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/STLExtras.h"
33 #include "llvm/ADT/SmallPtrSet.h"
34 #include "llvm/ADT/SmallString.h"
38 using namespace clang;
41 static bool functionHasPassObjectSizeParams(const FunctionDecl *FD) {
42 return llvm::any_of(FD->parameters(), [](const ParmVarDecl *P) {
43 return P->hasAttr<PassObjectSizeAttr>();
47 /// A convenience routine for creating a decayed reference to a function.
49 CreateFunctionRefExpr(Sema &S, FunctionDecl *Fn, NamedDecl *FoundDecl,
50 bool HadMultipleCandidates,
51 SourceLocation Loc = SourceLocation(),
52 const DeclarationNameLoc &LocInfo = DeclarationNameLoc()){
53 if (S.DiagnoseUseOfDecl(FoundDecl, Loc))
55 // If FoundDecl is different from Fn (such as if one is a template
56 // and the other a specialization), make sure DiagnoseUseOfDecl is
58 // FIXME: This would be more comprehensively addressed by modifying
59 // DiagnoseUseOfDecl to accept both the FoundDecl and the decl
61 if (FoundDecl != Fn && S.DiagnoseUseOfDecl(Fn, Loc))
63 if (auto *FPT = Fn->getType()->getAs<FunctionProtoType>())
64 S.ResolveExceptionSpec(Loc, FPT);
65 DeclRefExpr *DRE = new (S.Context) DeclRefExpr(Fn, false, Fn->getType(),
66 VK_LValue, Loc, LocInfo);
67 if (HadMultipleCandidates)
68 DRE->setHadMultipleCandidates(true);
70 S.MarkDeclRefReferenced(DRE);
71 return S.ImpCastExprToType(DRE, S.Context.getPointerType(DRE->getType()),
72 CK_FunctionToPointerDecay);
75 static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
76 bool InOverloadResolution,
77 StandardConversionSequence &SCS,
79 bool AllowObjCWritebackConversion);
81 static bool IsTransparentUnionStandardConversion(Sema &S, Expr* From,
83 bool InOverloadResolution,
84 StandardConversionSequence &SCS,
86 static OverloadingResult
87 IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
88 UserDefinedConversionSequence& User,
89 OverloadCandidateSet& Conversions,
91 bool AllowObjCConversionOnExplicit);
94 static ImplicitConversionSequence::CompareKind
95 CompareStandardConversionSequences(Sema &S, SourceLocation Loc,
96 const StandardConversionSequence& SCS1,
97 const StandardConversionSequence& SCS2);
99 static ImplicitConversionSequence::CompareKind
100 CompareQualificationConversions(Sema &S,
101 const StandardConversionSequence& SCS1,
102 const StandardConversionSequence& SCS2);
104 static ImplicitConversionSequence::CompareKind
105 CompareDerivedToBaseConversions(Sema &S, SourceLocation Loc,
106 const StandardConversionSequence& SCS1,
107 const StandardConversionSequence& SCS2);
109 /// GetConversionRank - Retrieve the implicit conversion rank
110 /// corresponding to the given implicit conversion kind.
111 ImplicitConversionRank clang::GetConversionRank(ImplicitConversionKind Kind) {
112 static const ImplicitConversionRank
113 Rank[(int)ICK_Num_Conversion_Kinds] = {
134 ICR_Complex_Real_Conversion,
137 ICR_Writeback_Conversion,
138 ICR_Exact_Match, // NOTE(gbiv): This may not be completely right --
139 // it was omitted by the patch that added
140 // ICK_Zero_Event_Conversion
142 ICR_C_Conversion_Extension
144 return Rank[(int)Kind];
147 /// GetImplicitConversionName - Return the name of this kind of
148 /// implicit conversion.
149 static const char* GetImplicitConversionName(ImplicitConversionKind Kind) {
150 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = {
154 "Function-to-pointer",
155 "Function pointer conversion",
157 "Integral promotion",
158 "Floating point promotion",
160 "Integral conversion",
161 "Floating conversion",
162 "Complex conversion",
163 "Floating-integral conversion",
164 "Pointer conversion",
165 "Pointer-to-member conversion",
166 "Boolean conversion",
167 "Compatible-types conversion",
168 "Derived-to-base conversion",
171 "Complex-real conversion",
172 "Block Pointer conversion",
173 "Transparent Union Conversion",
174 "Writeback conversion",
175 "OpenCL Zero Event Conversion",
176 "C specific type conversion",
177 "Incompatible pointer conversion"
182 /// StandardConversionSequence - Set the standard conversion
183 /// sequence to the identity conversion.
184 void StandardConversionSequence::setAsIdentityConversion() {
185 First = ICK_Identity;
186 Second = ICK_Identity;
187 Third = ICK_Identity;
188 DeprecatedStringLiteralToCharPtr = false;
189 QualificationIncludesObjCLifetime = false;
190 ReferenceBinding = false;
191 DirectBinding = false;
192 IsLvalueReference = true;
193 BindsToFunctionLvalue = false;
194 BindsToRvalue = false;
195 BindsImplicitObjectArgumentWithoutRefQualifier = false;
196 ObjCLifetimeConversionBinding = false;
197 CopyConstructor = nullptr;
200 /// getRank - Retrieve the rank of this standard conversion sequence
201 /// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the
202 /// implicit conversions.
203 ImplicitConversionRank StandardConversionSequence::getRank() const {
204 ImplicitConversionRank Rank = ICR_Exact_Match;
205 if (GetConversionRank(First) > Rank)
206 Rank = GetConversionRank(First);
207 if (GetConversionRank(Second) > Rank)
208 Rank = GetConversionRank(Second);
209 if (GetConversionRank(Third) > Rank)
210 Rank = GetConversionRank(Third);
214 /// isPointerConversionToBool - Determines whether this conversion is
215 /// a conversion of a pointer or pointer-to-member to bool. This is
216 /// used as part of the ranking of standard conversion sequences
217 /// (C++ 13.3.3.2p4).
218 bool StandardConversionSequence::isPointerConversionToBool() const {
219 // Note that FromType has not necessarily been transformed by the
220 // array-to-pointer or function-to-pointer implicit conversions, so
221 // check for their presence as well as checking whether FromType is
223 if (getToType(1)->isBooleanType() &&
224 (getFromType()->isPointerType() ||
225 getFromType()->isObjCObjectPointerType() ||
226 getFromType()->isBlockPointerType() ||
227 getFromType()->isNullPtrType() ||
228 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer))
234 /// isPointerConversionToVoidPointer - Determines whether this
235 /// conversion is a conversion of a pointer to a void pointer. This is
236 /// used as part of the ranking of standard conversion sequences (C++
239 StandardConversionSequence::
240 isPointerConversionToVoidPointer(ASTContext& Context) const {
241 QualType FromType = getFromType();
242 QualType ToType = getToType(1);
244 // Note that FromType has not necessarily been transformed by the
245 // array-to-pointer implicit conversion, so check for its presence
246 // and redo the conversion to get a pointer.
247 if (First == ICK_Array_To_Pointer)
248 FromType = Context.getArrayDecayedType(FromType);
250 if (Second == ICK_Pointer_Conversion && FromType->isAnyPointerType())
251 if (const PointerType* ToPtrType = ToType->getAs<PointerType>())
252 return ToPtrType->getPointeeType()->isVoidType();
257 /// Skip any implicit casts which could be either part of a narrowing conversion
258 /// or after one in an implicit conversion.
259 static const Expr *IgnoreNarrowingConversion(const Expr *Converted) {
260 while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Converted)) {
261 switch (ICE->getCastKind()) {
263 case CK_IntegralCast:
264 case CK_IntegralToBoolean:
265 case CK_IntegralToFloating:
266 case CK_BooleanToSignedIntegral:
267 case CK_FloatingToIntegral:
268 case CK_FloatingToBoolean:
269 case CK_FloatingCast:
270 Converted = ICE->getSubExpr();
281 /// Check if this standard conversion sequence represents a narrowing
282 /// conversion, according to C++11 [dcl.init.list]p7.
284 /// \param Ctx The AST context.
285 /// \param Converted The result of applying this standard conversion sequence.
286 /// \param ConstantValue If this is an NK_Constant_Narrowing conversion, the
287 /// value of the expression prior to the narrowing conversion.
288 /// \param ConstantType If this is an NK_Constant_Narrowing conversion, the
289 /// type of the expression prior to the narrowing conversion.
291 StandardConversionSequence::getNarrowingKind(ASTContext &Ctx,
292 const Expr *Converted,
293 APValue &ConstantValue,
294 QualType &ConstantType) const {
295 assert(Ctx.getLangOpts().CPlusPlus && "narrowing check outside C++");
297 // C++11 [dcl.init.list]p7:
298 // A narrowing conversion is an implicit conversion ...
299 QualType FromType = getToType(0);
300 QualType ToType = getToType(1);
302 // A conversion to an enumeration type is narrowing if the conversion to
303 // the underlying type is narrowing. This only arises for expressions of
304 // the form 'Enum{init}'.
305 if (auto *ET = ToType->getAs<EnumType>())
306 ToType = ET->getDecl()->getIntegerType();
309 // 'bool' is an integral type; dispatch to the right place to handle it.
310 case ICK_Boolean_Conversion:
311 if (FromType->isRealFloatingType())
312 goto FloatingIntegralConversion;
313 if (FromType->isIntegralOrUnscopedEnumerationType())
314 goto IntegralConversion;
315 // Boolean conversions can be from pointers and pointers to members
316 // [conv.bool], and those aren't considered narrowing conversions.
317 return NK_Not_Narrowing;
319 // -- from a floating-point type to an integer type, or
321 // -- from an integer type or unscoped enumeration type to a floating-point
322 // type, except where the source is a constant expression and the actual
323 // value after conversion will fit into the target type and will produce
324 // the original value when converted back to the original type, or
325 case ICK_Floating_Integral:
326 FloatingIntegralConversion:
327 if (FromType->isRealFloatingType() && ToType->isIntegralType(Ctx)) {
328 return NK_Type_Narrowing;
329 } else if (FromType->isIntegralType(Ctx) && ToType->isRealFloatingType()) {
330 llvm::APSInt IntConstantValue;
331 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
333 // If it's value-dependent, we can't tell whether it's narrowing.
334 if (Initializer->isValueDependent())
335 return NK_Dependent_Narrowing;
338 Initializer->isIntegerConstantExpr(IntConstantValue, Ctx)) {
339 // Convert the integer to the floating type.
340 llvm::APFloat Result(Ctx.getFloatTypeSemantics(ToType));
341 Result.convertFromAPInt(IntConstantValue, IntConstantValue.isSigned(),
342 llvm::APFloat::rmNearestTiesToEven);
344 llvm::APSInt ConvertedValue = IntConstantValue;
346 Result.convertToInteger(ConvertedValue,
347 llvm::APFloat::rmTowardZero, &ignored);
348 // If the resulting value is different, this was a narrowing conversion.
349 if (IntConstantValue != ConvertedValue) {
350 ConstantValue = APValue(IntConstantValue);
351 ConstantType = Initializer->getType();
352 return NK_Constant_Narrowing;
355 // Variables are always narrowings.
356 return NK_Variable_Narrowing;
359 return NK_Not_Narrowing;
361 // -- from long double to double or float, or from double to float, except
362 // where the source is a constant expression and the actual value after
363 // conversion is within the range of values that can be represented (even
364 // if it cannot be represented exactly), or
365 case ICK_Floating_Conversion:
366 if (FromType->isRealFloatingType() && ToType->isRealFloatingType() &&
367 Ctx.getFloatingTypeOrder(FromType, ToType) == 1) {
368 // FromType is larger than ToType.
369 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
371 // If it's value-dependent, we can't tell whether it's narrowing.
372 if (Initializer->isValueDependent())
373 return NK_Dependent_Narrowing;
375 if (Initializer->isCXX11ConstantExpr(Ctx, &ConstantValue)) {
377 assert(ConstantValue.isFloat());
378 llvm::APFloat FloatVal = ConstantValue.getFloat();
379 // Convert the source value into the target type.
381 llvm::APFloat::opStatus ConvertStatus = FloatVal.convert(
382 Ctx.getFloatTypeSemantics(ToType),
383 llvm::APFloat::rmNearestTiesToEven, &ignored);
384 // If there was no overflow, the source value is within the range of
385 // values that can be represented.
386 if (ConvertStatus & llvm::APFloat::opOverflow) {
387 ConstantType = Initializer->getType();
388 return NK_Constant_Narrowing;
391 return NK_Variable_Narrowing;
394 return NK_Not_Narrowing;
396 // -- from an integer type or unscoped enumeration type to an integer type
397 // that cannot represent all the values of the original type, except where
398 // the source is a constant expression and the actual value after
399 // conversion will fit into the target type and will produce the original
400 // value when converted back to the original type.
401 case ICK_Integral_Conversion:
402 IntegralConversion: {
403 assert(FromType->isIntegralOrUnscopedEnumerationType());
404 assert(ToType->isIntegralOrUnscopedEnumerationType());
405 const bool FromSigned = FromType->isSignedIntegerOrEnumerationType();
406 const unsigned FromWidth = Ctx.getIntWidth(FromType);
407 const bool ToSigned = ToType->isSignedIntegerOrEnumerationType();
408 const unsigned ToWidth = Ctx.getIntWidth(ToType);
410 if (FromWidth > ToWidth ||
411 (FromWidth == ToWidth && FromSigned != ToSigned) ||
412 (FromSigned && !ToSigned)) {
413 // Not all values of FromType can be represented in ToType.
414 llvm::APSInt InitializerValue;
415 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
417 // If it's value-dependent, we can't tell whether it's narrowing.
418 if (Initializer->isValueDependent())
419 return NK_Dependent_Narrowing;
421 if (!Initializer->isIntegerConstantExpr(InitializerValue, Ctx)) {
422 // Such conversions on variables are always narrowing.
423 return NK_Variable_Narrowing;
425 bool Narrowing = false;
426 if (FromWidth < ToWidth) {
427 // Negative -> unsigned is narrowing. Otherwise, more bits is never
429 if (InitializerValue.isSigned() && InitializerValue.isNegative())
432 // Add a bit to the InitializerValue so we don't have to worry about
433 // signed vs. unsigned comparisons.
434 InitializerValue = InitializerValue.extend(
435 InitializerValue.getBitWidth() + 1);
436 // Convert the initializer to and from the target width and signed-ness.
437 llvm::APSInt ConvertedValue = InitializerValue;
438 ConvertedValue = ConvertedValue.trunc(ToWidth);
439 ConvertedValue.setIsSigned(ToSigned);
440 ConvertedValue = ConvertedValue.extend(InitializerValue.getBitWidth());
441 ConvertedValue.setIsSigned(InitializerValue.isSigned());
442 // If the result is different, this was a narrowing conversion.
443 if (ConvertedValue != InitializerValue)
447 ConstantType = Initializer->getType();
448 ConstantValue = APValue(InitializerValue);
449 return NK_Constant_Narrowing;
452 return NK_Not_Narrowing;
456 // Other kinds of conversions are not narrowings.
457 return NK_Not_Narrowing;
461 /// dump - Print this standard conversion sequence to standard
462 /// error. Useful for debugging overloading issues.
463 LLVM_DUMP_METHOD void StandardConversionSequence::dump() const {
464 raw_ostream &OS = llvm::errs();
465 bool PrintedSomething = false;
466 if (First != ICK_Identity) {
467 OS << GetImplicitConversionName(First);
468 PrintedSomething = true;
471 if (Second != ICK_Identity) {
472 if (PrintedSomething) {
475 OS << GetImplicitConversionName(Second);
477 if (CopyConstructor) {
478 OS << " (by copy constructor)";
479 } else if (DirectBinding) {
480 OS << " (direct reference binding)";
481 } else if (ReferenceBinding) {
482 OS << " (reference binding)";
484 PrintedSomething = true;
487 if (Third != ICK_Identity) {
488 if (PrintedSomething) {
491 OS << GetImplicitConversionName(Third);
492 PrintedSomething = true;
495 if (!PrintedSomething) {
496 OS << "No conversions required";
500 /// dump - Print this user-defined conversion sequence to standard
501 /// error. Useful for debugging overloading issues.
502 void UserDefinedConversionSequence::dump() const {
503 raw_ostream &OS = llvm::errs();
504 if (Before.First || Before.Second || Before.Third) {
508 if (ConversionFunction)
509 OS << '\'' << *ConversionFunction << '\'';
511 OS << "aggregate initialization";
512 if (After.First || After.Second || After.Third) {
518 /// dump - Print this implicit conversion sequence to standard
519 /// error. Useful for debugging overloading issues.
520 void ImplicitConversionSequence::dump() const {
521 raw_ostream &OS = llvm::errs();
522 if (isStdInitializerListElement())
523 OS << "Worst std::initializer_list element conversion: ";
524 switch (ConversionKind) {
525 case StandardConversion:
526 OS << "Standard conversion: ";
529 case UserDefinedConversion:
530 OS << "User-defined conversion: ";
533 case EllipsisConversion:
534 OS << "Ellipsis conversion";
536 case AmbiguousConversion:
537 OS << "Ambiguous conversion";
540 OS << "Bad conversion";
547 void AmbiguousConversionSequence::construct() {
548 new (&conversions()) ConversionSet();
551 void AmbiguousConversionSequence::destruct() {
552 conversions().~ConversionSet();
556 AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) {
557 FromTypePtr = O.FromTypePtr;
558 ToTypePtr = O.ToTypePtr;
559 new (&conversions()) ConversionSet(O.conversions());
563 // Structure used by DeductionFailureInfo to store
564 // template argument information.
565 struct DFIArguments {
566 TemplateArgument FirstArg;
567 TemplateArgument SecondArg;
569 // Structure used by DeductionFailureInfo to store
570 // template parameter and template argument information.
571 struct DFIParamWithArguments : DFIArguments {
572 TemplateParameter Param;
574 // Structure used by DeductionFailureInfo to store template argument
575 // information and the index of the problematic call argument.
576 struct DFIDeducedMismatchArgs : DFIArguments {
577 TemplateArgumentList *TemplateArgs;
578 unsigned CallArgIndex;
582 /// \brief Convert from Sema's representation of template deduction information
583 /// to the form used in overload-candidate information.
585 clang::MakeDeductionFailureInfo(ASTContext &Context,
586 Sema::TemplateDeductionResult TDK,
587 TemplateDeductionInfo &Info) {
588 DeductionFailureInfo Result;
589 Result.Result = static_cast<unsigned>(TDK);
590 Result.HasDiagnostic = false;
592 case Sema::TDK_Success:
593 case Sema::TDK_Invalid:
594 case Sema::TDK_InstantiationDepth:
595 case Sema::TDK_TooManyArguments:
596 case Sema::TDK_TooFewArguments:
597 case Sema::TDK_MiscellaneousDeductionFailure:
598 case Sema::TDK_CUDATargetMismatch:
599 Result.Data = nullptr;
602 case Sema::TDK_Incomplete:
603 case Sema::TDK_InvalidExplicitArguments:
604 Result.Data = Info.Param.getOpaqueValue();
607 case Sema::TDK_DeducedMismatch: {
608 // FIXME: Should allocate from normal heap so that we can free this later.
609 auto *Saved = new (Context) DFIDeducedMismatchArgs;
610 Saved->FirstArg = Info.FirstArg;
611 Saved->SecondArg = Info.SecondArg;
612 Saved->TemplateArgs = Info.take();
613 Saved->CallArgIndex = Info.CallArgIndex;
618 case Sema::TDK_NonDeducedMismatch: {
619 // FIXME: Should allocate from normal heap so that we can free this later.
620 DFIArguments *Saved = new (Context) DFIArguments;
621 Saved->FirstArg = Info.FirstArg;
622 Saved->SecondArg = Info.SecondArg;
627 case Sema::TDK_Inconsistent:
628 case Sema::TDK_Underqualified: {
629 // FIXME: Should allocate from normal heap so that we can free this later.
630 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments;
631 Saved->Param = Info.Param;
632 Saved->FirstArg = Info.FirstArg;
633 Saved->SecondArg = Info.SecondArg;
638 case Sema::TDK_SubstitutionFailure:
639 Result.Data = Info.take();
640 if (Info.hasSFINAEDiagnostic()) {
641 PartialDiagnosticAt *Diag = new (Result.Diagnostic) PartialDiagnosticAt(
642 SourceLocation(), PartialDiagnostic::NullDiagnostic());
643 Info.takeSFINAEDiagnostic(*Diag);
644 Result.HasDiagnostic = true;
652 void DeductionFailureInfo::Destroy() {
653 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
654 case Sema::TDK_Success:
655 case Sema::TDK_Invalid:
656 case Sema::TDK_InstantiationDepth:
657 case Sema::TDK_Incomplete:
658 case Sema::TDK_TooManyArguments:
659 case Sema::TDK_TooFewArguments:
660 case Sema::TDK_InvalidExplicitArguments:
661 case Sema::TDK_CUDATargetMismatch:
664 case Sema::TDK_Inconsistent:
665 case Sema::TDK_Underqualified:
666 case Sema::TDK_DeducedMismatch:
667 case Sema::TDK_NonDeducedMismatch:
668 // FIXME: Destroy the data?
672 case Sema::TDK_SubstitutionFailure:
673 // FIXME: Destroy the template argument list?
675 if (PartialDiagnosticAt *Diag = getSFINAEDiagnostic()) {
676 Diag->~PartialDiagnosticAt();
677 HasDiagnostic = false;
682 case Sema::TDK_MiscellaneousDeductionFailure:
687 PartialDiagnosticAt *DeductionFailureInfo::getSFINAEDiagnostic() {
689 return static_cast<PartialDiagnosticAt*>(static_cast<void*>(Diagnostic));
693 TemplateParameter DeductionFailureInfo::getTemplateParameter() {
694 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
695 case Sema::TDK_Success:
696 case Sema::TDK_Invalid:
697 case Sema::TDK_InstantiationDepth:
698 case Sema::TDK_TooManyArguments:
699 case Sema::TDK_TooFewArguments:
700 case Sema::TDK_SubstitutionFailure:
701 case Sema::TDK_DeducedMismatch:
702 case Sema::TDK_NonDeducedMismatch:
703 case Sema::TDK_CUDATargetMismatch:
704 return TemplateParameter();
706 case Sema::TDK_Incomplete:
707 case Sema::TDK_InvalidExplicitArguments:
708 return TemplateParameter::getFromOpaqueValue(Data);
710 case Sema::TDK_Inconsistent:
711 case Sema::TDK_Underqualified:
712 return static_cast<DFIParamWithArguments*>(Data)->Param;
715 case Sema::TDK_MiscellaneousDeductionFailure:
719 return TemplateParameter();
722 TemplateArgumentList *DeductionFailureInfo::getTemplateArgumentList() {
723 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
724 case Sema::TDK_Success:
725 case Sema::TDK_Invalid:
726 case Sema::TDK_InstantiationDepth:
727 case Sema::TDK_TooManyArguments:
728 case Sema::TDK_TooFewArguments:
729 case Sema::TDK_Incomplete:
730 case Sema::TDK_InvalidExplicitArguments:
731 case Sema::TDK_Inconsistent:
732 case Sema::TDK_Underqualified:
733 case Sema::TDK_NonDeducedMismatch:
734 case Sema::TDK_CUDATargetMismatch:
737 case Sema::TDK_DeducedMismatch:
738 return static_cast<DFIDeducedMismatchArgs*>(Data)->TemplateArgs;
740 case Sema::TDK_SubstitutionFailure:
741 return static_cast<TemplateArgumentList*>(Data);
744 case Sema::TDK_MiscellaneousDeductionFailure:
751 const TemplateArgument *DeductionFailureInfo::getFirstArg() {
752 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
753 case Sema::TDK_Success:
754 case Sema::TDK_Invalid:
755 case Sema::TDK_InstantiationDepth:
756 case Sema::TDK_Incomplete:
757 case Sema::TDK_TooManyArguments:
758 case Sema::TDK_TooFewArguments:
759 case Sema::TDK_InvalidExplicitArguments:
760 case Sema::TDK_SubstitutionFailure:
761 case Sema::TDK_CUDATargetMismatch:
764 case Sema::TDK_Inconsistent:
765 case Sema::TDK_Underqualified:
766 case Sema::TDK_DeducedMismatch:
767 case Sema::TDK_NonDeducedMismatch:
768 return &static_cast<DFIArguments*>(Data)->FirstArg;
771 case Sema::TDK_MiscellaneousDeductionFailure:
778 const TemplateArgument *DeductionFailureInfo::getSecondArg() {
779 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
780 case Sema::TDK_Success:
781 case Sema::TDK_Invalid:
782 case Sema::TDK_InstantiationDepth:
783 case Sema::TDK_Incomplete:
784 case Sema::TDK_TooManyArguments:
785 case Sema::TDK_TooFewArguments:
786 case Sema::TDK_InvalidExplicitArguments:
787 case Sema::TDK_SubstitutionFailure:
788 case Sema::TDK_CUDATargetMismatch:
791 case Sema::TDK_Inconsistent:
792 case Sema::TDK_Underqualified:
793 case Sema::TDK_DeducedMismatch:
794 case Sema::TDK_NonDeducedMismatch:
795 return &static_cast<DFIArguments*>(Data)->SecondArg;
798 case Sema::TDK_MiscellaneousDeductionFailure:
805 llvm::Optional<unsigned> DeductionFailureInfo::getCallArgIndex() {
806 if (static_cast<Sema::TemplateDeductionResult>(Result) ==
807 Sema::TDK_DeducedMismatch)
808 return static_cast<DFIDeducedMismatchArgs*>(Data)->CallArgIndex;
813 void OverloadCandidateSet::destroyCandidates() {
814 for (iterator i = begin(), e = end(); i != e; ++i) {
815 for (unsigned ii = 0, ie = i->NumConversions; ii != ie; ++ii)
816 i->Conversions[ii].~ImplicitConversionSequence();
817 if (!i->Viable && i->FailureKind == ovl_fail_bad_deduction)
818 i->DeductionFailure.Destroy();
822 void OverloadCandidateSet::clear() {
824 ConversionSequenceAllocator.Reset();
825 NumInlineSequences = 0;
831 class UnbridgedCastsSet {
836 SmallVector<Entry, 2> Entries;
839 void save(Sema &S, Expr *&E) {
840 assert(E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast));
841 Entry entry = { &E, E };
842 Entries.push_back(entry);
843 E = S.stripARCUnbridgedCast(E);
847 for (SmallVectorImpl<Entry>::iterator
848 i = Entries.begin(), e = Entries.end(); i != e; ++i)
854 /// checkPlaceholderForOverload - Do any interesting placeholder-like
855 /// preprocessing on the given expression.
857 /// \param unbridgedCasts a collection to which to add unbridged casts;
858 /// without this, they will be immediately diagnosed as errors
860 /// Return true on unrecoverable error.
862 checkPlaceholderForOverload(Sema &S, Expr *&E,
863 UnbridgedCastsSet *unbridgedCasts = nullptr) {
864 if (const BuiltinType *placeholder = E->getType()->getAsPlaceholderType()) {
865 // We can't handle overloaded expressions here because overload
866 // resolution might reasonably tweak them.
867 if (placeholder->getKind() == BuiltinType::Overload) return false;
869 // If the context potentially accepts unbridged ARC casts, strip
870 // the unbridged cast and add it to the collection for later restoration.
871 if (placeholder->getKind() == BuiltinType::ARCUnbridgedCast &&
873 unbridgedCasts->save(S, E);
877 // Go ahead and check everything else.
878 ExprResult result = S.CheckPlaceholderExpr(E);
879 if (result.isInvalid())
890 /// checkArgPlaceholdersForOverload - Check a set of call operands for
892 static bool checkArgPlaceholdersForOverload(Sema &S,
894 UnbridgedCastsSet &unbridged) {
895 for (unsigned i = 0, e = Args.size(); i != e; ++i)
896 if (checkPlaceholderForOverload(S, Args[i], &unbridged))
902 // IsOverload - Determine whether the given New declaration is an
903 // overload of the declarations in Old. This routine returns false if
904 // New and Old cannot be overloaded, e.g., if New has the same
905 // signature as some function in Old (C++ 1.3.10) or if the Old
906 // declarations aren't functions (or function templates) at all. When
907 // it does return false, MatchedDecl will point to the decl that New
908 // cannot be overloaded with. This decl may be a UsingShadowDecl on
909 // top of the underlying declaration.
911 // Example: Given the following input:
913 // void f(int, float); // #1
914 // void f(int, int); // #2
915 // int f(int, int); // #3
917 // When we process #1, there is no previous declaration of "f",
918 // so IsOverload will not be used.
920 // When we process #2, Old contains only the FunctionDecl for #1. By
921 // comparing the parameter types, we see that #1 and #2 are overloaded
922 // (since they have different signatures), so this routine returns
923 // false; MatchedDecl is unchanged.
925 // When we process #3, Old is an overload set containing #1 and #2. We
926 // compare the signatures of #3 to #1 (they're overloaded, so we do
927 // nothing) and then #3 to #2. Since the signatures of #3 and #2 are
928 // identical (return types of functions are not part of the
929 // signature), IsOverload returns false and MatchedDecl will be set to
930 // point to the FunctionDecl for #2.
932 // 'NewIsUsingShadowDecl' indicates that 'New' is being introduced
933 // into a class by a using declaration. The rules for whether to hide
934 // shadow declarations ignore some properties which otherwise figure
935 // into a function template's signature.
937 Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old,
938 NamedDecl *&Match, bool NewIsUsingDecl) {
939 for (LookupResult::iterator I = Old.begin(), E = Old.end();
941 NamedDecl *OldD = *I;
943 bool OldIsUsingDecl = false;
944 if (isa<UsingShadowDecl>(OldD)) {
945 OldIsUsingDecl = true;
947 // We can always introduce two using declarations into the same
948 // context, even if they have identical signatures.
949 if (NewIsUsingDecl) continue;
951 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl();
954 // A using-declaration does not conflict with another declaration
955 // if one of them is hidden.
956 if ((OldIsUsingDecl || NewIsUsingDecl) && !isVisible(*I))
959 // If either declaration was introduced by a using declaration,
960 // we'll need to use slightly different rules for matching.
961 // Essentially, these rules are the normal rules, except that
962 // function templates hide function templates with different
963 // return types or template parameter lists.
964 bool UseMemberUsingDeclRules =
965 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord() &&
966 !New->getFriendObjectKind();
968 if (FunctionDecl *OldF = OldD->getAsFunction()) {
969 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) {
970 if (UseMemberUsingDeclRules && OldIsUsingDecl) {
971 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I));
975 if (!isa<FunctionTemplateDecl>(OldD) &&
976 !shouldLinkPossiblyHiddenDecl(*I, New))
982 } else if (isa<UsingDecl>(OldD) || isa<UsingPackDecl>(OldD)) {
983 // We can overload with these, which can show up when doing
984 // redeclaration checks for UsingDecls.
985 assert(Old.getLookupKind() == LookupUsingDeclName);
986 } else if (isa<TagDecl>(OldD)) {
987 // We can always overload with tags by hiding them.
988 } else if (auto *UUD = dyn_cast<UnresolvedUsingValueDecl>(OldD)) {
989 // Optimistically assume that an unresolved using decl will
990 // overload; if it doesn't, we'll have to diagnose during
991 // template instantiation.
993 // Exception: if the scope is dependent and this is not a class
994 // member, the using declaration can only introduce an enumerator.
995 if (UUD->getQualifier()->isDependent() && !UUD->isCXXClassMember()) {
997 return Ovl_NonFunction;
1001 // Only function declarations can be overloaded; object and type
1002 // declarations cannot be overloaded.
1004 return Ovl_NonFunction;
1008 return Ovl_Overload;
1011 bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old,
1012 bool UseMemberUsingDeclRules, bool ConsiderCudaAttrs) {
1013 // C++ [basic.start.main]p2: This function shall not be overloaded.
1017 // MSVCRT user defined entry points cannot be overloaded.
1018 if (New->isMSVCRTEntryPoint())
1021 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate();
1022 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate();
1024 // C++ [temp.fct]p2:
1025 // A function template can be overloaded with other function templates
1026 // and with normal (non-template) functions.
1027 if ((OldTemplate == nullptr) != (NewTemplate == nullptr))
1030 // Is the function New an overload of the function Old?
1031 QualType OldQType = Context.getCanonicalType(Old->getType());
1032 QualType NewQType = Context.getCanonicalType(New->getType());
1034 // Compare the signatures (C++ 1.3.10) of the two functions to
1035 // determine whether they are overloads. If we find any mismatch
1036 // in the signature, they are overloads.
1038 // If either of these functions is a K&R-style function (no
1039 // prototype), then we consider them to have matching signatures.
1040 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) ||
1041 isa<FunctionNoProtoType>(NewQType.getTypePtr()))
1044 const FunctionProtoType *OldType = cast<FunctionProtoType>(OldQType);
1045 const FunctionProtoType *NewType = cast<FunctionProtoType>(NewQType);
1047 // The signature of a function includes the types of its
1048 // parameters (C++ 1.3.10), which includes the presence or absence
1049 // of the ellipsis; see C++ DR 357).
1050 if (OldQType != NewQType &&
1051 (OldType->getNumParams() != NewType->getNumParams() ||
1052 OldType->isVariadic() != NewType->isVariadic() ||
1053 !FunctionParamTypesAreEqual(OldType, NewType)))
1056 // C++ [temp.over.link]p4:
1057 // The signature of a function template consists of its function
1058 // signature, its return type and its template parameter list. The names
1059 // of the template parameters are significant only for establishing the
1060 // relationship between the template parameters and the rest of the
1063 // We check the return type and template parameter lists for function
1064 // templates first; the remaining checks follow.
1066 // However, we don't consider either of these when deciding whether
1067 // a member introduced by a shadow declaration is hidden.
1068 if (!UseMemberUsingDeclRules && NewTemplate &&
1069 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(),
1070 OldTemplate->getTemplateParameters(),
1071 false, TPL_TemplateMatch) ||
1072 OldType->getReturnType() != NewType->getReturnType()))
1075 // If the function is a class member, its signature includes the
1076 // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself.
1078 // As part of this, also check whether one of the member functions
1079 // is static, in which case they are not overloads (C++
1080 // 13.1p2). While not part of the definition of the signature,
1081 // this check is important to determine whether these functions
1082 // can be overloaded.
1083 CXXMethodDecl *OldMethod = dyn_cast<CXXMethodDecl>(Old);
1084 CXXMethodDecl *NewMethod = dyn_cast<CXXMethodDecl>(New);
1085 if (OldMethod && NewMethod &&
1086 !OldMethod->isStatic() && !NewMethod->isStatic()) {
1087 if (OldMethod->getRefQualifier() != NewMethod->getRefQualifier()) {
1088 if (!UseMemberUsingDeclRules &&
1089 (OldMethod->getRefQualifier() == RQ_None ||
1090 NewMethod->getRefQualifier() == RQ_None)) {
1091 // C++0x [over.load]p2:
1092 // - Member function declarations with the same name and the same
1093 // parameter-type-list as well as member function template
1094 // declarations with the same name, the same parameter-type-list, and
1095 // the same template parameter lists cannot be overloaded if any of
1096 // them, but not all, have a ref-qualifier (8.3.5).
1097 Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload)
1098 << NewMethod->getRefQualifier() << OldMethod->getRefQualifier();
1099 Diag(OldMethod->getLocation(), diag::note_previous_declaration);
1104 // We may not have applied the implicit const for a constexpr member
1105 // function yet (because we haven't yet resolved whether this is a static
1106 // or non-static member function). Add it now, on the assumption that this
1107 // is a redeclaration of OldMethod.
1108 unsigned OldQuals = OldMethod->getTypeQualifiers();
1109 unsigned NewQuals = NewMethod->getTypeQualifiers();
1110 if (!getLangOpts().CPlusPlus14 && NewMethod->isConstexpr() &&
1111 !isa<CXXConstructorDecl>(NewMethod))
1112 NewQuals |= Qualifiers::Const;
1114 // We do not allow overloading based off of '__restrict'.
1115 OldQuals &= ~Qualifiers::Restrict;
1116 NewQuals &= ~Qualifiers::Restrict;
1117 if (OldQuals != NewQuals)
1121 // Though pass_object_size is placed on parameters and takes an argument, we
1122 // consider it to be a function-level modifier for the sake of function
1123 // identity. Either the function has one or more parameters with
1124 // pass_object_size or it doesn't.
1125 if (functionHasPassObjectSizeParams(New) !=
1126 functionHasPassObjectSizeParams(Old))
1129 // enable_if attributes are an order-sensitive part of the signature.
1130 for (specific_attr_iterator<EnableIfAttr>
1131 NewI = New->specific_attr_begin<EnableIfAttr>(),
1132 NewE = New->specific_attr_end<EnableIfAttr>(),
1133 OldI = Old->specific_attr_begin<EnableIfAttr>(),
1134 OldE = Old->specific_attr_end<EnableIfAttr>();
1135 NewI != NewE || OldI != OldE; ++NewI, ++OldI) {
1136 if (NewI == NewE || OldI == OldE)
1138 llvm::FoldingSetNodeID NewID, OldID;
1139 NewI->getCond()->Profile(NewID, Context, true);
1140 OldI->getCond()->Profile(OldID, Context, true);
1145 if (getLangOpts().CUDA && ConsiderCudaAttrs) {
1146 // Don't allow overloading of destructors. (In theory we could, but it
1147 // would be a giant change to clang.)
1148 if (isa<CXXDestructorDecl>(New))
1151 CUDAFunctionTarget NewTarget = IdentifyCUDATarget(New),
1152 OldTarget = IdentifyCUDATarget(Old);
1153 if (NewTarget == CFT_InvalidTarget)
1156 assert((OldTarget != CFT_InvalidTarget) && "Unexpected invalid target.");
1158 // Allow overloading of functions with same signature and different CUDA
1159 // target attributes.
1160 return NewTarget != OldTarget;
1163 // The signatures match; this is not an overload.
1167 /// \brief Checks availability of the function depending on the current
1168 /// function context. Inside an unavailable function, unavailability is ignored.
1170 /// \returns true if \arg FD is unavailable and current context is inside
1171 /// an available function, false otherwise.
1172 bool Sema::isFunctionConsideredUnavailable(FunctionDecl *FD) {
1173 if (!FD->isUnavailable())
1176 // Walk up the context of the caller.
1177 Decl *C = cast<Decl>(CurContext);
1179 if (C->isUnavailable())
1181 } while ((C = cast_or_null<Decl>(C->getDeclContext())));
1185 /// \brief Tries a user-defined conversion from From to ToType.
1187 /// Produces an implicit conversion sequence for when a standard conversion
1188 /// is not an option. See TryImplicitConversion for more information.
1189 static ImplicitConversionSequence
1190 TryUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
1191 bool SuppressUserConversions,
1193 bool InOverloadResolution,
1195 bool AllowObjCWritebackConversion,
1196 bool AllowObjCConversionOnExplicit) {
1197 ImplicitConversionSequence ICS;
1199 if (SuppressUserConversions) {
1200 // We're not in the case above, so there is no conversion that
1202 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1206 // Attempt user-defined conversion.
1207 OverloadCandidateSet Conversions(From->getExprLoc(),
1208 OverloadCandidateSet::CSK_Normal);
1209 switch (IsUserDefinedConversion(S, From, ToType, ICS.UserDefined,
1210 Conversions, AllowExplicit,
1211 AllowObjCConversionOnExplicit)) {
1214 ICS.setUserDefined();
1215 // C++ [over.ics.user]p4:
1216 // A conversion of an expression of class type to the same class
1217 // type is given Exact Match rank, and a conversion of an
1218 // expression of class type to a base class of that type is
1219 // given Conversion rank, in spite of the fact that a copy
1220 // constructor (i.e., a user-defined conversion function) is
1221 // called for those cases.
1222 if (CXXConstructorDecl *Constructor
1223 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) {
1225 = S.Context.getCanonicalType(From->getType().getUnqualifiedType());
1227 = S.Context.getCanonicalType(ToType).getUnqualifiedType();
1228 if (Constructor->isCopyConstructor() &&
1229 (FromCanon == ToCanon ||
1230 S.IsDerivedFrom(From->getLocStart(), FromCanon, ToCanon))) {
1231 // Turn this into a "standard" conversion sequence, so that it
1232 // gets ranked with standard conversion sequences.
1233 DeclAccessPair Found = ICS.UserDefined.FoundConversionFunction;
1235 ICS.Standard.setAsIdentityConversion();
1236 ICS.Standard.setFromType(From->getType());
1237 ICS.Standard.setAllToTypes(ToType);
1238 ICS.Standard.CopyConstructor = Constructor;
1239 ICS.Standard.FoundCopyConstructor = Found;
1240 if (ToCanon != FromCanon)
1241 ICS.Standard.Second = ICK_Derived_To_Base;
1248 ICS.Ambiguous.setFromType(From->getType());
1249 ICS.Ambiguous.setToType(ToType);
1250 for (OverloadCandidateSet::iterator Cand = Conversions.begin();
1251 Cand != Conversions.end(); ++Cand)
1253 ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
1257 case OR_No_Viable_Function:
1258 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1265 /// TryImplicitConversion - Attempt to perform an implicit conversion
1266 /// from the given expression (Expr) to the given type (ToType). This
1267 /// function returns an implicit conversion sequence that can be used
1268 /// to perform the initialization. Given
1270 /// void f(float f);
1271 /// void g(int i) { f(i); }
1273 /// this routine would produce an implicit conversion sequence to
1274 /// describe the initialization of f from i, which will be a standard
1275 /// conversion sequence containing an lvalue-to-rvalue conversion (C++
1276 /// 4.1) followed by a floating-integral conversion (C++ 4.9).
1278 /// Note that this routine only determines how the conversion can be
1279 /// performed; it does not actually perform the conversion. As such,
1280 /// it will not produce any diagnostics if no conversion is available,
1281 /// but will instead return an implicit conversion sequence of kind
1282 /// "BadConversion".
1284 /// If @p SuppressUserConversions, then user-defined conversions are
1286 /// If @p AllowExplicit, then explicit user-defined conversions are
1289 /// \param AllowObjCWritebackConversion Whether we allow the Objective-C
1290 /// writeback conversion, which allows __autoreleasing id* parameters to
1291 /// be initialized with __strong id* or __weak id* arguments.
1292 static ImplicitConversionSequence
1293 TryImplicitConversion(Sema &S, Expr *From, QualType ToType,
1294 bool SuppressUserConversions,
1296 bool InOverloadResolution,
1298 bool AllowObjCWritebackConversion,
1299 bool AllowObjCConversionOnExplicit) {
1300 ImplicitConversionSequence ICS;
1301 if (IsStandardConversion(S, From, ToType, InOverloadResolution,
1302 ICS.Standard, CStyle, AllowObjCWritebackConversion)){
1307 if (!S.getLangOpts().CPlusPlus) {
1308 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1312 // C++ [over.ics.user]p4:
1313 // A conversion of an expression of class type to the same class
1314 // type is given Exact Match rank, and a conversion of an
1315 // expression of class type to a base class of that type is
1316 // given Conversion rank, in spite of the fact that a copy/move
1317 // constructor (i.e., a user-defined conversion function) is
1318 // called for those cases.
1319 QualType FromType = From->getType();
1320 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() &&
1321 (S.Context.hasSameUnqualifiedType(FromType, ToType) ||
1322 S.IsDerivedFrom(From->getLocStart(), FromType, ToType))) {
1324 ICS.Standard.setAsIdentityConversion();
1325 ICS.Standard.setFromType(FromType);
1326 ICS.Standard.setAllToTypes(ToType);
1328 // We don't actually check at this point whether there is a valid
1329 // copy/move constructor, since overloading just assumes that it
1330 // exists. When we actually perform initialization, we'll find the
1331 // appropriate constructor to copy the returned object, if needed.
1332 ICS.Standard.CopyConstructor = nullptr;
1334 // Determine whether this is considered a derived-to-base conversion.
1335 if (!S.Context.hasSameUnqualifiedType(FromType, ToType))
1336 ICS.Standard.Second = ICK_Derived_To_Base;
1341 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
1342 AllowExplicit, InOverloadResolution, CStyle,
1343 AllowObjCWritebackConversion,
1344 AllowObjCConversionOnExplicit);
1347 ImplicitConversionSequence
1348 Sema::TryImplicitConversion(Expr *From, QualType ToType,
1349 bool SuppressUserConversions,
1351 bool InOverloadResolution,
1353 bool AllowObjCWritebackConversion) {
1354 return ::TryImplicitConversion(*this, From, ToType,
1355 SuppressUserConversions, AllowExplicit,
1356 InOverloadResolution, CStyle,
1357 AllowObjCWritebackConversion,
1358 /*AllowObjCConversionOnExplicit=*/false);
1361 /// PerformImplicitConversion - Perform an implicit conversion of the
1362 /// expression From to the type ToType. Returns the
1363 /// converted expression. Flavor is the kind of conversion we're
1364 /// performing, used in the error message. If @p AllowExplicit,
1365 /// explicit user-defined conversions are permitted.
1367 Sema::PerformImplicitConversion(Expr *From, QualType ToType,
1368 AssignmentAction Action, bool AllowExplicit) {
1369 ImplicitConversionSequence ICS;
1370 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS);
1374 Sema::PerformImplicitConversion(Expr *From, QualType ToType,
1375 AssignmentAction Action, bool AllowExplicit,
1376 ImplicitConversionSequence& ICS) {
1377 if (checkPlaceholderForOverload(*this, From))
1380 // Objective-C ARC: Determine whether we will allow the writeback conversion.
1381 bool AllowObjCWritebackConversion
1382 = getLangOpts().ObjCAutoRefCount &&
1383 (Action == AA_Passing || Action == AA_Sending);
1384 if (getLangOpts().ObjC1)
1385 CheckObjCBridgeRelatedConversions(From->getLocStart(),
1386 ToType, From->getType(), From);
1387 ICS = ::TryImplicitConversion(*this, From, ToType,
1388 /*SuppressUserConversions=*/false,
1390 /*InOverloadResolution=*/false,
1392 AllowObjCWritebackConversion,
1393 /*AllowObjCConversionOnExplicit=*/false);
1394 return PerformImplicitConversion(From, ToType, ICS, Action);
1397 /// \brief Determine whether the conversion from FromType to ToType is a valid
1398 /// conversion that strips "noexcept" or "noreturn" off the nested function
1400 bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
1401 QualType &ResultTy) {
1402 if (Context.hasSameUnqualifiedType(FromType, ToType))
1405 // Permit the conversion F(t __attribute__((noreturn))) -> F(t)
1406 // or F(t noexcept) -> F(t)
1407 // where F adds one of the following at most once:
1409 // - a member pointer
1410 // - a block pointer
1411 // Changes here need matching changes in FindCompositePointerType.
1412 CanQualType CanTo = Context.getCanonicalType(ToType);
1413 CanQualType CanFrom = Context.getCanonicalType(FromType);
1414 Type::TypeClass TyClass = CanTo->getTypeClass();
1415 if (TyClass != CanFrom->getTypeClass()) return false;
1416 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) {
1417 if (TyClass == Type::Pointer) {
1418 CanTo = CanTo.getAs<PointerType>()->getPointeeType();
1419 CanFrom = CanFrom.getAs<PointerType>()->getPointeeType();
1420 } else if (TyClass == Type::BlockPointer) {
1421 CanTo = CanTo.getAs<BlockPointerType>()->getPointeeType();
1422 CanFrom = CanFrom.getAs<BlockPointerType>()->getPointeeType();
1423 } else if (TyClass == Type::MemberPointer) {
1424 auto ToMPT = CanTo.getAs<MemberPointerType>();
1425 auto FromMPT = CanFrom.getAs<MemberPointerType>();
1426 // A function pointer conversion cannot change the class of the function.
1427 if (ToMPT->getClass() != FromMPT->getClass())
1429 CanTo = ToMPT->getPointeeType();
1430 CanFrom = FromMPT->getPointeeType();
1435 TyClass = CanTo->getTypeClass();
1436 if (TyClass != CanFrom->getTypeClass()) return false;
1437 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto)
1441 const auto *FromFn = cast<FunctionType>(CanFrom);
1442 FunctionType::ExtInfo FromEInfo = FromFn->getExtInfo();
1444 const auto *ToFn = cast<FunctionType>(CanTo);
1445 FunctionType::ExtInfo ToEInfo = ToFn->getExtInfo();
1447 bool Changed = false;
1449 // Drop 'noreturn' if not present in target type.
1450 if (FromEInfo.getNoReturn() && !ToEInfo.getNoReturn()) {
1451 FromFn = Context.adjustFunctionType(FromFn, FromEInfo.withNoReturn(false));
1455 // Drop 'noexcept' if not present in target type.
1456 if (const auto *FromFPT = dyn_cast<FunctionProtoType>(FromFn)) {
1457 const auto *ToFPT = cast<FunctionProtoType>(ToFn);
1458 if (FromFPT->isNothrow(Context) && !ToFPT->isNothrow(Context)) {
1459 FromFn = cast<FunctionType>(
1460 Context.getFunctionType(FromFPT->getReturnType(),
1461 FromFPT->getParamTypes(),
1462 FromFPT->getExtProtoInfo().withExceptionSpec(
1463 FunctionProtoType::ExceptionSpecInfo()))
1472 assert(QualType(FromFn, 0).isCanonical());
1473 if (QualType(FromFn, 0) != CanTo) return false;
1479 /// \brief Determine whether the conversion from FromType to ToType is a valid
1480 /// vector conversion.
1482 /// \param ICK Will be set to the vector conversion kind, if this is a vector
1484 static bool IsVectorConversion(Sema &S, QualType FromType,
1485 QualType ToType, ImplicitConversionKind &ICK) {
1486 // We need at least one of these types to be a vector type to have a vector
1488 if (!ToType->isVectorType() && !FromType->isVectorType())
1491 // Identical types require no conversions.
1492 if (S.Context.hasSameUnqualifiedType(FromType, ToType))
1495 // There are no conversions between extended vector types, only identity.
1496 if (ToType->isExtVectorType()) {
1497 // There are no conversions between extended vector types other than the
1498 // identity conversion.
1499 if (FromType->isExtVectorType())
1502 // Vector splat from any arithmetic type to a vector.
1503 if (FromType->isArithmeticType()) {
1504 ICK = ICK_Vector_Splat;
1509 // We can perform the conversion between vector types in the following cases:
1510 // 1)vector types are equivalent AltiVec and GCC vector types
1511 // 2)lax vector conversions are permitted and the vector types are of the
1513 if (ToType->isVectorType() && FromType->isVectorType()) {
1514 if (S.Context.areCompatibleVectorTypes(FromType, ToType) ||
1515 S.isLaxVectorConversion(FromType, ToType)) {
1516 ICK = ICK_Vector_Conversion;
1524 static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
1525 bool InOverloadResolution,
1526 StandardConversionSequence &SCS,
1529 /// IsStandardConversion - Determines whether there is a standard
1530 /// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the
1531 /// expression From to the type ToType. Standard conversion sequences
1532 /// only consider non-class types; for conversions that involve class
1533 /// types, use TryImplicitConversion. If a conversion exists, SCS will
1534 /// contain the standard conversion sequence required to perform this
1535 /// conversion and this routine will return true. Otherwise, this
1536 /// routine will return false and the value of SCS is unspecified.
1537 static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
1538 bool InOverloadResolution,
1539 StandardConversionSequence &SCS,
1541 bool AllowObjCWritebackConversion) {
1542 QualType FromType = From->getType();
1544 // Standard conversions (C++ [conv])
1545 SCS.setAsIdentityConversion();
1546 SCS.IncompatibleObjC = false;
1547 SCS.setFromType(FromType);
1548 SCS.CopyConstructor = nullptr;
1550 // There are no standard conversions for class types in C++, so
1551 // abort early. When overloading in C, however, we do permit them.
1552 if (S.getLangOpts().CPlusPlus &&
1553 (FromType->isRecordType() || ToType->isRecordType()))
1556 // The first conversion can be an lvalue-to-rvalue conversion,
1557 // array-to-pointer conversion, or function-to-pointer conversion
1560 if (FromType == S.Context.OverloadTy) {
1561 DeclAccessPair AccessPair;
1562 if (FunctionDecl *Fn
1563 = S.ResolveAddressOfOverloadedFunction(From, ToType, false,
1565 // We were able to resolve the address of the overloaded function,
1566 // so we can convert to the type of that function.
1567 FromType = Fn->getType();
1568 SCS.setFromType(FromType);
1570 // we can sometimes resolve &foo<int> regardless of ToType, so check
1571 // if the type matches (identity) or we are converting to bool
1572 if (!S.Context.hasSameUnqualifiedType(
1573 S.ExtractUnqualifiedFunctionType(ToType), FromType)) {
1575 // if the function type matches except for [[noreturn]], it's ok
1576 if (!S.IsFunctionConversion(FromType,
1577 S.ExtractUnqualifiedFunctionType(ToType), resultTy))
1578 // otherwise, only a boolean conversion is standard
1579 if (!ToType->isBooleanType())
1583 // Check if the "from" expression is taking the address of an overloaded
1584 // function and recompute the FromType accordingly. Take advantage of the
1585 // fact that non-static member functions *must* have such an address-of
1587 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn);
1588 if (Method && !Method->isStatic()) {
1589 assert(isa<UnaryOperator>(From->IgnoreParens()) &&
1590 "Non-unary operator on non-static member address");
1591 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode()
1593 "Non-address-of operator on non-static member address");
1594 const Type *ClassType
1595 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr();
1596 FromType = S.Context.getMemberPointerType(FromType, ClassType);
1597 } else if (isa<UnaryOperator>(From->IgnoreParens())) {
1598 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() ==
1600 "Non-address-of operator for overloaded function expression");
1601 FromType = S.Context.getPointerType(FromType);
1604 // Check that we've computed the proper type after overload resolution.
1605 // FIXME: FixOverloadedFunctionReference has side-effects; we shouldn't
1606 // be calling it from within an NDEBUG block.
1607 assert(S.Context.hasSameType(
1609 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType()));
1614 // Lvalue-to-rvalue conversion (C++11 4.1):
1615 // A glvalue (3.10) of a non-function, non-array type T can
1616 // be converted to a prvalue.
1617 bool argIsLValue = From->isGLValue();
1619 !FromType->isFunctionType() && !FromType->isArrayType() &&
1620 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) {
1621 SCS.First = ICK_Lvalue_To_Rvalue;
1624 // ... if the lvalue has atomic type, the value has the non-atomic version
1625 // of the type of the lvalue ...
