecl is an out-of-scope previous declaration + /// for a new delcaration with the same name. + static bool + isOutOfScopePreviousDeclaration(NamedDecl *PrevDecl, DeclContext *DC, + ASTContext &Context) { + if (!PrevDecl) + return false; + + if (!PrevDecl->hasLinkage()) + return false; + + if (Context.getLangOpts().CPlusPlus) { + // C++ [basic.link]p6: + // If there is a visible declaration of an entity with linkage + // having the same name and type, ignoring entities declared + // outside the innermost enclosing namespace scope, the block + // scope declaration declares that same entity and receives the + // linkage of the previous declaration. + DeclContext *OuterContext = DC->getRedeclContext(); + if (!OuterContext->isFunctionOrMethod()) + // This rule only applies to block-scope declarations. + return false; + + DeclContext *PrevOuterContext = PrevDecl->getDeclContext(); + if (PrevOuterContext->isRecord()) + // We found a member function: ignore it. + return false; + + // Find the innermost enclosing namespace for the new and + // previous declarations. + OuterContext = OuterContext->getEnclosingNamespaceContext(); + PrevOuterContext = PrevOuterContext->getEnclosingNamespaceContext(); + + // The previous declaration is in a different namespace, so it + // isn't the same function. + if (!OuterContext->Equals(PrevOuterContext)) + return false; + } + + return true; + } + + static void SetNestedNameSpecifier(Sema &S, DeclaratorDecl *DD, Declarator &D) { + CXXScopeSpec &SS = D.getCXXScopeSpec(); + if (!SS.isSet()) return; + DD->setQualifierInfo(SS.getWithLocInContext(S.Context)); + } + + bool Sema::inferObjCARCLifetime(ValueDecl *decl) { + QualType type = decl->getType(); + Qualifiers::ObjCLifetime lifetime = type.getObjCLifetime(); + if (lifetime == Qualifiers::OCL_Autoreleasing) { + // Various kinds of declaration aren't allowed to be __autoreleasing. + unsigned kind = -1U; + if (VarDecl *var = dyn_cast(decl)) { + if (var->hasAttr()) + kind = 0; // __block + else if (!var->hasLocalStorage()) + kind = 1; // global + } else if (isa(decl)) { + kind = 3; // ivar + } else if (isa(decl)) { + kind = 2; // field + } + + if (kind != -1U) { + Diag(decl->getLocation(), diag::err_arc_autoreleasing_var) + << kind; + } + } else if (lifetime == Qualifiers::OCL_None) { + // Try to infer lifetime. + if (!type->isObjCLifetimeType()) + return false; + + lifetime = type->getObjCARCImplicitLifetime(); + type = Context.getLifetimeQualifiedType(type, lifetime); + decl->setType(type); + } + + if (VarDecl *var = dyn_cast(decl)) { + // Thread-local variables cannot have lifetime. + if (lifetime && lifetime != Qualifiers::OCL_ExplicitNone && + var->getTLSKind()) { + Diag(var->getLocation(), diag::err_arc_thread_ownership) + << var->getType(); + return true; + } + } + + return false; + } + + static void checkAttributesAfterMerging(Sema &S, NamedDecl &ND) { + // Ensure that an auto decl is deduced otherwise the checks below might cache + // the wrong linkage. + assert(S.ParsingInitForAutoVars.count(&ND) == 0); + + // 'weak' only applies to declarations with external linkage. + if (WeakAttr *Attr = ND.getAttr()) { + if (!ND.isExternallyVisible()) { + S.Diag(Attr->getLocation(), diag::err_attribute_weak_static); + ND.dropAttr(); + } + } + if (WeakRefAttr *Attr = ND.getAttr()) { + if (ND.isExternallyVisible()) { + S.Diag(Attr->getLocation(), diag::err_attribute_weakref_not_static); + ND.dropAttr(); + ND.dropAttr(); + } + } + + if (auto *VD = dyn_cast(&ND)) { + if (VD->hasInit()) { + if (const auto *Attr = VD->getAttr()) { + assert(VD->isThisDeclarationADefinition() && + !VD->isExternallyVisible() && "Broken AliasAttr handled late!"); + S.Diag(Attr->getLocation(), diag::err_alias_is_definition) << VD << 0; + VD->dropAttr(); + } + } + } + + // 'selectany' only applies to externally visible variable declarations. + // It does not apply to functions. + if (SelectAnyAttr *Attr = ND.getAttr()) { + if (isa(ND) || !ND.isExternallyVisible()) { + S.Diag(Attr->getLocation(), + diag::err_attribute_selectany_non_extern_data); + ND.dropAttr(); + } + } + + if (const InheritableAttr *Attr = getDLLAttr(&ND)) { + // dll attributes require external linkage. Static locals may have external + // linkage but still cannot be explicitly imported or exported. ++ // Initialized variables in an anonymous spaces are exported. + auto *VD = dyn_cast(&ND); +- if (!ND.isExternallyVisible() || (VD && VD->isStaticLocal())) { ++ NamespaceDecl *NS = NULL; ++ if (VD) ++ NS = dyn_cast(VD->getDeclContext()); ++ int isAnonymousNS = NS && NS->getDeclName().isEmpty(); ++ if ((!ND.isExternallyVisible() && ++ (!isAnonymousNS || !(VD && VD->hasInit()))) || ++ (VD && VD->isStaticLocal())) { + S.Diag(ND.getLocation(), diag::err_attribute_dll_not_extern) + << &ND << Attr; + ND.setInvalidDecl(); + } + } + + // Virtual functions cannot be marked as 'notail'. + if (auto *Attr = ND.getAttr()) + if (auto *MD = dyn_cast(&ND)) + if (MD->isVirtual()) { + S.Diag(ND.getLocation(), + diag::err_invalid_attribute_on_virtual_function) + << Attr; + ND.dropAttr(); + } + + // Check the attributes on the function type, if any. + if (const auto *FD = dyn_cast(&ND)) { + // Don't declare this variable in the second operand of the for-statement; + // GCC miscompiles that by ending its lifetime before evaluating the + // third operand. See gcc.gnu.org/PR86769. + AttributedTypeLoc ATL; + for (TypeLoc TL = FD->getTypeSourceInfo()->getTypeLoc(); + (ATL = TL.getAsAdjusted()); + TL = ATL.getModifiedLoc()) { + // The [[lifetimebound]] attribute can be applied to the implicit object + // parameter of a non-static member function (other than a ctor or dtor) + // by applying it to the function type. + if (const auto *A = ATL.getAttrAs()) { + const auto *MD = dyn_cast(FD); + if (!MD || MD->isStatic()) { + S.Diag(A->getLocation(), diag::err_lifetimebound_no_object_param) + << !MD << A->getRange(); + } else if (isa(MD) || isa(MD)) { + S.Diag(A->getLocation(), diag::err_lifetimebound_ctor_dtor) + << isa(MD) << A->getRange(); + } + } + } + } + } + + static void checkDLLAttributeRedeclaration(Sema &S, NamedDecl *OldDecl, + NamedDecl *NewDecl, + bool IsSpecialization, + bool IsDefinition) { + if (OldDecl->isInvalidDecl() || NewDecl->isInvalidDecl()) + return; + + bool IsTemplate = false; + if (TemplateDecl *OldTD = dyn_cast(OldDecl)) { + OldDecl = OldTD->getTemplatedDecl(); + IsTemplate = true; + if (!IsSpecialization) + IsDefinition = false; + } + if (TemplateDecl *NewTD = dyn_cast(NewDecl)) { + NewDecl = NewTD->getTemplatedDecl(); + IsTemplate = true; + } + + if (!OldDecl || !NewDecl) + return; + + const DLLImportAttr *OldImportAttr = OldDecl->getAttr(); + const DLLExportAttr *OldExportAttr = OldDecl->getAttr(); + const DLLImportAttr *NewImportAttr = NewDecl->getAttr(); + const DLLExportAttr *NewExportAttr = NewDecl->getAttr(); + + // dllimport and dllexport are inheritable attributes so we have to exclude + // inherited attribute instances. + bool HasNewAttr = (NewImportAttr && !NewImportAttr->isInherited()) || + (NewExportAttr && !NewExportAttr->isInherited()); + + // A redeclaration is not allowed to add a dllimport or dllexport attribute, + // the only exception being explicit specializations. + // Implicitly generated declarations are also excluded for now because there + // is no other way to switch these to use dllimport or dllexport. + bool AddsAttr = !(OldImportAttr || OldExportAttr) && HasNewAttr; + + if (AddsAttr && !IsSpecialization && !OldDecl->isImplicit()) { + // Allow with a warning for free functions and global variables. + bool JustWarn = false; + if (!OldDecl->isCXXClassMember()) { + auto *VD = dyn_cast(OldDecl); + if (VD && !VD->getDescribedVarTemplate()) + JustWarn = true; + auto *FD = dyn_cast(OldDecl); + if (FD && FD->getTemplatedKind() == FunctionDecl::TK_NonTemplate) + JustWarn = true; + } + + // We cannot change a declaration that's been used because IR has already + // been emitted. Dllimported functions will still work though (modulo + // address equality) as they can use the thunk. + if (OldDecl->isUsed()) + if (!isa(OldDecl) || !NewImportAttr) + JustWarn = false; + + unsigned DiagID = JustWarn ? diag::warn_attribute_dll_redeclaration + : diag::err_attribute_dll_redeclaration; + S.Diag(NewDecl->getLocation(), DiagID) + << NewDecl + << (NewImportAttr ? (const Attr *)NewImportAttr : NewExportAttr); + S.Diag(OldDecl->getLocation(), diag::note_previous_declaration); + if (!JustWarn) { + NewDecl->setInvalidDecl(); + return; + } + } + + // A redeclaration is not allowed to drop a dllimport attribute, the only + // exceptions being inline function definitions (except for function + // templates), local extern declarations, qualified friend declarations or + // special MSVC extension: in the last case, the declaration is treated as if + // it were marked dllexport. + bool IsInline = false, IsStaticDataMember = false, IsQualifiedFriend = false; + bool IsMicrosoft = S.Context.getTargetInfo().getCXXABI().isMicrosoft(); + if (const auto *VD = dyn_cast(NewDecl)) { + // Ignore static data because out-of-line definitions are diagnosed + // separately. + IsStaticDataMember = VD->isStaticDataMember(); + IsDefinition = VD->isThisDeclarationADefinition(S.Context) != + VarDecl::DeclarationOnly; + } else if (const auto *FD = dyn_cast(NewDecl)) { + IsInline = FD->isInlined(); + IsQualifiedFriend = FD->getQualifier() && + FD->getFriendObjectKind() == Decl::FOK_Declared; + } + + if (OldImportAttr && !HasNewAttr && + (!IsInline || (IsMicrosoft && IsTemplate)) && !IsStaticDataMember && + !NewDecl->isLocalExternDecl() && !IsQualifiedFriend) { + if (IsMicrosoft && IsDefinition) { + S.Diag(NewDecl->getLocation(), + diag::warn_redeclaration_without_import_attribute) + << NewDecl; + S.Diag(OldDecl->getLocation(), diag::note_previous_declaration); + NewDecl->dropAttr(); + NewDecl->addAttr(::new (S.Context) DLLExportAttr( + NewImportAttr->getRange(), S.Context, + NewImportAttr->getSpellingListIndex())); + } else { + S.Diag(NewDecl->getLocation(), + diag::warn_redeclaration_without_attribute_prev_attribute_ignored) + << NewDecl << OldImportAttr; + S.Diag(OldDecl->getLocation(), diag::note_previous_declaration); + S.Diag(OldImportAttr->getLocation(), diag::note_previous_attribute); + OldDecl->dropAttr(); + NewDecl->dropAttr(); + } + } else if (IsInline && OldImportAttr && !IsMicrosoft) { + // In MinGW, seeing a function declared inline drops the dllimport + // attribute. + OldDecl->dropAttr(); + NewDecl->dropAttr(); + S.Diag(NewDecl->getLocation(), + diag::warn_dllimport_dropped_from_inline_function) + << NewDecl << OldImportAttr; + } + + // A specialization of a class template member function is processed here + // since it's a redeclaration. If the parent class is dllexport, the + // specialization inherits that attribute. This doesn't happen automatically + // since the parent class isn't instantiated until later. + if (const CXXMethodDecl *MD = dyn_cast(NewDecl)) { + if (MD->getTemplatedKind() == FunctionDecl::TK_MemberSpecialization && + !NewImportAttr && !NewExportAttr) { + if (const DLLExportAttr *ParentExportAttr = + MD->getParent()->getAttr()) { + DLLExportAttr *NewAttr = ParentExportAttr->clone(S.Context); + NewAttr->setInherited(true); + NewDecl->addAttr(NewAttr); + } + } + } + } + + /// Given that we are within the definition of the given function, + /// will that definition behave like C99's 'inline', where the + /// definition is discarded except for optimization purposes? + static bool isFunctionDefinitionDiscarded(Sema &S, FunctionDecl *FD) { + // Try to avoid calling GetGVALinkageForFunction. + + // All cases of this require the 'inline' keyword. + if (!FD->isInlined()) return false; + + // This is only possible in C++ with the gnu_inline attribute. + if (S.getLangOpts().CPlusPlus && !FD->hasAttr()) + return false; + + // Okay, go ahead and call the relatively-more-expensive function. + return S.Context.GetGVALinkageForFunction(FD) == GVA_AvailableExternally; + } + + /// Determine whether a variable is extern "C" prior to attaching + /// an initializer. We can't just call isExternC() here, because that + /// will also compute and cache whether the declaration is externally + /// visible, which might change when we attach the initializer. + /// + /// This can only be used if the declaration is known to not be a + /// redeclaration of an internal linkage declaration. + /// + /// For instance: + /// + /// auto x = []{}; + /// + /// Attaching the initializer here makes this declaration not externally + /// visible, because its type has internal linkage. + /// + /// FIXME: This is a hack. + template + static bool isIncompleteDeclExternC(Sema &S, const T *D) { + if (S.getLangOpts().CPlusPlus) { + // In C++, the overloadable attribute negates the effects of extern "C". + if (!D->isInExternCContext() || D->template hasAttr()) + return false; + + // So do CUDA's host/device attributes. + if (S.getLangOpts().CUDA && (D->template hasAttr() || + D->template hasAttr())) + return false; + } + return D->isExternC(); + } + + static bool shouldConsiderLinkage(const VarDecl *VD) { + const DeclContext *DC = VD->getDeclContext()->getRedeclContext(); + if (DC->isFunctionOrMethod() || isa(DC) || + isa(DC)) + return VD->hasExternalStorage(); + if (DC->isFileContext()) + return true; + if (DC->isRecord()) + return false; + llvm_unreachable("Unexpected context"); + } + + static bool shouldConsiderLinkage(const FunctionDecl *FD) { + const DeclContext *DC = FD->getDeclContext()->getRedeclContext(); + if (DC->isFileContext() || DC->isFunctionOrMethod() || + isa(DC) || isa(DC)) + return true; + if (DC->isRecord()) + return false; + llvm_unreachable("Unexpected context"); + } + + static bool hasParsedAttr(Scope *S, const Declarator &PD, + ParsedAttr::Kind Kind) { + // Check decl attributes on the DeclSpec. + if (PD.getDeclSpec().getAttributes().hasAttribute(Kind)) + return true; + + // Walk the declarator structure, checking decl attributes that were in a type + // position to the decl itself. + for (unsigned I = 0, E = PD.getNumTypeObjects(); I != E; ++I) { + if (PD.getTypeObject(I).getAttrs().hasAttribute(Kind)) + return true; + } + + // Finally, check attributes on the decl itself. + return PD.getAttributes().hasAttribute(Kind); + } + + /// Adjust the \c DeclContext for a function or variable that might be a + /// function-local external declaration. + bool Sema::adjustContextForLocalExternDecl(DeclContext *&DC) { + if (!DC->isFunctionOrMethod()) + return false; + + // If this is a local extern function or variable declared within a function + // template, don't add it into the enclosing namespace scope until it is + // instantiated; it might have a dependent type right now. + if (DC->isDependentContext()) + return true; + + // C++11 [basic.link]p7: + // When a block scope declaration of an entity with linkage is not found to + // refer to some other declaration, then that entity is a member of the + // innermost enclosing namespace. + // + // Per C++11 [namespace.def]p6, the innermost enclosing namespace is a + // semantically-enclosing namespace, not a lexically-enclosing one. + while (!DC->isFileContext() && !isa(DC)) + DC = DC->getParent(); + return true; + } + + /// Returns true if given declaration has external C language linkage. + static bool isDeclExternC(const Decl *D) { + if (const auto *FD = dyn_cast(D)) + return FD->isExternC(); + if (const auto *VD = dyn_cast(D)) + return VD->isExternC(); + + llvm_unreachable("Unknown type of decl!"); + } + + NamedDecl *Sema::ActOnVariableDeclarator( + Scope *S, Declarator &D, DeclContext *DC, TypeSourceInfo *TInfo, + LookupResult &Previous, MultiTemplateParamsArg TemplateParamLists, + bool &AddToScope, ArrayRef Bindings) { + QualType R = TInfo->getType(); + DeclarationName Name = GetNameForDeclarator(D).getName(); + + IdentifierInfo *II = Name.getAsIdentifierInfo(); + + if (D.isDecompositionDeclarator()) { + // Take the name of the first declarator as our name for diagnostic + // purposes. + auto &Decomp = D.getDecompositionDeclarator(); + if (!Decomp.bindings().empty()) { + II = Decomp.bindings()[0].Name; + Name = II; + } + } else if (!II) { + Diag(D.getIdentifierLoc(), diag::err_bad_variable_name) << Name; + return nullptr; + } + + if (getLangOpts().OpenCL) { + // OpenCL v2.0 s6.9.b - Image type can only be used as a function argument. + // OpenCL v2.0 s6.13.16.1 - Pipe type can only be used as a function + // argument. + if (R->isImageType() || R->isPipeType()) { + Diag(D.getIdentifierLoc(), + diag::err_opencl_type_can_only_be_used_as_function_parameter) + << R; + D.setInvalidType(); + return nullptr; + } + + // OpenCL v1.2 s6.9.r: + // The event type cannot be used to declare a program scope variable. + // OpenCL v2.0 s6.9.q: + // The clk_event_t and reserve_id_t types cannot be declared in program scope. + if (NULL == S->getParent()) { + if (R->isReserveIDT() || R->isClkEventT() || R->isEventT()) { + Diag(D.getIdentifierLoc(), + diag::err_invalid_type_for_program_scope_var) << R; + D.setInvalidType(); + return nullptr; + } + } + + // OpenCL v1.0 s6.8.a.3: Pointers to functions are not allowed. + QualType NR = R; + while (NR->isPointerType()) { + if (NR->isFunctionPointerType()) { + Diag(D.getIdentifierLoc(), diag::err_opencl_function_pointer); + D.setInvalidType(); + break; + } + NR = NR->getPointeeType(); + } + + if (!getOpenCLOptions().isEnabled("cl_khr_fp16")) { + // OpenCL v1.2 s6.1.1.1: reject declaring variables of the half and + // half array type (unless the cl_khr_fp16 extension is enabled). + if (Context.getBaseElementType(R)->isHalfType()) { + Diag(D.getIdentifierLoc(), diag::err_opencl_half_declaration) << R; + D.setInvalidType(); + } + } + + if (R->isSamplerT()) { + // OpenCL v1.2 s6.9.b p4: + // The sampler type cannot be used with the __local and __global address + // space qualifiers. + if (R.getAddressSpace() == LangAS::opencl_local || + R.getAddressSpace() == LangAS::opencl_global) { + Diag(D.getIdentifierLoc(), diag::err_wrong_sampler_addressspace); + } + + // OpenCL v1.2 s6.12.14.1: + // A global sampler must be declared with either the constant address + // space qualifier or with the const qualifier. + if (DC->isTranslationUnit() && + !(R.getAddressSpace() == LangAS::opencl_constant || + R.isConstQualified())) { + Diag(D.getIdentifierLoc(), diag::err_opencl_nonconst_global_sampler); + D.setInvalidType(); + } + } + + // OpenCL v1.2 s6.9.r: + // The event type cannot be used with the __local, __constant and __global + // address space qualifiers. + if (R->isEventT()) { + if (R.getAddressSpace() != LangAS::opencl_private) { + Diag(D.getBeginLoc(), diag::err_event_t_addr_space_qual); + D.setInvalidType(); + } + } + + // OpenCL C++ 1.0 s2.9: the thread_local storage qualifier is not + // supported. OpenCL C does not support thread_local either, and + // also reject all other thread storage class specifiers. + DeclSpec::TSCS TSC = D.getDeclSpec().getThreadStorageClassSpec(); + if (TSC != TSCS_unspecified) { + bool IsCXX = getLangOpts().OpenCLCPlusPlus; + Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(), + diag::err_opencl_unknown_type_specifier) + << IsCXX << getLangOpts().getOpenCLVersionTuple().getAsString() + << DeclSpec::getSpecifierName(TSC) << 1; + D.setInvalidType(); + return nullptr; + } + } + + DeclSpec::SCS SCSpec = D.getDeclSpec().getStorageClassSpec(); + StorageClass SC = StorageClassSpecToVarDeclStorageClass(D.getDeclSpec()); + + // dllimport globals without explicit storage class are treated as extern. We + // have to change the storage class this early to get the right DeclContext. + if (SC == SC_None && !DC->isRecord() && + hasParsedAttr(S, D, ParsedAttr::AT_DLLImport) && + !hasParsedAttr(S, D, ParsedAttr::AT_DLLExport)) + SC = SC_Extern; + + DeclContext *OriginalDC = DC; + bool IsLocalExternDecl = SC == SC_Extern && + adjustContextForLocalExternDecl(DC); + + if (SCSpec == DeclSpec::SCS_mutable) { + // mutable can only appear on non-static class members, so it's always + // an error here + Diag(D.getIdentifierLoc(), diag::err_mutable_nonmember); + D.setInvalidType(); + SC = SC_None; + } + + if (getLangOpts().CPlusPlus11 && SCSpec == DeclSpec::SCS_register && + !D.getAsmLabel() && !getSourceManager().isInSystemMacro( + D.getDeclSpec().getStorageClassSpecLoc())) { + // In C++11, the 'register' storage class specifier is deprecated. + // Suppress the warning in system macros, it's used in macros in some + // popular C system headers, such as in glibc's htonl() macro. + Diag(D.getDeclSpec().getStorageClassSpecLoc(), + getLangOpts().CPlusPlus17 ? diag::ext_register_storage_class + : diag::warn_deprecated_register) + << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc()); + } + + DiagnoseFunctionSpecifiers(D.getDeclSpec()); + + if (!DC->isRecord() && S->getFnParent() == nullptr) { + // C99 6.9p2: The storage-class specifiers auto and register shall not + // appear in the declaration specifiers in an external declaration. + // Global Register+Asm is a GNU extension we support. + if (SC == SC_Auto || (SC == SC_Register && !D.getAsmLabel())) { + Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope); + D.setInvalidType(); + } + } + + bool IsMemberSpecialization = false; + bool IsVariableTemplateSpecialization = false; + bool IsPartialSpecialization = false; + bool IsVariableTemplate = false; + VarDecl *NewVD = nullptr; + VarTemplateDecl *NewTemplate = nullptr; + TemplateParameterList *TemplateParams = nullptr; + if (!getLangOpts().CPlusPlus) { + NewVD = VarDecl::Create(Context, DC, D.getBeginLoc(), D.getIdentifierLoc(), + II, R, TInfo, SC); + + if (R->getContainedDeducedType()) + ParsingInitForAutoVars.insert(NewVD); + + if (D.isInvalidType()) + NewVD->setInvalidDecl(); + } else { + bool Invalid = false; + + if (DC->isRecord() && !CurContext->isRecord()) { + // This is an out-of-line definition of a static data member. + switch (SC) { + case SC_None: + break; + case SC_Static: + Diag(D.getDeclSpec().getStorageClassSpecLoc(), + diag::err_static_out_of_line) + << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc()); + break; + case SC_Auto: + case SC_Register: + case SC_Extern: + // [dcl.stc] p2: The auto or register specifiers shall be applied only + // to names of variables declared in a block or to function parameters. + // [dcl.stc] p6: The extern specifier cannot be used in the declaration + // of class members + + Diag(D.getDeclSpec().getStorageClassSpecLoc(), + diag::err_storage_class_for_static_member) + << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc()); + break; + case SC_PrivateExtern: + llvm_unreachable("C storage class in c++!"); + } + } + + if (SC == SC_Static && CurContext->isRecord()) { + if (const CXXRecordDecl *RD = dyn_cast(DC)) { + if (RD->isLocalClass()) + Diag(D.getIdentifierLoc(), + diag::err_static_data_member_not_allowed_in_local_class) + << Name << RD->getDeclName(); + + // C++98 [class.union]p1: If a union contains a static data member, + // the program is ill-formed. C++11 drops this restriction. + if (RD->isUnion()) + Diag(D.getIdentifierLoc(), + getLangOpts().CPlusPlus11 + ? diag::warn_cxx98_compat_static_data_member_in_union + : diag::ext_static_data_member_in_union) << Name; + // We conservatively disallow static data members in anonymous structs. + else if (!RD->getDeclName()) + Diag(D.getIdentifierLoc(), + diag::err_static_data_member_not_allowed_in_anon_struct) + << Name << RD->isUnion(); + } + } + + // Match up the template parameter lists with the scope specifier, then + // determine whether we have a template or a template specialization. + TemplateParams = MatchTemplateParametersToScopeSpecifier( + D.getDeclSpec().getBeginLoc(), D.getIdentifierLoc(), + D.getCXXScopeSpec(), + D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId + ? D.getName().TemplateId + : nullptr, + TemplateParamLists, + /*never a friend*/ false, IsMemberSpecialization, Invalid); + + if (TemplateParams) { + if (!TemplateParams->size() && + D.getName().getKind() != UnqualifiedIdKind::IK_TemplateId) { + // There is an extraneous 'template<>' for this variable. Complain + // about it, but allow the declaration of the variable. + Diag(TemplateParams->getTemplateLoc(), + diag::err_template_variable_noparams) + << II + << SourceRange(TemplateParams->getTemplateLoc(), + TemplateParams->getRAngleLoc()); + TemplateParams = nullptr; + } else { + if (D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId) { + // This is an explicit specialization or a partial specialization. + // FIXME: Check that we can declare a specialization here. + IsVariableTemplateSpecialization = true; + IsPartialSpecialization = TemplateParams->size() > 0; + } else { // if (TemplateParams->size() > 0) + // This is a template declaration. + IsVariableTemplate = true; + + // Check that we can declare a template here. + if (CheckTemplateDeclScope(S, TemplateParams)) + return nullptr; + + // Only C++1y supports variable templates (N3651). + Diag(D.getIdentifierLoc(), + getLangOpts().CPlusPlus14 + ? diag::warn_cxx11_compat_variable_template + : diag::ext_variable_template); + } + } + } else { + assert((Invalid || + D.getName().getKind() != UnqualifiedIdKind::IK_TemplateId) && + "should have a 'template<>' for this decl"); + } + + if (IsVariableTemplateSpecialization) { + SourceLocation TemplateKWLoc = + TemplateParamLists.size() > 0 + ? TemplateParamLists[0]->getTemplateLoc() + : SourceLocation(); + DeclResult Res = ActOnVarTemplateSpecialization( + S, D, TInfo, TemplateKWLoc, TemplateParams, SC, + IsPartialSpecialization); + if (Res.isInvalid()) + return nullptr; + NewVD = cast(Res.get()); + AddToScope = false; + } else if (D.isDecompositionDeclarator()) { + NewVD = DecompositionDecl::Create(Context, DC, D.getBeginLoc(), + D.getIdentifierLoc(), R, TInfo, SC, + Bindings); + } else + NewVD = VarDecl::Create(Context, DC, D.getBeginLoc(), + D.getIdentifierLoc(), II, R, TInfo, SC); + + // If this is supposed to be a variable template, create it as such. + if (IsVariableTemplate) { + NewTemplate = + VarTemplateDecl::Create(Context, DC, D.getIdentifierLoc(), Name, + TemplateParams, NewVD); + NewVD->setDescribedVarTemplate(NewTemplate); + } + + // If this decl has an auto type in need of deduction, make a note of the + // Decl so we can diagnose uses of it in its own initializer. + if (R->getContainedDeducedType()) + ParsingInitForAutoVars.insert(NewVD); + + if (D.isInvalidType() || Invalid) { + NewVD->setInvalidDecl(); + if (NewTemplate) + NewTemplate->setInvalidDecl(); + } + + SetNestedNameSpecifier(*this, NewVD, D); + + // If we have any template parameter lists that don't directly belong to + // the variable (matching the scope specifier), store them. + unsigned VDTemplateParamLists = TemplateParams ? 1 : 0; + if (TemplateParamLists.size() > VDTemplateParamLists) + NewVD->setTemplateParameterListsInfo( + Context, TemplateParamLists.drop_back(VDTemplateParamLists)); + + if (D.getDeclSpec().isConstexprSpecified()) { + NewVD->setConstexpr(true); + // C++1z [dcl.spec.constexpr]p1: + // A static data member declared with the constexpr specifier is + // implicitly an inline variable. + if (NewVD->isStaticDataMember() && getLangOpts().CPlusPlus17) + NewVD->setImplicitlyInline(); + } + } + + if (D.getDeclSpec().isInlineSpecified()) { + if (!getLangOpts().CPlusPlus) { + Diag(D.getDeclSpec().getInlineSpecLoc(), diag::err_inline_non_function) + << 0; + } else if (CurContext->isFunctionOrMethod()) { + // 'inline' is not allowed on block scope variable declaration. + Diag(D.getDeclSpec().getInlineSpecLoc(), + diag::err_inline_declaration_block_scope) << Name + << FixItHint::CreateRemoval(D.getDeclSpec().getInlineSpecLoc()); + } else { + Diag(D.getDeclSpec().getInlineSpecLoc(), + getLangOpts().CPlusPlus17 ? diag::warn_cxx14_compat_inline_variable + : diag::ext_inline_variable); + NewVD->setInlineSpecified(); + } + } + + // Set the lexical context. If the declarator has a C++ scope specifier, the + // lexical context will be different from the semantic context. + NewVD->setLexicalDeclContext(CurContext); + if (NewTemplate) + NewTemplate->setLexicalDeclContext(CurContext); + + if (IsLocalExternDecl) { + if (D.isDecompositionDeclarator()) + for (auto *B : Bindings) + B->setLocalExternDecl(); + else + NewVD->setLocalExternDecl(); + } + + bool EmitTLSUnsupportedError = false; + if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec()) { + // C++11 [dcl.stc]p4: + // When thread_local is applied to a variable of block scope the + // storage-class-specifier static is implied if it does not appear + // explicitly. + // Core issue: 'static' is not implied if the variable is declared + // 'extern'. + if (NewVD->hasLocalStorage() && + (SCSpec != DeclSpec::SCS_unspecified || + TSCS != DeclSpec::TSCS_thread_local || + !DC->isFunctionOrMethod())) + Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(), + diag::err_thread_non_global) + << DeclSpec::getSpecifierName(TSCS); + else if (!Context.getTargetInfo().isTLSSupported()) { + if (getLangOpts().CUDA || getLangOpts().OpenMPIsDevice) { + // Postpone error emission until we've collected attributes required to + // figure out whether it's a host or device variable and whether the + // error should be ignored. + EmitTLSUnsupportedError = true; + // We still need to mark the variable as TLS so it shows up in AST with + // proper storage class for other tools to use even if we're not going + // to emit any code for it. + NewVD->setTSCSpec(TSCS); + } else + Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(), + diag::err_thread_unsupported); + } else + NewVD->setTSCSpec(TSCS); + } + + // C99 6.7.4p3 + // An inline definition of a function with external linkage shall + // not contain a definition of a modifiable object with static or + // thread storage duration... + // We only apply this when the function is required to be defined + // elsewhere, i.e. when the function is not 'extern inline'. Note + // that a local variable with thread storage duration still has to + // be marked 'static'. Also note that it's possible to get these + // semantics in C++ using __attribute__((gnu_inline)). + if (SC == SC_Static && S->getFnParent() != nullptr && + !NewVD->getType().isConstQualified()) { + FunctionDecl *CurFD = getCurFunctionDecl(); + if (CurFD && isFunctionDefinitionDiscarded(*this, CurFD)) { + Diag(D.getDeclSpec().getStorageClassSpecLoc(), + diag::warn_static_local_in_extern_inline); + MaybeSuggestAddingStaticToDecl(CurFD); + } + } + + if (D.getDeclSpec().isModulePrivateSpecified()) { + if (IsVariableTemplateSpecialization) + Diag(NewVD->getLocation(), diag::err_module_private_specialization) + << (IsPartialSpecialization ? 1 : 0) + << FixItHint::CreateRemoval( + D.getDeclSpec().getModulePrivateSpecLoc()); + else if (IsMemberSpecialization) + Diag(NewVD->getLocation(), diag::err_module_private_specialization) + << 2 + << FixItHint::CreateRemoval(D.getDeclSpec().getModulePrivateSpecLoc()); + else if (NewVD->hasLocalStorage()) + Diag(NewVD->getLocation(), diag::err_module_private_local) + << 0 << NewVD->getDeclName() + << SourceRange(D.getDeclSpec().getModulePrivateSpecLoc()) + << FixItHint::CreateRemoval(D.getDeclSpec().getModulePrivateSpecLoc()); + else { + NewVD->setModulePrivate(); + if (NewTemplate) + NewTemplate->setModulePrivate(); + for (auto *B : Bindings) + B->setModulePrivate(); + } + } + + // Handle attributes prior to checking for duplicates in MergeVarDecl + ProcessDeclAttributes(S, NewVD, D); + + if (getLangOpts().CUDA || getLangOpts().OpenMPIsDevice) { + if (EmitTLSUnsupportedError && + ((getLangOpts().CUDA && DeclAttrsMatchCUDAMode(getLangOpts(), NewVD)) || + (getLangOpts().OpenMPIsDevice && + NewVD->hasAttr()))) + Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(), + diag::err_thread_unsupported); + // CUDA B.2.5: "__shared__ and __constant__ variables have implied static + // storage [duration]." + if (SC == SC_None && S->getFnParent() != nullptr && + (NewVD->hasAttr() || + NewVD->hasAttr())) { + NewVD->setStorageClass(SC_Static); + } + } + + // Ensure that dllimport globals without explicit storage class are treated as + // extern. The storage class is set above using parsed attributes. Now we can + // check the VarDecl itself. + assert(!NewVD->hasAttr() || + NewVD->getAttr()->isInherited() || + NewVD->isStaticDataMember() || NewVD->getStorageClass() != SC_None); + + // In auto-retain/release, infer strong retension for variables of + // retainable type. + if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(NewVD)) + NewVD->setInvalidDecl(); + + // Handle GNU asm-label extension (encoded as an attribute). + if (Expr *E = (Expr*)D.getAsmLabel()) { + // The parser guarantees this is a string. + StringLiteral *SE = cast(E); + StringRef Label = SE->getString(); + if (S->getFnParent() != nullptr) { + switch (SC) { + case SC_None: + case SC_Auto: + Diag(E->getExprLoc(), diag::warn_asm_label_on_auto_decl) << Label; + break; + case SC_Register: + // Local Named register + if (!Context.getTargetInfo().isValidGCCRegisterName(Label) && + DeclAttrsMatchCUDAMode(getLangOpts(), getCurFunctionDecl())) + Diag(E->getExprLoc(), diag::err_asm_unknown_register_name) << Label; + break; + case SC_Static: + case SC_Extern: + case SC_PrivateExtern: + break; + } + } else if (SC == SC_Register) { + // Global Named register + if (DeclAttrsMatchCUDAMode(getLangOpts(), NewVD)) { + const auto &TI = Context.getTargetInfo(); + bool HasSizeMismatch; + + if (!TI.isValidGCCRegisterName(Label)) + Diag(E->getExprLoc(), diag::err_asm_unknown_register_name) << Label; + else if (!TI.validateGlobalRegisterVariable(Label, + Context.getTypeSize(R), + HasSizeMismatch)) + Diag(E->getExprLoc(), diag::err_asm_invalid_global_var_reg) << Label; + else if (HasSizeMismatch) + Diag(E->getExprLoc(), diag::err_asm_register_size_mismatch) << Label; + } + + if (!R->isIntegralType(Context) && !R->isPointerType()) { + Diag(D.getBeginLoc(), diag::err_asm_bad_register_type); + NewVD->setInvalidDecl(true); + } + } + + NewVD->addAttr(::new (Context) AsmLabelAttr(SE->getStrTokenLoc(0), + Context, Label, 0)); + } else if (!ExtnameUndeclaredIdentifiers.empty()) { + llvm::DenseMap::iterator I = + ExtnameUndeclaredIdentifiers.find(NewVD->getIdentifier()); + if (I != ExtnameUndeclaredIdentifiers.end()) { + if (isDeclExternC(NewVD)) { + NewVD->addAttr(I->second); + ExtnameUndeclaredIdentifiers.erase(I); + } else + Diag(NewVD->getLocation(), diag::warn_redefine_extname_not_applied) + << /*Variable*/1 << NewVD; + } + } + + // Find the shadowed declaration before filtering for scope. + NamedDecl *ShadowedDecl = D.getCXXScopeSpec().isEmpty() + ? getShadowedDeclaration(NewVD, Previous) + : nullptr; + + // Don't consider existing declarations that are in a different + // scope and are out-of-semantic-context declarations (if the new + // declaration has linkage). + FilterLookupForScope(Previous, OriginalDC, S, shouldConsiderLinkage(NewVD), + D.getCXXScopeSpec().isNotEmpty() || + IsMemberSpecialization || + IsVariableTemplateSpecialization); + + // Check whether the previous declaration is in the same block scope. This + // affects whether we merge types with it, per C++11 [dcl.array]p3. + if (getLangOpts().CPlusPlus && + NewVD->isLocalVarDecl() && NewVD->hasExternalStorage()) + NewVD->setPreviousDeclInSameBlockScope( + Previous.isSingleResult() && !Previous.isShadowed() && + isDeclInScope(Previous.getFoundDecl(), OriginalDC, S, false)); + + if (!getLangOpts().CPlusPlus) { + D.setRedeclaration(CheckVariableDeclaration(NewVD, Previous)); + } else { + // If this is an explicit specialization of a static data member, check it. + if (IsMemberSpecialization && !NewVD->isInvalidDecl() && + CheckMemberSpecialization(NewVD, Previous)) + NewVD->setInvalidDecl(); + + // Merge the decl with the existing one if appropriate. + if (!Previous.empty()) { + if (Previous.isSingleResult() && + isa(Previous.getFoundDecl()) && + D.getCXXScopeSpec().isSet()) { + // The user tried to define a non-static data member + // out-of-line (C++ [dcl.meaning]p1). + Diag(NewVD->getLocation(), diag::err_nonstatic_member_out_of_line) + << D.getCXXScopeSpec().getRange(); + Previous.clear(); + NewVD->setInvalidDecl(); + } + } else if (D.getCXXScopeSpec().isSet()) { + // No previous declaration in the qualifying scope. + Diag(D.getIdentifierLoc(), diag::err_no_member) + << Name << computeDeclContext(D.getCXXScopeSpec(), true) + << D.getCXXScopeSpec().getRange(); + NewVD->setInvalidDecl(); + } + + if (!IsVariableTemplateSpecialization) + D.setRedeclaration(CheckVariableDeclaration(NewVD, Previous)); + + if (NewTemplate) { + VarTemplateDecl *PrevVarTemplate = + NewVD->getPreviousDecl() + ? NewVD->getPreviousDecl()->getDescribedVarTemplate() + : nullptr; + + // Check the template parameter list of this declaration, possibly + // merging in the template parameter list from the previous variable + // template declaration. + if (CheckTemplateParameterList( + TemplateParams, + PrevVarTemplate ? PrevVarTemplate->getTemplateParameters() + : nullptr, + (D.getCXXScopeSpec().isSet() && DC && DC->isRecord() && + DC->isDependentContext()) + ? TPC_ClassTemplateMember + : TPC_VarTemplate)) + NewVD->setInvalidDecl(); + + // If we are providing an explicit specialization of a static variable + // template, make a note of that. + if (PrevVarTemplate && + PrevVarTemplate->getInstantiatedFromMemberTemplate()) + PrevVarTemplate->setMemberSpecialization(); + } + } + + // Diagnose shadowed variables iff this isn't a redeclaration. + if (ShadowedDecl && !D.isRedeclaration()) + CheckShadow(NewVD, ShadowedDecl, Previous); + + ProcessPragmaWeak(S, NewVD); + + // If this is the first declaration of an extern C variable, update + // the map of such variables. + if (NewVD->isFirstDecl() && !NewVD->isInvalidDecl() && + isIncompleteDeclExternC(*this, NewVD)) + RegisterLocallyScopedExternCDecl(NewVD, S); + + if (getLangOpts().CPlusPlus && NewVD->isStaticLocal()) { + Decl *ManglingContextDecl; + if (MangleNumberingContext *MCtx = getCurrentMangleNumberContext( + NewVD->getDeclContext(), ManglingContextDecl)) { + Context.setManglingNumber( + NewVD, MCtx->getManglingNumber( + NewVD, getMSManglingNumber(getLangOpts(), S))); + Context.setStaticLocalNumber(NewVD, MCtx->getStaticLocalNumber(NewVD)); + } + } + + // Special handling of variable named 'main'. + if (Name.getAsIdentifierInfo() && Name.getAsIdentifierInfo()->isStr("main") && + NewVD->getDeclContext()->getRedeclContext()->isTranslationUnit() && + !getLangOpts().Freestanding && !NewVD->getDescribedVarTemplate()) { + + // C++ [basic.start.main]p3 + // A program that declares a variable main at global scope is ill-formed. + if (getLangOpts().CPlusPlus) + Diag(D.getBeginLoc(), diag::err_main_global_variable); + + // In C, and external-linkage variable named main results in undefined + // behavior. + else if (NewVD->hasExternalFormalLinkage()) + Diag(D.getBeginLoc(), diag::warn_main_redefined); + } + + if (D.isRedeclaration() && !Previous.empty()) { + NamedDecl *Prev = Previous.getRepresentativeDecl(); + checkDLLAttributeRedeclaration(*this, Prev, NewVD, IsMemberSpecialization, + D.isFunctionDefinition()); + } + + if (NewTemplate) { + if (NewVD->isInvalidDecl()) + NewTemplate->setInvalidDecl(); + ActOnDocumentableDecl(NewTemplate); + return NewTemplate; + } + + if (IsMemberSpecialization && !NewVD->isInvalidDecl()) + CompleteMemberSpecialization(NewVD, Previous); + + return NewVD; + } + + /// Enum describing the %select options in diag::warn_decl_shadow. + enum ShadowedDeclKind { + SDK_Local, + SDK_Global, + SDK_StaticMember, + SDK_Field, + SDK_Typedef, + SDK_Using + }; + + /// Determine what kind of declaration we're shadowing. + static ShadowedDeclKind computeShadowedDeclKind(const NamedDecl *ShadowedDecl, + const DeclContext *OldDC) { + if (isa(ShadowedDecl)) + return SDK_Using; + else if (isa(ShadowedDecl)) + return SDK_Typedef; + else if (isa(OldDC)) + return isa(ShadowedDecl) ? SDK_Field : SDK_StaticMember; + + return OldDC->isFileContext() ? SDK_Global : SDK_Local; + } + + /// Return the location of the capture if the given lambda captures the given + /// variable \p VD, or an invalid source location otherwise. + static SourceLocation getCaptureLocation(const LambdaScopeInfo *LSI, + const VarDecl *VD) { + for (const Capture &Capture : LSI->Captures) { + if (Capture.isVariableCapture() && Capture.getVariable() == VD) + return Capture.getLocation(); + } + return SourceLocation(); + } + + static bool shouldWarnIfShadowedDecl(const DiagnosticsEngine &Diags, + const LookupResult &R) { + // Only diagnose if we're shadowing an unambiguous field or variable. + if (R.getResultKind() != LookupResult::Found) + return false; + + // Return false if warning is ignored. + return !Diags.isIgnored(diag::warn_decl_shadow, R.getNameLoc()); + } + + /// Return the declaration shadowed by the given variable \p D, or null + /// if it doesn't shadow any declaration or shadowing warnings are disabled. + NamedDecl *Sema::getShadowedDeclaration(const VarDecl *D, + const LookupResult &R) { + if (!shouldWarnIfShadowedDecl(Diags, R)) + return nullptr; + + // Don't diagnose declarations at file scope. + if (D->hasGlobalStorage()) + return nullptr; + + NamedDecl *ShadowedDecl = R.getFoundDecl(); + return isa(ShadowedDecl) || isa(ShadowedDecl) + ? ShadowedDecl + : nullptr; + } + + /// Return the declaration shadowed by the given typedef \p D, or null + /// if it doesn't shadow any declaration or shadowing warnings are disabled. + NamedDecl *Sema::getShadowedDeclaration(const TypedefNameDecl *D, + const LookupResult &R) { + // Don't warn if typedef declaration is part of a class + if (D->getDeclContext()->isRecord()) + return nullptr; + + if (!shouldWarnIfShadowedDecl(Diags, R)) + return nullptr; + + NamedDecl *ShadowedDecl = R.getFoundDecl(); + return isa(ShadowedDecl) ? ShadowedDecl : nullptr; + } + + /// Diagnose variable or built-in function shadowing. Implements + /// -Wshadow. + /// + /// This method is called whenever a VarDecl is added to a "useful" + /// scope. + /// + /// \param ShadowedDecl the declaration that is shadowed by the given variable + /// \param R the lookup of the name + /// + void Sema::CheckShadow(NamedDecl *D, NamedDecl *ShadowedDecl, + const LookupResult &R) { + DeclContext *NewDC = D->getDeclContext(); + + if (FieldDecl *FD = dyn_cast(ShadowedDecl)) { + // Fields are not shadowed by variables in C++ static methods. + if (CXXMethodDecl *MD = dyn_cast(NewDC)) + if (MD->isStatic()) + return; + + // Fields shadowed by constructor parameters are a special case. Usually + // the constructor initializes the field with the parameter. + if (isa(NewDC)) + if (const auto PVD = dyn_cast(D)) { + // Remember that this was shadowed so we can either warn about its + // modification or its existence depending on warning settings. + ShadowingDecls.insert({PVD->getCanonicalDecl(), FD}); + return; + } + } + + if (VarDecl *shadowedVar = dyn_cast(ShadowedDecl)) + if (shadowedVar->isExternC()) { + // For shadowing external vars, make sure that we point to the global + // declaration, not a locally scoped extern declaration. + for (auto I : shadowedVar->redecls()) + if (I->isFileVarDecl()) { + ShadowedDecl = I; + break; + } + } + + DeclContext *OldDC = ShadowedDecl->getDeclContext()->getRedeclContext(); + + unsigned WarningDiag = diag::warn_decl_shadow; + SourceLocation CaptureLoc; + if (isa(D) && isa(ShadowedDecl) && NewDC && + isa(NewDC)) { + if (const auto *RD = dyn_cast(NewDC->getParent())) { + if (RD->isLambda() && OldDC->Encloses(NewDC->getLexicalParent())) { + if (RD->getLambdaCaptureDefault() == LCD_None) { + // Try to avoid warnings for lambdas with an explicit capture list. + const auto *LSI = cast(getCurFunction()); + // Warn only when the lambda captures the shadowed decl explicitly. + CaptureLoc = getCaptureLocation(LSI, cast(ShadowedDecl)); + if (CaptureLoc.isInvalid()) + WarningDiag = diag::warn_decl_shadow_uncaptured_local; + } else { + // Remember that this was shadowed so we can avoid the warning if the + // shadowed decl isn't captured and the warning settings allow it. + cast(getCurFunction()) + ->ShadowingDecls.push_back( + {cast(D), cast(ShadowedDecl)}); + return; + } + } + + if (cast(ShadowedDecl)->hasLocalStorage()) { + // A variable can't shadow a local variable in an enclosing scope, if + // they are separated by a non-capturing declaration context. + for (DeclContext *ParentDC = NewDC; + ParentDC && !ParentDC->Equals(OldDC); + ParentDC = getLambdaAwareParentOfDeclContext(ParentDC)) { + // Only block literals, captured statements, and lambda expressions + // can capture; other scopes don't. + if (!isa(ParentDC) && !isa(ParentDC) && + !isLambdaCallOperator(ParentDC)) { + return; + } + } + } + } + } + + // Only warn about certain kinds of shadowing for class members. + if (NewDC && NewDC->isRecord()) { + // In particular, don't warn about shadowing non-class members. + if (!OldDC->isRecord()) + return; + + // TODO: should we warn about static data members shadowing + // static data members from base classes? + + // TODO: don't diagnose for inaccessible shadowed members. + // This is hard to do perfectly because we might friend the + // shadowing context, but that's just a false negative. + } + + + DeclarationName Name = R.getLookupName(); + + // Emit warning and note. + if (getSourceManager().isInSystemMacro(R.getNameLoc())) + return; + ShadowedDeclKind Kind = computeShadowedDeclKind(ShadowedDecl, OldDC); + Diag(R.getNameLoc(), WarningDiag) << Name << Kind << OldDC; + if (!CaptureLoc.isInvalid()) + Diag(CaptureLoc, diag::note_var_explicitly_captured_here) + << Name << /*explicitly*/ 1; + Diag(ShadowedDecl->getLocation(), diag::note_previous_declaration); + } + + /// Diagnose shadowing for variables shadowed in the lambda record \p LambdaRD + /// when these variables are captured by the lambda. + void Sema::DiagnoseShadowingLambdaDecls(const LambdaScopeInfo *LSI) { + for (const auto &Shadow : LSI->ShadowingDecls) { + const VarDecl *ShadowedDecl = Shadow.ShadowedDecl; + // Try to avoid the warning when the shadowed decl isn't captured. + SourceLocation CaptureLoc = getCaptureLocation(LSI, ShadowedDecl); + const DeclContext *OldDC = ShadowedDecl->getDeclContext(); + Diag(Shadow.VD->getLocation(), CaptureLoc.isInvalid() + ? diag::warn_decl_shadow_uncaptured_local + : diag::warn_decl_shadow) + << Shadow.VD->getDeclName() + << computeShadowedDeclKind(ShadowedDecl, OldDC) << OldDC; + if (!CaptureLoc.isInvalid()) + Diag(CaptureLoc, diag::note_var_explicitly_captured_here) + << Shadow.VD->getDeclName() << /*explicitly*/ 0; + Diag(ShadowedDecl->getLocation(), diag::note_previous_declaration); + } + } + + /// Check -Wshadow without the advantage of a previous lookup. + void Sema::CheckShadow(Scope *S, VarDecl *D) { + if (Diags.isIgnored(diag::warn_decl_shadow, D->getLocation())) + return; + + LookupResult R(*this, D->getDeclName(), D->getLocation(), + Sema::LookupOrdinaryName, Sema::ForVisibleRedeclaration); + LookupName(R, S); + if (NamedDecl *ShadowedDecl = getShadowedDeclaration(D, R)) + CheckShadow(D, ShadowedDecl, R); + } + + /// Check if 'E', which is an expression that is about to be modified, refers + /// to a constructor parameter that shadows a field. + void Sema::CheckShadowingDeclModification(Expr *E, SourceLocation Loc) { + // Quickly ignore expressions that can't be shadowing ctor parameters. + if (!getLangOpts().CPlusPlus || ShadowingDecls.empty()) + return; + E = E->IgnoreParenImpCasts(); + auto *DRE = dyn_cast(E); + if (!DRE) + return; + const NamedDecl *D = cast(DRE->getDecl()->getCanonicalDecl()); + auto I = ShadowingDecls.find(D); + if (I == ShadowingDecls.end()) + return; + const NamedDecl *ShadowedDecl = I->second; + const DeclContext *OldDC = ShadowedDecl->getDeclContext(); + Diag(Loc, diag::warn_modifying_shadowing_decl) << D << OldDC; + Diag(D->getLocation(), diag::note_var_declared_here) << D; + Diag(ShadowedDecl->getLocation(), diag::note_previous_declaration); + + // Avoid issuing multiple warnings about the same decl. + ShadowingDecls.erase(I); + } + + /// Check for conflict between this global or extern "C" declaration and + /// previous global or extern "C" declarations. This is only used in C++. + template + static bool checkGlobalOrExternCConflict( + Sema &S, const T *ND, bool IsGlobal, LookupResult &Previous) { + assert(S.getLangOpts().CPlusPlus && "only C++ has extern \"C\""); + NamedDecl *Prev = S.findLocallyScopedExternCDecl(ND->getDeclName()); + + if (!Prev && IsGlobal && !isIncompleteDeclExternC(S, ND)) { + // The common case: this global doesn't conflict with any extern "C" + // declaration. + return false; + } + + if (Prev) { + if (!IsGlobal || isIncompleteDeclExternC(S, ND)) { + // Both the old and new declarations have C language linkage. This is a + // redeclaration. + Previous.clear(); + Previous.addDecl(Prev); + return true; + } + + // This is a global, non-extern "C" declaration, and there is a previous + // non-global extern "C" declaration. Diagnose if this is a variable + // declaration. + if (!isa(ND)) + return false; + } else { + // The declaration is extern "C". Check for any declaration in the + // translation unit which might conflict. + if (IsGlobal) { + // We have already performed the lookup into the translation unit. + IsGlobal = false; + for (LookupResult::iterator I = Previous.begin(), E = Previous.end(); + I != E; ++I) { + if (isa(*I)) { + Prev = *I; + break; + } + } + } else { + DeclContext::lookup_result R = + S.Context.getTranslationUnitDecl()->lookup(ND->getDeclName()); + for (DeclContext::lookup_result::iterator I = R.begin(), E = R.end(); + I != E; ++I) { + if (isa(*I)) { + Prev = *I; + break; + } + // FIXME: If we have any other entity with this name in global scope, + // the declaration is ill-formed, but that is a defect: it breaks the + // 'stat' hack, for instance. Only variables can have mangled name + // clashes with extern "C" declarations, so only they deserve a + // diagnostic. + } + } + + if (!Prev) + return false; + } + + // Use the first declaration's location to ensure we point at something which + // is lexically inside an extern "C" linkage-spec. + assert(Prev && "should have found a previous declaration to diagnose"); + if (FunctionDecl *FD = dyn_cast(Prev)) + Prev = FD->getFirstDecl(); + else + Prev = cast(Prev)->getFirstDecl(); + + S.Diag(ND->getLocation(), diag::err_extern_c_global_conflict) + << IsGlobal << ND; + S.Diag(Prev->getLocation(), diag::note_extern_c_global_conflict) + << IsGlobal; + return false; + } + + /// Apply special rules for handling extern "C" declarations. Returns \c true + /// if we have found that this is a redeclaration of some prior entity. + /// + /// Per C++ [dcl.link]p6: + /// Two declarations [for a function or variable] with C language linkage + /// with the same name that appear in different scopes refer to the same + /// [entity]. An entity with C language linkage shall not be declared with + /// the same name as an entity in global scope. + template + static bool checkForConflictWithNonVisibleExternC(Sema &S, const T *ND, + LookupResult &Previous) { + if (!S.getLangOpts().CPlusPlus) { + // In C, when declaring a global variable, look for a corresponding 'extern' + // variable declared in function scope. We don't need this in C++, because + // we find local extern decls in the surrounding file-scope DeclContext. + if (ND->getDeclContext()->getRedeclContext()->isTranslationUnit()) { + if (NamedDecl *Prev = S.findLocallyScopedExternCDecl(ND->getDeclName())) { + Previous.clear(); + Previous.addDecl(Prev); + return true; + } + } + return false; + } + + // A declaration in the translation unit can conflict with an extern "C" + // declaration. + if (ND->getDeclContext()->getRedeclContext()->isTranslationUnit()) + return checkGlobalOrExternCConflict(S, ND, /*IsGlobal*/true, Previous); + + // An extern "C" declaration can conflict with a declaration in the + // translation unit or can be a redeclaration of an extern "C" declaration + // in another scope. + if (isIncompleteDeclExternC(S,ND)) + return checkGlobalOrExternCConflict(S, ND, /*IsGlobal*/false, Previous); + + // Neither global nor extern "C": nothing to do. + return false; + } + + void Sema::CheckVariableDeclarationType(VarDecl *NewVD) { + // If the decl is already known invalid, don't check it. + if (NewVD->isInvalidDecl()) + return; + + QualType T = NewVD->getType(); + + // Defer checking an 'auto' type until its initializer is attached. + if (T->isUndeducedType()) + return; + + if (NewVD->hasAttrs()) + CheckAlignasUnderalignment(NewVD); + + if (T->isObjCObjectType()) { + Diag(NewVD->getLocation(), diag::err_statically_allocated_object) + << FixItHint::CreateInsertion(NewVD->getLocation(), "*"); + T = Context.getObjCObjectPointerType(T); + NewVD->setType(T); + } + + // Emit an error if an address space was applied to decl with local storage. + // This includes arrays of objects with address space qualifiers, but not + // automatic variables that point to other address spaces. + // ISO/IEC TR 18037 S5.1.2 + if (!getLangOpts().OpenCL && NewVD->hasLocalStorage() && + T.getAddressSpace() != LangAS::Default) { + Diag(NewVD->getLocation(), diag::err_as_qualified_auto_decl) << 0; + NewVD->setInvalidDecl(); + return; + } + + // OpenCL v1.2 s6.8 - The static qualifier is valid only in program + // scope. + if (getLangOpts().OpenCLVersion == 120 && + !getOpenCLOptions().isEnabled("cl_clang_storage_class_specifiers") && + NewVD->isStaticLocal()) { + Diag(NewVD->getLocation(), diag::err_static_function_scope); + NewVD->setInvalidDecl(); + return; + } + + if (getLangOpts().OpenCL) { + // OpenCL v2.0 s6.12.5 - The __block storage type is not supported. + if (NewVD->hasAttr()) { + Diag(NewVD->getLocation(), diag::err_opencl_block_storage_type); + return; + } + + if (T->isBlockPointerType()) { + // OpenCL v2.0 s6.12.5 - Any block declaration must be const qualified and + // can't use 'extern' storage class. + if (!T.isConstQualified()) { + Diag(NewVD->getLocation(), diag::err_opencl_invalid_block_declaration) + << 0 /*const*/; + NewVD->setInvalidDecl(); + return; + } + if (NewVD->hasExternalStorage()) { + Diag(NewVD->getLocation(), diag::err_opencl_extern_block_declaration); + NewVD->setInvalidDecl(); + return; + } + } + // OpenCL C v1.2 s6.5 - All program scope variables must be declared in the + // __constant address space. + // OpenCL C v2.0 s6.5.1 - Variables defined at program scope and static + // variables inside a function can also be declared in the global + // address space. + // OpenCL C++ v1.0 s2.5 inherits rule from OpenCL C v2.0 and allows local + // address space additionally. + // FIXME: Add local AS for OpenCL C++. + if (NewVD->isFileVarDecl() || NewVD->isStaticLocal() || + NewVD->hasExternalStorage()) { + if (!T->isSamplerT() && + !