diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp --- a/clang/lib/AST/ExprConstant.cpp +++ b/clang/lib/AST/ExprConstant.cpp @@ -8355,6 +8355,11 @@ bool LValueExprEvaluator::VisitMaterializeTemporaryExpr( const MaterializeTemporaryExpr *E) { + + // Do not constant fold an R-value. + if (Info.EvalMode == EvalInfo::EM_ConstantFold && !E->isLValue()) + return false; + // Walk through the expression to find the materialized temporary itself. SmallVector CommaLHSs; SmallVector Adjustments; diff --git a/clang/lib/CodeGen/CGExprConstant.cpp b/clang/lib/CodeGen/CGExprConstant.cpp --- a/clang/lib/CodeGen/CGExprConstant.cpp +++ b/clang/lib/CodeGen/CGExprConstant.cpp @@ -1215,11 +1215,6 @@ return Visit(E->getSubExpr(), T); } - llvm::Constant *VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E, - QualType T) { - return Visit(E->getSubExpr(), T); - } - llvm::Constant *EmitArrayInitialization(InitListExpr *ILE, QualType T) { auto *CAT = CGM.getContext().getAsConstantArrayType(ILE->getType()); assert(CAT && "can't emit array init for non-constant-bound array"); @@ -1322,7 +1317,12 @@ assert(CGM.getContext().hasSameUnqualifiedType(Ty, Arg->getType()) && "argument to copy ctor is of wrong type"); - return Visit(Arg, Ty); + // Look through the temporary; it's just converting the value to an + // lvalue to pass it to the constructor. + if (auto *MTE = dyn_cast(Arg)) + return Visit(MTE->getSubExpr(), Ty); + // Don't try to support arbitrary lvalue-to-rvalue conversions for now. + return nullptr; } return CGM.EmitNullConstant(Ty); @@ -1654,29 +1654,22 @@ InConstantContext = D.hasConstantInitialization(); QualType destType = D.getType(); + const Expr *E = D.getInit(); + assert(E && "No initializer to emit"); + + if (!destType->isReferenceType()) { + QualType nonMemoryDestType = getNonMemoryType(CGM, destType); + if (llvm::Constant *C = ConstExprEmitter(*this).Visit(const_cast(E), + nonMemoryDestType)) + return emitForMemory(C, destType); + } // Try to emit the initializer. Note that this can allow some things that // are not allowed by tryEmitPrivateForMemory alone. - if (auto value = D.evaluateValue()) { + if (APValue *value = D.evaluateValue()) return tryEmitPrivateForMemory(*value, destType); - } - - // FIXME: Implement C++11 [basic.start.init]p2: if the initializer of a - // reference is a constant expression, and the reference binds to a temporary, - // then constant initialization is performed. ConstExprEmitter will - // incorrectly emit a prvalue constant in this case, and the calling code - // interprets that as the (pointer) value of the reference, rather than the - // desired value of the referee. - if (destType->isReferenceType()) - return nullptr; - - const Expr *E = D.getInit(); - assert(E && "No initializer to emit"); - auto nonMemoryDestType = getNonMemoryType(CGM, destType); - auto C = - ConstExprEmitter(*this).Visit(const_cast(E), nonMemoryDestType); - return (C ? emitForMemory(C, destType) : nullptr); + return nullptr; } llvm::Constant * @@ -1743,6 +1736,10 @@ QualType destType) { assert(!destType->isVoidType() && "can't emit a void constant"); + if (llvm::Constant *C = + ConstExprEmitter(*this).Visit(const_cast(E), destType)) + return C; + Expr::EvalResult Result; bool Success = false; @@ -1752,13 +1749,10 @@ else Success = E->EvaluateAsRValue(Result, CGM.getContext(), InConstantContext); - llvm::Constant *C; if (Success && !Result.HasSideEffects) - C = tryEmitPrivate(Result.Val, destType); - else - C = ConstExprEmitter(*this).Visit(const_cast(E), destType); + return tryEmitPrivate(Result.Val, destType); - return C; + return nullptr; } llvm::Constant *CodeGenModule::getNullPointer(llvm::PointerType *T, QualType QT) { diff --git a/clang/test/CodeGenCXX/const-init-cxx11.cpp b/clang/test/CodeGenCXX/const-init-cxx11.cpp --- a/clang/test/CodeGenCXX/const-init-cxx11.cpp +++ b/clang/test/CodeGenCXX/const-init-cxx11.cpp @@ -88,7 +88,7 @@ struct E {}; struct Test2 : X, X, X, X {}; - // CHECK: @_ZN9BaseClass2t2E ={{.*}} constant {{.*}} undef + // CHECK: @_ZN9BaseClass2t2E ={{.*}} constant {{.*}} zeroinitializer, align 1 extern constexpr Test2 t2 = Test2(); struct __attribute((packed)) PackedD { double y = 2; }; diff --git a/clang/test/CodeGenCXX/const-init-cxx1y.cpp b/clang/test/CodeGenCXX/const-init-cxx1y.cpp --- a/clang/test/CodeGenCXX/const-init-cxx1y.cpp +++ b/clang/test/CodeGenCXX/const-init-cxx1y.cpp @@ -34,8 +34,8 @@ // 'c.temporary', not the value as modified by the partial evaluation within // the initialization of 'c.x'. A c = { 10, (++c.temporary, b.x) }; - // CHECK: @_ZGRN21ModifyStaticTemporary1cE_ = internal global i32 10 // CHECK: @_ZN21ModifyStaticTemporary1cE ={{.*}} global {{.*}} zeroinitializer + // CHECK: @_ZGRN21ModifyStaticTemporary1cE_ = internal global i32 10 } // CHECK: @_ZGRN28VariableTemplateWithConstRef1iIvEE_ = linkonce_odr constant i32 5, align 4 @@ -76,6 +76,13 @@ S *p = &s<1, 2, 3, 4>; } + +// CHECK: @_ZGR1z_ = internal global [2 x i32] [i32 10, i32 2], align 4 +// CHECK: @z = global { ptr, i32 } { ptr @_ZGR1z_, i32 10 }, align 8 +typedef int v[2]; +struct Z { int &&x, y; }; +Z z = { v{1,2}[0], z.x = 10 }; + // CHECK: __cxa_atexit({{.*}} @_ZN1BD1Ev, {{.*}} @b // CHECK: define diff --git a/clang/test/CodeGenOpenCL/amdgpu-nullptr.cl b/clang/test/CodeGenOpenCL/amdgpu-nullptr.cl --- a/clang/test/CodeGenOpenCL/amdgpu-nullptr.cl +++ b/clang/test/CodeGenOpenCL/amdgpu-nullptr.cl @@ -57,7 +57,7 @@ // CHECK: @fold_generic ={{.*}} local_unnamed_addr addrspace(1) global ptr null, align 8 generic int *fold_generic = (global int*)(generic float*)(private char*)0; -// CHECK: @fold_priv ={{.*}} local_unnamed_addr addrspace(1) global ptr addrspace(5) addrspacecast (ptr null to ptr addrspace(5)), align 4 +// CHECK: @fold_priv ={{.*}} local_unnamed_addr addrspace(1) global ptr addrspace(5) addrspacecast (ptr addrspace(1) null to ptr addrspace(5)), align 4 private short *fold_priv = (private short*)(generic int*)(global void*)0; // CHECK: @fold_priv_arith ={{.*}} local_unnamed_addr addrspace(1) global ptr addrspace(5) inttoptr (i32 9 to ptr addrspace(5)), align 4