r288866 - [c++17] P0135R1: Guaranteed copy elision.

Adrian Prantl via cfe-commits cfe-commits at lists.llvm.org
Fri Dec 9 08:20:29 PST 2016


> On Dec 8, 2016, at 7:31 PM, Duncan P. N. Exon Smith <dexonsmith at apple.com> wrote:
> 
> 
>> On 2016-Dec-08, at 19:29, Richard Smith <richard at metafoo.co.uk> wrote:
>> 
>> On 8 Dec 2016 7:17 pm, "Duncan P. N. Exon Smith via cfe-commits" <cfe-commits at lists.llvm.org> wrote:
>> +Eric, Marshall
>> 
>> I haven't looked, but: from the test name, "copy.fail.cpp", I suspect there is a bug/incompatibility in the test.  It likely relies on the compiler trying (and failing) to copy something in a context where r288866 guarantees that there is no copy.
>> 
>> Was this not fixed by "[libcxx] r289033 - Avoid C++17 guaranteed copy elision when testing for non-copyability"?
> 
> Yes, the bot is green now:
> http://lab.llvm.org:8080/green/job/clang-stage2-cmake-RgSan_check/2728/

That's great! Unfortunately this bot has a latency of more than 6 hours...

thanks,
adrian
> 
>> 
>>> On 2016-Dec-08, at 18:00, Adrian Prantl <aprantl at apple.com> wrote:
>>> 
>>> Hi Richard,
>>> 
>>> at this point this is more a heads-up than anything actionable, but I wanted to let you know that I bisected this bot failure (http://lab.llvm.org:8080/green/job/clang-stage2-cmake-RgSan_check/2721/consoleFull#10584592348254eaf0-7326-4999-85b0-388101f2d404) of std/input.output/stream.buffers/streambuf/streambuf.cons/copy.fail.cpp down to this commit.
>>> 
>>> I will follow up once I have a better understanding what is going on there.
>>> 
>>> -- adrian
>>> 
>>>> On Dec 6, 2016, at 3:52 PM, Richard Smith via cfe-commits <cfe-commits at lists.llvm.org> wrote:
>>>> 
>>>> 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>
>>>> 
>>>> 
>>>> _______________________________________________
>>>> cfe-commits mailing list
>>>> cfe-commits at lists.llvm.org
>>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
>>> 
>> 
>> _______________________________________________
>> cfe-commits mailing list
>> cfe-commits at lists.llvm.org
>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
>> 
> 



More information about the cfe-commits mailing list