1626 if (const AtomicType *Atomic = FromType->getAs<AtomicType>())
1627 FromType = Atomic->getValueType();
1629 // If T is a non-class type, the type of the rvalue is the
1630 // cv-unqualified version of T. Otherwise, the type of the rvalue
1631 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we
1632 // just strip the qualifiers because they don't matter.
1633 FromType = FromType.getUnqualifiedType();
1634 } else if (FromType->isArrayType()) {
1635 // Array-to-pointer conversion (C++ 4.2)
1636 SCS.First = ICK_Array_To_Pointer;
1638 // An lvalue or rvalue of type "array of N T" or "array of unknown
1639 // bound of T" can be converted to an rvalue of type "pointer to
1641 FromType = S.Context.getArrayDecayedType(FromType);
1643 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) {
1644 // This conversion is deprecated in C++03 (D.4)
1645 SCS.DeprecatedStringLiteralToCharPtr = true;
1647 // For the purpose of ranking in overload resolution
1648 // (13.3.3.1.1), this conversion is considered an
1649 // array-to-pointer conversion followed by a qualification
1650 // conversion (4.4). (C++ 4.2p2)
1651 SCS.Second = ICK_Identity;
1652 SCS.Third = ICK_Qualification;
1653 SCS.QualificationIncludesObjCLifetime = false;
1654 SCS.setAllToTypes(FromType);
1657 } else if (FromType->isFunctionType() && argIsLValue) {
1658 // Function-to-pointer conversion (C++ 4.3).
1659 SCS.First = ICK_Function_To_Pointer;
1661 if (auto *DRE = dyn_cast<DeclRefExpr>(From->IgnoreParenCasts()))
1662 if (auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl()))
1663 if (!S.checkAddressOfFunctionIsAvailable(FD))
1666 // An lvalue of function type T can be converted to an rvalue of
1667 // type "pointer to T." The result is a pointer to the
1668 // function. (C++ 4.3p1).
1669 FromType = S.Context.getPointerType(FromType);
1671 // We don't require any conversions for the first step.
1672 SCS.First = ICK_Identity;
1674 SCS.setToType(0, FromType);
1676 // The second conversion can be an integral promotion, floating
1677 // point promotion, integral conversion, floating point conversion,
1678 // floating-integral conversion, pointer conversion,
1679 // pointer-to-member conversion, or boolean conversion (C++ 4p1).
1680 // For overloading in C, this can also be a "compatible-type"
1682 bool IncompatibleObjC = false;
1683 ImplicitConversionKind SecondICK = ICK_Identity;
1684 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) {
1685 // The unqualified versions of the types are the same: there's no
1686 // conversion to do.
1687 SCS.Second = ICK_Identity;
1688 } else if (S.IsIntegralPromotion(From, FromType, ToType)) {
1689 // Integral promotion (C++ 4.5).
1690 SCS.Second = ICK_Integral_Promotion;
1691 FromType = ToType.getUnqualifiedType();
1692 } else if (S.IsFloatingPointPromotion(FromType, ToType)) {
1693 // Floating point promotion (C++ 4.6).
1694 SCS.Second = ICK_Floating_Promotion;
1695 FromType = ToType.getUnqualifiedType();
1696 } else if (S.IsComplexPromotion(FromType, ToType)) {
1697 // Complex promotion (Clang extension)
1698 SCS.Second = ICK_Complex_Promotion;
1699 FromType = ToType.getUnqualifiedType();
1700 } else if (ToType->isBooleanType() &&
1701 (FromType->isArithmeticType() ||
1702 FromType->isAnyPointerType() ||
1703 FromType->isBlockPointerType() ||
1704 FromType->isMemberPointerType() ||
1705 FromType->isNullPtrType())) {
1706 // Boolean conversions (C++ 4.12).
1707 SCS.Second = ICK_Boolean_Conversion;
1708 FromType = S.Context.BoolTy;
1709 } else if (FromType->isIntegralOrUnscopedEnumerationType() &&
1710 ToType->isIntegralType(S.Context)) {
1711 // Integral conversions (C++ 4.7).
1712 SCS.Second = ICK_Integral_Conversion;
1713 FromType = ToType.getUnqualifiedType();
1714 } else if (FromType->isAnyComplexType() && ToType->isAnyComplexType()) {
1715 // Complex conversions (C99 6.3.1.6)
1716 SCS.Second = ICK_Complex_Conversion;
1717 FromType = ToType.getUnqualifiedType();
1718 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) ||
1719 (ToType->isAnyComplexType() && FromType->isArithmeticType())) {
1720 // Complex-real conversions (C99 6.3.1.7)
1721 SCS.Second = ICK_Complex_Real;
1722 FromType = ToType.getUnqualifiedType();
1723 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) {
1724 // FIXME: disable conversions between long double and __float128 if
1725 // their representation is different until there is back end support
1726 // We of course allow this conversion if long double is really double.
1727 if (&S.Context.getFloatTypeSemantics(FromType) !=
1728 &S.Context.getFloatTypeSemantics(ToType)) {
1729 bool Float128AndLongDouble = ((FromType == S.Context.Float128Ty &&
1730 ToType == S.Context.LongDoubleTy) ||
1731 (FromType == S.Context.LongDoubleTy &&
1732 ToType == S.Context.Float128Ty));
1733 if (Float128AndLongDouble &&
1734 (&S.Context.getFloatTypeSemantics(S.Context.LongDoubleTy) !=
1735 &llvm::APFloat::IEEEdouble()))
1738 // Floating point conversions (C++ 4.8).
1739 SCS.Second = ICK_Floating_Conversion;
1740 FromType = ToType.getUnqualifiedType();
1741 } else if ((FromType->isRealFloatingType() &&
1742 ToType->isIntegralType(S.Context)) ||
1743 (FromType->isIntegralOrUnscopedEnumerationType() &&
1744 ToType->isRealFloatingType())) {
1745 // Floating-integral conversions (C++ 4.9).
1746 SCS.Second = ICK_Floating_Integral;
1747 FromType = ToType.getUnqualifiedType();
1748 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) {
1749 SCS.Second = ICK_Block_Pointer_Conversion;
1750 } else if (AllowObjCWritebackConversion &&
1751 S.isObjCWritebackConversion(FromType, ToType, FromType)) {
1752 SCS.Second = ICK_Writeback_Conversion;
1753 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution,
1754 FromType, IncompatibleObjC)) {
1755 // Pointer conversions (C++ 4.10).
1756 SCS.Second = ICK_Pointer_Conversion;
1757 SCS.IncompatibleObjC = IncompatibleObjC;
1758 FromType = FromType.getUnqualifiedType();
1759 } else if (S.IsMemberPointerConversion(From, FromType, ToType,
1760 InOverloadResolution, FromType)) {
1761 // Pointer to member conversions (4.11).
1762 SCS.Second = ICK_Pointer_Member;
1763 } else if (IsVectorConversion(S, FromType, ToType, SecondICK)) {
1764 SCS.Second = SecondICK;
1765 FromType = ToType.getUnqualifiedType();
1766 } else if (!S.getLangOpts().CPlusPlus &&
1767 S.Context.typesAreCompatible(ToType, FromType)) {
1768 // Compatible conversions (Clang extension for C function overloading)
1769 SCS.Second = ICK_Compatible_Conversion;
1770 FromType = ToType.getUnqualifiedType();
1771 } else if (IsTransparentUnionStandardConversion(S, From, ToType,
1772 InOverloadResolution,
1774 SCS.Second = ICK_TransparentUnionConversion;
1776 } else if (tryAtomicConversion(S, From, ToType, InOverloadResolution, SCS,
1778 // tryAtomicConversion has updated the standard conversion sequence
1781 } else if (ToType->isEventT() &&
1782 From->isIntegerConstantExpr(S.getASTContext()) &&
1783 From->EvaluateKnownConstInt(S.getASTContext()) == 0) {
1784 SCS.Second = ICK_Zero_Event_Conversion;
1786 } else if (ToType->isQueueT() &&
1787 From->isIntegerConstantExpr(S.getASTContext()) &&
1788 (From->EvaluateKnownConstInt(S.getASTContext()) == 0)) {
1789 SCS.Second = ICK_Zero_Queue_Conversion;
1792 // No second conversion required.
1793 SCS.Second = ICK_Identity;
1795 SCS.setToType(1, FromType);
1797 // The third conversion can be a function pointer conversion or a
1798 // qualification conversion (C++ [conv.fctptr], [conv.qual]).
1799 bool ObjCLifetimeConversion;
1800 if (S.IsFunctionConversion(FromType, ToType, FromType)) {
1801 // Function pointer conversions (removing 'noexcept') including removal of
1802 // 'noreturn' (Clang extension).
1803 SCS.Third = ICK_Function_Conversion;
1804 } else if (S.IsQualificationConversion(FromType, ToType, CStyle,
1805 ObjCLifetimeConversion)) {
1806 SCS.Third = ICK_Qualification;
1807 SCS.QualificationIncludesObjCLifetime = ObjCLifetimeConversion;
1810 // No conversion required
1811 SCS.Third = ICK_Identity;
1814 // C++ [over.best.ics]p6:
1815 // [...] Any difference in top-level cv-qualification is
1816 // subsumed by the initialization itself and does not constitute
1817 // a conversion. [...]
1818 QualType CanonFrom = S.Context.getCanonicalType(FromType);
1819 QualType CanonTo = S.Context.getCanonicalType(ToType);
1820 if (CanonFrom.getLocalUnqualifiedType()
1821 == CanonTo.getLocalUnqualifiedType() &&
1822 CanonFrom.getLocalQualifiers() != CanonTo.getLocalQualifiers()) {
1824 CanonFrom = CanonTo;
1827 SCS.setToType(2, FromType);
1829 if (CanonFrom == CanonTo)
1832 // If we have not converted the argument type to the parameter type,
1833 // this is a bad conversion sequence, unless we're resolving an overload in C.
1834 if (S.getLangOpts().CPlusPlus || !InOverloadResolution)
1837 ExprResult ER = ExprResult{From};
1838 Sema::AssignConvertType Conv =
1839 S.CheckSingleAssignmentConstraints(ToType, ER,
1841 /*DiagnoseCFAudited=*/false,
1842 /*ConvertRHS=*/false);
1843 ImplicitConversionKind SecondConv;
1845 case Sema::Compatible:
1846 SecondConv = ICK_C_Only_Conversion;
1848 // For our purposes, discarding qualifiers is just as bad as using an
1849 // incompatible pointer. Note that an IncompatiblePointer conversion can drop
1850 // qualifiers, as well.
1851 case Sema::CompatiblePointerDiscardsQualifiers:
1852 case Sema::IncompatiblePointer:
1853 case Sema::IncompatiblePointerSign:
1854 SecondConv = ICK_Incompatible_Pointer_Conversion;
1860 // First can only be an lvalue conversion, so we pretend that this was the
1861 // second conversion. First should already be valid from earlier in the
1863 SCS.Second = SecondConv;
1864 SCS.setToType(1, ToType);
1866 // Third is Identity, because Second should rank us worse than any other
1867 // conversion. This could also be ICK_Qualification, but it's simpler to just
1868 // lump everything in with the second conversion, and we don't gain anything
1869 // from making this ICK_Qualification.
1870 SCS.Third = ICK_Identity;
1871 SCS.setToType(2, ToType);
1876 IsTransparentUnionStandardConversion(Sema &S, Expr* From,
1878 bool InOverloadResolution,
1879 StandardConversionSequence &SCS,
1882 const RecordType *UT = ToType->getAsUnionType();
1883 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>())
1885 // The field to initialize within the transparent union.
1886 RecordDecl *UD = UT->getDecl();
1887 // It's compatible if the expression matches any of the fields.
1888 for (const auto *it : UD->fields()) {
1889 if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS,
1890 CStyle, /*ObjCWritebackConversion=*/false)) {
1891 ToType = it->getType();
1898 /// IsIntegralPromotion - Determines whether the conversion from the
1899 /// expression From (whose potentially-adjusted type is FromType) to
1900 /// ToType is an integral promotion (C++ 4.5). If so, returns true and
1901 /// sets PromotedType to the promoted type.
1902 bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) {
1903 const BuiltinType *To = ToType->getAs<BuiltinType>();
1904 // All integers are built-in.
1909 // An rvalue of type char, signed char, unsigned char, short int, or
1910 // unsigned short int can be converted to an rvalue of type int if
1911 // int can represent all the values of the source type; otherwise,
1912 // the source rvalue can be converted to an rvalue of type unsigned
1914 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() &&
1915 !FromType->isEnumeralType()) {
1916 if (// We can promote any signed, promotable integer type to an int
1917 (FromType->isSignedIntegerType() ||
1918 // We can promote any unsigned integer type whose size is
1919 // less than int to an int.
1920 Context.getTypeSize(FromType) < Context.getTypeSize(ToType))) {
1921 return To->getKind() == BuiltinType::Int;
1924 return To->getKind() == BuiltinType::UInt;
1927 // C++11 [conv.prom]p3:
1928 // A prvalue of an unscoped enumeration type whose underlying type is not
1929 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the
1930 // following types that can represent all the values of the enumeration
1931 // (i.e., the values in the range bmin to bmax as described in 7.2): int,
1932 // unsigned int, long int, unsigned long int, long long int, or unsigned
1933 // long long int. If none of the types in that list can represent all the
1934 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration
1935 // type can be converted to an rvalue a prvalue of the extended integer type
1936 // with lowest integer conversion rank (4.13) greater than the rank of long
1937 // long in which all the values of the enumeration can be represented. If
1938 // there are two such extended types, the signed one is chosen.
1939 // C++11 [conv.prom]p4:
1940 // A prvalue of an unscoped enumeration type whose underlying type is fixed
1941 // can be converted to a prvalue of its underlying type. Moreover, if
1942 // integral promotion can be applied to its underlying type, a prvalue of an
1943 // unscoped enumeration type whose underlying type is fixed can also be
1944 // converted to a prvalue of the promoted underlying type.
1945 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) {
1946 // C++0x 7.2p9: Note that this implicit enum to int conversion is not
1947 // provided for a scoped enumeration.
1948 if (FromEnumType->getDecl()->isScoped())
1951 // We can perform an integral promotion to the underlying type of the enum,
1952 // even if that's not the promoted type. Note that the check for promoting
1953 // the underlying type is based on the type alone, and does not consider
1954 // the bitfield-ness of the actual source expression.
1955 if (FromEnumType->getDecl()->isFixed()) {
1956 QualType Underlying = FromEnumType->getDecl()->getIntegerType();
1957 return Context.hasSameUnqualifiedType(Underlying, ToType) ||
1958 IsIntegralPromotion(nullptr, Underlying, ToType);
1961 // We have already pre-calculated the promotion type, so this is trivial.
1962 if (ToType->isIntegerType() &&
1963 isCompleteType(From->getLocStart(), FromType))
1964 return Context.hasSameUnqualifiedType(
1965 ToType, FromEnumType->getDecl()->getPromotionType());
1968 // C++0x [conv.prom]p2:
1969 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted
1970 // to an rvalue a prvalue of the first of the following types that can
1971 // represent all the values of its underlying type: int, unsigned int,
1972 // long int, unsigned long int, long long int, or unsigned long long int.
1973 // If none of the types in that list can represent all the values of its
1974 // underlying type, an rvalue a prvalue of type char16_t, char32_t,
1975 // or wchar_t can be converted to an rvalue a prvalue of its underlying
1977 if (FromType->isAnyCharacterType() && !FromType->isCharType() &&
1978 ToType->isIntegerType()) {
1979 // Determine whether the type we're converting from is signed or
1981 bool FromIsSigned = FromType->isSignedIntegerType();
1982 uint64_t FromSize = Context.getTypeSize(FromType);
1984 // The types we'll try to promote to, in the appropriate
1985 // order. Try each of these types.
1986 QualType PromoteTypes[6] = {
1987 Context.IntTy, Context.UnsignedIntTy,
1988 Context.LongTy, Context.UnsignedLongTy ,
1989 Context.LongLongTy, Context.UnsignedLongLongTy
1991 for (int Idx = 0; Idx < 6; ++Idx) {
1992 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]);
1993 if (FromSize < ToSize ||
1994 (FromSize == ToSize &&
1995 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) {
1996 // We found the type that we can promote to. If this is the
1997 // type we wanted, we have a promotion. Otherwise, no
1999 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]);
2004 // An rvalue for an integral bit-field (9.6) can be converted to an
2005 // rvalue of type int if int can represent all the values of the
2006 // bit-field; otherwise, it can be converted to unsigned int if
2007 // unsigned int can represent all the values of the bit-field. If
2008 // the bit-field is larger yet, no integral promotion applies to
2009 // it. If the bit-field has an enumerated type, it is treated as any
2010 // other value of that type for promotion purposes (C++ 4.5p3).
2011 // FIXME: We should delay checking of bit-fields until we actually perform the
2014 if (FieldDecl *MemberDecl = From->getSourceBitField()) {
2015 llvm::APSInt BitWidth;
2016 if (FromType->isIntegralType(Context) &&
2017 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) {
2018 llvm::APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned());
2019 ToSize = Context.getTypeSize(ToType);
2021 // Are we promoting to an int from a bitfield that fits in an int?
2022 if (BitWidth < ToSize ||
2023 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) {
2024 return To->getKind() == BuiltinType::Int;
2027 // Are we promoting to an unsigned int from an unsigned bitfield
2028 // that fits into an unsigned int?
2029 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) {
2030 return To->getKind() == BuiltinType::UInt;
2038 // An rvalue of type bool can be converted to an rvalue of type int,
2039 // with false becoming zero and true becoming one (C++ 4.5p4).
2040 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) {
2047 /// IsFloatingPointPromotion - Determines whether the conversion from
2048 /// FromType to ToType is a floating point promotion (C++ 4.6). If so,
2049 /// returns true and sets PromotedType to the promoted type.
2050 bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) {
2051 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>())
2052 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) {
2053 /// An rvalue of type float can be converted to an rvalue of type
2054 /// double. (C++ 4.6p1).
2055 if (FromBuiltin->getKind() == BuiltinType::Float &&
2056 ToBuiltin->getKind() == BuiltinType::Double)
2060 // When a float is promoted to double or long double, or a
2061 // double is promoted to long double [...].
2062 if (!getLangOpts().CPlusPlus &&
2063 (FromBuiltin->getKind() == BuiltinType::Float ||
2064 FromBuiltin->getKind() == BuiltinType::Double) &&
2065 (ToBuiltin->getKind() == BuiltinType::LongDouble ||
2066 ToBuiltin->getKind() == BuiltinType::Float128))
2069 // Half can be promoted to float.
2070 if (!getLangOpts().NativeHalfType &&
2071 FromBuiltin->getKind() == BuiltinType::Half &&
2072 ToBuiltin->getKind() == BuiltinType::Float)
2079 /// \brief Determine if a conversion is a complex promotion.
2081 /// A complex promotion is defined as a complex -> complex conversion
2082 /// where the conversion between the underlying real types is a
2083 /// floating-point or integral promotion.
2084 bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) {
2085 const ComplexType *FromComplex = FromType->getAs<ComplexType>();
2089 const ComplexType *ToComplex = ToType->getAs<ComplexType>();
2093 return IsFloatingPointPromotion(FromComplex->getElementType(),
2094 ToComplex->getElementType()) ||
2095 IsIntegralPromotion(nullptr, FromComplex->getElementType(),
2096 ToComplex->getElementType());
2099 /// BuildSimilarlyQualifiedPointerType - In a pointer conversion from
2100 /// the pointer type FromPtr to a pointer to type ToPointee, with the
2101 /// same type qualifiers as FromPtr has on its pointee type. ToType,
2102 /// if non-empty, will be a pointer to ToType that may or may not have
2103 /// the right set of qualifiers on its pointee.
2106 BuildSimilarlyQualifiedPointerType(const Type *FromPtr,
2107 QualType ToPointee, QualType ToType,
2108 ASTContext &Context,
2109 bool StripObjCLifetime = false) {
2110 assert((FromPtr->getTypeClass() == Type::Pointer ||
2111 FromPtr->getTypeClass() == Type::ObjCObjectPointer) &&
2112 "Invalid similarly-qualified pointer type");
2114 /// Conversions to 'id' subsume cv-qualifier conversions.
2115 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType())
2116 return ToType.getUnqualifiedType();
2118 QualType CanonFromPointee
2119 = Context.getCanonicalType(FromPtr->getPointeeType());
2120 QualType CanonToPointee = Context.getCanonicalType(ToPointee);
2121 Qualifiers Quals = CanonFromPointee.getQualifiers();
2123 if (StripObjCLifetime)
2124 Quals.removeObjCLifetime();
2126 // Exact qualifier match -> return the pointer type we're converting to.
2127 if (CanonToPointee.getLocalQualifiers() == Quals) {
2128 // ToType is exactly what we need. Return it.
2129 if (!ToType.isNull())
2130 return ToType.getUnqualifiedType();
2132 // Build a pointer to ToPointee. It has the right qualifiers
2134 if (isa<ObjCObjectPointerType>(ToType))
2135 return Context.getObjCObjectPointerType(ToPointee);
2136 return Context.getPointerType(ToPointee);
2139 // Just build a canonical type that has the right qualifiers.
2140 QualType QualifiedCanonToPointee
2141 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals);
2143 if (isa<ObjCObjectPointerType>(ToType))
2144 return Context.getObjCObjectPointerType(QualifiedCanonToPointee);
2145 return Context.getPointerType(QualifiedCanonToPointee);
2148 static bool isNullPointerConstantForConversion(Expr *Expr,
2149 bool InOverloadResolution,
2150 ASTContext &Context) {
2151 // Handle value-dependent integral null pointer constants correctly.
2152 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903
2153 if (Expr->isValueDependent() && !Expr->isTypeDependent() &&
2154 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType())
2155 return !InOverloadResolution;
2157 return Expr->isNullPointerConstant(Context,
2158 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
2159 : Expr::NPC_ValueDependentIsNull);
2162 /// IsPointerConversion - Determines whether the conversion of the
2163 /// expression From, which has the (possibly adjusted) type FromType,
2164 /// can be converted to the type ToType via a pointer conversion (C++
2165 /// 4.10). If so, returns true and places the converted type (that
2166 /// might differ from ToType in its cv-qualifiers at some level) into
2169 /// This routine also supports conversions to and from block pointers
2170 /// and conversions with Objective-C's 'id', 'id<protocols...>', and
2171 /// pointers to interfaces. FIXME: Once we've determined the
2172 /// appropriate overloading rules for Objective-C, we may want to
2173 /// split the Objective-C checks into a different routine; however,
2174 /// GCC seems to consider all of these conversions to be pointer
2175 /// conversions, so for now they live here. IncompatibleObjC will be
2176 /// set if the conversion is an allowed Objective-C conversion that
2177 /// should result in a warning.
2178 bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType,
2179 bool InOverloadResolution,
2180 QualType& ConvertedType,
2181 bool &IncompatibleObjC) {
2182 IncompatibleObjC = false;
2183 if (isObjCPointerConversion(FromType, ToType, ConvertedType,
2187 // Conversion from a null pointer constant to any Objective-C pointer type.
2188 if (ToType->isObjCObjectPointerType() &&
2189 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2190 ConvertedType = ToType;
2194 // Blocks: Block pointers can be converted to void*.
2195 if (FromType->isBlockPointerType() && ToType->isPointerType() &&
2196 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) {
2197 ConvertedType = ToType;
2200 // Blocks: A null pointer constant can be converted to a block
2202 if (ToType->isBlockPointerType() &&
2203 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2204 ConvertedType = ToType;
2208 // If the left-hand-side is nullptr_t, the right side can be a null
2209 // pointer constant.
2210 if (ToType->isNullPtrType() &&
2211 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2212 ConvertedType = ToType;
2216 const PointerType* ToTypePtr = ToType->getAs<PointerType>();
2220 // A null pointer constant can be converted to a pointer type (C++ 4.10p1).
2221 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2222 ConvertedType = ToType;
2226 // Beyond this point, both types need to be pointers
2227 // , including objective-c pointers.
2228 QualType ToPointeeType = ToTypePtr->getPointeeType();
2229 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType() &&
2230 !getLangOpts().ObjCAutoRefCount) {
2231 ConvertedType = BuildSimilarlyQualifiedPointerType(
2232 FromType->getAs<ObjCObjectPointerType>(),
2237 const PointerType *FromTypePtr = FromType->getAs<PointerType>();
2241 QualType FromPointeeType = FromTypePtr->getPointeeType();
2243 // If the unqualified pointee types are the same, this can't be a
2244 // pointer conversion, so don't do all of the work below.
2245 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType))
2248 // An rvalue of type "pointer to cv T," where T is an object type,
2249 // can be converted to an rvalue of type "pointer to cv void" (C++
2251 if (FromPointeeType->isIncompleteOrObjectType() &&
2252 ToPointeeType->isVoidType()) {
2253 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2256 /*StripObjCLifetime=*/true);
2260 // MSVC allows implicit function to void* type conversion.
2261 if (getLangOpts().MSVCCompat && FromPointeeType->isFunctionType() &&
2262 ToPointeeType->isVoidType()) {
2263 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2269 // When we're overloading in C, we allow a special kind of pointer
2270 // conversion for compatible-but-not-identical pointee types.
2271 if (!getLangOpts().CPlusPlus &&
2272 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) {
2273 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2279 // C++ [conv.ptr]p3:
2281 // An rvalue of type "pointer to cv D," where D is a class type,
2282 // can be converted to an rvalue of type "pointer to cv B," where
2283 // B is a base class (clause 10) of D. If B is an inaccessible
2284 // (clause 11) or ambiguous (10.2) base class of D, a program that
2285 // necessitates this conversion is ill-formed. The result of the
2286 // conversion is a pointer to the base class sub-object of the
2287 // derived class object. The null pointer value is converted to
2288 // the null pointer value of the destination type.
2290 // Note that we do not check for ambiguity or inaccessibility
2291 // here. That is handled by CheckPointerConversion.
2292 if (getLangOpts().CPlusPlus &&
2293 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() &&
2294 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) &&
2295 IsDerivedFrom(From->getLocStart(), FromPointeeType, ToPointeeType)) {
2296 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2302 if (FromPointeeType->isVectorType() && ToPointeeType->isVectorType() &&
2303 Context.areCompatibleVectorTypes(FromPointeeType, ToPointeeType)) {
2304 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2313 /// \brief Adopt the given qualifiers for the given type.
2314 static QualType AdoptQualifiers(ASTContext &Context, QualType T, Qualifiers Qs){
2315 Qualifiers TQs = T.getQualifiers();
2317 // Check whether qualifiers already match.
2321 if (Qs.compatiblyIncludes(TQs))
2322 return Context.getQualifiedType(T, Qs);
2324 return Context.getQualifiedType(T.getUnqualifiedType(), Qs);
2327 /// isObjCPointerConversion - Determines whether this is an
2328 /// Objective-C pointer conversion. Subroutine of IsPointerConversion,
2329 /// with the same arguments and return values.
2330 bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType,
2331 QualType& ConvertedType,
2332 bool &IncompatibleObjC) {
2333 if (!getLangOpts().ObjC1)
2336 // The set of qualifiers on the type we're converting from.
2337 Qualifiers FromQualifiers = FromType.getQualifiers();
2339 // First, we handle all conversions on ObjC object pointer types.
2340 const ObjCObjectPointerType* ToObjCPtr =
2341 ToType->getAs<ObjCObjectPointerType>();
2342 const ObjCObjectPointerType *FromObjCPtr =
2343 FromType->getAs<ObjCObjectPointerType>();
2345 if (ToObjCPtr && FromObjCPtr) {
2346 // If the pointee types are the same (ignoring qualifications),
2347 // then this is not a pointer conversion.
2348 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(),
2349 FromObjCPtr->getPointeeType()))
2352 // Conversion between Objective-C pointers.
2353 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) {
2354 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType();
2355 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType();
2356 if (getLangOpts().CPlusPlus && LHS && RHS &&
2357 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs(
2358 FromObjCPtr->getPointeeType()))
2360 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2361 ToObjCPtr->getPointeeType(),
2363 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2367 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) {
2368 // Okay: this is some kind of implicit downcast of Objective-C
2369 // interfaces, which is permitted. However, we're going to
2370 // complain about it.
2371 IncompatibleObjC = true;
2372 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2373 ToObjCPtr->getPointeeType(),
2375 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2379 // Beyond this point, both types need to be C pointers or block pointers.
2380 QualType ToPointeeType;
2381 if (const PointerType *ToCPtr = ToType->getAs<PointerType>())
2382 ToPointeeType = ToCPtr->getPointeeType();
2383 else if (const BlockPointerType *ToBlockPtr =
2384 ToType->getAs<BlockPointerType>()) {
2385 // Objective C++: We're able to convert from a pointer to any object
2386 // to a block pointer type.
2387 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) {
2388 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2391 ToPointeeType = ToBlockPtr->getPointeeType();
2393 else if (FromType->getAs<BlockPointerType>() &&
2394 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) {
2395 // Objective C++: We're able to convert from a block pointer type to a
2396 // pointer to any object.
2397 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2403 QualType FromPointeeType;
2404 if (const PointerType *FromCPtr = FromType->getAs<PointerType>())
2405 FromPointeeType = FromCPtr->getPointeeType();
2406 else if (const BlockPointerType *FromBlockPtr =
2407 FromType->getAs<BlockPointerType>())
2408 FromPointeeType = FromBlockPtr->getPointeeType();
2412 // If we have pointers to pointers, recursively check whether this
2413 // is an Objective-C conversion.
2414 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() &&
2415 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2416 IncompatibleObjC)) {
2417 // We always complain about this conversion.
2418 IncompatibleObjC = true;
2419 ConvertedType = Context.getPointerType(ConvertedType);
2420 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2423 // Allow conversion of pointee being objective-c pointer to another one;
2425 if (FromPointeeType->getAs<ObjCObjectPointerType>() &&
2426 ToPointeeType->getAs<ObjCObjectPointerType>() &&
2427 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2428 IncompatibleObjC)) {
2430 ConvertedType = Context.getPointerType(ConvertedType);
2431 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2435 // If we have pointers to functions or blocks, check whether the only
2436 // differences in the argument and result types are in Objective-C
2437 // pointer conversions. If so, we permit the conversion (but
2438 // complain about it).
2439 const FunctionProtoType *FromFunctionType
2440 = FromPointeeType->getAs<FunctionProtoType>();
2441 const FunctionProtoType *ToFunctionType
2442 = ToPointeeType->getAs<FunctionProtoType>();
2443 if (FromFunctionType && ToFunctionType) {
2444 // If the function types are exactly the same, this isn't an
2445 // Objective-C pointer conversion.
2446 if (Context.getCanonicalType(FromPointeeType)
2447 == Context.getCanonicalType(ToPointeeType))
2450 // Perform the quick checks that will tell us whether these
2451 // function types are obviously different.
2452 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2453 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() ||
2454 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals())
2457 bool HasObjCConversion = false;
2458 if (Context.getCanonicalType(FromFunctionType->getReturnType()) ==
2459 Context.getCanonicalType(ToFunctionType->getReturnType())) {
2460 // Okay, the types match exactly. Nothing to do.
2461 } else if (isObjCPointerConversion(FromFunctionType->getReturnType(),
2462 ToFunctionType->getReturnType(),
2463 ConvertedType, IncompatibleObjC)) {
2464 // Okay, we have an Objective-C pointer conversion.
2465 HasObjCConversion = true;
2467 // Function types are too different. Abort.
2471 // Check argument types.
2472 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2473 ArgIdx != NumArgs; ++ArgIdx) {
2474 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2475 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2476 if (Context.getCanonicalType(FromArgType)
2477 == Context.getCanonicalType(ToArgType)) {
2478 // Okay, the types match exactly. Nothing to do.
2479 } else if (isObjCPointerConversion(FromArgType, ToArgType,
2480 ConvertedType, IncompatibleObjC)) {
2481 // Okay, we have an Objective-C pointer conversion.
2482 HasObjCConversion = true;
2484 // Argument types are too different. Abort.
2489 if (HasObjCConversion) {
2490 // We had an Objective-C conversion. Allow this pointer
2491 // conversion, but complain about it.
2492 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2493 IncompatibleObjC = true;
2501 /// \brief Determine whether this is an Objective-C writeback conversion,
2502 /// used for parameter passing when performing automatic reference counting.
2504 /// \param FromType The type we're converting form.
2506 /// \param ToType The type we're converting to.
2508 /// \param ConvertedType The type that will be produced after applying
2509 /// this conversion.
2510 bool Sema::isObjCWritebackConversion(QualType FromType, QualType ToType,
2511 QualType &ConvertedType) {
2512 if (!getLangOpts().ObjCAutoRefCount ||
2513 Context.hasSameUnqualifiedType(FromType, ToType))
2516 // Parameter must be a pointer to __autoreleasing (with no other qualifiers).
2518 if (const PointerType *ToPointer = ToType->getAs<PointerType>())
2519 ToPointee = ToPointer->getPointeeType();
2523 Qualifiers ToQuals = ToPointee.getQualifiers();
2524 if (!ToPointee->isObjCLifetimeType() ||
2525 ToQuals.getObjCLifetime() != Qualifiers::OCL_Autoreleasing ||
2526 !ToQuals.withoutObjCLifetime().empty())
2529 // Argument must be a pointer to __strong to __weak.
2530 QualType FromPointee;
2531 if (const PointerType *FromPointer = FromType->getAs<PointerType>())
2532 FromPointee = FromPointer->getPointeeType();
2536 Qualifiers FromQuals = FromPointee.getQualifiers();
2537 if (!FromPointee->isObjCLifetimeType() ||
2538 (FromQuals.getObjCLifetime() != Qualifiers::OCL_Strong &&
2539 FromQuals.getObjCLifetime() != Qualifiers::OCL_Weak))
2542 // Make sure that we have compatible qualifiers.
2543 FromQuals.setObjCLifetime(Qualifiers::OCL_Autoreleasing);
2544 if (!ToQuals.compatiblyIncludes(FromQuals))
2547 // Remove qualifiers from the pointee type we're converting from; they
2548 // aren't used in the compatibility check belong, and we'll be adding back
2549 // qualifiers (with __autoreleasing) if the compatibility check succeeds.
2550 FromPointee = FromPointee.getUnqualifiedType();
2552 // The unqualified form of the pointee types must be compatible.
2553 ToPointee = ToPointee.getUnqualifiedType();
2554 bool IncompatibleObjC;
2555 if (Context.typesAreCompatible(FromPointee, ToPointee))
2556 FromPointee = ToPointee;
2557 else if (!isObjCPointerConversion(FromPointee, ToPointee, FromPointee,
2561 /// \brief Construct the type we're converting to, which is a pointer to
2562 /// __autoreleasing pointee.
2563 FromPointee = Context.getQualifiedType(FromPointee, FromQuals);
2564 ConvertedType = Context.getPointerType(FromPointee);
2568 bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType,
2569 QualType& ConvertedType) {
2570 QualType ToPointeeType;
2571 if (const BlockPointerType *ToBlockPtr =
2572 ToType->getAs<BlockPointerType>())
2573 ToPointeeType = ToBlockPtr->getPointeeType();
2577 QualType FromPointeeType;
2578 if (const BlockPointerType *FromBlockPtr =
2579 FromType->getAs<BlockPointerType>())
2580 FromPointeeType = FromBlockPtr->getPointeeType();
2583 // We have pointer to blocks, check whether the only
2584 // differences in the argument and result types are in Objective-C
2585 // pointer conversions. If so, we permit the conversion.
2587 const FunctionProtoType *FromFunctionType
2588 = FromPointeeType->getAs<FunctionProtoType>();
2589 const FunctionProtoType *ToFunctionType
2590 = ToPointeeType->getAs<FunctionProtoType>();
2592 if (!FromFunctionType || !ToFunctionType)
2595 if (Context.hasSameType(FromPointeeType, ToPointeeType))
2598 // Perform the quick checks that will tell us whether these
2599 // function types are obviously different.
2600 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2601 FromFunctionType->isVariadic() != ToFunctionType->isVariadic())
2604 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo();
2605 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo();
2606 if (FromEInfo != ToEInfo)
2609 bool IncompatibleObjC = false;
2610 if (Context.hasSameType(FromFunctionType->getReturnType(),
2611 ToFunctionType->getReturnType())) {
2612 // Okay, the types match exactly. Nothing to do.
2614 QualType RHS = FromFunctionType->getReturnType();
2615 QualType LHS = ToFunctionType->getReturnType();
2616 if ((!getLangOpts().CPlusPlus || !RHS->isRecordType()) &&
2617 !RHS.hasQualifiers() && LHS.hasQualifiers())
2618 LHS = LHS.getUnqualifiedType();
2620 if (Context.hasSameType(RHS,LHS)) {
2622 } else if (isObjCPointerConversion(RHS, LHS,
2623 ConvertedType, IncompatibleObjC)) {
2624 if (IncompatibleObjC)
2626 // Okay, we have an Objective-C pointer conversion.
2632 // Check argument types.
2633 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2634 ArgIdx != NumArgs; ++ArgIdx) {
2635 IncompatibleObjC = false;
2636 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2637 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2638 if (Context.hasSameType(FromArgType, ToArgType)) {
2639 // Okay, the types match exactly. Nothing to do.
2640 } else if (isObjCPointerConversion(ToArgType, FromArgType,
2641 ConvertedType, IncompatibleObjC)) {
2642 if (IncompatibleObjC)
2644 // Okay, we have an Objective-C pointer conversion.
2646 // Argument types are too different. Abort.
2649 if (!Context.doFunctionTypesMatchOnExtParameterInfos(FromFunctionType,
2653 ConvertedType = ToType;
2661 ft_parameter_mismatch,
2663 ft_qualifer_mismatch,
2667 /// Attempts to get the FunctionProtoType from a Type. Handles
2668 /// MemberFunctionPointers properly.
2669 static const FunctionProtoType *tryGetFunctionProtoType(QualType FromType) {
2670 if (auto *FPT = FromType->getAs<FunctionProtoType>())
2673 if (auto *MPT = FromType->getAs<MemberPointerType>())
2674 return MPT->getPointeeType()->getAs<FunctionProtoType>();
2679 /// HandleFunctionTypeMismatch - Gives diagnostic information for differeing
2680 /// function types. Catches different number of parameter, mismatch in
2681 /// parameter types, and different return types.
2682 void Sema::HandleFunctionTypeMismatch(PartialDiagnostic &PDiag,
2683 QualType FromType, QualType ToType) {
2684 // If either type is not valid, include no extra info.
2685 if (FromType.isNull() || ToType.isNull()) {
2686 PDiag << ft_default;
2690 // Get the function type from the pointers.
2691 if (FromType->isMemberPointerType() && ToType->isMemberPointerType()) {
2692 const MemberPointerType *FromMember = FromType->getAs<MemberPointerType>(),
2693 *ToMember = ToType->getAs<MemberPointerType>();
2694 if (!Context.hasSameType(FromMember->getClass(), ToMember->getClass())) {
2695 PDiag << ft_different_class << QualType(ToMember->getClass(), 0)
2696 << QualType(FromMember->getClass(), 0);
2699 FromType = FromMember->getPointeeType();
2700 ToType = ToMember->getPointeeType();
2703 if (FromType->isPointerType())
2704 FromType = FromType->getPointeeType();
2705 if (ToType->isPointerType())
2706 ToType = ToType->getPointeeType();
2708 // Remove references.
2709 FromType = FromType.getNonReferenceType();
2710 ToType = ToType.getNonReferenceType();
2712 // Don't print extra info for non-specialized template functions.
2713 if (FromType->isInstantiationDependentType() &&
2714 !FromType->getAs<TemplateSpecializationType>()) {
2715 PDiag << ft_default;
2719 // No extra info for same types.
2720 if (Context.hasSameType(FromType, ToType)) {
2721 PDiag << ft_default;
2725 const FunctionProtoType *FromFunction = tryGetFunctionProtoType(FromType),
2726 *ToFunction = tryGetFunctionProtoType(ToType);
2728 // Both types need to be function types.
2729 if (!FromFunction || !ToFunction) {
2730 PDiag << ft_default;
2734 if (FromFunction->getNumParams() != ToFunction->getNumParams()) {
2735 PDiag << ft_parameter_arity << ToFunction->getNumParams()
2736 << FromFunction->getNumParams();
2740 // Handle different parameter types.
2742 if (!FunctionParamTypesAreEqual(FromFunction, ToFunction, &ArgPos)) {
2743 PDiag << ft_parameter_mismatch << ArgPos + 1
2744 << ToFunction->getParamType(ArgPos)
2745 << FromFunction->getParamType(ArgPos);
2749 // Handle different return type.
2750 if (!Context.hasSameType(FromFunction->getReturnType(),
2751 ToFunction->getReturnType())) {
2752 PDiag << ft_return_type << ToFunction->getReturnType()
2753 << FromFunction->getReturnType();
2757 unsigned FromQuals = FromFunction->getTypeQuals(),
2758 ToQuals = ToFunction->getTypeQuals();
2759 if (FromQuals != ToQuals) {
2760 PDiag << ft_qualifer_mismatch << ToQuals << FromQuals;
2764 // Handle exception specification differences on canonical type (in C++17
2766 if (cast<FunctionProtoType>(FromFunction->getCanonicalTypeUnqualified())
2767 ->isNothrow(Context) !=
2768 cast<FunctionProtoType>(ToFunction->getCanonicalTypeUnqualified())
2769 ->isNothrow(Context)) {
2770 PDiag << ft_noexcept;
2774 // Unable to find a difference, so add no extra info.
2775 PDiag << ft_default;
2778 /// FunctionParamTypesAreEqual - This routine checks two function proto types
2779 /// for equality of their argument types. Caller has already checked that
2780 /// they have same number of arguments. If the parameters are different,
2781 /// ArgPos will have the parameter index of the first different parameter.
2782 bool Sema::FunctionParamTypesAreEqual(const FunctionProtoType *OldType,
2783 const FunctionProtoType *NewType,
2785 for (FunctionProtoType::param_type_iterator O = OldType->param_type_begin(),
2786 N = NewType->param_type_begin(),
2787 E = OldType->param_type_end();
2788 O && (O != E); ++O, ++N) {
2789 if (!Context.hasSameType(O->getUnqualifiedType(),
2790 N->getUnqualifiedType())) {
2792 *ArgPos = O - OldType->param_type_begin();
2799 /// CheckPointerConversion - Check the pointer conversion from the
2800 /// expression From to the type ToType. This routine checks for
2801 /// ambiguous or inaccessible derived-to-base pointer
2802 /// conversions for which IsPointerConversion has already returned
2803 /// true. It returns true and produces a diagnostic if there was an
2804 /// error, or returns false otherwise.
2805 bool Sema::CheckPointerConversion(Expr *From, QualType ToType,
2807 CXXCastPath& BasePath,
2808 bool IgnoreBaseAccess,
2810 QualType FromType = From->getType();
2811 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess;
2815 if (Diagnose && !IsCStyleOrFunctionalCast && !FromType->isAnyPointerType() &&
2816 From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) ==
2817 Expr::NPCK_ZeroExpression) {
2818 if (Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy))
2819 DiagRuntimeBehavior(From->getExprLoc(), From,
2820 PDiag(diag::warn_impcast_bool_to_null_pointer)
2821 << ToType << From->getSourceRange());
2822 else if (!isUnevaluatedContext())
2823 Diag(From->getExprLoc(), diag::warn_non_literal_null_pointer)
2824 << ToType << From->getSourceRange();
2826 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) {
2827 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) {
2828 QualType FromPointeeType = FromPtrType->getPointeeType(),
2829 ToPointeeType = ToPtrType->getPointeeType();
2831 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() &&
2832 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) {
2833 // We must have a derived-to-base conversion. Check an
2834 // ambiguous or inaccessible conversion.
2835 unsigned InaccessibleID = 0;
2836 unsigned AmbigiousID = 0;
2838 InaccessibleID = diag::err_upcast_to_inaccessible_base;
2839 AmbigiousID = diag::err_ambiguous_derived_to_base_conv;
2841 if (CheckDerivedToBaseConversion(
2842 FromPointeeType, ToPointeeType, InaccessibleID, AmbigiousID,
2843 From->getExprLoc(), From->getSourceRange(), DeclarationName(),
2844 &BasePath, IgnoreBaseAccess))
2847 // The conversion was successful.
2848 Kind = CK_DerivedToBase;
2851 if (Diagnose && !IsCStyleOrFunctionalCast &&
2852 FromPointeeType->isFunctionType() && ToPointeeType->isVoidType()) {
2853 assert(getLangOpts().MSVCCompat &&
2854 "this should only be possible with MSVCCompat!");
2855 Diag(From->getExprLoc(), diag::ext_ms_impcast_fn_obj)
2856 << From->getSourceRange();
2859 } else if (const ObjCObjectPointerType *ToPtrType =
2860 ToType->getAs<ObjCObjectPointerType>()) {
2861 if (const ObjCObjectPointerType *FromPtrType =
2862 FromType->getAs<ObjCObjectPointerType>()) {
2863 // Objective-C++ conversions are always okay.
2864 // FIXME: We should have a different class of conversions for the
2865 // Objective-C++ implicit conversions.
2866 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType())
2868 } else if (FromType->isBlockPointerType()) {
2869 Kind = CK_BlockPointerToObjCPointerCast;
2871 Kind = CK_CPointerToObjCPointerCast;
2873 } else if (ToType->isBlockPointerType()) {
2874 if (!FromType->isBlockPointerType())
2875 Kind = CK_AnyPointerToBlockPointerCast;
2878 // We shouldn't fall into this case unless it's valid for other
2880 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull))
2881 Kind = CK_NullToPointer;
2886 /// IsMemberPointerConversion - Determines whether the conversion of the
2887 /// expression From, which has the (possibly adjusted) type FromType, can be
2888 /// converted to the type ToType via a member pointer conversion (C++ 4.11).
2889 /// If so, returns true and places the converted type (that might differ from
2890 /// ToType in its cv-qualifiers at some level) into ConvertedType.
2891 bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType,
2893 bool InOverloadResolution,
2894 QualType &ConvertedType) {
2895 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>();
2899 // A null pointer constant can be converted to a member pointer (C++ 4.11p1)
2900 if (From->isNullPointerConstant(Context,
2901 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
2902 : Expr::NPC_ValueDependentIsNull)) {
2903 ConvertedType = ToType;
2907 // Otherwise, both types have to be member pointers.
2908 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>();
2912 // A pointer to member of B can be converted to a pointer to member of D,
2913 // where D is derived from B (C++ 4.11p2).
2914 QualType FromClass(FromTypePtr->getClass(), 0);
2915 QualType ToClass(ToTypePtr->getClass(), 0);
2917 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) &&
2918 IsDerivedFrom(From->getLocStart(), ToClass, FromClass)) {
2919 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(),
2920 ToClass.getTypePtr());
2927 /// CheckMemberPointerConversion - Check the member pointer conversion from the
2928 /// expression From to the type ToType. This routine checks for ambiguous or
2929 /// virtual or inaccessible base-to-derived member pointer conversions
2930 /// for which IsMemberPointerConversion has already returned true. It returns
2931 /// true and produces a diagnostic if there was an error, or returns false
2933 bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType,
2935 CXXCastPath &BasePath,
2936 bool IgnoreBaseAccess) {
2937 QualType FromType = From->getType();
2938 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>();
2940 // This must be a null pointer to member pointer conversion
2941 assert(From->isNullPointerConstant(Context,
2942 Expr::NPC_ValueDependentIsNull) &&
2943 "Expr must be null pointer constant!");
2944 Kind = CK_NullToMemberPointer;
2948 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>();
2949 assert(ToPtrType && "No member pointer cast has a target type "
2950 "that is not a member pointer.");
2952 QualType FromClass = QualType(FromPtrType->getClass(), 0);
2953 QualType ToClass = QualType(ToPtrType->getClass(), 0);
2955 // FIXME: What about dependent types?
2956 assert(FromClass->isRecordType() && "Pointer into non-class.");
2957 assert(ToClass->isRecordType() && "Pointer into non-class.");
2959 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2960 /*DetectVirtual=*/true);
2961 bool DerivationOkay =
2962 IsDerivedFrom(From->getLocStart(), ToClass, FromClass, Paths);
2963 assert(DerivationOkay &&
2964 "Should not have been called if derivation isn't OK.");
2965 (void)DerivationOkay;
2967 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass).
2968 getUnqualifiedType())) {
2969 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
2970 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv)
2971 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange();
2975 if (const RecordType *VBase = Paths.getDetectedVirtual()) {
2976 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual)
2977 << FromClass << ToClass << QualType(VBase, 0)
2978 << From->getSourceRange();
2982 if (!IgnoreBaseAccess)
2983 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass,
2985 diag::err_downcast_from_inaccessible_base);
2987 // Must be a base to derived member conversion.
2988 BuildBasePathArray(Paths, BasePath);
2989 Kind = CK_BaseToDerivedMemberPointer;
2993 /// Determine whether the lifetime conversion between the two given
2994 /// qualifiers sets is nontrivial.
2995 static bool isNonTrivialObjCLifetimeConversion(Qualifiers FromQuals,
2996 Qualifiers ToQuals) {
2997 // Converting anything to const __unsafe_unretained is trivial.
2998 if (ToQuals.hasConst() &&
2999 ToQuals.getObjCLifetime() == Qualifiers::OCL_ExplicitNone)
3005 /// IsQualificationConversion - Determines whether the conversion from
3006 /// an rvalue of type FromType to ToType is a qualification conversion
3009 /// \param ObjCLifetimeConversion Output parameter that will be set to indicate
3010 /// when the qualification conversion involves a change in the Objective-C
3011 /// object lifetime.
3013 Sema::IsQualificationConversion(QualType FromType, QualType ToType,
3014 bool CStyle, bool &ObjCLifetimeConversion) {
3015 FromType = Context.getCanonicalType(FromType);
3016 ToType = Context.getCanonicalType(ToType);
3017 ObjCLifetimeConversion = false;
3019 // If FromType and ToType are the same type, this is not a
3020 // qualification conversion.
3021 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType())
3025 // A conversion can add cv-qualifiers at levels other than the first
3026 // in multi-level pointers, subject to the following rules: [...]
3027 bool PreviousToQualsIncludeConst = true;
3028 bool UnwrappedAnyPointer = false;
3029 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) {
3030 // Within each iteration of the loop, we check the qualifiers to
3031 // determine if this still looks like a qualification
3032 // conversion. Then, if all is well, we unwrap one more level of
3033 // pointers or pointers-to-members and do it all again
3034 // until there are no more pointers or pointers-to-members left to
3036 UnwrappedAnyPointer = true;
3038 Qualifiers FromQuals = FromType.getQualifiers();
3039 Qualifiers ToQuals = ToType.getQualifiers();
3041 // Ignore __unaligned qualifier if this type is void.
3042 if (ToType.getUnqualifiedType()->isVoidType())
3043 FromQuals.removeUnaligned();
3046 // Check Objective-C lifetime conversions.
3047 if (FromQuals.getObjCLifetime() != ToQuals.getObjCLifetime() &&
3048 UnwrappedAnyPointer) {
3049 if (ToQuals.compatiblyIncludesObjCLifetime(FromQuals)) {
3050 if (isNonTrivialObjCLifetimeConversion(FromQuals, ToQuals))
3051 ObjCLifetimeConversion = true;
3052 FromQuals.removeObjCLifetime();
3053 ToQuals.removeObjCLifetime();
3055 // Qualification conversions cannot cast between different
3056 // Objective-C lifetime qualifiers.
3061 // Allow addition/removal of GC attributes but not changing GC attributes.
3062 if (FromQuals.getObjCGCAttr() != ToQuals.getObjCGCAttr() &&
3063 (!FromQuals.hasObjCGCAttr() || !ToQuals.hasObjCGCAttr())) {
3064 FromQuals.removeObjCGCAttr();
3065 ToQuals.removeObjCGCAttr();
3068 // -- for every j > 0, if const is in cv 1,j then const is in cv
3069 // 2,j, and similarly for volatile.
3070 if (!CStyle && !ToQuals.compatiblyIncludes(FromQuals))
3073 // -- if the cv 1,j and cv 2,j are different, then const is in
3074 // every cv for 0 < k < j.
3075 if (!CStyle && FromQuals.getCVRQualifiers() != ToQuals.getCVRQualifiers()
3076 && !PreviousToQualsIncludeConst)
3079 // Keep track of whether all prior cv-qualifiers in the "to" type
3081 PreviousToQualsIncludeConst
3082 = PreviousToQualsIncludeConst && ToQuals.hasConst();
3085 // We are left with FromType and ToType being the pointee types
3086 // after unwrapping the original FromType and ToType the same number
3087 // of types. If we unwrapped any pointers, and if FromType and
3088 // ToType have the same unqualified type (since we checked
3089 // qualifiers above), then this is a qualification conversion.
3090 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType);
3093 /// \brief - Determine whether this is a conversion from a scalar type to an
3096 /// If successful, updates \c SCS's second and third steps in the conversion
3097 /// sequence to finish the conversion.
3098 static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
3099 bool InOverloadResolution,
3100 StandardConversionSequence &SCS,
3102 const AtomicType *ToAtomic = ToType->getAs<AtomicType>();
3106 StandardConversionSequence InnerSCS;
3107 if (!IsStandardConversion(S, From, ToAtomic->getValueType(),
3108 InOverloadResolution, InnerSCS,
3109 CStyle, /*AllowObjCWritebackConversion=*/false))
3112 SCS.Second = InnerSCS.Second;
3113 SCS.setToType(1, InnerSCS.getToType(1));
3114 SCS.Third = InnerSCS.Third;
3115 SCS.QualificationIncludesObjCLifetime
3116 = InnerSCS.QualificationIncludesObjCLifetime;
3117 SCS.setToType(2, InnerSCS.getToType(2));
3121 static bool isFirstArgumentCompatibleWithType(ASTContext &Context,
3122 CXXConstructorDecl *Constructor,
3124 const FunctionProtoType *CtorType =
3125 Constructor->getType()->getAs<FunctionProtoType>();
3126 if (CtorType->getNumParams() > 0) {
3127 QualType FirstArg = CtorType->getParamType(0);
3128 if (Context.hasSameUnqualifiedType(Type, FirstArg.getNonReferenceType()))
3134 static OverloadingResult
3135 IsInitializerListConstructorConversion(Sema &S, Expr *From, QualType ToType,
3137 UserDefinedConversionSequence &User,
3138 OverloadCandidateSet &CandidateSet,
3139 bool AllowExplicit) {
3140 for (auto *D : S.LookupConstructors(To)) {
3141 auto Info = getConstructorInfo(D);
3145 bool Usable = !Info.Constructor->isInvalidDecl() &&
3146 S.isInitListConstructor(Info.Constructor) &&
3147 (AllowExplicit || !Info.Constructor->isExplicit());
3149 // If the first argument is (a reference to) the target type,
3150 // suppress conversions.
