1 //===--- SemaOverload.cpp - C++ Overloading -------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file provides Sema routines for C++ overloading.
12 //===----------------------------------------------------------------------===//
14 #include "clang/Sema/Overload.h"
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/CXXInheritance.h"
17 #include "clang/AST/DeclObjC.h"
18 #include "clang/AST/Expr.h"
19 #include "clang/AST/ExprCXX.h"
20 #include "clang/AST/ExprObjC.h"
21 #include "clang/AST/TypeOrdering.h"
22 #include "clang/Basic/Diagnostic.h"
23 #include "clang/Basic/DiagnosticOptions.h"
24 #include "clang/Basic/PartialDiagnostic.h"
25 #include "clang/Basic/TargetInfo.h"
26 #include "clang/Sema/Initialization.h"
27 #include "clang/Sema/Lookup.h"
28 #include "clang/Sema/SemaInternal.h"
29 #include "clang/Sema/Template.h"
30 #include "clang/Sema/TemplateDeduction.h"
31 #include "llvm/ADT/DenseSet.h"
32 #include "llvm/ADT/Optional.h"
33 #include "llvm/ADT/STLExtras.h"
34 #include "llvm/ADT/SmallPtrSet.h"
35 #include "llvm/ADT/SmallString.h"
39 using namespace clang;
42 static bool functionHasPassObjectSizeParams(const FunctionDecl *FD) {
43 return llvm::any_of(FD->parameters(), [](const ParmVarDecl *P) {
44 return P->hasAttr<PassObjectSizeAttr>();
48 /// A convenience routine for creating a decayed reference to a function.
50 CreateFunctionRefExpr(Sema &S, FunctionDecl *Fn, NamedDecl *FoundDecl,
51 const Expr *Base, bool HadMultipleCandidates,
52 SourceLocation Loc = SourceLocation(),
53 const DeclarationNameLoc &LocInfo = DeclarationNameLoc()){
54 if (S.DiagnoseUseOfDecl(FoundDecl, Loc))
56 // If FoundDecl is different from Fn (such as if one is a template
57 // and the other a specialization), make sure DiagnoseUseOfDecl is
59 // FIXME: This would be more comprehensively addressed by modifying
60 // DiagnoseUseOfDecl to accept both the FoundDecl and the decl
62 if (FoundDecl != Fn && S.DiagnoseUseOfDecl(Fn, Loc))
64 if (auto *FPT = Fn->getType()->getAs<FunctionProtoType>())
65 S.ResolveExceptionSpec(Loc, FPT);
66 DeclRefExpr *DRE = new (S.Context) DeclRefExpr(Fn, false, Fn->getType(),
67 VK_LValue, Loc, LocInfo);
68 if (HadMultipleCandidates)
69 DRE->setHadMultipleCandidates(true);
71 S.MarkDeclRefReferenced(DRE, Base);
72 return S.ImpCastExprToType(DRE, S.Context.getPointerType(DRE->getType()),
73 CK_FunctionToPointerDecay);
76 static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
77 bool InOverloadResolution,
78 StandardConversionSequence &SCS,
80 bool AllowObjCWritebackConversion);
82 static bool IsTransparentUnionStandardConversion(Sema &S, Expr* From,
84 bool InOverloadResolution,
85 StandardConversionSequence &SCS,
87 static OverloadingResult
88 IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
89 UserDefinedConversionSequence& User,
90 OverloadCandidateSet& Conversions,
92 bool AllowObjCConversionOnExplicit);
95 static ImplicitConversionSequence::CompareKind
96 CompareStandardConversionSequences(Sema &S, SourceLocation Loc,
97 const StandardConversionSequence& SCS1,
98 const StandardConversionSequence& SCS2);
100 static ImplicitConversionSequence::CompareKind
101 CompareQualificationConversions(Sema &S,
102 const StandardConversionSequence& SCS1,
103 const StandardConversionSequence& SCS2);
105 static ImplicitConversionSequence::CompareKind
106 CompareDerivedToBaseConversions(Sema &S, SourceLocation Loc,
107 const StandardConversionSequence& SCS1,
108 const StandardConversionSequence& SCS2);
110 /// GetConversionRank - Retrieve the implicit conversion rank
111 /// corresponding to the given implicit conversion kind.
112 ImplicitConversionRank clang::GetConversionRank(ImplicitConversionKind Kind) {
113 static const ImplicitConversionRank
114 Rank[(int)ICK_Num_Conversion_Kinds] = {
134 ICR_OCL_Scalar_Widening,
135 ICR_Complex_Real_Conversion,
138 ICR_Writeback_Conversion,
139 ICR_Exact_Match, // NOTE(gbiv): This may not be completely right --
140 // it was omitted by the patch that added
141 // ICK_Zero_Event_Conversion
143 ICR_C_Conversion_Extension
145 return Rank[(int)Kind];
148 /// GetImplicitConversionName - Return the name of this kind of
149 /// implicit conversion.
150 static const char* GetImplicitConversionName(ImplicitConversionKind Kind) {
151 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = {
155 "Function-to-pointer",
156 "Function pointer conversion",
158 "Integral promotion",
159 "Floating point promotion",
161 "Integral conversion",
162 "Floating conversion",
163 "Complex conversion",
164 "Floating-integral conversion",
165 "Pointer conversion",
166 "Pointer-to-member conversion",
167 "Boolean conversion",
168 "Compatible-types conversion",
169 "Derived-to-base conversion",
172 "Complex-real conversion",
173 "Block Pointer conversion",
174 "Transparent Union Conversion",
175 "Writeback conversion",
176 "OpenCL Zero Event Conversion",
177 "C specific type conversion",
178 "Incompatible pointer conversion"
183 /// StandardConversionSequence - Set the standard conversion
184 /// sequence to the identity conversion.
185 void StandardConversionSequence::setAsIdentityConversion() {
186 First = ICK_Identity;
187 Second = ICK_Identity;
188 Third = ICK_Identity;
189 DeprecatedStringLiteralToCharPtr = false;
190 QualificationIncludesObjCLifetime = false;
191 ReferenceBinding = false;
192 DirectBinding = false;
193 IsLvalueReference = true;
194 BindsToFunctionLvalue = false;
195 BindsToRvalue = false;
196 BindsImplicitObjectArgumentWithoutRefQualifier = false;
197 ObjCLifetimeConversionBinding = false;
198 CopyConstructor = nullptr;
201 /// getRank - Retrieve the rank of this standard conversion sequence
202 /// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the
203 /// implicit conversions.
204 ImplicitConversionRank StandardConversionSequence::getRank() const {
205 ImplicitConversionRank Rank = ICR_Exact_Match;
206 if (GetConversionRank(First) > Rank)
207 Rank = GetConversionRank(First);
208 if (GetConversionRank(Second) > Rank)
209 Rank = GetConversionRank(Second);
210 if (GetConversionRank(Third) > Rank)
211 Rank = GetConversionRank(Third);
215 /// isPointerConversionToBool - Determines whether this conversion is
216 /// a conversion of a pointer or pointer-to-member to bool. This is
217 /// used as part of the ranking of standard conversion sequences
218 /// (C++ 13.3.3.2p4).
219 bool StandardConversionSequence::isPointerConversionToBool() const {
220 // Note that FromType has not necessarily been transformed by the
221 // array-to-pointer or function-to-pointer implicit conversions, so
222 // check for their presence as well as checking whether FromType is
224 if (getToType(1)->isBooleanType() &&
225 (getFromType()->isPointerType() ||
226 getFromType()->isMemberPointerType() ||
227 getFromType()->isObjCObjectPointerType() ||
228 getFromType()->isBlockPointerType() ||
229 getFromType()->isNullPtrType() ||
230 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer))
236 /// isPointerConversionToVoidPointer - Determines whether this
237 /// conversion is a conversion of a pointer to a void pointer. This is
238 /// used as part of the ranking of standard conversion sequences (C++
241 StandardConversionSequence::
242 isPointerConversionToVoidPointer(ASTContext& Context) const {
243 QualType FromType = getFromType();
244 QualType ToType = getToType(1);
246 // Note that FromType has not necessarily been transformed by the
247 // array-to-pointer implicit conversion, so check for its presence
248 // and redo the conversion to get a pointer.
249 if (First == ICK_Array_To_Pointer)
250 FromType = Context.getArrayDecayedType(FromType);
252 if (Second == ICK_Pointer_Conversion && FromType->isAnyPointerType())
253 if (const PointerType* ToPtrType = ToType->getAs<PointerType>())
254 return ToPtrType->getPointeeType()->isVoidType();
259 /// Skip any implicit casts which could be either part of a narrowing conversion
260 /// or after one in an implicit conversion.
261 static const Expr *IgnoreNarrowingConversion(const Expr *Converted) {
262 while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Converted)) {
263 switch (ICE->getCastKind()) {
265 case CK_IntegralCast:
266 case CK_IntegralToBoolean:
267 case CK_IntegralToFloating:
268 case CK_BooleanToSignedIntegral:
269 case CK_FloatingToIntegral:
270 case CK_FloatingToBoolean:
271 case CK_FloatingCast:
272 Converted = ICE->getSubExpr();
283 /// Check if this standard conversion sequence represents a narrowing
284 /// conversion, according to C++11 [dcl.init.list]p7.
286 /// \param Ctx The AST context.
287 /// \param Converted The result of applying this standard conversion sequence.
288 /// \param ConstantValue If this is an NK_Constant_Narrowing conversion, the
289 /// value of the expression prior to the narrowing conversion.
290 /// \param ConstantType If this is an NK_Constant_Narrowing conversion, the
291 /// type of the expression prior to the narrowing conversion.
292 /// \param IgnoreFloatToIntegralConversion If true type-narrowing conversions
293 /// from floating point types to integral types should be ignored.
294 NarrowingKind StandardConversionSequence::getNarrowingKind(
295 ASTContext &Ctx, const Expr *Converted, APValue &ConstantValue,
296 QualType &ConstantType, bool IgnoreFloatToIntegralConversion) const {
297 assert(Ctx.getLangOpts().CPlusPlus && "narrowing check outside C++");
299 // C++11 [dcl.init.list]p7:
300 // A narrowing conversion is an implicit conversion ...
301 QualType FromType = getToType(0);
302 QualType ToType = getToType(1);
304 // A conversion to an enumeration type is narrowing if the conversion to
305 // the underlying type is narrowing. This only arises for expressions of
306 // the form 'Enum{init}'.
307 if (auto *ET = ToType->getAs<EnumType>())
308 ToType = ET->getDecl()->getIntegerType();
311 // 'bool' is an integral type; dispatch to the right place to handle it.
312 case ICK_Boolean_Conversion:
313 if (FromType->isRealFloatingType())
314 goto FloatingIntegralConversion;
315 if (FromType->isIntegralOrUnscopedEnumerationType())
316 goto IntegralConversion;
317 // Boolean conversions can be from pointers and pointers to members
318 // [conv.bool], and those aren't considered narrowing conversions.
319 return NK_Not_Narrowing;
321 // -- from a floating-point type to an integer type, or
323 // -- from an integer type or unscoped enumeration type to a floating-point
324 // type, except where the source is a constant expression and the actual
325 // value after conversion will fit into the target type and will produce
326 // the original value when converted back to the original type, or
327 case ICK_Floating_Integral:
328 FloatingIntegralConversion:
329 if (FromType->isRealFloatingType() && ToType->isIntegralType(Ctx)) {
330 return NK_Type_Narrowing;
331 } else if (FromType->isIntegralOrUnscopedEnumerationType() &&
332 ToType->isRealFloatingType()) {
333 if (IgnoreFloatToIntegralConversion)
334 return NK_Not_Narrowing;
335 llvm::APSInt IntConstantValue;
336 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
337 assert(Initializer && "Unknown conversion expression");
339 // If it's value-dependent, we can't tell whether it's narrowing.
340 if (Initializer->isValueDependent())
341 return NK_Dependent_Narrowing;
343 if (Initializer->isIntegerConstantExpr(IntConstantValue, Ctx)) {
344 // Convert the integer to the floating type.
345 llvm::APFloat Result(Ctx.getFloatTypeSemantics(ToType));
346 Result.convertFromAPInt(IntConstantValue, IntConstantValue.isSigned(),
347 llvm::APFloat::rmNearestTiesToEven);
349 llvm::APSInt ConvertedValue = IntConstantValue;
351 Result.convertToInteger(ConvertedValue,
352 llvm::APFloat::rmTowardZero, &ignored);
353 // If the resulting value is different, this was a narrowing conversion.
354 if (IntConstantValue != ConvertedValue) {
355 ConstantValue = APValue(IntConstantValue);
356 ConstantType = Initializer->getType();
357 return NK_Constant_Narrowing;
360 // Variables are always narrowings.
361 return NK_Variable_Narrowing;
364 return NK_Not_Narrowing;
366 // -- from long double to double or float, or from double to float, except
367 // where the source is a constant expression and the actual value after
368 // conversion is within the range of values that can be represented (even
369 // if it cannot be represented exactly), or
370 case ICK_Floating_Conversion:
371 if (FromType->isRealFloatingType() && ToType->isRealFloatingType() &&
372 Ctx.getFloatingTypeOrder(FromType, ToType) == 1) {
373 // FromType is larger than ToType.
374 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
376 // If it's value-dependent, we can't tell whether it's narrowing.
377 if (Initializer->isValueDependent())
378 return NK_Dependent_Narrowing;
380 if (Initializer->isCXX11ConstantExpr(Ctx, &ConstantValue)) {
382 assert(ConstantValue.isFloat());
383 llvm::APFloat FloatVal = ConstantValue.getFloat();
384 // Convert the source value into the target type.
386 llvm::APFloat::opStatus ConvertStatus = FloatVal.convert(
387 Ctx.getFloatTypeSemantics(ToType),
388 llvm::APFloat::rmNearestTiesToEven, &ignored);
389 // If there was no overflow, the source value is within the range of
390 // values that can be represented.
391 if (ConvertStatus & llvm::APFloat::opOverflow) {
392 ConstantType = Initializer->getType();
393 return NK_Constant_Narrowing;
396 return NK_Variable_Narrowing;
399 return NK_Not_Narrowing;
401 // -- from an integer type or unscoped enumeration type to an integer type
402 // that cannot represent all the values of the original type, except where
403 // the source is a constant expression and the actual value after
404 // conversion will fit into the target type and will produce the original
405 // value when converted back to the original type.
406 case ICK_Integral_Conversion:
407 IntegralConversion: {
408 assert(FromType->isIntegralOrUnscopedEnumerationType());
409 assert(ToType->isIntegralOrUnscopedEnumerationType());
410 const bool FromSigned = FromType->isSignedIntegerOrEnumerationType();
411 const unsigned FromWidth = Ctx.getIntWidth(FromType);
412 const bool ToSigned = ToType->isSignedIntegerOrEnumerationType();
413 const unsigned ToWidth = Ctx.getIntWidth(ToType);
415 if (FromWidth > ToWidth ||
416 (FromWidth == ToWidth && FromSigned != ToSigned) ||
417 (FromSigned && !ToSigned)) {
418 // Not all values of FromType can be represented in ToType.
419 llvm::APSInt InitializerValue;
420 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
422 // If it's value-dependent, we can't tell whether it's narrowing.
423 if (Initializer->isValueDependent())
424 return NK_Dependent_Narrowing;
426 if (!Initializer->isIntegerConstantExpr(InitializerValue, Ctx)) {
427 // Such conversions on variables are always narrowing.
428 return NK_Variable_Narrowing;
430 bool Narrowing = false;
431 if (FromWidth < ToWidth) {
432 // Negative -> unsigned is narrowing. Otherwise, more bits is never
434 if (InitializerValue.isSigned() && InitializerValue.isNegative())
437 // Add a bit to the InitializerValue so we don't have to worry about
438 // signed vs. unsigned comparisons.
439 InitializerValue = InitializerValue.extend(
440 InitializerValue.getBitWidth() + 1);
441 // Convert the initializer to and from the target width and signed-ness.
442 llvm::APSInt ConvertedValue = InitializerValue;
443 ConvertedValue = ConvertedValue.trunc(ToWidth);
444 ConvertedValue.setIsSigned(ToSigned);
445 ConvertedValue = ConvertedValue.extend(InitializerValue.getBitWidth());
446 ConvertedValue.setIsSigned(InitializerValue.isSigned());
447 // If the result is different, this was a narrowing conversion.
448 if (ConvertedValue != InitializerValue)
452 ConstantType = Initializer->getType();
453 ConstantValue = APValue(InitializerValue);
454 return NK_Constant_Narrowing;
457 return NK_Not_Narrowing;
461 // Other kinds of conversions are not narrowings.
462 return NK_Not_Narrowing;
466 /// dump - Print this standard conversion sequence to standard
467 /// error. Useful for debugging overloading issues.
468 LLVM_DUMP_METHOD void StandardConversionSequence::dump() const {
469 raw_ostream &OS = llvm::errs();
470 bool PrintedSomething = false;
471 if (First != ICK_Identity) {
472 OS << GetImplicitConversionName(First);
473 PrintedSomething = true;
476 if (Second != ICK_Identity) {
477 if (PrintedSomething) {
480 OS << GetImplicitConversionName(Second);
482 if (CopyConstructor) {
483 OS << " (by copy constructor)";
484 } else if (DirectBinding) {
485 OS << " (direct reference binding)";
486 } else if (ReferenceBinding) {
487 OS << " (reference binding)";
489 PrintedSomething = true;
492 if (Third != ICK_Identity) {
493 if (PrintedSomething) {
496 OS << GetImplicitConversionName(Third);
497 PrintedSomething = true;
500 if (!PrintedSomething) {
501 OS << "No conversions required";
505 /// dump - Print this user-defined conversion sequence to standard
506 /// error. Useful for debugging overloading issues.
507 void UserDefinedConversionSequence::dump() const {
508 raw_ostream &OS = llvm::errs();
509 if (Before.First || Before.Second || Before.Third) {
513 if (ConversionFunction)
514 OS << '\'' << *ConversionFunction << '\'';
516 OS << "aggregate initialization";
517 if (After.First || After.Second || After.Third) {
523 /// dump - Print this implicit conversion sequence to standard
524 /// error. Useful for debugging overloading issues.
525 void ImplicitConversionSequence::dump() const {
526 raw_ostream &OS = llvm::errs();
527 if (isStdInitializerListElement())
528 OS << "Worst std::initializer_list element conversion: ";
529 switch (ConversionKind) {
530 case StandardConversion:
531 OS << "Standard conversion: ";
534 case UserDefinedConversion:
535 OS << "User-defined conversion: ";
538 case EllipsisConversion:
539 OS << "Ellipsis conversion";
541 case AmbiguousConversion:
542 OS << "Ambiguous conversion";
545 OS << "Bad conversion";
552 void AmbiguousConversionSequence::construct() {
553 new (&conversions()) ConversionSet();
556 void AmbiguousConversionSequence::destruct() {
557 conversions().~ConversionSet();
561 AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) {
562 FromTypePtr = O.FromTypePtr;
563 ToTypePtr = O.ToTypePtr;
564 new (&conversions()) ConversionSet(O.conversions());
568 // Structure used by DeductionFailureInfo to store
569 // template argument information.
570 struct DFIArguments {
571 TemplateArgument FirstArg;
572 TemplateArgument SecondArg;
574 // Structure used by DeductionFailureInfo to store
575 // template parameter and template argument information.
576 struct DFIParamWithArguments : DFIArguments {
577 TemplateParameter Param;
579 // Structure used by DeductionFailureInfo to store template argument
580 // information and the index of the problematic call argument.
581 struct DFIDeducedMismatchArgs : DFIArguments {
582 TemplateArgumentList *TemplateArgs;
583 unsigned CallArgIndex;
587 /// Convert from Sema's representation of template deduction information
588 /// to the form used in overload-candidate information.
590 clang::MakeDeductionFailureInfo(ASTContext &Context,
591 Sema::TemplateDeductionResult TDK,
592 TemplateDeductionInfo &Info) {
593 DeductionFailureInfo Result;
594 Result.Result = static_cast<unsigned>(TDK);
595 Result.HasDiagnostic = false;
597 case Sema::TDK_Invalid:
598 case Sema::TDK_InstantiationDepth:
599 case Sema::TDK_TooManyArguments:
600 case Sema::TDK_TooFewArguments:
601 case Sema::TDK_MiscellaneousDeductionFailure:
602 case Sema::TDK_CUDATargetMismatch:
603 Result.Data = nullptr;
606 case Sema::TDK_Incomplete:
607 case Sema::TDK_InvalidExplicitArguments:
608 Result.Data = Info.Param.getOpaqueValue();
611 case Sema::TDK_DeducedMismatch:
612 case Sema::TDK_DeducedMismatchNested: {
613 // FIXME: Should allocate from normal heap so that we can free this later.
614 auto *Saved = new (Context) DFIDeducedMismatchArgs;
615 Saved->FirstArg = Info.FirstArg;
616 Saved->SecondArg = Info.SecondArg;
617 Saved->TemplateArgs = Info.take();
618 Saved->CallArgIndex = Info.CallArgIndex;
623 case Sema::TDK_NonDeducedMismatch: {
624 // FIXME: Should allocate from normal heap so that we can free this later.
625 DFIArguments *Saved = new (Context) DFIArguments;
626 Saved->FirstArg = Info.FirstArg;
627 Saved->SecondArg = Info.SecondArg;
632 case Sema::TDK_IncompletePack:
633 // FIXME: It's slightly wasteful to allocate two TemplateArguments for this.
634 case Sema::TDK_Inconsistent:
635 case Sema::TDK_Underqualified: {
636 // FIXME: Should allocate from normal heap so that we can free this later.
637 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments;
638 Saved->Param = Info.Param;
639 Saved->FirstArg = Info.FirstArg;
640 Saved->SecondArg = Info.SecondArg;
645 case Sema::TDK_SubstitutionFailure:
646 Result.Data = Info.take();
647 if (Info.hasSFINAEDiagnostic()) {
648 PartialDiagnosticAt *Diag = new (Result.Diagnostic) PartialDiagnosticAt(
649 SourceLocation(), PartialDiagnostic::NullDiagnostic());
650 Info.takeSFINAEDiagnostic(*Diag);
651 Result.HasDiagnostic = true;
655 case Sema::TDK_Success:
656 case Sema::TDK_NonDependentConversionFailure:
657 llvm_unreachable("not a deduction failure");
663 void DeductionFailureInfo::Destroy() {
664 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
665 case Sema::TDK_Success:
666 case Sema::TDK_Invalid:
667 case Sema::TDK_InstantiationDepth:
668 case Sema::TDK_Incomplete:
669 case Sema::TDK_TooManyArguments:
670 case Sema::TDK_TooFewArguments:
671 case Sema::TDK_InvalidExplicitArguments:
672 case Sema::TDK_CUDATargetMismatch:
673 case Sema::TDK_NonDependentConversionFailure:
676 case Sema::TDK_IncompletePack:
677 case Sema::TDK_Inconsistent:
678 case Sema::TDK_Underqualified:
679 case Sema::TDK_DeducedMismatch:
680 case Sema::TDK_DeducedMismatchNested:
681 case Sema::TDK_NonDeducedMismatch:
682 // FIXME: Destroy the data?
686 case Sema::TDK_SubstitutionFailure:
687 // FIXME: Destroy the template argument list?
689 if (PartialDiagnosticAt *Diag = getSFINAEDiagnostic()) {
690 Diag->~PartialDiagnosticAt();
691 HasDiagnostic = false;
696 case Sema::TDK_MiscellaneousDeductionFailure:
701 PartialDiagnosticAt *DeductionFailureInfo::getSFINAEDiagnostic() {
703 return static_cast<PartialDiagnosticAt*>(static_cast<void*>(Diagnostic));
707 TemplateParameter DeductionFailureInfo::getTemplateParameter() {
708 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
709 case Sema::TDK_Success:
710 case Sema::TDK_Invalid:
711 case Sema::TDK_InstantiationDepth:
712 case Sema::TDK_TooManyArguments:
713 case Sema::TDK_TooFewArguments:
714 case Sema::TDK_SubstitutionFailure:
715 case Sema::TDK_DeducedMismatch:
716 case Sema::TDK_DeducedMismatchNested:
717 case Sema::TDK_NonDeducedMismatch:
718 case Sema::TDK_CUDATargetMismatch:
719 case Sema::TDK_NonDependentConversionFailure:
720 return TemplateParameter();
722 case Sema::TDK_Incomplete:
723 case Sema::TDK_InvalidExplicitArguments:
724 return TemplateParameter::getFromOpaqueValue(Data);
726 case Sema::TDK_IncompletePack:
727 case Sema::TDK_Inconsistent:
728 case Sema::TDK_Underqualified:
729 return static_cast<DFIParamWithArguments*>(Data)->Param;
732 case Sema::TDK_MiscellaneousDeductionFailure:
736 return TemplateParameter();
739 TemplateArgumentList *DeductionFailureInfo::getTemplateArgumentList() {
740 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
741 case Sema::TDK_Success:
742 case Sema::TDK_Invalid:
743 case Sema::TDK_InstantiationDepth:
744 case Sema::TDK_TooManyArguments:
745 case Sema::TDK_TooFewArguments:
746 case Sema::TDK_Incomplete:
747 case Sema::TDK_IncompletePack:
748 case Sema::TDK_InvalidExplicitArguments:
749 case Sema::TDK_Inconsistent:
750 case Sema::TDK_Underqualified:
751 case Sema::TDK_NonDeducedMismatch:
752 case Sema::TDK_CUDATargetMismatch:
753 case Sema::TDK_NonDependentConversionFailure:
756 case Sema::TDK_DeducedMismatch:
757 case Sema::TDK_DeducedMismatchNested:
758 return static_cast<DFIDeducedMismatchArgs*>(Data)->TemplateArgs;
760 case Sema::TDK_SubstitutionFailure:
761 return static_cast<TemplateArgumentList*>(Data);
764 case Sema::TDK_MiscellaneousDeductionFailure:
771 const TemplateArgument *DeductionFailureInfo::getFirstArg() {
772 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
773 case Sema::TDK_Success:
774 case Sema::TDK_Invalid:
775 case Sema::TDK_InstantiationDepth:
776 case Sema::TDK_Incomplete:
777 case Sema::TDK_TooManyArguments:
778 case Sema::TDK_TooFewArguments:
779 case Sema::TDK_InvalidExplicitArguments:
780 case Sema::TDK_SubstitutionFailure:
781 case Sema::TDK_CUDATargetMismatch:
782 case Sema::TDK_NonDependentConversionFailure:
785 case Sema::TDK_IncompletePack:
786 case Sema::TDK_Inconsistent:
787 case Sema::TDK_Underqualified:
788 case Sema::TDK_DeducedMismatch:
789 case Sema::TDK_DeducedMismatchNested:
790 case Sema::TDK_NonDeducedMismatch:
791 return &static_cast<DFIArguments*>(Data)->FirstArg;
794 case Sema::TDK_MiscellaneousDeductionFailure:
801 const TemplateArgument *DeductionFailureInfo::getSecondArg() {
802 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
803 case Sema::TDK_Success:
804 case Sema::TDK_Invalid:
805 case Sema::TDK_InstantiationDepth:
806 case Sema::TDK_Incomplete:
807 case Sema::TDK_IncompletePack:
808 case Sema::TDK_TooManyArguments:
809 case Sema::TDK_TooFewArguments:
810 case Sema::TDK_InvalidExplicitArguments:
811 case Sema::TDK_SubstitutionFailure:
812 case Sema::TDK_CUDATargetMismatch:
813 case Sema::TDK_NonDependentConversionFailure:
816 case Sema::TDK_Inconsistent:
817 case Sema::TDK_Underqualified:
818 case Sema::TDK_DeducedMismatch:
819 case Sema::TDK_DeducedMismatchNested:
820 case Sema::TDK_NonDeducedMismatch:
821 return &static_cast<DFIArguments*>(Data)->SecondArg;
824 case Sema::TDK_MiscellaneousDeductionFailure:
831 llvm::Optional<unsigned> DeductionFailureInfo::getCallArgIndex() {
832 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
833 case Sema::TDK_DeducedMismatch:
834 case Sema::TDK_DeducedMismatchNested:
835 return static_cast<DFIDeducedMismatchArgs*>(Data)->CallArgIndex;
842 void OverloadCandidateSet::destroyCandidates() {
843 for (iterator i = begin(), e = end(); i != e; ++i) {
844 for (auto &C : i->Conversions)
845 C.~ImplicitConversionSequence();
846 if (!i->Viable && i->FailureKind == ovl_fail_bad_deduction)
847 i->DeductionFailure.Destroy();
851 void OverloadCandidateSet::clear(CandidateSetKind CSK) {
853 SlabAllocator.Reset();
854 NumInlineBytesUsed = 0;
861 class UnbridgedCastsSet {
866 SmallVector<Entry, 2> Entries;
869 void save(Sema &S, Expr *&E) {
870 assert(E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast));
871 Entry entry = { &E, E };
872 Entries.push_back(entry);
873 E = S.stripARCUnbridgedCast(E);
877 for (SmallVectorImpl<Entry>::iterator
878 i = Entries.begin(), e = Entries.end(); i != e; ++i)
884 /// checkPlaceholderForOverload - Do any interesting placeholder-like
885 /// preprocessing on the given expression.
887 /// \param unbridgedCasts a collection to which to add unbridged casts;
888 /// without this, they will be immediately diagnosed as errors
890 /// Return true on unrecoverable error.
892 checkPlaceholderForOverload(Sema &S, Expr *&E,
893 UnbridgedCastsSet *unbridgedCasts = nullptr) {
894 if (const BuiltinType *placeholder = E->getType()->getAsPlaceholderType()) {
895 // We can't handle overloaded expressions here because overload
896 // resolution might reasonably tweak them.
897 if (placeholder->getKind() == BuiltinType::Overload) return false;
899 // If the context potentially accepts unbridged ARC casts, strip
900 // the unbridged cast and add it to the collection for later restoration.
901 if (placeholder->getKind() == BuiltinType::ARCUnbridgedCast &&
903 unbridgedCasts->save(S, E);
907 // Go ahead and check everything else.
908 ExprResult result = S.CheckPlaceholderExpr(E);
909 if (result.isInvalid())
920 /// checkArgPlaceholdersForOverload - Check a set of call operands for
922 static bool checkArgPlaceholdersForOverload(Sema &S,
924 UnbridgedCastsSet &unbridged) {
925 for (unsigned i = 0, e = Args.size(); i != e; ++i)
926 if (checkPlaceholderForOverload(S, Args[i], &unbridged))
932 /// Determine whether the given New declaration is an overload of the
933 /// declarations in Old. This routine returns Ovl_Match or Ovl_NonFunction if
934 /// New and Old cannot be overloaded, e.g., if New has the same signature as
935 /// some function in Old (C++ 1.3.10) or if the Old declarations aren't
936 /// functions (or function templates) at all. When it does return Ovl_Match or
937 /// Ovl_NonFunction, MatchedDecl will point to the decl that New cannot be
938 /// overloaded with. This decl may be a UsingShadowDecl on top of the underlying
941 /// Example: Given the following input:
943 /// void f(int, float); // #1
944 /// void f(int, int); // #2
945 /// int f(int, int); // #3
947 /// When we process #1, there is no previous declaration of "f", so IsOverload
948 /// will not be used.
950 /// When we process #2, Old contains only the FunctionDecl for #1. By comparing
951 /// the parameter types, we see that #1 and #2 are overloaded (since they have
952 /// different signatures), so this routine returns Ovl_Overload; MatchedDecl is
955 /// When we process #3, Old is an overload set containing #1 and #2. We compare
956 /// the signatures of #3 to #1 (they're overloaded, so we do nothing) and then
957 /// #3 to #2. Since the signatures of #3 and #2 are identical (return types of
958 /// functions are not part of the signature), IsOverload returns Ovl_Match and
959 /// MatchedDecl will be set to point to the FunctionDecl for #2.
961 /// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced into a class
962 /// by a using declaration. The rules for whether to hide shadow declarations
963 /// ignore some properties which otherwise figure into a function template's
966 Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old,
967 NamedDecl *&Match, bool NewIsUsingDecl) {
968 for (LookupResult::iterator I = Old.begin(), E = Old.end();
970 NamedDecl *OldD = *I;
972 bool OldIsUsingDecl = false;
973 if (isa<UsingShadowDecl>(OldD)) {
974 OldIsUsingDecl = true;
976 // We can always introduce two using declarations into the same
977 // context, even if they have identical signatures.
978 if (NewIsUsingDecl) continue;
980 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl();
983 // A using-declaration does not conflict with another declaration
984 // if one of them is hidden.
985 if ((OldIsUsingDecl || NewIsUsingDecl) && !isVisible(*I))
988 // If either declaration was introduced by a using declaration,
989 // we'll need to use slightly different rules for matching.
990 // Essentially, these rules are the normal rules, except that
991 // function templates hide function templates with different
992 // return types or template parameter lists.
993 bool UseMemberUsingDeclRules =
994 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord() &&
995 !New->getFriendObjectKind();
997 if (FunctionDecl *OldF = OldD->getAsFunction()) {
998 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) {
999 if (UseMemberUsingDeclRules && OldIsUsingDecl) {
1000 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I));
1004 if (!isa<FunctionTemplateDecl>(OldD) &&
1005 !shouldLinkPossiblyHiddenDecl(*I, New))
1012 // Builtins that have custom typechecking or have a reference should
1013 // not be overloadable or redeclarable.
1014 if (!getASTContext().canBuiltinBeRedeclared(OldF)) {
1016 return Ovl_NonFunction;
1018 } else if (isa<UsingDecl>(OldD) || isa<UsingPackDecl>(OldD)) {
1019 // We can overload with these, which can show up when doing
1020 // redeclaration checks for UsingDecls.
1021 assert(Old.getLookupKind() == LookupUsingDeclName);
1022 } else if (isa<TagDecl>(OldD)) {
1023 // We can always overload with tags by hiding them.
1024 } else if (auto *UUD = dyn_cast<UnresolvedUsingValueDecl>(OldD)) {
1025 // Optimistically assume that an unresolved using decl will
1026 // overload; if it doesn't, we'll have to diagnose during
1027 // template instantiation.
1029 // Exception: if the scope is dependent and this is not a class
1030 // member, the using declaration can only introduce an enumerator.
1031 if (UUD->getQualifier()->isDependent() && !UUD->isCXXClassMember()) {
1033 return Ovl_NonFunction;
1037 // Only function declarations can be overloaded; object and type
1038 // declarations cannot be overloaded.
1040 return Ovl_NonFunction;
1044 return Ovl_Overload;
1047 bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old,
1048 bool UseMemberUsingDeclRules, bool ConsiderCudaAttrs) {
1049 // C++ [basic.start.main]p2: This function shall not be overloaded.
1053 // MSVCRT user defined entry points cannot be overloaded.
1054 if (New->isMSVCRTEntryPoint())
1057 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate();
1058 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate();
1060 // C++ [temp.fct]p2:
1061 // A function template can be overloaded with other function templates
1062 // and with normal (non-template) functions.
1063 if ((OldTemplate == nullptr) != (NewTemplate == nullptr))
1066 // Is the function New an overload of the function Old?
1067 QualType OldQType = Context.getCanonicalType(Old->getType());
1068 QualType NewQType = Context.getCanonicalType(New->getType());
1070 // Compare the signatures (C++ 1.3.10) of the two functions to
1071 // determine whether they are overloads. If we find any mismatch
1072 // in the signature, they are overloads.
1074 // If either of these functions is a K&R-style function (no
1075 // prototype), then we consider them to have matching signatures.
1076 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) ||
1077 isa<FunctionNoProtoType>(NewQType.getTypePtr()))
1080 const FunctionProtoType *OldType = cast<FunctionProtoType>(OldQType);
1081 const FunctionProtoType *NewType = cast<FunctionProtoType>(NewQType);
1083 // The signature of a function includes the types of its
1084 // parameters (C++ 1.3.10), which includes the presence or absence
1085 // of the ellipsis; see C++ DR 357).
1086 if (OldQType != NewQType &&
1087 (OldType->getNumParams() != NewType->getNumParams() ||
1088 OldType->isVariadic() != NewType->isVariadic() ||
1089 !FunctionParamTypesAreEqual(OldType, NewType)))
1092 // C++ [temp.over.link]p4:
1093 // The signature of a function template consists of its function
1094 // signature, its return type and its template parameter list. The names
1095 // of the template parameters are significant only for establishing the
1096 // relationship between the template parameters and the rest of the
1099 // We check the return type and template parameter lists for function
1100 // templates first; the remaining checks follow.
1102 // However, we don't consider either of these when deciding whether
1103 // a member introduced by a shadow declaration is hidden.
1104 if (!UseMemberUsingDeclRules && NewTemplate &&
1105 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(),
1106 OldTemplate->getTemplateParameters(),
1107 false, TPL_TemplateMatch) ||
1108 !Context.hasSameType(Old->getDeclaredReturnType(),
1109 New->getDeclaredReturnType())))
1112 // If the function is a class member, its signature includes the
1113 // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself.
1115 // As part of this, also check whether one of the member functions
1116 // is static, in which case they are not overloads (C++
1117 // 13.1p2). While not part of the definition of the signature,
1118 // this check is important to determine whether these functions
1119 // can be overloaded.
1120 CXXMethodDecl *OldMethod = dyn_cast<CXXMethodDecl>(Old);
1121 CXXMethodDecl *NewMethod = dyn_cast<CXXMethodDecl>(New);
1122 if (OldMethod && NewMethod &&
1123 !OldMethod->isStatic() && !NewMethod->isStatic()) {
1124 if (OldMethod->getRefQualifier() != NewMethod->getRefQualifier()) {
1125 if (!UseMemberUsingDeclRules &&
1126 (OldMethod->getRefQualifier() == RQ_None ||
1127 NewMethod->getRefQualifier() == RQ_None)) {
1128 // C++0x [over.load]p2:
1129 // - Member function declarations with the same name and the same
1130 // parameter-type-list as well as member function template
1131 // declarations with the same name, the same parameter-type-list, and
1132 // the same template parameter lists cannot be overloaded if any of
1133 // them, but not all, have a ref-qualifier (8.3.5).
1134 Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload)
1135 << NewMethod->getRefQualifier() << OldMethod->getRefQualifier();
1136 Diag(OldMethod->getLocation(), diag::note_previous_declaration);
1141 // We may not have applied the implicit const for a constexpr member
1142 // function yet (because we haven't yet resolved whether this is a static
1143 // or non-static member function). Add it now, on the assumption that this
1144 // is a redeclaration of OldMethod.
1145 unsigned OldQuals = OldMethod->getTypeQualifiers();
1146 unsigned NewQuals = NewMethod->getTypeQualifiers();
1147 if (!getLangOpts().CPlusPlus14 && NewMethod->isConstexpr() &&
1148 !isa<CXXConstructorDecl>(NewMethod))
1149 NewQuals |= Qualifiers::Const;
1151 // We do not allow overloading based off of '__restrict'.
1152 OldQuals &= ~Qualifiers::Restrict;
1153 NewQuals &= ~Qualifiers::Restrict;
1154 if (OldQuals != NewQuals)
1158 // Though pass_object_size is placed on parameters and takes an argument, we
1159 // consider it to be a function-level modifier for the sake of function
1160 // identity. Either the function has one or more parameters with
1161 // pass_object_size or it doesn't.
1162 if (functionHasPassObjectSizeParams(New) !=
1163 functionHasPassObjectSizeParams(Old))
1166 // enable_if attributes are an order-sensitive part of the signature.
1167 for (specific_attr_iterator<EnableIfAttr>
1168 NewI = New->specific_attr_begin<EnableIfAttr>(),
1169 NewE = New->specific_attr_end<EnableIfAttr>(),
1170 OldI = Old->specific_attr_begin<EnableIfAttr>(),
1171 OldE = Old->specific_attr_end<EnableIfAttr>();
1172 NewI != NewE || OldI != OldE; ++NewI, ++OldI) {
1173 if (NewI == NewE || OldI == OldE)
1175 llvm::FoldingSetNodeID NewID, OldID;
1176 NewI->getCond()->Profile(NewID, Context, true);
1177 OldI->getCond()->Profile(OldID, Context, true);
1182 if (getLangOpts().CUDA && ConsiderCudaAttrs) {
1183 // Don't allow overloading of destructors. (In theory we could, but it
1184 // would be a giant change to clang.)
1185 if (isa<CXXDestructorDecl>(New))
1188 CUDAFunctionTarget NewTarget = IdentifyCUDATarget(New),
1189 OldTarget = IdentifyCUDATarget(Old);
1190 if (NewTarget == CFT_InvalidTarget)
1193 assert((OldTarget != CFT_InvalidTarget) && "Unexpected invalid target.");
1195 // Allow overloading of functions with same signature and different CUDA
1196 // target attributes.
1197 return NewTarget != OldTarget;
1200 // The signatures match; this is not an overload.
1204 /// Checks availability of the function depending on the current
1205 /// function context. Inside an unavailable function, unavailability is ignored.
1207 /// \returns true if \arg FD is unavailable and current context is inside
1208 /// an available function, false otherwise.
1209 bool Sema::isFunctionConsideredUnavailable(FunctionDecl *FD) {
1210 if (!FD->isUnavailable())
1213 // Walk up the context of the caller.
1214 Decl *C = cast<Decl>(CurContext);
1216 if (C->isUnavailable())
1218 } while ((C = cast_or_null<Decl>(C->getDeclContext())));
1222 /// Tries a user-defined conversion from From to ToType.
1224 /// Produces an implicit conversion sequence for when a standard conversion
1225 /// is not an option. See TryImplicitConversion for more information.
1226 static ImplicitConversionSequence
1227 TryUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
1228 bool SuppressUserConversions,
1230 bool InOverloadResolution,
1232 bool AllowObjCWritebackConversion,
1233 bool AllowObjCConversionOnExplicit) {
1234 ImplicitConversionSequence ICS;
1236 if (SuppressUserConversions) {
1237 // We're not in the case above, so there is no conversion that
1239 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1243 // Attempt user-defined conversion.
1244 OverloadCandidateSet Conversions(From->getExprLoc(),
1245 OverloadCandidateSet::CSK_Normal);
1246 switch (IsUserDefinedConversion(S, From, ToType, ICS.UserDefined,
1247 Conversions, AllowExplicit,
1248 AllowObjCConversionOnExplicit)) {
1251 ICS.setUserDefined();
1252 // C++ [over.ics.user]p4:
1253 // A conversion of an expression of class type to the same class
1254 // type is given Exact Match rank, and a conversion of an
1255 // expression of class type to a base class of that type is
1256 // given Conversion rank, in spite of the fact that a copy
1257 // constructor (i.e., a user-defined conversion function) is
1258 // called for those cases.
1259 if (CXXConstructorDecl *Constructor
1260 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) {
1262 = S.Context.getCanonicalType(From->getType().getUnqualifiedType());
1264 = S.Context.getCanonicalType(ToType).getUnqualifiedType();
1265 if (Constructor->isCopyConstructor() &&
1266 (FromCanon == ToCanon ||
1267 S.IsDerivedFrom(From->getLocStart(), FromCanon, ToCanon))) {
1268 // Turn this into a "standard" conversion sequence, so that it
1269 // gets ranked with standard conversion sequences.
1270 DeclAccessPair Found = ICS.UserDefined.FoundConversionFunction;
1272 ICS.Standard.setAsIdentityConversion();
1273 ICS.Standard.setFromType(From->getType());
1274 ICS.Standard.setAllToTypes(ToType);
1275 ICS.Standard.CopyConstructor = Constructor;
1276 ICS.Standard.FoundCopyConstructor = Found;
1277 if (ToCanon != FromCanon)
1278 ICS.Standard.Second = ICK_Derived_To_Base;
1285 ICS.Ambiguous.setFromType(From->getType());
1286 ICS.Ambiguous.setToType(ToType);
1287 for (OverloadCandidateSet::iterator Cand = Conversions.begin();
1288 Cand != Conversions.end(); ++Cand)
1290 ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
1294 case OR_No_Viable_Function:
1295 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1302 /// TryImplicitConversion - Attempt to perform an implicit conversion
1303 /// from the given expression (Expr) to the given type (ToType). This
1304 /// function returns an implicit conversion sequence that can be used
1305 /// to perform the initialization. Given
1307 /// void f(float f);
1308 /// void g(int i) { f(i); }
1310 /// this routine would produce an implicit conversion sequence to
1311 /// describe the initialization of f from i, which will be a standard
1312 /// conversion sequence containing an lvalue-to-rvalue conversion (C++
1313 /// 4.1) followed by a floating-integral conversion (C++ 4.9).
1315 /// Note that this routine only determines how the conversion can be
1316 /// performed; it does not actually perform the conversion. As such,
1317 /// it will not produce any diagnostics if no conversion is available,
1318 /// but will instead return an implicit conversion sequence of kind
1319 /// "BadConversion".
1321 /// If @p SuppressUserConversions, then user-defined conversions are
1323 /// If @p AllowExplicit, then explicit user-defined conversions are
1326 /// \param AllowObjCWritebackConversion Whether we allow the Objective-C
1327 /// writeback conversion, which allows __autoreleasing id* parameters to
1328 /// be initialized with __strong id* or __weak id* arguments.
1329 static ImplicitConversionSequence
1330 TryImplicitConversion(Sema &S, Expr *From, QualType ToType,
1331 bool SuppressUserConversions,
1333 bool InOverloadResolution,
1335 bool AllowObjCWritebackConversion,
1336 bool AllowObjCConversionOnExplicit) {
1337 ImplicitConversionSequence ICS;
1338 if (IsStandardConversion(S, From, ToType, InOverloadResolution,
1339 ICS.Standard, CStyle, AllowObjCWritebackConversion)){
1344 if (!S.getLangOpts().CPlusPlus) {
1345 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1349 // C++ [over.ics.user]p4:
1350 // A conversion of an expression of class type to the same class
1351 // type is given Exact Match rank, and a conversion of an
1352 // expression of class type to a base class of that type is
1353 // given Conversion rank, in spite of the fact that a copy/move
1354 // constructor (i.e., a user-defined conversion function) is
1355 // called for those cases.
1356 QualType FromType = From->getType();
1357 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() &&
1358 (S.Context.hasSameUnqualifiedType(FromType, ToType) ||
1359 S.IsDerivedFrom(From->getLocStart(), FromType, ToType))) {
1361 ICS.Standard.setAsIdentityConversion();
1362 ICS.Standard.setFromType(FromType);
1363 ICS.Standard.setAllToTypes(ToType);
1365 // We don't actually check at this point whether there is a valid
1366 // copy/move constructor, since overloading just assumes that it
1367 // exists. When we actually perform initialization, we'll find the
1368 // appropriate constructor to copy the returned object, if needed.
1369 ICS.Standard.CopyConstructor = nullptr;
1371 // Determine whether this is considered a derived-to-base conversion.
1372 if (!S.Context.hasSameUnqualifiedType(FromType, ToType))
1373 ICS.Standard.Second = ICK_Derived_To_Base;
1378 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
1379 AllowExplicit, InOverloadResolution, CStyle,
1380 AllowObjCWritebackConversion,
1381 AllowObjCConversionOnExplicit);
1384 ImplicitConversionSequence
1385 Sema::TryImplicitConversion(Expr *From, QualType ToType,
1386 bool SuppressUserConversions,
1388 bool InOverloadResolution,
1390 bool AllowObjCWritebackConversion) {
1391 return ::TryImplicitConversion(*this, From, ToType,
1392 SuppressUserConversions, AllowExplicit,
1393 InOverloadResolution, CStyle,
1394 AllowObjCWritebackConversion,
1395 /*AllowObjCConversionOnExplicit=*/false);
1398 /// PerformImplicitConversion - Perform an implicit conversion of the
1399 /// expression From to the type ToType. Returns the
1400 /// converted expression. Flavor is the kind of conversion we're
1401 /// performing, used in the error message. If @p AllowExplicit,
1402 /// explicit user-defined conversions are permitted.
1404 Sema::PerformImplicitConversion(Expr *From, QualType ToType,
1405 AssignmentAction Action, bool AllowExplicit) {
1406 ImplicitConversionSequence ICS;
1407 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS);
1411 Sema::PerformImplicitConversion(Expr *From, QualType ToType,
1412 AssignmentAction Action, bool AllowExplicit,
1413 ImplicitConversionSequence& ICS) {
1414 if (checkPlaceholderForOverload(*this, From))
1417 // Objective-C ARC: Determine whether we will allow the writeback conversion.
1418 bool AllowObjCWritebackConversion
1419 = getLangOpts().ObjCAutoRefCount &&
1420 (Action == AA_Passing || Action == AA_Sending);
1421 if (getLangOpts().ObjC1)
1422 CheckObjCBridgeRelatedConversions(From->getLocStart(),
1423 ToType, From->getType(), From);
1424 ICS = ::TryImplicitConversion(*this, From, ToType,
1425 /*SuppressUserConversions=*/false,
1427 /*InOverloadResolution=*/false,
1429 AllowObjCWritebackConversion,
1430 /*AllowObjCConversionOnExplicit=*/false);
1431 return PerformImplicitConversion(From, ToType, ICS, Action);
1434 /// Determine whether the conversion from FromType to ToType is a valid
1435 /// conversion that strips "noexcept" or "noreturn" off the nested function
1437 bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
1438 QualType &ResultTy) {
1439 if (Context.hasSameUnqualifiedType(FromType, ToType))
1442 // Permit the conversion F(t __attribute__((noreturn))) -> F(t)
1443 // or F(t noexcept) -> F(t)
1444 // where F adds one of the following at most once:
1446 // - a member pointer
1447 // - a block pointer
1448 // Changes here need matching changes in FindCompositePointerType.
1449 CanQualType CanTo = Context.getCanonicalType(ToType);
1450 CanQualType CanFrom = Context.getCanonicalType(FromType);
1451 Type::TypeClass TyClass = CanTo->getTypeClass();
1452 if (TyClass != CanFrom->getTypeClass()) return false;
1453 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) {
1454 if (TyClass == Type::Pointer) {
1455 CanTo = CanTo.getAs<PointerType>()->getPointeeType();
1456 CanFrom = CanFrom.getAs<PointerType>()->getPointeeType();
1457 } else if (TyClass == Type::BlockPointer) {
1458 CanTo = CanTo.getAs<BlockPointerType>()->getPointeeType();
1459 CanFrom = CanFrom.getAs<BlockPointerType>()->getPointeeType();
1460 } else if (TyClass == Type::MemberPointer) {
1461 auto ToMPT = CanTo.getAs<MemberPointerType>();
1462 auto FromMPT = CanFrom.getAs<MemberPointerType>();
1463 // A function pointer conversion cannot change the class of the function.
1464 if (ToMPT->getClass() != FromMPT->getClass())
1466 CanTo = ToMPT->getPointeeType();
1467 CanFrom = FromMPT->getPointeeType();
1472 TyClass = CanTo->getTypeClass();
1473 if (TyClass != CanFrom->getTypeClass()) return false;
1474 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto)
1478 const auto *FromFn = cast<FunctionType>(CanFrom);
1479 FunctionType::ExtInfo FromEInfo = FromFn->getExtInfo();
1481 const auto *ToFn = cast<FunctionType>(CanTo);
1482 FunctionType::ExtInfo ToEInfo = ToFn->getExtInfo();
1484 bool Changed = false;
1486 // Drop 'noreturn' if not present in target type.
1487 if (FromEInfo.getNoReturn() && !ToEInfo.getNoReturn()) {
1488 FromFn = Context.adjustFunctionType(FromFn, FromEInfo.withNoReturn(false));
1492 // Drop 'noexcept' if not present in target type.
1493 if (const auto *FromFPT = dyn_cast<FunctionProtoType>(FromFn)) {
1494 const auto *ToFPT = cast<FunctionProtoType>(ToFn);
1495 if (FromFPT->isNothrow() && !ToFPT->isNothrow()) {
1496 FromFn = cast<FunctionType>(
1497 Context.getFunctionTypeWithExceptionSpec(QualType(FromFPT, 0),
1503 // Convert FromFPT's ExtParameterInfo if necessary. The conversion is valid
1504 // only if the ExtParameterInfo lists of the two function prototypes can be
1505 // merged and the merged list is identical to ToFPT's ExtParameterInfo list.
1506 SmallVector<FunctionProtoType::ExtParameterInfo, 4> NewParamInfos;
1507 bool CanUseToFPT, CanUseFromFPT;
1508 if (Context.mergeExtParameterInfo(ToFPT, FromFPT, CanUseToFPT,
1509 CanUseFromFPT, NewParamInfos) &&
1510 CanUseToFPT && !CanUseFromFPT) {
1511 FunctionProtoType::ExtProtoInfo ExtInfo = FromFPT->getExtProtoInfo();
1512 ExtInfo.ExtParameterInfos =
1513 NewParamInfos.empty() ? nullptr : NewParamInfos.data();
1514 QualType QT = Context.getFunctionType(FromFPT->getReturnType(),
1515 FromFPT->getParamTypes(), ExtInfo);
1516 FromFn = QT->getAs<FunctionType>();
1524 assert(QualType(FromFn, 0).isCanonical());
1525 if (QualType(FromFn, 0) != CanTo) return false;
1531 /// Determine whether the conversion from FromType to ToType is a valid
1532 /// vector conversion.
1534 /// \param ICK Will be set to the vector conversion kind, if this is a vector
1536 static bool IsVectorConversion(Sema &S, QualType FromType,
1537 QualType ToType, ImplicitConversionKind &ICK) {
1538 // We need at least one of these types to be a vector type to have a vector
1540 if (!ToType->isVectorType() && !FromType->isVectorType())
1543 // Identical types require no conversions.
1544 if (S.Context.hasSameUnqualifiedType(FromType, ToType))
1547 // There are no conversions between extended vector types, only identity.
1548 if (ToType->isExtVectorType()) {
1549 // There are no conversions between extended vector types other than the
1550 // identity conversion.
1551 if (FromType->isExtVectorType())
1554 // Vector splat from any arithmetic type to a vector.
1555 if (FromType->isArithmeticType()) {
1556 ICK = ICK_Vector_Splat;
1561 // We can perform the conversion between vector types in the following cases:
1562 // 1)vector types are equivalent AltiVec and GCC vector types
1563 // 2)lax vector conversions are permitted and the vector types are of the
1565 if (ToType->isVectorType() && FromType->isVectorType()) {
1566 if (S.Context.areCompatibleVectorTypes(FromType, ToType) ||
1567 S.isLaxVectorConversion(FromType, ToType)) {
1568 ICK = ICK_Vector_Conversion;
1576 static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
1577 bool InOverloadResolution,
1578 StandardConversionSequence &SCS,
1581 /// IsStandardConversion - Determines whether there is a standard
1582 /// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the
1583 /// expression From to the type ToType. Standard conversion sequences
1584 /// only consider non-class types; for conversions that involve class
1585 /// types, use TryImplicitConversion. If a conversion exists, SCS will
1586 /// contain the standard conversion sequence required to perform this
1587 /// conversion and this routine will return true. Otherwise, this
1588 /// routine will return false and the value of SCS is unspecified.
1589 static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
1590 bool InOverloadResolution,
1591 StandardConversionSequence &SCS,
1593 bool AllowObjCWritebackConversion) {
1594 QualType FromType = From->getType();
1596 // Standard conversions (C++ [conv])
1597 SCS.setAsIdentityConversion();
1598 SCS.IncompatibleObjC = false;
1599 SCS.setFromType(FromType);
1600 SCS.CopyConstructor = nullptr;
1602 // There are no standard conversions for class types in C++, so
1603 // abort early. When overloading in C, however, we do permit them.
1604 if (S.getLangOpts().CPlusPlus &&
1605 (FromType->isRecordType() || ToType->isRecordType()))
1608 // The first conversion can be an lvalue-to-rvalue conversion,
1609 // array-to-pointer conversion, or function-to-pointer conversion
1612 if (FromType == S.Context.OverloadTy) {
1613 DeclAccessPair AccessPair;
1614 if (FunctionDecl *Fn
1615 = S.ResolveAddressOfOverloadedFunction(From, ToType, false,
1617 // We were able to resolve the address of the overloaded function,
1618 // so we can convert to the type of that function.
1619 FromType = Fn->getType();
1620 SCS.setFromType(FromType);
1622 // we can sometimes resolve &foo<int> regardless of ToType, so check
1623 // if the type matches (identity) or we are converting to bool
1624 if (!S.Context.hasSameUnqualifiedType(
1625 S.ExtractUnqualifiedFunctionType(ToType), FromType)) {
1627 // if the function type matches except for [[noreturn]], it's ok
1628 if (!S.IsFunctionConversion(FromType,
1629 S.ExtractUnqualifiedFunctionType(ToType), resultTy))
1630 // otherwise, only a boolean conversion is standard
1631 if (!ToType->isBooleanType())
1635 // Check if the "from" expression is taking the address of an overloaded
1636 // function and recompute the FromType accordingly. Take advantage of the
1637 // fact that non-static member functions *must* have such an address-of
1639 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn);
1640 if (Method && !Method->isStatic()) {
1641 assert(isa<UnaryOperator>(From->IgnoreParens()) &&
1642 "Non-unary operator on non-static member address");
1643 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode()
1645 "Non-address-of operator on non-static member address");
1646 const Type *ClassType
1647 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr();
1648 FromType = S.Context.getMemberPointerType(FromType, ClassType);
1649 } else if (isa<UnaryOperator>(From->IgnoreParens())) {
1650 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() ==
1652 "Non-address-of operator for overloaded function expression");
1653 FromType = S.Context.getPointerType(FromType);
1656 // Check that we've computed the proper type after overload resolution.
1657 // FIXME: FixOverloadedFunctionReference has side-effects; we shouldn't
1658 // be calling it from within an NDEBUG block.
1659 assert(S.Context.hasSameType(
1661 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType()));
1666 // Lvalue-to-rvalue conversion (C++11 4.1):
1667 // A glvalue (3.10) of a non-function, non-array type T can
1668 // be converted to a prvalue.
1669 bool argIsLValue = From->isGLValue();
1671 !FromType->isFunctionType() && !FromType->isArrayType() &&
1672 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) {
1673 SCS.First = ICK_Lvalue_To_Rvalue;
1676 // ... if the lvalue has atomic type, the value has the non-atomic version
1677 // of the type of the lvalue ...
1678 if (const AtomicType *Atomic = FromType->getAs<AtomicType>())
1679 FromType = Atomic->getValueType();
1681 // If T is a non-class type, the type of the rvalue is the
1682 // cv-unqualified version of T. Otherwise, the type of the rvalue
1683 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we
1684 // just strip the qualifiers because they don't matter.
1685 FromType = FromType.getUnqualifiedType();
1686 } else if (FromType->isArrayType()) {
1687 // Array-to-pointer conversion (C++ 4.2)
1688 SCS.First = ICK_Array_To_Pointer;
1690 // An lvalue or rvalue of type "array of N T" or "array of unknown
1691 // bound of T" can be converted to an rvalue of type "pointer to
1693 FromType = S.Context.getArrayDecayedType(FromType);
1695 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) {
1696 // This conversion is deprecated in C++03 (D.4)
1697 SCS.DeprecatedStringLiteralToCharPtr = true;
1699 // For the purpose of ranking in overload resolution
1700 // (13.3.3.1.1), this conversion is considered an
1701 // array-to-pointer conversion followed by a qualification
1702 // conversion (4.4). (C++ 4.2p2)
1703 SCS.Second = ICK_Identity;
1704 SCS.Third = ICK_Qualification;
1705 SCS.QualificationIncludesObjCLifetime = false;
1706 SCS.setAllToTypes(FromType);
1709 } else if (FromType->isFunctionType() && argIsLValue) {
1710 // Function-to-pointer conversion (C++ 4.3).
1711 SCS.First = ICK_Function_To_Pointer;
1713 if (auto *DRE = dyn_cast<DeclRefExpr>(From->IgnoreParenCasts()))
1714 if (auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl()))
1715 if (!S.checkAddressOfFunctionIsAvailable(FD))
1718 // An lvalue of function type T can be converted to an rvalue of
1719 // type "pointer to T." The result is a pointer to the
1720 // function. (C++ 4.3p1).
1721 FromType = S.Context.getPointerType(FromType);
1723 // We don't require any conversions for the first step.
1724 SCS.First = ICK_Identity;
1726 SCS.setToType(0, FromType);
1728 // The second conversion can be an integral promotion, floating
1729 // point promotion, integral conversion, floating point conversion,
1730 // floating-integral conversion, pointer conversion,
1731 // pointer-to-member conversion, or boolean conversion (C++ 4p1).
1732 // For overloading in C, this can also be a "compatible-type"
1734 bool IncompatibleObjC = false;
1735 ImplicitConversionKind SecondICK = ICK_Identity;
1736 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) {
1737 // The unqualified versions of the types are the same: there's no
1738 // conversion to do.
1739 SCS.Second = ICK_Identity;
1740 } else if (S.IsIntegralPromotion(From, FromType, ToType)) {
1741 // Integral promotion (C++ 4.5).
1742 SCS.Second = ICK_Integral_Promotion;
1743 FromType = ToType.getUnqualifiedType();
1744 } else if (S.IsFloatingPointPromotion(FromType, ToType)) {
1745 // Floating point promotion (C++ 4.6).
1746 SCS.Second = ICK_Floating_Promotion;
1747 FromType = ToType.getUnqualifiedType();
1748 } else if (S.IsComplexPromotion(FromType, ToType)) {
1749 // Complex promotion (Clang extension)
1750 SCS.Second = ICK_Complex_Promotion;
1751 FromType = ToType.getUnqualifiedType();
1752 } else if (ToType->isBooleanType() &&
1753 (FromType->isArithmeticType() ||
1754 FromType->isAnyPointerType() ||
1755 FromType->isBlockPointerType() ||
1756 FromType->isMemberPointerType() ||
1757 FromType->isNullPtrType())) {
1758 // Boolean conversions (C++ 4.12).
1759 SCS.Second = ICK_Boolean_Conversion;
1760 FromType = S.Context.BoolTy;
1761 } else if (FromType->isIntegralOrUnscopedEnumerationType() &&
1762 ToType->isIntegralType(S.Context)) {
1763 // Integral conversions (C++ 4.7).
1764 SCS.Second = ICK_Integral_Conversion;
1765 FromType = ToType.getUnqualifiedType();
1766 } else if (FromType->isAnyComplexType() && ToType->isAnyComplexType()) {
1767 // Complex conversions (C99 6.3.1.6)
1768 SCS.Second = ICK_Complex_Conversion;
1769 FromType = ToType.getUnqualifiedType();
1770 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) ||
1771 (ToType->isAnyComplexType() && FromType->isArithmeticType())) {
1772 // Complex-real conversions (C99 6.3.1.7)
1773 SCS.Second = ICK_Complex_Real;
1774 FromType = ToType.getUnqualifiedType();
1775 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) {
1776 // FIXME: disable conversions between long double and __float128 if
1777 // their representation is different until there is back end support
1778 // We of course allow this conversion if long double is really double.
