r288866 - [c++17] P0135R1: Guaranteed copy elision.
Richard Smith via cfe-commits
cfe-commits at lists.llvm.org
Tue Dec 6 15:52:29 PST 2016
Author: rsmith
Date: Tue Dec 6 17:52:28 2016
New Revision: 288866
URL: http://llvm.org/viewvc/llvm-project?rev=288866&view=rev
Log:
[c++17] P0135R1: Guaranteed copy elision.
When an object of class type is initialized from a prvalue of the same type
(ignoring cv qualifications), use the prvalue to initialize the object directly
instead of inserting a redundant elidable call to a copy constructor.
Added:
cfe/trunk/test/CodeGenCXX/cxx1z-copy-omission.cpp
cfe/trunk/test/SemaCXX/cxx1z-copy-omission.cpp
Modified:
cfe/trunk/include/clang/AST/Expr.h
cfe/trunk/lib/AST/Expr.cpp
cfe/trunk/lib/AST/ExprConstant.cpp
cfe/trunk/lib/CodeGen/CGExpr.cpp
cfe/trunk/lib/CodeGen/CGExprAgg.cpp
cfe/trunk/lib/CodeGen/CGExprConstant.cpp
cfe/trunk/lib/Sema/SemaExprCXX.cpp
cfe/trunk/lib/Sema/SemaInit.cpp
cfe/trunk/lib/Sema/SemaOverload.cpp
cfe/trunk/test/CXX/drs/dr0xx.cpp
cfe/trunk/test/CXX/drs/dr10xx.cpp
cfe/trunk/test/CXX/drs/dr1xx.cpp
cfe/trunk/test/CXX/drs/dr4xx.cpp
cfe/trunk/test/SemaCXX/aggregate-initialization.cpp
cfe/trunk/www/cxx_dr_status.html
cfe/trunk/www/cxx_status.html
Modified: cfe/trunk/include/clang/AST/Expr.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/Expr.h?rev=288866&r1=288865&r2=288866&view=diff
==============================================================================
--- cfe/trunk/include/clang/AST/Expr.h (original)
+++ cfe/trunk/include/clang/AST/Expr.h Tue Dec 6 17:52:28 2016
@@ -3786,7 +3786,7 @@ public:
/// \brief Build an empty initializer list.
explicit InitListExpr(EmptyShell Empty)
- : Expr(InitListExprClass, Empty) { }
+ : Expr(InitListExprClass, Empty), AltForm(nullptr, true) { }
unsigned getNumInits() const { return InitExprs.size(); }
@@ -3894,6 +3894,11 @@ public:
// literal or an @encode?
bool isStringLiteralInit() const;
+ /// Is this a transparent initializer list (that is, an InitListExpr that is
+ /// purely syntactic, and whose semantics are that of the sole contained
+ /// initializer)?
+ bool isTransparent() const;
+
SourceLocation getLBraceLoc() const { return LBraceLoc; }
void setLBraceLoc(SourceLocation Loc) { LBraceLoc = Loc; }
SourceLocation getRBraceLoc() const { return RBraceLoc; }
Modified: cfe/trunk/lib/AST/Expr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/Expr.cpp?rev=288866&r1=288865&r2=288866&view=diff
==============================================================================
--- cfe/trunk/lib/AST/Expr.cpp (original)
+++ cfe/trunk/lib/AST/Expr.cpp Tue Dec 6 17:52:28 2016
@@ -1864,6 +1864,24 @@ bool InitListExpr::isStringLiteralInit()
return isa<StringLiteral>(Init) || isa<ObjCEncodeExpr>(Init);
}
+bool InitListExpr::isTransparent() const {
+ assert(isSemanticForm() && "syntactic form never semantically transparent");
+
+ // A glvalue InitListExpr is always just sugar.
+ if (isGLValue()) {
+ assert(getNumInits() == 1 && "multiple inits in glvalue init list");
+ return true;
+ }
+
+ // Otherwise, we're sugar if and only if we have exactly one initializer that
+ // is of the same type.
+ if (getNumInits() != 1 || !getInit(0))
+ return false;
+
+ return getType().getCanonicalType() ==
+ getInit(0)->getType().getCanonicalType();
+}
+
SourceLocation InitListExpr::getLocStart() const {
if (InitListExpr *SyntacticForm = getSyntacticForm())
return SyntacticForm->getLocStart();
@@ -2246,12 +2264,15 @@ bool Expr::isUnusedResultAWarning(const
// effects (e.g. a placement new with an uninitialized POD).