3151 bool SuppressUserConversions = isFirstArgumentCompatibleWithType(
3152 S.Context, Info.Constructor, ToType);
3153 if (Info.ConstructorTmpl)
3154 S.AddTemplateOverloadCandidate(Info.ConstructorTmpl, Info.FoundDecl,
3155 /*ExplicitArgs*/ nullptr, From,
3156 CandidateSet, SuppressUserConversions);
3158 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl, From,
3159 CandidateSet, SuppressUserConversions);
3163 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3165 OverloadCandidateSet::iterator Best;
3166 switch (auto Result =
3167 CandidateSet.BestViableFunction(S, From->getLocStart(),
3171 // Record the standard conversion we used and the conversion function.
3172 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function);
3173 QualType ThisType = Constructor->getThisType(S.Context);
3174 // Initializer lists don't have conversions as such.
3175 User.Before.setAsIdentityConversion();
3176 User.HadMultipleCandidates = HadMultipleCandidates;
3177 User.ConversionFunction = Constructor;
3178 User.FoundConversionFunction = Best->FoundDecl;
3179 User.After.setAsIdentityConversion();
3180 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType());
3181 User.After.setAllToTypes(ToType);
3185 case OR_No_Viable_Function:
3186 return OR_No_Viable_Function;
3188 return OR_Ambiguous;
3191 llvm_unreachable("Invalid OverloadResult!");
3194 /// Determines whether there is a user-defined conversion sequence
3195 /// (C++ [over.ics.user]) that converts expression From to the type
3196 /// ToType. If such a conversion exists, User will contain the
3197 /// user-defined conversion sequence that performs such a conversion
3198 /// and this routine will return true. Otherwise, this routine returns
3199 /// false and User is unspecified.
3201 /// \param AllowExplicit true if the conversion should consider C++0x
3202 /// "explicit" conversion functions as well as non-explicit conversion
3203 /// functions (C++0x [class.conv.fct]p2).
3205 /// \param AllowObjCConversionOnExplicit true if the conversion should
3206 /// allow an extra Objective-C pointer conversion on uses of explicit
3207 /// constructors. Requires \c AllowExplicit to also be set.
3208 static OverloadingResult
3209 IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
3210 UserDefinedConversionSequence &User,
3211 OverloadCandidateSet &CandidateSet,
3213 bool AllowObjCConversionOnExplicit) {
3214 assert(AllowExplicit || !AllowObjCConversionOnExplicit);
3216 // Whether we will only visit constructors.
3217 bool ConstructorsOnly = false;
3219 // If the type we are conversion to is a class type, enumerate its
3221 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) {
3222 // C++ [over.match.ctor]p1:
3223 // When objects of class type are direct-initialized (8.5), or
3224 // copy-initialized from an expression of the same or a
3225 // derived class type (8.5), overload resolution selects the
3226 // constructor. [...] For copy-initialization, the candidate
3227 // functions are all the converting constructors (12.3.1) of
3228 // that class. The argument list is the expression-list within
3229 // the parentheses of the initializer.
3230 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) ||
3231 (From->getType()->getAs<RecordType>() &&
3232 S.IsDerivedFrom(From->getLocStart(), From->getType(), ToType)))
3233 ConstructorsOnly = true;
3235 if (!S.isCompleteType(From->getExprLoc(), ToType)) {
3236 // We're not going to find any constructors.
3237 } else if (CXXRecordDecl *ToRecordDecl
3238 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) {
3240 Expr **Args = &From;
3241 unsigned NumArgs = 1;
3242 bool ListInitializing = false;
3243 if (InitListExpr *InitList = dyn_cast<InitListExpr>(From)) {
3244 // But first, see if there is an init-list-constructor that will work.
3245 OverloadingResult Result = IsInitializerListConstructorConversion(
3246 S, From, ToType, ToRecordDecl, User, CandidateSet, AllowExplicit);
3247 if (Result != OR_No_Viable_Function)
3250 CandidateSet.clear();
3252 // If we're list-initializing, we pass the individual elements as
3253 // arguments, not the entire list.
3254 Args = InitList->getInits();
3255 NumArgs = InitList->getNumInits();
3256 ListInitializing = true;
3259 for (auto *D : S.LookupConstructors(ToRecordDecl)) {
3260 auto Info = getConstructorInfo(D);
3264 bool Usable = !Info.Constructor->isInvalidDecl();
3265 if (ListInitializing)
3266 Usable = Usable && (AllowExplicit || !Info.Constructor->isExplicit());
3269 Info.Constructor->isConvertingConstructor(AllowExplicit);
3271 bool SuppressUserConversions = !ConstructorsOnly;
3272 if (SuppressUserConversions && ListInitializing) {
3273 SuppressUserConversions = false;
3275 // If the first argument is (a reference to) the target type,
3276 // suppress conversions.
3277 SuppressUserConversions = isFirstArgumentCompatibleWithType(
3278 S.Context, Info.Constructor, ToType);
3281 if (Info.ConstructorTmpl)
3282 S.AddTemplateOverloadCandidate(
3283 Info.ConstructorTmpl, Info.FoundDecl,
3284 /*ExplicitArgs*/ nullptr, llvm::makeArrayRef(Args, NumArgs),
3285 CandidateSet, SuppressUserConversions);
3287 // Allow one user-defined conversion when user specifies a
3288 // From->ToType conversion via an static cast (c-style, etc).
3289 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl,
3290 llvm::makeArrayRef(Args, NumArgs),
3291 CandidateSet, SuppressUserConversions);
3297 // Enumerate conversion functions, if we're allowed to.
3298 if (ConstructorsOnly || isa<InitListExpr>(From)) {
3299 } else if (!S.isCompleteType(From->getLocStart(), From->getType())) {
3300 // No conversion functions from incomplete types.
3301 } else if (const RecordType *FromRecordType
3302 = From->getType()->getAs<RecordType>()) {
3303 if (CXXRecordDecl *FromRecordDecl
3304 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) {
3305 // Add all of the conversion functions as candidates.
3306 const auto &Conversions = FromRecordDecl->getVisibleConversionFunctions();
3307 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
3308 DeclAccessPair FoundDecl = I.getPair();
3309 NamedDecl *D = FoundDecl.getDecl();
3310 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
3311 if (isa<UsingShadowDecl>(D))
3312 D = cast<UsingShadowDecl>(D)->getTargetDecl();
3314 CXXConversionDecl *Conv;
3315 FunctionTemplateDecl *ConvTemplate;
3316 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
3317 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
3319 Conv = cast<CXXConversionDecl>(D);
3321 if (AllowExplicit || !Conv->isExplicit()) {
3323 S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl,
3324 ActingContext, From, ToType,
3326 AllowObjCConversionOnExplicit);
3328 S.AddConversionCandidate(Conv, FoundDecl, ActingContext,
3329 From, ToType, CandidateSet,
3330 AllowObjCConversionOnExplicit);
3336 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3338 OverloadCandidateSet::iterator Best;
3339 switch (auto Result = CandidateSet.BestViableFunction(S, From->getLocStart(),
3343 // Record the standard conversion we used and the conversion function.
3344 if (CXXConstructorDecl *Constructor
3345 = dyn_cast<CXXConstructorDecl>(Best->Function)) {
3346 // C++ [over.ics.user]p1:
3347 // If the user-defined conversion is specified by a
3348 // constructor (12.3.1), the initial standard conversion
3349 // sequence converts the source type to the type required by
3350 // the argument of the constructor.
3352 QualType ThisType = Constructor->getThisType(S.Context);
3353 if (isa<InitListExpr>(From)) {
3354 // Initializer lists don't have conversions as such.
3355 User.Before.setAsIdentityConversion();
3357 if (Best->Conversions[0].isEllipsis())
3358 User.EllipsisConversion = true;
3360 User.Before = Best->Conversions[0].Standard;
3361 User.EllipsisConversion = false;
3364 User.HadMultipleCandidates = HadMultipleCandidates;
3365 User.ConversionFunction = Constructor;
3366 User.FoundConversionFunction = Best->FoundDecl;
3367 User.After.setAsIdentityConversion();
3368 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType());
3369 User.After.setAllToTypes(ToType);
3372 if (CXXConversionDecl *Conversion
3373 = dyn_cast<CXXConversionDecl>(Best->Function)) {
3374 // C++ [over.ics.user]p1:
3376 // [...] If the user-defined conversion is specified by a
3377 // conversion function (12.3.2), the initial standard
3378 // conversion sequence converts the source type to the
3379 // implicit object parameter of the conversion function.
3380 User.Before = Best->Conversions[0].Standard;
3381 User.HadMultipleCandidates = HadMultipleCandidates;
3382 User.ConversionFunction = Conversion;
3383 User.FoundConversionFunction = Best->FoundDecl;
3384 User.EllipsisConversion = false;
3386 // C++ [over.ics.user]p2:
3387 // The second standard conversion sequence converts the
3388 // result of the user-defined conversion to the target type
3389 // for the sequence. Since an implicit conversion sequence
3390 // is an initialization, the special rules for
3391 // initialization by user-defined conversion apply when
3392 // selecting the best user-defined conversion for a
3393 // user-defined conversion sequence (see 13.3.3 and
3395 User.After = Best->FinalConversion;
3398 llvm_unreachable("Not a constructor or conversion function?");
3400 case OR_No_Viable_Function:
3401 return OR_No_Viable_Function;
3404 return OR_Ambiguous;
3407 llvm_unreachable("Invalid OverloadResult!");
3411 Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) {
3412 ImplicitConversionSequence ICS;
3413 OverloadCandidateSet CandidateSet(From->getExprLoc(),
3414 OverloadCandidateSet::CSK_Normal);
3415 OverloadingResult OvResult =
3416 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined,
3417 CandidateSet, false, false);
3418 if (OvResult == OR_Ambiguous)
3419 Diag(From->getLocStart(), diag::err_typecheck_ambiguous_condition)
3420 << From->getType() << ToType << From->getSourceRange();
3421 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) {
3422 if (!RequireCompleteType(From->getLocStart(), ToType,
3423 diag::err_typecheck_nonviable_condition_incomplete,
3424 From->getType(), From->getSourceRange()))
3425 Diag(From->getLocStart(), diag::err_typecheck_nonviable_condition)
3426 << false << From->getType() << From->getSourceRange() << ToType;
3429 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, From);
3433 /// \brief Compare the user-defined conversion functions or constructors
3434 /// of two user-defined conversion sequences to determine whether any ordering
3436 static ImplicitConversionSequence::CompareKind
3437 compareConversionFunctions(Sema &S, FunctionDecl *Function1,
3438 FunctionDecl *Function2) {
3439 if (!S.getLangOpts().ObjC1 || !S.getLangOpts().CPlusPlus11)
3440 return ImplicitConversionSequence::Indistinguishable;
3443 // If both conversion functions are implicitly-declared conversions from
3444 // a lambda closure type to a function pointer and a block pointer,
3445 // respectively, always prefer the conversion to a function pointer,
3446 // because the function pointer is more lightweight and is more likely
3447 // to keep code working.
3448 CXXConversionDecl *Conv1 = dyn_cast_or_null<CXXConversionDecl>(Function1);
3450 return ImplicitConversionSequence::Indistinguishable;
3452 CXXConversionDecl *Conv2 = dyn_cast<CXXConversionDecl>(Function2);
3454 return ImplicitConversionSequence::Indistinguishable;
3456 if (Conv1->getParent()->isLambda() && Conv2->getParent()->isLambda()) {
3457 bool Block1 = Conv1->getConversionType()->isBlockPointerType();
3458 bool Block2 = Conv2->getConversionType()->isBlockPointerType();
3459 if (Block1 != Block2)
3460 return Block1 ? ImplicitConversionSequence::Worse
3461 : ImplicitConversionSequence::Better;
3464 return ImplicitConversionSequence::Indistinguishable;
3467 static bool hasDeprecatedStringLiteralToCharPtrConversion(
3468 const ImplicitConversionSequence &ICS) {
3469 return (ICS.isStandard() && ICS.Standard.DeprecatedStringLiteralToCharPtr) ||
3470 (ICS.isUserDefined() &&
3471 ICS.UserDefined.Before.DeprecatedStringLiteralToCharPtr);
3474 /// CompareImplicitConversionSequences - Compare two implicit
3475 /// conversion sequences to determine whether one is better than the
3476 /// other or if they are indistinguishable (C++ 13.3.3.2).
3477 static ImplicitConversionSequence::CompareKind
3478 CompareImplicitConversionSequences(Sema &S, SourceLocation Loc,
3479 const ImplicitConversionSequence& ICS1,
3480 const ImplicitConversionSequence& ICS2)
3482 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit
3483 // conversion sequences (as defined in 13.3.3.1)
3484 // -- a standard conversion sequence (13.3.3.1.1) is a better
3485 // conversion sequence than a user-defined conversion sequence or
3486 // an ellipsis conversion sequence, and
3487 // -- a user-defined conversion sequence (13.3.3.1.2) is a better
3488 // conversion sequence than an ellipsis conversion sequence
3491 // C++0x [over.best.ics]p10:
3492 // For the purpose of ranking implicit conversion sequences as
3493 // described in 13.3.3.2, the ambiguous conversion sequence is
3494 // treated as a user-defined sequence that is indistinguishable
3495 // from any other user-defined conversion sequence.
3497 // String literal to 'char *' conversion has been deprecated in C++03. It has
3498 // been removed from C++11. We still accept this conversion, if it happens at
3499 // the best viable function. Otherwise, this conversion is considered worse
3500 // than ellipsis conversion. Consider this as an extension; this is not in the
3501 // standard. For example:
3503 // int &f(...); // #1
3504 // void f(char*); // #2
3505 // void g() { int &r = f("foo"); }
3507 // In C++03, we pick #2 as the best viable function.
3508 // In C++11, we pick #1 as the best viable function, because ellipsis
3509 // conversion is better than string-literal to char* conversion (since there
3510 // is no such conversion in C++11). If there was no #1 at all or #1 couldn't
3511 // convert arguments, #2 would be the best viable function in C++11.
3512 // If the best viable function has this conversion, a warning will be issued
3513 // in C++03, or an ExtWarn (+SFINAE failure) will be issued in C++11.
3515 if (S.getLangOpts().CPlusPlus11 && !S.getLangOpts().WritableStrings &&
3516 hasDeprecatedStringLiteralToCharPtrConversion(ICS1) !=
3517 hasDeprecatedStringLiteralToCharPtrConversion(ICS2))
3518 return hasDeprecatedStringLiteralToCharPtrConversion(ICS1)
3519 ? ImplicitConversionSequence::Worse
3520 : ImplicitConversionSequence::Better;
3522 if (ICS1.getKindRank() < ICS2.getKindRank())
3523 return ImplicitConversionSequence::Better;
3524 if (ICS2.getKindRank() < ICS1.getKindRank())
3525 return ImplicitConversionSequence::Worse;
3527 // The following checks require both conversion sequences to be of
3529 if (ICS1.getKind() != ICS2.getKind())
3530 return ImplicitConversionSequence::Indistinguishable;
3532 ImplicitConversionSequence::CompareKind Result =
3533 ImplicitConversionSequence::Indistinguishable;
3535 // Two implicit conversion sequences of the same form are
3536 // indistinguishable conversion sequences unless one of the
3537 // following rules apply: (C++ 13.3.3.2p3):
3539 // List-initialization sequence L1 is a better conversion sequence than
3540 // list-initialization sequence L2 if:
3541 // - L1 converts to std::initializer_list<X> for some X and L2 does not, or,
3543 // - L1 converts to type "array of N1 T", L2 converts to type "array of N2 T",
3544 // and N1 is smaller than N2.,
3545 // even if one of the other rules in this paragraph would otherwise apply.
3546 if (!ICS1.isBad()) {
3547 if (ICS1.isStdInitializerListElement() &&
3548 !ICS2.isStdInitializerListElement())
3549 return ImplicitConversionSequence::Better;
3550 if (!ICS1.isStdInitializerListElement() &&
3551 ICS2.isStdInitializerListElement())
3552 return ImplicitConversionSequence::Worse;
3555 if (ICS1.isStandard())
3556 // Standard conversion sequence S1 is a better conversion sequence than
3557 // standard conversion sequence S2 if [...]
3558 Result = CompareStandardConversionSequences(S, Loc,
3559 ICS1.Standard, ICS2.Standard);
3560 else if (ICS1.isUserDefined()) {
3561 // User-defined conversion sequence U1 is a better conversion
3562 // sequence than another user-defined conversion sequence U2 if
3563 // they contain the same user-defined conversion function or
3564 // constructor and if the second standard conversion sequence of
3565 // U1 is better than the second standard conversion sequence of
3566 // U2 (C++ 13.3.3.2p3).
3567 if (ICS1.UserDefined.ConversionFunction ==
3568 ICS2.UserDefined.ConversionFunction)
3569 Result = CompareStandardConversionSequences(S, Loc,
3570 ICS1.UserDefined.After,
3571 ICS2.UserDefined.After);
3573 Result = compareConversionFunctions(S,
3574 ICS1.UserDefined.ConversionFunction,
3575 ICS2.UserDefined.ConversionFunction);
3581 static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) {
3582 while (Context.UnwrapSimilarPointerTypes(T1, T2)) {
3584 T1 = Context.getUnqualifiedArrayType(T1, Quals);
3585 T2 = Context.getUnqualifiedArrayType(T2, Quals);
3588 return Context.hasSameUnqualifiedType(T1, T2);
3591 // Per 13.3.3.2p3, compare the given standard conversion sequences to
3592 // determine if one is a proper subset of the other.
3593 static ImplicitConversionSequence::CompareKind
3594 compareStandardConversionSubsets(ASTContext &Context,
3595 const StandardConversionSequence& SCS1,
3596 const StandardConversionSequence& SCS2) {
3597 ImplicitConversionSequence::CompareKind Result
3598 = ImplicitConversionSequence::Indistinguishable;
3600 // the identity conversion sequence is considered to be a subsequence of
3601 // any non-identity conversion sequence
3602 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion())
3603 return ImplicitConversionSequence::Better;
3604 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion())
3605 return ImplicitConversionSequence::Worse;
3607 if (SCS1.Second != SCS2.Second) {
3608 if (SCS1.Second == ICK_Identity)
3609 Result = ImplicitConversionSequence::Better;
3610 else if (SCS2.Second == ICK_Identity)
3611 Result = ImplicitConversionSequence::Worse;
3613 return ImplicitConversionSequence::Indistinguishable;
3614 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1)))
3615 return ImplicitConversionSequence::Indistinguishable;
3617 if (SCS1.Third == SCS2.Third) {
3618 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result
3619 : ImplicitConversionSequence::Indistinguishable;
3622 if (SCS1.Third == ICK_Identity)
3623 return Result == ImplicitConversionSequence::Worse
3624 ? ImplicitConversionSequence::Indistinguishable
3625 : ImplicitConversionSequence::Better;
3627 if (SCS2.Third == ICK_Identity)
3628 return Result == ImplicitConversionSequence::Better
3629 ? ImplicitConversionSequence::Indistinguishable
3630 : ImplicitConversionSequence::Worse;
3632 return ImplicitConversionSequence::Indistinguishable;
3635 /// \brief Determine whether one of the given reference bindings is better
3636 /// than the other based on what kind of bindings they are.
3638 isBetterReferenceBindingKind(const StandardConversionSequence &SCS1,
3639 const StandardConversionSequence &SCS2) {
3640 // C++0x [over.ics.rank]p3b4:
3641 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an
3642 // implicit object parameter of a non-static member function declared
3643 // without a ref-qualifier, and *either* S1 binds an rvalue reference
3644 // to an rvalue and S2 binds an lvalue reference *or S1 binds an
3645 // lvalue reference to a function lvalue and S2 binds an rvalue
3648 // FIXME: Rvalue references. We're going rogue with the above edits,
3649 // because the semantics in the current C++0x working paper (N3225 at the
3650 // time of this writing) break the standard definition of std::forward
3651 // and std::reference_wrapper when dealing with references to functions.
3652 // Proposed wording changes submitted to CWG for consideration.
3653 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier ||
3654 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier)
3657 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue &&
3658 SCS2.IsLvalueReference) ||
3659 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue &&
3660 !SCS2.IsLvalueReference && SCS2.BindsToFunctionLvalue);
3663 /// CompareStandardConversionSequences - Compare two standard
3664 /// conversion sequences to determine whether one is better than the
3665 /// other or if they are indistinguishable (C++ 13.3.3.2p3).
3666 static ImplicitConversionSequence::CompareKind
3667 CompareStandardConversionSequences(Sema &S, SourceLocation Loc,
3668 const StandardConversionSequence& SCS1,
3669 const StandardConversionSequence& SCS2)
3671 // Standard conversion sequence S1 is a better conversion sequence
3672 // than standard conversion sequence S2 if (C++ 13.3.3.2p3):
3674 // -- S1 is a proper subsequence of S2 (comparing the conversion
3675 // sequences in the canonical form defined by 13.3.3.1.1,
3676 // excluding any Lvalue Transformation; the identity conversion
3677 // sequence is considered to be a subsequence of any
3678 // non-identity conversion sequence) or, if not that,
3679 if (ImplicitConversionSequence::CompareKind CK
3680 = compareStandardConversionSubsets(S.Context, SCS1, SCS2))
3683 // -- the rank of S1 is better than the rank of S2 (by the rules
3684 // defined below), or, if not that,
3685 ImplicitConversionRank Rank1 = SCS1.getRank();
3686 ImplicitConversionRank Rank2 = SCS2.getRank();
3688 return ImplicitConversionSequence::Better;
3689 else if (Rank2 < Rank1)
3690 return ImplicitConversionSequence::Worse;
3692 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank
3693 // are indistinguishable unless one of the following rules
3696 // A conversion that is not a conversion of a pointer, or
3697 // pointer to member, to bool is better than another conversion
3698 // that is such a conversion.
3699 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool())
3700 return SCS2.isPointerConversionToBool()
3701 ? ImplicitConversionSequence::Better
3702 : ImplicitConversionSequence::Worse;
3704 // C++ [over.ics.rank]p4b2:
3706 // If class B is derived directly or indirectly from class A,
3707 // conversion of B* to A* is better than conversion of B* to
3708 // void*, and conversion of A* to void* is better than conversion
3710 bool SCS1ConvertsToVoid
3711 = SCS1.isPointerConversionToVoidPointer(S.Context);
3712 bool SCS2ConvertsToVoid
3713 = SCS2.isPointerConversionToVoidPointer(S.Context);
3714 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) {
3715 // Exactly one of the conversion sequences is a conversion to
3716 // a void pointer; it's the worse conversion.
3717 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better
3718 : ImplicitConversionSequence::Worse;
3719 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) {
3720 // Neither conversion sequence converts to a void pointer; compare
3721 // their derived-to-base conversions.
3722 if (ImplicitConversionSequence::CompareKind DerivedCK
3723 = CompareDerivedToBaseConversions(S, Loc, SCS1, SCS2))
3725 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid &&
3726 !S.Context.hasSameType(SCS1.getFromType(), SCS2.getFromType())) {
3727 // Both conversion sequences are conversions to void
3728 // pointers. Compare the source types to determine if there's an
3729 // inheritance relationship in their sources.
3730 QualType FromType1 = SCS1.getFromType();
3731 QualType FromType2 = SCS2.getFromType();
3733 // Adjust the types we're converting from via the array-to-pointer
3734 // conversion, if we need to.
3735 if (SCS1.First == ICK_Array_To_Pointer)
3736 FromType1 = S.Context.getArrayDecayedType(FromType1);
3737 if (SCS2.First == ICK_Array_To_Pointer)
3738 FromType2 = S.Context.getArrayDecayedType(FromType2);
3740 QualType FromPointee1 = FromType1->getPointeeType().getUnqualifiedType();
3741 QualType FromPointee2 = FromType2->getPointeeType().getUnqualifiedType();
3743 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
3744 return ImplicitConversionSequence::Better;
3745 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
3746 return ImplicitConversionSequence::Worse;
3748 // Objective-C++: If one interface is more specific than the
3749 // other, it is the better one.
3750 const ObjCObjectPointerType* FromObjCPtr1
3751 = FromType1->getAs<ObjCObjectPointerType>();
3752 const ObjCObjectPointerType* FromObjCPtr2
3753 = FromType2->getAs<ObjCObjectPointerType>();
3754 if (FromObjCPtr1 && FromObjCPtr2) {
3755 bool AssignLeft = S.Context.canAssignObjCInterfaces(FromObjCPtr1,
3757 bool AssignRight = S.Context.canAssignObjCInterfaces(FromObjCPtr2,
3759 if (AssignLeft != AssignRight) {
3760 return AssignLeft? ImplicitConversionSequence::Better
3761 : ImplicitConversionSequence::Worse;
3766 // Compare based on qualification conversions (C++ 13.3.3.2p3,
3768 if (ImplicitConversionSequence::CompareKind QualCK
3769 = CompareQualificationConversions(S, SCS1, SCS2))
3772 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) {
3773 // Check for a better reference binding based on the kind of bindings.
3774 if (isBetterReferenceBindingKind(SCS1, SCS2))
3775 return ImplicitConversionSequence::Better;
3776 else if (isBetterReferenceBindingKind(SCS2, SCS1))
3777 return ImplicitConversionSequence::Worse;
3779 // C++ [over.ics.rank]p3b4:
3780 // -- S1 and S2 are reference bindings (8.5.3), and the types to
3781 // which the references refer are the same type except for
3782 // top-level cv-qualifiers, and the type to which the reference
3783 // initialized by S2 refers is more cv-qualified than the type
3784 // to which the reference initialized by S1 refers.
3785 QualType T1 = SCS1.getToType(2);
3786 QualType T2 = SCS2.getToType(2);
3787 T1 = S.Context.getCanonicalType(T1);
3788 T2 = S.Context.getCanonicalType(T2);
3789 Qualifiers T1Quals, T2Quals;
3790 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
3791 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
3792 if (UnqualT1 == UnqualT2) {
3793 // Objective-C++ ARC: If the references refer to objects with different
3794 // lifetimes, prefer bindings that don't change lifetime.
3795 if (SCS1.ObjCLifetimeConversionBinding !=
3796 SCS2.ObjCLifetimeConversionBinding) {
3797 return SCS1.ObjCLifetimeConversionBinding
3798 ? ImplicitConversionSequence::Worse
3799 : ImplicitConversionSequence::Better;
3802 // If the type is an array type, promote the element qualifiers to the
3803 // type for comparison.
3804 if (isa<ArrayType>(T1) && T1Quals)
3805 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals);
3806 if (isa<ArrayType>(T2) && T2Quals)
3807 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals);
3808 if (T2.isMoreQualifiedThan(T1))
3809 return ImplicitConversionSequence::Better;
3810 else if (T1.isMoreQualifiedThan(T2))
3811 return ImplicitConversionSequence::Worse;
3815 // In Microsoft mode, prefer an integral conversion to a
3816 // floating-to-integral conversion if the integral conversion
3817 // is between types of the same size.
3825 // Here, MSVC will call f(int) instead of generating a compile error
3826 // as clang will do in standard mode.
3827 if (S.getLangOpts().MSVCCompat && SCS1.Second == ICK_Integral_Conversion &&
3828 SCS2.Second == ICK_Floating_Integral &&
3829 S.Context.getTypeSize(SCS1.getFromType()) ==
3830 S.Context.getTypeSize(SCS1.getToType(2)))
3831 return ImplicitConversionSequence::Better;
3833 return ImplicitConversionSequence::Indistinguishable;
3836 /// CompareQualificationConversions - Compares two standard conversion
3837 /// sequences to determine whether they can be ranked based on their
3838 /// qualification conversions (C++ 13.3.3.2p3 bullet 3).
3839 static ImplicitConversionSequence::CompareKind
3840 CompareQualificationConversions(Sema &S,
3841 const StandardConversionSequence& SCS1,
3842 const StandardConversionSequence& SCS2) {
3844 // -- S1 and S2 differ only in their qualification conversion and
3845 // yield similar types T1 and T2 (C++ 4.4), respectively, and the
3846 // cv-qualification signature of type T1 is a proper subset of
3847 // the cv-qualification signature of type T2, and S1 is not the
3848 // deprecated string literal array-to-pointer conversion (4.2).
3849 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second ||
3850 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification)
3851 return ImplicitConversionSequence::Indistinguishable;
3853 // FIXME: the example in the standard doesn't use a qualification
3855 QualType T1 = SCS1.getToType(2);
3856 QualType T2 = SCS2.getToType(2);
3857 T1 = S.Context.getCanonicalType(T1);
3858 T2 = S.Context.getCanonicalType(T2);
3859 Qualifiers T1Quals, T2Quals;
3860 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
3861 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
3863 // If the types are the same, we won't learn anything by unwrapped
3865 if (UnqualT1 == UnqualT2)
3866 return ImplicitConversionSequence::Indistinguishable;
3868 // If the type is an array type, promote the element qualifiers to the type
3870 if (isa<ArrayType>(T1) && T1Quals)
3871 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals);
3872 if (isa<ArrayType>(T2) && T2Quals)
3873 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals);
3875 ImplicitConversionSequence::CompareKind Result
3876 = ImplicitConversionSequence::Indistinguishable;
3878 // Objective-C++ ARC:
3879 // Prefer qualification conversions not involving a change in lifetime
3880 // to qualification conversions that do not change lifetime.
3881 if (SCS1.QualificationIncludesObjCLifetime !=
3882 SCS2.QualificationIncludesObjCLifetime) {
3883 Result = SCS1.QualificationIncludesObjCLifetime
3884 ? ImplicitConversionSequence::Worse
3885 : ImplicitConversionSequence::Better;
3888 while (S.Context.UnwrapSimilarPointerTypes(T1, T2)) {
3889 // Within each iteration of the loop, we check the qualifiers to
3890 // determine if this still looks like a qualification
3891 // conversion. Then, if all is well, we unwrap one more level of
3892 // pointers or pointers-to-members and do it all again
3893 // until there are no more pointers or pointers-to-members left
3894 // to unwrap. This essentially mimics what
3895 // IsQualificationConversion does, but here we're checking for a
3896 // strict subset of qualifiers.
3897 if (T1.getCVRQualifiers() == T2.getCVRQualifiers())
3898 // The qualifiers are the same, so this doesn't tell us anything
3899 // about how the sequences rank.
3901 else if (T2.isMoreQualifiedThan(T1)) {
3902 // T1 has fewer qualifiers, so it could be the better sequence.
3903 if (Result == ImplicitConversionSequence::Worse)
3904 // Neither has qualifiers that are a subset of the other's
3906 return ImplicitConversionSequence::Indistinguishable;
3908 Result = ImplicitConversionSequence::Better;
3909 } else if (T1.isMoreQualifiedThan(T2)) {
3910 // T2 has fewer qualifiers, so it could be the better sequence.
3911 if (Result == ImplicitConversionSequence::Better)
3912 // Neither has qualifiers that are a subset of the other's
3914 return ImplicitConversionSequence::Indistinguishable;
3916 Result = ImplicitConversionSequence::Worse;
3918 // Qualifiers are disjoint.
3919 return ImplicitConversionSequence::Indistinguishable;
3922 // If the types after this point are equivalent, we're done.
3923 if (S.Context.hasSameUnqualifiedType(T1, T2))
3927 // Check that the winning standard conversion sequence isn't using
3928 // the deprecated string literal array to pointer conversion.
3930 case ImplicitConversionSequence::Better:
3931 if (SCS1.DeprecatedStringLiteralToCharPtr)
3932 Result = ImplicitConversionSequence::Indistinguishable;
3935 case ImplicitConversionSequence::Indistinguishable:
3938 case ImplicitConversionSequence::Worse:
3939 if (SCS2.DeprecatedStringLiteralToCharPtr)
3940 Result = ImplicitConversionSequence::Indistinguishable;
3947 /// CompareDerivedToBaseConversions - Compares two standard conversion
3948 /// sequences to determine whether they can be ranked based on their
3949 /// various kinds of derived-to-base conversions (C++
3950 /// [over.ics.rank]p4b3). As part of these checks, we also look at
3951 /// conversions between Objective-C interface types.
3952 static ImplicitConversionSequence::CompareKind
3953 CompareDerivedToBaseConversions(Sema &S, SourceLocation Loc,
3954 const StandardConversionSequence& SCS1,
3955 const StandardConversionSequence& SCS2) {
3956 QualType FromType1 = SCS1.getFromType();
3957 QualType ToType1 = SCS1.getToType(1);
3958 QualType FromType2 = SCS2.getFromType();
3959 QualType ToType2 = SCS2.getToType(1);
3961 // Adjust the types we're converting from via the array-to-pointer
3962 // conversion, if we need to.
3963 if (SCS1.First == ICK_Array_To_Pointer)
3964 FromType1 = S.Context.getArrayDecayedType(FromType1);
3965 if (SCS2.First == ICK_Array_To_Pointer)
3966 FromType2 = S.Context.getArrayDecayedType(FromType2);
3968 // Canonicalize all of the types.
3969 FromType1 = S.Context.getCanonicalType(FromType1);
3970 ToType1 = S.Context.getCanonicalType(ToType1);
3971 FromType2 = S.Context.getCanonicalType(FromType2);
3972 ToType2 = S.Context.getCanonicalType(ToType2);
3974 // C++ [over.ics.rank]p4b3:
3976 // If class B is derived directly or indirectly from class A and
3977 // class C is derived directly or indirectly from B,
3979 // Compare based on pointer conversions.
3980 if (SCS1.Second == ICK_Pointer_Conversion &&
3981 SCS2.Second == ICK_Pointer_Conversion &&
3982 /*FIXME: Remove if Objective-C id conversions get their own rank*/
3983 FromType1->isPointerType() && FromType2->isPointerType() &&
3984 ToType1->isPointerType() && ToType2->isPointerType()) {
3985 QualType FromPointee1
3986 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
3988 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
3989 QualType FromPointee2
3990 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
3992 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
3994 // -- conversion of C* to B* is better than conversion of C* to A*,
3995 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
3996 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
3997 return ImplicitConversionSequence::Better;
3998 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
3999 return ImplicitConversionSequence::Worse;
4002 // -- conversion of B* to A* is better than conversion of C* to A*,
4003 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) {
4004 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
4005 return ImplicitConversionSequence::Better;
4006 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
4007 return ImplicitConversionSequence::Worse;
4009 } else if (SCS1.Second == ICK_Pointer_Conversion &&
4010 SCS2.Second == ICK_Pointer_Conversion) {
4011 const ObjCObjectPointerType *FromPtr1
4012 = FromType1->getAs<ObjCObjectPointerType>();
4013 const ObjCObjectPointerType *FromPtr2
4014 = FromType2->getAs<ObjCObjectPointerType>();
4015 const ObjCObjectPointerType *ToPtr1
4016 = ToType1->getAs<ObjCObjectPointerType>();
4017 const ObjCObjectPointerType *ToPtr2
4018 = ToType2->getAs<ObjCObjectPointerType>();
4020 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) {
4021 // Apply the same conversion ranking rules for Objective-C pointer types
4022 // that we do for C++ pointers to class types. However, we employ the
4023 // Objective-C pseudo-subtyping relationship used for assignment of
4024 // Objective-C pointer types.
4026 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2);
4027 bool FromAssignRight
4028 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1);
4030 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2);
4032 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1);
4034 // A conversion to an a non-id object pointer type or qualified 'id'
4035 // type is better than a conversion to 'id'.
4036 if (ToPtr1->isObjCIdType() &&
4037 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl()))
4038 return ImplicitConversionSequence::Worse;
4039 if (ToPtr2->isObjCIdType() &&
4040 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl()))
4041 return ImplicitConversionSequence::Better;
4043 // A conversion to a non-id object pointer type is better than a
4044 // conversion to a qualified 'id' type
4045 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl())
4046 return ImplicitConversionSequence::Worse;
4047 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl())
4048 return ImplicitConversionSequence::Better;
4050 // A conversion to an a non-Class object pointer type or qualified 'Class'
4051 // type is better than a conversion to 'Class'.
4052 if (ToPtr1->isObjCClassType() &&
4053 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl()))
4054 return ImplicitConversionSequence::Worse;
4055 if (ToPtr2->isObjCClassType() &&
4056 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl()))
4057 return ImplicitConversionSequence::Better;
4059 // A conversion to a non-Class object pointer type is better than a
4060 // conversion to a qualified 'Class' type.
4061 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl())
4062 return ImplicitConversionSequence::Worse;
4063 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl())
4064 return ImplicitConversionSequence::Better;
4066 // -- "conversion of C* to B* is better than conversion of C* to A*,"
4067 if (S.Context.hasSameType(FromType1, FromType2) &&
4068 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() &&
4069 (ToAssignLeft != ToAssignRight))
4070 return ToAssignLeft? ImplicitConversionSequence::Worse
4071 : ImplicitConversionSequence::Better;
4073 // -- "conversion of B* to A* is better than conversion of C* to A*,"
4074 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) &&
4075 (FromAssignLeft != FromAssignRight))
4076 return FromAssignLeft? ImplicitConversionSequence::Better
4077 : ImplicitConversionSequence::Worse;
4081 // Ranking of member-pointer types.
4082 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member &&
4083 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() &&
4084 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) {
4085 const MemberPointerType * FromMemPointer1 =
4086 FromType1->getAs<MemberPointerType>();
4087 const MemberPointerType * ToMemPointer1 =
4088 ToType1->getAs<MemberPointerType>();
4089 const MemberPointerType * FromMemPointer2 =
4090 FromType2->getAs<MemberPointerType>();
4091 const MemberPointerType * ToMemPointer2 =
4092 ToType2->getAs<MemberPointerType>();
4093 const Type *FromPointeeType1 = FromMemPointer1->getClass();
4094 const Type *ToPointeeType1 = ToMemPointer1->getClass();
4095 const Type *FromPointeeType2 = FromMemPointer2->getClass();
4096 const Type *ToPointeeType2 = ToMemPointer2->getClass();
4097 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType();
4098 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType();
4099 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType();
4100 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType();
4101 // conversion of A::* to B::* is better than conversion of A::* to C::*,
4102 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
4103 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
4104 return ImplicitConversionSequence::Worse;
4105 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
4106 return ImplicitConversionSequence::Better;
4108 // conversion of B::* to C::* is better than conversion of A::* to C::*
4109 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) {
4110 if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
4111 return ImplicitConversionSequence::Better;
4112 else if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
4113 return ImplicitConversionSequence::Worse;
4117 if (SCS1.Second == ICK_Derived_To_Base) {
4118 // -- conversion of C to B is better than conversion of C to A,
4119 // -- binding of an expression of type C to a reference of type
4120 // B& is better than binding an expression of type C to a
4121 // reference of type A&,
4122 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4123 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4124 if (S.IsDerivedFrom(Loc, ToType1, ToType2))
4125 return ImplicitConversionSequence::Better;
4126 else if (S.IsDerivedFrom(Loc, ToType2, ToType1))
4127 return ImplicitConversionSequence::Worse;
4130 // -- conversion of B to A is better than conversion of C to A.
4131 // -- binding of an expression of type B to a reference of type
4132 // A& is better than binding an expression of type C to a
4133 // reference of type A&,
4134 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4135 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4136 if (S.IsDerivedFrom(Loc, FromType2, FromType1))
4137 return ImplicitConversionSequence::Better;
4138 else if (S.IsDerivedFrom(Loc, FromType1, FromType2))
4139 return ImplicitConversionSequence::Worse;
4143 return ImplicitConversionSequence::Indistinguishable;
4146 /// \brief Determine whether the given type is valid, e.g., it is not an invalid
4148 static bool isTypeValid(QualType T) {
4149 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl())
4150 return !Record->isInvalidDecl();
4155 /// CompareReferenceRelationship - Compare the two types T1 and T2 to
4156 /// determine whether they are reference-related,
4157 /// reference-compatible, reference-compatible with added
4158 /// qualification, or incompatible, for use in C++ initialization by
4159 /// reference (C++ [dcl.ref.init]p4). Neither type can be a reference
4160 /// type, and the first type (T1) is the pointee type of the reference
4161 /// type being initialized.
4162 Sema::ReferenceCompareResult
4163 Sema::CompareReferenceRelationship(SourceLocation Loc,
4164 QualType OrigT1, QualType OrigT2,
4165 bool &DerivedToBase,
4166 bool &ObjCConversion,
4167 bool &ObjCLifetimeConversion) {
4168 assert(!OrigT1->isReferenceType() &&
4169 "T1 must be the pointee type of the reference type");
4170 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type");
4172 QualType T1 = Context.getCanonicalType(OrigT1);
4173 QualType T2 = Context.getCanonicalType(OrigT2);
4174 Qualifiers T1Quals, T2Quals;
4175 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals);
4176 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals);
4178 // C++ [dcl.init.ref]p4:
4179 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is
4180 // reference-related to "cv2 T2" if T1 is the same type as T2, or
4181 // T1 is a base class of T2.
4182 DerivedToBase = false;
4183 ObjCConversion = false;
4184 ObjCLifetimeConversion = false;
4185 QualType ConvertedT2;
4186 if (UnqualT1 == UnqualT2) {
4188 } else if (isCompleteType(Loc, OrigT2) &&
4189 isTypeValid(UnqualT1) && isTypeValid(UnqualT2) &&
4190 IsDerivedFrom(Loc, UnqualT2, UnqualT1))
4191 DerivedToBase = true;
4192 else if (UnqualT1->isObjCObjectOrInterfaceType() &&
4193 UnqualT2->isObjCObjectOrInterfaceType() &&
4194 Context.canBindObjCObjectType(UnqualT1, UnqualT2))
4195 ObjCConversion = true;
4196 else if (UnqualT2->isFunctionType() &&
4197 IsFunctionConversion(UnqualT2, UnqualT1, ConvertedT2))
4198 // C++1z [dcl.init.ref]p4:
4199 // cv1 T1" is reference-compatible with "cv2 T2" if [...] T2 is "noexcept
4200 // function" and T1 is "function"
4202 // We extend this to also apply to 'noreturn', so allow any function
4203 // conversion between function types.
4204 return Ref_Compatible;
4206 return Ref_Incompatible;
4208 // At this point, we know that T1 and T2 are reference-related (at
4211 // If the type is an array type, promote the element qualifiers to the type
4213 if (isa<ArrayType>(T1) && T1Quals)
4214 T1 = Context.getQualifiedType(UnqualT1, T1Quals);
4215 if (isa<ArrayType>(T2) && T2Quals)
4216 T2 = Context.getQualifiedType(UnqualT2, T2Quals);
4218 // C++ [dcl.init.ref]p4:
4219 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is
4220 // reference-related to T2 and cv1 is the same cv-qualification
4221 // as, or greater cv-qualification than, cv2. For purposes of
4222 // overload resolution, cases for which cv1 is greater
4223 // cv-qualification than cv2 are identified as
4224 // reference-compatible with added qualification (see 13.3.3.2).
4226 // Note that we also require equivalence of Objective-C GC and address-space
4227 // qualifiers when performing these computations, so that e.g., an int in
4228 // address space 1 is not reference-compatible with an int in address
4230 if (T1Quals.getObjCLifetime() != T2Quals.getObjCLifetime() &&
4231 T1Quals.compatiblyIncludesObjCLifetime(T2Quals)) {
4232 if (isNonTrivialObjCLifetimeConversion(T2Quals, T1Quals))
4233 ObjCLifetimeConversion = true;
4235 T1Quals.removeObjCLifetime();
4236 T2Quals.removeObjCLifetime();
4239 // MS compiler ignores __unaligned qualifier for references; do the same.
4240 T1Quals.removeUnaligned();
4241 T2Quals.removeUnaligned();
4243 if (T1Quals.compatiblyIncludes(T2Quals))
4244 return Ref_Compatible;
4249 /// \brief Look for a user-defined conversion to an value reference-compatible
4250 /// with DeclType. Return true if something definite is found.
4252 FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS,
4253 QualType DeclType, SourceLocation DeclLoc,
4254 Expr *Init, QualType T2, bool AllowRvalues,
4255 bool AllowExplicit) {
4256 assert(T2->isRecordType() && "Can only find conversions of record types.");
4257 CXXRecordDecl *T2RecordDecl
4258 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl());
4260 OverloadCandidateSet CandidateSet(DeclLoc, OverloadCandidateSet::CSK_Normal);
4261 const auto &Conversions = T2RecordDecl->getVisibleConversionFunctions();
4262 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
4264 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
4265 if (isa<UsingShadowDecl>(D))
4266 D = cast<UsingShadowDecl>(D)->getTargetDecl();
4268 FunctionTemplateDecl *ConvTemplate
4269 = dyn_cast<FunctionTemplateDecl>(D);
4270 CXXConversionDecl *Conv;
4272 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
4274 Conv = cast<CXXConversionDecl>(D);
4276 // If this is an explicit conversion, and we're not allowed to consider
4277 // explicit conversions, skip it.
4278 if (!AllowExplicit && Conv->isExplicit())
4282 bool DerivedToBase = false;
4283 bool ObjCConversion = false;
4284 bool ObjCLifetimeConversion = false;
4286 // If we are initializing an rvalue reference, don't permit conversion
4287 // functions that return lvalues.
4288 if (!ConvTemplate && DeclType->isRValueReferenceType()) {
4289 const ReferenceType *RefType
4290 = Conv->getConversionType()->getAs<LValueReferenceType>();
4291 if (RefType && !RefType->getPointeeType()->isFunctionType())
4295 if (!ConvTemplate &&
4296 S.CompareReferenceRelationship(
4298 Conv->getConversionType().getNonReferenceType()
4299 .getUnqualifiedType(),
4300 DeclType.getNonReferenceType().getUnqualifiedType(),
4301 DerivedToBase, ObjCConversion, ObjCLifetimeConversion) ==
4302 Sema::Ref_Incompatible)
4305 // If the conversion function doesn't return a reference type,
4306 // it can't be considered for this conversion. An rvalue reference
4307 // is only acceptable if its referencee is a function type.
4309 const ReferenceType *RefType =
4310 Conv->getConversionType()->getAs<ReferenceType>();
4312 (!RefType->isLValueReferenceType() &&
4313 !RefType->getPointeeType()->isFunctionType()))
4318 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC,
4319 Init, DeclType, CandidateSet,
4320 /*AllowObjCConversionOnExplicit=*/false);
4322 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init,
4323 DeclType, CandidateSet,
4324 /*AllowObjCConversionOnExplicit=*/false);
4327 bool HadMultipleCandidates = (CandidateSet.size() > 1);
4329 OverloadCandidateSet::iterator Best;
4330 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) {
4332 // C++ [over.ics.ref]p1:
4334 // [...] If the parameter binds directly to the result of
4335 // applying a conversion function to the argument
4336 // expression, the implicit conversion sequence is a
4337 // user-defined conversion sequence (13.3.3.1.2), with the
4338 // second standard conversion sequence either an identity
4339 // conversion or, if the conversion function returns an
4340 // entity of a type that is a derived class of the parameter
4341 // type, a derived-to-base Conversion.
4342 if (!Best->FinalConversion.DirectBinding)
4345 ICS.setUserDefined();
4346 ICS.UserDefined.Before = Best->Conversions[0].Standard;
4347 ICS.UserDefined.After = Best->FinalConversion;
4348 ICS.UserDefined.HadMultipleCandidates = HadMultipleCandidates;
4349 ICS.UserDefined.ConversionFunction = Best->Function;
4350 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl;
4351 ICS.UserDefined.EllipsisConversion = false;
4352 assert(ICS.UserDefined.After.ReferenceBinding &&
4353 ICS.UserDefined.After.DirectBinding &&
4354 "Expected a direct reference binding!");
4359 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin();
4360 Cand != CandidateSet.end(); ++Cand)
4362 ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
4365 case OR_No_Viable_Function:
4367 // There was no suitable conversion, or we found a deleted
4368 // conversion; continue with other checks.
4372 llvm_unreachable("Invalid OverloadResult!");
4375 /// \brief Compute an implicit conversion sequence for reference
4377 static ImplicitConversionSequence
4378 TryReferenceInit(Sema &S, Expr *Init, QualType DeclType,
4379 SourceLocation DeclLoc,
4380 bool SuppressUserConversions,
4381 bool AllowExplicit) {
4382 assert(DeclType->isReferenceType() && "Reference init needs a reference");
4384 // Most paths end in a failed conversion.
4385 ImplicitConversionSequence ICS;
4386 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4388 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType();
4389 QualType T2 = Init->getType();
4391 // If the initializer is the address of an overloaded function, try
4392 // to resolve the overloaded function. If all goes well, T2 is the
4393 // type of the resulting function.
4394 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
4395 DeclAccessPair Found;
4396 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType,
4401 // Compute some basic properties of the types and the initializer.
4402 bool isRValRef = DeclType->isRValueReferenceType();
4403 bool DerivedToBase = false;
4404 bool ObjCConversion = false;
4405 bool ObjCLifetimeConversion = false;
4406 Expr::Classification InitCategory = Init->Classify(S.Context);
4407 Sema::ReferenceCompareResult RefRelationship
4408 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase,
4409 ObjCConversion, ObjCLifetimeConversion);
4412 // C++0x [dcl.init.ref]p5:
4413 // A reference to type "cv1 T1" is initialized by an expression
4414 // of type "cv2 T2" as follows:
4416 // -- If reference is an lvalue reference and the initializer expression
4418 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is
4419 // reference-compatible with "cv2 T2," or
4421 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here.
4422 if (InitCategory.isLValue() && RefRelationship == Sema::Ref_Compatible) {
4423 // C++ [over.ics.ref]p1:
4424 // When a parameter of reference type binds directly (8.5.3)
4425 // to an argument expression, the implicit conversion sequence
4426 // is the identity conversion, unless the argument expression
4427 // has a type that is a derived class of the parameter type,
4428 // in which case the implicit conversion sequence is a
4429 // derived-to-base Conversion (13.3.3.1).
4431 ICS.Standard.First = ICK_Identity;
4432 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base
4433 : ObjCConversion? ICK_Compatible_Conversion
4435 ICS.Standard.Third = ICK_Identity;
4436 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
4437 ICS.Standard.setToType(0, T2);
4438 ICS.Standard.setToType(1, T1);
4439 ICS.Standard.setToType(2, T1);
4440 ICS.Standard.ReferenceBinding = true;
4441 ICS.Standard.DirectBinding = true;
4442 ICS.Standard.IsLvalueReference = !isRValRef;
4443 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType();
4444 ICS.Standard.BindsToRvalue = false;
4445 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4446 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion;
4447 ICS.Standard.CopyConstructor = nullptr;
4448 ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
4450 // Nothing more to do: the inaccessibility/ambiguity check for
4451 // derived-to-base conversions is suppressed when we're
4452 // computing the implicit conversion sequence (C++
4453 // [over.best.ics]p2).
4457 // -- has a class type (i.e., T2 is a class type), where T1 is
4458 // not reference-related to T2, and can be implicitly
4459 // converted to an lvalue of type "cv3 T3," where "cv1 T1"
4460 // is reference-compatible with "cv3 T3" 92) (this
4461 // conversion is selected by enumerating the applicable
4462 // conversion functions (13.3.1.6) and choosing the best
4463 // one through overload resolution (13.3)),
4464 if (!SuppressUserConversions && T2->isRecordType() &&
4465 S.isCompleteType(DeclLoc, T2) &&
4466 RefRelationship == Sema::Ref_Incompatible) {
4467 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4468 Init, T2, /*AllowRvalues=*/false,
4474 // -- Otherwise, the reference shall be an lvalue reference to a
4475 // non-volatile const type (i.e., cv1 shall be const), or the reference
4476 // shall be an rvalue reference.
4477 if (!isRValRef && (!T1.isConstQualified() || T1.isVolatileQualified()))
4480 // -- If the initializer expression
4482 // -- is an xvalue, class prvalue, array prvalue or function
4483 // lvalue and "cv1 T1" is reference-compatible with "cv2 T2", or
4484 if (RefRelationship == Sema::Ref_Compatible &&
4485 (InitCategory.isXValue() ||
4486 (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) ||
4487 (InitCategory.isLValue() && T2->isFunctionType()))) {
4489 ICS.Standard.First = ICK_Identity;
4490 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base
4491 : ObjCConversion? ICK_Compatible_Conversion
4493 ICS.Standard.Third = ICK_Identity;
4494 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
4495 ICS.Standard.setToType(0, T2);
4496 ICS.Standard.setToType(1, T1);
4497 ICS.Standard.setToType(2, T1);
4498 ICS.Standard.ReferenceBinding = true;
4499 // In C++0x, this is always a direct binding. In C++98/03, it's a direct
4500 // binding unless we're binding to a class prvalue.
4501 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we
4502 // allow the use of rvalue references in C++98/03 for the benefit of
4503 // standard library implementors; therefore, we need the xvalue check here.
4504 ICS.Standard.DirectBinding =
4505 S.getLangOpts().CPlusPlus11 ||
4506 !(InitCategory.isPRValue() || T2->isRecordType());
4507 ICS.Standard.IsLvalueReference = !isRValRef;
4508 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType();
4509 ICS.Standard.BindsToRvalue = InitCategory.isRValue();
4510 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4511 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion;
4512 ICS.Standard.CopyConstructor = nullptr;
4513 ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
4517 // -- has a class type (i.e., T2 is a class type), where T1 is not
4518 // reference-related to T2, and can be implicitly converted to
4519 // an xvalue, class prvalue, or function lvalue of type
4520 // "cv3 T3", where "cv1 T1" is reference-compatible with
4523 // then the reference is bound to the value of the initializer
4524 // expression in the first case and to the result of the conversion
4525 // in the second case (or, in either case, to an appropriate base
4526 // class subobject).
4527 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4528 T2->isRecordType() && S.isCompleteType(DeclLoc, T2) &&
4529 FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4530 Init, T2, /*AllowRvalues=*/true,
4532 // In the second case, if the reference is an rvalue reference
4533 // and the second standard conversion sequence of the
4534 // user-defined conversion sequence includes an lvalue-to-rvalue
4535 // conversion, the program is ill-formed.
4536 if (ICS.isUserDefined() && isRValRef &&
4537 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue)
4538 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4543 // A temporary of function type cannot be created; don't even try.