(T.getAddressSpace() == LangAS::opencl_constant || + (T.getAddressSpace() == LangAS::opencl_global && + (getLangOpts().OpenCLVersion == 200 || + getLangOpts().OpenCLCPlusPlus)))) { + int Scope = NewVD->isStaticLocal() | NewVD->hasExternalStorage() << 1; + if (getLangOpts().OpenCLVersion == 200 || getLangOpts().OpenCLCPlusPlus) + Diag(NewVD->getLocation(), diag::err_opencl_global_invalid_addr_space) + << Scope << "global or constant"; + else + Diag(NewVD->getLocation(), diag::err_opencl_global_invalid_addr_space) + << Scope << "constant"; + NewVD->setInvalidDecl(); + return; + } + } else { + if (T.getAddressSpace() == LangAS::opencl_global) { + Diag(NewVD->getLocation(), diag::err_opencl_function_variable) + << 1 /*is any function*/ << "global"; + NewVD->setInvalidDecl(); + return; + } + if (T.getAddressSpace() == LangAS::opencl_constant || + T.getAddressSpace() == LangAS::opencl_local) { + FunctionDecl *FD = getCurFunctionDecl(); + // OpenCL v1.1 s6.5.2 and s6.5.3: no local or constant variables + // in functions. + if (FD && !FD->hasAttr()) { + if (T.getAddressSpace() == LangAS::opencl_constant) + Diag(NewVD->getLocation(), diag::err_opencl_function_variable) + << 0 /*non-kernel only*/ << "constant"; + else + Diag(NewVD->getLocation(), diag::err_opencl_function_variable) + << 0 /*non-kernel only*/ << "local"; + NewVD->setInvalidDecl(); + return; + } + // OpenCL v2.0 s6.5.2 and s6.5.3: local and constant variables must be + // in the outermost scope of a kernel function. + if (FD && FD->hasAttr()) { + if (!getCurScope()->isFunctionScope()) { + if (T.getAddressSpace() == LangAS::opencl_constant) + Diag(NewVD->getLocation(), diag::err_opencl_addrspace_scope) + << "constant"; + else + Diag(NewVD->getLocation(), diag::err_opencl_addrspace_scope) + << "local"; + NewVD->setInvalidDecl(); + return; + } + } + } else if (T.getAddressSpace() != LangAS::opencl_private) { + // Do not allow other address spaces on automatic variable. + Diag(NewVD->getLocation(), diag::err_as_qualified_auto_decl) << 1; + NewVD->setInvalidDecl(); + return; + } + } + } + + if (NewVD->hasLocalStorage() && T.isObjCGCWeak() + && !NewVD->hasAttr()) { + if (getLangOpts().getGC() != LangOptions::NonGC) + Diag(NewVD->getLocation(), diag::warn_gc_attribute_weak_on_local); + else { + assert(!getLangOpts().ObjCAutoRefCount); + Diag(NewVD->getLocation(), diag::warn_attribute_weak_on_local); + } + } + + bool isVM = T->isVariablyModifiedType(); + if (isVM || NewVD->hasAttr() || + NewVD->hasAttr()) + setFunctionHasBranchProtectedScope(); + + if ((isVM && NewVD->hasLinkage()) || + (T->isVariableArrayType() && NewVD->hasGlobalStorage())) { + bool SizeIsNegative; + llvm::APSInt Oversized; + TypeSourceInfo *FixedTInfo = TryToFixInvalidVariablyModifiedTypeSourceInfo( + NewVD->getTypeSourceInfo(), Context, SizeIsNegative, Oversized); + QualType FixedT; + if (FixedTInfo && T == NewVD->getTypeSourceInfo()->getType()) + FixedT = FixedTInfo->getType(); + else if (FixedTInfo) { + // Type and type-as-written are canonically different. We need to fix up + // both types separately. + FixedT = TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative, + Oversized); + } + if ((!FixedTInfo || FixedT.isNull()) && T->isVariableArrayType()) { + const VariableArrayType *VAT = Context.getAsVariableArrayType(T); + // FIXME: This won't give the correct result for + // int a[10][n]; + SourceRange SizeRange = VAT->getSizeExpr()->getSourceRange(); + + if (NewVD->isFileVarDecl()) + Diag(NewVD->getLocation(), diag::err_vla_decl_in_file_scope) + << SizeRange; + else if (NewVD->isStaticLocal()) + Diag(NewVD->getLocation(), diag::err_vla_decl_has_static_storage) + << SizeRange; + else + Diag(NewVD->getLocation(), diag::err_vla_decl_has_extern_linkage) + << SizeRange; + NewVD->setInvalidDecl(); + return; + } + + if (!FixedTInfo) { + if (NewVD->isFileVarDecl()) + Diag(NewVD->getLocation(), diag::err_vm_decl_in_file_scope); + else + Diag(NewVD->getLocation(), diag::err_vm_decl_has_extern_linkage); + NewVD->setInvalidDecl(); + return; + } + + Diag(NewVD->getLocation(), diag::warn_illegal_constant_array_size); + NewVD->setType(FixedT); + NewVD->setTypeSourceInfo(FixedTInfo); + } + + if (T->isVoidType()) { + // C++98 [dcl.stc]p5: The extern specifier can be applied only to the names + // of objects and functions. + if (NewVD->isThisDeclarationADefinition() || getLangOpts().CPlusPlus) { + Diag(NewVD->getLocation(), diag::err_typecheck_decl_incomplete_type) + << T; + NewVD->setInvalidDecl(); + return; + } + } + + if (!NewVD->hasLocalStorage() && NewVD->hasAttr()) { + Diag(NewVD->getLocation(), diag::err_block_on_nonlocal); + NewVD->setInvalidDecl(); + return; + } + + if (isVM && NewVD->hasAttr()) { + Diag(NewVD->getLocation(), diag::err_block_on_vm); + NewVD->setInvalidDecl(); + return; + } + + if (NewVD->isConstexpr() && !T->isDependentType() && + RequireLiteralType(NewVD->getLocation(), T, + diag::err_constexpr_var_non_literal)) { + NewVD->setInvalidDecl(); + return; + } + } + + /// Perform semantic checking on a newly-created variable + /// declaration. + /// + /// This routine performs all of the type-checking required for a + /// variable declaration once it has been built. It is used both to + /// check variables after they have been parsed and their declarators + /// have been translated into a declaration, and to check variables + /// that have been instantiated from a template. + /// + /// Sets NewVD->isInvalidDecl() if an error was encountered. + /// + /// Returns true if the variable declaration is a redeclaration. + bool Sema::CheckVariableDeclaration(VarDecl *NewVD, LookupResult &Previous) { + CheckVariableDeclarationType(NewVD); + + // If the decl is already known invalid, don't check it. + if (NewVD->isInvalidDecl()) + return false; + + // If we did not find anything by this name, look for a non-visible + // extern "C" declaration with the same name. + if (Previous.empty() && + checkForConflictWithNonVisibleExternC(*this, NewVD, Previous)) + Previous.setShadowed(); + + if (!Previous.empty()) { + MergeVarDecl(NewVD, Previous); + return true; + } + return false; + } + + namespace { + struct FindOverriddenMethod { + Sema *S; + CXXMethodDecl *Method; + + /// Member lookup function that determines whether a given C++ + /// method overrides a method in a base class, to be used with + /// CXXRecordDecl::lookupInBases(). + bool operator()(const CXXBaseSpecifier *Specifier, CXXBasePath &Path) { + RecordDecl *BaseRecord = + Specifier->getType()->getAs()->getDecl(); + + DeclarationName Name = Method->getDeclName(); + + // FIXME: Do we care about other names here too? + if (Name.getNameKind() == DeclarationName::CXXDestructorName) { + // We really want to find the base class destructor here. + QualType T = S->Context.getTypeDeclType(BaseRecord); + CanQualType CT = S->Context.getCanonicalType(T); + + Name = S->Context.DeclarationNames.getCXXDestructorName(CT); + } + + for (Path.Decls = BaseRecord->lookup(Name); !Path.Decls.empty(); + Path.Decls = Path.Decls.slice(1)) { + NamedDecl *D = Path.Decls.front(); + if (CXXMethodDecl *MD = dyn_cast(D)) { + if (MD->isVirtual() && !S->IsOverload(Method, MD, false)) + return true; + } + } + + return false; + } + }; + + enum OverrideErrorKind { OEK_All, OEK_NonDeleted, OEK_Deleted }; + } // end anonymous namespace + + /// Report an error regarding overriding, along with any relevant + /// overridden methods. + /// + /// \param DiagID the primary error to report. + /// \param MD the overriding method. + /// \param OEK which overrides to include as notes. + static void ReportOverrides(Sema& S, unsigned DiagID, const CXXMethodDecl *MD, + OverrideErrorKind OEK = OEK_All) { + S.Diag(MD->getLocation(), DiagID) << MD->getDeclName(); + for (const CXXMethodDecl *O : MD->overridden_methods()) { + // This check (& the OEK parameter) could be replaced by a predicate, but + // without lambdas that would be overkill. This is still nicer than writing + // out the diag loop 3 times. + if ((OEK == OEK_All) || + (OEK == OEK_NonDeleted && !O->isDeleted()) || + (OEK == OEK_Deleted && O->isDeleted())) + S.Diag(O->getLocation(), diag::note_overridden_virtual_function); + } + } + + /// AddOverriddenMethods - See if a method overrides any in the base classes, + /// and if so, check that it's a valid override and remember it. + bool Sema::AddOverriddenMethods(CXXRecordDecl *DC, CXXMethodDecl *MD) { + // Look for methods in base classes that this method might override. + CXXBasePaths Paths; + FindOverriddenMethod FOM; + FOM.Method = MD; + FOM.S = this; + bool hasDeletedOverridenMethods = false; + bool hasNonDeletedOverridenMethods = false; + bool AddedAny = false; + if (DC->lookupInBases(FOM, Paths)) { + for (auto *I : Paths.found_decls()) { + if (CXXMethodDecl *OldMD = dyn_cast(I)) { + MD->addOverriddenMethod(OldMD->getCanonicalDecl()); + if (!CheckOverridingFunctionReturnType(MD, OldMD) && + !CheckOverridingFunctionAttributes(MD, OldMD) && + !CheckOverridingFunctionExceptionSpec(MD, OldMD) && + !CheckIfOverriddenFunctionIsMarkedFinal(MD, OldMD)) { + hasDeletedOverridenMethods |= OldMD->isDeleted(); + hasNonDeletedOverridenMethods |= !OldMD->isDeleted(); + AddedAny = true; + } + } + } + } + + if (hasDeletedOverridenMethods && !MD->isDeleted()) { + ReportOverrides(*this, diag::err_non_deleted_override, MD, OEK_Deleted); + } + if (hasNonDeletedOverridenMethods && MD->isDeleted()) { + ReportOverrides(*this, diag::err_deleted_override, MD, OEK_NonDeleted); + } + + return AddedAny; + } + + namespace { + // Struct for holding all of the extra arguments needed by + // DiagnoseInvalidRedeclaration to call Sema::ActOnFunctionDeclarator. + struct ActOnFDArgs { + Scope *S; + Declarator &D; + MultiTemplateParamsArg TemplateParamLists; + bool AddToScope; + }; + } // end anonymous namespace + + namespace { + + // Callback to only accept typo corrections that have a non-zero edit distance. + // Also only accept corrections that have the same parent decl. + class DifferentNameValidatorCCC : public CorrectionCandidateCallback { + public: + DifferentNameValidatorCCC(ASTContext &Context, FunctionDecl *TypoFD, + CXXRecordDecl *Parent) + : Context(Context), OriginalFD(TypoFD), + ExpectedParent(Parent ? Parent->getCanonicalDecl() : nullptr) {} + + bool ValidateCandidate(const TypoCorrection &candidate) override { + if (candidate.getEditDistance() == 0) + return false; + + SmallVector MismatchedParams; + for (TypoCorrection::const_decl_iterator CDecl = candidate.begin(), + CDeclEnd = candidate.end(); + CDecl != CDeclEnd; ++CDecl) { + FunctionDecl *FD = dyn_cast(*CDecl); + + if (FD && !FD->hasBody() && + hasSimilarParameters(Context, FD, OriginalFD, MismatchedParams)) { + if (CXXMethodDecl *MD = dyn_cast(FD)) { + CXXRecordDecl *Parent = MD->getParent(); + if (Parent && Parent->getCanonicalDecl() == ExpectedParent) + return true; + } else if (!ExpectedParent) { + return true; + } + } + } + + return false; + } + + private: + ASTContext &Context; + FunctionDecl *OriginalFD; + CXXRecordDecl *ExpectedParent; + }; + + } // end anonymous namespace + + void Sema::MarkTypoCorrectedFunctionDefinition(const NamedDecl *F) { + TypoCorrectedFunctionDefinitions.insert(F); + } + + /// Generate diagnostics for an invalid function redeclaration. + /// + /// This routine handles generating the diagnostic messages for an invalid + /// function redeclaration, including finding possible similar declarations + /// or performing typo correction if there are no previous declarations with + /// the same name. + /// + /// Returns a NamedDecl iff typo correction was performed and substituting in + /// the new declaration name does not cause new errors. + static NamedDecl *DiagnoseInvalidRedeclaration( + Sema &SemaRef, LookupResult &Previous, FunctionDecl *NewFD, + ActOnFDArgs &ExtraArgs, bool IsLocalFriend, Scope *S) { + DeclarationName Name = NewFD->getDeclName(); + DeclContext *NewDC = NewFD->getDeclContext(); + SmallVector MismatchedParams; + SmallVector, 1> NearMatches; + TypoCorrection Correction; + bool IsDefinition = ExtraArgs.D.isFunctionDefinition(); + unsigned DiagMsg = + IsLocalFriend ? diag::err_no_matching_local_friend : + NewFD->getFriendObjectKind() ? diag::err_qualified_friend_no_match : + diag::err_member_decl_does_not_match; + LookupResult Prev(SemaRef, Name, NewFD->getLocation(), + IsLocalFriend ? Sema::LookupLocalFriendName + : Sema::LookupOrdinaryName, + Sema::ForVisibleRedeclaration); + + NewFD->setInvalidDecl(); + if (IsLocalFriend) + SemaRef.LookupName(Prev, S); + else + SemaRef.LookupQualifiedName(Prev, NewDC); + assert(!Prev.isAmbiguous() && + "Cannot have an ambiguity in previous-declaration lookup"); + CXXMethodDecl *MD = dyn_cast(NewFD); + if (!Prev.empty()) { + for (LookupResult::iterator Func = Prev.begin(), FuncEnd = Prev.end(); + Func != FuncEnd; ++Func) { + FunctionDecl *FD = dyn_cast(*Func); + if (FD && + hasSimilarParameters(SemaRef.Context, FD, NewFD, MismatchedParams)) { + // Add 1 to the index so that 0 can mean the mismatch didn't + // involve a parameter + unsigned ParamNum = + MismatchedParams.empty() ? 0 : MismatchedParams.front() + 1; + NearMatches.push_back(std::make_pair(FD, ParamNum)); + } + } + // If the qualified name lookup yielded nothing, try typo correction + } else if ((Correction = SemaRef.CorrectTypo( + Prev.getLookupNameInfo(), Prev.getLookupKind(), S, + &ExtraArgs.D.getCXXScopeSpec(), + llvm::make_unique( + SemaRef.Context, NewFD, MD ? MD->getParent() : nullptr), + Sema::CTK_ErrorRecovery, IsLocalFriend ? nullptr : NewDC))) { + // Set up everything for the call to ActOnFunctionDeclarator + ExtraArgs.D.SetIdentifier(Correction.getCorrectionAsIdentifierInfo(), + ExtraArgs.D.getIdentifierLoc()); + Previous.clear(); + Previous.setLookupName(Correction.getCorrection()); + for (TypoCorrection::decl_iterator CDecl = Correction.begin(), + CDeclEnd = Correction.end(); + CDecl != CDeclEnd; ++CDecl) { + FunctionDecl *FD = dyn_cast(*CDecl); + if (FD && !FD->hasBody() && + hasSimilarParameters(SemaRef.Context, FD, NewFD, MismatchedParams)) { + Previous.addDecl(FD); + } + } + bool wasRedeclaration = ExtraArgs.D.isRedeclaration(); + + NamedDecl *Result; + // Retry building the function declaration with the new previous + // declarations, and with errors suppressed. + { + // Trap errors. + Sema::SFINAETrap Trap(SemaRef); + + // TODO: Refactor ActOnFunctionDeclarator so that we can call only the + // pieces need to verify the typo-corrected C++ declaration and hopefully + // eliminate the need for the parameter pack ExtraArgs. + Result = SemaRef.ActOnFunctionDeclarator( + ExtraArgs.S, ExtraArgs.D, + Correction.getCorrectionDecl()->getDeclContext(), + NewFD->getTypeSourceInfo(), Previous, ExtraArgs.TemplateParamLists, + ExtraArgs.AddToScope); + + if (Trap.hasErrorOccurred()) + Result = nullptr; + } + + if (Result) { + // Determine which correction we picked. + Decl *Canonical = Result->getCanonicalDecl(); + for (LookupResult::iterator I = Previous.begin(), E = Previous.end(); + I != E; ++I) + if ((*I)->getCanonicalDecl() == Canonical) + Correction.setCorrectionDecl(*I); + + // Let Sema know about the correction. + SemaRef.MarkTypoCorrectedFunctionDefinition(Result); + SemaRef.diagnoseTypo( + Correction, + SemaRef.PDiag(IsLocalFriend + ? diag::err_no_matching_local_friend_suggest + : diag::err_member_decl_does_not_match_suggest) + << Name << NewDC << IsDefinition); + return Result; + } + + // Pretend the typo correction never occurred + ExtraArgs.D.SetIdentifier(Name.getAsIdentifierInfo(), + ExtraArgs.D.getIdentifierLoc()); + ExtraArgs.D.setRedeclaration(wasRedeclaration); + Previous.clear(); + Previous.setLookupName(Name); + } + + SemaRef.Diag(NewFD->getLocation(), DiagMsg) + << Name << NewDC << IsDefinition << NewFD->getLocation(); + + bool NewFDisConst = false; + if (CXXMethodDecl *NewMD = dyn_cast(NewFD)) + NewFDisConst = NewMD->isConst(); + + for (SmallVectorImpl >::iterator + NearMatch = NearMatches.begin(), NearMatchEnd = NearMatches.end(); + NearMatch != NearMatchEnd; ++NearMatch) { + FunctionDecl *FD = NearMatch->first; + CXXMethodDecl *MD = dyn_cast(FD); + bool FDisConst = MD && MD->isConst(); + bool IsMember = MD || !IsLocalFriend; + + // FIXME: These notes are poorly worded for the local friend case. + if (unsigned Idx = NearMatch->second) { + ParmVarDecl *FDParam = FD->getParamDecl(Idx-1); + SourceLocation Loc = FDParam->getTypeSpecStartLoc(); + if (Loc.isInvalid()) Loc = FD->getLocation(); + SemaRef.Diag(Loc, IsMember ? diag::note_member_def_close_param_match + : diag::note_local_decl_close_param_match) + << Idx << FDParam->getType() + << NewFD->getParamDecl(Idx - 1)->getType(); + } else if (FDisConst != NewFDisConst) { + SemaRef.Diag(FD->getLocation(), diag::note_member_def_close_const_match) + << NewFDisConst << FD->getSourceRange().getEnd(); + } else + SemaRef.Diag(FD->getLocation(), + IsMember ? diag::note_member_def_close_match + : diag::note_local_decl_close_match); + } + return nullptr; + } + + static StorageClass getFunctionStorageClass(Sema &SemaRef, Declarator &D) { + switch (D.getDeclSpec().getStorageClassSpec()) { + default: llvm_unreachable("Unknown storage class!"); + case DeclSpec::SCS_auto: + case DeclSpec::SCS_register: + case DeclSpec::SCS_mutable: + SemaRef.Diag(D.getDeclSpec().getStorageClassSpecLoc(), + diag::err_typecheck_sclass_func); + D.getMutableDeclSpec().ClearStorageClassSpecs(); + D.setInvalidType(); + break; + case DeclSpec::SCS_unspecified: break; + case DeclSpec::SCS_extern: + if (D.getDeclSpec().isExternInLinkageSpec()) + return SC_None; + return SC_Extern; + case DeclSpec::SCS_static: { + if (SemaRef.CurContext->getRedeclContext()->isFunctionOrMethod()) { + // C99 6.7.1p5: + // The declaration of an identifier for a function that has + // block scope shall have no explicit storage-class specifier + // other than extern + // See also (C++ [dcl.stc]p4). + SemaRef.Diag(D.getDeclSpec().getStorageClassSpecLoc(), + diag::err_static_block_func); + break; + } else + return SC_Static; + } + case DeclSpec::SCS_private_extern: return SC_PrivateExtern; + } + + // No explicit storage class has already been returned + return SC_None; + } + + static FunctionDecl* CreateNewFunctionDecl(Sema &SemaRef, Declarator &D, + DeclContext *DC, QualType &R, + TypeSourceInfo *TInfo, + StorageClass SC, + bool &IsVirtualOkay) { + DeclarationNameInfo NameInfo = SemaRef.GetNameForDeclarator(D); + DeclarationName Name = NameInfo.getName(); + + FunctionDecl *NewFD = nullptr; + bool isInline = D.getDeclSpec().isInlineSpecified(); + + if (!SemaRef.getLangOpts().CPlusPlus) { + // Determine whether the function was written with a + // prototype. This true when: + // - there is a prototype in the declarator, or + // - the type R of the function is some kind of typedef or other non- + // attributed reference to a type name (which eventually refers to a + // function type). + bool HasPrototype = + (D.isFunctionDeclarator() && D.getFunctionTypeInfo().hasPrototype) || + (!R->getAsAdjusted() && R->isFunctionProtoType()); + + NewFD = FunctionDecl::Create(SemaRef.Context, DC, D.getBeginLoc(), NameInfo, + R, TInfo, SC, isInline, HasPrototype, false); + if (D.isInvalidType()) + NewFD->setInvalidDecl(); + + return NewFD; + } + + bool isExplicit = D.getDeclSpec().isExplicitSpecified(); + bool isConstexpr = D.getDeclSpec().isConstexprSpecified(); + + // Check that the return type is not an abstract class type. + // For record types, this is done by the AbstractClassUsageDiagnoser once + // the class has been completely parsed. + if (!DC->isRecord() && + SemaRef.RequireNonAbstractType( + D.getIdentifierLoc(), R->getAs()->getReturnType(), + diag::err_abstract_type_in_decl, SemaRef.AbstractReturnType)) + D.setInvalidType(); + + if (Name.getNameKind() == DeclarationName::CXXConstructorName) { + // This is a C++ constructor declaration. + assert(DC->isRecord() && + "Constructors can only be declared in a member context"); + + R = SemaRef.CheckConstructorDeclarator(D, R, SC); + return CXXConstructorDecl::Create( + SemaRef.Context, cast(DC), D.getBeginLoc(), NameInfo, R, + TInfo, isExplicit, isInline, + /*isImplicitlyDeclared=*/false, isConstexpr); + + } else if (Name.getNameKind() == DeclarationName::CXXDestructorName) { + // This is a C++ destructor declaration. + if (DC->isRecord()) { + R = SemaRef.CheckDestructorDeclarator(D, R, SC); + CXXRecordDecl *Record = cast(DC); + CXXDestructorDecl *NewDD = + CXXDestructorDecl::Create(SemaRef.Context, Record, D.getBeginLoc(), + NameInfo, R, TInfo, isInline, + /*isImplicitlyDeclared=*/false); + + // If the destructor needs an implicit exception specification, set it + // now. FIXME: It'd be nice to be able to create the right type to start + // with, but the type needs to reference the destructor declaration. + if (SemaRef.getLangOpts().CPlusPlus11) + SemaRef.AdjustDestructorExceptionSpec(NewDD); + + IsVirtualOkay = true; + return NewDD; + + } else { + SemaRef.Diag(D.getIdentifierLoc(), diag::err_destructor_not_member); + D.setInvalidType(); + + // Create a FunctionDecl to satisfy the function definition parsing + // code path. + return FunctionDecl::Create(SemaRef.Context, DC, D.getBeginLoc(), + D.getIdentifierLoc(), Name, R, TInfo, SC, + isInline, + /*hasPrototype=*/true, isConstexpr); + } + + } else if (Name.getNameKind() == DeclarationName::CXXConversionFunctionName) { + if (!DC->isRecord()) { + SemaRef.Diag(D.getIdentifierLoc(), + diag::err_conv_function_not_member); + return nullptr; + } + + SemaRef.CheckConversionDeclarator(D, R, SC); + IsVirtualOkay = true; + return CXXConversionDecl::Create( + SemaRef.Context, cast(DC), D.getBeginLoc(), NameInfo, R, + TInfo, isInline, isExplicit, isConstexpr, SourceLocation()); + + } else if (Name.getNameKind() == DeclarationName::CXXDeductionGuideName) { + SemaRef.CheckDeductionGuideDeclarator(D, R, SC); + + return CXXDeductionGuideDecl::Create(SemaRef.Context, DC, D.getBeginLoc(), + isExplicit, NameInfo, R, TInfo, + D.getEndLoc()); + } else if (DC->isRecord()) { + // If the name of the function is the same as the name of the record, + // then this must be an invalid constructor that has a return type. + // (The parser checks for a return type and makes the declarator a + // constructor if it has no return type). + if (Name.getAsIdentifierInfo() && + Name.getAsIdentifierInfo() == cast(DC)->getIdentifier()){ + SemaRef.Diag(D.getIdentifierLoc(), diag::err_constructor_return_type) + << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc()) + << SourceRange(D.getIdentifierLoc()); + return nullptr; + } + + // This is a C++ method declaration. + CXXMethodDecl *Ret = CXXMethodDecl::Create( + SemaRef.Context, cast(DC), D.getBeginLoc(), NameInfo, R, + TInfo, SC, isInline, isConstexpr, SourceLocation()); + IsVirtualOkay = !Ret->isStatic(); + return Ret; + } else { + bool isFriend = + SemaRef.getLangOpts().CPlusPlus && D.getDeclSpec().isFriendSpecified(); + if (!isFriend && SemaRef.CurContext->isRecord()) + return nullptr; + + // Determine whether the function was written with a + // prototype. This true when: + // - we're in C++ (where every function has a prototype), + return FunctionDecl::Create(SemaRef.Context, DC, D.getBeginLoc(), NameInfo, + R, TInfo, SC, isInline, true /*HasPrototype*/, + isConstexpr); + } + } + + enum OpenCLParamType { + ValidKernelParam, + PtrPtrKernelParam, + PtrKernelParam, + InvalidAddrSpacePtrKernelParam, + InvalidKernelParam, + RecordKernelParam + }; + + static bool isOpenCLSizeDependentType(ASTContext &C, QualType Ty) { + // Size dependent types are just typedefs to normal integer types + // (e.g. unsigned long), so we cannot distinguish them from other typedefs to + // integers other than by their names. + StringRef SizeTypeNames[] = {"size_t", "intptr_t", "uintptr_t", "ptrdiff_t"}; + + // Remove typedefs one by one until we reach a typedef + // for a size dependent type. + QualType DesugaredTy = Ty; + do { + ArrayRef Names(SizeTypeNames); + auto Match = + std::find(Names.begin(), Names.end(), DesugaredTy.getAsString()); + if (Names.end() != Match) + return true; + + Ty = DesugaredTy; + DesugaredTy = Ty.getSingleStepDesugaredType(C); + } while (DesugaredTy != Ty); + + return false; + } + + static OpenCLParamType getOpenCLKernelParameterType(Sema &S, QualType PT) { + if (PT->isPointerType()) { + QualType PointeeType = PT->getPointeeType(); + if (PointeeType->isPointerType()) + return PtrPtrKernelParam; + if (PointeeType.getAddressSpace() == LangAS::opencl_generic || + PointeeType.getAddressSpace() == LangAS::opencl_private || + PointeeType.getAddressSpace() == LangAS::Default) + return InvalidAddrSpacePtrKernelParam; + return PtrKernelParam; + } + + // OpenCL v1.2 s6.9.k: + // Arguments to kernel functions in a program cannot be declared with the + // built-in scalar types bool, half, size_t, ptrdiff_t, intptr_t, and + // uintptr_t or a struct and/or union that contain fields declared to be one + // of these built-in scalar types. + if (isOpenCLSizeDependentType(S.getASTContext(), PT)) + return InvalidKernelParam; + + if (PT->isImageType()) + return PtrKernelParam; + + if (PT->isBooleanType() || PT->isEventT() || PT->isReserveIDT()) + return InvalidKernelParam; + + // OpenCL extension spec v1.2 s9.5: + // This extension adds support for half scalar and vector types as built-in + // types that can be used for arithmetic operations, conversions etc. + if (!S.getOpenCLOptions().isEnabled("cl_khr_fp16") && PT->isHalfType()) + return InvalidKernelParam; + + if (PT->isRecordType()) + return RecordKernelParam; + + // Look into an array argument to check if it has a forbidden type. + if (PT->isArrayType()) { + const Type *UnderlyingTy = PT->getPointeeOrArrayElementType(); + // Call ourself to check an underlying type of an array. Since the + // getPointeeOrArrayElementType returns an innermost type which is not an + // array, this recursive call only happens once. + return getOpenCLKernelParameterType(S, QualType(UnderlyingTy, 0)); + } + + return ValidKernelParam; + } + + static void checkIsValidOpenCLKernelParameter( + Sema &S, + Declarator &D, + ParmVarDecl *Param, + llvm::SmallPtrSetImpl &ValidTypes) { + QualType PT = Param->getType(); + + // Cache the valid types we encounter to avoid rechecking structs that are + // used again + if (ValidTypes.count(PT.getTypePtr())) + return; + + switch (getOpenCLKernelParameterType(S, PT)) { + case PtrPtrKernelParam: + // OpenCL v1.2 s6.9.a: + // A kernel function argument cannot be declared as a + // pointer to a pointer type. + S.Diag(Param->getLocation(), diag::err_opencl_ptrptr_kernel_param); + D.setInvalidType(); + return; + + case InvalidAddrSpacePtrKernelParam: + // OpenCL v1.0 s6.5: + // __kernel function arguments declared to be a pointer of a type can point + // to one of the following address spaces only : __global, __local or + // __constant. + S.Diag(Param->getLocation(), diag::err_kernel_arg_address_space); + D.setInvalidType(); + return; + + // OpenCL v1.2 s6.9.k: + // Arguments to kernel functions in a program cannot be declared with the + // built-in scalar types bool, half, size_t, ptrdiff_t, intptr_t, and + // uintptr_t or a struct and/or union that contain fields declared to be + // one of these built-in scalar types. + + case InvalidKernelParam: + // OpenCL v1.2 s6.8 n: + // A kernel function argument cannot be declared + // of event_t type. + // Do not diagnose half type since it is diagnosed as invalid argument + // type for any function elsewhere. + if (!PT->isHalfType()) { + S.Diag(Param->getLocation(), diag::err_bad_kernel_param_type) << PT; + + // Explain what typedefs are involved. + const TypedefType *Typedef = nullptr; + while ((Typedef = PT->getAs())) { + SourceLocation Loc = Typedef->getDecl()->getLocation(); + // SourceLocation may be invalid for a built-in type. + if (Loc.isValid()) + S.Diag(Loc, diag::note_entity_declared_at) << PT; + PT = Typedef->desugar(); + } + } + + D.setInvalidType(); + return; + + case PtrKernelParam: + case ValidKernelParam: + ValidTypes.insert(PT.getTypePtr()); + return; + + case RecordKernelParam: + break; + } + + // Track nested structs we will inspect + SmallVector VisitStack; + + // Track where we are in the nested structs. Items will migrate from + // VisitStack to HistoryStack as we do the DFS for bad field. + SmallVector HistoryStack; + HistoryStack.push_back(nullptr); + + // At this point we already handled everything except of a RecordType or + // an ArrayType of a RecordType. + assert((PT->isArrayType() || PT->isRecordType()) && "Unexpected type."); + const RecordType *RecTy = + PT->getPointeeOrArrayElementType()->getAs(); + const RecordDecl *OrigRecDecl = RecTy->getDecl(); + + VisitStack.push_back(RecTy->getDecl()); + assert(VisitStack.back() && "First decl null?"); + + do { + const Decl *Next = VisitStack.pop_back_val(); + if (!Next) { + assert(!HistoryStack.empty()); + // Found a marker, we have gone up a level + if (const FieldDecl *Hist = HistoryStack.pop_back_val()) + ValidTypes.insert(Hist->getType().getTypePtr()); + + continue; + } + + // Adds everything except the original parameter declaration (which is not a + // field itself) to the history stack. + const RecordDecl *RD; + if (const FieldDecl *Field = dyn_cast(Next)) { + HistoryStack.push_back(Field); + + QualType FieldTy = Field->getType(); + // Other field types (known to be valid or invalid) are handled while we + // walk around RecordDecl::fields(). + assert((FieldTy->isArrayType() || FieldTy->isRecordType()) && + "Unexpected type."); + const Type *FieldRecTy = FieldTy->getPointeeOrArrayElementType(); + + RD = FieldRecTy->castAs()->getDecl(); + } else { + RD = cast(Next); + } + + // Add a null marker so we know when we've gone back up a level + VisitStack.push_back(nullptr); + + for (const auto *FD : RD->fields()) { + QualType QT = FD->getType(); + + if (ValidTypes.count(QT.getTypePtr())) + continue; + + OpenCLParamType ParamType = getOpenCLKernelParameterType(S, QT); + if (ParamType == ValidKernelParam) + continue; + + if (ParamType == RecordKernelParam) { + VisitStack.push_back(FD); + continue; + } + + // OpenCL v1.2 s6.9.p: + // Arguments to kernel functions that are declared to be a struct or union + // do not allow OpenCL objects to be passed as elements of the struct or + // union. + if (ParamType == PtrKernelParam || ParamType == PtrPtrKernelParam || + ParamType == InvalidAddrSpacePtrKernelParam) { + S.Diag(Param->getLocation(), + diag::err_record_with_pointers_kernel_param) + << PT->isUnionType() + << PT; + } else { + S.Diag(Param->getLocation(), diag::err_bad_kernel_param_type) << PT; + } + + S.Diag(OrigRecDecl->getLocation(), diag::note_within_field_of_type) + << OrigRecDecl->getDeclName(); + + // We have an error, now let's go back up through history and show where + // the offending field came from + for (ArrayRef::const_iterator + I = HistoryStack.begin() + 1, + E = HistoryStack.end(); + I != E; ++I) { + const FieldDecl *OuterField = *I; + S.Diag(OuterField->getLocation(), diag::note_within_field_of_type) + << OuterField->getType(); + } + + S.Diag(FD->getLocation(), diag::note_illegal_field_declared_here) + << QT->isPointerType() + << QT; + D.setInvalidType(); + return; + } + } while (!VisitStack.empty()); + } + + /// Find the DeclContext in which a tag is implicitly declared if we see an + /// elaborated type specifier in the specified context, and lookup finds + /// nothing. + static DeclContext *getTagInjectionContext(DeclContext *DC) { + while (!DC->isFileContext() && !DC->isFunctionOrMethod()) + DC = DC->getParent(); + return DC; + } + + /// Find the Scope in which a tag is implicitly declared if we see an + /// elaborated type specifier in the specified context, and lookup finds + /// nothing. + static Scope *getTagInjectionScope(Scope *S, const LangOptions &LangOpts) { + while (S->isClassScope() || + (LangOpts.CPlusPlus && + S->isFunctionPrototypeScope()) || + ((S->getFlags() & Scope::DeclScope) == 0) || + (S->getEntity() && S->getEntity()->isTransparentContext())) + S = S->getParent(); + return S; + } + + NamedDecl* + Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC, + TypeSourceInfo *TInfo, LookupResult &Previous, + MultiTemplateParamsArg TemplateParamLists, + bool &AddToScope) { + QualType R = TInfo->getType(); + + assert(R->isFunctionType()); + + // TODO: consider using NameInfo for diagnostic. + DeclarationNameInfo NameInfo = GetNameForDeclarator(D); + DeclarationName Name = NameInfo.getName(); + StorageClass SC = getFunctionStorageClass(*this, D); + + if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec()) + Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(), + diag::err_invalid_thread) + << DeclSpec::getSpecifierName(TSCS); + + if (D.isFirstDeclarationOfMember()) + adjustMemberFunctionCC(R, D.isStaticMember(), D.isCtorOrDtor(), + D.getIdentifierLoc()); + + bool isFriend = false; + FunctionTemplateDecl *FunctionTemplate = nullptr; + bool isMemberSpecialization = false; + bool isFunctionTemplateSpecialization = false; + + bool isDependentClassScopeExplicitSpecialization = false; + bool HasExplicitTemplateArgs = false; + TemplateArgumentListInfo TemplateArgs; + + bool isVirtualOkay = false; + + DeclContext *OriginalDC = DC; + bool IsLocalExternDecl = adjustContextForLocalExternDecl(DC); + + FunctionDecl *NewFD = CreateNewFunctionDecl(*this, D, DC, R, TInfo, SC, + isVirtualOkay); + if (!NewFD) return nullptr; + + if (OriginalLexicalContext && OriginalLexicalContext->isObjCContainer()) + NewFD->setTopLevelDeclInObjCContainer(); + + // Set the lexical context. If this is a function-scope declaration, or has a + // C++ scope specifier, or is the object of a friend declaration, the lexical + // context will be different from the semantic context. + NewFD->setLexicalDeclContext(CurContext); + + if (IsLocalExternDecl) + NewFD->setLocalExternDecl(); + + if (getLangOpts().CPlusPlus) { + bool isInline = D.getDeclSpec().isInlineSpecified(); + bool isVirtual = D.getDeclSpec().isVirtualSpecified(); + bool isExplicit = D.getDeclSpec().isExplicitSpecified(); + bool isConstexpr = D.getDeclSpec().isConstexprSpecified(); + isFriend = D.getDeclSpec().isFriendSpecified(); + if (isFriend && !isInline && D.isFunctionDefinition()) { + // C++ [class.friend]p5 + // A function can be defined in a friend declaration of a + // class . . . . Such a function is implicitly inline. + NewFD->setImplicitlyInline(); + } + + // If this is a method defined in an __interface, and is not a constructor + // or an overloaded operator, then set the pure flag (isVirtual will already + // return true). + if (const CXXRecordDecl *Parent = + dyn_cast(NewFD->getDeclContext())) { + if (Parent->isInterface() && cast(NewFD)->isUserProvided()) + NewFD->setPure(true); + + // C++ [class.union]p2 + // A union can have member functions, but not virtual functions. + if (isVirtual && Parent->isUnion()) + Diag(D.getDeclSpec().getVirtualSpecLoc(), diag::err_virtual_in_union); + } + + SetNestedNameSpecifier(*this, NewFD, D); + isMemberSpecialization = false; + isFunctionTemplateSpecialization = false; + if (D.isInvalidType()) + NewFD->setInvalidDecl(); + + // Match up the template parameter lists with the scope specifier, then + // determine whether we have a template or a template specialization. + bool Invalid = false; + if (TemplateParameterList *TemplateParams = + MatchTemplateParametersToScopeSpecifier( + D.getDeclSpec().getBeginLoc(), D.getIdentifierLoc(), + D.getCXXScopeSpec(), + D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId + ? D.getName().TemplateId + : nullptr, + TemplateParamLists, isFriend, isMemberSpecialization, + Invalid)) { + if (TemplateParams->size() > 0) { + // This is a function template + + // Check that we can declare a template here. + if (CheckTemplateDeclScope(S, TemplateParams)) + NewFD->setInvalidDecl(); + + // A destructor cannot be a template. + if (Name.getNameKind() == DeclarationName::CXXDestructorName) { + Diag(NewFD->getLocation(), diag::err_destructor_template); + NewFD->setInvalidDecl(); + } + + // If we're adding a template to a dependent context, we may need to + // rebuilding some of the types used within the template parameter list, + // now that we know what the current instantiation is. + if (DC->isDependentContext()) { + ContextRAII SavedContext(*this, DC); + if (RebuildTemplateParamsInCurrentInstantiation(TemplateParams)) + Invalid = true; + } + + FunctionTemplate = FunctionTemplateDecl::Create(Context, DC, + NewFD->getLocation(), + Name, TemplateParams, + NewFD); + FunctionTemplate->setLexicalDeclContext(CurContext); + NewFD->setDescribedFunctionTemplate(FunctionTemplate); + + // For source fidelity, store the other template param lists. + if (TemplateParamLists.size() > 1) { + NewFD->setTemplateParameterListsInfo(Context, + TemplateParamLists.drop_back(1)); + } + } else { + // This is a function template specialization. + isFunctionTemplateSpecialization = true; + // For source fidelity, store all the template param lists. + if (TemplateParamLists.size() > 0) + NewFD->setTemplateParameterListsInfo(Context, TemplateParamLists); + + // C++0x [temp.expl.spec]p20 forbids "template<> friend void foo(int);". + if (isFriend) { + // We want to remove the "template<>", found here. + SourceRange RemoveRange = TemplateParams->getSourceRange(); + + // If we remove the template<> and the name is not a + // template-id, we're actually silently creating a problem: + // the friend declaration will refer to an untemplated decl, + // and clearly the user wants a template specialization. So + // we need to insert '<>' after the name. + SourceLocation InsertLoc; + if (D.getName().getKind() != UnqualifiedIdKind::IK_TemplateId) { + InsertLoc = D.getName().getSourceRange().getEnd(); + InsertLoc = getLocForEndOfToken(InsertLoc); + } + + Diag(D.getIdentifierLoc(), diag::err_template_spec_decl_friend) + << Name << RemoveRange + << FixItHint::CreateRemoval(RemoveRange) + << FixItHint::CreateInsertion(InsertLoc, "<>"); + } + } + } else { + // All template param lists were matched against the scope specifier: + // this is NOT (an explicit specialization of) a template. + if (TemplateParamLists.size() > 0) + // For source fidelity, store all the template param lists. + NewFD->setTemplateParameterListsInfo(Context, TemplateParamLists); + } + + if (Invalid) { + NewFD->setInvalidDecl(); + if (FunctionTemplate) + FunctionTemplate->setInvalidDecl(); + } + + // C++ [dcl.fct.spec]p5: + // The virtual specifier shall only be used in declarations of + // nonstatic class member functions that appear within a + // member-specification of a class declaration; see 10.3. + // + if (isVirtual && !NewFD->isInvalidDecl()) { + if (!isVirtualOkay) { + Diag(D.getDeclSpec().getVirtualSpecLoc(), + diag::err_virtual_non_function); + } else if (!CurContext->isRecord()) { + // 'virtual' was specified outside of the class. + Diag(D.getDeclSpec().getVirtualSpecLoc(), + diag::err_virtual_out_of_class) + << FixItHint::CreateRemoval(D.getDeclSpec().getVirtualSpecLoc()); + } else if (NewFD->getDescribedFunctionTemplate()) { + // C++ [temp.mem]p3: + // A member function template shall not be virtual. + Diag(D.getDeclSpec().getVirtualSpecLoc(), + diag::err_virtual_member_function_template) + << FixItHint::CreateRemoval(D.getDeclSpec().getVirtualSpecLoc()); + } else { + // Okay: Add virtual to the method. + NewFD->setVirtualAsWritten(true); + } + + if (getLangOpts().CPlusPlus14 && + NewFD->getReturnType()->isUndeducedType()) + Diag(D.getDeclSpec().getVirtualSpecLoc(), diag::err_auto_fn_virtual); + } + + if (getLangOpts().CPlusPlus14 && + (NewFD->isDependentContext() || + (isFriend && CurContext->isDependentContext())) && + NewFD->getReturnType()->isUndeducedType()) { + // If the function template is referenced directly (for instance, as a + // member of the current instantiation), pretend it has a dependent type. + // This is not really justified by the standard, but is the only sane + // thing to do. + // FIXME: For a friend function, we have not marked the function as being + // a friend yet, so 'isDependentContext' on the FD doesn't work. + const FunctionProtoType *FPT = + NewFD->getType()->castAs(); + QualType Result = + SubstAutoType(FPT->getReturnType(), Context.DependentTy); + NewFD->setType(Context.getFunctionType(Result, FPT->getParamTypes(), + FPT->getExtProtoInfo())); + } + + // C++ [dcl.fct.spec]p3: + // The inline specifier shall not appear on a block scope function + // declaration. + if (isInline && !NewFD->isInvalidDecl()) { + if (CurContext->isFunctionOrMethod()) { + // 'inline' is not allowed on block scope function declaration. + Diag(D.getDeclSpec().getInlineSpecLoc(), + diag::err_inline_declaration_block_scope) << Name + << FixItHint::CreateRemoval(D.getDeclSpec().getInlineSpecLoc()); + } + } + + // C++ [dcl.fct.spec]p6: + // The explicit specifier shall be used only in the declaration of a + // constructor or conversion function within its class definition; + // see 12.3.1 and 12.3.2. + if (isExplicit && !NewFD->isInvalidDecl() && + !isa(NewFD)) { + if (!CurContext->isRecord()) { + // 'explicit' was specified outside of the class. + Diag(D.getDeclSpec().getExplicitSpecLoc(), + diag::err_explicit_out_of_class) + << FixItHint::CreateRemoval(D.getDeclSpec().getExplicitSpecLoc()); + } else if (!isa(NewFD) && + !isa(NewFD)) { + // 'explicit' was specified on a function that wasn't a constructor + // or conversion function. + Diag(D.getDeclSpec().getExplicitSpecLoc(), + diag::err_explicit_non_ctor_or_conv_function) + << FixItHint::CreateRemoval(D.getDeclSpec().getExplicitSpecLoc()); + } + } + + if (isConstexpr) { + // C++11 [dcl.constexpr]p2: constexpr functions and constexpr constructors + // are implicitly inline. + NewFD->setImplicitlyInline(); + + // C++11 [dcl.constexpr]p3: functions declared constexpr are required to + // be either constructors or to return a literal type. Therefore, + // destructors cannot be declared constexpr. + if (isa(NewFD)) + Diag(D.getDeclSpec().getConstexprSpecLoc(), diag::err_constexpr_dtor); + } + + // If __module_private__ was specified, mark the function accordingly. + if (D.getDeclSpec().isModulePrivateSpecified()) { + if (isFunctionTemplateSpecialization) { + SourceLocation ModulePrivateLoc + = D.getDeclSpec().getModulePrivateSpecLoc(); + Diag(ModulePrivateLoc, diag::err_module_private_specialization) + << 0 + << FixItHint::CreateRemoval(ModulePrivateLoc); + } else { + NewFD->setModulePrivate(); + if (FunctionTemplate) + FunctionTemplate->setModulePrivate(); + } + } + + if (isFriend) { + if (FunctionTemplate) { + FunctionTemplate->setObjectOfFriendDecl(); + FunctionTemplate->setAccess(AS_public); + } + NewFD->setObjectOfFriendDecl(); + NewFD->setAccess(AS_public); + } + + // If a function is defined as defaulted or deleted, mark it as such now. + // FIXME: Does this ever happen? ActOnStartOfFunctionDef forces the function + // definition kind to FDK_Definition. + switch (D.getFunctionDefinitionKind()) { + case FDK_Declaration: + case FDK_Definition: + break; + + case FDK_Defaulted: + NewFD->setDefaulted(); + break; + + case FDK_Deleted: + NewFD->setDeletedAsWritten(); + break; + } + + if (isa(NewFD) && DC == CurContext && + D.isFunctionDefinition()) { + // C++ [class.mfct]p2: + // A member function may be defined (8.4) in its class definition, in + // which case it is an inline member function (7.1.2) + NewFD->setImplicitlyInline(); + } + + if (SC == SC_Static && isa(NewFD) && + !CurContext->isRecord()) { + // C++ [class.static]p1: + // A data or function member of a class may be declared static + // in a class definition, in which case it is a static member of + // the class. + + // Complain about the 'static' specifier if it's on an out-of-line + // member function definition. + + // MSVC permits the use of a 'static' storage specifier on an out-of-line + // member function template declaration, warn about this. + Diag(D.getDeclSpec().getStorageClassSpecLoc(), + NewFD->getDescribedFunctionTemplate() && getLangOpts().MSVCCompat + ? diag::ext_static_out_of_line : diag::err_static_out_of_line) + << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc()); + } + + // C++11 [except.spec]p15: + // A deallocation function with no exception-specification is treated + // as if it were specified with noexcept(true). + const FunctionProtoType *FPT = R->getAs(); + if ((Name.getCXXOverloadedOperator() == OO_Delete || + Name.getCXXOverloadedOperator() == OO_Array_Delete) && + getLangOpts().CPlusPlus11 && FPT && !FPT->hasExceptionSpec()) + NewFD->setType(Context.getFunctionType( + FPT->getReturnType(), FPT->getParamTypes(), + FPT->getExtProtoInfo().withExceptionSpec(EST_BasicNoexcept))); + } + + // Filter out previous declarations that don't match the scope. + FilterLookupForScope(Previous, OriginalDC, S, shouldConsiderLinkage(NewFD), + D.getCXXScopeSpec().isNotEmpty() || + isMemberSpecialization || + isFunctionTemplateSpecialization); + + // Handle GNU asm-label extension (encoded as an attribute). + if (Expr *E = (Expr*) D.getAsmLabel()) { + // The parser guarantees this is a string. + StringLiteral *SE = cast(E); + NewFD->addAttr(::new (Context) AsmLabelAttr(SE->getStrTokenLoc(0), Context, + SE->getString(), 0)); + } else if (!ExtnameUndeclaredIdentifiers.empty()) { + llvm::DenseMap::iterator I = + ExtnameUndeclaredIdentifiers.find(NewFD->getIdentifier()); + if (I != ExtnameUndeclaredIdentifiers.end()) { + if (isDeclExternC(NewFD)) { + NewFD->addAttr(I->second); + ExtnameUndeclaredIdentifiers.erase(I); + } else + Diag(NewFD->getLocation(), diag::warn_redefine_extname_not_applied) + << /*Variable*/0 << NewFD; + } + } + + // Copy the parameter declarations from the declarator D to the function + // declaration NewFD, if they are available. First scavenge them into Params. + SmallVector Params; + unsigned FTIIdx; + if (D.isFunctionDeclarator(FTIIdx)) { + DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(FTIIdx).Fun; + + // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs + // function that takes no arguments, not a function that takes a + // single void argument. + // We let through "const void" here because Sema::GetTypeForDeclarator + // already checks for that case. + if (FTIHasNonVoidParameters(FTI) && FTI.Params[0].Param) { + for (unsigned i = 0, e = FTI.NumParams; i != e; ++i) { + ParmVarDecl *Param = cast(FTI.Params[i].Param); + assert(Param->getDeclContext() != NewFD && "Was set before ?"); + Param->setDeclContext(NewFD); + Params.push_back(Param); + + if (Param->isInvalidDecl()) + NewFD->setInvalidDecl(); + } + } + + if (!getLangOpts().CPlusPlus) { + // In C, find all the tag declarations from the prototype and move them + // into the function DeclContext. Remove them from the surrounding tag + // injection context of the function, which is typically but not always + // the TU. + DeclContext *PrototypeTagContext = + getTagInjectionContext(NewFD->getLexicalDeclContext()); + for (NamedDecl *NonParmDecl : FTI.getDeclsInPrototype()) { + auto *TD = dyn_cast(NonParmDecl); + + // We don't want to reparent enumerators. Look at their parent enum + // instead. + if (!TD) { + if (auto *ECD = dyn_cast(NonParmDecl)) + TD = cast(ECD->getDeclContext()); + } + if (!TD) + continue; + DeclContext *TagDC = TD->getLexicalDeclContext(); + if (!TagDC->containsDecl(TD)) + continue; + TagDC->removeDecl(TD); + TD->setDeclContext(NewFD); + NewFD->addDecl(TD); + + // Preserve the lexical DeclContext if it is not the surrounding tag + // injection context of the FD. In this example, the semantic context of + // E will be f and the lexical context will be S, while both the + // semantic and lexical contexts of S will be f: + // void f(struct S { enum E { a } f; } s); + if (TagDC != PrototypeTagContext) + TD->setLexicalDeclContext(TagDC); + } + } + } else if (const FunctionProtoType *FT = R->getAs()) { + // When we're declaring a function with a typedef, typeof, etc as in the + // following example, we'll need to synthesize (unnamed) + // parameters for use in the declaration. + // + // @code + // typedef void fn(int); + // fn f; + // @endcode + + // Synthesize a parameter for each argument type. + for (const auto &AI : FT->param_types()) { + ParmVarDecl *Param = + BuildParmVarDeclForTypedef(NewFD, D.getIdentifierLoc(), AI); + Param->setScopeInfo(0, Params.size()); + Params.push_back(Param); + } + } else { + assert(R->isFunctionNoProtoType() && NewFD->getNumParams() == 0 && + "Should not need args for typedef of non-prototype fn"); + } + + // Finally, we know we have the right number of parameters, install them. + NewFD->setParams(Params); + + if (D.getDeclSpec().isNoreturnSpecified()) + NewFD->addAttr( + ::new(Context) C11NoReturnAttr(D.getDeclSpec().getNoreturnSpecLoc(), + Context, 0)); + + // Functions returning a variably modified type violate C99 6.7.5.2p2 + // because all functions have linkage. + if (!NewFD->isInvalidDecl() && + NewFD->getReturnType()->isVariablyModifiedType()) { + Diag(NewFD->getLocation(), diag::err_vm_func_decl); + NewFD->setInvalidDecl(); + } + + // Apply an implicit SectionAttr if '#pragma clang section text' is active + if (PragmaClangTextSection.Valid && D.isFunctionDefinition() && + !NewFD->hasAttr()) { + NewFD->addAttr(PragmaClangTextSectionAttr::CreateImplicit(Context, + PragmaClangTextSection.SectionName, + PragmaClangTextSection.PragmaLocation)); + } + + // Apply an implicit SectionAttr if #pragma code_seg is active. + if (CodeSegStack.CurrentValue && D.isFunctionDefinition() && + !NewFD->hasAttr()) { + NewFD->addAttr( + SectionAttr::CreateImplicit(Context, SectionAttr::Declspec_allocate, + CodeSegStack.CurrentValue->getString(), + CodeSegStack.CurrentPragmaLocation)); + if (UnifySection(CodeSegStack.CurrentValue->getString(), + ASTContext::PSF_Implicit | ASTContext::PSF_Execute | + ASTContext::PSF_Read, + NewFD)) + NewFD->dropAttr(); + } + + // Apply an implicit CodeSegAttr from class declspec or + // apply an implicit SectionAttr from #pragma code_seg if active. + if (!NewFD->hasAttr()) { + if (Attr *SAttr = getImplicitCodeSegOrSectionAttrForFunction(NewFD, + D.isFunctionDefinition())) { + NewFD->addAttr(SAttr); + } + } + + // Handle attributes. + ProcessDeclAttributes(S, NewFD, D); + + if (getLangOpts().OpenCL) { + // OpenCL v1.1 s6.5: Using an address space qualifier in a function return + // type declaration will generate a compilation error. + LangAS AddressSpace = NewFD->getReturnType().getAddressSpace(); + if (AddressSpace != LangAS::Default) { + Diag(NewFD->getLocation(), + diag::err_opencl_return_value_with_address_space); + NewFD->setInvalidDecl(); + } + } + + if (!getLangOpts().CPlusPlus) { + // Perform semantic checking on the function declaration. + if (!NewFD->isInvalidDecl() && NewFD->isMain()) + CheckMain(NewFD, D.getDeclSpec()); + + if (!NewFD->isInvalidDecl() && NewFD->isMSVCRTEntryPoint()) + CheckMSVCRTEntryPoint(NewFD); + + if (!NewFD->isInvalidDecl()) + D.setRedeclaration(CheckFunctionDeclaration(S, NewFD, Previous, + isMemberSpecialization)); + else if (!Previous.empty()) + // Recover gracefully from an invalid redeclaration. + D.setRedeclaration(true); + assert((NewFD->isInvalidDecl() || !D.isRedeclaration() || + Previous.getResultKind() != LookupResult::FoundOverloaded) && + "previous declaration set still overloaded"); + + // Diagnose no-prototype function declarations with calling conventions that + // don't support variadic calls. Only do this in C and do it after merging + // possibly prototyped redeclarations. + const FunctionType *FT = NewFD->getType()->castAs(); + if (isa(FT) && !D.isFunctionDefinition()) { + CallingConv CC = FT->getExtInfo().getCC(); + if (!supportsVariadicCall(CC)) { + // Windows system headers sometimes accidentally use stdcall without + // (void) parameters, so we relax this to a warning. + int DiagID = + CC == CC_X86StdCall ? diag::warn_cconv_knr : diag::err_cconv_knr; + Diag(NewFD->getLocation(), DiagID) + << FunctionType::getNameForCallConv(CC); + } + } + } else { + // C++11 [replacement.functions]p3: + // The program's definitions shall not be specified as inline. + // + // N.B. We diagnose declarations instead of definitions per LWG issue 2340. + // + // Suppress the diagnostic if the function is __attribute__((used)), since + // that forces an external definition to be emitted. + if (D.getDeclSpec().isInlineSpecified() && + NewFD->isReplaceableGlobalAllocationFunction() && + !NewFD->hasAttr()) + Diag(D.getDeclSpec().getInlineSpecLoc(), + diag::ext_operator_new_delete_declared_inline) + << NewFD->getDeclName(); + + // If the declarator is a template-id, translate the parser's template + // argument list into our AST format. + if (D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId) { + TemplateIdAnnotation *TemplateId = D.getName().TemplateId; + TemplateArgs.setLAngleLoc(TemplateId->LAngleLoc); + TemplateArgs.setRAngleLoc(TemplateId->RAngleLoc); + ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(), + TemplateId->NumArgs); + translateTemplateArguments(TemplateArgsPtr, + TemplateArgs); + + HasExplicitTemplateArgs = true; + + if (NewFD->isInvalidDecl()) { + HasExplicitTemplateArgs = false; + } else if (FunctionTemplate) { + // Function template with explicit template arguments. + Diag(D.getIdentifierLoc(), diag::err_function_template_partial_spec) + << SourceRange(TemplateId->LAngleLoc, TemplateId->RAngleLoc); + + HasExplicitTemplateArgs = false; + } else { + assert((isFunctionTemplateSpecialization || + D.getDeclSpec().isFriendSpecified()) && + "should have a 'template<>' for this decl"); + // "friend void foo<>(int);" is an implicit specialization decl. + isFunctionTemplateSpecialization = true; + } + } else if (isFriend && isFunctionTemplateSpecialization) { + // This combination is only possible in a recovery case; the user + // wrote something like: + // template <> friend void foo(int); + // which we're recovering from as if the user had written: + // friend void foo<>(int); + // Go ahead and fake up a template id. + HasExplicitTemplateArgs = true; + TemplateArgs.setLAngleLoc(D.getIdentifierLoc()); + TemplateArgs.setRAngleLoc(D.getIdentifierLoc()); + } + + // We do not add HD attributes to specializations here because + // they may have different constexpr-ness compared to their + // templates and, after maybeAddCUDAHostDeviceAttrs() is applied, + // may end up with different effective targets. Instead, a + // specialization inherits its target attributes from its template + // in the CheckFunctionTemplateSpecialization() call below. + if (getLangOpts().CUDA & !isFunctionTemplateSpecialization) + maybeAddCUDAHostDeviceAttrs(NewFD, Previous); + + // If it's a friend (and only if it's a friend), it's possible + // that either the specialized function type or the specialized + // template is dependent, and therefore matching will fail. In + // this case, don't check the specialization yet. + bool InstantiationDependent = false; + if (isFunctionTemplateSpecialization && isFriend && + (NewFD->getType()->isDependentType() || DC->isDependentContext() || + TemplateSpecializationType::anyDependentTemplateArguments( + TemplateArgs, + InstantiationDependent))) { + assert(HasExplicitTemplateArgs && + "friend function specialization without template args"); + if (CheckDependentFunctionTemplateSpecialization(NewFD, TemplateArgs, + Previous)) + NewFD->setInvalidDecl(); + } else if (isFunctionTemplateSpecialization) { + if (CurContext->isDependentContext() && CurContext->isRecord() + && !isFriend) { + isDependentClassScopeExplicitSpecialization = true; + } else if (!NewFD->isInvalidDecl() && + CheckFunctionTemplateSpecialization( + NewFD, (HasExplicitTemplateArgs ? &TemplateArgs : nullptr), + Previous)) + NewFD->setInvalidDecl(); + + // C++ [dcl.stc]p1: + // A storage-class-specifier shall not be specified in an explicit + // specialization (14.7.3) + FunctionTemplateSpecializationInfo *Info = + NewFD->getTemplateSpecializationInfo(); + if (Info && SC != SC_None) { + if (SC != Info->getTemplate()->getTemplatedDecl()->getStorageClass()) + Diag(NewFD->getLocation(), + diag::err_explicit_specialization_inconsistent_storage_class) + << SC + << FixItHint::CreateRemoval( + D.getDeclSpec().getStorageClassSpecLoc()); + + else + Diag(NewFD->getLocation(), + diag::ext_explicit_specialization_storage_class) + << FixItHint::CreateRemoval( + D.getDeclSpec().getStorageClassSpecLoc()); + } + } else if (isMemberSpecialization && isa(NewFD)) { + if (CheckMemberSpecialization(NewFD, Previous)) + NewFD->setInvalidDecl(); + } + + // Perform semantic checking on the function declaration. + if (!isDependentClassScopeExplicitSpecialization) { + if (!NewFD->isInvalidDecl() && NewFD->isMain()) + CheckMain(NewFD, D.getDeclSpec()); + + if (!NewFD->isInvalidDecl() && NewFD->isMSVCRTEntryPoint()) + CheckMSVCRTEntryPoint(NewFD); + + if (!NewFD->isInvalidDecl()) + D.setRedeclaration(CheckFunctionDeclaration(S, NewFD, Previous, + isMemberSpecialization)); + else if (!Previous.empty()) + // Recover gracefully from an invalid redeclaration. + D.setRedeclaration(true); + } + + assert((NewFD->isInvalidDecl() || !D.isRedeclaration() || + Previous.getResultKind() != LookupResult::FoundOverloaded) && + "previous declaration set still overloaded"); + + NamedDecl *PrincipalDecl = (FunctionTemplate + ? cast(FunctionTemplate) + : NewFD); + + if (isFriend && NewFD->getPreviousDecl()) { + AccessSpecifier Access = AS_public; + if (!NewFD->isInvalidDecl()) + Access = NewFD->getPreviousDecl()->getAccess(); + + NewFD->setAccess(Access); + if (FunctionTemplate) FunctionTemplate->setAccess(Access); + } + + if (NewFD->isOverloadedOperator() && !DC->isRecord() && + PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary)) + PrincipalDecl->setNonMemberOperator(); + + // If we have a function template, check the template parameter + // list. This will check and merge default template arguments. + if (FunctionTemplate) { + FunctionTemplateDecl *PrevTemplate = + FunctionTemplate->getPreviousDecl(); + CheckTemplateParameterList(FunctionTemplate->getTemplateParameters(), + PrevTemplate ? PrevTemplate->getTemplateParameters() + : nullptr, + D.getDeclSpec().isFriendSpecified() + ? (D.isFunctionDefinition() + ? TPC_FriendFunctionTemplateDefinition + : TPC_FriendFunctionTemplate) + : (D.getCXXScopeSpec().isSet() && + DC && DC->isRecord() && + DC->isDependentContext()) + ? TPC_ClassTemplateMember + : TPC_FunctionTemplate); + } + + if (NewFD->isInvalidDecl()) { + // Ignore all the rest of this. + } else if (!D.isRedeclaration()) { + struct ActOnFDArgs ExtraArgs = { S, D, TemplateParamLists, + AddToScope }; + // Fake up an access specifier if it's supposed to be a class member. + if (isa(NewFD->getDeclContext())) + NewFD->setAccess(AS_public); + + // Qualified decls generally require a previous declaration. + if (D.getCXXScopeSpec().isSet()) { + // ...with the major exception of templated-scope or + // dependent-scope friend declarations. + + // TODO: we currently also suppress this check in dependent + // contexts because (1) the parameter depth will be off when + // matching friend templates and (2) we might actually be + // selecting a friend based on a dependent factor. But there + // are situations where these conditions don't apply and we + // can actually do this check immediately. + // + // Unless the scope is dependent, it's always an error if qualified + // redeclaration lookup found nothing at all. Diagnose that now; + // nothing will diagnose that error later. + if (isFriend && + (D.getCXXScopeSpec().getScopeRep()->isDependent() || + (!Previous.empty() && (TemplateParamLists.size() || + CurContext->isDependentContext())))) { + // ignore these + } else { + // The user tried to provide an out-of-line definition for a + // function that is a member of a class or namespace, but there + // was no such member function declared (C++ [class.mfct]p2, + // C++ [namespace.memdef]p2). For example: + // + // class X { + // void f() const; + // }; + // + // void X::f() { } // ill-formed + // + // Complain about this problem, and attempt to suggest close + // matches (e.g., those that differ only in cv-qualifiers and + // whether the parameter types are references). + + if (NamedDecl *Result = DiagnoseInvalidRedeclaration( + *this, Previous, NewFD, ExtraArgs, false, nullptr)) { + AddToScope = ExtraArgs.AddToScope; + return Result; + } + } + + // Unqualified local friend declarations are required to resolve + // to something. + } else if (isFriend && cast(CurContext)->isLocalClass()) { + if (NamedDecl *Result = DiagnoseInvalidRedeclaration( + *this, Previous, NewFD, ExtraArgs, true, S)) { + AddToScope = ExtraArgs.AddToScope; + return Result; + } + } + } else if (!D.isFunctionDefinition() && + isa(NewFD) && NewFD->isOutOfLine() && + !isFriend && !isFunctionTemplateSpecialization && + !isMemberSpecialization) { + // An out-of-line member function declaration must also be a + // definition (C++ [class.mfct]p2). + // Note that this is not the case for explicit specializations of + // function templates or member functions of class templates, per + // C++ [temp.expl.spec]p2. We also allow these declarations as an + // extension for compatibility with old SWIG code which likes to + // generate them. + Diag(NewFD->getLocation(), diag::ext_out_of_line_declaration) + << D.getCXXScopeSpec().getRange(); + } + } + + ProcessPragmaWeak(S, NewFD); + checkAttributesAfterMerging(*this, *NewFD); + + AddKnownFunctionAttributes(NewFD); + + if (NewFD->hasAttr() && + !NewFD->getType()->getAs()) { + Diag(NewFD->getLocation(), + diag::err_attribute_overloadable_no_prototype) + << NewFD; + + // Turn this into a variadic function with no parameters. + const FunctionType *FT = NewFD->getType()->getAs(); + FunctionProtoType::ExtProtoInfo EPI( + Context.getDefaultCallingConvention(true, false)); + EPI.Variadic = true; + EPI.ExtInfo = FT->getExtInfo(); + + QualType R = Context.getFunctionType(FT->getReturnType(), None, EPI); + NewFD->setType(R); + } + + // If there's a #pragma GCC visibility in scope, and this isn't a class + // member, set the visibility of this function. + if (!DC->isRecord() && NewFD->isExternallyVisible()) + AddPushedVisibilityAttribute(NewFD); + + // If there's a #pragma clang arc_cf_code_audited in scope, consider + // marking the function. + AddCFAuditedAttribute(NewFD); + + // If this is a function definition, check if we have to apply optnone due to + // a pragma. + if(D.isFunctionDefinition()) + AddRangeBasedOptnone(NewFD); + + // If this is the first declaration of an extern C variable, update + // the map of such variables. + if (NewFD->isFirstDecl() && !NewFD->isInvalidDecl() && + isIncompleteDeclExternC(*this, NewFD)) + RegisterLocallyScopedExternCDecl(NewFD, S); + + // Set this FunctionDecl's range up to the right paren. + NewFD->setRangeEnd(D.getSourceRange().getEnd()); + + if (D.isRedeclaration() && !Previous.empty()) { + NamedDecl *Prev = Previous.getRepresentativeDecl(); + checkDLLAttributeRedeclaration(*this, Prev, NewFD, + isMemberSpecialization || + isFunctionTemplateSpecialization, + D.isFunctionDefinition()); + } + + if (getLangOpts().CUDA) { + IdentifierInfo *II = NewFD->getIdentifier(); + if (II && II->isStr(getCudaConfigureFuncName()) && + !NewFD->isInvalidDecl() && + NewFD->getDeclContext()->getRedeclContext()->isTranslationUnit()) { + if (!R->getAs()->getReturnType()->isScalarType()) + Diag(NewFD->getLocation(), diag::err_config_scalar_return) + << getCudaConfigureFuncName(); + Context.setcudaConfigureCallDecl(NewFD); + } + + // Variadic functions, other than a *declaration* of printf, are not allowed + // in device-side CUDA code, unless someone passed + // -fcuda-allow-variadic-functions. + if (!getLangOpts().CUDAAllowVariadicFunctions && NewFD->isVariadic() && + (NewFD->hasAttr() || + NewFD->hasAttr()) && + !(II && II->isStr("printf") && NewFD->isExternC() && + !D.isFunctionDefinition())) { + Diag(NewFD->getLocation(), diag::err_variadic_device_fn); + } + } + + MarkUnusedFileScopedDecl(NewFD); + + if (getLangOpts().CPlusPlus) { + if (FunctionTemplate) { + if (NewFD->isInvalidDecl()) + FunctionTemplate->setInvalidDecl(); + return FunctionTemplate; + } + + if (isMemberSpecialization && !NewFD->isInvalidDecl()) + CompleteMemberSpecialization(NewFD, Previous); + } + + if (NewFD->hasAttr()) { + // OpenCL v1.2 s6.8 static is invalid for kernel functions. + if ((getLangOpts().OpenCLVersion >= 120) + && (SC == SC_Static)) { + Diag(D.getIdentifierLoc(), diag::err_static_kernel); + D.setInvalidType(); + } + + // OpenCL v1.2, s6.9 -- Kernels can only have return type void. + if (!NewFD->getReturnType()->isVoidType()) { + SourceRange RTRange = NewFD->getReturnTypeSourceRange(); + Diag(D.getIdentifierLoc(), diag::err_expected_kernel_void_return_type) + << (RTRange.isValid() ? FixItHint::CreateReplacement(RTRange, "void") + : FixItHint()); + D.setInvalidType(); + } + + llvm::SmallPtrSet ValidTypes; + for (auto Param : NewFD->parameters()) + checkIsValidOpenCLKernelParameter(*this, D, Param, ValidTypes); + } + for (const ParmVarDecl *Param : NewFD->parameters()) { + QualType PT = Param->getType(); + + // OpenCL 2.0 pipe restrictions forbids pipe packet types to be non-value + // types. + if (getLangOpts().OpenCLVersion >= 200) { + if(const PipeType *PipeTy = PT->getAs()) { + QualType ElemTy = PipeTy->getElementType(); + if (ElemTy->isReferenceType() || ElemTy->isPointerType()) { + Diag(Param->getTypeSpecStartLoc(), diag::err_reference_pipe_type ); + D.setInvalidType(); + } + } + } + } + + // Here we have an function template explicit specialization at class scope. + // The actual specialization will be postponed to template instatiation + // time via the ClassScopeFunctionSpecializationDecl node. + if (isDependentClassScopeExplicitSpecialization) { + ClassScopeFunctionSpecializationDecl *NewSpec = + ClassScopeFunctionSpecializationDecl::Create( + Context, CurContext, NewFD->getLocation(), + cast(NewFD), + HasExplicitTemplateArgs, TemplateArgs); + CurContext->addDecl(NewSpec); + AddToScope = false; + } + + // Diagnose availability attributes. Availability cannot be used on functions + // that are run during load/unload. + if (const auto *attr = NewFD->getAttr()) { + if (NewFD->hasAttr()) { + Diag(attr->getLocation(), diag::warn_availability_on_static_initializer) + << 1; + NewFD->dropAttr(); + } + if (NewFD->hasAttr()) { + Diag(attr->getLocation(), diag::warn_availability_on_static_initializer) + << 2; + NewFD->dropAttr(); + } + } + + return NewFD; + } + + /// Return a CodeSegAttr from a containing class. The Microsoft docs say + /// when __declspec(code_seg) "is applied to a class, all member functions of + /// the class and nested classes -- this includes compiler-generated special + /// member functions -- are put in the specified segment." + /// The actual behavior is a little more complicated. The Microsoft compiler + /// won't check outer classes if there is an active value from #pragma code_seg. + /// The CodeSeg is always applied from the direct parent but only from outer + /// classes when the #pragma code_seg stack is empty. See: + /// https://reviews.llvm.org/D22931, the Microsoft feedback page is no longer + /// available since MS has removed the page. + static Attr *getImplicitCodeSegAttrFromClass(Sema &S, const FunctionDecl *FD) { + const auto *Method = dyn_cast(FD); + if (!Method) + return nullptr; + const CXXRecordDecl *Parent = Method->getParent(); + if (const auto *SAttr = Parent->getAttr()) { + Attr *NewAttr = SAttr->clone(S.getASTContext()); + NewAttr->setImplicit(true); + return NewAttr; + } + + // The Microsoft compiler won't check outer classes for the CodeSeg + // when the #pragma code_seg stack is active. + if (S.CodeSegStack.CurrentValue) + return nullptr; + + while ((Parent = dyn_cast(Parent->getParent()))) { + if (const auto *SAttr = Parent->getAttr()) { + Attr *NewAttr = SAttr->clone(S.getASTContext()); + NewAttr->setImplicit(true); + return NewAttr; + } + } + return nullptr; + } + + /// Returns an implicit CodeSegAttr if a __declspec(code_seg) is found on a + /// containing class. Otherwise it will return implicit SectionAttr if the + /// function is a definition and there is an active value on CodeSegStack + /// (from the current #pragma code-seg value). + /// + /// \param FD Function being declared. + /// \param IsDefinition Whether it is a definition or just a declarartion. + /// \returns A CodeSegAttr or SectionAttr to apply to the function or + /// nullptr if no attribute should be added. + Attr *Sema::getImplicitCodeSegOrSectionAttrForFunction(const FunctionDecl *FD, + bool IsDefinition) { + if (Attr *A = getImplicitCodeSegAttrFromClass(*this, FD)) + return A; + if (!FD->hasAttr() && IsDefinition && + CodeSegStack.CurrentValue) { + return SectionAttr::CreateImplicit(getASTContext(), + SectionAttr::Declspec_allocate, + CodeSegStack.CurrentValue->getString(), + CodeSegStack.CurrentPragmaLocation); + } + return nullptr; + } + + /// Determines if we can perform a correct type check for \p D as a + /// redeclaration of \p PrevDecl. If not, we can generally still perform a + /// best-effort check. + /// + /// \param NewD The new declaration. + /// \param OldD The old declaration. + /// \param NewT The portion of the type of the new declaration to check. + /// \param OldT The portion of the type of the old declaration to check. + bool Sema::canFullyTypeCheckRedeclaration(ValueDecl *NewD, ValueDecl *OldD, + QualType NewT, QualType OldT) { + if (!NewD->getLexicalDeclContext()->isDependentContext()) + return true; + + // For dependently-typed local extern declarations and friends, we can't + // perform a correct type check in general until instantiation: + // + // int f(); + // template void g() { T f(); } + // + // (valid if g() is only instantiated with T = int). + if (NewT->isDependentType() && + (NewD->isLocalExternDecl() || NewD->getFriendObjectKind())) + return false; + + // Similarly, if the previous declaration was a dependent local extern + // declaration, we don't really know its type yet. + if (OldT->isDependentType() && OldD->isLocalExternDecl()) + return false; + + return true; + } + + /// Checks if the new declaration declared in dependent context must be + /// put in the same redeclaration chain as the specified declaration. + /// + /// \param D Declaration that is checked. + /// \param PrevDecl Previous declaration found with proper lookup method for the + /// same declaration name. + /// \returns True if D must be added to the redeclaration chain which PrevDecl + /// belongs to. + /// + bool Sema::shouldLinkDependentDeclWithPrevious(Decl *D, Decl *PrevDecl) { + if (!D->getLexicalDeclContext()->isDependentContext()) + return true; + + // Don't chain dependent friend function definitions until instantiation, to + // permit cases like + // + // void func(); + // template class C1 { friend void func() {} }; + // template class C2 { friend void func() {} }; + // + // ... which is valid if only one of C1 and C2 is ever instantiated. + // + // FIXME: This need only apply to function definitions. For now, we proxy + // this by checking for a file-scope function. We do not want this to apply + // to friend declarations nominating member functions, because that gets in + // the way of access checks. + if (D->getFriendObjectKind() && D->getDeclContext()->isFileContext()) + return false; + + auto *VD = dyn_cast(D); + auto *PrevVD = dyn_cast(PrevDecl); + return !VD || !PrevVD || + canFullyTypeCheckRedeclaration(VD, PrevVD, VD->getType(), + PrevVD->getType()); + } + + /// Check the target attribute of the function for MultiVersion + /// validity. + /// + /// Returns true if there was an error, false otherwise. + static bool CheckMultiVersionValue(Sema &S, const FunctionDecl *FD) { + const auto *TA = FD->getAttr(); + assert(TA && "MultiVersion Candidate requires a target attribute"); + TargetAttr::ParsedTargetAttr ParseInfo = TA->parse(); + const TargetInfo &TargetInfo = S.Context.getTargetInfo(); + enum ErrType { Feature = 0, Architecture = 1 }; + + if (!ParseInfo.Architecture.empty() && + !TargetInfo.validateCpuIs(ParseInfo.Architecture)) { + S.Diag(FD->getLocation(), diag::err_bad_multiversion_option) + << Architecture << ParseInfo.Architecture; + return true; + } + + for (const auto &Feat : ParseInfo.Features) { + auto BareFeat = StringRef{Feat}.substr(1); + if (Feat[0] == '-') { + S.Diag(FD->getLocation(), diag::err_bad_multiversion_option) + << Feature << ("no-" + BareFeat).str(); + return true; + } + + if (!TargetInfo.validateCpuSupports(BareFeat) || + !TargetInfo.isValidFeatureName(BareFeat)) { + S.Diag(FD->getLocation(), diag::err_bad_multiversion_option) + << Feature << BareFeat; + return true; + } + } + return false; + } + + static bool HasNonMultiVersionAttributes(const FunctionDecl *FD, + MultiVersionKind MVType) { + for (const Attr *A : FD->attrs()) { + switch (A->getKind()) { + case attr::CPUDispatch: + case attr::CPUSpecific: + if (MVType != MultiVersionKind::CPUDispatch && + MVType != MultiVersionKind::CPUSpecific) + return true; + break; + case attr::Target: + if (MVType != MultiVersionKind::Target) + return true; + break; + default: + return true; + } + } + return false; + } + + static bool CheckMultiVersionAdditionalRules(Sema &S, const FunctionDecl *OldFD, + const FunctionDecl *NewFD, + bool CausesMV, + MultiVersionKind MVType) { + enum DoesntSupport { + FuncTemplates = 0, + VirtFuncs = 1, + DeducedReturn = 2, + Constructors = 3, + Destructors = 4, + DeletedFuncs = 5, + DefaultedFuncs = 6, + ConstexprFuncs = 7, + }; + enum Different { + CallingConv = 0, + ReturnType = 1, + ConstexprSpec = 2, + InlineSpec = 3, + StorageClass = 4, + Linkage = 5 + }; + + bool IsCPUSpecificCPUDispatchMVType = + MVType == MultiVersionKind::CPUDispatch || + MVType == MultiVersionKind::CPUSpecific; + + if (OldFD && !OldFD->getType()->getAs()) { + S.Diag(OldFD->getLocation(), diag::err_multiversion_noproto); + S.Diag(NewFD->getLocation(), diag::note_multiversioning_caused_here); + return true; + } + + if (!NewFD->getType()->getAs()) + return S.Diag(NewFD->getLocation(), diag::err_multiversion_noproto); + + if (!S.getASTContext().getTargetInfo().supportsMultiVersioning()) { + S.Diag(NewFD->getLocation(), diag::err_multiversion_not_supported); + if (OldFD) + S.Diag(OldFD->getLocation(), diag::note_previous_declaration); + return true; + } + + // For now, disallow all other attributes. These should be opt-in, but + // an analysis of all of them is a future FIXME. + if (CausesMV && OldFD && HasNonMultiVersionAttributes(OldFD, MVType)) { + S.Diag(OldFD->getLocation(), diag::err_multiversion_no_other_attrs) + << IsCPUSpecificCPUDispatchMVType; + S.Diag(NewFD->getLocation(), diag::note_multiversioning_caused_here); + return true; + } + + if (HasNonMultiVersionAttributes(NewFD, MVType)) + return S.Diag(NewFD->getLocation(), diag::err_multiversion_no_other_attrs) + << IsCPUSpecificCPUDispatchMVType; + + if (NewFD->getTemplatedKind() == FunctionDecl::TK_FunctionTemplate) + return S.Diag(NewFD->getLocation(), diag::err_multiversion_doesnt_support) + << IsCPUSpecificCPUDispatchMVType << FuncTemplates; + + if (const auto *NewCXXFD = dyn_cast(NewFD)) { + if (NewCXXFD->isVirtual()) + return S.Diag(NewCXXFD->getLocation(), + diag::err_multiversion_doesnt_support) + << IsCPUSpecificCPUDispatchMVType << VirtFuncs; + + if (const auto *NewCXXCtor = dyn_cast(NewFD)) + return S.Diag(NewCXXCtor->getLocation(), + diag::err_multiversion_doesnt_support) + << IsCPUSpecificCPUDispatchMVType << Constructors; + + if (const auto *NewCXXDtor = dyn_cast(NewFD)) + return S.Diag(NewCXXDtor->getLocation(), + diag::err_multiversion_doesnt_support) + << IsCPUSpecificCPUDispatchMVType << Destructors; + } + + if (NewFD->isDeleted()) + return S.Diag(NewFD->getLocation(), diag::err_multiversion_doesnt_support) + << IsCPUSpecificCPUDispatchMVType << DeletedFuncs; + + if (NewFD->isDefaulted()) + return S.Diag(NewFD->getLocation(), diag::err_multiversion_doesnt_support) + << IsCPUSpecificCPUDispatchMVType << DefaultedFuncs; + + if (NewFD->isConstexpr() && (MVType == MultiVersionKind::CPUDispatch || + MVType == MultiVersionKind::CPUSpecific)) + return S.Diag(NewFD->getLocation(), diag::err_multiversion_doesnt_support) + << IsCPUSpecificCPUDispatchMVType << ConstexprFuncs; + + QualType NewQType = S.getASTContext().getCanonicalType(NewFD->getType()); + const auto *NewType = cast(NewQType); + QualType NewReturnType = NewType->getReturnType(); + + if (NewReturnType->isUndeducedType()) + return S.Diag(NewFD->getLocation(), diag::err_multiversion_doesnt_support) + << IsCPUSpecificCPUDispatchMVType << DeducedReturn; + + // Only allow transition to MultiVersion if it hasn't been used. + if (OldFD && CausesMV && OldFD->isUsed(false)) + return S.Diag(NewFD->getLocation(), diag::err_multiversion_after_used); + + // Ensure the return type is identical. + if (OldFD) { + QualType OldQType = S.getASTContext().getCanonicalType(OldFD->getType()); + const auto *OldType = cast(OldQType); + FunctionType::ExtInfo OldTypeInfo = OldType->getExtInfo(); + FunctionType::ExtInfo NewTypeInfo = NewType->getExtInfo(); + + if (OldTypeInfo.getCC() != NewTypeInfo.getCC()) + return S.Diag(NewFD->getLocation(), diag::err_multiversion_diff) + << CallingConv; + + QualType OldReturnType = OldType->getReturnType(); + + if (OldReturnType != NewReturnType) + return S.Diag(NewFD->getLocation(), diag::err_multiversion_diff) + << ReturnType; + + if (OldFD->isConstexpr() != NewFD->isConstexpr()) + return S.Diag(NewFD->getLocation(), diag::err_multiversion_diff) + << ConstexprSpec; + + if (OldFD->isInlineSpecified() != NewFD->isInlineSpecified()) + return S.Diag(NewFD->getLocation(), diag::err_multiversion_diff) + << InlineSpec; + + if (OldFD->getStorageClass() != NewFD->getStorageClass()) + return S.Diag(NewFD->getLocation(), diag::err_multiversion_diff) + << StorageClass; + + if (OldFD->isExternC() != NewFD->isExternC()) + return S.Diag(NewFD->getLocation(), diag::err_multiversion_diff) + << Linkage; + + if (S.CheckEquivalentExceptionSpec( + OldFD->getType()->getAs(), OldFD->getLocation(), + NewFD->getType()->getAs(), NewFD->getLocation())) + return true; + } + return false; + } + + /// Check the validity of a multiversion function declaration that is the + /// first of its kind. Also sets the multiversion'ness' of the function itself. + /// + /// This sets NewFD->isInvalidDecl() to true if there was an error. + /// + /// Returns true if there was an error, false otherwise. + static bool CheckMultiVersionFirstFunction(Sema &S, FunctionDecl *FD, + MultiVersionKind MVType, + const TargetAttr *TA, + const CPUDispatchAttr *CPUDisp, + const CPUSpecificAttr *CPUSpec) { + assert(MVType != MultiVersionKind::None && + "Function lacks multiversion attribute"); + + // Target only causes MV if it is default, otherwise this is a normal + // function. + if (MVType == MultiVersionKind::Target && !TA->isDefaultVersion()) + return false; + + if (MVType == MultiVersionKind::Target && CheckMultiVersionValue(S, FD)) { + FD->setInvalidDecl(); + return true; + } + + if (CheckMultiVersionAdditionalRules(S, nullptr, FD, true, MVType)) { + FD->setInvalidDecl(); + return true; + } + + FD->setIsMultiVersion(); + return false; + } + + static bool PreviousDeclsHaveMultiVersionAttribute(const FunctionDecl *FD) { + for (const Decl *D = FD->getPreviousDecl(); D; D = D->getPreviousDecl()) { + if (D->getAsFunction()->getMultiVersionKind() != MultiVersionKind::None) + return true; + } + + return false; + } + + static bool CheckTargetCausesMultiVersioning( + Sema &S, FunctionDecl *OldFD, FunctionDecl *NewFD, const TargetAttr *NewTA, + bool &Redeclaration, NamedDecl *&OldDecl, bool &MergeTypeWithPrevious, + LookupResult &Previous) { + const auto *OldTA = OldFD->getAttr(); + TargetAttr::ParsedTargetAttr NewParsed = NewTA->parse(); + // Sort order doesn't matter, it just needs to be consistent. + llvm::sort(NewParsed.Features); + + // If the old decl is NOT MultiVersioned yet, and we don't cause that + // to change, this is a simple redeclaration. + if (!NewTA->isDefaultVersion() && + (!OldTA || OldTA->getFeaturesStr() == NewTA->getFeaturesStr())) + return false; + + // Otherwise, this decl causes MultiVersioning. + if (!S.getASTContext().getTargetInfo().supportsMultiVersioning()) { + S.Diag(NewFD->getLocation(), diag::err_multiversion_not_supported); + S.Diag(OldFD->getLocation(), diag::note_previous_declaration); + NewFD->setInvalidDecl(); + return true; + } + + if (CheckMultiVersionAdditionalRules(S, OldFD, NewFD, true, + MultiVersionKind::Target)) { + NewFD->setInvalidDecl(); + return true; + } + + if (CheckMultiVersionValue(S, NewFD)) { + NewFD->setInvalidDecl(); + return true; + } + + // If this is 'default', permit the forward declaration. + if (!OldFD->isMultiVersion() && !OldTA && NewTA->isDefaultVersion()) { + Redeclaration = true; + OldDecl = OldFD; + OldFD->setIsMultiVersion(); + NewFD->setIsMultiVersion(); + return false; + } + + if (CheckMultiVersionValue(S, OldFD)) { + S.Diag(NewFD->getLocation(), diag::note_multiversioning_caused_here); + NewFD->setInvalidDecl(); + return true; + } + + TargetAttr::ParsedTargetAttr OldParsed = + OldTA->parse(std::less()); + + if (OldParsed == NewParsed) { + S.Diag(NewFD->getLocation(), diag::err_multiversion_duplicate); + S.Diag(OldFD->getLocation(), diag::note_previous_declaration); + NewFD->setInvalidDecl(); + return true; + } + + for (const auto *FD : OldFD->redecls()) { + const auto *CurTA = FD->getAttr(); + // We allow forward declarations before ANY multiversioning attributes, but + // nothing after the fact. + if (PreviousDeclsHaveMultiVersionAttribute(FD) && + (!CurTA || CurTA->isInherited())) { + S.Diag(FD->getLocation(), diag::err_multiversion_required_in_redecl) + << 0; + S.Diag(NewFD->getLocation(), diag::note_multiversioning_caused_here); + NewFD->setInvalidDecl(); + return true; + } + } + + OldFD->setIsMultiVersion(); + NewFD->setIsMultiVersion(); + Redeclaration = false; + MergeTypeWithPrevious = false; + OldDecl = nullptr; + Previous.clear(); + return false; + } + + /// Check the validity of a new function declaration being added to an existing + /// multiversioned declaration collection. + static bool CheckMultiVersionAdditionalDecl( + Sema &S, FunctionDecl *OldFD, FunctionDecl *NewFD, + MultiVersionKind NewMVType, const TargetAttr *NewTA, + const CPUDispatchAttr *NewCPUDisp, const CPUSpecificAttr *NewCPUSpec, + bool &Redeclaration, NamedDecl *&OldDecl, bool &MergeTypeWithPrevious, + LookupResult &Previous) { + + MultiVersionKind OldMVType = OldFD->getMultiVersionKind(); + // Disallow mixing of multiversioning types. + if ((OldMVType == MultiVersionKind::Target && + NewMVType != MultiVersionKind::Target) || + (NewMVType == MultiVersionKind::Target && + OldMVType != MultiVersionKind::Target)) { + S.Diag(NewFD->getLocation(), diag::err_multiversion_types_mixed); + S.Diag(OldFD->getLocation(), diag::note_previous_declaration); + NewFD->setInvalidDecl(); + return true; + } + + TargetAttr::ParsedTargetAttr NewParsed; + if (NewTA) { + NewParsed = NewTA->parse(); + llvm::sort(NewParsed.Features); + } + + bool UseMemberUsingDeclRules = + S.CurContext->isRecord() && !NewFD->getFriendObjectKind(); + + // Next, check ALL non-overloads to see if this is a redeclaration of a + // previous member of the MultiVersion set. + for (NamedDecl *ND : Previous) { + FunctionDecl *CurFD = ND->getAsFunction(); + if (!CurFD) + continue; + if (S.IsOverload(NewFD, CurFD, UseMemberUsingDeclRules)) + continue; + + if (NewMVType == MultiVersionKind::Target) { + const auto *CurTA = CurFD->getAttr(); + if (CurTA->getFeaturesStr() == NewTA->getFeaturesStr()) { + NewFD->setIsMultiVersion(); + Redeclaration = true; + OldDecl = ND; + return false; + } + + TargetAttr::ParsedTargetAttr CurParsed = + CurTA->parse(std::less()); + if (CurParsed == NewParsed) { + S.Diag(NewFD->getLocation(), diag::err_multiversion_duplicate); + S.Diag(CurFD->getLocation(), diag::note_previous_declaration); + NewFD->setInvalidDecl(); + return true; + } + } else { + const auto *CurCPUSpec = CurFD->getAttr(); + const auto *CurCPUDisp = CurFD->getAttr(); + // Handle CPUDispatch/CPUSpecific versions. + // Only 1 CPUDispatch function is allowed, this will make it go through + // the redeclaration errors. + if (NewMVType == MultiVersionKind::CPUDispatch && + CurFD->hasAttr()) { + if (CurCPUDisp->cpus_size() == NewCPUDisp->cpus_size() && + std::equal( + CurCPUDisp->cpus_begin(), CurCPUDisp->cpus_end(), + NewCPUDisp->cpus_begin(), + [](const IdentifierInfo *Cur, const IdentifierInfo *New) { + return Cur->getName() == New->getName(); + })) { + NewFD->setIsMultiVersion(); + Redeclaration = true; + OldDecl = ND; + return false; + } + + // If the declarations don't match, this is an error condition. + S.Diag(NewFD->getLocation(), diag::err_cpu_dispatch_mismatch); + S.Diag(CurFD->getLocation(), diag::note_previous_declaration); + NewFD->setInvalidDecl(); + return true; + } + if (NewMVType == MultiVersionKind::CPUSpecific && CurCPUSpec) { + + if (CurCPUSpec->cpus_size() == NewCPUSpec->cpus_size() && + std::equal( + CurCPUSpec->cpus_begin(), CurCPUSpec->cpus_end(), + NewCPUSpec->cpus_begin(), + [](const IdentifierInfo *Cur, const IdentifierInfo *New) { + return Cur->getName() == New->getName(); + })) { + NewFD->setIsMultiVersion(); + Redeclaration = true; + OldDecl = ND; + return false; + } + + // Only 1 version of CPUSpecific is allowed for each CPU. + for (const IdentifierInfo *CurII : CurCPUSpec->cpus()) { + for (const IdentifierInfo *NewII : NewCPUSpec->cpus()) { + if (CurII == NewII) { + S.Diag(NewFD->getLocation(), diag::err_cpu_specific_multiple_defs) + << NewII; + S.Diag(CurFD->getLocation(), diag::note_previous_declaration); + NewFD->setInvalidDecl(); + return true; + } + } + } + } + // If the two decls aren't the same MVType, there is no possible error + // condition. + } + } + + // Else, this is simply a non-redecl case. Checking the 'value' is only + // necessary in the Target case, since The CPUSpecific/Dispatch cases are + // handled in the attribute adding step. + if (NewMVType == MultiVersionKind::Target && + CheckMultiVersionValue(S, NewFD)) { + NewFD->setInvalidDecl(); + return true; + } + + if (CheckMultiVersionAdditionalRules(S, OldFD, NewFD, + !OldFD->isMultiVersion(), NewMVType)) { + NewFD->setInvalidDecl(); + return true; + } + + // Permit forward declarations in the case where these two are compatible. + if (!OldFD->isMultiVersion()) { + OldFD->setIsMultiVersion(); + NewFD->setIsMultiVersion(); + Redeclaration = true; + OldDecl = OldFD; + return false; + } + + NewFD->setIsMultiVersion(); + Redeclaration = false; + MergeTypeWithPrevious = false; + OldDecl = nullptr; + Previous.clear(); + return false; + } + + + /// Check the validity of a mulitversion function declaration. + /// Also sets the multiversion'ness' of the function itself. + /// + /// This sets NewFD->isInvalidDecl() to true if there was an error. + /// + /// Returns true if there was an error, false otherwise. + static bool CheckMultiVersionFunction(Sema &S, FunctionDecl *NewFD, + bool &Redeclaration, NamedDecl *&OldDecl, + bool &MergeTypeWithPrevious, + LookupResult &Previous) { + const auto *NewTA = NewFD->getAttr(); + const auto *NewCPUDisp = NewFD->getAttr(); + const auto *NewCPUSpec = NewFD->getAttr(); + + // Mixing Multiversioning types is prohibited. + if ((NewTA && NewCPUDisp) || (NewTA && NewCPUSpec) || + (NewCPUDisp && NewCPUSpec)) { + S.Diag(NewFD->getLocation(), diag::err_multiversion_types_mixed); + NewFD->setInvalidDecl(); + return true; + } + + MultiVersionKind MVType = NewFD->getMultiVersionKind(); + + // Main isn't allowed to become a multiversion function, however it IS + // permitted to have 'main' be marked with the 'target' optimization hint. + if (NewFD->isMain()) { + if ((MVType == MultiVersionKind::Target && NewTA->isDefaultVersion()) || + MVType == MultiVersionKind::CPUDispatch || + MVType == MultiVersionKind::CPUSpecific) { + S.Diag(NewFD->getLocation(), diag::err_multiversion_not_allowed_on_main); + NewFD->setInvalidDecl(); + return true; + } + return false; + } + + if (!OldDecl || !OldDecl->getAsFunction() || + OldDecl->getDeclContext()->getRedeclContext() != + NewFD->getDeclContext()->getRedeclContext()) { + // If there's no previous declaration, AND this isn't attempting to cause + // multiversioning, this isn't an error condition. + if (MVType == MultiVersionKind::None) + return false; + return CheckMultiVersionFirstFunction(S, NewFD, MVType, NewTA, NewCPUDisp, + NewCPUSpec); + } + + FunctionDecl *OldFD = OldDecl->getAsFunction(); + + if (!OldFD->isMultiVersion() && MVType == MultiVersionKind::None) + return false; + + if (OldFD->isMultiVersion() && MVType == MultiVersionKind::None) { + S.Diag(NewFD->getLocation(), diag::err_multiversion_required_in_redecl) + << (OldFD->getMultiVersionKind() != MultiVersionKind::Target); + NewFD->setInvalidDecl(); + return true; + } + + // Handle the target potentially causes multiversioning case. + if (!OldFD->isMultiVersion() && MVType == MultiVersionKind::Target) + return CheckTargetCausesMultiVersioning(S, OldFD, NewFD, NewTA, + Redeclaration, OldDecl, + MergeTypeWithPrevious, Previous); + + // At this point, we have a multiversion function decl (in OldFD) AND an + // appropriate attribute in the current function decl. Resolve that these are + // still compatible with previous declarations. + return CheckMultiVersionAdditionalDecl( + S, OldFD, NewFD, MVType, NewTA, NewCPUDisp, NewCPUSpec, Redeclaration, + OldDecl, MergeTypeWithPrevious, Previous); + } + + /// Perform semantic checking of a new function declaration. + /// + /// Performs semantic analysis of the new function declaration + /// NewFD. This routine performs all semantic checking that does not + /// require the actual declarator involved in the declaration, and is + /// used both for the declaration of functions as they are parsed + /// (called via ActOnDeclarator) and for the declaration of functions + /// that have been instantiated via C++ template instantiation (called + /// via InstantiateDecl). + /// + /// \param IsMemberSpecialization whether this new function declaration is + /// a member specialization (that replaces any definition provided by the + /// previous declaration). + /// + /// This sets NewFD->isInvalidDecl() to true if there was an error. + /// + /// \returns true if the function declaration is a redeclaration. + bool Sema::CheckFunctionDeclaration(Scope *S, FunctionDecl *NewFD, + LookupResult &Previous, + bool IsMemberSpecialization) { + assert(!NewFD->getReturnType()->isVariablyModifiedType() && + "Variably modified return types are not handled here"); + + // Determine whether the type of this function should be merged with + // a previous visible declaration. This never happens for functions in C++, + // and always happens in C if the previous declaration was visible. + bool MergeTypeWithPrevious = !getLangOpts().CPlusPlus && + !Previous.isShadowed(); + + bool Redeclaration = false; + NamedDecl *OldDecl = nullptr; + bool MayNeedOverloadableChecks = false; + + // Merge or overload the declaration with an existing declaration of + // the same name, if appropriate. + if (!Previous.empty()) { + // Determine whether NewFD is an overload of PrevDecl or + // a declaration that requires merging. If it's an overload, + // there's no more work to do here; we'll just add the new + // function to the scope. + if (!AllowOverloadingOfFunction(Previous, Context, NewFD)) { + NamedDecl *Candidate = Previous.getRepresentativeDecl(); + if (shouldLinkPossiblyHiddenDecl(Candidate, NewFD)) { + Redeclaration = true; + OldDecl = Candidate; + } + } else { + MayNeedOverloadableChecks = true; + switch (CheckOverload(S, NewFD, Previous, OldDecl, + /*NewIsUsingDecl*/ false)) { + case Ovl_Match: + Redeclaration = true; + break; + + case Ovl_NonFunction: + Redeclaration = true; + break; + + case Ovl_Overload: + Redeclaration = false; + break; + } + } + } + + // Check for a previous extern "C" declaration with this name. + if (!Redeclaration && + checkForConflictWithNonVisibleExternC(*this, NewFD, Previous)) { + if (!Previous.empty()) { + // This is an extern "C" declaration with the same name as a previous + // declaration, and thus redeclares that entity... + Redeclaration = true; + OldDecl = Previous.getFoundDecl(); + MergeTypeWithPrevious = false; + + // ... except in the presence of __attribute__((overloadable)). + if (OldDecl->hasAttr() || + NewFD->hasAttr()) { + if (IsOverload(NewFD, cast(OldDecl), false)) { + MayNeedOverloadableChecks = true; + Redeclaration = false; + OldDecl = nullptr; + } + } + } + } + + if (CheckMultiVersionFunction(*this, NewFD, Redeclaration, OldDecl, + MergeTypeWithPrevious, Previous)) + return Redeclaration; + + // C++11 [dcl.constexpr]p8: + // A constexpr specifier for a non-static member function that is not + // a constructor declares that member function to be const. + // + // This needs to be delayed until we know whether this is an out-of-line + // definition of a static member function. + // + // This rule is not present in C++1y, so we produce a backwards + // compatibility warning whenever it happens in C++11. + CXXMethodDecl *MD = dyn_cast(NewFD); + if (!getLangOpts().CPlusPlus14 && MD && MD->isConstexpr() && + !MD->isStatic() && !isa(MD) && + !MD->getMethodQualifiers().hasConst()) { + CXXMethodDecl *OldMD = nullptr; + if (OldDecl) + OldMD = dyn_cast_or_null(OldDecl->getAsFunction()); + if (!OldMD || !OldMD->isStatic()) { + const FunctionProtoType *FPT = + MD->getType()->castAs(); + FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo(); + EPI.TypeQuals.addConst(); + MD->setType(Context.getFunctionType(FPT->getReturnType(), + FPT->getParamTypes(), EPI)); + + // Warn that we did this, if we're not performing template instantiation. + // In that case, we'll have warned already when the template was defined. + if (!inTemplateInstantiation()) { + SourceLocation AddConstLoc; + if (FunctionTypeLoc FTL = MD->getTypeSourceInfo()->getTypeLoc() + .IgnoreParens().getAs()) + AddConstLoc = getLocForEndOfToken(FTL.getRParenLoc()); + + Diag(MD->getLocation(), diag::warn_cxx14_compat_constexpr_not_const) + << FixItHint::CreateInsertion(AddConstLoc, " const"); + } + } + } + + if (Redeclaration) { + // NewFD and OldDecl represent declarations that need to be + // merged. + if (MergeFunctionDecl(NewFD, OldDecl, S, MergeTypeWithPrevious)) { + NewFD->setInvalidDecl(); + return Redeclaration; + } + + Previous.clear(); + Previous.addDecl(OldDecl); + + if (FunctionTemplateDecl *OldTemplateDecl = + dyn_cast(OldDecl)) { + auto *OldFD = OldTemplateDecl->getTemplatedDecl(); + FunctionTemplateDecl *NewTemplateDecl + = NewFD->getDescribedFunctionTemplate(); + assert(NewTemplateDecl && "Template/non-template mismatch"); + + // The call to MergeFunctionDecl above may have created some state in + // NewTemplateDecl that needs to be merged with OldTemplateDecl before we + // can add it as a redeclaration. + NewTemplateDecl->mergePrevDecl(OldTemplateDecl); + + NewFD->setPreviousDeclaration(OldFD); + adjustDeclContextForDeclaratorDecl(NewFD, OldFD); + if (NewFD->isCXXClassMember()) { + NewFD->setAccess(OldTemplateDecl->getAccess()); + NewTemplateDecl->setAccess(OldTemplateDecl->getAccess()); + } + + // If this is an explicit specialization of a member that is a function + // template, mark it as a member specialization. + if (IsMemberSpecialization && + NewTemplateDecl->getInstantiatedFromMemberTemplate()) { + NewTemplateDecl->setMemberSpecialization(); + assert(OldTemplateDecl->isMemberSpecialization()); + // Explicit specializations of a member template do not inherit deleted + // status from the parent member template that they are specializing. + if (OldFD->isDeleted()) { + // FIXME: This assert will not hold in the presence of modules. + assert(OldFD->getCanonicalDecl() == OldFD); + // FIXME: We need an update record for this AST mutation. + OldFD->setDeletedAsWritten(false); + } + } + + } else { + if (shouldLinkDependentDeclWithPrevious(NewFD, OldDecl)) { + auto *OldFD = cast(OldDecl); + // This needs to happen first so that 'inline' propagates. + NewFD->setPreviousDeclaration(OldFD); + adjustDeclContextForDeclaratorDecl(NewFD, OldFD); + if (NewFD->isCXXClassMember()) + NewFD->setAccess(OldFD->getAccess()); + } + } + } else if (!getLangOpts().CPlusPlus && MayNeedOverloadableChecks && + !NewFD->getAttr()) { + assert((Previous.empty() || + llvm::any_of(Previous, + [](const NamedDecl *ND) { + return ND->hasAttr(); + })) && + "Non-redecls shouldn't happen without overloadable present"); + + auto OtherUnmarkedIter = llvm::find_if(Previous, [](const NamedDecl *ND) { + const auto *FD = dyn_cast(ND); + return FD && !FD->hasAttr(); + }); + + if (OtherUnmarkedIter != Previous.end()) { + Diag(NewFD->getLocation(), + diag::err_attribute_overloadable_multiple_unmarked_overloads); + Diag((*OtherUnmarkedIter)->getLocation(), + diag::note_attribute_overloadable_prev_overload) + << false; + + NewFD->addAttr(OverloadableAttr::CreateImplicit(Context)); + } + } + + // Semantic checking for this function declaration (in