diff --git a/clang/include/clang/Sema/Initialization.h b/clang/include/clang/Sema/Initialization.h --- a/clang/include/clang/Sema/Initialization.h +++ b/clang/include/clang/Sema/Initialization.h @@ -298,8 +298,8 @@ /// Create the initialization entity for the result of a function. static InitializedEntity InitializeResult(SourceLocation ReturnLoc, - QualType Type, bool NRVO) { - return InitializedEntity(EK_Result, ReturnLoc, Type, NRVO); + QualType Type) { + return InitializedEntity(EK_Result, ReturnLoc, Type); } static InitializedEntity InitializeStmtExprResult(SourceLocation ReturnLoc, @@ -308,20 +308,20 @@ } static InitializedEntity InitializeBlock(SourceLocation BlockVarLoc, - QualType Type, bool NRVO) { - return InitializedEntity(EK_BlockElement, BlockVarLoc, Type, NRVO); + QualType Type) { + return InitializedEntity(EK_BlockElement, BlockVarLoc, Type); } static InitializedEntity InitializeLambdaToBlock(SourceLocation BlockVarLoc, - QualType Type, bool NRVO) { + QualType Type) { return InitializedEntity(EK_LambdaToBlockConversionBlockElement, - BlockVarLoc, Type, NRVO); + BlockVarLoc, Type); } /// Create the initialization entity for an exception object. static InitializedEntity InitializeException(SourceLocation ThrowLoc, - QualType Type, bool NRVO) { - return InitializedEntity(EK_Exception, ThrowLoc, Type, NRVO); + QualType Type) { + return InitializedEntity(EK_Exception, ThrowLoc, Type); } /// Create the initialization entity for an object allocated via new. diff --git a/clang/lib/CodeGen/CGExprCXX.cpp b/clang/lib/CodeGen/CGExprCXX.cpp --- a/clang/lib/CodeGen/CGExprCXX.cpp +++ b/clang/lib/CodeGen/CGExprCXX.cpp @@ -609,15 +609,13 @@ return; // Elide the constructor if we're constructing from a temporary. - // The temporary check is required because Sema sets this on NRVO - // returns. if (getLangOpts().ElideConstructors && E->isElidable()) { - assert(getContext().hasSameUnqualifiedType(E->getType(), - E->getArg(0)->getType())); - if (E->getArg(0)->isTemporaryObject(getContext(), CD->getParent())) { - EmitAggExpr(E->getArg(0), Dest); - return; - } + const Expr *SrcObj = E->getArg(0); + assert(SrcObj->isTemporaryObject(getContext(), CD->getParent())); + assert( + getContext().hasSameUnqualifiedType(E->getType(), SrcObj->getType())); + EmitAggExpr(SrcObj, Dest); + return; } if (const ArrayType *arrayType diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp --- a/clang/lib/Sema/Sema.cpp +++ b/clang/lib/Sema/Sema.cpp @@ -2020,7 +2020,7 @@ Expr *VarRef = new (S.Context) DeclRefExpr(S.Context, VD, false, T, VK_LValue, Loc); ExprResult Result; - auto IE = InitializedEntity::InitializeBlock(Loc, T, false); + auto IE = InitializedEntity::InitializeBlock(Loc, T); if (S.getLangOpts().CPlusPlus2b) { auto *E = ImplicitCastExpr::Create(S.Context, T, CK_NoOp, VarRef, nullptr, VK_XValue, FPOptionsOverride()); diff --git a/clang/lib/Sema/SemaCoroutine.cpp b/clang/lib/Sema/SemaCoroutine.cpp --- a/clang/lib/Sema/SemaCoroutine.cpp +++ b/clang/lib/Sema/SemaCoroutine.cpp @@ -1533,7 +1533,7 @@ if (GroType->isVoidType()) { // Trigger a nice error message. InitializedEntity Entity = - InitializedEntity::InitializeResult(Loc, FnRetType, false); + InitializedEntity::InitializeResult(Loc, FnRetType); S.PerformCopyInitialization(Entity, SourceLocation(), ReturnValue); noteMemberDeclaredHere(S, ReturnValue, Fn); return false; diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp --- a/clang/lib/Sema/SemaDeclCXX.cpp +++ b/clang/lib/Sema/SemaDeclCXX.cpp @@ -15300,6 +15300,14 @@ // can be omitted by constructing the temporary object // directly into the target of the omitted copy/move if (ConstructKind == CXXConstructExpr::CK_Complete && Constructor && + // FIXME: These two conditions are wrong: + // * Converting constructors should also be allowed + // * They have more than one real argument, provided + // they are default from the second on. + // But to fix this, the logic that digs down into a CXXConstructExpr + // to find the source object needs to handle this. + // Right now it assumes the source object is passed directly as the + // first argument. Constructor->isCopyOrMoveConstructor() && hasOneRealArgument(ExprArgs)) { Expr *SubExpr = ExprArgs[0]; Elidable = SubExpr->isTemporaryObject( diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp --- a/clang/lib/Sema/SemaExpr.cpp +++ b/clang/lib/Sema/SemaExpr.cpp @@ -15711,7 +15711,7 @@ if (!Result.isInvalid()) { Result = PerformCopyInitialization( InitializedEntity::InitializeBlock(Var->getLocation(), - Cap.getCaptureType(), false), + Cap.getCaptureType()), Loc, Result.get()); } diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp --- a/clang/lib/Sema/SemaExprCXX.cpp +++ b/clang/lib/Sema/SemaExprCXX.cpp @@ -893,9 +893,8 @@ if (CheckCXXThrowOperand(OpLoc, ExceptionObjectTy, Ex)) return ExprError(); - InitializedEntity Entity = InitializedEntity::InitializeException( - OpLoc, ExceptionObjectTy, - /*NRVO=*/NRInfo.isCopyElidable()); + InitializedEntity Entity = + InitializedEntity::InitializeException(OpLoc, ExceptionObjectTy); ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRInfo, Ex); if (Res.isInvalid()) return ExprError(); diff --git a/clang/lib/Sema/SemaLambda.cpp b/clang/lib/Sema/SemaLambda.cpp --- a/clang/lib/Sema/SemaLambda.cpp +++ b/clang/lib/Sema/SemaLambda.cpp @@ -1978,8 +1978,7 @@ CallOperator->markUsed(Context); ExprResult Init = PerformCopyInitialization( - InitializedEntity::InitializeLambdaToBlock(ConvLocation, Src->getType(), - /*NRVO=*/false), + InitializedEntity::InitializeLambdaToBlock(ConvLocation, Src->getType()), CurrentLocation, Src); if (!Init.isInvalid()) Init = ActOnFinishFullExpr(Init.get(), /*DiscardedValue*/ false); diff --git a/clang/lib/Sema/SemaObjCProperty.cpp b/clang/lib/Sema/SemaObjCProperty.cpp --- a/clang/lib/Sema/SemaObjCProperty.cpp +++ b/clang/lib/Sema/SemaObjCProperty.cpp @@ -1467,8 +1467,7 @@ LoadSelfExpr, true, true); ExprResult Res = PerformCopyInitialization( InitializedEntity::InitializeResult(PropertyDiagLoc, - getterMethod->getReturnType(), - /*NRVO=*/false), + getterMethod->getReturnType()), PropertyDiagLoc, IvarRefExpr); if (!Res.isInvalid()) { Expr *ResExpr = Res.getAs(); diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp --- a/clang/lib/Sema/SemaStmt.cpp +++ b/clang/lib/Sema/SemaStmt.cpp @@ -3653,8 +3653,8 @@ // In C++ the return statement is handled via a copy initialization. // the C version of which boils down to CheckSingleAssignmentConstraints. - InitializedEntity Entity = InitializedEntity::InitializeResult( - ReturnLoc, FnRetType, NRVOCandidate != nullptr); + InitializedEntity Entity = + InitializedEntity::InitializeResult(ReturnLoc, FnRetType); ExprResult Res = PerformMoveOrCopyInitialization( Entity, NRInfo, RetValExp, SupressSimplerImplicitMoves); if (Res.isInvalid()) { @@ -4085,8 +4085,8 @@ // the C version of which boils down to CheckSingleAssignmentConstraints. if (!HasDependentReturnType && !RetValExp->isTypeDependent()) { // we have a non-void function with an expression, continue checking - InitializedEntity Entity = InitializedEntity::InitializeResult( - ReturnLoc, RetType, NRVOCandidate != nullptr); + InitializedEntity Entity = + InitializedEntity::InitializeResult(ReturnLoc, RetType); ExprResult Res = PerformMoveOrCopyInitialization( Entity, NRInfo, RetValExp, SupressSimplerImplicitMoves); if (Res.isInvalid()) { diff --git a/clang/test/CodeGen/nrvo-tracking.cpp b/clang/test/CodeGen/nrvo-tracking.cpp --- a/clang/test/CodeGen/nrvo-tracking.cpp +++ b/clang/test/CodeGen/nrvo-tracking.cpp @@ -282,3 +282,40 @@ } } // namespace test_alignas + +namespace PR51862 { + +template T test() { + T a; + T b; + if (0) + return a; + return b; +} + +struct A { + A(); + A(A &); + A(int); + operator int(); +}; + +// CHECK-LABEL: define{{.*}} void @_ZN7PR518624testINS_1AEEET_v +// CHECK: call i32 @_ZN7PR518621AcviEv +// CHECK-NEXT: call void @_ZN7PR518621AC1Ei +// CHECK-NEXT: call void @llvm.lifetime.end +template A test(); + +struct BSub {}; +struct B : BSub { + B(); + B(B &); + B(const BSub &); +}; + +// CHECK-LABEL: define{{.*}} void @_ZN7PR518624testINS_1BEEET_v +// CHECK: call void @_ZN7PR518621BC1ERKNS_4BSubE +// CHECK-NEXT: call void @llvm.lifetime.end +template B test(); + +} // namespace PR51862 diff --git a/clang/test/CodeGenCXX/copy-elision.cpp b/clang/test/CodeGenCXX/copy-elision.cpp new file mode 100644 --- /dev/null +++ b/clang/test/CodeGenCXX/copy-elision.cpp @@ -0,0 +1,34 @@ +// RUN: %clang_cc1 -std=c++14 -triple x86_64-unknown-unknown-gnu -emit-llvm -O1 -fexperimental-new-pass-manager -o - %s | FileCheck %s + +template T test() { + return T(); +} + +struct A { + A(); + A(A &); + A(int); + operator int(); +}; + +// FIXME: There should be copy elision here. +// CHECK-LABEL: define{{.*}} void @_Z4testI1AET_v +// CHECK: call void @_ZN1AC1Ev +// CHECK-NEXT: call i32 @_ZN1AcviEv +// CHECK-NEXT: call void @_ZN1AC1Ei +// CHECK-NEXT: call void @llvm.lifetime.end +template A test(); + +struct BSub {}; +struct B : BSub { + B(); + B(B &); + B(const BSub &); +}; + +// FIXME: There should be copy elision here. +// CHECK-LABEL: define{{.*}} void @_Z4testI1BET_v +// CHECK: call void @_ZN1BC1Ev +// CHECK: call void @_ZN1BC1ERK4BSub +// CHECK-NEXT: call void @llvm.lifetime.end +template B test();