4544 if (T1->isFunctionType())
4547 // -- Otherwise, a temporary of type "cv1 T1" is created and
4548 // initialized from the initializer expression using the
4549 // rules for a non-reference copy initialization (8.5). The
4550 // reference is then bound to the temporary. If T1 is
4551 // reference-related to T2, cv1 must be the same
4552 // cv-qualification as, or greater cv-qualification than,
4553 // cv2; otherwise, the program is ill-formed.
4554 if (RefRelationship == Sema::Ref_Related) {
4555 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then
4556 // we would be reference-compatible or reference-compatible with
4557 // added qualification. But that wasn't the case, so the reference
4558 // initialization fails.
4560 // Note that we only want to check address spaces and cvr-qualifiers here.
4561 // ObjC GC, lifetime and unaligned qualifiers aren't important.
4562 Qualifiers T1Quals = T1.getQualifiers();
4563 Qualifiers T2Quals = T2.getQualifiers();
4564 T1Quals.removeObjCGCAttr();
4565 T1Quals.removeObjCLifetime();
4566 T2Quals.removeObjCGCAttr();
4567 T2Quals.removeObjCLifetime();
4568 // MS compiler ignores __unaligned qualifier for references; do the same.
4569 T1Quals.removeUnaligned();
4570 T2Quals.removeUnaligned();
4571 if (!T1Quals.compatiblyIncludes(T2Quals))
4575 // If at least one of the types is a class type, the types are not
4576 // related, and we aren't allowed any user conversions, the
4577 // reference binding fails. This case is important for breaking
4578 // recursion, since TryImplicitConversion below will attempt to
4579 // create a temporary through the use of a copy constructor.
4580 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4581 (T1->isRecordType() || T2->isRecordType()))
4584 // If T1 is reference-related to T2 and the reference is an rvalue
4585 // reference, the initializer expression shall not be an lvalue.
4586 if (RefRelationship >= Sema::Ref_Related &&
4587 isRValRef && Init->Classify(S.Context).isLValue())
4590 // C++ [over.ics.ref]p2:
4591 // When a parameter of reference type is not bound directly to
4592 // an argument expression, the conversion sequence is the one
4593 // required to convert the argument expression to the
4594 // underlying type of the reference according to
4595 // 13.3.3.1. Conceptually, this conversion sequence corresponds
4596 // to copy-initializing a temporary of the underlying type with
4597 // the argument expression. Any difference in top-level
4598 // cv-qualification is subsumed by the initialization itself
4599 // and does not constitute a conversion.
4600 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions,
4601 /*AllowExplicit=*/false,
4602 /*InOverloadResolution=*/false,
4604 /*AllowObjCWritebackConversion=*/false,
4605 /*AllowObjCConversionOnExplicit=*/false);
4607 // Of course, that's still a reference binding.
4608 if (ICS.isStandard()) {
4609 ICS.Standard.ReferenceBinding = true;
4610 ICS.Standard.IsLvalueReference = !isRValRef;
4611 ICS.Standard.BindsToFunctionLvalue = false;
4612 ICS.Standard.BindsToRvalue = true;
4613 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4614 ICS.Standard.ObjCLifetimeConversionBinding = false;
4615 } else if (ICS.isUserDefined()) {
4616 const ReferenceType *LValRefType =
4617 ICS.UserDefined.ConversionFunction->getReturnType()
4618 ->getAs<LValueReferenceType>();
4620 // C++ [over.ics.ref]p3:
4621 // Except for an implicit object parameter, for which see 13.3.1, a
4622 // standard conversion sequence cannot be formed if it requires [...]
4623 // binding an rvalue reference to an lvalue other than a function
4625 // Note that the function case is not possible here.
4626 if (DeclType->isRValueReferenceType() && LValRefType) {
4627 // FIXME: This is the wrong BadConversionSequence. The problem is binding
4628 // an rvalue reference to a (non-function) lvalue, not binding an lvalue
4629 // reference to an rvalue!
4630 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, Init, DeclType);
4634 ICS.UserDefined.After.ReferenceBinding = true;
4635 ICS.UserDefined.After.IsLvalueReference = !isRValRef;
4636 ICS.UserDefined.After.BindsToFunctionLvalue = false;
4637 ICS.UserDefined.After.BindsToRvalue = !LValRefType;
4638 ICS.UserDefined.After.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4639 ICS.UserDefined.After.ObjCLifetimeConversionBinding = false;
4645 static ImplicitConversionSequence
4646 TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
4647 bool SuppressUserConversions,
4648 bool InOverloadResolution,
4649 bool AllowObjCWritebackConversion,
4650 bool AllowExplicit = false);
4652 /// TryListConversion - Try to copy-initialize a value of type ToType from the
4653 /// initializer list From.
4654 static ImplicitConversionSequence
4655 TryListConversion(Sema &S, InitListExpr *From, QualType ToType,
4656 bool SuppressUserConversions,
4657 bool InOverloadResolution,
4658 bool AllowObjCWritebackConversion) {
4659 // C++11 [over.ics.list]p1:
4660 // When an argument is an initializer list, it is not an expression and
4661 // special rules apply for converting it to a parameter type.
4663 ImplicitConversionSequence Result;
4664 Result.setBad(BadConversionSequence::no_conversion, From, ToType);
4666 // We need a complete type for what follows. Incomplete types can never be
4667 // initialized from init lists.
4668 if (!S.isCompleteType(From->getLocStart(), ToType))
4672 // If the parameter type is a class X and the initializer list has a single
4673 // element of type cv U, where U is X or a class derived from X, the
4674 // implicit conversion sequence is the one required to convert the element
4675 // to the parameter type.
4677 // Otherwise, if the parameter type is a character array [... ]
4678 // and the initializer list has a single element that is an
4679 // appropriately-typed string literal (8.5.2 [dcl.init.string]), the
4680 // implicit conversion sequence is the identity conversion.
4681 if (From->getNumInits() == 1) {
4682 if (ToType->isRecordType()) {
4683 QualType InitType = From->getInit(0)->getType();
4684 if (S.Context.hasSameUnqualifiedType(InitType, ToType) ||
4685 S.IsDerivedFrom(From->getLocStart(), InitType, ToType))
4686 return TryCopyInitialization(S, From->getInit(0), ToType,
4687 SuppressUserConversions,
4688 InOverloadResolution,
4689 AllowObjCWritebackConversion);
4691 // FIXME: Check the other conditions here: array of character type,
4692 // initializer is a string literal.
4693 if (ToType->isArrayType()) {
4694 InitializedEntity Entity =
4695 InitializedEntity::InitializeParameter(S.Context, ToType,
4696 /*Consumed=*/false);
4697 if (S.CanPerformCopyInitialization(Entity, From)) {
4698 Result.setStandard();
4699 Result.Standard.setAsIdentityConversion();
4700 Result.Standard.setFromType(ToType);
4701 Result.Standard.setAllToTypes(ToType);
4707 // C++14 [over.ics.list]p2: Otherwise, if the parameter type [...] (below).
4708 // C++11 [over.ics.list]p2:
4709 // If the parameter type is std::initializer_list<X> or "array of X" and
4710 // all the elements can be implicitly converted to X, the implicit
4711 // conversion sequence is the worst conversion necessary to convert an
4712 // element of the list to X.
4714 // C++14 [over.ics.list]p3:
4715 // Otherwise, if the parameter type is "array of N X", if the initializer
4716 // list has exactly N elements or if it has fewer than N elements and X is
4717 // default-constructible, and if all the elements of the initializer list
4718 // can be implicitly converted to X, the implicit conversion sequence is
4719 // the worst conversion necessary to convert an element of the list to X.
4721 // FIXME: We're missing a lot of these checks.
4722 bool toStdInitializerList = false;
4724 if (ToType->isArrayType())
4725 X = S.Context.getAsArrayType(ToType)->getElementType();
4727 toStdInitializerList = S.isStdInitializerList(ToType, &X);
4729 for (unsigned i = 0, e = From->getNumInits(); i < e; ++i) {
4730 Expr *Init = From->getInit(i);
4731 ImplicitConversionSequence ICS =
4732 TryCopyInitialization(S, Init, X, SuppressUserConversions,
4733 InOverloadResolution,
4734 AllowObjCWritebackConversion);
4735 // If a single element isn't convertible, fail.
4740 // Otherwise, look for the worst conversion.
4741 if (Result.isBad() ||
4742 CompareImplicitConversionSequences(S, From->getLocStart(), ICS,
4744 ImplicitConversionSequence::Worse)
4748 // For an empty list, we won't have computed any conversion sequence.
4749 // Introduce the identity conversion sequence.
4750 if (From->getNumInits() == 0) {
4751 Result.setStandard();
4752 Result.Standard.setAsIdentityConversion();
4753 Result.Standard.setFromType(ToType);
4754 Result.Standard.setAllToTypes(ToType);
4757 Result.setStdInitializerListElement(toStdInitializerList);
4761 // C++14 [over.ics.list]p4:
4762 // C++11 [over.ics.list]p3:
4763 // Otherwise, if the parameter is a non-aggregate class X and overload
4764 // resolution chooses a single best constructor [...] the implicit
4765 // conversion sequence is a user-defined conversion sequence. If multiple
4766 // constructors are viable but none is better than the others, the
4767 // implicit conversion sequence is a user-defined conversion sequence.
4768 if (ToType->isRecordType() && !ToType->isAggregateType()) {
4769 // This function can deal with initializer lists.
4770 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
4771 /*AllowExplicit=*/false,
4772 InOverloadResolution, /*CStyle=*/false,
4773 AllowObjCWritebackConversion,
4774 /*AllowObjCConversionOnExplicit=*/false);
4777 // C++14 [over.ics.list]p5:
4778 // C++11 [over.ics.list]p4:
4779 // Otherwise, if the parameter has an aggregate type which can be
4780 // initialized from the initializer list [...] the implicit conversion
4781 // sequence is a user-defined conversion sequence.
4782 if (ToType->isAggregateType()) {
4783 // Type is an aggregate, argument is an init list. At this point it comes
4784 // down to checking whether the initialization works.
4785 // FIXME: Find out whether this parameter is consumed or not.
4786 // FIXME: Expose SemaInit's aggregate initialization code so that we don't
4787 // need to call into the initialization code here; overload resolution
4788 // should not be doing that.
4789 InitializedEntity Entity =
4790 InitializedEntity::InitializeParameter(S.Context, ToType,
4791 /*Consumed=*/false);
4792 if (S.CanPerformCopyInitialization(Entity, From)) {
4793 Result.setUserDefined();
4794 Result.UserDefined.Before.setAsIdentityConversion();
4795 // Initializer lists don't have a type.
4796 Result.UserDefined.Before.setFromType(QualType());
4797 Result.UserDefined.Before.setAllToTypes(QualType());
4799 Result.UserDefined.After.setAsIdentityConversion();
4800 Result.UserDefined.After.setFromType(ToType);
4801 Result.UserDefined.After.setAllToTypes(ToType);
4802 Result.UserDefined.ConversionFunction = nullptr;
4807 // C++14 [over.ics.list]p6:
4808 // C++11 [over.ics.list]p5:
4809 // Otherwise, if the parameter is a reference, see 13.3.3.1.4.
4810 if (ToType->isReferenceType()) {
4811 // The standard is notoriously unclear here, since 13.3.3.1.4 doesn't
4812 // mention initializer lists in any way. So we go by what list-
4813 // initialization would do and try to extrapolate from that.
4815 QualType T1 = ToType->getAs<ReferenceType>()->getPointeeType();
4817 // If the initializer list has a single element that is reference-related
4818 // to the parameter type, we initialize the reference from that.
4819 if (From->getNumInits() == 1) {
4820 Expr *Init = From->getInit(0);
4822 QualType T2 = Init->getType();
4824 // If the initializer is the address of an overloaded function, try
4825 // to resolve the overloaded function. If all goes well, T2 is the
4826 // type of the resulting function.
4827 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
4828 DeclAccessPair Found;
4829 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(
4830 Init, ToType, false, Found))
4834 // Compute some basic properties of the types and the initializer.
4835 bool dummy1 = false;
4836 bool dummy2 = false;
4837 bool dummy3 = false;
4838 Sema::ReferenceCompareResult RefRelationship
4839 = S.CompareReferenceRelationship(From->getLocStart(), T1, T2, dummy1,
4842 if (RefRelationship >= Sema::Ref_Related) {
4843 return TryReferenceInit(S, Init, ToType, /*FIXME*/From->getLocStart(),
4844 SuppressUserConversions,
4845 /*AllowExplicit=*/false);
4849 // Otherwise, we bind the reference to a temporary created from the
4850 // initializer list.
4851 Result = TryListConversion(S, From, T1, SuppressUserConversions,
4852 InOverloadResolution,
4853 AllowObjCWritebackConversion);
4854 if (Result.isFailure())
4856 assert(!Result.isEllipsis() &&
4857 "Sub-initialization cannot result in ellipsis conversion.");
4859 // Can we even bind to a temporary?
4860 if (ToType->isRValueReferenceType() ||
4861 (T1.isConstQualified() && !T1.isVolatileQualified())) {
4862 StandardConversionSequence &SCS = Result.isStandard() ? Result.Standard :
4863 Result.UserDefined.After;
4864 SCS.ReferenceBinding = true;
4865 SCS.IsLvalueReference = ToType->isLValueReferenceType();
4866 SCS.BindsToRvalue = true;
4867 SCS.BindsToFunctionLvalue = false;
4868 SCS.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4869 SCS.ObjCLifetimeConversionBinding = false;
4871 Result.setBad(BadConversionSequence::lvalue_ref_to_rvalue,
4876 // C++14 [over.ics.list]p7:
4877 // C++11 [over.ics.list]p6:
4878 // Otherwise, if the parameter type is not a class:
4879 if (!ToType->isRecordType()) {
4880 // - if the initializer list has one element that is not itself an
4881 // initializer list, the implicit conversion sequence is the one
4882 // required to convert the element to the parameter type.
4883 unsigned NumInits = From->getNumInits();
4884 if (NumInits == 1 && !isa<InitListExpr>(From->getInit(0)))
4885 Result = TryCopyInitialization(S, From->getInit(0), ToType,
4886 SuppressUserConversions,
4887 InOverloadResolution,
4888 AllowObjCWritebackConversion);
4889 // - if the initializer list has no elements, the implicit conversion
4890 // sequence is the identity conversion.
4891 else if (NumInits == 0) {
4892 Result.setStandard();
4893 Result.Standard.setAsIdentityConversion();
4894 Result.Standard.setFromType(ToType);
4895 Result.Standard.setAllToTypes(ToType);
4900 // C++14 [over.ics.list]p8:
4901 // C++11 [over.ics.list]p7:
4902 // In all cases other than those enumerated above, no conversion is possible
4906 /// TryCopyInitialization - Try to copy-initialize a value of type
4907 /// ToType from the expression From. Return the implicit conversion
4908 /// sequence required to pass this argument, which may be a bad
4909 /// conversion sequence (meaning that the argument cannot be passed to
4910 /// a parameter of this type). If @p SuppressUserConversions, then we
4911 /// do not permit any user-defined conversion sequences.
4912 static ImplicitConversionSequence
4913 TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
4914 bool SuppressUserConversions,
4915 bool InOverloadResolution,
4916 bool AllowObjCWritebackConversion,
4917 bool AllowExplicit) {
4918 if (InitListExpr *FromInitList = dyn_cast<InitListExpr>(From))
4919 return TryListConversion(S, FromInitList, ToType, SuppressUserConversions,
4920 InOverloadResolution,AllowObjCWritebackConversion);
4922 if (ToType->isReferenceType())
4923 return TryReferenceInit(S, From, ToType,
4924 /*FIXME:*/From->getLocStart(),
4925 SuppressUserConversions,
4928 return TryImplicitConversion(S, From, ToType,
4929 SuppressUserConversions,
4930 /*AllowExplicit=*/false,
4931 InOverloadResolution,
4933 AllowObjCWritebackConversion,
4934 /*AllowObjCConversionOnExplicit=*/false);
4937 static bool TryCopyInitialization(const CanQualType FromQTy,
4938 const CanQualType ToQTy,
4941 ExprValueKind FromVK) {
4942 OpaqueValueExpr TmpExpr(Loc, FromQTy, FromVK);
4943 ImplicitConversionSequence ICS =
4944 TryCopyInitialization(S, &TmpExpr, ToQTy, true, true, false);
4946 return !ICS.isBad();
4949 /// TryObjectArgumentInitialization - Try to initialize the object
4950 /// parameter of the given member function (@c Method) from the
4951 /// expression @p From.
4952 static ImplicitConversionSequence
4953 TryObjectArgumentInitialization(Sema &S, SourceLocation Loc, QualType FromType,
4954 Expr::Classification FromClassification,
4955 CXXMethodDecl *Method,
4956 CXXRecordDecl *ActingContext) {
4957 QualType ClassType = S.Context.getTypeDeclType(ActingContext);
4958 // [class.dtor]p2: A destructor can be invoked for a const, volatile or
4959 // const volatile object.
4960 unsigned Quals = isa<CXXDestructorDecl>(Method) ?
4961 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers();
4962 QualType ImplicitParamType = S.Context.getCVRQualifiedType(ClassType, Quals);
4964 // Set up the conversion sequence as a "bad" conversion, to allow us
4966 ImplicitConversionSequence ICS;
4968 // We need to have an object of class type.
4969 if (const PointerType *PT = FromType->getAs<PointerType>()) {
4970 FromType = PT->getPointeeType();
4972 // When we had a pointer, it's implicitly dereferenced, so we
4973 // better have an lvalue.
4974 assert(FromClassification.isLValue());
4977 assert(FromType->isRecordType());
4979 // C++0x [over.match.funcs]p4:
4980 // For non-static member functions, the type of the implicit object
4983 // - "lvalue reference to cv X" for functions declared without a
4984 // ref-qualifier or with the & ref-qualifier
4985 // - "rvalue reference to cv X" for functions declared with the &&
4988 // where X is the class of which the function is a member and cv is the
4989 // cv-qualification on the member function declaration.
4991 // However, when finding an implicit conversion sequence for the argument, we
4992 // are not allowed to perform user-defined conversions
4993 // (C++ [over.match.funcs]p5). We perform a simplified version of
4994 // reference binding here, that allows class rvalues to bind to
4995 // non-constant references.
4997 // First check the qualifiers.
4998 QualType FromTypeCanon = S.Context.getCanonicalType(FromType);
4999 if (ImplicitParamType.getCVRQualifiers()
5000 != FromTypeCanon.getLocalCVRQualifiers() &&
5001 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) {
5002 ICS.setBad(BadConversionSequence::bad_qualifiers,
5003 FromType, ImplicitParamType);
5007 // Check that we have either the same type or a derived type. It
5008 // affects the conversion rank.
5009 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType);
5010 ImplicitConversionKind SecondKind;
5011 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) {
5012 SecondKind = ICK_Identity;
5013 } else if (S.IsDerivedFrom(Loc, FromType, ClassType))
5014 SecondKind = ICK_Derived_To_Base;
5016 ICS.setBad(BadConversionSequence::unrelated_class,
5017 FromType, ImplicitParamType);
5021 // Check the ref-qualifier.
5022 switch (Method->getRefQualifier()) {
5024 // Do nothing; we don't care about lvalueness or rvalueness.
5028 if (!FromClassification.isLValue() && Quals != Qualifiers::Const) {
5029 // non-const lvalue reference cannot bind to an rvalue
5030 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType,
5037 if (!FromClassification.isRValue()) {
5038 // rvalue reference cannot bind to an lvalue
5039 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType,
5046 // Success. Mark this as a reference binding.
5048 ICS.Standard.setAsIdentityConversion();
5049 ICS.Standard.Second = SecondKind;
5050 ICS.Standard.setFromType(FromType);
5051 ICS.Standard.setAllToTypes(ImplicitParamType);
5052 ICS.Standard.ReferenceBinding = true;
5053 ICS.Standard.DirectBinding = true;
5054 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue;
5055 ICS.Standard.BindsToFunctionLvalue = false;
5056 ICS.Standard.BindsToRvalue = FromClassification.isRValue();
5057 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier
5058 = (Method->getRefQualifier() == RQ_None);
5062 /// PerformObjectArgumentInitialization - Perform initialization of
5063 /// the implicit object parameter for the given Method with the given
5066 Sema::PerformObjectArgumentInitialization(Expr *From,
5067 NestedNameSpecifier *Qualifier,
5068 NamedDecl *FoundDecl,
5069 CXXMethodDecl *Method) {
5070 QualType FromRecordType, DestType;
5071 QualType ImplicitParamRecordType =
5072 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType();
5074 Expr::Classification FromClassification;
5075 if (const PointerType *PT = From->getType()->getAs<PointerType>()) {
5076 FromRecordType = PT->getPointeeType();
5077 DestType = Method->getThisType(Context);
5078 FromClassification = Expr::Classification::makeSimpleLValue();
5080 FromRecordType = From->getType();
5081 DestType = ImplicitParamRecordType;
5082 FromClassification = From->Classify(Context);
5085 // Note that we always use the true parent context when performing
5086 // the actual argument initialization.
5087 ImplicitConversionSequence ICS = TryObjectArgumentInitialization(
5088 *this, From->getLocStart(), From->getType(), FromClassification, Method,
5089 Method->getParent());
5091 if (ICS.Bad.Kind == BadConversionSequence::bad_qualifiers) {
5092 Qualifiers FromQs = FromRecordType.getQualifiers();
5093 Qualifiers ToQs = DestType.getQualifiers();
5094 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers();
5096 Diag(From->getLocStart(),
5097 diag::err_member_function_call_bad_cvr)
5098 << Method->getDeclName() << FromRecordType << (CVR - 1)
5099 << From->getSourceRange();
5100 Diag(Method->getLocation(), diag::note_previous_decl)
5101 << Method->getDeclName();
5106 return Diag(From->getLocStart(),
5107 diag::err_implicit_object_parameter_init)
5108 << ImplicitParamRecordType << FromRecordType << From->getSourceRange();
5111 if (ICS.Standard.Second == ICK_Derived_To_Base) {
5112 ExprResult FromRes =
5113 PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method);
5114 if (FromRes.isInvalid())
5116 From = FromRes.get();
5119 if (!Context.hasSameType(From->getType(), DestType))
5120 From = ImpCastExprToType(From, DestType, CK_NoOp,
5121 From->getValueKind()).get();
5125 /// TryContextuallyConvertToBool - Attempt to contextually convert the
5126 /// expression From to bool (C++0x [conv]p3).
5127 static ImplicitConversionSequence
5128 TryContextuallyConvertToBool(Sema &S, Expr *From) {
5129 return TryImplicitConversion(S, From, S.Context.BoolTy,
5130 /*SuppressUserConversions=*/false,
5131 /*AllowExplicit=*/true,
5132 /*InOverloadResolution=*/false,
5134 /*AllowObjCWritebackConversion=*/false,
5135 /*AllowObjCConversionOnExplicit=*/false);
5138 /// PerformContextuallyConvertToBool - Perform a contextual conversion
5139 /// of the expression From to bool (C++0x [conv]p3).
5140 ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) {
5141 if (checkPlaceholderForOverload(*this, From))
5144 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From);
5146 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting);
5148 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy))
5149 return Diag(From->getLocStart(),
5150 diag::err_typecheck_bool_condition)
5151 << From->getType() << From->getSourceRange();
5155 /// Check that the specified conversion is permitted in a converted constant
5156 /// expression, according to C++11 [expr.const]p3. Return true if the conversion
5158 static bool CheckConvertedConstantConversions(Sema &S,
5159 StandardConversionSequence &SCS) {
5160 // Since we know that the target type is an integral or unscoped enumeration
5161 // type, most conversion kinds are impossible. All possible First and Third
5162 // conversions are fine.
5163 switch (SCS.Second) {
5165 case ICK_Function_Conversion:
5166 case ICK_Integral_Promotion:
5167 case ICK_Integral_Conversion: // Narrowing conversions are checked elsewhere.
5168 case ICK_Zero_Queue_Conversion:
5171 case ICK_Boolean_Conversion:
5172 // Conversion from an integral or unscoped enumeration type to bool is
5173 // classified as ICK_Boolean_Conversion, but it's also arguably an integral
5174 // conversion, so we allow it in a converted constant expression.
5176 // FIXME: Per core issue 1407, we should not allow this, but that breaks
5177 // a lot of popular code. We should at least add a warning for this
5178 // (non-conforming) extension.
5179 return SCS.getFromType()->isIntegralOrUnscopedEnumerationType() &&
5180 SCS.getToType(2)->isBooleanType();
5182 case ICK_Pointer_Conversion:
5183 case ICK_Pointer_Member:
5184 // C++1z: null pointer conversions and null member pointer conversions are
5185 // only permitted if the source type is std::nullptr_t.
5186 return SCS.getFromType()->isNullPtrType();
5188 case ICK_Floating_Promotion:
5189 case ICK_Complex_Promotion:
5190 case ICK_Floating_Conversion:
5191 case ICK_Complex_Conversion:
5192 case ICK_Floating_Integral:
5193 case ICK_Compatible_Conversion:
5194 case ICK_Derived_To_Base:
5195 case ICK_Vector_Conversion:
5196 case ICK_Vector_Splat:
5197 case ICK_Complex_Real:
5198 case ICK_Block_Pointer_Conversion:
5199 case ICK_TransparentUnionConversion:
5200 case ICK_Writeback_Conversion:
5201 case ICK_Zero_Event_Conversion:
5202 case ICK_C_Only_Conversion:
5203 case ICK_Incompatible_Pointer_Conversion:
5206 case ICK_Lvalue_To_Rvalue:
5207 case ICK_Array_To_Pointer:
5208 case ICK_Function_To_Pointer:
5209 llvm_unreachable("found a first conversion kind in Second");
5211 case ICK_Qualification:
5212 llvm_unreachable("found a third conversion kind in Second");
5214 case ICK_Num_Conversion_Kinds:
5218 llvm_unreachable("unknown conversion kind");
5221 /// CheckConvertedConstantExpression - Check that the expression From is a
5222 /// converted constant expression of type T, perform the conversion and produce
5223 /// the converted expression, per C++11 [expr.const]p3.
5224 static ExprResult CheckConvertedConstantExpression(Sema &S, Expr *From,
5225 QualType T, APValue &Value,
5228 assert(S.getLangOpts().CPlusPlus11 &&
5229 "converted constant expression outside C++11");
5231 if (checkPlaceholderForOverload(S, From))
5234 // C++1z [expr.const]p3:
5235 // A converted constant expression of type T is an expression,
5236 // implicitly converted to type T, where the converted
5237 // expression is a constant expression and the implicit conversion
5238 // sequence contains only [... list of conversions ...].
5239 // C++1z [stmt.if]p2:
5240 // If the if statement is of the form if constexpr, the value of the
5241 // condition shall be a contextually converted constant expression of type
5243 ImplicitConversionSequence ICS =
5244 CCE == Sema::CCEK_ConstexprIf
5245 ? TryContextuallyConvertToBool(S, From)
5246 : TryCopyInitialization(S, From, T,
5247 /*SuppressUserConversions=*/false,
5248 /*InOverloadResolution=*/false,
5249 /*AllowObjcWritebackConversion=*/false,
5250 /*AllowExplicit=*/false);
5251 StandardConversionSequence *SCS = nullptr;
5252 switch (ICS.getKind()) {
5253 case ImplicitConversionSequence::StandardConversion:
5254 SCS = &ICS.Standard;
5256 case ImplicitConversionSequence::UserDefinedConversion:
5257 // We are converting to a non-class type, so the Before sequence
5259 SCS = &ICS.UserDefined.After;
5261 case ImplicitConversionSequence::AmbiguousConversion:
5262 case ImplicitConversionSequence::BadConversion:
5263 if (!S.DiagnoseMultipleUserDefinedConversion(From, T))
5264 return S.Diag(From->getLocStart(),
5265 diag::err_typecheck_converted_constant_expression)
5266 << From->getType() << From->getSourceRange() << T;
5269 case ImplicitConversionSequence::EllipsisConversion:
5270 llvm_unreachable("ellipsis conversion in converted constant expression");
5273 // Check that we would only use permitted conversions.
5274 if (!CheckConvertedConstantConversions(S, *SCS)) {
5275 return S.Diag(From->getLocStart(),
5276 diag::err_typecheck_converted_constant_expression_disallowed)
5277 << From->getType() << From->getSourceRange() << T;
5279 // [...] and where the reference binding (if any) binds directly.
5280 if (SCS->ReferenceBinding && !SCS->DirectBinding) {
5281 return S.Diag(From->getLocStart(),
5282 diag::err_typecheck_converted_constant_expression_indirect)
5283 << From->getType() << From->getSourceRange() << T;
5287 S.PerformImplicitConversion(From, T, ICS, Sema::AA_Converting);
5288 if (Result.isInvalid())
5291 // Check for a narrowing implicit conversion.
5292 APValue PreNarrowingValue;
5293 QualType PreNarrowingType;
5294 switch (SCS->getNarrowingKind(S.Context, Result.get(), PreNarrowingValue,
5295 PreNarrowingType)) {
5296 case NK_Dependent_Narrowing:
5297 // Implicit conversion to a narrower type, but the expression is
5298 // value-dependent so we can't tell whether it's actually narrowing.
5299 case NK_Variable_Narrowing:
5300 // Implicit conversion to a narrower type, and the value is not a constant
5301 // expression. We'll diagnose this in a moment.
5302 case NK_Not_Narrowing:
5305 case NK_Constant_Narrowing:
5306 S.Diag(From->getLocStart(), diag::ext_cce_narrowing)
5307 << CCE << /*Constant*/1
5308 << PreNarrowingValue.getAsString(S.Context, PreNarrowingType) << T;
5311 case NK_Type_Narrowing:
5312 S.Diag(From->getLocStart(), diag::ext_cce_narrowing)
5313 << CCE << /*Constant*/0 << From->getType() << T;
5317 if (Result.get()->isValueDependent()) {
5322 // Check the expression is a constant expression.
5323 SmallVector<PartialDiagnosticAt, 8> Notes;
5324 Expr::EvalResult Eval;
5327 if ((T->isReferenceType()
5328 ? !Result.get()->EvaluateAsLValue(Eval, S.Context)
5329 : !Result.get()->EvaluateAsRValue(Eval, S.Context)) ||
5330 (RequireInt && !Eval.Val.isInt())) {
5331 // The expression can't be folded, so we can't keep it at this position in
5333 Result = ExprError();
5337 if (Notes.empty()) {
5338 // It's a constant expression.
5343 // It's not a constant expression. Produce an appropriate diagnostic.
5344 if (Notes.size() == 1 &&
5345 Notes[0].second.getDiagID() == diag::note_invalid_subexpr_in_const_expr)
5346 S.Diag(Notes[0].first, diag::err_expr_not_cce) << CCE;
5348 S.Diag(From->getLocStart(), diag::err_expr_not_cce)
5349 << CCE << From->getSourceRange();
5350 for (unsigned I = 0; I < Notes.size(); ++I)
5351 S.Diag(Notes[I].first, Notes[I].second);
5356 ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5357 APValue &Value, CCEKind CCE) {
5358 return ::CheckConvertedConstantExpression(*this, From, T, Value, CCE, false);
5361 ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5362 llvm::APSInt &Value,
5364 assert(T->isIntegralOrEnumerationType() && "unexpected converted const type");
5367 auto R = ::CheckConvertedConstantExpression(*this, From, T, V, CCE, true);
5368 if (!R.isInvalid() && !R.get()->isValueDependent())
5374 /// dropPointerConversions - If the given standard conversion sequence
5375 /// involves any pointer conversions, remove them. This may change
5376 /// the result type of the conversion sequence.
5377 static void dropPointerConversion(StandardConversionSequence &SCS) {
5378 if (SCS.Second == ICK_Pointer_Conversion) {
5379 SCS.Second = ICK_Identity;
5380 SCS.Third = ICK_Identity;
5381 SCS.ToTypePtrs[2] = SCS.ToTypePtrs[1] = SCS.ToTypePtrs[0];
5385 /// TryContextuallyConvertToObjCPointer - Attempt to contextually
5386 /// convert the expression From to an Objective-C pointer type.
5387 static ImplicitConversionSequence
5388 TryContextuallyConvertToObjCPointer(Sema &S, Expr *From) {
5389 // Do an implicit conversion to 'id'.
5390 QualType Ty = S.Context.getObjCIdType();
5391 ImplicitConversionSequence ICS
5392 = TryImplicitConversion(S, From, Ty,
5393 // FIXME: Are these flags correct?
5394 /*SuppressUserConversions=*/false,
5395 /*AllowExplicit=*/true,
5396 /*InOverloadResolution=*/false,
5398 /*AllowObjCWritebackConversion=*/false,
5399 /*AllowObjCConversionOnExplicit=*/true);
5401 // Strip off any final conversions to 'id'.
5402 switch (ICS.getKind()) {
5403 case ImplicitConversionSequence::BadConversion:
5404 case ImplicitConversionSequence::AmbiguousConversion:
5405 case ImplicitConversionSequence::EllipsisConversion:
5408 case ImplicitConversionSequence::UserDefinedConversion:
5409 dropPointerConversion(ICS.UserDefined.After);
5412 case ImplicitConversionSequence::StandardConversion:
5413 dropPointerConversion(ICS.Standard);
5420 /// PerformContextuallyConvertToObjCPointer - Perform a contextual
5421 /// conversion of the expression From to an Objective-C pointer type.
5422 /// Returns a valid but null ExprResult if no conversion sequence exists.
5423 ExprResult Sema::PerformContextuallyConvertToObjCPointer(Expr *From) {
5424 if (checkPlaceholderForOverload(*this, From))
5427 QualType Ty = Context.getObjCIdType();
5428 ImplicitConversionSequence ICS =
5429 TryContextuallyConvertToObjCPointer(*this, From);
5431 return PerformImplicitConversion(From, Ty, ICS, AA_Converting);
5432 return ExprResult();
5435 /// Determine whether the provided type is an integral type, or an enumeration
5436 /// type of a permitted flavor.
5437 bool Sema::ICEConvertDiagnoser::match(QualType T) {
5438 return AllowScopedEnumerations ? T->isIntegralOrEnumerationType()
5439 : T->isIntegralOrUnscopedEnumerationType();
5443 diagnoseAmbiguousConversion(Sema &SemaRef, SourceLocation Loc, Expr *From,
5444 Sema::ContextualImplicitConverter &Converter,
5445 QualType T, UnresolvedSetImpl &ViableConversions) {
5447 if (Converter.Suppress)
5450 Converter.diagnoseAmbiguous(SemaRef, Loc, T) << From->getSourceRange();
5451 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5452 CXXConversionDecl *Conv =
5453 cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl());
5454 QualType ConvTy = Conv->getConversionType().getNonReferenceType();
5455 Converter.noteAmbiguous(SemaRef, Conv, ConvTy);
5461 diagnoseNoViableConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5462 Sema::ContextualImplicitConverter &Converter,
5463 QualType T, bool HadMultipleCandidates,
5464 UnresolvedSetImpl &ExplicitConversions) {
5465 if (ExplicitConversions.size() == 1 && !Converter.Suppress) {
5466 DeclAccessPair Found = ExplicitConversions[0];
5467 CXXConversionDecl *Conversion =
5468 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5470 // The user probably meant to invoke the given explicit
5471 // conversion; use it.
5472 QualType ConvTy = Conversion->getConversionType().getNonReferenceType();
5473 std::string TypeStr;
5474 ConvTy.getAsStringInternal(TypeStr, SemaRef.getPrintingPolicy());
5476 Converter.diagnoseExplicitConv(SemaRef, Loc, T, ConvTy)
5477 << FixItHint::CreateInsertion(From->getLocStart(),
5478 "static_cast<" + TypeStr + ">(")
5479 << FixItHint::CreateInsertion(
5480 SemaRef.getLocForEndOfToken(From->getLocEnd()), ")");
5481 Converter.noteExplicitConv(SemaRef, Conversion, ConvTy);
5483 // If we aren't in a SFINAE context, build a call to the
5484 // explicit conversion function.
5485 if (SemaRef.isSFINAEContext())
5488 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5489 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5490 HadMultipleCandidates);
5491 if (Result.isInvalid())
5493 // Record usage of conversion in an implicit cast.
5494 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5495 CK_UserDefinedConversion, Result.get(),
5496 nullptr, Result.get()->getValueKind());
5501 static bool recordConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5502 Sema::ContextualImplicitConverter &Converter,
5503 QualType T, bool HadMultipleCandidates,
5504 DeclAccessPair &Found) {
5505 CXXConversionDecl *Conversion =
5506 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5507 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5509 QualType ToType = Conversion->getConversionType().getNonReferenceType();
5510 if (!Converter.SuppressConversion) {
5511 if (SemaRef.isSFINAEContext())
5514 Converter.diagnoseConversion(SemaRef, Loc, T, ToType)
5515 << From->getSourceRange();
5518 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5519 HadMultipleCandidates);
5520 if (Result.isInvalid())
5522 // Record usage of conversion in an implicit cast.
5523 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5524 CK_UserDefinedConversion, Result.get(),
5525 nullptr, Result.get()->getValueKind());
5529 static ExprResult finishContextualImplicitConversion(
5530 Sema &SemaRef, SourceLocation Loc, Expr *From,
5531 Sema::ContextualImplicitConverter &Converter) {
5532 if (!Converter.match(From->getType()) && !Converter.Suppress)
5533 Converter.diagnoseNoMatch(SemaRef, Loc, From->getType())
5534 << From->getSourceRange();
5536 return SemaRef.DefaultLvalueConversion(From);
5540 collectViableConversionCandidates(Sema &SemaRef, Expr *From, QualType ToType,
5541 UnresolvedSetImpl &ViableConversions,
5542 OverloadCandidateSet &CandidateSet) {
5543 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5544 DeclAccessPair FoundDecl = ViableConversions[I];
5545 NamedDecl *D = FoundDecl.getDecl();
5546 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
5547 if (isa<UsingShadowDecl>(D))
5548 D = cast<UsingShadowDecl>(D)->getTargetDecl();
5550 CXXConversionDecl *Conv;
5551 FunctionTemplateDecl *ConvTemplate;
5552 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
5553 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5555 Conv = cast<CXXConversionDecl>(D);
5558 SemaRef.AddTemplateConversionCandidate(
5559 ConvTemplate, FoundDecl, ActingContext, From, ToType, CandidateSet,
5560 /*AllowObjCConversionOnExplicit=*/false);
5562 SemaRef.AddConversionCandidate(Conv, FoundDecl, ActingContext, From,
5563 ToType, CandidateSet,
5564 /*AllowObjCConversionOnExplicit=*/false);
5568 /// \brief Attempt to convert the given expression to a type which is accepted
5569 /// by the given converter.
5571 /// This routine will attempt to convert an expression of class type to a
5572 /// type accepted by the specified converter. In C++11 and before, the class
5573 /// must have a single non-explicit conversion function converting to a matching
5574 /// type. In C++1y, there can be multiple such conversion functions, but only
5575 /// one target type.
5577 /// \param Loc The source location of the construct that requires the
5580 /// \param From The expression we're converting from.
5582 /// \param Converter Used to control and diagnose the conversion process.
5584 /// \returns The expression, converted to an integral or enumeration type if
5586 ExprResult Sema::PerformContextualImplicitConversion(
5587 SourceLocation Loc, Expr *From, ContextualImplicitConverter &Converter) {
5588 // We can't perform any more checking for type-dependent expressions.
5589 if (From->isTypeDependent())
5592 // Process placeholders immediately.
5593 if (From->hasPlaceholderType()) {
5594 ExprResult result = CheckPlaceholderExpr(From);
5595 if (result.isInvalid())
5597 From = result.get();
5600 // If the expression already has a matching type, we're golden.
5601 QualType T = From->getType();
5602 if (Converter.match(T))
5603 return DefaultLvalueConversion(From);
5605 // FIXME: Check for missing '()' if T is a function type?
5607 // We can only perform contextual implicit conversions on objects of class
5609 const RecordType *RecordTy = T->getAs<RecordType>();
5610 if (!RecordTy || !getLangOpts().CPlusPlus) {
5611 if (!Converter.Suppress)
5612 Converter.diagnoseNoMatch(*this, Loc, T) << From->getSourceRange();
5616 // We must have a complete class type.
5617 struct TypeDiagnoserPartialDiag : TypeDiagnoser {
5618 ContextualImplicitConverter &Converter;
5621 TypeDiagnoserPartialDiag(ContextualImplicitConverter &Converter, Expr *From)
5622 : Converter(Converter), From(From) {}
5624 void diagnose(Sema &S, SourceLocation Loc, QualType T) override {
5625 Converter.diagnoseIncomplete(S, Loc, T) << From->getSourceRange();
5627 } IncompleteDiagnoser(Converter, From);
5629 if (Converter.Suppress ? !isCompleteType(Loc, T)
5630 : RequireCompleteType(Loc, T, IncompleteDiagnoser))
5633 // Look for a conversion to an integral or enumeration type.
5635 ViableConversions; // These are *potentially* viable in C++1y.
5636 UnresolvedSet<4> ExplicitConversions;
5637 const auto &Conversions =
5638 cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions();
5640 bool HadMultipleCandidates =
5641 (std::distance(Conversions.begin(), Conversions.end()) > 1);
5643 // To check that there is only one target type, in C++1y:
5645 bool HasUniqueTargetType = true;
5647 // Collect explicit or viable (potentially in C++1y) conversions.
5648 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
5649 NamedDecl *D = (*I)->getUnderlyingDecl();
5650 CXXConversionDecl *Conversion;
5651 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
5653 if (getLangOpts().CPlusPlus14)
5654 Conversion = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5656 continue; // C++11 does not consider conversion operator templates(?).
5658 Conversion = cast<CXXConversionDecl>(D);
5660 assert((!ConvTemplate || getLangOpts().CPlusPlus14) &&
5661 "Conversion operator templates are considered potentially "
5664 QualType CurToType = Conversion->getConversionType().getNonReferenceType();
5665 if (Converter.match(CurToType) || ConvTemplate) {
5667 if (Conversion->isExplicit()) {
5668 // FIXME: For C++1y, do we need this restriction?
5669 // cf. diagnoseNoViableConversion()
5671 ExplicitConversions.addDecl(I.getDecl(), I.getAccess());
5673 if (!ConvTemplate && getLangOpts().CPlusPlus14) {
5674 if (ToType.isNull())
5675 ToType = CurToType.getUnqualifiedType();
5676 else if (HasUniqueTargetType &&
5677 (CurToType.getUnqualifiedType() != ToType))
5678 HasUniqueTargetType = false;
5680 ViableConversions.addDecl(I.getDecl(), I.getAccess());
5685 if (getLangOpts().CPlusPlus14) {
5687 // ... An expression e of class type E appearing in such a context
5688 // is said to be contextually implicitly converted to a specified
5689 // type T and is well-formed if and only if e can be implicitly
5690 // converted to a type T that is determined as follows: E is searched
5691 // for conversion functions whose return type is cv T or reference to
5692 // cv T such that T is allowed by the context. There shall be
5693 // exactly one such T.
5695 // If no unique T is found:
5696 if (ToType.isNull()) {
5697 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5698 HadMultipleCandidates,
5699 ExplicitConversions))
5701 return finishContextualImplicitConversion(*this, Loc, From, Converter);
5704 // If more than one unique Ts are found:
5705 if (!HasUniqueTargetType)
5706 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5709 // If one unique T is found:
5710 // First, build a candidate set from the previously recorded
5711 // potentially viable conversions.
5712 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Normal);
5713 collectViableConversionCandidates(*this, From, ToType, ViableConversions,
5716 // Then, perform overload resolution over the candidate set.
5717 OverloadCandidateSet::iterator Best;
5718 switch (CandidateSet.BestViableFunction(*this, Loc, Best)) {
5720 // Apply this conversion.
5721 DeclAccessPair Found =
5722 DeclAccessPair::make(Best->Function, Best->FoundDecl.getAccess());
5723 if (recordConversion(*this, Loc, From, Converter, T,
5724 HadMultipleCandidates, Found))
5729 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5731 case OR_No_Viable_Function:
5732 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5733 HadMultipleCandidates,
5734 ExplicitConversions))
5736 // fall through 'OR_Deleted' case.
5738 // We'll complain below about a non-integral condition type.
5742 switch (ViableConversions.size()) {
5744 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5745 HadMultipleCandidates,
5746 ExplicitConversions))
5749 // We'll complain below about a non-integral condition type.
5753 // Apply this conversion.
5754 DeclAccessPair Found = ViableConversions[0];
5755 if (recordConversion(*this, Loc, From, Converter, T,
5756 HadMultipleCandidates, Found))
5761 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5766 return finishContextualImplicitConversion(*this, Loc, From, Converter);
5769 /// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is
5770 /// an acceptable non-member overloaded operator for a call whose
5771 /// arguments have types T1 (and, if non-empty, T2). This routine
5772 /// implements the check in C++ [over.match.oper]p3b2 concerning
5773 /// enumeration types.
5774 static bool IsAcceptableNonMemberOperatorCandidate(ASTContext &Context,
5776 ArrayRef<Expr *> Args) {
5777 QualType T1 = Args[0]->getType();
5778 QualType T2 = Args.size() > 1 ? Args[1]->getType() : QualType();
5780 if (T1->isDependentType() || (!T2.isNull() && T2->isDependentType()))
5783 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType()))
5786 const FunctionProtoType *Proto = Fn->getType()->getAs<FunctionProtoType>();
5787 if (Proto->getNumParams() < 1)
5790 if (T1->isEnumeralType()) {
5791 QualType ArgType = Proto->getParamType(0).getNonReferenceType();
5792 if (Context.hasSameUnqualifiedType(T1, ArgType))
5796 if (Proto->getNumParams() < 2)
5799 if (!T2.isNull() && T2->isEnumeralType()) {
5800 QualType ArgType = Proto->getParamType(1).getNonReferenceType();
5801 if (Context.hasSameUnqualifiedType(T2, ArgType))
5808 /// AddOverloadCandidate - Adds the given function to the set of
5809 /// candidate functions, using the given function call arguments. If
5810 /// @p SuppressUserConversions, then don't allow user-defined
5811 /// conversions via constructors or conversion operators.
5813 /// \param PartialOverloading true if we are performing "partial" overloading
5814 /// based on an incomplete set of function arguments. This feature is used by
5815 /// code completion.
5817 Sema::AddOverloadCandidate(FunctionDecl *Function,
5818 DeclAccessPair FoundDecl,
5819 ArrayRef<Expr *> Args,
5820 OverloadCandidateSet &CandidateSet,
5821 bool SuppressUserConversions,
5822 bool PartialOverloading,
5823 bool AllowExplicit) {
5824 const FunctionProtoType *Proto
5825 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>());
5826 assert(Proto && "Functions without a prototype cannot be overloaded");
5827 assert(!Function->getDescribedFunctionTemplate() &&
5828 "Use AddTemplateOverloadCandidate for function templates");
5830 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) {
5831 if (!isa<CXXConstructorDecl>(Method)) {
5832 // If we get here, it's because we're calling a member function
5833 // that is named without a member access expression (e.g.,
5834 // "this->f") that was either written explicitly or created
5835 // implicitly. This can happen with a qualified call to a member
5836 // function, e.g., X::f(). We use an empty type for the implied
5837 // object argument (C++ [over.call.func]p3), and the acting context
5839 AddMethodCandidate(Method, FoundDecl, Method->getParent(),
5840 QualType(), Expr::Classification::makeSimpleLValue(),
5841 Args, CandidateSet, SuppressUserConversions,
5842 PartialOverloading);
5845 // We treat a constructor like a non-member function, since its object
5846 // argument doesn't participate in overload resolution.
5849 if (!CandidateSet.isNewCandidate(Function))
5852 // C++ [over.match.oper]p3:
5853 // if no operand has a class type, only those non-member functions in the
5854 // lookup set that have a first parameter of type T1 or "reference to
5855 // (possibly cv-qualified) T1", when T1 is an enumeration type, or (if there
5856 // is a right operand) a second parameter of type T2 or "reference to
5857 // (possibly cv-qualified) T2", when T2 is an enumeration type, are
5858 // candidate functions.
5859 if (CandidateSet.getKind() == OverloadCandidateSet::CSK_Operator &&
5860 !IsAcceptableNonMemberOperatorCandidate(Context, Function, Args))
5863 // C++11 [class.copy]p11: [DR1402]
5864 // A defaulted move constructor that is defined as deleted is ignored by
5865 // overload resolution.
5866 CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function);
5867 if (Constructor && Constructor->isDefaulted() && Constructor->isDeleted() &&
5868 Constructor->isMoveConstructor())
5871 // Overload resolution is always an unevaluated context.
5872 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated);
5874 // Add this candidate
5875 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size());
5876 Candidate.FoundDecl = FoundDecl;
5877 Candidate.Function = Function;
5878 Candidate.Viable = true;
5879 Candidate.IsSurrogate = false;
5880 Candidate.IgnoreObjectArgument = false;
5881 Candidate.ExplicitCallArguments = Args.size();
5884 // C++ [class.copy]p3:
5885 // A member function template is never instantiated to perform the copy
5886 // of a class object to an object of its class type.
5887 QualType ClassType = Context.getTypeDeclType(Constructor->getParent());
5888 if (Args.size() == 1 && Constructor->isSpecializationCopyingObject() &&
5889 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) ||
5890 IsDerivedFrom(Args[0]->getLocStart(), Args[0]->getType(),
5892 Candidate.Viable = false;
5893 Candidate.FailureKind = ovl_fail_illegal_constructor;
5898 unsigned NumParams = Proto->getNumParams();
5900 // (C++ 13.3.2p2): A candidate function having fewer than m
5901 // parameters is viable only if it has an ellipsis in its parameter
5903 if (TooManyArguments(NumParams, Args.size(), PartialOverloading) &&
5904 !Proto->isVariadic()) {
5905 Candidate.Viable = false;
5906 Candidate.FailureKind = ovl_fail_too_many_arguments;
5910 // (C++ 13.3.2p2): A candidate function having more than m parameters
5911 // is viable only if the (m+1)st parameter has a default argument
5912 // (8.3.6). For the purposes of overload resolution, the
5913 // parameter list is truncated on the right, so that there are
5914 // exactly m parameters.
5915 unsigned MinRequiredArgs = Function->getMinRequiredArguments();
5916 if (Args.size() < MinRequiredArgs && !PartialOverloading) {
5917 // Not enough arguments.
5918 Candidate.Viable = false;
5919 Candidate.FailureKind = ovl_fail_too_few_arguments;
5923 // (CUDA B.1): Check for invalid calls between targets.
5924 if (getLangOpts().CUDA)
5925 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext))
5926 // Skip the check for callers that are implicit members, because in this
5927 // case we may not yet know what the member's target is; the target is
5928 // inferred for the member automatically, based on the bases and fields of
5930 if (!Caller->isImplicit() && !IsAllowedCUDACall(Caller, Function)) {
5931 Candidate.Viable = false;
5932 Candidate.FailureKind = ovl_fail_bad_target;
5936 // Determine the implicit conversion sequences for each of the
5938 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) {
5939 if (ArgIdx < NumParams) {
5940 // (C++ 13.3.2p3): for F to be a viable function, there shall
5941 // exist for each argument an implicit conversion sequence
5942 // (13.3.3.1) that converts that argument to the corresponding
5944 QualType ParamType = Proto->getParamType(ArgIdx);
5945 Candidate.Conversions[ArgIdx]
5946 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
5947 SuppressUserConversions,
5948 /*InOverloadResolution=*/true,
5949 /*AllowObjCWritebackConversion=*/
5950 getLangOpts().ObjCAutoRefCount,
5952 if (Candidate.Conversions[ArgIdx].isBad()) {
5953 Candidate.Viable = false;
5954 Candidate.FailureKind = ovl_fail_bad_conversion;
5958 // (C++ 13.3.2p2): For the purposes of overload resolution, any
5959 // argument for which there is no corresponding parameter is
5960 // considered to ""match the ellipsis" (C+ 13.3.3.1.3).
5961 Candidate.Conversions[ArgIdx].setEllipsis();
5965 if (EnableIfAttr *FailedAttr = CheckEnableIf(Function, Args)) {
5966 Candidate.Viable = false;
5967 Candidate.FailureKind = ovl_fail_enable_if;
5968 Candidate.DeductionFailure.Data = FailedAttr;
5972 if (LangOpts.OpenCL && isOpenCLDisabledDecl(Function)) {
5973 Candidate.Viable = false;
5974 Candidate.FailureKind = ovl_fail_ext_disabled;
5980 Sema::SelectBestMethod(Selector Sel, MultiExprArg Args, bool IsInstance,
5981 SmallVectorImpl<ObjCMethodDecl *> &Methods) {
5982 if (Methods.size() <= 1)
5985 for (unsigned b = 0, e = Methods.size(); b < e; b++) {
5987 ObjCMethodDecl *Method = Methods[b];
5988 unsigned NumNamedArgs = Sel.getNumArgs();
5989 // Method might have more arguments than selector indicates. This is due
5990 // to addition of c-style arguments in method.
5991 if (Method->param_size() > NumNamedArgs)
5992 NumNamedArgs = Method->param_size();
5993 if (Args.size() < NumNamedArgs)
5996 for (unsigned i = 0; i < NumNamedArgs; i++) {
5997 // We can't do any type-checking on a type-dependent argument.
5998 if (Args[i]->isTypeDependent()) {
6003 ParmVarDecl *param = Method->parameters()[i];
6004 Expr *argExpr = Args[i];
6005 assert(argExpr && "SelectBestMethod(): missing expression");
6007 // Strip the unbridged-cast placeholder expression off unless it's
6008 // a consumed argument.
6009 if (argExpr->hasPlaceholderType(BuiltinType::ARCUnbridgedCast) &&
6010 !param->hasAttr<CFConsumedAttr>())
6011 argExpr = stripARCUnbridgedCast(argExpr);
6013 // If the parameter is __unknown_anytype, move on to the next method.
6014 if (param->getType() == Context.UnknownAnyTy) {
6019 ImplicitConversionSequence ConversionState
6020 = TryCopyInitialization(*this, argExpr, param->getType(),
6021 /*SuppressUserConversions*/false,
6022 /*InOverloadResolution=*/true,
6023 /*AllowObjCWritebackConversion=*/
6024 getLangOpts().ObjCAutoRefCount,
6025 /*AllowExplicit*/false);
6026 // This function looks for a reasonably-exact match, so we consider
6027 // incompatible pointer conversions to be a failure here.
6028 if (ConversionState.isBad() ||
6029 (ConversionState.isStandard() &&
6030 ConversionState.Standard.Second ==
6031 ICK_Incompatible_Pointer_Conversion)) {
6036 // Promote additional arguments to variadic methods.