1779 if (&S.Context.getFloatTypeSemantics(FromType) !=
1780 &S.Context.getFloatTypeSemantics(ToType)) {
1781 bool Float128AndLongDouble = ((FromType == S.Context.Float128Ty &&
1782 ToType == S.Context.LongDoubleTy) ||
1783 (FromType == S.Context.LongDoubleTy &&
1784 ToType == S.Context.Float128Ty));
1785 if (Float128AndLongDouble &&
1786 (&S.Context.getFloatTypeSemantics(S.Context.LongDoubleTy) ==
1787 &llvm::APFloat::PPCDoubleDouble()))
1790 // Floating point conversions (C++ 4.8).
1791 SCS.Second = ICK_Floating_Conversion;
1792 FromType = ToType.getUnqualifiedType();
1793 } else if ((FromType->isRealFloatingType() &&
1794 ToType->isIntegralType(S.Context)) ||
1795 (FromType->isIntegralOrUnscopedEnumerationType() &&
1796 ToType->isRealFloatingType())) {
1797 // Floating-integral conversions (C++ 4.9).
1798 SCS.Second = ICK_Floating_Integral;
1799 FromType = ToType.getUnqualifiedType();
1800 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) {
1801 SCS.Second = ICK_Block_Pointer_Conversion;
1802 } else if (AllowObjCWritebackConversion &&
1803 S.isObjCWritebackConversion(FromType, ToType, FromType)) {
1804 SCS.Second = ICK_Writeback_Conversion;
1805 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution,
1806 FromType, IncompatibleObjC)) {
1807 // Pointer conversions (C++ 4.10).
1808 SCS.Second = ICK_Pointer_Conversion;
1809 SCS.IncompatibleObjC = IncompatibleObjC;
1810 FromType = FromType.getUnqualifiedType();
1811 } else if (S.IsMemberPointerConversion(From, FromType, ToType,
1812 InOverloadResolution, FromType)) {
1813 // Pointer to member conversions (4.11).
1814 SCS.Second = ICK_Pointer_Member;
1815 } else if (IsVectorConversion(S, FromType, ToType, SecondICK)) {
1816 SCS.Second = SecondICK;
1817 FromType = ToType.getUnqualifiedType();
1818 } else if (!S.getLangOpts().CPlusPlus &&
1819 S.Context.typesAreCompatible(ToType, FromType)) {
1820 // Compatible conversions (Clang extension for C function overloading)
1821 SCS.Second = ICK_Compatible_Conversion;
1822 FromType = ToType.getUnqualifiedType();
1823 } else if (IsTransparentUnionStandardConversion(S, From, ToType,
1824 InOverloadResolution,
1826 SCS.Second = ICK_TransparentUnionConversion;
1828 } else if (tryAtomicConversion(S, From, ToType, InOverloadResolution, SCS,
1830 // tryAtomicConversion has updated the standard conversion sequence
1833 } else if (ToType->isEventT() &&
1834 From->isIntegerConstantExpr(S.getASTContext()) &&
1835 From->EvaluateKnownConstInt(S.getASTContext()) == 0) {
1836 SCS.Second = ICK_Zero_Event_Conversion;
1838 } else if (ToType->isQueueT() &&
1839 From->isIntegerConstantExpr(S.getASTContext()) &&
1840 (From->EvaluateKnownConstInt(S.getASTContext()) == 0)) {
1841 SCS.Second = ICK_Zero_Queue_Conversion;
1844 // No second conversion required.
1845 SCS.Second = ICK_Identity;
1847 SCS.setToType(1, FromType);
1849 // The third conversion can be a function pointer conversion or a
1850 // qualification conversion (C++ [conv.fctptr], [conv.qual]).
1851 bool ObjCLifetimeConversion;
1852 if (S.IsFunctionConversion(FromType, ToType, FromType)) {
1853 // Function pointer conversions (removing 'noexcept') including removal of
1854 // 'noreturn' (Clang extension).
1855 SCS.Third = ICK_Function_Conversion;
1856 } else if (S.IsQualificationConversion(FromType, ToType, CStyle,
1857 ObjCLifetimeConversion)) {
1858 SCS.Third = ICK_Qualification;
1859 SCS.QualificationIncludesObjCLifetime = ObjCLifetimeConversion;
1862 // No conversion required
1863 SCS.Third = ICK_Identity;
1866 // C++ [over.best.ics]p6:
1867 // [...] Any difference in top-level cv-qualification is
1868 // subsumed by the initialization itself and does not constitute
1869 // a conversion. [...]
1870 QualType CanonFrom = S.Context.getCanonicalType(FromType);
1871 QualType CanonTo = S.Context.getCanonicalType(ToType);
1872 if (CanonFrom.getLocalUnqualifiedType()
1873 == CanonTo.getLocalUnqualifiedType() &&
1874 CanonFrom.getLocalQualifiers() != CanonTo.getLocalQualifiers()) {
1876 CanonFrom = CanonTo;
1879 SCS.setToType(2, FromType);
1881 if (CanonFrom == CanonTo)
1884 // If we have not converted the argument type to the parameter type,
1885 // this is a bad conversion sequence, unless we're resolving an overload in C.
1886 if (S.getLangOpts().CPlusPlus || !InOverloadResolution)
1889 ExprResult ER = ExprResult{From};
1890 Sema::AssignConvertType Conv =
1891 S.CheckSingleAssignmentConstraints(ToType, ER,
1893 /*DiagnoseCFAudited=*/false,
1894 /*ConvertRHS=*/false);
1895 ImplicitConversionKind SecondConv;
1897 case Sema::Compatible:
1898 SecondConv = ICK_C_Only_Conversion;
1900 // For our purposes, discarding qualifiers is just as bad as using an
1901 // incompatible pointer. Note that an IncompatiblePointer conversion can drop
1902 // qualifiers, as well.
1903 case Sema::CompatiblePointerDiscardsQualifiers:
1904 case Sema::IncompatiblePointer:
1905 case Sema::IncompatiblePointerSign:
1906 SecondConv = ICK_Incompatible_Pointer_Conversion;
1912 // First can only be an lvalue conversion, so we pretend that this was the
1913 // second conversion. First should already be valid from earlier in the
1915 SCS.Second = SecondConv;
1916 SCS.setToType(1, ToType);
1918 // Third is Identity, because Second should rank us worse than any other
1919 // conversion. This could also be ICK_Qualification, but it's simpler to just
1920 // lump everything in with the second conversion, and we don't gain anything
1921 // from making this ICK_Qualification.
1922 SCS.Third = ICK_Identity;
1923 SCS.setToType(2, ToType);
1928 IsTransparentUnionStandardConversion(Sema &S, Expr* From,
1930 bool InOverloadResolution,
1931 StandardConversionSequence &SCS,
1934 const RecordType *UT = ToType->getAsUnionType();
1935 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>())
1937 // The field to initialize within the transparent union.
1938 RecordDecl *UD = UT->getDecl();
1939 // It's compatible if the expression matches any of the fields.
1940 for (const auto *it : UD->fields()) {
1941 if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS,
1942 CStyle, /*ObjCWritebackConversion=*/false)) {
1943 ToType = it->getType();
1950 /// IsIntegralPromotion - Determines whether the conversion from the
1951 /// expression From (whose potentially-adjusted type is FromType) to
1952 /// ToType is an integral promotion (C++ 4.5). If so, returns true and
1953 /// sets PromotedType to the promoted type.
1954 bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) {
1955 const BuiltinType *To = ToType->getAs<BuiltinType>();
1956 // All integers are built-in.
1961 // An rvalue of type char, signed char, unsigned char, short int, or
1962 // unsigned short int can be converted to an rvalue of type int if
1963 // int can represent all the values of the source type; otherwise,
1964 // the source rvalue can be converted to an rvalue of type unsigned
1966 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() &&
1967 !FromType->isEnumeralType()) {
1968 if (// We can promote any signed, promotable integer type to an int
1969 (FromType->isSignedIntegerType() ||
1970 // We can promote any unsigned integer type whose size is
1971 // less than int to an int.
1972 Context.getTypeSize(FromType) < Context.getTypeSize(ToType))) {
1973 return To->getKind() == BuiltinType::Int;
1976 return To->getKind() == BuiltinType::UInt;
1979 // C++11 [conv.prom]p3:
1980 // A prvalue of an unscoped enumeration type whose underlying type is not
1981 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the
1982 // following types that can represent all the values of the enumeration
1983 // (i.e., the values in the range bmin to bmax as described in 7.2): int,
1984 // unsigned int, long int, unsigned long int, long long int, or unsigned
1985 // long long int. If none of the types in that list can represent all the
1986 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration
1987 // type can be converted to an rvalue a prvalue of the extended integer type
1988 // with lowest integer conversion rank (4.13) greater than the rank of long
1989 // long in which all the values of the enumeration can be represented. If
1990 // there are two such extended types, the signed one is chosen.
1991 // C++11 [conv.prom]p4:
1992 // A prvalue of an unscoped enumeration type whose underlying type is fixed
1993 // can be converted to a prvalue of its underlying type. Moreover, if
1994 // integral promotion can be applied to its underlying type, a prvalue of an
1995 // unscoped enumeration type whose underlying type is fixed can also be
1996 // converted to a prvalue of the promoted underlying type.
1997 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) {
1998 // C++0x 7.2p9: Note that this implicit enum to int conversion is not
1999 // provided for a scoped enumeration.
2000 if (FromEnumType->getDecl()->isScoped())
2003 // We can perform an integral promotion to the underlying type of the enum,
2004 // even if that's not the promoted type. Note that the check for promoting
2005 // the underlying type is based on the type alone, and does not consider
2006 // the bitfield-ness of the actual source expression.
2007 if (FromEnumType->getDecl()->isFixed()) {
2008 QualType Underlying = FromEnumType->getDecl()->getIntegerType();
2009 return Context.hasSameUnqualifiedType(Underlying, ToType) ||
2010 IsIntegralPromotion(nullptr, Underlying, ToType);
2013 // We have already pre-calculated the promotion type, so this is trivial.
2014 if (ToType->isIntegerType() &&
2015 isCompleteType(From->getLocStart(), FromType))
2016 return Context.hasSameUnqualifiedType(
2017 ToType, FromEnumType->getDecl()->getPromotionType());
2019 // C++ [conv.prom]p5:
2020 // If the bit-field has an enumerated type, it is treated as any other
2021 // value of that type for promotion purposes.
2023 // ... so do not fall through into the bit-field checks below in C++.
2024 if (getLangOpts().CPlusPlus)
2028 // C++0x [conv.prom]p2:
2029 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted
2030 // to an rvalue a prvalue of the first of the following types that can
2031 // represent all the values of its underlying type: int, unsigned int,
2032 // long int, unsigned long int, long long int, or unsigned long long int.
2033 // If none of the types in that list can represent all the values of its
2034 // underlying type, an rvalue a prvalue of type char16_t, char32_t,
2035 // or wchar_t can be converted to an rvalue a prvalue of its underlying
2037 if (FromType->isAnyCharacterType() && !FromType->isCharType() &&
2038 ToType->isIntegerType()) {
2039 // Determine whether the type we're converting from is signed or
2041 bool FromIsSigned = FromType->isSignedIntegerType();
2042 uint64_t FromSize = Context.getTypeSize(FromType);
2044 // The types we'll try to promote to, in the appropriate
2045 // order. Try each of these types.
2046 QualType PromoteTypes[6] = {
2047 Context.IntTy, Context.UnsignedIntTy,
2048 Context.LongTy, Context.UnsignedLongTy ,
2049 Context.LongLongTy, Context.UnsignedLongLongTy
2051 for (int Idx = 0; Idx < 6; ++Idx) {
2052 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]);
2053 if (FromSize < ToSize ||
2054 (FromSize == ToSize &&
2055 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) {
2056 // We found the type that we can promote to. If this is the
2057 // type we wanted, we have a promotion. Otherwise, no
2059 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]);
2064 // An rvalue for an integral bit-field (9.6) can be converted to an
2065 // rvalue of type int if int can represent all the values of the
2066 // bit-field; otherwise, it can be converted to unsigned int if
2067 // unsigned int can represent all the values of the bit-field. If
2068 // the bit-field is larger yet, no integral promotion applies to
2069 // it. If the bit-field has an enumerated type, it is treated as any
2070 // other value of that type for promotion purposes (C++ 4.5p3).
2071 // FIXME: We should delay checking of bit-fields until we actually perform the
2074 // FIXME: In C, only bit-fields of types _Bool, int, or unsigned int may be
2075 // promoted, per C11 6.3.1.1/2. We promote all bit-fields (including enum
2076 // bit-fields and those whose underlying type is larger than int) for GCC
2079 if (FieldDecl *MemberDecl = From->getSourceBitField()) {
2080 llvm::APSInt BitWidth;
2081 if (FromType->isIntegralType(Context) &&
2082 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) {
2083 llvm::APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned());
2084 ToSize = Context.getTypeSize(ToType);
2086 // Are we promoting to an int from a bitfield that fits in an int?
2087 if (BitWidth < ToSize ||
2088 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) {
2089 return To->getKind() == BuiltinType::Int;
2092 // Are we promoting to an unsigned int from an unsigned bitfield
2093 // that fits into an unsigned int?
2094 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) {
2095 return To->getKind() == BuiltinType::UInt;
2103 // An rvalue of type bool can be converted to an rvalue of type int,
2104 // with false becoming zero and true becoming one (C++ 4.5p4).
2105 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) {
2112 /// IsFloatingPointPromotion - Determines whether the conversion from
2113 /// FromType to ToType is a floating point promotion (C++ 4.6). If so,
2114 /// returns true and sets PromotedType to the promoted type.
2115 bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) {
2116 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>())
2117 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) {
2118 /// An rvalue of type float can be converted to an rvalue of type
2119 /// double. (C++ 4.6p1).
2120 if (FromBuiltin->getKind() == BuiltinType::Float &&
2121 ToBuiltin->getKind() == BuiltinType::Double)
2125 // When a float is promoted to double or long double, or a
2126 // double is promoted to long double [...].
2127 if (!getLangOpts().CPlusPlus &&
2128 (FromBuiltin->getKind() == BuiltinType::Float ||
2129 FromBuiltin->getKind() == BuiltinType::Double) &&
2130 (ToBuiltin->getKind() == BuiltinType::LongDouble ||
2131 ToBuiltin->getKind() == BuiltinType::Float128))
2134 // Half can be promoted to float.
2135 if (!getLangOpts().NativeHalfType &&
2136 FromBuiltin->getKind() == BuiltinType::Half &&
2137 ToBuiltin->getKind() == BuiltinType::Float)
2144 /// Determine if a conversion is a complex promotion.
2146 /// A complex promotion is defined as a complex -> complex conversion
2147 /// where the conversion between the underlying real types is a
2148 /// floating-point or integral promotion.
2149 bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) {
2150 const ComplexType *FromComplex = FromType->getAs<ComplexType>();
2154 const ComplexType *ToComplex = ToType->getAs<ComplexType>();
2158 return IsFloatingPointPromotion(FromComplex->getElementType(),
2159 ToComplex->getElementType()) ||
2160 IsIntegralPromotion(nullptr, FromComplex->getElementType(),
2161 ToComplex->getElementType());
2164 /// BuildSimilarlyQualifiedPointerType - In a pointer conversion from
2165 /// the pointer type FromPtr to a pointer to type ToPointee, with the
2166 /// same type qualifiers as FromPtr has on its pointee type. ToType,
2167 /// if non-empty, will be a pointer to ToType that may or may not have
2168 /// the right set of qualifiers on its pointee.
2171 BuildSimilarlyQualifiedPointerType(const Type *FromPtr,
2172 QualType ToPointee, QualType ToType,
2173 ASTContext &Context,
2174 bool StripObjCLifetime = false) {
2175 assert((FromPtr->getTypeClass() == Type::Pointer ||
2176 FromPtr->getTypeClass() == Type::ObjCObjectPointer) &&
2177 "Invalid similarly-qualified pointer type");
2179 /// Conversions to 'id' subsume cv-qualifier conversions.
2180 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType())
2181 return ToType.getUnqualifiedType();
2183 QualType CanonFromPointee
2184 = Context.getCanonicalType(FromPtr->getPointeeType());
2185 QualType CanonToPointee = Context.getCanonicalType(ToPointee);
2186 Qualifiers Quals = CanonFromPointee.getQualifiers();
2188 if (StripObjCLifetime)
2189 Quals.removeObjCLifetime();
2191 // Exact qualifier match -> return the pointer type we're converting to.
2192 if (CanonToPointee.getLocalQualifiers() == Quals) {
2193 // ToType is exactly what we need. Return it.
2194 if (!ToType.isNull())
2195 return ToType.getUnqualifiedType();
2197 // Build a pointer to ToPointee. It has the right qualifiers
2199 if (isa<ObjCObjectPointerType>(ToType))
2200 return Context.getObjCObjectPointerType(ToPointee);
2201 return Context.getPointerType(ToPointee);
2204 // Just build a canonical type that has the right qualifiers.
2205 QualType QualifiedCanonToPointee
2206 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals);
2208 if (isa<ObjCObjectPointerType>(ToType))
2209 return Context.getObjCObjectPointerType(QualifiedCanonToPointee);
2210 return Context.getPointerType(QualifiedCanonToPointee);
2213 static bool isNullPointerConstantForConversion(Expr *Expr,
2214 bool InOverloadResolution,
2215 ASTContext &Context) {
2216 // Handle value-dependent integral null pointer constants correctly.
2217 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903
2218 if (Expr->isValueDependent() && !Expr->isTypeDependent() &&
2219 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType())
2220 return !InOverloadResolution;
2222 return Expr->isNullPointerConstant(Context,
2223 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
2224 : Expr::NPC_ValueDependentIsNull);
2227 /// IsPointerConversion - Determines whether the conversion of the
2228 /// expression From, which has the (possibly adjusted) type FromType,
2229 /// can be converted to the type ToType via a pointer conversion (C++
2230 /// 4.10). If so, returns true and places the converted type (that
2231 /// might differ from ToType in its cv-qualifiers at some level) into
2234 /// This routine also supports conversions to and from block pointers
2235 /// and conversions with Objective-C's 'id', 'id<protocols...>', and
2236 /// pointers to interfaces. FIXME: Once we've determined the
2237 /// appropriate overloading rules for Objective-C, we may want to
2238 /// split the Objective-C checks into a different routine; however,
2239 /// GCC seems to consider all of these conversions to be pointer
2240 /// conversions, so for now they live here. IncompatibleObjC will be
2241 /// set if the conversion is an allowed Objective-C conversion that
2242 /// should result in a warning.
2243 bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType,
2244 bool InOverloadResolution,
2245 QualType& ConvertedType,
2246 bool &IncompatibleObjC) {
2247 IncompatibleObjC = false;
2248 if (isObjCPointerConversion(FromType, ToType, ConvertedType,
2252 // Conversion from a null pointer constant to any Objective-C pointer type.
2253 if (ToType->isObjCObjectPointerType() &&
2254 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2255 ConvertedType = ToType;
2259 // Blocks: Block pointers can be converted to void*.
2260 if (FromType->isBlockPointerType() && ToType->isPointerType() &&
2261 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) {
2262 ConvertedType = ToType;
2265 // Blocks: A null pointer constant can be converted to a block
2267 if (ToType->isBlockPointerType() &&
2268 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2269 ConvertedType = ToType;
2273 // If the left-hand-side is nullptr_t, the right side can be a null
2274 // pointer constant.
2275 if (ToType->isNullPtrType() &&
2276 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2277 ConvertedType = ToType;
2281 const PointerType* ToTypePtr = ToType->getAs<PointerType>();
2285 // A null pointer constant can be converted to a pointer type (C++ 4.10p1).
2286 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2287 ConvertedType = ToType;
2291 // Beyond this point, both types need to be pointers
2292 // , including objective-c pointers.
2293 QualType ToPointeeType = ToTypePtr->getPointeeType();
2294 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType() &&
2295 !getLangOpts().ObjCAutoRefCount) {
2296 ConvertedType = BuildSimilarlyQualifiedPointerType(
2297 FromType->getAs<ObjCObjectPointerType>(),
2302 const PointerType *FromTypePtr = FromType->getAs<PointerType>();
2306 QualType FromPointeeType = FromTypePtr->getPointeeType();
2308 // If the unqualified pointee types are the same, this can't be a
2309 // pointer conversion, so don't do all of the work below.
2310 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType))
2313 // An rvalue of type "pointer to cv T," where T is an object type,
2314 // can be converted to an rvalue of type "pointer to cv void" (C++
2316 if (FromPointeeType->isIncompleteOrObjectType() &&
2317 ToPointeeType->isVoidType()) {
2318 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2321 /*StripObjCLifetime=*/true);
2325 // MSVC allows implicit function to void* type conversion.
2326 if (getLangOpts().MSVCCompat && FromPointeeType->isFunctionType() &&
2327 ToPointeeType->isVoidType()) {
2328 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2334 // When we're overloading in C, we allow a special kind of pointer
2335 // conversion for compatible-but-not-identical pointee types.
2336 if (!getLangOpts().CPlusPlus &&
2337 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) {
2338 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2344 // C++ [conv.ptr]p3:
2346 // An rvalue of type "pointer to cv D," where D is a class type,
2347 // can be converted to an rvalue of type "pointer to cv B," where
2348 // B is a base class (clause 10) of D. If B is an inaccessible
2349 // (clause 11) or ambiguous (10.2) base class of D, a program that
2350 // necessitates this conversion is ill-formed. The result of the
2351 // conversion is a pointer to the base class sub-object of the
2352 // derived class object. The null pointer value is converted to
2353 // the null pointer value of the destination type.
2355 // Note that we do not check for ambiguity or inaccessibility
2356 // here. That is handled by CheckPointerConversion.
2357 if (getLangOpts().CPlusPlus &&
2358 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() &&
2359 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) &&
2360 IsDerivedFrom(From->getLocStart(), FromPointeeType, ToPointeeType)) {
2361 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2367 if (FromPointeeType->isVectorType() && ToPointeeType->isVectorType() &&
2368 Context.areCompatibleVectorTypes(FromPointeeType, ToPointeeType)) {
2369 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2378 /// Adopt the given qualifiers for the given type.
2379 static QualType AdoptQualifiers(ASTContext &Context, QualType T, Qualifiers Qs){
2380 Qualifiers TQs = T.getQualifiers();
2382 // Check whether qualifiers already match.
2386 if (Qs.compatiblyIncludes(TQs))
2387 return Context.getQualifiedType(T, Qs);
2389 return Context.getQualifiedType(T.getUnqualifiedType(), Qs);
2392 /// isObjCPointerConversion - Determines whether this is an
2393 /// Objective-C pointer conversion. Subroutine of IsPointerConversion,
2394 /// with the same arguments and return values.
2395 bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType,
2396 QualType& ConvertedType,
2397 bool &IncompatibleObjC) {
2398 if (!getLangOpts().ObjC1)
2401 // The set of qualifiers on the type we're converting from.
2402 Qualifiers FromQualifiers = FromType.getQualifiers();
2404 // First, we handle all conversions on ObjC object pointer types.
2405 const ObjCObjectPointerType* ToObjCPtr =
2406 ToType->getAs<ObjCObjectPointerType>();
2407 const ObjCObjectPointerType *FromObjCPtr =
2408 FromType->getAs<ObjCObjectPointerType>();
2410 if (ToObjCPtr && FromObjCPtr) {
2411 // If the pointee types are the same (ignoring qualifications),
2412 // then this is not a pointer conversion.
2413 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(),
2414 FromObjCPtr->getPointeeType()))
2417 // Conversion between Objective-C pointers.
2418 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) {
2419 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType();
2420 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType();
2421 if (getLangOpts().CPlusPlus && LHS && RHS &&
2422 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs(
2423 FromObjCPtr->getPointeeType()))
2425 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2426 ToObjCPtr->getPointeeType(),
2428 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2432 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) {
2433 // Okay: this is some kind of implicit downcast of Objective-C
2434 // interfaces, which is permitted. However, we're going to
2435 // complain about it.
2436 IncompatibleObjC = true;
2437 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2438 ToObjCPtr->getPointeeType(),
2440 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2444 // Beyond this point, both types need to be C pointers or block pointers.
2445 QualType ToPointeeType;
2446 if (const PointerType *ToCPtr = ToType->getAs<PointerType>())
2447 ToPointeeType = ToCPtr->getPointeeType();
2448 else if (const BlockPointerType *ToBlockPtr =
2449 ToType->getAs<BlockPointerType>()) {
2450 // Objective C++: We're able to convert from a pointer to any object
2451 // to a block pointer type.
2452 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) {
2453 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2456 ToPointeeType = ToBlockPtr->getPointeeType();
2458 else if (FromType->getAs<BlockPointerType>() &&
2459 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) {
2460 // Objective C++: We're able to convert from a block pointer type to a
2461 // pointer to any object.
2462 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2468 QualType FromPointeeType;
2469 if (const PointerType *FromCPtr = FromType->getAs<PointerType>())
2470 FromPointeeType = FromCPtr->getPointeeType();
2471 else if (const BlockPointerType *FromBlockPtr =
2472 FromType->getAs<BlockPointerType>())
2473 FromPointeeType = FromBlockPtr->getPointeeType();
2477 // If we have pointers to pointers, recursively check whether this
2478 // is an Objective-C conversion.
2479 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() &&
2480 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2481 IncompatibleObjC)) {
2482 // We always complain about this conversion.
2483 IncompatibleObjC = true;
2484 ConvertedType = Context.getPointerType(ConvertedType);
2485 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2488 // Allow conversion of pointee being objective-c pointer to another one;
2490 if (FromPointeeType->getAs<ObjCObjectPointerType>() &&
2491 ToPointeeType->getAs<ObjCObjectPointerType>() &&
2492 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2493 IncompatibleObjC)) {
2495 ConvertedType = Context.getPointerType(ConvertedType);
2496 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2500 // If we have pointers to functions or blocks, check whether the only
2501 // differences in the argument and result types are in Objective-C
2502 // pointer conversions. If so, we permit the conversion (but
2503 // complain about it).
2504 const FunctionProtoType *FromFunctionType
2505 = FromPointeeType->getAs<FunctionProtoType>();
2506 const FunctionProtoType *ToFunctionType
2507 = ToPointeeType->getAs<FunctionProtoType>();
2508 if (FromFunctionType && ToFunctionType) {
2509 // If the function types are exactly the same, this isn't an
2510 // Objective-C pointer conversion.
2511 if (Context.getCanonicalType(FromPointeeType)
2512 == Context.getCanonicalType(ToPointeeType))
2515 // Perform the quick checks that will tell us whether these
2516 // function types are obviously different.
2517 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2518 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() ||
2519 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals())
2522 bool HasObjCConversion = false;
2523 if (Context.getCanonicalType(FromFunctionType->getReturnType()) ==
2524 Context.getCanonicalType(ToFunctionType->getReturnType())) {
2525 // Okay, the types match exactly. Nothing to do.
2526 } else if (isObjCPointerConversion(FromFunctionType->getReturnType(),
2527 ToFunctionType->getReturnType(),
2528 ConvertedType, IncompatibleObjC)) {
2529 // Okay, we have an Objective-C pointer conversion.
2530 HasObjCConversion = true;
2532 // Function types are too different. Abort.
2536 // Check argument types.
2537 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2538 ArgIdx != NumArgs; ++ArgIdx) {
2539 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2540 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2541 if (Context.getCanonicalType(FromArgType)
2542 == Context.getCanonicalType(ToArgType)) {
2543 // Okay, the types match exactly. Nothing to do.
2544 } else if (isObjCPointerConversion(FromArgType, ToArgType,
2545 ConvertedType, IncompatibleObjC)) {
2546 // Okay, we have an Objective-C pointer conversion.
2547 HasObjCConversion = true;
2549 // Argument types are too different. Abort.
2554 if (HasObjCConversion) {
2555 // We had an Objective-C conversion. Allow this pointer
2556 // conversion, but complain about it.
2557 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2558 IncompatibleObjC = true;
2566 /// Determine whether this is an Objective-C writeback conversion,
2567 /// used for parameter passing when performing automatic reference counting.
2569 /// \param FromType The type we're converting form.
2571 /// \param ToType The type we're converting to.
2573 /// \param ConvertedType The type that will be produced after applying
2574 /// this conversion.
2575 bool Sema::isObjCWritebackConversion(QualType FromType, QualType ToType,
2576 QualType &ConvertedType) {
2577 if (!getLangOpts().ObjCAutoRefCount ||
2578 Context.hasSameUnqualifiedType(FromType, ToType))
2581 // Parameter must be a pointer to __autoreleasing (with no other qualifiers).
2583 if (const PointerType *ToPointer = ToType->getAs<PointerType>())
2584 ToPointee = ToPointer->getPointeeType();
2588 Qualifiers ToQuals = ToPointee.getQualifiers();
2589 if (!ToPointee->isObjCLifetimeType() ||
2590 ToQuals.getObjCLifetime() != Qualifiers::OCL_Autoreleasing ||
2591 !ToQuals.withoutObjCLifetime().empty())
2594 // Argument must be a pointer to __strong to __weak.
2595 QualType FromPointee;
2596 if (const PointerType *FromPointer = FromType->getAs<PointerType>())
2597 FromPointee = FromPointer->getPointeeType();
2601 Qualifiers FromQuals = FromPointee.getQualifiers();
2602 if (!FromPointee->isObjCLifetimeType() ||
2603 (FromQuals.getObjCLifetime() != Qualifiers::OCL_Strong &&
2604 FromQuals.getObjCLifetime() != Qualifiers::OCL_Weak))
2607 // Make sure that we have compatible qualifiers.
2608 FromQuals.setObjCLifetime(Qualifiers::OCL_Autoreleasing);
2609 if (!ToQuals.compatiblyIncludes(FromQuals))
2612 // Remove qualifiers from the pointee type we're converting from; they
2613 // aren't used in the compatibility check belong, and we'll be adding back
2614 // qualifiers (with __autoreleasing) if the compatibility check succeeds.
2615 FromPointee = FromPointee.getUnqualifiedType();
2617 // The unqualified form of the pointee types must be compatible.
2618 ToPointee = ToPointee.getUnqualifiedType();
2619 bool IncompatibleObjC;
2620 if (Context.typesAreCompatible(FromPointee, ToPointee))
2621 FromPointee = ToPointee;
2622 else if (!isObjCPointerConversion(FromPointee, ToPointee, FromPointee,
2626 /// Construct the type we're converting to, which is a pointer to
2627 /// __autoreleasing pointee.
2628 FromPointee = Context.getQualifiedType(FromPointee, FromQuals);
2629 ConvertedType = Context.getPointerType(FromPointee);
2633 bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType,
2634 QualType& ConvertedType) {
2635 QualType ToPointeeType;
2636 if (const BlockPointerType *ToBlockPtr =
2637 ToType->getAs<BlockPointerType>())
2638 ToPointeeType = ToBlockPtr->getPointeeType();
2642 QualType FromPointeeType;
2643 if (const BlockPointerType *FromBlockPtr =
2644 FromType->getAs<BlockPointerType>())
2645 FromPointeeType = FromBlockPtr->getPointeeType();
2648 // We have pointer to blocks, check whether the only
2649 // differences in the argument and result types are in Objective-C
2650 // pointer conversions. If so, we permit the conversion.
2652 const FunctionProtoType *FromFunctionType
2653 = FromPointeeType->getAs<FunctionProtoType>();
2654 const FunctionProtoType *ToFunctionType
2655 = ToPointeeType->getAs<FunctionProtoType>();
2657 if (!FromFunctionType || !ToFunctionType)
2660 if (Context.hasSameType(FromPointeeType, ToPointeeType))
2663 // Perform the quick checks that will tell us whether these
2664 // function types are obviously different.
2665 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2666 FromFunctionType->isVariadic() != ToFunctionType->isVariadic())
2669 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo();
2670 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo();
2671 if (FromEInfo != ToEInfo)
2674 bool IncompatibleObjC = false;
2675 if (Context.hasSameType(FromFunctionType->getReturnType(),
2676 ToFunctionType->getReturnType())) {
2677 // Okay, the types match exactly. Nothing to do.
2679 QualType RHS = FromFunctionType->getReturnType();
2680 QualType LHS = ToFunctionType->getReturnType();
2681 if ((!getLangOpts().CPlusPlus || !RHS->isRecordType()) &&
2682 !RHS.hasQualifiers() && LHS.hasQualifiers())
2683 LHS = LHS.getUnqualifiedType();
2685 if (Context.hasSameType(RHS,LHS)) {
2687 } else if (isObjCPointerConversion(RHS, LHS,
2688 ConvertedType, IncompatibleObjC)) {
2689 if (IncompatibleObjC)
2691 // Okay, we have an Objective-C pointer conversion.
2697 // Check argument types.
2698 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2699 ArgIdx != NumArgs; ++ArgIdx) {
2700 IncompatibleObjC = false;
2701 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2702 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2703 if (Context.hasSameType(FromArgType, ToArgType)) {
2704 // Okay, the types match exactly. Nothing to do.
2705 } else if (isObjCPointerConversion(ToArgType, FromArgType,
2706 ConvertedType, IncompatibleObjC)) {
2707 if (IncompatibleObjC)
2709 // Okay, we have an Objective-C pointer conversion.
2711 // Argument types are too different. Abort.
2715 SmallVector<FunctionProtoType::ExtParameterInfo, 4> NewParamInfos;
2716 bool CanUseToFPT, CanUseFromFPT;
2717 if (!Context.mergeExtParameterInfo(ToFunctionType, FromFunctionType,
2718 CanUseToFPT, CanUseFromFPT,
2722 ConvertedType = ToType;
2730 ft_parameter_mismatch,
2732 ft_qualifer_mismatch,
2736 /// Attempts to get the FunctionProtoType from a Type. Handles
2737 /// MemberFunctionPointers properly.
2738 static const FunctionProtoType *tryGetFunctionProtoType(QualType FromType) {
2739 if (auto *FPT = FromType->getAs<FunctionProtoType>())
2742 if (auto *MPT = FromType->getAs<MemberPointerType>())
2743 return MPT->getPointeeType()->getAs<FunctionProtoType>();
2748 /// HandleFunctionTypeMismatch - Gives diagnostic information for differeing
2749 /// function types. Catches different number of parameter, mismatch in
2750 /// parameter types, and different return types.
2751 void Sema::HandleFunctionTypeMismatch(PartialDiagnostic &PDiag,
2752 QualType FromType, QualType ToType) {
2753 // If either type is not valid, include no extra info.
2754 if (FromType.isNull() || ToType.isNull()) {
2755 PDiag << ft_default;
2759 // Get the function type from the pointers.
2760 if (FromType->isMemberPointerType() && ToType->isMemberPointerType()) {
2761 const MemberPointerType *FromMember = FromType->getAs<MemberPointerType>(),
2762 *ToMember = ToType->getAs<MemberPointerType>();
2763 if (!Context.hasSameType(FromMember->getClass(), ToMember->getClass())) {
2764 PDiag << ft_different_class << QualType(ToMember->getClass(), 0)
2765 << QualType(FromMember->getClass(), 0);
2768 FromType = FromMember->getPointeeType();
2769 ToType = ToMember->getPointeeType();
2772 if (FromType->isPointerType())
2773 FromType = FromType->getPointeeType();
2774 if (ToType->isPointerType())
2775 ToType = ToType->getPointeeType();
2777 // Remove references.
2778 FromType = FromType.getNonReferenceType();
2779 ToType = ToType.getNonReferenceType();
2781 // Don't print extra info for non-specialized template functions.
2782 if (FromType->isInstantiationDependentType() &&
2783 !FromType->getAs<TemplateSpecializationType>()) {
2784 PDiag << ft_default;
2788 // No extra info for same types.
2789 if (Context.hasSameType(FromType, ToType)) {
2790 PDiag << ft_default;
2794 const FunctionProtoType *FromFunction = tryGetFunctionProtoType(FromType),
2795 *ToFunction = tryGetFunctionProtoType(ToType);
2797 // Both types need to be function types.
2798 if (!FromFunction || !ToFunction) {
2799 PDiag << ft_default;
2803 if (FromFunction->getNumParams() != ToFunction->getNumParams()) {
2804 PDiag << ft_parameter_arity << ToFunction->getNumParams()
2805 << FromFunction->getNumParams();
2809 // Handle different parameter types.
2811 if (!FunctionParamTypesAreEqual(FromFunction, ToFunction, &ArgPos)) {
2812 PDiag << ft_parameter_mismatch << ArgPos + 1
2813 << ToFunction->getParamType(ArgPos)
2814 << FromFunction->getParamType(ArgPos);
2818 // Handle different return type.
2819 if (!Context.hasSameType(FromFunction->getReturnType(),
2820 ToFunction->getReturnType())) {
2821 PDiag << ft_return_type << ToFunction->getReturnType()
2822 << FromFunction->getReturnType();
2826 unsigned FromQuals = FromFunction->getTypeQuals(),
2827 ToQuals = ToFunction->getTypeQuals();
2828 if (FromQuals != ToQuals) {
2829 PDiag << ft_qualifer_mismatch << ToQuals << FromQuals;
2833 // Handle exception specification differences on canonical type (in C++17
2835 if (cast<FunctionProtoType>(FromFunction->getCanonicalTypeUnqualified())
2837 cast<FunctionProtoType>(ToFunction->getCanonicalTypeUnqualified())
2839 PDiag << ft_noexcept;
2843 // Unable to find a difference, so add no extra info.
2844 PDiag << ft_default;
2847 /// FunctionParamTypesAreEqual - This routine checks two function proto types
2848 /// for equality of their argument types. Caller has already checked that
2849 /// they have same number of arguments. If the parameters are different,
2850 /// ArgPos will have the parameter index of the first different parameter.
2851 bool Sema::FunctionParamTypesAreEqual(const FunctionProtoType *OldType,
2852 const FunctionProtoType *NewType,
2854 for (FunctionProtoType::param_type_iterator O = OldType->param_type_begin(),
2855 N = NewType->param_type_begin(),
2856 E = OldType->param_type_end();
2857 O && (O != E); ++O, ++N) {
2858 if (!Context.hasSameType(O->getUnqualifiedType(),
2859 N->getUnqualifiedType())) {
2861 *ArgPos = O - OldType->param_type_begin();
2868 /// CheckPointerConversion - Check the pointer conversion from the
2869 /// expression From to the type ToType. This routine checks for
2870 /// ambiguous or inaccessible derived-to-base pointer
2871 /// conversions for which IsPointerConversion has already returned
2872 /// true. It returns true and produces a diagnostic if there was an
2873 /// error, or returns false otherwise.
2874 bool Sema::CheckPointerConversion(Expr *From, QualType ToType,
2876 CXXCastPath& BasePath,
2877 bool IgnoreBaseAccess,
2879 QualType FromType = From->getType();
2880 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess;
2884 if (Diagnose && !IsCStyleOrFunctionalCast && !FromType->isAnyPointerType() &&
2885 From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) ==
2886 Expr::NPCK_ZeroExpression) {
2887 if (Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy))
2888 DiagRuntimeBehavior(From->getExprLoc(), From,
2889 PDiag(diag::warn_impcast_bool_to_null_pointer)
2890 << ToType << From->getSourceRange());
2891 else if (!isUnevaluatedContext())
2892 Diag(From->getExprLoc(), diag::warn_non_literal_null_pointer)
2893 << ToType << From->getSourceRange();
2895 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) {
2896 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) {
2897 QualType FromPointeeType = FromPtrType->getPointeeType(),
2898 ToPointeeType = ToPtrType->getPointeeType();
2900 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() &&
2901 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) {
2902 // We must have a derived-to-base conversion. Check an
2903 // ambiguous or inaccessible conversion.
2904 unsigned InaccessibleID = 0;
2905 unsigned AmbigiousID = 0;
2907 InaccessibleID = diag::err_upcast_to_inaccessible_base;
2908 AmbigiousID = diag::err_ambiguous_derived_to_base_conv;
2910 if (CheckDerivedToBaseConversion(
2911 FromPointeeType, ToPointeeType, InaccessibleID, AmbigiousID,
2912 From->getExprLoc(), From->getSourceRange(), DeclarationName(),
2913 &BasePath, IgnoreBaseAccess))
2916 // The conversion was successful.
2917 Kind = CK_DerivedToBase;
2920 if (Diagnose && !IsCStyleOrFunctionalCast &&
2921 FromPointeeType->isFunctionType() && ToPointeeType->isVoidType()) {
2922 assert(getLangOpts().MSVCCompat &&
2923 "this should only be possible with MSVCCompat!");
2924 Diag(From->getExprLoc(), diag::ext_ms_impcast_fn_obj)
2925 << From->getSourceRange();
2928 } else if (const ObjCObjectPointerType *ToPtrType =
2929 ToType->getAs<ObjCObjectPointerType>()) {
2930 if (const ObjCObjectPointerType *FromPtrType =
2931 FromType->getAs<ObjCObjectPointerType>()) {
2932 // Objective-C++ conversions are always okay.
2933 // FIXME: We should have a different class of conversions for the
2934 // Objective-C++ implicit conversions.
2935 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType())
2937 } else if (FromType->isBlockPointerType()) {
2938 Kind = CK_BlockPointerToObjCPointerCast;
2940 Kind = CK_CPointerToObjCPointerCast;
2942 } else if (ToType->isBlockPointerType()) {
2943 if (!FromType->isBlockPointerType())
2944 Kind = CK_AnyPointerToBlockPointerCast;
2947 // We shouldn't fall into this case unless it's valid for other
2949 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull))
2950 Kind = CK_NullToPointer;
2955 /// IsMemberPointerConversion - Determines whether the conversion of the
2956 /// expression From, which has the (possibly adjusted) type FromType, can be
2957 /// converted to the type ToType via a member pointer conversion (C++ 4.11).
2958 /// If so, returns true and places the converted type (that might differ from
2959 /// ToType in its cv-qualifiers at some level) into ConvertedType.
2960 bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType,
2962 bool InOverloadResolution,
2963 QualType &ConvertedType) {
2964 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>();
2968 // A null pointer constant can be converted to a member pointer (C++ 4.11p1)
2969 if (From->isNullPointerConstant(Context,
2970 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
2971 : Expr::NPC_ValueDependentIsNull)) {
2972 ConvertedType = ToType;
2976 // Otherwise, both types have to be member pointers.
2977 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>();
2981 // A pointer to member of B can be converted to a pointer to member of D,
2982 // where D is derived from B (C++ 4.11p2).
2983 QualType FromClass(FromTypePtr->getClass(), 0);
2984 QualType ToClass(ToTypePtr->getClass(), 0);
2986 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) &&
2987 IsDerivedFrom(From->getLocStart(), ToClass, FromClass)) {
2988 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(),
2989 ToClass.getTypePtr());
2996 /// CheckMemberPointerConversion - Check the member pointer conversion from the
2997 /// expression From to the type ToType. This routine checks for ambiguous or
2998 /// virtual or inaccessible base-to-derived member pointer conversions
2999 /// for which IsMemberPointerConversion has already returned true. It returns
3000 /// true and produces a diagnostic if there was an error, or returns false
3002 bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType,
3004 CXXCastPath &BasePath,
3005 bool IgnoreBaseAccess) {
3006 QualType FromType = From->getType();
3007 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>();
3009 // This must be a null pointer to member pointer conversion
3010 assert(From->isNullPointerConstant(Context,
3011 Expr::NPC_ValueDependentIsNull) &&
3012 "Expr must be null pointer constant!");
3013 Kind = CK_NullToMemberPointer;
3017 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>();
3018 assert(ToPtrType && "No member pointer cast has a target type "
3019 "that is not a member pointer.");
3021 QualType FromClass = QualType(FromPtrType->getClass(), 0);
3022 QualType ToClass = QualType(ToPtrType->getClass(), 0);
3024 // FIXME: What about dependent types?
3025 assert(FromClass->isRecordType() && "Pointer into non-class.");
3026 assert(ToClass->isRecordType() && "Pointer into non-class.");
3028 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
3029 /*DetectVirtual=*/true);
3030 bool DerivationOkay =
3031 IsDerivedFrom(From->getLocStart(), ToClass, FromClass, Paths);
3032 assert(DerivationOkay &&
3033 "Should not have been called if derivation isn't OK.");
3034 (void)DerivationOkay;
3036 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass).
3037 getUnqualifiedType())) {
3038 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
3039 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv)
3040 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange();
3044 if (const RecordType *VBase = Paths.getDetectedVirtual()) {
3045 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual)
3046 << FromClass << ToClass << QualType(VBase, 0)
3047 << From->getSourceRange();
3051 if (!IgnoreBaseAccess)
3052 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass,
3054 diag::err_downcast_from_inaccessible_base);
3056 // Must be a base to derived member conversion.
3057 BuildBasePathArray(Paths, BasePath);
3058 Kind = CK_BaseToDerivedMemberPointer;
3062 /// Determine whether the lifetime conversion between the two given
3063 /// qualifiers sets is nontrivial.
3064 static bool isNonTrivialObjCLifetimeConversion(Qualifiers FromQuals,
3065 Qualifiers ToQuals) {
3066 // Converting anything to const __unsafe_unretained is trivial.
3067 if (ToQuals.hasConst() &&
3068 ToQuals.getObjCLifetime() == Qualifiers::OCL_ExplicitNone)
3074 /// IsQualificationConversion - Determines whether the conversion from
3075 /// an rvalue of type FromType to ToType is a qualification conversion
3078 /// \param ObjCLifetimeConversion Output parameter that will be set to indicate
3079 /// when the qualification conversion involves a change in the Objective-C
3080 /// object lifetime.
3082 Sema::IsQualificationConversion(QualType FromType, QualType ToType,
3083 bool CStyle, bool &ObjCLifetimeConversion) {
3084 FromType = Context.getCanonicalType(FromType);
3085 ToType = Context.getCanonicalType(ToType);
3086 ObjCLifetimeConversion = false;
3088 // If FromType and ToType are the same type, this is not a
3089 // qualification conversion.
3090 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType())
3094 // A conversion can add cv-qualifiers at levels other than the first
3095 // in multi-level pointers, subject to the following rules: [...]
3096 bool PreviousToQualsIncludeConst = true;
3097 bool UnwrappedAnyPointer = false;
3098 while (Context.UnwrapSimilarTypes(FromType, ToType)) {
3099 // Within each iteration of the loop, we check the qualifiers to
3100 // determine if this still looks like a qualification
3101 // conversion. Then, if all is well, we unwrap one more level of
3102 // pointers or pointers-to-members and do it all again
3103 // until there are no more pointers or pointers-to-members left to
3105 UnwrappedAnyPointer = true;
3107 Qualifiers FromQuals = FromType.getQualifiers();
3108 Qualifiers ToQuals = ToType.getQualifiers();
3110 // Ignore __unaligned qualifier if this type is void.
3111 if (ToType.getUnqualifiedType()->isVoidType())
3112 FromQuals.removeUnaligned();
3115 // Check Objective-C lifetime conversions.
3116 if (FromQuals.getObjCLifetime() != ToQuals.getObjCLifetime() &&
3117 UnwrappedAnyPointer) {
3118 if (ToQuals.compatiblyIncludesObjCLifetime(FromQuals)) {
3119 if (isNonTrivialObjCLifetimeConversion(FromQuals, ToQuals))
3120 ObjCLifetimeConversion = true;
3121 FromQuals.removeObjCLifetime();
3122 ToQuals.removeObjCLifetime();
3124 // Qualification conversions cannot cast between different
3125 // Objective-C lifetime qualifiers.
3130 // Allow addition/removal of GC attributes but not changing GC attributes.
3131 if (FromQuals.getObjCGCAttr() != ToQuals.getObjCGCAttr() &&
3132 (!FromQuals.hasObjCGCAttr() || !ToQuals.hasObjCGCAttr())) {
3133 FromQuals.removeObjCGCAttr();
3134 ToQuals.removeObjCGCAttr();
3137 // -- for every j > 0, if const is in cv 1,j then const is in cv
3138 // 2,j, and similarly for volatile.
3139 if (!CStyle && !ToQuals.compatiblyIncludes(FromQuals))
3142 // -- if the cv 1,j and cv 2,j are different, then const is in
3143 // every cv for 0 < k < j.
3144 if (!CStyle && FromQuals.getCVRQualifiers() != ToQuals.getCVRQualifiers()
3145 && !PreviousToQualsIncludeConst)
3148 // Keep track of whether all prior cv-qualifiers in the "to" type
3150 PreviousToQualsIncludeConst
3151 = PreviousToQualsIncludeConst && ToQuals.hasConst();
3154 // Allows address space promotion by language rules implemented in
3155 // Type::Qualifiers::isAddressSpaceSupersetOf.
3156 Qualifiers FromQuals = FromType.getQualifiers();
3157 Qualifiers ToQuals = ToType.getQualifiers();
3158 if (!ToQuals.isAddressSpaceSupersetOf(FromQuals) &&
3159 !FromQuals.isAddressSpaceSupersetOf(ToQuals)) {
3163 // We are left with FromType and ToType being the pointee types
3164 // after unwrapping the original FromType and ToType the same number
3165 // of types. If we unwrapped any pointers, and if FromType and
3166 // ToType have the same unqualified type (since we checked
3167 // qualifiers above), then this is a qualification conversion.
3168 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType);
3171 /// - Determine whether this is a conversion from a scalar type to an
3174 /// If successful, updates \c SCS's second and third steps in the conversion
3175 /// sequence to finish the conversion.
3176 static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
3177 bool InOverloadResolution,
3178 StandardConversionSequence &SCS,
3180 const AtomicType *ToAtomic = ToType->getAs<AtomicType>();
3184 StandardConversionSequence InnerSCS;
3185 if (!IsStandardConversion(S, From, ToAtomic->getValueType(),
3186 InOverloadResolution, InnerSCS,
3187 CStyle, /*AllowObjCWritebackConversion=*/false))
3190 SCS.Second = InnerSCS.Second;
3191 SCS.setToType(1, InnerSCS.getToType(1));
3192 SCS.Third = InnerSCS.Third;
3193 SCS.QualificationIncludesObjCLifetime
3194 = InnerSCS.QualificationIncludesObjCLifetime;
3195 SCS.setToType(2, InnerSCS.getToType(2));
3199 static bool isFirstArgumentCompatibleWithType(ASTContext &Context,
3200 CXXConstructorDecl *Constructor,
3202 const FunctionProtoType *CtorType =
3203 Constructor->getType()->getAs<FunctionProtoType>();
3204 if (CtorType->getNumParams() > 0) {
3205 QualType FirstArg = CtorType->getParamType(0);
3206 if (Context.hasSameUnqualifiedType(Type, FirstArg.getNonReferenceType()))
3212 static OverloadingResult
3213 IsInitializerListConstructorConversion(Sema &S, Expr *From, QualType ToType,
3215 UserDefinedConversionSequence &User,
3216 OverloadCandidateSet &CandidateSet,
3217 bool AllowExplicit) {
3218 CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion);
3219 for (auto *D : S.LookupConstructors(To)) {
3220 auto Info = getConstructorInfo(D);
3224 bool Usable = !Info.Constructor->isInvalidDecl() &&
3225 S.isInitListConstructor(Info.Constructor) &&
3226 (AllowExplicit || !Info.Constructor->isExplicit());
3228 // If the first argument is (a reference to) the target type,
3229 // suppress conversions.
3230 bool SuppressUserConversions = isFirstArgumentCompatibleWithType(
3231 S.Context, Info.Constructor, ToType);
3232 if (Info.ConstructorTmpl)
3233 S.AddTemplateOverloadCandidate(Info.ConstructorTmpl, Info.FoundDecl,
3234 /*ExplicitArgs*/ nullptr, From,
3235 CandidateSet, SuppressUserConversions);
3237 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl, From,
3238 CandidateSet, SuppressUserConversions);
3242 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3244 OverloadCandidateSet::iterator Best;
3245 switch (auto Result =
3246 CandidateSet.BestViableFunction(S, From->getLocStart(),
3250 // Record the standard conversion we used and the conversion function.
3251 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function);
3252 QualType ThisType = Constructor->getThisType(S.Context);
3253 // Initializer lists don't have conversions as such.
3254 User.Before.setAsIdentityConversion();
3255 User.HadMultipleCandidates = HadMultipleCandidates;
3256 User.ConversionFunction = Constructor;
3257 User.FoundConversionFunction = Best->FoundDecl;
3258 User.After.setAsIdentityConversion();
3259 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType());
3260 User.After.setAllToTypes(ToType);
3264 case OR_No_Viable_Function:
3265 return OR_No_Viable_Function;
3267 return OR_Ambiguous;
3270 llvm_unreachable("Invalid OverloadResult!");
3273 /// Determines whether there is a user-defined conversion sequence
3274 /// (C++ [over.ics.user]) that converts expression From to the type
3275 /// ToType. If such a conversion exists, User will contain the
3276 /// user-defined conversion sequence that performs such a conversion
3277 /// and this routine will return true. Otherwise, this routine returns
3278 /// false and User is unspecified.
3280 /// \param AllowExplicit true if the conversion should consider C++0x
3281 /// "explicit" conversion functions as well as non-explicit conversion
3282 /// functions (C++0x [class.conv.fct]p2).
3284 /// \param AllowObjCConversionOnExplicit true if the conversion should
3285 /// allow an extra Objective-C pointer conversion on uses of explicit
3286 /// constructors. Requires \c AllowExplicit to also be set.
3287 static OverloadingResult
3288 IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
3289 UserDefinedConversionSequence &User,
3290 OverloadCandidateSet &CandidateSet,
3292 bool AllowObjCConversionOnExplicit) {
3293 assert(AllowExplicit || !AllowObjCConversionOnExplicit);
3294 CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion);
3296 // Whether we will only visit constructors.
3297 bool ConstructorsOnly = false;
3299 // If the type we are conversion to is a class type, enumerate its
3301 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) {
3302 // C++ [over.match.ctor]p1:
3303 // When objects of class type are direct-initialized (8.5), or
3304 // copy-initialized from an expression of the same or a
3305 // derived class type (8.5), overload resolution selects the
3306 // constructor. [...] For copy-initialization, the candidate
3307 // functions are all the converting constructors (12.3.1) of
3308 // that class. The argument list is the expression-list within
3309 // the parentheses of the initializer.
3310 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) ||
3311 (From->getType()->getAs<RecordType>() &&
3312 S.IsDerivedFrom(From->getLocStart(), From->getType(), ToType)))
3313 ConstructorsOnly = true;
3315 if (!S.isCompleteType(From->getExprLoc(), ToType)) {
3316 // We're not going to find any constructors.
3317 } else if (CXXRecordDecl *ToRecordDecl
3318 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) {
3320 Expr **Args = &From;
3321 unsigned NumArgs = 1;
3322 bool ListInitializing = false;
3323 if (InitListExpr *InitList = dyn_cast<InitListExpr>(From)) {
3324 // But first, see if there is an init-list-constructor that will work.
3325 OverloadingResult Result = IsInitializerListConstructorConversion(
3326 S, From, ToType, ToRecordDecl, User, CandidateSet, AllowExplicit);
3327 if (Result != OR_No_Viable_Function)
3331 OverloadCandidateSet::CSK_InitByUserDefinedConversion);
3333 // If we're list-initializing, we pass the individual elements as
3334 // arguments, not the entire list.
3335 Args = InitList->getInits();
3336 NumArgs = InitList->getNumInits();
3337 ListInitializing = true;
3340 for (auto *D : S.LookupConstructors(ToRecordDecl)) {
3341 auto Info = getConstructorInfo(D);
3345 bool Usable = !Info.Constructor->isInvalidDecl();
3346 if (ListInitializing)
3347 Usable = Usable && (AllowExplicit || !Info.Constructor->isExplicit());
3350 Info.Constructor->isConvertingConstructor(AllowExplicit);
3352 bool SuppressUserConversions = !ConstructorsOnly;
3353 if (SuppressUserConversions && ListInitializing) {
3354 SuppressUserConversions = false;
3356 // If the first argument is (a reference to) the target type,
3357 // suppress conversions.
3358 SuppressUserConversions = isFirstArgumentCompatibleWithType(
3359 S.Context, Info.Constructor, ToType);
3362 if (Info.ConstructorTmpl)
3363 S.AddTemplateOverloadCandidate(
3364 Info.ConstructorTmpl, Info.FoundDecl,
3365 /*ExplicitArgs*/ nullptr, llvm::makeArrayRef(Args, NumArgs),
3366 CandidateSet, SuppressUserConversions);
3368 // Allow one user-defined conversion when user specifies a
3369 // From->ToType conversion via an static cast (c-style, etc).
3370 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl,
3371 llvm::makeArrayRef(Args, NumArgs),
3372 CandidateSet, SuppressUserConversions);
3378 // Enumerate conversion functions, if we're allowed to.
3379 if (ConstructorsOnly || isa<InitListExpr>(From)) {
3380 } else if (!S.isCompleteType(From->getLocStart(), From->getType())) {
3381 // No conversion functions from incomplete types.
3382 } else if (const RecordType *FromRecordType
3383 = From->getType()->getAs<RecordType>()) {
3384 if (CXXRecordDecl *FromRecordDecl
3385 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) {
3386 // Add all of the conversion functions as candidates.
3387 const auto &Conversions = FromRecordDecl->getVisibleConversionFunctions();
3388 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
3389 DeclAccessPair FoundDecl = I.getPair();
3390 NamedDecl *D = FoundDecl.getDecl();
3391 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
3392 if (isa<UsingShadowDecl>(D))
3393 D = cast<UsingShadowDecl>(D)->getTargetDecl();
3395 CXXConversionDecl *Conv;
3396 FunctionTemplateDecl *ConvTemplate;
3397 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
3398 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
3400 Conv = cast<CXXConversionDecl>(D);
3402 if (AllowExplicit || !Conv->isExplicit()) {
3404 S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl,
3405 ActingContext, From, ToType,
3407 AllowObjCConversionOnExplicit);
3409 S.AddConversionCandidate(Conv, FoundDecl, ActingContext,
3410 From, ToType, CandidateSet,
3411 AllowObjCConversionOnExplicit);
3417 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3419 OverloadCandidateSet::iterator Best;
3420 switch (auto Result = CandidateSet.BestViableFunction(S, From->getLocStart(),
3424 // Record the standard conversion we used and the conversion function.
3425 if (CXXConstructorDecl *Constructor
3426 = dyn_cast<CXXConstructorDecl>(Best->Function)) {
3427 // C++ [over.ics.user]p1:
3428 // If the user-defined conversion is specified by a
3429 // constructor (12.3.1), the initial standard conversion
3430 // sequence converts the source type to the type required by
3431 // the argument of the constructor.
3433 QualType ThisType = Constructor->getThisType(S.Context);
3434 if (isa<InitListExpr>(From)) {
3435 // Initializer lists don't have conversions as such.
3436 User.Before.setAsIdentityConversion();
3438 if (Best->Conversions[0].isEllipsis())
3439 User.EllipsisConversion = true;
3441 User.Before = Best->Conversions[0].Standard;
3442 User.EllipsisConversion = false;
3445 User.HadMultipleCandidates = HadMultipleCandidates;
3446 User.ConversionFunction = Constructor;
3447 User.FoundConversionFunction = Best->FoundDecl;
3448 User.After.setAsIdentityConversion();
3449 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType());
3450 User.After.setAllToTypes(ToType);
3453 if (CXXConversionDecl *Conversion
3454 = dyn_cast<CXXConversionDecl>(Best->Function)) {
3455 // C++ [over.ics.user]p1:
3457 // [...] If the user-defined conversion is specified by a
3458 // conversion function (12.3.2), the initial standard
3459 // conversion sequence converts the source type to the
3460 // implicit object parameter of the conversion function.
3461 User.Before = Best->Conversions[0].Standard;
3462 User.HadMultipleCandidates = HadMultipleCandidates;
3463 User.ConversionFunction = Conversion;
3464 User.FoundConversionFunction = Best->FoundDecl;
3465 User.EllipsisConversion = false;
3467 // C++ [over.ics.user]p2:
3468 // The second standard conversion sequence converts the
3469 // result of the user-defined conversion to the target type
3470 // for the sequence. Since an implicit conversion sequence
3471 // is an initialization, the special rules for
3472 // initialization by user-defined conversion apply when
3473 // selecting the best user-defined conversion for a
3474 // user-defined conversion sequence (see 13.3.3 and
3476 User.After = Best->FinalConversion;
3479 llvm_unreachable("Not a constructor or conversion function?");
3481 case OR_No_Viable_Function:
3482 return OR_No_Viable_Function;
3485 return OR_Ambiguous;
3488 llvm_unreachable("Invalid OverloadResult!");
3492 Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) {
3493 ImplicitConversionSequence ICS;
3494 OverloadCandidateSet CandidateSet(From->getExprLoc(),
3495 OverloadCandidateSet::CSK_Normal);
3496 OverloadingResult OvResult =
3497 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined,
3498 CandidateSet, false, false);
3499 if (OvResult == OR_Ambiguous)
3500 Diag(From->getLocStart(), diag::err_typecheck_ambiguous_condition)
3501 << From->getType() << ToType << From->getSourceRange();
3502 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) {
3503 if (!RequireCompleteType(From->getLocStart(), ToType,
3504 diag::err_typecheck_nonviable_condition_incomplete,
3505 From->getType(), From->getSourceRange()))
3506 Diag(From->getLocStart(), diag::err_typecheck_nonviable_condition)
3507 << false << From->getType() << From->getSourceRange() << ToType;
3510 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, From);
3514 /// Compare the user-defined conversion functions or constructors
3515 /// of two user-defined conversion sequences to determine whether any ordering
3517 static ImplicitConversionSequence::CompareKind
3518 compareConversionFunctions(Sema &S, FunctionDecl *Function1,
3519 FunctionDecl *Function2) {
3520 if (!S.getLangOpts().ObjC1 || !S.getLangOpts().CPlusPlus11)
3521 return ImplicitConversionSequence::Indistinguishable;
3524 // If both conversion functions are implicitly-declared conversions from
3525 // a lambda closure type to a function pointer and a block pointer,
3526 // respectively, always prefer the conversion to a function pointer,
3527 // because the function pointer is more lightweight and is more likely
3528 // to keep code working.
3529 CXXConversionDecl *Conv1 = dyn_cast_or_null<CXXConversionDecl>(Function1);
3531 return ImplicitConversionSequence::Indistinguishable;
3533 CXXConversionDecl *Conv2 = dyn_cast<CXXConversionDecl>(Function2);
3535 return ImplicitConversionSequence::Indistinguishable;
3537 if (Conv1->getParent()->isLambda() && Conv2->getParent()->isLambda()) {
3538 bool Block1 = Conv1->getConversionType()->isBlockPointerType();
3539 bool Block2 = Conv2->getConversionType()->isBlockPointerType();
3540 if (Block1 != Block2)
3541 return Block1 ? ImplicitConversionSequence::Worse
3542 : ImplicitConversionSequence::Better;
3545 return ImplicitConversionSequence::Indistinguishable;
3548 static bool hasDeprecatedStringLiteralToCharPtrConversion(
3549 const ImplicitConversionSequence &ICS) {
3550 return (ICS.isStandard() && ICS.Standard.DeprecatedStringLiteralToCharPtr) ||
3551 (ICS.isUserDefined() &&
3552 ICS.UserDefined.Before.DeprecatedStringLiteralToCharPtr);
3555 /// CompareImplicitConversionSequences - Compare two implicit
3556 /// conversion sequences to determine whether one is better than the
3557 /// other or if they are indistinguishable (C++ 13.3.3.2).