case CXXDeleteExprClass:
return false;
+ case MaterializeTemporaryExprClass:
+ return cast<MaterializeTemporaryExpr>(this)->GetTemporaryExpr()
+ ->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
case CXXBindTemporaryExprClass:
- return (cast<CXXBindTemporaryExpr>(this)
- ->getSubExpr()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx));
+ return cast<CXXBindTemporaryExpr>(this)->getSubExpr()
+ ->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
case ExprWithCleanupsClass:
- return (cast<ExprWithCleanups>(this)
- ->getSubExpr()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx));
+ return cast<ExprWithCleanups>(this)->getSubExpr()
+ ->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx);
}
}
Modified: cfe/trunk/lib/AST/ExprConstant.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ExprConstant.cpp?rev=288866&r1=288865&r2=288866&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ExprConstant.cpp (original)
+++ cfe/trunk/lib/AST/ExprConstant.cpp Tue Dec 6 17:52:28 2016
@@ -5670,6 +5670,9 @@ bool RecordExprEvaluator::VisitCastExpr(
}
bool RecordExprEvaluator::VisitInitListExpr(const InitListExpr *E) {
+ if (E->isTransparent())
+ return Visit(E->getInit(0));
+
const RecordDecl *RD = E->getType()->castAs<RecordType>()->getDecl();
if (RD->isInvalidDecl()) return false;
const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
Modified: cfe/trunk/lib/CodeGen/CGExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExpr.cpp?rev=288866&r1=288865&r2=288866&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExpr.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExpr.cpp Tue Dec 6 17:52:28 2016
@@ -3522,7 +3522,7 @@ LValue CodeGenFunction::EmitInitListLVal
return EmitAggExprToLValue(E);
// An lvalue initializer list must be initializing a reference.
- assert(E->getNumInits() == 1 && "reference init with multiple values");
+ assert(E->isTransparent() && "non-transparent glvalue init list");
return EmitLValue(E->getInit(0));
}
Modified: cfe/trunk/lib/CodeGen/CGExprAgg.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExprAgg.cpp?rev=288866&r1=288865&r2=288866&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExprAgg.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExprAgg.cpp Tue Dec 6 17:52:28 2016
@@ -1145,15 +1145,15 @@ void AggExprEmitter::VisitInitListExpr(I
if (E->hadArrayRangeDesignator())
CGF.ErrorUnsupported(E, "GNU array range designator extension");
+ if (E->isTransparent())
+ return Visit(E->getInit(0));
+
AggValueSlot Dest = EnsureSlot(E->getType());
LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType());
// Handle initialization of an array.
if (E->getType()->isArrayType()) {
- if (E->isStringLiteralInit())
- return Visit(E->getInit(0));
-
QualType elementType =
CGF.getContext().getAsArrayType(E->getType())->getElementType();
@@ -1162,16 +1162,6 @@ void AggExprEmitter::VisitInitListExpr(I
return;
}
- if (E->getType()->isAtomicType()) {
- // An _Atomic(T) object can be list-initialized from an expression
- // of the same type.
- assert(E->getNumInits() == 1 &&
- CGF.getContext().hasSameUnqualifiedType(E->getInit(0)->getType(),
- E->getType()) &&
- "unexpected list initialization for atomic object");
- return Visit(E->getInit(0));
- }
-
assert(E->getType()->isRecordType() && "Only support structs/unions here!");
// Do struct initialization; this code just sets each individual member
Modified: cfe/trunk/lib/CodeGen/CGExprConstant.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExprConstant.cpp?rev=288866&r1=288865&r2=288866&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExprConstant.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExprConstant.cpp Tue Dec 6 17:52:28 2016
@@ -778,9 +778,6 @@ public:
}
llvm::Constant *EmitArrayInitialization(InitListExpr *ILE) {
- if (ILE->isStringLiteralInit())
- return Visit(ILE->getInit(0));
-
llvm::ArrayType *AType =
cast<llvm::ArrayType>(ConvertType(ILE->getType()));
llvm::Type *ElemTy = AType->getElementType();
@@ -845,6 +842,9 @@ public:
}
llvm::Constant *VisitInitListExpr(InitListExpr *ILE) {
+ if (ILE->isTransparent())
+ return Visit(ILE->getInit(0));
+
if (ILE->getType()->isArrayType())
return EmitArrayInitialization(ILE);
Modified: cfe/trunk/lib/Sema/SemaExprCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExprCXX.cpp?rev=288866&r1=288865&r2=288866&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExprCXX.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExprCXX.cpp Tue Dec 6 17:52:28 2016
@@ -6836,6 +6836,16 @@ ExprResult Sema::IgnoredValueConversions
return E;
E = Res.get();
}
+
+ // C++1z:
+ // If the expression is a prvalue after this optional conversion, the
+ // temporary materialization conversion is applied.
+ //
+ // We skip this step: IR generation is able to synthesize the storage for
+ // itself in the aggregate case, and adding the extra node to the AST is
+ // just clutter.
+ // FIXME: We don't emit lifetime markers for the temporaries due to this.