6037 if (Match && Method->isVariadic()) {
6038 for (unsigned i = NumNamedArgs, e = Args.size(); i < e; ++i) {
6039 if (Args[i]->isTypeDependent()) {
6043 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod,
6045 if (Arg.isInvalid()) {
6051 // Check for extra arguments to non-variadic methods.
6052 if (Args.size() != NumNamedArgs)
6054 else if (Match && NumNamedArgs == 0 && Methods.size() > 1) {
6055 // Special case when selectors have no argument. In this case, select
6056 // one with the most general result type of 'id'.
6057 for (unsigned b = 0, e = Methods.size(); b < e; b++) {
6058 QualType ReturnT = Methods[b]->getReturnType();
6059 if (ReturnT->isObjCIdType())
6071 // specific_attr_iterator iterates over enable_if attributes in reverse, and
6072 // enable_if is order-sensitive. As a result, we need to reverse things
6073 // sometimes. Size of 4 elements is arbitrary.
6074 static SmallVector<EnableIfAttr *, 4>
6075 getOrderedEnableIfAttrs(const FunctionDecl *Function) {
6076 SmallVector<EnableIfAttr *, 4> Result;
6077 if (!Function->hasAttrs())
6080 const auto &FuncAttrs = Function->getAttrs();
6081 for (Attr *Attr : FuncAttrs)
6082 if (auto *EnableIf = dyn_cast<EnableIfAttr>(Attr))
6083 Result.push_back(EnableIf);
6085 std::reverse(Result.begin(), Result.end());
6089 EnableIfAttr *Sema::CheckEnableIf(FunctionDecl *Function, ArrayRef<Expr *> Args,
6090 bool MissingImplicitThis) {
6091 auto EnableIfAttrs = getOrderedEnableIfAttrs(Function);
6092 if (EnableIfAttrs.empty())
6095 SFINAETrap Trap(*this);
6096 SmallVector<Expr *, 16> ConvertedArgs;
6097 bool InitializationFailed = false;
6099 // Ignore any variadic arguments. Converting them is pointless, since the
6100 // user can't refer to them in the enable_if condition.
6101 unsigned ArgSizeNoVarargs = std::min(Function->param_size(), Args.size());
6103 // Convert the arguments.
6104 for (unsigned I = 0; I != ArgSizeNoVarargs; ++I) {
6106 if (I == 0 && !MissingImplicitThis && isa<CXXMethodDecl>(Function) &&
6107 !cast<CXXMethodDecl>(Function)->isStatic() &&
6108 !isa<CXXConstructorDecl>(Function)) {
6109 CXXMethodDecl *Method = cast<CXXMethodDecl>(Function);
6110 R = PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/nullptr,
6113 R = PerformCopyInitialization(InitializedEntity::InitializeParameter(
6114 Context, Function->getParamDecl(I)),
6115 SourceLocation(), Args[I]);
6118 if (R.isInvalid()) {
6119 InitializationFailed = true;
6123 ConvertedArgs.push_back(R.get());
6126 if (InitializationFailed || Trap.hasErrorOccurred())
6127 return EnableIfAttrs[0];
6129 // Push default arguments if needed.
6130 if (!Function->isVariadic() && Args.size() < Function->getNumParams()) {
6131 for (unsigned i = Args.size(), e = Function->getNumParams(); i != e; ++i) {
6132 ParmVarDecl *P = Function->getParamDecl(i);
6133 ExprResult R = PerformCopyInitialization(
6134 InitializedEntity::InitializeParameter(Context,
6135 Function->getParamDecl(i)),
6137 P->hasUninstantiatedDefaultArg() ? P->getUninstantiatedDefaultArg()
6138 : P->getDefaultArg());
6139 if (R.isInvalid()) {
6140 InitializationFailed = true;
6143 ConvertedArgs.push_back(R.get());
6146 if (InitializationFailed || Trap.hasErrorOccurred())
6147 return EnableIfAttrs[0];
6150 for (auto *EIA : EnableIfAttrs) {
6152 // FIXME: This doesn't consider value-dependent cases, because doing so is
6153 // very difficult. Ideally, we should handle them more gracefully.
6154 if (!EIA->getCond()->EvaluateWithSubstitution(
6155 Result, Context, Function, llvm::makeArrayRef(ConvertedArgs)))
6158 if (!Result.isInt() || !Result.getInt().getBoolValue())
6164 /// \brief Add all of the function declarations in the given function set to
6165 /// the overload candidate set.
6166 void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns,
6167 ArrayRef<Expr *> Args,
6168 OverloadCandidateSet& CandidateSet,
6169 TemplateArgumentListInfo *ExplicitTemplateArgs,
6170 bool SuppressUserConversions,
6171 bool PartialOverloading) {
6172 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) {
6173 NamedDecl *D = F.getDecl()->getUnderlyingDecl();
6174 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
6175 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic())
6176 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(),
6177 cast<CXXMethodDecl>(FD)->getParent(),
6178 Args[0]->getType(), Args[0]->Classify(Context),
6179 Args.slice(1), CandidateSet,
6180 SuppressUserConversions, PartialOverloading);
6182 AddOverloadCandidate(FD, F.getPair(), Args, CandidateSet,
6183 SuppressUserConversions, PartialOverloading);
6185 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D);
6186 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) &&
6187 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic())
6188 AddMethodTemplateCandidate(FunTmpl, F.getPair(),
6189 cast<CXXRecordDecl>(FunTmpl->getDeclContext()),
6190 ExplicitTemplateArgs,
6192 Args[0]->Classify(Context), Args.slice(1),
6193 CandidateSet, SuppressUserConversions,
6194 PartialOverloading);
6196 AddTemplateOverloadCandidate(FunTmpl, F.getPair(),
6197 ExplicitTemplateArgs, Args,
6198 CandidateSet, SuppressUserConversions,
6199 PartialOverloading);
6204 /// AddMethodCandidate - Adds a named decl (which is some kind of
6205 /// method) as a method candidate to the given overload set.
6206 void Sema::AddMethodCandidate(DeclAccessPair FoundDecl,
6207 QualType ObjectType,
6208 Expr::Classification ObjectClassification,
6209 ArrayRef<Expr *> Args,
6210 OverloadCandidateSet& CandidateSet,
6211 bool SuppressUserConversions) {
6212 NamedDecl *Decl = FoundDecl.getDecl();
6213 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext());
6215 if (isa<UsingShadowDecl>(Decl))
6216 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl();
6218 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) {
6219 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) &&
6220 "Expected a member function template");
6221 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext,
6222 /*ExplicitArgs*/ nullptr,
6223 ObjectType, ObjectClassification,
6225 SuppressUserConversions);
6227 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext,
6228 ObjectType, ObjectClassification,
6230 CandidateSet, SuppressUserConversions);
6234 /// AddMethodCandidate - Adds the given C++ member function to the set
6235 /// of candidate functions, using the given function call arguments
6236 /// and the object argument (@c Object). For example, in a call
6237 /// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain
6238 /// both @c a1 and @c a2. If @p SuppressUserConversions, then don't
6239 /// allow user-defined conversions via constructors or conversion
6242 Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl,
6243 CXXRecordDecl *ActingContext, QualType ObjectType,
6244 Expr::Classification ObjectClassification,
6245 ArrayRef<Expr *> Args,
6246 OverloadCandidateSet &CandidateSet,
6247 bool SuppressUserConversions,
6248 bool PartialOverloading) {
6249 const FunctionProtoType *Proto
6250 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>());
6251 assert(Proto && "Methods without a prototype cannot be overloaded");
6252 assert(!isa<CXXConstructorDecl>(Method) &&
6253 "Use AddOverloadCandidate for constructors");
6255 if (!CandidateSet.isNewCandidate(Method))
6258 // C++11 [class.copy]p23: [DR1402]
6259 // A defaulted move assignment operator that is defined as deleted is
6260 // ignored by overload resolution.
6261 if (Method->isDefaulted() && Method->isDeleted() &&
6262 Method->isMoveAssignmentOperator())
6265 // Overload resolution is always an unevaluated context.
6266 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated);
6268 // Add this candidate
6269 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1);
6270 Candidate.FoundDecl = FoundDecl;
6271 Candidate.Function = Method;
6272 Candidate.IsSurrogate = false;
6273 Candidate.IgnoreObjectArgument = false;
6274 Candidate.ExplicitCallArguments = Args.size();
6276 unsigned NumParams = Proto->getNumParams();
6278 // (C++ 13.3.2p2): A candidate function having fewer than m
6279 // parameters is viable only if it has an ellipsis in its parameter
6281 if (TooManyArguments(NumParams, Args.size(), PartialOverloading) &&
6282 !Proto->isVariadic()) {
6283 Candidate.Viable = false;
6284 Candidate.FailureKind = ovl_fail_too_many_arguments;
6288 // (C++ 13.3.2p2): A candidate function having more than m parameters
6289 // is viable only if the (m+1)st parameter has a default argument
6290 // (8.3.6). For the purposes of overload resolution, the
6291 // parameter list is truncated on the right, so that there are
6292 // exactly m parameters.
6293 unsigned MinRequiredArgs = Method->getMinRequiredArguments();
6294 if (Args.size() < MinRequiredArgs && !PartialOverloading) {
6295 // Not enough arguments.
6296 Candidate.Viable = false;
6297 Candidate.FailureKind = ovl_fail_too_few_arguments;
6301 Candidate.Viable = true;
6303 if (Method->isStatic() || ObjectType.isNull())
6304 // The implicit object argument is ignored.
6305 Candidate.IgnoreObjectArgument = true;
6307 // Determine the implicit conversion sequence for the object
6309 Candidate.Conversions[0] = TryObjectArgumentInitialization(
6310 *this, CandidateSet.getLocation(), ObjectType, ObjectClassification,
6311 Method, ActingContext);
6312 if (Candidate.Conversions[0].isBad()) {
6313 Candidate.Viable = false;
6314 Candidate.FailureKind = ovl_fail_bad_conversion;
6319 // (CUDA B.1): Check for invalid calls between targets.
6320 if (getLangOpts().CUDA)
6321 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext))
6322 if (!IsAllowedCUDACall(Caller, Method)) {
6323 Candidate.Viable = false;
6324 Candidate.FailureKind = ovl_fail_bad_target;
6328 // Determine the implicit conversion sequences for each of the
6330 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) {
6331 if (ArgIdx < NumParams) {
6332 // (C++ 13.3.2p3): for F to be a viable function, there shall
6333 // exist for each argument an implicit conversion sequence
6334 // (13.3.3.1) that converts that argument to the corresponding
6336 QualType ParamType = Proto->getParamType(ArgIdx);
6337 Candidate.Conversions[ArgIdx + 1]
6338 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
6339 SuppressUserConversions,
6340 /*InOverloadResolution=*/true,
6341 /*AllowObjCWritebackConversion=*/
6342 getLangOpts().ObjCAutoRefCount);
6343 if (Candidate.Conversions[ArgIdx + 1].isBad()) {
6344 Candidate.Viable = false;
6345 Candidate.FailureKind = ovl_fail_bad_conversion;
6349 // (C++ 13.3.2p2): For the purposes of overload resolution, any
6350 // argument for which there is no corresponding parameter is
6351 // considered to "match the ellipsis" (C+ 13.3.3.1.3).
6352 Candidate.Conversions[ArgIdx + 1].setEllipsis();
6356 if (EnableIfAttr *FailedAttr = CheckEnableIf(Method, Args, true)) {
6357 Candidate.Viable = false;
6358 Candidate.FailureKind = ovl_fail_enable_if;
6359 Candidate.DeductionFailure.Data = FailedAttr;
6364 /// \brief Add a C++ member function template as a candidate to the candidate
6365 /// set, using template argument deduction to produce an appropriate member
6366 /// function template specialization.
6368 Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl,
6369 DeclAccessPair FoundDecl,
6370 CXXRecordDecl *ActingContext,
6371 TemplateArgumentListInfo *ExplicitTemplateArgs,
6372 QualType ObjectType,
6373 Expr::Classification ObjectClassification,
6374 ArrayRef<Expr *> Args,
6375 OverloadCandidateSet& CandidateSet,
6376 bool SuppressUserConversions,
6377 bool PartialOverloading) {
6378 if (!CandidateSet.isNewCandidate(MethodTmpl))
6381 // C++ [over.match.funcs]p7:
6382 // In each case where a candidate is a function template, candidate
6383 // function template specializations are generated using template argument
6384 // deduction (14.8.3, 14.8.2). Those candidates are then handled as
6385 // candidate functions in the usual way.113) A given name can refer to one
6386 // or more function templates and also to a set of overloaded non-template
6387 // functions. In such a case, the candidate functions generated from each
6388 // function template are combined with the set of non-template candidate
6390 TemplateDeductionInfo Info(CandidateSet.getLocation());
6391 FunctionDecl *Specialization = nullptr;
6392 if (TemplateDeductionResult Result
6393 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, Args,
6394 Specialization, Info, PartialOverloading)) {
6395 OverloadCandidate &Candidate = CandidateSet.addCandidate();
6396 Candidate.FoundDecl = FoundDecl;
6397 Candidate.Function = MethodTmpl->getTemplatedDecl();
6398 Candidate.Viable = false;
6399 Candidate.FailureKind = ovl_fail_bad_deduction;
6400 Candidate.IsSurrogate = false;
6401 Candidate.IgnoreObjectArgument = false;
6402 Candidate.ExplicitCallArguments = Args.size();
6403 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
6408 // Add the function template specialization produced by template argument
6409 // deduction as a candidate.
6410 assert(Specialization && "Missing member function template specialization?");
6411 assert(isa<CXXMethodDecl>(Specialization) &&
6412 "Specialization is not a member function?");
6413 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl,
6414 ActingContext, ObjectType, ObjectClassification, Args,
6415 CandidateSet, SuppressUserConversions, PartialOverloading);
6418 /// \brief Add a C++ function template specialization as a candidate
6419 /// in the candidate set, using template argument deduction to produce
6420 /// an appropriate function template specialization.
6422 Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate,
6423 DeclAccessPair FoundDecl,
6424 TemplateArgumentListInfo *ExplicitTemplateArgs,
6425 ArrayRef<Expr *> Args,
6426 OverloadCandidateSet& CandidateSet,
6427 bool SuppressUserConversions,
6428 bool PartialOverloading) {
6429 if (!CandidateSet.isNewCandidate(FunctionTemplate))
6432 // C++ [over.match.funcs]p7:
6433 // In each case where a candidate is a function template, candidate
6434 // function template specializations are generated using template argument
6435 // deduction (14.8.3, 14.8.2). Those candidates are then handled as
6436 // candidate functions in the usual way.113) A given name can refer to one
6437 // or more function templates and also to a set of overloaded non-template
6438 // functions. In such a case, the candidate functions generated from each
6439 // function template are combined with the set of non-template candidate
6441 TemplateDeductionInfo Info(CandidateSet.getLocation());
6442 FunctionDecl *Specialization = nullptr;
6443 if (TemplateDeductionResult Result
6444 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, Args,
6445 Specialization, Info, PartialOverloading)) {
6446 OverloadCandidate &Candidate = CandidateSet.addCandidate();
6447 Candidate.FoundDecl = FoundDecl;
6448 Candidate.Function = FunctionTemplate->getTemplatedDecl();
6449 Candidate.Viable = false;
6450 Candidate.FailureKind = ovl_fail_bad_deduction;
6451 Candidate.IsSurrogate = false;
6452 Candidate.IgnoreObjectArgument = false;
6453 Candidate.ExplicitCallArguments = Args.size();
6454 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
6459 // Add the function template specialization produced by template argument
6460 // deduction as a candidate.
6461 assert(Specialization && "Missing function template specialization?");
6462 AddOverloadCandidate(Specialization, FoundDecl, Args, CandidateSet,
6463 SuppressUserConversions, PartialOverloading);
6466 /// Determine whether this is an allowable conversion from the result
6467 /// of an explicit conversion operator to the expected type, per C++
6468 /// [over.match.conv]p1 and [over.match.ref]p1.
6470 /// \param ConvType The return type of the conversion function.
6472 /// \param ToType The type we are converting to.
6474 /// \param AllowObjCPointerConversion Allow a conversion from one
6475 /// Objective-C pointer to another.
6477 /// \returns true if the conversion is allowable, false otherwise.
6478 static bool isAllowableExplicitConversion(Sema &S,
6479 QualType ConvType, QualType ToType,
6480 bool AllowObjCPointerConversion) {
6481 QualType ToNonRefType = ToType.getNonReferenceType();
6483 // Easy case: the types are the same.
6484 if (S.Context.hasSameUnqualifiedType(ConvType, ToNonRefType))
6487 // Allow qualification conversions.
6488 bool ObjCLifetimeConversion;
6489 if (S.IsQualificationConversion(ConvType, ToNonRefType, /*CStyle*/false,
6490 ObjCLifetimeConversion))
6493 // If we're not allowed to consider Objective-C pointer conversions,
6495 if (!AllowObjCPointerConversion)
6498 // Is this an Objective-C pointer conversion?
6499 bool IncompatibleObjC = false;
6500 QualType ConvertedType;
6501 return S.isObjCPointerConversion(ConvType, ToNonRefType, ConvertedType,
6505 /// AddConversionCandidate - Add a C++ conversion function as a
6506 /// candidate in the candidate set (C++ [over.match.conv],
6507 /// C++ [over.match.copy]). From is the expression we're converting from,
6508 /// and ToType is the type that we're eventually trying to convert to
6509 /// (which may or may not be the same type as the type that the
6510 /// conversion function produces).
6512 Sema::AddConversionCandidate(CXXConversionDecl *Conversion,
6513 DeclAccessPair FoundDecl,
6514 CXXRecordDecl *ActingContext,
6515 Expr *From, QualType ToType,
6516 OverloadCandidateSet& CandidateSet,
6517 bool AllowObjCConversionOnExplicit) {
6518 assert(!Conversion->getDescribedFunctionTemplate() &&
6519 "Conversion function templates use AddTemplateConversionCandidate");
6520 QualType ConvType = Conversion->getConversionType().getNonReferenceType();
6521 if (!CandidateSet.isNewCandidate(Conversion))
6524 // If the conversion function has an undeduced return type, trigger its
6526 if (getLangOpts().CPlusPlus14 && ConvType->isUndeducedType()) {
6527 if (DeduceReturnType(Conversion, From->getExprLoc()))
6529 ConvType = Conversion->getConversionType().getNonReferenceType();
6532 // Per C++ [over.match.conv]p1, [over.match.ref]p1, an explicit conversion
6533 // operator is only a candidate if its return type is the target type or
6534 // can be converted to the target type with a qualification conversion.
6535 if (Conversion->isExplicit() &&
6536 !isAllowableExplicitConversion(*this, ConvType, ToType,
6537 AllowObjCConversionOnExplicit))
6540 // Overload resolution is always an unevaluated context.
6541 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated);
6543 // Add this candidate
6544 OverloadCandidate &Candidate = CandidateSet.addCandidate(1);
6545 Candidate.FoundDecl = FoundDecl;
6546 Candidate.Function = Conversion;
6547 Candidate.IsSurrogate = false;
6548 Candidate.IgnoreObjectArgument = false;
6549 Candidate.FinalConversion.setAsIdentityConversion();
6550 Candidate.FinalConversion.setFromType(ConvType);
6551 Candidate.FinalConversion.setAllToTypes(ToType);
6552 Candidate.Viable = true;
6553 Candidate.ExplicitCallArguments = 1;
6555 // C++ [over.match.funcs]p4:
6556 // For conversion functions, the function is considered to be a member of
6557 // the class of the implicit implied object argument for the purpose of
6558 // defining the type of the implicit object parameter.
6560 // Determine the implicit conversion sequence for the implicit
6561 // object parameter.
6562 QualType ImplicitParamType = From->getType();
6563 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>())
6564 ImplicitParamType = FromPtrType->getPointeeType();
6565 CXXRecordDecl *ConversionContext
6566 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl());
6568 Candidate.Conversions[0] = TryObjectArgumentInitialization(
6569 *this, CandidateSet.getLocation(), From->getType(),
6570 From->Classify(Context), Conversion, ConversionContext);
6572 if (Candidate.Conversions[0].isBad()) {
6573 Candidate.Viable = false;
6574 Candidate.FailureKind = ovl_fail_bad_conversion;
6578 // We won't go through a user-defined type conversion function to convert a
6579 // derived to base as such conversions are given Conversion Rank. They only
6580 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user]
6582 = Context.getCanonicalType(From->getType().getUnqualifiedType());
6583 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType();
6584 if (FromCanon == ToCanon ||
6585 IsDerivedFrom(CandidateSet.getLocation(), FromCanon, ToCanon)) {
6586 Candidate.Viable = false;
6587 Candidate.FailureKind = ovl_fail_trivial_conversion;
6591 // To determine what the conversion from the result of calling the
6592 // conversion function to the type we're eventually trying to
6593 // convert to (ToType), we need to synthesize a call to the
6594 // conversion function and attempt copy initialization from it. This
6595 // makes sure that we get the right semantics with respect to
6596 // lvalues/rvalues and the type. Fortunately, we can allocate this
6597 // call on the stack and we don't need its arguments to be
6599 DeclRefExpr ConversionRef(Conversion, false, Conversion->getType(),
6600 VK_LValue, From->getLocStart());
6601 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack,
6602 Context.getPointerType(Conversion->getType()),
6603 CK_FunctionToPointerDecay,
6604 &ConversionRef, VK_RValue);
6606 QualType ConversionType = Conversion->getConversionType();
6607 if (!isCompleteType(From->getLocStart(), ConversionType)) {
6608 Candidate.Viable = false;
6609 Candidate.FailureKind = ovl_fail_bad_final_conversion;
6613 ExprValueKind VK = Expr::getValueKindForType(ConversionType);
6615 // Note that it is safe to allocate CallExpr on the stack here because
6616 // there are 0 arguments (i.e., nothing is allocated using ASTContext's
6618 QualType CallResultType = ConversionType.getNonLValueExprType(Context);
6619 CallExpr Call(Context, &ConversionFn, None, CallResultType, VK,
6620 From->getLocStart());
6621 ImplicitConversionSequence ICS =
6622 TryCopyInitialization(*this, &Call, ToType,
6623 /*SuppressUserConversions=*/true,
6624 /*InOverloadResolution=*/false,
6625 /*AllowObjCWritebackConversion=*/false);
6627 switch (ICS.getKind()) {
6628 case ImplicitConversionSequence::StandardConversion:
6629 Candidate.FinalConversion = ICS.Standard;
6631 // C++ [over.ics.user]p3:
6632 // If the user-defined conversion is specified by a specialization of a
6633 // conversion function template, the second standard conversion sequence
6634 // shall have exact match rank.
6635 if (Conversion->getPrimaryTemplate() &&
6636 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) {
6637 Candidate.Viable = false;
6638 Candidate.FailureKind = ovl_fail_final_conversion_not_exact;
6642 // C++0x [dcl.init.ref]p5:
6643 // In the second case, if the reference is an rvalue reference and
6644 // the second standard conversion sequence of the user-defined
6645 // conversion sequence includes an lvalue-to-rvalue conversion, the
6646 // program is ill-formed.
6647 if (ToType->isRValueReferenceType() &&
6648 ICS.Standard.First == ICK_Lvalue_To_Rvalue) {
6649 Candidate.Viable = false;
6650 Candidate.FailureKind = ovl_fail_bad_final_conversion;
6655 case ImplicitConversionSequence::BadConversion:
6656 Candidate.Viable = false;
6657 Candidate.FailureKind = ovl_fail_bad_final_conversion;
6662 "Can only end up with a standard conversion sequence or failure");
6665 if (EnableIfAttr *FailedAttr = CheckEnableIf(Conversion, None)) {
6666 Candidate.Viable = false;
6667 Candidate.FailureKind = ovl_fail_enable_if;
6668 Candidate.DeductionFailure.Data = FailedAttr;
6673 /// \brief Adds a conversion function template specialization
6674 /// candidate to the overload set, using template argument deduction
6675 /// to deduce the template arguments of the conversion function
6676 /// template from the type that we are converting to (C++
6677 /// [temp.deduct.conv]).
6679 Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate,
6680 DeclAccessPair FoundDecl,
6681 CXXRecordDecl *ActingDC,
6682 Expr *From, QualType ToType,
6683 OverloadCandidateSet &CandidateSet,
6684 bool AllowObjCConversionOnExplicit) {
6685 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) &&
6686 "Only conversion function templates permitted here");
6688 if (!CandidateSet.isNewCandidate(FunctionTemplate))
6691 TemplateDeductionInfo Info(CandidateSet.getLocation());
6692 CXXConversionDecl *Specialization = nullptr;
6693 if (TemplateDeductionResult Result
6694 = DeduceTemplateArguments(FunctionTemplate, ToType,
6695 Specialization, Info)) {
6696 OverloadCandidate &Candidate = CandidateSet.addCandidate();
6697 Candidate.FoundDecl = FoundDecl;
6698 Candidate.Function = FunctionTemplate->getTemplatedDecl();
6699 Candidate.Viable = false;
6700 Candidate.FailureKind = ovl_fail_bad_deduction;
6701 Candidate.IsSurrogate = false;
6702 Candidate.IgnoreObjectArgument = false;
6703 Candidate.ExplicitCallArguments = 1;
6704 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
6709 // Add the conversion function template specialization produced by
6710 // template argument deduction as a candidate.
6711 assert(Specialization && "Missing function template specialization?");
6712 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType,
6713 CandidateSet, AllowObjCConversionOnExplicit);
6716 /// AddSurrogateCandidate - Adds a "surrogate" candidate function that
6717 /// converts the given @c Object to a function pointer via the
6718 /// conversion function @c Conversion, and then attempts to call it
6719 /// with the given arguments (C++ [over.call.object]p2-4). Proto is
6720 /// the type of function that we'll eventually be calling.
6721 void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion,
6722 DeclAccessPair FoundDecl,
6723 CXXRecordDecl *ActingContext,
6724 const FunctionProtoType *Proto,
6726 ArrayRef<Expr *> Args,
6727 OverloadCandidateSet& CandidateSet) {
6728 if (!CandidateSet.isNewCandidate(Conversion))
6731 // Overload resolution is always an unevaluated context.
6732 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated);
6734 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1);
6735 Candidate.FoundDecl = FoundDecl;
6736 Candidate.Function = nullptr;
6737 Candidate.Surrogate = Conversion;
6738 Candidate.Viable = true;
6739 Candidate.IsSurrogate = true;
6740 Candidate.IgnoreObjectArgument = false;
6741 Candidate.ExplicitCallArguments = Args.size();
6743 // Determine the implicit conversion sequence for the implicit
6744 // object parameter.
6745 ImplicitConversionSequence ObjectInit = TryObjectArgumentInitialization(
6746 *this, CandidateSet.getLocation(), Object->getType(),
6747 Object->Classify(Context), Conversion, ActingContext);
6748 if (ObjectInit.isBad()) {
6749 Candidate.Viable = false;
6750 Candidate.FailureKind = ovl_fail_bad_conversion;
6751 Candidate.Conversions[0] = ObjectInit;
6755 // The first conversion is actually a user-defined conversion whose
6756 // first conversion is ObjectInit's standard conversion (which is
6757 // effectively a reference binding). Record it as such.
6758 Candidate.Conversions[0].setUserDefined();
6759 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard;
6760 Candidate.Conversions[0].UserDefined.EllipsisConversion = false;
6761 Candidate.Conversions[0].UserDefined.HadMultipleCandidates = false;
6762 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion;
6763 Candidate.Conversions[0].UserDefined.FoundConversionFunction = FoundDecl;
6764 Candidate.Conversions[0].UserDefined.After
6765 = Candidate.Conversions[0].UserDefined.Before;
6766 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion();
6769 unsigned NumParams = Proto->getNumParams();
6771 // (C++ 13.3.2p2): A candidate function having fewer than m
6772 // parameters is viable only if it has an ellipsis in its parameter
6774 if (Args.size() > NumParams && !Proto->isVariadic()) {
6775 Candidate.Viable = false;
6776 Candidate.FailureKind = ovl_fail_too_many_arguments;
6780 // Function types don't have any default arguments, so just check if
6781 // we have enough arguments.
6782 if (Args.size() < NumParams) {
6783 // Not enough arguments.
6784 Candidate.Viable = false;
6785 Candidate.FailureKind = ovl_fail_too_few_arguments;
6789 // Determine the implicit conversion sequences for each of the
6791 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
6792 if (ArgIdx < NumParams) {
6793 // (C++ 13.3.2p3): for F to be a viable function, there shall
6794 // exist for each argument an implicit conversion sequence
6795 // (13.3.3.1) that converts that argument to the corresponding
6797 QualType ParamType = Proto->getParamType(ArgIdx);
6798 Candidate.Conversions[ArgIdx + 1]
6799 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
6800 /*SuppressUserConversions=*/false,
6801 /*InOverloadResolution=*/false,
6802 /*AllowObjCWritebackConversion=*/
6803 getLangOpts().ObjCAutoRefCount);
6804 if (Candidate.Conversions[ArgIdx + 1].isBad()) {
6805 Candidate.Viable = false;
6806 Candidate.FailureKind = ovl_fail_bad_conversion;
6810 // (C++ 13.3.2p2): For the purposes of overload resolution, any
6811 // argument for which there is no corresponding parameter is
6812 // considered to ""match the ellipsis" (C+ 13.3.3.1.3).
6813 Candidate.Conversions[ArgIdx + 1].setEllipsis();
6817 if (EnableIfAttr *FailedAttr = CheckEnableIf(Conversion, None)) {
6818 Candidate.Viable = false;
6819 Candidate.FailureKind = ovl_fail_enable_if;
6820 Candidate.DeductionFailure.Data = FailedAttr;
6825 /// \brief Add overload candidates for overloaded operators that are
6826 /// member functions.
6828 /// Add the overloaded operator candidates that are member functions
6829 /// for the operator Op that was used in an operator expression such
6830 /// as "x Op y". , Args/NumArgs provides the operator arguments, and
6831 /// CandidateSet will store the added overload candidates. (C++
6832 /// [over.match.oper]).
6833 void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op,
6834 SourceLocation OpLoc,
6835 ArrayRef<Expr *> Args,
6836 OverloadCandidateSet& CandidateSet,
6837 SourceRange OpRange) {
6838 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
6840 // C++ [over.match.oper]p3:
6841 // For a unary operator @ with an operand of a type whose
6842 // cv-unqualified version is T1, and for a binary operator @ with
6843 // a left operand of a type whose cv-unqualified version is T1 and
6844 // a right operand of a type whose cv-unqualified version is T2,
6845 // three sets of candidate functions, designated member
6846 // candidates, non-member candidates and built-in candidates, are
6847 // constructed as follows:
6848 QualType T1 = Args[0]->getType();
6850 // -- If T1 is a complete class type or a class currently being
6851 // defined, the set of member candidates is the result of the
6852 // qualified lookup of T1::operator@ (13.3.1.1.1); otherwise,
6853 // the set of member candidates is empty.
6854 if (const RecordType *T1Rec = T1->getAs<RecordType>()) {
6855 // Complete the type if it can be completed.
6856 if (!isCompleteType(OpLoc, T1) && !T1Rec->isBeingDefined())
6858 // If the type is neither complete nor being defined, bail out now.
6859 if (!T1Rec->getDecl()->getDefinition())
6862 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName);
6863 LookupQualifiedName(Operators, T1Rec->getDecl());
6864 Operators.suppressDiagnostics();
6866 for (LookupResult::iterator Oper = Operators.begin(),
6867 OperEnd = Operators.end();
6870 AddMethodCandidate(Oper.getPair(), Args[0]->getType(),
6871 Args[0]->Classify(Context),
6874 /* SuppressUserConversions = */ false);
6878 /// AddBuiltinCandidate - Add a candidate for a built-in
6879 /// operator. ResultTy and ParamTys are the result and parameter types
6880 /// of the built-in candidate, respectively. Args and NumArgs are the
6881 /// arguments being passed to the candidate. IsAssignmentOperator
6882 /// should be true when this built-in candidate is an assignment
6883 /// operator. NumContextualBoolArguments is the number of arguments
6884 /// (at the beginning of the argument list) that will be contextually
6885 /// converted to bool.
6886 void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys,
6887 ArrayRef<Expr *> Args,
6888 OverloadCandidateSet& CandidateSet,
6889 bool IsAssignmentOperator,
6890 unsigned NumContextualBoolArguments) {
6891 // Overload resolution is always an unevaluated context.
6892 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated);
6894 // Add this candidate
6895 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size());
6896 Candidate.FoundDecl = DeclAccessPair::make(nullptr, AS_none);
6897 Candidate.Function = nullptr;
6898 Candidate.IsSurrogate = false;
6899 Candidate.IgnoreObjectArgument = false;
6900 Candidate.BuiltinTypes.ResultTy = ResultTy;
6901 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx)
6902 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx];
6904 // Determine the implicit conversion sequences for each of the
6906 Candidate.Viable = true;
6907 Candidate.ExplicitCallArguments = Args.size();
6908 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
6909 // C++ [over.match.oper]p4:
6910 // For the built-in assignment operators, conversions of the
6911 // left operand are restricted as follows:
6912 // -- no temporaries are introduced to hold the left operand, and
6913 // -- no user-defined conversions are applied to the left
6914 // operand to achieve a type match with the left-most
6915 // parameter of a built-in candidate.
6917 // We block these conversions by turning off user-defined
6918 // conversions, since that is the only way that initialization of
6919 // a reference to a non-class type can occur from something that
6920 // is not of the same type.
6921 if (ArgIdx < NumContextualBoolArguments) {
6922 assert(ParamTys[ArgIdx] == Context.BoolTy &&
6923 "Contextual conversion to bool requires bool type");
6924 Candidate.Conversions[ArgIdx]
6925 = TryContextuallyConvertToBool(*this, Args[ArgIdx]);
6927 Candidate.Conversions[ArgIdx]
6928 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx],
6929 ArgIdx == 0 && IsAssignmentOperator,
6930 /*InOverloadResolution=*/false,
6931 /*AllowObjCWritebackConversion=*/
6932 getLangOpts().ObjCAutoRefCount);
6934 if (Candidate.Conversions[ArgIdx].isBad()) {
6935 Candidate.Viable = false;
6936 Candidate.FailureKind = ovl_fail_bad_conversion;
6944 /// BuiltinCandidateTypeSet - A set of types that will be used for the
6945 /// candidate operator functions for built-in operators (C++
6946 /// [over.built]). The types are separated into pointer types and
6947 /// enumeration types.
6948 class BuiltinCandidateTypeSet {
6949 /// TypeSet - A set of types.
6950 typedef llvm::SetVector<QualType, SmallVector<QualType, 8>,
6951 llvm::SmallPtrSet<QualType, 8>> TypeSet;
6953 /// PointerTypes - The set of pointer types that will be used in the
6954 /// built-in candidates.
6955 TypeSet PointerTypes;
6957 /// MemberPointerTypes - The set of member pointer types that will be
6958 /// used in the built-in candidates.
6959 TypeSet MemberPointerTypes;
6961 /// EnumerationTypes - The set of enumeration types that will be
6962 /// used in the built-in candidates.
6963 TypeSet EnumerationTypes;
6965 /// \brief The set of vector types that will be used in the built-in
6967 TypeSet VectorTypes;
6969 /// \brief A flag indicating non-record types are viable candidates
6970 bool HasNonRecordTypes;
6972 /// \brief A flag indicating whether either arithmetic or enumeration types
6973 /// were present in the candidate set.
6974 bool HasArithmeticOrEnumeralTypes;
6976 /// \brief A flag indicating whether the nullptr type was present in the
6978 bool HasNullPtrType;
6980 /// Sema - The semantic analysis instance where we are building the
6981 /// candidate type set.
6984 /// Context - The AST context in which we will build the type sets.
6985 ASTContext &Context;
6987 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
6988 const Qualifiers &VisibleQuals);
6989 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty);
6992 /// iterator - Iterates through the types that are part of the set.
6993 typedef TypeSet::iterator iterator;
6995 BuiltinCandidateTypeSet(Sema &SemaRef)
6996 : HasNonRecordTypes(false),
6997 HasArithmeticOrEnumeralTypes(false),
6998 HasNullPtrType(false),
7000 Context(SemaRef.Context) { }
7002 void AddTypesConvertedFrom(QualType Ty,
7004 bool AllowUserConversions,
7005 bool AllowExplicitConversions,
7006 const Qualifiers &VisibleTypeConversionsQuals);
7008 /// pointer_begin - First pointer type found;
7009 iterator pointer_begin() { return PointerTypes.begin(); }
7011 /// pointer_end - Past the last pointer type found;
7012 iterator pointer_end() { return PointerTypes.end(); }
7014 /// member_pointer_begin - First member pointer type found;
7015 iterator member_pointer_begin() { return MemberPointerTypes.begin(); }
7017 /// member_pointer_end - Past the last member pointer type found;
7018 iterator member_pointer_end() { return MemberPointerTypes.end(); }
7020 /// enumeration_begin - First enumeration type found;
7021 iterator enumeration_begin() { return EnumerationTypes.begin(); }
7023 /// enumeration_end - Past the last enumeration type found;
7024 iterator enumeration_end() { return EnumerationTypes.end(); }
7026 iterator vector_begin() { return VectorTypes.begin(); }
7027 iterator vector_end() { return VectorTypes.end(); }
7029 bool hasNonRecordTypes() { return HasNonRecordTypes; }
7030 bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; }
7031 bool hasNullPtrType() const { return HasNullPtrType; }
7034 } // end anonymous namespace
7036 /// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to
7037 /// the set of pointer types along with any more-qualified variants of
7038 /// that type. For example, if @p Ty is "int const *", this routine
7039 /// will add "int const *", "int const volatile *", "int const
7040 /// restrict *", and "int const volatile restrict *" to the set of
7041 /// pointer types. Returns true if the add of @p Ty itself succeeded,
7042 /// false otherwise.
7044 /// FIXME: what to do about extended qualifiers?
7046 BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
7047 const Qualifiers &VisibleQuals) {
7049 // Insert this type.
7050 if (!PointerTypes.insert(Ty))
7054 const PointerType *PointerTy = Ty->getAs<PointerType>();
7055 bool buildObjCPtr = false;
7057 const ObjCObjectPointerType *PTy = Ty->castAs<ObjCObjectPointerType>();
7058 PointeeTy = PTy->getPointeeType();
7059 buildObjCPtr = true;
7061 PointeeTy = PointerTy->getPointeeType();
7064 // Don't add qualified variants of arrays. For one, they're not allowed
7065 // (the qualifier would sink to the element type), and for another, the
7066 // only overload situation where it matters is subscript or pointer +- int,
7067 // and those shouldn't have qualifier variants anyway.
7068 if (PointeeTy->isArrayType())
7071 unsigned BaseCVR = PointeeTy.getCVRQualifiers();
7072 bool hasVolatile = VisibleQuals.hasVolatile();
7073 bool hasRestrict = VisibleQuals.hasRestrict();
7075 // Iterate through all strict supersets of BaseCVR.
7076 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) {
7077 if ((CVR | BaseCVR) != CVR) continue;
7078 // Skip over volatile if no volatile found anywhere in the types.
7079 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue;
7081 // Skip over restrict if no restrict found anywhere in the types, or if
7082 // the type cannot be restrict-qualified.
7083 if ((CVR & Qualifiers::Restrict) &&
7085 (!(PointeeTy->isAnyPointerType() || PointeeTy->isReferenceType()))))
7088 // Build qualified pointee type.
7089 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR);
7091 // Build qualified pointer type.
7092 QualType QPointerTy;
7094 QPointerTy = Context.getPointerType(QPointeeTy);
7096 QPointerTy = Context.getObjCObjectPointerType(QPointeeTy);
7098 // Insert qualified pointer type.
7099 PointerTypes.insert(QPointerTy);
7105 /// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty
7106 /// to the set of pointer types along with any more-qualified variants of
7107 /// that type. For example, if @p Ty is "int const *", this routine
7108 /// will add "int const *", "int const volatile *", "int const
7109 /// restrict *", and "int const volatile restrict *" to the set of
7110 /// pointer types. Returns true if the add of @p Ty itself succeeded,
7111 /// false otherwise.
7113 /// FIXME: what to do about extended qualifiers?
7115 BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants(
7117 // Insert this type.
7118 if (!MemberPointerTypes.insert(Ty))
7121 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>();
7122 assert(PointerTy && "type was not a member pointer type!");
7124 QualType PointeeTy = PointerTy->getPointeeType();
7125 // Don't add qualified variants of arrays. For one, they're not allowed
7126 // (the qualifier would sink to the element type), and for another, the
7127 // only overload situation where it matters is subscript or pointer +- int,
7128 // and those shouldn't have qualifier variants anyway.
7129 if (PointeeTy->isArrayType())
7131 const Type *ClassTy = PointerTy->getClass();
7133 // Iterate through all strict supersets of the pointee type's CVR
7135 unsigned BaseCVR = PointeeTy.getCVRQualifiers();
7136 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) {
7137 if ((CVR | BaseCVR) != CVR) continue;
7139 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR);
7140 MemberPointerTypes.insert(
7141 Context.getMemberPointerType(QPointeeTy, ClassTy));
7147 /// AddTypesConvertedFrom - Add each of the types to which the type @p
7148 /// Ty can be implicit converted to the given set of @p Types. We're
7149 /// primarily interested in pointer types and enumeration types. We also
7150 /// take member pointer types, for the conditional operator.
7151 /// AllowUserConversions is true if we should look at the conversion
7152 /// functions of a class type, and AllowExplicitConversions if we
7153 /// should also include the explicit conversion functions of a class
7156 BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty,
7158 bool AllowUserConversions,
7159 bool AllowExplicitConversions,
7160 const Qualifiers &VisibleQuals) {
7161 // Only deal with canonical types.
7162 Ty = Context.getCanonicalType(Ty);
7164 // Look through reference types; they aren't part of the type of an
7165 // expression for the purposes of conversions.
7166 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>())
7167 Ty = RefTy->getPointeeType();
7169 // If we're dealing with an array type, decay to the pointer.
7170 if (Ty->isArrayType())
7171 Ty = SemaRef.Context.getArrayDecayedType(Ty);
7173 // Otherwise, we don't care about qualifiers on the type.
7174 Ty = Ty.getLocalUnqualifiedType();
7176 // Flag if we ever add a non-record type.
7177 const RecordType *TyRec = Ty->getAs<RecordType>();
7178 HasNonRecordTypes = HasNonRecordTypes || !TyRec;
7180 // Flag if we encounter an arithmetic type.
7181 HasArithmeticOrEnumeralTypes =
7182 HasArithmeticOrEnumeralTypes || Ty->isArithmeticType();
7184 if (Ty->isObjCIdType() || Ty->isObjCClassType())
7185 PointerTypes.insert(Ty);
7186 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) {
7187 // Insert our type, and its more-qualified variants, into the set
7189 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals))
7191 } else if (Ty->isMemberPointerType()) {
7192 // Member pointers are far easier, since the pointee can't be converted.
7193 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty))
7195 } else if (Ty->isEnumeralType()) {
7196 HasArithmeticOrEnumeralTypes = true;
7197 EnumerationTypes.insert(Ty);
7198 } else if (Ty->isVectorType()) {
7199 // We treat vector types as arithmetic types in many contexts as an
7201 HasArithmeticOrEnumeralTypes = true;
7202 VectorTypes.insert(Ty);
7203 } else if (Ty->isNullPtrType()) {
7204 HasNullPtrType = true;
7205 } else if (AllowUserConversions && TyRec) {
7206 // No conversion functions in incomplete types.
7207 if (!SemaRef.isCompleteType(Loc, Ty))
7210 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl());
7211 for (NamedDecl *D : ClassDecl->getVisibleConversionFunctions()) {
7212 if (isa<UsingShadowDecl>(D))
7213 D = cast<UsingShadowDecl>(D)->getTargetDecl();
7215 // Skip conversion function templates; they don't tell us anything
7216 // about which builtin types we can convert to.
7217 if (isa<FunctionTemplateDecl>(D))
7220 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D);
7221 if (AllowExplicitConversions || !Conv->isExplicit()) {
7222 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false,
7229 /// \brief Helper function for AddBuiltinOperatorCandidates() that adds
7230 /// the volatile- and non-volatile-qualified assignment operators for the
7231 /// given type to the candidate set.
7232 static void AddBuiltinAssignmentOperatorCandidates(Sema &S,
7234 ArrayRef<Expr *> Args,
7235 OverloadCandidateSet &CandidateSet) {
7236 QualType ParamTypes[2];
7238 // T& operator=(T&, T)
7239 ParamTypes[0] = S.Context.getLValueReferenceType(T);
7241 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7242 /*IsAssignmentOperator=*/true);
7244 if (!S.Context.getCanonicalType(T).isVolatileQualified()) {
7245 // volatile T& operator=(volatile T&, T)
7247 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T));
7249 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7250 /*IsAssignmentOperator=*/true);
7254 /// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers,
7255 /// if any, found in visible type conversion functions found in ArgExpr's type.
7256 static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) {
7258 const RecordType *TyRec;
7259 if (const MemberPointerType *RHSMPType =
7260 ArgExpr->getType()->getAs<MemberPointerType>())
7261 TyRec = RHSMPType->getClass()->getAs<RecordType>();
7263 TyRec = ArgExpr->getType()->getAs<RecordType>();
7265 // Just to be safe, assume the worst case.
7266 VRQuals.addVolatile();
7267 VRQuals.addRestrict();
7271 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl());
7272 if (!ClassDecl->hasDefinition())
7275 for (NamedDecl *D : ClassDecl->getVisibleConversionFunctions()) {
7276 if (isa<UsingShadowDecl>(D))
7277 D = cast<UsingShadowDecl>(D)->getTargetDecl();
7278 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) {
7279 QualType CanTy = Context.getCanonicalType(Conv->getConversionType());
7280 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>())
7281 CanTy = ResTypeRef->getPointeeType();
7282 // Need to go down the pointer/mempointer chain and add qualifiers
7286 if (CanTy.isRestrictQualified())
7287 VRQuals.addRestrict();
7288 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>())
7289 CanTy = ResTypePtr->getPointeeType();
7290 else if (const MemberPointerType *ResTypeMPtr =
7291 CanTy->getAs<MemberPointerType>())
7292 CanTy = ResTypeMPtr->getPointeeType();
7295 if (CanTy.isVolatileQualified())
7296 VRQuals.addVolatile();
7297 if (VRQuals.hasRestrict() && VRQuals.hasVolatile())
7307 /// \brief Helper class to manage the addition of builtin operator overload
7308 /// candidates. It provides shared state and utility methods used throughout
7309 /// the process, as well as a helper method to add each group of builtin
7310 /// operator overloads from the standard to a candidate set.
7311 class BuiltinOperatorOverloadBuilder {
7312 // Common instance state available to all overload candidate addition methods.
7314 ArrayRef<Expr *> Args;
7315 Qualifiers VisibleTypeConversionsQuals;
7316 bool HasArithmeticOrEnumeralCandidateType;
7317 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes;
7318 OverloadCandidateSet &CandidateSet;
7320 // Define some constants used to index and iterate over the arithemetic types
7321 // provided via the getArithmeticType() method below.
7322 // The "promoted arithmetic types" are the arithmetic
7323 // types are that preserved by promotion (C++ [over.built]p2).
7324 static const unsigned FirstIntegralType = 4;
7325 static const unsigned LastIntegralType = 21;
7326 static const unsigned FirstPromotedIntegralType = 4,
7327 LastPromotedIntegralType = 12;
7328 static const unsigned FirstPromotedArithmeticType = 0,
7329 LastPromotedArithmeticType = 12;
7330 static const unsigned NumArithmeticTypes = 21;
7332 /// \brief Get the canonical type for a given arithmetic type index.
7333 CanQualType getArithmeticType(unsigned index) {
7334 assert(index < NumArithmeticTypes);
7335 static CanQualType ASTContext::* const
7336 ArithmeticTypes[NumArithmeticTypes] = {
7337 // Start of promoted types.
7338 &ASTContext::FloatTy,
7339 &ASTContext::DoubleTy,
7340 &ASTContext::LongDoubleTy,
7341 &ASTContext::Float128Ty,
7343 // Start of integral types.
7345 &ASTContext::LongTy,
7346 &ASTContext::LongLongTy,
7347 &ASTContext::Int128Ty,
7348 &ASTContext::UnsignedIntTy,
7349 &ASTContext::UnsignedLongTy,
7350 &ASTContext::UnsignedLongLongTy,
7351 &ASTContext::UnsignedInt128Ty,
7352 // End of promoted types.
7354 &ASTContext::BoolTy,
7355 &ASTContext::CharTy,
7356 &ASTContext::WCharTy,
7357 &ASTContext::Char16Ty,
7358 &ASTContext::Char32Ty,
7359 &ASTContext::SignedCharTy,
7360 &ASTContext::ShortTy,
7361 &ASTContext::UnsignedCharTy,
7362 &ASTContext::UnsignedShortTy,
7363 // End of integral types.
7364 // FIXME: What about complex? What about half?
7366 return S.Context.*ArithmeticTypes[index];
7369 /// \brief Gets the canonical type resulting from the usual arithemetic
7370 /// converions for the given arithmetic types.
7371 CanQualType getUsualArithmeticConversions(unsigned L, unsigned R) {
7372 // Accelerator table for performing the usual arithmetic conversions.
7373 // The rules are basically:
7374 // - if either is floating-point, use the wider floating-point
7375 // - if same signedness, use the higher rank
7376 // - if same size, use unsigned of the higher rank
7377 // - use the larger type
7378 // These rules, together with the axiom that higher ranks are
7379 // never smaller, are sufficient to precompute all of these results
7380 // *except* when dealing with signed types of higher rank.
7381 // (we could precompute SLL x UI for all known platforms, but it's
7382 // better not to make any assumptions).
7383 // We assume that int128 has a higher rank than long long on all platforms.
7384 enum PromotedType : int8_t {
7386 Flt, Dbl, LDbl, SI, SL, SLL, S128, UI, UL, ULL, U128
7388 static const PromotedType ConversionsTable[LastPromotedArithmeticType]
7389 [LastPromotedArithmeticType] = {
7390 /* Flt*/ { Flt, Dbl, LDbl, Flt, Flt, Flt, Flt, Flt, Flt, Flt, Flt },
7391 /* Dbl*/ { Dbl, Dbl, LDbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl },
7392 /*LDbl*/ { LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl },
7393 /* SI*/ { Flt, Dbl, LDbl, SI, SL, SLL, S128, UI, UL, ULL, U128 },
7394 /* SL*/ { Flt, Dbl, LDbl, SL, SL, SLL, S128, Dep, UL, ULL, U128 },
7395 /* SLL*/ { Flt, Dbl, LDbl, SLL, SLL, SLL, S128, Dep, Dep, ULL, U128 },
7396 /*S128*/ { Flt, Dbl, LDbl, S128, S128, S128, S128, S128, S128, S128, U128 },
7397 /* UI*/ { Flt, Dbl, LDbl, UI, Dep, Dep, S128, UI, UL, ULL, U128 },
7398 /* UL*/ { Flt, Dbl, LDbl, UL, UL, Dep, S128, UL, UL, ULL, U128 },
7399 /* ULL*/ { Flt, Dbl, LDbl, ULL, ULL, ULL, S128, ULL, ULL, ULL, U128 },
7400 /*U128*/ { Flt, Dbl, LDbl, U128, U128, U128, U128, U128, U128, U128, U128 },
7403 assert(L < LastPromotedArithmeticType);
7404 assert(R < LastPromotedArithmeticType);
7405 int Idx = ConversionsTable[L][R];
7407 // Fast path: the table gives us a concrete answer.
7408 if (Idx != Dep) return getArithmeticType(Idx);
7410 // Slow path: we need to compare widths.
7411 // An invariant is that the signed type has higher rank.
7412 CanQualType LT = getArithmeticType(L),
7413 RT = getArithmeticType(R);
7414 unsigned LW = S.Context.getIntWidth(LT),
7415 RW = S.Context.getIntWidth(RT);
7417 // If they're different widths, use the signed type.
7418 if (LW > RW) return LT;
7419 else if (LW < RW) return RT;
7421 // Otherwise, use the unsigned type of the signed type's rank.
7422 if (L == SL || R == SL) return S.Context.UnsignedLongTy;
7423 assert(L == SLL || R == SLL);
7424 return S.Context.UnsignedLongLongTy;
7427 /// \brief Helper method to factor out the common pattern of adding overloads
7428 /// for '++' and '--' builtin operators.
7429 void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy,
7432 QualType ParamTypes[2] = {
7433 S.Context.getLValueReferenceType(CandidateTy),
7437 // Non-volatile version.
7438 if (Args.size() == 1)
7439 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
7441 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet);
7443 // Use a heuristic to reduce number of builtin candidates in the set:
7444 // add volatile version only if there are conversions to a volatile type.
7447 S.Context.getLValueReferenceType(
7448 S.Context.getVolatileType(CandidateTy));
7449 if (Args.size() == 1)
7450 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
7452 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet);
7455 // Add restrict version only if there are conversions to a restrict type
7456 // and our candidate type is a non-restrict-qualified pointer.
7457 if (HasRestrict && CandidateTy->isAnyPointerType() &&
7458 !CandidateTy.isRestrictQualified()) {
7460 = S.Context.getLValueReferenceType(
7461 S.Context.getCVRQualifiedType(CandidateTy, Qualifiers::Restrict));
7462 if (Args.size() == 1)
7463 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
7465 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet);
7469 = S.Context.getLValueReferenceType(
7470 S.Context.getCVRQualifiedType(CandidateTy,
7471 (Qualifiers::Volatile |
7472 Qualifiers::Restrict)));
7473 if (Args.size() == 1)
7474 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
7476 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet);
7483 BuiltinOperatorOverloadBuilder(
7484 Sema &S, ArrayRef<Expr *> Args,
7485 Qualifiers VisibleTypeConversionsQuals,
7486 bool HasArithmeticOrEnumeralCandidateType,
7487 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes,
7488 OverloadCandidateSet &CandidateSet)
7490 VisibleTypeConversionsQuals(VisibleTypeConversionsQuals),
7491 HasArithmeticOrEnumeralCandidateType(
7492 HasArithmeticOrEnumeralCandidateType),
7493 CandidateTypes(CandidateTypes),
7494 CandidateSet(CandidateSet) {
7495 // Validate some of our static helper constants in debug builds.