isolation). + + if (getLangOpts().CPlusPlus) { + // C++-specific checks. + if (CXXConstructorDecl *Constructor = dyn_cast(NewFD)) { + CheckConstructor(Constructor); + } else if (CXXDestructorDecl *Destructor = + dyn_cast(NewFD)) { + CXXRecordDecl *Record = Destructor->getParent(); + QualType ClassType = Context.getTypeDeclType(Record); + + // FIXME: Shouldn't we be able to perform this check even when the class + // type is dependent? Both gcc and edg can handle that. + if (!ClassType->isDependentType()) { + DeclarationName Name + = Context.DeclarationNames.getCXXDestructorName( + Context.getCanonicalType(ClassType)); + if (NewFD->getDeclName() != Name) { + Diag(NewFD->getLocation(), diag::err_destructor_name); + NewFD->setInvalidDecl(); + return Redeclaration; + } + } + } else if (CXXConversionDecl *Conversion + = dyn_cast(NewFD)) { + ActOnConversionDeclarator(Conversion); + } else if (auto *Guide = dyn_cast(NewFD)) { + if (auto *TD = Guide->getDescribedFunctionTemplate()) + CheckDeductionGuideTemplate(TD); + + // A deduction guide is not on the list of entities that can be + // explicitly specialized. + if (Guide->getTemplateSpecializationKind() == TSK_ExplicitSpecialization) + Diag(Guide->getBeginLoc(), diag::err_deduction_guide_specialized) + << /*explicit specialization*/ 1; + } + + // Find any virtual functions that this function overrides. + if (CXXMethodDecl *Method = dyn_cast(NewFD)) { + if (!Method->isFunctionTemplateSpecialization() && + !Method->getDescribedFunctionTemplate() && + Method->isCanonicalDecl()) { + if (AddOverriddenMethods(Method->getParent(), Method)) { + // If the function was marked as "static", we have a problem. + if (NewFD->getStorageClass() == SC_Static) { + ReportOverrides(*this, diag::err_static_overrides_virtual, Method); + } + } + } + + if (Method->isStatic()) + checkThisInStaticMemberFunctionType(Method); + } + + // Extra checking for C++ overloaded operators (C++ [over.oper]). + if (NewFD->isOverloadedOperator() && + CheckOverloadedOperatorDeclaration(NewFD)) { + NewFD->setInvalidDecl(); + return Redeclaration; + } + + // Extra checking for C++0x literal operators (C++0x [over.literal]). + if (NewFD->getLiteralIdentifier() && + CheckLiteralOperatorDeclaration(NewFD)) { + NewFD->setInvalidDecl(); + return Redeclaration; + } + + // In C++, check default arguments now that we have merged decls. Unless + // the lexical context is the class, because in this case this is done + // during delayed parsing anyway. + if (!CurContext->isRecord()) + CheckCXXDefaultArguments(NewFD); + + // If this function declares a builtin function, check the type of this + // declaration against the expected type for the builtin. + if (unsigned BuiltinID = NewFD->getBuiltinID()) { + ASTContext::GetBuiltinTypeError Error; + LookupPredefedObjCSuperType(*this, S, NewFD->getIdentifier()); + QualType T = Context.GetBuiltinType(BuiltinID, Error); + // If the type of the builtin differs only in its exception + // specification, that's OK. + // FIXME: If the types do differ in this way, it would be better to + // retain the 'noexcept' form of the type. + if (!T.isNull() && + !Context.hasSameFunctionTypeIgnoringExceptionSpec(T, + NewFD->getType())) + // The type of this function differs from the type of the builtin, + // so forget about the builtin entirely. + Context.BuiltinInfo.forgetBuiltin(BuiltinID, Context.Idents); + } + + // If this function is declared as being extern "C", then check to see if + // the function returns a UDT (class, struct, or union type) that is not C + // compatible, and if it does, warn the user. + // But, issue any diagnostic on the first declaration only. + if (Previous.empty() && NewFD->isExternC()) { + QualType R = NewFD->getReturnType(); + if (R->isIncompleteType() && !R->isVoidType()) + Diag(NewFD->getLocation(), diag::warn_return_value_udt_incomplete) + << NewFD << R; + else if (!R.isPODType(Context) && !R->isVoidType() && + !R->isObjCObjectPointerType()) + Diag(NewFD->getLocation(), diag::warn_return_value_udt) << NewFD << R; + } + + // C++1z [dcl.fct]p6: + // [...] whether the function has a non-throwing exception-specification + // [is] part of the function type + // + // This results in an ABI break between C++14 and C++17 for functions whose + // declared type includes an exception-specification in a parameter or + // return type. (Exception specifications on the function itself are OK in + // most cases, and exception specifications are not permitted in most other + // contexts where they could make it into a mangling.) + if (!getLangOpts().CPlusPlus17 && !NewFD->getPrimaryTemplate()) { + auto HasNoexcept = [&](QualType T) -> bool { + // Strip off declarator chunks that could be between us and a function + // type. We don't need to look far, exception specifications are very + // restricted prior to C++17. + if (auto *RT = T->getAs()) + T = RT->getPointeeType(); + else if (T->isAnyPointerType()) + T = T->getPointeeType(); + else if (auto *MPT = T->getAs()) + T = MPT->getPointeeType(); + if (auto *FPT = T->getAs()) + if (FPT->isNothrow()) + return true; + return false; + }; + + auto *FPT = NewFD->getType()->castAs(); + bool AnyNoexcept = HasNoexcept(FPT->getReturnType()); + for (QualType T : FPT->param_types()) + AnyNoexcept |= HasNoexcept(T); + if (AnyNoexcept) + Diag(NewFD->getLocation(), + diag::warn_cxx17_compat_exception_spec_in_signature) + << NewFD; + } + + if (!Redeclaration && LangOpts.CUDA) + checkCUDATargetOverload(NewFD, Previous); + } + return Redeclaration; + } + + void Sema::CheckMain(FunctionDecl* FD, const DeclSpec& DS) { + // C++11 [basic.start.main]p3: + // A program that [...] declares main to be inline, static or + // constexpr is ill-formed. + // C11 6.7.4p4: In a hosted environment, no function specifier(s) shall + // appear in a declaration of main. + // static main is not an error under C99, but we should warn about it. + // We accept _Noreturn main as an extension. + if (FD->getStorageClass() == SC_Static) + Diag(DS.getStorageClassSpecLoc(), getLangOpts().CPlusPlus + ? diag::err_static_main : diag::warn_static_main) + << FixItHint::CreateRemoval(DS.getStorageClassSpecLoc()); + if (FD->isInlineSpecified()) + Diag(DS.getInlineSpecLoc(), diag::err_inline_main) + << FixItHint::CreateRemoval(DS.getInlineSpecLoc()); + if (DS.isNoreturnSpecified()) { + SourceLocation NoreturnLoc = DS.getNoreturnSpecLoc(); + SourceRange NoreturnRange(NoreturnLoc, getLocForEndOfToken(NoreturnLoc)); + Diag(NoreturnLoc, diag::ext_noreturn_main); + Diag(NoreturnLoc, diag::note_main_remove_noreturn) + << FixItHint::CreateRemoval(NoreturnRange); + } + if (FD->isConstexpr()) { + Diag(DS.getConstexprSpecLoc(), diag::err_constexpr_main) + << FixItHint::CreateRemoval(DS.getConstexprSpecLoc()); + FD->setConstexpr(false); + } + + if (getLangOpts().OpenCL) { + Diag(FD->getLocation(), diag::err_opencl_no_main) + << FD->hasAttr(); + FD->setInvalidDecl(); + return; + } + + QualType T = FD->getType(); + assert(T->isFunctionType() && "function decl is not of function type"); + const FunctionType* FT = T->castAs(); + + // Set default calling convention for main() + if (FT->getCallConv() != CC_C) { + FT = Context.adjustFunctionType(FT, FT->getExtInfo().withCallingConv(CC_C)); + FD->setType(QualType(FT, 0)); + T = Context.getCanonicalType(FD->getType()); + } + + if (getLangOpts().GNUMode && !getLangOpts().CPlusPlus) { + // In C with GNU extensions we allow main() to have non-integer return + // type, but we should warn about the extension, and we disable the + // implicit-return-zero rule. + + // GCC in C mode accepts qualified 'int'. + if (Context.hasSameUnqualifiedType(FT->getReturnType(), Context.IntTy)) + FD->setHasImplicitReturnZero(true); + else { + Diag(FD->getTypeSpecStartLoc(), diag::ext_main_returns_nonint); + SourceRange RTRange = FD->getReturnTypeSourceRange(); + if (RTRange.isValid()) + Diag(RTRange.getBegin(), diag::note_main_change_return_type) + << FixItHint::CreateReplacement(RTRange, "int"); + } + } else { + // In C and C++, main magically returns 0 if you fall off the end; + // set the flag which tells us that. + // This is C++ [basic.start.main]p5 and C99 5.1.2.2.3. + + // All the standards say that main() should return 'int'. + if (Context.hasSameType(FT->getReturnType(), Context.IntTy)) + FD->setHasImplicitReturnZero(true); + else { + // Otherwise, this is just a flat-out error. + SourceRange RTRange = FD->getReturnTypeSourceRange(); + Diag(FD->getTypeSpecStartLoc(), diag::err_main_returns_nonint) + << (RTRange.isValid() ? FixItHint::CreateReplacement(RTRange, "int") + : FixItHint()); + FD->setInvalidDecl(true); + } + } + + // Treat protoless main() as nullary. + if (isa(FT)) return; + + const FunctionProtoType* FTP = cast(FT); + unsigned nparams = FTP->getNumParams(); + assert(FD->getNumParams() == nparams); + + bool HasExtraParameters = (nparams > 3); + + if (FTP->isVariadic()) { + Diag(FD->getLocation(), diag::ext_variadic_main); + // FIXME: if we had information about the location of the ellipsis, we + // could add a FixIt hint to remove it as a parameter. + } + + // Darwin passes an undocumented fourth argument of type char**. If + // other platforms start sprouting these, the logic below will start + // getting shifty. + if (nparams == 4 && Context.getTargetInfo().getTriple().isOSDarwin()) + HasExtraParameters = false; + + if (HasExtraParameters) { + Diag(FD->getLocation(), diag::err_main_surplus_args) << nparams; + FD->setInvalidDecl(true); + nparams = 3; + } + + // FIXME: a lot of the following diagnostics would be improved + // if we had some location information about types. + + QualType CharPP = + Context.getPointerType(Context.getPointerType(Context.CharTy)); + QualType Expected[] = { Context.IntTy, CharPP, CharPP, CharPP }; + + for (unsigned i = 0; i < nparams; ++i) { + QualType AT = FTP->getParamType(i); + + bool mismatch = true; + + if (Context.hasSameUnqualifiedType(AT, Expected[i])) + mismatch = false; + else if (Expected[i] == CharPP) { + // As an extension, the following forms are okay: + // char const ** + // char const * const * + // char * const * + + QualifierCollector qs; + const PointerType* PT; + if ((PT = qs.strip(AT)->getAs()) && + (PT = qs.strip(PT->getPointeeType())->getAs()) && + Context.hasSameType(QualType(qs.strip(PT->getPointeeType()), 0), + Context.CharTy)) { + qs.removeConst(); + mismatch = !qs.empty(); + } + } + + if (mismatch) { + Diag(FD->getLocation(), diag::err_main_arg_wrong) << i << Expected[i]; + // TODO: suggest replacing given type with expected type + FD->setInvalidDecl(true); + } + } + + if (nparams == 1 && !FD->isInvalidDecl()) { + Diag(FD->getLocation(), diag::warn_main_one_arg); + } + + if (!FD->isInvalidDecl() && FD->getDescribedFunctionTemplate()) { + Diag(FD->getLocation(), diag::err_mainlike_template_decl) << FD; + FD->setInvalidDecl(); + } + } + + void Sema::CheckMSVCRTEntryPoint(FunctionDecl *FD) { + QualType T = FD->getType(); + assert(T->isFunctionType() && "function decl is not of function type"); + const FunctionType *FT = T->castAs(); + + // Set an implicit return of 'zero' if the function can return some integral, + // enumeration, pointer or nullptr type. + if (FT->getReturnType()->isIntegralOrEnumerationType() || + FT->getReturnType()->isAnyPointerType() || + FT->getReturnType()->isNullPtrType()) + // DllMain is exempt because a return value of zero means it failed. + if (FD->getName() != "DllMain") + FD->setHasImplicitReturnZero(true); + + if (!FD->isInvalidDecl() && FD->getDescribedFunctionTemplate()) { + Diag(FD->getLocation(), diag::err_mainlike_template_decl) << FD; + FD->setInvalidDecl(); + } + } + + bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { + // FIXME: Need strict checking. In C89, we need to check for + // any assignment, increment, decrement, function-calls, or + // commas outside of a sizeof. In C99, it's the same list, + // except that the aforementioned are allowed in unevaluated + // expressions. Everything else falls under the + // "may accept other forms of constant expressions" exception. + // (We never end up here for C++, so the constant expression + // rules there don't matter.) + const Expr *Culprit; + if (Init->isConstantInitializer(Context, false, &Culprit)) + return false; + Diag(Culprit->getExprLoc(), diag::err_init_element_not_constant) + << Culprit->getSourceRange(); + return true; + } + + namespace { + // Visits an initialization expression to see if OrigDecl is evaluated in + // its own initialization and throws a warning if it does. + class SelfReferenceChecker + : public EvaluatedExprVisitor { + Sema &S; + Decl *OrigDecl; + bool isRecordType; + bool isPODType; + bool isReferenceType; + + bool isInitList; + llvm::SmallVector InitFieldIndex; + + public: + typedef EvaluatedExprVisitor Inherited; + + SelfReferenceChecker(Sema &S, Decl *OrigDecl) : Inherited(S.Context), + S(S), OrigDecl(OrigDecl) { + isPODType = false; + isRecordType = false; + isReferenceType = false; + isInitList = false; + if (ValueDecl *VD = dyn_cast(OrigDecl)) { + isPODType = VD->getType().isPODType(S.Context); + isRecordType = VD->getType()->isRecordType(); + isReferenceType = VD->getType()->isReferenceType(); + } + } + + // For most expressions, just call the visitor. For initializer lists, + // track the index of the field being initialized since fields are + // initialized in order allowing use of previously initialized fields. + void CheckExpr(Expr *E) { + InitListExpr *InitList = dyn_cast(E); + if (!InitList) { + Visit(E); + return; + } + + // Track and increment the index here. + isInitList = true; + InitFieldIndex.push_back(0); + for (auto Child : InitList->children()) { + CheckExpr(cast(Child)); + ++InitFieldIndex.back(); + } + InitFieldIndex.pop_back(); + } + + // Returns true if MemberExpr is checked and no further checking is needed. + // Returns false if additional checking is required. + bool CheckInitListMemberExpr(MemberExpr *E, bool CheckReference) { + llvm::SmallVector Fields; + Expr *Base = E; + bool ReferenceField = false; + + // Get the field members used. + while (MemberExpr *ME = dyn_cast(Base)) { + FieldDecl *FD = dyn_cast(ME->getMemberDecl()); + if (!FD) + return false; + Fields.push_back(FD); + if (FD->getType()->isReferenceType()) + ReferenceField = true; + Base = ME->getBase()->IgnoreParenImpCasts(); + } + + // Keep checking only if the base Decl is the same. + DeclRefExpr *DRE = dyn_cast(Base); + if (!DRE || DRE->getDecl() != OrigDecl) + return false; + + // A reference field can be bound to an unininitialized field. + if (CheckReference && !ReferenceField) + return true; + + // Convert FieldDecls to their index number. + llvm::SmallVector UsedFieldIndex; + for (const FieldDecl *I : llvm::reverse(Fields)) + UsedFieldIndex.push_back(I->getFieldIndex()); + + // See if a warning is needed by checking the first difference in index + // numbers. If field being used has index less than the field being + // initialized, then the use is safe. + 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; + } + + // TODO: Add a different warning which will print the field names. + HandleDeclRefExpr(DRE); + return true; + } + + // For most expressions, the cast is directly above the DeclRefExpr. + // For conditional operators, the cast can be outside the conditional + // operator if both expressions are DeclRefExpr's. + void HandleValue(Expr *E) { + E = E->IgnoreParens(); + if (DeclRefExpr* DRE = dyn_cast(E)) { + HandleDeclRefExpr(DRE); + return; + } + + if (ConditionalOperator *CO = dyn_cast(E)) { + Visit(CO->getCond()); + HandleValue(CO->getTrueExpr()); + HandleValue(CO->getFalseExpr()); + return; + } + + if (BinaryConditionalOperator *BCO = + dyn_cast(E)) { + Visit(BCO->getCond()); + HandleValue(BCO->getFalseExpr()); + return; + } + + if (OpaqueValueExpr *OVE = dyn_cast(E)) { + HandleValue(OVE->getSourceExpr()); + return; + } + + if (BinaryOperator *BO = dyn_cast(E)) { + if (BO->getOpcode() == BO_Comma) { + Visit(BO->getLHS()); + HandleValue(BO->getRHS()); + return; + } + } + + if (isa(E)) { + if (isInitList) { + if (CheckInitListMemberExpr(cast(E), + false /*CheckReference*/)) + return; + } + + Expr *Base = E->IgnoreParenImpCasts(); + while (MemberExpr *ME = dyn_cast(Base)) { + // Check for static member variables and don't warn on them. + if (!isa(ME->getMemberDecl())) + return; + Base = ME->getBase()->IgnoreParenImpCasts(); + } + if (DeclRefExpr *DRE = dyn_cast(Base)) + HandleDeclRefExpr(DRE); + return; + } + + Visit(E); + } + + // Reference types not handled in HandleValue are handled here since all + // uses of references are bad, not just r-value uses. + void VisitDeclRefExpr(DeclRefExpr *E) { + if (isReferenceType) + HandleDeclRefExpr(E); + } + + void VisitImplicitCastExpr(ImplicitCastExpr *E) { + if (E->getCastKind() == CK_LValueToRValue) { + HandleValue(E->getSubExpr()); + return; + } + + Inherited::VisitImplicitCastExpr(E); + } + + void VisitMemberExpr(MemberExpr *E) { + if (isInitList) { + if (CheckInitListMemberExpr(E, true /*CheckReference*/)) + return; + } + + // Don't warn on arrays since they can be treated as pointers. + if (E->getType()->canDecayToPointerType()) return; + + // Warn when a non-static method call is followed by non-static member + // field accesses, which is followed by a DeclRefExpr. + CXXMethodDecl *MD = dyn_cast(E->getMemberDecl()); + bool Warn = (MD && !MD->isStatic()); + Expr *Base = E->getBase()->IgnoreParenImpCasts(); + while (MemberExpr *ME = dyn_cast(Base)) { + if (!isa(ME->getMemberDecl())) + Warn = false; + Base = ME->getBase()->IgnoreParenImpCasts(); + } + + if (DeclRefExpr *DRE = dyn_cast(Base)) { + if (Warn) + HandleDeclRefExpr(DRE); + return; + } + + // The base of a MemberExpr is not a MemberExpr or a DeclRefExpr. + // Visit that expression. + Visit(Base); + } + + 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()); + } + + void VisitUnaryOperator(UnaryOperator *E) { + // For POD record types, addresses of its own members are well-defined. + if (E->getOpcode() == UO_AddrOf && isRecordType && + isa(E->getSubExpr()->IgnoreParens())) { + if (!isPODType) + HandleValue(E->getSubExpr()); + return; + } + + if (E->isIncrementDecrementOp()) { + HandleValue(E->getSubExpr()); + return; + } + + Inherited::VisitUnaryOperator(E); + } + + void VisitObjCMessageExpr(ObjCMessageExpr *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); + return; + } + Inherited::VisitCXXConstructExpr(E); + } + + void VisitCallExpr(CallExpr *E) { + // Treat std::move as a use. + if (E->isCallToStdMove()) { + HandleValue(E->getArg(0)); + return; + } + + Inherited::VisitCallExpr(E); + } + + void VisitBinaryOperator(BinaryOperator *E) { + if (E->isCompoundAssignmentOp()) { + HandleValue(E->getLHS()); + Visit(E->getRHS()); + return; + } + + Inherited::VisitBinaryOperator(E); + } + + // A custom visitor for BinaryConditionalOperator is needed because the + // regular visitor would check the condition and true expression separately + // but both point to the same place giving duplicate diagnostics. + void VisitBinaryConditionalOperator(BinaryConditionalOperator *E) { + Visit(E->getCond()); + Visit(E->getFalseExpr()); + } + + void HandleDeclRefExpr(DeclRefExpr *DRE) { + Decl* ReferenceDecl = DRE->getDecl(); + if (OrigDecl != ReferenceDecl) return; + unsigned diag; + if (isReferenceType) { + diag = diag::warn_uninit_self_reference_in_reference_init; + } else if (cast(OrigDecl)->isStaticLocal()) { + diag = diag::warn_static_self_reference_in_init; + } else if (isa(OrigDecl->getDeclContext()) || + isa(OrigDecl->getDeclContext()) || + DRE->getDecl()->getType()->isRecordType()) { + diag = diag::warn_uninit_self_reference_in_init; + } else { + // Local variables will be handled by the CFG analysis. + return; + } + + S.DiagRuntimeBehavior(DRE->getBeginLoc(), DRE, + S.PDiag(diag) + << DRE->getDecl() << OrigDecl->getLocation() + << DRE->getSourceRange()); + } + }; + + /// CheckSelfReference - Warns if OrigDecl is used in expression E. + static void CheckSelfReference(Sema &S, Decl* OrigDecl, Expr *E, + bool DirectInit) { + // Parameters arguments are occassionially constructed with itself, + // for instance, in recursive functions. Skip them. + if (isa(OrigDecl)) + return; + + E = E->IgnoreParens(); + + // Skip checking T a = a where T is not a record or reference type. + // Doing so is a way to silence uninitialized warnings. + if (!DirectInit && !cast(OrigDecl)->getType()->isRecordType()) + if (ImplicitCastExpr *ICE = dyn_cast(E)) + if (ICE->getCastKind() == CK_LValueToRValue) + if (DeclRefExpr *DRE = dyn_cast(ICE->getSubExpr())) + if (DRE->getDecl() == OrigDecl) + return; + + SelfReferenceChecker(S, OrigDecl).CheckExpr(E); + } + } // end anonymous namespace + + namespace { + // Simple wrapper to add the name of a variable or (if no variable is + // available) a DeclarationName into a diagnostic. + struct VarDeclOrName { + VarDecl *VDecl; + DeclarationName Name; + + friend const Sema::SemaDiagnosticBuilder & + operator<<(const Sema::SemaDiagnosticBuilder &Diag, VarDeclOrName VN) { + return VN.VDecl ? Diag << VN.VDecl : Diag << VN.Name; + } + }; + } // end anonymous namespace + + QualType Sema::deduceVarTypeFromInitializer(VarDecl *VDecl, + DeclarationName Name, QualType Type, + TypeSourceInfo *TSI, + SourceRange Range, bool DirectInit, + Expr *&Init) { + bool IsInitCapture = !VDecl; + assert((!VDecl || !VDecl->isInitCapture()) && + "init captures are expected to be deduced prior to initialization"); + + VarDeclOrName VN{VDecl, Name}; + + DeducedType *Deduced = Type->getContainedDeducedType(); + assert(Deduced && "deduceVarTypeFromInitializer for non-deduced type"); + + // C++11 [dcl.spec.auto]p3 + if (!Init) { + assert(VDecl && "no init for init capture deduction?"); + + // Except for class argument deduction, and then for an initializing + // declaration only, i.e. no static at class scope or extern. + if (!isa(Deduced) || + VDecl->hasExternalStorage() || + VDecl->isStaticDataMember()) { + Diag(VDecl->getLocation(), diag::err_auto_var_requires_init) + << VDecl->getDeclName() << Type; + return QualType(); + } + } + + ArrayRef DeduceInits; + if (Init) + DeduceInits = Init; + + if (DirectInit) { + if (auto *PL = dyn_cast_or_null(Init)) + DeduceInits = PL->exprs(); + } + + if (isa(Deduced)) { + assert(VDecl && "non-auto type for init capture deduction?"); + InitializedEntity Entity = InitializedEntity::InitializeVariable(VDecl); + InitializationKind Kind = InitializationKind::CreateForInit( + VDecl->getLocation(), DirectInit, Init); + // FIXME: Initialization should not be taking a mutable list of inits. + SmallVector InitsCopy(DeduceInits.begin(), DeduceInits.end()); + return DeduceTemplateSpecializationFromInitializer(TSI, Entity, Kind, + InitsCopy); + } + + if (DirectInit) { + if (auto *IL = dyn_cast(Init)) + DeduceInits = IL->inits(); + } + + // Deduction only works if we have exactly one source expression. + if (DeduceInits.empty()) { + // It isn't possible to write this directly, but it is possible to + // end up in this situation with "auto x(some_pack...);" + Diag(Init->getBeginLoc(), IsInitCapture + ? diag::err_init_capture_no_expression + : diag::err_auto_var_init_no_expression) + << VN << Type << Range; + return QualType(); + } + + if (DeduceInits.size() > 1) { + Diag(DeduceInits[1]->getBeginLoc(), + IsInitCapture ? diag::err_init_capture_multiple_expressions + : diag::err_auto_var_init_multiple_expressions) + << VN << Type << Range; + return QualType(); + } + + Expr *DeduceInit = DeduceInits[0]; + if (DirectInit && isa(DeduceInit)) { + Diag(Init->getBeginLoc(), IsInitCapture + ? diag::err_init_capture_paren_braces + : diag::err_auto_var_init_paren_braces) + << isa(Init) << VN << Type << Range; + return QualType(); + } + + // Expressions default to 'id' when we're in a debugger. + bool DefaultedAnyToId = false; + if (getLangOpts().DebuggerCastResultToId && + Init->getType() == Context.UnknownAnyTy && !IsInitCapture) { + ExprResult Result = forceUnknownAnyToType(Init, Context.getObjCIdType()); + if (Result.isInvalid()) { + return QualType(); + } + Init = Result.get(); + DefaultedAnyToId = true; + } + + // C++ [dcl.decomp]p1: + // If the assignment-expression [...] has array type A and no ref-qualifier + // is present, e has type cv A + if (VDecl && isa(VDecl) && + Context.hasSameUnqualifiedType(Type, Context.getAutoDeductType()) && + DeduceInit->getType()->isConstantArrayType()) + return Context.getQualifiedType(DeduceInit->getType(), + Type.getQualifiers()); + + QualType DeducedType; + if (DeduceAutoType(TSI, DeduceInit, DeducedType) == DAR_Failed) { + if (!IsInitCapture) + DiagnoseAutoDeductionFailure(VDecl, DeduceInit); + else if (isa(Init)) + Diag(Range.getBegin(), + diag::err_init_capture_deduction_failure_from_init_list) + << VN + << (DeduceInit->getType().isNull() ? TSI->getType() + : DeduceInit->getType()) + << DeduceInit->getSourceRange(); + else + Diag(Range.getBegin(), diag::err_init_capture_deduction_failure) + << VN << TSI->getType() + << (DeduceInit->getType().isNull() ? TSI->getType() + : DeduceInit->getType()) + << DeduceInit->getSourceRange(); + } else + Init = DeduceInit; + + // Warn if we deduced 'id'. 'auto' usually implies type-safety, but using + // 'id' instead of a specific object type prevents most of our usual + // checks. + // We only want to warn outside of template instantiations, though: + // inside a template, the 'id' could have come from a parameter. + if (!inTemplateInstantiation() && !DefaultedAnyToId && !IsInitCapture && + !DeducedType.isNull() && DeducedType->isObjCIdType()) { + SourceLocation Loc = TSI->getTypeLoc().getBeginLoc(); + Diag(Loc, diag::warn_auto_var_is_id) << VN << Range; + } + + return DeducedType; + } + + bool Sema::DeduceVariableDeclarationType(VarDecl *VDecl, bool DirectInit, + Expr *&Init) { + QualType DeducedType = deduceVarTypeFromInitializer( + VDecl, VDecl->getDeclName(), VDecl->getType(), VDecl->getTypeSourceInfo(), + VDecl->getSourceRange(), DirectInit, Init); + if (DeducedType.isNull()) { + VDecl->setInvalidDecl(); + return true; + } + + VDecl->setType(DeducedType); + assert(VDecl->isLinkageValid()); + + // In ARC, infer lifetime. + if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(VDecl)) + VDecl->setInvalidDecl(); + + // If this is a redeclaration, check that the type we just deduced matches + // the previously declared type. + if (VarDecl *Old = VDecl->getPreviousDecl()) { + // We never need to merge the type, because we cannot form an incomplete + // array of auto, nor deduce such a type. + MergeVarDeclTypes(VDecl, Old, /*MergeTypeWithPrevious*/ false); + } + + // Check the deduced type is valid for a variable declaration. + CheckVariableDeclarationType(VDecl); + return VDecl->isInvalidDecl(); + } + + /// AddInitializerToDecl - Adds the initializer Init to the + /// declaration dcl. If DirectInit is true, this is C++ direct + /// initialization rather than copy initialization. + void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init, bool DirectInit) { + // If there is no declaration, there was an error parsing it. Just ignore + // the initializer. + if (!RealDecl || RealDecl->isInvalidDecl()) { + CorrectDelayedTyposInExpr(Init, dyn_cast_or_null(RealDecl)); + return; + } + + if (CXXMethodDecl *Method = dyn_cast(RealDecl)) { + // Pure-specifiers are handled in ActOnPureSpecifier. + Diag(Method->getLocation(), diag::err_member_function_initialization) + << Method->getDeclName() << Init->getSourceRange(); + Method->setInvalidDecl(); + return; + } + + VarDecl *VDecl = dyn_cast(RealDecl); + if (!VDecl) { + assert(!isa(RealDecl) && "field init shouldn't get here"); + Diag(RealDecl->getLocation(), diag::err_illegal_initializer); + RealDecl->setInvalidDecl(); + return; + } + + // C++11 [decl.spec.auto]p6. Deduce the type which 'auto' stands in for. + if (VDecl->getType()->isUndeducedType()) { + // Attempt typo correction early so that the type of the init expression can + // be deduced based on the chosen correction if the original init contains a + // TypoExpr. + ExprResult Res = CorrectDelayedTyposInExpr(Init, VDecl); + if (!Res.isUsable()) { + RealDecl->setInvalidDecl(); + return; + } + Init = Res.get(); + + if (DeduceVariableDeclarationType(VDecl, DirectInit, Init)) + return; + } + + // dllimport cannot be used on variable definitions. + if (VDecl->hasAttr() && !VDecl->isStaticDataMember()) { + Diag(VDecl->getLocation(), diag::err_attribute_dllimport_data_definition); + VDecl->setInvalidDecl(); + return; + } + + if (VDecl->isLocalVarDecl() && VDecl->hasExternalStorage()) { + // C99 6.7.8p5. C++ has no such restriction, but that is a defect. + Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); + VDecl->setInvalidDecl(); + return; + } + + if (!VDecl->getType()->isDependentType()) { + // A definition must end up with a complete type, which means it must be + // complete with the restriction that an array type might be completed by + // the initializer; note that later code assumes this restriction. + QualType BaseDeclType = VDecl->getType(); + if (const ArrayType *Array = Context.getAsIncompleteArrayType(BaseDeclType)) + BaseDeclType = Array->getElementType(); + if (RequireCompleteType(VDecl->getLocation(), BaseDeclType, + diag::err_typecheck_decl_incomplete_type)) { + RealDecl->setInvalidDecl(); + return; + } + + // The variable can not have an abstract class type. + if (RequireNonAbstractType(VDecl->getLocation(), VDecl->getType(), + diag::err_abstract_type_in_decl, + AbstractVariableType)) + VDecl->setInvalidDecl(); + } + + // If adding the initializer will turn this declaration into a definition, + // and we already have a definition for this variable, diagnose or otherwise + // handle the situation. + VarDecl *Def; + if ((Def = VDecl->getDefinition()) && Def != VDecl && + (!VDecl->isStaticDataMember() || VDecl->isOutOfLine()) && + !VDecl->isThisDeclarationADemotedDefinition() && + checkVarDeclRedefinition(Def, VDecl)) + return; + + if (getLangOpts().CPlusPlus) { + // C++ [class.static.data]p4 + // If a static data member is of const integral or const + // enumeration type, its declaration in the class definition can + // specify a constant-initializer which shall be an integral + // constant expression (5.19). In that case, the member can appear + // in integral constant expressions. The member shall still be + // defined in a namespace scope if it is used in the program and the + // namespace scope definition shall not contain an initializer. + // + // We already performed a redefinition check above, but for static + // data members we also need to check whether there was an in-class + // declaration with an initializer. + if (VDecl->isStaticDataMember() && VDecl->getCanonicalDecl()->hasInit()) { + Diag(Init->getExprLoc(), diag::err_static_data_member_reinitialization) + << VDecl->getDeclName(); + Diag(VDecl->getCanonicalDecl()->getInit()->getExprLoc(), + diag::note_previous_initializer) + << 0; + return; + } + + if (VDecl->hasLocalStorage()) + setFunctionHasBranchProtectedScope(); + + if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer)) { + VDecl->setInvalidDecl(); + return; + } + } + + // OpenCL 1.1 6.5.2: "Variables allocated in the __local address space inside + // a kernel function cannot be initialized." + if (VDecl->getType().getAddressSpace() == LangAS::opencl_local) { + Diag(VDecl->getLocation(), diag::err_local_cant_init); + VDecl->setInvalidDecl(); + return; + } + + // Get the decls type and save a reference for later, since + // CheckInitializerTypes may change it. + QualType DclT = VDecl->getType(), SavT = DclT; + + // Expressions default to 'id' when we're in a debugger + // and we are assigning it to a variable of Objective-C pointer type. + if (getLangOpts().DebuggerCastResultToId && DclT->isObjCObjectPointerType() && + Init->getType() == Context.UnknownAnyTy) { + ExprResult Result = forceUnknownAnyToType(Init, Context.getObjCIdType()); + if (Result.isInvalid()) { + VDecl->setInvalidDecl(); + return; + } + Init = Result.get(); + } + + // Perform the initialization. + ParenListExpr *CXXDirectInit = dyn_cast(Init); + if (!VDecl->isInvalidDecl()) { + InitializedEntity Entity = InitializedEntity::InitializeVariable(VDecl); + InitializationKind Kind = InitializationKind::CreateForInit( + VDecl->getLocation(), DirectInit, Init); + + MultiExprArg Args = Init; + if (CXXDirectInit) + Args = MultiExprArg(CXXDirectInit->getExprs(), + CXXDirectInit->getNumExprs()); + + // Try to correct any TypoExprs in the initialization arguments. + for (size_t Idx = 0; Idx < Args.size(); ++Idx) { + ExprResult Res = CorrectDelayedTyposInExpr( + Args[Idx], VDecl, [this, Entity, Kind](Expr *E) { + InitializationSequence Init(*this, Entity, Kind, MultiExprArg(E)); + return Init.Failed() ? ExprError() : E; + }); + if (Res.isInvalid()) { + VDecl->setInvalidDecl(); + } else if (Res.get() != Args[Idx]) { + Args[Idx] = Res.get(); + } + } + if (VDecl->isInvalidDecl()) + return; + + InitializationSequence InitSeq(*this, Entity, Kind, Args, + /*TopLevelOfInitList=*/false, + /*TreatUnavailableAsInvalid=*/false); + ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Args, &DclT); + if (Result.isInvalid()) { + VDecl->setInvalidDecl(); + return; + } + + Init = Result.getAs(); + } + + // Check for self-references within variable initializers. + // Variables declared within a function/method body (except for references) + // are handled by a dataflow analysis. + if (!VDecl->hasLocalStorage() || VDecl->getType()->isRecordType() || + VDecl->getType()->isReferenceType()) { + CheckSelfReference(*this, RealDecl, Init, DirectInit); + } + + // If the type changed, it means we had an incomplete type that was + // completed by the initializer. For example: + // int ary[] = { 1, 3, 5 }; + // "ary" transitions from an IncompleteArrayType to a ConstantArrayType. + if (!VDecl->isInvalidDecl() && (DclT != SavT)) + VDecl->setType(DclT); + + if (!VDecl->isInvalidDecl()) { + checkUnsafeAssigns(VDecl->getLocation(), VDecl->getType(), Init); + + if (VDecl->hasAttr()) + checkRetainCycles(VDecl, Init); + + // It is safe to assign a weak reference into a strong variable. + // Although this code can still have problems: + // id x = self.weakProp; + // id y = self.weakProp; + // we do not warn to warn spuriously when 'x' and 'y' are on separate + // paths through the function. This should be revisited if + // -Wrepeated-use-of-weak is made flow-sensitive. + if (FunctionScopeInfo *FSI = getCurFunction()) + if ((VDecl->getType().getObjCLifetime() == Qualifiers::OCL_Strong || + VDecl->getType().isNonWeakInMRRWithObjCWeak(Context)) && + !Diags.isIgnored(diag::warn_arc_repeated_use_of_weak, + Init->getBeginLoc())) + FSI->markSafeWeakUse(Init); + } + + // The initialization is usually a full-expression. + // + // FIXME: If this is a braced initialization of an aggregate, it is not + // an expression, and each individual field initializer is a separate + // full-expression. For instance, in: + // + // struct Temp { ~Temp(); }; + // struct S { S(Temp); }; + // struct T { S a, b; } t = { Temp(), Temp() } + // + // we should destroy the first Temp before constructing the second. + ExprResult Result = + ActOnFinishFullExpr(Init, VDecl->getLocation(), + /*DiscardedValue*/ false, VDecl->isConstexpr()); + if (Result.isInvalid()) { + VDecl->setInvalidDecl(); + return; + } + Init = Result.get(); + + // Attach the initializer to the decl. + VDecl->setInit(Init); + + if (VDecl->isLocalVarDecl()) { + // Don't check the initializer if the declaration is malformed. + if (VDecl->isInvalidDecl()) { + // do nothing + + // OpenCL v1.2 s6.5.3: __constant locals must be constant-initialized. + // This is true even in OpenCL C++. + } else if (VDecl->getType().getAddressSpace() == LangAS::opencl_constant) { + CheckForConstantInitializer(Init, DclT); + + // Otherwise, C++ does not restrict the initializer. + } else if (getLangOpts().CPlusPlus) { + // do nothing + + // C99 6.7.8p4: All the expressions in an initializer for an object that has + // static storage duration shall be constant expressions or string literals. + } else if (VDecl->getStorageClass() == SC_Static) { + CheckForConstantInitializer(Init, DclT); + + // C89 is stricter than C99 for aggregate initializers. + // C89 6.5.7p3: All the expressions [...] in an initializer list + // for an object that has aggregate or union type shall be + // constant expressions. + } else if (!getLangOpts().C99 && VDecl->getType()->isAggregateType() && + isa(Init)) { + const Expr *Culprit; + if (!Init->isConstantInitializer(Context, false, &Culprit)) { + Diag(Culprit->getExprLoc(), + diag::ext_aggregate_init_not_constant) + << Culprit->getSourceRange(); + } + } + } else if (VDecl->isStaticDataMember() && !VDecl->isInline() && + VDecl->getLexicalDeclContext()->isRecord()) { + // This is an in-class initialization for a static data member, e.g., + // + // struct S { + // static const int value = 17; + // }; + + // C++ [class.mem]p4: + // A member-declarator can contain a constant-initializer only + // if it declares a static member (9.4) of const integral or + // const enumeration type, see 9.4.2. + // + // C++11 [class.static.data]p3: + // If a non-volatile non-inline const static data member is of integral + // or enumeration type, its declaration in the class definition can + // specify a brace-or-equal-initializer in which every initializer-clause + // that is an assignment-expression is a constant expression. A static + // data member of literal type can be declared in the class definition + // with the constexpr specifier; if so, its declaration shall specify a + // brace-or-equal-initializer in which every initializer-clause that is + // an assignment-expression is a constant expression. + + // Do nothing on dependent types. + if (DclT->isDependentType()) { + + // Allow any 'static constexpr' members, whether or not they are of literal + // type. We separately check that every constexpr variable is of literal + // type. + } else if (VDecl->isConstexpr()) { + + // Require constness. + } else if (!DclT.isConstQualified()) { + Diag(VDecl->getLocation(), diag::err_in_class_initializer_non_const) + << Init->getSourceRange(); + VDecl->setInvalidDecl(); + + // We allow integer constant expressions in all cases. + } else if (DclT->isIntegralOrEnumerationType()) { + // Check whether the expression is a constant expression. + SourceLocation Loc; + if (getLangOpts().CPlusPlus11 && DclT.isVolatileQualified()) + // In C++11, a non-constexpr const static data member with an + // in-class initializer cannot be volatile. + Diag(VDecl->getLocation(), diag::err_in_class_initializer_volatile); + else if (Init->isValueDependent()) + ; // Nothing to check. + else if (Init->isIntegerConstantExpr(Context, &Loc)) + ; // Ok, it's an ICE! + else if (Init->getType()->isScopedEnumeralType() && + Init->isCXX11ConstantExpr(Context)) + ; // Ok, it is a scoped-enum constant expression. + else if (Init->isEvaluatable(Context)) { + // If we can constant fold the initializer through heroics, accept it, + // but report this as a use of an extension for -pedantic. + Diag(Loc, diag::ext_in_class_initializer_non_constant) + << Init->getSourceRange(); + } else { + // Otherwise, this is some crazy unknown case. Report the issue at the + // location provided by the isIntegerConstantExpr failed check. + Diag(Loc, diag::err_in_class_initializer_non_constant) + << Init->getSourceRange(); + VDecl->setInvalidDecl(); + } + + // We allow foldable floating-point constants as an extension. + } else if (DclT->isFloatingType()) { // also permits complex, which is ok + // In C++98, this is a GNU extension. In C++11, it is not, but we support + // it anyway and provide a fixit to add the 'constexpr'. + if (getLangOpts().CPlusPlus11) { + Diag(VDecl->getLocation(), + diag::ext_in_class_initializer_float_type_cxx11) + << DclT << Init->getSourceRange(); + Diag(VDecl->getBeginLoc(), + diag::note_in_class_initializer_float_type_cxx11) + << FixItHint::CreateInsertion(VDecl->getBeginLoc(), "constexpr "); + } else { + Diag(VDecl->getLocation(), diag::ext_in_class_initializer_float_type) + << DclT << Init->getSourceRange(); + + if (!Init->isValueDependent() && !Init->isEvaluatable(Context)) { + Diag(Init->getExprLoc(), diag::err_in_class_initializer_non_constant) + << Init->getSourceRange(); + VDecl->setInvalidDecl(); + } + } + + // Suggest adding 'constexpr' in C++11 for literal types. + } else if (getLangOpts().CPlusPlus11 && DclT->isLiteralType(Context)) { + Diag(VDecl->getLocation(), diag::err_in_class_initializer_literal_type) + << DclT << Init->getSourceRange() + << FixItHint::CreateInsertion(VDecl->getBeginLoc(), "constexpr "); + VDecl->setConstexpr(true); + + } else { + Diag(VDecl->getLocation(), diag::err_in_class_initializer_bad_type) + << DclT << Init->getSourceRange(); + VDecl->setInvalidDecl(); + } + } else if (VDecl->isFileVarDecl()) { + // In C, extern is typically used to avoid tentative definitions when + // declaring variables in headers, but adding an intializer makes it a + // definition. This is somewhat confusing, so GCC and Clang both warn on it. + // In C++, extern is often used to give implictly static const variables + // external linkage, so don't warn in that case. If selectany is present, + // this might be header code intended for C and C++ inclusion, so apply the + // C++ rules. + if (VDecl->getStorageClass() == SC_Extern && + ((!getLangOpts().CPlusPlus && !VDecl->hasAttr()) || + !Context.getBaseElementType(VDecl->getType()).isConstQualified()) && + !(getLangOpts().CPlusPlus && VDecl->isExternC()) && + !isTemplateInstantiation(VDecl->getTemplateSpecializationKind())) + Diag(VDecl->getLocation(), diag::warn_extern_init); + ++ // In Microsoft C++ mode, a const variable defined in namespace scope has ++ // external linkage by default if the variable is declared with ++ // __declspec(dllexport). ++ if (Context.getTargetInfo().getCXXABI().isMicrosoft() && ++ getLangOpts().CPlusPlus && ++ VDecl->getType().isConstQualified() && ++ VDecl->hasAttr() && ++ VDecl->getDefinition()) ++ VDecl->setStorageClass(SC_Extern); ++ + // C99 6.7.8p4. All file scoped initializers need to be constant. + if (!getLangOpts().CPlusPlus && !VDecl->isInvalidDecl()) + CheckForConstantInitializer(Init, DclT); + } + + // We will represent direct-initialization similarly to copy-initialization: + // int x(1); -as-> int x = 1; + // ClassType x(a,b,c); -as-> ClassType x = ClassType(a,b,c); + // + // Clients that want to distinguish between the two forms, can check for + // direct initializer using VarDecl::getInitStyle(). + // A major benefit is that clients that don't particularly care about which + // exactly form was it (like the CodeGen) can handle both cases without + // special case code. + + // C++ 8.5p11: + // The form of initialization (using parentheses or '=') is generally + // insignificant, but does matter when the entity being initialized has a + // class type. + if (CXXDirectInit) { + assert(DirectInit && "Call-style initializer must be direct init."); + VDecl->setInitStyle(VarDecl::CallInit); + } else if (DirectInit) { + // This must be list-initialization. No other way is direct-initialization. + VDecl->setInitStyle(VarDecl::ListInit); + } + + CheckCompleteVariableDeclaration(VDecl); + } + + /// ActOnInitializerError - Given that there was an error parsing an + /// initializer for the given declaration, try to return to some form + /// of sanity. + void Sema::ActOnInitializerError(Decl *D) { + // Our main concern here is re-establishing invariants like "a + // variable's type is either dependent or complete". + if (!D || D->isInvalidDecl()) return; + + VarDecl *VD = dyn_cast(D); + if (!VD) return; + + // Bindings are not usable if we can't make sense of the initializer. + if (auto *DD = dyn_cast(D)) + for (auto *BD : DD->bindings()) + BD->setInvalidDecl(); + + // Auto types are meaningless if we can't make sense of the initializer. + if (ParsingInitForAutoVars.count(D)) { + D->setInvalidDecl(); + return; + } + + QualType Ty = VD->getType(); + if (Ty->isDependentType()) return; + + // Require a complete type. + if (RequireCompleteType(VD->getLocation(), + Context.getBaseElementType(Ty), + diag::err_typecheck_decl_incomplete_type)) { + VD->setInvalidDecl(); + return; + } + + // Require a non-abstract type. + if (RequireNonAbstractType(VD->getLocation(), Ty, + diag::err_abstract_type_in_decl, + AbstractVariableType)) { + VD->setInvalidDecl(); + return; + } + + // Don't bother complaining about constructors or destructors, + // though. + } + + void Sema::ActOnUninitializedDecl(Decl *RealDecl) { + // If there is no declaration, there was an error parsing it. Just ignore it. + if (!RealDecl) + return; + + if (VarDecl *Var = dyn_cast(RealDecl)) { + QualType Type = Var->getType(); + + // C++1z [dcl.dcl]p1 grammar implies that an initializer is mandatory. + if (isa(RealDecl)) { + Diag(Var->getLocation(), diag::err_decomp_decl_requires_init) << Var; + Var->setInvalidDecl(); + return; + } + + Expr *TmpInit = nullptr; + if (Type->isUndeducedType() && + DeduceVariableDeclarationType(Var, false, TmpInit)) + return; + + // C++11 [class.static.data]p3: A static data member can be declared with + // the constexpr specifier; if so, its declaration shall specify + // a brace-or-equal-initializer. + // C++11 [dcl.constexpr]p1: The constexpr specifier shall be applied only to + // the definition of a variable [...] or the declaration of a static data + // member. + if (Var->isConstexpr() && !Var->isThisDeclarationADefinition() && + !Var->isThisDeclarationADemotedDefinition()) { + if (Var->isStaticDataMember()) { + // C++1z removes the relevant rule; the in-class declaration is always + // a definition there. + if (!getLangOpts().CPlusPlus17) { + Diag(Var->getLocation(), + diag::err_constexpr_static_mem_var_requires_init) + << Var->getDeclName(); + Var->setInvalidDecl(); + return; + } + } else { + Diag(Var->getLocation(), diag::err_invalid_constexpr_var_decl); + Var->setInvalidDecl(); + return; + } + } + + // OpenCL v1.1 s6.5.3: variables declared in the constant address space must + // be initialized. + if (!Var->isInvalidDecl() && + Var->getType().getAddressSpace() == LangAS::opencl_constant && + Var->getStorageClass() != SC_Extern && !Var->getInit()) { + Diag(Var->getLocation(), diag::err_opencl_constant_no_init); + Var->setInvalidDecl(); + return; + } + + switch (Var->isThisDeclarationADefinition()) { + case VarDecl::Definition: + if (!Var->isStaticDataMember() || !Var->getAnyInitializer()) + break; + + // We have an out-of-line definition of a static data member + // that has an in-class initializer, so we type-check this like + // a declaration. + // + LLVM_FALLTHROUGH; + + case VarDecl::DeclarationOnly: + // It's only a declaration. + + // Block scope. C99 6.7p7: If an identifier for an object is + // declared with no linkage (C99 6.2.2p6), the type for the + // object shall be complete. + if (!Type->isDependentType() && Var->isLocalVarDecl() && + !Var->hasLinkage() && !Var->isInvalidDecl() && + RequireCompleteType(Var->getLocation(), Type, + diag::err_typecheck_decl_incomplete_type)) + Var->setInvalidDecl(); + + // Make sure that the type is not abstract. + if (!Type->isDependentType() && !Var->isInvalidDecl() && + RequireNonAbstractType(Var->getLocation(), Type, + diag::err_abstract_type_in_decl, + AbstractVariableType)) + Var->setInvalidDecl(); + if (!Type->isDependentType() && !Var->isInvalidDecl() && + Var->getStorageClass() == SC_PrivateExtern) { + Diag(Var->getLocation(), diag::warn_private_extern); + Diag(Var->getLocation(), diag::note_private_extern); + } + + return; + + case VarDecl::TentativeDefinition: + // File scope. C99 6.9.2p2: A declaration of an identifier for an + // object that has file scope without an initializer, and without a + // storage-class specifier or with the storage-class specifier "static", + // constitutes a tentative definition. Note: A tentative definition with + // external linkage is valid (C99 6.2.2p5). + if (!Var->isInvalidDecl()) { + if (const IncompleteArrayType *ArrayT + = Context.getAsIncompleteArrayType(Type)) { + if (RequireCompleteType(Var->getLocation(), + ArrayT->getElementType(), + diag::err_illegal_decl_array_incomplete_type)) + Var->setInvalidDecl(); + } else if (Var->getStorageClass() == SC_Static) { + // C99 6.9.2p3: If the declaration of an identifier for an object is + // a tentative definition and has internal linkage (C99 6.2.2p3), the + // declared type shall not be an incomplete type. + // NOTE: code such as the following + // static struct s; + // struct s { int a; }; + // is accepted by gcc. Hence here we issue a warning instead of + // an error and we do not invalidate the static declaration. + // NOTE: to avoid multiple warnings, only check the first declaration. + if (Var->isFirstDecl()) + RequireCompleteType(Var->getLocation(), Type, + diag::ext_typecheck_decl_incomplete_type); + } + } + + // Record the tentative definition; we're done. + if (!Var->isInvalidDecl()) + TentativeDefinitions.push_back(Var); + return; + } + + // Provide a specific diagnostic for uninitialized variable + // definitions with incomplete array type. + if (Type->isIncompleteArrayType()) { + Diag(Var->getLocation(), + diag::err_typecheck_incomplete_array_needs_initializer); + Var->setInvalidDecl(); + return; + } + + // Provide a specific diagnostic for uninitialized variable + // definitions with reference type. + if (Type->isReferenceType()) { + Diag(Var->getLocation(), diag::err_reference_var_requires_init) + << Var->getDeclName() + << SourceRange(Var->getLocation(), Var->getLocation()); + Var->setInvalidDecl(); + return; + } + + // Do not attempt to type-check the default initializer for a + // variable with dependent type. + if (Type->isDependentType()) + return; + + if (Var->isInvalidDecl()) + return; + + if (!Var->hasAttr()) { + if (RequireCompleteType(Var->getLocation(), + Context.getBaseElementType(Type), + diag::err_typecheck_decl_incomplete_type)) { + Var->setInvalidDecl(); + return; + } + } else { + return; + } + + // The variable can not have an abstract class type. + if (RequireNonAbstractType(Var->getLocation(), Type, + diag::err_abstract_type_in_decl, + AbstractVariableType)) { + Var->setInvalidDecl(); + return; + } + + // Check for jumps past the implicit initializer. C++0x + // clarifies that this applies to a "variable with automatic + // storage duration", not a "local variable". + // C++11 [stmt.dcl]p3 + // A program that jumps from a point where a variable with automatic + // storage duration is not in scope to a point where it is in scope is + // ill-formed unless the variable has scalar type, class type with a + // trivial default constructor and a trivial destructor, a cv-qualified + // version of one of these types, or an array of one of the preceding + // types and is declared without an initializer. + if (getLangOpts().CPlusPlus && Var->hasLocalStorage()) { + if (const RecordType *Record + = Context.getBaseElementType(Type)->getAs()) { + CXXRecordDecl *CXXRecord = cast(Record->getDecl()); + // Mark the function (if we're in one) for further checking even if the + // looser rules of C++11 do not require such checks, so that we can + // diagnose incompatibilities with C++98. + if (!CXXRecord->isPOD()) + setFunctionHasBranchProtectedScope(); + } + } + + // C++03 [dcl.init]p9: + // If no initializer is specified for an object, and the + // object is of (possibly cv-qualified) non-POD class type (or + // array thereof), the object shall be default-initialized; if + // the object is of const-qualified type, the underlying class + // type shall have a user-declared default + // constructor. Otherwise, if no initializer is specified for + // a non- static object, the object and its subobjects, if + // any, have an indeterminate initial value); if the object + // or any of its subobjects are of const-qualified type, the + // program is ill-formed. + // C++0x [dcl.init]p11: + // If no initializer is specified for an object, the object is + // default-initialized; [...]