+ // FIXME: Do any other AST consumers care about this?
return E;
}
Modified: cfe/trunk/lib/Sema/SemaInit.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaInit.cpp?rev=288866&r1=288865&r2=288866&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaInit.cpp (original)
+++ cfe/trunk/lib/Sema/SemaInit.cpp Tue Dec 6 17:52:28 2016
@@ -3546,8 +3546,14 @@ static void TryConstructorInitialization
InitializationSequence &Sequence,
bool IsListInit = false,
bool IsInitListCopy = false) {
- assert((!IsListInit || (Args.size() == 1 && isa<InitListExpr>(Args[0]))) &&
- "IsListInit must come with a single initializer list argument.");
+ assert(((!IsListInit && !IsInitListCopy) ||
+ (Args.size() == 1 && isa<InitListExpr>(Args[0]))) &&
+ "IsListInit/IsInitListCopy must come with a single initializer list "
+ "argument.");
+ InitListExpr *ILE =
+ (IsListInit || IsInitListCopy) ? cast<InitListExpr>(Args[0]) : nullptr;
+ MultiExprArg UnwrappedArgs =
+ ILE ? MultiExprArg(ILE->getInits(), ILE->getNumInits()) : Args;
// The type we're constructing needs to be complete.
if (!S.isCompleteType(Kind.getLocation(), DestType)) {
@@ -3555,6 +3561,35 @@ static void TryConstructorInitialization
return;
}
+ // C++1z [dcl.init]p17:
+ // - If the initializer expression is a prvalue and the cv-unqualified
+ // version of the source type is the same class as the class of the
+ // destination, the initializer expression is used to initialize the
+ // destination object.
+ // Per DR (no number yet), this does not apply when initializing a base
+ // class or delegating to another constructor from a mem-initializer.
+ if (S.getLangOpts().CPlusPlus1z &&
+ Entity.getKind() != InitializedEntity::EK_Base &&
+ Entity.getKind() != InitializedEntity::EK_Delegating &&
+ UnwrappedArgs.size() == 1 && UnwrappedArgs[0]->isRValue() &&
+ S.Context.hasSameUnqualifiedType(UnwrappedArgs[0]->getType(), DestType)) {
+ // Convert qualifications if necessary.
+ QualType InitType = UnwrappedArgs[0]->getType();
+ ImplicitConversionSequence ICS;
+ ICS.setStandard();
+ ICS.Standard.setAsIdentityConversion();
+ ICS.Standard.setFromType(InitType);
+ ICS.Standard.setAllToTypes(InitType);
+ if (!S.Context.hasSameType(InitType, DestType)) {
+ ICS.Standard.Third = ICK_Qualification;
+ ICS.Standard.setToType(2, DestType);
+ }
+ Sequence.AddConversionSequenceStep(ICS, DestType);
+ if (ILE)
+ Sequence.RewrapReferenceInitList(DestType, ILE);
+ return;
+ }
+
const RecordType *DestRecordType = DestType->getAs<RecordType>();
assert(DestRecordType && "Constructor initialization requires record type");
CXXRecordDecl *DestRecordDecl
@@ -3588,20 +3623,16 @@ static void TryConstructorInitialization
// constructors of the class T and the argument list consists of the
// initializer list as a single argument.
if (IsListInit) {
- InitListExpr *ILE = cast<InitListExpr>(Args[0]);
AsInitializerList = true;
// If the initializer list has no elements and T has a default constructor,
// the first phase is omitted.
- if (ILE->getNumInits() != 0 || !DestRecordDecl->hasDefaultConstructor())
+ if (!(UnwrappedArgs.empty() && DestRecordDecl->hasDefaultConstructor()))
Result = ResolveConstructorOverload(S, Kind.getLocation(), Args,
CandidateSet, Ctors, Best,
CopyInitialization, AllowExplicit,
/*OnlyListConstructor=*/true,
IsListInit);
-
- // Time to unwrap the init list.
- Args = MultiExprArg(ILE->getInits(), ILE->getNumInits());
}
// C++11 [over.match.list]p1:
@@ -3611,7 +3642,7 @@ static void TryConstructorInitialization
// elements of the initializer list.
if (Result == OR_No_Viable_Function) {
AsInitializerList = false;
- Result = ResolveConstructorOverload(S, Kind.getLocation(), Args,
+ Result = ResolveConstructorOverload(S, Kind.getLocation(), UnwrappedArgs,
CandidateSet, Ctors, Best,
CopyInitialization, AllowExplicit,
/*OnlyListConstructors=*/false,
@@ -3821,8 +3852,8 @@ static void TryListInitialization(Sema &
QualType InitType = InitList->getInit(0)->getType();
if (S.Context.hasSameUnqualifiedType(InitType, DestType) ||
S.IsDerivedFrom(InitList->getLocStart(), InitType, DestType)) {
- Expr *InitAsExpr = InitList->getInit(0);
- TryConstructorInitialization(S, Entity, Kind, InitAsExpr, DestType,
+ Expr *InitListAsExpr = InitList;
+ TryConstructorInitialization(S, Entity, Kind, InitListAsExpr, DestType,
Sequence, /*InitListSyntax*/ false,
/*IsInitListCopy*/ true);
return;
@@ -4332,16 +4363,21 @@ static void TryReferenceInitializationCo
}
// - If the initializer expression
+ // C++14-and-before:
// - is an xvalue, class prvalue, array prvalue, or function lvalue and
// "cv1 T1" is reference-compatible with "cv2 T2"
+ // C++1z:
+ // - is an rvalue or function lvalue and "cv1 T1" is reference-compatible
+ // with "cv2 T2"
// Note: functions are handled below.