7496 assert(getArithmeticType(FirstPromotedIntegralType) == S.Context.IntTy &&
7497 "Invalid first promoted integral type");
7498 assert(getArithmeticType(LastPromotedIntegralType - 1)
7499 == S.Context.UnsignedInt128Ty &&
7500 "Invalid last promoted integral type");
7501 assert(getArithmeticType(FirstPromotedArithmeticType)
7502 == S.Context.FloatTy &&
7503 "Invalid first promoted arithmetic type");
7504 assert(getArithmeticType(LastPromotedArithmeticType - 1)
7505 == S.Context.UnsignedInt128Ty &&
7506 "Invalid last promoted arithmetic type");
7509 // C++ [over.built]p3:
7511 // For every pair (T, VQ), where T is an arithmetic type, and VQ
7512 // is either volatile or empty, there exist candidate operator
7513 // functions of the form
7515 // VQ T& operator++(VQ T&);
7516 // T operator++(VQ T&, int);
7518 // C++ [over.built]p4:
7520 // For every pair (T, VQ), where T is an arithmetic type other
7521 // than bool, and VQ is either volatile or empty, there exist
7522 // candidate operator functions of the form
7524 // VQ T& operator--(VQ T&);
7525 // T operator--(VQ T&, int);
7526 void addPlusPlusMinusMinusArithmeticOverloads(OverloadedOperatorKind Op) {
7527 if (!HasArithmeticOrEnumeralCandidateType)
7530 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1);
7531 Arith < NumArithmeticTypes; ++Arith) {
7532 addPlusPlusMinusMinusStyleOverloads(
7533 getArithmeticType(Arith),
7534 VisibleTypeConversionsQuals.hasVolatile(),
7535 VisibleTypeConversionsQuals.hasRestrict());
7539 // C++ [over.built]p5:
7541 // For every pair (T, VQ), where T is a cv-qualified or
7542 // cv-unqualified object type, and VQ is either volatile or
7543 // empty, there exist candidate operator functions of the form
7545 // T*VQ& operator++(T*VQ&);
7546 // T*VQ& operator--(T*VQ&);
7547 // T* operator++(T*VQ&, int);
7548 // T* operator--(T*VQ&, int);
7549 void addPlusPlusMinusMinusPointerOverloads() {
7550 for (BuiltinCandidateTypeSet::iterator
7551 Ptr = CandidateTypes[0].pointer_begin(),
7552 PtrEnd = CandidateTypes[0].pointer_end();
7553 Ptr != PtrEnd; ++Ptr) {
7554 // Skip pointer types that aren't pointers to object types.
7555 if (!(*Ptr)->getPointeeType()->isObjectType())
7558 addPlusPlusMinusMinusStyleOverloads(*Ptr,
7559 (!(*Ptr).isVolatileQualified() &&
7560 VisibleTypeConversionsQuals.hasVolatile()),
7561 (!(*Ptr).isRestrictQualified() &&
7562 VisibleTypeConversionsQuals.hasRestrict()));
7566 // C++ [over.built]p6:
7567 // For every cv-qualified or cv-unqualified object type T, there
7568 // exist candidate operator functions of the form
7570 // T& operator*(T*);
7572 // C++ [over.built]p7:
7573 // For every function type T that does not have cv-qualifiers or a
7574 // ref-qualifier, there exist candidate operator functions of the form
7575 // T& operator*(T*);
7576 void addUnaryStarPointerOverloads() {
7577 for (BuiltinCandidateTypeSet::iterator
7578 Ptr = CandidateTypes[0].pointer_begin(),
7579 PtrEnd = CandidateTypes[0].pointer_end();
7580 Ptr != PtrEnd; ++Ptr) {
7581 QualType ParamTy = *Ptr;
7582 QualType PointeeTy = ParamTy->getPointeeType();
7583 if (!PointeeTy->isObjectType() && !PointeeTy->isFunctionType())
7586 if (const FunctionProtoType *Proto =PointeeTy->getAs<FunctionProtoType>())
7587 if (Proto->getTypeQuals() || Proto->getRefQualifier())
7590 S.AddBuiltinCandidate(S.Context.getLValueReferenceType(PointeeTy),
7591 &ParamTy, Args, CandidateSet);
7595 // C++ [over.built]p9:
7596 // For every promoted arithmetic type T, there exist candidate
7597 // operator functions of the form
7601 void addUnaryPlusOrMinusArithmeticOverloads() {
7602 if (!HasArithmeticOrEnumeralCandidateType)
7605 for (unsigned Arith = FirstPromotedArithmeticType;
7606 Arith < LastPromotedArithmeticType; ++Arith) {
7607 QualType ArithTy = getArithmeticType(Arith);
7608 S.AddBuiltinCandidate(ArithTy, &ArithTy, Args, CandidateSet);
7611 // Extension: We also add these operators for vector types.
7612 for (BuiltinCandidateTypeSet::iterator
7613 Vec = CandidateTypes[0].vector_begin(),
7614 VecEnd = CandidateTypes[0].vector_end();
7615 Vec != VecEnd; ++Vec) {
7616 QualType VecTy = *Vec;
7617 S.AddBuiltinCandidate(VecTy, &VecTy, Args, CandidateSet);
7621 // C++ [over.built]p8:
7622 // For every type T, there exist candidate operator functions of
7625 // T* operator+(T*);
7626 void addUnaryPlusPointerOverloads() {
7627 for (BuiltinCandidateTypeSet::iterator
7628 Ptr = CandidateTypes[0].pointer_begin(),
7629 PtrEnd = CandidateTypes[0].pointer_end();
7630 Ptr != PtrEnd; ++Ptr) {
7631 QualType ParamTy = *Ptr;
7632 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, CandidateSet);
7636 // C++ [over.built]p10:
7637 // For every promoted integral type T, there exist candidate
7638 // operator functions of the form
7641 void addUnaryTildePromotedIntegralOverloads() {
7642 if (!HasArithmeticOrEnumeralCandidateType)
7645 for (unsigned Int = FirstPromotedIntegralType;
7646 Int < LastPromotedIntegralType; ++Int) {
7647 QualType IntTy = getArithmeticType(Int);
7648 S.AddBuiltinCandidate(IntTy, &IntTy, Args, CandidateSet);
7651 // Extension: We also add this operator for vector types.
7652 for (BuiltinCandidateTypeSet::iterator
7653 Vec = CandidateTypes[0].vector_begin(),
7654 VecEnd = CandidateTypes[0].vector_end();
7655 Vec != VecEnd; ++Vec) {
7656 QualType VecTy = *Vec;
7657 S.AddBuiltinCandidate(VecTy, &VecTy, Args, CandidateSet);
7661 // C++ [over.match.oper]p16:
7662 // For every pointer to member type T or type std::nullptr_t, there
7663 // exist candidate operator functions of the form
7665 // bool operator==(T,T);
7666 // bool operator!=(T,T);
7667 void addEqualEqualOrNotEqualMemberPointerOrNullptrOverloads() {
7668 /// Set of (canonical) types that we've already handled.
7669 llvm::SmallPtrSet<QualType, 8> AddedTypes;
7671 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7672 for (BuiltinCandidateTypeSet::iterator
7673 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(),
7674 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end();
7675 MemPtr != MemPtrEnd;
7677 // Don't add the same builtin candidate twice.
7678 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr)).second)
7681 QualType ParamTypes[2] = { *MemPtr, *MemPtr };
7682 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet);
7685 if (CandidateTypes[ArgIdx].hasNullPtrType()) {
7686 CanQualType NullPtrTy = S.Context.getCanonicalType(S.Context.NullPtrTy);
7687 if (AddedTypes.insert(NullPtrTy).second) {
7688 QualType ParamTypes[2] = { NullPtrTy, NullPtrTy };
7689 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args,
7696 // C++ [over.built]p15:
7698 // For every T, where T is an enumeration type or a pointer type,
7699 // there exist candidate operator functions of the form
7701 // bool operator<(T, T);
7702 // bool operator>(T, T);
7703 // bool operator<=(T, T);
7704 // bool operator>=(T, T);
7705 // bool operator==(T, T);
7706 // bool operator!=(T, T);
7707 void addRelationalPointerOrEnumeralOverloads() {
7708 // C++ [over.match.oper]p3:
7709 // [...]the built-in candidates include all of the candidate operator
7710 // functions defined in 13.6 that, compared to the given operator, [...]
7711 // do not have the same parameter-type-list as any non-template non-member
7714 // Note that in practice, this only affects enumeration types because there
7715 // aren't any built-in candidates of record type, and a user-defined operator
7716 // must have an operand of record or enumeration type. Also, the only other
7717 // overloaded operator with enumeration arguments, operator=,
7718 // cannot be overloaded for enumeration types, so this is the only place
7719 // where we must suppress candidates like this.
7720 llvm::DenseSet<std::pair<CanQualType, CanQualType> >
7721 UserDefinedBinaryOperators;
7723 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7724 if (CandidateTypes[ArgIdx].enumeration_begin() !=
7725 CandidateTypes[ArgIdx].enumeration_end()) {
7726 for (OverloadCandidateSet::iterator C = CandidateSet.begin(),
7727 CEnd = CandidateSet.end();
7729 if (!C->Viable || !C->Function || C->Function->getNumParams() != 2)
7732 if (C->Function->isFunctionTemplateSpecialization())
7735 QualType FirstParamType =
7736 C->Function->getParamDecl(0)->getType().getUnqualifiedType();
7737 QualType SecondParamType =
7738 C->Function->getParamDecl(1)->getType().getUnqualifiedType();
7740 // Skip if either parameter isn't of enumeral type.
7741 if (!FirstParamType->isEnumeralType() ||
7742 !SecondParamType->isEnumeralType())
7745 // Add this operator to the set of known user-defined operators.
7746 UserDefinedBinaryOperators.insert(
7747 std::make_pair(S.Context.getCanonicalType(FirstParamType),
7748 S.Context.getCanonicalType(SecondParamType)));
7753 /// Set of (canonical) types that we've already handled.
7754 llvm::SmallPtrSet<QualType, 8> AddedTypes;
7756 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7757 for (BuiltinCandidateTypeSet::iterator
7758 Ptr = CandidateTypes[ArgIdx].pointer_begin(),
7759 PtrEnd = CandidateTypes[ArgIdx].pointer_end();
7760 Ptr != PtrEnd; ++Ptr) {
7761 // Don't add the same builtin candidate twice.
7762 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
7765 QualType ParamTypes[2] = { *Ptr, *Ptr };
7766 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet);
7768 for (BuiltinCandidateTypeSet::iterator
7769 Enum = CandidateTypes[ArgIdx].enumeration_begin(),
7770 EnumEnd = CandidateTypes[ArgIdx].enumeration_end();
7771 Enum != EnumEnd; ++Enum) {
7772 CanQualType CanonType = S.Context.getCanonicalType(*Enum);
7774 // Don't add the same builtin candidate twice, or if a user defined
7775 // candidate exists.
7776 if (!AddedTypes.insert(CanonType).second ||
7777 UserDefinedBinaryOperators.count(std::make_pair(CanonType,
7781 QualType ParamTypes[2] = { *Enum, *Enum };
7782 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet);
7787 // C++ [over.built]p13:
7789 // For every cv-qualified or cv-unqualified object type T
7790 // there exist candidate operator functions of the form
7792 // T* operator+(T*, ptrdiff_t);
7793 // T& operator[](T*, ptrdiff_t); [BELOW]
7794 // T* operator-(T*, ptrdiff_t);
7795 // T* operator+(ptrdiff_t, T*);
7796 // T& operator[](ptrdiff_t, T*); [BELOW]
7798 // C++ [over.built]p14:
7800 // For every T, where T is a pointer to object type, there
7801 // exist candidate operator functions of the form
7803 // ptrdiff_t operator-(T, T);
7804 void addBinaryPlusOrMinusPointerOverloads(OverloadedOperatorKind Op) {
7805 /// Set of (canonical) types that we've already handled.
7806 llvm::SmallPtrSet<QualType, 8> AddedTypes;
7808 for (int Arg = 0; Arg < 2; ++Arg) {
7809 QualType AsymmetricParamTypes[2] = {
7810 S.Context.getPointerDiffType(),
7811 S.Context.getPointerDiffType(),
7813 for (BuiltinCandidateTypeSet::iterator
7814 Ptr = CandidateTypes[Arg].pointer_begin(),
7815 PtrEnd = CandidateTypes[Arg].pointer_end();
7816 Ptr != PtrEnd; ++Ptr) {
7817 QualType PointeeTy = (*Ptr)->getPointeeType();
7818 if (!PointeeTy->isObjectType())
7821 AsymmetricParamTypes[Arg] = *Ptr;
7822 if (Arg == 0 || Op == OO_Plus) {
7823 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t)
7824 // T* operator+(ptrdiff_t, T*);
7825 S.AddBuiltinCandidate(*Ptr, AsymmetricParamTypes, Args, CandidateSet);
7827 if (Op == OO_Minus) {
7828 // ptrdiff_t operator-(T, T);
7829 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
7832 QualType ParamTypes[2] = { *Ptr, *Ptr };
7833 S.AddBuiltinCandidate(S.Context.getPointerDiffType(), ParamTypes,
7834 Args, CandidateSet);
7840 // C++ [over.built]p12:
7842 // For every pair of promoted arithmetic types L and R, there
7843 // exist candidate operator functions of the form
7845 // LR operator*(L, R);
7846 // LR operator/(L, R);
7847 // LR operator+(L, R);
7848 // LR operator-(L, R);
7849 // bool operator<(L, R);
7850 // bool operator>(L, R);
7851 // bool operator<=(L, R);
7852 // bool operator>=(L, R);
7853 // bool operator==(L, R);
7854 // bool operator!=(L, R);
7856 // where LR is the result of the usual arithmetic conversions
7857 // between types L and R.
7859 // C++ [over.built]p24:
7861 // For every pair of promoted arithmetic types L and R, there exist
7862 // candidate operator functions of the form
7864 // LR operator?(bool, L, R);
7866 // where LR is the result of the usual arithmetic conversions
7867 // between types L and R.
7868 // Our candidates ignore the first parameter.
7869 void addGenericBinaryArithmeticOverloads(bool isComparison) {
7870 if (!HasArithmeticOrEnumeralCandidateType)
7873 for (unsigned Left = FirstPromotedArithmeticType;
7874 Left < LastPromotedArithmeticType; ++Left) {
7875 for (unsigned Right = FirstPromotedArithmeticType;
7876 Right < LastPromotedArithmeticType; ++Right) {
7877 QualType LandR[2] = { getArithmeticType(Left),
7878 getArithmeticType(Right) };
7880 isComparison ? S.Context.BoolTy
7881 : getUsualArithmeticConversions(Left, Right);
7882 S.AddBuiltinCandidate(Result, LandR, Args, CandidateSet);
7886 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the
7887 // conditional operator for vector types.
7888 for (BuiltinCandidateTypeSet::iterator
7889 Vec1 = CandidateTypes[0].vector_begin(),
7890 Vec1End = CandidateTypes[0].vector_end();
7891 Vec1 != Vec1End; ++Vec1) {
7892 for (BuiltinCandidateTypeSet::iterator
7893 Vec2 = CandidateTypes[1].vector_begin(),
7894 Vec2End = CandidateTypes[1].vector_end();
7895 Vec2 != Vec2End; ++Vec2) {
7896 QualType LandR[2] = { *Vec1, *Vec2 };
7897 QualType Result = S.Context.BoolTy;
7898 if (!isComparison) {
7899 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType())
7905 S.AddBuiltinCandidate(Result, LandR, Args, CandidateSet);
7910 // C++ [over.built]p17:
7912 // For every pair of promoted integral types L and R, there
7913 // exist candidate operator functions of the form
7915 // LR operator%(L, R);
7916 // LR operator&(L, R);
7917 // LR operator^(L, R);
7918 // LR operator|(L, R);
7919 // L operator<<(L, R);
7920 // L operator>>(L, R);
7922 // where LR is the result of the usual arithmetic conversions
7923 // between types L and R.
7924 void addBinaryBitwiseArithmeticOverloads(OverloadedOperatorKind Op) {
7925 if (!HasArithmeticOrEnumeralCandidateType)
7928 for (unsigned Left = FirstPromotedIntegralType;
7929 Left < LastPromotedIntegralType; ++Left) {
7930 for (unsigned Right = FirstPromotedIntegralType;
7931 Right < LastPromotedIntegralType; ++Right) {
7932 QualType LandR[2] = { getArithmeticType(Left),
7933 getArithmeticType(Right) };
7934 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater)
7936 : getUsualArithmeticConversions(Left, Right);
7937 S.AddBuiltinCandidate(Result, LandR, Args, CandidateSet);
7942 // C++ [over.built]p20:
7944 // For every pair (T, VQ), where T is an enumeration or
7945 // pointer to member type and VQ is either volatile or
7946 // empty, there exist candidate operator functions of the form
7948 // VQ T& operator=(VQ T&, T);
7949 void addAssignmentMemberPointerOrEnumeralOverloads() {
7950 /// Set of (canonical) types that we've already handled.
7951 llvm::SmallPtrSet<QualType, 8> AddedTypes;
7953 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) {
7954 for (BuiltinCandidateTypeSet::iterator
7955 Enum = CandidateTypes[ArgIdx].enumeration_begin(),
7956 EnumEnd = CandidateTypes[ArgIdx].enumeration_end();
7957 Enum != EnumEnd; ++Enum) {
7958 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum)).second)
7961 AddBuiltinAssignmentOperatorCandidates(S, *Enum, Args, CandidateSet);
7964 for (BuiltinCandidateTypeSet::iterator
7965 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(),
7966 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end();
7967 MemPtr != MemPtrEnd; ++MemPtr) {
7968 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr)).second)
7971 AddBuiltinAssignmentOperatorCandidates(S, *MemPtr, Args, CandidateSet);
7976 // C++ [over.built]p19:
7978 // For every pair (T, VQ), where T is any type and VQ is either
7979 // volatile or empty, there exist candidate operator functions
7982 // T*VQ& operator=(T*VQ&, T*);
7984 // C++ [over.built]p21:
7986 // For every pair (T, VQ), where T is a cv-qualified or
7987 // cv-unqualified object type and VQ is either volatile or
7988 // empty, there exist candidate operator functions of the form
7990 // T*VQ& operator+=(T*VQ&, ptrdiff_t);
7991 // T*VQ& operator-=(T*VQ&, ptrdiff_t);
7992 void addAssignmentPointerOverloads(bool isEqualOp) {
7993 /// Set of (canonical) types that we've already handled.
7994 llvm::SmallPtrSet<QualType, 8> AddedTypes;
7996 for (BuiltinCandidateTypeSet::iterator
7997 Ptr = CandidateTypes[0].pointer_begin(),
7998 PtrEnd = CandidateTypes[0].pointer_end();
7999 Ptr != PtrEnd; ++Ptr) {
8000 // If this is operator=, keep track of the builtin candidates we added.
8002 AddedTypes.insert(S.Context.getCanonicalType(*Ptr));
8003 else if (!(*Ptr)->getPointeeType()->isObjectType())
8006 // non-volatile version
8007 QualType ParamTypes[2] = {
8008 S.Context.getLValueReferenceType(*Ptr),
8009 isEqualOp ? *Ptr : S.Context.getPointerDiffType(),
8011 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8012 /*IsAssigmentOperator=*/ isEqualOp);
8014 bool NeedVolatile = !(*Ptr).isVolatileQualified() &&
8015 VisibleTypeConversionsQuals.hasVolatile();
8019 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr));
8020 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8021 /*IsAssigmentOperator=*/isEqualOp);
8024 if (!(*Ptr).isRestrictQualified() &&
8025 VisibleTypeConversionsQuals.hasRestrict()) {
8028 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr));
8029 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8030 /*IsAssigmentOperator=*/isEqualOp);
8033 // volatile restrict version
8035 = S.Context.getLValueReferenceType(
8036 S.Context.getCVRQualifiedType(*Ptr,
8037 (Qualifiers::Volatile |
8038 Qualifiers::Restrict)));
8039 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8040 /*IsAssigmentOperator=*/isEqualOp);
8046 for (BuiltinCandidateTypeSet::iterator
8047 Ptr = CandidateTypes[1].pointer_begin(),
8048 PtrEnd = CandidateTypes[1].pointer_end();
8049 Ptr != PtrEnd; ++Ptr) {
8050 // Make sure we don't add the same candidate twice.
8051 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
8054 QualType ParamTypes[2] = {
8055 S.Context.getLValueReferenceType(*Ptr),
8059 // non-volatile version
8060 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8061 /*IsAssigmentOperator=*/true);
8063 bool NeedVolatile = !(*Ptr).isVolatileQualified() &&
8064 VisibleTypeConversionsQuals.hasVolatile();
8068 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr));
8069 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8070 /*IsAssigmentOperator=*/true);
8073 if (!(*Ptr).isRestrictQualified() &&
8074 VisibleTypeConversionsQuals.hasRestrict()) {
8077 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr));
8078 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8079 /*IsAssigmentOperator=*/true);
8082 // volatile restrict version
8084 = S.Context.getLValueReferenceType(
8085 S.Context.getCVRQualifiedType(*Ptr,
8086 (Qualifiers::Volatile |
8087 Qualifiers::Restrict)));
8088 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8089 /*IsAssigmentOperator=*/true);
8096 // C++ [over.built]p18:
8098 // For every triple (L, VQ, R), where L is an arithmetic type,
8099 // VQ is either volatile or empty, and R is a promoted
8100 // arithmetic type, there exist candidate operator functions of
8103 // VQ L& operator=(VQ L&, R);
8104 // VQ L& operator*=(VQ L&, R);
8105 // VQ L& operator/=(VQ L&, R);
8106 // VQ L& operator+=(VQ L&, R);
8107 // VQ L& operator-=(VQ L&, R);
8108 void addAssignmentArithmeticOverloads(bool isEqualOp) {
8109 if (!HasArithmeticOrEnumeralCandidateType)
8112 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) {
8113 for (unsigned Right = FirstPromotedArithmeticType;
8114 Right < LastPromotedArithmeticType; ++Right) {
8115 QualType ParamTypes[2];
8116 ParamTypes[1] = getArithmeticType(Right);
8118 // Add this built-in operator as a candidate (VQ is empty).
8120 S.Context.getLValueReferenceType(getArithmeticType(Left));
8121 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8122 /*IsAssigmentOperator=*/isEqualOp);
8124 // Add this built-in operator as a candidate (VQ is 'volatile').
8125 if (VisibleTypeConversionsQuals.hasVolatile()) {
8127 S.Context.getVolatileType(getArithmeticType(Left));
8128 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
8129 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8130 /*IsAssigmentOperator=*/isEqualOp);
8135 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types.
8136 for (BuiltinCandidateTypeSet::iterator
8137 Vec1 = CandidateTypes[0].vector_begin(),
8138 Vec1End = CandidateTypes[0].vector_end();
8139 Vec1 != Vec1End; ++Vec1) {
8140 for (BuiltinCandidateTypeSet::iterator
8141 Vec2 = CandidateTypes[1].vector_begin(),
8142 Vec2End = CandidateTypes[1].vector_end();
8143 Vec2 != Vec2End; ++Vec2) {
8144 QualType ParamTypes[2];
8145 ParamTypes[1] = *Vec2;
8146 // Add this built-in operator as a candidate (VQ is empty).
8147 ParamTypes[0] = S.Context.getLValueReferenceType(*Vec1);
8148 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8149 /*IsAssigmentOperator=*/isEqualOp);
8151 // Add this built-in operator as a candidate (VQ is 'volatile').
8152 if (VisibleTypeConversionsQuals.hasVolatile()) {
8153 ParamTypes[0] = S.Context.getVolatileType(*Vec1);
8154 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
8155 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8156 /*IsAssigmentOperator=*/isEqualOp);
8162 // C++ [over.built]p22:
8164 // For every triple (L, VQ, R), where L is an integral type, VQ
8165 // is either volatile or empty, and R is a promoted integral
8166 // type, there exist candidate operator functions of the form
8168 // VQ L& operator%=(VQ L&, R);
8169 // VQ L& operator<<=(VQ L&, R);
8170 // VQ L& operator>>=(VQ L&, R);
8171 // VQ L& operator&=(VQ L&, R);
8172 // VQ L& operator^=(VQ L&, R);
8173 // VQ L& operator|=(VQ L&, R);
8174 void addAssignmentIntegralOverloads() {
8175 if (!HasArithmeticOrEnumeralCandidateType)
8178 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) {
8179 for (unsigned Right = FirstPromotedIntegralType;
8180 Right < LastPromotedIntegralType; ++Right) {
8181 QualType ParamTypes[2];
8182 ParamTypes[1] = getArithmeticType(Right);
8184 // Add this built-in operator as a candidate (VQ is empty).
8186 S.Context.getLValueReferenceType(getArithmeticType(Left));
8187 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
8188 if (VisibleTypeConversionsQuals.hasVolatile()) {
8189 // Add this built-in operator as a candidate (VQ is 'volatile').
8190 ParamTypes[0] = getArithmeticType(Left);
8191 ParamTypes[0] = S.Context.getVolatileType(ParamTypes[0]);
8192 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
8193 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
8199 // C++ [over.operator]p23:
8201 // There also exist candidate operator functions of the form
8203 // bool operator!(bool);
8204 // bool operator&&(bool, bool);
8205 // bool operator||(bool, bool);
8206 void addExclaimOverload() {
8207 QualType ParamTy = S.Context.BoolTy;
8208 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, CandidateSet,
8209 /*IsAssignmentOperator=*/false,
8210 /*NumContextualBoolArguments=*/1);
8212 void addAmpAmpOrPipePipeOverload() {
8213 QualType ParamTypes[2] = { S.Context.BoolTy, S.Context.BoolTy };
8214 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet,
8215 /*IsAssignmentOperator=*/false,
8216 /*NumContextualBoolArguments=*/2);
8219 // C++ [over.built]p13:
8221 // For every cv-qualified or cv-unqualified object type T there
8222 // exist candidate operator functions of the form
8224 // T* operator+(T*, ptrdiff_t); [ABOVE]
8225 // T& operator[](T*, ptrdiff_t);
8226 // T* operator-(T*, ptrdiff_t); [ABOVE]
8227 // T* operator+(ptrdiff_t, T*); [ABOVE]
8228 // T& operator[](ptrdiff_t, T*);
8229 void addSubscriptOverloads() {
8230 for (BuiltinCandidateTypeSet::iterator
8231 Ptr = CandidateTypes[0].pointer_begin(),
8232 PtrEnd = CandidateTypes[0].pointer_end();
8233 Ptr != PtrEnd; ++Ptr) {
8234 QualType ParamTypes[2] = { *Ptr, S.Context.getPointerDiffType() };
8235 QualType PointeeType = (*Ptr)->getPointeeType();
8236 if (!PointeeType->isObjectType())
8239 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType);
8241 // T& operator[](T*, ptrdiff_t)
8242 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, CandidateSet);
8245 for (BuiltinCandidateTypeSet::iterator
8246 Ptr = CandidateTypes[1].pointer_begin(),
8247 PtrEnd = CandidateTypes[1].pointer_end();
8248 Ptr != PtrEnd; ++Ptr) {
8249 QualType ParamTypes[2] = { S.Context.getPointerDiffType(), *Ptr };
8250 QualType PointeeType = (*Ptr)->getPointeeType();
8251 if (!PointeeType->isObjectType())
8254 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType);
8256 // T& operator[](ptrdiff_t, T*)
8257 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, CandidateSet);
8261 // C++ [over.built]p11:
8262 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type,
8263 // C1 is the same type as C2 or is a derived class of C2, T is an object
8264 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
8265 // there exist candidate operator functions of the form
8267 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
8269 // where CV12 is the union of CV1 and CV2.
8270 void addArrowStarOverloads() {
8271 for (BuiltinCandidateTypeSet::iterator
8272 Ptr = CandidateTypes[0].pointer_begin(),
8273 PtrEnd = CandidateTypes[0].pointer_end();
8274 Ptr != PtrEnd; ++Ptr) {
8275 QualType C1Ty = (*Ptr);
8277 QualifierCollector Q1;
8278 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0);
8279 if (!isa<RecordType>(C1))
8281 // heuristic to reduce number of builtin candidates in the set.
8282 // Add volatile/restrict version only if there are conversions to a
8283 // volatile/restrict type.
8284 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile())
8286 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict())
8288 for (BuiltinCandidateTypeSet::iterator
8289 MemPtr = CandidateTypes[1].member_pointer_begin(),
8290 MemPtrEnd = CandidateTypes[1].member_pointer_end();
8291 MemPtr != MemPtrEnd; ++MemPtr) {
8292 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr);
8293 QualType C2 = QualType(mptr->getClass(), 0);
8294 C2 = C2.getUnqualifiedType();
8295 if (C1 != C2 && !S.IsDerivedFrom(CandidateSet.getLocation(), C1, C2))
8297 QualType ParamTypes[2] = { *Ptr, *MemPtr };
8299 QualType T = mptr->getPointeeType();
8300 if (!VisibleTypeConversionsQuals.hasVolatile() &&
8301 T.isVolatileQualified())
8303 if (!VisibleTypeConversionsQuals.hasRestrict() &&
8304 T.isRestrictQualified())
8306 T = Q1.apply(S.Context, T);
8307 QualType ResultTy = S.Context.getLValueReferenceType(T);
8308 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, CandidateSet);
8313 // Note that we don't consider the first argument, since it has been
8314 // contextually converted to bool long ago. The candidates below are
8315 // therefore added as binary.
8317 // C++ [over.built]p25:
8318 // For every type T, where T is a pointer, pointer-to-member, or scoped
8319 // enumeration type, there exist candidate operator functions of the form
8321 // T operator?(bool, T, T);
8323 void addConditionalOperatorOverloads() {
8324 /// Set of (canonical) types that we've already handled.
8325 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8327 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) {
8328 for (BuiltinCandidateTypeSet::iterator
8329 Ptr = CandidateTypes[ArgIdx].pointer_begin(),
8330 PtrEnd = CandidateTypes[ArgIdx].pointer_end();
8331 Ptr != PtrEnd; ++Ptr) {
8332 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
8335 QualType ParamTypes[2] = { *Ptr, *Ptr };
8336 S.AddBuiltinCandidate(*Ptr, ParamTypes, Args, CandidateSet);
8339 for (BuiltinCandidateTypeSet::iterator
8340 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(),
8341 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end();
8342 MemPtr != MemPtrEnd; ++MemPtr) {
8343 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr)).second)
8346 QualType ParamTypes[2] = { *MemPtr, *MemPtr };
8347 S.AddBuiltinCandidate(*MemPtr, ParamTypes, Args, CandidateSet);
8350 if (S.getLangOpts().CPlusPlus11) {
8351 for (BuiltinCandidateTypeSet::iterator
8352 Enum = CandidateTypes[ArgIdx].enumeration_begin(),
8353 EnumEnd = CandidateTypes[ArgIdx].enumeration_end();
8354 Enum != EnumEnd; ++Enum) {
8355 if (!(*Enum)->getAs<EnumType>()->getDecl()->isScoped())
8358 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum)).second)
8361 QualType ParamTypes[2] = { *Enum, *Enum };
8362 S.AddBuiltinCandidate(*Enum, ParamTypes, Args, CandidateSet);
8369 } // end anonymous namespace
8371 /// AddBuiltinOperatorCandidates - Add the appropriate built-in
8372 /// operator overloads to the candidate set (C++ [over.built]), based
8373 /// on the operator @p Op and the arguments given. For example, if the
8374 /// operator is a binary '+', this routine might add "int
8375 /// operator+(int, int)" to cover integer addition.
8376 void Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op,
8377 SourceLocation OpLoc,
8378 ArrayRef<Expr *> Args,
8379 OverloadCandidateSet &CandidateSet) {
8380 // Find all of the types that the arguments can convert to, but only
8381 // if the operator we're looking at has built-in operator candidates
8382 // that make use of these types. Also record whether we encounter non-record
8383 // candidate types or either arithmetic or enumeral candidate types.
8384 Qualifiers VisibleTypeConversionsQuals;
8385 VisibleTypeConversionsQuals.addConst();
8386 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx)
8387 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]);
8389 bool HasNonRecordCandidateType = false;
8390 bool HasArithmeticOrEnumeralCandidateType = false;
8391 SmallVector<BuiltinCandidateTypeSet, 2> CandidateTypes;
8392 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
8393 CandidateTypes.emplace_back(*this);
8394 CandidateTypes[ArgIdx].AddTypesConvertedFrom(Args[ArgIdx]->getType(),
8397 (Op == OO_Exclaim ||
8400 VisibleTypeConversionsQuals);
8401 HasNonRecordCandidateType = HasNonRecordCandidateType ||
8402 CandidateTypes[ArgIdx].hasNonRecordTypes();
8403 HasArithmeticOrEnumeralCandidateType =
8404 HasArithmeticOrEnumeralCandidateType ||
8405 CandidateTypes[ArgIdx].hasArithmeticOrEnumeralTypes();
8408 // Exit early when no non-record types have been added to the candidate set
8409 // for any of the arguments to the operator.
8411 // We can't exit early for !, ||, or &&, since there we have always have
8412 // 'bool' overloads.
8413 if (!HasNonRecordCandidateType &&
8414 !(Op == OO_Exclaim || Op == OO_AmpAmp || Op == OO_PipePipe))
8417 // Setup an object to manage the common state for building overloads.
8418 BuiltinOperatorOverloadBuilder OpBuilder(*this, Args,
8419 VisibleTypeConversionsQuals,
8420 HasArithmeticOrEnumeralCandidateType,
8421 CandidateTypes, CandidateSet);
8423 // Dispatch over the operation to add in only those overloads which apply.
8426 case NUM_OVERLOADED_OPERATORS:
8427 llvm_unreachable("Expected an overloaded operator");
8432 case OO_Array_Delete:
8435 "Special operators don't use AddBuiltinOperatorCandidates");
8440 // C++ [over.match.oper]p3:
8441 // -- For the operator ',', the unary operator '&', the
8442 // operator '->', or the operator 'co_await', the
8443 // built-in candidates set is empty.
8446 case OO_Plus: // '+' is either unary or binary
8447 if (Args.size() == 1)
8448 OpBuilder.addUnaryPlusPointerOverloads();
8451 case OO_Minus: // '-' is either unary or binary
8452 if (Args.size() == 1) {
8453 OpBuilder.addUnaryPlusOrMinusArithmeticOverloads();
8455 OpBuilder.addBinaryPlusOrMinusPointerOverloads(Op);
8456 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false);
8460 case OO_Star: // '*' is either unary or binary
8461 if (Args.size() == 1)
8462 OpBuilder.addUnaryStarPointerOverloads();
8464 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false);
8468 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false);
8473 OpBuilder.addPlusPlusMinusMinusArithmeticOverloads(Op);
8474 OpBuilder.addPlusPlusMinusMinusPointerOverloads();
8478 case OO_ExclaimEqual:
8479 OpBuilder.addEqualEqualOrNotEqualMemberPointerOrNullptrOverloads();
8485 case OO_GreaterEqual:
8486 OpBuilder.addRelationalPointerOrEnumeralOverloads();
8487 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/true);
8494 case OO_GreaterGreater:
8495 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op);
8498 case OO_Amp: // '&' is either unary or binary
8499 if (Args.size() == 1)
8500 // C++ [over.match.oper]p3:
8501 // -- For the operator ',', the unary operator '&', or the
8502 // operator '->', the built-in candidates set is empty.
8505 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op);
8509 OpBuilder.addUnaryTildePromotedIntegralOverloads();
8513 OpBuilder.addAssignmentMemberPointerOrEnumeralOverloads();
8518 OpBuilder.addAssignmentPointerOverloads(Op == OO_Equal);
8523 OpBuilder.addAssignmentArithmeticOverloads(Op == OO_Equal);
8526 case OO_PercentEqual:
8527 case OO_LessLessEqual:
8528 case OO_GreaterGreaterEqual:
8532 OpBuilder.addAssignmentIntegralOverloads();
8536 OpBuilder.addExclaimOverload();
8541 OpBuilder.addAmpAmpOrPipePipeOverload();
8545 OpBuilder.addSubscriptOverloads();
8549 OpBuilder.addArrowStarOverloads();
8552 case OO_Conditional:
8553 OpBuilder.addConditionalOperatorOverloads();
8554 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false);
8559 /// \brief Add function candidates found via argument-dependent lookup
8560 /// to the set of overloading candidates.
8562 /// This routine performs argument-dependent name lookup based on the
8563 /// given function name (which may also be an operator name) and adds
8564 /// all of the overload candidates found by ADL to the overload
8565 /// candidate set (C++ [basic.lookup.argdep]).
8567 Sema::AddArgumentDependentLookupCandidates(DeclarationName Name,
8569 ArrayRef<Expr *> Args,
8570 TemplateArgumentListInfo *ExplicitTemplateArgs,
8571 OverloadCandidateSet& CandidateSet,
8572 bool PartialOverloading) {
8575 // FIXME: This approach for uniquing ADL results (and removing
8576 // redundant candidates from the set) relies on pointer-equality,
8577 // which means we need to key off the canonical decl. However,
8578 // always going back to the canonical decl might not get us the
8579 // right set of default arguments. What default arguments are
8580 // we supposed to consider on ADL candidates, anyway?
8582 // FIXME: Pass in the explicit template arguments?
8583 ArgumentDependentLookup(Name, Loc, Args, Fns);
8585 // Erase all of the candidates we already knew about.
8586 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(),
8587 CandEnd = CandidateSet.end();
8588 Cand != CandEnd; ++Cand)
8589 if (Cand->Function) {
8590 Fns.erase(Cand->Function);
8591 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate())
8595 // For each of the ADL candidates we found, add it to the overload
8597 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) {
8598 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none);
8599 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) {
8600 if (ExplicitTemplateArgs)
8603 AddOverloadCandidate(FD, FoundDecl, Args, CandidateSet, false,
8604 PartialOverloading);
8606 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I),
8607 FoundDecl, ExplicitTemplateArgs,
8608 Args, CandidateSet, PartialOverloading);
8613 enum class Comparison { Equal, Better, Worse };
8616 /// Compares the enable_if attributes of two FunctionDecls, for the purposes of
8617 /// overload resolution.
8619 /// Cand1's set of enable_if attributes are said to be "better" than Cand2's iff
8620 /// Cand1's first N enable_if attributes have precisely the same conditions as
8621 /// Cand2's first N enable_if attributes (where N = the number of enable_if
8622 /// attributes on Cand2), and Cand1 has more than N enable_if attributes.
8624 /// Note that you can have a pair of candidates such that Cand1's enable_if
8625 /// attributes are worse than Cand2's, and Cand2's enable_if attributes are
8626 /// worse than Cand1's.
8627 static Comparison compareEnableIfAttrs(const Sema &S, const FunctionDecl *Cand1,
8628 const FunctionDecl *Cand2) {
8629 // Common case: One (or both) decls don't have enable_if attrs.
8630 bool Cand1Attr = Cand1->hasAttr<EnableIfAttr>();
8631 bool Cand2Attr = Cand2->hasAttr<EnableIfAttr>();
8632 if (!Cand1Attr || !Cand2Attr) {
8633 if (Cand1Attr == Cand2Attr)
8634 return Comparison::Equal;
8635 return Cand1Attr ? Comparison::Better : Comparison::Worse;
8638 // FIXME: The next several lines are just
8639 // specific_attr_iterator<EnableIfAttr> but going in declaration order,
8640 // instead of reverse order which is how they're stored in the AST.
8641 auto Cand1Attrs = getOrderedEnableIfAttrs(Cand1);
8642 auto Cand2Attrs = getOrderedEnableIfAttrs(Cand2);
8644 // It's impossible for Cand1 to be better than (or equal to) Cand2 if Cand1
8645 // has fewer enable_if attributes than Cand2.
8646 if (Cand1Attrs.size() < Cand2Attrs.size())
8647 return Comparison::Worse;
8649 auto Cand1I = Cand1Attrs.begin();
8650 llvm::FoldingSetNodeID Cand1ID, Cand2ID;
8651 for (auto &Cand2A : Cand2Attrs) {
8655 auto &Cand1A = *Cand1I++;
8656 Cand1A->getCond()->Profile(Cand1ID, S.getASTContext(), true);
8657 Cand2A->getCond()->Profile(Cand2ID, S.getASTContext(), true);
8658 if (Cand1ID != Cand2ID)
8659 return Comparison::Worse;
8662 return Cand1I == Cand1Attrs.end() ? Comparison::Equal : Comparison::Better;
8665 /// isBetterOverloadCandidate - Determines whether the first overload
8666 /// candidate is a better candidate than the second (C++ 13.3.3p1).
8667 bool clang::isBetterOverloadCandidate(Sema &S, const OverloadCandidate &Cand1,
8668 const OverloadCandidate &Cand2,
8670 bool UserDefinedConversion) {
8671 // Define viable functions to be better candidates than non-viable
8674 return Cand1.Viable;
8675 else if (!Cand1.Viable)
8678 // C++ [over.match.best]p1:
8680 // -- if F is a static member function, ICS1(F) is defined such
8681 // that ICS1(F) is neither better nor worse than ICS1(G) for
8682 // any function G, and, symmetrically, ICS1(G) is neither
8683 // better nor worse than ICS1(F).
8684 unsigned StartArg = 0;
8685 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument)
8688 auto IsIllFormedConversion = [&](const ImplicitConversionSequence &ICS) {
8689 // We don't allow incompatible pointer conversions in C++.
8690 if (!S.getLangOpts().CPlusPlus)
8691 return ICS.isStandard() &&
8692 ICS.Standard.Second == ICK_Incompatible_Pointer_Conversion;
8694 // The only ill-formed conversion we allow in C++ is the string literal to
8695 // char* conversion, which is only considered ill-formed after C++11.
8696 return S.getLangOpts().CPlusPlus11 && !S.getLangOpts().WritableStrings &&
8697 hasDeprecatedStringLiteralToCharPtrConversion(ICS);
8700 // Define functions that don't require ill-formed conversions for a given
8701 // argument to be better candidates than functions that do.
8702 unsigned NumArgs = Cand1.NumConversions;
8703 assert(Cand2.NumConversions == NumArgs && "Overload candidate mismatch");
8704 bool HasBetterConversion = false;
8705 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) {
8706 bool Cand1Bad = IsIllFormedConversion(Cand1.Conversions[ArgIdx]);
8707 bool Cand2Bad = IsIllFormedConversion(Cand2.Conversions[ArgIdx]);
8708 if (Cand1Bad != Cand2Bad) {
8711 HasBetterConversion = true;
8715 if (HasBetterConversion)
8718 // C++ [over.match.best]p1:
8719 // A viable function F1 is defined to be a better function than another
8720 // viable function F2 if for all arguments i, ICSi(F1) is not a worse
8721 // conversion sequence than ICSi(F2), and then...
8722 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) {
8723 switch (CompareImplicitConversionSequences(S, Loc,
8724 Cand1.Conversions[ArgIdx],
8725 Cand2.Conversions[ArgIdx])) {
8726 case ImplicitConversionSequence::Better:
8727 // Cand1 has a better conversion sequence.
8728 HasBetterConversion = true;
8731 case ImplicitConversionSequence::Worse:
8732 // Cand1 can't be better than Cand2.
8735 case ImplicitConversionSequence::Indistinguishable:
8741 // -- for some argument j, ICSj(F1) is a better conversion sequence than
8742 // ICSj(F2), or, if not that,
8743 if (HasBetterConversion)
8746 // -- the context is an initialization by user-defined conversion
8747 // (see 8.5, 13.3.1.5) and the standard conversion sequence
8748 // from the return type of F1 to the destination type (i.e.,
8749 // the type of the entity being initialized) is a better
8750 // conversion sequence than the standard conversion sequence
8751 // from the return type of F2 to the destination type.
8752 if (UserDefinedConversion && Cand1.Function && Cand2.Function &&
8753 isa<CXXConversionDecl>(Cand1.Function) &&
8754 isa<CXXConversionDecl>(Cand2.Function)) {
8755 // First check whether we prefer one of the conversion functions over the
8756 // other. This only distinguishes the results in non-standard, extension
8757 // cases such as the conversion from a lambda closure type to a function
8758 // pointer or block.
8759 ImplicitConversionSequence::CompareKind Result =
8760 compareConversionFunctions(S, Cand1.Function, Cand2.Function);
8761 if (Result == ImplicitConversionSequence::Indistinguishable)
8762 Result = CompareStandardConversionSequences(S, Loc,
8763 Cand1.FinalConversion,
8764 Cand2.FinalConversion);
8766 if (Result != ImplicitConversionSequence::Indistinguishable)
8767 return Result == ImplicitConversionSequence::Better;
8769 // FIXME: Compare kind of reference binding if conversion functions
8770 // convert to a reference type used in direct reference binding, per
8771 // C++14 [over.match.best]p1 section 2 bullet 3.
8774 // -- F1 is a non-template function and F2 is a function template
8775 // specialization, or, if not that,
8776 bool Cand1IsSpecialization = Cand1.Function &&
8777 Cand1.Function->getPrimaryTemplate();
8778 bool Cand2IsSpecialization = Cand2.Function &&
8779 Cand2.Function->getPrimaryTemplate();
8780 if (Cand1IsSpecialization != Cand2IsSpecialization)
8781 return Cand2IsSpecialization;
8783 // -- F1 and F2 are function template specializations, and the function
8784 // template for F1 is more specialized than the template for F2
8785 // according to the partial ordering rules described in 14.5.5.2, or,
8787 if (Cand1IsSpecialization && Cand2IsSpecialization) {
8788 if (FunctionTemplateDecl *BetterTemplate
8789 = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(),
8790 Cand2.Function->getPrimaryTemplate(),
8792 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion
8794 Cand1.ExplicitCallArguments,
8795 Cand2.ExplicitCallArguments))
8796 return BetterTemplate == Cand1.Function->getPrimaryTemplate();
8799 // FIXME: Work around a defect in the C++17 inheriting constructor wording.
8800 // A derived-class constructor beats an (inherited) base class constructor.
8801 bool Cand1IsInherited =
8802 dyn_cast_or_null<ConstructorUsingShadowDecl>(Cand1.FoundDecl.getDecl());
8803 bool Cand2IsInherited =
8804 dyn_cast_or_null<ConstructorUsingShadowDecl>(Cand2.FoundDecl.getDecl());
8805 if (Cand1IsInherited != Cand2IsInherited)
8806 return Cand2IsInherited;
8807 else if (Cand1IsInherited) {
8808 assert(Cand2IsInherited);
8809 auto *Cand1Class = cast<CXXRecordDecl>(Cand1.Function->getDeclContext());
8810 auto *Cand2Class = cast<CXXRecordDecl>(Cand2.Function->getDeclContext());
8811 if (Cand1Class->isDerivedFrom(Cand2Class))
8813 if (Cand2Class->isDerivedFrom(Cand1Class))
8815 // Inherited from sibling base classes: still ambiguous.
8818 // Check for enable_if value-based overload resolution.
8819 if (Cand1.Function && Cand2.Function) {
8820 Comparison Cmp = compareEnableIfAttrs(S, Cand1.Function, Cand2.Function);
8821 if (Cmp != Comparison::Equal)
8822 return Cmp == Comparison::Better;
8825 if (S.getLangOpts().CUDA && Cand1.Function && Cand2.Function) {
8826 FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext);
8827 return S.IdentifyCUDAPreference(Caller, Cand1.Function) >
8828 S.IdentifyCUDAPreference(Caller, Cand2.Function);
8831 bool HasPS1 = Cand1.Function != nullptr &&
8832 functionHasPassObjectSizeParams(Cand1.Function);
8833 bool HasPS2 = Cand2.Function != nullptr &&
8834 functionHasPassObjectSizeParams(Cand2.Function);
8835 return HasPS1 != HasPS2 && HasPS1;
8838 /// Determine whether two declarations are "equivalent" for the purposes of
8839 /// name lookup and overload resolution. This applies when the same internal/no
8840 /// linkage entity is defined by two modules (probably by textually including
8841 /// the same header). In such a case, we don't consider the declarations to
8842 /// declare the same entity, but we also don't want lookups with both
8843 /// declarations visible to be ambiguous in some cases (this happens when using
8844 /// a modularized libstdc++).
8845 bool Sema::isEquivalentInternalLinkageDeclaration(const NamedDecl *A,
8846 const NamedDecl *B) {
8847 auto *VA = dyn_cast_or_null<ValueDecl>(A);
8848 auto *VB = dyn_cast_or_null<ValueDecl>(B);
8852 // The declarations must be declaring the same name as an internal linkage
8853 // entity in different modules.
8854 if (!VA->getDeclContext()->getRedeclContext()->Equals(
8855 VB->getDeclContext()->getRedeclContext()) ||
8856 getOwningModule(const_cast<ValueDecl *>(VA)) ==
8857 getOwningModule(const_cast<ValueDecl *>(VB)) ||
8858 VA->isExternallyVisible() || VB->isExternallyVisible())
8861 // Check that the declarations appear to be equivalent.
8863 // FIXME: Checking the type isn't really enough to resolve the ambiguity.
8864 // For constants and functions, we should check the initializer or body is
8865 // the same. For non-constant variables, we shouldn't allow it at all.
8866 if (Context.hasSameType(VA->getType(), VB->getType()))
8869 // Enum constants within unnamed enumerations will have different types, but
8870 // may still be similar enough to be interchangeable for our purposes.
8871 if (auto *EA = dyn_cast<EnumConstantDecl>(VA)) {
8872 if (auto *EB = dyn_cast<EnumConstantDecl>(VB)) {
8873 // Only handle anonymous enums. If the enumerations were named and
8874 // equivalent, they would have been merged to the same type.
8875 auto *EnumA = cast<EnumDecl>(EA->getDeclContext());
8876 auto *EnumB = cast<EnumDecl>(EB->getDeclContext());
8877 if (EnumA->hasNameForLinkage() || EnumB->hasNameForLinkage() ||
8878 !Context.hasSameType(EnumA->getIntegerType(),
8879 EnumB->getIntegerType()))
8881 // Allow this only if the value is the same for both enumerators.
8882 return llvm::APSInt::isSameValue(EA->getInitVal(), EB->getInitVal());
8886 // Nothing else is sufficiently similar.
8890 void Sema::diagnoseEquivalentInternalLinkageDeclarations(
8891 SourceLocation Loc, const NamedDecl *D, ArrayRef<const NamedDecl *> Equiv) {
8892 Diag(Loc, diag::ext_equivalent_internal_linkage_decl_in_modules) << D;
8894 Module *M = getOwningModule(const_cast<NamedDecl*>(D));
8895 Diag(D->getLocation(), diag::note_equivalent_internal_linkage_decl)
8896 << !M << (M ? M->getFullModuleName() : "");
8898 for (auto *E : Equiv) {
8899 Module *M = getOwningModule(const_cast<NamedDecl*>(E));
8900 Diag(E->getLocation(), diag::note_equivalent_internal_linkage_decl)
8901 << !M << (M ? M->getFullModuleName() : "");
8905 /// \brief Computes the best viable function (C++ 13.3.3)
8906 /// within an overload candidate set.
8908 /// \param Loc The location of the function name (or operator symbol) for
8909 /// which overload resolution occurs.
8911 /// \param Best If overload resolution was successful or found a deleted
8912 /// function, \p Best points to the candidate function found.
8914 /// \returns The result of overload resolution.
8916 OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc,
8918 bool UserDefinedConversion) {
8919 llvm::SmallVector<OverloadCandidate *, 16> Candidates;
8920 std::transform(begin(), end(), std::back_inserter(Candidates),
8921 [](OverloadCandidate &Cand) { return &Cand; });
8923 // [CUDA] HD->H or HD->D calls are technically not allowed by CUDA but
8924 // are accepted by both clang and NVCC. However, during a particular
8925 // compilation mode only one call variant is viable. We need to
8926 // exclude non-viable overload candidates from consideration based
8927 // only on their host/device attributes. Specifically, if one
8928 // candidate call is WrongSide and the other is SameSide, we ignore
8929 // the WrongSide candidate.
8930 if (S.getLangOpts().CUDA) {
8931 const FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext);
8932 bool ContainsSameSideCandidate =
8933 llvm::any_of(Candidates, [&](OverloadCandidate *Cand) {
8934 return Cand->Function &&
8935 S.IdentifyCUDAPreference(Caller, Cand->Function) ==
8938 if (ContainsSameSideCandidate) {
8939 auto IsWrongSideCandidate = [&](OverloadCandidate *Cand) {
8940 return Cand->Function &&
8941 S.IdentifyCUDAPreference(Caller, Cand->Function) ==
8942 Sema::CFP_WrongSide;
8944 llvm::erase_if(Candidates, IsWrongSideCandidate);
8948 // Find the best viable function.
8950 for (auto *Cand : Candidates)
8952 if (Best == end() || isBetterOverloadCandidate(S, *Cand, *Best, Loc,
8953 UserDefinedConversion))
8956 // If we didn't find any viable functions, abort.
8958 return OR_No_Viable_Function;
8960 llvm::SmallVector<const NamedDecl *, 4> EquivalentCands;
8962 // Make sure that this function is better than every other viable
8963 // function. If not, we have an ambiguity.
8964 for (auto *Cand : Candidates) {
8967 !isBetterOverloadCandidate(S, *Best, *Cand, Loc,
8968 UserDefinedConversion)) {
8969 if (S.isEquivalentInternalLinkageDeclaration(Best->Function,
8971 EquivalentCands.push_back(Cand->Function);
8976 return OR_Ambiguous;
8980 // Best is the best viable function.
8981 if (Best->Function &&
8982 (Best->Function->isDeleted() ||
8983 S.isFunctionConsideredUnavailable(Best->Function)))
8986 if (!EquivalentCands.empty())
8987 S.diagnoseEquivalentInternalLinkageDeclarations(Loc, Best->Function,
8995 enum OverloadCandidateKind {
8999 oc_function_template,
9001 oc_constructor_template,
9002 oc_implicit_default_constructor,
9003 oc_implicit_copy_constructor,
9004 oc_implicit_move_constructor,
9005 oc_implicit_copy_assignment,
9006 oc_implicit_move_assignment,
9007 oc_inherited_constructor,
9008 oc_inherited_constructor_template
9011 static OverloadCandidateKind
9012 ClassifyOverloadCandidate(Sema &S, NamedDecl *Found, FunctionDecl *Fn,
9013 std::string &Description) {
9014 bool isTemplate = false;
9016 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) {
9018 Description = S.getTemplateArgumentBindingsText(
9019 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs());
9022 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) {
9023 if (!Ctor->isImplicit()) {
9024 if (isa<ConstructorUsingShadowDecl>(Found))
9025 return isTemplate ? oc_inherited_constructor_template
9026 : oc_inherited_constructor;
9028 return isTemplate ? oc_constructor_template : oc_constructor;
9031 if (Ctor->isDefaultConstructor())
9032 return oc_implicit_default_constructor;
9034 if (Ctor->isMoveConstructor())
9035 return oc_implicit_move_constructor;
9037 assert(Ctor->isCopyConstructor() &&
9038 "unexpected sort of implicit constructor");
9039 return oc_implicit_copy_constructor;
9042 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) {
9043 // This actually gets spelled 'candidate function' for now, but
9044 // it doesn't hurt to split it out.