3558 static ImplicitConversionSequence::CompareKind
3559 CompareImplicitConversionSequences(Sema &S, SourceLocation Loc,
3560 const ImplicitConversionSequence& ICS1,
3561 const ImplicitConversionSequence& ICS2)
3563 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit
3564 // conversion sequences (as defined in 13.3.3.1)
3565 // -- a standard conversion sequence (13.3.3.1.1) is a better
3566 // conversion sequence than a user-defined conversion sequence or
3567 // an ellipsis conversion sequence, and
3568 // -- a user-defined conversion sequence (13.3.3.1.2) is a better
3569 // conversion sequence than an ellipsis conversion sequence
3572 // C++0x [over.best.ics]p10:
3573 // For the purpose of ranking implicit conversion sequences as
3574 // described in 13.3.3.2, the ambiguous conversion sequence is
3575 // treated as a user-defined sequence that is indistinguishable
3576 // from any other user-defined conversion sequence.
3578 // String literal to 'char *' conversion has been deprecated in C++03. It has
3579 // been removed from C++11. We still accept this conversion, if it happens at
3580 // the best viable function. Otherwise, this conversion is considered worse
3581 // than ellipsis conversion. Consider this as an extension; this is not in the
3582 // standard. For example:
3584 // int &f(...); // #1
3585 // void f(char*); // #2
3586 // void g() { int &r = f("foo"); }
3588 // In C++03, we pick #2 as the best viable function.
3589 // In C++11, we pick #1 as the best viable function, because ellipsis
3590 // conversion is better than string-literal to char* conversion (since there
3591 // is no such conversion in C++11). If there was no #1 at all or #1 couldn't
3592 // convert arguments, #2 would be the best viable function in C++11.
3593 // If the best viable function has this conversion, a warning will be issued
3594 // in C++03, or an ExtWarn (+SFINAE failure) will be issued in C++11.
3596 if (S.getLangOpts().CPlusPlus11 && !S.getLangOpts().WritableStrings &&
3597 hasDeprecatedStringLiteralToCharPtrConversion(ICS1) !=
3598 hasDeprecatedStringLiteralToCharPtrConversion(ICS2))
3599 return hasDeprecatedStringLiteralToCharPtrConversion(ICS1)
3600 ? ImplicitConversionSequence::Worse
3601 : ImplicitConversionSequence::Better;
3603 if (ICS1.getKindRank() < ICS2.getKindRank())
3604 return ImplicitConversionSequence::Better;
3605 if (ICS2.getKindRank() < ICS1.getKindRank())
3606 return ImplicitConversionSequence::Worse;
3608 // The following checks require both conversion sequences to be of
3610 if (ICS1.getKind() != ICS2.getKind())
3611 return ImplicitConversionSequence::Indistinguishable;
3613 ImplicitConversionSequence::CompareKind Result =
3614 ImplicitConversionSequence::Indistinguishable;
3616 // Two implicit conversion sequences of the same form are
3617 // indistinguishable conversion sequences unless one of the
3618 // following rules apply: (C++ 13.3.3.2p3):
3620 // List-initialization sequence L1 is a better conversion sequence than
3621 // list-initialization sequence L2 if:
3622 // - L1 converts to std::initializer_list<X> for some X and L2 does not, or,
3624 // - L1 converts to type "array of N1 T", L2 converts to type "array of N2 T",
3625 // and N1 is smaller than N2.,
3626 // even if one of the other rules in this paragraph would otherwise apply.
3627 if (!ICS1.isBad()) {
3628 if (ICS1.isStdInitializerListElement() &&
3629 !ICS2.isStdInitializerListElement())
3630 return ImplicitConversionSequence::Better;
3631 if (!ICS1.isStdInitializerListElement() &&
3632 ICS2.isStdInitializerListElement())
3633 return ImplicitConversionSequence::Worse;
3636 if (ICS1.isStandard())
3637 // Standard conversion sequence S1 is a better conversion sequence than
3638 // standard conversion sequence S2 if [...]
3639 Result = CompareStandardConversionSequences(S, Loc,
3640 ICS1.Standard, ICS2.Standard);
3641 else if (ICS1.isUserDefined()) {
3642 // User-defined conversion sequence U1 is a better conversion
3643 // sequence than another user-defined conversion sequence U2 if
3644 // they contain the same user-defined conversion function or
3645 // constructor and if the second standard conversion sequence of
3646 // U1 is better than the second standard conversion sequence of
3647 // U2 (C++ 13.3.3.2p3).
3648 if (ICS1.UserDefined.ConversionFunction ==
3649 ICS2.UserDefined.ConversionFunction)
3650 Result = CompareStandardConversionSequences(S, Loc,
3651 ICS1.UserDefined.After,
3652 ICS2.UserDefined.After);
3654 Result = compareConversionFunctions(S,
3655 ICS1.UserDefined.ConversionFunction,
3656 ICS2.UserDefined.ConversionFunction);
3662 // Per 13.3.3.2p3, compare the given standard conversion sequences to
3663 // determine if one is a proper subset of the other.
3664 static ImplicitConversionSequence::CompareKind
3665 compareStandardConversionSubsets(ASTContext &Context,
3666 const StandardConversionSequence& SCS1,
3667 const StandardConversionSequence& SCS2) {
3668 ImplicitConversionSequence::CompareKind Result
3669 = ImplicitConversionSequence::Indistinguishable;
3671 // the identity conversion sequence is considered to be a subsequence of
3672 // any non-identity conversion sequence
3673 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion())
3674 return ImplicitConversionSequence::Better;
3675 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion())
3676 return ImplicitConversionSequence::Worse;
3678 if (SCS1.Second != SCS2.Second) {
3679 if (SCS1.Second == ICK_Identity)
3680 Result = ImplicitConversionSequence::Better;
3681 else if (SCS2.Second == ICK_Identity)
3682 Result = ImplicitConversionSequence::Worse;
3684 return ImplicitConversionSequence::Indistinguishable;
3685 } else if (!Context.hasSimilarType(SCS1.getToType(1), SCS2.getToType(1)))
3686 return ImplicitConversionSequence::Indistinguishable;
3688 if (SCS1.Third == SCS2.Third) {
3689 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result
3690 : ImplicitConversionSequence::Indistinguishable;
3693 if (SCS1.Third == ICK_Identity)
3694 return Result == ImplicitConversionSequence::Worse
3695 ? ImplicitConversionSequence::Indistinguishable
3696 : ImplicitConversionSequence::Better;
3698 if (SCS2.Third == ICK_Identity)
3699 return Result == ImplicitConversionSequence::Better
3700 ? ImplicitConversionSequence::Indistinguishable
3701 : ImplicitConversionSequence::Worse;
3703 return ImplicitConversionSequence::Indistinguishable;
3706 /// Determine whether one of the given reference bindings is better
3707 /// than the other based on what kind of bindings they are.
3709 isBetterReferenceBindingKind(const StandardConversionSequence &SCS1,
3710 const StandardConversionSequence &SCS2) {
3711 // C++0x [over.ics.rank]p3b4:
3712 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an
3713 // implicit object parameter of a non-static member function declared
3714 // without a ref-qualifier, and *either* S1 binds an rvalue reference
3715 // to an rvalue and S2 binds an lvalue reference *or S1 binds an
3716 // lvalue reference to a function lvalue and S2 binds an rvalue
3719 // FIXME: Rvalue references. We're going rogue with the above edits,
3720 // because the semantics in the current C++0x working paper (N3225 at the
3721 // time of this writing) break the standard definition of std::forward
3722 // and std::reference_wrapper when dealing with references to functions.
3723 // Proposed wording changes submitted to CWG for consideration.
3724 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier ||
3725 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier)
3728 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue &&
3729 SCS2.IsLvalueReference) ||
3730 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue &&
3731 !SCS2.IsLvalueReference && SCS2.BindsToFunctionLvalue);
3734 /// CompareStandardConversionSequences - Compare two standard
3735 /// conversion sequences to determine whether one is better than the
3736 /// other or if they are indistinguishable (C++ 13.3.3.2p3).
3737 static ImplicitConversionSequence::CompareKind
3738 CompareStandardConversionSequences(Sema &S, SourceLocation Loc,
3739 const StandardConversionSequence& SCS1,
3740 const StandardConversionSequence& SCS2)
3742 // Standard conversion sequence S1 is a better conversion sequence
3743 // than standard conversion sequence S2 if (C++ 13.3.3.2p3):
3745 // -- S1 is a proper subsequence of S2 (comparing the conversion
3746 // sequences in the canonical form defined by 13.3.3.1.1,
3747 // excluding any Lvalue Transformation; the identity conversion
3748 // sequence is considered to be a subsequence of any
3749 // non-identity conversion sequence) or, if not that,
3750 if (ImplicitConversionSequence::CompareKind CK
3751 = compareStandardConversionSubsets(S.Context, SCS1, SCS2))
3754 // -- the rank of S1 is better than the rank of S2 (by the rules
3755 // defined below), or, if not that,
3756 ImplicitConversionRank Rank1 = SCS1.getRank();
3757 ImplicitConversionRank Rank2 = SCS2.getRank();
3759 return ImplicitConversionSequence::Better;
3760 else if (Rank2 < Rank1)
3761 return ImplicitConversionSequence::Worse;
3763 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank
3764 // are indistinguishable unless one of the following rules
3767 // A conversion that is not a conversion of a pointer, or
3768 // pointer to member, to bool is better than another conversion
3769 // that is such a conversion.
3770 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool())
3771 return SCS2.isPointerConversionToBool()
3772 ? ImplicitConversionSequence::Better
3773 : ImplicitConversionSequence::Worse;
3775 // C++ [over.ics.rank]p4b2:
3777 // If class B is derived directly or indirectly from class A,
3778 // conversion of B* to A* is better than conversion of B* to
3779 // void*, and conversion of A* to void* is better than conversion
3781 bool SCS1ConvertsToVoid
3782 = SCS1.isPointerConversionToVoidPointer(S.Context);
3783 bool SCS2ConvertsToVoid
3784 = SCS2.isPointerConversionToVoidPointer(S.Context);
3785 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) {
3786 // Exactly one of the conversion sequences is a conversion to
3787 // a void pointer; it's the worse conversion.
3788 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better
3789 : ImplicitConversionSequence::Worse;
3790 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) {
3791 // Neither conversion sequence converts to a void pointer; compare
3792 // their derived-to-base conversions.
3793 if (ImplicitConversionSequence::CompareKind DerivedCK
3794 = CompareDerivedToBaseConversions(S, Loc, SCS1, SCS2))
3796 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid &&
3797 !S.Context.hasSameType(SCS1.getFromType(), SCS2.getFromType())) {
3798 // Both conversion sequences are conversions to void
3799 // pointers. Compare the source types to determine if there's an
3800 // inheritance relationship in their sources.
3801 QualType FromType1 = SCS1.getFromType();
3802 QualType FromType2 = SCS2.getFromType();
3804 // Adjust the types we're converting from via the array-to-pointer
3805 // conversion, if we need to.
3806 if (SCS1.First == ICK_Array_To_Pointer)
3807 FromType1 = S.Context.getArrayDecayedType(FromType1);
3808 if (SCS2.First == ICK_Array_To_Pointer)
3809 FromType2 = S.Context.getArrayDecayedType(FromType2);
3811 QualType FromPointee1 = FromType1->getPointeeType().getUnqualifiedType();
3812 QualType FromPointee2 = FromType2->getPointeeType().getUnqualifiedType();
3814 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
3815 return ImplicitConversionSequence::Better;
3816 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
3817 return ImplicitConversionSequence::Worse;
3819 // Objective-C++: If one interface is more specific than the
3820 // other, it is the better one.
3821 const ObjCObjectPointerType* FromObjCPtr1
3822 = FromType1->getAs<ObjCObjectPointerType>();
3823 const ObjCObjectPointerType* FromObjCPtr2
3824 = FromType2->getAs<ObjCObjectPointerType>();
3825 if (FromObjCPtr1 && FromObjCPtr2) {
3826 bool AssignLeft = S.Context.canAssignObjCInterfaces(FromObjCPtr1,
3828 bool AssignRight = S.Context.canAssignObjCInterfaces(FromObjCPtr2,
3830 if (AssignLeft != AssignRight) {
3831 return AssignLeft? ImplicitConversionSequence::Better
3832 : ImplicitConversionSequence::Worse;
3837 // Compare based on qualification conversions (C++ 13.3.3.2p3,
3839 if (ImplicitConversionSequence::CompareKind QualCK
3840 = CompareQualificationConversions(S, SCS1, SCS2))
3843 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) {
3844 // Check for a better reference binding based on the kind of bindings.
3845 if (isBetterReferenceBindingKind(SCS1, SCS2))
3846 return ImplicitConversionSequence::Better;
3847 else if (isBetterReferenceBindingKind(SCS2, SCS1))
3848 return ImplicitConversionSequence::Worse;
3850 // C++ [over.ics.rank]p3b4:
3851 // -- S1 and S2 are reference bindings (8.5.3), and the types to
3852 // which the references refer are the same type except for
3853 // top-level cv-qualifiers, and the type to which the reference
3854 // initialized by S2 refers is more cv-qualified than the type
3855 // to which the reference initialized by S1 refers.
3856 QualType T1 = SCS1.getToType(2);
3857 QualType T2 = SCS2.getToType(2);
3858 T1 = S.Context.getCanonicalType(T1);
3859 T2 = S.Context.getCanonicalType(T2);
3860 Qualifiers T1Quals, T2Quals;
3861 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
3862 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
3863 if (UnqualT1 == UnqualT2) {
3864 // Objective-C++ ARC: If the references refer to objects with different
3865 // lifetimes, prefer bindings that don't change lifetime.
3866 if (SCS1.ObjCLifetimeConversionBinding !=
3867 SCS2.ObjCLifetimeConversionBinding) {
3868 return SCS1.ObjCLifetimeConversionBinding
3869 ? ImplicitConversionSequence::Worse
3870 : ImplicitConversionSequence::Better;
3873 // If the type is an array type, promote the element qualifiers to the
3874 // type for comparison.
3875 if (isa<ArrayType>(T1) && T1Quals)
3876 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals);
3877 if (isa<ArrayType>(T2) && T2Quals)
3878 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals);
3879 if (T2.isMoreQualifiedThan(T1))
3880 return ImplicitConversionSequence::Better;
3881 else if (T1.isMoreQualifiedThan(T2))
3882 return ImplicitConversionSequence::Worse;
3886 // In Microsoft mode, prefer an integral conversion to a
3887 // floating-to-integral conversion if the integral conversion
3888 // is between types of the same size.
3896 // Here, MSVC will call f(int) instead of generating a compile error
3897 // as clang will do in standard mode.
3898 if (S.getLangOpts().MSVCCompat && SCS1.Second == ICK_Integral_Conversion &&
3899 SCS2.Second == ICK_Floating_Integral &&
3900 S.Context.getTypeSize(SCS1.getFromType()) ==
3901 S.Context.getTypeSize(SCS1.getToType(2)))
3902 return ImplicitConversionSequence::Better;
3904 return ImplicitConversionSequence::Indistinguishable;
3907 /// CompareQualificationConversions - Compares two standard conversion
3908 /// sequences to determine whether they can be ranked based on their
3909 /// qualification conversions (C++ 13.3.3.2p3 bullet 3).
3910 static ImplicitConversionSequence::CompareKind
3911 CompareQualificationConversions(Sema &S,
3912 const StandardConversionSequence& SCS1,
3913 const StandardConversionSequence& SCS2) {
3915 // -- S1 and S2 differ only in their qualification conversion and
3916 // yield similar types T1 and T2 (C++ 4.4), respectively, and the
3917 // cv-qualification signature of type T1 is a proper subset of
3918 // the cv-qualification signature of type T2, and S1 is not the
3919 // deprecated string literal array-to-pointer conversion (4.2).
3920 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second ||
3921 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification)
3922 return ImplicitConversionSequence::Indistinguishable;
3924 // FIXME: the example in the standard doesn't use a qualification
3926 QualType T1 = SCS1.getToType(2);
3927 QualType T2 = SCS2.getToType(2);
3928 T1 = S.Context.getCanonicalType(T1);
3929 T2 = S.Context.getCanonicalType(T2);
3930 Qualifiers T1Quals, T2Quals;
3931 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
3932 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
3934 // If the types are the same, we won't learn anything by unwrapped
3936 if (UnqualT1 == UnqualT2)
3937 return ImplicitConversionSequence::Indistinguishable;
3939 // If the type is an array type, promote the element qualifiers to the type
3941 if (isa<ArrayType>(T1) && T1Quals)
3942 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals);
3943 if (isa<ArrayType>(T2) && T2Quals)
3944 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals);
3946 ImplicitConversionSequence::CompareKind Result
3947 = ImplicitConversionSequence::Indistinguishable;
3949 // Objective-C++ ARC:
3950 // Prefer qualification conversions not involving a change in lifetime
3951 // to qualification conversions that do not change lifetime.
3952 if (SCS1.QualificationIncludesObjCLifetime !=
3953 SCS2.QualificationIncludesObjCLifetime) {
3954 Result = SCS1.QualificationIncludesObjCLifetime
3955 ? ImplicitConversionSequence::Worse
3956 : ImplicitConversionSequence::Better;
3959 while (S.Context.UnwrapSimilarTypes(T1, T2)) {
3960 // Within each iteration of the loop, we check the qualifiers to
3961 // determine if this still looks like a qualification
3962 // conversion. Then, if all is well, we unwrap one more level of
3963 // pointers or pointers-to-members and do it all again
3964 // until there are no more pointers or pointers-to-members left
3965 // to unwrap. This essentially mimics what
3966 // IsQualificationConversion does, but here we're checking for a
3967 // strict subset of qualifiers.
3968 if (T1.getCVRQualifiers() == T2.getCVRQualifiers())
3969 // The qualifiers are the same, so this doesn't tell us anything
3970 // about how the sequences rank.
3972 else if (T2.isMoreQualifiedThan(T1)) {
3973 // T1 has fewer qualifiers, so it could be the better sequence.
3974 if (Result == ImplicitConversionSequence::Worse)
3975 // Neither has qualifiers that are a subset of the other's
3977 return ImplicitConversionSequence::Indistinguishable;
3979 Result = ImplicitConversionSequence::Better;
3980 } else if (T1.isMoreQualifiedThan(T2)) {
3981 // T2 has fewer qualifiers, so it could be the better sequence.
3982 if (Result == ImplicitConversionSequence::Better)
3983 // Neither has qualifiers that are a subset of the other's
3985 return ImplicitConversionSequence::Indistinguishable;
3987 Result = ImplicitConversionSequence::Worse;
3989 // Qualifiers are disjoint.
3990 return ImplicitConversionSequence::Indistinguishable;
3993 // If the types after this point are equivalent, we're done.
3994 if (S.Context.hasSameUnqualifiedType(T1, T2))
3998 // Check that the winning standard conversion sequence isn't using
3999 // the deprecated string literal array to pointer conversion.
4001 case ImplicitConversionSequence::Better:
4002 if (SCS1.DeprecatedStringLiteralToCharPtr)
4003 Result = ImplicitConversionSequence::Indistinguishable;
4006 case ImplicitConversionSequence::Indistinguishable:
4009 case ImplicitConversionSequence::Worse:
4010 if (SCS2.DeprecatedStringLiteralToCharPtr)
4011 Result = ImplicitConversionSequence::Indistinguishable;
4018 /// CompareDerivedToBaseConversions - Compares two standard conversion
4019 /// sequences to determine whether they can be ranked based on their
4020 /// various kinds of derived-to-base conversions (C++
4021 /// [over.ics.rank]p4b3). As part of these checks, we also look at
4022 /// conversions between Objective-C interface types.
4023 static ImplicitConversionSequence::CompareKind
4024 CompareDerivedToBaseConversions(Sema &S, SourceLocation Loc,
4025 const StandardConversionSequence& SCS1,
4026 const StandardConversionSequence& SCS2) {
4027 QualType FromType1 = SCS1.getFromType();
4028 QualType ToType1 = SCS1.getToType(1);
4029 QualType FromType2 = SCS2.getFromType();
4030 QualType ToType2 = SCS2.getToType(1);
4032 // Adjust the types we're converting from via the array-to-pointer
4033 // conversion, if we need to.
4034 if (SCS1.First == ICK_Array_To_Pointer)
4035 FromType1 = S.Context.getArrayDecayedType(FromType1);
4036 if (SCS2.First == ICK_Array_To_Pointer)
4037 FromType2 = S.Context.getArrayDecayedType(FromType2);
4039 // Canonicalize all of the types.
4040 FromType1 = S.Context.getCanonicalType(FromType1);
4041 ToType1 = S.Context.getCanonicalType(ToType1);
4042 FromType2 = S.Context.getCanonicalType(FromType2);
4043 ToType2 = S.Context.getCanonicalType(ToType2);
4045 // C++ [over.ics.rank]p4b3:
4047 // If class B is derived directly or indirectly from class A and
4048 // class C is derived directly or indirectly from B,
4050 // Compare based on pointer conversions.
4051 if (SCS1.Second == ICK_Pointer_Conversion &&
4052 SCS2.Second == ICK_Pointer_Conversion &&
4053 /*FIXME: Remove if Objective-C id conversions get their own rank*/
4054 FromType1->isPointerType() && FromType2->isPointerType() &&
4055 ToType1->isPointerType() && ToType2->isPointerType()) {
4056 QualType FromPointee1
4057 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4059 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4060 QualType FromPointee2
4061 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4063 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4065 // -- conversion of C* to B* is better than conversion of C* to A*,
4066 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
4067 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
4068 return ImplicitConversionSequence::Better;
4069 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
4070 return ImplicitConversionSequence::Worse;
4073 // -- conversion of B* to A* is better than conversion of C* to A*,
4074 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) {
4075 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
4076 return ImplicitConversionSequence::Better;
4077 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
4078 return ImplicitConversionSequence::Worse;
4080 } else if (SCS1.Second == ICK_Pointer_Conversion &&
4081 SCS2.Second == ICK_Pointer_Conversion) {
4082 const ObjCObjectPointerType *FromPtr1
4083 = FromType1->getAs<ObjCObjectPointerType>();
4084 const ObjCObjectPointerType *FromPtr2
4085 = FromType2->getAs<ObjCObjectPointerType>();
4086 const ObjCObjectPointerType *ToPtr1
4087 = ToType1->getAs<ObjCObjectPointerType>();
4088 const ObjCObjectPointerType *ToPtr2
4089 = ToType2->getAs<ObjCObjectPointerType>();
4091 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) {
4092 // Apply the same conversion ranking rules for Objective-C pointer types
4093 // that we do for C++ pointers to class types. However, we employ the
4094 // Objective-C pseudo-subtyping relationship used for assignment of
4095 // Objective-C pointer types.
4097 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2);
4098 bool FromAssignRight
4099 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1);
4101 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2);
4103 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1);
4105 // A conversion to an a non-id object pointer type or qualified 'id'
4106 // type is better than a conversion to 'id'.
4107 if (ToPtr1->isObjCIdType() &&
4108 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl()))
4109 return ImplicitConversionSequence::Worse;
4110 if (ToPtr2->isObjCIdType() &&
4111 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl()))
4112 return ImplicitConversionSequence::Better;
4114 // A conversion to a non-id object pointer type is better than a
4115 // conversion to a qualified 'id' type
4116 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl())
4117 return ImplicitConversionSequence::Worse;
4118 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl())
4119 return ImplicitConversionSequence::Better;
4121 // A conversion to an a non-Class object pointer type or qualified 'Class'
4122 // type is better than a conversion to 'Class'.
4123 if (ToPtr1->isObjCClassType() &&
4124 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl()))
4125 return ImplicitConversionSequence::Worse;
4126 if (ToPtr2->isObjCClassType() &&
4127 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl()))
4128 return ImplicitConversionSequence::Better;
4130 // A conversion to a non-Class object pointer type is better than a
4131 // conversion to a qualified 'Class' type.
4132 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl())
4133 return ImplicitConversionSequence::Worse;
4134 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl())
4135 return ImplicitConversionSequence::Better;
4137 // -- "conversion of C* to B* is better than conversion of C* to A*,"
4138 if (S.Context.hasSameType(FromType1, FromType2) &&
4139 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() &&
4140 (ToAssignLeft != ToAssignRight)) {
4141 if (FromPtr1->isSpecialized()) {
4142 // "conversion of B<A> * to B * is better than conversion of B * to
4145 FromPtr1->getInterfaceDecl() == ToPtr1->getInterfaceDecl();
4147 FromPtr1->getInterfaceDecl() == ToPtr2->getInterfaceDecl();
4150 return ImplicitConversionSequence::Better;
4151 } else if (IsSecondSame)
4152 return ImplicitConversionSequence::Worse;
4154 return ToAssignLeft? ImplicitConversionSequence::Worse
4155 : ImplicitConversionSequence::Better;
4158 // -- "conversion of B* to A* is better than conversion of C* to A*,"
4159 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) &&
4160 (FromAssignLeft != FromAssignRight))
4161 return FromAssignLeft? ImplicitConversionSequence::Better
4162 : ImplicitConversionSequence::Worse;
4166 // Ranking of member-pointer types.
4167 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member &&
4168 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() &&
4169 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) {
4170 const MemberPointerType * FromMemPointer1 =
4171 FromType1->getAs<MemberPointerType>();
4172 const MemberPointerType * ToMemPointer1 =
4173 ToType1->getAs<MemberPointerType>();
4174 const MemberPointerType * FromMemPointer2 =
4175 FromType2->getAs<MemberPointerType>();
4176 const MemberPointerType * ToMemPointer2 =
4177 ToType2->getAs<MemberPointerType>();
4178 const Type *FromPointeeType1 = FromMemPointer1->getClass();
4179 const Type *ToPointeeType1 = ToMemPointer1->getClass();
4180 const Type *FromPointeeType2 = FromMemPointer2->getClass();
4181 const Type *ToPointeeType2 = ToMemPointer2->getClass();
4182 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType();
4183 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType();
4184 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType();
4185 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType();
4186 // conversion of A::* to B::* is better than conversion of A::* to C::*,
4187 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
4188 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
4189 return ImplicitConversionSequence::Worse;
4190 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
4191 return ImplicitConversionSequence::Better;
4193 // conversion of B::* to C::* is better than conversion of A::* to C::*
4194 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) {
4195 if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
4196 return ImplicitConversionSequence::Better;
4197 else if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
4198 return ImplicitConversionSequence::Worse;
4202 if (SCS1.Second == ICK_Derived_To_Base) {
4203 // -- conversion of C to B is better than conversion of C to A,
4204 // -- binding of an expression of type C to a reference of type
4205 // B& is better than binding an expression of type C to a
4206 // reference of type A&,
4207 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4208 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4209 if (S.IsDerivedFrom(Loc, ToType1, ToType2))
4210 return ImplicitConversionSequence::Better;
4211 else if (S.IsDerivedFrom(Loc, ToType2, ToType1))
4212 return ImplicitConversionSequence::Worse;
4215 // -- conversion of B to A is better than conversion of C to A.
4216 // -- binding of an expression of type B to a reference of type
4217 // A& is better than binding an expression of type C to a
4218 // reference of type A&,
4219 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4220 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4221 if (S.IsDerivedFrom(Loc, FromType2, FromType1))
4222 return ImplicitConversionSequence::Better;
4223 else if (S.IsDerivedFrom(Loc, FromType1, FromType2))
4224 return ImplicitConversionSequence::Worse;
4228 return ImplicitConversionSequence::Indistinguishable;
4231 /// Determine whether the given type is valid, e.g., it is not an invalid
4233 static bool isTypeValid(QualType T) {
4234 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl())
4235 return !Record->isInvalidDecl();
4240 /// CompareReferenceRelationship - Compare the two types T1 and T2 to
4241 /// determine whether they are reference-related,
4242 /// reference-compatible, reference-compatible with added
4243 /// qualification, or incompatible, for use in C++ initialization by
4244 /// reference (C++ [dcl.ref.init]p4). Neither type can be a reference
4245 /// type, and the first type (T1) is the pointee type of the reference
4246 /// type being initialized.
4247 Sema::ReferenceCompareResult
4248 Sema::CompareReferenceRelationship(SourceLocation Loc,
4249 QualType OrigT1, QualType OrigT2,
4250 bool &DerivedToBase,
4251 bool &ObjCConversion,
4252 bool &ObjCLifetimeConversion) {
4253 assert(!OrigT1->isReferenceType() &&
4254 "T1 must be the pointee type of the reference type");
4255 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type");
4257 QualType T1 = Context.getCanonicalType(OrigT1);
4258 QualType T2 = Context.getCanonicalType(OrigT2);
4259 Qualifiers T1Quals, T2Quals;
4260 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals);
4261 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals);
4263 // C++ [dcl.init.ref]p4:
4264 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is
4265 // reference-related to "cv2 T2" if T1 is the same type as T2, or
4266 // T1 is a base class of T2.
4267 DerivedToBase = false;
4268 ObjCConversion = false;
4269 ObjCLifetimeConversion = false;
4270 QualType ConvertedT2;
4271 if (UnqualT1 == UnqualT2) {
4273 } else if (isCompleteType(Loc, OrigT2) &&
4274 isTypeValid(UnqualT1) && isTypeValid(UnqualT2) &&
4275 IsDerivedFrom(Loc, UnqualT2, UnqualT1))
4276 DerivedToBase = true;
4277 else if (UnqualT1->isObjCObjectOrInterfaceType() &&
4278 UnqualT2->isObjCObjectOrInterfaceType() &&
4279 Context.canBindObjCObjectType(UnqualT1, UnqualT2))
4280 ObjCConversion = true;
4281 else if (UnqualT2->isFunctionType() &&
4282 IsFunctionConversion(UnqualT2, UnqualT1, ConvertedT2))
4283 // C++1z [dcl.init.ref]p4:
4284 // cv1 T1" is reference-compatible with "cv2 T2" if [...] T2 is "noexcept
4285 // function" and T1 is "function"
4287 // We extend this to also apply to 'noreturn', so allow any function
4288 // conversion between function types.
4289 return Ref_Compatible;
4291 return Ref_Incompatible;
4293 // At this point, we know that T1 and T2 are reference-related (at
4296 // If the type is an array type, promote the element qualifiers to the type
4298 if (isa<ArrayType>(T1) && T1Quals)
4299 T1 = Context.getQualifiedType(UnqualT1, T1Quals);
4300 if (isa<ArrayType>(T2) && T2Quals)
4301 T2 = Context.getQualifiedType(UnqualT2, T2Quals);
4303 // C++ [dcl.init.ref]p4:
4304 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is
4305 // reference-related to T2 and cv1 is the same cv-qualification
4306 // as, or greater cv-qualification than, cv2. For purposes of
4307 // overload resolution, cases for which cv1 is greater
4308 // cv-qualification than cv2 are identified as
4309 // reference-compatible with added qualification (see 13.3.3.2).
4311 // Note that we also require equivalence of Objective-C GC and address-space
4312 // qualifiers when performing these computations, so that e.g., an int in
4313 // address space 1 is not reference-compatible with an int in address
4315 if (T1Quals.getObjCLifetime() != T2Quals.getObjCLifetime() &&
4316 T1Quals.compatiblyIncludesObjCLifetime(T2Quals)) {
4317 if (isNonTrivialObjCLifetimeConversion(T2Quals, T1Quals))
4318 ObjCLifetimeConversion = true;
4320 T1Quals.removeObjCLifetime();
4321 T2Quals.removeObjCLifetime();
4324 // MS compiler ignores __unaligned qualifier for references; do the same.
4325 T1Quals.removeUnaligned();
4326 T2Quals.removeUnaligned();
4328 if (T1Quals.compatiblyIncludes(T2Quals))
4329 return Ref_Compatible;
4334 /// Look for a user-defined conversion to a value reference-compatible
4335 /// with DeclType. Return true if something definite is found.
4337 FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS,
4338 QualType DeclType, SourceLocation DeclLoc,
4339 Expr *Init, QualType T2, bool AllowRvalues,
4340 bool AllowExplicit) {
4341 assert(T2->isRecordType() && "Can only find conversions of record types.");
4342 CXXRecordDecl *T2RecordDecl
4343 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl());
4345 OverloadCandidateSet CandidateSet(
4346 DeclLoc, OverloadCandidateSet::CSK_InitByUserDefinedConversion);
4347 const auto &Conversions = T2RecordDecl->getVisibleConversionFunctions();
4348 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
4350 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
4351 if (isa<UsingShadowDecl>(D))
4352 D = cast<UsingShadowDecl>(D)->getTargetDecl();
4354 FunctionTemplateDecl *ConvTemplate
4355 = dyn_cast<FunctionTemplateDecl>(D);
4356 CXXConversionDecl *Conv;
4358 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
4360 Conv = cast<CXXConversionDecl>(D);
4362 // If this is an explicit conversion, and we're not allowed to consider
4363 // explicit conversions, skip it.
4364 if (!AllowExplicit && Conv->isExplicit())
4368 bool DerivedToBase = false;
4369 bool ObjCConversion = false;
4370 bool ObjCLifetimeConversion = false;
4372 // If we are initializing an rvalue reference, don't permit conversion
4373 // functions that return lvalues.
4374 if (!ConvTemplate && DeclType->isRValueReferenceType()) {
4375 const ReferenceType *RefType
4376 = Conv->getConversionType()->getAs<LValueReferenceType>();
4377 if (RefType && !RefType->getPointeeType()->isFunctionType())
4381 if (!ConvTemplate &&
4382 S.CompareReferenceRelationship(
4384 Conv->getConversionType().getNonReferenceType()
4385 .getUnqualifiedType(),
4386 DeclType.getNonReferenceType().getUnqualifiedType(),
4387 DerivedToBase, ObjCConversion, ObjCLifetimeConversion) ==
4388 Sema::Ref_Incompatible)
4391 // If the conversion function doesn't return a reference type,
4392 // it can't be considered for this conversion. An rvalue reference
4393 // is only acceptable if its referencee is a function type.
4395 const ReferenceType *RefType =
4396 Conv->getConversionType()->getAs<ReferenceType>();
4398 (!RefType->isLValueReferenceType() &&
4399 !RefType->getPointeeType()->isFunctionType()))
4404 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC,
4405 Init, DeclType, CandidateSet,
4406 /*AllowObjCConversionOnExplicit=*/false);
4408 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init,
4409 DeclType, CandidateSet,
4410 /*AllowObjCConversionOnExplicit=*/false);
4413 bool HadMultipleCandidates = (CandidateSet.size() > 1);
4415 OverloadCandidateSet::iterator Best;
4416 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best)) {
4418 // C++ [over.ics.ref]p1:
4420 // [...] If the parameter binds directly to the result of
4421 // applying a conversion function to the argument
4422 // expression, the implicit conversion sequence is a
4423 // user-defined conversion sequence (13.3.3.1.2), with the
4424 // second standard conversion sequence either an identity
4425 // conversion or, if the conversion function returns an
4426 // entity of a type that is a derived class of the parameter
4427 // type, a derived-to-base Conversion.
4428 if (!Best->FinalConversion.DirectBinding)
4431 ICS.setUserDefined();
4432 ICS.UserDefined.Before = Best->Conversions[0].Standard;
4433 ICS.UserDefined.After = Best->FinalConversion;
4434 ICS.UserDefined.HadMultipleCandidates = HadMultipleCandidates;
4435 ICS.UserDefined.ConversionFunction = Best->Function;
4436 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl;
4437 ICS.UserDefined.EllipsisConversion = false;
4438 assert(ICS.UserDefined.After.ReferenceBinding &&
4439 ICS.UserDefined.After.DirectBinding &&
4440 "Expected a direct reference binding!");
4445 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin();
4446 Cand != CandidateSet.end(); ++Cand)
4448 ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
4451 case OR_No_Viable_Function:
4453 // There was no suitable conversion, or we found a deleted
4454 // conversion; continue with other checks.
4458 llvm_unreachable("Invalid OverloadResult!");
4461 /// Compute an implicit conversion sequence for reference
4463 static ImplicitConversionSequence
4464 TryReferenceInit(Sema &S, Expr *Init, QualType DeclType,
4465 SourceLocation DeclLoc,
4466 bool SuppressUserConversions,
4467 bool AllowExplicit) {
4468 assert(DeclType->isReferenceType() && "Reference init needs a reference");
4470 // Most paths end in a failed conversion.
4471 ImplicitConversionSequence ICS;
4472 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4474 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType();
4475 QualType T2 = Init->getType();
4477 // If the initializer is the address of an overloaded function, try
4478 // to resolve the overloaded function. If all goes well, T2 is the
4479 // type of the resulting function.
4480 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
4481 DeclAccessPair Found;
4482 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType,
4487 // Compute some basic properties of the types and the initializer.
4488 bool isRValRef = DeclType->isRValueReferenceType();
4489 bool DerivedToBase = false;
4490 bool ObjCConversion = false;
4491 bool ObjCLifetimeConversion = false;
4492 Expr::Classification InitCategory = Init->Classify(S.Context);
4493 Sema::ReferenceCompareResult RefRelationship
4494 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase,
4495 ObjCConversion, ObjCLifetimeConversion);
4498 // C++0x [dcl.init.ref]p5:
4499 // A reference to type "cv1 T1" is initialized by an expression
4500 // of type "cv2 T2" as follows:
4502 // -- If reference is an lvalue reference and the initializer expression
4504 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is
4505 // reference-compatible with "cv2 T2," or
4507 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here.
4508 if (InitCategory.isLValue() && RefRelationship == Sema::Ref_Compatible) {
4509 // C++ [over.ics.ref]p1:
4510 // When a parameter of reference type binds directly (8.5.3)
4511 // to an argument expression, the implicit conversion sequence
4512 // is the identity conversion, unless the argument expression
4513 // has a type that is a derived class of the parameter type,
4514 // in which case the implicit conversion sequence is a
4515 // derived-to-base Conversion (13.3.3.1).
4517 ICS.Standard.First = ICK_Identity;
4518 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base
4519 : ObjCConversion? ICK_Compatible_Conversion
4521 ICS.Standard.Third = ICK_Identity;
4522 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
4523 ICS.Standard.setToType(0, T2);
4524 ICS.Standard.setToType(1, T1);
4525 ICS.Standard.setToType(2, T1);
4526 ICS.Standard.ReferenceBinding = true;
4527 ICS.Standard.DirectBinding = true;
4528 ICS.Standard.IsLvalueReference = !isRValRef;
4529 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType();
4530 ICS.Standard.BindsToRvalue = false;
4531 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4532 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion;
4533 ICS.Standard.CopyConstructor = nullptr;
4534 ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
4536 // Nothing more to do: the inaccessibility/ambiguity check for
4537 // derived-to-base conversions is suppressed when we're
4538 // computing the implicit conversion sequence (C++
4539 // [over.best.ics]p2).
4543 // -- has a class type (i.e., T2 is a class type), where T1 is
4544 // not reference-related to T2, and can be implicitly
4545 // converted to an lvalue of type "cv3 T3," where "cv1 T1"
4546 // is reference-compatible with "cv3 T3" 92) (this
4547 // conversion is selected by enumerating the applicable
4548 // conversion functions (13.3.1.6) and choosing the best
4549 // one through overload resolution (13.3)),
4550 if (!SuppressUserConversions && T2->isRecordType() &&
4551 S.isCompleteType(DeclLoc, T2) &&
4552 RefRelationship == Sema::Ref_Incompatible) {
4553 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4554 Init, T2, /*AllowRvalues=*/false,
4560 // -- Otherwise, the reference shall be an lvalue reference to a
4561 // non-volatile const type (i.e., cv1 shall be const), or the reference
4562 // shall be an rvalue reference.
4563 if (!isRValRef && (!T1.isConstQualified() || T1.isVolatileQualified()))
4566 // -- If the initializer expression
4568 // -- is an xvalue, class prvalue, array prvalue or function
4569 // lvalue and "cv1 T1" is reference-compatible with "cv2 T2", or
4570 if (RefRelationship == Sema::Ref_Compatible &&
4571 (InitCategory.isXValue() ||
4572 (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) ||
4573 (InitCategory.isLValue() && T2->isFunctionType()))) {
4575 ICS.Standard.First = ICK_Identity;
4576 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base
4577 : ObjCConversion? ICK_Compatible_Conversion
4579 ICS.Standard.Third = ICK_Identity;
4580 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
4581 ICS.Standard.setToType(0, T2);
4582 ICS.Standard.setToType(1, T1);
4583 ICS.Standard.setToType(2, T1);
4584 ICS.Standard.ReferenceBinding = true;
4585 // In C++0x, this is always a direct binding. In C++98/03, it's a direct
4586 // binding unless we're binding to a class prvalue.
4587 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we
4588 // allow the use of rvalue references in C++98/03 for the benefit of
4589 // standard library implementors; therefore, we need the xvalue check here.
4590 ICS.Standard.DirectBinding =
4591 S.getLangOpts().CPlusPlus11 ||
4592 !(InitCategory.isPRValue() || T2->isRecordType());
4593 ICS.Standard.IsLvalueReference = !isRValRef;
4594 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType();
4595 ICS.Standard.BindsToRvalue = InitCategory.isRValue();
4596 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4597 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion;
4598 ICS.Standard.CopyConstructor = nullptr;
4599 ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
4603 // -- has a class type (i.e., T2 is a class type), where T1 is not
4604 // reference-related to T2, and can be implicitly converted to
4605 // an xvalue, class prvalue, or function lvalue of type
4606 // "cv3 T3", where "cv1 T1" is reference-compatible with
4609 // then the reference is bound to the value of the initializer
4610 // expression in the first case and to the result of the conversion
4611 // in the second case (or, in either case, to an appropriate base
4612 // class subobject).
4613 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4614 T2->isRecordType() && S.isCompleteType(DeclLoc, T2) &&
4615 FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4616 Init, T2, /*AllowRvalues=*/true,
4618 // In the second case, if the reference is an rvalue reference
4619 // and the second standard conversion sequence of the
4620 // user-defined conversion sequence includes an lvalue-to-rvalue
4621 // conversion, the program is ill-formed.
4622 if (ICS.isUserDefined() && isRValRef &&
4623 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue)
4624 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4629 // A temporary of function type cannot be created; don't even try.
4630 if (T1->isFunctionType())
4633 // -- Otherwise, a temporary of type "cv1 T1" is created and
4634 // initialized from the initializer expression using the
4635 // rules for a non-reference copy initialization (8.5). The
4636 // reference is then bound to the temporary. If T1 is
4637 // reference-related to T2, cv1 must be the same
4638 // cv-qualification as, or greater cv-qualification than,
4639 // cv2; otherwise, the program is ill-formed.
4640 if (RefRelationship == Sema::Ref_Related) {
4641 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then
4642 // we would be reference-compatible or reference-compatible with
4643 // added qualification. But that wasn't the case, so the reference
4644 // initialization fails.
4646 // Note that we only want to check address spaces and cvr-qualifiers here.
4647 // ObjC GC, lifetime and unaligned qualifiers aren't important.
4648 Qualifiers T1Quals = T1.getQualifiers();
4649 Qualifiers T2Quals = T2.getQualifiers();
4650 T1Quals.removeObjCGCAttr();
4651 T1Quals.removeObjCLifetime();
4652 T2Quals.removeObjCGCAttr();
4653 T2Quals.removeObjCLifetime();
4654 // MS compiler ignores __unaligned qualifier for references; do the same.
4655 T1Quals.removeUnaligned();
4656 T2Quals.removeUnaligned();
4657 if (!T1Quals.compatiblyIncludes(T2Quals))
4661 // If at least one of the types is a class type, the types are not
4662 // related, and we aren't allowed any user conversions, the
4663 // reference binding fails. This case is important for breaking
4664 // recursion, since TryImplicitConversion below will attempt to
4665 // create a temporary through the use of a copy constructor.
4666 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4667 (T1->isRecordType() || T2->isRecordType()))
4670 // If T1 is reference-related to T2 and the reference is an rvalue
4671 // reference, the initializer expression shall not be an lvalue.
4672 if (RefRelationship >= Sema::Ref_Related &&
4673 isRValRef && Init->Classify(S.Context).isLValue())
4676 // C++ [over.ics.ref]p2:
4677 // When a parameter of reference type is not bound directly to
4678 // an argument expression, the conversion sequence is the one
4679 // required to convert the argument expression to the
4680 // underlying type of the reference according to
4681 // 13.3.3.1. Conceptually, this conversion sequence corresponds
4682 // to copy-initializing a temporary of the underlying type with
4683 // the argument expression. Any difference in top-level
4684 // cv-qualification is subsumed by the initialization itself
4685 // and does not constitute a conversion.
4686 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions,
4687 /*AllowExplicit=*/false,
4688 /*InOverloadResolution=*/false,
4690 /*AllowObjCWritebackConversion=*/false,
4691 /*AllowObjCConversionOnExplicit=*/false);
4693 // Of course, that's still a reference binding.
4694 if (ICS.isStandard()) {
4695 ICS.Standard.ReferenceBinding = true;
4696 ICS.Standard.IsLvalueReference = !isRValRef;
4697 ICS.Standard.BindsToFunctionLvalue = false;
4698 ICS.Standard.BindsToRvalue = true;
4699 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4700 ICS.Standard.ObjCLifetimeConversionBinding = false;
4701 } else if (ICS.isUserDefined()) {
4702 const ReferenceType *LValRefType =
4703 ICS.UserDefined.ConversionFunction->getReturnType()
4704 ->getAs<LValueReferenceType>();
4706 // C++ [over.ics.ref]p3:
4707 // Except for an implicit object parameter, for which see 13.3.1, a
4708 // standard conversion sequence cannot be formed if it requires [...]
4709 // binding an rvalue reference to an lvalue other than a function
4711 // Note that the function case is not possible here.
4712 if (DeclType->isRValueReferenceType() && LValRefType) {
4713 // FIXME: This is the wrong BadConversionSequence. The problem is binding
4714 // an rvalue reference to a (non-function) lvalue, not binding an lvalue
4715 // reference to an rvalue!
4716 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, Init, DeclType);
4720 ICS.UserDefined.After.ReferenceBinding = true;
4721 ICS.UserDefined.After.IsLvalueReference = !isRValRef;
4722 ICS.UserDefined.After.BindsToFunctionLvalue = false;
4723 ICS.UserDefined.After.BindsToRvalue = !LValRefType;
4724 ICS.UserDefined.After.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4725 ICS.UserDefined.After.ObjCLifetimeConversionBinding = false;
4731 static ImplicitConversionSequence
4732 TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
4733 bool SuppressUserConversions,
4734 bool InOverloadResolution,
4735 bool AllowObjCWritebackConversion,
4736 bool AllowExplicit = false);
4738 /// TryListConversion - Try to copy-initialize a value of type ToType from the
4739 /// initializer list From.
4740 static ImplicitConversionSequence
4741 TryListConversion(Sema &S, InitListExpr *From, QualType ToType,
4742 bool SuppressUserConversions,
4743 bool InOverloadResolution,
4744 bool AllowObjCWritebackConversion) {
4745 // C++11 [over.ics.list]p1:
4746 // When an argument is an initializer list, it is not an expression and
4747 // special rules apply for converting it to a parameter type.
4749 ImplicitConversionSequence Result;
4750 Result.setBad(BadConversionSequence::no_conversion, From, ToType);
4752 // We need a complete type for what follows. Incomplete types can never be
4753 // initialized from init lists.
4754 if (!S.isCompleteType(From->getLocStart(), ToType))
4758 // If the parameter type is a class X and the initializer list has a single
4759 // element of type cv U, where U is X or a class derived from X, the
4760 // implicit conversion sequence is the one required to convert the element
4761 // to the parameter type.
4763 // Otherwise, if the parameter type is a character array [... ]
4764 // and the initializer list has a single element that is an
4765 // appropriately-typed string literal (8.5.2 [dcl.init.string]), the
4766 // implicit conversion sequence is the identity conversion.
4767 if (From->getNumInits() == 1) {
4768 if (ToType->isRecordType()) {
4769 QualType InitType = From->getInit(0)->getType();
4770 if (S.Context.hasSameUnqualifiedType(InitType, ToType) ||
4771 S.IsDerivedFrom(From->getLocStart(), InitType, ToType))
4772 return TryCopyInitialization(S, From->getInit(0), ToType,
4773 SuppressUserConversions,
4774 InOverloadResolution,
4775 AllowObjCWritebackConversion);
4777 // FIXME: Check the other conditions here: array of character type,
4778 // initializer is a string literal.
4779 if (ToType->isArrayType()) {
4780 InitializedEntity Entity =
4781 InitializedEntity::InitializeParameter(S.Context, ToType,
4782 /*Consumed=*/false);
4783 if (S.CanPerformCopyInitialization(Entity, From)) {
4784 Result.setStandard();
4785 Result.Standard.setAsIdentityConversion();
4786 Result.Standard.setFromType(ToType);
4787 Result.Standard.setAllToTypes(ToType);
4793 // C++14 [over.ics.list]p2: Otherwise, if the parameter type [...] (below).
4794 // C++11 [over.ics.list]p2:
4795 // If the parameter type is std::initializer_list<X> or "array of X" and
4796 // all the elements can be implicitly converted to X, the implicit
4797 // conversion sequence is the worst conversion necessary to convert an
4798 // element of the list to X.
4800 // C++14 [over.ics.list]p3:
4801 // Otherwise, if the parameter type is "array of N X", if the initializer
4802 // list has exactly N elements or if it has fewer than N elements and X is
4803 // default-constructible, and if all the elements of the initializer list
4804 // can be implicitly converted to X, the implicit conversion sequence is
4805 // the worst conversion necessary to convert an element of the list to X.
4807 // FIXME: We're missing a lot of these checks.
4808 bool toStdInitializerList = false;
4810 if (ToType->isArrayType())
4811 X = S.Context.getAsArrayType(ToType)->getElementType();
4813 toStdInitializerList = S.isStdInitializerList(ToType, &X);
4815 for (unsigned i = 0, e = From->getNumInits(); i < e; ++i) {
4816 Expr *Init = From->getInit(i);
4817 ImplicitConversionSequence ICS =
4818 TryCopyInitialization(S, Init, X, SuppressUserConversions,
4819 InOverloadResolution,
4820 AllowObjCWritebackConversion);
4821 // If a single element isn't convertible, fail.
4826 // Otherwise, look for the worst conversion.
4827 if (Result.isBad() ||
4828 CompareImplicitConversionSequences(S, From->getLocStart(), ICS,
4830 ImplicitConversionSequence::Worse)
4834 // For an empty list, we won't have computed any conversion sequence.
4835 // Introduce the identity conversion sequence.
4836 if (From->getNumInits() == 0) {
4837 Result.setStandard();
4838 Result.Standard.setAsIdentityConversion();
4839 Result.Standard.setFromType(ToType);
4840 Result.Standard.setAllToTypes(ToType);
4843 Result.setStdInitializerListElement(toStdInitializerList);
4847 // C++14 [over.ics.list]p4:
4848 // C++11 [over.ics.list]p3:
4849 // Otherwise, if the parameter is a non-aggregate class X and overload
4850 // resolution chooses a single best constructor [...] the implicit
4851 // conversion sequence is a user-defined conversion sequence. If multiple
4852 // constructors are viable but none is better than the others, the
4853 // implicit conversion sequence is a user-defined conversion sequence.
4854 if (ToType->isRecordType() && !ToType->isAggregateType()) {
4855 // This function can deal with initializer lists.
4856 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
4857 /*AllowExplicit=*/false,
4858 InOverloadResolution, /*CStyle=*/false,
4859 AllowObjCWritebackConversion,
4860 /*AllowObjCConversionOnExplicit=*/false);
4863 // C++14 [over.ics.list]p5:
4864 // C++11 [over.ics.list]p4:
4865 // Otherwise, if the parameter has an aggregate type which can be
4866 // initialized from the initializer list [...] the implicit conversion
4867 // sequence is a user-defined conversion sequence.
4868 if (ToType->isAggregateType()) {
4869 // Type is an aggregate, argument is an init list. At this point it comes
4870 // down to checking whether the initialization works.
4871 // FIXME: Find out whether this parameter is consumed or not.
4872 // FIXME: Expose SemaInit's aggregate initialization code so that we don't
4873 // need to call into the initialization code here; overload resolution
4874 // should not be doing that.
4875 InitializedEntity Entity =
4876 InitializedEntity::InitializeParameter(S.Context, ToType,
4877 /*Consumed=*/false);
4878 if (S.CanPerformCopyInitialization(Entity, From)) {
4879 Result.setUserDefined();
4880 Result.UserDefined.Before.setAsIdentityConversion();
4881 // Initializer lists don't have a type.
4882 Result.UserDefined.Before.setFromType(QualType());
4883 Result.UserDefined.Before.setAllToTypes(QualType());
4885 Result.UserDefined.After.setAsIdentityConversion();
4886 Result.UserDefined.After.setFromType(ToType);
4887 Result.UserDefined.After.setAllToTypes(ToType);
4888 Result.UserDefined.ConversionFunction = nullptr;
4893 // C++14 [over.ics.list]p6:
4894 // C++11 [over.ics.list]p5:
4895 // Otherwise, if the parameter is a reference, see 13.3.3.1.4.
4896 if (ToType->isReferenceType()) {
4897 // The standard is notoriously unclear here, since 13.3.3.1.4 doesn't
4898 // mention initializer lists in any way. So we go by what list-
4899 // initialization would do and try to extrapolate from that.
4901 QualType T1 = ToType->getAs<ReferenceType>()->getPointeeType();
4903 // If the initializer list has a single element that is reference-related
4904 // to the parameter type, we initialize the reference from that.
4905 if (From->getNumInits() == 1) {
4906 Expr *Init = From->getInit(0);
4908 QualType T2 = Init->getType();
4910 // If the initializer is the address of an overloaded function, try
4911 // to resolve the overloaded function. If all goes well, T2 is the
4912 // type of the resulting function.
4913 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
4914 DeclAccessPair Found;
4915 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(
4916 Init, ToType, false, Found))
4920 // Compute some basic properties of the types and the initializer.
4921 bool dummy1 = false;
4922 bool dummy2 = false;
4923 bool dummy3 = false;
4924 Sema::ReferenceCompareResult RefRelationship
4925 = S.CompareReferenceRelationship(From->getLocStart(), T1, T2, dummy1,
4928 if (RefRelationship >= Sema::Ref_Related) {
4929 return TryReferenceInit(S, Init, ToType, /*FIXME*/From->getLocStart(),
4930 SuppressUserConversions,
4931 /*AllowExplicit=*/false);
4935 // Otherwise, we bind the reference to a temporary created from the
4936 // initializer list.
4937 Result = TryListConversion(S, From, T1, SuppressUserConversions,
4938 InOverloadResolution,
4939 AllowObjCWritebackConversion);
4940 if (Result.isFailure())
4942 assert(!Result.isEllipsis() &&
4943 "Sub-initialization cannot result in ellipsis conversion.");
4945 // Can we even bind to a temporary?
4946 if (ToType->isRValueReferenceType() ||
4947 (T1.isConstQualified() && !T1.isVolatileQualified())) {
4948 StandardConversionSequence &SCS = Result.isStandard() ? Result.Standard :
4949 Result.UserDefined.After;
4950 SCS.ReferenceBinding = true;
4951 SCS.IsLvalueReference = ToType->isLValueReferenceType();
4952 SCS.BindsToRvalue = true;
4953 SCS.BindsToFunctionLvalue = false;
4954 SCS.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4955 SCS.ObjCLifetimeConversionBinding = false;
4957 Result.setBad(BadConversionSequence::lvalue_ref_to_rvalue,
4962 // C++14 [over.ics.list]p7:
4963 // C++11 [over.ics.list]p6:
4964 // Otherwise, if the parameter type is not a class:
4965 if (!ToType->isRecordType()) {
4966 // - if the initializer list has one element that is not itself an
4967 // initializer list, the implicit conversion sequence is the one
4968 // required to convert the element to the parameter type.
4969 unsigned NumInits = From->getNumInits();
4970 if (NumInits == 1 && !isa<InitListExpr>(From->getInit(0)))
4971 Result = TryCopyInitialization(S, From->getInit(0), ToType,
4972 SuppressUserConversions,
4973 InOverloadResolution,
4974 AllowObjCWritebackConversion);
4975 // - if the initializer list has no elements, the implicit conversion
4976 // sequence is the identity conversion.
4977 else if (NumInits == 0) {
4978 Result.setStandard();
4979 Result.Standard.setAsIdentityConversion();
4980 Result.Standard.setFromType(ToType);
4981 Result.Standard.setAllToTypes(ToType);
4986 // C++14 [over.ics.list]p8:
4987 // C++11 [over.ics.list]p7:
4988 // In all cases other than those enumerated above, no conversion is possible
4992 /// TryCopyInitialization - Try to copy-initialize a value of type
4993 /// ToType from the expression From. Return the implicit conversion
4994 /// sequence required to pass this argument, which may be a bad
4995 /// conversion sequence (meaning that the argument cannot be passed to
4996 /// a parameter of this type). If @p SuppressUserConversions, then we
4997 /// do not permit any user-defined conversion sequences.
4998 static ImplicitConversionSequence
4999 TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
5000 bool SuppressUserConversions,
5001 bool InOverloadResolution,
5002 bool AllowObjCWritebackConversion,
5003 bool AllowExplicit) {
5004 if (InitListExpr *FromInitList = dyn_cast<InitListExpr>(From))
5005 return TryListConversion(S, FromInitList, ToType, SuppressUserConversions,
5006 InOverloadResolution,AllowObjCWritebackConversion);
5008 if (ToType->isReferenceType())
5009 return TryReferenceInit(S, From, ToType,
5010 /*FIXME:*/From->getLocStart(),
5011 SuppressUserConversions,
5014 return TryImplicitConversion(S, From, ToType,
5015 SuppressUserConversions,
5016 /*AllowExplicit=*/false,
5017 InOverloadResolution,
5019 AllowObjCWritebackConversion,
5020 /*AllowObjCConversionOnExplicit=*/false);
5023 static bool TryCopyInitialization(const CanQualType FromQTy,
5024 const CanQualType ToQTy,
5027 ExprValueKind FromVK) {
5028 OpaqueValueExpr TmpExpr(Loc, FromQTy, FromVK);
5029 ImplicitConversionSequence ICS =
5030 TryCopyInitialization(S, &TmpExpr, ToQTy, true, true, false);
5032 return !ICS.isBad();
5035 /// TryObjectArgumentInitialization - Try to initialize the object
5036 /// parameter of the given member function (@c Method) from the
5037 /// expression @p From.
5038 static ImplicitConversionSequence
5039 TryObjectArgumentInitialization(Sema &S, SourceLocation Loc, QualType FromType,
5040 Expr::Classification FromClassification,
5041 CXXMethodDecl *Method,
5042 CXXRecordDecl *ActingContext) {
5043 QualType ClassType = S.Context.getTypeDeclType(ActingContext);
5044 // [class.dtor]p2: A destructor can be invoked for a const, volatile or
5045 // const volatile object.
5046 unsigned Quals = isa<CXXDestructorDecl>(Method) ?
5047 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers();
5048 QualType ImplicitParamType = S.Context.getCVRQualifiedType(ClassType, Quals);
5050 // Set up the conversion sequence as a "bad" conversion, to allow us
5052 ImplicitConversionSequence ICS;
5054 // We need to have an object of class type.
5055 if (const PointerType *PT = FromType->getAs<PointerType>()) {
5056 FromType = PT->getPointeeType();
5058 // When we had a pointer, it's implicitly dereferenced, so we
5059 // better have an lvalue.
5060 assert(FromClassification.isLValue());
5063 assert(FromType->isRecordType());
5065 // C++0x [over.match.funcs]p4:
5066 // For non-static member functions, the type of the implicit object
5069 // - "lvalue reference to cv X" for functions declared without a
5070 // ref-qualifier or with the & ref-qualifier
5071 // - "rvalue reference to cv X" for functions declared with the &&
5074 // where X is the class of which the function is a member and cv is the
5075 // cv-qualification on the member function declaration.
5077 // However, when finding an implicit conversion sequence for the argument, we
5078 // are not allowed to perform user-defined conversions
5079 // (C++ [over.match.funcs]p5). We perform a simplified version of
5080 // reference binding here, that allows class rvalues to bind to
5081 // non-constant references.
5083 // First check the qualifiers.
5084 QualType FromTypeCanon = S.Context.getCanonicalType(FromType);
5085 if (ImplicitParamType.getCVRQualifiers()
5086 != FromTypeCanon.getLocalCVRQualifiers() &&
5087 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) {
5088 ICS.setBad(BadConversionSequence::bad_qualifiers,
5089 FromType, ImplicitParamType);
5093 // Check that we have either the same type or a derived type. It
5094 // affects the conversion rank.
5095 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType);
5096 ImplicitConversionKind SecondKind;
5097 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) {
5098 SecondKind = ICK_Identity;
5099 } else if (S.IsDerivedFrom(Loc, FromType, ClassType))
5100 SecondKind = ICK_Derived_To_Base;
5102 ICS.setBad(BadConversionSequence::unrelated_class,
5103 FromType, ImplicitParamType);
5107 // Check the ref-qualifier.
5108 switch (Method->getRefQualifier()) {
5110 // Do nothing; we don't care about lvalueness or rvalueness.
5114 if (!FromClassification.isLValue() && Quals != Qualifiers::Const) {
5115 // non-const lvalue reference cannot bind to an rvalue
5116 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType,
5123 if (!FromClassification.isRValue()) {
5124 // rvalue reference cannot bind to an lvalue
5125 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType,
5132 // Success. Mark this as a reference binding.
5134 ICS.Standard.setAsIdentityConversion();
5135 ICS.Standard.Second = SecondKind;
5136 ICS.Standard.setFromType(FromType);
5137 ICS.Standard.setAllToTypes(ImplicitParamType);
5138 ICS.Standard.ReferenceBinding = true;
5139 ICS.Standard.DirectBinding = true;
5140 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue;
5141 ICS.Standard.BindsToFunctionLvalue = false;
5142 ICS.Standard.BindsToRvalue = FromClassification.isRValue();
5143 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier
5144 = (Method->getRefQualifier() == RQ_None);
5148 /// PerformObjectArgumentInitialization - Perform initialization of
5149 /// the implicit object parameter for the given Method with the given
5152 Sema::PerformObjectArgumentInitialization(Expr *From,
5153 NestedNameSpecifier *Qualifier,
5154 NamedDecl *FoundDecl,
5155 CXXMethodDecl *Method) {
5156 QualType FromRecordType, DestType;
5157 QualType ImplicitParamRecordType =
5158 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType();
5160 Expr::Classification FromClassification;
5161 if (const PointerType *PT = From->getType()->getAs<PointerType>()) {
5162 FromRecordType = PT->getPointeeType();
5163 DestType = Method->getThisType(Context);
5164 FromClassification = Expr::Classification::makeSimpleLValue();
5166 FromRecordType = From->getType();
5167 DestType = ImplicitParamRecordType;
5168 FromClassification = From->Classify(Context);
5170 // When performing member access on an rvalue, materialize a temporary.