if (!T1Function &&
(RefRelationship == Sema::Ref_Compatible ||
(Kind.isCStyleOrFunctionalCast() &&
RefRelationship == Sema::Ref_Related)) &&
(InitCategory.isXValue() ||
- (InitCategory.isPRValue() && T2->isRecordType()) ||
- (InitCategory.isPRValue() && T2->isArrayType()))) {
+ (InitCategory.isPRValue() &&
+ (S.getLangOpts().CPlusPlus1z || T2->isRecordType() ||
+ T2->isArrayType())))) {
ExprValueKind ValueKind = InitCategory.isXValue()? VK_XValue : VK_RValue;
if (InitCategory.isPRValue() && T2->isRecordType()) {
// The corresponding bullet in C++03 [dcl.init.ref]p5 gives the
@@ -6604,7 +6640,26 @@ InitializationSequence::Perform(Sema &S,
CreatedObject = Conversion->getReturnType()->isRecordType();
}
+ // C++14 and before:
+ // - if the function is a constructor, the call initializes a temporary
+ // of the cv-unqualified version of the destination type [...]
+ // C++1z:
+ // - if the function is a constructor, the call is a prvalue of the
+ // cv-unqualified version of the destination type whose return object
+ // is initialized by the constructor [...]
+ // Both:
+ // The [..] call is used to direct-initialize, according to the rules
+ // above, the object that is the destination of the
+ // copy-initialization.
+ // In C++14 and before, that always means the "constructors are
+ // considered" bullet, because we have arrived at a reference-related
+ // type. In C++1z, it only means that if the types are different or we
+ // didn't produce a prvalue, so just check for that case here.
bool RequiresCopy = !IsCopy && !isReferenceBinding(Steps.back());
+ if (S.getLangOpts().CPlusPlus1z && CurInit.get()->isRValue() &&
+ S.Context.hasSameUnqualifiedType(
+ Entity.getType().getNonReferenceType(), CurInit.get()->getType()))
+ RequiresCopy = false;
bool MaybeBindToTemp = RequiresCopy || shouldBindAsTemporary(Entity);
if (!MaybeBindToTemp && CreatedObject && shouldDestroyTemporary(Entity)) {
Modified: cfe/trunk/lib/Sema/SemaOverload.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaOverload.cpp?rev=288866&r1=288865&r2=288866&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaOverload.cpp (original)
+++ cfe/trunk/lib/Sema/SemaOverload.cpp Tue Dec 6 17:52:28 2016
@@ -4979,7 +4979,7 @@ TryObjectArgumentInitialization(Sema &S,
// cv-qualification on the member function declaration.
//
// However, when finding an implicit conversion sequence for the argument, we
- // are not allowed to create temporaries or perform user-defined conversions
+ // are not allowed to perform user-defined conversions
// (C++ [over.match.funcs]p5). We perform a simplified version of
// reference binding here, that allows class rvalues to bind to
// non-constant references.
Modified: cfe/trunk/test/CXX/drs/dr0xx.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/drs/dr0xx.cpp?rev=288866&r1=288865&r2=288866&view=diff
==============================================================================
--- cfe/trunk/test/CXX/drs/dr0xx.cpp (original)
+++ cfe/trunk/test/CXX/drs/dr0xx.cpp Tue Dec 6 17:52:28 2016
@@ -248,7 +248,7 @@ namespace dr20 { // dr20: yes
private:
X(const X&); // expected-note {{here}}
};
- X f();
+ X &f();
X x = f(); // expected-error {{private}}
}
@@ -316,8 +316,15 @@ namespace dr25 { // dr25: yes
namespace dr26 { // dr26: yes
struct A { A(A, const A & = A()); }; // expected-error {{must pass its first argument by reference}}
struct B {
- B(); // expected-note {{candidate}}
- B(const B &, B = B()); // expected-error {{no matching constructor}} expected-note {{candidate}} expected-note {{here}}
+ B(); // expected-note 0-1{{candidate}}
+ B(const B &, B = B());
+#if __cplusplus <= 201402L
+ // expected-error at -2 {{no matching constructor}} expected-note at -2 {{candidate}} expected-note at -2 {{here}}
+#endif
+ };
+ struct C {
+ static C &f();
+ C(const C &, C = f()); // expected-error {{no matching constructor}} expected-note {{candidate}} expected-note {{here}}
};
}
@@ -662,25 +669,33 @@ namespace dr58 { // dr58: yes
namespace dr59 { // dr59: yes
template<typename T> struct convert_to { operator T() const; };
- struct A {}; // expected-note 2{{volatile qualifier}} expected-note 2{{requires 0 arguments}}