9045 if (!Meth->isImplicit())
9046 return isTemplate ? oc_method_template : oc_method;
9048 if (Meth->isMoveAssignmentOperator())
9049 return oc_implicit_move_assignment;
9051 if (Meth->isCopyAssignmentOperator())
9052 return oc_implicit_copy_assignment;
9054 assert(isa<CXXConversionDecl>(Meth) && "expected conversion");
9058 return isTemplate ? oc_function_template : oc_function;
9061 void MaybeEmitInheritedConstructorNote(Sema &S, Decl *FoundDecl) {
9062 // FIXME: It'd be nice to only emit a note once per using-decl per overload
9064 if (auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(FoundDecl))
9065 S.Diag(FoundDecl->getLocation(),
9066 diag::note_ovl_candidate_inherited_constructor)
9067 << Shadow->getNominatedBaseClass();
9070 } // end anonymous namespace
9072 static bool isFunctionAlwaysEnabled(const ASTContext &Ctx,
9073 const FunctionDecl *FD) {
9074 for (auto *EnableIf : FD->specific_attrs<EnableIfAttr>()) {
9076 if (!EnableIf->getCond()->EvaluateAsBooleanCondition(AlwaysTrue, Ctx))
9084 /// \brief Returns true if we can take the address of the function.
9086 /// \param Complain - If true, we'll emit a diagnostic
9087 /// \param InOverloadResolution - For the purposes of emitting a diagnostic, are
9088 /// we in overload resolution?
9089 /// \param Loc - The location of the statement we're complaining about. Ignored
9090 /// if we're not complaining, or if we're in overload resolution.
9091 static bool checkAddressOfFunctionIsAvailable(Sema &S, const FunctionDecl *FD,
9093 bool InOverloadResolution,
9094 SourceLocation Loc) {
9095 if (!isFunctionAlwaysEnabled(S.Context, FD)) {
9097 if (InOverloadResolution)
9098 S.Diag(FD->getLocStart(),
9099 diag::note_addrof_ovl_candidate_disabled_by_enable_if_attr);
9101 S.Diag(Loc, diag::err_addrof_function_disabled_by_enable_if_attr) << FD;
9106 auto I = llvm::find_if(FD->parameters(), [](const ParmVarDecl *P) {
9107 return P->hasAttr<PassObjectSizeAttr>();
9109 if (I == FD->param_end())
9113 // Add one to ParamNo because it's user-facing
9114 unsigned ParamNo = std::distance(FD->param_begin(), I) + 1;
9115 if (InOverloadResolution)
9116 S.Diag(FD->getLocation(),
9117 diag::note_ovl_candidate_has_pass_object_size_params)
9120 S.Diag(Loc, diag::err_address_of_function_with_pass_object_size_params)
9126 static bool checkAddressOfCandidateIsAvailable(Sema &S,
9127 const FunctionDecl *FD) {
9128 return checkAddressOfFunctionIsAvailable(S, FD, /*Complain=*/true,
9129 /*InOverloadResolution=*/true,
9130 /*Loc=*/SourceLocation());
9133 bool Sema::checkAddressOfFunctionIsAvailable(const FunctionDecl *Function,
9135 SourceLocation Loc) {
9136 return ::checkAddressOfFunctionIsAvailable(*this, Function, Complain,
9137 /*InOverloadResolution=*/false,
9141 // Notes the location of an overload candidate.
9142 void Sema::NoteOverloadCandidate(NamedDecl *Found, FunctionDecl *Fn,
9143 QualType DestType, bool TakingAddress) {
9144 if (TakingAddress && !checkAddressOfCandidateIsAvailable(*this, Fn))
9148 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Found, Fn, FnDesc);
9149 PartialDiagnostic PD = PDiag(diag::note_ovl_candidate)
9150 << (unsigned) K << Fn << FnDesc;
9152 HandleFunctionTypeMismatch(PD, Fn->getType(), DestType);
9153 Diag(Fn->getLocation(), PD);
9154 MaybeEmitInheritedConstructorNote(*this, Found);
9157 // Notes the location of all overload candidates designated through
9159 void Sema::NoteAllOverloadCandidates(Expr *OverloadedExpr, QualType DestType,
9160 bool TakingAddress) {
9161 assert(OverloadedExpr->getType() == Context.OverloadTy);
9163 OverloadExpr::FindResult Ovl = OverloadExpr::find(OverloadedExpr);
9164 OverloadExpr *OvlExpr = Ovl.Expression;
9166 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
9167 IEnd = OvlExpr->decls_end();
9169 if (FunctionTemplateDecl *FunTmpl =
9170 dyn_cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()) ) {
9171 NoteOverloadCandidate(*I, FunTmpl->getTemplatedDecl(), DestType,
9173 } else if (FunctionDecl *Fun
9174 = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()) ) {
9175 NoteOverloadCandidate(*I, Fun, DestType, TakingAddress);
9180 /// Diagnoses an ambiguous conversion. The partial diagnostic is the
9181 /// "lead" diagnostic; it will be given two arguments, the source and
9182 /// target types of the conversion.
9183 void ImplicitConversionSequence::DiagnoseAmbiguousConversion(
9185 SourceLocation CaretLoc,
9186 const PartialDiagnostic &PDiag) const {
9187 S.Diag(CaretLoc, PDiag)
9188 << Ambiguous.getFromType() << Ambiguous.getToType();
9189 // FIXME: The note limiting machinery is borrowed from
9190 // OverloadCandidateSet::NoteCandidates; there's an opportunity for
9191 // refactoring here.
9192 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
9193 unsigned CandsShown = 0;
9194 AmbiguousConversionSequence::const_iterator I, E;
9195 for (I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) {
9196 if (CandsShown >= 4 && ShowOverloads == Ovl_Best)
9199 S.NoteOverloadCandidate(I->first, I->second);
9202 S.Diag(SourceLocation(), diag::note_ovl_too_many_candidates) << int(E - I);
9205 static void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand,
9206 unsigned I, bool TakingCandidateAddress) {
9207 const ImplicitConversionSequence &Conv = Cand->Conversions[I];
9208 assert(Conv.isBad());
9209 assert(Cand->Function && "for now, candidate must be a function");
9210 FunctionDecl *Fn = Cand->Function;
9212 // There's a conversion slot for the object argument if this is a
9213 // non-constructor method. Note that 'I' corresponds the
9214 // conversion-slot index.
9215 bool isObjectArgument = false;
9216 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) {
9218 isObjectArgument = true;
9224 OverloadCandidateKind FnKind =
9225 ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn, FnDesc);
9227 Expr *FromExpr = Conv.Bad.FromExpr;
9228 QualType FromTy = Conv.Bad.getFromType();
9229 QualType ToTy = Conv.Bad.getToType();
9231 if (FromTy == S.Context.OverloadTy) {
9232 assert(FromExpr && "overload set argument came from implicit argument?");
9233 Expr *E = FromExpr->IgnoreParens();
9234 if (isa<UnaryOperator>(E))
9235 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens();
9236 DeclarationName Name = cast<OverloadExpr>(E)->getName();
9238 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload)
9239 << (unsigned) FnKind << FnDesc
9240 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9241 << ToTy << Name << I+1;
9242 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9246 // Do some hand-waving analysis to see if the non-viability is due
9247 // to a qualifier mismatch.
9248 CanQualType CFromTy = S.Context.getCanonicalType(FromTy);
9249 CanQualType CToTy = S.Context.getCanonicalType(ToTy);
9250 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>())
9251 CToTy = RT->getPointeeType();
9253 // TODO: detect and diagnose the full richness of const mismatches.
9254 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>())
9255 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) {
9256 CFromTy = FromPT->getPointeeType();
9257 CToTy = ToPT->getPointeeType();
9261 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() &&
9262 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) {
9263 Qualifiers FromQs = CFromTy.getQualifiers();
9264 Qualifiers ToQs = CToTy.getQualifiers();
9266 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) {
9267 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace)
9268 << (unsigned) FnKind << FnDesc
9269 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9271 << FromQs.getAddressSpace() << ToQs.getAddressSpace()
9272 << (unsigned) isObjectArgument << I+1;
9273 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9277 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) {
9278 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_ownership)
9279 << (unsigned) FnKind << FnDesc
9280 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9282 << FromQs.getObjCLifetime() << ToQs.getObjCLifetime()
9283 << (unsigned) isObjectArgument << I+1;
9284 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9288 if (FromQs.getObjCGCAttr() != ToQs.getObjCGCAttr()) {
9289 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_gc)
9290 << (unsigned) FnKind << FnDesc
9291 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9293 << FromQs.getObjCGCAttr() << ToQs.getObjCGCAttr()
9294 << (unsigned) isObjectArgument << I+1;
9295 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9299 if (FromQs.hasUnaligned() != ToQs.hasUnaligned()) {
9300 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_unaligned)
9301 << (unsigned) FnKind << FnDesc
9302 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9303 << FromTy << FromQs.hasUnaligned() << I+1;
9304 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9308 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers();
9309 assert(CVR && "unexpected qualifiers mismatch");
9311 if (isObjectArgument) {
9312 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this)
9313 << (unsigned) FnKind << FnDesc
9314 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9315 << FromTy << (CVR - 1);
9317 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr)
9318 << (unsigned) FnKind << FnDesc
9319 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9320 << FromTy << (CVR - 1) << I+1;
9322 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9326 // Special diagnostic for failure to convert an initializer list, since
9327 // telling the user that it has type void is not useful.
9328 if (FromExpr && isa<InitListExpr>(FromExpr)) {
9329 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_list_argument)
9330 << (unsigned) FnKind << FnDesc
9331 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9332 << FromTy << ToTy << (unsigned) isObjectArgument << I+1;
9333 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9337 // Diagnose references or pointers to incomplete types differently,
9338 // since it's far from impossible that the incompleteness triggered
9340 QualType TempFromTy = FromTy.getNonReferenceType();
9341 if (const PointerType *PTy = TempFromTy->getAs<PointerType>())
9342 TempFromTy = PTy->getPointeeType();
9343 if (TempFromTy->isIncompleteType()) {
9344 // Emit the generic diagnostic and, optionally, add the hints to it.
9345 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete)
9346 << (unsigned) FnKind << FnDesc
9347 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9348 << FromTy << ToTy << (unsigned) isObjectArgument << I+1
9349 << (unsigned) (Cand->Fix.Kind);
9351 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9355 // Diagnose base -> derived pointer conversions.
9356 unsigned BaseToDerivedConversion = 0;
9357 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) {
9358 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) {
9359 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs(
9360 FromPtrTy->getPointeeType()) &&
9361 !FromPtrTy->getPointeeType()->isIncompleteType() &&
9362 !ToPtrTy->getPointeeType()->isIncompleteType() &&
9363 S.IsDerivedFrom(SourceLocation(), ToPtrTy->getPointeeType(),
9364 FromPtrTy->getPointeeType()))
9365 BaseToDerivedConversion = 1;
9367 } else if (const ObjCObjectPointerType *FromPtrTy
9368 = FromTy->getAs<ObjCObjectPointerType>()) {
9369 if (const ObjCObjectPointerType *ToPtrTy
9370 = ToTy->getAs<ObjCObjectPointerType>())
9371 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl())
9372 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl())
9373 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs(
9374 FromPtrTy->getPointeeType()) &&
9375 FromIface->isSuperClassOf(ToIface))
9376 BaseToDerivedConversion = 2;
9377 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) {
9378 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) &&
9379 !FromTy->isIncompleteType() &&
9380 !ToRefTy->getPointeeType()->isIncompleteType() &&
9381 S.IsDerivedFrom(SourceLocation(), ToRefTy->getPointeeType(), FromTy)) {
9382 BaseToDerivedConversion = 3;
9383 } else if (ToTy->isLValueReferenceType() && !FromExpr->isLValue() &&
9384 ToTy.getNonReferenceType().getCanonicalType() ==
9385 FromTy.getNonReferenceType().getCanonicalType()) {
9386 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_lvalue)
9387 << (unsigned) FnKind << FnDesc
9388 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9389 << (unsigned) isObjectArgument << I + 1;
9390 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9395 if (BaseToDerivedConversion) {
9396 S.Diag(Fn->getLocation(),
9397 diag::note_ovl_candidate_bad_base_to_derived_conv)
9398 << (unsigned) FnKind << FnDesc
9399 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9400 << (BaseToDerivedConversion - 1)
9401 << FromTy << ToTy << I+1;
9402 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9406 if (isa<ObjCObjectPointerType>(CFromTy) &&
9407 isa<PointerType>(CToTy)) {
9408 Qualifiers FromQs = CFromTy.getQualifiers();
9409 Qualifiers ToQs = CToTy.getQualifiers();
9410 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) {
9411 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_arc_conv)
9412 << (unsigned) FnKind << FnDesc
9413 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9414 << FromTy << ToTy << (unsigned) isObjectArgument << I+1;
9415 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9420 if (TakingCandidateAddress &&
9421 !checkAddressOfCandidateIsAvailable(S, Cand->Function))
9424 // Emit the generic diagnostic and, optionally, add the hints to it.
9425 PartialDiagnostic FDiag = S.PDiag(diag::note_ovl_candidate_bad_conv);
9426 FDiag << (unsigned) FnKind << FnDesc
9427 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9428 << FromTy << ToTy << (unsigned) isObjectArgument << I + 1
9429 << (unsigned) (Cand->Fix.Kind);
9431 // If we can fix the conversion, suggest the FixIts.
9432 for (std::vector<FixItHint>::iterator HI = Cand->Fix.Hints.begin(),
9433 HE = Cand->Fix.Hints.end(); HI != HE; ++HI)
9435 S.Diag(Fn->getLocation(), FDiag);
9437 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9440 /// Additional arity mismatch diagnosis specific to a function overload
9441 /// candidates. This is not covered by the more general DiagnoseArityMismatch()
9442 /// over a candidate in any candidate set.
9443 static bool CheckArityMismatch(Sema &S, OverloadCandidate *Cand,
9445 FunctionDecl *Fn = Cand->Function;
9446 unsigned MinParams = Fn->getMinRequiredArguments();
9448 // With invalid overloaded operators, it's possible that we think we
9449 // have an arity mismatch when in fact it looks like we have the
9450 // right number of arguments, because only overloaded operators have
9451 // the weird behavior of overloading member and non-member functions.
9452 // Just don't report anything.
9453 if (Fn->isInvalidDecl() &&
9454 Fn->getDeclName().getNameKind() == DeclarationName::CXXOperatorName)
9457 if (NumArgs < MinParams) {
9458 assert((Cand->FailureKind == ovl_fail_too_few_arguments) ||
9459 (Cand->FailureKind == ovl_fail_bad_deduction &&
9460 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments));
9462 assert((Cand->FailureKind == ovl_fail_too_many_arguments) ||
9463 (Cand->FailureKind == ovl_fail_bad_deduction &&
9464 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments));
9470 /// General arity mismatch diagnosis over a candidate in a candidate set.
9471 static void DiagnoseArityMismatch(Sema &S, NamedDecl *Found, Decl *D,
9472 unsigned NumFormalArgs) {
9473 assert(isa<FunctionDecl>(D) &&
9474 "The templated declaration should at least be a function"
9475 " when diagnosing bad template argument deduction due to too many"
9476 " or too few arguments");
9478 FunctionDecl *Fn = cast<FunctionDecl>(D);
9480 // TODO: treat calls to a missing default constructor as a special case
9481 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>();
9482 unsigned MinParams = Fn->getMinRequiredArguments();
9484 // at least / at most / exactly
9485 unsigned mode, modeCount;
9486 if (NumFormalArgs < MinParams) {
9487 if (MinParams != FnTy->getNumParams() || FnTy->isVariadic() ||
9488 FnTy->isTemplateVariadic())
9489 mode = 0; // "at least"
9491 mode = 2; // "exactly"
9492 modeCount = MinParams;
9494 if (MinParams != FnTy->getNumParams())
9495 mode = 1; // "at most"
9497 mode = 2; // "exactly"
9498 modeCount = FnTy->getNumParams();
9501 std::string Description;
9502 OverloadCandidateKind FnKind =
9503 ClassifyOverloadCandidate(S, Found, Fn, Description);
9505 if (modeCount == 1 && Fn->getParamDecl(0)->getDeclName())
9506 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity_one)
9507 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != nullptr)
9508 << mode << Fn->getParamDecl(0) << NumFormalArgs;
9510 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity)
9511 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != nullptr)
9512 << mode << modeCount << NumFormalArgs;
9513 MaybeEmitInheritedConstructorNote(S, Found);
9516 /// Arity mismatch diagnosis specific to a function overload candidate.
9517 static void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand,
9518 unsigned NumFormalArgs) {
9519 if (!CheckArityMismatch(S, Cand, NumFormalArgs))
9520 DiagnoseArityMismatch(S, Cand->FoundDecl, Cand->Function, NumFormalArgs);
9523 static TemplateDecl *getDescribedTemplate(Decl *Templated) {
9524 if (TemplateDecl *TD = Templated->getDescribedTemplate())
9526 llvm_unreachable("Unsupported: Getting the described template declaration"
9527 " for bad deduction diagnosis");
9530 /// Diagnose a failed template-argument deduction.
9531 static void DiagnoseBadDeduction(Sema &S, NamedDecl *Found, Decl *Templated,
9532 DeductionFailureInfo &DeductionFailure,
9534 bool TakingCandidateAddress) {
9535 TemplateParameter Param = DeductionFailure.getTemplateParameter();
9537 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) ||
9538 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) ||
9539 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>());
9540 switch (DeductionFailure.Result) {
9541 case Sema::TDK_Success:
9542 llvm_unreachable("TDK_success while diagnosing bad deduction");
9544 case Sema::TDK_Incomplete: {
9545 assert(ParamD && "no parameter found for incomplete deduction result");
9546 S.Diag(Templated->getLocation(),
9547 diag::note_ovl_candidate_incomplete_deduction)
9548 << ParamD->getDeclName();
9549 MaybeEmitInheritedConstructorNote(S, Found);
9553 case Sema::TDK_Underqualified: {
9554 assert(ParamD && "no parameter found for bad qualifiers deduction result");
9555 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD);
9557 QualType Param = DeductionFailure.getFirstArg()->getAsType();
9559 // Param will have been canonicalized, but it should just be a
9560 // qualified version of ParamD, so move the qualifiers to that.
9561 QualifierCollector Qs;
9563 QualType NonCanonParam = Qs.apply(S.Context, TParam->getTypeForDecl());
9564 assert(S.Context.hasSameType(Param, NonCanonParam));
9566 // Arg has also been canonicalized, but there's nothing we can do
9567 // about that. It also doesn't matter as much, because it won't
9568 // have any template parameters in it (because deduction isn't
9569 // done on dependent types).
9570 QualType Arg = DeductionFailure.getSecondArg()->getAsType();
9572 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_underqualified)
9573 << ParamD->getDeclName() << Arg << NonCanonParam;
9574 MaybeEmitInheritedConstructorNote(S, Found);
9578 case Sema::TDK_Inconsistent: {
9579 assert(ParamD && "no parameter found for inconsistent deduction result");
9581 if (isa<TemplateTypeParmDecl>(ParamD))
9583 else if (isa<NonTypeTemplateParmDecl>(ParamD)) {
9584 // Deduction might have failed because we deduced arguments of two
9585 // different types for a non-type template parameter.
9586 // FIXME: Use a different TDK value for this.
9588 DeductionFailure.getFirstArg()->getNonTypeTemplateArgumentType();
9590 DeductionFailure.getSecondArg()->getNonTypeTemplateArgumentType();
9591 if (!S.Context.hasSameType(T1, T2)) {
9592 S.Diag(Templated->getLocation(),
9593 diag::note_ovl_candidate_inconsistent_deduction_types)
9594 << ParamD->getDeclName() << *DeductionFailure.getFirstArg() << T1
9595 << *DeductionFailure.getSecondArg() << T2;
9596 MaybeEmitInheritedConstructorNote(S, Found);
9605 S.Diag(Templated->getLocation(),
9606 diag::note_ovl_candidate_inconsistent_deduction)
9607 << which << ParamD->getDeclName() << *DeductionFailure.getFirstArg()
9608 << *DeductionFailure.getSecondArg();
9609 MaybeEmitInheritedConstructorNote(S, Found);
9613 case Sema::TDK_InvalidExplicitArguments:
9614 assert(ParamD && "no parameter found for invalid explicit arguments");
9615 if (ParamD->getDeclName())
9616 S.Diag(Templated->getLocation(),
9617 diag::note_ovl_candidate_explicit_arg_mismatch_named)
9618 << ParamD->getDeclName();
9621 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD))
9622 index = TTP->getIndex();
9623 else if (NonTypeTemplateParmDecl *NTTP
9624 = dyn_cast<NonTypeTemplateParmDecl>(ParamD))
9625 index = NTTP->getIndex();
9627 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex();
9628 S.Diag(Templated->getLocation(),
9629 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed)
9632 MaybeEmitInheritedConstructorNote(S, Found);
9635 case Sema::TDK_TooManyArguments:
9636 case Sema::TDK_TooFewArguments:
9637 DiagnoseArityMismatch(S, Found, Templated, NumArgs);
9640 case Sema::TDK_InstantiationDepth:
9641 S.Diag(Templated->getLocation(),
9642 diag::note_ovl_candidate_instantiation_depth);
9643 MaybeEmitInheritedConstructorNote(S, Found);
9646 case Sema::TDK_SubstitutionFailure: {
9647 // Format the template argument list into the argument string.
9648 SmallString<128> TemplateArgString;
9649 if (TemplateArgumentList *Args =
9650 DeductionFailure.getTemplateArgumentList()) {
9651 TemplateArgString = " ";
9652 TemplateArgString += S.getTemplateArgumentBindingsText(
9653 getDescribedTemplate(Templated)->getTemplateParameters(), *Args);
9656 // If this candidate was disabled by enable_if, say so.
9657 PartialDiagnosticAt *PDiag = DeductionFailure.getSFINAEDiagnostic();
9658 if (PDiag && PDiag->second.getDiagID() ==
9659 diag::err_typename_nested_not_found_enable_if) {
9660 // FIXME: Use the source range of the condition, and the fully-qualified
9661 // name of the enable_if template. These are both present in PDiag.
9662 S.Diag(PDiag->first, diag::note_ovl_candidate_disabled_by_enable_if)
9663 << "'enable_if'" << TemplateArgString;
9667 // Format the SFINAE diagnostic into the argument string.
9668 // FIXME: Add a general mechanism to include a PartialDiagnostic *'s
9669 // formatted message in another diagnostic.
9670 SmallString<128> SFINAEArgString;
9673 SFINAEArgString = ": ";
9674 R = SourceRange(PDiag->first, PDiag->first);
9675 PDiag->second.EmitToString(S.getDiagnostics(), SFINAEArgString);
9678 S.Diag(Templated->getLocation(),
9679 diag::note_ovl_candidate_substitution_failure)
9680 << TemplateArgString << SFINAEArgString << R;
9681 MaybeEmitInheritedConstructorNote(S, Found);
9685 case Sema::TDK_DeducedMismatch: {
9686 // Format the template argument list into the argument string.
9687 SmallString<128> TemplateArgString;
9688 if (TemplateArgumentList *Args =
9689 DeductionFailure.getTemplateArgumentList()) {
9690 TemplateArgString = " ";
9691 TemplateArgString += S.getTemplateArgumentBindingsText(
9692 getDescribedTemplate(Templated)->getTemplateParameters(), *Args);
9695 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_deduced_mismatch)
9696 << (*DeductionFailure.getCallArgIndex() + 1)
9697 << *DeductionFailure.getFirstArg() << *DeductionFailure.getSecondArg()
9698 << TemplateArgString;
9702 case Sema::TDK_NonDeducedMismatch: {
9703 // FIXME: Provide a source location to indicate what we couldn't match.
9704 TemplateArgument FirstTA = *DeductionFailure.getFirstArg();
9705 TemplateArgument SecondTA = *DeductionFailure.getSecondArg();
9706 if (FirstTA.getKind() == TemplateArgument::Template &&
9707 SecondTA.getKind() == TemplateArgument::Template) {
9708 TemplateName FirstTN = FirstTA.getAsTemplate();
9709 TemplateName SecondTN = SecondTA.getAsTemplate();
9710 if (FirstTN.getKind() == TemplateName::Template &&
9711 SecondTN.getKind() == TemplateName::Template) {
9712 if (FirstTN.getAsTemplateDecl()->getName() ==
9713 SecondTN.getAsTemplateDecl()->getName()) {
9714 // FIXME: This fixes a bad diagnostic where both templates are named
9715 // the same. This particular case is a bit difficult since:
9716 // 1) It is passed as a string to the diagnostic printer.
9717 // 2) The diagnostic printer only attempts to find a better
9718 // name for types, not decls.
9719 // Ideally, this should folded into the diagnostic printer.
9720 S.Diag(Templated->getLocation(),
9721 diag::note_ovl_candidate_non_deduced_mismatch_qualified)
9722 << FirstTN.getAsTemplateDecl() << SecondTN.getAsTemplateDecl();
9728 if (TakingCandidateAddress && isa<FunctionDecl>(Templated) &&
9729 !checkAddressOfCandidateIsAvailable(S, cast<FunctionDecl>(Templated)))
9732 // FIXME: For generic lambda parameters, check if the function is a lambda
9733 // call operator, and if so, emit a prettier and more informative
9734 // diagnostic that mentions 'auto' and lambda in addition to
9735 // (or instead of?) the canonical template type parameters.
9736 S.Diag(Templated->getLocation(),
9737 diag::note_ovl_candidate_non_deduced_mismatch)
9738 << FirstTA << SecondTA;
9741 // TODO: diagnose these individually, then kill off
9742 // note_ovl_candidate_bad_deduction, which is uselessly vague.
9743 case Sema::TDK_MiscellaneousDeductionFailure:
9744 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_bad_deduction);
9745 MaybeEmitInheritedConstructorNote(S, Found);
9747 case Sema::TDK_CUDATargetMismatch:
9748 S.Diag(Templated->getLocation(),
9749 diag::note_cuda_ovl_candidate_target_mismatch);
9754 /// Diagnose a failed template-argument deduction, for function calls.
9755 static void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand,
9757 bool TakingCandidateAddress) {
9758 unsigned TDK = Cand->DeductionFailure.Result;
9759 if (TDK == Sema::TDK_TooFewArguments || TDK == Sema::TDK_TooManyArguments) {
9760 if (CheckArityMismatch(S, Cand, NumArgs))
9763 DiagnoseBadDeduction(S, Cand->FoundDecl, Cand->Function, // pattern
9764 Cand->DeductionFailure, NumArgs, TakingCandidateAddress);
9767 /// CUDA: diagnose an invalid call across targets.
9768 static void DiagnoseBadTarget(Sema &S, OverloadCandidate *Cand) {
9769 FunctionDecl *Caller = cast<FunctionDecl>(S.CurContext);
9770 FunctionDecl *Callee = Cand->Function;
9772 Sema::CUDAFunctionTarget CallerTarget = S.IdentifyCUDATarget(Caller),
9773 CalleeTarget = S.IdentifyCUDATarget(Callee);
9776 OverloadCandidateKind FnKind =
9777 ClassifyOverloadCandidate(S, Cand->FoundDecl, Callee, FnDesc);
9779 S.Diag(Callee->getLocation(), diag::note_ovl_candidate_bad_target)
9780 << (unsigned)FnKind << CalleeTarget << CallerTarget;
9782 // This could be an implicit constructor for which we could not infer the
9783 // target due to a collsion. Diagnose that case.
9784 CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Callee);
9785 if (Meth != nullptr && Meth->isImplicit()) {
9786 CXXRecordDecl *ParentClass = Meth->getParent();
9787 Sema::CXXSpecialMember CSM;
9792 case oc_implicit_default_constructor:
9793 CSM = Sema::CXXDefaultConstructor;
9795 case oc_implicit_copy_constructor:
9796 CSM = Sema::CXXCopyConstructor;
9798 case oc_implicit_move_constructor:
9799 CSM = Sema::CXXMoveConstructor;
9801 case oc_implicit_copy_assignment:
9802 CSM = Sema::CXXCopyAssignment;
9804 case oc_implicit_move_assignment:
9805 CSM = Sema::CXXMoveAssignment;
9809 bool ConstRHS = false;
9810 if (Meth->getNumParams()) {
9811 if (const ReferenceType *RT =
9812 Meth->getParamDecl(0)->getType()->getAs<ReferenceType>()) {
9813 ConstRHS = RT->getPointeeType().isConstQualified();
9817 S.inferCUDATargetForImplicitSpecialMember(ParentClass, CSM, Meth,
9818 /* ConstRHS */ ConstRHS,
9819 /* Diagnose */ true);
9823 static void DiagnoseFailedEnableIfAttr(Sema &S, OverloadCandidate *Cand) {
9824 FunctionDecl *Callee = Cand->Function;
9825 EnableIfAttr *Attr = static_cast<EnableIfAttr*>(Cand->DeductionFailure.Data);
9827 S.Diag(Callee->getLocation(),
9828 diag::note_ovl_candidate_disabled_by_enable_if_attr)
9829 << Attr->getCond()->getSourceRange() << Attr->getMessage();
9832 static void DiagnoseOpenCLExtensionDisabled(Sema &S, OverloadCandidate *Cand) {
9833 FunctionDecl *Callee = Cand->Function;
9835 S.Diag(Callee->getLocation(),
9836 diag::note_ovl_candidate_disabled_by_extension);
9839 /// Generates a 'note' diagnostic for an overload candidate. We've
9840 /// already generated a primary error at the call site.
9842 /// It really does need to be a single diagnostic with its caret
9843 /// pointed at the candidate declaration. Yes, this creates some
9844 /// major challenges of technical writing. Yes, this makes pointing
9845 /// out problems with specific arguments quite awkward. It's still
9846 /// better than generating twenty screens of text for every failed
9849 /// It would be great to be able to express per-candidate problems
9850 /// more richly for those diagnostic clients that cared, but we'd
9851 /// still have to be just as careful with the default diagnostics.
9852 static void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand,
9854 bool TakingCandidateAddress) {
9855 FunctionDecl *Fn = Cand->Function;
9857 // Note deleted candidates, but only if they're viable.
9858 if (Cand->Viable && (Fn->isDeleted() ||
9859 S.isFunctionConsideredUnavailable(Fn))) {
9861 OverloadCandidateKind FnKind =
9862 ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn, FnDesc);
9864 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted)
9866 << (Fn->isDeleted() ? (Fn->isDeletedAsWritten() ? 1 : 2) : 0);
9867 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9871 // We don't really have anything else to say about viable candidates.
9873 S.NoteOverloadCandidate(Cand->FoundDecl, Fn);
9877 switch (Cand->FailureKind) {
9878 case ovl_fail_too_many_arguments:
9879 case ovl_fail_too_few_arguments:
9880 return DiagnoseArityMismatch(S, Cand, NumArgs);
9882 case ovl_fail_bad_deduction:
9883 return DiagnoseBadDeduction(S, Cand, NumArgs,
9884 TakingCandidateAddress);
9886 case ovl_fail_illegal_constructor: {
9887 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_illegal_constructor)
9888 << (Fn->getPrimaryTemplate() ? 1 : 0);
9889 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9893 case ovl_fail_trivial_conversion:
9894 case ovl_fail_bad_final_conversion:
9895 case ovl_fail_final_conversion_not_exact:
9896 return S.NoteOverloadCandidate(Cand->FoundDecl, Fn);
9898 case ovl_fail_bad_conversion: {
9899 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0);
9900 for (unsigned N = Cand->NumConversions; I != N; ++I)
9901 if (Cand->Conversions[I].isBad())
9902 return DiagnoseBadConversion(S, Cand, I, TakingCandidateAddress);
9904 // FIXME: this currently happens when we're called from SemaInit
9905 // when user-conversion overload fails. Figure out how to handle
9906 // those conditions and diagnose them well.
9907 return S.NoteOverloadCandidate(Cand->FoundDecl, Fn);
9910 case ovl_fail_bad_target:
9911 return DiagnoseBadTarget(S, Cand);
9913 case ovl_fail_enable_if:
9914 return DiagnoseFailedEnableIfAttr(S, Cand);
9916 case ovl_fail_ext_disabled:
9917 return DiagnoseOpenCLExtensionDisabled(S, Cand);
9919 case ovl_fail_addr_not_available: {
9920 bool Available = checkAddressOfCandidateIsAvailable(S, Cand->Function);
9928 static void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) {
9929 // Desugar the type of the surrogate down to a function type,
9930 // retaining as many typedefs as possible while still showing
9931 // the function type (and, therefore, its parameter types).
9932 QualType FnType = Cand->Surrogate->getConversionType();
9933 bool isLValueReference = false;
9934 bool isRValueReference = false;
9935 bool isPointer = false;
9936 if (const LValueReferenceType *FnTypeRef =
9937 FnType->getAs<LValueReferenceType>()) {
9938 FnType = FnTypeRef->getPointeeType();
9939 isLValueReference = true;
9940 } else if (const RValueReferenceType *FnTypeRef =
9941 FnType->getAs<RValueReferenceType>()) {
9942 FnType = FnTypeRef->getPointeeType();
9943 isRValueReference = true;
9945 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) {
9946 FnType = FnTypePtr->getPointeeType();
9949 // Desugar down to a function type.
9950 FnType = QualType(FnType->getAs<FunctionType>(), 0);
9951 // Reconstruct the pointer/reference as appropriate.
9952 if (isPointer) FnType = S.Context.getPointerType(FnType);
9953 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType);
9954 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType);
9956 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand)
9960 static void NoteBuiltinOperatorCandidate(Sema &S, StringRef Opc,
9961 SourceLocation OpLoc,
9962 OverloadCandidate *Cand) {
9963 assert(Cand->NumConversions <= 2 && "builtin operator is not binary");
9964 std::string TypeStr("operator");
9967 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString();
9968 if (Cand->NumConversions == 1) {
9970 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr;
9973 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString();
9975 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr;
9979 static void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc,
9980 OverloadCandidate *Cand) {
9981 unsigned NoOperands = Cand->NumConversions;
9982 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) {
9983 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx];
9984 if (ICS.isBad()) break; // all meaningless after first invalid
9985 if (!ICS.isAmbiguous()) continue;
9987 ICS.DiagnoseAmbiguousConversion(
9988 S, OpLoc, S.PDiag(diag::note_ambiguous_type_conversion));
9992 static SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) {
9994 return Cand->Function->getLocation();
9995 if (Cand->IsSurrogate)
9996 return Cand->Surrogate->getLocation();
9997 return SourceLocation();
10000 static unsigned RankDeductionFailure(const DeductionFailureInfo &DFI) {
10001 switch ((Sema::TemplateDeductionResult)DFI.Result) {
10002 case Sema::TDK_Success:
10003 llvm_unreachable("TDK_success while diagnosing bad deduction");
10005 case Sema::TDK_Invalid:
10006 case Sema::TDK_Incomplete:
10009 case Sema::TDK_Underqualified:
10010 case Sema::TDK_Inconsistent:
10013 case Sema::TDK_SubstitutionFailure:
10014 case Sema::TDK_DeducedMismatch:
10015 case Sema::TDK_NonDeducedMismatch:
10016 case Sema::TDK_MiscellaneousDeductionFailure:
10017 case Sema::TDK_CUDATargetMismatch:
10020 case Sema::TDK_InstantiationDepth:
10023 case Sema::TDK_InvalidExplicitArguments:
10026 case Sema::TDK_TooManyArguments:
10027 case Sema::TDK_TooFewArguments:
10030 llvm_unreachable("Unhandled deduction result");
10034 struct CompareOverloadCandidatesForDisplay {
10036 SourceLocation Loc;
10039 CompareOverloadCandidatesForDisplay(Sema &S, SourceLocation Loc, size_t nArgs)
10040 : S(S), NumArgs(nArgs) {}
10042 bool operator()(const OverloadCandidate *L,
10043 const OverloadCandidate *R) {
10044 // Fast-path this check.
10045 if (L == R) return false;
10047 // Order first by viability.
10049 if (!R->Viable) return true;
10051 // TODO: introduce a tri-valued comparison for overload
10052 // candidates. Would be more worthwhile if we had a sort
10053 // that could exploit it.
10054 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation())) return true;
10055 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation())) return false;
10056 } else if (R->Viable)
10059 assert(L->Viable == R->Viable);
10061 // Criteria by which we can sort non-viable candidates:
10063 // 1. Arity mismatches come after other candidates.
10064 if (L->FailureKind == ovl_fail_too_many_arguments ||
10065 L->FailureKind == ovl_fail_too_few_arguments) {
10066 if (R->FailureKind == ovl_fail_too_many_arguments ||
10067 R->FailureKind == ovl_fail_too_few_arguments) {
10068 int LDist = std::abs((int)L->getNumParams() - (int)NumArgs);
10069 int RDist = std::abs((int)R->getNumParams() - (int)NumArgs);
10070 if (LDist == RDist) {
10071 if (L->FailureKind == R->FailureKind)
10072 // Sort non-surrogates before surrogates.
10073 return !L->IsSurrogate && R->IsSurrogate;
10074 // Sort candidates requiring fewer parameters than there were
10075 // arguments given after candidates requiring more parameters
10076 // than there were arguments given.
10077 return L->FailureKind == ovl_fail_too_many_arguments;
10079 return LDist < RDist;
10083 if (R->FailureKind == ovl_fail_too_many_arguments ||
10084 R->FailureKind == ovl_fail_too_few_arguments)
10087 // 2. Bad conversions come first and are ordered by the number
10088 // of bad conversions and quality of good conversions.
10089 if (L->FailureKind == ovl_fail_bad_conversion) {
10090 if (R->FailureKind != ovl_fail_bad_conversion)
10093 // The conversion that can be fixed with a smaller number of changes,
10095 unsigned numLFixes = L->Fix.NumConversionsFixed;
10096 unsigned numRFixes = R->Fix.NumConversionsFixed;
10097 numLFixes = (numLFixes == 0) ? UINT_MAX : numLFixes;
10098 numRFixes = (numRFixes == 0) ? UINT_MAX : numRFixes;
10099 if (numLFixes != numRFixes) {
10100 return numLFixes < numRFixes;
10103 // If there's any ordering between the defined conversions...
10104 // FIXME: this might not be transitive.
10105 assert(L->NumConversions == R->NumConversions);
10107 int leftBetter = 0;
10108 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument);
10109 for (unsigned E = L->NumConversions; I != E; ++I) {
10110 switch (CompareImplicitConversionSequences(S, Loc,
10112 R->Conversions[I])) {
10113 case ImplicitConversionSequence::Better:
10117 case ImplicitConversionSequence::Worse:
10121 case ImplicitConversionSequence::Indistinguishable:
10125 if (leftBetter > 0) return true;
10126 if (leftBetter < 0) return false;
10128 } else if (R->FailureKind == ovl_fail_bad_conversion)
10131 if (L->FailureKind == ovl_fail_bad_deduction) {
10132 if (R->FailureKind != ovl_fail_bad_deduction)
10135 if (L->DeductionFailure.Result != R->DeductionFailure.Result)
10136 return RankDeductionFailure(L->DeductionFailure)
10137 < RankDeductionFailure(R->DeductionFailure);
10138 } else if (R->FailureKind == ovl_fail_bad_deduction)
10144 // Sort everything else by location.
10145 SourceLocation LLoc = GetLocationForCandidate(L);
10146 SourceLocation RLoc = GetLocationForCandidate(R);
10148 // Put candidates without locations (e.g. builtins) at the end.
10149 if (LLoc.isInvalid()) return false;
10150 if (RLoc.isInvalid()) return true;
10152 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc);
10157 /// CompleteNonViableCandidate - Normally, overload resolution only
10158 /// computes up to the first. Produces the FixIt set if possible.
10159 static void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand,
10160 ArrayRef<Expr *> Args) {
10161 assert(!Cand->Viable);
10163 // Don't do anything on failures other than bad conversion.
10164 if (Cand->FailureKind != ovl_fail_bad_conversion) return;
10166 // We only want the FixIts if all the arguments can be corrected.
10167 bool Unfixable = false;
10168 // Use a implicit copy initialization to check conversion fixes.
10169 Cand->Fix.setConversionChecker(TryCopyInitialization);
10171 // Skip forward to the first bad conversion.
10172 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0);
10173 unsigned ConvCount = Cand->NumConversions;
10175 assert(ConvIdx != ConvCount && "no bad conversion in candidate");
10177 if (Cand->Conversions[ConvIdx - 1].isBad()) {
10178 Unfixable = !Cand->TryToFixBadConversion(ConvIdx - 1, S);
10183 if (ConvIdx == ConvCount)
10186 assert(!Cand->Conversions[ConvIdx].isInitialized() &&
10187 "remaining conversion is initialized?");
10189 // FIXME: this should probably be preserved from the overload
10190 // operation somehow.
10191 bool SuppressUserConversions = false;
10193 const FunctionProtoType* Proto;
10194 unsigned ArgIdx = ConvIdx;
10196 if (Cand->IsSurrogate) {
10198 = Cand->Surrogate->getConversionType().getNonReferenceType();
10199 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
10200 ConvType = ConvPtrType->getPointeeType();
10201 Proto = ConvType->getAs<FunctionProtoType>();
10203 } else if (Cand->Function) {
10204 Proto = Cand->Function->getType()->getAs<FunctionProtoType>();
10205 if (isa<CXXMethodDecl>(Cand->Function) &&
10206 !isa<CXXConstructorDecl>(Cand->Function))
10209 // Builtin binary operator with a bad first conversion.
10210 assert(ConvCount <= 3);
10211 for (; ConvIdx != ConvCount; ++ConvIdx)
10212 Cand->Conversions[ConvIdx]
10213 = TryCopyInitialization(S, Args[ConvIdx],
10214 Cand->BuiltinTypes.ParamTypes[ConvIdx],
10215 SuppressUserConversions,
10216 /*InOverloadResolution*/ true,
10217 /*AllowObjCWritebackConversion=*/
10218 S.getLangOpts().ObjCAutoRefCount);
10222 // Fill in the rest of the conversions.
10223 unsigned NumParams = Proto->getNumParams();
10224 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) {
10225 if (ArgIdx < NumParams) {
10226 Cand->Conversions[ConvIdx] = TryCopyInitialization(
10227 S, Args[ArgIdx], Proto->getParamType(ArgIdx), SuppressUserConversions,
10228 /*InOverloadResolution=*/true,
10229 /*AllowObjCWritebackConversion=*/
10230 S.getLangOpts().ObjCAutoRefCount);
10231 // Store the FixIt in the candidate if it exists.
10232 if (!Unfixable && Cand->Conversions[ConvIdx].isBad())
10233 Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S);
10236 Cand->Conversions[ConvIdx].setEllipsis();
10240 /// PrintOverloadCandidates - When overload resolution fails, prints
10241 /// diagnostic messages containing the candidates in the candidate
10243 void OverloadCandidateSet::NoteCandidates(
10244 Sema &S, OverloadCandidateDisplayKind OCD, ArrayRef<Expr *> Args,
10245 StringRef Opc, SourceLocation OpLoc,
10246 llvm::function_ref<bool(OverloadCandidate &)> Filter) {
10247 // Sort the candidates by viability and position. Sorting directly would
10248 // be prohibitive, so we make a set of pointers and sort those.
10249 SmallVector<OverloadCandidate*, 32> Cands;
10250 if (OCD == OCD_AllCandidates) Cands.reserve(size());
10251 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) {
10252 if (!Filter(*Cand))
10255 Cands.push_back(Cand);
10256 else if (OCD == OCD_AllCandidates) {
10257 CompleteNonViableCandidate(S, Cand, Args);
10258 if (Cand->Function || Cand->IsSurrogate)
10259 Cands.push_back(Cand);
10260 // Otherwise, this a non-viable builtin candidate. We do not, in general,
10261 // want to list every possible builtin candidate.
10265 std::sort(Cands.begin(), Cands.end(),
10266 CompareOverloadCandidatesForDisplay(S, OpLoc, Args.size()));
10268 bool ReportedAmbiguousConversions = false;
10270 SmallVectorImpl<OverloadCandidate*>::iterator I, E;
10271 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
10272 unsigned CandsShown = 0;
10273 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) {
10274 OverloadCandidate *Cand = *I;
10276 // Set an arbitrary limit on the number of candidate functions we'll spam
10277 // the user with. FIXME: This limit should depend on details of the
10279 if (CandsShown >= 4 && ShowOverloads == Ovl_Best) {
10284 if (Cand->Function)
10285 NoteFunctionCandidate(S, Cand, Args.size(),
10286 /*TakingCandidateAddress=*/false);
10287 else if (Cand->IsSurrogate)
10288 NoteSurrogateCandidate(S, Cand);
10290 assert(Cand->Viable &&
10291 "Non-viable built-in candidates are not added to Cands.");
10292 // Generally we only see ambiguities including viable builtin
10293 // operators if overload resolution got screwed up by an
10294 // ambiguous user-defined conversion.
10296 // FIXME: It's quite possible for different conversions to see
10297 // different ambiguities, though.
10298 if (!ReportedAmbiguousConversions) {
10299 NoteAmbiguousUserConversions(S, OpLoc, Cand);
10300 ReportedAmbiguousConversions = true;
10303 // If this is a viable builtin, print it.
10304 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand);
10309 S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I);
10312 static SourceLocation
10313 GetLocationForCandidate(const TemplateSpecCandidate *Cand) {
10314 return Cand->Specialization ? Cand->Specialization->getLocation()
10315 : SourceLocation();
10319 struct CompareTemplateSpecCandidatesForDisplay {
10321 CompareTemplateSpecCandidatesForDisplay(Sema &S) : S(S) {}
10323 bool operator()(const TemplateSpecCandidate *L,
10324 const TemplateSpecCandidate *R) {
10325 // Fast-path this check.
10329 // Assuming that both candidates are not matches...
10331 // Sort by the ranking of deduction failures.
10332 if (L->DeductionFailure.Result != R->DeductionFailure.Result)
10333 return RankDeductionFailure(L->DeductionFailure) <
10334 RankDeductionFailure(R->DeductionFailure);
10336 // Sort everything else by location.
10337 SourceLocation LLoc = GetLocationForCandidate(L);
10338 SourceLocation RLoc = GetLocationForCandidate(R);
10340 // Put candidates without locations (e.g. builtins) at the end.
10341 if (LLoc.isInvalid())
10343 if (RLoc.isInvalid())
10346 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc);
10351 /// Diagnose a template argument deduction failure.
10352 /// We are treating these failures as overload failures due to bad
10354 void TemplateSpecCandidate::NoteDeductionFailure(Sema &S,
10355 bool ForTakingAddress) {
10356 DiagnoseBadDeduction(S, FoundDecl, Specialization, // pattern
10357 DeductionFailure, /*NumArgs=*/0, ForTakingAddress);
10360 void TemplateSpecCandidateSet::destroyCandidates() {
10361 for (iterator i = begin(), e = end(); i != e; ++i) {
10362 i->DeductionFailure.Destroy();
10366 void TemplateSpecCandidateSet::clear() {
10367 destroyCandidates();
10368 Candidates.clear();
10371 /// NoteCandidates - When no template specialization match is found, prints
10372 /// diagnostic messages containing the non-matching specializations that form
10373 /// the candidate set.
10374 /// This is analoguous to OverloadCandidateSet::NoteCandidates() with
10375 /// OCD == OCD_AllCandidates and Cand->Viable == false.
10376 void TemplateSpecCandidateSet::NoteCandidates(Sema &S, SourceLocation Loc) {
10377 // Sort the candidates by position (assuming no candidate is a match).
10378 // Sorting directly would be prohibitive, so we make a set of pointers
10380 SmallVector<TemplateSpecCandidate *, 32> Cands;
10381 Cands.reserve(size());
10382 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) {
10383 if (Cand->Specialization)
10384 Cands.push_back(Cand);
10385 // Otherwise, this is a non-matching builtin candidate. We do not,
10386 // in general, want to list every possible builtin candidate.
10389 std::sort(Cands.begin(), Cands.end(),
10390 CompareTemplateSpecCandidatesForDisplay(S));
10392 // FIXME: Perhaps rename OverloadsShown and getShowOverloads()
10393 // for generalization purposes (?).
10394 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
10396 SmallVectorImpl<TemplateSpecCandidate *>::iterator I, E;
10397 unsigned CandsShown = 0;
10398 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) {
10399 TemplateSpecCandidate *Cand = *I;
10401 // Set an arbitrary limit on the number of candidates we'll spam
10402 // the user with. FIXME: This limit should depend on details of the
10404 if (CandsShown >= 4 && ShowOverloads == Ovl_Best)
10408 assert(Cand->Specialization &&
10409 "Non-matching built-in candidates are not added to Cands.");
10410 Cand->NoteDeductionFailure(S, ForTakingAddress);
10414 S.Diag(Loc, diag::note_ovl_too_many_candidates) << int(E - I);
10417 // [PossiblyAFunctionType] --> [Return]
10418 // NonFunctionType --> NonFunctionType
10420 // R (*)(A) --> R (A)
10421 // R (&)(A) --> R (A)
10422 // R (S::*)(A) --> R (A)
10423 QualType Sema::ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType) {
10424 QualType Ret = PossiblyAFunctionType;
10425 if (const PointerType *ToTypePtr =
10426 PossiblyAFunctionType->getAs<PointerType>())
10427 Ret = ToTypePtr->getPointeeType();
10428 else if (const ReferenceType *ToTypeRef =
10429 PossiblyAFunctionType->getAs<ReferenceType>())
10430 Ret = ToTypeRef->getPointeeType();
10431 else if (const MemberPointerType *MemTypePtr =
10432 PossiblyAFunctionType->getAs<MemberPointerType>())
10433 Ret = MemTypePtr->getPointeeType();
10435 Context.getCanonicalType(Ret).getUnqualifiedType();
10439 static bool completeFunctionType(Sema &S, FunctionDecl *FD, SourceLocation Loc,
10440 bool Complain = true) {
10441 if (S.getLangOpts().CPlusPlus14 && FD->getReturnType()->isUndeducedType() &&
10442 S.DeduceReturnType(FD, Loc, Complain))
10445 auto *FPT = FD->getType()->castAs<FunctionProtoType>();
10446 if (S.getLangOpts().CPlusPlus1z &&
10447 isUnresolvedExceptionSpec(FPT->getExceptionSpecType()) &&
10448 !S.ResolveExceptionSpec(Loc, FPT))
10455 // A helper class to help with address of function resolution
10456 // - allows us to avoid passing around all those ugly parameters
10457 class AddressOfFunctionResolver {
10460 const QualType& TargetType;
10461 QualType TargetFunctionType; // Extracted function type from target type
10464 //DeclAccessPair& ResultFunctionAccessPair;
10465 ASTContext& Context;
10467 bool TargetTypeIsNonStaticMemberFunction;
10468 bool FoundNonTemplateFunction;
10469 bool StaticMemberFunctionFromBoundPointer;
10470 bool HasComplained;
10472 OverloadExpr::FindResult OvlExprInfo;
10473 OverloadExpr *OvlExpr;
10474 TemplateArgumentListInfo OvlExplicitTemplateArgs;
10475 SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches;
10476 TemplateSpecCandidateSet FailedCandidates;
10479 AddressOfFunctionResolver(Sema &S, Expr *SourceExpr,
10480 const QualType &TargetType, bool Complain)
10481 : S(S), SourceExpr(SourceExpr), TargetType(TargetType),
10482 Complain(Complain), Context(S.getASTContext()),
10483 TargetTypeIsNonStaticMemberFunction(
10484 !!TargetType->getAs<MemberPointerType>()),
10485 FoundNonTemplateFunction(false),
10486 StaticMemberFunctionFromBoundPointer(false),
10487 HasComplained(false),
10488 OvlExprInfo(OverloadExpr::find(SourceExpr)),
10489 OvlExpr(OvlExprInfo.Expression),
10490 FailedCandidates(OvlExpr->getNameLoc(), /*ForTakingAddress=*/true) {
10491 ExtractUnqualifiedFunctionTypeFromTargetType();
10493 if (TargetFunctionType->isFunctionType()) {
10494 if (UnresolvedMemberExpr *UME = dyn_cast<UnresolvedMemberExpr>(OvlExpr))
10495 if (!UME->isImplicitAccess() &&
10496 !S.ResolveSingleFunctionTemplateSpecialization(UME))
10497 StaticMemberFunctionFromBoundPointer = true;
10498 } else if (OvlExpr->hasExplicitTemplateArgs()) {
10499 DeclAccessPair dap;
10500 if (FunctionDecl *Fn = S.ResolveSingleFunctionTemplateSpecialization(
10501 OvlExpr, false, &dap)) {
10502 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn))
10503 if (!Method->isStatic()) {
10504 // If the target type is a non-function type and the function found
10505 // is a non-static member function, pretend as if that was the
10506 // target, it's the only possible type to end up with.
10507 TargetTypeIsNonStaticMemberFunction = true;
10509 // And skip adding the function if its not in the proper form.
10510 // We'll diagnose this due to an empty set of functions.
10511 if (!OvlExprInfo.HasFormOfMemberPointer)
10515 Matches.push_back(std::make_pair(dap, Fn));
10520 if (OvlExpr->hasExplicitTemplateArgs())
10521 OvlExpr->copyTemplateArgumentsInto(OvlExplicitTemplateArgs);
10523 if (FindAllFunctionsThatMatchTargetTypeExactly()) {
10524 // C++ [over.over]p4:
10525 // If more than one function is selected, [...]