. + InitializedEntity Entity = InitializedEntity::InitializeVariable(Var); + InitializationKind Kind + = InitializationKind::CreateDefault(Var->getLocation()); + + InitializationSequence InitSeq(*this, Entity, Kind, None); + ExprResult Init = InitSeq.Perform(*this, Entity, Kind, None); + if (Init.isInvalid()) + Var->setInvalidDecl(); + else if (Init.get()) { + Var->setInit(MaybeCreateExprWithCleanups(Init.get())); + // This is important for template substitution. + Var->setInitStyle(VarDecl::CallInit); + } + + CheckCompleteVariableDeclaration(Var); + } + } + + void Sema::ActOnCXXForRangeDecl(Decl *D) { + // If there is no declaration, there was an error parsing it. Ignore it. + if (!D) + return; + + VarDecl *VD = dyn_cast(D); + if (!VD) { + Diag(D->getLocation(), diag::err_for_range_decl_must_be_var); + D->setInvalidDecl(); + return; + } + + VD->setCXXForRangeDecl(true); + + // for-range-declaration cannot be given a storage class specifier. + int Error = -1; + switch (VD->getStorageClass()) { + case SC_None: + break; + case SC_Extern: + Error = 0; + break; + case SC_Static: + Error = 1; + break; + case SC_PrivateExtern: + Error = 2; + break; + case SC_Auto: + Error = 3; + break; + case SC_Register: + Error = 4; + break; + } + if (Error != -1) { + Diag(VD->getOuterLocStart(), diag::err_for_range_storage_class) + << VD->getDeclName() << Error; + D->setInvalidDecl(); + } + } + + StmtResult + Sema::ActOnCXXForRangeIdentifier(Scope *S, SourceLocation IdentLoc, + IdentifierInfo *Ident, + ParsedAttributes &Attrs, + SourceLocation AttrEnd) { + // C++1y [stmt.iter]p1: + // A range-based for statement of the form + // for ( for-range-identifier : for-range-initializer ) statement + // is equivalent to + // for ( auto&& for-range-identifier : for-range-initializer ) statement + DeclSpec DS(Attrs.getPool().getFactory()); + + const char *PrevSpec; + unsigned DiagID; + DS.SetTypeSpecType(DeclSpec::TST_auto, IdentLoc, PrevSpec, DiagID, + getPrintingPolicy()); + + Declarator D(DS, DeclaratorContext::ForContext); + D.SetIdentifier(Ident, IdentLoc); + D.takeAttributes(Attrs, AttrEnd); + + ParsedAttributes EmptyAttrs(Attrs.getPool().getFactory()); + D.AddTypeInfo(DeclaratorChunk::getReference(0, IdentLoc, /*lvalue*/ false), + IdentLoc); + Decl *Var = ActOnDeclarator(S, D); + cast(Var)->setCXXForRangeDecl(true); + FinalizeDeclaration(Var); + return ActOnDeclStmt(FinalizeDeclaratorGroup(S, DS, Var), IdentLoc, + AttrEnd.isValid() ? AttrEnd : IdentLoc); + } + + void Sema::CheckCompleteVariableDeclaration(VarDecl *var) { + if (var->isInvalidDecl()) return; + + if (getLangOpts().OpenCL) { + // OpenCL v2.0 s6.12.5 - Every block variable declaration must have an + // initialiser + if (var->getTypeSourceInfo()->getType()->isBlockPointerType() && + !var->hasInit()) { + Diag(var->getLocation(), diag::err_opencl_invalid_block_declaration) + << 1 /*Init*/; + var->setInvalidDecl(); + return; + } + } + + // In Objective-C, don't allow jumps past the implicit initialization of a + // local retaining variable. + if (getLangOpts().ObjC && + var->hasLocalStorage()) { + switch (var->getType().getObjCLifetime()) { + case Qualifiers::OCL_None: + case Qualifiers::OCL_ExplicitNone: + case Qualifiers::OCL_Autoreleasing: + break; + + case Qualifiers::OCL_Weak: + case Qualifiers::OCL_Strong: + setFunctionHasBranchProtectedScope(); + break; + } + } + + if (var->hasLocalStorage() && + var->getType().isDestructedType() == QualType::DK_nontrivial_c_struct) + setFunctionHasBranchProtectedScope(); + + // Warn about externally-visible variables being defined without a + // prior declaration. We only want to do this for global + // declarations, but we also specifically need to avoid doing it for + // class members because the linkage of an anonymous class can + // change if it's later given a typedef name. + if (var->isThisDeclarationADefinition() && + var->getDeclContext()->getRedeclContext()->isFileContext() && + var->isExternallyVisible() && var->hasLinkage() && + !var->isInline() && !var->getDescribedVarTemplate() && + !isTemplateInstantiation(var->getTemplateSpecializationKind()) && + !getDiagnostics().isIgnored(diag::warn_missing_variable_declarations, + var->getLocation())) { + // Find a previous declaration that's not a definition. + VarDecl *prev = var->getPreviousDecl(); + while (prev && prev->isThisDeclarationADefinition()) + prev = prev->getPreviousDecl(); + + if (!prev) + Diag(var->getLocation(), diag::warn_missing_variable_declarations) << var; + } + + // Cache the result of checking for constant initialization. + Optional CacheHasConstInit; + const Expr *CacheCulprit; + auto checkConstInit = [&]() mutable { + if (!CacheHasConstInit) + CacheHasConstInit = var->getInit()->isConstantInitializer( + Context, var->getType()->isReferenceType(), &CacheCulprit); + return *CacheHasConstInit; + }; + + if (var->getTLSKind() == VarDecl::TLS_Static) { + if (var->getType().isDestructedType()) { + // GNU C++98 edits for __thread, [basic.start.term]p3: + // The type of an object with thread storage duration shall not + // have a non-trivial destructor. + Diag(var->getLocation(), diag::err_thread_nontrivial_dtor); + if (getLangOpts().CPlusPlus11) + Diag(var->getLocation(), diag::note_use_thread_local); + } else if (getLangOpts().CPlusPlus && var->hasInit()) { + if (!checkConstInit()) { + // GNU C++98 edits for __thread, [basic.start.init]p4: + // An object of thread storage duration shall not require dynamic + // initialization. + // FIXME: Need strict checking here. + Diag(CacheCulprit->getExprLoc(), diag::err_thread_dynamic_init) + << CacheCulprit->getSourceRange(); + if (getLangOpts().CPlusPlus11) + Diag(var->getLocation(), diag::note_use_thread_local); + } + } + } + + // Apply section attributes and pragmas to global variables. + bool GlobalStorage = var->hasGlobalStorage(); + if (GlobalStorage && var->isThisDeclarationADefinition() && + !inTemplateInstantiation()) { + PragmaStack *Stack = nullptr; + int SectionFlags = ASTContext::PSF_Implicit | ASTContext::PSF_Read; + if (var->getType().isConstQualified()) + Stack = &ConstSegStack; + else if (!var->getInit()) { + Stack = &BSSSegStack; + SectionFlags |= ASTContext::PSF_Write; + } else { + Stack = &DataSegStack; + SectionFlags |= ASTContext::PSF_Write; + } + if (Stack->CurrentValue && !var->hasAttr()) { + var->addAttr(SectionAttr::CreateImplicit( + Context, SectionAttr::Declspec_allocate, + Stack->CurrentValue->getString(), Stack->CurrentPragmaLocation)); + } + if (const SectionAttr *SA = var->getAttr()) + if (UnifySection(SA->getName(), SectionFlags, var)) + var->dropAttr(); + + // Apply the init_seg attribute if this has an initializer. If the + // initializer turns out to not be dynamic, we'll end up ignoring this + // attribute. + if (CurInitSeg && var->getInit()) + var->addAttr(InitSegAttr::CreateImplicit(Context, CurInitSeg->getString(), + CurInitSegLoc)); + } + + // All the following checks are C++ only. + if (!getLangOpts().CPlusPlus) { + // If this variable must be emitted, add it as an initializer for the + // current module. + if (Context.DeclMustBeEmitted(var) && !ModuleScopes.empty()) + Context.addModuleInitializer(ModuleScopes.back().Module, var); + return; + } + + if (auto *DD = dyn_cast(var)) + CheckCompleteDecompositionDeclaration(DD); + + QualType type = var->getType(); + if (type->isDependentType()) return; + + if (var->hasAttr()) + getCurFunction()->addByrefBlockVar(var); + + Expr *Init = var->getInit(); + bool IsGlobal = GlobalStorage && !var->isStaticLocal(); + QualType baseType = Context.getBaseElementType(type); + + if (Init && !Init->isValueDependent()) { + if (var->isConstexpr()) { + SmallVector Notes; + if (!var->evaluateValue(Notes) || !var->isInitICE()) { + SourceLocation DiagLoc = var->getLocation(); + // If the note doesn't add any useful information other than a source + // location, fold it into the primary diagnostic. + if (Notes.size() == 1 && Notes[0].second.getDiagID() == + diag::note_invalid_subexpr_in_const_expr) { + DiagLoc = Notes[0].first; + Notes.clear(); + } + Diag(DiagLoc, diag::err_constexpr_var_requires_const_init) + << var << Init->getSourceRange(); + for (unsigned I = 0, N = Notes.size(); I != N; ++I) + Diag(Notes[I].first, Notes[I].second); + } + } else if (var->isUsableInConstantExpressions(Context)) { + // Check whether the initializer of a const variable of integral or + // enumeration type is an ICE now, since we can't tell whether it was + // initialized by a constant expression if we check later. + var->checkInitIsICE(); + } + + // Don't emit further diagnostics about constexpr globals since they + // were just diagnosed. + if (!var->isConstexpr() && GlobalStorage && + var->hasAttr()) { + // FIXME: Need strict checking in C++03 here. + bool DiagErr = getLangOpts().CPlusPlus11 + ? !var->checkInitIsICE() : !checkConstInit(); + if (DiagErr) { + auto attr = var->getAttr(); + Diag(var->getLocation(), diag::err_require_constant_init_failed) + << Init->getSourceRange(); + Diag(attr->getLocation(), diag::note_declared_required_constant_init_here) + << attr->getRange(); + if (getLangOpts().CPlusPlus11) { + APValue Value; + SmallVector Notes; + Init->EvaluateAsInitializer(Value, getASTContext(), var, Notes); + for (auto &it : Notes) + Diag(it.first, it.second); + } else { + Diag(CacheCulprit->getExprLoc(), + diag::note_invalid_subexpr_in_const_expr) + << CacheCulprit->getSourceRange(); + } + } + } + else if (!var->isConstexpr() && IsGlobal && + !getDiagnostics().isIgnored(diag::warn_global_constructor, + var->getLocation())) { + // Warn about globals which don't have a constant initializer. Don't + // warn about globals with a non-trivial destructor because we already + // warned about them. + CXXRecordDecl *RD = baseType->getAsCXXRecordDecl(); + if (!(RD && !RD->hasTrivialDestructor())) { + if (!checkConstInit()) + Diag(var->getLocation(), diag::warn_global_constructor) + << Init->getSourceRange(); + } + } + } + + // Require the destructor. + if (const RecordType *recordType = baseType->getAs()) + FinalizeVarWithDestructor(var, recordType); + + // If this variable must be emitted, add it as an initializer for the current + // module. + if (Context.DeclMustBeEmitted(var) && !ModuleScopes.empty()) + Context.addModuleInitializer(ModuleScopes.back().Module, var); + } + + /// Determines if a variable's alignment is dependent. + static bool hasDependentAlignment(VarDecl *VD) { + if (VD->getType()->isDependentType()) + return true; + for (auto *I : VD->specific_attrs()) + if (I->isAlignmentDependent()) + return true; + return false; + } + + /// Check if VD needs to be dllexport/dllimport due to being in a + /// dllexport/import function. + void Sema::CheckStaticLocalForDllExport(VarDecl *VD) { + assert(VD->isStaticLocal()); + + auto *FD = dyn_cast_or_null(VD->getParentFunctionOrMethod()); + + // Find outermost function when VD is in lambda function. + while (FD && !getDLLAttr(FD) && + !FD->hasAttr() && + !FD->hasAttr()) { + FD = dyn_cast_or_null(FD->getParentFunctionOrMethod()); + } + + if (!FD) + return; + + // Static locals inherit dll attributes from their function. + if (Attr *A = getDLLAttr(FD)) { + auto *NewAttr = cast(A->clone(getASTContext())); + NewAttr->setInherited(true); + VD->addAttr(NewAttr); + } else if (Attr *A = FD->getAttr()) { + auto *NewAttr = ::new (getASTContext()) DLLExportAttr(A->getRange(), + getASTContext(), + A->getSpellingListIndex()); + NewAttr->setInherited(true); + VD->addAttr(NewAttr); + + // Export this function to enforce exporting this static variable even + // if it is not used in this compilation unit. + if (!FD->hasAttr()) + FD->addAttr(NewAttr); + + } else if (Attr *A = FD->getAttr()) { + auto *NewAttr = ::new (getASTContext()) DLLImportAttr(A->getRange(), + getASTContext(), + A->getSpellingListIndex()); + NewAttr->setInherited(true); + VD->addAttr(NewAttr); + } + } + + /// FinalizeDeclaration - called by ParseDeclarationAfterDeclarator to perform + /// any semantic actions necessary after any initializer has been attached. + void Sema::FinalizeDeclaration(Decl *ThisDecl) { + // Note that we are no longer parsing the initializer for this declaration. + ParsingInitForAutoVars.erase(ThisDecl); + + VarDecl *VD = dyn_cast_or_null(ThisDecl); + if (!VD) + return; + + // Apply an implicit SectionAttr if '#pragma clang section bss|data|rodata' is active + if (VD->hasGlobalStorage() && VD->isThisDeclarationADefinition() && + !inTemplateInstantiation() && !VD->hasAttr()) { + if (PragmaClangBSSSection.Valid) + VD->addAttr(PragmaClangBSSSectionAttr::CreateImplicit(Context, + PragmaClangBSSSection.SectionName, + PragmaClangBSSSection.PragmaLocation)); + if (PragmaClangDataSection.Valid) + VD->addAttr(PragmaClangDataSectionAttr::CreateImplicit(Context, + PragmaClangDataSection.SectionName, + PragmaClangDataSection.PragmaLocation)); + if (PragmaClangRodataSection.Valid) + VD->addAttr(PragmaClangRodataSectionAttr::CreateImplicit(Context, + PragmaClangRodataSection.SectionName, + PragmaClangRodataSection.PragmaLocation)); + } + + if (auto *DD = dyn_cast(ThisDecl)) { + for (auto *BD : DD->bindings()) { + FinalizeDeclaration(BD); + } + } + + checkAttributesAfterMerging(*this, *VD); + + // Perform TLS alignment check here after attributes attached to the variable + // which may affect the alignment have been processed. Only perform the check + // if the target has a maximum TLS alignment (zero means no constraints). + if (unsigned MaxAlign = Context.getTargetInfo().getMaxTLSAlign()) { + // Protect the check so that it's not performed on dependent types and + // dependent alignments (we can't determine the alignment in that case). + if (VD->getTLSKind() && !hasDependentAlignment(VD) && + !VD->isInvalidDecl()) { + CharUnits MaxAlignChars = Context.toCharUnitsFromBits(MaxAlign); + if (Context.getDeclAlign(VD) > MaxAlignChars) { + Diag(VD->getLocation(), diag::err_tls_var_aligned_over_maximum) + << (unsigned)Context.getDeclAlign(VD).getQuantity() << VD + << (unsigned)MaxAlignChars.getQuantity(); + } + } + } + + if (VD->isStaticLocal()) { + CheckStaticLocalForDllExport(VD); + + if (dyn_cast_or_null(VD->getParentFunctionOrMethod())) { + // CUDA 8.0 E.3.9.4: Within the body of a __device__ or __global__ + // function, only __shared__ variables or variables without any device + // memory qualifiers may be declared with static storage class. + // Note: It is unclear how a function-scope non-const static variable + // without device memory qualifier is implemented, therefore only static + // const variable without device memory qualifier is allowed. + [&]() { + if (!getLangOpts().CUDA) + return; + if (VD->hasAttr()) + return; + if (VD->getType().isConstQualified() && + !(VD->hasAttr() || VD->hasAttr())) + return; + if (CUDADiagIfDeviceCode(VD->getLocation(), + diag::err_device_static_local_var) + << CurrentCUDATarget()) + VD->setInvalidDecl(); + }(); + } + } + + // Perform check for initializers of device-side global variables. + // CUDA allows empty constructors as initializers (see E.2.3.1, CUDA + // 7.5). We must also apply the same checks to all __shared__ + // variables whether they are local or not. CUDA also allows + // constant initializers for __constant__ and __device__ variables. + if (getLangOpts().CUDA) + checkAllowedCUDAInitializer(VD); + + // Grab the dllimport or dllexport attribute off of the VarDecl. + const InheritableAttr *DLLAttr = getDLLAttr(VD); + + // Imported static data members cannot be defined out-of-line. + if (const auto *IA = dyn_cast_or_null(DLLAttr)) { + if (VD->isStaticDataMember() && VD->isOutOfLine() && + VD->isThisDeclarationADefinition()) { + // We allow definitions of dllimport class template static data members + // with a warning. + CXXRecordDecl *Context = + cast(VD->getFirstDecl()->getDeclContext()); + bool IsClassTemplateMember = + isa(Context) || + Context->getDescribedClassTemplate(); + + Diag(VD->getLocation(), + IsClassTemplateMember + ? diag::warn_attribute_dllimport_static_field_definition + : diag::err_attribute_dllimport_static_field_definition); + Diag(IA->getLocation(), diag::note_attribute); + if (!IsClassTemplateMember) + VD->setInvalidDecl(); + } + } + + // dllimport/dllexport variables cannot be thread local, their TLS index + // isn't exported with the variable. + if (DLLAttr && VD->getTLSKind()) { + auto *F = dyn_cast_or_null(VD->getParentFunctionOrMethod()); + if (F && getDLLAttr(F)) { + assert(VD->isStaticLocal()); + // But if this is a static local in a dlimport/dllexport function, the + // function will never be inlined, which means the var would never be + // imported, so having it marked import/export is safe. + } else { + Diag(VD->getLocation(), diag::err_attribute_dll_thread_local) << VD + << DLLAttr; + VD->setInvalidDecl(); + } + } + + if (UsedAttr *Attr = VD->getAttr()) { + if (!Attr->isInherited() && !VD->isThisDeclarationADefinition()) { + Diag(Attr->getLocation(), diag::warn_attribute_ignored) << Attr; + VD->dropAttr(); + } + } + + const DeclContext *DC = VD->getDeclContext(); + // If there's a #pragma GCC visibility in scope, and this isn't a class + // member, set the visibility of this variable. + if (DC->getRedeclContext()->isFileContext() && VD->isExternallyVisible()) + AddPushedVisibilityAttribute(VD); + + // FIXME: Warn on unused var template partial specializations. + if (VD->isFileVarDecl() && !isa(VD)) + MarkUnusedFileScopedDecl(VD); + + // Now we have parsed the initializer and can update the table of magic + // tag values. + if (!VD->hasAttr() || + !VD->getType()->isIntegralOrEnumerationType()) + return; + + for (const auto *I : ThisDecl->specific_attrs()) { + const Expr *MagicValueExpr = VD->getInit(); + if (!MagicValueExpr) { + continue; + } + llvm::APSInt MagicValueInt; + if (!MagicValueExpr->isIntegerConstantExpr(MagicValueInt, Context)) { + Diag(I->getRange().getBegin(), + diag::err_type_tag_for_datatype_not_ice) + << LangOpts.CPlusPlus << MagicValueExpr->getSourceRange(); + continue; + } + if (MagicValueInt.getActiveBits() > 64) { + Diag(I->getRange().getBegin(), + diag::err_type_tag_for_datatype_too_large) + << LangOpts.CPlusPlus << MagicValueExpr->getSourceRange(); + continue; + } + uint64_t MagicValue = MagicValueInt.getZExtValue(); + RegisterTypeTagForDatatype(I->getArgumentKind(), + MagicValue, + I->getMatchingCType(), + I->getLayoutCompatible(), + I->getMustBeNull()); + } + } + + static bool hasDeducedAuto(DeclaratorDecl *DD) { + auto *VD = dyn_cast(DD); + return VD && !VD->getType()->hasAutoForTrailingReturnType(); + } + + Sema::DeclGroupPtrTy Sema::FinalizeDeclaratorGroup(Scope *S, const DeclSpec &DS, + ArrayRef Group) { + SmallVector Decls; + + if (DS.isTypeSpecOwned()) + Decls.push_back(DS.getRepAsDecl()); + + DeclaratorDecl *FirstDeclaratorInGroup = nullptr; + DecompositionDecl *FirstDecompDeclaratorInGroup = nullptr; + bool DiagnosedMultipleDecomps = false; + DeclaratorDecl *FirstNonDeducedAutoInGroup = nullptr; + bool DiagnosedNonDeducedAuto = false; + + for (unsigned i = 0, e = Group.size(); i != e; ++i) { + if (Decl *D = Group[i]) { + // For declarators, there are some additional syntactic-ish checks we need + // to perform. + if (auto *DD = dyn_cast(D)) { + if (!FirstDeclaratorInGroup) + FirstDeclaratorInGroup = DD; + if (!FirstDecompDeclaratorInGroup) + FirstDecompDeclaratorInGroup = dyn_cast(D); + if (!FirstNonDeducedAutoInGroup && DS.hasAutoTypeSpec() && + !hasDeducedAuto(DD)) + FirstNonDeducedAutoInGroup = DD; + + if (FirstDeclaratorInGroup != DD) { + // A decomposition declaration cannot be combined with any other + // declaration in the same group. + if (FirstDecompDeclaratorInGroup && !DiagnosedMultipleDecomps) { + Diag(FirstDecompDeclaratorInGroup->getLocation(), + diag::err_decomp_decl_not_alone) + << FirstDeclaratorInGroup->getSourceRange() + << DD->getSourceRange(); + DiagnosedMultipleDecomps = true; + } + + // A declarator that uses 'auto' in any way other than to declare a + // variable with a deduced type cannot be combined with any other + // declarator in the same group. + if (FirstNonDeducedAutoInGroup && !DiagnosedNonDeducedAuto) { + Diag(FirstNonDeducedAutoInGroup->getLocation(), + diag::err_auto_non_deduced_not_alone) + << FirstNonDeducedAutoInGroup->getType() + ->hasAutoForTrailingReturnType() + << FirstDeclaratorInGroup->getSourceRange() + << DD->getSourceRange(); + DiagnosedNonDeducedAuto = true; + } + } + } + + Decls.push_back(D); + } + } + + if (DeclSpec::isDeclRep(DS.getTypeSpecType())) { + if (TagDecl *Tag = dyn_cast_or_null(DS.getRepAsDecl())) { + handleTagNumbering(Tag, S); + if (FirstDeclaratorInGroup && !Tag->hasNameForLinkage() && + getLangOpts().CPlusPlus) + Context.addDeclaratorForUnnamedTagDecl(Tag, FirstDeclaratorInGroup); + } + } + + return BuildDeclaratorGroup(Decls); + } + + /// BuildDeclaratorGroup - convert a list of declarations into a declaration + /// group, performing any necessary semantic checking. + Sema::DeclGroupPtrTy + Sema::BuildDeclaratorGroup(MutableArrayRef Group) { + // C++14 [dcl.spec.auto]p7: (DR1347) + // If the type that replaces the placeholder type is not the same in each + // deduction, the program is ill-formed. + if (Group.size() > 1) { + QualType Deduced; + VarDecl *DeducedDecl = nullptr; + for (unsigned i = 0, e = Group.size(); i != e; ++i) { + VarDecl *D = dyn_cast(Group[i]); + if (!D || D->isInvalidDecl()) + break; + DeducedType *DT = D->getType()->getContainedDeducedType(); + if (!DT || DT->getDeducedType().isNull()) + continue; + if (Deduced.isNull()) { + Deduced = DT->getDeducedType(); + DeducedDecl = D; + } else if (!Context.hasSameType(DT->getDeducedType(), Deduced)) { + auto *AT = dyn_cast(DT); + Diag(D->getTypeSourceInfo()->getTypeLoc().getBeginLoc(), + diag::err_auto_different_deductions) + << (AT ? (unsigned)AT->getKeyword() : 3) + << Deduced << DeducedDecl->getDeclName() + << DT->getDeducedType() << D->getDeclName() + << DeducedDecl->getInit()->getSourceRange() + << D->getInit()->getSourceRange(); + D->setInvalidDecl(); + break; + } + } + } + + ActOnDocumentableDecls(Group); + + return DeclGroupPtrTy::make( + DeclGroupRef::Create(Context, Group.data(), Group.size())); + } + + void Sema::ActOnDocumentableDecl(Decl *D) { + ActOnDocumentableDecls(D); + } + + void Sema::ActOnDocumentableDecls(ArrayRef Group) { + // Don't parse the comment if Doxygen diagnostics are ignored. + if (Group.empty() || !Group[0]) + return; + + if (Diags.isIgnored(diag::warn_doc_param_not_found, + Group[0]->getLocation()) && + Diags.isIgnored(diag::warn_unknown_comment_command_name, + Group[0]->getLocation())) + return; + + if (Group.size() >= 2) { + // This is a decl group. Normally it will contain only declarations + // produced from declarator list. But in case we have any definitions or + // additional declaration references: + // 'typedef struct S {} S;' + // 'typedef struct S *S;' + // 'struct S *pS;' + // FinalizeDeclaratorGroup adds these as separate declarations. + Decl *MaybeTagDecl = Group[0]; + if (MaybeTagDecl && isa(MaybeTagDecl)) { + Group = Group.slice(1); + } + } + + // See if there are any new comments that are not attached to a decl. + ArrayRef Comments = Context.getRawCommentList().getComments(); + if (!Comments.empty() && + !Comments.back()->isAttached()) { + // There is at least one comment that not attached to a decl. + // Maybe it should be attached to one of these decls? + // + // Note that this way we pick up not only comments that precede the + // declaration, but also comments that *follow* the declaration -- thanks to + // the lookahead in the lexer: we've consumed the semicolon and looked + // ahead through comments. + for (unsigned i = 0, e = Group.size(); i != e; ++i) + Context.getCommentForDecl(Group[i], &PP); + } + } + + /// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() + /// to introduce parameters into function prototype scope. + Decl *Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { + const DeclSpec &DS = D.getDeclSpec(); + + // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. + + // C++03 [dcl.stc]p2 also permits 'auto'. + StorageClass SC = SC_None; + if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { + SC = SC_Register; + // In C++11, the 'register' storage class specifier is deprecated. + // In C++17, it is not allowed, but we tolerate it as an extension. + if (getLangOpts().CPlusPlus11) { + Diag(DS.getStorageClassSpecLoc(), + getLangOpts().CPlusPlus17 ? diag::ext_register_storage_class + : diag::warn_deprecated_register) + << FixItHint::CreateRemoval(DS.getStorageClassSpecLoc()); + } + } else if (getLangOpts().CPlusPlus && + DS.getStorageClassSpec() == DeclSpec::SCS_auto) { + SC = SC_Auto; + } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { + Diag(DS.getStorageClassSpecLoc(), + diag::err_invalid_storage_class_in_func_decl); + D.getMutableDeclSpec().ClearStorageClassSpecs(); + } + + if (DeclSpec::TSCS TSCS = DS.getThreadStorageClassSpec()) + Diag(DS.getThreadStorageClassSpecLoc(), diag::err_invalid_thread) + << DeclSpec::getSpecifierName(TSCS); + if (DS.isInlineSpecified()) + Diag(DS.getInlineSpecLoc(), diag::err_inline_non_function) + << getLangOpts().CPlusPlus17; + if (DS.isConstexprSpecified()) + Diag(DS.getConstexprSpecLoc(), diag::err_invalid_constexpr) + << 0; + + DiagnoseFunctionSpecifiers(DS); + + TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S); + QualType parmDeclType = TInfo->getType(); + + if (getLangOpts().CPlusPlus) { + // Check that there are no default arguments inside the type of this + // parameter. + CheckExtraCXXDefaultArguments(D); + + // Parameter declarators cannot be qualified (C++ [dcl.meaning]p1). + if (D.getCXXScopeSpec().isSet()) { + Diag(D.getIdentifierLoc(), diag::err_qualified_param_declarator) + << D.getCXXScopeSpec().getRange(); + D.getCXXScopeSpec().clear(); + } + } + + // Ensure we have a valid name + IdentifierInfo *II = nullptr; + if (D.hasName()) { + II = D.getIdentifier(); + if (!II) { + Diag(D.getIdentifierLoc(), diag::err_bad_parameter_name) + << GetNameForDeclarator(D).getName(); + D.setInvalidType(true); + } + } + + // Check for redeclaration of parameters, e.g. int foo(int x, int x); + if (II) { + LookupResult R(*this, II, D.getIdentifierLoc(), LookupOrdinaryName, + ForVisibleRedeclaration); + LookupName(R, S); + if (R.isSingleResult()) { + NamedDecl *PrevDecl = R.getFoundDecl(); + if (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; + } else if (S->isDeclScope(PrevDecl)) { + Diag(D.getIdentifierLoc(), diag::err_param_redefinition) << II; + Diag(PrevDecl->getLocation(), diag::note_previous_declaration); + + // Recover by removing the name + II = nullptr; + D.SetIdentifier(nullptr, D.getIdentifierLoc()); + D.setInvalidType(true); + } + } + } + + // Temporarily put parameter variables in the translation unit, not + // the enclosing context. This prevents them from accidentally + // looking like class members in C++. + ParmVarDecl *New = + CheckParameter(Context.getTranslationUnitDecl(), D.getBeginLoc(), + D.getIdentifierLoc(), II, parmDeclType, TInfo, SC); + + if (D.isInvalidType()) + New->setInvalidDecl(); + + assert(S->isFunctionPrototypeScope()); + assert(S->getFunctionPrototypeDepth() >= 1); + New->setScopeInfo(S->getFunctionPrototypeDepth() - 1, + S->getNextFunctionPrototypeIndex()); + + // Add the parameter declaration into this scope. + S->AddDecl(New); + if (II) + IdResolver.AddDecl(New); + + ProcessDeclAttributes(S, New, D); + + if (D.getDeclSpec().isModulePrivateSpecified()) + Diag(New->getLocation(), diag::err_module_private_local) + << 1 << New->getDeclName() + << SourceRange(D.getDeclSpec().getModulePrivateSpecLoc()) + << FixItHint::CreateRemoval(D.getDeclSpec().getModulePrivateSpecLoc()); + + if (New->hasAttr()) { + Diag(New->getLocation(), diag::err_block_on_nonlocal); + } + return New; + } + + /// Synthesizes a variable for a parameter arising from a + /// typedef. + ParmVarDecl *Sema::BuildParmVarDeclForTypedef(DeclContext *DC, + SourceLocation Loc, + QualType T) { + /* FIXME: setting StartLoc == Loc. + Would it be worth to modify callers so as to provide proper source + location for the unnamed parameters, embedding the parameter's type? */ + ParmVarDecl *Param = ParmVarDecl::Create(Context, DC, Loc, Loc, nullptr, + T, Context.getTrivialTypeSourceInfo(T, Loc), + SC_None, nullptr); + Param->setImplicit(); + return Param; + } + + void Sema::DiagnoseUnusedParameters(ArrayRef Parameters) { + // Don't diagnose unused-parameter errors in template instantiations; we + // will already have done so in the template itself. + if (inTemplateInstantiation()) + return; + + for (const ParmVarDecl *Parameter : Parameters) { + if (!Parameter->isReferenced() && Parameter->getDeclName() && + !Parameter->hasAttr()) { + Diag(Parameter->getLocation(), diag::warn_unused_parameter) + << Parameter->getDeclName(); + } + } + } + + void Sema::DiagnoseSizeOfParametersAndReturnValue( + ArrayRef Parameters, QualType ReturnTy, NamedDecl *D) { + if (LangOpts.NumLargeByValueCopy == 0) // No check. + return; + + // Warn if the return value is pass-by-value and larger than the specified + // threshold. + if (!ReturnTy->isDependentType() && ReturnTy.isPODType(Context)) { + unsigned Size = Context.getTypeSizeInChars(ReturnTy).getQuantity(); + if (Size > LangOpts.NumLargeByValueCopy) + Diag(D->getLocation(), diag::warn_return_value_size) + << D->getDeclName() << Size; + } + + // Warn if any parameter is pass-by-value and larger than the specified + // threshold. + for (const ParmVarDecl *Parameter : Parameters) { + QualType T = Parameter->getType(); + if (T->isDependentType() || !T.isPODType(Context)) + continue; + unsigned Size = Context.getTypeSizeInChars(T).getQuantity(); + if (Size > LangOpts.NumLargeByValueCopy) + Diag(Parameter->getLocation(), diag::warn_parameter_size) + << Parameter->getDeclName() << Size; + } + } + + ParmVarDecl *Sema::CheckParameter(DeclContext *DC, SourceLocation StartLoc, + SourceLocation NameLoc, IdentifierInfo *Name, + QualType T, TypeSourceInfo *TSInfo, + StorageClass SC) { + // In ARC, infer a lifetime qualifier for appropriate parameter types. + if (getLangOpts().ObjCAutoRefCount && + T.getObjCLifetime() == Qualifiers::OCL_None && + T->isObjCLifetimeType()) { + + Qualifiers::ObjCLifetime lifetime; + + // Special cases for arrays: + // - if it's const, use __unsafe_unretained + // - otherwise, it's an error + if (T->isArrayType()) { + if (!T.isConstQualified()) { + if (DelayedDiagnostics.shouldDelayDiagnostics()) + DelayedDiagnostics.add( + sema::DelayedDiagnostic::makeForbiddenType( + NameLoc, diag::err_arc_array_param_no_ownership, T, false)); + else + Diag(NameLoc, diag::err_arc_array_param_no_ownership) + << TSInfo->getTypeLoc().getSourceRange(); + } + lifetime = Qualifiers::OCL_ExplicitNone; + } else { + lifetime = T->getObjCARCImplicitLifetime(); + } + T = Context.getLifetimeQualifiedType(T, lifetime); + } + + ParmVarDecl *New = ParmVarDecl::Create(Context, DC, StartLoc, NameLoc, Name, + Context.getAdjustedParameterType(T), + TSInfo, SC, nullptr); + + // Parameters can not be abstract class types. + // For record types, this is done by the AbstractClassUsageDiagnoser once + // the class has been completely parsed. + if (!CurContext->isRecord() && + RequireNonAbstractType(NameLoc, T, diag::err_abstract_type_in_decl, + AbstractParamType)) + New->setInvalidDecl(); + + // Parameter declarators cannot be interface types. All ObjC objects are + // passed by reference. + if (T->isObjCObjectType()) { + SourceLocation TypeEndLoc = + getLocForEndOfToken(TSInfo->getTypeLoc().getEndLoc()); + Diag(NameLoc, + diag::err_object_cannot_be_passed_returned_by_value) << 1 << T + << FixItHint::CreateInsertion(TypeEndLoc, "*"); + T = Context.getObjCObjectPointerType(T); + New->setType(T); + } + + // ISO/IEC TR 18037 S6.7.3: "The type of an object with automatic storage + // duration shall not be qualified by an address-space qualifier." + // Since all parameters have automatic store duration, they can not have + // an address space. + if (T.getAddressSpace() != LangAS::Default && + // OpenCL allows function arguments declared to be an array of a type + // to be qualified with an address space. + !(getLangOpts().OpenCL && + (T->isArrayType() || T.getAddressSpace() == LangAS::opencl_private))) { + Diag(NameLoc, diag::err_arg_with_address_space); + New->setInvalidDecl(); + } + + return New; + } + + void Sema::ActOnFinishKNRParamDeclarations(Scope *S, Declarator &D, + SourceLocation LocAfterDecls) { + DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo(); + + // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' + // for a K&R function. + if (!FTI.hasPrototype) { + for (int i = FTI.NumParams; i != 0; /* decrement in loop */) { + --i; + if (FTI.Params[i].Param == nullptr) { + SmallString<256> Code; + llvm::raw_svector_ostream(Code) + << " int " << FTI.Params[i].Ident->getName() << ";\n"; + Diag(FTI.Params[i].IdentLoc, diag::ext_param_not_declared) + << FTI.Params[i].Ident + << FixItHint::CreateInsertion(LocAfterDecls, Code); + + // Implicitly declare the argument as type 'int' for lack of a better + // type. + AttributeFactory attrs; + DeclSpec DS(attrs); + const char* PrevSpec; // unused + unsigned DiagID; // unused + DS.SetTypeSpecType(DeclSpec::TST_int, FTI.Params[i].IdentLoc, PrevSpec, + DiagID, Context.getPrintingPolicy()); + // Use the identifier location for the type source range. + DS.SetRangeStart(FTI.Params[i].IdentLoc); + DS.SetRangeEnd(FTI.Params[i].IdentLoc); + Declarator ParamD(DS, DeclaratorContext::KNRTypeListContext); + ParamD.SetIdentifier(FTI.Params[i].Ident, FTI.Params[i].IdentLoc); + FTI.Params[i].Param = ActOnParamDeclarator(S, ParamD); + } + } + } + } + + Decl * + Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D, + MultiTemplateParamsArg TemplateParameterLists, + SkipBodyInfo *SkipBody) { + assert(getCurFunctionDecl() == nullptr && "Function parsing confused"); + assert(D.isFunctionDeclarator() && "Not a function declarator!"); + Scope *ParentScope = FnBodyScope->getParent(); + + D.setFunctionDefinitionKind(FDK_Definition); + Decl *DP = HandleDeclarator(ParentScope, D, TemplateParameterLists); + return ActOnStartOfFunctionDef(FnBodyScope, DP, SkipBody); + } + + void Sema::ActOnFinishInlineFunctionDef(FunctionDecl *D) { + Consumer.HandleInlineFunctionDefinition(D); + } + + static bool ShouldWarnAboutMissingPrototype(const FunctionDecl *FD, + const FunctionDecl*& PossibleZeroParamPrototype) { + // Don't warn about invalid declarations. + if (FD->isInvalidDecl()) + return false; + + // Or declarations that aren't global. + if (!FD->isGlobal()) + return false; + + // Don't warn about C++ member functions. + if (isa(FD)) + return false; + + // Don't warn about 'main'. + if (FD->isMain()) + return false; + + // Don't warn about inline functions. + if (FD->isInlined()) + return false; + + // Don't warn about function templates. + if (FD->getDescribedFunctionTemplate()) + return false; + + // Don't warn about function template specializations. + if (FD->isFunctionTemplateSpecialization()) + return false; + + // Don't warn for OpenCL kernels. + if (FD->hasAttr()) + return false; + + // Don't warn on explicitly deleted functions. + if (FD->isDeleted()) + return false; + + bool MissingPrototype = true; + for (const FunctionDecl *Prev = FD->getPreviousDecl(); + Prev; Prev = Prev->getPreviousDecl()) { + // Ignore any declarations that occur in function or method + // scope, because they aren't visible from the header. + if (Prev->getLexicalDeclContext()->isFunctionOrMethod()) + continue; + + MissingPrototype = !Prev->getType()->isFunctionProtoType(); + if (FD->getNumParams() == 0) + PossibleZeroParamPrototype = Prev; + break; + } + + return MissingPrototype; + } + + void + Sema::CheckForFunctionRedefinition(FunctionDecl *FD, + const FunctionDecl *EffectiveDefinition, + SkipBodyInfo *SkipBody) { + const FunctionDecl *Definition = EffectiveDefinition; + if (!Definition && !FD->isDefined(Definition) && !FD->isCXXClassMember()) { + // If this is a friend function defined in a class template, it does not + // have a body until it is used, nevertheless it is a definition, see + // [temp.inst]p2: + // + // ... for the purpose of determining whether an instantiated redeclaration + // is valid according to [basic.def.odr] and [class.mem], a declaration that + // corresponds to a definition in the template is considered to be a + // definition. + // + // The following code must produce redefinition error: + // + // template struct C20 { friend void func_20() {} }; + // C20 c20i; + // void func_20() {} + // + for (auto I : FD->redecls()) { + if (I != FD && !I->isInvalidDecl() && + I->getFriendObjectKind() != Decl::FOK_None) { + if (FunctionDecl *Original = I->getInstantiatedFromMemberFunction()) { + if (FunctionDecl *OrigFD = FD->getInstantiatedFromMemberFunction()) { + // A merged copy of the same function, instantiated as a member of + // the same class, is OK. + if (declaresSameEntity(OrigFD, Original) && + declaresSameEntity(cast(I->getLexicalDeclContext()), + cast(FD->getLexicalDeclContext()))) + continue; + } + + if (Original->isThisDeclarationADefinition()) { + Definition = I; + break; + } + } + } + } + } + + if (!Definition) + // Similar to friend functions a friend function template may be a + // definition and do not have a body if it is instantiated in a class + // template. + if (FunctionTemplateDecl *FTD = FD->getDescribedFunctionTemplate()) { + for (auto I : FTD->redecls()) { + auto D = cast(I); + if (D != FTD) { + assert(!D->isThisDeclarationADefinition() && + "More than one definition in redeclaration chain"); + if (D->getFriendObjectKind() != Decl::FOK_None) + if (FunctionTemplateDecl *FT = + D->getInstantiatedFromMemberTemplate()) { + if (FT->isThisDeclarationADefinition()) { + Definition = D->getTemplatedDecl(); + break; + } + } + } + } + } + + if (!Definition) + return; + + if (canRedefineFunction(Definition, getLangOpts())) + return; + + // Don't emit an error when this is redefinition of a typo-corrected + // definition. + if (TypoCorrectedFunctionDefinitions.count(Definition)) + return; + + // If we don't have a visible definition of the function, and it's inline or + // a template, skip the new definition. + if (SkipBody && !hasVisibleDefinition(Definition) && + (Definition->getFormalLinkage() == InternalLinkage || + Definition->isInlined() || + Definition->getDescribedFunctionTemplate() || + Definition->getNumTemplateParameterLists())) { + SkipBody->ShouldSkip = true; + SkipBody->Previous = const_cast(Definition); + if (auto *TD = Definition->getDescribedFunctionTemplate()) + makeMergedDefinitionVisible(TD); + makeMergedDefinitionVisible(const_cast(Definition)); + return; + } + + if (getLangOpts().GNUMode && Definition->isInlineSpecified() && + Definition->getStorageClass() == SC_Extern) + Diag(FD->getLocation(), diag::err_redefinition_extern_inline) + << FD->getDeclName() << getLangOpts().CPlusPlus; + else + Diag(FD->getLocation(), diag::err_redefinition) << FD->getDeclName(); + + Diag(Definition->getLocation(), diag::note_previous_definition); + FD->setInvalidDecl(); + } + + static void RebuildLambdaScopeInfo(CXXMethodDecl *CallOperator, + Sema &S) { + CXXRecordDecl *const LambdaClass = CallOperator->getParent(); + + LambdaScopeInfo *LSI = S.PushLambdaScope(); + LSI->CallOperator = CallOperator; + LSI->Lambda = LambdaClass; + LSI->ReturnType = CallOperator->getReturnType(); + const LambdaCaptureDefault LCD = LambdaClass->getLambdaCaptureDefault(); + + if (LCD == LCD_None) + LSI->ImpCaptureStyle = CapturingScopeInfo::ImpCap_None; + else if (LCD == LCD_ByCopy) + LSI->ImpCaptureStyle = CapturingScopeInfo::ImpCap_LambdaByval; + else if (LCD == LCD_ByRef) + LSI->ImpCaptureStyle = CapturingScopeInfo::ImpCap_LambdaByref; + DeclarationNameInfo DNI = CallOperator->getNameInfo(); + + LSI->IntroducerRange = DNI.getCXXOperatorNameRange(); + LSI->Mutable = !CallOperator->isConst(); + + // Add the captures to the LSI so they can be noted as already + // captured within tryCaptureVar. + auto I = LambdaClass->field_begin(); + for (const auto &C : LambdaClass->captures()) { + if (C.capturesVariable()) { + VarDecl *VD = C.getCapturedVar(); + if (VD->isInitCapture()) + S.CurrentInstantiationScope->InstantiatedLocal(VD, VD); + QualType CaptureType = VD->getType(); + const bool ByRef = C.getCaptureKind() == LCK_ByRef; + LSI->addCapture(VD, /*IsBlock*/false, ByRef, + /*RefersToEnclosingVariableOrCapture*/true, C.getLocation(), + /*EllipsisLoc*/C.isPackExpansion() + ? C.getEllipsisLoc() : SourceLocation(), + CaptureType, /*Expr*/ nullptr); + + } else if (C.capturesThis()) { + LSI->addThisCapture(/*Nested*/ false, C.getLocation(), + /*Expr*/ nullptr, + C.getCaptureKind() == LCK_StarThis); + } else { + LSI->addVLATypeCapture(C.getLocation(), I->getType()); + } + ++I; + } + } + + Decl *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Decl *D, + SkipBodyInfo *SkipBody) { + if (!D) { + // Parsing the function declaration failed in some way. Push on a fake scope + // anyway so we can try to parse the function body. + PushFunctionScope(); + PushExpressionEvaluationContext(ExprEvalContexts.back().Context); + return D; + } + + FunctionDecl *FD = nullptr; + + if (FunctionTemplateDecl *FunTmpl = dyn_cast(D)) + FD = FunTmpl->getTemplatedDecl(); + else + FD = cast(D); + + // Do not push if it is a lambda because one is already pushed when building + // the lambda in ActOnStartOfLambdaDefinition(). + if (!isLambdaCallOperator(FD)) + PushExpressionEvaluationContext(ExprEvalContexts.back().Context); + + // Check for defining attributes before the check for redefinition. + if (const auto *Attr = FD->getAttr()) { + Diag(Attr->getLocation(), diag::err_alias_is_definition) << FD << 0; + FD->dropAttr(); + FD->setInvalidDecl(); + } + if (const auto *Attr = FD->getAttr()) { + Diag(Attr->getLocation(), diag::err_alias_is_definition) << FD << 1; + FD->dropAttr(); + FD->setInvalidDecl(); + } + + // See if this is a redefinition. If 'will have body' is already set, then + // these checks were already performed when it was set. + if (!FD->willHaveBody() && !FD->isLateTemplateParsed()) { + CheckForFunctionRedefinition(FD, nullptr, SkipBody); + + // If we're skipping the body, we're done. Don't enter the scope. + if (SkipBody && SkipBody->ShouldSkip) + return D; + } + + // Mark this function as "will have a body eventually". This lets users to + // call e.g. isInlineDefinitionExternallyVisible while we're still parsing + // this function. + FD->setWillHaveBody(); + + // If we are instantiating a generic lambda call operator, push + // a LambdaScopeInfo onto the function stack. But use the information + // that's already been calculated (ActOnLambdaExpr) to prime the current + // LambdaScopeInfo. + // When the template operator is being specialized, the LambdaScopeInfo, + // has to be properly restored so that tryCaptureVariable doesn't try + // and capture any new variables. In addition when calculating potential + // captures during transformation of nested lambdas, it is necessary to + // have the LSI properly restored. + if (isGenericLambdaCallOperatorSpecialization(FD)) { + assert(inTemplateInstantiation() && + "There should be an active template instantiation on the stack " + "when instantiating a generic lambda!"); + RebuildLambdaScopeInfo(cast(D), *this); + } else { + // Enter a new function scope + PushFunctionScope(); + } + + // Builtin functions cannot be defined. + if (unsigned BuiltinID = FD->getBuiltinID()) { + if (!Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID) && + !Context.BuiltinInfo.isPredefinedRuntimeFunction(BuiltinID)) { + Diag(FD->getLocation(), diag::err_builtin_definition) << FD; + FD->setInvalidDecl(); + } + } + + // The return type of a function definition must be complete + // (C99 6.9.1p3, C++ [dcl.fct]p6). + QualType ResultType = FD->getReturnType(); + if (!ResultType->isDependentType() && !ResultType->isVoidType() && + !FD->isInvalidDecl() && + RequireCompleteType(FD->getLocation(), ResultType, + diag::err_func_def_incomplete_result)) + FD->setInvalidDecl(); + + if (FnBodyScope) + PushDeclContext(FnBodyScope, FD); + + // Check the validity of our function parameters + CheckParmsForFunctionDef(FD->parameters(), + /*CheckParameterNames=*/true); + + // Add non-parameter declarations already in the function to the current + // scope. + if (FnBodyScope) { + for (Decl *NPD : FD->decls()) { + auto *NonParmDecl = dyn_cast(NPD); + if (!NonParmDecl) + continue; + assert(!isa(NonParmDecl) && + "parameters should not be in newly created FD yet"); + + // If the decl has a name, make it accessible in the current scope. + if (NonParmDecl->getDeclName()) + PushOnScopeChains(NonParmDecl, FnBodyScope, /*AddToContext=*/false); + + // Similarly, dive into enums and fish their constants out, making them + // accessible in this scope. + if (auto *ED = dyn_cast(NonParmDecl)) { + for (auto *EI : ED->enumerators()) + PushOnScopeChains(EI, FnBodyScope, /*AddToContext=*/false); + } + } + } + + // Introduce our parameters into the function scope + for (auto Param : FD->parameters()) { + Param->setOwningFunction(FD); + + // If this has an identifier, add it to the scope stack. + if (Param->getIdentifier() && FnBodyScope) { + CheckShadow(FnBodyScope, Param); + + PushOnScopeChains(Param, FnBodyScope); + } + } + + // Ensure that the function's exception specification is instantiated. + if (const FunctionProtoType *FPT = FD->getType()->getAs()) + ResolveExceptionSpec(D->getLocation(), FPT); + + // dllimport cannot be applied to non-inline function definitions. + if (FD->hasAttr() && !FD->isInlined() && + !FD->isTemplateInstantiation()) { + assert(!FD->hasAttr()); + Diag(FD->getLocation(), diag::err_attribute_dllimport_function_definition); + FD->setInvalidDecl(); + return D; + } + // We want to attach documentation to original Decl (which might be + // a function template). + ActOnDocumentableDecl(D); + if (getCurLexicalContext()->isObjCContainer() && + getCurLexicalContext()->getDeclKind() != Decl::ObjCCategoryImpl && + getCurLexicalContext()->getDeclKind() != Decl::ObjCImplementation) + Diag(FD->getLocation(), diag::warn_function_def_in_objc_container); + + return D; + } + + /// Given the set of return statements within a function body, + /// compute the variables that are subject to the named return value + /// optimization. + /// + /// Each of the variables that is subject to the named return value + /// optimization will be marked as NRVO variables in the AST, and any + /// return statement that has a marked NRVO variable as its NRVO candidate can + /// use the named return value optimization. + /// + /// This function applies a very simplistic algorithm for NRVO: if every return + /// statement in the scope of a variable has the same NRVO candidate, that + /// candidate is an NRVO variable. + void Sema::computeNRVO(Stmt *Body, FunctionScopeInfo *Scope) { + ReturnStmt **Returns = Scope->Returns.data(); + + for (unsigned I = 0, E = Scope->Returns.size(); I != E; ++I) { + if (const VarDecl *NRVOCandidate = Returns[I]->getNRVOCandidate()) { + if (!NRVOCandidate->isNRVOVariable()) + Returns[I]->setNRVOCandidate(nullptr); + } + } + } + + bool Sema::canDelayFunctionBody(const Declarator &D) { + // We can't delay parsing the body of a constexpr function template (yet). + if (D.getDeclSpec().isConstexprSpecified()) + return false; + + // We can't delay parsing the body of a function template with a deduced + // return type (yet). + if (D.getDeclSpec().hasAutoTypeSpec()) { + // If the placeholder introduces a non-deduced trailing return type, + // we can still delay parsing it. + if (D.getNumTypeObjects()) { + const auto &Outer = D.getTypeObject(D.getNumTypeObjects() - 1); + if (Outer.Kind == DeclaratorChunk::Function && + Outer.Fun.hasTrailingReturnType()) { + QualType Ty = GetTypeFromParser(Outer.Fun.getTrailingReturnType()); + return Ty.isNull() || !Ty->isUndeducedType(); + } + } + return false; + } + + return true; + } + + bool Sema::canSkipFunctionBody(Decl *D) { + // We cannot skip the body of a function (or function template) which is + // constexpr, since we may need to evaluate its body in order to parse the + // rest of the file. + // We cannot skip the body of a function with an undeduced return type, + // because any callers of that function need to know the type. + if (const FunctionDecl *FD = D->getAsFunction()) { + if (FD->isConstexpr()) + return false; + // We can't simply call Type::isUndeducedType here, because inside template + // auto can be deduced to a dependent type, which is not considered + // "undeduced". + if (FD->getReturnType()->getContainedDeducedType()) + return false; + } + return Consumer.shouldSkipFunctionBody(D); + } + + Decl *Sema::ActOnSkippedFunctionBody(Decl *Decl) { + if (!Decl) + return nullptr; + if (FunctionDecl *FD = Decl->getAsFunction()) + FD->setHasSkippedBody(); + else if (ObjCMethodDecl *MD = dyn_cast(Decl)) + MD->setHasSkippedBody(); + return Decl; + } + + Decl *Sema::ActOnFinishFunctionBody(Decl *D, Stmt *BodyArg) { + return ActOnFinishFunctionBody(D, BodyArg, false); + } + + /// RAII object that pops an ExpressionEvaluationContext when exiting a function + /// body. + class ExitFunctionBodyRAII { + public: + ExitFunctionBodyRAII(Sema &S, bool IsLambda) : S(S), IsLambda(IsLambda) {} + ~ExitFunctionBodyRAII() { + if (!IsLambda) + S.PopExpressionEvaluationContext(); + } + + private: + Sema &S; + bool IsLambda = false; + }; + + Decl *Sema::ActOnFinishFunctionBody(Decl *dcl, Stmt *Body, + bool IsInstantiation) { + FunctionDecl *FD = dcl ? dcl->getAsFunction() : nullptr; + + sema::AnalysisBasedWarnings::Policy WP = AnalysisWarnings.getDefaultPolicy(); + sema::AnalysisBasedWarnings::Policy *ActivePolicy = nullptr; + + if (getLangOpts().CoroutinesTS && getCurFunction()->isCoroutine()) + CheckCompletedCoroutineBody(FD, Body); + + // Do not call PopExpressionEvaluationContext() if it is a lambda because one + // is already popped when finishing the lambda in BuildLambdaExpr(). This is + // meant to pop the context added in ActOnStartOfFunctionDef(). + ExitFunctionBodyRAII ExitRAII(*this, isLambdaCallOperator(FD)); + + if (FD) { + FD->setBody(Body); + FD->setWillHaveBody(false); + + if (getLangOpts().CPlusPlus14) { + if (!FD->isInvalidDecl() && Body && !FD->isDependentContext() && + FD->getReturnType()->isUndeducedType()) { + // If the function has a deduced result type but contains no 'return' + // statements, the result type as written must be exactly 'auto', and + // the deduced result type is 'void'. + if (!FD->getReturnType()->getAs()) { + Diag(dcl->getLocation(), diag::err_auto_fn_no_return_but_not_auto) + << FD->getReturnType(); + FD->setInvalidDecl(); + } else { + // Substitute 'void' for the 'auto' in the type. + TypeLoc ResultType = getReturnTypeLoc(FD); + Context.adjustDeducedFunctionResultType( + FD, SubstAutoType(ResultType.getType(), Context.VoidTy)); + } + } + } else if (getLangOpts().CPlusPlus11 && isLambdaCallOperator(FD)) { + // In C++11, we don't use 'auto' deduction rules for lambda call + // operators because we don't support return type deduction. + auto *LSI = getCurLambda(); + if (LSI->HasImplicitReturnType) { + deduceClosureReturnType(*LSI); + + // C++11 [expr.prim.lambda]p4: + // [...] if there are no return statements in the compound-statement + // [the deduced type is] the type void + QualType RetType = + LSI->ReturnType.isNull() ? Context.VoidTy : LSI->ReturnType; + + // Update the return type to the deduced type. + const FunctionProtoType *Proto = + FD->getType()->getAs(); + FD->setType(Context.getFunctionType(RetType, Proto->getParamTypes(), + Proto->getExtProtoInfo())); + } + } + + // If the function implicitly returns zero (like 'main') or is naked, + // don't complain about missing return statements. + if (FD->hasImplicitReturnZero() || FD->hasAttr()) + WP.disableCheckFallThrough(); + + // MSVC permits the use of pure specifier (=0) on function definition, + // defined at class scope, warn about this non-standard construct. + if (getLangOpts().MicrosoftExt && FD->isPure() && FD->isCanonicalDecl()) + Diag(FD->getLocation(), diag::ext_pure_function_definition); + + if (!FD->isInvalidDecl()) { + // Don't diagnose unused parameters of defaulted or deleted functions. + if (!FD->isDeleted() && !FD->isDefaulted() && !FD->hasSkippedBody()) + DiagnoseUnusedParameters(FD->parameters()); + DiagnoseSizeOfParametersAndReturnValue(FD->parameters(), + FD->getReturnType(), FD); + + // If this is a structor, we need a vtable. + if (CXXConstructorDecl *Constructor = dyn_cast(FD)) + MarkVTableUsed(FD->getLocation(), Constructor->getParent()); + else if (CXXDestructorDecl *Destructor = dyn_cast(FD)) + MarkVTableUsed(FD->getLocation(), Destructor->getParent()); + + // Try to apply the named return value optimization. We have to check + // if we can do this here because lambdas keep return statements around + // to deduce an implicit return type. + if (FD->getReturnType()->isRecordType() && + (!getLangOpts().CPlusPlus || !FD->isDependentContext())) + computeNRVO(Body, getCurFunction()); + } + + // GNU warning -Wmissing-prototypes: + // Warn if a global function is defined without a previous + // prototype declaration. This warning is issued even if the + // definition itself provides a prototype. The aim is to detect + // global functions that fail to be declared in header files. + const FunctionDecl *PossibleZeroParamPrototype = nullptr; + if (ShouldWarnAboutMissingPrototype(FD, PossibleZeroParamPrototype)) { + Diag(FD->getLocation(), diag::warn_missing_prototype) << FD; + + if (PossibleZeroParamPrototype) { + // We found a declaration that is not a prototype, + // but that could be a zero-parameter prototype + if (TypeSourceInfo *TI = + PossibleZeroParamPrototype->getTypeSourceInfo()) { + TypeLoc TL = TI->getTypeLoc(); + if (FunctionNoProtoTypeLoc FTL = TL.getAs()) + Diag(PossibleZeroParamPrototype->getLocation(), + diag::note_declaration_not_a_prototype) + << PossibleZeroParamPrototype + << FixItHint::CreateInsertion(FTL.getRParenLoc(), "void"); + } + } + + // GNU warning -Wstrict-prototypes + // Warn if K&R function is defined without a previous declaration. + // This warning is issued only if the definition itself does not provide + // a prototype. Only K&R definitions do not provide a prototype. + // An empty list in a function declarator that is part of a definition + // of that function specifies that the function has no parameters + // (C99 6.7.5.3p14) + if (!FD->hasWrittenPrototype() && FD->getNumParams() > 0 && + !LangOpts.CPlusPlus) { + TypeSourceInfo *TI = FD->getTypeSourceInfo(); + TypeLoc TL = TI->getTypeLoc(); + FunctionTypeLoc FTL = TL.getAsAdjusted(); + Diag(FTL.getLParenLoc(), diag::warn_strict_prototypes) << 2; + } + } + + // Warn on CPUDispatch with an actual body. + if (FD->isMultiVersion() && FD->hasAttr() && Body) + if (const auto *CmpndBody = dyn_cast(Body)) + if (!CmpndBody->body_empty()) + Diag(CmpndBody->body_front()->getBeginLoc(), + diag::warn_dispatch_body_ignored); + + if (auto *MD = dyn_cast(FD)) { + const CXXMethodDecl *KeyFunction; + if (MD->isOutOfLine() && (MD = MD->getCanonicalDecl()) && + MD->isVirtual() && + (KeyFunction = Context.getCurrentKeyFunction(MD->getParent())) && + MD == KeyFunction->getCanonicalDecl()) { + // Update the key-function state if necessary for this ABI. + if (FD->isInlined() && + !Context.getTargetInfo().getCXXABI().canKeyFunctionBeInline()) { + Context.setNonKeyFunction(MD); + + // If the newly-chosen key function is already defined, then we + // need to mark the vtable as used retroactively. + KeyFunction = Context.getCurrentKeyFunction(MD->getParent()); + const FunctionDecl *Definition; + if (KeyFunction && KeyFunction->isDefined(Definition)) + MarkVTableUsed(Definition->getLocation(), MD->getParent(), true); + } else { + // We just defined they key function; mark the vtable as used. + MarkVTableUsed(FD->getLocation(), MD->getParent(), true); + } + } + } + + assert((FD == getCurFunctionDecl() || getCurLambda()->CallOperator == FD) && + "Function parsing confused"); + } else if (ObjCMethodDecl *MD = dyn_cast_or_null(dcl)) { + assert(MD == getCurMethodDecl() && "Method parsing confused"); + MD->setBody(Body); + if (!MD->isInvalidDecl()) { + if (!MD->hasSkippedBody()) + DiagnoseUnusedParameters(MD->parameters()); + DiagnoseSizeOfParametersAndReturnValue(MD->parameters(), + MD->getReturnType(), MD); + + if (Body) + computeNRVO(Body, getCurFunction()); + } + if (getCurFunction()->ObjCShouldCallSuper) { + Diag(MD->getEndLoc(), diag::warn_objc_missing_super_call) + << MD->getSelector().getAsString(); + getCurFunction()->ObjCShouldCallSuper = false; + } + if (getCurFunction()->ObjCWarnForNoDesignatedInitChain) { + const ObjCMethodDecl *InitMethod = nullptr; + bool isDesignated = + MD->isDesignatedInitializerForTheInterface(&InitMethod); + assert(isDesignated && InitMethod); + (void)isDesignated; + + auto superIsNSObject = [&](const ObjCMethodDecl *MD) { + auto IFace = MD->getClassInterface(); + if (!IFace) + return false; + auto SuperD = IFace->getSuperClass(); + if (!SuperD) + return false; + return SuperD->getIdentifier() == + NSAPIObj->getNSClassId(NSAPI::ClassId_NSObject); + }; + // Don't issue this warning for unavailable inits or direct subclasses + // of NSObject. + if (!MD->isUnavailable() && !superIsNSObject(MD)) { + Diag(MD->getLocation(), + diag::warn_objc_designated_init_missing_super_call); + Diag(InitMethod->getLocation(), + diag::note_objc_designated_init_marked_here); + } + getCurFunction()->ObjCWarnForNoDesignatedInitChain = false; + } + if (getCurFunction()->ObjCWarnForNoInitDelegation) { + // Don't issue this warning for unavaialable inits. + if (!MD->isUnavailable()) + Diag(MD->getLocation(), + diag::warn_objc_secondary_init_missing_init_call); + getCurFunction()->ObjCWarnForNoInitDelegation = false; + } + } else { + // Parsing the function declaration failed in some way. Pop the fake scope + // we pushed on. + PopFunctionScopeInfo(ActivePolicy, dcl); + return nullptr; + } + + if (Body && getCurFunction()->HasPotentialAvailabilityViolations) + DiagnoseUnguardedAvailabilityViolations(dcl); + + assert(!getCurFunction()->ObjCShouldCallSuper && + "This should only be set for ObjC methods, which should have been " + "handled in the block above."); + + // Verify and clean out per-function state. + if (Body && (!FD || !FD->isDefaulted())) { + // C++ constructors that have function-try-blocks can't have return + // statements in the handlers of that block. (C++ [except.handle]p14) + // Verify this. + if (FD && isa(FD) && isa(Body)) + DiagnoseReturnInConstructorExceptionHandler(cast(Body)); + + // Verify that gotos and switch cases don't jump into scopes illegally. + if (getCurFunction()->NeedsScopeChecking() && + !PP.isCodeCompletionEnabled()) + DiagnoseInvalidJumps(Body); + + if (CXXDestructorDecl *Destructor = dyn_cast(dcl)) { + if (!Destructor->getParent()->isDependentType()) + CheckDestructor(Destructor); + + MarkBaseAndMemberDestructorsReferenced(Destructor->getLocation(), + Destructor->getParent()); + } + + // If any errors have occurred, clear out any temporaries that may have + // been leftover. This ensures that these temporaries won't be picked up for + // deletion in some later function. + if (getDiagnostics().hasErrorOccurred() || + getDiagnostics().getSuppressAllDiagnostics()) { + DiscardCleanupsInEvaluationContext(); + } + if (!getDiagnostics().hasUncompilableErrorOccurred() && + !isa(dcl)) { + // Since the body is valid, issue any analysis-based warnings that are + // enabled. + ActivePolicy = &WP; + } + + if (!IsInstantiation && FD && FD->isConstexpr() && !FD->isInvalidDecl() && + (!CheckConstexprFunctionDecl(FD) || + !CheckConstexprFunctionBody(FD, Body))) + FD->setInvalidDecl(); + + if (FD && FD->hasAttr()) { + for (const Stmt *S : Body->children()) { + // Allow local register variables without initializer as they don't + // require prologue. + bool RegisterVariables = false; + if (auto *DS = dyn_cast(S)) { + for (const auto *Decl : DS->decls()) { + if (const auto *Var = dyn_cast(Decl)) { + RegisterVariables = + Var->hasAttr() && !Var->hasInit(); + if (!RegisterVariables) + break; + } + } + } + if (RegisterVariables) + continue; + if (!isa(S) && !isa(S)) { + Diag(S->getBeginLoc(), diag::err_non_asm_stmt_in_naked_function); + Diag(FD->getAttr()->getLocation(), diag::note_attribute); + FD->setInvalidDecl(); + break; + } + } + } + + assert(ExprCleanupObjects.size() == + ExprEvalContexts.back().NumCleanupObjects && + "Leftover temporaries in function"); + assert(!Cleanup.exprNeedsCleanups() && "Unaccounted cleanups in function"); + assert(MaybeODRUseExprs.empty() && + "Leftover expressions for odr-use checking"); + } + + if (!IsInstantiation) + PopDeclContext(); + + PopFunctionScopeInfo(ActivePolicy, dcl); + // If any errors have occurred, clear out any temporaries that may have + // been leftover. This ensures that these temporaries won't be picked up for + // deletion in some later function. + if (getDiagnostics().hasErrorOccurred()) { + DiscardCleanupsInEvaluationContext(); + } + + return dcl; + } + + /// When we finish delayed parsing of an attribute, we must attach it to the + /// relevant Decl. + void Sema::ActOnFinishDelayedAttribute(Scope *S, Decl *D, + ParsedAttributes &Attrs) { + // Always attach attributes to the underlying decl. + if (TemplateDecl *TD = dyn_cast(D)) + D = TD->getTemplatedDecl(); + ProcessDeclAttributeList(S, D, Attrs); + + if (CXXMethodDecl *Method = dyn_cast_or_null(D)) + if (Method->isStatic()) + checkThisInStaticMemberFunctionAttributes(Method); + } + + /// ImplicitlyDefineFunction - An undeclared identifier was used in a function + /// call, forming a call to an implicitly defined function (per C99 6.5.1p2). + NamedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, + IdentifierInfo &II, Scope *S) { + // Find the scope in which the identifier is injected and the corresponding + // DeclContext. + // FIXME: C89 does not say what happens if there is no enclosing block scope. + // In that case, we inject the declaration into the translation unit scope + // instead. + Scope *BlockScope = S; + while (!BlockScope->isCompoundStmtScope() && BlockScope->getParent()) + BlockScope = BlockScope->getParent(); + + Scope *ContextScope = BlockScope; + while (!ContextScope->getEntity()) + ContextScope = ContextScope->getParent(); + ContextRAII SavedContext(*this, ContextScope->getEntity()); + + // Before we produce a declaration for an implicitly defined + // function, see whether there was a locally-scoped declaration of + // this name as a function or variable. If so, use that + // (non-visible) declaration, and complain about it. + NamedDecl *ExternCPrev = findLocallyScopedExternCDecl(&II); + if (ExternCPrev) { + // We still need to inject the function into the enclosing block scope so + // that later (non-call) uses can see it. + PushOnScopeChains(ExternCPrev, BlockScope, /*AddToContext*/false); + + // C89 footnote 38: + // If in fact it is not defined as having type "function returning int", + // the behavior is undefined. + if (!isa(ExternCPrev) || + !Context.typesAreCompatible( + cast(ExternCPrev)->getType(), + Context.getFunctionNoProtoType(Context.IntTy))) { + Diag(Loc, diag::ext_use_out_of_scope_declaration) + << ExternCPrev << !getLangOpts().C99; + Diag(ExternCPrev->getLocation(), diag::note_previous_declaration); + return ExternCPrev; + } + } + + // Extension in C99. Legal in C90, but warn about it. + unsigned diag_id; + if (II.getName().startswith("__builtin_")) + diag_id = diag::warn_builtin_unknown; + // OpenCL v2.0 s6.9.u - Implicit function declaration is not supported. + else if (getLangOpts().OpenCL) + diag_id = diag::err_opencl_implicit_function_decl; + else if (getLangOpts().C99) + diag_id = diag::ext_implicit_function_decl; + else + diag_id = diag::warn_implicit_function_decl; + Diag(Loc, diag_id) << &II; + + // If we found a prior declaration of this function, don't bother building + // another one. We've already pushed that one into scope, so there's nothing + // more to do. + if (ExternCPrev) + return ExternCPrev; + + // Because typo correction is expensive, only do it if the implicit + // function declaration is going to be treated as an error. + if (Diags.getDiagnosticLevel(diag_id, Loc) >= DiagnosticsEngine::Error) { + TypoCorrection Corrected; + if (S && + (Corrected = CorrectTypo( + DeclarationNameInfo(&II, Loc), LookupOrdinaryName, S, nullptr, + llvm::make_unique>(), CTK_NonError))) + diagnoseTypo(Corrected, PDiag(diag::note_function_suggestion), + /*ErrorRecovery*/false); + } + + // Set a Declarator for the implicit definition: int foo(); + const char *Dummy; + AttributeFactory attrFactory; + DeclSpec DS(attrFactory); + unsigned DiagID; + bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy, DiagID, + Context.getPrintingPolicy()); + (void)Error; // Silence warning. + assert(!Error && "Error setting up implicit decl!"); + SourceLocation NoLoc; + Declarator D(DS, DeclaratorContext::BlockContext); + D.AddTypeInfo(DeclaratorChunk::getFunction(/*HasProto=*/false, + /*IsAmbiguous=*/false, + /*LParenLoc=*/NoLoc, + /*Params=*/nullptr, + /*NumParams=*/0, + /*EllipsisLoc=*/NoLoc, + /*RParenLoc=*/NoLoc, + /*RefQualifierIsLvalueRef=*/true, + /*RefQualifierLoc=*/NoLoc, + /*MutableLoc=*/NoLoc, EST_None, + /*ESpecRange=*/SourceRange(), + /*Exceptions=*/nullptr, + /*ExceptionRanges=*/nullptr, + /*NumExceptions=*/0, + /*NoexceptExpr=*/nullptr, + /*ExceptionSpecTokens=*/nullptr, + /*DeclsInPrototype=*/None, Loc, + Loc, D), + std::move(DS.getAttributes()), SourceLocation()); + D.SetIdentifier(&II, Loc); + + // Insert this function into the enclosing block scope. + FunctionDecl *FD = cast(ActOnDeclarator(BlockScope, D)); + FD->setImplicit(); + + AddKnownFunctionAttributes(FD); + + return FD; + } + + /// Adds any function attributes that we know a priori based on + /// the declaration of this function. + /// + /// These attributes can apply both to implicitly-declared builtins + /// (like __builtin___printf_chk) or to library-declared functions + /// like NSLog or printf. + /// + /// We need to check for duplicate attributes both here and where user-written + /// attributes are applied to declarations. + void Sema::AddKnownFunctionAttributes(FunctionDecl *FD) { + if (FD->isInvalidDecl()) + return; + + // If this is a built-in function, map its builtin attributes to + // actual attributes. + if (unsigned BuiltinID = FD->getBuiltinID()) { + // Handle printf-formatting attributes. + unsigned FormatIdx; + bool HasVAListArg; + if (Context.BuiltinInfo.isPrintfLike(BuiltinID, FormatIdx, HasVAListArg)) { + if (!FD->hasAttr()) { + const char *fmt = "printf"; + unsigned int NumParams = FD->getNumParams(); + if (FormatIdx < NumParams && // NumParams may be 0 (e.g. vfprintf) + FD->getParamDecl(FormatIdx)->getType()->isObjCObjectPointerType()) + fmt = "NSString"; + FD->addAttr(FormatAttr::CreateImplicit(Context, + &Context.Idents.get(fmt), + FormatIdx+1, + HasVAListArg ? 0 : FormatIdx+2, + FD->getLocation())); + } + } + if (Context.BuiltinInfo.isScanfLike(BuiltinID, FormatIdx, + HasVAListArg)) { + if (!FD->hasAttr()) + FD->addAttr(FormatAttr::CreateImplicit(Context, + &Context.Idents.get("scanf"), + FormatIdx+1, + HasVAListArg ? 0 : FormatIdx+2, + FD->getLocation())); + } + + // Handle automatically recognized callbacks. + SmallVector Encoding; + if (!FD->hasAttr() && + Context.BuiltinInfo.performsCallback(BuiltinID, Encoding)) + FD->addAttr(CallbackAttr::CreateImplicit( + Context, Encoding.data(), Encoding.size(), FD->getLocation())); + + // Mark const if we don't care about errno and that is the only thing + // preventing the function from being const. This allows IRgen to use LLVM + // intrinsics for such functions. + if (!getLangOpts().MathErrno && !FD->hasAttr() && + Context.BuiltinInfo.isConstWithoutErrno(BuiltinID)) + FD->addAttr(ConstAttr::CreateImplicit(Context, FD->getLocation())); + + // We make "fma" on some platforms const because we know it does not set + // errno in those environments even though it could set errno based on the + // C standard. + const llvm::Triple &Trip = Context.getTargetInfo().getTriple(); + if ((Trip.isGNUEnvironment() || Trip.isAndroid() || Trip.isOSMSVCRT()) && + !FD->hasAttr()) { + switch (BuiltinID) { + case Builtin::BI__builtin_fma: + case Builtin::BI__builtin_fmaf: + case Builtin::BI__builtin_fmal: + case Builtin::BIfma: + case Builtin::BIfmaf: + case Builtin::BIfmal: + FD->addAttr(ConstAttr::CreateImplicit(Context, FD->getLocation())); + break; + default: + break; + } + } + + if (Context.BuiltinInfo.isReturnsTwice(BuiltinID) && + !FD->hasAttr()) + FD->addAttr(ReturnsTwiceAttr::CreateImplicit(Context, + FD->getLocation())); + if (Context.BuiltinInfo.isNoThrow(BuiltinID) && !FD->hasAttr()) + FD->addAttr(NoThrowAttr::CreateImplicit(Context, FD->getLocation())); + if (Context.BuiltinInfo.isPure(BuiltinID) && !FD->hasAttr()) + FD->addAttr(PureAttr::CreateImplicit(Context, FD->getLocation())); + if (Context.BuiltinInfo.isConst(BuiltinID) && !FD->hasAttr()) + FD->addAttr(ConstAttr::CreateImplicit(Context, FD->getLocation())); + if (getLangOpts().CUDA && Context.BuiltinInfo.isTSBuiltin(BuiltinID) && + !FD->hasAttr() && !FD->hasAttr()) { + // Add the appropriate attribute, depending on the CUDA compilation mode + // and which target the builtin belongs to. For example, during host + // compilation, aux builtins are __device__, while the rest are __host__. + if (getLangOpts().CUDAIsDevice != + Context.BuiltinInfo.isAuxBuiltinID(BuiltinID)) + FD->addAttr(CUDADeviceAttr::CreateImplicit(Context, FD->getLocation())); + else + FD->addAttr(CUDAHostAttr::CreateImplicit(Context, FD->getLocation())); + } + } + + // If C++ exceptions are enabled but we are told extern "C" functions cannot + // throw, add an implicit nothrow attribute to any extern "C" function we come + // across. + if (getLangOpts().CXXExceptions && getLangOpts().ExternCNoUnwind && + FD->isExternC() && !FD->hasAttr()) { + const auto *FPT = FD->getType()->getAs(); + if (!FPT || FPT->getExceptionSpecType() == EST_None) + FD->addAttr(NoThrowAttr::CreateImplicit(Context, FD->getLocation())); + } + + IdentifierInfo *Name = FD->getIdentifier(); + if (!Name) + return; + if ((!getLangOpts().CPlusPlus && + FD->getDeclContext()->isTranslationUnit()) || + (isa(FD->getDeclContext()) && + cast(FD->getDeclContext())->getLanguage() == + LinkageSpecDecl::lang_c)) { + // Okay: this could be a libc/libm/Objective-C function we know + // about. + } else + return; + + if (Name->isStr("asprintf") || Name->isStr("vasprintf")) { + // FIXME: asprintf and vasprintf aren't C99 functions. Should they be + // target-specific builtins, perhaps? + if (!FD->hasAttr()) + FD->addAttr(FormatAttr::CreateImplicit(Context, + &Context.Idents.get("printf"), 2, + Name->isStr("vasprintf") ? 0 : 3, + FD->getLocation())); + } + + if (Name->isStr("__CFStringMakeConstantString")) { + // We already have a __builtin___CFStringMakeConstantString, + // but builds that use -fno-constant-cfstrings don't go through that. + if (!FD->hasAttr()) + FD->addAttr(FormatArgAttr::CreateImplicit(Context, ParamIdx(1, FD), + FD->getLocation())); + } + } + + TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, + TypeSourceInfo *TInfo) { + assert(D.getIdentifier() && "Wrong callback for declspec without declarator"); + assert(!T.isNull() && "GetTypeForDeclarator() returned null type"); + + if (!TInfo) { + assert(D.isInvalidType() && "no declarator info for valid type"); + TInfo = Context.getTrivialTypeSourceInfo(T); + } + + // Scope manipulation handled by caller. + TypedefDecl *NewTD = + TypedefDecl::Create(Context, CurContext, D.getBeginLoc(), + D.getIdentifierLoc(), D.getIdentifier(), TInfo); + + // Bail out immediately if we have an invalid declaration. + if (D.isInvalidType()) { + NewTD->setInvalidDecl(); + return NewTD; + } + + if (D.getDeclSpec().isModulePrivateSpecified()) { + if (CurContext->isFunctionOrMethod()) + Diag(NewTD->getLocation(), diag::err_module_private_local) + << 2 << NewTD->getDeclName() + << SourceRange(D.getDeclSpec().getModulePrivateSpecLoc()) + << FixItHint::CreateRemoval(D.getDeclSpec().getModulePrivateSpecLoc()); + else + NewTD->setModulePrivate(); + } + + // C++ [dcl.typedef]p8: + // If the typedef declaration defines an unnamed class (or + // enum), the first typedef-name declared by the declaration + // to be that class type (or enum type) is used to denote the + // class type (or enum type) for linkage purposes only. + // We need to check whether the type was declared in the declaration. + switch (D.getDeclSpec().getTypeSpecType()) { + case TST_enum: + case TST_struct: + case TST_interface: + case TST_union: + case TST_class: { + TagDecl *tagFromDeclSpec = cast(D.getDeclSpec().getRepAsDecl()); + setTagNameForLinkagePurposes(tagFromDeclSpec, NewTD); + break; + } + + default: + break; + } + + return NewTD; + } + + /// Check that this is a valid underlying type for an enum declaration. + bool Sema::CheckEnumUnderlyingType(TypeSourceInfo *TI) { + SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc(); + QualType T = TI->getType(); + + if (T->isDependentType()) + return false; + + if (const BuiltinType *BT = T->getAs()) + if (BT->isInteger()) + return false; + + Diag(UnderlyingLoc, diag::err_enum_invalid_underlying) << T; + return true; + } + + /// Check whether this is a valid redeclaration of a previous enumeration. + /// \return true if the redeclaration was invalid. + bool Sema::CheckEnumRedeclaration(SourceLocation EnumLoc, bool IsScoped, + QualType EnumUnderlyingTy, bool IsFixed, + const EnumDecl *Prev) { + if (IsScoped != Prev->isScoped()) { + Diag(EnumLoc, diag::err_enum_redeclare_scoped_mismatch) + << Prev->isScoped(); + Diag(Prev->getLocation(), diag::note_previous_declaration); + return true; + } + + if (IsFixed && Prev->isFixed()) { + if (!EnumUnderlyingTy->isDependentType() && + !Prev->getIntegerType()->isDependentType() && + !Context.hasSameUnqualifiedType(EnumUnderlyingTy, + Prev->getIntegerType())) { + // TODO: Highlight the underlying type of the redeclaration. + Diag(EnumLoc, diag::err_enum_redeclare_type_mismatch) + << EnumUnderlyingTy << Prev->getIntegerType(); + Diag(Prev->getLocation(), diag::note_previous_declaration) + << Prev->getIntegerTypeRange(); + return true; + } + } else if (IsFixed != Prev->isFixed()) { + Diag(EnumLoc, diag::err_enum_redeclare_fixed_mismatch) + << Prev->isFixed(); + Diag(Prev->getLocation(), diag::note_previous_declaration); + return true; + } + + return false; + } + + /// Get diagnostic %select index for tag kind for + /// redeclaration diagnostic message. + /// WARNING: Indexes apply to particular diagnostics only! + /// + /// \returns diagnostic %select index. + static unsigned getRedeclDiagFromTagKind(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 redecl diagnostic!"); + } + } + + /// Determine if tag kind is a class-key compatible with + /// class for redeclaration (class, struct, or __interface). + /// + /// \returns true iff the tag kind is compatible. + static bool isClassCompatTagKind(TagTypeKind Tag) + { + return Tag == TTK_Struct || Tag == TTK_Class || Tag == TTK_Interface; + } + + Sema::NonTagKind Sema::getNonTagTypeDeclKind(const Decl *PrevDecl, + TagTypeKind TTK) { + if (isa(PrevDecl)) + return NTK_Typedef; + else if (isa(PrevDecl)) + return NTK_TypeAlias; + else if (isa(PrevDecl)) + return NTK_Template; + else if (isa(PrevDecl)) + return NTK_TypeAliasTemplate; + else if (isa(PrevDecl)) + return NTK_TemplateTemplateArgument; + switch (TTK) { + case TTK_Struct: + case TTK_Interface: + case TTK_Class: + return getLangOpts().CPlusPlus ? NTK_NonClass : NTK_NonStruct; + case TTK_Union: + return NTK_NonUnion; + case TTK_Enum: + return NTK_NonEnum; + } + llvm_unreachable("invalid TTK"); + } + + /// Determine whether a tag with a given kind is acceptable + /// as a redeclaration of the given tag declaration. + /// + /// \returns true if the new tag kind is acceptable, false otherwise. + bool Sema::isAcceptableTagRedeclaration(const TagDecl *Previous, + TagTypeKind NewTag, bool isDefinition, + SourceLocation NewTagLoc, + const IdentifierInfo *Name) { + // C++ [dcl.type.elab]p3: + // The class-key or enum keyword present in the + // elaborated-type-specifier shall agree in kind with the + // declaration to which the name in the elaborated-type-specifier + // refers. This rule also applies to the form of + // elaborated-type-specifier that declares a class-name or + // friend class since it can be construed as referring to the + // definition of the class. Thus, in any + // elaborated-type-specifier, the enum keyword shall be used to + // refer to an enumeration (7.2), the union class-key shall be + // used to refer to a union (clause 9), and either the class or + // struct class-key shall be used to refer to a class (clause 9) + // declared using the class or struct class-key. + TagTypeKind OldTag = Previous->getTagKind(); + if (OldTag != NewTag && + !(isClassCompatTagKind(OldTag) && isClassCompatTagKind(NewTag))) + return false; + + // Tags are compatible, but we might still want to warn on mismatched tags. + // Non-class tags can't be mismatched at this point. + if (!isClassCompatTagKind(NewTag)) + return true; + + // Declarations for which -Wmismatched-tags is disabled are entirely ignored + // by our warning analysis. We don't want to warn about mismatches with (eg) + // declarations in system headers that are designed to be specialized, but if + // a user asks us to warn, we should warn if their code contains mismatched + // declarations. + auto IsIgnoredLoc = [&](SourceLocation Loc) { + return getDiagnostics().isIgnored(diag::warn_struct_class_tag_mismatch, + Loc); + }; + if (IsIgnoredLoc(NewTagLoc)) + return true; + + auto IsIgnored = [&](const TagDecl *Tag) { + return IsIgnoredLoc(Tag->getLocation()); + }; + while (IsIgnored(Previous)) { + Previous = Previous->getPreviousDecl(); + if (!Previous) + return true; + OldTag = Previous->getTagKind(); + } + + bool isTemplate = false; + if (const CXXRecordDecl *Record = dyn_cast(Previous)) + isTemplate = Record->getDescribedClassTemplate(); + + if (inTemplateInstantiation()) { + if (OldTag != NewTag) { + // In a template instantiation, do not offer fix-its for tag mismatches + // since they usually mess up the template instead of fixing the problem. + Diag(NewTagLoc, diag::warn_struct_class_tag_mismatch) + << getRedeclDiagFromTagKind(NewTag) << isTemplate << Name + << getRedeclDiagFromTagKind(OldTag); + // FIXME: Note previous location? + } + return true; + } + + if (isDefinition) { + // On definitions, check all previous tags and issue a fix-it for each + // one that doesn't match the current tag. + if (Previous->getDefinition()) { + // Don't suggest fix-its for redefinitions. + return true; + } + + bool previousMismatch = false; + for (const TagDecl *I : Previous->redecls()) { + if (I->getTagKind() != NewTag) { + // Ignore previous declarations for which the warning was disabled. + if (IsIgnored(I)) + continue; + + if (!previousMismatch) { + previousMismatch = true; + Diag(NewTagLoc, diag::warn_struct_class_previous_tag_mismatch) + << getRedeclDiagFromTagKind(NewTag) << isTemplate << Name + << getRedeclDiagFromTagKind(I->getTagKind()); + } + Diag(I->getInnerLocStart(), diag::note_struct_class_suggestion) + << getRedeclDiagFromTagKind(NewTag) + << FixItHint::CreateReplacement(I->getInnerLocStart(), + TypeWithKeyword::getTagTypeKindName(NewTag)); + } + } + return true; + } + + // Identify the prevailing tag kind: this is the kind of the definition (if + // there is a non-ignored definition), or otherwise the kind of the prior + // (non-ignored) declaration. + const TagDecl *PrevDef = Previous->getDefinition(); + if (PrevDef && IsIgnored(PrevDef)) + PrevDef = nullptr; + const TagDecl *Redecl = PrevDef ? PrevDef : Previous; + if (Redecl->getTagKind() != NewTag) { + Diag(NewTagLoc, diag::warn_struct_class_tag_mismatch) + << getRedeclDiagFromTagKind(NewTag) << isTemplate << Name + << getRedeclDiagFromTagKind(OldTag); + Diag(Redecl->getLocation(), diag::note_previous_use); + + // If there is a previous definition, suggest a fix-it. + if (PrevDef) { + Diag(NewTagLoc, diag::note_struct_class_suggestion) + << getRedeclDiagFromTagKind(Redecl->getTagKind()) + << FixItHint::CreateReplacement(SourceRange(NewTagLoc), + TypeWithKeyword::getTagTypeKindName(Redecl->getTagKind())); + } + } + + return true; + } + + /// Add a minimal nested name specifier fixit hint to allow lookup of a tag name + /// from an outer enclosing namespace or file scope inside a friend declaration. + /// This should provide the commented out code in the following snippet: + /// namespace N { + /// struct X; + /// namespace M { + /// struct Y { friend struct /*N::*/ X; }; + /// } + /// } + static FixItHint createFriendTagNNSFixIt(Sema &SemaRef, NamedDecl *ND, Scope *S, + SourceLocation NameLoc) { + // While the decl is in a namespace, do repeated lookup of that name and see + // if we get the same namespace back. If we do not, continue until + // translation unit scope, at which point we have a fully qualified NNS. + SmallVector Namespaces; + DeclContext *DC = ND->getDeclContext()->getRedeclContext(); + for (; !DC->isTranslationUnit(); DC = DC->getParent()) { + // This tag should be declared in a namespace, which can only be enclosed by + // other namespaces. Bail if there's an anonymous namespace in the chain. + NamespaceDecl *Namespace = dyn_cast(DC); + if (!Namespace || Namespace->isAnonymousNamespace()) + return FixItHint(); + IdentifierInfo *II = Namespace->getIdentifier(); + Namespaces.push_back(II); + NamedDecl *Lookup = SemaRef.LookupSingleName( + S, II, NameLoc, Sema::LookupNestedNameSpecifierName); + if (Lookup == Namespace) + break; + } + + // Once we have all the namespaces, reverse them to go outermost first, and + // build an NNS. + SmallString<64> Insertion; + llvm::raw_svector_ostream OS(Insertion); + if (DC->isTranslationUnit()) + OS << "::"; + std::reverse(Namespaces.begin(), Namespaces.end()); + for (auto *II : Namespaces) + OS << II->getName() << "::"; + return FixItHint::CreateInsertion(NameLoc, Insertion); + } + + /// Determine whether a tag originally declared in context \p OldDC can + /// be redeclared with an unqualified name in \p NewDC (assuming name lookup + /// found a declaration in \p OldDC as a previous decl, perhaps through a + /// using-declaration). + static bool isAcceptableTagRedeclContext(Sema &S, DeclContext *OldDC, + DeclContext *NewDC) { + OldDC = OldDC->getRedeclContext(); + NewDC = NewDC->getRedeclContext(); + + if (OldDC->Equals(NewDC)) + return true; + + // In MSVC mode, we allow a redeclaration if the contexts are related (either + // encloses the other). + if (S.getLangOpts().MSVCCompat && + (OldDC->Encloses(NewDC) || NewDC->Encloses(OldDC))) + return true; + + return false; + } + + /// This is invoked when we see 'struct foo' or 'struct {'. In the + /// former case, Name will be non-null. In the later case, Name will be null. + /// TagSpec indicates what kind of tag this is. TUK indicates whether this is a + /// reference/declaration/definition of a tag. + /// + /// \param IsTypeSpecifier \c true if this is a type-specifier (or + /// trailing-type-specifier) other than one in an alias-declaration. + /// + /// \param SkipBody If non-null, will be set to indicate if the caller should + /// skip the definition of this tag and treat it as if it were a declaration. + Decl *Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK, + SourceLocation KWLoc, CXXScopeSpec &SS, + IdentifierInfo *Name, SourceLocation NameLoc, + const ParsedAttributesView &Attrs, AccessSpecifier AS, + SourceLocation ModulePrivateLoc, + MultiTemplateParamsArg TemplateParameterLists, + bool &OwnedDecl, bool &IsDependent, + SourceLocation ScopedEnumKWLoc, + bool ScopedEnumUsesClassTag, TypeResult UnderlyingType, + bool IsTypeSpecifier, bool IsTemplateParamOrArg, + SkipBodyInfo *SkipBody) { + // If this is not a definition, it must have a name. + IdentifierInfo *OrigName = Name; + assert((Name != nullptr || TUK == TUK_Definition) && + "Nameless record must be a definition!"); + assert(TemplateParameterLists.size() == 0 || TUK != TUK_Reference); + + OwnedDecl = false; + TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); + bool ScopedEnum = ScopedEnumKWLoc.isValid(); + + // FIXME: Check member specializations more carefully. + bool isMemberSpecialization = false; + bool Invalid = false; + + // We only need to do this matching if we have template parameters + // or a scope specifier, which also conveniently avoids this work + // for non-C++ cases. + if (TemplateParameterLists.size() > 0 || + (SS.isNotEmpty() && TUK != TUK_Reference)) { + if (TemplateParameterList *TemplateParams = + MatchTemplateParametersToScopeSpecifier( + KWLoc, NameLoc, SS, nullptr, TemplateParameterLists, + TUK == TUK_Friend, isMemberSpecialization, Invalid)) { + if (Kind == TTK_Enum) { + Diag(KWLoc, diag::err_enum_template); + return nullptr; + } + + if (TemplateParams->size() > 0) { + // This is a declaration or definition of a class template (which may + // be a member of another template). + + if (Invalid) + return nullptr; + + OwnedDecl = false; + DeclResult Result = CheckClassTemplate( + S, TagSpec, TUK, KWLoc, SS, Name, NameLoc, Attrs, TemplateParams, + AS, ModulePrivateLoc, + /*FriendLoc*/ SourceLocation(), TemplateParameterLists.size() - 1, + TemplateParameterLists.data(), SkipBody); + return Result.get(); + } else { + // The "template<>" header is extraneous. + Diag(TemplateParams->getTemplateLoc(), diag::err_template_tag_noparams) + << TypeWithKeyword::getTagTypeKindName(Kind) << Name; + isMemberSpecialization = true; + } + } + } + + // Figure out the underlying type if this a enum declaration. We need to do + // this early, because it's needed to detect if this is an incompatible + // redeclaration. + llvm::PointerUnion EnumUnderlying; + bool IsFixed = !UnderlyingType.isUnset() || ScopedEnum; + + if (Kind == TTK_Enum) { + if (UnderlyingType.isInvalid() || (!UnderlyingType.get() && ScopedEnum)) { + // No underlying type explicitly specified, or we failed to parse the + // type, default to int. + EnumUnderlying = Context.IntTy.getTypePtr(); + } else if (UnderlyingType.get()) { + // C++0x 7.2p2: The type-specifier-seq of an enum-base shall name an + // integral type; any cv-qualification is ignored. + TypeSourceInfo *TI = nullptr; + GetTypeFromParser(UnderlyingType.get(), &TI); + EnumUnderlying = TI; + + if (CheckEnumUnderlyingType(TI)) + // Recover by falling back to int. + EnumUnderlying = Context.IntTy.getTypePtr(); + + if (DiagnoseUnexpandedParameterPack(TI->getTypeLoc().getBeginLoc(), TI, + UPPC_FixedUnderlyingType)) + EnumUnderlying = Context.IntTy.getTypePtr(); + + } else if (Context.getTargetInfo().getCXXABI().isMicrosoft()) { + // For MSVC ABI compatibility, unfixed enums must use an underlying type + // of 'int'. However, if this is an unfixed forward declaration, don't set + // the underlying type unless the user enables -fms-compatibility. This + // makes unfixed forward declared enums incomplete and is more conforming. + if (TUK == TUK_Definition || getLangOpts().MSVCCompat) + EnumUnderlying = Context.IntTy.getTypePtr(); + } + } + + DeclContext *SearchDC = CurContext; + DeclContext *DC = CurContext; + bool isStdBadAlloc = false; + bool isStdAlignValT = false; + + RedeclarationKind Redecl = forRedeclarationInCurContext(); + if (TUK == TUK_Friend || TUK == TUK_Reference) + Redecl = NotForRedeclaration; + + /// Create a new tag decl in C/ObjC. Since the ODR-like semantics for ObjC/C + /// implemented asks for structural equivalence checking, the returned decl + /// here is passed back to the parser, allowing the tag body to be parsed. + auto createTagFromNewDecl = [&]() -> TagDecl * { + assert(!getLangOpts().CPlusPlus && "not meant for C++ usage"); + // If there is an identifier, use the location of the identifier as the + // location of the decl, otherwise use the location of the struct/union + // keyword. + SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; + TagDecl *New = nullptr; + + if (Kind == TTK_Enum) { + New = EnumDecl::Create(Context, SearchDC, KWLoc, Loc, Name, nullptr, + ScopedEnum, ScopedEnumUsesClassTag, IsFixed); + // If this is an undefined enum, bail. + if (TUK != TUK_Definition && !Invalid) + return nullptr; + if (EnumUnderlying) { + EnumDecl *ED = cast(New); + if (TypeSourceInfo *TI = EnumUnderlying.dyn_cast()) + ED->setIntegerTypeSourceInfo(TI); + else + ED->setIntegerType(QualType(EnumUnderlying.get(), 0)); + ED->setPromotionType(ED->getIntegerType()); + } + } else { // struct/union + New = RecordDecl::Create(Context, Kind, SearchDC, KWLoc, Loc, Name, + nullptr); + } + + if (RecordDecl *RD = dyn_cast(New)) { + // Add alignment attributes if necessary; these attributes are checked + // when the ASTContext lays out the structure. + // + // It is important for implementing the correct semantics that this + // happen here (in ActOnTag). The #pragma pack stack is + // maintained as a result of parser callbacks which can occur at + // many points during the parsing of a struct declaration (because + // the #pragma tokens are effectively skipped over during the + // parsing of the struct). + if (TUK == TUK_Definition && (!SkipBody || !SkipBody->ShouldSkip)) { + AddAlignmentAttributesForRecord(RD); + AddMsStructLayoutForRecord(RD); + } + } + New->setLexicalDeclContext(CurContext); + return New; + }; + + LookupResult Previous(*this, Name, NameLoc, LookupTagName, Redecl); + if (Name && SS.isNotEmpty()) { + // We have a nested-name tag ('struct foo::bar'). + + // Check for invalid 'foo::'. + if (SS.isInvalid()) { + Name = nullptr; + goto CreateNewDecl; + } + + // If this is a friend or a reference to a class in a dependent + // context, don't try to make a decl for it. + if (TUK == TUK_Friend || TUK == TUK_Reference) { + DC = computeDeclContext(SS, false); + if (!DC) { + IsDependent = true; + return nullptr; + } + } else { + DC = computeDeclContext(SS, true); + if (!DC) { + Diag(SS.getRange().getBegin(), diag::err_dependent_nested_name_spec) + << SS.getRange(); + return nullptr; + } + } + + if (RequireCompleteDeclContext(SS, DC)) + return nullptr; + + SearchDC = DC; + // Look-up name inside 'foo::'. + LookupQualifiedName(Previous, DC); + + if (Previous.isAmbiguous()) + return nullptr; + + if (Previous.empty()) { + // Name lookup did not find anything. However, if the + // nested-name-specifier refers to the current instantiation, + // and that current instantiation has any dependent base + // classes, we might find something at instantiation time: treat + // this as a dependent elaborated-type-specifier. + // But this only makes any sense for reference-like lookups. + if (Previous.wasNotFoundInCurrentInstantiation() && + (TUK == TUK_Reference || TUK == TUK_Friend)) { + IsDependent = true; + return nullptr; + } + + // A tag 'foo::bar' must already exist. + Diag(NameLoc, diag::err_not_tag_in_scope) + << Kind << Name << DC << SS.getRange(); + Name = nullptr; + Invalid = true; + goto CreateNewDecl; + } + } else if (Name) { + // C++14 [class.mem]p14: + // If T is the name of a class, then each of the following shall have a + // name different from T: + // -- every member of class T that is itself a type + if (TUK != TUK_Reference && TUK != TUK_Friend && + DiagnoseClassNameShadow(SearchDC, DeclarationNameInfo(Name, NameLoc))) + return nullptr; + + // If this is a named struct, check to see if there was a previous forward + // declaration or definition. + // FIXME: We're looking into outer scopes here, even when we + // shouldn't be. Doing so can result in ambiguities that we + // shouldn't be diagnosing. + LookupName(Previous, S); + + // When declaring or defining a tag, ignore ambiguities introduced + // by types using'ed into this scope. + if (Previous.isAmbiguous() && + (TUK == TUK_Definition || TUK == TUK_Declaration)) { + LookupResult::Filter F = Previous.makeFilter(); + while (F.hasNext()) { + NamedDecl *ND = F.next(); + if (!ND->getDeclContext()->getRedeclContext()->Equals( + SearchDC->getRedeclContext())) + F.erase(); + } + F.done(); + } + + // 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. + // + // MSVC doesn't implement the above rule for types, so a friend tag + // declaration may be a redeclaration of a type declared in an enclosing + // scope. They do implement this rule for friend functions. + // + // Does it matter that this should be by scope instead of by + // semantic context? + if (!Previous.empty() && TUK == TUK_Friend) { + DeclContext *EnclosingNS = SearchDC->getEnclosingNamespaceContext(); + LookupResult::Filter F = Previous.makeFilter(); + bool FriendSawTagOutsideEnclosingNamespace = false; + while (F.hasNext()) { + NamedDecl *ND = F.next(); + DeclContext *DC = ND->getDeclContext()->getRedeclContext(); + if (DC->isFileContext() && + !EnclosingNS->Encloses(ND->getDeclContext())) { + if (getLangOpts().MSVCCompat) + FriendSawTagOutsideEnclosingNamespace = true; + else + F.erase(); + } + } + F.done(); + + // Diagnose this MSVC extension in the easy case where lookup would have + // unambiguously found something outside the enclosing namespace. + if (Previous.isSingleResult() && FriendSawTagOutsideEnclosingNamespace) { + NamedDecl *ND = Previous.getFoundDecl(); + Diag(NameLoc, diag::ext_friend_tag_redecl_outside_namespace) + << createFriendTagNNSFixIt(*this, ND, S, NameLoc); + } + } + + // Note: there used to be some attempt at recovery here. + if (Previous.isAmbiguous()) + return nullptr; + + if (!getLangOpts().CPlusPlus && TUK != TUK_Reference) { + // FIXME: This makes sure that we ignore the contexts associated + // with C structs, unions, and enums when looking for a matching + // tag declaration or definition. See the similar lookup tweak + // in Sema::LookupName; is there a better way to deal with this? + while (isa(SearchDC) || isa(SearchDC)) + SearchDC = SearchDC->getParent(); + } + } + + if (Previous.isSingleResult() && + Previous.getFoundDecl()->isTemplateParameter()) { + // Maybe we will complain about the shadowed template parameter. + DiagnoseTemplateParameterShadow(NameLoc, Previous.getFoundDecl()); + // Just pretend that we didn't see the previous declaration. + Previous.clear(); + } + + if (getLangOpts().CPlusPlus && Name && DC && StdNamespace && + DC->Equals(getStdNamespace())) { + if (Name->isStr("bad_alloc")) { + // This is a declaration of or a reference to "std::bad_alloc". + isStdBadAlloc = true; + + // If std::bad_alloc has been implicitly declared (but made invisible to + // name lookup), fill in this implicit declaration as the previous + // declaration, so that the declarations get chained appropriately. + if (Previous.empty() && StdBadAlloc) + Previous.addDecl(getStdBadAlloc()); + } else if (Name->isStr("align_val_t")) { + isStdAlignValT = true; + if (Previous.empty() && StdAlignValT) + Previous.addDecl(getStdAlignValT()); + } + } + + // If we didn't find a previous declaration, and this is a reference + // (or friend reference), move to the correct scope. In C++, we + // also need to do a redeclaration lookup there, just in case + // there's a shadow friend decl. + if (Name && Previous.empty() && + (TUK == TUK_Reference || TUK == TUK_Friend || IsTemplateParamOrArg)) { + if (Invalid) goto CreateNewDecl; + assert(SS.isEmpty()); + + if (TUK == TUK_Reference || IsTemplateParamOrArg) { + // C++ [basic.scope.pdecl]p5: + // -- for an elaborated-type-specifier of the form + // + // class-key identifier + // + // if the elaborated-type-specifier is used in the + // decl-specifier-seq or parameter-declaration-clause of a + // function defined in namespace scope, the identifier is + // declared as a class-name in the namespace that contains + // the declaration; otherwise, except as a friend + // declaration, the identifier is declared in the smallest + // non-class, non-function-prototype scope that contains the + // declaration. + // + // C99 6.7.2.3p8 has a similar (but not identical!) provision for + // C structs and unions. + // + // It is an error in C++ to declare (rather than define) an enum + // type, including via an elaborated type specifier. We'll + // diagnose that later; for now, declare the enum in the same + // scope as we would have picked for any other tag type. + // + // GNU C also supports this behavior as part of its incomplete + // enum types extension, while GNU C++ does not. + // + // Find the context where we'll be declaring the tag. + // FIXME: We would like to maintain the current DeclContext as the + // lexical context, + SearchDC = getTagInjectionContext(SearchDC); + + // Find the scope where we'll be declaring the tag. + S = getTagInjectionScope(S, getLangOpts()); + } else { + assert(TUK == TUK_Friend); + // 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. + SearchDC = SearchDC->getEnclosingNamespaceContext(); + } + + // In C++, we need to do a redeclaration lookup to properly + // diagnose some problems. + // FIXME: redeclaration lookup is also used (with and without C++) to find a + // hidden declaration so that we don't get ambiguity errors when using a + // type declared by an elaborated-type-specifier. In C that is not correct + // and we should instead merge compatible types found by lookup. + if (getLangOpts().CPlusPlus) { + Previous.setRedeclarationKind(forRedeclarationInCurContext()); + LookupQualifiedName(Previous, SearchDC); + } else { + Previous.setRedeclarationKind(forRedeclarationInCurContext()); + LookupName(Previous, S); + } + } + + // If we have a known previous declaration to use, then use it. + if (Previous.empty() && SkipBody && SkipBody->Previous) + Previous.addDecl(SkipBody->Previous); + + if (!Previous.empty()) { + NamedDecl *PrevDecl = Previous.getFoundDecl(); + NamedDecl *DirectPrevDecl = Previous.getRepresentativeDecl(); + + // It's okay to have a tag decl in the same scope as a typedef + // which hides a tag decl in the same scope. Finding this + // insanity with a redeclaration lookup can only actually happen + // in C++. + // + // This is also okay for elaborated-type-specifiers, which is + // technically forbidden by the current standard but which is + // okay according to the likely resolution of an open issue; + // see http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#407 + if (getLangOpts().CPlusPlus) { + if (TypedefNameDecl *TD = dyn_cast(PrevDecl)) { + if (const TagType *TT = TD->getUnderlyingType()->getAs()) { + TagDecl *Tag = TT->getDecl(); + if (Tag->getDeclName() == Name && + Tag->getDeclContext()->getRedeclContext() + ->Equals(TD->getDeclContext()->getRedeclContext())) { + PrevDecl = Tag; + Previous.clear(); + Previous.addDecl(Tag); + Previous.resolveKind(); + } + } + } + } + + // If this is a redeclaration of a using shadow declaration, it must + // declare a tag in the same context. In MSVC mode, we allow a + // redefinition if either context is within the other. + if (auto *Shadow = dyn_cast(DirectPrevDecl)) { + auto *OldTag = dyn_cast(PrevDecl); + if (SS.isEmpty() && TUK != TUK_Reference && TUK != TUK_Friend && + isDeclInScope(Shadow, SearchDC, S, isMemberSpecialization) && + !