- struct B : A {}; // expected-note 2{{volatile qualifier}} expected-note 2{{requires 0 arguments}}
-#if __cplusplus >= 201103L // move constructors
- // expected-note at -3 2{{volatile qualifier}}
- // expected-note at -3 2{{volatile qualifier}}
-#endif
+ struct A {}; // expected-note 5+{{candidate}}
+ struct B : A {}; // expected-note 0+{{candidate}}
A a1 = convert_to<A>();
A a2 = convert_to<A&>();
A a3 = convert_to<const A>();
- A a4 = convert_to<const volatile A>(); // expected-error {{no viable}}
+ A a4 = convert_to<const volatile A>();
+#if __cplusplus <= 201402L
+ // expected-error at -2 {{no viable}}
+#endif
A a5 = convert_to<const volatile A&>(); // expected-error {{no viable}}
B b1 = convert_to<B>();
B b2 = convert_to<B&>();
B b3 = convert_to<const B>();
- B b4 = convert_to<const volatile B>(); // expected-error {{no viable}}
+ B b4 = convert_to<const volatile B>();
+#if __cplusplus <= 201402L
+ // expected-error at -2 {{no viable}}
+#endif
B b5 = convert_to<const volatile B&>(); // expected-error {{no viable}}
+ A c1 = convert_to<B>();
+ A c2 = convert_to<B&>();
+ A c3 = convert_to<const B>();
+ A c4 = convert_to<const volatile B>(); // expected-error {{no viable}}
+ A c5 = convert_to<const volatile B&>(); // expected-error {{no viable}}
+
int n1 = convert_to<int>();
int n2 = convert_to<int&>();
int n3 = convert_to<const int>();
@@ -920,14 +935,17 @@ namespace dr84 { // dr84: yes
struct A { operator B() const; };
struct C {};
struct B {
- B(B&); // expected-note {{candidate}}
- B(C); // expected-note {{no known conversion from 'dr84::B' to 'dr84::C'}}
+ B(B&); // expected-note 0-1{{candidate}}
+ B(C); // expected-note 0-1{{no known conversion from 'dr84::B' to 'dr84::C'}}
operator C() const;
};
A a;
// Cannot use B(C) / operator C() pair to construct the B from the B temporary
- // here.
- B b = a; // expected-error {{no viable}}
+ // here. In C++1z, we initialize the B object directly using 'A::operator B()'.
+ B b = a;
+#if __cplusplus <= 201402L
+ // expected-error at -2 {{no viable}}
+#endif
}
namespace dr85 { // dr85: yes
Modified: cfe/trunk/test/CXX/drs/dr10xx.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/drs/dr10xx.cpp?rev=288866&r1=288865&r2=288866&view=diff
==============================================================================
--- cfe/trunk/test/CXX/drs/dr10xx.cpp (original)
+++ cfe/trunk/test/CXX/drs/dr10xx.cpp Tue Dec 6 17:52:28 2016
@@ -3,8 +3,6 @@
// RUN: %clang_cc1 -std=c++14 %s -verify -fexceptions -fcxx-exceptions -pedantic-errors
// RUN: %clang_cc1 -std=c++1z %s -verify -fexceptions -fcxx-exceptions -pedantic-errors
-// expected-no-diagnostics
-
namespace std {
__extension__ typedef __SIZE_TYPE__ size_t;
@@ -32,6 +30,18 @@ namespace dr1048 { // dr1048: 3.6
#endif
}
+namespace dr1054 { // dr1054: no
+ // FIXME: Test is incomplete.
+ struct A {} volatile a;
+ void f() {
+ // FIXME: This is wrong: an lvalue-to-rvalue conversion is applied here,
+ // which copy-initializes a temporary from 'a'. Therefore this is
+ // ill-formed because A does not have a volatile copy constructor.
+ // (We might want to track this aspect under dr1383 instead?)
+ a; // expected-warning {{assign into a variable to force a volatile load}}
+ }
+}
+
namespace dr1070 { // dr1070: 3.5
#if __cplusplus >= 201103L
struct A {
Modified: cfe/trunk/test/CXX/drs/dr1xx.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/drs/dr1xx.cpp?rev=288866&r1=288865&r2=288866&view=diff
==============================================================================
--- cfe/trunk/test/CXX/drs/dr1xx.cpp (original)
+++ cfe/trunk/test/CXX/drs/dr1xx.cpp Tue Dec 6 17:52:28 2016
@@ -576,11 +576,18 @@ namespace dr151 { // dr151: yes
namespace dr152 { // dr152: yes
struct A {
- A(); // expected-note {{not viable}}
+ A(); // expected-note 0-2{{not viable}}
explicit A(const A&);
};
- A a1 = A(); // expected-error {{no matching constructor}}
+ A a1 = A();
+#if __cplusplus <= 201402L
+ // expected-error at -2 {{no matching constructor}}
+#endif
A a2((A()));
+
+ A &f();
+ A a3 = f(); // expected-error {{no matching constructor}}