5171 if (From->isRValue()) {
5172 From = CreateMaterializeTemporaryExpr(FromRecordType, From,
5173 Method->getRefQualifier() !=
5174 RefQualifierKind::RQ_RValue);
5178 // Note that we always use the true parent context when performing
5179 // the actual argument initialization.
5180 ImplicitConversionSequence ICS = TryObjectArgumentInitialization(
5181 *this, From->getLocStart(), From->getType(), FromClassification, Method,
5182 Method->getParent());
5184 switch (ICS.Bad.Kind) {
5185 case BadConversionSequence::bad_qualifiers: {
5186 Qualifiers FromQs = FromRecordType.getQualifiers();
5187 Qualifiers ToQs = DestType.getQualifiers();
5188 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers();
5190 Diag(From->getLocStart(),
5191 diag::err_member_function_call_bad_cvr)
5192 << Method->getDeclName() << FromRecordType << (CVR - 1)
5193 << From->getSourceRange();
5194 Diag(Method->getLocation(), diag::note_previous_decl)
5195 << Method->getDeclName();
5201 case BadConversionSequence::lvalue_ref_to_rvalue:
5202 case BadConversionSequence::rvalue_ref_to_lvalue: {
5203 bool IsRValueQualified =
5204 Method->getRefQualifier() == RefQualifierKind::RQ_RValue;
5205 Diag(From->getLocStart(), diag::err_member_function_call_bad_ref)
5206 << Method->getDeclName() << FromClassification.isRValue()
5207 << IsRValueQualified;
5208 Diag(Method->getLocation(), diag::note_previous_decl)
5209 << Method->getDeclName();
5213 case BadConversionSequence::no_conversion:
5214 case BadConversionSequence::unrelated_class:
5218 return Diag(From->getLocStart(),
5219 diag::err_member_function_call_bad_type)
5220 << ImplicitParamRecordType << FromRecordType << From->getSourceRange();
5223 if (ICS.Standard.Second == ICK_Derived_To_Base) {
5224 ExprResult FromRes =
5225 PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method);
5226 if (FromRes.isInvalid())
5228 From = FromRes.get();
5231 if (!Context.hasSameType(From->getType(), DestType))
5232 From = ImpCastExprToType(From, DestType, CK_NoOp,
5233 From->getValueKind()).get();
5237 /// TryContextuallyConvertToBool - Attempt to contextually convert the
5238 /// expression From to bool (C++0x [conv]p3).
5239 static ImplicitConversionSequence
5240 TryContextuallyConvertToBool(Sema &S, Expr *From) {
5241 return TryImplicitConversion(S, From, S.Context.BoolTy,
5242 /*SuppressUserConversions=*/false,
5243 /*AllowExplicit=*/true,
5244 /*InOverloadResolution=*/false,
5246 /*AllowObjCWritebackConversion=*/false,
5247 /*AllowObjCConversionOnExplicit=*/false);
5250 /// PerformContextuallyConvertToBool - Perform a contextual conversion
5251 /// of the expression From to bool (C++0x [conv]p3).
5252 ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) {
5253 if (checkPlaceholderForOverload(*this, From))
5256 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From);
5258 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting);
5260 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy))
5261 return Diag(From->getLocStart(),
5262 diag::err_typecheck_bool_condition)
5263 << From->getType() << From->getSourceRange();
5267 /// Check that the specified conversion is permitted in a converted constant
5268 /// expression, according to C++11 [expr.const]p3. Return true if the conversion
5270 static bool CheckConvertedConstantConversions(Sema &S,
5271 StandardConversionSequence &SCS) {
5272 // Since we know that the target type is an integral or unscoped enumeration
5273 // type, most conversion kinds are impossible. All possible First and Third
5274 // conversions are fine.
5275 switch (SCS.Second) {
5277 case ICK_Function_Conversion:
5278 case ICK_Integral_Promotion:
5279 case ICK_Integral_Conversion: // Narrowing conversions are checked elsewhere.
5280 case ICK_Zero_Queue_Conversion:
5283 case ICK_Boolean_Conversion:
5284 // Conversion from an integral or unscoped enumeration type to bool is
5285 // classified as ICK_Boolean_Conversion, but it's also arguably an integral
5286 // conversion, so we allow it in a converted constant expression.
5288 // FIXME: Per core issue 1407, we should not allow this, but that breaks
5289 // a lot of popular code. We should at least add a warning for this
5290 // (non-conforming) extension.
5291 return SCS.getFromType()->isIntegralOrUnscopedEnumerationType() &&
5292 SCS.getToType(2)->isBooleanType();
5294 case ICK_Pointer_Conversion:
5295 case ICK_Pointer_Member:
5296 // C++1z: null pointer conversions and null member pointer conversions are
5297 // only permitted if the source type is std::nullptr_t.
5298 return SCS.getFromType()->isNullPtrType();
5300 case ICK_Floating_Promotion:
5301 case ICK_Complex_Promotion:
5302 case ICK_Floating_Conversion:
5303 case ICK_Complex_Conversion:
5304 case ICK_Floating_Integral:
5305 case ICK_Compatible_Conversion:
5306 case ICK_Derived_To_Base:
5307 case ICK_Vector_Conversion:
5308 case ICK_Vector_Splat:
5309 case ICK_Complex_Real:
5310 case ICK_Block_Pointer_Conversion:
5311 case ICK_TransparentUnionConversion:
5312 case ICK_Writeback_Conversion:
5313 case ICK_Zero_Event_Conversion:
5314 case ICK_C_Only_Conversion:
5315 case ICK_Incompatible_Pointer_Conversion:
5318 case ICK_Lvalue_To_Rvalue:
5319 case ICK_Array_To_Pointer:
5320 case ICK_Function_To_Pointer:
5321 llvm_unreachable("found a first conversion kind in Second");
5323 case ICK_Qualification:
5324 llvm_unreachable("found a third conversion kind in Second");
5326 case ICK_Num_Conversion_Kinds:
5330 llvm_unreachable("unknown conversion kind");
5333 /// CheckConvertedConstantExpression - Check that the expression From is a
5334 /// converted constant expression of type T, perform the conversion and produce
5335 /// the converted expression, per C++11 [expr.const]p3.
5336 static ExprResult CheckConvertedConstantExpression(Sema &S, Expr *From,
5337 QualType T, APValue &Value,
5340 assert(S.getLangOpts().CPlusPlus11 &&
5341 "converted constant expression outside C++11");
5343 if (checkPlaceholderForOverload(S, From))
5346 // C++1z [expr.const]p3:
5347 // A converted constant expression of type T is an expression,
5348 // implicitly converted to type T, where the converted
5349 // expression is a constant expression and the implicit conversion
5350 // sequence contains only [... list of conversions ...].
5351 // C++1z [stmt.if]p2:
5352 // If the if statement is of the form if constexpr, the value of the
5353 // condition shall be a contextually converted constant expression of type
5355 ImplicitConversionSequence ICS =
5356 CCE == Sema::CCEK_ConstexprIf
5357 ? TryContextuallyConvertToBool(S, From)
5358 : TryCopyInitialization(S, From, T,
5359 /*SuppressUserConversions=*/false,
5360 /*InOverloadResolution=*/false,
5361 /*AllowObjcWritebackConversion=*/false,
5362 /*AllowExplicit=*/false);
5363 StandardConversionSequence *SCS = nullptr;
5364 switch (ICS.getKind()) {
5365 case ImplicitConversionSequence::StandardConversion:
5366 SCS = &ICS.Standard;
5368 case ImplicitConversionSequence::UserDefinedConversion:
5369 // We are converting to a non-class type, so the Before sequence
5371 SCS = &ICS.UserDefined.After;
5373 case ImplicitConversionSequence::AmbiguousConversion:
5374 case ImplicitConversionSequence::BadConversion:
5375 if (!S.DiagnoseMultipleUserDefinedConversion(From, T))
5376 return S.Diag(From->getLocStart(),
5377 diag::err_typecheck_converted_constant_expression)
5378 << From->getType() << From->getSourceRange() << T;
5381 case ImplicitConversionSequence::EllipsisConversion:
5382 llvm_unreachable("ellipsis conversion in converted constant expression");
5385 // Check that we would only use permitted conversions.
5386 if (!CheckConvertedConstantConversions(S, *SCS)) {
5387 return S.Diag(From->getLocStart(),
5388 diag::err_typecheck_converted_constant_expression_disallowed)
5389 << From->getType() << From->getSourceRange() << T;
5391 // [...] and where the reference binding (if any) binds directly.
5392 if (SCS->ReferenceBinding && !SCS->DirectBinding) {
5393 return S.Diag(From->getLocStart(),
5394 diag::err_typecheck_converted_constant_expression_indirect)
5395 << From->getType() << From->getSourceRange() << T;
5399 S.PerformImplicitConversion(From, T, ICS, Sema::AA_Converting);
5400 if (Result.isInvalid())
5403 // Check for a narrowing implicit conversion.
5404 APValue PreNarrowingValue;
5405 QualType PreNarrowingType;
5406 switch (SCS->getNarrowingKind(S.Context, Result.get(), PreNarrowingValue,
5407 PreNarrowingType)) {
5408 case NK_Dependent_Narrowing:
5409 // Implicit conversion to a narrower type, but the expression is
5410 // value-dependent so we can't tell whether it's actually narrowing.
5411 case NK_Variable_Narrowing:
5412 // Implicit conversion to a narrower type, and the value is not a constant
5413 // expression. We'll diagnose this in a moment.
5414 case NK_Not_Narrowing:
5417 case NK_Constant_Narrowing:
5418 S.Diag(From->getLocStart(), diag::ext_cce_narrowing)
5419 << CCE << /*Constant*/1
5420 << PreNarrowingValue.getAsString(S.Context, PreNarrowingType) << T;
5423 case NK_Type_Narrowing:
5424 S.Diag(From->getLocStart(), diag::ext_cce_narrowing)
5425 << CCE << /*Constant*/0 << From->getType() << T;
5429 if (Result.get()->isValueDependent()) {
5434 // Check the expression is a constant expression.
5435 SmallVector<PartialDiagnosticAt, 8> Notes;
5436 Expr::EvalResult Eval;
5438 Expr::ConstExprUsage Usage = CCE == Sema::CCEK_TemplateArg
5439 ? Expr::EvaluateForMangling
5440 : Expr::EvaluateForCodeGen;
5442 if (!Result.get()->EvaluateAsConstantExpr(Eval, Usage, S.Context) ||
5443 (RequireInt && !Eval.Val.isInt())) {
5444 // The expression can't be folded, so we can't keep it at this position in
5446 Result = ExprError();
5450 if (Notes.empty()) {
5451 // It's a constant expression.
5456 // It's not a constant expression. Produce an appropriate diagnostic.
5457 if (Notes.size() == 1 &&
5458 Notes[0].second.getDiagID() == diag::note_invalid_subexpr_in_const_expr)
5459 S.Diag(Notes[0].first, diag::err_expr_not_cce) << CCE;
5461 S.Diag(From->getLocStart(), diag::err_expr_not_cce)
5462 << CCE << From->getSourceRange();
5463 for (unsigned I = 0; I < Notes.size(); ++I)
5464 S.Diag(Notes[I].first, Notes[I].second);
5469 ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5470 APValue &Value, CCEKind CCE) {
5471 return ::CheckConvertedConstantExpression(*this, From, T, Value, CCE, false);
5474 ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5475 llvm::APSInt &Value,
5477 assert(T->isIntegralOrEnumerationType() && "unexpected converted const type");
5480 auto R = ::CheckConvertedConstantExpression(*this, From, T, V, CCE, true);
5481 if (!R.isInvalid() && !R.get()->isValueDependent())
5487 /// dropPointerConversions - If the given standard conversion sequence
5488 /// involves any pointer conversions, remove them. This may change
5489 /// the result type of the conversion sequence.
5490 static void dropPointerConversion(StandardConversionSequence &SCS) {
5491 if (SCS.Second == ICK_Pointer_Conversion) {
5492 SCS.Second = ICK_Identity;
5493 SCS.Third = ICK_Identity;
5494 SCS.ToTypePtrs[2] = SCS.ToTypePtrs[1] = SCS.ToTypePtrs[0];
5498 /// TryContextuallyConvertToObjCPointer - Attempt to contextually
5499 /// convert the expression From to an Objective-C pointer type.
5500 static ImplicitConversionSequence
5501 TryContextuallyConvertToObjCPointer(Sema &S, Expr *From) {
5502 // Do an implicit conversion to 'id'.
5503 QualType Ty = S.Context.getObjCIdType();
5504 ImplicitConversionSequence ICS
5505 = TryImplicitConversion(S, From, Ty,
5506 // FIXME: Are these flags correct?
5507 /*SuppressUserConversions=*/false,
5508 /*AllowExplicit=*/true,
5509 /*InOverloadResolution=*/false,
5511 /*AllowObjCWritebackConversion=*/false,
5512 /*AllowObjCConversionOnExplicit=*/true);
5514 // Strip off any final conversions to 'id'.
5515 switch (ICS.getKind()) {
5516 case ImplicitConversionSequence::BadConversion:
5517 case ImplicitConversionSequence::AmbiguousConversion:
5518 case ImplicitConversionSequence::EllipsisConversion:
5521 case ImplicitConversionSequence::UserDefinedConversion:
5522 dropPointerConversion(ICS.UserDefined.After);
5525 case ImplicitConversionSequence::StandardConversion:
5526 dropPointerConversion(ICS.Standard);
5533 /// PerformContextuallyConvertToObjCPointer - Perform a contextual
5534 /// conversion of the expression From to an Objective-C pointer type.
5535 /// Returns a valid but null ExprResult if no conversion sequence exists.
5536 ExprResult Sema::PerformContextuallyConvertToObjCPointer(Expr *From) {
5537 if (checkPlaceholderForOverload(*this, From))
5540 QualType Ty = Context.getObjCIdType();
5541 ImplicitConversionSequence ICS =
5542 TryContextuallyConvertToObjCPointer(*this, From);
5544 return PerformImplicitConversion(From, Ty, ICS, AA_Converting);
5545 return ExprResult();
5548 /// Determine whether the provided type is an integral type, or an enumeration
5549 /// type of a permitted flavor.
5550 bool Sema::ICEConvertDiagnoser::match(QualType T) {
5551 return AllowScopedEnumerations ? T->isIntegralOrEnumerationType()
5552 : T->isIntegralOrUnscopedEnumerationType();
5556 diagnoseAmbiguousConversion(Sema &SemaRef, SourceLocation Loc, Expr *From,
5557 Sema::ContextualImplicitConverter &Converter,
5558 QualType T, UnresolvedSetImpl &ViableConversions) {
5560 if (Converter.Suppress)
5563 Converter.diagnoseAmbiguous(SemaRef, Loc, T) << From->getSourceRange();
5564 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5565 CXXConversionDecl *Conv =
5566 cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl());
5567 QualType ConvTy = Conv->getConversionType().getNonReferenceType();
5568 Converter.noteAmbiguous(SemaRef, Conv, ConvTy);
5574 diagnoseNoViableConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5575 Sema::ContextualImplicitConverter &Converter,
5576 QualType T, bool HadMultipleCandidates,
5577 UnresolvedSetImpl &ExplicitConversions) {
5578 if (ExplicitConversions.size() == 1 && !Converter.Suppress) {
5579 DeclAccessPair Found = ExplicitConversions[0];
5580 CXXConversionDecl *Conversion =
5581 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5583 // The user probably meant to invoke the given explicit
5584 // conversion; use it.
5585 QualType ConvTy = Conversion->getConversionType().getNonReferenceType();
5586 std::string TypeStr;
5587 ConvTy.getAsStringInternal(TypeStr, SemaRef.getPrintingPolicy());
5589 Converter.diagnoseExplicitConv(SemaRef, Loc, T, ConvTy)
5590 << FixItHint::CreateInsertion(From->getLocStart(),
5591 "static_cast<" + TypeStr + ">(")
5592 << FixItHint::CreateInsertion(
5593 SemaRef.getLocForEndOfToken(From->getLocEnd()), ")");
5594 Converter.noteExplicitConv(SemaRef, Conversion, ConvTy);
5596 // If we aren't in a SFINAE context, build a call to the
5597 // explicit conversion function.
5598 if (SemaRef.isSFINAEContext())
5601 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5602 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5603 HadMultipleCandidates);
5604 if (Result.isInvalid())
5606 // Record usage of conversion in an implicit cast.
5607 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5608 CK_UserDefinedConversion, Result.get(),
5609 nullptr, Result.get()->getValueKind());
5614 static bool recordConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5615 Sema::ContextualImplicitConverter &Converter,
5616 QualType T, bool HadMultipleCandidates,
5617 DeclAccessPair &Found) {
5618 CXXConversionDecl *Conversion =
5619 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5620 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5622 QualType ToType = Conversion->getConversionType().getNonReferenceType();
5623 if (!Converter.SuppressConversion) {
5624 if (SemaRef.isSFINAEContext())
5627 Converter.diagnoseConversion(SemaRef, Loc, T, ToType)
5628 << From->getSourceRange();
5631 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5632 HadMultipleCandidates);
5633 if (Result.isInvalid())
5635 // Record usage of conversion in an implicit cast.
5636 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5637 CK_UserDefinedConversion, Result.get(),
5638 nullptr, Result.get()->getValueKind());
5642 static ExprResult finishContextualImplicitConversion(
5643 Sema &SemaRef, SourceLocation Loc, Expr *From,
5644 Sema::ContextualImplicitConverter &Converter) {
5645 if (!Converter.match(From->getType()) && !Converter.Suppress)
5646 Converter.diagnoseNoMatch(SemaRef, Loc, From->getType())
5647 << From->getSourceRange();
5649 return SemaRef.DefaultLvalueConversion(From);
5653 collectViableConversionCandidates(Sema &SemaRef, Expr *From, QualType ToType,
5654 UnresolvedSetImpl &ViableConversions,
5655 OverloadCandidateSet &CandidateSet) {
5656 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5657 DeclAccessPair FoundDecl = ViableConversions[I];
5658 NamedDecl *D = FoundDecl.getDecl();
5659 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
5660 if (isa<UsingShadowDecl>(D))
5661 D = cast<UsingShadowDecl>(D)->getTargetDecl();
5663 CXXConversionDecl *Conv;
5664 FunctionTemplateDecl *ConvTemplate;
5665 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
5666 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5668 Conv = cast<CXXConversionDecl>(D);
5671 SemaRef.AddTemplateConversionCandidate(
5672 ConvTemplate, FoundDecl, ActingContext, From, ToType, CandidateSet,
5673 /*AllowObjCConversionOnExplicit=*/false);
5675 SemaRef.AddConversionCandidate(Conv, FoundDecl, ActingContext, From,
5676 ToType, CandidateSet,
5677 /*AllowObjCConversionOnExplicit=*/false);
5681 /// Attempt to convert the given expression to a type which is accepted
5682 /// by the given converter.
5684 /// This routine will attempt to convert an expression of class type to a
5685 /// type accepted by the specified converter. In C++11 and before, the class
5686 /// must have a single non-explicit conversion function converting to a matching
5687 /// type. In C++1y, there can be multiple such conversion functions, but only
5688 /// one target type.
5690 /// \param Loc The source location of the construct that requires the
5693 /// \param From The expression we're converting from.
5695 /// \param Converter Used to control and diagnose the conversion process.
5697 /// \returns The expression, converted to an integral or enumeration type if
5699 ExprResult Sema::PerformContextualImplicitConversion(
5700 SourceLocation Loc, Expr *From, ContextualImplicitConverter &Converter) {
5701 // We can't perform any more checking for type-dependent expressions.
5702 if (From->isTypeDependent())
5705 // Process placeholders immediately.
5706 if (From->hasPlaceholderType()) {
5707 ExprResult result = CheckPlaceholderExpr(From);
5708 if (result.isInvalid())
5710 From = result.get();
5713 // If the expression already has a matching type, we're golden.
5714 QualType T = From->getType();
5715 if (Converter.match(T))
5716 return DefaultLvalueConversion(From);
5718 // FIXME: Check for missing '()' if T is a function type?
5720 // We can only perform contextual implicit conversions on objects of class
5722 const RecordType *RecordTy = T->getAs<RecordType>();
5723 if (!RecordTy || !getLangOpts().CPlusPlus) {
5724 if (!Converter.Suppress)
5725 Converter.diagnoseNoMatch(*this, Loc, T) << From->getSourceRange();
5729 // We must have a complete class type.
5730 struct TypeDiagnoserPartialDiag : TypeDiagnoser {
5731 ContextualImplicitConverter &Converter;
5734 TypeDiagnoserPartialDiag(ContextualImplicitConverter &Converter, Expr *From)
5735 : Converter(Converter), From(From) {}
5737 void diagnose(Sema &S, SourceLocation Loc, QualType T) override {
5738 Converter.diagnoseIncomplete(S, Loc, T) << From->getSourceRange();
5740 } IncompleteDiagnoser(Converter, From);
5742 if (Converter.Suppress ? !isCompleteType(Loc, T)
5743 : RequireCompleteType(Loc, T, IncompleteDiagnoser))
5746 // Look for a conversion to an integral or enumeration type.
5748 ViableConversions; // These are *potentially* viable in C++1y.
5749 UnresolvedSet<4> ExplicitConversions;
5750 const auto &Conversions =
5751 cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions();
5753 bool HadMultipleCandidates =
5754 (std::distance(Conversions.begin(), Conversions.end()) > 1);
5756 // To check that there is only one target type, in C++1y:
5758 bool HasUniqueTargetType = true;
5760 // Collect explicit or viable (potentially in C++1y) conversions.
5761 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
5762 NamedDecl *D = (*I)->getUnderlyingDecl();
5763 CXXConversionDecl *Conversion;
5764 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
5766 if (getLangOpts().CPlusPlus14)
5767 Conversion = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5769 continue; // C++11 does not consider conversion operator templates(?).
5771 Conversion = cast<CXXConversionDecl>(D);
5773 assert((!ConvTemplate || getLangOpts().CPlusPlus14) &&
5774 "Conversion operator templates are considered potentially "
5777 QualType CurToType = Conversion->getConversionType().getNonReferenceType();
5778 if (Converter.match(CurToType) || ConvTemplate) {
5780 if (Conversion->isExplicit()) {
5781 // FIXME: For C++1y, do we need this restriction?
5782 // cf. diagnoseNoViableConversion()
5784 ExplicitConversions.addDecl(I.getDecl(), I.getAccess());
5786 if (!ConvTemplate && getLangOpts().CPlusPlus14) {
5787 if (ToType.isNull())
5788 ToType = CurToType.getUnqualifiedType();
5789 else if (HasUniqueTargetType &&
5790 (CurToType.getUnqualifiedType() != ToType))
5791 HasUniqueTargetType = false;
5793 ViableConversions.addDecl(I.getDecl(), I.getAccess());
5798 if (getLangOpts().CPlusPlus14) {
5800 // ... An expression e of class type E appearing in such a context
5801 // is said to be contextually implicitly converted to a specified
5802 // type T and is well-formed if and only if e can be implicitly
5803 // converted to a type T that is determined as follows: E is searched
5804 // for conversion functions whose return type is cv T or reference to
5805 // cv T such that T is allowed by the context. There shall be
5806 // exactly one such T.
5808 // If no unique T is found:
5809 if (ToType.isNull()) {
5810 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5811 HadMultipleCandidates,
5812 ExplicitConversions))
5814 return finishContextualImplicitConversion(*this, Loc, From, Converter);
5817 // If more than one unique Ts are found:
5818 if (!HasUniqueTargetType)
5819 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5822 // If one unique T is found:
5823 // First, build a candidate set from the previously recorded
5824 // potentially viable conversions.
5825 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Normal);
5826 collectViableConversionCandidates(*this, From, ToType, ViableConversions,
5829 // Then, perform overload resolution over the candidate set.
5830 OverloadCandidateSet::iterator Best;
5831 switch (CandidateSet.BestViableFunction(*this, Loc, Best)) {
5833 // Apply this conversion.
5834 DeclAccessPair Found =
5835 DeclAccessPair::make(Best->Function, Best->FoundDecl.getAccess());
5836 if (recordConversion(*this, Loc, From, Converter, T,
5837 HadMultipleCandidates, Found))
5842 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5844 case OR_No_Viable_Function:
5845 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5846 HadMultipleCandidates,
5847 ExplicitConversions))
5851 // We'll complain below about a non-integral condition type.
5855 switch (ViableConversions.size()) {
5857 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5858 HadMultipleCandidates,
5859 ExplicitConversions))
5862 // We'll complain below about a non-integral condition type.
5866 // Apply this conversion.
5867 DeclAccessPair Found = ViableConversions[0];
5868 if (recordConversion(*this, Loc, From, Converter, T,
5869 HadMultipleCandidates, Found))
5874 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5879 return finishContextualImplicitConversion(*this, Loc, From, Converter);
5882 /// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is
5883 /// an acceptable non-member overloaded operator for a call whose
5884 /// arguments have types T1 (and, if non-empty, T2). This routine
5885 /// implements the check in C++ [over.match.oper]p3b2 concerning
5886 /// enumeration types.
5887 static bool IsAcceptableNonMemberOperatorCandidate(ASTContext &Context,
5889 ArrayRef<Expr *> Args) {
5890 QualType T1 = Args[0]->getType();
5891 QualType T2 = Args.size() > 1 ? Args[1]->getType() : QualType();
5893 if (T1->isDependentType() || (!T2.isNull() && T2->isDependentType()))
5896 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType()))
5899 const FunctionProtoType *Proto = Fn->getType()->getAs<FunctionProtoType>();
5900 if (Proto->getNumParams() < 1)
5903 if (T1->isEnumeralType()) {
5904 QualType ArgType = Proto->getParamType(0).getNonReferenceType();
5905 if (Context.hasSameUnqualifiedType(T1, ArgType))
5909 if (Proto->getNumParams() < 2)
5912 if (!T2.isNull() && T2->isEnumeralType()) {
5913 QualType ArgType = Proto->getParamType(1).getNonReferenceType();
5914 if (Context.hasSameUnqualifiedType(T2, ArgType))
5921 /// AddOverloadCandidate - Adds the given function to the set of
5922 /// candidate functions, using the given function call arguments. If
5923 /// @p SuppressUserConversions, then don't allow user-defined
5924 /// conversions via constructors or conversion operators.
5926 /// \param PartialOverloading true if we are performing "partial" overloading
5927 /// based on an incomplete set of function arguments. This feature is used by
5928 /// code completion.
5930 Sema::AddOverloadCandidate(FunctionDecl *Function,
5931 DeclAccessPair FoundDecl,
5932 ArrayRef<Expr *> Args,
5933 OverloadCandidateSet &CandidateSet,
5934 bool SuppressUserConversions,
5935 bool PartialOverloading,
5937 ConversionSequenceList EarlyConversions) {
5938 const FunctionProtoType *Proto
5939 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>());
5940 assert(Proto && "Functions without a prototype cannot be overloaded");
5941 assert(!Function->getDescribedFunctionTemplate() &&
5942 "Use AddTemplateOverloadCandidate for function templates");
5944 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) {
5945 if (!isa<CXXConstructorDecl>(Method)) {
5946 // If we get here, it's because we're calling a member function
5947 // that is named without a member access expression (e.g.,
5948 // "this->f") that was either written explicitly or created
5949 // implicitly. This can happen with a qualified call to a member
5950 // function, e.g., X::f(). We use an empty type for the implied
5951 // object argument (C++ [over.call.func]p3), and the acting context
5953 AddMethodCandidate(Method, FoundDecl, Method->getParent(), QualType(),
5954 Expr::Classification::makeSimpleLValue(), Args,
5955 CandidateSet, SuppressUserConversions,
5956 PartialOverloading, EarlyConversions);
5959 // We treat a constructor like a non-member function, since its object
5960 // argument doesn't participate in overload resolution.
5963 if (!CandidateSet.isNewCandidate(Function))
5966 // C++ [over.match.oper]p3:
5967 // if no operand has a class type, only those non-member functions in the
5968 // lookup set that have a first parameter of type T1 or "reference to
5969 // (possibly cv-qualified) T1", when T1 is an enumeration type, or (if there
5970 // is a right operand) a second parameter of type T2 or "reference to
5971 // (possibly cv-qualified) T2", when T2 is an enumeration type, are
5972 // candidate functions.
5973 if (CandidateSet.getKind() == OverloadCandidateSet::CSK_Operator &&
5974 !IsAcceptableNonMemberOperatorCandidate(Context, Function, Args))
5977 // C++11 [class.copy]p11: [DR1402]
5978 // A defaulted move constructor that is defined as deleted is ignored by
5979 // overload resolution.
5980 CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function);
5981 if (Constructor && Constructor->isDefaulted() && Constructor->isDeleted() &&
5982 Constructor->isMoveConstructor())
5985 // Overload resolution is always an unevaluated context.
5986 EnterExpressionEvaluationContext Unevaluated(
5987 *this, Sema::ExpressionEvaluationContext::Unevaluated);
5989 // Add this candidate
5990 OverloadCandidate &Candidate =
5991 CandidateSet.addCandidate(Args.size(), EarlyConversions);
5992 Candidate.FoundDecl = FoundDecl;
5993 Candidate.Function = Function;
5994 Candidate.Viable = true;
5995 Candidate.IsSurrogate = false;
5996 Candidate.IgnoreObjectArgument = false;
5997 Candidate.ExplicitCallArguments = Args.size();
5999 if (Function->isMultiVersion() && Function->hasAttr<TargetAttr>() &&
6000 !Function->getAttr<TargetAttr>()->isDefaultVersion()) {
6001 Candidate.Viable = false;
6002 Candidate.FailureKind = ovl_non_default_multiversion_function;
6007 // C++ [class.copy]p3:
6008 // A member function template is never instantiated to perform the copy
6009 // of a class object to an object of its class type.
6010 QualType ClassType = Context.getTypeDeclType(Constructor->getParent());
6011 if (Args.size() == 1 && Constructor->isSpecializationCopyingObject() &&
6012 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) ||
6013 IsDerivedFrom(Args[0]->getLocStart(), Args[0]->getType(),
6015 Candidate.Viable = false;
6016 Candidate.FailureKind = ovl_fail_illegal_constructor;
6020 // C++ [over.match.funcs]p8: (proposed DR resolution)
6021 // A constructor inherited from class type C that has a first parameter
6022 // of type "reference to P" (including such a constructor instantiated
6023 // from a template) is excluded from the set of candidate functions when
6024 // constructing an object of type cv D if the argument list has exactly
6025 // one argument and D is reference-related to P and P is reference-related
6027 auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(FoundDecl.getDecl());
6028 if (Shadow && Args.size() == 1 && Constructor->getNumParams() >= 1 &&
6029 Constructor->getParamDecl(0)->getType()->isReferenceType()) {
6030 QualType P = Constructor->getParamDecl(0)->getType()->getPointeeType();
6031 QualType C = Context.getRecordType(Constructor->getParent());
6032 QualType D = Context.getRecordType(Shadow->getParent());
6033 SourceLocation Loc = Args.front()->getExprLoc();
6034 if ((Context.hasSameUnqualifiedType(P, C) || IsDerivedFrom(Loc, P, C)) &&
6035 (Context.hasSameUnqualifiedType(D, P) || IsDerivedFrom(Loc, D, P))) {
6036 Candidate.Viable = false;
6037 Candidate.FailureKind = ovl_fail_inhctor_slice;
6043 unsigned NumParams = Proto->getNumParams();
6045 // (C++ 13.3.2p2): A candidate function having fewer than m
6046 // parameters is viable only if it has an ellipsis in its parameter
6048 if (TooManyArguments(NumParams, Args.size(), PartialOverloading) &&
6049 !Proto->isVariadic()) {
6050 Candidate.Viable = false;
6051 Candidate.FailureKind = ovl_fail_too_many_arguments;
6055 // (C++ 13.3.2p2): A candidate function having more than m parameters
6056 // is viable only if the (m+1)st parameter has a default argument
6057 // (8.3.6). For the purposes of overload resolution, the
6058 // parameter list is truncated on the right, so that there are
6059 // exactly m parameters.
6060 unsigned MinRequiredArgs = Function->getMinRequiredArguments();
6061 if (Args.size() < MinRequiredArgs && !PartialOverloading) {
6062 // Not enough arguments.
6063 Candidate.Viable = false;
6064 Candidate.FailureKind = ovl_fail_too_few_arguments;
6068 // (CUDA B.1): Check for invalid calls between targets.
6069 if (getLangOpts().CUDA)
6070 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext))
6071 // Skip the check for callers that are implicit members, because in this
6072 // case we may not yet know what the member's target is; the target is
6073 // inferred for the member automatically, based on the bases and fields of
6075 if (!Caller->isImplicit() && !IsAllowedCUDACall(Caller, Function)) {
6076 Candidate.Viable = false;
6077 Candidate.FailureKind = ovl_fail_bad_target;
6081 // Determine the implicit conversion sequences for each of the
6083 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) {
6084 if (Candidate.Conversions[ArgIdx].isInitialized()) {
6085 // We already formed a conversion sequence for this parameter during
6086 // template argument deduction.
6087 } else if (ArgIdx < NumParams) {
6088 // (C++ 13.3.2p3): for F to be a viable function, there shall
6089 // exist for each argument an implicit conversion sequence
6090 // (13.3.3.1) that converts that argument to the corresponding
6092 QualType ParamType = Proto->getParamType(ArgIdx);
6093 Candidate.Conversions[ArgIdx]
6094 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
6095 SuppressUserConversions,
6096 /*InOverloadResolution=*/true,
6097 /*AllowObjCWritebackConversion=*/
6098 getLangOpts().ObjCAutoRefCount,
6100 if (Candidate.Conversions[ArgIdx].isBad()) {
6101 Candidate.Viable = false;
6102 Candidate.FailureKind = ovl_fail_bad_conversion;
6106 // (C++ 13.3.2p2): For the purposes of overload resolution, any
6107 // argument for which there is no corresponding parameter is
6108 // considered to ""match the ellipsis" (C+ 13.3.3.1.3).
6109 Candidate.Conversions[ArgIdx].setEllipsis();
6113 if (EnableIfAttr *FailedAttr = CheckEnableIf(Function, Args)) {
6114 Candidate.Viable = false;
6115 Candidate.FailureKind = ovl_fail_enable_if;
6116 Candidate.DeductionFailure.Data = FailedAttr;
6120 if (LangOpts.OpenCL && isOpenCLDisabledDecl(Function)) {
6121 Candidate.Viable = false;
6122 Candidate.FailureKind = ovl_fail_ext_disabled;
6128 Sema::SelectBestMethod(Selector Sel, MultiExprArg Args, bool IsInstance,
6129 SmallVectorImpl<ObjCMethodDecl *> &Methods) {
6130 if (Methods.size() <= 1)
6133 for (unsigned b = 0, e = Methods.size(); b < e; b++) {
6135 ObjCMethodDecl *Method = Methods[b];
6136 unsigned NumNamedArgs = Sel.getNumArgs();
6137 // Method might have more arguments than selector indicates. This is due
6138 // to addition of c-style arguments in method.
6139 if (Method->param_size() > NumNamedArgs)
6140 NumNamedArgs = Method->param_size();
6141 if (Args.size() < NumNamedArgs)
6144 for (unsigned i = 0; i < NumNamedArgs; i++) {
6145 // We can't do any type-checking on a type-dependent argument.
6146 if (Args[i]->isTypeDependent()) {
6151 ParmVarDecl *param = Method->parameters()[i];
6152 Expr *argExpr = Args[i];
6153 assert(argExpr && "SelectBestMethod(): missing expression");
6155 // Strip the unbridged-cast placeholder expression off unless it's
6156 // a consumed argument.
6157 if (argExpr->hasPlaceholderType(BuiltinType::ARCUnbridgedCast) &&
6158 !param->hasAttr<CFConsumedAttr>())
6159 argExpr = stripARCUnbridgedCast(argExpr);
6161 // If the parameter is __unknown_anytype, move on to the next method.
6162 if (param->getType() == Context.UnknownAnyTy) {
6167 ImplicitConversionSequence ConversionState
6168 = TryCopyInitialization(*this, argExpr, param->getType(),
6169 /*SuppressUserConversions*/false,
6170 /*InOverloadResolution=*/true,
6171 /*AllowObjCWritebackConversion=*/
6172 getLangOpts().ObjCAutoRefCount,
6173 /*AllowExplicit*/false);
6174 // This function looks for a reasonably-exact match, so we consider
6175 // incompatible pointer conversions to be a failure here.
6176 if (ConversionState.isBad() ||
6177 (ConversionState.isStandard() &&
6178 ConversionState.Standard.Second ==
6179 ICK_Incompatible_Pointer_Conversion)) {
6184 // Promote additional arguments to variadic methods.
6185 if (Match && Method->isVariadic()) {
6186 for (unsigned i = NumNamedArgs, e = Args.size(); i < e; ++i) {
6187 if (Args[i]->isTypeDependent()) {
6191 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod,
6193 if (Arg.isInvalid()) {
6199 // Check for extra arguments to non-variadic methods.
6200 if (Args.size() != NumNamedArgs)
6202 else if (Match && NumNamedArgs == 0 && Methods.size() > 1) {
6203 // Special case when selectors have no argument. In this case, select
6204 // one with the most general result type of 'id'.
6205 for (unsigned b = 0, e = Methods.size(); b < e; b++) {
6206 QualType ReturnT = Methods[b]->getReturnType();
6207 if (ReturnT->isObjCIdType())
6219 // specific_attr_iterator iterates over enable_if attributes in reverse, and
6220 // enable_if is order-sensitive. As a result, we need to reverse things
6221 // sometimes. Size of 4 elements is arbitrary.
6222 static SmallVector<EnableIfAttr *, 4>
6223 getOrderedEnableIfAttrs(const FunctionDecl *Function) {
6224 SmallVector<EnableIfAttr *, 4> Result;
6225 if (!Function->hasAttrs())
6228 const auto &FuncAttrs = Function->getAttrs();
6229 for (Attr *Attr : FuncAttrs)
6230 if (auto *EnableIf = dyn_cast<EnableIfAttr>(Attr))
6231 Result.push_back(EnableIf);
6233 std::reverse(Result.begin(), Result.end());
6238 convertArgsForAvailabilityChecks(Sema &S, FunctionDecl *Function, Expr *ThisArg,
6239 ArrayRef<Expr *> Args, Sema::SFINAETrap &Trap,
6240 bool MissingImplicitThis, Expr *&ConvertedThis,
6241 SmallVectorImpl<Expr *> &ConvertedArgs) {
6243 CXXMethodDecl *Method = cast<CXXMethodDecl>(Function);
6244 assert(!isa<CXXConstructorDecl>(Method) &&
6245 "Shouldn't have `this` for ctors!");
6246 assert(!Method->isStatic() && "Shouldn't have `this` for static methods!");
6247 ExprResult R = S.PerformObjectArgumentInitialization(
6248 ThisArg, /*Qualifier=*/nullptr, Method, Method);
6251 ConvertedThis = R.get();
6253 if (auto *MD = dyn_cast<CXXMethodDecl>(Function)) {
6255 assert((MissingImplicitThis || MD->isStatic() ||
6256 isa<CXXConstructorDecl>(MD)) &&
6257 "Expected `this` for non-ctor instance methods");
6259 ConvertedThis = nullptr;
6262 // Ignore any variadic arguments. Converting them is pointless, since the
6263 // user can't refer to them in the function condition.
6264 unsigned ArgSizeNoVarargs = std::min(Function->param_size(), Args.size());
6266 // Convert the arguments.
6267 for (unsigned I = 0; I != ArgSizeNoVarargs; ++I) {
6269 R = S.PerformCopyInitialization(InitializedEntity::InitializeParameter(
6270 S.Context, Function->getParamDecl(I)),
6271 SourceLocation(), Args[I]);
6276 ConvertedArgs.push_back(R.get());
6279 if (Trap.hasErrorOccurred())
6282 // Push default arguments if needed.
6283 if (!Function->isVariadic() && Args.size() < Function->getNumParams()) {
6284 for (unsigned i = Args.size(), e = Function->getNumParams(); i != e; ++i) {
6285 ParmVarDecl *P = Function->getParamDecl(i);
6286 Expr *DefArg = P->hasUninstantiatedDefaultArg()
6287 ? P->getUninstantiatedDefaultArg()
6288 : P->getDefaultArg();
6289 // This can only happen in code completion, i.e. when PartialOverloading
6294 S.PerformCopyInitialization(InitializedEntity::InitializeParameter(
6295 S.Context, Function->getParamDecl(i)),
6296 SourceLocation(), DefArg);
6299 ConvertedArgs.push_back(R.get());
6302 if (Trap.hasErrorOccurred())
6308 EnableIfAttr *Sema::CheckEnableIf(FunctionDecl *Function, ArrayRef<Expr *> Args,
6309 bool MissingImplicitThis) {
6310 SmallVector<EnableIfAttr *, 4> EnableIfAttrs =
6311 getOrderedEnableIfAttrs(Function);
6312 if (EnableIfAttrs.empty())
6315 SFINAETrap Trap(*this);
6316 SmallVector<Expr *, 16> ConvertedArgs;
6317 // FIXME: We should look into making enable_if late-parsed.
6318 Expr *DiscardedThis;
6319 if (!convertArgsForAvailabilityChecks(
6320 *this, Function, /*ThisArg=*/nullptr, Args, Trap,
6321 /*MissingImplicitThis=*/true, DiscardedThis, ConvertedArgs))
6322 return EnableIfAttrs[0];
6324 for (auto *EIA : EnableIfAttrs) {
6326 // FIXME: This doesn't consider value-dependent cases, because doing so is
6327 // very difficult. Ideally, we should handle them more gracefully.
6328 if (!EIA->getCond()->EvaluateWithSubstitution(
6329 Result, Context, Function, llvm::makeArrayRef(ConvertedArgs)))
6332 if (!Result.isInt() || !Result.getInt().getBoolValue())
6338 template <typename CheckFn>
6339 static bool diagnoseDiagnoseIfAttrsWith(Sema &S, const NamedDecl *ND,
6340 bool ArgDependent, SourceLocation Loc,
6341 CheckFn &&IsSuccessful) {
6342 SmallVector<const DiagnoseIfAttr *, 8> Attrs;
6343 for (const auto *DIA : ND->specific_attrs<DiagnoseIfAttr>()) {
6344 if (ArgDependent == DIA->getArgDependent())
6345 Attrs.push_back(DIA);
6348 // Common case: No diagnose_if attributes, so we can quit early.
6352 auto WarningBegin = std::stable_partition(
6353 Attrs.begin(), Attrs.end(),
6354 [](const DiagnoseIfAttr *DIA) { return DIA->isError(); });
6356 // Note that diagnose_if attributes are late-parsed, so they appear in the
6357 // correct order (unlike enable_if attributes).
6358 auto ErrAttr = llvm::find_if(llvm::make_range(Attrs.begin(), WarningBegin),
6360 if (ErrAttr != WarningBegin) {
6361 const DiagnoseIfAttr *DIA = *ErrAttr;
6362 S.Diag(Loc, diag::err_diagnose_if_succeeded) << DIA->getMessage();
6363 S.Diag(DIA->getLocation(), diag::note_from_diagnose_if)
6364 << DIA->getParent() << DIA->getCond()->getSourceRange();
6368 for (const auto *DIA : llvm::make_range(WarningBegin, Attrs.end()))
6369 if (IsSuccessful(DIA)) {
6370 S.Diag(Loc, diag::warn_diagnose_if_succeeded) << DIA->getMessage();
6371 S.Diag(DIA->getLocation(), diag::note_from_diagnose_if)
6372 << DIA->getParent() << DIA->getCond()->getSourceRange();
6378 bool Sema::diagnoseArgDependentDiagnoseIfAttrs(const FunctionDecl *Function,
6379 const Expr *ThisArg,
6380 ArrayRef<const Expr *> Args,
6381 SourceLocation Loc) {
6382 return diagnoseDiagnoseIfAttrsWith(
6383 *this, Function, /*ArgDependent=*/true, Loc,
6384 [&](const DiagnoseIfAttr *DIA) {
6386 // It's sane to use the same Args for any redecl of this function, since
6387 // EvaluateWithSubstitution only cares about the position of each
6388 // argument in the arg list, not the ParmVarDecl* it maps to.
6389 if (!DIA->getCond()->EvaluateWithSubstitution(
6390 Result, Context, cast<FunctionDecl>(DIA->getParent()), Args, ThisArg))
6392 return Result.isInt() && Result.getInt().getBoolValue();
6396 bool Sema::diagnoseArgIndependentDiagnoseIfAttrs(const NamedDecl *ND,
6397 SourceLocation Loc) {
6398 return diagnoseDiagnoseIfAttrsWith(
6399 *this, ND, /*ArgDependent=*/false, Loc,
6400 [&](const DiagnoseIfAttr *DIA) {
6402 return DIA->getCond()->EvaluateAsBooleanCondition(Result, Context) &&
6407 /// Add all of the function declarations in the given function set to
6408 /// the overload candidate set.
6409 void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns,
6410 ArrayRef<Expr *> Args,
6411 OverloadCandidateSet &CandidateSet,
6412 TemplateArgumentListInfo *ExplicitTemplateArgs,
6413 bool SuppressUserConversions,
6414 bool PartialOverloading,
6415 bool FirstArgumentIsBase) {
6416 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) {
6417 NamedDecl *D = F.getDecl()->getUnderlyingDecl();
6418 ArrayRef<Expr *> FunctionArgs = Args;
6420 FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(D);
6422 FunTmpl ? FunTmpl->getTemplatedDecl() : cast<FunctionDecl>(D);
6424 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) {
6425 QualType ObjectType;
6426 Expr::Classification ObjectClassification;
6427 if (Args.size() > 0) {
6428 if (Expr *E = Args[0]) {
6429 // Use the explicit base to restrict the lookup:
6430 ObjectType = E->getType();
6431 ObjectClassification = E->Classify(Context);
6432 } // .. else there is an implicit base.
6433 FunctionArgs = Args.slice(1);
6436 AddMethodTemplateCandidate(
6437 FunTmpl, F.getPair(),
6438 cast<CXXRecordDecl>(FunTmpl->getDeclContext()),
6439 ExplicitTemplateArgs, ObjectType, ObjectClassification,
6440 FunctionArgs, CandidateSet, SuppressUserConversions,
6441 PartialOverloading);
6443 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(),
6444 cast<CXXMethodDecl>(FD)->getParent(), ObjectType,
6445 ObjectClassification, FunctionArgs, CandidateSet,
6446 SuppressUserConversions, PartialOverloading);
6449 // This branch handles both standalone functions and static methods.
6451 // Slice the first argument (which is the base) when we access
6452 // static method as non-static.
6453 if (Args.size() > 0 &&
6454 (!Args[0] || (FirstArgumentIsBase && isa<CXXMethodDecl>(FD) &&
6455 !isa<CXXConstructorDecl>(FD)))) {
6456 assert(cast<CXXMethodDecl>(FD)->isStatic());
6457 FunctionArgs = Args.slice(1);
6460 AddTemplateOverloadCandidate(
6461 FunTmpl, F.getPair(), ExplicitTemplateArgs, FunctionArgs,
6462 CandidateSet, SuppressUserConversions, PartialOverloading);
6464 AddOverloadCandidate(FD, F.getPair(), FunctionArgs, CandidateSet,
6465 SuppressUserConversions, PartialOverloading);
6471 /// AddMethodCandidate - Adds a named decl (which is some kind of
6472 /// method) as a method candidate to the given overload set.
6473 void Sema::AddMethodCandidate(DeclAccessPair FoundDecl,
6474 QualType ObjectType,
6475 Expr::Classification ObjectClassification,
6476 ArrayRef<Expr *> Args,
6477 OverloadCandidateSet& CandidateSet,
6478 bool SuppressUserConversions) {
6479 NamedDecl *Decl = FoundDecl.getDecl();
6480 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext());
6482 if (isa<UsingShadowDecl>(Decl))
6483 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl();
6485 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) {
6486 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) &&
6487 "Expected a member function template");
6488 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext,
6489 /*ExplicitArgs*/ nullptr, ObjectType,
6490 ObjectClassification, Args, CandidateSet,
6491 SuppressUserConversions);
6493 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext,
6494 ObjectType, ObjectClassification, Args, CandidateSet,
6495 SuppressUserConversions);
6499 /// AddMethodCandidate - Adds the given C++ member function to the set
6500 /// of candidate functions, using the given function call arguments
6501 /// and the object argument (@c Object). For example, in a call
6502 /// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain
6503 /// both @c a1 and @c a2. If @p SuppressUserConversions, then don't
6504 /// allow user-defined conversions via constructors or conversion
6507 Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl,
6508 CXXRecordDecl *ActingContext, QualType ObjectType,
6509 Expr::Classification ObjectClassification,
6510 ArrayRef<Expr *> Args,
6511 OverloadCandidateSet &CandidateSet,
6512 bool SuppressUserConversions,
6513 bool PartialOverloading,
6514 ConversionSequenceList EarlyConversions) {
6515 const FunctionProtoType *Proto
6516 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>());
6517 assert(Proto && "Methods without a prototype cannot be overloaded");
6518 assert(!isa<CXXConstructorDecl>(Method) &&
6519 "Use AddOverloadCandidate for constructors");
6521 if (!CandidateSet.isNewCandidate(Method))
6524 // C++11 [class.copy]p23: [DR1402]
6525 // A defaulted move assignment operator that is defined as deleted is
6526 // ignored by overload resolution.
6527 if (Method->isDefaulted() && Method->isDeleted() &&
6528 Method->isMoveAssignmentOperator())
6531 // Overload resolution is always an unevaluated context.
6532 EnterExpressionEvaluationContext Unevaluated(
6533 *this, Sema::ExpressionEvaluationContext::Unevaluated);
6535 // Add this candidate
6536 OverloadCandidate &Candidate =
6537 CandidateSet.addCandidate(Args.size() + 1, EarlyConversions);
6538 Candidate.FoundDecl = FoundDecl;
6539 Candidate.Function = Method;
6540 Candidate.IsSurrogate = false;
6541 Candidate.IgnoreObjectArgument = false;
6542 Candidate.ExplicitCallArguments = Args.size();
6544 unsigned NumParams = Proto->getNumParams();
6546 // (C++ 13.3.2p2): A candidate function having fewer than m
6547 // parameters is viable only if it has an ellipsis in its parameter
6549 if (TooManyArguments(NumParams, Args.size(), PartialOverloading) &&
6550 !Proto->isVariadic()) {
6551 Candidate.Viable = false;
6552 Candidate.FailureKind = ovl_fail_too_many_arguments;
6556 // (C++ 13.3.2p2): A candidate function having more than m parameters
6557 // is viable only if the (m+1)st parameter has a default argument
6558 // (8.3.6). For the purposes of overload resolution, the
6559 // parameter list is truncated on the right, so that there are
6560 // exactly m parameters.
6561 unsigned MinRequiredArgs = Method->getMinRequiredArguments();
6562 if (Args.size() < MinRequiredArgs && !PartialOverloading) {
6563 // Not enough arguments.
6564 Candidate.Viable = false;
6565 Candidate.FailureKind = ovl_fail_too_few_arguments;
6569 Candidate.Viable = true;
6571 if (Method->isStatic() || ObjectType.isNull())
6572 // The implicit object argument is ignored.
6573 Candidate.IgnoreObjectArgument = true;
6575 // Determine the implicit conversion sequence for the object
6577 Candidate.Conversions[0] = TryObjectArgumentInitialization(
6578 *this, CandidateSet.getLocation(), ObjectType, ObjectClassification,
6579 Method, ActingContext);
6580 if (Candidate.Conversions[0].isBad()) {
6581 Candidate.Viable = false;
6582 Candidate.FailureKind = ovl_fail_bad_conversion;
6587 // (CUDA B.1): Check for invalid calls between targets.
6588 if (getLangOpts().CUDA)
6589 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext))
6590 if (!IsAllowedCUDACall(Caller, Method)) {
6591 Candidate.Viable = false;
6592 Candidate.FailureKind = ovl_fail_bad_target;
6596 // Determine the implicit conversion sequences for each of the
6598 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) {
6599 if (Candidate.Conversions[ArgIdx + 1].isInitialized()) {
6600 // We already formed a conversion sequence for this parameter during
6601 // template argument deduction.
6602 } else if (ArgIdx < NumParams) {
6603 // (C++ 13.3.2p3): for F to be a viable function, there shall
6604 // exist for each argument an implicit conversion sequence
6605 // (13.3.3.1) that converts that argument to the corresponding
6607 QualType ParamType = Proto->getParamType(ArgIdx);
6608 Candidate.Conversions[ArgIdx + 1]
6609 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
6610 SuppressUserConversions,
6611 /*InOverloadResolution=*/true,
6612 /*AllowObjCWritebackConversion=*/
6613 getLangOpts().ObjCAutoRefCount);
6614 if (Candidate.Conversions[ArgIdx + 1].isBad()) {
6615 Candidate.Viable = false;
6616 Candidate.FailureKind = ovl_fail_bad_conversion;
6620 // (C++ 13.3.2p2): For the purposes of overload resolution, any
6621 // argument for which there is no corresponding parameter is
6622 // considered to "match the ellipsis" (C+ 13.3.3.1.3).
6623 Candidate.Conversions[ArgIdx + 1].setEllipsis();
6627 if (EnableIfAttr *FailedAttr = CheckEnableIf(Method, Args, true)) {
6628 Candidate.Viable = false;
6629 Candidate.FailureKind = ovl_fail_enable_if;
6630 Candidate.DeductionFailure.Data = FailedAttr;
6634 if (Method->isMultiVersion() && Method->hasAttr<TargetAttr>() &&
6635 !Method->getAttr<TargetAttr>()->isDefaultVersion()) {
6636 Candidate.Viable = false;
6637 Candidate.FailureKind = ovl_non_default_multiversion_function;
6641 /// Add a C++ member function template as a candidate to the candidate
6642 /// set, using template argument deduction to produce an appropriate member
6643 /// function template specialization.
6645 Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl,
6646 DeclAccessPair FoundDecl,
6647 CXXRecordDecl *ActingContext,
6648 TemplateArgumentListInfo *ExplicitTemplateArgs,
6649 QualType ObjectType,
6650 Expr::Classification ObjectClassification,
6651 ArrayRef<Expr *> Args,
6652 OverloadCandidateSet& CandidateSet,
6653 bool SuppressUserConversions,
6654 bool PartialOverloading) {
6655 if (!CandidateSet.isNewCandidate(MethodTmpl))
6658 // C++ [over.match.funcs]p7:
6659 // In each case where a candidate is a function template, candidate
6660 // function template specializations are generated using template argument
6661 // deduction (14.8.3, 14.8.2). Those candidates are then handled as
6662 // candidate functions in the usual way.113) A given name can refer to one
6663 // or more function templates and also to a set of overloaded non-template
6664 // functions. In such a case, the candidate functions generated from each
6665 // function template are combined with the set of non-template candidate
6667 TemplateDeductionInfo Info(CandidateSet.getLocation());
6668 FunctionDecl *Specialization = nullptr;
6669 ConversionSequenceList Conversions;
6670 if (TemplateDeductionResult Result = DeduceTemplateArguments(
6671 MethodTmpl, ExplicitTemplateArgs, Args, Specialization, Info,
6672 PartialOverloading, [&](ArrayRef<QualType> ParamTypes) {
6673 return CheckNonDependentConversions(
6674 MethodTmpl, ParamTypes, Args, CandidateSet, Conversions,
6675 SuppressUserConversions, ActingContext, ObjectType,
6676 ObjectClassification);
6678 OverloadCandidate &Candidate =
6679 CandidateSet.addCandidate(Conversions.size(), Conversions);
6680 Candidate.FoundDecl = FoundDecl;
6681 Candidate.Function = MethodTmpl->getTemplatedDecl();
6682 Candidate.Viable = false;
6683 Candidate.IsSurrogate = false;
6684 Candidate.IgnoreObjectArgument =
6685 cast<CXXMethodDecl>(Candidate.Function)->isStatic() ||
6686 ObjectType.isNull();
6687 Candidate.ExplicitCallArguments = Args.size();
6688 if (Result == TDK_NonDependentConversionFailure)
6689 Candidate.FailureKind = ovl_fail_bad_conversion;
6691 Candidate.FailureKind = ovl_fail_bad_deduction;
6692 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
6698 // Add the function template specialization produced by template argument
6699 // deduction as a candidate.
6700 assert(Specialization && "Missing member function template specialization?");
6701 assert(isa<CXXMethodDecl>(Specialization) &&
6702 "Specialization is not a member function?");
6703 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl,
6704 ActingContext, ObjectType, ObjectClassification, Args,
6705 CandidateSet, SuppressUserConversions, PartialOverloading,
6709 /// Add a C++ function template specialization as a candidate
6710 /// in the candidate set, using template argument deduction to produce
6711 /// an appropriate function template specialization.
6713 Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate,
6714 DeclAccessPair FoundDecl,
6715 TemplateArgumentListInfo *ExplicitTemplateArgs,
6716 ArrayRef<Expr *> Args,
6717 OverloadCandidateSet& CandidateSet,
6718 bool SuppressUserConversions,
6719 bool PartialOverloading) {
6720 if (!CandidateSet.isNewCandidate(FunctionTemplate))
6723 // C++ [over.match.funcs]p7:
6724 // In each case where a candidate is a function template, candidate
6725 // function template specializations are generated using template argument
6726 // deduction (14.8.3, 14.8.2). Those candidates are then handled as
6727 // candidate functions in the usual way.113) A given name can refer to one
6728 // or more function templates and also to a set of overloaded non-template
6729 // functions. In such a case, the candidate functions generated from each
6730 // function template are combined with the set of non-template candidate
6732 TemplateDeductionInfo Info(CandidateSet.getLocation());
6733 FunctionDecl *Specialization = nullptr;
6734 ConversionSequenceList Conversions;
6735 if (TemplateDeductionResult Result = DeduceTemplateArguments(
6736 FunctionTemplate, ExplicitTemplateArgs, Args, Specialization, Info,
6737 PartialOverloading, [&](ArrayRef<QualType> ParamTypes) {
6738 return CheckNonDependentConversions(FunctionTemplate, ParamTypes,
6739 Args, CandidateSet, Conversions,
6740 SuppressUserConversions);
6742 OverloadCandidate &Candidate =
6743 CandidateSet.addCandidate(Conversions.size(), Conversions);
6744 Candidate.FoundDecl = FoundDecl;
6745 Candidate.Function = FunctionTemplate->getTemplatedDecl();
6746 Candidate.Viable = false;
6747 Candidate.IsSurrogate = false;
6748 // Ignore the object argument if there is one, since we don't have an object
6750 Candidate.IgnoreObjectArgument =
6751 isa<CXXMethodDecl>(Candidate.Function) &&
6752 !isa<CXXConstructorDecl>(Candidate.Function);
6753 Candidate.ExplicitCallArguments = Args.size();
6754 if (Result == TDK_NonDependentConversionFailure)
6755 Candidate.FailureKind = ovl_fail_bad_conversion;
6757 Candidate.FailureKind = ovl_fail_bad_deduction;
6758 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
6764 // Add the function template specialization produced by template argument
6765 // deduction as a candidate.
6766 assert(Specialization && "Missing function template specialization?");
6767 AddOverloadCandidate(Specialization, FoundDecl, Args, CandidateSet,
6768 SuppressUserConversions, PartialOverloading,
6769 /*AllowExplicit*/false, Conversions);
6772 /// Check that implicit conversion sequences can be formed for each argument
6773 /// whose corresponding parameter has a non-dependent type, per DR1391's
6774 /// [temp.deduct.call]p10.
6775 bool Sema::CheckNonDependentConversions(
6776 FunctionTemplateDecl *FunctionTemplate, ArrayRef<QualType> ParamTypes,
6777 ArrayRef<Expr *> Args, OverloadCandidateSet &CandidateSet,
6778 ConversionSequenceList &Conversions, bool SuppressUserConversions,
6779 CXXRecordDecl *ActingContext, QualType ObjectType,
6780 Expr::Classification ObjectClassification) {
6781 // FIXME: The cases in which we allow explicit conversions for constructor
6782 // arguments never consider calling a constructor template. It's not clear
6784 const bool AllowExplicit = false;
6786 auto *FD = FunctionTemplate->getTemplatedDecl();
6787 auto *Method = dyn_cast<CXXMethodDecl>(FD);
6788 bool HasThisConversion = Method && !isa<CXXConstructorDecl>(Method);
6789 unsigned ThisConversions = HasThisConversion ? 1 : 0;
6792 CandidateSet.allocateConversionSequences(ThisConversions + Args.size());
6794 // Overload resolution is always an unevaluated context.
6795 EnterExpressionEvaluationContext Unevaluated(
6796 *this, Sema::ExpressionEvaluationContext::Unevaluated);
6798 // For a method call, check the 'this' conversion here too. DR1391 doesn't
6799 // require that, but this check should never result in a hard error, and
6800 // overload resolution is permitted to sidestep instantiations.
6801 if (HasThisConversion && !cast<CXXMethodDecl>(FD)->isStatic() &&
6802 !ObjectType.isNull()) {
6803 Conversions[0] = TryObjectArgumentInitialization(
6804 *this, CandidateSet.getLocation(), ObjectType, ObjectClassification,
6805 Method, ActingContext);
6806 if (Conversions[0].isBad())
6810 for (unsigned I = 0, N = std::min(ParamTypes.size(), Args.size()); I != N;
6812 QualType ParamType = ParamTypes[I];
6813 if (!ParamType->isDependentType()) {
6814 Conversions[ThisConversions + I]
6815 = TryCopyInitialization(*this, Args[I], ParamType,
6816 SuppressUserConversions,
6817 /*InOverloadResolution=*/true,
6818 /*AllowObjCWritebackConversion=*/
6819 getLangOpts().ObjCAutoRefCount,
6821 if (Conversions[ThisConversions + I].isBad())
6829 /// Determine whether this is an allowable conversion from the result
6830 /// of an explicit conversion operator to the expected type, per C++
6831 /// [over.match.conv]p1 and [over.match.ref]p1.
6833 /// \param ConvType The return type of the conversion function.
6835 /// \param ToType The type we are converting to.
6837 /// \param AllowObjCPointerConversion Allow a conversion from one
6838 /// Objective-C pointer to another.
6840 /// \returns true if the conversion is allowable, false otherwise.
6841 static bool isAllowableExplicitConversion(Sema &S,
6842 QualType ConvType, QualType ToType,
6843 bool AllowObjCPointerConversion) {
6844 QualType ToNonRefType = ToType.getNonReferenceType();
6846 // Easy case: the types are the same.
6847 if (S.Context.hasSameUnqualifiedType(ConvType, ToNonRefType))
6850 // Allow qualification conversions.
6851 bool ObjCLifetimeConversion;
6852 if (S.IsQualificationConversion(ConvType, ToNonRefType, /*CStyle*/false,
6853 ObjCLifetimeConversion))
6856 // If we're not allowed to consider Objective-C pointer conversions,
6858 if (!AllowObjCPointerConversion)
6861 // Is this an Objective-C pointer conversion?