(OldTag && isAcceptableTagRedeclContext( + *this, OldTag->getDeclContext(), SearchDC))) { + Diag(KWLoc, diag::err_using_decl_conflict_reverse); + Diag(Shadow->getTargetDecl()->getLocation(), + diag::note_using_decl_target); + Diag(Shadow->getUsingDecl()->getLocation(), diag::note_using_decl) + << 0; + // Recover by ignoring the old declaration. + Previous.clear(); + goto CreateNewDecl; + } + } + + if (TagDecl *PrevTagDecl = dyn_cast(PrevDecl)) { + // If this is a use of a previous tag, or if the tag is already declared + // in the same scope (so that the definition/declaration completes or + // rementions the tag), reuse the decl. + if (TUK == TUK_Reference || TUK == TUK_Friend || + isDeclInScope(DirectPrevDecl, SearchDC, S, + SS.isNotEmpty() || isMemberSpecialization)) { + // Make sure that this wasn't declared as an enum and now used as a + // struct or something similar. + if (!isAcceptableTagRedeclaration(PrevTagDecl, Kind, + TUK == TUK_Definition, KWLoc, + Name)) { + bool SafeToContinue + = (PrevTagDecl->getTagKind() != TTK_Enum && + Kind != TTK_Enum); + if (SafeToContinue) + Diag(KWLoc, diag::err_use_with_wrong_tag) + << Name + << FixItHint::CreateReplacement(SourceRange(KWLoc), + PrevTagDecl->getKindName()); + else + Diag(KWLoc, diag::err_use_with_wrong_tag) << Name; + Diag(PrevTagDecl->getLocation(), diag::note_previous_use); + + if (SafeToContinue) + Kind = PrevTagDecl->getTagKind(); + else { + // Recover by making this an anonymous redefinition. + Name = nullptr; + Previous.clear(); + Invalid = true; + } + } + + if (Kind == TTK_Enum && PrevTagDecl->getTagKind() == TTK_Enum) { + const EnumDecl *PrevEnum = cast(PrevTagDecl); + + // If this is an elaborated-type-specifier for a scoped enumeration, + // the 'class' keyword is not necessary and not permitted. + if (TUK == TUK_Reference || TUK == TUK_Friend) { + if (ScopedEnum) + Diag(ScopedEnumKWLoc, diag::err_enum_class_reference) + << PrevEnum->isScoped() + << FixItHint::CreateRemoval(ScopedEnumKWLoc); + return PrevTagDecl; + } + + QualType EnumUnderlyingTy; + if (TypeSourceInfo *TI = EnumUnderlying.dyn_cast()) + EnumUnderlyingTy = TI->getType().getUnqualifiedType(); + else if (const Type *T = EnumUnderlying.dyn_cast()) + EnumUnderlyingTy = QualType(T, 0); + + // All conflicts with previous declarations are recovered by + // returning the previous declaration, unless this is a definition, + // in which case we want the caller to bail out. + if (CheckEnumRedeclaration(NameLoc.isValid() ? NameLoc : KWLoc, + ScopedEnum, EnumUnderlyingTy, + IsFixed, PrevEnum)) + return TUK == TUK_Declaration ? PrevTagDecl : nullptr; + } + + // C++11 [class.mem]p1: + // A member shall not be declared twice in the member-specification, + // except that a nested class or member class template can be declared + // and then later defined. + if (TUK == TUK_Declaration && PrevDecl->isCXXClassMember() && + S->isDeclScope(PrevDecl)) { + Diag(NameLoc, diag::ext_member_redeclared); + Diag(PrevTagDecl->getLocation(), diag::note_previous_declaration); + } + + if (!Invalid) { + // If this is a use, just return the declaration we found, unless + // we have attributes. + if (TUK == TUK_Reference || TUK == TUK_Friend) { + if (!Attrs.empty()) { + // FIXME: Diagnose these attributes. For now, we create a new + // declaration to hold them. + } else if (TUK == TUK_Reference && + (PrevTagDecl->getFriendObjectKind() == + Decl::FOK_Undeclared || + PrevDecl->getOwningModule() != getCurrentModule()) && + SS.isEmpty()) { + // This declaration is a reference to an existing entity, but + // has different visibility from that entity: it either makes + // a friend visible or it makes a type visible in a new module. + // In either case, create a new declaration. We only do this if + // the declaration would have meant the same thing if no prior + // declaration were found, that is, if it was found in the same + // scope where we would have injected a declaration. + if (!getTagInjectionContext(CurContext)->getRedeclContext() + ->Equals(PrevDecl->getDeclContext()->getRedeclContext())) + return PrevTagDecl; + // This is in the injected scope, create a new declaration in + // that scope. + S = getTagInjectionScope(S, getLangOpts()); + } else { + return PrevTagDecl; + } + } + + // Diagnose attempts to redefine a tag. + if (TUK == TUK_Definition) { + if (NamedDecl *Def = PrevTagDecl->getDefinition()) { + // If we're defining a specialization and the previous definition + // is from an implicit instantiation, don't emit an error + // here; we'll catch this in the general case below. + bool IsExplicitSpecializationAfterInstantiation = false; + if (isMemberSpecialization) { + if (CXXRecordDecl *RD = dyn_cast(Def)) + IsExplicitSpecializationAfterInstantiation = + RD->getTemplateSpecializationKind() != + TSK_ExplicitSpecialization; + else if (EnumDecl *ED = dyn_cast(Def)) + IsExplicitSpecializationAfterInstantiation = + ED->getTemplateSpecializationKind() != + TSK_ExplicitSpecialization; + } + + // Note that clang allows ODR-like semantics for ObjC/C, i.e., do + // not keep more that one definition around (merge them). However, + // ensure the decl passes the structural compatibility check in + // C11 6.2.7/1 (or 6.1.2.6/1 in C89). + NamedDecl *Hidden = nullptr; + if (SkipBody && !hasVisibleDefinition(Def, &Hidden)) { + // There is a definition of this tag, but it is not visible. We + // explicitly make use of C++'s one definition rule here, and + // assume that this definition is identical to the hidden one + // we already have. Make the existing definition visible and + // use it in place of this one. + if (!getLangOpts().CPlusPlus) { + // Postpone making the old definition visible until after we + // complete parsing the new one and do the structural + // comparison. + SkipBody->CheckSameAsPrevious = true; + SkipBody->New = createTagFromNewDecl(); + SkipBody->Previous = Def; + return Def; + } else { + SkipBody->ShouldSkip = true; + SkipBody->Previous = Def; + makeMergedDefinitionVisible(Hidden); + // Carry on and handle it like a normal definition. We'll + // skip starting the definitiion later. + } + } else if (!IsExplicitSpecializationAfterInstantiation) { + // A redeclaration in function prototype scope in C isn't + // visible elsewhere, so merely issue a warning. + if (!getLangOpts().CPlusPlus && S->containedInPrototypeScope()) + Diag(NameLoc, diag::warn_redefinition_in_param_list) << Name; + else + Diag(NameLoc, diag::err_redefinition) << Name; + notePreviousDefinition(Def, + NameLoc.isValid() ? NameLoc : KWLoc); + // If this is a redefinition, recover by making this + // struct be anonymous, which will make any later + // references get the previous definition. + Name = nullptr; + Previous.clear(); + Invalid = true; + } + } else { + // If the type is currently being defined, complain + // about a nested redefinition. + auto *TD = Context.getTagDeclType(PrevTagDecl)->getAsTagDecl(); + if (TD->isBeingDefined()) { + Diag(NameLoc, diag::err_nested_redefinition) << Name; + Diag(PrevTagDecl->getLocation(), + diag::note_previous_definition); + Name = nullptr; + Previous.clear(); + Invalid = true; + } + } + + // Okay, this is definition of a previously declared or referenced + // tag. We're going to create a new Decl for it. + } + + // Okay, we're going to make a redeclaration. If this is some kind + // of reference, make sure we build the redeclaration in the same DC + // as the original, and ignore the current access specifier. + if (TUK == TUK_Friend || TUK == TUK_Reference) { + SearchDC = PrevTagDecl->getDeclContext(); + AS = AS_none; + } + } + // If we get here we have (another) forward declaration or we + // have a definition. Just create a new decl. + + } else { + // If we get here, this is a definition of a new tag type in a nested + // scope, e.g. "struct foo; void bar() { struct foo; }", just create a + // new decl/type. We set PrevDecl to NULL so that the entities + // have distinct types. + Previous.clear(); + } + // If we get here, we're going to create a new Decl. If PrevDecl + // is non-NULL, it's a definition of the tag declared by + // PrevDecl. If it's NULL, we have a new definition. + + // Otherwise, PrevDecl is not a tag, but was found with tag + // lookup. This is only actually possible in C++, where a few + // things like templates still live in the tag namespace. + } else { + // Use a better diagnostic if an elaborated-type-specifier + // found the wrong kind of type on the first + // (non-redeclaration) lookup. + if ((TUK == TUK_Reference || TUK == TUK_Friend) && + !Previous.isForRedeclaration()) { + NonTagKind NTK = getNonTagTypeDeclKind(PrevDecl, Kind); + Diag(NameLoc, diag::err_tag_reference_non_tag) << PrevDecl << NTK + << Kind; + Diag(PrevDecl->getLocation(), diag::note_declared_at); + Invalid = true; + + // Otherwise, only diagnose if the declaration is in scope. + } else if (!isDeclInScope(DirectPrevDecl, SearchDC, S, + SS.isNotEmpty() || isMemberSpecialization)) { + // do nothing + + // Diagnose implicit declarations introduced by elaborated types. + } else if (TUK == TUK_Reference || TUK == TUK_Friend) { + NonTagKind NTK = getNonTagTypeDeclKind(PrevDecl, Kind); + Diag(NameLoc, diag::err_tag_reference_conflict) << NTK; + Diag(PrevDecl->getLocation(), diag::note_previous_decl) << PrevDecl; + Invalid = true; + + // Otherwise it's a declaration. Call out a particularly common + // case here. + } else if (TypedefNameDecl *TND = dyn_cast(PrevDecl)) { + unsigned Kind = 0; + if (isa(PrevDecl)) Kind = 1; + Diag(NameLoc, diag::err_tag_definition_of_typedef) + << Name << Kind << TND->getUnderlyingType(); + Diag(PrevDecl->getLocation(), diag::note_previous_decl) << PrevDecl; + Invalid = true; + + // Otherwise, diagnose. + } else { + // The tag name clashes with something else in the target scope, + // issue an error and recover by making this tag be anonymous. + Diag(NameLoc, diag::err_redefinition_different_kind) << Name; + notePreviousDefinition(PrevDecl, NameLoc); + Name = nullptr; + Invalid = true; + } + + // The existing declaration isn't relevant to us; we're in a + // new scope, so clear out the previous declaration. + Previous.clear(); + } + } + + CreateNewDecl: + + TagDecl *PrevDecl = nullptr; + if (Previous.isSingleResult()) + PrevDecl = cast(Previous.getFoundDecl()); + + // If there is an identifier, use the location of the identifier as the + // location of the decl, otherwise use the location of the struct/union + // keyword. + SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; + + // Otherwise, create a new declaration. If there is a previous + // declaration of the same entity, the two will be linked via + // PrevDecl. + TagDecl *New; + + if (Kind == TTK_Enum) { + // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: + // enum X { A, B, C } D; D should chain to X. + New = EnumDecl::Create(Context, SearchDC, KWLoc, Loc, Name, + cast_or_null(PrevDecl), ScopedEnum, + ScopedEnumUsesClassTag, IsFixed); + + if (isStdAlignValT && (!StdAlignValT || getStdAlignValT()->isImplicit())) + StdAlignValT = cast(New); + + // If this is an undefined enum, warn. + if (TUK != TUK_Definition && !Invalid) { + TagDecl *Def; + if (IsFixed && cast(New)->isFixed()) { + // C++0x: 7.2p2: opaque-enum-declaration. + // Conflicts are diagnosed above. Do nothing. + } + else if (PrevDecl && (Def = cast(PrevDecl)->getDefinition())) { + Diag(Loc, diag::ext_forward_ref_enum_def) + << New; + Diag(Def->getLocation(), diag::note_previous_definition); + } else { + unsigned DiagID = diag::ext_forward_ref_enum; + if (getLangOpts().MSVCCompat) + DiagID = diag::ext_ms_forward_ref_enum; + else if (getLangOpts().CPlusPlus) + DiagID = diag::err_forward_ref_enum; + Diag(Loc, DiagID); + } + } + + if (EnumUnderlying) { + EnumDecl *ED = cast(New); + if (TypeSourceInfo *TI = EnumUnderlying.dyn_cast()) + ED->setIntegerTypeSourceInfo(TI); + else + ED->setIntegerType(QualType(EnumUnderlying.get(), 0)); + ED->setPromotionType(ED->getIntegerType()); + assert(ED->isComplete() && "enum with type should be complete"); + } + } else { + // struct/union/class + + // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: + // struct X { int A; } D; D should chain to X. + if (getLangOpts().CPlusPlus) { + // FIXME: Look for a way to use RecordDecl for simple structs. + New = CXXRecordDecl::Create(Context, Kind, SearchDC, KWLoc, Loc, Name, + cast_or_null(PrevDecl)); + + if (isStdBadAlloc && (!StdBadAlloc || getStdBadAlloc()->isImplicit())) + StdBadAlloc = cast(New); + } else + New = RecordDecl::Create(Context, Kind, SearchDC, KWLoc, Loc, Name, + cast_or_null(PrevDecl)); + } + + // C++11 [dcl.type]p3: + // A type-specifier-seq shall not define a class or enumeration [...]. + if (getLangOpts().CPlusPlus && (IsTypeSpecifier || IsTemplateParamOrArg) && + TUK == TUK_Definition) { + Diag(New->getLocation(), diag::err_type_defined_in_type_specifier) + << Context.getTagDeclType(New); + Invalid = true; + } + + if (!Invalid && getLangOpts().CPlusPlus && TUK == TUK_Definition && + DC->getDeclKind() == Decl::Enum) { + Diag(New->getLocation(), diag::err_type_defined_in_enum) + << Context.getTagDeclType(New); + Invalid = true; + } + + // Maybe add qualifier info. + if (SS.isNotEmpty()) { + if (SS.isSet()) { + // If this is either a declaration or a definition, check the + // nested-name-specifier against the current context. + if ((TUK == TUK_Definition || TUK == TUK_Declaration) && + diagnoseQualifiedDeclaration(SS, DC, OrigName, Loc, + isMemberSpecialization)) + Invalid = true; + + New->setQualifierInfo(SS.getWithLocInContext(Context)); + if (TemplateParameterLists.size() > 0) { + New->setTemplateParameterListsInfo(Context, TemplateParameterLists); + } + } + else + Invalid = true; + } + + if (RecordDecl *RD = dyn_cast(New)) { + // Add alignment attributes if necessary; these attributes are checked when + // the ASTContext lays out the structure. + // + // It is important for implementing the correct semantics that this + // happen here (in ActOnTag). The #pragma pack stack is + // maintained as a result of parser callbacks which can occur at + // many points during the parsing of a struct declaration (because + // the #pragma tokens are effectively skipped over during the + // parsing of the struct). + if (TUK == TUK_Definition && (!SkipBody || !SkipBody->ShouldSkip)) { + AddAlignmentAttributesForRecord(RD); + AddMsStructLayoutForRecord(RD); + } + } + + if (ModulePrivateLoc.isValid()) { + if (isMemberSpecialization) + Diag(New->getLocation(), diag::err_module_private_specialization) + << 2 + << FixItHint::CreateRemoval(ModulePrivateLoc); + // __module_private__ does not apply to local classes. However, we only + // diagnose this as an error when the declaration specifiers are + // freestanding. Here, we just ignore the __module_private__. + else if (!SearchDC->isFunctionOrMethod()) + New->setModulePrivate(); + } + + // If this is a specialization of a member class (of a class template), + // check the specialization. + if (isMemberSpecialization && CheckMemberSpecialization(New, Previous)) + Invalid = true; + + // If we're declaring or defining a tag in function prototype scope in C, + // note that this type can only be used within the function and add it to + // the list of decls to inject into the function definition scope. + if ((Name || Kind == TTK_Enum) && + getNonFieldDeclScope(S)->isFunctionPrototypeScope()) { + if (getLangOpts().CPlusPlus) { + // C++ [dcl.fct]p6: + // Types shall not be defined in return or parameter types. + if (TUK == TUK_Definition && !IsTypeSpecifier) { + Diag(Loc, diag::err_type_defined_in_param_type) + << Name; + Invalid = true; + } + } else if (!PrevDecl) { + Diag(Loc, diag::warn_decl_in_param_list) << Context.getTagDeclType(New); + } + } + + if (Invalid) + New->setInvalidDecl(); + + // Set the lexical context. If the tag has a C++ scope specifier, the + // lexical context will be different from the semantic context. + New->setLexicalDeclContext(CurContext); + + // Mark this as a friend decl if applicable. + // In Microsoft mode, a friend declaration also acts as a forward + // declaration so we always pass true to setObjectOfFriendDecl to make + // the tag name visible. + if (TUK == TUK_Friend) + New->setObjectOfFriendDecl(getLangOpts().MSVCCompat); + + // Set the access specifier. + if (!Invalid && SearchDC->isRecord()) + SetMemberAccessSpecifier(New, PrevDecl, AS); + + if (PrevDecl) + CheckRedeclarationModuleOwnership(New, PrevDecl); + + if (TUK == TUK_Definition && (!SkipBody || !SkipBody->ShouldSkip)) + New->startDefinition(); + + ProcessDeclAttributeList(S, New, Attrs); + AddPragmaAttributes(S, New); + + // If this has an identifier, add it to the scope stack. + if (TUK == TUK_Friend) { + // We might be replacing an existing declaration in the lookup tables; + // if so, borrow its access specifier. + if (PrevDecl) + New->setAccess(PrevDecl->getAccess()); + + DeclContext *DC = New->getDeclContext()->getRedeclContext(); + DC->makeDeclVisibleInContext(New); + if (Name) // can be null along some error paths + if (Scope *EnclosingScope = getScopeForDeclContext(S, DC)) + PushOnScopeChains(New, EnclosingScope, /* AddToContext = */ false); + } else if (Name) { + S = getNonFieldDeclScope(S); + PushOnScopeChains(New, S, true); + } else { + CurContext->addDecl(New); + } + + // If this is the C FILE type, notify the AST context. + if (IdentifierInfo *II = New->getIdentifier()) + if (!New->isInvalidDecl() && + New->getDeclContext()->getRedeclContext()->isTranslationUnit() && + II->isStr("FILE")) + Context.setFILEDecl(New); + + if (PrevDecl) + mergeDeclAttributes(New, PrevDecl); + + // If there's a #pragma GCC visibility in scope, set the visibility of this + // record. + AddPushedVisibilityAttribute(New); + + if (isMemberSpecialization && !New->isInvalidDecl()) + CompleteMemberSpecialization(New, Previous); + + OwnedDecl = true; + // In C++, don't return an invalid declaration. We can't recover well from + // the cases where we make the type anonymous. + if (Invalid && getLangOpts().CPlusPlus) { + if (New->isBeingDefined()) + if (auto RD = dyn_cast(New)) + RD->completeDefinition(); + return nullptr; + } else if (SkipBody && SkipBody->ShouldSkip) { + return SkipBody->Previous; + } else { + return New; + } + } + + void Sema::ActOnTagStartDefinition(Scope *S, Decl *TagD) { + AdjustDeclIfTemplate(TagD); + TagDecl *Tag = cast(TagD); + + // Enter the tag context. + PushDeclContext(S, Tag); + + ActOnDocumentableDecl(TagD); + + // If there's a #pragma GCC visibility in scope, set the visibility of this + // record. + AddPushedVisibilityAttribute(Tag); + } + + bool Sema::ActOnDuplicateDefinition(DeclSpec &DS, Decl *Prev, + SkipBodyInfo &SkipBody) { + if (!hasStructuralCompatLayout(Prev, SkipBody.New)) + return false; + + // Make the previous decl visible. + makeMergedDefinitionVisible(SkipBody.Previous); + return true; + } + + Decl *Sema::ActOnObjCContainerStartDefinition(Decl *IDecl) { + assert(isa(IDecl) && + "ActOnObjCContainerStartDefinition - Not ObjCContainerDecl"); + DeclContext *OCD = cast(IDecl); + assert(getContainingDC(OCD) == CurContext && + "The next DeclContext should be lexically contained in the current one."); + CurContext = OCD; + return IDecl; + } + + void Sema::ActOnStartCXXMemberDeclarations(Scope *S, Decl *TagD, + SourceLocation FinalLoc, + bool IsFinalSpelledSealed, + SourceLocation LBraceLoc) { + AdjustDeclIfTemplate(TagD); + CXXRecordDecl *Record = cast(TagD); + + FieldCollector->StartClass(); + + if (!Record->getIdentifier()) + return; + + if (FinalLoc.isValid()) + Record->addAttr(new (Context) + FinalAttr(FinalLoc, Context, IsFinalSpelledSealed)); + + // C++ [class]p2: + // [...] The class-name is also inserted into the scope of the + // class itself; this is known as the injected-class-name. For + // purposes of access checking, the injected-class-name is treated + // as if it were a public member name. + CXXRecordDecl *InjectedClassName = CXXRecordDecl::Create( + Context, Record->getTagKind(), CurContext, Record->getBeginLoc(), + Record->getLocation(), Record->getIdentifier(), + /*PrevDecl=*/nullptr, + /*DelayTypeCreation=*/true); + Context.getTypeDeclType(InjectedClassName, Record); + InjectedClassName->setImplicit(); + InjectedClassName->setAccess(AS_public); + if (ClassTemplateDecl *Template = Record->getDescribedClassTemplate()) + InjectedClassName->setDescribedClassTemplate(Template); + PushOnScopeChains(InjectedClassName, S); + assert(InjectedClassName->isInjectedClassName() && + "Broken injected-class-name"); + } + + void Sema::ActOnTagFinishDefinition(Scope *S, Decl *TagD, + SourceRange BraceRange) { + AdjustDeclIfTemplate(TagD); + TagDecl *Tag = cast(TagD); + Tag->setBraceRange(BraceRange); + + // Make sure we "complete" the definition even it is invalid. + if (Tag->isBeingDefined()) { + assert(Tag->isInvalidDecl() && "We should already have completed it"); + if (RecordDecl *RD = dyn_cast(Tag)) + RD->completeDefinition(); + } + + if (isa(Tag)) { + FieldCollector->FinishClass(); + } + + // Exit this scope of this tag's definition. + PopDeclContext(); + + if (getCurLexicalContext()->isObjCContainer() && + Tag->getDeclContext()->isFileContext()) + Tag->setTopLevelDeclInObjCContainer(); + + // Notify the consumer that we've defined a tag. + if (!Tag->isInvalidDecl()) + Consumer.HandleTagDeclDefinition(Tag); + } + + void Sema::ActOnObjCContainerFinishDefinition() { + // Exit this scope of this interface definition. + PopDeclContext(); + } + + void Sema::ActOnObjCTemporaryExitContainerContext(DeclContext *DC) { + assert(DC == CurContext && "Mismatch of container contexts"); + OriginalLexicalContext = DC; + ActOnObjCContainerFinishDefinition(); + } + + void Sema::ActOnObjCReenterContainerContext(DeclContext *DC) { + ActOnObjCContainerStartDefinition(cast(DC)); + OriginalLexicalContext = nullptr; + } + + void Sema::ActOnTagDefinitionError(Scope *S, Decl *TagD) { + AdjustDeclIfTemplate(TagD); + TagDecl *Tag = cast(TagD); + Tag->setInvalidDecl(); + + // Make sure we "complete" the definition even it is invalid. + if (Tag->isBeingDefined()) { + if (RecordDecl *RD = dyn_cast(Tag)) + RD->completeDefinition(); + } + + // We're undoing ActOnTagStartDefinition here, not + // ActOnStartCXXMemberDeclarations, so we don't have to mess with + // the FieldCollector. + + PopDeclContext(); + } + + // Note that FieldName may be null for anonymous bitfields. + ExprResult Sema::VerifyBitField(SourceLocation FieldLoc, + IdentifierInfo *FieldName, + QualType FieldTy, bool IsMsStruct, + Expr *BitWidth, bool *ZeroWidth) { + // Default to true; that shouldn't confuse checks for emptiness + if (ZeroWidth) + *ZeroWidth = true; + + // C99 6.7.2.1p4 - verify the field type. + // C++ 9.6p3: A bit-field shall have integral or enumeration type. + if (!FieldTy->isDependentType() && !FieldTy->isIntegralOrEnumerationType()) { + // Handle incomplete types with specific error. + if (RequireCompleteType(FieldLoc, FieldTy, diag::err_field_incomplete)) + return ExprError(); + if (FieldName) + return Diag(FieldLoc, diag::err_not_integral_type_bitfield) + << FieldName << FieldTy << BitWidth->getSourceRange(); + return Diag(FieldLoc, diag::err_not_integral_type_anon_bitfield) + << FieldTy << BitWidth->getSourceRange(); + } else if (DiagnoseUnexpandedParameterPack(const_cast(BitWidth), + UPPC_BitFieldWidth)) + return ExprError(); + + // If the bit-width is type- or value-dependent, don't try to check + // it now. + if (BitWidth->isValueDependent() || BitWidth->isTypeDependent()) + return BitWidth; + + llvm::APSInt Value; + ExprResult ICE = VerifyIntegerConstantExpression(BitWidth, &Value); + if (ICE.isInvalid()) + return ICE; + BitWidth = ICE.get(); + + if (Value != 0 && ZeroWidth) + *ZeroWidth = false; + + // Zero-width bitfield is ok for anonymous field. + if (Value == 0 && FieldName) + return Diag(FieldLoc, diag::err_bitfield_has_zero_width) << FieldName; + + if (Value.isSigned() && Value.isNegative()) { + if (FieldName) + return Diag(FieldLoc, diag::err_bitfield_has_negative_width) + << FieldName << Value.toString(10); + return Diag(FieldLoc, diag::err_anon_bitfield_has_negative_width) + << Value.toString(10); + } + + if (!FieldTy->isDependentType()) { + uint64_t TypeStorageSize = Context.getTypeSize(FieldTy); + uint64_t TypeWidth = Context.getIntWidth(FieldTy); + bool BitfieldIsOverwide = Value.ugt(TypeWidth); + + // Over-wide bitfields are an error in C or when using the MSVC bitfield + // ABI. + bool CStdConstraintViolation = + BitfieldIsOverwide && !getLangOpts().CPlusPlus; + bool MSBitfieldViolation = + Value.ugt(TypeStorageSize) && + (IsMsStruct || Context.getTargetInfo().getCXXABI().isMicrosoft()); + if (CStdConstraintViolation || MSBitfieldViolation) { + unsigned DiagWidth = + CStdConstraintViolation ? TypeWidth : TypeStorageSize; + if (FieldName) + return Diag(FieldLoc, diag::err_bitfield_width_exceeds_type_width) + << FieldName << (unsigned)Value.getZExtValue() + << !CStdConstraintViolation << DiagWidth; + + return Diag(FieldLoc, diag::err_anon_bitfield_width_exceeds_type_width) + << (unsigned)Value.getZExtValue() << !CStdConstraintViolation + << DiagWidth; + } + + // Warn on types where the user might conceivably expect to get all + // specified bits as value bits: that's all integral types other than + // 'bool'. + if (BitfieldIsOverwide && !FieldTy->isBooleanType()) { + if (FieldName) + Diag(FieldLoc, diag::warn_bitfield_width_exceeds_type_width) + << FieldName << (unsigned)Value.getZExtValue() + << (unsigned)TypeWidth; + else + Diag(FieldLoc, diag::warn_anon_bitfield_width_exceeds_type_width) + << (unsigned)Value.getZExtValue() << (unsigned)TypeWidth; + } + } + + return BitWidth; + } + + /// ActOnField - Each field of a C struct/union is passed into this in order + /// to create a FieldDecl object for it. + Decl *Sema::ActOnField(Scope *S, Decl *TagD, SourceLocation DeclStart, + Declarator &D, Expr *BitfieldWidth) { + FieldDecl *Res = HandleField(S, cast_or_null(TagD), + DeclStart, D, static_cast(BitfieldWidth), + /*InitStyle=*/ICIS_NoInit, AS_public); + return Res; + } + + /// HandleField - Analyze a field of a C struct or a C++ data member. + /// + FieldDecl *Sema::HandleField(Scope *S, RecordDecl *Record, + SourceLocation DeclStart, + Declarator &D, Expr *BitWidth, + InClassInitStyle InitStyle, + AccessSpecifier AS) { + if (D.isDecompositionDeclarator()) { + const DecompositionDeclarator &Decomp = D.getDecompositionDeclarator(); + Diag(Decomp.getLSquareLoc(), diag::err_decomp_decl_context) + << Decomp.getSourceRange(); + return nullptr; + } + + IdentifierInfo *II = D.getIdentifier(); + SourceLocation Loc = DeclStart; + if (II) 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; + } + Previous.suppressDiagnostics(); + + 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; + + bool Mutable + = (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_mutable); + SourceLocation TSSL = D.getBeginLoc(); + FieldDecl *NewFD + = CheckFieldDecl(II, T, TInfo, Record, Loc, Mutable, BitWidth, InitStyle, + TSSL, AS, PrevDecl, &D); + + if (NewFD->isInvalidDecl()) + Record->setInvalidDecl(); + + if (D.getDeclSpec().isModulePrivateSpecified()) + NewFD->setModulePrivate(); + + if (NewFD->isInvalidDecl() && PrevDecl) { + // Don't introduce NewFD into scope; there's already something + // with the same name in the same scope. + } else if (II) { + PushOnScopeChains(NewFD, S); + } else + Record->addDecl(NewFD); + + return NewFD; + } + + /// Build a new FieldDecl and check its well-formedness. + /// + /// This routine builds a new FieldDecl given the fields name, type, + /// record, etc. \p PrevDecl should refer to any previous declaration + /// with the same name and in the same scope as the field to be + /// created. + /// + /// \returns a new FieldDecl. + /// + /// \todo The Declarator argument is a hack. It will be removed once + FieldDecl *Sema::CheckFieldDecl(DeclarationName Name, QualType T, + TypeSourceInfo *TInfo, + RecordDecl *Record, SourceLocation Loc, + bool Mutable, Expr *BitWidth, + InClassInitStyle InitStyle, + SourceLocation TSSL, + AccessSpecifier AS, NamedDecl *PrevDecl, + Declarator *D) { + IdentifierInfo *II = Name.getAsIdentifierInfo(); + bool InvalidDecl = false; + if (D) InvalidDecl = D->isInvalidType(); + + // If we receive a broken type, recover by assuming 'int' and + // marking this declaration as invalid. + if (T.isNull()) { + InvalidDecl = true; + T = Context.IntTy; + } + + QualType EltTy = Context.getBaseElementType(T); + if (!EltTy->isDependentType()) { + if (RequireCompleteType(Loc, EltTy, diag::err_field_incomplete)) { + // Fields of incomplete type force their record to be invalid. + Record->setInvalidDecl(); + InvalidDecl = true; + } else { + NamedDecl *Def; + EltTy->isIncompleteType(&Def); + if (Def && Def->isInvalidDecl()) { + Record->setInvalidDecl(); + InvalidDecl = true; + } + } + } + + // TR 18037 does not allow fields to be declared with address space + if (T.getQualifiers().hasAddressSpace() || T->isDependentAddressSpaceType() || + T->getBaseElementTypeUnsafe()->isDependentAddressSpaceType()) { + Diag(Loc, diag::err_field_with_address_space); + Record->setInvalidDecl(); + InvalidDecl = true; + } + + if (LangOpts.OpenCL) { + // OpenCL v1.2 s6.9b,r & OpenCL v2.0 s6.12.5 - The following types cannot be + // used as structure or union field: image, sampler, event or block types. + if (T->isEventT() || T->isImageType() || T->isSamplerT() || + T->isBlockPointerType()) { + Diag(Loc, diag::err_opencl_type_struct_or_union_field) << T; + Record->setInvalidDecl(); + InvalidDecl = true; + } + // OpenCL v1.2 s6.9.c: bitfields are not supported. + if (BitWidth) { + Diag(Loc, diag::err_opencl_bitfields); + InvalidDecl = true; + } + } + + // Anonymous bit-fields cannot be cv-qualified (CWG 2229). + if (!InvalidDecl && getLangOpts().CPlusPlus && !II && BitWidth && + T.hasQualifiers()) { + InvalidDecl = true; + Diag(Loc, diag::err_anon_bitfield_qualifiers); + } + + // C99 6.7.2.1p8: A member of a structure or union may have any type other + // than a variably modified type. + if (!InvalidDecl && T->isVariablyModifiedType()) { + bool SizeIsNegative; + llvm::APSInt Oversized; + + TypeSourceInfo *FixedTInfo = + TryToFixInvalidVariablyModifiedTypeSourceInfo(TInfo, Context, + SizeIsNegative, + Oversized); + if (FixedTInfo) { + Diag(Loc, diag::warn_illegal_constant_array_size); + TInfo = FixedTInfo; + T = FixedTInfo->getType(); + } else { + if (SizeIsNegative) + Diag(Loc, diag::err_typecheck_negative_array_size); + else if (Oversized.getBoolValue()) + Diag(Loc, diag::err_array_too_large) + << Oversized.toString(10); + else + Diag(Loc, diag::err_typecheck_field_variable_size); + InvalidDecl = true; + } + } + + // Fields can not have abstract class types + if (!InvalidDecl && RequireNonAbstractType(Loc, T, + diag::err_abstract_type_in_decl, + AbstractFieldType)) + InvalidDecl = true; + + bool ZeroWidth = false; + if (InvalidDecl) + BitWidth = nullptr; + // If this is declared as a bit-field, check the bit-field. + if (BitWidth) { + BitWidth = VerifyBitField(Loc, II, T, Record->isMsStruct(Context), BitWidth, + &ZeroWidth).get(); + if (!BitWidth) { + InvalidDecl = true; + BitWidth = nullptr; + ZeroWidth = false; + } + } + + // Check that 'mutable' is consistent with the type of the declaration. + if (!InvalidDecl && Mutable) { + unsigned DiagID = 0; + if (T->isReferenceType()) + DiagID = getLangOpts().MSVCCompat ? diag::ext_mutable_reference + : diag::err_mutable_reference; + else if (T.isConstQualified()) + DiagID = diag::err_mutable_const; + + if (DiagID) { + SourceLocation ErrLoc = Loc; + if (D && D->getDeclSpec().getStorageClassSpecLoc().isValid()) + ErrLoc = D->getDeclSpec().getStorageClassSpecLoc(); + Diag(ErrLoc, DiagID); + if (DiagID != diag::ext_mutable_reference) { + Mutable = false; + InvalidDecl = true; + } + } + } + + // C++11 [class.union]p8 (DR1460): + // At most one variant member of a union may have a + // brace-or-equal-initializer. + if (InitStyle != ICIS_NoInit) + checkDuplicateDefaultInit(*this, cast(Record), Loc); + + FieldDecl *NewFD = FieldDecl::Create(Context, Record, TSSL, Loc, II, T, TInfo, + BitWidth, Mutable, InitStyle); + if (InvalidDecl) + NewFD->setInvalidDecl(); + + if (PrevDecl && !isa(PrevDecl)) { + Diag(Loc, diag::err_duplicate_member) << II; + Diag(PrevDecl->getLocation(), diag::note_previous_declaration); + NewFD->setInvalidDecl(); + } + + if (!InvalidDecl && getLangOpts().CPlusPlus) { + if (Record->isUnion()) { + if (const RecordType *RT = EltTy->getAs()) { + CXXRecordDecl* RDecl = cast(RT->getDecl()); + if (RDecl->getDefinition()) { + // C++ [class.union]p1: An object of a class with a non-trivial + // constructor, a non-trivial copy constructor, a non-trivial + // destructor, or a non-trivial copy assignment operator + // cannot be a member of a union, nor can an array of such + // objects. + if (CheckNontrivialField(NewFD)) + NewFD->setInvalidDecl(); + } + } + + // C++ [class.union]p1: If a union contains a member of reference type, + // the program is ill-formed, except when compiling with MSVC extensions + // enabled. + if (EltTy->isReferenceType()) { + Diag(NewFD->getLocation(), getLangOpts().MicrosoftExt ? + diag::ext_union_member_of_reference_type : + diag::err_union_member_of_reference_type) + << NewFD->getDeclName() << EltTy; + if (!getLangOpts().MicrosoftExt) + NewFD->setInvalidDecl(); + } + } + } + + // FIXME: We need to pass in the attributes given an AST + // representation, not a parser representation. + if (D) { + // FIXME: The current scope is almost... but not entirely... correct here. + ProcessDeclAttributes(getCurScope(), NewFD, *D); + + if (NewFD->hasAttrs()) + CheckAlignasUnderalignment(NewFD); + } + + // In auto-retain/release, infer strong retension for fields of + // retainable type. + if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(NewFD)) + NewFD->setInvalidDecl(); + + if (T.isObjCGCWeak()) + Diag(Loc, diag::warn_attribute_weak_on_field); + + NewFD->setAccess(AS); + return NewFD; + } + + bool Sema::CheckNontrivialField(FieldDecl *FD) { + assert(FD); + assert(getLangOpts().CPlusPlus && "valid check only for C++"); + + if (FD->isInvalidDecl() || FD->getType()->isDependentType()) + return false; + + QualType EltTy = Context.getBaseElementType(FD->getType()); + if (const RecordType *RT = EltTy->getAs()) { + CXXRecordDecl *RDecl = cast(RT->getDecl()); + if (RDecl->getDefinition()) { + // We check for copy constructors before constructors + // because otherwise we'll never get complaints about + // copy constructors. + + CXXSpecialMember member = CXXInvalid; + // We're required to check for any non-trivial constructors. Since the + // implicit default constructor is suppressed if there are any + // user-declared constructors, we just need to check that there is a + // trivial default constructor and a trivial copy constructor. (We don't + // worry about move constructors here, since this is a C++98 check.) + if (RDecl->hasNonTrivialCopyConstructor()) + member = CXXCopyConstructor; + else if (!RDecl->hasTrivialDefaultConstructor()) + member = CXXDefaultConstructor; + else if (RDecl->hasNonTrivialCopyAssignment()) + member = CXXCopyAssignment; + else if (RDecl->hasNonTrivialDestructor()) + member = CXXDestructor; + + if (member != CXXInvalid) { + if (!getLangOpts().CPlusPlus11 && + getLangOpts().ObjCAutoRefCount && RDecl->hasObjectMember()) { + // Objective-C++ ARC: it is an error to have a non-trivial field of + // a union. However, system headers in Objective-C programs + // occasionally have Objective-C lifetime objects within unions, + // and rather than cause the program to fail, we make those + // members unavailable. + SourceLocation Loc = FD->getLocation(); + if (getSourceManager().isInSystemHeader(Loc)) { + if (!FD->hasAttr()) + FD->addAttr(UnavailableAttr::CreateImplicit(Context, "", + UnavailableAttr::IR_ARCFieldWithOwnership, Loc)); + return false; + } + } + + Diag(FD->getLocation(), getLangOpts().CPlusPlus11 ? + diag::warn_cxx98_compat_nontrivial_union_or_anon_struct_member : + diag::err_illegal_union_or_anon_struct_member) + << FD->getParent()->isUnion() << FD->getDeclName() << member; + DiagnoseNontrivial(RDecl, member); + return !getLangOpts().CPlusPlus11; + } + } + } + + return false; + } + + /// TranslateIvarVisibility - Translate visibility from a token ID to an + /// AST enum value. + static ObjCIvarDecl::AccessControl + TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { + switch (ivarVisibility) { + default: llvm_unreachable("Unknown visitibility kind"); + case tok::objc_private: return ObjCIvarDecl::Private; + case tok::objc_public: return ObjCIvarDecl::Public; + case tok::objc_protected: return ObjCIvarDecl::Protected; + case tok::objc_package: return ObjCIvarDecl::Package; + } + } + + /// ActOnIvar - Each ivar field of an objective-c class is passed into this + /// in order to create an IvarDecl object for it. + Decl *Sema::ActOnIvar(Scope *S, + SourceLocation DeclStart, + Declarator &D, Expr *BitfieldWidth, + tok::ObjCKeywordKind Visibility) { + + IdentifierInfo *II = D.getIdentifier(); + Expr *BitWidth = (Expr*)BitfieldWidth; + SourceLocation Loc = DeclStart; + if (II) Loc = D.getIdentifierLoc(); + + // FIXME: Unnamed fields can be handled in various different ways, for + // example, unnamed unions inject all members into the struct namespace! + + TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S); + QualType T = TInfo->getType(); + + if (BitWidth) { + // 6.7.2.1p3, 6.7.2.1p4 + BitWidth = VerifyBitField(Loc, II, T, /*IsMsStruct*/false, BitWidth).get(); + if (!BitWidth) + D.setInvalidType(); + } else { + // Not a bitfield. + + // validate II. + + } + if (T->isReferenceType()) { + Diag(Loc, diag::err_ivar_reference_type); + D.setInvalidType(); + } + // C99 6.7.2.1p8: A member of a structure or union may have any type other + // than a variably modified type. + else if (T->isVariablyModifiedType()) { + Diag(Loc, diag::err_typecheck_ivar_variable_size); + D.setInvalidType(); + } + + // Get the visibility (access control) for this ivar. + ObjCIvarDecl::AccessControl ac = + Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) + : ObjCIvarDecl::None; + // Must set ivar's DeclContext to its enclosing interface. + ObjCContainerDecl *EnclosingDecl = cast(CurContext); + if (!EnclosingDecl || EnclosingDecl->isInvalidDecl()) + return nullptr; + ObjCContainerDecl *EnclosingContext; + if (ObjCImplementationDecl *IMPDecl = + dyn_cast(EnclosingDecl)) { + if (LangOpts.ObjCRuntime.isFragile()) { + // Case of ivar declared in an implementation. Context is that of its class. + EnclosingContext = IMPDecl->getClassInterface(); + assert(EnclosingContext && "Implementation has no class interface!"); + } + else + EnclosingContext = EnclosingDecl; + } else { + if (ObjCCategoryDecl *CDecl = + dyn_cast(EnclosingDecl)) { + if (LangOpts.ObjCRuntime.isFragile() || !CDecl->IsClassExtension()) { + Diag(Loc, diag::err_misplaced_ivar) << CDecl->IsClassExtension(); + return nullptr; + } + } + EnclosingContext = EnclosingDecl; + } + + // Construct the decl. + ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, EnclosingContext, + DeclStart, Loc, II, T, + TInfo, ac, (Expr *)BitfieldWidth); + + if (II) { + NamedDecl *PrevDecl = LookupSingleName(S, II, Loc, LookupMemberName, + ForVisibleRedeclaration); + if (PrevDecl && isDeclInScope(PrevDecl, EnclosingContext, S) + && !isa(PrevDecl)) { + Diag(Loc, diag::err_duplicate_member) << II; + Diag(PrevDecl->getLocation(), diag::note_previous_declaration); + NewID->setInvalidDecl(); + } + } + + // Process attributes attached to the ivar. + ProcessDeclAttributes(S, NewID, D); + + if (D.isInvalidType()) + NewID->setInvalidDecl(); + + // In ARC, infer 'retaining' for ivars of retainable type. + if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(NewID)) + NewID->setInvalidDecl(); + + if (D.getDeclSpec().isModulePrivateSpecified()) + NewID->setModulePrivate(); + + if (II) { + // FIXME: When interfaces are DeclContexts, we'll need to add + // these to the interface. + S->AddDecl(NewID); + IdResolver.AddDecl(NewID); + } + + if (LangOpts.ObjCRuntime.isNonFragile() && + !NewID->isInvalidDecl() && isa(EnclosingDecl)) + Diag(Loc, diag::warn_ivars_in_interface); + + return NewID; + } + + /// ActOnLastBitfield - This routine handles synthesized bitfields rules for + /// class and class extensions. For every class \@interface and class + /// extension \@interface, if the last ivar is a bitfield of any type, + /// then add an implicit `char :0` ivar to the end of that interface. + void Sema::ActOnLastBitfield(SourceLocation DeclLoc, + SmallVectorImpl &AllIvarDecls) { + if (LangOpts.ObjCRuntime.isFragile() || AllIvarDecls.empty()) + return; + + Decl *ivarDecl = AllIvarDecls[AllIvarDecls.size()-1]; + ObjCIvarDecl *Ivar = cast(ivarDecl); + + if (!Ivar->isBitField() || Ivar->isZeroLengthBitField(Context)) + return; + ObjCInterfaceDecl *ID = dyn_cast(CurContext); + if (!ID) { + if (ObjCCategoryDecl *CD = dyn_cast(CurContext)) { + if (!CD->IsClassExtension()) + return; + } + // No need to add this to end of @implementation. + else + return; + } + // All conditions are met. Add a new bitfield to the tail end of ivars. + llvm::APInt Zero(Context.getTypeSize(Context.IntTy), 0); + Expr * BW = IntegerLiteral::Create(Context, Zero, Context.IntTy, DeclLoc); + + Ivar = ObjCIvarDecl::Create(Context, cast(CurContext), + DeclLoc, DeclLoc, nullptr, + Context.CharTy, + Context.getTrivialTypeSourceInfo(Context.CharTy, + DeclLoc), + ObjCIvarDecl::Private, BW, + true); + AllIvarDecls.push_back(Ivar); + } + + void Sema::ActOnFields(Scope *S, SourceLocation RecLoc, Decl *EnclosingDecl, + ArrayRef Fields, SourceLocation LBrac, + SourceLocation RBrac, + const ParsedAttributesView &Attrs) { + assert(EnclosingDecl && "missing record or interface decl"); + + // If this is an Objective-C @implementation or category and we have + // new fields here we should reset the layout of the interface since + // it will now change. + if (!Fields.empty() && isa(EnclosingDecl)) { + ObjCContainerDecl *DC = cast(EnclosingDecl); + switch (DC->getKind()) { + default: break; + case Decl::ObjCCategory: + Context.ResetObjCLayout(cast(DC)->getClassInterface()); + break; + case Decl::ObjCImplementation: + Context. + ResetObjCLayout(cast(DC)->getClassInterface()); + break; + } + } + + RecordDecl *Record = dyn_cast(EnclosingDecl); + CXXRecordDecl *CXXRecord = dyn_cast(EnclosingDecl); + + // Start counting up the number of named members; make sure to include + // members of anonymous structs and unions in the total. + unsigned NumNamedMembers = 0; + if (Record) { + for (const auto *I : Record->decls()) { + if (const auto *IFD = dyn_cast(I)) + if (IFD->getDeclName()) + ++NumNamedMembers; + } + } + + // Verify that all the fields are okay. + SmallVector RecFields; + + bool ObjCFieldLifetimeErrReported = false; + for (ArrayRef::iterator i = Fields.begin(), end = Fields.end(); + i != end; ++i) { + FieldDecl *FD = cast(*i); + + // Get the type for the field. + const Type *FDTy = FD->getType().getTypePtr(); + + if (!FD->isAnonymousStructOrUnion()) { + // Remember all fields written by the user. + RecFields.push_back(FD); + } + + // If the field is already invalid for some reason, don't emit more + // diagnostics about it. + if (FD->isInvalidDecl()) { + EnclosingDecl->setInvalidDecl(); + continue; + } + + // C99 6.7.2.1p2: + // A structure or union shall not contain a member with + // incomplete or function type (hence, a structure shall not + // contain an instance of itself, but may contain a pointer to + // an instance of itself), except that the last member of a + // structure with more than one named member may have incomplete + // array type; such a structure (and any union containing, + // possibly recursively, a member that is such a structure) + // shall not be a member of a structure or an element of an + // array. + bool IsLastField = (i + 1 == Fields.end()); + if (FDTy->isFunctionType()) { + // Field declared as a function. + Diag(FD->getLocation(), diag::err_field_declared_as_function) + << FD->getDeclName(); + FD->setInvalidDecl(); + EnclosingDecl->setInvalidDecl(); + continue; + } else if (FDTy->isIncompleteArrayType() && + (Record || isa(EnclosingDecl))) { + if (Record) { + // Flexible array member. + // Microsoft and g++ is more permissive regarding flexible array. + // It will accept flexible array in union and also + // as the sole element of a struct/class. + unsigned DiagID = 0; + if (!Record->isUnion() && !IsLastField) { + Diag(FD->getLocation(), diag::err_flexible_array_not_at_end) + << FD->getDeclName() << FD->getType() << Record->getTagKind(); + Diag((*(i + 1))->getLocation(), diag::note_next_field_declaration); + FD->setInvalidDecl(); + EnclosingDecl->setInvalidDecl(); + continue; + } else if (Record->isUnion()) + DiagID = getLangOpts().MicrosoftExt + ? diag::ext_flexible_array_union_ms + : getLangOpts().CPlusPlus + ? diag::ext_flexible_array_union_gnu + : diag::err_flexible_array_union; + else if (NumNamedMembers < 1) + DiagID = getLangOpts().MicrosoftExt + ? diag::ext_flexible_array_empty_aggregate_ms + : getLangOpts().CPlusPlus + ? diag::ext_flexible_array_empty_aggregate_gnu + : diag::err_flexible_array_empty_aggregate; + + if (DiagID) + Diag(FD->getLocation(), DiagID) << FD->getDeclName() + << Record->getTagKind(); + // While the layout of types that contain virtual bases is not specified + // by the C++ standard, both the Itanium and Microsoft C++ ABIs place + // virtual bases after the derived members. This would make a flexible + // array member declared at the end of an object not adjacent to the end + // of the type. + if (CXXRecord && CXXRecord->getNumVBases() != 0) + Diag(FD->getLocation(), diag::err_flexible_array_virtual_base) + << FD->getDeclName() << Record->getTagKind(); + if (!getLangOpts().C99) + Diag(FD->getLocation(), diag::ext_c99_flexible_array_member) + << FD->getDeclName() << Record->getTagKind(); + + // If the element type has a non-trivial destructor, we would not + // implicitly destroy the elements, so disallow it for now. + // + // FIXME: GCC allows this. We should probably either implicitly delete + // the destructor of the containing class, or just allow this. + QualType BaseElem = Context.getBaseElementType(FD->getType()); + if (!BaseElem->isDependentType() && BaseElem.isDestructedType()) { + Diag(FD->getLocation(), diag::err_flexible_array_has_nontrivial_dtor) + << FD->getDeclName() << FD->getType(); + FD->setInvalidDecl(); + EnclosingDecl->setInvalidDecl(); + continue; + } + // Okay, we have a legal flexible array member at the end of the struct. + Record->setHasFlexibleArrayMember(true); + } else { + // In ObjCContainerDecl ivars with incomplete array type are accepted, + // unless they are followed by another ivar. That check is done + // elsewhere, after synthesized ivars are known. + } + } else if (!FDTy->isDependentType() && + RequireCompleteType(FD->getLocation(), FD->getType(), + diag::err_field_incomplete)) { + // Incomplete type + FD->setInvalidDecl(); + EnclosingDecl->setInvalidDecl(); + continue; + } else if (const RecordType *FDTTy = FDTy->getAs()) { + if (Record && FDTTy->getDecl()->hasFlexibleArrayMember()) { + // A type which contains a flexible array member is considered to be a + // flexible array member. + Record->setHasFlexibleArrayMember(true); + if (!Record->isUnion()) { + // If this is a struct/class and this is not the last element, reject + // it. Note that GCC supports variable sized arrays in the middle of + // structures. + if (!IsLastField) + Diag(FD->getLocation(), diag::ext_variable_sized_type_in_struct) + << FD->getDeclName() << FD->getType(); + else { + // We support flexible arrays at the end of structs in + // other structs as an extension. + Diag(FD->getLocation(), diag::ext_flexible_array_in_struct) + << FD->getDeclName(); + } + } + } + if (isa(EnclosingDecl) && + RequireNonAbstractType(FD->getLocation(), FD->getType(), + diag::err_abstract_type_in_decl, + AbstractIvarType)) { + // Ivars can not have abstract class types + FD->setInvalidDecl(); + } + if (Record && FDTTy->getDecl()->hasObjectMember()) + Record->setHasObjectMember(true); + if (Record && FDTTy->getDecl()->hasVolatileMember()) + Record->setHasVolatileMember(true); + if (Record && Record->isUnion() && + FD->getType().isNonTrivialPrimitiveCType(Context)) + Diag(FD->getLocation(), + diag::err_nontrivial_primitive_type_in_union); + } else if (FDTy->isObjCObjectType()) { + /// A field cannot be an Objective-c object + Diag(FD->getLocation(), diag::err_statically_allocated_object) + << FixItHint::CreateInsertion(FD->getLocation(), "*"); + QualType T = Context.getObjCObjectPointerType(FD->getType()); + FD->setType(T); + } else if (getLangOpts().allowsNonTrivialObjCLifetimeQualifiers() && + Record && !ObjCFieldLifetimeErrReported && Record->isUnion() && + !getLangOpts().CPlusPlus) { + // It's an error in ARC or Weak if a field has lifetime. + // We don't want to report this in a system header, though, + // so we just make the field unavailable. + // FIXME: that's really not sufficient; we need to make the type + // itself invalid to, say, initialize or copy. + QualType T = FD->getType(); + if (T.hasNonTrivialObjCLifetime()) { + SourceLocation loc = FD->getLocation(); + if (getSourceManager().isInSystemHeader(loc)) { + if (!FD->hasAttr()) { + FD->addAttr(UnavailableAttr::CreateImplicit(Context, "", + UnavailableAttr::IR_ARCFieldWithOwnership, loc)); + } + } else { + Diag(FD->getLocation(), diag::err_arc_objc_object_in_tag) + << T->isBlockPointerType() << Record->getTagKind(); + } + ObjCFieldLifetimeErrReported = true; + } + } else if (getLangOpts().ObjC && + getLangOpts().getGC() != LangOptions::NonGC && + Record && !Record->hasObjectMember()) { + if (FD->getType()->isObjCObjectPointerType() || + FD->getType().isObjCGCStrong()) + Record->setHasObjectMember(true); + else if (Context.getAsArrayType(FD->getType())) { + QualType BaseType = Context.getBaseElementType(FD->getType()); + if (BaseType->isRecordType() && + BaseType->getAs()->getDecl()->hasObjectMember()) + Record->setHasObjectMember(true); + else if (BaseType->isObjCObjectPointerType() || + BaseType.isObjCGCStrong()) + Record->setHasObjectMember(true); + } + } + + if (Record && !getLangOpts().CPlusPlus && !FD->hasAttr()) { + QualType FT = FD->getType(); + if (FT.isNonTrivialToPrimitiveDefaultInitialize()) + Record->setNonTrivialToPrimitiveDefaultInitialize(true); + QualType::PrimitiveCopyKind PCK = FT.isNonTrivialToPrimitiveCopy(); + if (PCK != QualType::PCK_Trivial && PCK != QualType::PCK_VolatileTrivial) + Record->setNonTrivialToPrimitiveCopy(true); + if (FT.isDestructedType()) { + Record->setNonTrivialToPrimitiveDestroy(true); + Record->setParamDestroyedInCallee(true); + } + + if (const auto *RT = FT->getAs()) { + if (RT->getDecl()->getArgPassingRestrictions() == + RecordDecl::APK_CanNeverPassInRegs) + Record->setArgPassingRestrictions(RecordDecl::APK_CanNeverPassInRegs); + } else if (FT.getQualifiers().getObjCLifetime() == Qualifiers::OCL_Weak) + Record->setArgPassingRestrictions(RecordDecl::APK_CanNeverPassInRegs); + } + + if (Record && FD->getType().isVolatileQualified()) + Record->setHasVolatileMember(true); + // Keep track of the number of named members. + if (FD->getIdentifier()) + ++NumNamedMembers; + } + + // Okay, we successfully defined 'Record'. + if (Record) { + bool Completed = false; + if (CXXRecord) { + if (!CXXRecord->isInvalidDecl()) { + // Set access bits correctly on the directly-declared conversions. + for (CXXRecordDecl::conversion_iterator + I = CXXRecord->conversion_begin(), + E = CXXRecord->conversion_end(); I != E; ++I) + I.setAccess((*I)->getAccess()); + } + + if (!CXXRecord->isDependentType()) { + // Add any implicitly-declared members to this class. + AddImplicitlyDeclaredMembersToClass(CXXRecord); + + if (!CXXRecord->isInvalidDecl()) { + // If we have virtual base classes, we may end up finding multiple + // final overriders for a given virtual function. Check for this + // problem now. + if (CXXRecord->getNumVBases()) { + CXXFinalOverriderMap FinalOverriders; + CXXRecord->getFinalOverriders(FinalOverriders); + + 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) { + assert(SO->second.size() > 0 && + "Virtual function without overriding functions?"); + if (SO->second.size() == 1) + continue; + + // C++ [class.virtual]p2: + // In a derived class, if a virtual member function of a base + // class subobject has more than one final overrider the + // program is ill-formed. + Diag(Record->getLocation(), diag::err_multiple_final_overriders) + << (const NamedDecl *)M->first << Record; + Diag(M->first->getLocation(), + diag::note_overridden_virtual_function); + for (OverridingMethods::overriding_iterator + OM = SO->second.begin(), + OMEnd = SO->second.end(); + OM != OMEnd; ++OM) + Diag(OM->Method->getLocation(), diag::note_final_overrider) + << (const NamedDecl *)M->first << OM->Method->getParent(); + + Record->setInvalidDecl(); + } + } + CXXRecord->completeDefinition(&FinalOverriders); + Completed = true; + } + } + } + } + + if (!Completed) + Record->completeDefinition(); + + // Handle attributes before checking the layout. + ProcessDeclAttributeList(S, Record, Attrs); + + // We may have deferred checking for a deleted destructor. Check now. + if (CXXRecord) { + auto *Dtor = CXXRecord->getDestructor(); + if (Dtor && Dtor->isImplicit() && + ShouldDeleteSpecialMember(Dtor, CXXDestructor)) { + CXXRecord->setImplicitDestructorIsDeleted(); + SetDeclDeleted(Dtor, CXXRecord->getLocation()); + } + } + + if (Record->hasAttrs()) { + CheckAlignasUnderalignment(Record); + + if (const MSInheritanceAttr *IA = Record->getAttr()) + checkMSInheritanceAttrOnDefinition(cast(Record), + IA->getRange(), IA->getBestCase(), + IA->getSemanticSpelling()); + } + + // Check if the structure/union declaration is a type that can have zero + // size in C. For C this is a language extension, for C++ it may cause + // compatibility problems. + bool CheckForZeroSize; + if (!getLangOpts().CPlusPlus) { + CheckForZeroSize = true; + } else { + // For C++ filter out types that cannot be referenced in C code. + CXXRecordDecl *CXXRecord = cast(Record); + CheckForZeroSize = + CXXRecord->getLexicalDeclContext()->isExternCContext() && + !CXXRecord->isDependentType() && + CXXRecord->isCLike(); + } + if (CheckForZeroSize) { + bool ZeroSize = true; + bool IsEmpty = true; + unsigned NonBitFields = 0; + for (RecordDecl::field_iterator I = Record->field_begin(), + E = Record->field_end(); + (NonBitFields == 0 || ZeroSize) && I != E; ++I) { + IsEmpty = false; + if (I->isUnnamedBitfield()) { + if (!I->isZeroLengthBitField(Context)) + ZeroSize = false; + } else { + ++NonBitFields; + QualType FieldType = I->getType(); + if (FieldType->isIncompleteType() || + !Context.getTypeSizeInChars(FieldType).isZero()) + ZeroSize = false; + } + } + + // Empty structs are an extension in C (C99 6.7.2.1p7). They are + // allowed in C++, but warn if its declaration is inside + // extern "C" block. + if (ZeroSize) { + Diag(RecLoc, getLangOpts().CPlusPlus ? + diag::warn_zero_size_struct_union_in_extern_c : + diag::warn_zero_size_struct_union_compat) + << IsEmpty << Record->isUnion() << (NonBitFields > 1); + } + + // Structs without named members are extension in C (C99 6.7.2.1p7), + // but are accepted by GCC. + if (NonBitFields == 0 && !getLangOpts().CPlusPlus) { + Diag(RecLoc, IsEmpty ? diag::ext_empty_struct_union : + diag::ext_no_named_members_in_struct_union) + << Record->isUnion(); + } + } + } else { + ObjCIvarDecl **ClsFields = + reinterpret_cast(RecFields.data()); + if (ObjCInterfaceDecl *ID = dyn_cast(EnclosingDecl)) { + ID->setEndOfDefinitionLoc(RBrac); + // Add ivar's to class's DeclContext. + for (unsigned i = 0, e = RecFields.size(); i != e; ++i) { + ClsFields[i]->setLexicalDeclContext(ID); + ID->addDecl(ClsFields[i]); + } + // Must enforce the rule that ivars in the base classes may not be + // duplicates. + if (ID->getSuperClass()) + DiagnoseDuplicateIvars(ID, ID->getSuperClass()); + } else if (ObjCImplementationDecl *IMPDecl = + dyn_cast(EnclosingDecl)) { + assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl"); + for (unsigned I = 0, N = RecFields.size(); I != N; ++I) + // Ivar declared in @implementation never belongs to the implementation. + // Only it is in implementation's lexical context. + ClsFields[I]->setLexicalDeclContext(IMPDecl); + CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); + IMPDecl->setIvarLBraceLoc(LBrac); + IMPDecl->setIvarRBraceLoc(RBrac); + } else if (ObjCCategoryDecl *CDecl = + dyn_cast(EnclosingDecl)) { + // case of ivars in class extension; all other cases have been + // reported as errors elsewhere. + // FIXME. Class extension does not have a LocEnd field. + // CDecl->setLocEnd(RBrac); + // Add ivar's to class extension's DeclContext. + // Diagnose redeclaration of private ivars. + ObjCInterfaceDecl *IDecl = CDecl->getClassInterface(); + for (unsigned i = 0, e = RecFields.size(); i != e; ++i) { + if (IDecl) { + if (const ObjCIvarDecl *ClsIvar = + IDecl->getIvarDecl(ClsFields[i]->getIdentifier())) { + Diag(ClsFields[i]->getLocation(), + diag::err_duplicate_ivar_declaration); + Diag(ClsIvar->getLocation(), diag::note_previous_definition); + continue; + } + for (const auto *Ext : IDecl->known_extensions()) { + if (const ObjCIvarDecl *ClsExtIvar + = Ext->getIvarDecl(ClsFields[i]->getIdentifier())) { + Diag(ClsFields[i]->getLocation(), + diag::err_duplicate_ivar_declaration); + Diag(ClsExtIvar->getLocation(), diag::note_previous_definition); + continue; + } + } + } + ClsFields[i]->setLexicalDeclContext(CDecl); + CDecl->addDecl(ClsFields[i]); + } + CDecl->setIvarLBraceLoc(LBrac); + CDecl->setIvarRBraceLoc(RBrac); + } + } + } + + /// Determine whether the given integral value is representable within + /// the given type T. + static bool isRepresentableIntegerValue(ASTContext &Context, + llvm::APSInt &Value, + QualType T) { + assert((T->isIntegralType(Context) || T->isEnumeralType()) && + "Integral type required!"); + unsigned BitWidth = Context.getIntWidth(T); + + if (Value.isUnsigned() || Value.isNonNegative()) { + if (T->isSignedIntegerOrEnumerationType()) + --BitWidth; + return Value.getActiveBits() <= BitWidth; + } + return Value.getMinSignedBits() <= BitWidth; + } + + // Given an integral type, return the next larger integral type + // (or a NULL type of no such type exists). + static QualType getNextLargerIntegralType(ASTContext &Context, QualType T) { + // FIXME: Int128/UInt128 support, which also needs to be introduced into + // enum checking below. + assert((T->isIntegralType(Context) || + T->isEnumeralType()) && "Integral type required!"); + const unsigned NumTypes = 4; + QualType SignedIntegralTypes[NumTypes] = { + Context.ShortTy, Context.IntTy, Context.LongTy, Context.LongLongTy + }; + QualType UnsignedIntegralTypes[NumTypes] = { + Context.UnsignedShortTy, Context.UnsignedIntTy, Context.UnsignedLongTy, + Context.UnsignedLongLongTy + }; + + unsigned BitWidth = Context.getTypeSize(T); + QualType *Types = T->isSignedIntegerOrEnumerationType()? SignedIntegralTypes + : UnsignedIntegralTypes; + for (unsigned I = 0; I != NumTypes; ++I) + if (Context.getTypeSize(Types[I]) > BitWidth) + return Types[I]; + + return QualType(); + } + + EnumConstantDecl *Sema::CheckEnumConstant(EnumDecl *Enum, + EnumConstantDecl *LastEnumConst, + SourceLocation IdLoc, + IdentifierInfo *Id, + Expr *Val) { + unsigned IntWidth = Context.getTargetInfo().getIntWidth(); + llvm::APSInt EnumVal(IntWidth); + QualType EltTy; + + if (Val && DiagnoseUnexpandedParameterPack(Val, UPPC_EnumeratorValue)) + Val = nullptr; + + if (Val) + Val = DefaultLvalueConversion(Val).get(); + + if (Val) { + if (Enum->isDependentType() || Val->isTypeDependent()) + EltTy = Context.DependentTy; + else { + if (getLangOpts().CPlusPlus11 && Enum->isFixed() && + !getLangOpts().MSVCCompat) { + // C++11 [dcl.enum]p5: If the underlying type is fixed, [...] the + // constant-expression in the enumerator-definition shall be a converted + // constant expression of the underlying type. + EltTy = Enum->getIntegerType(); + ExprResult Converted = + CheckConvertedConstantExpression(Val, EltTy, EnumVal, + CCEK_Enumerator); + if (Converted.isInvalid()) + Val = nullptr; + else + Val = Converted.get(); + } else if (!Val->isValueDependent() && + !(Val = VerifyIntegerConstantExpression(Val, + &EnumVal).get())) { + // C99 6.7.2.2p2: Make sure we have an integer constant expression. + } else { + if (Enum->isComplete()) { + EltTy = Enum->getIntegerType(); + + // In Obj-C and Microsoft mode, require the enumeration value to be + // representable in the underlying type of the enumeration. In C++11, + // we perform a non-narrowing conversion as part of converted constant + // expression checking. + if (!isRepresentableIntegerValue(Context, EnumVal, EltTy)) { + if (getLangOpts().MSVCCompat) { + Diag(IdLoc, diag::ext_enumerator_too_large) << EltTy; + Val = ImpCastExprToType(Val, EltTy, CK_IntegralCast).get(); + } else + Diag(IdLoc, diag::err_enumerator_too_large) << EltTy; + } else + Val = ImpCastExprToType(Val, EltTy, + EltTy->isBooleanType() ? + CK_IntegralToBoolean : CK_IntegralCast) + .get(); + } else if (getLangOpts().CPlusPlus) { + // C++11 [dcl.enum]p5: + // If the underlying type is not fixed, the type of each enumerator + // is the type of its initializing value: + // - If an initializer is specified for an enumerator, the + // initializing value has the same type as the expression. + EltTy = Val->getType(); + } else { + // C99 6.7.2.2p2: + // The expression that defines the value of an enumeration constant + // shall be an integer constant expression that has a value + // representable as an int. + + // Complain if the value is not representable in an int. + if (!isRepresentableIntegerValue(Context, EnumVal, Context.IntTy)) + Diag(IdLoc, diag::ext_enum_value_not_int) + << EnumVal.toString(10) << Val->getSourceRange() + << (EnumVal.isUnsigned() || EnumVal.isNonNegative()); + else if (!Context.hasSameType(Val->getType(), Context.IntTy)) { + // Force the type of the expression to 'int'. + Val = ImpCastExprToType(Val, Context.IntTy, CK_IntegralCast).get(); + } + EltTy = Val->getType(); + } + } + } + } + + if (!Val) { + if (Enum->isDependentType()) + EltTy = Context.DependentTy; + else if (!LastEnumConst) { + // C++0x [dcl.enum]p5: + // If the underlying type is not fixed, the type of each enumerator + // is the type of its initializing value: + // - If no initializer is specified for the first enumerator, the + // initializing value has an unspecified integral type. + // + // GCC uses 'int' for its unspecified integral type, as does + // C99 6.7.2.2p3. + if (Enum->isFixed()) { + EltTy = Enum->getIntegerType(); + } + else { + EltTy = Context.IntTy; + } + } else { + // Assign the last value + 1. + EnumVal = LastEnumConst->getInitVal(); + ++EnumVal; + EltTy = LastEnumConst->getType(); + + // Check for overflow on increment. + if (EnumVal < LastEnumConst->getInitVal()) { + // C++0x [dcl.enum]p5: + // If the underlying type is not fixed, the type of each enumerator + // is the type of its initializing value: + // + // - Otherwise the type of the initializing value is the same as + // the type of the initializing value of the preceding enumerator + // unless the incremented value is not representable in that type, + // in which case the type is an unspecified integral type + // sufficient to contain the incremented value. If no such type + // exists, the program is ill-formed. + QualType T = getNextLargerIntegralType(Context, EltTy); + if (T.isNull() || Enum->isFixed()) { + // There is no integral type larger enough to represent this + // value. Complain, then allow the value to wrap around. + EnumVal = LastEnumConst->getInitVal(); + EnumVal = EnumVal.zext(EnumVal.getBitWidth() * 2); + ++EnumVal; + if (Enum->isFixed()) + // When the underlying type is fixed, this is ill-formed. + Diag(IdLoc, diag::err_enumerator_wrapped) + << EnumVal.toString(10) + << EltTy; + else + Diag(IdLoc, diag::ext_enumerator_increment_too_large) + << EnumVal.toString(10); + } else { + EltTy = T; + } + + // Retrieve the last enumerator's value, extent that type to the + // type that is supposed to be large enough to represent the incremented + // value, then increment. + EnumVal = LastEnumConst->getInitVal(); + EnumVal.setIsSigned(EltTy->isSignedIntegerOrEnumerationType()); + EnumVal = EnumVal.zextOrTrunc(Context.getIntWidth(EltTy)); + ++EnumVal; + + // If we're not in C++, diagnose the overflow of enumerator values, + // which in C99 means that the enumerator value is not representable in + // an int (C99 6.7.2.2p2). However, we support GCC's extension that + // permits enumerator values that are representable in some larger + // integral type. + if (!getLangOpts().CPlusPlus && !T.isNull()) + Diag(IdLoc, diag::warn_enum_value_overflow); + } else if (!getLangOpts().CPlusPlus && + !isRepresentableIntegerValue(Context, EnumVal, EltTy)) { + // Enforce C99 6.7.2.2p2 even when we compute the next value. + Diag(IdLoc, diag::ext_enum_value_not_int) + << EnumVal.toString(10) << 1; + } + } + } + + if (!EltTy->isDependentType()) { + // Make the enumerator value match the signedness and size of the + // enumerator's type. + EnumVal = EnumVal.extOrTrunc(Context.getIntWidth(EltTy)); + EnumVal.setIsSigned(EltTy->isSignedIntegerOrEnumerationType()); + } + + return EnumConstantDecl::Create(Context, Enum, IdLoc, Id, EltTy, + Val, EnumVal); + } + + Sema::SkipBodyInfo Sema::shouldSkipAnonEnumBody(Scope *S, IdentifierInfo *II, + SourceLocation IILoc) { + if (!(getLangOpts().Modules || getLangOpts().ModulesLocalVisibility) || + !getLangOpts().CPlusPlus) + return SkipBodyInfo(); + + // We have an anonymous enum definition. Look up the first enumerator to + // determine if we should merge the definition with an existing one and + // skip the body. + NamedDecl *PrevDecl = LookupSingleName(S, II, IILoc, LookupOrdinaryName, + forRedeclarationInCurContext()); + auto *PrevECD = dyn_cast_or_null(PrevDecl); + if (!PrevECD) + return SkipBodyInfo(); + + EnumDecl *PrevED = cast(PrevECD->getDeclContext()); + NamedDecl *Hidden; + if (!PrevED->getDeclName() && !hasVisibleDefinition(PrevED, &Hidden)) { + SkipBodyInfo Skip; + Skip.Previous = Hidden; + return Skip; + } + + return SkipBodyInfo(); + } + + Decl *Sema::ActOnEnumConstant(Scope *S, Decl *theEnumDecl, Decl *lastEnumConst, + SourceLocation IdLoc, IdentifierInfo *Id, + const ParsedAttributesView &Attrs, + SourceLocation EqualLoc, Expr *Val) { + EnumDecl *TheEnumDecl = cast(theEnumDecl); + EnumConstantDecl *LastEnumConst = + cast_or_null(lastEnumConst); + + // The scope passed in may not be a decl scope. Zip up the scope tree until + // we find one that is. + S = getNonFieldDeclScope(S); + + // Verify that there isn't already something declared with this name in this + // scope. + LookupResult R(*this, Id, IdLoc, LookupOrdinaryName, ForVisibleRedeclaration); + LookupName(R, S); + NamedDecl *PrevDecl = R.getAsSingle(); + + if (PrevDecl && PrevDecl->isTemplateParameter()) { + // Maybe we will complain about the shadowed template parameter. + DiagnoseTemplateParameterShadow(IdLoc, PrevDecl); + // Just pretend that we didn't see the previous declaration. + PrevDecl = nullptr; + } + + // C++ [class.mem]p15: + // If T is the name of a class, then each of the following shall have a name + // different from T: + // - every enumerator of every member of class T that is an unscoped + // enumerated type + if (getLangOpts().CPlusPlus && !TheEnumDecl->isScoped()) + DiagnoseClassNameShadow(TheEnumDecl->getDeclContext(), + DeclarationNameInfo(Id, IdLoc)); + + EnumConstantDecl *New = + CheckEnumConstant(TheEnumDecl, LastEnumConst, IdLoc, Id, Val); + if (!New) + return nullptr; + + if (PrevDecl) { + if (!TheEnumDecl->isScoped() && isa(PrevDecl)) { + // Check for other kinds of shadowing not already handled. + CheckShadow(New, PrevDecl, R); + } + + // When in C++, we may get a TagDecl with the same name; in this case the + // enum constant will 'hide' the tag. + assert((getLangOpts().CPlusPlus || !isa(PrevDecl)) && + "Received TagDecl when not in C++!"); + if (!isa(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { + if (isa(PrevDecl)) + Diag(IdLoc, diag::err_redefinition_of_enumerator) << Id; + else + Diag(IdLoc, diag::err_redefinition) << Id; + notePreviousDefinition(PrevDecl, IdLoc); + return nullptr; + } + } + + // Process attributes. + ProcessDeclAttributeList(S, New, Attrs); + AddPragmaAttributes(S, New); + + // Register this decl in the current scope stack. + New->setAccess(TheEnumDecl->getAccess()); + PushOnScopeChains(New, S); + + ActOnDocumentableDecl(New); + + return New; + } + + // Returns true when the enum initial expression does not trigger the + // duplicate enum warning. A few common cases are exempted as follows: + // Element2 = Element1 + // Element2 = Element1 + 1 + // Element2 = Element1 - 1 + // Where Element2 and Element1 are from the same enum. + static bool ValidDuplicateEnum(EnumConstantDecl *ECD, EnumDecl *Enum) { + Expr *InitExpr = ECD->getInitExpr(); + if (!InitExpr) + return true; + InitExpr = InitExpr->IgnoreImpCasts(); + + if (BinaryOperator *BO = dyn_cast(InitExpr)) { + if (!BO->isAdditiveOp()) + return true; + IntegerLiteral *IL = dyn_cast(BO->getRHS()); + if (!IL) + return true; + if (IL->getValue() != 1) + return true; + + InitExpr = BO->getLHS(); + } + + // This checks if the elements are from the same enum. + DeclRefExpr *DRE = dyn_cast(InitExpr); + if (!DRE) + return true; + + EnumConstantDecl *EnumConstant = dyn_cast(DRE->getDecl()); + if (!EnumConstant) + return true; + + if (cast(TagDecl::castFromDeclContext(ECD->getDeclContext())) != + Enum) + return true; + + return false; + } + + // Emits a warning when an element is implicitly set a value that + // a previous element has already been set to. + static void CheckForDuplicateEnumValues(Sema &S, ArrayRef Elements, + EnumDecl *Enum, QualType EnumType) { + // Avoid anonymous enums + if (!Enum->getIdentifier()) + return; + + // Only check for small enums. + if (Enum->getNumPositiveBits() > 63 || Enum->getNumNegativeBits() > 64) + return; + + if (S.Diags.isIgnored(diag::warn_duplicate_enum_values, Enum->getLocation())) + return; + + typedef SmallVector ECDVector; + typedef SmallVector, 3> DuplicatesVector; + + typedef llvm::PointerUnion DeclOrVector; + typedef std::unordered_map ValueToVectorMap; + + // Use int64_t as a key to avoid needing special handling for DenseMap keys. + auto EnumConstantToKey = [](const EnumConstantDecl *D) { + llvm::APSInt Val = D->getInitVal(); + return Val.isSigned() ? Val.getSExtValue() : Val.getZExtValue(); + }; + + DuplicatesVector DupVector; + ValueToVectorMap EnumMap; + + // Populate the EnumMap with all values represented by enum constants without + // an initializer. + for (auto *Element : Elements) { + EnumConstantDecl *ECD = cast_or_null(Element); + + // Null EnumConstantDecl means a previous diagnostic has been emitted for + // this constant. Skip this enum since it may be ill-formed. + if (!ECD) { + return; + } + + // Constants with initalizers are handled in the next loop. + if (ECD->getInitExpr()) + continue; + + // Duplicate values are handled in the next loop. + EnumMap.insert({EnumConstantToKey(ECD), ECD}); + } + + if (EnumMap.size() == 0) + return; + + // Create vectors for any values that has duplicates. + for (auto *Element : Elements) { + // The last loop returned if any constant was null. + EnumConstantDecl *ECD = cast(Element); + if (!ValidDuplicateEnum(ECD, Enum)) + continue; + + auto Iter = EnumMap.find(EnumConstantToKey(ECD)); + if (Iter == EnumMap.end()) + continue; + + DeclOrVector& Entry = Iter->second; + if (EnumConstantDecl *D = Entry.dyn_cast()) { + // Ensure constants are different. + if (D == ECD) + continue; + + // Create new vector and push values onto it. + auto Vec = llvm::make_unique(); + Vec->push_back(D); + Vec->push_back(ECD); + + // Update entry to point to the duplicates vector. + Entry = Vec.get(); + + // Store the vector somewhere we can consult later for quick emission of + // diagnostics. + DupVector.emplace_back(std::move(Vec)); + continue; + } + + ECDVector *Vec = Entry.get(); + // Make sure constants are not added more than once. + if (*Vec->begin() == ECD) + continue; + + Vec->push_back(ECD); + } + + // Emit diagnostics. + for (const auto &Vec : DupVector) { + assert(Vec->size() > 1 && "ECDVector should have at least 2 elements."); + + // Emit warning for one enum constant. + auto *FirstECD = Vec->front(); + S.Diag(FirstECD->getLocation(), diag::warn_duplicate_enum_values) + << FirstECD << FirstECD->getInitVal().toString(10) + << FirstECD->getSourceRange(); + + // Emit one note for each of the remaining enum constants with + // the same value. + for (auto *ECD : llvm::make_range(Vec->begin() + 1, Vec->end())) + S.Diag(ECD->getLocation(), diag::note_duplicate_element) + << ECD << ECD->getInitVal().toString(10) + << ECD->getSourceRange(); + } + } + + bool Sema::IsValueInFlagEnum(const EnumDecl *ED, const llvm::APInt &Val, + bool AllowMask) const { + assert(ED->isClosedFlag() && "looking for value in non-flag or open enum"); + assert(ED->isCompleteDefinition() && "expected enum definition"); + + auto R = FlagBitsCache.insert(std::make_pair(ED, llvm::APInt())); + llvm::APInt &FlagBits = R.first->second; + + if (R.second) { + for (auto *E : ED->enumerators()) { + const auto &EVal = E->getInitVal(); + // Only single-bit enumerators introduce new flag values. + if (EVal.isPowerOf2()) + FlagBits = FlagBits.zextOrSelf(EVal.getBitWidth()) | EVal; + } + } + + // A value is in a flag enum if either its bits are a subset of the enum's + // flag bits (the first condition) or we are allowing masks and the same is + // true of its complement (the second condition). When masks are allowed, we + // allow the common idiom of ~(enum1 | enum2) to be a valid enum value. + // + // While it's true that any value could be used as a mask, the assumption is + // that a mask will have all of the insignificant bits set. Anything else is + // likely a logic error. + llvm::APInt FlagMask = ~FlagBits.zextOrTrunc(Val.getBitWidth()); + return !(FlagMask & Val) || (AllowMask && !(FlagMask & ~Val)); + } + + void Sema::ActOnEnumBody(SourceLocation EnumLoc, SourceRange BraceRange, + Decl *EnumDeclX, ArrayRef Elements, Scope *S, + const ParsedAttributesView &Attrs) { + EnumDecl *Enum = cast(EnumDeclX); + QualType EnumType = Context.getTypeDeclType(Enum); + + ProcessDeclAttributeList(S, Enum, Attrs); + + if (Enum->isDependentType()) { + for (unsigned i = 0, e = Elements.size(); i != e; ++i) { + EnumConstantDecl *ECD = + cast_or_null(Elements[i]); + if (!ECD) continue; + + ECD->setType(EnumType); + } + + Enum->completeDefinition(Context.DependentTy, Context.DependentTy, 0, 0); + return; + } + + // TODO: If the result value doesn't fit in an int, it must be a long or long + // long value. ISO C does not support this, but GCC does as an extension, + // emit a warning. + unsigned IntWidth = Context.getTargetInfo().getIntWidth(); + unsigned CharWidth = Context.getTargetInfo().getCharWidth(); + unsigned ShortWidth = Context.getTargetInfo().getShortWidth(); + + // Verify that all the values are okay, compute the size of the values, and + // reverse the list. + unsigned NumNegativeBits = 0; + unsigned NumPositiveBits = 0; + + // Keep track of whether all elements have type int. + bool AllElementsInt = true; + + for (unsigned i = 0, e = Elements.size(); i != e; ++i) { + EnumConstantDecl *ECD = + cast_or_null(Elements[i]); + if (!ECD) continue; // Already issued a diagnostic. + + const llvm::APSInt &InitVal = ECD->getInitVal(); + + // Keep track of the size of positive and negative values. + if (InitVal.isUnsigned() || InitVal.isNonNegative()) + NumPositiveBits = std::max(NumPositiveBits, + (unsigned)InitVal.getActiveBits()); + else + NumNegativeBits = std::max(NumNegativeBits, + (unsigned)InitVal.getMinSignedBits()); + + // Keep track of whether every enum element has type int (very common). + if (AllElementsInt) + AllElementsInt = ECD->getType() == Context.IntTy; + } + + // Figure out the type that should be used for this enum. + QualType BestType; + unsigned BestWidth; + + // C++0x N3000 [conv.prom]p3: + // An rvalue of an unscoped enumeration type whose underlying + // type is not fixed can be converted to an rvalue of the first + // of the following types that can represent all the values of + // the enumeration: int, unsigned int, long int, unsigned long + // int, long long int, or unsigned long long int. + // C99 6.4.4.3p2: + // An identifier declared as an enumeration constant has type int. + // The C99 rule is modified by a gcc extension + QualType BestPromotionType; + + bool Packed = Enum->hasAttr(); + // -fshort-enums is the equivalent to specifying the packed attribute on all + // enum definitions. + if (LangOpts.ShortEnums) + Packed = true; + + // If the enum already has a type because it is fixed or dictated by the + // target, promote that type instead of analyzing the enumerators. + if (Enum->isComplete()) { + BestType = Enum->getIntegerType(); + if (BestType->isPromotableIntegerType()) + BestPromotionType = Context.getPromotedIntegerType(BestType); + else + BestPromotionType = BestType; + + BestWidth = Context.getIntWidth(BestType); + } + else if (NumNegativeBits) { + // If there is a negative value, figure out the smallest integer type (of + // int/long/longlong) that fits. + // If it's packed, check also if it fits a char or a short. + if (Packed && NumNegativeBits <= CharWidth && NumPositiveBits < CharWidth) { + BestType = Context.SignedCharTy; + BestWidth = CharWidth; + } else if (Packed && NumNegativeBits <= ShortWidth && + NumPositiveBits < ShortWidth) { + BestType = Context.ShortTy; + BestWidth = ShortWidth; + } else if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { + BestType = Context.IntTy; + BestWidth = IntWidth; + } else { + BestWidth = Context.getTargetInfo().getLongWidth(); + + if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) { + BestType = Context.LongTy; + } else { + BestWidth = Context.getTargetInfo().getLongLongWidth(); + + if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) + Diag(Enum->getLocation(), diag::ext_enum_too_large); + BestType = Context.LongLongTy; + } + } + BestPromotionType = (BestWidth <= IntWidth ? Context.IntTy : BestType); + } else { + // If there is no negative value, figure out the smallest type that fits + // all of the enumerator values. + // If it's packed, check also if it fits a char or a short. + if (Packed && NumPositiveBits <= CharWidth) { + BestType = Context.UnsignedCharTy; + BestPromotionType = Context.IntTy; + BestWidth = CharWidth; + } else if (Packed && NumPositiveBits <= ShortWidth) { + BestType = Context.UnsignedShortTy; + BestPromotionType = Context.IntTy; + BestWidth = ShortWidth; + } else if (NumPositiveBits <= IntWidth) { + BestType = Context.UnsignedIntTy; + BestWidth = IntWidth; + BestPromotionType + = (NumPositiveBits == BestWidth || !getLangOpts().CPlusPlus) + ? Context.UnsignedIntTy : Context.IntTy; + } else if (NumPositiveBits <= + (BestWidth = Context.getTargetInfo().getLongWidth())) { + BestType = Context.UnsignedLongTy; + BestPromotionType + = (NumPositiveBits == BestWidth || !getLangOpts().CPlusPlus) + ? Context.UnsignedLongTy : Context.LongTy; + } else { + BestWidth = Context.getTargetInfo().getLongLongWidth(); + assert(NumPositiveBits <= BestWidth && + "How could an initializer get larger than ULL?"); + BestType = Context.UnsignedLongLongTy; + BestPromotionType + = (NumPositiveBits == BestWidth || !getLangOpts().CPlusPlus) + ? Context.UnsignedLongLongTy : Context.LongLongTy; + } + } + + // Loop over all of the enumerator constants, changing their types to match + // the type of the enum if needed. + for (auto *D : Elements) { + auto *ECD = cast_or_null(D); + if (!ECD) continue; // Already issued a diagnostic. + + // Standard C says the enumerators have int type, but we allow, as an + // extension, the enumerators to be larger than int size. If each + // enumerator value fits in an int, type it as an int, otherwise type it the + // same as the enumerator decl itself. This means that in "enum { X = 1U }" + // that X has type 'int', not 'unsigned'. + + // Determine whether the value fits into an int. + llvm::APSInt InitVal = ECD->getInitVal(); + + // If it fits into an integer type, force it. Otherwise force it to match + // the enum decl type. + QualType NewTy; + unsigned NewWidth; + bool NewSign; + if (!getLangOpts().CPlusPlus && + !Enum->isFixed() && + isRepresentableIntegerValue(Context, InitVal, Context.IntTy)) { + NewTy = Context.IntTy; + NewWidth = IntWidth; + NewSign = true; + } else if (ECD->getType() == BestType) { + // Already the right type! + if (getLangOpts().CPlusPlus) + // C++ [dcl.enum]p4: Following the closing brace of an + // enum-specifier, each enumerator has the type of its + // enumeration. + ECD->setType(EnumType); + continue; + } else { + NewTy = BestType; + NewWidth = BestWidth; + NewSign = BestType->isSignedIntegerOrEnumerationType(); + } + + // Adjust the APSInt value. + InitVal = InitVal.extOrTrunc(NewWidth); + InitVal.setIsSigned(NewSign); + ECD->setInitVal(InitVal); + + // Adjust the Expr initializer and type. + if (ECD->getInitExpr() && + !Context.hasSameType(NewTy, ECD->getInitExpr()->getType())) + ECD->setInitExpr(ImplicitCastExpr::Create(Context, NewTy, + CK_IntegralCast, + ECD->getInitExpr(), + /*base paths*/ nullptr, + VK_RValue)); + if (getLangOpts().CPlusPlus) + // C++ [dcl.enum]p4: Following the closing brace of an + // enum-specifier, each enumerator has the type of its + // enumeration. + ECD->setType(EnumType); + else + ECD->setType(NewTy); + } + + Enum->completeDefinition(BestType, BestPromotionType, + NumPositiveBits, NumNegativeBits); + + CheckForDuplicateEnumValues(*this, Elements, Enum, EnumType); + + if (Enum->isClosedFlag()) { + for (Decl *D : Elements) { + EnumConstantDecl *ECD = cast_or_null(D); + if (!ECD) continue; // Already issued a diagnostic. + + llvm::APSInt InitVal = ECD->getInitVal(); + if (InitVal != 0 && !InitVal.isPowerOf2() && + !IsValueInFlagEnum(Enum, InitVal, true)) + Diag(ECD->getLocation(), diag::warn_flag_enum_constant_out_of_range) + << ECD << Enum; + } + } + + // Now that the enum type is defined, ensure it's not been underaligned. + if (Enum->hasAttrs()) + CheckAlignasUnderalignment(Enum); + } + + Decl *Sema::ActOnFileScopeAsmDecl(Expr *expr, + SourceLocation StartLoc, + SourceLocation EndLoc) { + StringLiteral *AsmString = cast(expr); + + FileScopeAsmDecl *New = FileScopeAsmDecl::Create(Context, CurContext, + AsmString, StartLoc, + EndLoc); + CurContext->addDecl(New); + return New; + } + + static void checkModuleImportContext(Sema &S, Module *M, + SourceLocation ImportLoc, DeclContext *DC, + bool FromInclude = false) { + SourceLocation ExternCLoc; + + if (auto *LSD = dyn_cast(DC)) { + switch (LSD->getLanguage()) { + case LinkageSpecDecl::lang_c: + if (ExternCLoc.isInvalid()) + ExternCLoc = LSD->getBeginLoc(); + break; + case LinkageSpecDecl::lang_cxx: + break; + } + DC = LSD->getParent(); + } + + while (isa(DC) || isa(DC)) + DC = DC->getParent(); + + if (!isa(DC)) { + S.Diag(ImportLoc, (FromInclude && S.isModuleVisible(M)) + ? diag::ext_module_import_not_at_top_level_noop + : diag::err_module_import_not_at_top_level_fatal) + << M->getFullModuleName() << DC; + S.Diag(cast(DC)->getBeginLoc(), + diag::note_module_import_not_at_top_level) + << DC; + } else if (!M->IsExternC && ExternCLoc.isValid()) { + S.Diag(ImportLoc, diag::ext_module_import_in_extern_c) + << M->getFullModuleName(); + S.Diag(ExternCLoc, diag::note_extern_c_begins_here); + } + } + + Sema::DeclGroupPtrTy Sema::ActOnModuleDecl(SourceLocation StartLoc, + SourceLocation ModuleLoc, + ModuleDeclKind MDK, + ModuleIdPath Path) { + assert(getLangOpts().ModulesTS && + "should only have module decl in modules TS"); + + // A module implementation unit requires that we are not compiling a module + // of any kind. A module interface unit requires that we are not compiling a + // module map. + switch (getLangOpts().getCompilingModule()) { + case LangOptions::CMK_None: + // It's OK to compile a module interface as a normal translation unit. + break; + + case LangOptions::CMK_ModuleInterface: + if (MDK != ModuleDeclKind::Implementation) + break; + + // We were asked to compile a module interface unit but this is a module + // implementation unit. That indicates the 'export' is missing. + Diag(ModuleLoc, diag::err_module_interface_implementation_mismatch) + << FixItHint::CreateInsertion(ModuleLoc, "export "); + MDK = ModuleDeclKind::Interface; + break; + + case LangOptions::CMK_ModuleMap: + Diag(ModuleLoc, diag::err_module_decl_in_module_map_module); + return nullptr; + + case LangOptions::CMK_HeaderModule: + Diag(ModuleLoc, diag::err_module_decl_in_header_module); + return nullptr; + } + + assert(ModuleScopes.size() == 1 && "expected to be at global module scope"); + + // FIXME: Most of this work should be done by the preprocessor rather than + // here, in order to support macro import. + + // Only one module-declaration is permitted per source file. + if (ModuleScopes.back().Module->Kind == Module::ModuleInterfaceUnit) { + Diag(ModuleLoc, diag::err_module_redeclaration); + Diag(VisibleModules.getImportLoc(ModuleScopes.back().Module), + diag::note_prev_module_declaration); + return nullptr; + } + + // Flatten the dots in a module name. Unlike Clang's hierarchical module map + // modules, the dots here are just another character that can appear in a + // module name. + std::string ModuleName; + for (auto &Piece : Path) { + if (!ModuleName.empty()) + ModuleName += "."; + ModuleName += Piece.first->getName(); + } + + // If a module name was explicitly specified on the command line, it must be + // correct. + if (!getLangOpts().CurrentModule.empty() && + getLangOpts().CurrentModule != ModuleName) { + Diag(Path.front().second, diag::err_current_module_name_mismatch) + << SourceRange(Path.front().second, Path.back().second) + << getLangOpts().CurrentModule; + return nullptr; + } + const_cast(getLangOpts()).CurrentModule = ModuleName; + + auto &Map = PP.getHeaderSearchInfo().getModuleMap(); + Module *Mod; + + switch (MDK) { + case ModuleDeclKind::Interface: { + // We can't have parsed or imported a definition of this module or parsed a + // module map defining it already. + if (auto *M = Map.findModule(ModuleName)) { + Diag(Path[0].second, diag::err_module_redefinition) << ModuleName; + if (M->DefinitionLoc.isValid()) + Diag(M->DefinitionLoc, diag::note_prev_module_definition); + else if (const auto *FE = M->getASTFile()) + Diag(M->DefinitionLoc, diag::note_prev_module_definition_from_ast_file) + << FE->getName(); + Mod = M; + break; + } + + // Create a Module for the module that we're defining. + Mod = Map.createModuleForInterfaceUnit(ModuleLoc, ModuleName, + ModuleScopes.front().Module); + assert(Mod && "module creation should not fail"); + break; + } + + case ModuleDeclKind::Partition: + // FIXME: Check we are in a submodule of the named module. + return nullptr; + + case ModuleDeclKind::Implementation: + std::pair ModuleNameLoc( + PP.getIdentifierInfo(ModuleName), Path[0].second); + Mod = getModuleLoader().loadModule(ModuleLoc, {ModuleNameLoc}, + Module::AllVisible, + /*IsIncludeDirective=*/false); + if (!Mod) { + Diag(ModuleLoc, diag::err_module_not_defined) << ModuleName; + // Create an empty module interface unit for error recovery. + Mod = Map.createModuleForInterfaceUnit(ModuleLoc, ModuleName, + ModuleScopes.front().Module); + } + break; + } + + // Switch from the global module to the named module. + ModuleScopes.back().Module = Mod; + ModuleScopes.back().ModuleInterface = MDK != ModuleDeclKind::Implementation; + VisibleModules.setVisible(Mod, ModuleLoc); + + // From now on, we have an owning module for all declarations we see. + // However, those declarations are module-private unless explicitly + // exported. + auto *TU = Context.getTranslationUnitDecl(); + TU->setModuleOwnershipKind(Decl::ModuleOwnershipKind::ModulePrivate); + TU->setLocalOwningModule(Mod); + + // FIXME: Create a ModuleDecl. + return nullptr; + } + + DeclResult Sema::ActOnModuleImport(SourceLocation StartLoc, + SourceLocation ImportLoc, + ModuleIdPath Path) { + // Flatten the module path for a Modules TS module name. + std::pair ModuleNameLoc; + if (getLangOpts().ModulesTS) { + std::string ModuleName; + for (auto &Piece : Path) { + if (!ModuleName.empty()) + ModuleName += "."; + ModuleName += Piece.first->getName(); + } + ModuleNameLoc = {PP.getIdentifierInfo(ModuleName), Path[0].second}; + Path = ModuleIdPath(ModuleNameLoc); + } + + Module *Mod = + getModuleLoader().loadModule(ImportLoc, Path, Module::AllVisible, + /*IsIncludeDirective=*/false); + if (!Mod) + return true; + + VisibleModules.setVisible(Mod, ImportLoc); + + checkModuleImportContext(*this, Mod, ImportLoc, CurContext); + + // FIXME: we should support importing a submodule within a different submodule + // of the same top-level module. Until we do, make it an error rather than + // silently ignoring the import. + // Import-from-implementation is valid in the Modules TS. FIXME: Should we + // warn on a redundant import of the current module? + if (Mod->getTopLevelModuleName() == getLangOpts().CurrentModule && + (getLangOpts().isCompilingModule() || !getLangOpts().ModulesTS)) + Diag(ImportLoc, getLangOpts().isCompilingModule() + ? diag::err_module_self_import + : diag::err_module_import_in_implementation) + << Mod->getFullModuleName() << getLangOpts().CurrentModule; + + SmallVector IdentifierLocs; + Module *ModCheck = Mod; + for (unsigned I = 0, N = Path.size(); I != N; ++I) { + // If we've run out of module parents, just drop the remaining identifiers. + // We need the length to be consistent. + if (!ModCheck) + break; + ModCheck = ModCheck->Parent; + + IdentifierLocs.push_back(Path[I].second); + } + + ImportDecl *Import = ImportDecl::Create(Context, CurContext, StartLoc, + Mod, IdentifierLocs); + if (!ModuleScopes.empty()) + Context.addModuleInitializer(ModuleScopes.back().Module, Import); + CurContext->addDecl(Import); + + // Re-export the module if needed. + if (Import->isExported() && + !ModuleScopes.empty() && ModuleScopes.back().ModuleInterface) + getCurrentModule()->Exports.emplace_back(Mod, false); + + return Import; + } + + void Sema::ActOnModuleInclude(SourceLocation DirectiveLoc, Module *Mod) { + checkModuleImportContext(*this, Mod, DirectiveLoc, CurContext, true); + BuildModuleInclude(DirectiveLoc, Mod); + } + + void Sema::BuildModuleInclude(SourceLocation DirectiveLoc, Module *Mod) { + // Determine whether we're in the #include buffer for a module. The #includes + // in that buffer do not qualify as module imports; they're just an + // implementation detail of us building the module. + // + // FIXME: Should we even get ActOnModuleInclude calls for those? + bool IsInModuleIncludes = + TUKind == TU_Module && + getSourceManager().isWrittenInMainFile(DirectiveLoc); + + bool ShouldAddImport = !IsInModuleIncludes; + + // If this module import was due to an inclusion directive, create an + // implicit import declaration to capture it in the AST. + if (ShouldAddImport) { + TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl(); + ImportDecl *ImportD = ImportDecl::CreateImplicit(getASTContext(), TU, + DirectiveLoc, Mod, + DirectiveLoc); + if (!ModuleScopes.empty()) + Context.addModuleInitializer(ModuleScopes.back().Module, ImportD); + TU->addDecl(ImportD); + Consumer.HandleImplicitImportDecl(ImportD); + } + + getModuleLoader().makeModuleVisible(Mod, Module::AllVisible, DirectiveLoc); + VisibleModules.setVisible(Mod, DirectiveLoc); + } + + void Sema::ActOnModuleBegin(SourceLocation DirectiveLoc, Module *Mod) { + checkModuleImportContext(*this, Mod, DirectiveLoc, CurContext, true); + + ModuleScopes.push_back({}); + ModuleScopes.back().Module = Mod; + if (getLangOpts().ModulesLocalVisibility) + ModuleScopes.back().OuterVisibleModules = std::move(VisibleModules); + + VisibleModules.setVisible(Mod, DirectiveLoc); + + // The enclosing context is now part of this module. + // FIXME: Consider creating a child DeclContext to hold the entities + // lexically within the module. + if (getLangOpts().trackLocalOwningModule()) { + for (auto *DC = CurContext; DC; DC = DC->getLexicalParent()) { + cast(DC)->setModuleOwnershipKind( + getLangOpts().ModulesLocalVisibility + ? Decl::ModuleOwnershipKind::VisibleWhenImported + : Decl::ModuleOwnershipKind::Visible); + cast(DC)->setLocalOwningModule(Mod); + } + } + } + + void Sema::ActOnModuleEnd(SourceLocation EomLoc, Module *Mod) { + if (getLangOpts().ModulesLocalVisibility) { + VisibleModules = std::move(ModuleScopes.back().OuterVisibleModules); + // Leaving a module hides namespace names, so our visible namespace cache + // is now out of date. + VisibleNamespaceCache.clear(); + } + + assert(!ModuleScopes.empty() && ModuleScopes.back().Module == Mod && + "left the wrong module scope"); + ModuleScopes.pop_back(); + + // We got to the end of processing a local module. Create an + // ImportDecl as we would for an imported module. + FileID File = getSourceManager().getFileID(EomLoc); + SourceLocation DirectiveLoc; + if (EomLoc == getSourceManager().getLocForEndOfFile(File)) { + // We reached the end of a #included module header. Use the #include loc. + assert(File != getSourceManager().getMainFileID() && + "end of submodule in main source file"); + DirectiveLoc = getSourceManager().getIncludeLoc(File); + } else { + // We reached an EOM pragma. Use the pragma location. + DirectiveLoc = EomLoc; + } + BuildModuleInclude(DirectiveLoc, Mod); + + // Any further declarations are in whatever module we returned to. + if (getLangOpts().trackLocalOwningModule()) { + // The parser guarantees that this is the same context that we entered + // the module within. + for (auto *DC = CurContext; DC; DC = DC->getLexicalParent()) { + cast(DC)->setLocalOwningModule(getCurrentModule()); + if (!getCurrentModule()) + cast(DC)->setModuleOwnershipKind( + Decl::ModuleOwnershipKind::Unowned); + } + } + } + + void Sema::createImplicitModuleImportForErrorRecovery(SourceLocation Loc, + Module *Mod) { + // Bail if we're not allowed to implicitly import a module here. + if (isSFINAEContext() || !getLangOpts().ModulesErrorRecovery || + VisibleModules.isVisible(Mod)) + return; + + // Create the implicit import declaration. + TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl(); + ImportDecl *ImportD = ImportDecl::CreateImplicit(getASTContext(), TU, + Loc, Mod, Loc); + TU->addDecl(ImportD); + Consumer.HandleImplicitImportDecl(ImportD); + + // Make the module visible. + getModuleLoader().makeModuleVisible(Mod, Module::AllVisible, Loc); + VisibleModules.setVisible(Mod, Loc); + } + + /// We have parsed the start of an export declaration, including the '{' + /// (if present). + Decl *Sema::ActOnStartExportDecl(Scope *S, SourceLocation ExportLoc, + SourceLocation LBraceLoc) { + ExportDecl *D = ExportDecl::Create(Context, CurContext, ExportLoc); + + // C++ Modules TS draft: + // An export-declaration shall appear in the purview of a module other than + // the global module. + if (ModuleScopes.empty() || !ModuleScopes.back().ModuleInterface) + Diag(ExportLoc, diag::err_export_not_in_module_interface); + + // An export-declaration [...] shall not contain more than one + // export keyword. + // + // The intent here is that an export-declaration cannot appear within another + // export-declaration. + if (D->isExported()) + Diag(ExportLoc, diag::err_export_within_export); + + CurContext->addDecl(D); + PushDeclContext(S, D); + D->setModuleOwnershipKind(Decl::ModuleOwnershipKind::VisibleWhenImported); + return D; + } + + /// Complete the definition of an export declaration. + Decl *Sema::ActOnFinishExportDecl(Scope *S, Decl *D, SourceLocation RBraceLoc) { + auto *ED = cast(D); + if (RBraceLoc.isValid()) + ED->setRBraceLoc(RBraceLoc); + + // FIXME: Diagnose export of internal-linkage declaration (including + // anonymous namespace). + + PopDeclContext(); + return D; + } + + void Sema::ActOnPragmaRedefineExtname(IdentifierInfo* Name, + IdentifierInfo* AliasName, + SourceLocation PragmaLoc, + SourceLocation NameLoc, + SourceLocation AliasNameLoc) { + NamedDecl *PrevDecl = LookupSingleName(TUScope, Name, NameLoc, + LookupOrdinaryName); + AsmLabelAttr *Attr = + AsmLabelAttr::CreateImplicit(Context, AliasName->getName(), AliasNameLoc); + + // If a declaration that: + // 1) declares a function or a variable + // 2) has external linkage + // already exists, add a label attribute to it. + if (PrevDecl && (isa(PrevDecl) || isa(PrevDecl))) { + if (isDeclExternC(PrevDecl)) + PrevDecl->addAttr(Attr); + else + Diag(PrevDecl->getLocation(), diag::warn_redefine_extname_not_applied) + << /*Variable*/(isa(PrevDecl) ? 0 : 1) << PrevDecl; + // Otherwise, add a label atttibute to ExtnameUndeclaredIdentifiers. + } else + (void)ExtnameUndeclaredIdentifiers.insert(std::make_pair(Name, Attr)); + } + + void Sema::ActOnPragmaWeakID(IdentifierInfo* Name, + SourceLocation PragmaLoc, + SourceLocation NameLoc) { + Decl *PrevDecl = LookupSingleName(TUScope, Name, NameLoc, LookupOrdinaryName); + + if (PrevDecl) { + PrevDecl->addAttr(WeakAttr::CreateImplicit(Context, PragmaLoc)); + } else { + (void)WeakUndeclaredIdentifiers.insert( + std::pair + (Name, WeakInfo((IdentifierInfo*)nullptr, NameLoc))); + } + } + + void Sema::ActOnPragmaWeakAlias(IdentifierInfo* Name, + IdentifierInfo* AliasName, + SourceLocation PragmaLoc, + SourceLocation NameLoc, + SourceLocation AliasNameLoc) { + Decl *PrevDecl = LookupSingleName(TUScope, AliasName, AliasNameLoc, + LookupOrdinaryName); + WeakInfo W = WeakInfo(Name, NameLoc); + + if (PrevDecl && (isa(PrevDecl) || isa(PrevDecl))) { + if (!PrevDecl->hasAttr()) + if (NamedDecl *ND = dyn_cast(PrevDecl)) + DeclApplyPragmaWeak(TUScope, ND, W); + } else { + (void)WeakUndeclaredIdentifiers.insert( + std::pair(AliasName, W)); + } + } + + Decl *Sema::getObjCDeclContext() const { + return (dyn_cast_or_null(CurContext)); + } +diff --git a/test/CodeGen/dllexport-1.c b/test/CodeGen/dllexport-1.c +new file mode 100644 +index 0000000000..d926318870 +--- /dev/null ++++ b/test/CodeGen/dllexport-1.c +@@ -0,0 +1,17 @@ ++// RUN: %clang_cc1 -emit-llvm -fms-extensions -o - %s | FileCheck %s ++ ++ ++// Export const variable. ++ ++// CHECK: @x = dso_local dllexport constant i32 3, align 4 ++// CHECK: @z = dso_local constant i32 4, align 4 ++// CHECK: @y = common dso_local dllexport global i32 0, align 4 ++ ++__declspec(dllexport) int const x = 3; ++__declspec(dllexport) const int y; ++extern int const z = 4; // expected-warning{{'extern' variable has an initializer}} ++ ++int main() { ++ int a = x + y + z; ++ return a; ++} +diff --git a/test/Sema/dllexport-1.cpp b/test/Sema/dllexport-1.cpp +new file mode 100644 +index 0000000000..64c6989c67 +--- /dev/null ++++ b/test/Sema/dllexport-1.cpp +@@ -0,0 +1,6 @@ ++// RUN: %clang_cc1 -fsyntax-only -fms-extensions -verify %s ++ ++// Export const variable initialization. ++ ++// expected-no-diagnostics ++__declspec(dllexport) int const x = 3; +diff --git a/test/Sema/dllexport-2.cpp b/test/Sema/dllexport-2.cpp +new file mode 100644 +index 0000000000..c8be4e9bd7 +--- /dev/null ++++ b/test/Sema/dllexport-2.cpp +@@ -0,0 +1,14 @@ ++// RUN: %clang_cc1 -fsyntax-only -fms-extensions -verify %s ++ ++// Export const variable. ++ ++__declspec(dllexport) int const j; // expected-error {{default initialization of an object of const type 'const int'}} // expected-error {{'j' must have external linkage when declared 'dllexport'}} ++ ++// With typedef ++typedef const int CInt; ++__declspec(dllexport) CInt j2; // expected-error {{default initialization of an object of const type 'CInt' (aka 'const int')}} //expected-error {{'j2' must have external linkage when declared 'dllexport'}} ++__declspec(dllexport) CInt j3 = 3; ++ ++ ++// In an anonymous namespace ++namespace { __declspec(dllexport) int const x = 3; } Index: test/CodeGen/dllexport-1.c =================================================================== --- /dev/null +++ test/CodeGen/dllexport-1.c @@ -0,0 +1,17 @@ +// RUN: %clang_cc1 -emit-llvm -fms-extensions -o - %s | FileCheck %s + + +// Export const variable. + +// CHECK: @x = dso_local dllexport constant i32 3, align 4 +// CHECK: @z = dso_local constant i32 4, align 4 +// CHECK: @y = common dso_local dllexport global i32 0, align 4 + +__declspec(dllexport) int const x = 3; +__declspec(dllexport) const int y; +extern int const z = 4; // expected-warning{{'extern' variable has an initializer}} + +int main() { + int a = x + y + z; + return a; +} Index: test/Sema/dllexport-1.cpp =================================================================== --- /dev/null +++ test/Sema/dllexport-1.cpp @@ -0,0 +1,6 @@ +// RUN: %clang_cc1 -fsyntax-only -fms-extensions -verify %s + +// Export const variable initialization. + +// expected-no-diagnostics +__declspec(dllexport) int const x = 3; Index: test/Sema/dllexport-2.cpp =================================================================== --- /dev/null +++ test/Sema/dllexport-2.cpp @@ -0,0 +1,14 @@ +// RUN: %clang_cc1 -fsyntax-only -fms-extensions -verify %s + +// Export const variable. + +__declspec(dllexport) int const j; // expected-error {{default initialization of an object of const type 'const int'}} // expected-error {{'j' must have external linkage when declared 'dllexport'}} + +// With typedef +typedef const int CInt; +__declspec(dllexport) CInt j2; // expected-error {{default initialization of an object of const type 'CInt' (aka 'const int')}} //expected-error {{'j2' must have external linkage when declared 'dllexport'}} +__declspec(dllexport) CInt j3 = 3; + + +// In an anonymous namespace +namespace { __declspec(dllexport) int const x = 3; }