+ A a4(f());
}
// dr153: na
@@ -823,11 +830,20 @@ namespace dr176 { // dr176: yes
namespace dr177 { // dr177: yes
struct B {};
struct A {
- A(A &); // expected-note {{not viable: expects an l-value}}
- A(const B &); // expected-note {{not viable: no known conversion from 'dr177::A' to}}
+ A(A &); // expected-note 0-1{{not viable: expects an l-value}}
+ A(const B &); // expected-note 0-1{{not viable: no known conversion from 'dr177::A' to}}
};
B b;
- A a = b; // expected-error {{no viable constructor copying variable}}
+ A a = b;
+#if __cplusplus <= 201402L
+ // expected-error at -2 {{no viable constructor copying variable}}
+#endif
+
+ struct C { C(C&); }; // expected-note {{not viable: no known conversion from 'dr177::D' to 'dr177::C &'}}
+ struct D : C {};
+ struct E { operator D(); };
+ E e;
+ C c = e; // expected-error {{no viable constructor copying variable of type 'dr177::D'}}
}
namespace dr178 { // dr178: yes
Modified: cfe/trunk/test/CXX/drs/dr4xx.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/drs/dr4xx.cpp?rev=288866&r1=288865&r2=288866&view=diff
==============================================================================
--- cfe/trunk/test/CXX/drs/dr4xx.cpp (original)
+++ cfe/trunk/test/CXX/drs/dr4xx.cpp Tue Dec 6 17:52:28 2016
@@ -553,12 +553,21 @@ namespace dr446 { // dr446: yes
void(b ? a : a);
b ? A() : a; // expected-error {{deleted}}
b ? a : A(); // expected-error {{deleted}}
- b ? A() : A(); // expected-error {{deleted}}
+ b ? A() : A();
+#if __cplusplus <= 201402L
+ // expected-error at -2 {{deleted}}
+#endif
void(b ? a : c);
b ? a : C(); // expected-error {{deleted}}
- b ? c : A(); // expected-error {{deleted}}
- b ? A() : C(); // expected-error {{deleted}}
+ b ? c : A();
+#if __cplusplus <= 201402L
+ // expected-error at -2 {{deleted}}
+#endif
+ b ? A() : C();
+#if __cplusplus <= 201402L
+ // expected-error at -2 {{deleted}}
+#endif
}
}
@@ -874,10 +883,12 @@ namespace dr479 { // dr479: yes
void f() {
throw S();
// expected-error at -1 {{temporary of type 'dr479::S' has private destructor}}
- // expected-error at -2 {{calling a private constructor}}
- // expected-error at -3 {{exception object of type 'dr479::S' has private destructor}}
+ // expected-error at -2 {{exception object of type 'dr479::S' has private destructor}}
#if __cplusplus < 201103L
- // expected-error at -5 {{C++98 requires an accessible copy constructor}}
+ // expected-error at -4 {{C++98 requires an accessible copy constructor}}
+#endif
+#if __cplusplus <= 201402L
+ // expected-error at -7 {{calling a private constructor}} (copy ctor)
#endif
}
void g() {
Added: cfe/trunk/test/CodeGenCXX/cxx1z-copy-omission.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/cxx1z-copy-omission.cpp?rev=288866&view=auto
==============================================================================
--- cfe/trunk/test/CodeGenCXX/cxx1z-copy-omission.cpp (added)
+++ cfe/trunk/test/CodeGenCXX/cxx1z-copy-omission.cpp Tue Dec 6 17:52:28 2016
@@ -0,0 +1,81 @@
+// RUN: %clang_cc1 -std=c++1z -emit-llvm -triple x86_64-linux-gnu -o - %s | FileCheck %s
+
+struct A {
+ A(int);
+ A(A&&);
+ A(const A&);
+ ~A();
+
+ int arr[10];
+};
+
+A f();
+void h();
+
+// CHECK-LABEL: define {{.*}} @_Z1gv(
+void g() {
+ // CHECK: %[[A:.*]] = alloca
+ // CHECK-NOT: alloca
+ // CHECK-NOT: call
+ // CHECK: call {{.*}} @_Z1fv({{.*}}* sret %[[A]])
+ A a = A( A{ f() } );
+ // CHECK-NOT: call
+
+ // CHECK: call void @_Z1hv(
+ h();
+ // CHECK-NOT: call
+
+ // CHECK: call void @_ZN1AD1Ev({{.*}}* %[[A]])
+ // CHECK-NOT: call
+ // CHECK-LABEL: }
+}
+
+void f(A);
+
+// CHECK-LABEL: define {{.*}} @_Z1hv(
+void h() {
+ // CHECK: %[[A:.*]] = alloca
+ // CHECK-NOT: alloca
+ // CHECK-NOT: call
+
+ // CHECK: call {{.*}} @_Z1fv({{.*}}* sret %[[A]])
+ // CHECK-NOT: call
+ // CHECK: call {{.*}} @_Z1f1A({{.*}}* %[[A]])
+ f(f());
+ // CHECK-NOT: call
+ // CHECK: call void @_ZN1AD1Ev({{.*}}* %[[A]])
+
+ // CHECK: call void @_Z1hv(
+ h();
+
+ // CHECK-NOT: call
+ // CHECK-LABEL: }
+}
+
+// We still pass classes with trivial copy/move constructors and destructors in
+// registers, even if the copy is formally omitted.