6862 bool IncompatibleObjC = false;
6863 QualType ConvertedType;
6864 return S.isObjCPointerConversion(ConvType, ToNonRefType, ConvertedType,
6868 /// AddConversionCandidate - Add a C++ conversion function as a
6869 /// candidate in the candidate set (C++ [over.match.conv],
6870 /// C++ [over.match.copy]). From is the expression we're converting from,
6871 /// and ToType is the type that we're eventually trying to convert to
6872 /// (which may or may not be the same type as the type that the
6873 /// conversion function produces).
6875 Sema::AddConversionCandidate(CXXConversionDecl *Conversion,
6876 DeclAccessPair FoundDecl,
6877 CXXRecordDecl *ActingContext,
6878 Expr *From, QualType ToType,
6879 OverloadCandidateSet& CandidateSet,
6880 bool AllowObjCConversionOnExplicit,
6881 bool AllowResultConversion) {
6882 assert(!Conversion->getDescribedFunctionTemplate() &&
6883 "Conversion function templates use AddTemplateConversionCandidate");
6884 QualType ConvType = Conversion->getConversionType().getNonReferenceType();
6885 if (!CandidateSet.isNewCandidate(Conversion))
6888 // If the conversion function has an undeduced return type, trigger its
6890 if (getLangOpts().CPlusPlus14 && ConvType->isUndeducedType()) {
6891 if (DeduceReturnType(Conversion, From->getExprLoc()))
6893 ConvType = Conversion->getConversionType().getNonReferenceType();
6896 // If we don't allow any conversion of the result type, ignore conversion
6897 // functions that don't convert to exactly (possibly cv-qualified) T.
6898 if (!AllowResultConversion &&
6899 !Context.hasSameUnqualifiedType(Conversion->getConversionType(), ToType))
6902 // Per C++ [over.match.conv]p1, [over.match.ref]p1, an explicit conversion
6903 // operator is only a candidate if its return type is the target type or
6904 // can be converted to the target type with a qualification conversion.
6905 if (Conversion->isExplicit() &&
6906 !isAllowableExplicitConversion(*this, ConvType, ToType,
6907 AllowObjCConversionOnExplicit))
6910 // Overload resolution is always an unevaluated context.
6911 EnterExpressionEvaluationContext Unevaluated(
6912 *this, Sema::ExpressionEvaluationContext::Unevaluated);
6914 // Add this candidate
6915 OverloadCandidate &Candidate = CandidateSet.addCandidate(1);
6916 Candidate.FoundDecl = FoundDecl;
6917 Candidate.Function = Conversion;
6918 Candidate.IsSurrogate = false;
6919 Candidate.IgnoreObjectArgument = false;
6920 Candidate.FinalConversion.setAsIdentityConversion();
6921 Candidate.FinalConversion.setFromType(ConvType);
6922 Candidate.FinalConversion.setAllToTypes(ToType);
6923 Candidate.Viable = true;
6924 Candidate.ExplicitCallArguments = 1;
6926 // C++ [over.match.funcs]p4:
6927 // For conversion functions, the function is considered to be a member of
6928 // the class of the implicit implied object argument for the purpose of
6929 // defining the type of the implicit object parameter.
6931 // Determine the implicit conversion sequence for the implicit
6932 // object parameter.
6933 QualType ImplicitParamType = From->getType();
6934 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>())
6935 ImplicitParamType = FromPtrType->getPointeeType();
6936 CXXRecordDecl *ConversionContext
6937 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl());
6939 Candidate.Conversions[0] = TryObjectArgumentInitialization(
6940 *this, CandidateSet.getLocation(), From->getType(),
6941 From->Classify(Context), Conversion, ConversionContext);
6943 if (Candidate.Conversions[0].isBad()) {
6944 Candidate.Viable = false;
6945 Candidate.FailureKind = ovl_fail_bad_conversion;
6949 // We won't go through a user-defined type conversion function to convert a
6950 // derived to base as such conversions are given Conversion Rank. They only
6951 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user]
6953 = Context.getCanonicalType(From->getType().getUnqualifiedType());
6954 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType();
6955 if (FromCanon == ToCanon ||
6956 IsDerivedFrom(CandidateSet.getLocation(), FromCanon, ToCanon)) {
6957 Candidate.Viable = false;
6958 Candidate.FailureKind = ovl_fail_trivial_conversion;
6962 // To determine what the conversion from the result of calling the
6963 // conversion function to the type we're eventually trying to
6964 // convert to (ToType), we need to synthesize a call to the
6965 // conversion function and attempt copy initialization from it. This
6966 // makes sure that we get the right semantics with respect to
6967 // lvalues/rvalues and the type. Fortunately, we can allocate this
6968 // call on the stack and we don't need its arguments to be
6970 DeclRefExpr ConversionRef(Conversion, false, Conversion->getType(),
6971 VK_LValue, From->getLocStart());
6972 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack,
6973 Context.getPointerType(Conversion->getType()),
6974 CK_FunctionToPointerDecay,
6975 &ConversionRef, VK_RValue);
6977 QualType ConversionType = Conversion->getConversionType();
6978 if (!isCompleteType(From->getLocStart(), ConversionType)) {
6979 Candidate.Viable = false;
6980 Candidate.FailureKind = ovl_fail_bad_final_conversion;
6984 ExprValueKind VK = Expr::getValueKindForType(ConversionType);
6986 // Note that it is safe to allocate CallExpr on the stack here because
6987 // there are 0 arguments (i.e., nothing is allocated using ASTContext's
6989 QualType CallResultType = ConversionType.getNonLValueExprType(Context);
6990 CallExpr Call(Context, &ConversionFn, None, CallResultType, VK,
6991 From->getLocStart());
6992 ImplicitConversionSequence ICS =
6993 TryCopyInitialization(*this, &Call, ToType,
6994 /*SuppressUserConversions=*/true,
6995 /*InOverloadResolution=*/false,
6996 /*AllowObjCWritebackConversion=*/false);
6998 switch (ICS.getKind()) {
6999 case ImplicitConversionSequence::StandardConversion:
7000 Candidate.FinalConversion = ICS.Standard;
7002 // C++ [over.ics.user]p3:
7003 // If the user-defined conversion is specified by a specialization of a
7004 // conversion function template, the second standard conversion sequence
7005 // shall have exact match rank.
7006 if (Conversion->getPrimaryTemplate() &&
7007 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) {
7008 Candidate.Viable = false;
7009 Candidate.FailureKind = ovl_fail_final_conversion_not_exact;
7013 // C++0x [dcl.init.ref]p5:
7014 // In the second case, if the reference is an rvalue reference and
7015 // the second standard conversion sequence of the user-defined
7016 // conversion sequence includes an lvalue-to-rvalue conversion, the
7017 // program is ill-formed.
7018 if (ToType->isRValueReferenceType() &&
7019 ICS.Standard.First == ICK_Lvalue_To_Rvalue) {
7020 Candidate.Viable = false;
7021 Candidate.FailureKind = ovl_fail_bad_final_conversion;
7026 case ImplicitConversionSequence::BadConversion:
7027 Candidate.Viable = false;
7028 Candidate.FailureKind = ovl_fail_bad_final_conversion;
7033 "Can only end up with a standard conversion sequence or failure");
7036 if (EnableIfAttr *FailedAttr = CheckEnableIf(Conversion, None)) {
7037 Candidate.Viable = false;
7038 Candidate.FailureKind = ovl_fail_enable_if;
7039 Candidate.DeductionFailure.Data = FailedAttr;
7043 if (Conversion->isMultiVersion() && Conversion->hasAttr<TargetAttr>() &&
7044 !Conversion->getAttr<TargetAttr>()->isDefaultVersion()) {
7045 Candidate.Viable = false;
7046 Candidate.FailureKind = ovl_non_default_multiversion_function;
7050 /// Adds a conversion function template specialization
7051 /// candidate to the overload set, using template argument deduction
7052 /// to deduce the template arguments of the conversion function
7053 /// template from the type that we are converting to (C++
7054 /// [temp.deduct.conv]).
7056 Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate,
7057 DeclAccessPair FoundDecl,
7058 CXXRecordDecl *ActingDC,
7059 Expr *From, QualType ToType,
7060 OverloadCandidateSet &CandidateSet,
7061 bool AllowObjCConversionOnExplicit,
7062 bool AllowResultConversion) {
7063 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) &&
7064 "Only conversion function templates permitted here");
7066 if (!CandidateSet.isNewCandidate(FunctionTemplate))
7069 TemplateDeductionInfo Info(CandidateSet.getLocation());
7070 CXXConversionDecl *Specialization = nullptr;
7071 if (TemplateDeductionResult Result
7072 = DeduceTemplateArguments(FunctionTemplate, ToType,
7073 Specialization, Info)) {
7074 OverloadCandidate &Candidate = CandidateSet.addCandidate();
7075 Candidate.FoundDecl = FoundDecl;
7076 Candidate.Function = FunctionTemplate->getTemplatedDecl();
7077 Candidate.Viable = false;
7078 Candidate.FailureKind = ovl_fail_bad_deduction;
7079 Candidate.IsSurrogate = false;
7080 Candidate.IgnoreObjectArgument = false;
7081 Candidate.ExplicitCallArguments = 1;
7082 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
7087 // Add the conversion function template specialization produced by
7088 // template argument deduction as a candidate.
7089 assert(Specialization && "Missing function template specialization?");
7090 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType,
7091 CandidateSet, AllowObjCConversionOnExplicit,
7092 AllowResultConversion);
7095 /// AddSurrogateCandidate - Adds a "surrogate" candidate function that
7096 /// converts the given @c Object to a function pointer via the
7097 /// conversion function @c Conversion, and then attempts to call it
7098 /// with the given arguments (C++ [over.call.object]p2-4). Proto is
7099 /// the type of function that we'll eventually be calling.
7100 void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion,
7101 DeclAccessPair FoundDecl,
7102 CXXRecordDecl *ActingContext,
7103 const FunctionProtoType *Proto,
7105 ArrayRef<Expr *> Args,
7106 OverloadCandidateSet& CandidateSet) {
7107 if (!CandidateSet.isNewCandidate(Conversion))
7110 // Overload resolution is always an unevaluated context.
7111 EnterExpressionEvaluationContext Unevaluated(
7112 *this, Sema::ExpressionEvaluationContext::Unevaluated);
7114 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1);
7115 Candidate.FoundDecl = FoundDecl;
7116 Candidate.Function = nullptr;
7117 Candidate.Surrogate = Conversion;
7118 Candidate.Viable = true;
7119 Candidate.IsSurrogate = true;
7120 Candidate.IgnoreObjectArgument = false;
7121 Candidate.ExplicitCallArguments = Args.size();
7123 // Determine the implicit conversion sequence for the implicit
7124 // object parameter.
7125 ImplicitConversionSequence ObjectInit = TryObjectArgumentInitialization(
7126 *this, CandidateSet.getLocation(), Object->getType(),
7127 Object->Classify(Context), Conversion, ActingContext);
7128 if (ObjectInit.isBad()) {
7129 Candidate.Viable = false;
7130 Candidate.FailureKind = ovl_fail_bad_conversion;
7131 Candidate.Conversions[0] = ObjectInit;
7135 // The first conversion is actually a user-defined conversion whose
7136 // first conversion is ObjectInit's standard conversion (which is
7137 // effectively a reference binding). Record it as such.
7138 Candidate.Conversions[0].setUserDefined();
7139 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard;
7140 Candidate.Conversions[0].UserDefined.EllipsisConversion = false;
7141 Candidate.Conversions[0].UserDefined.HadMultipleCandidates = false;
7142 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion;
7143 Candidate.Conversions[0].UserDefined.FoundConversionFunction = FoundDecl;
7144 Candidate.Conversions[0].UserDefined.After
7145 = Candidate.Conversions[0].UserDefined.Before;
7146 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion();
7149 unsigned NumParams = Proto->getNumParams();
7151 // (C++ 13.3.2p2): A candidate function having fewer than m
7152 // parameters is viable only if it has an ellipsis in its parameter
7154 if (Args.size() > NumParams && !Proto->isVariadic()) {
7155 Candidate.Viable = false;
7156 Candidate.FailureKind = ovl_fail_too_many_arguments;
7160 // Function types don't have any default arguments, so just check if
7161 // we have enough arguments.
7162 if (Args.size() < NumParams) {
7163 // Not enough arguments.
7164 Candidate.Viable = false;
7165 Candidate.FailureKind = ovl_fail_too_few_arguments;
7169 // Determine the implicit conversion sequences for each of the
7171 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7172 if (ArgIdx < NumParams) {
7173 // (C++ 13.3.2p3): for F to be a viable function, there shall
7174 // exist for each argument an implicit conversion sequence
7175 // (13.3.3.1) that converts that argument to the corresponding
7177 QualType ParamType = Proto->getParamType(ArgIdx);
7178 Candidate.Conversions[ArgIdx + 1]
7179 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
7180 /*SuppressUserConversions=*/false,
7181 /*InOverloadResolution=*/false,
7182 /*AllowObjCWritebackConversion=*/
7183 getLangOpts().ObjCAutoRefCount);
7184 if (Candidate.Conversions[ArgIdx + 1].isBad()) {
7185 Candidate.Viable = false;
7186 Candidate.FailureKind = ovl_fail_bad_conversion;
7190 // (C++ 13.3.2p2): For the purposes of overload resolution, any
7191 // argument for which there is no corresponding parameter is
7192 // considered to ""match the ellipsis" (C+ 13.3.3.1.3).
7193 Candidate.Conversions[ArgIdx + 1].setEllipsis();
7197 if (EnableIfAttr *FailedAttr = CheckEnableIf(Conversion, None)) {
7198 Candidate.Viable = false;
7199 Candidate.FailureKind = ovl_fail_enable_if;
7200 Candidate.DeductionFailure.Data = FailedAttr;
7205 /// Add overload candidates for overloaded operators that are
7206 /// member functions.
7208 /// Add the overloaded operator candidates that are member functions
7209 /// for the operator Op that was used in an operator expression such
7210 /// as "x Op y". , Args/NumArgs provides the operator arguments, and
7211 /// CandidateSet will store the added overload candidates. (C++
7212 /// [over.match.oper]).
7213 void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op,
7214 SourceLocation OpLoc,
7215 ArrayRef<Expr *> Args,
7216 OverloadCandidateSet& CandidateSet,
7217 SourceRange OpRange) {
7218 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
7220 // C++ [over.match.oper]p3:
7221 // For a unary operator @ with an operand of a type whose
7222 // cv-unqualified version is T1, and for a binary operator @ with
7223 // a left operand of a type whose cv-unqualified version is T1 and
7224 // a right operand of a type whose cv-unqualified version is T2,
7225 // three sets of candidate functions, designated member
7226 // candidates, non-member candidates and built-in candidates, are
7227 // constructed as follows:
7228 QualType T1 = Args[0]->getType();
7230 // -- If T1 is a complete class type or a class currently being
7231 // defined, the set of member candidates is the result of the
7232 // qualified lookup of T1::operator@ (13.3.1.1.1); otherwise,
7233 // the set of member candidates is empty.
7234 if (const RecordType *T1Rec = T1->getAs<RecordType>()) {
7235 // Complete the type if it can be completed.
7236 if (!isCompleteType(OpLoc, T1) && !T1Rec->isBeingDefined())
7238 // If the type is neither complete nor being defined, bail out now.
7239 if (!T1Rec->getDecl()->getDefinition())
7242 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName);
7243 LookupQualifiedName(Operators, T1Rec->getDecl());
7244 Operators.suppressDiagnostics();
7246 for (LookupResult::iterator Oper = Operators.begin(),
7247 OperEnd = Operators.end();
7250 AddMethodCandidate(Oper.getPair(), Args[0]->getType(),
7251 Args[0]->Classify(Context), Args.slice(1),
7252 CandidateSet, /*SuppressUserConversions=*/false);
7256 /// AddBuiltinCandidate - Add a candidate for a built-in
7257 /// operator. ResultTy and ParamTys are the result and parameter types
7258 /// of the built-in candidate, respectively. Args and NumArgs are the
7259 /// arguments being passed to the candidate. IsAssignmentOperator
7260 /// should be true when this built-in candidate is an assignment
7261 /// operator. NumContextualBoolArguments is the number of arguments
7262 /// (at the beginning of the argument list) that will be contextually
7263 /// converted to bool.
7264 void Sema::AddBuiltinCandidate(QualType *ParamTys, ArrayRef<Expr *> Args,
7265 OverloadCandidateSet& CandidateSet,
7266 bool IsAssignmentOperator,
7267 unsigned NumContextualBoolArguments) {
7268 // Overload resolution is always an unevaluated context.
7269 EnterExpressionEvaluationContext Unevaluated(
7270 *this, Sema::ExpressionEvaluationContext::Unevaluated);
7272 // Add this candidate
7273 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size());
7274 Candidate.FoundDecl = DeclAccessPair::make(nullptr, AS_none);
7275 Candidate.Function = nullptr;
7276 Candidate.IsSurrogate = false;
7277 Candidate.IgnoreObjectArgument = false;
7278 std::copy(ParamTys, ParamTys + Args.size(), Candidate.BuiltinParamTypes);
7280 // Determine the implicit conversion sequences for each of the
7282 Candidate.Viable = true;
7283 Candidate.ExplicitCallArguments = Args.size();
7284 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7285 // C++ [over.match.oper]p4:
7286 // For the built-in assignment operators, conversions of the
7287 // left operand are restricted as follows:
7288 // -- no temporaries are introduced to hold the left operand, and
7289 // -- no user-defined conversions are applied to the left
7290 // operand to achieve a type match with the left-most
7291 // parameter of a built-in candidate.
7293 // We block these conversions by turning off user-defined
7294 // conversions, since that is the only way that initialization of
7295 // a reference to a non-class type can occur from something that
7296 // is not of the same type.
7297 if (ArgIdx < NumContextualBoolArguments) {
7298 assert(ParamTys[ArgIdx] == Context.BoolTy &&
7299 "Contextual conversion to bool requires bool type");
7300 Candidate.Conversions[ArgIdx]
7301 = TryContextuallyConvertToBool(*this, Args[ArgIdx]);
7303 Candidate.Conversions[ArgIdx]
7304 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx],
7305 ArgIdx == 0 && IsAssignmentOperator,
7306 /*InOverloadResolution=*/false,
7307 /*AllowObjCWritebackConversion=*/
7308 getLangOpts().ObjCAutoRefCount);
7310 if (Candidate.Conversions[ArgIdx].isBad()) {
7311 Candidate.Viable = false;
7312 Candidate.FailureKind = ovl_fail_bad_conversion;
7320 /// BuiltinCandidateTypeSet - A set of types that will be used for the
7321 /// candidate operator functions for built-in operators (C++
7322 /// [over.built]). The types are separated into pointer types and
7323 /// enumeration types.
7324 class BuiltinCandidateTypeSet {
7325 /// TypeSet - A set of types.
7326 typedef llvm::SetVector<QualType, SmallVector<QualType, 8>,
7327 llvm::SmallPtrSet<QualType, 8>> TypeSet;
7329 /// PointerTypes - The set of pointer types that will be used in the
7330 /// built-in candidates.
7331 TypeSet PointerTypes;
7333 /// MemberPointerTypes - The set of member pointer types that will be
7334 /// used in the built-in candidates.
7335 TypeSet MemberPointerTypes;
7337 /// EnumerationTypes - The set of enumeration types that will be
7338 /// used in the built-in candidates.
7339 TypeSet EnumerationTypes;
7341 /// The set of vector types that will be used in the built-in
7343 TypeSet VectorTypes;
7345 /// A flag indicating non-record types are viable candidates
7346 bool HasNonRecordTypes;
7348 /// A flag indicating whether either arithmetic or enumeration types
7349 /// were present in the candidate set.
7350 bool HasArithmeticOrEnumeralTypes;
7352 /// A flag indicating whether the nullptr type was present in the
7354 bool HasNullPtrType;
7356 /// Sema - The semantic analysis instance where we are building the
7357 /// candidate type set.
7360 /// Context - The AST context in which we will build the type sets.
7361 ASTContext &Context;
7363 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
7364 const Qualifiers &VisibleQuals);
7365 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty);
7368 /// iterator - Iterates through the types that are part of the set.
7369 typedef TypeSet::iterator iterator;
7371 BuiltinCandidateTypeSet(Sema &SemaRef)
7372 : HasNonRecordTypes(false),
7373 HasArithmeticOrEnumeralTypes(false),
7374 HasNullPtrType(false),
7376 Context(SemaRef.Context) { }
7378 void AddTypesConvertedFrom(QualType Ty,
7380 bool AllowUserConversions,
7381 bool AllowExplicitConversions,
7382 const Qualifiers &VisibleTypeConversionsQuals);
7384 /// pointer_begin - First pointer type found;
7385 iterator pointer_begin() { return PointerTypes.begin(); }
7387 /// pointer_end - Past the last pointer type found;
7388 iterator pointer_end() { return PointerTypes.end(); }
7390 /// member_pointer_begin - First member pointer type found;
7391 iterator member_pointer_begin() { return MemberPointerTypes.begin(); }
7393 /// member_pointer_end - Past the last member pointer type found;
7394 iterator member_pointer_end() { return MemberPointerTypes.end(); }
7396 /// enumeration_begin - First enumeration type found;
7397 iterator enumeration_begin() { return EnumerationTypes.begin(); }
7399 /// enumeration_end - Past the last enumeration type found;
7400 iterator enumeration_end() { return EnumerationTypes.end(); }
7402 iterator vector_begin() { return VectorTypes.begin(); }
7403 iterator vector_end() { return VectorTypes.end(); }
7405 bool hasNonRecordTypes() { return HasNonRecordTypes; }
7406 bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; }
7407 bool hasNullPtrType() const { return HasNullPtrType; }
7410 } // end anonymous namespace
7412 /// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to
7413 /// the set of pointer types along with any more-qualified variants of
7414 /// that type. For example, if @p Ty is "int const *", this routine
7415 /// will add "int const *", "int const volatile *", "int const
7416 /// restrict *", and "int const volatile restrict *" to the set of
7417 /// pointer types. Returns true if the add of @p Ty itself succeeded,
7418 /// false otherwise.
7420 /// FIXME: what to do about extended qualifiers?
7422 BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
7423 const Qualifiers &VisibleQuals) {
7425 // Insert this type.
7426 if (!PointerTypes.insert(Ty))
7430 const PointerType *PointerTy = Ty->getAs<PointerType>();
7431 bool buildObjCPtr = false;
7433 const ObjCObjectPointerType *PTy = Ty->castAs<ObjCObjectPointerType>();
7434 PointeeTy = PTy->getPointeeType();
7435 buildObjCPtr = true;
7437 PointeeTy = PointerTy->getPointeeType();
7440 // Don't add qualified variants of arrays. For one, they're not allowed
7441 // (the qualifier would sink to the element type), and for another, the
7442 // only overload situation where it matters is subscript or pointer +- int,
7443 // and those shouldn't have qualifier variants anyway.
7444 if (PointeeTy->isArrayType())
7447 unsigned BaseCVR = PointeeTy.getCVRQualifiers();
7448 bool hasVolatile = VisibleQuals.hasVolatile();
7449 bool hasRestrict = VisibleQuals.hasRestrict();
7451 // Iterate through all strict supersets of BaseCVR.
7452 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) {
7453 if ((CVR | BaseCVR) != CVR) continue;
7454 // Skip over volatile if no volatile found anywhere in the types.
7455 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue;
7457 // Skip over restrict if no restrict found anywhere in the types, or if
7458 // the type cannot be restrict-qualified.
7459 if ((CVR & Qualifiers::Restrict) &&
7461 (!(PointeeTy->isAnyPointerType() || PointeeTy->isReferenceType()))))
7464 // Build qualified pointee type.
7465 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR);
7467 // Build qualified pointer type.
7468 QualType QPointerTy;
7470 QPointerTy = Context.getPointerType(QPointeeTy);
7472 QPointerTy = Context.getObjCObjectPointerType(QPointeeTy);
7474 // Insert qualified pointer type.
7475 PointerTypes.insert(QPointerTy);
7481 /// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty
7482 /// to the set of pointer types along with any more-qualified variants of
7483 /// that type. For example, if @p Ty is "int const *", this routine
7484 /// will add "int const *", "int const volatile *", "int const
7485 /// restrict *", and "int const volatile restrict *" to the set of
7486 /// pointer types. Returns true if the add of @p Ty itself succeeded,
7487 /// false otherwise.
7489 /// FIXME: what to do about extended qualifiers?
7491 BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants(
7493 // Insert this type.
7494 if (!MemberPointerTypes.insert(Ty))
7497 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>();
7498 assert(PointerTy && "type was not a member pointer type!");
7500 QualType PointeeTy = PointerTy->getPointeeType();
7501 // Don't add qualified variants of arrays. For one, they're not allowed
7502 // (the qualifier would sink to the element type), and for another, the
7503 // only overload situation where it matters is subscript or pointer +- int,
7504 // and those shouldn't have qualifier variants anyway.
7505 if (PointeeTy->isArrayType())
7507 const Type *ClassTy = PointerTy->getClass();
7509 // Iterate through all strict supersets of the pointee type's CVR
7511 unsigned BaseCVR = PointeeTy.getCVRQualifiers();
7512 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) {
7513 if ((CVR | BaseCVR) != CVR) continue;
7515 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR);
7516 MemberPointerTypes.insert(
7517 Context.getMemberPointerType(QPointeeTy, ClassTy));
7523 /// AddTypesConvertedFrom - Add each of the types to which the type @p
7524 /// Ty can be implicit converted to the given set of @p Types. We're
7525 /// primarily interested in pointer types and enumeration types. We also
7526 /// take member pointer types, for the conditional operator.
7527 /// AllowUserConversions is true if we should look at the conversion
7528 /// functions of a class type, and AllowExplicitConversions if we
7529 /// should also include the explicit conversion functions of a class
7532 BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty,
7534 bool AllowUserConversions,
7535 bool AllowExplicitConversions,
7536 const Qualifiers &VisibleQuals) {
7537 // Only deal with canonical types.
7538 Ty = Context.getCanonicalType(Ty);
7540 // Look through reference types; they aren't part of the type of an
7541 // expression for the purposes of conversions.
7542 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>())
7543 Ty = RefTy->getPointeeType();
7545 // If we're dealing with an array type, decay to the pointer.
7546 if (Ty->isArrayType())
7547 Ty = SemaRef.Context.getArrayDecayedType(Ty);
7549 // Otherwise, we don't care about qualifiers on the type.
7550 Ty = Ty.getLocalUnqualifiedType();
7552 // Flag if we ever add a non-record type.
7553 const RecordType *TyRec = Ty->getAs<RecordType>();
7554 HasNonRecordTypes = HasNonRecordTypes || !TyRec;
7556 // Flag if we encounter an arithmetic type.
7557 HasArithmeticOrEnumeralTypes =
7558 HasArithmeticOrEnumeralTypes || Ty->isArithmeticType();
7560 if (Ty->isObjCIdType() || Ty->isObjCClassType())
7561 PointerTypes.insert(Ty);
7562 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) {
7563 // Insert our type, and its more-qualified variants, into the set
7565 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals))
7567 } else if (Ty->isMemberPointerType()) {
7568 // Member pointers are far easier, since the pointee can't be converted.
7569 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty))
7571 } else if (Ty->isEnumeralType()) {
7572 HasArithmeticOrEnumeralTypes = true;
7573 EnumerationTypes.insert(Ty);
7574 } else if (Ty->isVectorType()) {
7575 // We treat vector types as arithmetic types in many contexts as an
7577 HasArithmeticOrEnumeralTypes = true;
7578 VectorTypes.insert(Ty);
7579 } else if (Ty->isNullPtrType()) {
7580 HasNullPtrType = true;
7581 } else if (AllowUserConversions && TyRec) {
7582 // No conversion functions in incomplete types.
7583 if (!SemaRef.isCompleteType(Loc, Ty))
7586 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl());
7587 for (NamedDecl *D : ClassDecl->getVisibleConversionFunctions()) {
7588 if (isa<UsingShadowDecl>(D))
7589 D = cast<UsingShadowDecl>(D)->getTargetDecl();
7591 // Skip conversion function templates; they don't tell us anything
7592 // about which builtin types we can convert to.
7593 if (isa<FunctionTemplateDecl>(D))
7596 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D);
7597 if (AllowExplicitConversions || !Conv->isExplicit()) {
7598 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false,
7605 /// Helper function for AddBuiltinOperatorCandidates() that adds
7606 /// the volatile- and non-volatile-qualified assignment operators for the
7607 /// given type to the candidate set.
7608 static void AddBuiltinAssignmentOperatorCandidates(Sema &S,
7610 ArrayRef<Expr *> Args,
7611 OverloadCandidateSet &CandidateSet) {
7612 QualType ParamTypes[2];
7614 // T& operator=(T&, T)
7615 ParamTypes[0] = S.Context.getLValueReferenceType(T);
7617 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
7618 /*IsAssignmentOperator=*/true);
7620 if (!S.Context.getCanonicalType(T).isVolatileQualified()) {
7621 // volatile T& operator=(volatile T&, T)
7623 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T));
7625 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
7626 /*IsAssignmentOperator=*/true);
7630 /// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers,
7631 /// if any, found in visible type conversion functions found in ArgExpr's type.
7632 static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) {
7634 const RecordType *TyRec;
7635 if (const MemberPointerType *RHSMPType =
7636 ArgExpr->getType()->getAs<MemberPointerType>())
7637 TyRec = RHSMPType->getClass()->getAs<RecordType>();
7639 TyRec = ArgExpr->getType()->getAs<RecordType>();
7641 // Just to be safe, assume the worst case.
7642 VRQuals.addVolatile();
7643 VRQuals.addRestrict();
7647 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl());
7648 if (!ClassDecl->hasDefinition())
7651 for (NamedDecl *D : ClassDecl->getVisibleConversionFunctions()) {
7652 if (isa<UsingShadowDecl>(D))
7653 D = cast<UsingShadowDecl>(D)->getTargetDecl();
7654 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) {
7655 QualType CanTy = Context.getCanonicalType(Conv->getConversionType());
7656 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>())
7657 CanTy = ResTypeRef->getPointeeType();
7658 // Need to go down the pointer/mempointer chain and add qualifiers
7662 if (CanTy.isRestrictQualified())
7663 VRQuals.addRestrict();
7664 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>())
7665 CanTy = ResTypePtr->getPointeeType();
7666 else if (const MemberPointerType *ResTypeMPtr =
7667 CanTy->getAs<MemberPointerType>())
7668 CanTy = ResTypeMPtr->getPointeeType();
7671 if (CanTy.isVolatileQualified())
7672 VRQuals.addVolatile();
7673 if (VRQuals.hasRestrict() && VRQuals.hasVolatile())
7683 /// Helper class to manage the addition of builtin operator overload
7684 /// candidates. It provides shared state and utility methods used throughout
7685 /// the process, as well as a helper method to add each group of builtin
7686 /// operator overloads from the standard to a candidate set.
7687 class BuiltinOperatorOverloadBuilder {
7688 // Common instance state available to all overload candidate addition methods.
7690 ArrayRef<Expr *> Args;
7691 Qualifiers VisibleTypeConversionsQuals;
7692 bool HasArithmeticOrEnumeralCandidateType;
7693 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes;
7694 OverloadCandidateSet &CandidateSet;
7696 static constexpr int ArithmeticTypesCap = 24;
7697 SmallVector<CanQualType, ArithmeticTypesCap> ArithmeticTypes;
7699 // Define some indices used to iterate over the arithemetic types in
7700 // ArithmeticTypes. The "promoted arithmetic types" are the arithmetic
7701 // types are that preserved by promotion (C++ [over.built]p2).
7702 unsigned FirstIntegralType,
7704 unsigned FirstPromotedIntegralType,
7705 LastPromotedIntegralType;
7706 unsigned FirstPromotedArithmeticType,
7707 LastPromotedArithmeticType;
7708 unsigned NumArithmeticTypes;
7710 void InitArithmeticTypes() {
7711 // Start of promoted types.
7712 FirstPromotedArithmeticType = 0;
7713 ArithmeticTypes.push_back(S.Context.FloatTy);
7714 ArithmeticTypes.push_back(S.Context.DoubleTy);
7715 ArithmeticTypes.push_back(S.Context.LongDoubleTy);
7716 if (S.Context.getTargetInfo().hasFloat128Type())
7717 ArithmeticTypes.push_back(S.Context.Float128Ty);
7719 // Start of integral types.
7720 FirstIntegralType = ArithmeticTypes.size();
7721 FirstPromotedIntegralType = ArithmeticTypes.size();
7722 ArithmeticTypes.push_back(S.Context.IntTy);
7723 ArithmeticTypes.push_back(S.Context.LongTy);
7724 ArithmeticTypes.push_back(S.Context.LongLongTy);
7725 if (S.Context.getTargetInfo().hasInt128Type())
7726 ArithmeticTypes.push_back(S.Context.Int128Ty);
7727 ArithmeticTypes.push_back(S.Context.UnsignedIntTy);
7728 ArithmeticTypes.push_back(S.Context.UnsignedLongTy);
7729 ArithmeticTypes.push_back(S.Context.UnsignedLongLongTy);
7730 if (S.Context.getTargetInfo().hasInt128Type())
7731 ArithmeticTypes.push_back(S.Context.UnsignedInt128Ty);
7732 LastPromotedIntegralType = ArithmeticTypes.size();
7733 LastPromotedArithmeticType = ArithmeticTypes.size();
7734 // End of promoted types.
7736 ArithmeticTypes.push_back(S.Context.BoolTy);
7737 ArithmeticTypes.push_back(S.Context.CharTy);
7738 ArithmeticTypes.push_back(S.Context.WCharTy);
7739 if (S.Context.getLangOpts().Char8)
7740 ArithmeticTypes.push_back(S.Context.Char8Ty);
7741 ArithmeticTypes.push_back(S.Context.Char16Ty);
7742 ArithmeticTypes.push_back(S.Context.Char32Ty);
7743 ArithmeticTypes.push_back(S.Context.SignedCharTy);
7744 ArithmeticTypes.push_back(S.Context.ShortTy);
7745 ArithmeticTypes.push_back(S.Context.UnsignedCharTy);
7746 ArithmeticTypes.push_back(S.Context.UnsignedShortTy);
7747 LastIntegralType = ArithmeticTypes.size();
7748 NumArithmeticTypes = ArithmeticTypes.size();
7749 // End of integral types.
7750 // FIXME: What about complex? What about half?
7752 assert(ArithmeticTypes.size() <= ArithmeticTypesCap &&
7753 "Enough inline storage for all arithmetic types.");
7756 /// Helper method to factor out the common pattern of adding overloads
7757 /// for '++' and '--' builtin operators.
7758 void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy,
7761 QualType ParamTypes[2] = {
7762 S.Context.getLValueReferenceType(CandidateTy),
7766 // Non-volatile version.
7767 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
7769 // Use a heuristic to reduce number of builtin candidates in the set:
7770 // add volatile version only if there are conversions to a volatile type.
7773 S.Context.getLValueReferenceType(
7774 S.Context.getVolatileType(CandidateTy));
7775 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
7778 // Add restrict version only if there are conversions to a restrict type
7779 // and our candidate type is a non-restrict-qualified pointer.
7780 if (HasRestrict && CandidateTy->isAnyPointerType() &&
7781 !CandidateTy.isRestrictQualified()) {
7783 = S.Context.getLValueReferenceType(
7784 S.Context.getCVRQualifiedType(CandidateTy, Qualifiers::Restrict));
7785 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
7789 = S.Context.getLValueReferenceType(
7790 S.Context.getCVRQualifiedType(CandidateTy,
7791 (Qualifiers::Volatile |
7792 Qualifiers::Restrict)));
7793 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
7800 BuiltinOperatorOverloadBuilder(
7801 Sema &S, ArrayRef<Expr *> Args,
7802 Qualifiers VisibleTypeConversionsQuals,
7803 bool HasArithmeticOrEnumeralCandidateType,
7804 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes,
7805 OverloadCandidateSet &CandidateSet)
7807 VisibleTypeConversionsQuals(VisibleTypeConversionsQuals),
7808 HasArithmeticOrEnumeralCandidateType(
7809 HasArithmeticOrEnumeralCandidateType),
7810 CandidateTypes(CandidateTypes),
7811 CandidateSet(CandidateSet) {
7813 InitArithmeticTypes();
7816 // Increment is deprecated for bool since C++17.
7818 // C++ [over.built]p3:
7820 // For every pair (T, VQ), where T is an arithmetic type other
7821 // than bool, and VQ is either volatile or empty, there exist
7822 // candidate operator functions of the form
7824 // VQ T& operator++(VQ T&);
7825 // T operator++(VQ T&, int);
7827 // C++ [over.built]p4:
7829 // For every pair (T, VQ), where T is an arithmetic type other
7830 // than bool, and VQ is either volatile or empty, there exist
7831 // candidate operator functions of the form
7833 // VQ T& operator--(VQ T&);
7834 // T operator--(VQ T&, int);
7835 void addPlusPlusMinusMinusArithmeticOverloads(OverloadedOperatorKind Op) {
7836 if (!HasArithmeticOrEnumeralCandidateType)
7839 for (unsigned Arith = 0; Arith < NumArithmeticTypes; ++Arith) {
7840 const auto TypeOfT = ArithmeticTypes[Arith];
7841 if (TypeOfT == S.Context.BoolTy) {
7842 if (Op == OO_MinusMinus)
7844 if (Op == OO_PlusPlus && S.getLangOpts().CPlusPlus17)
7847 addPlusPlusMinusMinusStyleOverloads(
7849 VisibleTypeConversionsQuals.hasVolatile(),
7850 VisibleTypeConversionsQuals.hasRestrict());
7854 // C++ [over.built]p5:
7856 // For every pair (T, VQ), where T is a cv-qualified or
7857 // cv-unqualified object type, and VQ is either volatile or
7858 // empty, there exist candidate operator functions of the form
7860 // T*VQ& operator++(T*VQ&);
7861 // T*VQ& operator--(T*VQ&);
7862 // T* operator++(T*VQ&, int);
7863 // T* operator--(T*VQ&, int);
7864 void addPlusPlusMinusMinusPointerOverloads() {
7865 for (BuiltinCandidateTypeSet::iterator
7866 Ptr = CandidateTypes[0].pointer_begin(),
7867 PtrEnd = CandidateTypes[0].pointer_end();
7868 Ptr != PtrEnd; ++Ptr) {
7869 // Skip pointer types that aren't pointers to object types.
7870 if (!(*Ptr)->getPointeeType()->isObjectType())
7873 addPlusPlusMinusMinusStyleOverloads(*Ptr,
7874 (!(*Ptr).isVolatileQualified() &&
7875 VisibleTypeConversionsQuals.hasVolatile()),
7876 (!(*Ptr).isRestrictQualified() &&
7877 VisibleTypeConversionsQuals.hasRestrict()));
7881 // C++ [over.built]p6:
7882 // For every cv-qualified or cv-unqualified object type T, there
7883 // exist candidate operator functions of the form
7885 // T& operator*(T*);
7887 // C++ [over.built]p7:
7888 // For every function type T that does not have cv-qualifiers or a
7889 // ref-qualifier, there exist candidate operator functions of the form
7890 // T& operator*(T*);
7891 void addUnaryStarPointerOverloads() {
7892 for (BuiltinCandidateTypeSet::iterator
7893 Ptr = CandidateTypes[0].pointer_begin(),
7894 PtrEnd = CandidateTypes[0].pointer_end();
7895 Ptr != PtrEnd; ++Ptr) {
7896 QualType ParamTy = *Ptr;
7897 QualType PointeeTy = ParamTy->getPointeeType();
7898 if (!PointeeTy->isObjectType() && !PointeeTy->isFunctionType())
7901 if (const FunctionProtoType *Proto =PointeeTy->getAs<FunctionProtoType>())
7902 if (Proto->getTypeQuals() || Proto->getRefQualifier())
7905 S.AddBuiltinCandidate(&ParamTy, Args, CandidateSet);
7909 // C++ [over.built]p9:
7910 // For every promoted arithmetic type T, there exist candidate
7911 // operator functions of the form
7915 void addUnaryPlusOrMinusArithmeticOverloads() {
7916 if (!HasArithmeticOrEnumeralCandidateType)
7919 for (unsigned Arith = FirstPromotedArithmeticType;
7920 Arith < LastPromotedArithmeticType; ++Arith) {
7921 QualType ArithTy = ArithmeticTypes[Arith];
7922 S.AddBuiltinCandidate(&ArithTy, Args, CandidateSet);
7925 // Extension: We also add these operators for vector types.
7926 for (BuiltinCandidateTypeSet::iterator
7927 Vec = CandidateTypes[0].vector_begin(),
7928 VecEnd = CandidateTypes[0].vector_end();
7929 Vec != VecEnd; ++Vec) {
7930 QualType VecTy = *Vec;
7931 S.AddBuiltinCandidate(&VecTy, Args, CandidateSet);
7935 // C++ [over.built]p8:
7936 // For every type T, there exist candidate operator functions of
7939 // T* operator+(T*);
7940 void addUnaryPlusPointerOverloads() {
7941 for (BuiltinCandidateTypeSet::iterator
7942 Ptr = CandidateTypes[0].pointer_begin(),
7943 PtrEnd = CandidateTypes[0].pointer_end();
7944 Ptr != PtrEnd; ++Ptr) {
7945 QualType ParamTy = *Ptr;
7946 S.AddBuiltinCandidate(&ParamTy, Args, CandidateSet);
7950 // C++ [over.built]p10:
7951 // For every promoted integral type T, there exist candidate
7952 // operator functions of the form
7955 void addUnaryTildePromotedIntegralOverloads() {
7956 if (!HasArithmeticOrEnumeralCandidateType)
7959 for (unsigned Int = FirstPromotedIntegralType;
7960 Int < LastPromotedIntegralType; ++Int) {
7961 QualType IntTy = ArithmeticTypes[Int];
7962 S.AddBuiltinCandidate(&IntTy, Args, CandidateSet);
7965 // Extension: We also add this operator for vector types.
7966 for (BuiltinCandidateTypeSet::iterator
7967 Vec = CandidateTypes[0].vector_begin(),
7968 VecEnd = CandidateTypes[0].vector_end();
7969 Vec != VecEnd; ++Vec) {
7970 QualType VecTy = *Vec;
7971 S.AddBuiltinCandidate(&VecTy, Args, CandidateSet);
7975 // C++ [over.match.oper]p16:
7976 // For every pointer to member type T or type std::nullptr_t, there
7977 // exist candidate operator functions of the form
7979 // bool operator==(T,T);
7980 // bool operator!=(T,T);
7981 void addEqualEqualOrNotEqualMemberPointerOrNullptrOverloads() {
7982 /// Set of (canonical) types that we've already handled.
7983 llvm::SmallPtrSet<QualType, 8> AddedTypes;
7985 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7986 for (BuiltinCandidateTypeSet::iterator
7987 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(),
7988 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end();
7989 MemPtr != MemPtrEnd;
7991 // Don't add the same builtin candidate twice.
7992 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr)).second)
7995 QualType ParamTypes[2] = { *MemPtr, *MemPtr };
7996 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
7999 if (CandidateTypes[ArgIdx].hasNullPtrType()) {
8000 CanQualType NullPtrTy = S.Context.getCanonicalType(S.Context.NullPtrTy);
8001 if (AddedTypes.insert(NullPtrTy).second) {
8002 QualType ParamTypes[2] = { NullPtrTy, NullPtrTy };
8003 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8009 // C++ [over.built]p15:
8011 // For every T, where T is an enumeration type or a pointer type,
8012 // there exist candidate operator functions of the form
8014 // bool operator<(T, T);
8015 // bool operator>(T, T);
8016 // bool operator<=(T, T);
8017 // bool operator>=(T, T);
8018 // bool operator==(T, T);
8019 // bool operator!=(T, T);
8020 // R operator<=>(T, T)
8021 void addGenericBinaryPointerOrEnumeralOverloads() {
8022 // C++ [over.match.oper]p3:
8023 // [...]the built-in candidates include all of the candidate operator
8024 // functions defined in 13.6 that, compared to the given operator, [...]
8025 // do not have the same parameter-type-list as any non-template non-member
8028 // Note that in practice, this only affects enumeration types because there
8029 // aren't any built-in candidates of record type, and a user-defined operator
8030 // must have an operand of record or enumeration type. Also, the only other
8031 // overloaded operator with enumeration arguments, operator=,
8032 // cannot be overloaded for enumeration types, so this is the only place
8033 // where we must suppress candidates like this.
8034 llvm::DenseSet<std::pair<CanQualType, CanQualType> >
8035 UserDefinedBinaryOperators;
8037 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
8038 if (CandidateTypes[ArgIdx].enumeration_begin() !=
8039 CandidateTypes[ArgIdx].enumeration_end()) {
8040 for (OverloadCandidateSet::iterator C = CandidateSet.begin(),
8041 CEnd = CandidateSet.end();
8043 if (!C->Viable || !C->Function || C->Function->getNumParams() != 2)
8046 if (C->Function->isFunctionTemplateSpecialization())
8049 QualType FirstParamType =
8050 C->Function->getParamDecl(0)->getType().getUnqualifiedType();
8051 QualType SecondParamType =
8052 C->Function->getParamDecl(1)->getType().getUnqualifiedType();
8054 // Skip if either parameter isn't of enumeral type.
8055 if (!FirstParamType->isEnumeralType() ||
8056 !SecondParamType->isEnumeralType())
8059 // Add this operator to the set of known user-defined operators.
8060 UserDefinedBinaryOperators.insert(
8061 std::make_pair(S.Context.getCanonicalType(FirstParamType),
8062 S.Context.getCanonicalType(SecondParamType)));
8067 /// Set of (canonical) types that we've already handled.
8068 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8070 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
8071 for (BuiltinCandidateTypeSet::iterator
8072 Ptr = CandidateTypes[ArgIdx].pointer_begin(),
8073 PtrEnd = CandidateTypes[ArgIdx].pointer_end();
8074 Ptr != PtrEnd; ++Ptr) {
8075 // Don't add the same builtin candidate twice.
8076 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
8079 QualType ParamTypes[2] = { *Ptr, *Ptr };
8080 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8082 for (BuiltinCandidateTypeSet::iterator
8083 Enum = CandidateTypes[ArgIdx].enumeration_begin(),
8084 EnumEnd = CandidateTypes[ArgIdx].enumeration_end();
8085 Enum != EnumEnd; ++Enum) {
8086 CanQualType CanonType = S.Context.getCanonicalType(*Enum);
8088 // Don't add the same builtin candidate twice, or if a user defined
8089 // candidate exists.
8090 if (!AddedTypes.insert(CanonType).second ||
8091 UserDefinedBinaryOperators.count(std::make_pair(CanonType,
8094 QualType ParamTypes[2] = { *Enum, *Enum };
8095 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8100 // C++ [over.built]p13:
8102 // For every cv-qualified or cv-unqualified object type T
8103 // there exist candidate operator functions of the form
8105 // T* operator+(T*, ptrdiff_t);
8106 // T& operator[](T*, ptrdiff_t); [BELOW]
8107 // T* operator-(T*, ptrdiff_t);
8108 // T* operator+(ptrdiff_t, T*);
8109 // T& operator[](ptrdiff_t, T*); [BELOW]
8111 // C++ [over.built]p14:
8113 // For every T, where T is a pointer to object type, there
8114 // exist candidate operator functions of the form
8116 // ptrdiff_t operator-(T, T);
8117 void addBinaryPlusOrMinusPointerOverloads(OverloadedOperatorKind Op) {
8118 /// Set of (canonical) types that we've already handled.
8119 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8121 for (int Arg = 0; Arg < 2; ++Arg) {
8122 QualType AsymmetricParamTypes[2] = {
8123 S.Context.getPointerDiffType(),
8124 S.Context.getPointerDiffType(),
8126 for (BuiltinCandidateTypeSet::iterator
8127 Ptr = CandidateTypes[Arg].pointer_begin(),
8128 PtrEnd = CandidateTypes[Arg].pointer_end();
8129 Ptr != PtrEnd; ++Ptr) {
8130 QualType PointeeTy = (*Ptr)->getPointeeType();
8131 if (!PointeeTy->isObjectType())
8134 AsymmetricParamTypes[Arg] = *Ptr;
8135 if (Arg == 0 || Op == OO_Plus) {
8136 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t)
8137 // T* operator+(ptrdiff_t, T*);
8138 S.AddBuiltinCandidate(AsymmetricParamTypes, Args, CandidateSet);
8140 if (Op == OO_Minus) {
8141 // ptrdiff_t operator-(T, T);
8142 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
8145 QualType ParamTypes[2] = { *Ptr, *Ptr };
8146 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8152 // C++ [over.built]p12:
8154 // For every pair of promoted arithmetic types L and R, there
8155 // exist candidate operator functions of the form
8157 // LR operator*(L, R);
8158 // LR operator/(L, R);
8159 // LR operator+(L, R);
8160 // LR operator-(L, R);
8161 // bool operator<(L, R);
8162 // bool operator>(L, R);
8163 // bool operator<=(L, R);
8164 // bool operator>=(L, R);
8165 // bool operator==(L, R);
8166 // bool operator!=(L, R);
8168 // where LR is the result of the usual arithmetic conversions
8169 // between types L and R.
8171 // C++ [over.built]p24:
8173 // For every pair of promoted arithmetic types L and R, there exist
8174 // candidate operator functions of the form
8176 // LR operator?(bool, L, R);
8178 // where LR is the result of the usual arithmetic conversions
8179 // between types L and R.
8180 // Our candidates ignore the first parameter.
8181 void addGenericBinaryArithmeticOverloads() {
8182 if (!HasArithmeticOrEnumeralCandidateType)
8185 for (unsigned Left = FirstPromotedArithmeticType;
8186 Left < LastPromotedArithmeticType; ++Left) {
8187 for (unsigned Right = FirstPromotedArithmeticType;
8188 Right < LastPromotedArithmeticType; ++Right) {
8189 QualType LandR[2] = { ArithmeticTypes[Left],
8190 ArithmeticTypes[Right] };
8191 S.AddBuiltinCandidate(LandR, Args, CandidateSet);
8195 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the
8196 // conditional operator for vector types.
8197 for (BuiltinCandidateTypeSet::iterator
8198 Vec1 = CandidateTypes[0].vector_begin(),
8199 Vec1End = CandidateTypes[0].vector_end();
8200 Vec1 != Vec1End; ++Vec1) {
8201 for (BuiltinCandidateTypeSet::iterator
8202 Vec2 = CandidateTypes[1].vector_begin(),
8203 Vec2End = CandidateTypes[1].vector_end();
8204 Vec2 != Vec2End; ++Vec2) {
8205 QualType LandR[2] = { *Vec1, *Vec2 };
8206 S.AddBuiltinCandidate(LandR, Args, CandidateSet);
8211 // C++2a [over.built]p14:
8213 // For every integral type T there exists a candidate operator function
8216 // std::strong_ordering operator<=>(T, T)
8218 // C++2a [over.built]p15:
8220 // For every pair of floating-point types L and R, there exists a candidate
8221 // operator function of the form
8223 // std::partial_ordering operator<=>(L, R);
8225 // FIXME: The current specification for integral types doesn't play nice with
8226 // the direction of p0946r0, which allows mixed integral and unscoped-enum
8227 // comparisons. Under the current spec this can lead to ambiguity during
8228 // overload resolution. For example:
8230 // enum A : int {a};
8231 // auto x = (a <=> (long)42);
8233 // error: call is ambiguous for arguments 'A' and 'long'.
8234 // note: candidate operator<=>(int, int)
8235 // note: candidate operator<=>(long, long)
8237 // To avoid this error, this function deviates from the specification and adds
8238 // the mixed overloads `operator<=>(L, R)` where L and R are promoted
8239 // arithmetic types (the same as the generic relational overloads).
8241 // For now this function acts as a placeholder.
8242 void addThreeWayArithmeticOverloads() {
8243 addGenericBinaryArithmeticOverloads();
8246 // C++ [over.built]p17:
8248 // For every pair of promoted integral types L and R, there
8249 // exist candidate operator functions of the form
8251 // LR operator%(L, R);
8252 // LR operator&(L, R);
8253 // LR operator^(L, R);
8254 // LR operator|(L, R);
8255 // L operator<<(L, R);
8256 // L operator>>(L, R);
8258 // where LR is the result of the usual arithmetic conversions
8259 // between types L and R.
8260 void addBinaryBitwiseArithmeticOverloads(OverloadedOperatorKind Op) {
8261 if (!HasArithmeticOrEnumeralCandidateType)
8264 for (unsigned Left = FirstPromotedIntegralType;
8265 Left < LastPromotedIntegralType; ++Left) {
8266 for (unsigned Right = FirstPromotedIntegralType;
8267 Right < LastPromotedIntegralType; ++Right) {
8268 QualType LandR[2] = { ArithmeticTypes[Left],
8269 ArithmeticTypes[Right] };
8270 S.AddBuiltinCandidate(LandR, Args, CandidateSet);
8275 // C++ [over.built]p20:
8277 // For every pair (T, VQ), where T is an enumeration or
8278 // pointer to member type and VQ is either volatile or
8279 // empty, there exist candidate operator functions of the form
8281 // VQ T& operator=(VQ T&, T);
8282 void addAssignmentMemberPointerOrEnumeralOverloads() {
8283 /// Set of (canonical) types that we've already handled.
8284 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8286 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) {
8287 for (BuiltinCandidateTypeSet::iterator
8288 Enum = CandidateTypes[ArgIdx].enumeration_begin(),
8289 EnumEnd = CandidateTypes[ArgIdx].enumeration_end();
8290 Enum != EnumEnd; ++Enum) {
8291 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum)).second)
8294 AddBuiltinAssignmentOperatorCandidates(S, *Enum, Args, CandidateSet);
8297 for (BuiltinCandidateTypeSet::iterator
8298 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(),
8299 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end();
8300 MemPtr != MemPtrEnd; ++MemPtr) {
8301 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr)).second)
8304 AddBuiltinAssignmentOperatorCandidates(S, *MemPtr, Args, CandidateSet);
8309 // C++ [over.built]p19:
8311 // For every pair (T, VQ), where T is any type and VQ is either
8312 // volatile or empty, there exist candidate operator functions
8315 // T*VQ& operator=(T*VQ&, T*);
8317 // C++ [over.built]p21:
8319 // For every pair (T, VQ), where T is a cv-qualified or
8320 // cv-unqualified object type and VQ is either volatile or
8321 // empty, there exist candidate operator functions of the form
8323 // T*VQ& operator+=(T*VQ&, ptrdiff_t);
8324 // T*VQ& operator-=(T*VQ&, ptrdiff_t);
8325 void addAssignmentPointerOverloads(bool isEqualOp) {
8326 /// Set of (canonical) types that we've already handled.
8327 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8329 for (BuiltinCandidateTypeSet::iterator
8330 Ptr = CandidateTypes[0].pointer_begin(),
8331 PtrEnd = CandidateTypes[0].pointer_end();
8332 Ptr != PtrEnd; ++Ptr) {
8333 // If this is operator=, keep track of the builtin candidates we added.
8335 AddedTypes.insert(S.Context.getCanonicalType(*Ptr));
8336 else if (!(*Ptr)->getPointeeType()->isObjectType())
8339 // non-volatile version
8340 QualType ParamTypes[2] = {
8341 S.Context.getLValueReferenceType(*Ptr),
8342 isEqualOp ? *Ptr : S.Context.getPointerDiffType(),
8344 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8345 /*IsAssigmentOperator=*/ isEqualOp);
8347 bool NeedVolatile = !(*Ptr).isVolatileQualified() &&
8348 VisibleTypeConversionsQuals.hasVolatile();
8352 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr));
8353 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8354 /*IsAssigmentOperator=*/isEqualOp);
8357 if (!(*Ptr).isRestrictQualified() &&
8358 VisibleTypeConversionsQuals.hasRestrict()) {
8361 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr));
8362 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8363 /*IsAssigmentOperator=*/isEqualOp);
8366 // volatile restrict version
8368 = S.Context.getLValueReferenceType(
8369 S.Context.getCVRQualifiedType(*Ptr,
8370 (Qualifiers::Volatile |
8371 Qualifiers::Restrict)));
8372 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8373 /*IsAssigmentOperator=*/isEqualOp);
8379 for (BuiltinCandidateTypeSet::iterator
8380 Ptr = CandidateTypes[1].pointer_begin(),
8381 PtrEnd = CandidateTypes[1].pointer_end();
8382 Ptr != PtrEnd; ++Ptr) {
8383 // Make sure we don't add the same candidate twice.
8384 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
8387 QualType ParamTypes[2] = {
8388 S.Context.getLValueReferenceType(*Ptr),
8392 // non-volatile version
8393 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8394 /*IsAssigmentOperator=*/true);
8396 bool NeedVolatile = !(*Ptr).isVolatileQualified() &&
8397 VisibleTypeConversionsQuals.hasVolatile();
8401 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr));
8402 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8403 /*IsAssigmentOperator=*/true);
8406 if (!(*Ptr).isRestrictQualified() &&
8407 VisibleTypeConversionsQuals.hasRestrict()) {
8410 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr));
8411 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8412 /*IsAssigmentOperator=*/true);
8415 // volatile restrict version
8417 = S.Context.getLValueReferenceType(
8418 S.Context.getCVRQualifiedType(*Ptr,
8419 (Qualifiers::Volatile |
8420 Qualifiers::Restrict)));
8421 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8422 /*IsAssigmentOperator=*/true);
8429 // C++ [over.built]p18:
8431 // For every triple (L, VQ, R), where L is an arithmetic type,
8432 // VQ is either volatile or empty, and R is a promoted
8433 // arithmetic type, there exist candidate operator functions of
8436 // VQ L& operator=(VQ L&, R);
8437 // VQ L& operator*=(VQ L&, R);
8438 // VQ L& operator/=(VQ L&, R);
8439 // VQ L& operator+=(VQ L&, R);
8440 // VQ L& operator-=(VQ L&, R);
8441 void addAssignmentArithmeticOverloads(bool isEqualOp) {
8442 if (!HasArithmeticOrEnumeralCandidateType)
8445 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) {
8446 for (unsigned Right = FirstPromotedArithmeticType;
8447 Right < LastPromotedArithmeticType; ++Right) {
8448 QualType ParamTypes[2];
8449 ParamTypes[1] = ArithmeticTypes[Right];
8451 // Add this built-in operator as a candidate (VQ is empty).
8453 S.Context.getLValueReferenceType(ArithmeticTypes[Left]);
8454 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8455 /*IsAssigmentOperator=*/isEqualOp);
8457 // Add this built-in operator as a candidate (VQ is 'volatile').
8458 if (VisibleTypeConversionsQuals.hasVolatile()) {
8460 S.Context.getVolatileType(ArithmeticTypes[Left]);
8461 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
8462 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8463 /*IsAssigmentOperator=*/isEqualOp);
8468 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types.
8469 for (BuiltinCandidateTypeSet::iterator
8470 Vec1 = CandidateTypes[0].vector_begin(),
8471 Vec1End = CandidateTypes[0].vector_end();
8472 Vec1 != Vec1End; ++Vec1) {
8473 for (BuiltinCandidateTypeSet::iterator
8474 Vec2 = CandidateTypes[1].vector_begin(),
8475 Vec2End = CandidateTypes[1].vector_end();
8476 Vec2 != Vec2End; ++Vec2) {
8477 QualType ParamTypes[2];
8478 ParamTypes[1] = *Vec2;
8479 // Add this built-in operator as a candidate (VQ is empty).
8480 ParamTypes[0] = S.Context.getLValueReferenceType(*Vec1);
8481 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8482 /*IsAssigmentOperator=*/isEqualOp);
8484 // Add this built-in operator as a candidate (VQ is 'volatile').
8485 if (VisibleTypeConversionsQuals.hasVolatile()) {
8486 ParamTypes[0] = S.Context.getVolatileType(*Vec1);
8487 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
8488 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8489 /*IsAssigmentOperator=*/isEqualOp);
8495 // C++ [over.built]p22:
8497 // For every triple (L, VQ, R), where L is an integral type, VQ
8498 // is either volatile or empty, and R is a promoted integral
8499 // type, there exist candidate operator functions of the form
8501 // VQ L& operator%=(VQ L&, R);
8502 // VQ L& operator<<=(VQ L&, R);
8503 // VQ L& operator>>=(VQ L&, R);
8504 // VQ L& operator&=(VQ L&, R);
8505 // VQ L& operator^=(VQ L&, R);
8506 // VQ L& operator|=(VQ L&, R);
8507 void addAssignmentIntegralOverloads() {
8508 if (!HasArithmeticOrEnumeralCandidateType)
8511 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) {
8512 for (unsigned Right = FirstPromotedIntegralType;
8513 Right < LastPromotedIntegralType; ++Right) {
8514 QualType ParamTypes[2];
8515 ParamTypes[1] = ArithmeticTypes[Right];
8517 // Add this built-in operator as a candidate (VQ is empty).
8519 S.Context.getLValueReferenceType(ArithmeticTypes[Left]);
8520 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8521 if (VisibleTypeConversionsQuals.hasVolatile()) {
8522 // Add this built-in operator as a candidate (VQ is 'volatile').
8523 ParamTypes[0] = ArithmeticTypes[Left];
8524 ParamTypes[0] = S.Context.getVolatileType(ParamTypes[0]);
8525 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
8526 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8532 // C++ [over.operator]p23:
8534 // There also exist candidate operator functions of the form
8536 // bool operator!(bool);
8537 // bool operator&&(bool, bool);
8538 // bool operator||(bool, bool);
8539 void addExclaimOverload() {
8540 QualType ParamTy = S.Context.BoolTy;
8541 S.AddBuiltinCandidate(&ParamTy, Args, CandidateSet,
8542 /*IsAssignmentOperator=*/false,
8543 /*NumContextualBoolArguments=*/1);
8545 void addAmpAmpOrPipePipeOverload() {
8546 QualType ParamTypes[2] = { S.Context.BoolTy, S.Context.BoolTy };
8547 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8548 /*IsAssignmentOperator=*/false,
8549 /*NumContextualBoolArguments=*/2);
8552 // C++ [over.built]p13:
8554 // For every cv-qualified or cv-unqualified object type T there
8555 // exist candidate operator functions of the form
8557 // T* operator+(T*, ptrdiff_t); [ABOVE]
8558 // T& operator[](T*, ptrdiff_t);
8559 // T* operator-(T*, ptrdiff_t); [ABOVE]
8560 // T* operator+(ptrdiff_t, T*); [ABOVE]
8561 // T& operator[](ptrdiff_t, T*);
8562 void addSubscriptOverloads() {
8563 for (BuiltinCandidateTypeSet::iterator
8564 Ptr = CandidateTypes[0].pointer_begin(),
8565 PtrEnd = CandidateTypes[0].pointer_end();
8566 Ptr != PtrEnd; ++Ptr) {
8567 QualType ParamTypes[2] = { *Ptr, S.Context.getPointerDiffType() };
8568 QualType PointeeType = (*Ptr)->getPointeeType();
8569 if (!PointeeType->isObjectType())
8572 // T& operator[](T*, ptrdiff_t)
8573 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8576 for (BuiltinCandidateTypeSet::iterator
8577 Ptr = CandidateTypes[1].pointer_begin(),
8578 PtrEnd = CandidateTypes[1].pointer_end();
8579 Ptr != PtrEnd; ++Ptr) {
8580 QualType ParamTypes[2] = { S.Context.getPointerDiffType(), *Ptr };
8581 QualType PointeeType = (*Ptr)->getPointeeType();
8582 if (!PointeeType->isObjectType())
8585 // T& operator[](ptrdiff_t, T*)
8586 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8590 // C++ [over.built]p11:
8591 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type,
8592 // C1 is the same type as C2 or is a derived class of C2, T is an object
8593 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
8594 // there exist candidate operator functions of the form
8596 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
8598 // where CV12 is the union of CV1 and CV2.
8599 void addArrowStarOverloads() {
8600 for (BuiltinCandidateTypeSet::iterator
8601 Ptr = CandidateTypes[0].pointer_begin(),
8602 PtrEnd = CandidateTypes[0].pointer_end();
8603 Ptr != PtrEnd; ++Ptr) {
8604 QualType C1Ty = (*Ptr);
8606 QualifierCollector Q1;
8607 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0);
8608 if (!isa<RecordType>(C1))
8610 // heuristic to reduce number of builtin candidates in the set.
8611 // Add volatile/restrict version only if there are conversions to a
8612 // volatile/restrict type.
8613 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile())
8615 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict())
8617 for (BuiltinCandidateTypeSet::iterator
8618 MemPtr = CandidateTypes[1].member_pointer_begin(),
8619 MemPtrEnd = CandidateTypes[1].member_pointer_end();
8620 MemPtr != MemPtrEnd; ++MemPtr) {
8621 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr);
8622 QualType C2 = QualType(mptr->getClass(), 0);
8623 C2 = C2.getUnqualifiedType();
8624 if (C1 != C2 && !S.IsDerivedFrom(CandidateSet.getLocation(), C1, C2))
8626 QualType ParamTypes[2] = { *Ptr, *MemPtr };
8628 QualType T = mptr->getPointeeType();
8629 if (!VisibleTypeConversionsQuals.hasVolatile() &&
8630 T.isVolatileQualified())
8632 if (!VisibleTypeConversionsQuals.hasRestrict() &&
8633 T.isRestrictQualified())
8635 T = Q1.apply(S.Context, T);
8636 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8641 // Note that we don't consider the first argument, since it has been
8642 // contextually converted to bool long ago. The candidates below are
8643 // therefore added as binary.
8645 // C++ [over.built]p25:
8646 // For every type T, where T is a pointer, pointer-to-member, or scoped
8647 // enumeration type, there exist candidate operator functions of the form
8649 // T operator?(bool, T, T);
8651 void addConditionalOperatorOverloads() {
8652 /// Set of (canonical) types that we've already handled.
8653 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8655 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) {
8656 for (BuiltinCandidateTypeSet::iterator
8657 Ptr = CandidateTypes[ArgIdx].pointer_begin(),
8658 PtrEnd = CandidateTypes[ArgIdx].pointer_end();
8659 Ptr != PtrEnd; ++Ptr) {
8660 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
8663 QualType ParamTypes[2] = { *Ptr, *Ptr };
8664 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8667 for (BuiltinCandidateTypeSet::iterator
8668 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(),
8669 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end();
8670 MemPtr != MemPtrEnd; ++MemPtr) {
8671 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr)).second)
8674 QualType ParamTypes[2] = { *MemPtr, *MemPtr };
8675 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8678 if (S.getLangOpts().CPlusPlus11) {
8679 for (BuiltinCandidateTypeSet::iterator
8680 Enum = CandidateTypes[ArgIdx].enumeration_begin(),
8681 EnumEnd = CandidateTypes[ArgIdx].enumeration_end();
8682 Enum != EnumEnd; ++Enum) {
8683 if (!(*Enum)->getAs<EnumType>()->getDecl()->isScoped())
8686 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum)).second)
8689 QualType ParamTypes[2] = { *Enum, *Enum };
8690 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8697 } // end anonymous namespace
8699 /// AddBuiltinOperatorCandidates - Add the appropriate built-in
8700 /// operator overloads to the candidate set (C++ [over.built]), based
8701 /// on the operator @p Op and the arguments given. For example, if the
8702 /// operator is a binary '+', this routine might add "int
8703 /// operator+(int, int)" to cover integer addition.
8704 void Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op,
8705 SourceLocation OpLoc,
8706 ArrayRef<Expr *> Args,
8707 OverloadCandidateSet &CandidateSet) {
8708 // Find all of the types that the arguments can convert to, but only
8709 // if the operator we're looking at has built-in operator candidates
8710 // that make use of these types. Also record whether we encounter non-record
8711 // candidate types or either arithmetic or enumeral candidate types.
8712 Qualifiers VisibleTypeConversionsQuals;
8713 VisibleTypeConversionsQuals.addConst();
8714 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx)
8715 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]);
8717 bool HasNonRecordCandidateType = false;
8718 bool HasArithmeticOrEnumeralCandidateType = false;
8719 SmallVector<BuiltinCandidateTypeSet, 2> CandidateTypes;
8720 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
8721 CandidateTypes.emplace_back(*this);
8722 CandidateTypes[ArgIdx].AddTypesConvertedFrom(Args[ArgIdx]->getType(),
8725 (Op == OO_Exclaim ||
8728 VisibleTypeConversionsQuals);
8729 HasNonRecordCandidateType = HasNonRecordCandidateType ||
8730 CandidateTypes[ArgIdx].hasNonRecordTypes();
8731 HasArithmeticOrEnumeralCandidateType =
8732 HasArithmeticOrEnumeralCandidateType ||
8733 CandidateTypes[ArgIdx].hasArithmeticOrEnumeralTypes();
8736 // Exit early when no non-record types have been added to the candidate set
8737 // for any of the arguments to the operator.
8739 // We can't exit early for !, ||, or &&, since there we have always have
8740 // 'bool' overloads.
8741 if (!HasNonRecordCandidateType &&
8742 !(Op == OO_Exclaim || Op == OO_AmpAmp || Op == OO_PipePipe))
8745 // Setup an object to manage the common state for building overloads.
8746 BuiltinOperatorOverloadBuilder OpBuilder(*this, Args,
8747 VisibleTypeConversionsQuals,
8748 HasArithmeticOrEnumeralCandidateType,
8749 CandidateTypes, CandidateSet);
8751 // Dispatch over the operation to add in only those overloads which apply.
8754 case NUM_OVERLOADED_OPERATORS:
8755 llvm_unreachable("Expected an overloaded operator");
8760 case OO_Array_Delete:
8763 "Special operators don't use AddBuiltinOperatorCandidates");
8768 // C++ [over.match.oper]p3:
8769 // -- For the operator ',', the unary operator '&', the
8770 // operator '->', or the operator 'co_await', the
8771 // built-in candidates set is empty.
8774 case OO_Plus: // '+' is either unary or binary
8775 if (Args.size() == 1)
8776 OpBuilder.addUnaryPlusPointerOverloads();
8779 case OO_Minus: // '-' is either unary or binary
8780 if (Args.size() == 1) {
8781 OpBuilder.addUnaryPlusOrMinusArithmeticOverloads();
8783 OpBuilder.addBinaryPlusOrMinusPointerOverloads(Op);
8784 OpBuilder.addGenericBinaryArithmeticOverloads();
8788 case OO_Star: // '*' is either unary or binary
8789 if (Args.size() == 1)
8790 OpBuilder.addUnaryStarPointerOverloads();
8792 OpBuilder.addGenericBinaryArithmeticOverloads();
8796 OpBuilder.addGenericBinaryArithmeticOverloads();
8801 OpBuilder.addPlusPlusMinusMinusArithmeticOverloads(Op);
8802 OpBuilder.addPlusPlusMinusMinusPointerOverloads();
8806 case OO_ExclaimEqual:
8807 OpBuilder.addEqualEqualOrNotEqualMemberPointerOrNullptrOverloads();
8813 case OO_GreaterEqual:
8814 OpBuilder.addGenericBinaryPointerOrEnumeralOverloads();
8815 OpBuilder.addGenericBinaryArithmeticOverloads();
8819 OpBuilder.addGenericBinaryPointerOrEnumeralOverloads();
8820 OpBuilder.addThreeWayArithmeticOverloads();
8827 case OO_GreaterGreater:
8828 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op);
8831 case OO_Amp: // '&' is either unary or binary
8832 if (Args.size() == 1)
8833 // C++ [over.match.oper]p3:
8834 // -- For the operator ',', the unary operator '&', or the
8835 // operator '->', the built-in candidates set is empty.
8838 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op);
8842 OpBuilder.addUnaryTildePromotedIntegralOverloads();
8846 OpBuilder.addAssignmentMemberPointerOrEnumeralOverloads();
8851 OpBuilder.addAssignmentPointerOverloads(Op == OO_Equal);
8856 OpBuilder.addAssignmentArithmeticOverloads(Op == OO_Equal);
8859 case OO_PercentEqual:
8860 case OO_LessLessEqual:
8861 case OO_GreaterGreaterEqual:
8865 OpBuilder.addAssignmentIntegralOverloads();
8869 OpBuilder.addExclaimOverload();
8874 OpBuilder.addAmpAmpOrPipePipeOverload();
8878 OpBuilder.addSubscriptOverloads();
8882 OpBuilder.addArrowStarOverloads();
8885 case OO_Conditional:
8886 OpBuilder.addConditionalOperatorOverloads();
8887 OpBuilder.addGenericBinaryArithmeticOverloads();
8892 /// Add function candidates found via argument-dependent lookup
8893 /// to the set of overloading candidates.
8895 /// This routine performs argument-dependent name lookup based on the
8896 /// given function name (which may also be an operator name) and adds
8897 /// all of the overload candidates found by ADL to the overload
8898 /// candidate set (C++ [basic.lookup.argdep]).
8900 Sema::AddArgumentDependentLookupCandidates(DeclarationName Name,
8902 ArrayRef<Expr *> Args,
8903 TemplateArgumentListInfo *ExplicitTemplateArgs,
8904 OverloadCandidateSet& CandidateSet,
8905 bool PartialOverloading) {
8908 // FIXME: This approach for uniquing ADL results (and removing
8909 // redundant candidates from the set) relies on pointer-equality,
8910 // which means we need to key off the canonical decl. However,
8911 // always going back to the canonical decl might not get us the
8912 // right set of default arguments. What default arguments are
8913 // we supposed to consider on ADL candidates, anyway?
8915 // FIXME: Pass in the explicit template arguments?
8916 ArgumentDependentLookup(Name, Loc, Args, Fns);
8918 // Erase all of the candidates we already knew about.
8919 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(),
8920 CandEnd = CandidateSet.end();
8921 Cand != CandEnd; ++Cand)
8922 if (Cand->Function) {
8923 Fns.erase(Cand->Function);
8924 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate())
8928 // For each of the ADL candidates we found, add it to the overload
8930 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) {
8931 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none);
8932 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) {
8933 if (ExplicitTemplateArgs)
8936 AddOverloadCandidate(FD, FoundDecl, Args, CandidateSet, false,
8937 PartialOverloading);
8939 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I),
8940 FoundDecl, ExplicitTemplateArgs,
8941 Args, CandidateSet, PartialOverloading);
8946 enum class Comparison { Equal, Better, Worse };
8949 /// Compares the enable_if attributes of two FunctionDecls, for the purposes of
8950 /// overload resolution.
8952 /// Cand1's set of enable_if attributes are said to be "better" than Cand2's iff
8953 /// Cand1's first N enable_if attributes have precisely the same conditions as
8954 /// Cand2's first N enable_if attributes (where N = the number of enable_if
8955 /// attributes on Cand2), and Cand1 has more than N enable_if attributes.
8957 /// Note that you can have a pair of candidates such that Cand1's enable_if
8958 /// attributes are worse than Cand2's, and Cand2's enable_if attributes are
8959 /// worse than Cand1's.
8960 static Comparison compareEnableIfAttrs(const Sema &S, const FunctionDecl *Cand1,
8961 const FunctionDecl *Cand2) {
8962 // Common case: One (or both) decls don't have enable_if attrs.
8963 bool Cand1Attr = Cand1->hasAttr<EnableIfAttr>();
8964 bool Cand2Attr = Cand2->hasAttr<EnableIfAttr>();
8965 if (!Cand1Attr || !Cand2Attr) {
8966 if (Cand1Attr == Cand2Attr)
8967 return Comparison::Equal;
8968 return Cand1Attr ? Comparison::Better : Comparison::Worse;
8971 // FIXME: The next several lines are just
8972 // specific_attr_iterator<EnableIfAttr> but going in declaration order,
8973 // instead of reverse order which is how they're stored in the AST.
8974 auto Cand1Attrs = getOrderedEnableIfAttrs(Cand1);
8975 auto Cand2Attrs = getOrderedEnableIfAttrs(Cand2);
8977 // It's impossible for Cand1 to be better than (or equal to) Cand2 if Cand1
8978 // has fewer enable_if attributes than Cand2.
8979 if (Cand1Attrs.size() < Cand2Attrs.size())
8980 return Comparison::Worse;
8982 auto Cand1I = Cand1Attrs.begin();
8983 llvm::FoldingSetNodeID Cand1ID, Cand2ID;
8984 for (auto &Cand2A : Cand2Attrs) {
8988 auto &Cand1A = *Cand1I++;
8989 Cand1A->getCond()->Profile(Cand1ID, S.getASTContext(), true);
8990 Cand2A->getCond()->Profile(Cand2ID, S.getASTContext(), true);
8991 if (Cand1ID != Cand2ID)
8992 return Comparison::Worse;
8995 return Cand1I == Cand1Attrs.end() ? Comparison::Equal : Comparison::Better;
8998 static bool isBetterMultiversionCandidate(const OverloadCandidate &Cand1,
8999 const OverloadCandidate &Cand2) {
9000 if (!Cand1.Function || !Cand1.Function->isMultiVersion() || !Cand2.Function ||
9001 !Cand2.Function->isMultiVersion())
9004 // If this is a cpu_dispatch/cpu_specific multiversion situation, prefer
9005 // cpu_dispatch, else arbitrarily based on the identifiers.
9006 bool Cand1CPUDisp = Cand1.Function->hasAttr<CPUDispatchAttr>();
9007 bool Cand2CPUDisp = Cand2.Function->hasAttr<CPUDispatchAttr>();
9008 const auto *Cand1CPUSpec = Cand1.Function->getAttr<CPUSpecificAttr>();
9009 const auto *Cand2CPUSpec = Cand2.Function->getAttr<CPUSpecificAttr>();
9011 if (!Cand1CPUDisp && !Cand2CPUDisp && !Cand1CPUSpec && !Cand2CPUSpec)
9014 if (Cand1CPUDisp && !Cand2CPUDisp)
9016 if (Cand2CPUDisp && !Cand1CPUDisp)
9019 if (Cand1CPUSpec && Cand2CPUSpec) {
9020 if (Cand1CPUSpec->cpus_size() != Cand2CPUSpec->cpus_size())
9021 return Cand1CPUSpec->cpus_size() < Cand2CPUSpec->cpus_size();
9023 std::pair<CPUSpecificAttr::cpus_iterator, CPUSpecificAttr::cpus_iterator>
9024 FirstDiff = std::mismatch(
9025 Cand1CPUSpec->cpus_begin(), Cand1CPUSpec->cpus_end(),
9026 Cand2CPUSpec->cpus_begin(),
9027 [](const IdentifierInfo *LHS, const IdentifierInfo *RHS) {
9028 return LHS->getName() == RHS->getName();
9031 assert(FirstDiff.first != Cand1CPUSpec->cpus_end() &&
9032 "Two different cpu-specific versions should not have the same "
9033 "identifier list, otherwise they'd be the same decl!");
9034 return (*FirstDiff.first)->getName() < (*FirstDiff.second)->getName();
9036 llvm_unreachable("No way to get here unless both had cpu_dispatch");
9039 /// isBetterOverloadCandidate - Determines whether the first overload
9040 /// candidate is a better candidate than the second (C++ 13.3.3p1).
9041 bool clang::isBetterOverloadCandidate(
9042 Sema &S, const OverloadCandidate &Cand1, const OverloadCandidate &Cand2,
9043 SourceLocation Loc, OverloadCandidateSet::CandidateSetKind Kind) {
9044 // Define viable functions to be better candidates than non-viable
9047 return Cand1.Viable;
9048 else if (!Cand1.Viable)
9051 // C++ [over.match.best]p1:
9053 // -- if F is a static member function, ICS1(F) is defined such
9054 // that ICS1(F) is neither better nor worse than ICS1(G) for
9055 // any function G, and, symmetrically, ICS1(G) is neither
9056 // better nor worse than ICS1(F).
9057 unsigned StartArg = 0;
9058 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument)
9061 auto IsIllFormedConversion = [&](const ImplicitConversionSequence &ICS) {
9062 // We don't allow incompatible pointer conversions in C++.
9063 if (!S.getLangOpts().CPlusPlus)
9064 return ICS.isStandard() &&
9065 ICS.Standard.Second == ICK_Incompatible_Pointer_Conversion;
9067 // The only ill-formed conversion we allow in C++ is the string literal to
9068 // char* conversion, which is only considered ill-formed after C++11.
9069 return S.getLangOpts().CPlusPlus11 && !S.getLangOpts().WritableStrings &&
9070 hasDeprecatedStringLiteralToCharPtrConversion(ICS);
9073 // Define functions that don't require ill-formed conversions for a given
9074 // argument to be better candidates than functions that do.
9075 unsigned NumArgs = Cand1.Conversions.size();
9076 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch");
9077 bool HasBetterConversion = false;
9078 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) {
9079 bool Cand1Bad = IsIllFormedConversion(Cand1.Conversions[ArgIdx]);
9080 bool Cand2Bad = IsIllFormedConversion(Cand2.Conversions[ArgIdx]);
9081 if (Cand1Bad != Cand2Bad) {
9084 HasBetterConversion = true;
9088 if (HasBetterConversion)
9091 // C++ [over.match.best]p1:
9092 // A viable function F1 is defined to be a better function than another
9093 // viable function F2 if for all arguments i, ICSi(F1) is not a worse
9094 // conversion sequence than ICSi(F2), and then...
9095 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) {
9096 switch (CompareImplicitConversionSequences(S, Loc,
9097 Cand1.Conversions[ArgIdx],
9098 Cand2.Conversions[ArgIdx])) {
9099 case ImplicitConversionSequence::Better:
9100 // Cand1 has a better conversion sequence.
9101 HasBetterConversion = true;
9104 case ImplicitConversionSequence::Worse:
9105 // Cand1 can't be better than Cand2.
9108 case ImplicitConversionSequence::Indistinguishable:
9114 // -- for some argument j, ICSj(F1) is a better conversion sequence than
9115 // ICSj(F2), or, if not that,
9116 if (HasBetterConversion)
9119 // -- the context is an initialization by user-defined conversion
9120 // (see 8.5, 13.3.1.5) and the standard conversion sequence
9121 // from the return type of F1 to the destination type (i.e.,
9122 // the type of the entity being initialized) is a better
9123 // conversion sequence than the standard conversion sequence
9124 // from the return type of F2 to the destination type.
9125 if (Kind == OverloadCandidateSet::CSK_InitByUserDefinedConversion &&
9126 Cand1.Function && Cand2.Function &&
9127 isa<CXXConversionDecl>(Cand1.Function) &&
9128 isa<CXXConversionDecl>(Cand2.Function)) {
9129 // First check whether we prefer one of the conversion functions over the
9130 // other. This only distinguishes the results in non-standard, extension
9131 // cases such as the conversion from a lambda closure type to a function
9132 // pointer or block.
9133 ImplicitConversionSequence::CompareKind Result =
9134 compareConversionFunctions(S, Cand1.Function, Cand2.Function);
9135 if (Result == ImplicitConversionSequence::Indistinguishable)
9136 Result = CompareStandardConversionSequences(S, Loc,
9137 Cand1.FinalConversion,
9138 Cand2.FinalConversion);
9140 if (Result != ImplicitConversionSequence::Indistinguishable)
9141 return Result == ImplicitConversionSequence::Better;
9143 // FIXME: Compare kind of reference binding if conversion functions
9144 // convert to a reference type used in direct reference binding, per
9145 // C++14 [over.match.best]p1 section 2 bullet 3.
9148 // FIXME: Work around a defect in the C++17 guaranteed copy elision wording,
9149 // as combined with the resolution to CWG issue 243.
9151 // When the context is initialization by constructor ([over.match.ctor] or
9152 // either phase of [over.match.list]), a constructor is preferred over
9153 // a conversion function.
9154 if (Kind == OverloadCandidateSet::CSK_InitByConstructor && NumArgs == 1 &&
9155 Cand1.Function && Cand2.Function &&
9156 isa<CXXConstructorDecl>(Cand1.Function) !=
9157 isa<CXXConstructorDecl>(Cand2.Function))
9158 return isa<CXXConstructorDecl>(Cand1.Function);
9160 // -- F1 is a non-template function and F2 is a function template
9161 // specialization, or, if not that,
9162 bool Cand1IsSpecialization = Cand1.Function &&
9163 Cand1.Function->getPrimaryTemplate();
9164 bool Cand2IsSpecialization = Cand2.Function &&
9165 Cand2.Function->getPrimaryTemplate();
9166 if (Cand1IsSpecialization != Cand2IsSpecialization)
9167 return Cand2IsSpecialization;
9169 // -- F1 and F2 are function template specializations, and the function
9170 // template for F1 is more specialized than the template for F2
9171 // according to the partial ordering rules described in 14.5.5.2, or,
9173 if (Cand1IsSpecialization && Cand2IsSpecialization) {
9174 if (FunctionTemplateDecl *BetterTemplate
9175 = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(),
9176 Cand2.Function->getPrimaryTemplate(),
9178 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion
9180 Cand1.ExplicitCallArguments,
9181 Cand2.ExplicitCallArguments))
9182 return BetterTemplate == Cand1.Function->getPrimaryTemplate();
9185 // FIXME: Work around a defect in the C++17 inheriting constructor wording.
9186 // A derived-class constructor beats an (inherited) base class constructor.
9187 bool Cand1IsInherited =
9188 dyn_cast_or_null<ConstructorUsingShadowDecl>(Cand1.FoundDecl.getDecl());
9189 bool Cand2IsInherited =
9190 dyn_cast_or_null<ConstructorUsingShadowDecl>(Cand2.FoundDecl.getDecl());
9191 if (Cand1IsInherited != Cand2IsInherited)
9192 return Cand2IsInherited;
9193 else if (Cand1IsInherited) {
9194 assert(Cand2IsInherited);
9195 auto *Cand1Class = cast<CXXRecordDecl>(Cand1.Function->getDeclContext());
9196 auto *Cand2Class = cast<CXXRecordDecl>(Cand2.Function->getDeclContext());
9197 if (Cand1Class->isDerivedFrom(Cand2Class))
9199 if (Cand2Class->isDerivedFrom(Cand1Class))
9201 // Inherited from sibling base classes: still ambiguous.
9204 // Check C++17 tie-breakers for deduction guides.
9206 auto *Guide1 = dyn_cast_or_null<CXXDeductionGuideDecl>(Cand1.Function);
9207 auto *Guide2 = dyn_cast_or_null<CXXDeductionGuideDecl>(Cand2.Function);
9208 if (Guide1 && Guide2) {
9209 // -- F1 is generated from a deduction-guide and F2 is not
9210 if (Guide1->isImplicit() != Guide2->isImplicit())
9211 return Guide2->isImplicit();
9213 // -- F1 is the copy deduction candidate(16.3.1.8) and F2 is not
9214 if (Guide1->isCopyDeductionCandidate())
9219 // Check for enable_if value-based overload resolution.
9220 if (Cand1.Function && Cand2.Function) {
9221 Comparison Cmp = compareEnableIfAttrs(S, Cand1.Function, Cand2.Function);
9222 if (Cmp != Comparison::Equal)
9223 return Cmp == Comparison::Better;
9226 if (S.getLangOpts().CUDA && Cand1.Function && Cand2.Function) {
9227 FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext);
9228 return S.IdentifyCUDAPreference(Caller, Cand1.Function) >
9229 S.IdentifyCUDAPreference(Caller, Cand2.Function);
9232 bool HasPS1 = Cand1.Function != nullptr &&
9233 functionHasPassObjectSizeParams(Cand1.Function);
9234 bool HasPS2 = Cand2.Function != nullptr &&
9235 functionHasPassObjectSizeParams(Cand2.Function);
9236 if (HasPS1 != HasPS2 && HasPS1)
9239 return isBetterMultiversionCandidate(Cand1, Cand2);
9242 /// Determine whether two declarations are "equivalent" for the purposes of
9243 /// name lookup and overload resolution. This applies when the same internal/no
9244 /// linkage entity is defined by two modules (probably by textually including
9245 /// the same header). In such a case, we don't consider the declarations to
9246 /// declare the same entity, but we also don't want lookups with both
9247 /// declarations visible to be ambiguous in some cases (this happens when using
9248 /// a modularized libstdc++).
9249 bool Sema::isEquivalentInternalLinkageDeclaration(const NamedDecl *A,
9250 const NamedDecl *B) {
9251 auto *VA = dyn_cast_or_null<ValueDecl>(A);
9252 auto *VB = dyn_cast_or_null<ValueDecl>(B);
9256 // The declarations must be declaring the same name as an internal linkage
9257 // entity in different modules.
9258 if (!VA->getDeclContext()->getRedeclContext()->Equals(
9259 VB->getDeclContext()->getRedeclContext()) ||
9260 getOwningModule(const_cast<ValueDecl *>(VA)) ==
9261 getOwningModule(const_cast<ValueDecl *>(VB)) ||
9262 VA->isExternallyVisible() || VB->isExternallyVisible())
9265 // Check that the declarations appear to be equivalent.
9267 // FIXME: Checking the type isn't really enough to resolve the ambiguity.
9268 // For constants and functions, we should check the initializer or body is
9269 // the same. For non-constant variables, we shouldn't allow it at all.
9270 if (Context.hasSameType(VA->getType(), VB->getType()))
9273 // Enum constants within unnamed enumerations will have different types, but
9274 // may still be similar enough to be interchangeable for our purposes.
9275 if (auto *EA = dyn_cast<EnumConstantDecl>(VA)) {
9276 if (auto *EB = dyn_cast<EnumConstantDecl>(VB)) {
9277 // Only handle anonymous enums. If the enumerations were named and
9278 // equivalent, they would have been merged to the same type.
9279 auto *EnumA = cast<EnumDecl>(EA->getDeclContext());
9280 auto *EnumB = cast<EnumDecl>(EB->getDeclContext());
9281 if (EnumA->hasNameForLinkage() || EnumB->hasNameForLinkage() ||
9282 !Context.hasSameType(EnumA->getIntegerType(),
9283 EnumB->getIntegerType()))
9285 // Allow this only if the value is the same for both enumerators.
9286 return llvm::APSInt::isSameValue(EA->getInitVal(), EB->getInitVal());
9290 // Nothing else is sufficiently similar.
9294 void Sema::diagnoseEquivalentInternalLinkageDeclarations(
9295 SourceLocation Loc, const NamedDecl *D, ArrayRef<const NamedDecl *> Equiv) {
9296 Diag(Loc, diag::ext_equivalent_internal_linkage_decl_in_modules) << D;
9298 Module *M = getOwningModule(const_cast<NamedDecl*>(D));
9299 Diag(D->getLocation(), diag::note_equivalent_internal_linkage_decl)
9300 << !M << (M ? M->getFullModuleName() : "");
9302 for (auto *E : Equiv) {
9303 Module *M = getOwningModule(const_cast<NamedDecl*>(E));
9304 Diag(E->getLocation(), diag::note_equivalent_internal_linkage_decl)
9305 << !M << (M ? M->getFullModuleName() : "");
9309 /// Computes the best viable function (C++ 13.3.3)
9310 /// within an overload candidate set.
9312 /// \param Loc The location of the function name (or operator symbol) for
9313 /// which overload resolution occurs.
9315 /// \param Best If overload resolution was successful or found a deleted
9316 /// function, \p Best points to the candidate function found.
9318 /// \returns The result of overload resolution.
9320 OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc,
9322 llvm::SmallVector<OverloadCandidate *, 16> Candidates;
9323 std::transform(begin(), end(), std::back_inserter(Candidates),
9324 [](OverloadCandidate &Cand) { return &Cand; });
9326 // [CUDA] HD->H or HD->D calls are technically not allowed by CUDA but
9327 // are accepted by both clang and NVCC. However, during a particular
9328 // compilation mode only one call variant is viable. We need to
9329 // exclude non-viable overload candidates from consideration based
9330 // only on their host/device attributes. Specifically, if one
9331 // candidate call is WrongSide and the other is SameSide, we ignore
9332 // the WrongSide candidate.
9333 if (S.getLangOpts().CUDA) {
9334 const FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext);
9335 bool ContainsSameSideCandidate =
9336 llvm::any_of(Candidates, [&](OverloadCandidate *Cand) {
9337 return Cand->Function &&
9338 S.IdentifyCUDAPreference(Caller, Cand->Function) ==
9341 if (ContainsSameSideCandidate) {
9342 auto IsWrongSideCandidate = [&](OverloadCandidate *Cand) {
9343 return Cand->Function &&
9344 S.IdentifyCUDAPreference(Caller, Cand->Function) ==
9345 Sema::CFP_WrongSide;
9347 llvm::erase_if(Candidates, IsWrongSideCandidate);
9351 // Find the best viable function.
9353 for (auto *Cand : Candidates)
9355 if (Best == end() ||
9356 isBetterOverloadCandidate(S, *Cand, *Best, Loc, Kind))
9359 // If we didn't find any viable functions, abort.
9361 return OR_No_Viable_Function;
9363 llvm::SmallVector<const NamedDecl *, 4> EquivalentCands;
9365 // Make sure that this function is better than every other viable
9366 // function. If not, we have an ambiguity.
9367 for (auto *Cand : Candidates) {
9368 if (Cand->Viable && Cand != Best &&
9369 !isBetterOverloadCandidate(S, *Best, *Cand, Loc, Kind)) {
9370 if (S.isEquivalentInternalLinkageDeclaration(Best->Function,
9372 EquivalentCands.push_back(Cand->Function);
9377 return OR_Ambiguous;
9381 // Best is the best viable function.
9382 if (Best->Function &&
9383 (Best->Function->isDeleted() ||
9384 S.isFunctionConsideredUnavailable(Best->Function)))
9387 if (!EquivalentCands.empty())
9388 S.diagnoseEquivalentInternalLinkageDeclarations(Loc, Best->Function,
9396 enum OverloadCandidateKind {
9400 oc_implicit_default_constructor,
9401 oc_implicit_copy_constructor,
9402 oc_implicit_move_constructor,
9403 oc_implicit_copy_assignment,
9404 oc_implicit_move_assignment,
9405 oc_inherited_constructor
9408 enum OverloadCandidateSelect {
9411 ocs_described_template,
9414 static std::pair<OverloadCandidateKind, OverloadCandidateSelect>
9415 ClassifyOverloadCandidate(Sema &S, NamedDecl *Found, FunctionDecl *Fn,
9416 std::string &Description) {
9418 bool isTemplate = Fn->isTemplateDecl() || Found->isTemplateDecl();
9419 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) {
9421 Description = S.getTemplateArgumentBindingsText(
9422 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs());
9425 OverloadCandidateSelect Select = [&]() {
9426 if (!Description.empty())
9427 return ocs_described_template;
9428 return isTemplate ? ocs_template : ocs_non_template;
9431 OverloadCandidateKind Kind = [&]() {
9432 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) {
9433 if (!Ctor->isImplicit()) {
9434 if (isa<ConstructorUsingShadowDecl>(Found))
9435 return oc_inherited_constructor;
9437 return oc_constructor;
9440 if (Ctor->isDefaultConstructor())
9441 return oc_implicit_default_constructor;
9443 if (Ctor->isMoveConstructor())
9444 return oc_implicit_move_constructor;
9446 assert(Ctor->isCopyConstructor() &&
9447 "unexpected sort of implicit constructor");
9448 return oc_implicit_copy_constructor;
9451 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) {
9452 // This actually gets spelled 'candidate function' for now, but
9453 // it doesn't hurt to split it out.
9454 if (!Meth->isImplicit())
9457 if (Meth->isMoveAssignmentOperator())
9458 return oc_implicit_move_assignment;
9460 if (Meth->isCopyAssignmentOperator())
9461 return oc_implicit_copy_assignment;
9463 assert(isa<CXXConversionDecl>(Meth) && "expected conversion");
9470 return std::make_pair(Kind, Select);
9473 void MaybeEmitInheritedConstructorNote(Sema &S, Decl *FoundDecl) {
9474 // FIXME: It'd be nice to only emit a note once per using-decl per overload
9476 if (auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(FoundDecl))
9477 S.Diag(FoundDecl->getLocation(),
9478 diag::note_ovl_candidate_inherited_constructor)
9479 << Shadow->getNominatedBaseClass();
9482 } // end anonymous namespace
9484 static bool isFunctionAlwaysEnabled(const ASTContext &Ctx,
9485 const FunctionDecl *FD) {
9486 for (auto *EnableIf : FD->specific_attrs<EnableIfAttr>()) {
9488 if (!EnableIf->getCond()->EvaluateAsBooleanCondition(AlwaysTrue, Ctx))
9496 /// Returns true if we can take the address of the function.
9498 /// \param Complain - If true, we'll emit a diagnostic
9499 /// \param InOverloadResolution - For the purposes of emitting a diagnostic, are
9500 /// we in overload resolution?
9501 /// \param Loc - The location of the statement we're complaining about. Ignored
9502 /// if we're not complaining, or if we're in overload resolution.
9503 static bool checkAddressOfFunctionIsAvailable(Sema &S, const FunctionDecl *FD,
9505 bool InOverloadResolution,
9506 SourceLocation Loc) {
9507 if (!isFunctionAlwaysEnabled(S.Context, FD)) {
9509 if (InOverloadResolution)
9510 S.Diag(FD->getLocStart(),
9511 diag::note_addrof_ovl_candidate_disabled_by_enable_if_attr);
9513 S.Diag(Loc, diag::err_addrof_function_disabled_by_enable_if_attr) << FD;
9518 auto I = llvm::find_if(FD->parameters(), [](const ParmVarDecl *P) {
9519 return P->hasAttr<PassObjectSizeAttr>();
9521 if (I == FD->param_end())
9525 // Add one to ParamNo because it's user-facing
9526 unsigned ParamNo = std::distance(FD->param_begin(), I) + 1;
9527 if (InOverloadResolution)
9528 S.Diag(FD->getLocation(),
9529 diag::note_ovl_candidate_has_pass_object_size_params)
9532 S.Diag(Loc, diag::err_address_of_function_with_pass_object_size_params)
9538 static bool checkAddressOfCandidateIsAvailable(Sema &S,
9539 const FunctionDecl *FD) {
9540 return checkAddressOfFunctionIsAvailable(S, FD, /*Complain=*/true,
9541 /*InOverloadResolution=*/true,
9542 /*Loc=*/SourceLocation());
9545 bool Sema::checkAddressOfFunctionIsAvailable(const FunctionDecl *Function,
9547 SourceLocation Loc) {
9548 return ::checkAddressOfFunctionIsAvailable(*this, Function, Complain,
9549 /*InOverloadResolution=*/false,
9553 // Notes the location of an overload candidate.
9554 void Sema::NoteOverloadCandidate(NamedDecl *Found, FunctionDecl *Fn,
9555 QualType DestType, bool TakingAddress) {
9556 if (TakingAddress && !checkAddressOfCandidateIsAvailable(*this, Fn))
9558 if (Fn->isMultiVersion() && Fn->hasAttr<TargetAttr>() &&
9559 !Fn->getAttr<TargetAttr>()->isDefaultVersion())
9563 std::pair<OverloadCandidateKind, OverloadCandidateSelect> KSPair =
9564 ClassifyOverloadCandidate(*this, Found, Fn, FnDesc);
9565 PartialDiagnostic PD = PDiag(diag::note_ovl_candidate)
9566 << (unsigned)KSPair.first << (unsigned)KSPair.second
9569 HandleFunctionTypeMismatch(PD, Fn->getType(), DestType);
9570 Diag(Fn->getLocation(), PD);
9571 MaybeEmitInheritedConstructorNote(*this, Found);
9574 // Notes the location of all overload candidates designated through
9576 void Sema::NoteAllOverloadCandidates(Expr *OverloadedExpr, QualType DestType,
9577 bool TakingAddress) {
9578 assert(OverloadedExpr->getType() == Context.OverloadTy);
9580 OverloadExpr::FindResult Ovl = OverloadExpr::find(OverloadedExpr);
9581 OverloadExpr *OvlExpr = Ovl.Expression;
9583 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
9584 IEnd = OvlExpr->decls_end();
9586 if (FunctionTemplateDecl *FunTmpl =
9587 dyn_cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()) ) {
9588 NoteOverloadCandidate(*I, FunTmpl->getTemplatedDecl(), DestType,
9590 } else if (FunctionDecl *Fun
9591 = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()) ) {
9592 NoteOverloadCandidate(*I, Fun, DestType, TakingAddress);
9597 /// Diagnoses an ambiguous conversion. The partial diagnostic is the
9598 /// "lead" diagnostic; it will be given two arguments, the source and
9599 /// target types of the conversion.
9600 void ImplicitConversionSequence::DiagnoseAmbiguousConversion(
9602 SourceLocation CaretLoc,
9603 const PartialDiagnostic &PDiag) const {
9604 S.Diag(CaretLoc, PDiag)
9605 << Ambiguous.getFromType() << Ambiguous.getToType();
9606 // FIXME: The note limiting machinery is borrowed from
9607 // OverloadCandidateSet::NoteCandidates; there's an opportunity for
9608 // refactoring here.
9609 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
9610 unsigned CandsShown = 0;
9611 AmbiguousConversionSequence::const_iterator I, E;
9612 for (I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) {
9613 if (CandsShown >= 4 && ShowOverloads == Ovl_Best)
9616 S.NoteOverloadCandidate(I->first, I->second);
9619 S.Diag(SourceLocation(), diag::note_ovl_too_many_candidates) << int(E - I);
9622 static void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand,
9623 unsigned I, bool TakingCandidateAddress) {
9624 const ImplicitConversionSequence &Conv = Cand->Conversions[I];
9625 assert(Conv.isBad());
9626 assert(Cand->Function && "for now, candidate must be a function");
9627 FunctionDecl *Fn = Cand->Function;
9629 // There's a conversion slot for the object argument if this is a
9630 // non-constructor method. Note that 'I' corresponds the
9631 // conversion-slot index.
9632 bool isObjectArgument = false;
9633 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) {
9635 isObjectArgument = true;
9641 std::pair<OverloadCandidateKind, OverloadCandidateSelect> FnKindPair =
9642 ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn, FnDesc);
9644 Expr *FromExpr = Conv.Bad.FromExpr;
9645 QualType FromTy = Conv.Bad.getFromType();
9646 QualType ToTy = Conv.Bad.getToType();
9648 if (FromTy == S.Context.OverloadTy) {
9649 assert(FromExpr && "overload set argument came from implicit argument?");
9650 Expr *E = FromExpr->IgnoreParens();
9651 if (isa<UnaryOperator>(E))
9652 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens();
9653 DeclarationName Name = cast<OverloadExpr>(E)->getName();
9655 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload)
9656 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9657 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << ToTy
9659 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9663 // Do some hand-waving analysis to see if the non-viability is due
9664 // to a qualifier mismatch.
9665 CanQualType CFromTy = S.Context.getCanonicalType(FromTy);
9666 CanQualType CToTy = S.Context.getCanonicalType(ToTy);
9667 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>())
9668 CToTy = RT->getPointeeType();
9670 // TODO: detect and diagnose the full richness of const mismatches.
9671 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>())
9672 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) {
9673 CFromTy = FromPT->getPointeeType();
9674 CToTy = ToPT->getPointeeType();
9678 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() &&
9679 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) {
9680 Qualifiers FromQs = CFromTy.getQualifiers();
9681 Qualifiers ToQs = CToTy.getQualifiers();
9683 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) {
9684 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace)
9685 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9686 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
9687 << ToTy << (unsigned)isObjectArgument << I + 1;
9688 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9692 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) {
9693 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_ownership)
9694 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9695 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
9696 << FromQs.getObjCLifetime() << ToQs.getObjCLifetime()
9697 << (unsigned)isObjectArgument << I + 1;
9698 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9702 if (FromQs.getObjCGCAttr() != ToQs.getObjCGCAttr()) {
9703 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_gc)
9704 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9705 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
9706 << FromQs.getObjCGCAttr() << ToQs.getObjCGCAttr()
9707 << (unsigned)isObjectArgument << I + 1;
9708 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9712 if (FromQs.hasUnaligned() != ToQs.hasUnaligned()) {
9713 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_unaligned)
9714 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9715 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
9716 << FromQs.hasUnaligned() << I + 1;
9717 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9721 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers();
9722 assert(CVR && "unexpected qualifiers mismatch");
9724 if (isObjectArgument) {
9725 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this)
9726 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9727 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
9730 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr)
9731 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9732 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
9733 << (CVR - 1) << I + 1;
9735 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9739 // Special diagnostic for failure to convert an initializer list, since
9740 // telling the user that it has type void is not useful.
9741 if (FromExpr && isa<InitListExpr>(FromExpr)) {
9742 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_list_argument)
9743 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9744 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
9745 << ToTy << (unsigned)isObjectArgument << I + 1;
9746 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9750 // Diagnose references or pointers to incomplete types differently,
9751 // since it's far from impossible that the incompleteness triggered
9753 QualType TempFromTy = FromTy.getNonReferenceType();
9754 if (const PointerType *PTy = TempFromTy->getAs<PointerType>())
9755 TempFromTy = PTy->getPointeeType();
9756 if (TempFromTy->isIncompleteType()) {
9757 // Emit the generic diagnostic and, optionally, add the hints to it.
9758 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete)
9759 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9760 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
9761 << ToTy << (unsigned)isObjectArgument << I + 1
9762 << (unsigned)(Cand->Fix.Kind);
9764 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9768 // Diagnose base -> derived pointer conversions.
9769 unsigned BaseToDerivedConversion = 0;
9770 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) {
9771 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) {
9772 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs(
9773 FromPtrTy->getPointeeType()) &&
9774 !FromPtrTy->getPointeeType()->isIncompleteType() &&
9775 !ToPtrTy->getPointeeType()->isIncompleteType() &&
9776 S.IsDerivedFrom(SourceLocation(), ToPtrTy->getPointeeType(),
9777 FromPtrTy->getPointeeType()))
9778 BaseToDerivedConversion = 1;
9780 } else if (const ObjCObjectPointerType *FromPtrTy
9781 = FromTy->getAs<ObjCObjectPointerType>()) {
9782 if (const ObjCObjectPointerType *ToPtrTy
9783 = ToTy->getAs<ObjCObjectPointerType>())
9784 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl())
9785 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl())
9786 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs(
9787 FromPtrTy->getPointeeType()) &&
9788 FromIface->isSuperClassOf(ToIface))
9789 BaseToDerivedConversion = 2;
9790 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) {
9791 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) &&
9792 !FromTy->isIncompleteType() &&
9793 !ToRefTy->getPointeeType()->isIncompleteType() &&
9794 S.IsDerivedFrom(SourceLocation(), ToRefTy->getPointeeType(), FromTy)) {
9795 BaseToDerivedConversion = 3;
9796 } else if (ToTy->isLValueReferenceType() && !FromExpr->isLValue() &&
9797 ToTy.getNonReferenceType().getCanonicalType() ==
9798 FromTy.getNonReferenceType().getCanonicalType()) {
9799 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_lvalue)
9800 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9801 << (unsigned)isObjectArgument << I + 1
9802 << (FromExpr ? FromExpr->getSourceRange() : SourceRange());
9803 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9808 if (BaseToDerivedConversion) {
9809 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_base_to_derived_conv)
9810 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9811 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9812 << (BaseToDerivedConversion - 1) << FromTy << ToTy << I + 1;
9813 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9817 if (isa<ObjCObjectPointerType>(CFromTy) &&
9818 isa<PointerType>(CToTy)) {
9819 Qualifiers FromQs = CFromTy.getQualifiers();
9820 Qualifiers ToQs = CToTy.getQualifiers();
9821 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) {
9822 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_arc_conv)
9823 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second
9824 << FnDesc << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9825 << FromTy << ToTy << (unsigned)isObjectArgument << I + 1;
9826 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9831 if (TakingCandidateAddress &&
9832 !checkAddressOfCandidateIsAvailable(S, Cand->Function))
9835 // Emit the generic diagnostic and, optionally, add the hints to it.
9836 PartialDiagnostic FDiag = S.PDiag(diag::note_ovl_candidate_bad_conv);
9837 FDiag << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9838 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
9839 << ToTy << (unsigned)isObjectArgument << I + 1
9840 << (unsigned)(Cand->Fix.Kind);
9842 // If we can fix the conversion, suggest the FixIts.
9843 for (std::vector<FixItHint>::iterator HI = Cand->Fix.Hints.begin(),
9844 HE = Cand->Fix.Hints.end(); HI != HE; ++HI)
9846 S.Diag(Fn->getLocation(), FDiag);
9848 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9851 /// Additional arity mismatch diagnosis specific to a function overload
9852 /// candidates. This is not covered by the more general DiagnoseArityMismatch()
9853 /// over a candidate in any candidate set.
9854 static bool CheckArityMismatch(Sema &S, OverloadCandidate *Cand,
9856 FunctionDecl *Fn = Cand->Function;
9857 unsigned MinParams = Fn->getMinRequiredArguments();
9859 // With invalid overloaded operators, it's possible that we think we
9860 // have an arity mismatch when in fact it looks like we have the
9861 // right number of arguments, because only overloaded operators have
9862 // the weird behavior of overloading member and non-member functions.
9863 // Just don't report anything.
9864 if (Fn->isInvalidDecl() &&
9865 Fn->getDeclName().getNameKind() == DeclarationName::CXXOperatorName)
9868 if (NumArgs < MinParams) {
9869 assert((Cand->FailureKind == ovl_fail_too_few_arguments) ||
9870 (Cand->FailureKind == ovl_fail_bad_deduction &&
9871 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments));
9873 assert((Cand->FailureKind == ovl_fail_too_many_arguments) ||
9874 (Cand->FailureKind == ovl_fail_bad_deduction &&
9875 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments));
9881 /// General arity mismatch diagnosis over a candidate in a candidate set.
9882 static void DiagnoseArityMismatch(Sema &S, NamedDecl *Found, Decl *D,
9883 unsigned NumFormalArgs) {
9884 assert(isa<FunctionDecl>(D) &&
9885 "The templated declaration should at least be a function"
9886 " when diagnosing bad template argument deduction due to too many"
9887 " or too few arguments");
9889 FunctionDecl *Fn = cast<FunctionDecl>(D);
9891 // TODO: treat calls to a missing default constructor as a special case
9892 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>();
9893 unsigned MinParams = Fn->getMinRequiredArguments();
9895 // at least / at most / exactly
9896 unsigned mode, modeCount;
9897 if (NumFormalArgs < MinParams) {
9898 if (MinParams != FnTy->getNumParams() || FnTy->isVariadic() ||
9899 FnTy->isTemplateVariadic())
9900 mode = 0; // "at least"
9902 mode = 2; // "exactly"
9903 modeCount = MinParams;
9905 if (MinParams != FnTy->getNumParams())
9906 mode = 1; // "at most"
9908 mode = 2; // "exactly"
9909 modeCount = FnTy->getNumParams();
9912 std::string Description;
9913 std::pair<OverloadCandidateKind, OverloadCandidateSelect> FnKindPair =
9914 ClassifyOverloadCandidate(S, Found, Fn, Description);
9916 if (modeCount == 1 && Fn->getParamDecl(0)->getDeclName())
9917 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity_one)
9918 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second
9919 << Description << mode << Fn->getParamDecl(0) << NumFormalArgs;
9921 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity)
9922 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second
9923 << Description << mode << modeCount << NumFormalArgs;
9925 MaybeEmitInheritedConstructorNote(S, Found);
9928 /// Arity mismatch diagnosis specific to a function overload candidate.
9929 static void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand,
9930 unsigned NumFormalArgs) {
9931 if (!CheckArityMismatch(S, Cand, NumFormalArgs))
9932 DiagnoseArityMismatch(S, Cand->FoundDecl, Cand->Function, NumFormalArgs);
9935 static TemplateDecl *getDescribedTemplate(Decl *Templated) {
9936 if (TemplateDecl *TD = Templated->getDescribedTemplate())
9938 llvm_unreachable("Unsupported: Getting the described template declaration"
9939 " for bad deduction diagnosis");
9942 /// Diagnose a failed template-argument deduction.
9943 static void DiagnoseBadDeduction(Sema &S, NamedDecl *Found, Decl *Templated,
9944 DeductionFailureInfo &DeductionFailure,
9946 bool TakingCandidateAddress) {
9947 TemplateParameter Param = DeductionFailure.getTemplateParameter();
9949 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) ||
9950 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) ||
9951 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>());
9952 switch (DeductionFailure.Result) {
9953 case Sema::TDK_Success:
9954 llvm_unreachable("TDK_success while diagnosing bad deduction");
9956 case Sema::TDK_Incomplete: {
9957 assert(ParamD && "no parameter found for incomplete deduction result");
9958 S.Diag(Templated->getLocation(),
9959 diag::note_ovl_candidate_incomplete_deduction)
9960 << ParamD->getDeclName();
9961 MaybeEmitInheritedConstructorNote(S, Found);
9965 case Sema::TDK_IncompletePack: {
9966 assert(ParamD && "no parameter found for incomplete deduction result");
9967 S.Diag(Templated->getLocation(),
9968 diag::note_ovl_candidate_incomplete_deduction_pack)
9969 << ParamD->getDeclName()
9970 << (DeductionFailure.getFirstArg()->pack_size() + 1)
9971 << *DeductionFailure.getFirstArg();
9972 MaybeEmitInheritedConstructorNote(S, Found);
9976 case Sema::TDK_Underqualified: {
9977 assert(ParamD && "no parameter found for bad qualifiers deduction result");
9978 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD);
9980 QualType Param = DeductionFailure.getFirstArg()->getAsType();
9982 // Param will have been canonicalized, but it should just be a
9983 // qualified version of ParamD, so move the qualifiers to that.
9984 QualifierCollector Qs;
9986 QualType NonCanonParam = Qs.apply(S.Context, TParam->getTypeForDecl());
9987 assert(S.Context.hasSameType(Param, NonCanonParam));
9989 // Arg has also been canonicalized, but there's nothing we can do
9990 // about that. It also doesn't matter as much, because it won't
9991 // have any template parameters in it (because deduction isn't
9992 // done on dependent types).
9993 QualType Arg = DeductionFailure.getSecondArg()->getAsType();
9995 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_underqualified)
9996 << ParamD->getDeclName() << Arg << NonCanonParam;
9997 MaybeEmitInheritedConstructorNote(S, Found);
10001 case Sema::TDK_Inconsistent: {
10002 assert(ParamD && "no parameter found for inconsistent deduction result");
10004 if (isa<TemplateTypeParmDecl>(ParamD))
10006 else if (isa<NonTypeTemplateParmDecl>(ParamD)) {
10007 // Deduction might have failed because we deduced arguments of two
10008 // different types for a non-type template parameter.
10009 // FIXME: Use a different TDK value for this.
10011 DeductionFailure.getFirstArg()->getNonTypeTemplateArgumentType();
10013 DeductionFailure.getSecondArg()->getNonTypeTemplateArgumentType();
10014 if (!S.Context.hasSameType(T1, T2)) {
10015 S.Diag(Templated->getLocation(),
10016 diag::note_ovl_candidate_inconsistent_deduction_types)
10017 << ParamD->getDeclName() << *DeductionFailure.getFirstArg() << T1
10018 << *DeductionFailure.getSecondArg() << T2;
10019 MaybeEmitInheritedConstructorNote(S, Found);
10028 S.Diag(Templated->getLocation(),
10029 diag::note_ovl_candidate_inconsistent_deduction)
10030 << which << ParamD->getDeclName() << *DeductionFailure.getFirstArg()
10031 << *DeductionFailure.getSecondArg();
10032 MaybeEmitInheritedConstructorNote(S, Found);
10036 case Sema::TDK_InvalidExplicitArguments:
10037 assert(ParamD && "no parameter found for invalid explicit arguments");
10038 if (ParamD->getDeclName())
10039 S.Diag(Templated->getLocation(),
10040 diag::note_ovl_candidate_explicit_arg_mismatch_named)
10041 << ParamD->getDeclName();
10044 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD))
10045 index = TTP->getIndex();
10046 else if (NonTypeTemplateParmDecl *NTTP
10047 = dyn_cast<NonTypeTemplateParmDecl>(ParamD))
10048 index = NTTP->getIndex();
10050 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex();
10051 S.Diag(Templated->getLocation(),
10052 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed)
10055 MaybeEmitInheritedConstructorNote(S, Found);
10058 case Sema::TDK_TooManyArguments:
10059 case Sema::TDK_TooFewArguments:
10060 DiagnoseArityMismatch(S, Found, Templated, NumArgs);
10063 case Sema::TDK_InstantiationDepth:
10064 S.Diag(Templated->getLocation(),
10065 diag::note_ovl_candidate_instantiation_depth);
10066 MaybeEmitInheritedConstructorNote(S, Found);
10069 case Sema::TDK_SubstitutionFailure: {
10070 // Format the template argument list into the argument string.
10071 SmallString<128> TemplateArgString;
10072 if (TemplateArgumentList *Args =
10073 DeductionFailure.getTemplateArgumentList()) {
10074 TemplateArgString = " ";
10075 TemplateArgString += S.getTemplateArgumentBindingsText(
10076 getDescribedTemplate(Templated)->getTemplateParameters(), *Args);
10079 // If this candidate was disabled by enable_if, say so.
10080 PartialDiagnosticAt *PDiag = DeductionFailure.getSFINAEDiagnostic();
10081 if (PDiag && PDiag->second.getDiagID() ==
10082 diag::err_typename_nested_not_found_enable_if) {
10083 // FIXME: Use the source range of the condition, and the fully-qualified
10084 // name of the enable_if template. These are both present in PDiag.
10085 S.Diag(PDiag->first, diag::note_ovl_candidate_disabled_by_enable_if)
10086 << "'enable_if'" << TemplateArgString;
10090 // We found a specific requirement that disabled the enable_if.
10091 if (PDiag && PDiag->second.getDiagID() ==
10092 diag::err_typename_nested_not_found_requirement) {
10093 S.Diag(Templated->getLocation(),
10094 diag::note_ovl_candidate_disabled_by_requirement)
10095 << PDiag->second.getStringArg(0) << TemplateArgString;
10099 // Format the SFINAE diagnostic into the argument string.
10100 // FIXME: Add a general mechanism to include a PartialDiagnostic *'s
10101 // formatted message in another diagnostic.
10102 SmallString<128> SFINAEArgString;
10105 SFINAEArgString = ": ";
10106 R = SourceRange(PDiag->first, PDiag->first);
10107 PDiag->second.EmitToString(S.getDiagnostics(), SFINAEArgString);
10110 S.Diag(Templated->getLocation(),
10111 diag::note_ovl_candidate_substitution_failure)
10112 << TemplateArgString << SFINAEArgString << R;
10113 MaybeEmitInheritedConstructorNote(S, Found);
10117 case Sema::TDK_DeducedMismatch:
10118 case Sema::TDK_DeducedMismatchNested: {
10119 // Format the template argument list into the argument string.
10120 SmallString<128> TemplateArgString;
10121 if (TemplateArgumentList *Args =
10122 DeductionFailure.getTemplateArgumentList()) {
10123 TemplateArgString = " ";
10124 TemplateArgString += S.getTemplateArgumentBindingsText(
10125 getDescribedTemplate(Templated)->getTemplateParameters(), *Args);
10128 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_deduced_mismatch)
10129 << (*DeductionFailure.getCallArgIndex() + 1)
10130 << *DeductionFailure.getFirstArg() << *DeductionFailure.getSecondArg()
10131 << TemplateArgString
10132 << (DeductionFailure.Result == Sema::TDK_DeducedMismatchNested);
10136 case Sema::TDK_NonDeducedMismatch: {
10137 // FIXME: Provide a source location to indicate what we couldn't match.
10138 TemplateArgument FirstTA = *DeductionFailure.getFirstArg();
10139 TemplateArgument SecondTA = *DeductionFailure.getSecondArg();
10140 if (FirstTA.getKind() == TemplateArgument::Template &&
10141 SecondTA.getKind() == TemplateArgument::Template) {
10142 TemplateName FirstTN = FirstTA.getAsTemplate();
10143 TemplateName SecondTN = SecondTA.getAsTemplate();
10144 if (FirstTN.getKind() == TemplateName::Template &&
10145 SecondTN.getKind() == TemplateName::Template) {
10146 if (FirstTN.getAsTemplateDecl()->getName() ==
10147 SecondTN.getAsTemplateDecl()->getName()) {
10148 // FIXME: This fixes a bad diagnostic where both templates are named
10149 // the same. This particular case is a bit difficult since:
10150 // 1) It is passed as a string to the diagnostic printer.
10151 // 2) The diagnostic printer only attempts to find a better
10152 // name for types, not decls.
10153 // Ideally, this should folded into the diagnostic printer.
10154 S.Diag(Templated->getLocation(),
10155 diag::note_ovl_candidate_non_deduced_mismatch_qualified)
10156 << FirstTN.getAsTemplateDecl() << SecondTN.getAsTemplateDecl();
10162 if (TakingCandidateAddress && isa<FunctionDecl>(Templated) &&
10163 !checkAddressOfCandidateIsAvailable(S, cast<FunctionDecl>(Templated)))
10166 // FIXME: For generic lambda parameters, check if the function is a lambda
10167 // call operator, and if so, emit a prettier and more informative
10168 // diagnostic that mentions 'auto' and lambda in addition to
10169 // (or instead of?) the canonical template type parameters.
10170 S.Diag(Templated->getLocation(),
10171 diag::note_ovl_candidate_non_deduced_mismatch)
10172 << FirstTA << SecondTA;
10175 // TODO: diagnose these individually, then kill off
10176 // note_ovl_candidate_bad_deduction, which is uselessly vague.
10177 case Sema::TDK_MiscellaneousDeductionFailure:
10178 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_bad_deduction);
10179 MaybeEmitInheritedConstructorNote(S, Found);
10181 case Sema::TDK_CUDATargetMismatch:
10182 S.Diag(Templated->getLocation(),
10183 diag::note_cuda_ovl_candidate_target_mismatch);
10188 /// Diagnose a failed template-argument deduction, for function calls.
10189 static void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand,
10191 bool TakingCandidateAddress) {
10192 unsigned TDK = Cand->DeductionFailure.Result;
10193 if (TDK == Sema::TDK_TooFewArguments || TDK == Sema::TDK_TooManyArguments) {
10194 if (CheckArityMismatch(S, Cand, NumArgs))
10197 DiagnoseBadDeduction(S, Cand->FoundDecl, Cand->Function, // pattern
10198 Cand->DeductionFailure, NumArgs, TakingCandidateAddress);
10201 /// CUDA: diagnose an invalid call across targets.
10202 static void DiagnoseBadTarget(Sema &S, OverloadCandidate *Cand) {
10203 FunctionDecl *Caller = cast<FunctionDecl>(S.CurContext);
10204 FunctionDecl *Callee = Cand->Function;
10206 Sema::CUDAFunctionTarget CallerTarget = S.IdentifyCUDATarget(Caller),
10207 CalleeTarget = S.IdentifyCUDATarget(Callee);
10209 std::string FnDesc;
10210 std::pair<OverloadCandidateKind, OverloadCandidateSelect> FnKindPair =
10211 ClassifyOverloadCandidate(S, Cand->FoundDecl, Callee, FnDesc);
10213 S.Diag(Callee->getLocation(), diag::note_ovl_candidate_bad_target)
10214 << (unsigned)FnKindPair.first << (unsigned)ocs_non_template
10215 << FnDesc /* Ignored */
10216 << CalleeTarget << CallerTarget;
10218 // This could be an implicit constructor for which we could not infer the
10219 // target due to a collsion. Diagnose that case.
10220 CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Callee);
10221 if (Meth != nullptr && Meth->isImplicit()) {
10222 CXXRecordDecl *ParentClass = Meth->getParent();
10223 Sema::CXXSpecialMember CSM;
10225 switch (FnKindPair.first) {
10228 case oc_implicit_default_constructor:
10229 CSM = Sema::CXXDefaultConstructor;
10231 case oc_implicit_copy_constructor:
10232 CSM = Sema::CXXCopyConstructor;
10234 case oc_implicit_move_constructor:
10235 CSM = Sema::CXXMoveConstructor;
10237 case oc_implicit_copy_assignment:
10238 CSM = Sema::CXXCopyAssignment;
10240 case oc_implicit_move_assignment:
10241 CSM = Sema::CXXMoveAssignment;
10245 bool ConstRHS = false;
10246 if (Meth->getNumParams()) {
10247 if (const ReferenceType *RT =
10248 Meth->getParamDecl(0)->getType()->getAs<ReferenceType>()) {
10249 ConstRHS = RT->getPointeeType().isConstQualified();
10253 S.inferCUDATargetForImplicitSpecialMember(ParentClass, CSM, Meth,
10254 /* ConstRHS */ ConstRHS,
10255 /* Diagnose */ true);
10259 static void DiagnoseFailedEnableIfAttr(Sema &S, OverloadCandidate *Cand) {
10260 FunctionDecl *Callee = Cand->Function;
10261 EnableIfAttr *Attr = static_cast<EnableIfAttr*>(Cand->DeductionFailure.Data);
10263 S.Diag(Callee->getLocation(),
10264 diag::note_ovl_candidate_disabled_by_function_cond_attr)
10265 << Attr->getCond()->getSourceRange() << Attr->getMessage();
10268 static void DiagnoseOpenCLExtensionDisabled(Sema &S, OverloadCandidate *Cand) {
10269 FunctionDecl *Callee = Cand->Function;
10271 S.Diag(Callee->getLocation(),
10272 diag::note_ovl_candidate_disabled_by_extension);
10275 /// Generates a 'note' diagnostic for an overload candidate. We've
10276 /// already generated a primary error at the call site.
10278 /// It really does need to be a single diagnostic with its caret
10279 /// pointed at the candidate declaration. Yes, this creates some
10280 /// major challenges of technical writing. Yes, this makes pointing
10281 /// out problems with specific arguments quite awkward. It's still
10282 /// better than generating twenty screens of text for every failed
10285 /// It would be great to be able to express per-candidate problems
10286 /// more richly for those diagnostic clients that cared, but we'd
10287 /// still have to be just as careful with the default diagnostics.
10288 static void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand,
10290 bool TakingCandidateAddress) {
10291 FunctionDecl *Fn = Cand->Function;
10293 // Note deleted candidates, but only if they're viable.