+struct B {
+ B(int);
+ int n;
+};
+
+B fB();
+void fB(B);
+
+// CHECK-LABEL: define {{.*}} @_Z1iv(
+void i() {
+ // CHECK: %[[B:.*]] = alloca
+ // CHECK-NOT: alloca
+ // CHECK-NOT: call
+
+ // CHECK: %[[B_N:.*]] = call i32 @_Z2fBv()
+ // CHECK-NOT: call
+ // CHECK: store i32 %[[B_N]],
+ // CHECK-NOT: call
+ // CHECK: %[[B_N:.*]] = load i32
+ // CHECK-NOT: call
+ // CHECK: call void @_Z2fB1B(i32 %[[B_N]])
+ fB(fB());
+
+ // CHECK-LABEL: }
+}
Modified: cfe/trunk/test/SemaCXX/aggregate-initialization.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/aggregate-initialization.cpp?rev=288866&r1=288865&r2=288866&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/aggregate-initialization.cpp (original)
+++ cfe/trunk/test/SemaCXX/aggregate-initialization.cpp Tue Dec 6 17:52:28 2016
@@ -57,7 +57,7 @@ struct A {
A(int);
~A();
- A(const A&) = delete; // expected-note 2 {{'A' has been explicitly marked deleted here}}
+ A(const A&) = delete; // expected-note 0-2{{'A' has been explicitly marked deleted here}}
};
struct B {
@@ -70,10 +70,16 @@ struct C {
void f() {
A as1[1] = { };
- A as2[1] = { 1 }; // expected-error {{copying array element of type 'A' invokes deleted constructor}}
+ A as2[1] = { 1 };
+#if __cplusplus <= 201402L
+ // expected-error at -2 {{copying array element of type 'A' invokes deleted constructor}}
+#endif
B b1 = { };
- B b2 = { 1 }; // expected-error {{copying member subobject of type 'A' invokes deleted constructor}}
+ B b2 = { 1 };
+#if __cplusplus <= 201402L
+ // expected-error at -2 {{copying member subobject of type 'A' invokes deleted constructor}}
+#endif
C c1 = { 1 };
}
Added: cfe/trunk/test/SemaCXX/cxx1z-copy-omission.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/cxx1z-copy-omission.cpp?rev=288866&view=auto
==============================================================================
--- cfe/trunk/test/SemaCXX/cxx1z-copy-omission.cpp (added)
+++ cfe/trunk/test/SemaCXX/cxx1z-copy-omission.cpp Tue Dec 6 17:52:28 2016
@@ -0,0 +1,134 @@
+// RUN: %clang_cc1 -std=c++1z -verify %s
+
+struct Noncopyable {
+ Noncopyable();
+ Noncopyable(const Noncopyable &) = delete; // expected-note 1+{{deleted}}
+ virtual ~Noncopyable();
+};
+struct Derived : Noncopyable {};
+struct NoncopyableAggr {
+ Noncopyable nc;
+};
+struct Indestructible {
+ Indestructible();
+ ~Indestructible() = delete; // expected-note 1+{{deleted}}
+};
+struct Incomplete; // expected-note 1+{{declar}}
+
+Noncopyable make(int kind = 0) {
+ switch (kind) {
+ case 0: return {};
+ case 1: return Noncopyable();
+ case 2: return Noncopyable{};
+ case 3: return make();
+ }
+ __builtin_unreachable();
+}
+
+Indestructible make_indestructible();
+Incomplete make_incomplete(); // expected-note 1+{{here}}
+
+void take(Noncopyable nc) {}
+
+Noncopyable nrvo() {
+ Noncopyable nrvo;
+ return nrvo; // expected-error {{deleted constructor}}
+}
+
+Noncopyable nc1 = make();
+Noncopyable nc2 = Noncopyable();
+Noncopyable nc3 = Derived(); // expected-error {{deleted constructor}}
+
+NoncopyableAggr nca1 = NoncopyableAggr{};
+NoncopyableAggr nca2 = NoncopyableAggr{{}};
+NoncopyableAggr nca3 = NoncopyableAggr{NoncopyableAggr{Noncopyable()}};
+
+void test_expressions(bool b) {
+ auto lambda = [a = make()] {};
+
+ take({});
+ take(Noncopyable());
+ take(Noncopyable{});
+ take(make());
+
+ Noncopyable &&dc1 = dynamic_cast<Noncopyable&&>(Noncopyable());
+ Noncopyable &&dc2 = dynamic_cast<Noncopyable&&>(nc1);
+ Noncopyable &&dc3 = dynamic_cast<Noncopyable&&>(Derived());
+
+ Noncopyable sc1 = static_cast<Noncopyable>(Noncopyable());
+ Noncopyable sc2 = static_cast<Noncopyable>(nc1); // expected-error {{deleted}}
+ Noncopyable sc3 = static_cast<Noncopyable&&>(Noncopyable()); // expected-error {{deleted}}
+ Noncopyable sc4 = static_cast<Noncopyable>(static_cast<Noncopyable&&>(Noncopyable())); // expected-error {{deleted}}
+
+ Noncopyable cc1 = (Noncopyable)Noncopyable();
+ Noncopyable cc2 = (Noncopyable)Derived(); // expected-error {{deleted}}
+
+ Noncopyable fc1 = Noncopyable(Noncopyable());
+ Noncopyable fc2 = Noncopyable(Derived()); // expected-error {{deleted}}
+
+ // We must check for a complete type for every materialized temporary. (Note
+ // that in the special case of the top level of a decltype, no temporary is
+ // materialized.)