10294 if (Cand->Viable) {
10295 if (Fn->isDeleted() || S.isFunctionConsideredUnavailable(Fn)) {
10296 std::string FnDesc;
10297 std::pair<OverloadCandidateKind, OverloadCandidateSelect> FnKindPair =
10298 ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn, FnDesc);
10300 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted)
10301 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10302 << (Fn->isDeleted() ? (Fn->isDeletedAsWritten() ? 1 : 2) : 0);
10303 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10307 // We don't really have anything else to say about viable candidates.
10308 S.NoteOverloadCandidate(Cand->FoundDecl, Fn);
10312 switch (Cand->FailureKind) {
10313 case ovl_fail_too_many_arguments:
10314 case ovl_fail_too_few_arguments:
10315 return DiagnoseArityMismatch(S, Cand, NumArgs);
10317 case ovl_fail_bad_deduction:
10318 return DiagnoseBadDeduction(S, Cand, NumArgs,
10319 TakingCandidateAddress);
10321 case ovl_fail_illegal_constructor: {
10322 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_illegal_constructor)
10323 << (Fn->getPrimaryTemplate() ? 1 : 0);
10324 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10328 case ovl_fail_trivial_conversion:
10329 case ovl_fail_bad_final_conversion:
10330 case ovl_fail_final_conversion_not_exact:
10331 return S.NoteOverloadCandidate(Cand->FoundDecl, Fn);
10333 case ovl_fail_bad_conversion: {
10334 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0);
10335 for (unsigned N = Cand->Conversions.size(); I != N; ++I)
10336 if (Cand->Conversions[I].isBad())
10337 return DiagnoseBadConversion(S, Cand, I, TakingCandidateAddress);
10339 // FIXME: this currently happens when we're called from SemaInit
10340 // when user-conversion overload fails. Figure out how to handle
10341 // those conditions and diagnose them well.
10342 return S.NoteOverloadCandidate(Cand->FoundDecl, Fn);
10345 case ovl_fail_bad_target:
10346 return DiagnoseBadTarget(S, Cand);
10348 case ovl_fail_enable_if:
10349 return DiagnoseFailedEnableIfAttr(S, Cand);
10351 case ovl_fail_ext_disabled:
10352 return DiagnoseOpenCLExtensionDisabled(S, Cand);
10354 case ovl_fail_inhctor_slice:
10355 // It's generally not interesting to note copy/move constructors here.
10356 if (cast<CXXConstructorDecl>(Fn)->isCopyOrMoveConstructor())
10358 S.Diag(Fn->getLocation(),
10359 diag::note_ovl_candidate_inherited_constructor_slice)
10360 << (Fn->getPrimaryTemplate() ? 1 : 0)
10361 << Fn->getParamDecl(0)->getType()->isRValueReferenceType();
10362 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10365 case ovl_fail_addr_not_available: {
10366 bool Available = checkAddressOfCandidateIsAvailable(S, Cand->Function);
10368 assert(!Available);
10371 case ovl_non_default_multiversion_function:
10372 // Do nothing, these should simply be ignored.
10377 static void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) {
10378 // Desugar the type of the surrogate down to a function type,
10379 // retaining as many typedefs as possible while still showing
10380 // the function type (and, therefore, its parameter types).
10381 QualType FnType = Cand->Surrogate->getConversionType();
10382 bool isLValueReference = false;
10383 bool isRValueReference = false;
10384 bool isPointer = false;
10385 if (const LValueReferenceType *FnTypeRef =
10386 FnType->getAs<LValueReferenceType>()) {
10387 FnType = FnTypeRef->getPointeeType();
10388 isLValueReference = true;
10389 } else if (const RValueReferenceType *FnTypeRef =
10390 FnType->getAs<RValueReferenceType>()) {
10391 FnType = FnTypeRef->getPointeeType();
10392 isRValueReference = true;
10394 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) {
10395 FnType = FnTypePtr->getPointeeType();
10398 // Desugar down to a function type.
10399 FnType = QualType(FnType->getAs<FunctionType>(), 0);
10400 // Reconstruct the pointer/reference as appropriate.
10401 if (isPointer) FnType = S.Context.getPointerType(FnType);
10402 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType);
10403 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType);
10405 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand)
10409 static void NoteBuiltinOperatorCandidate(Sema &S, StringRef Opc,
10410 SourceLocation OpLoc,
10411 OverloadCandidate *Cand) {
10412 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary");
10413 std::string TypeStr("operator");
10416 TypeStr += Cand->BuiltinParamTypes[0].getAsString();
10417 if (Cand->Conversions.size() == 1) {
10419 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr;
10422 TypeStr += Cand->BuiltinParamTypes[1].getAsString();
10424 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr;
10428 static void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc,
10429 OverloadCandidate *Cand) {
10430 for (const ImplicitConversionSequence &ICS : Cand->Conversions) {
10431 if (ICS.isBad()) break; // all meaningless after first invalid
10432 if (!ICS.isAmbiguous()) continue;
10434 ICS.DiagnoseAmbiguousConversion(
10435 S, OpLoc, S.PDiag(diag::note_ambiguous_type_conversion));
10439 static SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) {
10440 if (Cand->Function)
10441 return Cand->Function->getLocation();
10442 if (Cand->IsSurrogate)
10443 return Cand->Surrogate->getLocation();
10444 return SourceLocation();
10447 static unsigned RankDeductionFailure(const DeductionFailureInfo &DFI) {
10448 switch ((Sema::TemplateDeductionResult)DFI.Result) {
10449 case Sema::TDK_Success:
10450 case Sema::TDK_NonDependentConversionFailure:
10451 llvm_unreachable("non-deduction failure while diagnosing bad deduction");
10453 case Sema::TDK_Invalid:
10454 case Sema::TDK_Incomplete:
10455 case Sema::TDK_IncompletePack:
10458 case Sema::TDK_Underqualified:
10459 case Sema::TDK_Inconsistent:
10462 case Sema::TDK_SubstitutionFailure:
10463 case Sema::TDK_DeducedMismatch:
10464 case Sema::TDK_DeducedMismatchNested:
10465 case Sema::TDK_NonDeducedMismatch:
10466 case Sema::TDK_MiscellaneousDeductionFailure:
10467 case Sema::TDK_CUDATargetMismatch:
10470 case Sema::TDK_InstantiationDepth:
10473 case Sema::TDK_InvalidExplicitArguments:
10476 case Sema::TDK_TooManyArguments:
10477 case Sema::TDK_TooFewArguments:
10480 llvm_unreachable("Unhandled deduction result");
10484 struct CompareOverloadCandidatesForDisplay {
10486 SourceLocation Loc;
10488 OverloadCandidateSet::CandidateSetKind CSK;
10490 CompareOverloadCandidatesForDisplay(
10491 Sema &S, SourceLocation Loc, size_t NArgs,
10492 OverloadCandidateSet::CandidateSetKind CSK)
10493 : S(S), NumArgs(NArgs), CSK(CSK) {}
10495 bool operator()(const OverloadCandidate *L,
10496 const OverloadCandidate *R) {
10497 // Fast-path this check.
10498 if (L == R) return false;
10500 // Order first by viability.
10502 if (!R->Viable) return true;
10504 // TODO: introduce a tri-valued comparison for overload
10505 // candidates. Would be more worthwhile if we had a sort
10506 // that could exploit it.
10507 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation(), CSK))
10509 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation(), CSK))
10511 } else if (R->Viable)
10514 assert(L->Viable == R->Viable);
10516 // Criteria by which we can sort non-viable candidates:
10518 // 1. Arity mismatches come after other candidates.
10519 if (L->FailureKind == ovl_fail_too_many_arguments ||
10520 L->FailureKind == ovl_fail_too_few_arguments) {
10521 if (R->FailureKind == ovl_fail_too_many_arguments ||
10522 R->FailureKind == ovl_fail_too_few_arguments) {
10523 int LDist = std::abs((int)L->getNumParams() - (int)NumArgs);
10524 int RDist = std::abs((int)R->getNumParams() - (int)NumArgs);
10525 if (LDist == RDist) {
10526 if (L->FailureKind == R->FailureKind)
10527 // Sort non-surrogates before surrogates.
10528 return !L->IsSurrogate && R->IsSurrogate;
10529 // Sort candidates requiring fewer parameters than there were
10530 // arguments given after candidates requiring more parameters
10531 // than there were arguments given.
10532 return L->FailureKind == ovl_fail_too_many_arguments;
10534 return LDist < RDist;
10538 if (R->FailureKind == ovl_fail_too_many_arguments ||
10539 R->FailureKind == ovl_fail_too_few_arguments)
10542 // 2. Bad conversions come first and are ordered by the number
10543 // of bad conversions and quality of good conversions.
10544 if (L->FailureKind == ovl_fail_bad_conversion) {
10545 if (R->FailureKind != ovl_fail_bad_conversion)
10548 // The conversion that can be fixed with a smaller number of changes,
10550 unsigned numLFixes = L->Fix.NumConversionsFixed;
10551 unsigned numRFixes = R->Fix.NumConversionsFixed;
10552 numLFixes = (numLFixes == 0) ? UINT_MAX : numLFixes;
10553 numRFixes = (numRFixes == 0) ? UINT_MAX : numRFixes;
10554 if (numLFixes != numRFixes) {
10555 return numLFixes < numRFixes;
10558 // If there's any ordering between the defined conversions...
10559 // FIXME: this might not be transitive.
10560 assert(L->Conversions.size() == R->Conversions.size());
10562 int leftBetter = 0;
10563 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument);
10564 for (unsigned E = L->Conversions.size(); I != E; ++I) {
10565 switch (CompareImplicitConversionSequences(S, Loc,
10567 R->Conversions[I])) {
10568 case ImplicitConversionSequence::Better:
10572 case ImplicitConversionSequence::Worse:
10576 case ImplicitConversionSequence::Indistinguishable:
10580 if (leftBetter > 0) return true;
10581 if (leftBetter < 0) return false;
10583 } else if (R->FailureKind == ovl_fail_bad_conversion)
10586 if (L->FailureKind == ovl_fail_bad_deduction) {
10587 if (R->FailureKind != ovl_fail_bad_deduction)
10590 if (L->DeductionFailure.Result != R->DeductionFailure.Result)
10591 return RankDeductionFailure(L->DeductionFailure)
10592 < RankDeductionFailure(R->DeductionFailure);
10593 } else if (R->FailureKind == ovl_fail_bad_deduction)
10599 // Sort everything else by location.
10600 SourceLocation LLoc = GetLocationForCandidate(L);
10601 SourceLocation RLoc = GetLocationForCandidate(R);
10603 // Put candidates without locations (e.g. builtins) at the end.
10604 if (LLoc.isInvalid()) return false;
10605 if (RLoc.isInvalid()) return true;
10607 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc);
10612 /// CompleteNonViableCandidate - Normally, overload resolution only
10613 /// computes up to the first bad conversion. Produces the FixIt set if
10615 static void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand,
10616 ArrayRef<Expr *> Args) {
10617 assert(!Cand->Viable);
10619 // Don't do anything on failures other than bad conversion.
10620 if (Cand->FailureKind != ovl_fail_bad_conversion) return;
10622 // We only want the FixIts if all the arguments can be corrected.
10623 bool Unfixable = false;
10624 // Use a implicit copy initialization to check conversion fixes.
10625 Cand->Fix.setConversionChecker(TryCopyInitialization);
10627 // Attempt to fix the bad conversion.
10628 unsigned ConvCount = Cand->Conversions.size();
10629 for (unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); /**/;
10631 assert(ConvIdx != ConvCount && "no bad conversion in candidate");
10632 if (Cand->Conversions[ConvIdx].isInitialized() &&
10633 Cand->Conversions[ConvIdx].isBad()) {
10634 Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S);
10639 // FIXME: this should probably be preserved from the overload
10640 // operation somehow.
10641 bool SuppressUserConversions = false;
10643 unsigned ConvIdx = 0;
10644 ArrayRef<QualType> ParamTypes;
10646 if (Cand->IsSurrogate) {
10648 = Cand->Surrogate->getConversionType().getNonReferenceType();
10649 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
10650 ConvType = ConvPtrType->getPointeeType();
10651 ParamTypes = ConvType->getAs<FunctionProtoType>()->getParamTypes();
10652 // Conversion 0 is 'this', which doesn't have a corresponding argument.
10654 } else if (Cand->Function) {
10656 Cand->Function->getType()->getAs<FunctionProtoType>()->getParamTypes();
10657 if (isa<CXXMethodDecl>(Cand->Function) &&
10658 !isa<CXXConstructorDecl>(Cand->Function)) {
10659 // Conversion 0 is 'this', which doesn't have a corresponding argument.
10663 // Builtin operator.
10664 assert(ConvCount <= 3);
10665 ParamTypes = Cand->BuiltinParamTypes;
10668 // Fill in the rest of the conversions.
10669 for (unsigned ArgIdx = 0; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) {
10670 if (Cand->Conversions[ConvIdx].isInitialized()) {
10671 // We've already checked this conversion.
10672 } else if (ArgIdx < ParamTypes.size()) {
10673 if (ParamTypes[ArgIdx]->isDependentType())
10674 Cand->Conversions[ConvIdx].setAsIdentityConversion(
10675 Args[ArgIdx]->getType());
10677 Cand->Conversions[ConvIdx] =
10678 TryCopyInitialization(S, Args[ArgIdx], ParamTypes[ArgIdx],
10679 SuppressUserConversions,
10680 /*InOverloadResolution=*/true,
10681 /*AllowObjCWritebackConversion=*/
10682 S.getLangOpts().ObjCAutoRefCount);
10683 // Store the FixIt in the candidate if it exists.
10684 if (!Unfixable && Cand->Conversions[ConvIdx].isBad())
10685 Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S);
10688 Cand->Conversions[ConvIdx].setEllipsis();
10692 /// When overload resolution fails, prints diagnostic messages containing the
10693 /// candidates in the candidate set.
10694 void OverloadCandidateSet::NoteCandidates(
10695 Sema &S, OverloadCandidateDisplayKind OCD, ArrayRef<Expr *> Args,
10696 StringRef Opc, SourceLocation OpLoc,
10697 llvm::function_ref<bool(OverloadCandidate &)> Filter) {
10698 // Sort the candidates by viability and position. Sorting directly would
10699 // be prohibitive, so we make a set of pointers and sort those.
10700 SmallVector<OverloadCandidate*, 32> Cands;
10701 if (OCD == OCD_AllCandidates) Cands.reserve(size());
10702 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) {
10703 if (!Filter(*Cand))
10706 Cands.push_back(Cand);
10707 else if (OCD == OCD_AllCandidates) {
10708 CompleteNonViableCandidate(S, Cand, Args);
10709 if (Cand->Function || Cand->IsSurrogate)
10710 Cands.push_back(Cand);
10711 // Otherwise, this a non-viable builtin candidate. We do not, in general,
10712 // want to list every possible builtin candidate.
10716 std::stable_sort(Cands.begin(), Cands.end(),
10717 CompareOverloadCandidatesForDisplay(S, OpLoc, Args.size(), Kind));
10719 bool ReportedAmbiguousConversions = false;
10721 SmallVectorImpl<OverloadCandidate*>::iterator I, E;
10722 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
10723 unsigned CandsShown = 0;
10724 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) {
10725 OverloadCandidate *Cand = *I;
10727 // Set an arbitrary limit on the number of candidate functions we'll spam
10728 // the user with. FIXME: This limit should depend on details of the
10730 if (CandsShown >= 4 && ShowOverloads == Ovl_Best) {
10735 if (Cand->Function)
10736 NoteFunctionCandidate(S, Cand, Args.size(),
10737 /*TakingCandidateAddress=*/false);
10738 else if (Cand->IsSurrogate)
10739 NoteSurrogateCandidate(S, Cand);
10741 assert(Cand->Viable &&
10742 "Non-viable built-in candidates are not added to Cands.");
10743 // Generally we only see ambiguities including viable builtin
10744 // operators if overload resolution got screwed up by an
10745 // ambiguous user-defined conversion.
10747 // FIXME: It's quite possible for different conversions to see
10748 // different ambiguities, though.
10749 if (!ReportedAmbiguousConversions) {
10750 NoteAmbiguousUserConversions(S, OpLoc, Cand);
10751 ReportedAmbiguousConversions = true;
10754 // If this is a viable builtin, print it.
10755 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand);
10760 S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I);
10763 static SourceLocation
10764 GetLocationForCandidate(const TemplateSpecCandidate *Cand) {
10765 return Cand->Specialization ? Cand->Specialization->getLocation()
10766 : SourceLocation();
10770 struct CompareTemplateSpecCandidatesForDisplay {
10772 CompareTemplateSpecCandidatesForDisplay(Sema &S) : S(S) {}
10774 bool operator()(const TemplateSpecCandidate *L,
10775 const TemplateSpecCandidate *R) {
10776 // Fast-path this check.
10780 // Assuming that both candidates are not matches...
10782 // Sort by the ranking of deduction failures.
10783 if (L->DeductionFailure.Result != R->DeductionFailure.Result)
10784 return RankDeductionFailure(L->DeductionFailure) <
10785 RankDeductionFailure(R->DeductionFailure);
10787 // Sort everything else by location.
10788 SourceLocation LLoc = GetLocationForCandidate(L);
10789 SourceLocation RLoc = GetLocationForCandidate(R);
10791 // Put candidates without locations (e.g. builtins) at the end.
10792 if (LLoc.isInvalid())
10794 if (RLoc.isInvalid())
10797 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc);
10802 /// Diagnose a template argument deduction failure.
10803 /// We are treating these failures as overload failures due to bad
10805 void TemplateSpecCandidate::NoteDeductionFailure(Sema &S,
10806 bool ForTakingAddress) {
10807 DiagnoseBadDeduction(S, FoundDecl, Specialization, // pattern
10808 DeductionFailure, /*NumArgs=*/0, ForTakingAddress);
10811 void TemplateSpecCandidateSet::destroyCandidates() {
10812 for (iterator i = begin(), e = end(); i != e; ++i) {
10813 i->DeductionFailure.Destroy();
10817 void TemplateSpecCandidateSet::clear() {
10818 destroyCandidates();
10819 Candidates.clear();
10822 /// NoteCandidates - When no template specialization match is found, prints
10823 /// diagnostic messages containing the non-matching specializations that form
10824 /// the candidate set.
10825 /// This is analoguous to OverloadCandidateSet::NoteCandidates() with
10826 /// OCD == OCD_AllCandidates and Cand->Viable == false.
10827 void TemplateSpecCandidateSet::NoteCandidates(Sema &S, SourceLocation Loc) {
10828 // Sort the candidates by position (assuming no candidate is a match).
10829 // Sorting directly would be prohibitive, so we make a set of pointers
10831 SmallVector<TemplateSpecCandidate *, 32> Cands;
10832 Cands.reserve(size());
10833 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) {
10834 if (Cand->Specialization)
10835 Cands.push_back(Cand);
10836 // Otherwise, this is a non-matching builtin candidate. We do not,
10837 // in general, want to list every possible builtin candidate.
10840 llvm::sort(Cands.begin(), Cands.end(),
10841 CompareTemplateSpecCandidatesForDisplay(S));
10843 // FIXME: Perhaps rename OverloadsShown and getShowOverloads()
10844 // for generalization purposes (?).
10845 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
10847 SmallVectorImpl<TemplateSpecCandidate *>::iterator I, E;
10848 unsigned CandsShown = 0;
10849 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) {
10850 TemplateSpecCandidate *Cand = *I;
10852 // Set an arbitrary limit on the number of candidates we'll spam
10853 // the user with. FIXME: This limit should depend on details of the
10855 if (CandsShown >= 4 && ShowOverloads == Ovl_Best)
10859 assert(Cand->Specialization &&
10860 "Non-matching built-in candidates are not added to Cands.");
10861 Cand->NoteDeductionFailure(S, ForTakingAddress);
10865 S.Diag(Loc, diag::note_ovl_too_many_candidates) << int(E - I);
10868 // [PossiblyAFunctionType] --> [Return]
10869 // NonFunctionType --> NonFunctionType
10871 // R (*)(A) --> R (A)
10872 // R (&)(A) --> R (A)
10873 // R (S::*)(A) --> R (A)
10874 QualType Sema::ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType) {
10875 QualType Ret = PossiblyAFunctionType;
10876 if (const PointerType *ToTypePtr =
10877 PossiblyAFunctionType->getAs<PointerType>())
10878 Ret = ToTypePtr->getPointeeType();
10879 else if (const ReferenceType *ToTypeRef =
10880 PossiblyAFunctionType->getAs<ReferenceType>())
10881 Ret = ToTypeRef->getPointeeType();
10882 else if (const MemberPointerType *MemTypePtr =
10883 PossiblyAFunctionType->getAs<MemberPointerType>())
10884 Ret = MemTypePtr->getPointeeType();
10886 Context.getCanonicalType(Ret).getUnqualifiedType();
10890 static bool completeFunctionType(Sema &S, FunctionDecl *FD, SourceLocation Loc,
10891 bool Complain = true) {
10892 if (S.getLangOpts().CPlusPlus14 && FD->getReturnType()->isUndeducedType() &&
10893 S.DeduceReturnType(FD, Loc, Complain))
10896 auto *FPT = FD->getType()->castAs<FunctionProtoType>();
10897 if (S.getLangOpts().CPlusPlus17 &&
10898 isUnresolvedExceptionSpec(FPT->getExceptionSpecType()) &&
10899 !S.ResolveExceptionSpec(Loc, FPT))
10906 // A helper class to help with address of function resolution
10907 // - allows us to avoid passing around all those ugly parameters
10908 class AddressOfFunctionResolver {
10911 const QualType& TargetType;
10912 QualType TargetFunctionType; // Extracted function type from target type
10915 //DeclAccessPair& ResultFunctionAccessPair;
10916 ASTContext& Context;
10918 bool TargetTypeIsNonStaticMemberFunction;
10919 bool FoundNonTemplateFunction;
10920 bool StaticMemberFunctionFromBoundPointer;
10921 bool HasComplained;
10923 OverloadExpr::FindResult OvlExprInfo;
10924 OverloadExpr *OvlExpr;
10925 TemplateArgumentListInfo OvlExplicitTemplateArgs;
10926 SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches;
10927 TemplateSpecCandidateSet FailedCandidates;
10930 AddressOfFunctionResolver(Sema &S, Expr *SourceExpr,
10931 const QualType &TargetType, bool Complain)
10932 : S(S), SourceExpr(SourceExpr), TargetType(TargetType),
10933 Complain(Complain), Context(S.getASTContext()),
10934 TargetTypeIsNonStaticMemberFunction(
10935 !!TargetType->getAs<MemberPointerType>()),
10936 FoundNonTemplateFunction(false),
10937 StaticMemberFunctionFromBoundPointer(false),
10938 HasComplained(false),
10939 OvlExprInfo(OverloadExpr::find(SourceExpr)),
10940 OvlExpr(OvlExprInfo.Expression),
10941 FailedCandidates(OvlExpr->getNameLoc(), /*ForTakingAddress=*/true) {
10942 ExtractUnqualifiedFunctionTypeFromTargetType();
10944 if (TargetFunctionType->isFunctionType()) {
10945 if (UnresolvedMemberExpr *UME = dyn_cast<UnresolvedMemberExpr>(OvlExpr))
10946 if (!UME->isImplicitAccess() &&
10947 !S.ResolveSingleFunctionTemplateSpecialization(UME))
10948 StaticMemberFunctionFromBoundPointer = true;
10949 } else if (OvlExpr->hasExplicitTemplateArgs()) {
10950 DeclAccessPair dap;
10951 if (FunctionDecl *Fn = S.ResolveSingleFunctionTemplateSpecialization(
10952 OvlExpr, false, &dap)) {
10953 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn))
10954 if (!Method->isStatic()) {
10955 // If the target type is a non-function type and the function found
10956 // is a non-static member function, pretend as if that was the
10957 // target, it's the only possible type to end up with.
10958 TargetTypeIsNonStaticMemberFunction = true;
10960 // And skip adding the function if its not in the proper form.
10961 // We'll diagnose this due to an empty set of functions.
10962 if (!OvlExprInfo.HasFormOfMemberPointer)
10966 Matches.push_back(std::make_pair(dap, Fn));
10971 if (OvlExpr->hasExplicitTemplateArgs())
10972 OvlExpr->copyTemplateArgumentsInto(OvlExplicitTemplateArgs);
10974 if (FindAllFunctionsThatMatchTargetTypeExactly()) {
10975 // C++ [over.over]p4:
10976 // If more than one function is selected, [...]
10977 if (Matches.size() > 1 && !eliminiateSuboptimalOverloadCandidates()) {
10978 if (FoundNonTemplateFunction)
10979 EliminateAllTemplateMatches();
10981 EliminateAllExceptMostSpecializedTemplate();
10985 if (S.getLangOpts().CUDA && Matches.size() > 1)
10986 EliminateSuboptimalCudaMatches();
10989 bool hasComplained() const { return HasComplained; }
10992 bool candidateHasExactlyCorrectType(const FunctionDecl *FD) {
10994 return Context.hasSameUnqualifiedType(TargetFunctionType, FD->getType()) ||
10995 S.IsFunctionConversion(FD->getType(), TargetFunctionType, Discard);
10998 /// \return true if A is considered a better overload candidate for the
10999 /// desired type than B.
11000 bool isBetterCandidate(const FunctionDecl *A, const FunctionDecl *B) {
11001 // If A doesn't have exactly the correct type, we don't want to classify it
11002 // as "better" than anything else. This way, the user is required to
11003 // disambiguate for us if there are multiple candidates and no exact match.
11004 return candidateHasExactlyCorrectType(A) &&
11005 (!candidateHasExactlyCorrectType(B) ||
11006 compareEnableIfAttrs(S, A, B) == Comparison::Better);
11009 /// \return true if we were able to eliminate all but one overload candidate,
11010 /// false otherwise.
11011 bool eliminiateSuboptimalOverloadCandidates() {
11012 // Same algorithm as overload resolution -- one pass to pick the "best",
11013 // another pass to be sure that nothing is better than the best.
11014 auto Best = Matches.begin();
11015 for (auto I = Matches.begin()+1, E = Matches.end(); I != E; ++I)
11016 if (isBetterCandidate(I->second, Best->second))
11019 const FunctionDecl *BestFn = Best->second;
11020 auto IsBestOrInferiorToBest = [this, BestFn](
11021 const std::pair<DeclAccessPair, FunctionDecl *> &Pair) {
11022 return BestFn == Pair.second || isBetterCandidate(BestFn, Pair.second);
11025 // Note: We explicitly leave Matches unmodified if there isn't a clear best
11026 // option, so we can potentially give the user a better error
11027 if (!std::all_of(Matches.begin(), Matches.end(), IsBestOrInferiorToBest))
11029 Matches[0] = *Best;
11034 bool isTargetTypeAFunction() const {
11035 return TargetFunctionType->isFunctionType();
11038 // [ToType] [Return]
11040 // R (*)(A) --> R (A), IsNonStaticMemberFunction = false
11041 // R (&)(A) --> R (A), IsNonStaticMemberFunction = false
11042 // R (S::*)(A) --> R (A), IsNonStaticMemberFunction = true
11043 void inline ExtractUnqualifiedFunctionTypeFromTargetType() {
11044 TargetFunctionType = S.ExtractUnqualifiedFunctionType(TargetType);
11047 // return true if any matching specializations were found
11048 bool AddMatchingTemplateFunction(FunctionTemplateDecl* FunctionTemplate,
11049 const DeclAccessPair& CurAccessFunPair) {
11050 if (CXXMethodDecl *Method
11051 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) {
11052 // Skip non-static function templates when converting to pointer, and
11053 // static when converting to member pointer.
11054 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction)
11057 else if (TargetTypeIsNonStaticMemberFunction)
11060 // C++ [over.over]p2:
11061 // If the name is a function template, template argument deduction is
11062 // done (14.8.2.2), and if the argument deduction succeeds, the
11063 // resulting template argument list is used to generate a single
11064 // function template specialization, which is added to the set of
11065 // overloaded functions considered.
11066 FunctionDecl *Specialization = nullptr;
11067 TemplateDeductionInfo Info(FailedCandidates.getLocation());
11068 if (Sema::TemplateDeductionResult Result
11069 = S.DeduceTemplateArguments(FunctionTemplate,
11070 &OvlExplicitTemplateArgs,
11071 TargetFunctionType, Specialization,
11072 Info, /*IsAddressOfFunction*/true)) {
11073 // Make a note of the failed deduction for diagnostics.
11074 FailedCandidates.addCandidate()
11075 .set(CurAccessFunPair, FunctionTemplate->getTemplatedDecl(),
11076 MakeDeductionFailureInfo(Context, Result, Info));
11080 // Template argument deduction ensures that we have an exact match or
11081 // compatible pointer-to-function arguments that would be adjusted by ICS.
11082 // This function template specicalization works.
11083 assert(S.isSameOrCompatibleFunctionType(
11084 Context.getCanonicalType(Specialization->getType()),
11085 Context.getCanonicalType(TargetFunctionType)));
11087 if (!S.checkAddressOfFunctionIsAvailable(Specialization))
11090 Matches.push_back(std::make_pair(CurAccessFunPair, Specialization));
11094 bool AddMatchingNonTemplateFunction(NamedDecl* Fn,
11095 const DeclAccessPair& CurAccessFunPair) {
11096 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) {
11097 // Skip non-static functions when converting to pointer, and static
11098 // when converting to member pointer.
11099 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction)
11102 else if (TargetTypeIsNonStaticMemberFunction)
11105 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) {
11106 if (S.getLangOpts().CUDA)
11107 if (FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext))
11108 if (!Caller->isImplicit() && !S.IsAllowedCUDACall(Caller, FunDecl))
11110 if (FunDecl->isMultiVersion()) {
11111 const auto *TA = FunDecl->getAttr<TargetAttr>();
11112 if (TA && !TA->isDefaultVersion())
11116 // If any candidate has a placeholder return type, trigger its deduction
11118 if (completeFunctionType(S, FunDecl, SourceExpr->getLocStart(),
11120 HasComplained |= Complain;
11124 if (!S.checkAddressOfFunctionIsAvailable(FunDecl))
11127 // If we're in C, we need to support types that aren't exactly identical.
11128 if (!S.getLangOpts().CPlusPlus ||
11129 candidateHasExactlyCorrectType(FunDecl)) {
11130 Matches.push_back(std::make_pair(
11131 CurAccessFunPair, cast<FunctionDecl>(FunDecl->getCanonicalDecl())));
11132 FoundNonTemplateFunction = true;
11140 bool FindAllFunctionsThatMatchTargetTypeExactly() {
11143 // If the overload expression doesn't have the form of a pointer to
11144 // member, don't try to convert it to a pointer-to-member type.
11145 if (IsInvalidFormOfPointerToMemberFunction())
11148 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
11149 E = OvlExpr->decls_end();
11151 // Look through any using declarations to find the underlying function.
11152 NamedDecl *Fn = (*I)->getUnderlyingDecl();
11154 // C++ [over.over]p3:
11155 // Non-member functions and static member functions match
11156 // targets of type "pointer-to-function" or "reference-to-function."
11157 // Nonstatic member functions match targets of
11158 // type "pointer-to-member-function."
11159 // Note that according to DR 247, the containing class does not matter.
11160 if (FunctionTemplateDecl *FunctionTemplate
11161 = dyn_cast<FunctionTemplateDecl>(Fn)) {
11162 if (AddMatchingTemplateFunction(FunctionTemplate, I.getPair()))
11165 // If we have explicit template arguments supplied, skip non-templates.
11166 else if (!OvlExpr->hasExplicitTemplateArgs() &&
11167 AddMatchingNonTemplateFunction(Fn, I.getPair()))
11170 assert(Ret || Matches.empty());
11174 void EliminateAllExceptMostSpecializedTemplate() {
11175 // [...] and any given function template specialization F1 is
11176 // eliminated if the set contains a second function template
11177 // specialization whose function template is more specialized
11178 // than the function template of F1 according to the partial
11179 // ordering rules of 14.5.5.2.
11181 // The algorithm specified above is quadratic. We instead use a
11182 // two-pass algorithm (similar to the one used to identify the
11183 // best viable function in an overload set) that identifies the
11184 // best function template (if it exists).
11186 UnresolvedSet<4> MatchesCopy; // TODO: avoid!
11187 for (unsigned I = 0, E = Matches.size(); I != E; ++I)
11188 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess());
11190 // TODO: It looks like FailedCandidates does not serve much purpose
11191 // here, since the no_viable diagnostic has index 0.
11192 UnresolvedSetIterator Result = S.getMostSpecialized(
11193 MatchesCopy.begin(), MatchesCopy.end(), FailedCandidates,
11194 SourceExpr->getLocStart(), S.PDiag(),
11195 S.PDiag(diag::err_addr_ovl_ambiguous)
11196 << Matches[0].second->getDeclName(),
11197 S.PDiag(diag::note_ovl_candidate)
11198 << (unsigned)oc_function << (unsigned)ocs_described_template,
11199 Complain, TargetFunctionType);
11201 if (Result != MatchesCopy.end()) {
11202 // Make it the first and only element
11203 Matches[0].first = Matches[Result - MatchesCopy.begin()].first;
11204 Matches[0].second = cast<FunctionDecl>(*Result);
11207 HasComplained |= Complain;
11210 void EliminateAllTemplateMatches() {
11211 // [...] any function template specializations in the set are
11212 // eliminated if the set also contains a non-template function, [...]
11213 for (unsigned I = 0, N = Matches.size(); I != N; ) {
11214 if (Matches[I].second->getPrimaryTemplate() == nullptr)
11217 Matches[I] = Matches[--N];
11223 void EliminateSuboptimalCudaMatches() {
11224 S.EraseUnwantedCUDAMatches(dyn_cast<FunctionDecl>(S.CurContext), Matches);
11228 void ComplainNoMatchesFound() const {
11229 assert(Matches.empty());
11230 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_no_viable)
11231 << OvlExpr->getName() << TargetFunctionType
11232 << OvlExpr->getSourceRange();
11233 if (FailedCandidates.empty())
11234 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType,
11235 /*TakingAddress=*/true);
11237 // We have some deduction failure messages. Use them to diagnose
11238 // the function templates, and diagnose the non-template candidates
11240 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
11241 IEnd = OvlExpr->decls_end();
11243 if (FunctionDecl *Fun =
11244 dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()))
11245 if (!functionHasPassObjectSizeParams(Fun))
11246 S.NoteOverloadCandidate(*I, Fun, TargetFunctionType,
11247 /*TakingAddress=*/true);
11248 FailedCandidates.NoteCandidates(S, OvlExpr->getLocStart());
11252 bool IsInvalidFormOfPointerToMemberFunction() const {
11253 return TargetTypeIsNonStaticMemberFunction &&
11254 !OvlExprInfo.HasFormOfMemberPointer;
11257 void ComplainIsInvalidFormOfPointerToMemberFunction() const {
11258 // TODO: Should we condition this on whether any functions might
11259 // have matched, or is it more appropriate to do that in callers?
11260 // TODO: a fixit wouldn't hurt.
11261 S.Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier)
11262 << TargetType << OvlExpr->getSourceRange();
11265 bool IsStaticMemberFunctionFromBoundPointer() const {
11266 return StaticMemberFunctionFromBoundPointer;
11269 void ComplainIsStaticMemberFunctionFromBoundPointer() const {
11270 S.Diag(OvlExpr->getLocStart(),
11271 diag::err_invalid_form_pointer_member_function)
11272 << OvlExpr->getSourceRange();
11275 void ComplainOfInvalidConversion() const {
11276 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_not_func_ptrref)
11277 << OvlExpr->getName() << TargetType;
11280 void ComplainMultipleMatchesFound() const {
11281 assert(Matches.size() > 1);
11282 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_ambiguous)
11283 << OvlExpr->getName()
11284 << OvlExpr->getSourceRange();
11285 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType,
11286 /*TakingAddress=*/true);
11289 bool hadMultipleCandidates() const { return (OvlExpr->getNumDecls() > 1); }
11291 int getNumMatches() const { return Matches.size(); }
11293 FunctionDecl* getMatchingFunctionDecl() const {
11294 if (Matches.size() != 1) return nullptr;
11295 return Matches[0].second;
11298 const DeclAccessPair* getMatchingFunctionAccessPair() const {
11299 if (Matches.size() != 1) return nullptr;
11300 return &Matches[0].first;
11305 /// ResolveAddressOfOverloadedFunction - Try to resolve the address of
11306 /// an overloaded function (C++ [over.over]), where @p From is an
11307 /// expression with overloaded function type and @p ToType is the type
11308 /// we're trying to resolve to. For example:
11314 /// int (*pfd)(double) = f; // selects f(double)
11317 /// This routine returns the resulting FunctionDecl if it could be
11318 /// resolved, and NULL otherwise. When @p Complain is true, this
11319 /// routine will emit diagnostics if there is an error.
11321 Sema::ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr,
11322 QualType TargetType,
11324 DeclAccessPair &FoundResult,
11325 bool *pHadMultipleCandidates) {
11326 assert(AddressOfExpr->getType() == Context.OverloadTy);
11328 AddressOfFunctionResolver Resolver(*this, AddressOfExpr, TargetType,
11330 int NumMatches = Resolver.getNumMatches();
11331 FunctionDecl *Fn = nullptr;
11332 bool ShouldComplain = Complain && !Resolver.hasComplained();
11333 if (NumMatches == 0 && ShouldComplain) {
11334 if (Resolver.IsInvalidFormOfPointerToMemberFunction())
11335 Resolver.ComplainIsInvalidFormOfPointerToMemberFunction();
11337 Resolver.ComplainNoMatchesFound();
11339 else if (NumMatches > 1 && ShouldComplain)
11340 Resolver.ComplainMultipleMatchesFound();
11341 else if (NumMatches == 1) {
11342 Fn = Resolver.getMatchingFunctionDecl();
11344 if (auto *FPT = Fn->getType()->getAs<FunctionProtoType>())
11345 ResolveExceptionSpec(AddressOfExpr->getExprLoc(), FPT);
11346 FoundResult = *Resolver.getMatchingFunctionAccessPair();
11348 if (Resolver.IsStaticMemberFunctionFromBoundPointer())
11349 Resolver.ComplainIsStaticMemberFunctionFromBoundPointer();
11351 CheckAddressOfMemberAccess(AddressOfExpr, FoundResult);
11355 if (pHadMultipleCandidates)
11356 *pHadMultipleCandidates = Resolver.hadMultipleCandidates();
11360 /// Given an expression that refers to an overloaded function, try to
11361 /// resolve that function to a single function that can have its address taken.
11362 /// This will modify `Pair` iff it returns non-null.
11364 /// This routine can only realistically succeed if all but one candidates in the
11365 /// overload set for SrcExpr cannot have their addresses taken.
11367 Sema::resolveAddressOfOnlyViableOverloadCandidate(Expr *E,
11368 DeclAccessPair &Pair) {
11369 OverloadExpr::FindResult R = OverloadExpr::find(E);
11370 OverloadExpr *Ovl = R.Expression;
11371 FunctionDecl *Result = nullptr;
11372 DeclAccessPair DAP;
11373 // Don't use the AddressOfResolver because we're specifically looking for
11374 // cases where we have one overload candidate that lacks
11375 // enable_if/pass_object_size/...
11376 for (auto I = Ovl->decls_begin(), E = Ovl->decls_end(); I != E; ++I) {
11377 auto *FD = dyn_cast<FunctionDecl>(I->getUnderlyingDecl());
11381 if (!checkAddressOfFunctionIsAvailable(FD))
11384 // We have more than one result; quit.
11396 /// Given an overloaded function, tries to turn it into a non-overloaded
11397 /// function reference using resolveAddressOfOnlyViableOverloadCandidate. This
11398 /// will perform access checks, diagnose the use of the resultant decl, and, if
11399 /// requested, potentially perform a function-to-pointer decay.
11401 /// Returns false if resolveAddressOfOnlyViableOverloadCandidate fails.
11402 /// Otherwise, returns true. This may emit diagnostics and return true.
11403 bool Sema::resolveAndFixAddressOfOnlyViableOverloadCandidate(
11404 ExprResult &SrcExpr, bool DoFunctionPointerConverion) {
11405 Expr *E = SrcExpr.get();
11406 assert(E->getType() == Context.OverloadTy && "SrcExpr must be an overload");
11408 DeclAccessPair DAP;
11409 FunctionDecl *Found = resolveAddressOfOnlyViableOverloadCandidate(E, DAP);
11410 if (!Found || Found->isCPUDispatchMultiVersion() ||
11411 Found->isCPUSpecificMultiVersion())
11414 // Emitting multiple diagnostics for a function that is both inaccessible and
11415 // unavailable is consistent with our behavior elsewhere. So, always check
11417 DiagnoseUseOfDecl(Found, E->getExprLoc());
11418 CheckAddressOfMemberAccess(E, DAP);
11419 Expr *Fixed = FixOverloadedFunctionReference(E, DAP, Found);
11420 if (DoFunctionPointerConverion && Fixed->getType()->isFunctionType())
11421 SrcExpr = DefaultFunctionArrayConversion(Fixed, /*Diagnose=*/false);
11427 /// Given an expression that refers to an overloaded function, try to
11428 /// resolve that overloaded function expression down to a single function.
11430 /// This routine can only resolve template-ids that refer to a single function
11431 /// template, where that template-id refers to a single template whose template
11432 /// arguments are either provided by the template-id or have defaults,
11433 /// as described in C++0x [temp.arg.explicit]p3.
11435 /// If no template-ids are found, no diagnostics are emitted and NULL is
11438 Sema::ResolveSingleFunctionTemplateSpecialization(OverloadExpr *ovl,
11440 DeclAccessPair *FoundResult) {
11441 // C++ [over.over]p1:
11442 // [...] [Note: any redundant set of parentheses surrounding the
11443 // overloaded function name is ignored (5.1). ]
11444 // C++ [over.over]p1:
11445 // [...] The overloaded function name can be preceded by the &
11448 // If we didn't actually find any template-ids, we're done.
11449 if (!ovl->hasExplicitTemplateArgs())
11452 TemplateArgumentListInfo ExplicitTemplateArgs;
11453 ovl->copyTemplateArgumentsInto(ExplicitTemplateArgs);
11454 TemplateSpecCandidateSet FailedCandidates(ovl->getNameLoc());
11456 // Look through all of the overloaded functions, searching for one
11457 // whose type matches exactly.
11458 FunctionDecl *Matched = nullptr;
11459 for (UnresolvedSetIterator I = ovl->decls_begin(),
11460 E = ovl->decls_end(); I != E; ++I) {
11461 // C++0x [temp.arg.explicit]p3:
11462 // [...] In contexts where deduction is done and fails, or in contexts
11463 // where deduction is not done, if a template argument list is
11464 // specified and it, along with any default template arguments,
11465 // identifies a single function template specialization, then the
11466 // template-id is an lvalue for the function template specialization.
11467 FunctionTemplateDecl *FunctionTemplate
11468 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl());
11470 // C++ [over.over]p2:
11471 // If the name is a function template, template argument deduction is
11472 // done (14.8.2.2), and if the argument deduction succeeds, the
11473 // resulting template argument list is used to generate a single
11474 // function template specialization, which is added to the set of
11475 // overloaded functions considered.
11476 FunctionDecl *Specialization = nullptr;
11477 TemplateDeductionInfo Info(FailedCandidates.getLocation());
11478 if (TemplateDeductionResult Result
11479 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs,
11480 Specialization, Info,
11481 /*IsAddressOfFunction*/true)) {
11482 // Make a note of the failed deduction for diagnostics.
11483 // TODO: Actually use the failed-deduction info?
11484 FailedCandidates.addCandidate()
11485 .set(I.getPair(), FunctionTemplate->getTemplatedDecl(),
11486 MakeDeductionFailureInfo(Context, Result, Info));
11490 assert(Specialization && "no specialization and no error?");
11492 // Multiple matches; we can't resolve to a single declaration.
11495 Diag(ovl->getExprLoc(), diag::err_addr_ovl_ambiguous)
11497 NoteAllOverloadCandidates(ovl);
11502 Matched = Specialization;
11503 if (FoundResult) *FoundResult = I.getPair();
11507 completeFunctionType(*this, Matched, ovl->getExprLoc(), Complain))
11513 // Resolve and fix an overloaded expression that can be resolved
11514 // because it identifies a single function template specialization.
11516 // Last three arguments should only be supplied if Complain = true
11518 // Return true if it was logically possible to so resolve the
11519 // expression, regardless of whether or not it succeeded. Always
11520 // returns true if 'complain' is set.
11521 bool Sema::ResolveAndFixSingleFunctionTemplateSpecialization(
11522 ExprResult &SrcExpr, bool doFunctionPointerConverion,
11523 bool complain, SourceRange OpRangeForComplaining,
11524 QualType DestTypeForComplaining,
11525 unsigned DiagIDForComplaining) {
11526 assert(SrcExpr.get()->getType() == Context.OverloadTy);
11528 OverloadExpr::FindResult ovl = OverloadExpr::find(SrcExpr.get());
11530 DeclAccessPair found;
11531 ExprResult SingleFunctionExpression;
11532 if (FunctionDecl *fn = ResolveSingleFunctionTemplateSpecialization(
11533 ovl.Expression, /*complain*/ false, &found)) {
11534 if (DiagnoseUseOfDecl(fn, SrcExpr.get()->getLocStart())) {
11535 SrcExpr = ExprError();
11539 // It is only correct to resolve to an instance method if we're
11540 // resolving a form that's permitted to be a pointer to member.
11541 // Otherwise we'll end up making a bound member expression, which
11542 // is illegal in all the contexts we resolve like this.
11543 if (!ovl.HasFormOfMemberPointer &&
11544 isa<CXXMethodDecl>(fn) &&
11545 cast<CXXMethodDecl>(fn)->isInstance()) {
11546 if (!complain) return false;
11548 Diag(ovl.Expression->getExprLoc(),
11549 diag::err_bound_member_function)
11550 << 0 << ovl.Expression->getSourceRange();
11552 // TODO: I believe we only end up here if there's a mix of
11553 // static and non-static candidates (otherwise the expression
11554 // would have 'bound member' type, not 'overload' type).
11555 // Ideally we would note which candidate was chosen and why
11556 // the static candidates were rejected.
11557 SrcExpr = ExprError();
11561 // Fix the expression to refer to 'fn'.
11562 SingleFunctionExpression =
11563 FixOverloadedFunctionReference(SrcExpr.get(), found, fn);
11565 // If desired, do function-to-pointer decay.
11566 if (doFunctionPointerConverion) {
11567 SingleFunctionExpression =
11568 DefaultFunctionArrayLvalueConversion(SingleFunctionExpression.get());
11569 if (SingleFunctionExpression.isInvalid()) {
11570 SrcExpr = ExprError();
11576 if (!SingleFunctionExpression.isUsable()) {
11578 Diag(OpRangeForComplaining.getBegin(), DiagIDForComplaining)
11579 << ovl.Expression->getName()
11580 << DestTypeForComplaining
11581 << OpRangeForComplaining
11582 << ovl.Expression->getQualifierLoc().getSourceRange();
11583 NoteAllOverloadCandidates(SrcExpr.get());
11585 SrcExpr = ExprError();
11592 SrcExpr = SingleFunctionExpression;
11596 /// Add a single candidate to the overload set.
11597 static void AddOverloadedCallCandidate(Sema &S,
11598 DeclAccessPair FoundDecl,
11599 TemplateArgumentListInfo *ExplicitTemplateArgs,
11600 ArrayRef<Expr *> Args,
11601 OverloadCandidateSet &CandidateSet,
11602 bool PartialOverloading,
11604 NamedDecl *Callee = FoundDecl.getDecl();
11605 if (isa<UsingShadowDecl>(Callee))
11606 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl();
11608 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) {
11609 if (ExplicitTemplateArgs) {
11610 assert(!KnownValid && "Explicit template arguments?");
11613 // Prevent ill-formed function decls to be added as overload candidates.
11614 if (!dyn_cast<FunctionProtoType>(Func->getType()->getAs<FunctionType>()))
11617 S.AddOverloadCandidate(Func, FoundDecl, Args, CandidateSet,
11618 /*SuppressUsedConversions=*/false,
11619 PartialOverloading);
11623 if (FunctionTemplateDecl *FuncTemplate
11624 = dyn_cast<FunctionTemplateDecl>(Callee)) {
11625 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl,
11626 ExplicitTemplateArgs, Args, CandidateSet,
11627 /*SuppressUsedConversions=*/false,
11628 PartialOverloading);
11632 assert(!KnownValid && "unhandled case in overloaded call candidate");
11635 /// Add the overload candidates named by callee and/or found by argument
11636 /// dependent lookup to the given overload set.
11637 void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE,
11638 ArrayRef<Expr *> Args,
11639 OverloadCandidateSet &CandidateSet,
11640 bool PartialOverloading) {
11643 // Verify that ArgumentDependentLookup is consistent with the rules
11644 // in C++0x [basic.lookup.argdep]p3:
11646 // Let X be the lookup set produced by unqualified lookup (3.4.1)
11647 // and let Y be the lookup set produced by argument dependent
11648 // lookup (defined as follows). If X contains
11650 // -- a declaration of a class member, or
11652 // -- a block-scope function declaration that is not a
11653 // using-declaration, or
11655 // -- a declaration that is neither a function or a function
11658 // then Y is empty.
11660 if (ULE->requiresADL()) {
11661 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(),
11662 E = ULE->decls_end(); I != E; ++I) {
11663 assert(!(*I)->getDeclContext()->isRecord());
11664 assert(isa<UsingShadowDecl>(*I) ||
11665 !(*I)->getDeclContext()->isFunctionOrMethod());
11666 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate());
11671 // It would be nice to avoid this copy.
11672 TemplateArgumentListInfo TABuffer;
11673 TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr;
11674 if (ULE->hasExplicitTemplateArgs()) {
11675 ULE->copyTemplateArgumentsInto(TABuffer);
11676 ExplicitTemplateArgs = &TABuffer;
11679 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(),
11680 E = ULE->decls_end(); I != E; ++I)
11681 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, Args,
11682 CandidateSet, PartialOverloading,
11683 /*KnownValid*/ true);
11685 if (ULE->requiresADL())
11686 AddArgumentDependentLookupCandidates(ULE->getName(), ULE->getExprLoc(),
11687 Args, ExplicitTemplateArgs,
11688 CandidateSet, PartialOverloading);
11691 /// Determine whether a declaration with the specified name could be moved into
11692 /// a different namespace.
11693 static bool canBeDeclaredInNamespace(const DeclarationName &Name) {
11694 switch (Name.getCXXOverloadedOperator()) {
11695 case OO_New: case OO_Array_New:
11696 case OO_Delete: case OO_Array_Delete:
11704 /// Attempt to recover from an ill-formed use of a non-dependent name in a
11705 /// template, where the non-dependent name was declared after the template
11706 /// was defined. This is common in code written for a compilers which do not
11707 /// correctly implement two-stage name lookup.
11709 /// Returns true if a viable candidate was found and a diagnostic was issued.
11711 DiagnoseTwoPhaseLookup(Sema &SemaRef, SourceLocation FnLoc,
11712 const CXXScopeSpec &SS, LookupResult &R,
11713 OverloadCandidateSet::CandidateSetKind CSK,
11714 TemplateArgumentListInfo *ExplicitTemplateArgs,
11715 ArrayRef<Expr *> Args,
11716 bool *DoDiagnoseEmptyLookup = nullptr) {
11717 if (!SemaRef.inTemplateInstantiation() || !SS.isEmpty())
11720 for (DeclContext *DC = SemaRef.CurContext; DC; DC = DC->getParent()) {
11721 if (DC->isTransparentContext())
11724 SemaRef.LookupQualifiedName(R, DC);
11727 R.suppressDiagnostics();
11729 if (isa<CXXRecordDecl>(DC)) {
11730 // Don't diagnose names we find in classes; we get much better
11731 // diagnostics for these from DiagnoseEmptyLookup.
11733 if (DoDiagnoseEmptyLookup)
11734 *DoDiagnoseEmptyLookup = true;
11738 OverloadCandidateSet Candidates(FnLoc, CSK);
11739 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
11740 AddOverloadedCallCandidate(SemaRef, I.getPair(),
11741 ExplicitTemplateArgs, Args,
11742 Candidates, false, /*KnownValid*/ false);
11744 OverloadCandidateSet::iterator Best;
11745 if (Candidates.BestViableFunction(SemaRef, FnLoc, Best) != OR_Success) {
11746 // No viable functions. Don't bother the user with notes for functions
11747 // which don't work and shouldn't be found anyway.
11752 // Find the namespaces where ADL would have looked, and suggest
11753 // declaring the function there instead.
11754 Sema::AssociatedNamespaceSet AssociatedNamespaces;
11755 Sema::AssociatedClassSet AssociatedClasses;
11756 SemaRef.FindAssociatedClassesAndNamespaces(FnLoc, Args,
11757 AssociatedNamespaces,
11758 AssociatedClasses);
11759 Sema::AssociatedNamespaceSet SuggestedNamespaces;
11760 if (canBeDeclaredInNamespace(R.getLookupName())) {
11761 DeclContext *Std = SemaRef.getStdNamespace();
11762 for (Sema::AssociatedNamespaceSet::iterator
11763 it = AssociatedNamespaces.begin(),
11764 end = AssociatedNamespaces.end(); it != end; ++it) {
11765 // Never suggest declaring a function within namespace 'std'.
11766 if (Std && Std->Encloses(*it))
11769 // Never suggest declaring a function within a namespace with a
11770 // reserved name, like __gnu_cxx.
11771 NamespaceDecl *NS = dyn_cast<NamespaceDecl>(*it);
11773 NS->getQualifiedNameAsString().find("__") != std::string::npos)
11776 SuggestedNamespaces.insert(*it);
11780 SemaRef.Diag(R.getNameLoc(), diag::err_not_found_by_two_phase_lookup)
11781 << R.getLookupName();
11782 if (SuggestedNamespaces.empty()) {
11783 SemaRef.Diag(Best->Function->getLocation(),
11784 diag::note_not_found_by_two_phase_lookup)
11785 << R.getLookupName() << 0;
11786 } else if (SuggestedNamespaces.size() == 1) {
11787 SemaRef.Diag(Best->Function->getLocation(),
11788 diag::note_not_found_by_two_phase_lookup)
11789 << R.getLookupName() << 1 << *SuggestedNamespaces.begin();
11791 // FIXME: It would be useful to list the associated namespaces here,
11792 // but the diagnostics infrastructure doesn't provide a way to produce
11793 // a localized representation of a list of items.
11794 SemaRef.Diag(Best->Function->getLocation(),
11795 diag::note_not_found_by_two_phase_lookup)
11796 << R.getLookupName() << 2;
11799 // Try to recover by calling this function.
11809 /// Attempt to recover from ill-formed use of a non-dependent operator in a
11810 /// template, where the non-dependent operator was declared after the template
11813 /// Returns true if a viable candidate was found and a diagnostic was issued.
11815 DiagnoseTwoPhaseOperatorLookup(Sema &SemaRef, OverloadedOperatorKind Op,
11816 SourceLocation OpLoc,
11817 ArrayRef<Expr *> Args) {
11818 DeclarationName OpName =
11819 SemaRef.Context.DeclarationNames.getCXXOperatorName(Op);
11820 LookupResult R(SemaRef, OpName, OpLoc, Sema::LookupOperatorName);
11821 return DiagnoseTwoPhaseLookup(SemaRef, OpLoc, CXXScopeSpec(), R,
11822 OverloadCandidateSet::CSK_Operator,
11823 /*ExplicitTemplateArgs=*/nullptr, Args);
11827 class BuildRecoveryCallExprRAII {
11830 BuildRecoveryCallExprRAII(Sema &S) : SemaRef(S) {
11831 assert(SemaRef.IsBuildingRecoveryCallExpr == false);
11832 SemaRef.IsBuildingRecoveryCallExpr = true;
11835 ~BuildRecoveryCallExprRAII() {
11836 SemaRef.IsBuildingRecoveryCallExpr = false;
11842 static std::unique_ptr<CorrectionCandidateCallback>
11843 MakeValidator(Sema &SemaRef, MemberExpr *ME, size_t NumArgs,
11844 bool HasTemplateArgs, bool AllowTypoCorrection) {
11845 if (!AllowTypoCorrection)
11846 return llvm::make_unique<NoTypoCorrectionCCC>();
11847 return llvm::make_unique<FunctionCallFilterCCC>(SemaRef, NumArgs,
11848 HasTemplateArgs, ME);
11851 /// Attempts to recover from a call where no functions were found.
11853 /// Returns true if new candidates were found.
11855 BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn,
11856 UnresolvedLookupExpr *ULE,
11857 SourceLocation LParenLoc,
11858 MutableArrayRef<Expr *> Args,
11859 SourceLocation RParenLoc,
11860 bool EmptyLookup, bool AllowTypoCorrection) {
11861 // Do not try to recover if it is already building a recovery call.
11862 // This stops infinite loops for template instantiations like
11864 // template <typename T> auto foo(T t) -> decltype(foo(t)) {}
11865 // template <typename T> auto foo(T t) -> decltype(foo(&t)) {}
11867 if (SemaRef.IsBuildingRecoveryCallExpr)
11868 return ExprError();
11869 BuildRecoveryCallExprRAII RCE(SemaRef);
11872 SS.Adopt(ULE->getQualifierLoc());
11873 SourceLocation TemplateKWLoc = ULE->getTemplateKeywordLoc();
11875 TemplateArgumentListInfo TABuffer;
11876 TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr;
11877 if (ULE->hasExplicitTemplateArgs()) {
11878 ULE->copyTemplateArgumentsInto(TABuffer);
11879 ExplicitTemplateArgs = &TABuffer;
11882 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(),
11883 Sema::LookupOrdinaryName);
11884 bool DoDiagnoseEmptyLookup = EmptyLookup;
11885 if (!DiagnoseTwoPhaseLookup(SemaRef, Fn->getExprLoc(), SS, R,
11886 OverloadCandidateSet::CSK_Normal,
11887 ExplicitTemplateArgs, Args,
11888 &DoDiagnoseEmptyLookup) &&
11889 (!DoDiagnoseEmptyLookup || SemaRef.DiagnoseEmptyLookup(
11891 MakeValidator(SemaRef, dyn_cast<MemberExpr>(Fn), Args.size(),
11892 ExplicitTemplateArgs != nullptr, AllowTypoCorrection),
11893 ExplicitTemplateArgs, Args)))
11894 return ExprError();
11896 assert(!R.empty() && "lookup results empty despite recovery");
11898 // If recovery created an ambiguity, just bail out.
11899 if (R.isAmbiguous()) {
11900 R.suppressDiagnostics();
11901 return ExprError();
11904 // Build an implicit member call if appropriate. Just drop the
11905 // casts and such from the call, we don't really care.
11906 ExprResult NewFn = ExprError();
11907 if ((*R.begin())->isCXXClassMember())
11908 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, TemplateKWLoc, R,
11909 ExplicitTemplateArgs, S);
11910 else if (ExplicitTemplateArgs || TemplateKWLoc.isValid())
11911 NewFn = SemaRef.BuildTemplateIdExpr(SS, TemplateKWLoc, R, false,
11912 ExplicitTemplateArgs);
11914 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false);
11916 if (NewFn.isInvalid())
11917 return ExprError();
11919 // This shouldn't cause an infinite loop because we're giving it
11920 // an expression with viable lookup results, which should never
11922 return SemaRef.ActOnCallExpr(/*Scope*/ nullptr, NewFn.get(), LParenLoc,
11923 MultiExprArg(Args.data(), Args.size()),
11927 /// Constructs and populates an OverloadedCandidateSet from
11928 /// the given function.
11929 /// \returns true when an the ExprResult output parameter has been set.
11930 bool Sema::buildOverloadedCallSet(Scope *S, Expr *Fn,
11931 UnresolvedLookupExpr *ULE,
11933 SourceLocation RParenLoc,
11934 OverloadCandidateSet *CandidateSet,
11935 ExprResult *Result) {
11937 if (ULE->requiresADL()) {
11938 // To do ADL, we must have found an unqualified name.
11939 assert(!ULE->getQualifier() && "qualified name with ADL");
11941 // We don't perform ADL for implicit declarations of builtins.
11942 // Verify that this was correctly set up.
11944 if (ULE->decls_begin() + 1 == ULE->decls_end() &&
11945 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) &&
11946 F->getBuiltinID() && F->isImplicit())
11947 llvm_unreachable("performing ADL for builtin");
11949 // We don't perform ADL in C.
11950 assert(getLangOpts().CPlusPlus && "ADL enabled in C");
11954 UnbridgedCastsSet UnbridgedCasts;
11955 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts)) {
11956 *Result = ExprError();
11960 // Add the functions denoted by the callee to the set of candidate
11961 // functions, including those from argument-dependent lookup.
11962 AddOverloadedCallCandidates(ULE, Args, *CandidateSet);
11964 if (getLangOpts().MSVCCompat &&
11965 CurContext->isDependentContext() && !isSFINAEContext() &&
11966 (isa<FunctionDecl>(CurContext) || isa<CXXRecordDecl>(CurContext))) {
11968 OverloadCandidateSet::iterator Best;
11969 if (CandidateSet->empty() ||
11970 CandidateSet->BestViableFunction(*this, Fn->getLocStart(), Best) ==
11971 OR_No_Viable_Function) {
11972 // In Microsoft mode, if we are inside a template class member function then
11973 // create a type dependent CallExpr. The goal is to postpone name lookup
11974 // to instantiation time to be able to search into type dependent base
11976 CallExpr *CE = new (Context) CallExpr(
11977 Context, Fn, Args, Context.DependentTy, VK_RValue, RParenLoc);
11978 CE->setTypeDependent(true);
11979 CE->setValueDependent(true);
11980 CE->setInstantiationDependent(true);
11986 if (CandidateSet->empty())
11989 UnbridgedCasts.restore();
11993 /// FinishOverloadedCallExpr - given an OverloadCandidateSet, builds and returns
11994 /// the completed call expression. If overload resolution fails, emits
11995 /// diagnostics and returns ExprError()
11996 static ExprResult FinishOverloadedCallExpr(Sema &SemaRef, Scope *S, Expr *Fn,
11997 UnresolvedLookupExpr *ULE,
11998 SourceLocation LParenLoc,
12000 SourceLocation RParenLoc,
12002 OverloadCandidateSet *CandidateSet,
12003 OverloadCandidateSet::iterator *Best,
12004 OverloadingResult OverloadResult,
12005 bool AllowTypoCorrection) {
12006 if (CandidateSet->empty())
12007 return BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc, Args,
12008 RParenLoc, /*EmptyLookup=*/true,
12009 AllowTypoCorrection);
12011 switch (OverloadResult) {
12013 FunctionDecl *FDecl = (*Best)->Function;
12014 SemaRef.CheckUnresolvedLookupAccess(ULE, (*Best)->FoundDecl);
12015 if (SemaRef.DiagnoseUseOfDecl(FDecl, ULE->getNameLoc()))
12016 return ExprError();
12017 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl);
12018 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, RParenLoc,
12022 case OR_No_Viable_Function: {
12023 // Try to recover by looking for viable functions which the user might
12024 // have meant to call.
12025 ExprResult Recovery = BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc,
12027 /*EmptyLookup=*/false,
12028 AllowTypoCorrection);
12029 if (!Recovery.isInvalid())
12032 // If the user passes in a function that we can't take the address of, we
12033 // generally end up emitting really bad error messages. Here, we attempt to
12034 // emit better ones.
12035 for (const Expr *Arg : Args) {
12036 if (!Arg->getType()->isFunctionType())
12038 if (auto *DRE = dyn_cast<DeclRefExpr>(Arg->IgnoreParenImpCasts())) {
12039 auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl());
12041 !SemaRef.checkAddressOfFunctionIsAvailable(FD, /*Complain=*/true,
12042 Arg->getExprLoc()))
12043 return ExprError();
12047 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_no_viable_function_in_call)
12048 << ULE->getName() << Fn->getSourceRange();
12049 CandidateSet->NoteCandidates(SemaRef, OCD_AllCandidates, Args);
12054 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_ambiguous_call)
12055 << ULE->getName() << Fn->getSourceRange();
12056 CandidateSet->NoteCandidates(SemaRef, OCD_ViableCandidates, Args);
12060 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_deleted_call)
12061 << (*Best)->Function->isDeleted()
12063 << SemaRef.getDeletedOrUnavailableSuffix((*Best)->Function)
12064 << Fn->getSourceRange();
12065 CandidateSet->NoteCandidates(SemaRef, OCD_AllCandidates, Args);
12067 // We emitted an error for the unavailable/deleted function call but keep
12068 // the call in the AST.
12069 FunctionDecl *FDecl = (*Best)->Function;
12070 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl);
12071 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, RParenLoc,
12076 // Overload resolution failed.
12077 return ExprError();
12080 static void markUnaddressableCandidatesUnviable(Sema &S,
12081 OverloadCandidateSet &CS) {
12082 for (auto I = CS.begin(), E = CS.end(); I != E; ++I) {
12084 !S.checkAddressOfFunctionIsAvailable(I->Function, /*Complain=*/false)) {
12086 I->FailureKind = ovl_fail_addr_not_available;
12091 /// BuildOverloadedCallExpr - Given the call expression that calls Fn
12092 /// (which eventually refers to the declaration Func) and the call
12093 /// arguments Args/NumArgs, attempt to resolve the function call down
12094 /// to a specific function. If overload resolution succeeds, returns
12095 /// the call expression produced by overload resolution.
12096 /// Otherwise, emits diagnostics and returns ExprError.
12097 ExprResult Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn,
12098 UnresolvedLookupExpr *ULE,
12099 SourceLocation LParenLoc,
12101 SourceLocation RParenLoc,
12103 bool AllowTypoCorrection,
12104 bool CalleesAddressIsTaken) {
12105 OverloadCandidateSet CandidateSet(Fn->getExprLoc(),
12106 OverloadCandidateSet::CSK_Normal);
12109 if (buildOverloadedCallSet(S, Fn, ULE, Args, LParenLoc, &CandidateSet,
12113 // If the user handed us something like `(&Foo)(Bar)`, we need to ensure that
12114 // functions that aren't addressible are considered unviable.
12115 if (CalleesAddressIsTaken)
12116 markUnaddressableCandidatesUnviable(*this, CandidateSet);
12118 OverloadCandidateSet::iterator Best;
12119 OverloadingResult OverloadResult =
12120 CandidateSet.BestViableFunction(*this, Fn->getLocStart(), Best);
12122 return FinishOverloadedCallExpr(*this, S, Fn, ULE, LParenLoc, Args,
12123 RParenLoc, ExecConfig, &CandidateSet,
12124 &Best, OverloadResult,
12125 AllowTypoCorrection);
12128 static bool IsOverloaded(const UnresolvedSetImpl &Functions) {
12129 return Functions.size() > 1 ||
12130 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin()));
12133 /// Create a unary operation that may resolve to an overloaded
12136 /// \param OpLoc The location of the operator itself (e.g., '*').
12138 /// \param Opc The UnaryOperatorKind that describes this operator.
12140 /// \param Fns The set of non-member functions that will be
12141 /// considered by overload resolution. The caller needs to build this
12142 /// set based on the context using, e.g.,
12143 /// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This
12144 /// set should not contain any member functions; those will be added
12145 /// by CreateOverloadedUnaryOp().
12147 /// \param Input The input argument.
12149 Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, UnaryOperatorKind Opc,
12150 const UnresolvedSetImpl &Fns,
12151 Expr *Input, bool PerformADL) {
12152 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc);
12153 assert(Op != OO_None && "Invalid opcode for overloaded unary operator");
12154 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
12155 // TODO: provide better source location info.
12156 DeclarationNameInfo OpNameInfo(OpName, OpLoc);
12158 if (checkPlaceholderForOverload(*this, Input))
12159 return ExprError();
12161 Expr *Args[2] = { Input, nullptr };
12162 unsigned NumArgs = 1;
12164 // For post-increment and post-decrement, add the implicit '0' as
12165 // the second argument, so that we know this is a post-increment or
12167 if (Opc == UO_PostInc || Opc == UO_PostDec) {
12168 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false);
12169 Args[1] = IntegerLiteral::Create(Context, Zero, Context.IntTy,
12174 ArrayRef<Expr *> ArgsArray(Args, NumArgs);
12176 if (Input->isTypeDependent()) {
12178 return new (Context) UnaryOperator(Input, Opc, Context.DependentTy,
12179 VK_RValue, OK_Ordinary, OpLoc, false);
12181 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
12182 UnresolvedLookupExpr *Fn
12183 = UnresolvedLookupExpr::Create(Context, NamingClass,
12184 NestedNameSpecifierLoc(), OpNameInfo,
12185 /*ADL*/ true, IsOverloaded(Fns),
12186 Fns.begin(), Fns.end());
12187 return new (Context)
12188 CXXOperatorCallExpr(Context, Op, Fn, ArgsArray, Context.DependentTy,
12189 VK_RValue, OpLoc, FPOptions());
12192 // Build an empty overload set.
12193 OverloadCandidateSet CandidateSet(OpLoc, OverloadCandidateSet::CSK_Operator);
12195 // Add the candidates from the given function set.
12196 AddFunctionCandidates(Fns, ArgsArray, CandidateSet);
12198 // Add operator candidates that are member functions.
12199 AddMemberOperatorCandidates(Op, OpLoc, ArgsArray, CandidateSet);
12201 // Add candidates from ADL.
12203 AddArgumentDependentLookupCandidates(OpName, OpLoc, ArgsArray,
12204 /*ExplicitTemplateArgs*/nullptr,
12208 // Add builtin operator candidates.
12209 AddBuiltinOperatorCandidates(Op, OpLoc, ArgsArray, CandidateSet);
12211 bool HadMultipleCandidates = (CandidateSet.size() > 1);
12213 // Perform overload resolution.
12214 OverloadCandidateSet::iterator Best;
12215 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
12217 // We found a built-in operator or an overloaded operator.
12218 FunctionDecl *FnDecl = Best->Function;
12221 Expr *Base = nullptr;
12222 // We matched an overloaded operator. Build a call to that
12225 // Convert the arguments.
12226 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) {
12227 CheckMemberOperatorAccess(OpLoc, Args[0], nullptr, Best->FoundDecl);
12229 ExprResult InputRes =
12230 PerformObjectArgumentInitialization(Input, /*Qualifier=*/nullptr,
12231 Best->FoundDecl, Method);
12232 if (InputRes.isInvalid())
12233 return ExprError();
12234 Base = Input = InputRes.get();
12236 // Convert the arguments.
12237 ExprResult InputInit
12238 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
12240 FnDecl->getParamDecl(0)),
12243 if (InputInit.isInvalid())
12244 return ExprError();
12245 Input = InputInit.get();
12248 // Build the actual expression node.
12249 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, Best->FoundDecl,
12250 Base, HadMultipleCandidates,
12252 if (FnExpr.isInvalid())
12253 return ExprError();
12255 // Determine the result type.
12256 QualType ResultTy = FnDecl->getReturnType();
12257 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
12258 ResultTy = ResultTy.getNonLValueExprType(Context);
12261 CallExpr *TheCall =
12262 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.get(), ArgsArray,
12263 ResultTy, VK, OpLoc, FPOptions());
12265 if (CheckCallReturnType(FnDecl->getReturnType(), OpLoc, TheCall, FnDecl))
12266 return ExprError();
12268 if (CheckFunctionCall(FnDecl, TheCall,
12269 FnDecl->getType()->castAs<FunctionProtoType>()))
12270 return ExprError();
12272 return MaybeBindToTemporary(TheCall);
12274 // We matched a built-in operator. Convert the arguments, then
12275 // break out so that we will build the appropriate built-in
12277 ExprResult InputRes = PerformImplicitConversion(
12278 Input, Best->BuiltinParamTypes[0], Best->Conversions[0], AA_Passing,
12279 CCK_ForBuiltinOverloadedOp);
12280 if (InputRes.isInvalid())
12281 return ExprError();
12282 Input = InputRes.get();
12287 case OR_No_Viable_Function:
12288 // This is an erroneous use of an operator which can be overloaded by
12289 // a non-member function. Check for non-member operators which were
12290 // defined too late to be candidates.
12291 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, ArgsArray))
12292 // FIXME: Recover by calling the found function.
12293 return ExprError();
12295 // No viable function; fall through to handling this as a
12296 // built-in operator, which will produce an error message for us.
12300 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary)
12301 << UnaryOperator::getOpcodeStr(Opc)
12302 << Input->getType()
12303 << Input->getSourceRange();
12304 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, ArgsArray,
12305 UnaryOperator::getOpcodeStr(Opc), OpLoc);
12306 return ExprError();
12309 Diag(OpLoc, diag::err_ovl_deleted_oper)
12310 << Best->Function->isDeleted()
12311 << UnaryOperator::getOpcodeStr(Opc)
12312 << getDeletedOrUnavailableSuffix(Best->Function)
12313 << Input->getSourceRange();
12314 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, ArgsArray,
12315 UnaryOperator::getOpcodeStr(Opc), OpLoc);
12316 return ExprError();
12319 // Either we found no viable overloaded operator or we matched a
12320 // built-in operator. In either case, fall through to trying to
12321 // build a built-in operation.
12322 return CreateBuiltinUnaryOp(OpLoc, Opc, Input);
12325 /// Create a binary operation that may resolve to an overloaded
12328 /// \param OpLoc The location of the operator itself (e.g., '+').
12330 /// \param Opc The BinaryOperatorKind that describes this operator.
12332 /// \param Fns The set of non-member functions that will be
12333 /// considered by overload resolution. The caller needs to build this
12334 /// set based on the context using, e.g.,
12335 /// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This
12336 /// set should not contain any member functions; those will be added
12337 /// by CreateOverloadedBinOp().
12339 /// \param LHS Left-hand argument.
12340 /// \param RHS Right-hand argument.
12342 Sema::CreateOverloadedBinOp(SourceLocation OpLoc,
12343 BinaryOperatorKind Opc,
12344 const UnresolvedSetImpl &Fns,
12345 Expr *LHS, Expr *RHS, bool PerformADL) {
12346 Expr *Args[2] = { LHS, RHS };
12347 LHS=RHS=nullptr; // Please use only Args instead of LHS/RHS couple
12349 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc);
12350 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
12352 // If either side is type-dependent, create an appropriate dependent
12354 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) {
12356 // If there are no functions to store, just build a dependent
12357 // BinaryOperator or CompoundAssignment.
12358 if (Opc <= BO_Assign || Opc > BO_OrAssign)
12359 return new (Context) BinaryOperator(
12360 Args[0], Args[1], Opc, Context.DependentTy, VK_RValue, OK_Ordinary,
12361 OpLoc, FPFeatures);
12363 return new (Context) CompoundAssignOperator(
12364 Args[0], Args[1], Opc, Context.DependentTy, VK_LValue, OK_Ordinary,
12365 Context.DependentTy, Context.DependentTy, OpLoc,
12369 // FIXME: save results of ADL from here?
12370 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
12371 // TODO: provide better source location info in DNLoc component.
12372 DeclarationNameInfo OpNameInfo(OpName, OpLoc);
12373 UnresolvedLookupExpr *Fn
12374 = UnresolvedLookupExpr::Create(Context, NamingClass,
12375 NestedNameSpecifierLoc(), OpNameInfo,
12376 /*ADL*/PerformADL, IsOverloaded(Fns),
12377 Fns.begin(), Fns.end());
12378 return new (Context)
12379 CXXOperatorCallExpr(Context, Op, Fn, Args, Context.DependentTy,
12380 VK_RValue, OpLoc, FPFeatures);
12383 // Always do placeholder-like conversions on the RHS.
12384 if (checkPlaceholderForOverload(*this, Args[1]))
12385 return ExprError();
12387 // Do placeholder-like conversion on the LHS; note that we should
12388 // not get here with a PseudoObject LHS.
12389 assert(Args[0]->getObjectKind() != OK_ObjCProperty);
12390 if (checkPlaceholderForOverload(*this, Args[0]))
12391 return ExprError();
12393 // If this is the assignment operator, we only perform overload resolution
12394 // if the left-hand side is a class or enumeration type. This is actually
12395 // a hack. The standard requires that we do overload resolution between the
12396 // various built-in candidates, but as DR507 points out, this can lead to
12397 // problems. So we do it this way, which pretty much follows what GCC does.
12398 // Note that we go the traditional code path for compound assignment forms.
12399 if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType())
12400 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
12402 // If this is the .* operator, which is not overloadable, just
12403 // create a built-in binary operator.
12404 if (Opc == BO_PtrMemD)
12405 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
12407 // Build an empty overload set.
12408 OverloadCandidateSet CandidateSet(OpLoc, OverloadCandidateSet::CSK_Operator);
12410 // Add the candidates from the given function set.
12411 AddFunctionCandidates(Fns, Args, CandidateSet);
12413 // Add operator candidates that are member functions.
12414 AddMemberOperatorCandidates(Op, OpLoc, Args, CandidateSet);
12416 // Add candidates from ADL. Per [over.match.oper]p2, this lookup is not
12417 // performed for an assignment operator (nor for operator[] nor operator->,
12418 // which don't get here).
12419 if (Opc != BO_Assign && PerformADL)
12420 AddArgumentDependentLookupCandidates(OpName, OpLoc, Args,
12421 /*ExplicitTemplateArgs*/ nullptr,
12424 // Add builtin operator candidates.
12425 AddBuiltinOperatorCandidates(Op, OpLoc, Args, CandidateSet);
12427 bool HadMultipleCandidates = (CandidateSet.size() > 1);
12429 // Perform overload resolution.
12430 OverloadCandidateSet::iterator Best;
12431 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
12433 // We found a built-in operator or an overloaded operator.
12434 FunctionDecl *FnDecl = Best->Function;
12437 Expr *Base = nullptr;
12438 // We matched an overloaded operator. Build a call to that
12441 // Convert the arguments.
12442 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) {
12443 // Best->Access is only meaningful for class members.
12444 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl);
12447 PerformCopyInitialization(
12448 InitializedEntity::InitializeParameter(Context,
12449 FnDecl->getParamDecl(0)),
12450 SourceLocation(), Args[1]);
12451 if (Arg1.isInvalid())
12452 return ExprError();
12455 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/nullptr,
12456 Best->FoundDecl, Method);
12457 if (Arg0.isInvalid())
12458 return ExprError();
12459 Base = Args[0] = Arg0.getAs<Expr>();
12460 Args[1] = RHS = Arg1.getAs<Expr>();
12462 // Convert the arguments.
12463 ExprResult Arg0 = PerformCopyInitialization(
12464 InitializedEntity::InitializeParameter(Context,
12465 FnDecl->getParamDecl(0)),
12466 SourceLocation(), Args[0]);
12467 if (Arg0.isInvalid())
12468 return ExprError();
12471 PerformCopyInitialization(
12472 InitializedEntity::InitializeParameter(Context,
12473 FnDecl->getParamDecl(1)),
12474 SourceLocation(), Args[1]);
12475 if (Arg1.isInvalid())
12476 return ExprError();
12477 Args[0] = LHS = Arg0.getAs<Expr>();
12478 Args[1] = RHS = Arg1.getAs<Expr>();
12481 // Build the actual expression node.
12482 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl,
12483 Best->FoundDecl, Base,
12484 HadMultipleCandidates, OpLoc);
12485 if (FnExpr.isInvalid())
12486 return ExprError();
12488 // Determine the result type.
12489 QualType ResultTy = FnDecl->getReturnType();
12490 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
12491 ResultTy = ResultTy.getNonLValueExprType(Context);
12493 CXXOperatorCallExpr *TheCall =
12494 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.get(),
12495 Args, ResultTy, VK, OpLoc,
12498 if (CheckCallReturnType(FnDecl->getReturnType(), OpLoc, TheCall,
12500 return ExprError();
12502 ArrayRef<const Expr *> ArgsArray(Args, 2);
12503 const Expr *ImplicitThis = nullptr;
12504 // Cut off the implicit 'this'.
12505 if (isa<CXXMethodDecl>(FnDecl)) {
12506 ImplicitThis = ArgsArray[0];
12507 ArgsArray = ArgsArray.slice(1);
12510 // Check for a self move.
12511 if (Op == OO_Equal)
12512 DiagnoseSelfMove(Args[0], Args[1], OpLoc);
12514 checkCall(FnDecl, nullptr, ImplicitThis, ArgsArray,
12515 isa<CXXMethodDecl>(FnDecl), OpLoc, TheCall->getSourceRange(),
12516 VariadicDoesNotApply);
12518 return MaybeBindToTemporary(TheCall);
12520 // We matched a built-in operator. Convert the arguments, then
12521 // break out so that we will build the appropriate built-in
12523 ExprResult ArgsRes0 = PerformImplicitConversion(
12524 Args[0], Best->BuiltinParamTypes[0], Best->Conversions[0],
12525 AA_Passing, CCK_ForBuiltinOverloadedOp);
12526 if (ArgsRes0.isInvalid())
12527 return ExprError();
12528 Args[0] = ArgsRes0.get();
12530 ExprResult ArgsRes1 = PerformImplicitConversion(
12531 Args[1], Best->BuiltinParamTypes[1], Best->Conversions[1],
12532 AA_Passing, CCK_ForBuiltinOverloadedOp);
12533 if (ArgsRes1.isInvalid())
12534 return ExprError();
12535 Args[1] = ArgsRes1.get();
12540 case OR_No_Viable_Function: {
12541 // C++ [over.match.oper]p9:
12542 // If the operator is the operator , [...] and there are no
12543 // viable functions, then the operator is assumed to be the
12544 // built-in operator and interpreted according to clause 5.
12545 if (Opc == BO_Comma)
12548 // For class as left operand for assignment or compound assignment
12549 // operator do not fall through to handling in built-in, but report that
12550 // no overloaded assignment operator found
12551 ExprResult Result = ExprError();
12552 if (Args[0]->getType()->isRecordType() &&
12553 Opc >= BO_Assign && Opc <= BO_OrAssign) {
12554 Diag(OpLoc, diag::err_ovl_no_viable_oper)
12555 << BinaryOperator::getOpcodeStr(Opc)
12556 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12557 if (Args[0]->getType()->isIncompleteType()) {
12558 Diag(OpLoc, diag::note_assign_lhs_incomplete)
12559 << Args[0]->getType()
12560 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12563 // This is an erroneous use of an operator which can be overloaded by
12564 // a non-member function. Check for non-member operators which were
12565 // defined too late to be candidates.
12566 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, Args))
12567 // FIXME: Recover by calling the found function.
12568 return ExprError();
12570 // No viable function; try to create a built-in operation, which will
12571 // produce an error. Then, show the non-viable candidates.
12572 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
12574 assert(Result.isInvalid() &&
12575 "C++ binary operator overloading is missing candidates!");
12576 if (Result.isInvalid())
12577 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args,
12578 BinaryOperator::getOpcodeStr(Opc), OpLoc);
12583 Diag(OpLoc, diag::err_ovl_ambiguous_oper_binary)
12584 << BinaryOperator::getOpcodeStr(Opc)
12585 << Args[0]->getType() << Args[1]->getType()
12586 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12587 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args,
12588 BinaryOperator::getOpcodeStr(Opc), OpLoc);
12589 return ExprError();
12592 if (isImplicitlyDeleted(Best->Function)) {
12593 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
12594 Diag(OpLoc, diag::err_ovl_deleted_special_oper)
12595 << Context.getRecordType(Method->getParent())
12596 << getSpecialMember(Method);
12598 // The user probably meant to call this special member. Just
12599 // explain why it's deleted.
12600 NoteDeletedFunction(Method);
12601 return ExprError();
12603 Diag(OpLoc, diag::err_ovl_deleted_oper)
12604 << Best->Function->isDeleted()
12605 << BinaryOperator::getOpcodeStr(Opc)
12606 << getDeletedOrUnavailableSuffix(Best->Function)
12607 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12609 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args,
12610 BinaryOperator::getOpcodeStr(Opc), OpLoc);
12611 return ExprError();
12614 // We matched a built-in operator; build it.
12615 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
12619 Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc,
12620 SourceLocation RLoc,
12621 Expr *Base, Expr *Idx) {
12622 Expr *Args[2] = { Base, Idx };
12623 DeclarationName OpName =
12624 Context.DeclarationNames.getCXXOperatorName(OO_Subscript);
12626 // If either side is type-dependent, create an appropriate dependent
12628 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) {
12630 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
12631 // CHECKME: no 'operator' keyword?
12632 DeclarationNameInfo OpNameInfo(OpName, LLoc);
12633 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc));
12634 UnresolvedLookupExpr *Fn
12635 = UnresolvedLookupExpr::Create(Context, NamingClass,
12636 NestedNameSpecifierLoc(), OpNameInfo,
12637 /*ADL*/ true, /*Overloaded*/ false,
12638 UnresolvedSetIterator(),
12639 UnresolvedSetIterator());
12640 // Can't add any actual overloads yet
12642 return new (Context)
12643 CXXOperatorCallExpr(Context, OO_Subscript, Fn, Args,
12644 Context.DependentTy, VK_RValue, RLoc, FPOptions());
12647 // Handle placeholders on both operands.
12648 if (checkPlaceholderForOverload(*this, Args[0]))
12649 return ExprError();
12650 if (checkPlaceholderForOverload(*this, Args[1]))
12651 return ExprError();
12653 // Build an empty overload set.
12654 OverloadCandidateSet CandidateSet(LLoc, OverloadCandidateSet::CSK_Operator);
12656 // Subscript can only be overloaded as a member function.
12658 // Add operator candidates that are member functions.
12659 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, CandidateSet);
12661 // Add builtin operator candidates.
12662 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, CandidateSet);
12664 bool HadMultipleCandidates = (CandidateSet.size() > 1);
12666 // Perform overload resolution.
12667 OverloadCandidateSet::iterator Best;
12668 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) {
12670 // We found a built-in operator or an overloaded operator.
12671 FunctionDecl *FnDecl = Best->Function;
12674 // We matched an overloaded operator. Build a call to that
12677 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl);
12679 // Convert the arguments.
12680 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl);
12682 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/nullptr,
12683 Best->FoundDecl, Method);
12684 if (Arg0.isInvalid())
12685 return ExprError();
12686 Args[0] = Arg0.get();
12688 // Convert the arguments.
12689 ExprResult InputInit
12690 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
12692 FnDecl->getParamDecl(0)),
12695 if (InputInit.isInvalid())
12696 return ExprError();
12698 Args[1] = InputInit.getAs<Expr>();
12700 // Build the actual expression node.
12701 DeclarationNameInfo OpLocInfo(OpName, LLoc);
12702 OpLocInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc));
12703 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl,
12706 HadMultipleCandidates,
12707 OpLocInfo.getLoc(),
12708 OpLocInfo.getInfo());
12709 if (FnExpr.isInvalid())
12710 return ExprError();
12712 // Determine the result type
12713 QualType ResultTy = FnDecl->getReturnType();
12714 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
12715 ResultTy = ResultTy.getNonLValueExprType(Context);
12717 CXXOperatorCallExpr *TheCall =
12718 new (Context) CXXOperatorCallExpr(Context, OO_Subscript,
12719 FnExpr.get(), Args,
12720 ResultTy, VK, RLoc,
12723 if (CheckCallReturnType(FnDecl->getReturnType(), LLoc, TheCall, FnDecl))
12724 return ExprError();
12726 if (CheckFunctionCall(Method, TheCall,
12727 Method->getType()->castAs<FunctionProtoType>()))
12728 return ExprError();
12730 return MaybeBindToTemporary(TheCall);
12732 // We matched a built-in operator. Convert the arguments, then
12733 // break out so that we will build the appropriate built-in
12735 ExprResult ArgsRes0 = PerformImplicitConversion(
12736 Args[0], Best->BuiltinParamTypes[0], Best->Conversions[0],
12737 AA_Passing, CCK_ForBuiltinOverloadedOp);
12738 if (ArgsRes0.isInvalid())
12739 return ExprError();
12740 Args[0] = ArgsRes0.get();
12742 ExprResult ArgsRes1 = PerformImplicitConversion(
12743 Args[1], Best->BuiltinParamTypes[1], Best->Conversions[1],
12744 AA_Passing, CCK_ForBuiltinOverloadedOp);
12745 if (ArgsRes1.isInvalid())
12746 return ExprError();
12747 Args[1] = ArgsRes1.get();
12753 case OR_No_Viable_Function: {
12754 if (CandidateSet.empty())
12755 Diag(LLoc, diag::err_ovl_no_oper)
12756 << Args[0]->getType() << /*subscript*/ 0
12757 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12759 Diag(LLoc, diag::err_ovl_no_viable_subscript)
12760 << Args[0]->getType()
12761 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12762 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args,
12764 return ExprError();
12768 Diag(LLoc, diag::err_ovl_ambiguous_oper_binary)
12770 << Args[0]->getType() << Args[1]->getType()
12771 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12772 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args,
12774 return ExprError();
12777 Diag(LLoc, diag::err_ovl_deleted_oper)
12778 << Best->Function->isDeleted() << "[]"
12779 << getDeletedOrUnavailableSuffix(Best->Function)
12780 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12781 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args,
12783 return ExprError();
12786 // We matched a built-in operator; build it.
12787 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc);
12790 /// BuildCallToMemberFunction - Build a call to a member
12791 /// function. MemExpr is the expression that refers to the member
12792 /// function (and includes the object parameter), Args/NumArgs are the
12793 /// arguments to the function call (not including the object
12794 /// parameter). The caller needs to validate that the member
12795 /// expression refers to a non-static member function or an overloaded
12796 /// member function.
12798 Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE,
12799 SourceLocation LParenLoc,
12801 SourceLocation RParenLoc) {
12802 assert(MemExprE->getType() == Context.BoundMemberTy ||
12803 MemExprE->getType() == Context.OverloadTy);
12805 // Dig out the member expression. This holds both the object
12806 // argument and the member function we're referring to.
12807 Expr *NakedMemExpr = MemExprE->IgnoreParens();
12809 // Determine whether this is a call to a pointer-to-member function.
12810 if (BinaryOperator *op = dyn_cast<BinaryOperator>(NakedMemExpr)) {
12811 assert(op->getType() == Context.BoundMemberTy);
12812 assert(op->getOpcode() == BO_PtrMemD || op->getOpcode() == BO_PtrMemI);
12815 op->getRHS()->getType()->castAs<MemberPointerType>()->getPointeeType();
12817 const FunctionProtoType *proto = fnType->castAs<FunctionProtoType>();
12818 QualType resultType = proto->getCallResultType(Context);
12819 ExprValueKind valueKind = Expr::getValueKindForType(proto->getReturnType());
12821 // Check that the object type isn't more qualified than the
12822 // member function we're calling.
12823 Qualifiers funcQuals = Qualifiers::fromCVRMask(proto->getTypeQuals());
12825 QualType objectType = op->getLHS()->getType();
12826 if (op->getOpcode() == BO_PtrMemI)
12827 objectType = objectType->castAs<PointerType>()->getPointeeType();
12828 Qualifiers objectQuals = objectType.getQualifiers();
12830 Qualifiers difference = objectQuals - funcQuals;
12831 difference.removeObjCGCAttr();
12832 difference.removeAddressSpace();
12834 std::string qualsString = difference.getAsString();
12835 Diag(LParenLoc, diag::err_pointer_to_member_call_drops_quals)
12836 << fnType.getUnqualifiedType()
12838 << (qualsString.find(' ') == std::string::npos ? 1 : 2);
12841 CXXMemberCallExpr *call
12842 = new (Context) CXXMemberCallExpr(Context, MemExprE, Args,
12843 resultType, valueKind, RParenLoc);
12845 if (CheckCallReturnType(proto->getReturnType(), op->getRHS()->getLocStart(),
12847 return ExprError();
12849 if (ConvertArgumentsForCall(call, op, nullptr, proto, Args, RParenLoc))
12850 return ExprError();
12852 if (CheckOtherCall(call, proto))
12853 return ExprError();
12855 return MaybeBindToTemporary(call);
12858 if (isa<CXXPseudoDestructorExpr>(NakedMemExpr))
12859 return new (Context)
12860 CallExpr(Context, MemExprE, Args, Context.VoidTy, VK_RValue, RParenLoc);
12862 UnbridgedCastsSet UnbridgedCasts;
12863 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts))
12864 return ExprError();
12866 MemberExpr *MemExpr;
12867 CXXMethodDecl *Method = nullptr;
12868 DeclAccessPair FoundDecl = DeclAccessPair::make(nullptr, AS_public);
12869 NestedNameSpecifier *Qualifier = nullptr;
12870 if (isa<MemberExpr>(NakedMemExpr)) {
12871 MemExpr = cast<MemberExpr>(NakedMemExpr);
12872 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl());
12873 FoundDecl = MemExpr->getFoundDecl();
12874 Qualifier = MemExpr->getQualifier();
12875 UnbridgedCasts.restore();
12877 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr);
12878 Qualifier = UnresExpr->getQualifier();
12880 QualType ObjectType = UnresExpr->getBaseType();
12881 Expr::Classification ObjectClassification
12882 = UnresExpr->isArrow()? Expr::Classification::makeSimpleLValue()
12883 : UnresExpr->getBase()->Classify(Context);
12885 // Add overload candidates
12886 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc(),
12887 OverloadCandidateSet::CSK_Normal);
12889 // FIXME: avoid copy.
12890 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
12891 if (UnresExpr->hasExplicitTemplateArgs()) {
12892 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer);
12893 TemplateArgs = &TemplateArgsBuffer;
12896 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(),
12897 E = UnresExpr->decls_end(); I != E; ++I) {
12899 NamedDecl *Func = *I;
12900 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext());
12901 if (isa<UsingShadowDecl>(Func))
12902 Func = cast<UsingShadowDecl>(Func)->getTargetDecl();
12905 // Microsoft supports direct constructor calls.
12906 if (getLangOpts().MicrosoftExt && isa<CXXConstructorDecl>(Func)) {
12907 AddOverloadCandidate(cast<CXXConstructorDecl>(Func), I.getPair(),
12908 Args, CandidateSet);
12909 } else if ((Method = dyn_cast<CXXMethodDecl>(Func))) {
12910 // If explicit template arguments were provided, we can't call a
12911 // non-template member function.
12915 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType,
12916 ObjectClassification, Args, CandidateSet,
12917 /*SuppressUserConversions=*/false);
12919 AddMethodTemplateCandidate(
12920 cast<FunctionTemplateDecl>(Func), I.getPair(), ActingDC,
12921 TemplateArgs, ObjectType, ObjectClassification, Args, CandidateSet,
12922 /*SuppressUsedConversions=*/false);
12926 DeclarationName DeclName = UnresExpr->getMemberName();
12928 UnbridgedCasts.restore();
12930 OverloadCandidateSet::iterator Best;
12931 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getLocStart(),
12934 Method = cast<CXXMethodDecl>(Best->Function);
12935 FoundDecl = Best->FoundDecl;
12936 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl);
12937 if (DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()))
12938 return ExprError();
12939 // If FoundDecl is different from Method (such as if one is a template
12940 // and the other a specialization), make sure DiagnoseUseOfDecl is
12942 // FIXME: This would be more comprehensively addressed by modifying
12943 // DiagnoseUseOfDecl to accept both the FoundDecl and the decl
12945 if (Method != FoundDecl.getDecl() &&
12946 DiagnoseUseOfDecl(Method, UnresExpr->getNameLoc()))
12947 return ExprError();
12950 case OR_No_Viable_Function:
12951 Diag(UnresExpr->getMemberLoc(),
12952 diag::err_ovl_no_viable_member_function_in_call)
12953 << DeclName << MemExprE->getSourceRange();
12954 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
12955 // FIXME: Leaking incoming expressions!
12956 return ExprError();
12959 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call)
12960 << DeclName << MemExprE->getSourceRange();
12961 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
12962 // FIXME: Leaking incoming expressions!
12963 return ExprError();
12966 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call)
12967 << Best->Function->isDeleted()
12969 << getDeletedOrUnavailableSuffix(Best->Function)
12970 << MemExprE->getSourceRange();
12971 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
12972 // FIXME: Leaking incoming expressions!
12973 return ExprError();
12976 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method);
12978 // If overload resolution picked a static member, build a
12979 // non-member call based on that function.
12980 if (Method->isStatic()) {
12981 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, Args,
12985 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens());
12988 QualType ResultType = Method->getReturnType();
12989 ExprValueKind VK = Expr::getValueKindForType(ResultType);
12990 ResultType = ResultType.getNonLValueExprType(Context);
12992 assert(Method && "Member call to something that isn't a method?");
12993 CXXMemberCallExpr *TheCall =
12994 new (Context) CXXMemberCallExpr(Context, MemExprE, Args,
12995 ResultType, VK, RParenLoc);
12997 // Check for a valid return type.
12998 if (CheckCallReturnType(Method->getReturnType(), MemExpr->getMemberLoc(),
13000 return ExprError();
13002 // Convert the object argument (for a non-static member function call).
13003 // We only need to do this if there was actually an overload; otherwise
13004 // it was done at lookup.
13005 if (!Method->isStatic()) {
13006 ExprResult ObjectArg =
13007 PerformObjectArgumentInitialization(MemExpr->getBase(), Qualifier,
13008 FoundDecl, Method);
13009 if (ObjectArg.isInvalid())
13010 return ExprError();
13011 MemExpr->setBase(ObjectArg.get());
13014 // Convert the rest of the arguments
13015 const FunctionProtoType *Proto =
13016 Method->getType()->getAs<FunctionProtoType>();
13017 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args,
13019 return ExprError();
13021 DiagnoseSentinelCalls(Method, LParenLoc, Args);
13023 if (CheckFunctionCall(Method, TheCall, Proto))
13024 return ExprError();
13026 // In the case the method to call was not selected by the overloading
13027 // resolution process, we still need to handle the enable_if attribute. Do
13028 // that here, so it will not hide previous -- and more relevant -- errors.
13029 if (auto *MemE = dyn_cast<MemberExpr>(NakedMemExpr)) {
13030 if (const EnableIfAttr *Attr = CheckEnableIf(Method, Args, true)) {
13031 Diag(MemE->getMemberLoc(),
13032 diag::err_ovl_no_viable_member_function_in_call)
13033 << Method << Method->getSourceRange();
13034 Diag(Method->getLocation(),
13035 diag::note_ovl_candidate_disabled_by_function_cond_attr)
13036 << Attr->getCond()->getSourceRange() << Attr->getMessage();
13037 return ExprError();
13041 if ((isa<CXXConstructorDecl>(CurContext) ||
13042 isa<CXXDestructorDecl>(CurContext)) &&
13043 TheCall->getMethodDecl()->isPure()) {
13044 const CXXMethodDecl *MD = TheCall->getMethodDecl();
13046 if (isa<CXXThisExpr>(MemExpr->getBase()->IgnoreParenCasts()) &&
13047 MemExpr->performsVirtualDispatch(getLangOpts())) {
13048 Diag(MemExpr->getLocStart(),
13049 diag::warn_call_to_pure_virtual_member_function_from_ctor_dtor)
13050 << MD->getDeclName() << isa<CXXDestructorDecl>(CurContext)
13051 << MD->getParent()->getDeclName();
13053 Diag(MD->getLocStart(), diag::note_previous_decl) << MD->getDeclName();
13054 if (getLangOpts().AppleKext)
13055 Diag(MemExpr->getLocStart(),
13056 diag::note_pure_qualified_call_kext)
13057 << MD->getParent()->getDeclName()
13058 << MD->getDeclName();
13062 if (CXXDestructorDecl *DD =
13063 dyn_cast<CXXDestructorDecl>(TheCall->getMethodDecl())) {
13064 // a->A::f() doesn't go through the vtable, except in AppleKext mode.
13065 bool CallCanBeVirtual = !MemExpr->hasQualifier() || getLangOpts().AppleKext;
13066 CheckVirtualDtorCall(DD, MemExpr->getLocStart(), /*IsDelete=*/false,
13067 CallCanBeVirtual, /*WarnOnNonAbstractTypes=*/true,
13068 MemExpr->getMemberLoc());
13071 return MaybeBindToTemporary(TheCall);
13074 /// BuildCallToObjectOfClassType - Build a call to an object of class
13075 /// type (C++ [over.call.object]), which can end up invoking an
13076 /// overloaded function call operator (@c operator()) or performing a
13077 /// user-defined conversion on the object argument.
13079 Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj,
13080 SourceLocation LParenLoc,
13082 SourceLocation RParenLoc) {
13083 if (checkPlaceholderForOverload(*this, Obj))
13084 return ExprError();
13085 ExprResult Object = Obj;
13087 UnbridgedCastsSet UnbridgedCasts;
13088 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts))
13089 return ExprError();
13091 assert(Object.get()->getType()->isRecordType() &&
13092 "Requires object type argument");
13093 const RecordType *Record = Object.get()->getType()->getAs<RecordType>();
13095 // C++ [over.call.object]p1:
13096 // If the primary-expression E in the function call syntax
13097 // evaluates to a class object of type "cv T", then the set of
13098 // candidate functions includes at least the function call
13099 // operators of T. The function call operators of T are obtained by
13100 // ordinary lookup of the name operator() in the context of
13102 OverloadCandidateSet CandidateSet(LParenLoc,
13103 OverloadCandidateSet::CSK_Operator);
13104 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call);
13106 if (RequireCompleteType(LParenLoc, Object.get()->getType(),
13107 diag::err_incomplete_object_call, Object.get()))
13110 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName);
13111 LookupQualifiedName(R, Record->getDecl());
13112 R.suppressDiagnostics();
13114 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end();
13115 Oper != OperEnd; ++Oper) {
13116 AddMethodCandidate(Oper.getPair(), Object.get()->getType(),
13117 Object.get()->Classify(Context), Args, CandidateSet,
13118 /*SuppressUserConversions=*/false);
13121 // C++ [over.call.object]p2:
13122 // In addition, for each (non-explicit in C++0x) conversion function
13123 // declared in T of the form
13125 // operator conversion-type-id () cv-qualifier;
13127 // where cv-qualifier is the same cv-qualification as, or a
13128 // greater cv-qualification than, cv, and where conversion-type-id
13129 // denotes the type "pointer to function of (P1,...,Pn) returning
13130 // R", or the type "reference to pointer to function of
13131 // (P1,...,Pn) returning R", or the type "reference to function
13132 // of (P1,...,Pn) returning R", a surrogate call function [...]
13133 // is also considered as a candidate function. Similarly,
13134 // surrogate call functions are added to the set of candidate
13135 // functions for each conversion function declared in an
13136 // accessible base class provided the function is not hidden
13137 // within T by another intervening declaration.
13138 const auto &Conversions =
13139 cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions();
13140 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
13142 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
13143 if (isa<UsingShadowDecl>(D))
13144 D = cast<UsingShadowDecl>(D)->getTargetDecl();
13146 // Skip over templated conversion functions; they aren't
13148 if (isa<FunctionTemplateDecl>(D))
13151 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D);
13152 if (!Conv->isExplicit()) {
13153 // Strip the reference type (if any) and then the pointer type (if
13154 // any) to get down to what might be a function type.
13155 QualType ConvType = Conv->getConversionType().getNonReferenceType();
13156 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
13157 ConvType = ConvPtrType->getPointeeType();
13159 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>())
13161 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto,
13162 Object.get(), Args, CandidateSet);
13167 bool HadMultipleCandidates = (CandidateSet.size() > 1);
13169 // Perform overload resolution.
13170 OverloadCandidateSet::iterator Best;
13171 switch (CandidateSet.BestViableFunction(*this, Object.get()->getLocStart(),
13174 // Overload resolution succeeded; we'll build the appropriate call
13178 case OR_No_Viable_Function:
13179 if (CandidateSet.empty())
13180 Diag(Object.get()->getLocStart(), diag::err_ovl_no_oper)
13181 << Object.get()->getType() << /*call*/ 1
13182 << Object.get()->getSourceRange();
13184 Diag(Object.get()->getLocStart(),
13185 diag::err_ovl_no_viable_object_call)
13186 << Object.get()->getType() << Object.get()->getSourceRange();
13187 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
13191 Diag(Object.get()->getLocStart(),
13192 diag::err_ovl_ambiguous_object_call)
13193 << Object.get()->getType() << Object.get()->getSourceRange();
13194 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args);
13198 Diag(Object.get()->getLocStart(),
13199 diag::err_ovl_deleted_object_call)
13200 << Best->Function->isDeleted()
13201 << Object.get()->getType()
13202 << getDeletedOrUnavailableSuffix(Best->Function)
13203 << Object.get()->getSourceRange();
13204 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
13208 if (Best == CandidateSet.end())
13211 UnbridgedCasts.restore();
13213 if (Best->Function == nullptr) {
13214 // Since there is no function declaration, this is one of the
13215 // surrogate candidates. Dig out the conversion function.
13216 CXXConversionDecl *Conv
13217 = cast<CXXConversionDecl>(
13218 Best->Conversions[0].UserDefined.ConversionFunction);
13220 CheckMemberOperatorAccess(LParenLoc, Object.get(), nullptr,
13222 if (DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc))
13223 return ExprError();
13224 assert(Conv == Best->FoundDecl.getDecl() &&
13225 "Found Decl & conversion-to-functionptr should be same, right?!");
13226 // We selected one of the surrogate functions that converts the
13227 // object parameter to a function pointer. Perform the conversion
13228 // on the object argument, then let ActOnCallExpr finish the job.
13230 // Create an implicit member expr to refer to the conversion operator.
13231 // and then call it.
13232 ExprResult Call = BuildCXXMemberCallExpr(Object.get(), Best->FoundDecl,
13233 Conv, HadMultipleCandidates);
13234 if (Call.isInvalid())
13235 return ExprError();
13236 // Record usage of conversion in an implicit cast.
13237 Call = ImplicitCastExpr::Create(Context, Call.get()->getType(),
13238 CK_UserDefinedConversion, Call.get(),
13239 nullptr, VK_RValue);
13241 return ActOnCallExpr(S, Call.get(), LParenLoc, Args, RParenLoc);
13244 CheckMemberOperatorAccess(LParenLoc, Object.get(), nullptr, Best->FoundDecl);
13246 // We found an overloaded operator(). Build a CXXOperatorCallExpr
13247 // that calls this method, using Object for the implicit object
13248 // parameter and passing along the remaining arguments.
13249 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
13251 // An error diagnostic has already been printed when parsing the declaration.
13252 if (Method->isInvalidDecl())
13253 return ExprError();
13255 const FunctionProtoType *Proto =
13256 Method->getType()->getAs<FunctionProtoType>();
13258 unsigned NumParams = Proto->getNumParams();
13260 DeclarationNameInfo OpLocInfo(
13261 Context.DeclarationNames.getCXXOperatorName(OO_Call), LParenLoc);
13262 OpLocInfo.setCXXOperatorNameRange(SourceRange(LParenLoc, RParenLoc));
13263 ExprResult NewFn = CreateFunctionRefExpr(*this, Method, Best->FoundDecl,
13264 Obj, HadMultipleCandidates,
13265 OpLocInfo.getLoc(),
13266 OpLocInfo.getInfo());
13267 if (NewFn.isInvalid())
13270 // Build the full argument list for the method call (the implicit object
13271 // parameter is placed at the beginning of the list).
13272 SmallVector<Expr *, 8> MethodArgs(Args.size() + 1);
13273 MethodArgs[0] = Object.get();
13274 std::copy(Args.begin(), Args.end(), MethodArgs.begin() + 1);
13276 // Once we've built TheCall, all of the expressions are properly
13278 QualType ResultTy = Method->getReturnType();
13279 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
13280 ResultTy = ResultTy.getNonLValueExprType(Context);
13282 CXXOperatorCallExpr *TheCall = new (Context)
13283 CXXOperatorCallExpr(Context, OO_Call, NewFn.get(), MethodArgs, ResultTy,
13284 VK, RParenLoc, FPOptions());
13286 if (CheckCallReturnType(Method->getReturnType(), LParenLoc, TheCall, Method))
13289 // We may have default arguments. If so, we need to allocate more
13290 // slots in the call for them.
13291 if (Args.size() < NumParams)
13292 TheCall->setNumArgs(Context, NumParams + 1);
13294 bool IsError = false;
13296 // Initialize the implicit object parameter.
13297 ExprResult ObjRes =
13298 PerformObjectArgumentInitialization(Object.get(), /*Qualifier=*/nullptr,
13299 Best->FoundDecl, Method);
13300 if (ObjRes.isInvalid())
13304 TheCall->setArg(0, Object.get());
13306 // Check the argument types.
13307 for (unsigned i = 0; i != NumParams; i++) {
13309 if (i < Args.size()) {
13312 // Pass the argument.
13314 ExprResult InputInit
13315 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
13317 Method->getParamDecl(i)),
13318 SourceLocation(), Arg);
13320 IsError |= InputInit.isInvalid();
13321 Arg = InputInit.getAs<Expr>();
13324 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i));
13325 if (DefArg.isInvalid()) {
13330 Arg = DefArg.getAs<Expr>();
13333 TheCall->setArg(i + 1, Arg);
13336 // If this is a variadic call, handle args passed through "...".
13337 if (Proto->isVariadic()) {
13338 // Promote the arguments (C99 6.5.2.2p7).
13339 for (unsigned i = NumParams, e = Args.size(); i < e; i++) {
13340 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod,
13342 IsError |= Arg.isInvalid();
13343 TheCall->setArg(i + 1, Arg.get());
13347 if (IsError) return true;
13349 DiagnoseSentinelCalls(Method, LParenLoc, Args);
13351 if (CheckFunctionCall(Method, TheCall, Proto))
13354 return MaybeBindToTemporary(TheCall);
13357 /// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator->
13358 /// (if one exists), where @c Base is an expression of class type and
13359 /// @c Member is the name of the member we're trying to find.
13361 Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc,
13362 bool *NoArrowOperatorFound) {
13363 assert(Base->getType()->isRecordType() &&
13364 "left-hand side must have class type");
13366 if (checkPlaceholderForOverload(*this, Base))
13367 return ExprError();
13369 SourceLocation Loc = Base->getExprLoc();
13371 // C++ [over.ref]p1:
13373 // [...] An expression x->m is interpreted as (x.operator->())->m
13374 // for a class object x of type T if T::operator->() exists and if
13375 // the operator is selected as the best match function by the
13376 // overload resolution mechanism (13.3).
13377 DeclarationName OpName =
13378 Context.DeclarationNames.getCXXOperatorName(OO_Arrow);
13379 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Operator);
13380 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>();
13382 if (RequireCompleteType(Loc, Base->getType(),
13383 diag::err_typecheck_incomplete_tag, Base))
13384 return ExprError();
13386 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName);
13387 LookupQualifiedName(R, BaseRecord->getDecl());
13388 R.suppressDiagnostics();
13390 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end();
13391 Oper != OperEnd; ++Oper) {
13392 AddMethodCandidate(Oper.getPair(), Base->getType(), Base->Classify(Context),
13393 None, CandidateSet, /*SuppressUserConversions=*/false);
13396 bool HadMultipleCandidates = (CandidateSet.size() > 1);
13398 // Perform overload resolution.
13399 OverloadCandidateSet::iterator Best;
13400 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
13402 // Overload resolution succeeded; we'll build the call below.
13405 case OR_No_Viable_Function:
13406 if (CandidateSet.empty()) {
13407 QualType BaseType = Base->getType();
13408 if (NoArrowOperatorFound) {
13409 // Report this specific error to the caller instead of emitting a
13410 // diagnostic, as requested.
13411 *NoArrowOperatorFound = true;
13412 return ExprError();
13414 Diag(OpLoc, diag::err_typecheck_member_reference_arrow)
13415 << BaseType << Base->getSourceRange();
13416 if (BaseType->isRecordType() && !BaseType->isPointerType()) {
13417 Diag(OpLoc, diag::note_typecheck_member_reference_suggestion)
13418 << FixItHint::CreateReplacement(OpLoc, ".");
13421 Diag(OpLoc, diag::err_ovl_no_viable_oper)
13422 << "operator->" << Base->getSourceRange();
13423 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Base);
13424 return ExprError();
13427 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary)
13428 << "->" << Base->getType() << Base->getSourceRange();
13429 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Base);
13430 return ExprError();
13433 Diag(OpLoc, diag::err_ovl_deleted_oper)
13434 << Best->Function->isDeleted()
13436 << getDeletedOrUnavailableSuffix(Best->Function)
13437 << Base->getSourceRange();
13438 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Base);
13439 return ExprError();
13442 CheckMemberOperatorAccess(OpLoc, Base, nullptr, Best->FoundDecl);
13444 // Convert the object parameter.
13445 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
13446 ExprResult BaseResult =
13447 PerformObjectArgumentInitialization(Base, /*Qualifier=*/nullptr,
13448 Best->FoundDecl, Method);
13449 if (BaseResult.isInvalid())
13450 return ExprError();
13451 Base = BaseResult.get();
13453 // Build the operator call.
13454 ExprResult FnExpr = CreateFunctionRefExpr(*this, Method, Best->FoundDecl,
13455 Base, HadMultipleCandidates, OpLoc);
13456 if (FnExpr.isInvalid())
13457 return ExprError();
13459 QualType ResultTy = Method->getReturnType();
13460 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
13461 ResultTy = ResultTy.getNonLValueExprType(Context);
13462 CXXOperatorCallExpr *TheCall =
13463 new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr.get(),
13464 Base, ResultTy, VK, OpLoc, FPOptions());
13466 if (CheckCallReturnType(Method->getReturnType(), OpLoc, TheCall, Method))
13467 return ExprError();
13469 if (CheckFunctionCall(Method, TheCall,
13470 Method->getType()->castAs<FunctionProtoType>()))
13471 return ExprError();
13473 return MaybeBindToTemporary(TheCall);
13476 /// BuildLiteralOperatorCall - Build a UserDefinedLiteral by creating a call to
13477 /// a literal operator described by the provided lookup results.
13478 ExprResult Sema::BuildLiteralOperatorCall(LookupResult &R,
13479 DeclarationNameInfo &SuffixInfo,
13480 ArrayRef<Expr*> Args,
13481 SourceLocation LitEndLoc,
13482 TemplateArgumentListInfo *TemplateArgs) {
13483 SourceLocation UDSuffixLoc = SuffixInfo.getCXXLiteralOperatorNameLoc();
13485 OverloadCandidateSet CandidateSet(UDSuffixLoc,
13486 OverloadCandidateSet::CSK_Normal);
13487 AddFunctionCandidates(R.asUnresolvedSet(), Args, CandidateSet, TemplateArgs,
13488 /*SuppressUserConversions=*/true);
13490 bool HadMultipleCandidates = (CandidateSet.size() > 1);
13492 // Perform overload resolution. This will usually be trivial, but might need
13493 // to perform substitutions for a literal operator template.
13494 OverloadCandidateSet::iterator Best;
13495 switch (CandidateSet.BestViableFunction(*this, UDSuffixLoc, Best)) {
13500 case OR_No_Viable_Function:
13501 Diag(UDSuffixLoc, diag::err_ovl_no_viable_function_in_call)
13502 << R.getLookupName();
13503 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
13504 return ExprError();
13507 Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName();
13508 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args);
13509 return ExprError();
13512 FunctionDecl *FD = Best->Function;
13513 ExprResult Fn = CreateFunctionRefExpr(*this, FD, Best->FoundDecl,
13514 nullptr, HadMultipleCandidates,
13515 SuffixInfo.getLoc(),
13516 SuffixInfo.getInfo());
13517 if (Fn.isInvalid())
13520 // Check the argument types. This should almost always be a no-op, except
13521 // that array-to-pointer decay is applied to string literals.
13523 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
13524 ExprResult InputInit = PerformCopyInitialization(
13525 InitializedEntity::InitializeParameter(Context, FD->getParamDecl(ArgIdx)),
13526 SourceLocation(), Args[ArgIdx]);
13527 if (InputInit.isInvalid())
13529 ConvArgs[ArgIdx] = InputInit.get();
13532 QualType ResultTy = FD->getReturnType();
13533 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
13534 ResultTy = ResultTy.getNonLValueExprType(Context);
13536 UserDefinedLiteral *UDL =
13537 new (Context) UserDefinedLiteral(Context, Fn.get(),
13538 llvm::makeArrayRef(ConvArgs, Args.size()),
13539 ResultTy, VK, LitEndLoc, UDSuffixLoc);
13541 if (CheckCallReturnType(FD->getReturnType(), UDSuffixLoc, UDL, FD))
13542 return ExprError();
13544 if (CheckFunctionCall(FD, UDL, nullptr))
13545 return ExprError();
13547 return MaybeBindToTemporary(UDL);
13550 /// Build a call to 'begin' or 'end' for a C++11 for-range statement. If the
13551 /// given LookupResult is non-empty, it is assumed to describe a member which
13552 /// will be invoked. Otherwise, the function will be found via argument
13553 /// dependent lookup.
13554 /// CallExpr is set to a valid expression and FRS_Success returned on success,
13555 /// otherwise CallExpr is set to ExprError() and some non-success value
13557 Sema::ForRangeStatus
13558 Sema::BuildForRangeBeginEndCall(SourceLocation Loc,
13559 SourceLocation RangeLoc,
13560 const DeclarationNameInfo &NameInfo,
13561 LookupResult &MemberLookup,
13562 OverloadCandidateSet *CandidateSet,
13563 Expr *Range, ExprResult *CallExpr) {
13564 Scope *S = nullptr;
13566 CandidateSet->clear(OverloadCandidateSet::CSK_Normal);
13567 if (!MemberLookup.empty()) {
13568 ExprResult MemberRef =
13569 BuildMemberReferenceExpr(Range, Range->getType(), Loc,
13570 /*IsPtr=*/false, CXXScopeSpec(),
13571 /*TemplateKWLoc=*/SourceLocation(),
13572 /*FirstQualifierInScope=*/nullptr,
13574 /*TemplateArgs=*/nullptr, S);
13575 if (MemberRef.isInvalid()) {
13576 *CallExpr = ExprError();
13577 return FRS_DiagnosticIssued;
13579 *CallExpr = ActOnCallExpr(S, MemberRef.get(), Loc, None, Loc, nullptr);
13580 if (CallExpr->isInvalid()) {
13581 *CallExpr = ExprError();
13582 return FRS_DiagnosticIssued;
13585 UnresolvedSet<0> FoundNames;
13586 UnresolvedLookupExpr *Fn =
13587 UnresolvedLookupExpr::Create(Context, /*NamingClass=*/nullptr,
13588 NestedNameSpecifierLoc(), NameInfo,
13589 /*NeedsADL=*/true, /*Overloaded=*/false,
13590 FoundNames.begin(), FoundNames.end());
13592 bool CandidateSetError = buildOverloadedCallSet(S, Fn, Fn, Range, Loc,
13593 CandidateSet, CallExpr);
13594 if (CandidateSet->empty() || CandidateSetError) {
13595 *CallExpr = ExprError();
13596 return FRS_NoViableFunction;
13598 OverloadCandidateSet::iterator Best;
13599 OverloadingResult OverloadResult =
13600 CandidateSet->BestViableFunction(*this, Fn->getLocStart(), Best);
13602 if (OverloadResult == OR_No_Viable_Function) {
13603 *CallExpr = ExprError();
13604 return FRS_NoViableFunction;
13606 *CallExpr = FinishOverloadedCallExpr(*this, S, Fn, Fn, Loc, Range,
13607 Loc, nullptr, CandidateSet, &Best,
13609 /*AllowTypoCorrection=*/false);
13610 if (CallExpr->isInvalid() || OverloadResult != OR_Success) {
13611 *CallExpr = ExprError();
13612 return FRS_DiagnosticIssued;
13615 return FRS_Success;
13619 /// FixOverloadedFunctionReference - E is an expression that refers to
13620 /// a C++ overloaded function (possibly with some parentheses and
13621 /// perhaps a '&' around it). We have resolved the overloaded function
13622 /// to the function declaration Fn, so patch up the expression E to
13623 /// refer (possibly indirectly) to Fn. Returns the new expr.
13624 Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found,
13625 FunctionDecl *Fn) {
13626 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
13627 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(),
13629 if (SubExpr == PE->getSubExpr())
13632 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr);
13635 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
13636 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(),
13638 assert(Context.hasSameType(ICE->getSubExpr()->getType(),
13639 SubExpr->getType()) &&
13640 "Implicit cast type cannot be determined from overload");
13641 assert(ICE->path_empty() && "fixing up hierarchy conversion?");
13642 if (SubExpr == ICE->getSubExpr())
13645 return ImplicitCastExpr::Create(Context, ICE->getType(),
13646 ICE->getCastKind(),
13648 ICE->getValueKind());
13651 if (auto *GSE = dyn_cast<GenericSelectionExpr>(E)) {
13652 if (!GSE->isResultDependent()) {
13654 FixOverloadedFunctionReference(GSE->getResultExpr(), Found, Fn);
13655 if (SubExpr == GSE->getResultExpr())
13658 // Replace the resulting type information before rebuilding the generic
13659 // selection expression.
13660 ArrayRef<Expr *> A = GSE->getAssocExprs();
13661 SmallVector<Expr *, 4> AssocExprs(A.begin(), A.end());
13662 unsigned ResultIdx = GSE->getResultIndex();
13663 AssocExprs[ResultIdx] = SubExpr;
13665 return new (Context) GenericSelectionExpr(
13666 Context, GSE->getGenericLoc(), GSE->getControllingExpr(),
13667 GSE->getAssocTypeSourceInfos(), AssocExprs, GSE->getDefaultLoc(),
13668 GSE->getRParenLoc(), GSE->containsUnexpandedParameterPack(),
13671 // Rather than fall through to the unreachable, return the original generic
13672 // selection expression.
13676 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) {
13677 assert(UnOp->getOpcode() == UO_AddrOf &&
13678 "Can only take the address of an overloaded function");
13679 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) {
13680 if (Method->isStatic()) {
13681 // Do nothing: static member functions aren't any different
13682 // from non-member functions.
13684 // Fix the subexpression, which really has to be an
13685 // UnresolvedLookupExpr holding an overloaded member function
13687 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(),
13689 if (SubExpr == UnOp->getSubExpr())
13692 assert(isa<DeclRefExpr>(SubExpr)
13693 && "fixed to something other than a decl ref");
13694 assert(cast<DeclRefExpr>(SubExpr)->getQualifier()
13695 && "fixed to a member ref with no nested name qualifier");
13697 // We have taken the address of a pointer to member
13698 // function. Perform the computation here so that we get the
13699 // appropriate pointer to member type.
13701 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext()));
13702 QualType MemPtrType
13703 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr());
13704 // Under the MS ABI, lock down the inheritance model now.
13705 if (Context.getTargetInfo().getCXXABI().isMicrosoft())
13706 (void)isCompleteType(UnOp->getOperatorLoc(), MemPtrType);
13708 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, MemPtrType,
13709 VK_RValue, OK_Ordinary,
13710 UnOp->getOperatorLoc(), false);
13713 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(),
13715 if (SubExpr == UnOp->getSubExpr())
13718 return new (Context) UnaryOperator(SubExpr, UO_AddrOf,
13719 Context.getPointerType(SubExpr->getType()),
13720 VK_RValue, OK_Ordinary,
13721 UnOp->getOperatorLoc(), false);
13724 // C++ [except.spec]p17:
13725 // An exception-specification is considered to be needed when:
13726 // - in an expression the function is the unique lookup result or the
13727 // selected member of a set of overloaded functions
13728 if (auto *FPT = Fn->getType()->getAs<FunctionProtoType>())
13729 ResolveExceptionSpec(E->getExprLoc(), FPT);
13731 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) {
13732 // FIXME: avoid copy.
13733 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
13734 if (ULE->hasExplicitTemplateArgs()) {
13735 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer);
13736 TemplateArgs = &TemplateArgsBuffer;
13739 DeclRefExpr *DRE = DeclRefExpr::Create(Context,
13740 ULE->getQualifierLoc(),
13741 ULE->getTemplateKeywordLoc(),
13743 /*enclosing*/ false, // FIXME?
13749 MarkDeclRefReferenced(DRE);
13750 DRE->setHadMultipleCandidates(ULE->getNumDecls() > 1);
13754 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) {
13755 // FIXME: avoid copy.
13756 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
13757 if (MemExpr->hasExplicitTemplateArgs()) {
13758 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer);
13759 TemplateArgs = &TemplateArgsBuffer;
13764 // If we're filling in a static method where we used to have an
13765 // implicit member access, rewrite to a simple decl ref.
13766 if (MemExpr->isImplicitAccess()) {
13767 if (cast<CXXMethodDecl>(Fn)->isStatic()) {
13768 DeclRefExpr *DRE = DeclRefExpr::Create(Context,
13769 MemExpr->getQualifierLoc(),
13770 MemExpr->getTemplateKeywordLoc(),
13772 /*enclosing*/ false,
13773 MemExpr->getMemberLoc(),
13778 MarkDeclRefReferenced(DRE);
13779 DRE->setHadMultipleCandidates(MemExpr->getNumDecls() > 1);
13782 SourceLocation Loc = MemExpr->getMemberLoc();
13783 if (MemExpr->getQualifier())
13784 Loc = MemExpr->getQualifierLoc().getBeginLoc();
13785 CheckCXXThisCapture(Loc);
13786 Base = new (Context) CXXThisExpr(Loc,
13787 MemExpr->getBaseType(),
13788 /*isImplicit=*/true);
13791 Base = MemExpr->getBase();
13793 ExprValueKind valueKind;
13795 if (cast<CXXMethodDecl>(Fn)->isStatic()) {
13796 valueKind = VK_LValue;
13797 type = Fn->getType();
13799 valueKind = VK_RValue;
13800 type = Context.BoundMemberTy;
13803 MemberExpr *ME = MemberExpr::Create(
13804 Context, Base, MemExpr->isArrow(), MemExpr->getOperatorLoc(),
13805 MemExpr->getQualifierLoc(), MemExpr->getTemplateKeywordLoc(), Fn, Found,
13806 MemExpr->getMemberNameInfo(), TemplateArgs, type, valueKind,
13808 ME->setHadMultipleCandidates(true);
13809 MarkMemberReferenced(ME);
13813 llvm_unreachable("Invalid reference to overloaded function");
13816 ExprResult Sema::FixOverloadedFunctionReference(ExprResult E,
13817 DeclAccessPair Found,
13818 FunctionDecl *Fn) {
13819 return FixOverloadedFunctionReference(E.get(), Found, Fn);