+ make_incomplete(); // expected-error {{incomplete}}
+ make_incomplete().a; // expected-error {{incomplete}}
+ make_incomplete().*(int Incomplete::*)nullptr; // expected-error {{incomplete}}
+ dynamic_cast<Incomplete&&>(make_incomplete()); // expected-error {{incomplete}}
+ const_cast<Incomplete&&>(make_incomplete()); // expected-error {{incomplete}}
+
+ sizeof(Indestructible{}); // expected-error {{deleted}}
+ sizeof(make_indestructible()); // expected-error {{deleted}}
+ sizeof(make_incomplete()); // expected-error {{incomplete}}
+ typeid(Indestructible{}); // expected-error {{deleted}}
+ typeid(make_indestructible()); // expected-error {{deleted}}
+ typeid(make_incomplete()); // expected-error {{incomplete}}
+
+ // FIXME: The first two cases here are now also valid in C++17 onwards.
+ using I = decltype(Indestructible()); // expected-error {{deleted}}
+ using I = decltype(Indestructible{}); // expected-error {{deleted}}
+ using I = decltype(make_indestructible());
+ using J = decltype(make_incomplete());
+
+ Noncopyable cond1 = b ? Noncopyable() : make();
+ Noncopyable cond2 = b ? Noncopyable() : Derived(); // expected-error {{incompatible}}
+ Noncopyable cond3 = b ? Derived() : Noncopyable(); // expected-error {{incompatible}}
+ Noncopyable cond4 = b ? Noncopyable() : nc1; // expected-error {{deleted}}
+ Noncopyable cond5 = b ? nc1 : Noncopyable(); // expected-error {{deleted}}
+ // Could convert both to an xvalue of type Noncopyable here, but we're not
+ // permitted to consider that.
+ Noncopyable &&cond6 = b ? Noncopyable() : Derived(); // expected-error {{incompatible}}
+ Noncopyable &&cond7 = b ? Derived() : Noncopyable(); // expected-error {{incompatible}}
+ // Could convert both to a const lvalue of type Noncopyable here, but we're
+ // not permitted to consider that, either.
+ const Noncopyable cnc;
+ const Noncopyable &cond8 = b ? cnc : Derived(); // expected-error {{incompatible}}
+ const Noncopyable &cond9 = b ? Derived() : cnc; // expected-error {{incompatible}}
+
+ extern const volatile Noncopyable make_cv();
+ Noncopyable cv_difference1 = make_cv();
+ const volatile Noncopyable cv_difference2 = make();
+}
+
+template<typename T> struct ConversionFunction { operator T(); };
+Noncopyable cf1 = ConversionFunction<Noncopyable>();
+Noncopyable cf2 = ConversionFunction<Noncopyable&&>(); // expected-error {{deleted}}
+Noncopyable cf3 = ConversionFunction<const volatile Noncopyable>();
+const volatile Noncopyable cf4 = ConversionFunction<Noncopyable>();
+Noncopyable cf5 = ConversionFunction<Derived>(); // expected-error {{deleted}}
+
+struct AsMember {
+ Noncopyable member;
+ AsMember() : member(make()) {}
+};
+// FIXME: DR (no number yet): we still get a copy for base or delegating construction.
+struct AsBase : Noncopyable {
+ AsBase() : Noncopyable(make()) {} // expected-error {{deleted}}
+};
+struct AsDelegating final {
+ AsDelegating(const AsDelegating &) = delete;
+ static AsDelegating make(int);
+
+ // The base constructor version of this is problematic; the complete object
+ // version would be OK. Perhaps we could allow copy omission here for final
+ // classes?
+ AsDelegating(int n) : AsDelegating(make(n)) {} // expected-error {{deleted}}
+};
Modified: cfe/trunk/www/cxx_dr_status.html
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/www/cxx_dr_status.html?rev=288866&r1=288865&r2=288866&view=diff
==============================================================================
--- cfe/trunk/www/cxx_dr_status.html (original)
+++ cfe/trunk/www/cxx_dr_status.html Tue Dec 6 17:52:28 2016
@@ -6139,7 +6139,7 @@ and <I>POD class</I></td>
<td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#1054">1054</a></td>
<td>C++11</td>
<td>Lvalue-to-rvalue conversions in expression statements</td>
- <td class="none" align="center">Unknown</td>
+ <td class="none" align="center">No</td>
</tr>
<tr id="1055">
<td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#1055">1055</a></td>
Modified: cfe/trunk/www/cxx_status.html
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/www/cxx_status.html?rev=288866&r1=288865&r2=288866&view=diff
==============================================================================
--- cfe/trunk/www/cxx_status.html (original)
+++ cfe/trunk/www/cxx_status.html Tue Dec 6 17:52:28 2016
@@ -694,7 +694,7 @@ as the draft C++1z standard evolves.
<tr>
<td>Guaranteed copy elision</td>
<td><a href="http://wg21.link/p0135r1">P0135R1</a></td>
- <td class="none" align="center">No</td>
+ <td class="svn" align="center">SVN</td>
</tr>
<tr>
<td rowspan=2>Stricter expression evaluation order</td>
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