10526 if (Matches.size() > 1 && !eliminiateSuboptimalOverloadCandidates()) {
10527 if (FoundNonTemplateFunction)
10528 EliminateAllTemplateMatches();
10530 EliminateAllExceptMostSpecializedTemplate();
10534 if (S.getLangOpts().CUDA && Matches.size() > 1)
10535 EliminateSuboptimalCudaMatches();
10538 bool hasComplained() const { return HasComplained; }
10541 bool candidateHasExactlyCorrectType(const FunctionDecl *FD) {
10543 return Context.hasSameUnqualifiedType(TargetFunctionType, FD->getType()) ||
10544 S.IsFunctionConversion(FD->getType(), TargetFunctionType, Discard);
10547 /// \return true if A is considered a better overload candidate for the
10548 /// desired type than B.
10549 bool isBetterCandidate(const FunctionDecl *A, const FunctionDecl *B) {
10550 // If A doesn't have exactly the correct type, we don't want to classify it
10551 // as "better" than anything else. This way, the user is required to
10552 // disambiguate for us if there are multiple candidates and no exact match.
10553 return candidateHasExactlyCorrectType(A) &&
10554 (!candidateHasExactlyCorrectType(B) ||
10555 compareEnableIfAttrs(S, A, B) == Comparison::Better);
10558 /// \return true if we were able to eliminate all but one overload candidate,
10559 /// false otherwise.
10560 bool eliminiateSuboptimalOverloadCandidates() {
10561 // Same algorithm as overload resolution -- one pass to pick the "best",
10562 // another pass to be sure that nothing is better than the best.
10563 auto Best = Matches.begin();
10564 for (auto I = Matches.begin()+1, E = Matches.end(); I != E; ++I)
10565 if (isBetterCandidate(I->second, Best->second))
10568 const FunctionDecl *BestFn = Best->second;
10569 auto IsBestOrInferiorToBest = [this, BestFn](
10570 const std::pair<DeclAccessPair, FunctionDecl *> &Pair) {
10571 return BestFn == Pair.second || isBetterCandidate(BestFn, Pair.second);
10574 // Note: We explicitly leave Matches unmodified if there isn't a clear best
10575 // option, so we can potentially give the user a better error
10576 if (!std::all_of(Matches.begin(), Matches.end(), IsBestOrInferiorToBest))
10578 Matches[0] = *Best;
10583 bool isTargetTypeAFunction() const {
10584 return TargetFunctionType->isFunctionType();
10587 // [ToType] [Return]
10589 // R (*)(A) --> R (A), IsNonStaticMemberFunction = false
10590 // R (&)(A) --> R (A), IsNonStaticMemberFunction = false
10591 // R (S::*)(A) --> R (A), IsNonStaticMemberFunction = true
10592 void inline ExtractUnqualifiedFunctionTypeFromTargetType() {
10593 TargetFunctionType = S.ExtractUnqualifiedFunctionType(TargetType);
10596 // return true if any matching specializations were found
10597 bool AddMatchingTemplateFunction(FunctionTemplateDecl* FunctionTemplate,
10598 const DeclAccessPair& CurAccessFunPair) {
10599 if (CXXMethodDecl *Method
10600 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) {
10601 // Skip non-static function templates when converting to pointer, and
10602 // static when converting to member pointer.
10603 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction)
10606 else if (TargetTypeIsNonStaticMemberFunction)
10609 // C++ [over.over]p2:
10610 // If the name is a function template, template argument deduction is
10611 // done (14.8.2.2), and if the argument deduction succeeds, the
10612 // resulting template argument list is used to generate a single
10613 // function template specialization, which is added to the set of
10614 // overloaded functions considered.
10615 FunctionDecl *Specialization = nullptr;
10616 TemplateDeductionInfo Info(FailedCandidates.getLocation());
10617 if (Sema::TemplateDeductionResult Result
10618 = S.DeduceTemplateArguments(FunctionTemplate,
10619 &OvlExplicitTemplateArgs,
10620 TargetFunctionType, Specialization,
10621 Info, /*IsAddressOfFunction*/true)) {
10622 // Make a note of the failed deduction for diagnostics.
10623 FailedCandidates.addCandidate()
10624 .set(CurAccessFunPair, FunctionTemplate->getTemplatedDecl(),
10625 MakeDeductionFailureInfo(Context, Result, Info));
10629 // Template argument deduction ensures that we have an exact match or
10630 // compatible pointer-to-function arguments that would be adjusted by ICS.
10631 // This function template specicalization works.
10632 assert(S.isSameOrCompatibleFunctionType(
10633 Context.getCanonicalType(Specialization->getType()),
10634 Context.getCanonicalType(TargetFunctionType)));
10636 if (!S.checkAddressOfFunctionIsAvailable(Specialization))
10639 Matches.push_back(std::make_pair(CurAccessFunPair, Specialization));
10643 bool AddMatchingNonTemplateFunction(NamedDecl* Fn,
10644 const DeclAccessPair& CurAccessFunPair) {
10645 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) {
10646 // Skip non-static functions when converting to pointer, and static
10647 // when converting to member pointer.
10648 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction)
10651 else if (TargetTypeIsNonStaticMemberFunction)
10654 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) {
10655 if (S.getLangOpts().CUDA)
10656 if (FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext))
10657 if (!Caller->isImplicit() && !S.IsAllowedCUDACall(Caller, FunDecl))
10660 // If any candidate has a placeholder return type, trigger its deduction
10662 if (completeFunctionType(S, FunDecl, SourceExpr->getLocStart(),
10664 HasComplained |= Complain;
10668 if (!S.checkAddressOfFunctionIsAvailable(FunDecl))
10671 // If we're in C, we need to support types that aren't exactly identical.
10672 if (!S.getLangOpts().CPlusPlus ||
10673 candidateHasExactlyCorrectType(FunDecl)) {
10674 Matches.push_back(std::make_pair(
10675 CurAccessFunPair, cast<FunctionDecl>(FunDecl->getCanonicalDecl())));
10676 FoundNonTemplateFunction = true;
10684 bool FindAllFunctionsThatMatchTargetTypeExactly() {
10687 // If the overload expression doesn't have the form of a pointer to
10688 // member, don't try to convert it to a pointer-to-member type.
10689 if (IsInvalidFormOfPointerToMemberFunction())
10692 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
10693 E = OvlExpr->decls_end();
10695 // Look through any using declarations to find the underlying function.
10696 NamedDecl *Fn = (*I)->getUnderlyingDecl();
10698 // C++ [over.over]p3:
10699 // Non-member functions and static member functions match
10700 // targets of type "pointer-to-function" or "reference-to-function."
10701 // Nonstatic member functions match targets of
10702 // type "pointer-to-member-function."
10703 // Note that according to DR 247, the containing class does not matter.
10704 if (FunctionTemplateDecl *FunctionTemplate
10705 = dyn_cast<FunctionTemplateDecl>(Fn)) {
10706 if (AddMatchingTemplateFunction(FunctionTemplate, I.getPair()))
10709 // If we have explicit template arguments supplied, skip non-templates.
10710 else if (!OvlExpr->hasExplicitTemplateArgs() &&
10711 AddMatchingNonTemplateFunction(Fn, I.getPair()))
10714 assert(Ret || Matches.empty());
10718 void EliminateAllExceptMostSpecializedTemplate() {
10719 // [...] and any given function template specialization F1 is
10720 // eliminated if the set contains a second function template
10721 // specialization whose function template is more specialized
10722 // than the function template of F1 according to the partial
10723 // ordering rules of 14.5.5.2.
10725 // The algorithm specified above is quadratic. We instead use a
10726 // two-pass algorithm (similar to the one used to identify the
10727 // best viable function in an overload set) that identifies the
10728 // best function template (if it exists).
10730 UnresolvedSet<4> MatchesCopy; // TODO: avoid!
10731 for (unsigned I = 0, E = Matches.size(); I != E; ++I)
10732 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess());
10734 // TODO: It looks like FailedCandidates does not serve much purpose
10735 // here, since the no_viable diagnostic has index 0.
10736 UnresolvedSetIterator Result = S.getMostSpecialized(
10737 MatchesCopy.begin(), MatchesCopy.end(), FailedCandidates,
10738 SourceExpr->getLocStart(), S.PDiag(),
10739 S.PDiag(diag::err_addr_ovl_ambiguous)
10740 << Matches[0].second->getDeclName(),
10741 S.PDiag(diag::note_ovl_candidate)
10742 << (unsigned)oc_function_template,
10743 Complain, TargetFunctionType);
10745 if (Result != MatchesCopy.end()) {
10746 // Make it the first and only element
10747 Matches[0].first = Matches[Result - MatchesCopy.begin()].first;
10748 Matches[0].second = cast<FunctionDecl>(*Result);
10751 HasComplained |= Complain;
10754 void EliminateAllTemplateMatches() {
10755 // [...] any function template specializations in the set are
10756 // eliminated if the set also contains a non-template function, [...]
10757 for (unsigned I = 0, N = Matches.size(); I != N; ) {
10758 if (Matches[I].second->getPrimaryTemplate() == nullptr)
10761 Matches[I] = Matches[--N];
10767 void EliminateSuboptimalCudaMatches() {
10768 S.EraseUnwantedCUDAMatches(dyn_cast<FunctionDecl>(S.CurContext), Matches);
10772 void ComplainNoMatchesFound() const {
10773 assert(Matches.empty());
10774 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_no_viable)
10775 << OvlExpr->getName() << TargetFunctionType
10776 << OvlExpr->getSourceRange();
10777 if (FailedCandidates.empty())
10778 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType,
10779 /*TakingAddress=*/true);
10781 // We have some deduction failure messages. Use them to diagnose
10782 // the function templates, and diagnose the non-template candidates
10784 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
10785 IEnd = OvlExpr->decls_end();
10787 if (FunctionDecl *Fun =
10788 dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()))
10789 if (!functionHasPassObjectSizeParams(Fun))
10790 S.NoteOverloadCandidate(*I, Fun, TargetFunctionType,
10791 /*TakingAddress=*/true);
10792 FailedCandidates.NoteCandidates(S, OvlExpr->getLocStart());
10796 bool IsInvalidFormOfPointerToMemberFunction() const {
10797 return TargetTypeIsNonStaticMemberFunction &&
10798 !OvlExprInfo.HasFormOfMemberPointer;
10801 void ComplainIsInvalidFormOfPointerToMemberFunction() const {
10802 // TODO: Should we condition this on whether any functions might
10803 // have matched, or is it more appropriate to do that in callers?
10804 // TODO: a fixit wouldn't hurt.
10805 S.Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier)
10806 << TargetType << OvlExpr->getSourceRange();
10809 bool IsStaticMemberFunctionFromBoundPointer() const {
10810 return StaticMemberFunctionFromBoundPointer;
10813 void ComplainIsStaticMemberFunctionFromBoundPointer() const {
10814 S.Diag(OvlExpr->getLocStart(),
10815 diag::err_invalid_form_pointer_member_function)
10816 << OvlExpr->getSourceRange();
10819 void ComplainOfInvalidConversion() const {
10820 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_not_func_ptrref)
10821 << OvlExpr->getName() << TargetType;
10824 void ComplainMultipleMatchesFound() const {
10825 assert(Matches.size() > 1);
10826 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_ambiguous)
10827 << OvlExpr->getName()
10828 << OvlExpr->getSourceRange();
10829 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType,
10830 /*TakingAddress=*/true);
10833 bool hadMultipleCandidates() const { return (OvlExpr->getNumDecls() > 1); }
10835 int getNumMatches() const { return Matches.size(); }
10837 FunctionDecl* getMatchingFunctionDecl() const {
10838 if (Matches.size() != 1) return nullptr;
10839 return Matches[0].second;
10842 const DeclAccessPair* getMatchingFunctionAccessPair() const {
10843 if (Matches.size() != 1) return nullptr;
10844 return &Matches[0].first;
10849 /// ResolveAddressOfOverloadedFunction - Try to resolve the address of
10850 /// an overloaded function (C++ [over.over]), where @p From is an
10851 /// expression with overloaded function type and @p ToType is the type
10852 /// we're trying to resolve to. For example:
10858 /// int (*pfd)(double) = f; // selects f(double)
10861 /// This routine returns the resulting FunctionDecl if it could be
10862 /// resolved, and NULL otherwise. When @p Complain is true, this
10863 /// routine will emit diagnostics if there is an error.
10865 Sema::ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr,
10866 QualType TargetType,
10868 DeclAccessPair &FoundResult,
10869 bool *pHadMultipleCandidates) {
10870 assert(AddressOfExpr->getType() == Context.OverloadTy);
10872 AddressOfFunctionResolver Resolver(*this, AddressOfExpr, TargetType,
10874 int NumMatches = Resolver.getNumMatches();
10875 FunctionDecl *Fn = nullptr;
10876 bool ShouldComplain = Complain && !Resolver.hasComplained();
10877 if (NumMatches == 0 && ShouldComplain) {
10878 if (Resolver.IsInvalidFormOfPointerToMemberFunction())
10879 Resolver.ComplainIsInvalidFormOfPointerToMemberFunction();
10881 Resolver.ComplainNoMatchesFound();
10883 else if (NumMatches > 1 && ShouldComplain)
10884 Resolver.ComplainMultipleMatchesFound();
10885 else if (NumMatches == 1) {
10886 Fn = Resolver.getMatchingFunctionDecl();
10888 if (auto *FPT = Fn->getType()->getAs<FunctionProtoType>())
10889 ResolveExceptionSpec(AddressOfExpr->getExprLoc(), FPT);
10890 FoundResult = *Resolver.getMatchingFunctionAccessPair();
10892 if (Resolver.IsStaticMemberFunctionFromBoundPointer())
10893 Resolver.ComplainIsStaticMemberFunctionFromBoundPointer();
10895 CheckAddressOfMemberAccess(AddressOfExpr, FoundResult);
10899 if (pHadMultipleCandidates)
10900 *pHadMultipleCandidates = Resolver.hadMultipleCandidates();
10904 /// \brief Given an expression that refers to an overloaded function, try to
10905 /// resolve that function to a single function that can have its address taken.
10906 /// This will modify `Pair` iff it returns non-null.
10908 /// This routine can only realistically succeed if all but one candidates in the
10909 /// overload set for SrcExpr cannot have their addresses taken.
10911 Sema::resolveAddressOfOnlyViableOverloadCandidate(Expr *E,
10912 DeclAccessPair &Pair) {
10913 OverloadExpr::FindResult R = OverloadExpr::find(E);
10914 OverloadExpr *Ovl = R.Expression;
10915 FunctionDecl *Result = nullptr;
10916 DeclAccessPair DAP;
10917 // Don't use the AddressOfResolver because we're specifically looking for
10918 // cases where we have one overload candidate that lacks
10919 // enable_if/pass_object_size/...
10920 for (auto I = Ovl->decls_begin(), E = Ovl->decls_end(); I != E; ++I) {
10921 auto *FD = dyn_cast<FunctionDecl>(I->getUnderlyingDecl());
10925 if (!checkAddressOfFunctionIsAvailable(FD))
10928 // We have more than one result; quit.
10940 /// \brief Given an overloaded function, tries to turn it into a non-overloaded
10941 /// function reference using resolveAddressOfOnlyViableOverloadCandidate. This
10942 /// will perform access checks, diagnose the use of the resultant decl, and, if
10943 /// necessary, perform a function-to-pointer decay.
10945 /// Returns false if resolveAddressOfOnlyViableOverloadCandidate fails.
10946 /// Otherwise, returns true. This may emit diagnostics and return true.
10947 bool Sema::resolveAndFixAddressOfOnlyViableOverloadCandidate(
10948 ExprResult &SrcExpr) {
10949 Expr *E = SrcExpr.get();
10950 assert(E->getType() == Context.OverloadTy && "SrcExpr must be an overload");
10952 DeclAccessPair DAP;
10953 FunctionDecl *Found = resolveAddressOfOnlyViableOverloadCandidate(E, DAP);
10957 // Emitting multiple diagnostics for a function that is both inaccessible and
10958 // unavailable is consistent with our behavior elsewhere. So, always check
10960 DiagnoseUseOfDecl(Found, E->getExprLoc());
10961 CheckAddressOfMemberAccess(E, DAP);
10962 Expr *Fixed = FixOverloadedFunctionReference(E, DAP, Found);
10963 if (Fixed->getType()->isFunctionType())
10964 SrcExpr = DefaultFunctionArrayConversion(Fixed, /*Diagnose=*/false);
10970 /// \brief Given an expression that refers to an overloaded function, try to
10971 /// resolve that overloaded function expression down to a single function.
10973 /// This routine can only resolve template-ids that refer to a single function
10974 /// template, where that template-id refers to a single template whose template
10975 /// arguments are either provided by the template-id or have defaults,
10976 /// as described in C++0x [temp.arg.explicit]p3.
10978 /// If no template-ids are found, no diagnostics are emitted and NULL is
10981 Sema::ResolveSingleFunctionTemplateSpecialization(OverloadExpr *ovl,
10983 DeclAccessPair *FoundResult) {
10984 // C++ [over.over]p1:
10985 // [...] [Note: any redundant set of parentheses surrounding the
10986 // overloaded function name is ignored (5.1). ]
10987 // C++ [over.over]p1:
10988 // [...] The overloaded function name can be preceded by the &
10991 // If we didn't actually find any template-ids, we're done.
10992 if (!ovl->hasExplicitTemplateArgs())
10995 TemplateArgumentListInfo ExplicitTemplateArgs;
10996 ovl->copyTemplateArgumentsInto(ExplicitTemplateArgs);
10997 TemplateSpecCandidateSet FailedCandidates(ovl->getNameLoc());
10999 // Look through all of the overloaded functions, searching for one
11000 // whose type matches exactly.
11001 FunctionDecl *Matched = nullptr;
11002 for (UnresolvedSetIterator I = ovl->decls_begin(),
11003 E = ovl->decls_end(); I != E; ++I) {
11004 // C++0x [temp.arg.explicit]p3:
11005 // [...] In contexts where deduction is done and fails, or in contexts
11006 // where deduction is not done, if a template argument list is
11007 // specified and it, along with any default template arguments,
11008 // identifies a single function template specialization, then the
11009 // template-id is an lvalue for the function template specialization.
11010 FunctionTemplateDecl *FunctionTemplate
11011 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl());
11013 // C++ [over.over]p2:
11014 // If the name is a function template, template argument deduction is
11015 // done (14.8.2.2), and if the argument deduction succeeds, the
11016 // resulting template argument list is used to generate a single
11017 // function template specialization, which is added to the set of
11018 // overloaded functions considered.
11019 FunctionDecl *Specialization = nullptr;
11020 TemplateDeductionInfo Info(FailedCandidates.getLocation());
11021 if (TemplateDeductionResult Result
11022 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs,
11023 Specialization, Info,
11024 /*IsAddressOfFunction*/true)) {
11025 // Make a note of the failed deduction for diagnostics.
11026 // TODO: Actually use the failed-deduction info?
11027 FailedCandidates.addCandidate()
11028 .set(I.getPair(), FunctionTemplate->getTemplatedDecl(),
11029 MakeDeductionFailureInfo(Context, Result, Info));
11033 assert(Specialization && "no specialization and no error?");
11035 // Multiple matches; we can't resolve to a single declaration.
11038 Diag(ovl->getExprLoc(), diag::err_addr_ovl_ambiguous)
11040 NoteAllOverloadCandidates(ovl);
11045 Matched = Specialization;
11046 if (FoundResult) *FoundResult = I.getPair();
11050 completeFunctionType(*this, Matched, ovl->getExprLoc(), Complain))
11059 // Resolve and fix an overloaded expression that can be resolved
11060 // because it identifies a single function template specialization.
11062 // Last three arguments should only be supplied if Complain = true
11064 // Return true if it was logically possible to so resolve the
11065 // expression, regardless of whether or not it succeeded. Always
11066 // returns true if 'complain' is set.
11067 bool Sema::ResolveAndFixSingleFunctionTemplateSpecialization(
11068 ExprResult &SrcExpr, bool doFunctionPointerConverion,
11069 bool complain, SourceRange OpRangeForComplaining,
11070 QualType DestTypeForComplaining,
11071 unsigned DiagIDForComplaining) {
11072 assert(SrcExpr.get()->getType() == Context.OverloadTy);
11074 OverloadExpr::FindResult ovl = OverloadExpr::find(SrcExpr.get());
11076 DeclAccessPair found;
11077 ExprResult SingleFunctionExpression;
11078 if (FunctionDecl *fn = ResolveSingleFunctionTemplateSpecialization(
11079 ovl.Expression, /*complain*/ false, &found)) {
11080 if (DiagnoseUseOfDecl(fn, SrcExpr.get()->getLocStart())) {
11081 SrcExpr = ExprError();
11085 // It is only correct to resolve to an instance method if we're
11086 // resolving a form that's permitted to be a pointer to member.
11087 // Otherwise we'll end up making a bound member expression, which
11088 // is illegal in all the contexts we resolve like this.
11089 if (!ovl.HasFormOfMemberPointer &&
11090 isa<CXXMethodDecl>(fn) &&
11091 cast<CXXMethodDecl>(fn)->isInstance()) {
11092 if (!complain) return false;
11094 Diag(ovl.Expression->getExprLoc(),
11095 diag::err_bound_member_function)
11096 << 0 << ovl.Expression->getSourceRange();
11098 // TODO: I believe we only end up here if there's a mix of
11099 // static and non-static candidates (otherwise the expression
11100 // would have 'bound member' type, not 'overload' type).
11101 // Ideally we would note which candidate was chosen and why
11102 // the static candidates were rejected.
11103 SrcExpr = ExprError();
11107 // Fix the expression to refer to 'fn'.
11108 SingleFunctionExpression =
11109 FixOverloadedFunctionReference(SrcExpr.get(), found, fn);
11111 // If desired, do function-to-pointer decay.
11112 if (doFunctionPointerConverion) {
11113 SingleFunctionExpression =
11114 DefaultFunctionArrayLvalueConversion(SingleFunctionExpression.get());
11115 if (SingleFunctionExpression.isInvalid()) {
11116 SrcExpr = ExprError();
11122 if (!SingleFunctionExpression.isUsable()) {
11124 Diag(OpRangeForComplaining.getBegin(), DiagIDForComplaining)
11125 << ovl.Expression->getName()
11126 << DestTypeForComplaining
11127 << OpRangeForComplaining
11128 << ovl.Expression->getQualifierLoc().getSourceRange();
11129 NoteAllOverloadCandidates(SrcExpr.get());
11131 SrcExpr = ExprError();
11138 SrcExpr = SingleFunctionExpression;
11142 /// \brief Add a single candidate to the overload set.
11143 static void AddOverloadedCallCandidate(Sema &S,
11144 DeclAccessPair FoundDecl,
11145 TemplateArgumentListInfo *ExplicitTemplateArgs,
11146 ArrayRef<Expr *> Args,
11147 OverloadCandidateSet &CandidateSet,
11148 bool PartialOverloading,
11150 NamedDecl *Callee = FoundDecl.getDecl();
11151 if (isa<UsingShadowDecl>(Callee))
11152 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl();
11154 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) {
11155 if (ExplicitTemplateArgs) {
11156 assert(!KnownValid && "Explicit template arguments?");
11159 S.AddOverloadCandidate(Func, FoundDecl, Args, CandidateSet,
11160 /*SuppressUsedConversions=*/false,
11161 PartialOverloading);
11165 if (FunctionTemplateDecl *FuncTemplate
11166 = dyn_cast<FunctionTemplateDecl>(Callee)) {
11167 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl,
11168 ExplicitTemplateArgs, Args, CandidateSet,
11169 /*SuppressUsedConversions=*/false,
11170 PartialOverloading);
11174 assert(!KnownValid && "unhandled case in overloaded call candidate");
11177 /// \brief Add the overload candidates named by callee and/or found by argument
11178 /// dependent lookup to the given overload set.
11179 void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE,
11180 ArrayRef<Expr *> Args,
11181 OverloadCandidateSet &CandidateSet,
11182 bool PartialOverloading) {
11185 // Verify that ArgumentDependentLookup is consistent with the rules
11186 // in C++0x [basic.lookup.argdep]p3:
11188 // Let X be the lookup set produced by unqualified lookup (3.4.1)
11189 // and let Y be the lookup set produced by argument dependent
11190 // lookup (defined as follows). If X contains
11192 // -- a declaration of a class member, or
11194 // -- a block-scope function declaration that is not a
11195 // using-declaration, or
11197 // -- a declaration that is neither a function or a function
11200 // then Y is empty.
11202 if (ULE->requiresADL()) {
11203 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(),
11204 E = ULE->decls_end(); I != E; ++I) {
11205 assert(!(*I)->getDeclContext()->isRecord());
11206 assert(isa<UsingShadowDecl>(*I) ||
11207 !(*I)->getDeclContext()->isFunctionOrMethod());
11208 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate());
11213 // It would be nice to avoid this copy.
11214 TemplateArgumentListInfo TABuffer;
11215 TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr;
11216 if (ULE->hasExplicitTemplateArgs()) {
11217 ULE->copyTemplateArgumentsInto(TABuffer);
11218 ExplicitTemplateArgs = &TABuffer;
11221 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(),
11222 E = ULE->decls_end(); I != E; ++I)
11223 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, Args,
11224 CandidateSet, PartialOverloading,
11225 /*KnownValid*/ true);
11227 if (ULE->requiresADL())
11228 AddArgumentDependentLookupCandidates(ULE->getName(), ULE->getExprLoc(),
11229 Args, ExplicitTemplateArgs,
11230 CandidateSet, PartialOverloading);
11233 /// Determine whether a declaration with the specified name could be moved into
11234 /// a different namespace.
11235 static bool canBeDeclaredInNamespace(const DeclarationName &Name) {
11236 switch (Name.getCXXOverloadedOperator()) {
11237 case OO_New: case OO_Array_New:
11238 case OO_Delete: case OO_Array_Delete:
11246 /// Attempt to recover from an ill-formed use of a non-dependent name in a
11247 /// template, where the non-dependent name was declared after the template
11248 /// was defined. This is common in code written for a compilers which do not
11249 /// correctly implement two-stage name lookup.
11251 /// Returns true if a viable candidate was found and a diagnostic was issued.
11253 DiagnoseTwoPhaseLookup(Sema &SemaRef, SourceLocation FnLoc,
11254 const CXXScopeSpec &SS, LookupResult &R,
11255 OverloadCandidateSet::CandidateSetKind CSK,
11256 TemplateArgumentListInfo *ExplicitTemplateArgs,
11257 ArrayRef<Expr *> Args,
11258 bool *DoDiagnoseEmptyLookup = nullptr) {
11259 if (SemaRef.ActiveTemplateInstantiations.empty() || !SS.isEmpty())
11262 for (DeclContext *DC = SemaRef.CurContext; DC; DC = DC->getParent()) {
11263 if (DC->isTransparentContext())
11266 SemaRef.LookupQualifiedName(R, DC);
11269 R.suppressDiagnostics();
11271 if (isa<CXXRecordDecl>(DC)) {
11272 // Don't diagnose names we find in classes; we get much better
11273 // diagnostics for these from DiagnoseEmptyLookup.
11275 if (DoDiagnoseEmptyLookup)
11276 *DoDiagnoseEmptyLookup = true;
11280 OverloadCandidateSet Candidates(FnLoc, CSK);
11281 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
11282 AddOverloadedCallCandidate(SemaRef, I.getPair(),
11283 ExplicitTemplateArgs, Args,
11284 Candidates, false, /*KnownValid*/ false);
11286 OverloadCandidateSet::iterator Best;
11287 if (Candidates.BestViableFunction(SemaRef, FnLoc, Best) != OR_Success) {
11288 // No viable functions. Don't bother the user with notes for functions
11289 // which don't work and shouldn't be found anyway.
11294 // Find the namespaces where ADL would have looked, and suggest
11295 // declaring the function there instead.
11296 Sema::AssociatedNamespaceSet AssociatedNamespaces;
11297 Sema::AssociatedClassSet AssociatedClasses;
11298 SemaRef.FindAssociatedClassesAndNamespaces(FnLoc, Args,
11299 AssociatedNamespaces,
11300 AssociatedClasses);
11301 Sema::AssociatedNamespaceSet SuggestedNamespaces;
11302 if (canBeDeclaredInNamespace(R.getLookupName())) {
11303 DeclContext *Std = SemaRef.getStdNamespace();
11304 for (Sema::AssociatedNamespaceSet::iterator
11305 it = AssociatedNamespaces.begin(),
11306 end = AssociatedNamespaces.end(); it != end; ++it) {
11307 // Never suggest declaring a function within namespace 'std'.
11308 if (Std && Std->Encloses(*it))
11311 // Never suggest declaring a function within a namespace with a
11312 // reserved name, like __gnu_cxx.
11313 NamespaceDecl *NS = dyn_cast<NamespaceDecl>(*it);
11315 NS->getQualifiedNameAsString().find("__") != std::string::npos)
11318 SuggestedNamespaces.insert(*it);
11322 SemaRef.Diag(R.getNameLoc(), diag::err_not_found_by_two_phase_lookup)
11323 << R.getLookupName();
11324 if (SuggestedNamespaces.empty()) {
11325 SemaRef.Diag(Best->Function->getLocation(),
11326 diag::note_not_found_by_two_phase_lookup)
11327 << R.getLookupName() << 0;
11328 } else if (SuggestedNamespaces.size() == 1) {
11329 SemaRef.Diag(Best->Function->getLocation(),
11330 diag::note_not_found_by_two_phase_lookup)
11331 << R.getLookupName() << 1 << *SuggestedNamespaces.begin();
11333 // FIXME: It would be useful to list the associated namespaces here,
11334 // but the diagnostics infrastructure doesn't provide a way to produce
11335 // a localized representation of a list of items.
11336 SemaRef.Diag(Best->Function->getLocation(),
11337 diag::note_not_found_by_two_phase_lookup)
11338 << R.getLookupName() << 2;
11341 // Try to recover by calling this function.
11351 /// Attempt to recover from ill-formed use of a non-dependent operator in a
11352 /// template, where the non-dependent operator was declared after the template
11355 /// Returns true if a viable candidate was found and a diagnostic was issued.
11357 DiagnoseTwoPhaseOperatorLookup(Sema &SemaRef, OverloadedOperatorKind Op,
11358 SourceLocation OpLoc,
11359 ArrayRef<Expr *> Args) {
11360 DeclarationName OpName =
11361 SemaRef.Context.DeclarationNames.getCXXOperatorName(Op);
11362 LookupResult R(SemaRef, OpName, OpLoc, Sema::LookupOperatorName);
11363 return DiagnoseTwoPhaseLookup(SemaRef, OpLoc, CXXScopeSpec(), R,
11364 OverloadCandidateSet::CSK_Operator,
11365 /*ExplicitTemplateArgs=*/nullptr, Args);
11369 class BuildRecoveryCallExprRAII {
11372 BuildRecoveryCallExprRAII(Sema &S) : SemaRef(S) {
11373 assert(SemaRef.IsBuildingRecoveryCallExpr == false);
11374 SemaRef.IsBuildingRecoveryCallExpr = true;
11377 ~BuildRecoveryCallExprRAII() {
11378 SemaRef.IsBuildingRecoveryCallExpr = false;
11384 static std::unique_ptr<CorrectionCandidateCallback>
11385 MakeValidator(Sema &SemaRef, MemberExpr *ME, size_t NumArgs,
11386 bool HasTemplateArgs, bool AllowTypoCorrection) {
11387 if (!AllowTypoCorrection)
11388 return llvm::make_unique<NoTypoCorrectionCCC>();
11389 return llvm::make_unique<FunctionCallFilterCCC>(SemaRef, NumArgs,
11390 HasTemplateArgs, ME);
11393 /// Attempts to recover from a call where no functions were found.
11395 /// Returns true if new candidates were found.
11397 BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn,
11398 UnresolvedLookupExpr *ULE,
11399 SourceLocation LParenLoc,
11400 MutableArrayRef<Expr *> Args,
11401 SourceLocation RParenLoc,
11402 bool EmptyLookup, bool AllowTypoCorrection) {
11403 // Do not try to recover if it is already building a recovery call.
11404 // This stops infinite loops for template instantiations like
11406 // template <typename T> auto foo(T t) -> decltype(foo(t)) {}
11407 // template <typename T> auto foo(T t) -> decltype(foo(&t)) {}
11409 if (SemaRef.IsBuildingRecoveryCallExpr)
11410 return ExprError();
11411 BuildRecoveryCallExprRAII RCE(SemaRef);
11414 SS.Adopt(ULE->getQualifierLoc());
11415 SourceLocation TemplateKWLoc = ULE->getTemplateKeywordLoc();
11417 TemplateArgumentListInfo TABuffer;
11418 TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr;
11419 if (ULE->hasExplicitTemplateArgs()) {
11420 ULE->copyTemplateArgumentsInto(TABuffer);
11421 ExplicitTemplateArgs = &TABuffer;
11424 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(),
11425 Sema::LookupOrdinaryName);
11426 bool DoDiagnoseEmptyLookup = EmptyLookup;
11427 if (!DiagnoseTwoPhaseLookup(SemaRef, Fn->getExprLoc(), SS, R,
11428 OverloadCandidateSet::CSK_Normal,
11429 ExplicitTemplateArgs, Args,
11430 &DoDiagnoseEmptyLookup) &&
11431 (!DoDiagnoseEmptyLookup || SemaRef.DiagnoseEmptyLookup(
11433 MakeValidator(SemaRef, dyn_cast<MemberExpr>(Fn), Args.size(),
11434 ExplicitTemplateArgs != nullptr, AllowTypoCorrection),
11435 ExplicitTemplateArgs, Args)))
11436 return ExprError();
11438 assert(!R.empty() && "lookup results empty despite recovery");
11440 // If recovery created an ambiguity, just bail out.
11441 if (R.isAmbiguous()) {
11442 R.suppressDiagnostics();
11443 return ExprError();
11446 // Build an implicit member call if appropriate. Just drop the
11447 // casts and such from the call, we don't really care.
11448 ExprResult NewFn = ExprError();
11449 if ((*R.begin())->isCXXClassMember())
11450 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, TemplateKWLoc, R,
11451 ExplicitTemplateArgs, S);
11452 else if (ExplicitTemplateArgs || TemplateKWLoc.isValid())
11453 NewFn = SemaRef.BuildTemplateIdExpr(SS, TemplateKWLoc, R, false,
11454 ExplicitTemplateArgs);
11456 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false);
11458 if (NewFn.isInvalid())
11459 return ExprError();
11461 // This shouldn't cause an infinite loop because we're giving it
11462 // an expression with viable lookup results, which should never
11464 return SemaRef.ActOnCallExpr(/*Scope*/ nullptr, NewFn.get(), LParenLoc,
11465 MultiExprArg(Args.data(), Args.size()),
11469 /// \brief Constructs and populates an OverloadedCandidateSet from
11470 /// the given function.
11471 /// \returns true when an the ExprResult output parameter has been set.
11472 bool Sema::buildOverloadedCallSet(Scope *S, Expr *Fn,
11473 UnresolvedLookupExpr *ULE,
11475 SourceLocation RParenLoc,
11476 OverloadCandidateSet *CandidateSet,
11477 ExprResult *Result) {
11479 if (ULE->requiresADL()) {
11480 // To do ADL, we must have found an unqualified name.
11481 assert(!ULE->getQualifier() && "qualified name with ADL");
11483 // We don't perform ADL for implicit declarations of builtins.
11484 // Verify that this was correctly set up.
11486 if (ULE->decls_begin() + 1 == ULE->decls_end() &&
11487 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) &&
11488 F->getBuiltinID() && F->isImplicit())
11489 llvm_unreachable("performing ADL for builtin");
11491 // We don't perform ADL in C.
11492 assert(getLangOpts().CPlusPlus && "ADL enabled in C");
11496 UnbridgedCastsSet UnbridgedCasts;
11497 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts)) {
11498 *Result = ExprError();
11502 // Add the functions denoted by the callee to the set of candidate
11503 // functions, including those from argument-dependent lookup.
11504 AddOverloadedCallCandidates(ULE, Args, *CandidateSet);
11506 if (getLangOpts().MSVCCompat &&
11507 CurContext->isDependentContext() && !isSFINAEContext() &&
11508 (isa<FunctionDecl>(CurContext) || isa<CXXRecordDecl>(CurContext))) {
11510 OverloadCandidateSet::iterator Best;
11511 if (CandidateSet->empty() ||
11512 CandidateSet->BestViableFunction(*this, Fn->getLocStart(), Best) ==
11513 OR_No_Viable_Function) {
11514 // In Microsoft mode, if we are inside a template class member function then
11515 // create a type dependent CallExpr. The goal is to postpone name lookup
11516 // to instantiation time to be able to search into type dependent base
11518 CallExpr *CE = new (Context) CallExpr(
11519 Context, Fn, Args, Context.DependentTy, VK_RValue, RParenLoc);
11520 CE->setTypeDependent(true);
11521 CE->setValueDependent(true);
11522 CE->setInstantiationDependent(true);
11528 if (CandidateSet->empty())
11531 UnbridgedCasts.restore();
11535 /// FinishOverloadedCallExpr - given an OverloadCandidateSet, builds and returns
11536 /// the completed call expression. If overload resolution fails, emits
11537 /// diagnostics and returns ExprError()
11538 static ExprResult FinishOverloadedCallExpr(Sema &SemaRef, Scope *S, Expr *Fn,
11539 UnresolvedLookupExpr *ULE,
11540 SourceLocation LParenLoc,
11542 SourceLocation RParenLoc,
11544 OverloadCandidateSet *CandidateSet,
11545 OverloadCandidateSet::iterator *Best,
11546 OverloadingResult OverloadResult,
11547 bool AllowTypoCorrection) {
11548 if (CandidateSet->empty())
11549 return BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc, Args,
11550 RParenLoc, /*EmptyLookup=*/true,
11551 AllowTypoCorrection);
11553 switch (OverloadResult) {
11555 FunctionDecl *FDecl = (*Best)->Function;
11556 SemaRef.CheckUnresolvedLookupAccess(ULE, (*Best)->FoundDecl);
11557 if (SemaRef.DiagnoseUseOfDecl(FDecl, ULE->getNameLoc()))
11558 return ExprError();
11559 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl);
11560 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, RParenLoc,
11564 case OR_No_Viable_Function: {
11565 // Try to recover by looking for viable functions which the user might
11566 // have meant to call.
11567 ExprResult Recovery = BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc,
11569 /*EmptyLookup=*/false,
11570 AllowTypoCorrection);
11571 if (!Recovery.isInvalid())
11574 // If the user passes in a function that we can't take the address of, we
11575 // generally end up emitting really bad error messages. Here, we attempt to
11576 // emit better ones.
11577 for (const Expr *Arg : Args) {
11578 if (!Arg->getType()->isFunctionType())
11580 if (auto *DRE = dyn_cast<DeclRefExpr>(Arg->IgnoreParenImpCasts())) {
11581 auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl());
11583 !SemaRef.checkAddressOfFunctionIsAvailable(FD, /*Complain=*/true,
11584 Arg->getExprLoc()))
11585 return ExprError();
11589 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_no_viable_function_in_call)
11590 << ULE->getName() << Fn->getSourceRange();
11591 CandidateSet->NoteCandidates(SemaRef, OCD_AllCandidates, Args);
11596 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_ambiguous_call)
11597 << ULE->getName() << Fn->getSourceRange();
11598 CandidateSet->NoteCandidates(SemaRef, OCD_ViableCandidates, Args);
11602 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_deleted_call)
11603 << (*Best)->Function->isDeleted()
11605 << SemaRef.getDeletedOrUnavailableSuffix((*Best)->Function)
11606 << Fn->getSourceRange();
11607 CandidateSet->NoteCandidates(SemaRef, OCD_AllCandidates, Args);
11609 // We emitted an error for the unvailable/deleted function call but keep
11610 // the call in the AST.
11611 FunctionDecl *FDecl = (*Best)->Function;
11612 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl);
11613 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, RParenLoc,
11618 // Overload resolution failed.
11619 return ExprError();
11622 static void markUnaddressableCandidatesUnviable(Sema &S,
11623 OverloadCandidateSet &CS) {
11624 for (auto I = CS.begin(), E = CS.end(); I != E; ++I) {
11626 !S.checkAddressOfFunctionIsAvailable(I->Function, /*Complain=*/false)) {
11628 I->FailureKind = ovl_fail_addr_not_available;
11633 /// BuildOverloadedCallExpr - Given the call expression that calls Fn
11634 /// (which eventually refers to the declaration Func) and the call
11635 /// arguments Args/NumArgs, attempt to resolve the function call down
11636 /// to a specific function. If overload resolution succeeds, returns
11637 /// the call expression produced by overload resolution.
11638 /// Otherwise, emits diagnostics and returns ExprError.
11639 ExprResult Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn,
11640 UnresolvedLookupExpr *ULE,
11641 SourceLocation LParenLoc,
11643 SourceLocation RParenLoc,
11645 bool AllowTypoCorrection,
11646 bool CalleesAddressIsTaken) {
11647 OverloadCandidateSet CandidateSet(Fn->getExprLoc(),
11648 OverloadCandidateSet::CSK_Normal);
11651 if (buildOverloadedCallSet(S, Fn, ULE, Args, LParenLoc, &CandidateSet,
11655 // If the user handed us something like `(&Foo)(Bar)`, we need to ensure that
11656 // functions that aren't addressible are considered unviable.
11657 if (CalleesAddressIsTaken)
11658 markUnaddressableCandidatesUnviable(*this, CandidateSet);
11660 OverloadCandidateSet::iterator Best;
11661 OverloadingResult OverloadResult =
11662 CandidateSet.BestViableFunction(*this, Fn->getLocStart(), Best);
11664 return FinishOverloadedCallExpr(*this, S, Fn, ULE, LParenLoc, Args,
11665 RParenLoc, ExecConfig, &CandidateSet,
11666 &Best, OverloadResult,
11667 AllowTypoCorrection);
11670 static bool IsOverloaded(const UnresolvedSetImpl &Functions) {
11671 return Functions.size() > 1 ||
11672 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin()));
11675 /// \brief Create a unary operation that may resolve to an overloaded
11678 /// \param OpLoc The location of the operator itself (e.g., '*').
11680 /// \param Opc The UnaryOperatorKind that describes this operator.
11682 /// \param Fns The set of non-member functions that will be
11683 /// considered by overload resolution. The caller needs to build this
11684 /// set based on the context using, e.g.,
11685 /// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This
11686 /// set should not contain any member functions; those will be added
11687 /// by CreateOverloadedUnaryOp().
11689 /// \param Input The input argument.
11691 Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, UnaryOperatorKind Opc,
11692 const UnresolvedSetImpl &Fns,
11694 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc);
11695 assert(Op != OO_None && "Invalid opcode for overloaded unary operator");
11696 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
11697 // TODO: provide better source location info.
11698 DeclarationNameInfo OpNameInfo(OpName, OpLoc);
11700 if (checkPlaceholderForOverload(*this, Input))
11701 return ExprError();
11703 Expr *Args[2] = { Input, nullptr };
11704 unsigned NumArgs = 1;
11706 // For post-increment and post-decrement, add the implicit '0' as
11707 // the second argument, so that we know this is a post-increment or
11709 if (Opc == UO_PostInc || Opc == UO_PostDec) {
11710 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false);
11711 Args[1] = IntegerLiteral::Create(Context, Zero, Context.IntTy,
11716 ArrayRef<Expr *> ArgsArray(Args, NumArgs);
11718 if (Input->isTypeDependent()) {
11720 return new (Context) UnaryOperator(Input, Opc, Context.DependentTy,
11721 VK_RValue, OK_Ordinary, OpLoc);
11723 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
11724 UnresolvedLookupExpr *Fn
11725 = UnresolvedLookupExpr::Create(Context, NamingClass,
11726 NestedNameSpecifierLoc(), OpNameInfo,
11727 /*ADL*/ true, IsOverloaded(Fns),
11728 Fns.begin(), Fns.end());
11729 return new (Context)
11730 CXXOperatorCallExpr(Context, Op, Fn, ArgsArray, Context.DependentTy,
11731 VK_RValue, OpLoc, false);
11734 // Build an empty overload set.
11735 OverloadCandidateSet CandidateSet(OpLoc, OverloadCandidateSet::CSK_Operator);
11737 // Add the candidates from the given function set.
11738 AddFunctionCandidates(Fns, ArgsArray, CandidateSet);
11740 // Add operator candidates that are member functions.
11741 AddMemberOperatorCandidates(Op, OpLoc, ArgsArray, CandidateSet);
11743 // Add candidates from ADL.
11744 AddArgumentDependentLookupCandidates(OpName, OpLoc, ArgsArray,
11745 /*ExplicitTemplateArgs*/nullptr,
11748 // Add builtin operator candidates.
11749 AddBuiltinOperatorCandidates(Op, OpLoc, ArgsArray, CandidateSet);
11751 bool HadMultipleCandidates = (CandidateSet.size() > 1);
11753 // Perform overload resolution.
11754 OverloadCandidateSet::iterator Best;
11755 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
11757 // We found a built-in operator or an overloaded operator.
11758 FunctionDecl *FnDecl = Best->Function;
11761 // We matched an overloaded operator. Build a call to that
11764 // Convert the arguments.
11765 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) {
11766 CheckMemberOperatorAccess(OpLoc, Args[0], nullptr, Best->FoundDecl);
11768 ExprResult InputRes =
11769 PerformObjectArgumentInitialization(Input, /*Qualifier=*/nullptr,
11770 Best->FoundDecl, Method);
11771 if (InputRes.isInvalid())
11772 return ExprError();
11773 Input = InputRes.get();
11775 // Convert the arguments.
11776 ExprResult InputInit
11777 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
11779 FnDecl->getParamDecl(0)),
11782 if (InputInit.isInvalid())
11783 return ExprError();
11784 Input = InputInit.get();
11787 // Build the actual expression node.
11788 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, Best->FoundDecl,
11789 HadMultipleCandidates, OpLoc);
11790 if (FnExpr.isInvalid())
11791 return ExprError();
11793 // Determine the result type.
11794 QualType ResultTy = FnDecl->getReturnType();
11795 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
11796 ResultTy = ResultTy.getNonLValueExprType(Context);
11799 CallExpr *TheCall =
11800 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.get(), ArgsArray,
11801 ResultTy, VK, OpLoc, false);
11803 if (CheckCallReturnType(FnDecl->getReturnType(), OpLoc, TheCall, FnDecl))
11804 return ExprError();
11806 return MaybeBindToTemporary(TheCall);
11808 // We matched a built-in operator. Convert the arguments, then
11809 // break out so that we will build the appropriate built-in
11811 ExprResult InputRes =
11812 PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0],
11813 Best->Conversions[0], AA_Passing);
11814 if (InputRes.isInvalid())
11815 return ExprError();
11816 Input = InputRes.get();
11821 case OR_No_Viable_Function:
11822 // This is an erroneous use of an operator which can be overloaded by
11823 // a non-member function. Check for non-member operators which were
11824 // defined too late to be candidates.
11825 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, ArgsArray))
11826 // FIXME: Recover by calling the found function.
11827 return ExprError();
11829 // No viable function; fall through to handling this as a
11830 // built-in operator, which will produce an error message for us.
11834 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary)
11835 << UnaryOperator::getOpcodeStr(Opc)
11836 << Input->getType()
11837 << Input->getSourceRange();
11838 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, ArgsArray,
11839 UnaryOperator::getOpcodeStr(Opc), OpLoc);
11840 return ExprError();
11843 Diag(OpLoc, diag::err_ovl_deleted_oper)
11844 << Best->Function->isDeleted()
11845 << UnaryOperator::getOpcodeStr(Opc)
11846 << getDeletedOrUnavailableSuffix(Best->Function)
11847 << Input->getSourceRange();
11848 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, ArgsArray,
11849 UnaryOperator::getOpcodeStr(Opc), OpLoc);
11850 return ExprError();
11853 // Either we found no viable overloaded operator or we matched a
11854 // built-in operator. In either case, fall through to trying to
11855 // build a built-in operation.
11856 return CreateBuiltinUnaryOp(OpLoc, Opc, Input);
11859 /// \brief Create a binary operation that may resolve to an overloaded
11862 /// \param OpLoc The location of the operator itself (e.g., '+').
11864 /// \param Opc The BinaryOperatorKind that describes this operator.
11866 /// \param Fns The set of non-member functions that will be
11867 /// considered by overload resolution. The caller needs to build this
11868 /// set based on the context using, e.g.,
11869 /// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This
11870 /// set should not contain any member functions; those will be added
11871 /// by CreateOverloadedBinOp().
11873 /// \param LHS Left-hand argument.
11874 /// \param RHS Right-hand argument.
11876 Sema::CreateOverloadedBinOp(SourceLocation OpLoc,
11877 BinaryOperatorKind Opc,
11878 const UnresolvedSetImpl &Fns,
11879 Expr *LHS, Expr *RHS) {
11880 Expr *Args[2] = { LHS, RHS };
11881 LHS=RHS=nullptr; // Please use only Args instead of LHS/RHS couple
11883 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc);
11884 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
11886 // If either side is type-dependent, create an appropriate dependent
11888 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) {
11890 // If there are no functions to store, just build a dependent
11891 // BinaryOperator or CompoundAssignment.
11892 if (Opc <= BO_Assign || Opc > BO_OrAssign)
11893 return new (Context) BinaryOperator(
11894 Args[0], Args[1], Opc, Context.DependentTy, VK_RValue, OK_Ordinary,
11895 OpLoc, FPFeatures.fp_contract);
11897 return new (Context) CompoundAssignOperator(
11898 Args[0], Args[1], Opc, Context.DependentTy, VK_LValue, OK_Ordinary,
11899 Context.DependentTy, Context.DependentTy, OpLoc,
11900 FPFeatures.fp_contract);
11903 // FIXME: save results of ADL from here?
11904 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
11905 // TODO: provide better source location info in DNLoc component.
11906 DeclarationNameInfo OpNameInfo(OpName, OpLoc);
11907 UnresolvedLookupExpr *Fn
11908 = UnresolvedLookupExpr::Create(Context, NamingClass,
11909 NestedNameSpecifierLoc(), OpNameInfo,
11910 /*ADL*/ true, IsOverloaded(Fns),
11911 Fns.begin(), Fns.end());
11912 return new (Context)
11913 CXXOperatorCallExpr(Context, Op, Fn, Args, Context.DependentTy,
11914 VK_RValue, OpLoc, FPFeatures.fp_contract);
11917 // Always do placeholder-like conversions on the RHS.
11918 if (checkPlaceholderForOverload(*this, Args[1]))
11919 return ExprError();
11921 // Do placeholder-like conversion on the LHS; note that we should
11922 // not get here with a PseudoObject LHS.
11923 assert(Args[0]->getObjectKind() != OK_ObjCProperty);
11924 if (checkPlaceholderForOverload(*this, Args[0]))
11925 return ExprError();
11927 // If this is the assignment operator, we only perform overload resolution
11928 // if the left-hand side is a class or enumeration type. This is actually
11929 // a hack. The standard requires that we do overload resolution between the
11930 // various built-in candidates, but as DR507 points out, this can lead to
11931 // problems. So we do it this way, which pretty much follows what GCC does.
11932 // Note that we go the traditional code path for compound assignment forms.
11933 if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType())
11934 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
11936 // If this is the .* operator, which is not overloadable, just
11937 // create a built-in binary operator.
11938 if (Opc == BO_PtrMemD)
11939 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
11941 // Build an empty overload set.
11942 OverloadCandidateSet CandidateSet(OpLoc, OverloadCandidateSet::CSK_Operator);
11944 // Add the candidates from the given function set.
11945 AddFunctionCandidates(Fns, Args, CandidateSet);
11947 // Add operator candidates that are member functions.
11948 AddMemberOperatorCandidates(Op, OpLoc, Args, CandidateSet);
11950 // Add candidates from ADL. Per [over.match.oper]p2, this lookup is not
11951 // performed for an assignment operator (nor for operator[] nor operator->,
11952 // which don't get here).
11953 if (Opc != BO_Assign)
11954 AddArgumentDependentLookupCandidates(OpName, OpLoc, Args,
11955 /*ExplicitTemplateArgs*/ nullptr,
11958 // Add builtin operator candidates.
11959 AddBuiltinOperatorCandidates(Op, OpLoc, Args, CandidateSet);
11961 bool HadMultipleCandidates = (CandidateSet.size() > 1);
11963 // Perform overload resolution.
11964 OverloadCandidateSet::iterator Best;
11965 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
11967 // We found a built-in operator or an overloaded operator.
11968 FunctionDecl *FnDecl = Best->Function;
11971 // We matched an overloaded operator. Build a call to that
11974 // Convert the arguments.
11975 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) {
11976 // Best->Access is only meaningful for class members.
11977 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl);
11980 PerformCopyInitialization(
11981 InitializedEntity::InitializeParameter(Context,
11982 FnDecl->getParamDecl(0)),
11983 SourceLocation(), Args[1]);
11984 if (Arg1.isInvalid())
11985 return ExprError();
11988 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/nullptr,
11989 Best->FoundDecl, Method);
11990 if (Arg0.isInvalid())
11991 return ExprError();
11992 Args[0] = Arg0.getAs<Expr>();
11993 Args[1] = RHS = Arg1.getAs<Expr>();
11995 // Convert the arguments.
11996 ExprResult Arg0 = PerformCopyInitialization(
11997 InitializedEntity::InitializeParameter(Context,
11998 FnDecl->getParamDecl(0)),
11999 SourceLocation(), Args[0]);
12000 if (Arg0.isInvalid())
12001 return ExprError();
12004 PerformCopyInitialization(
12005 InitializedEntity::InitializeParameter(Context,
12006 FnDecl->getParamDecl(1)),
12007 SourceLocation(), Args[1]);
12008 if (Arg1.isInvalid())
12009 return ExprError();
12010 Args[0] = LHS = Arg0.getAs<Expr>();
12011 Args[1] = RHS = Arg1.getAs<Expr>();
12014 // Build the actual expression node.
12015 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl,
12017 HadMultipleCandidates, OpLoc);
12018 if (FnExpr.isInvalid())
12019 return ExprError();
12021 // Determine the result type.
12022 QualType ResultTy = FnDecl->getReturnType();
12023 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
12024 ResultTy = ResultTy.getNonLValueExprType(Context);
12026 CXXOperatorCallExpr *TheCall =
12027 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.get(),
12028 Args, ResultTy, VK, OpLoc,
12029 FPFeatures.fp_contract);
12031 if (CheckCallReturnType(FnDecl->getReturnType(), OpLoc, TheCall,
12033 return ExprError();
12035 ArrayRef<const Expr *> ArgsArray(Args, 2);
12036 // Cut off the implicit 'this'.
12037 if (isa<CXXMethodDecl>(FnDecl))
12038 ArgsArray = ArgsArray.slice(1);
12040 // Check for a self move.
12041 if (Op == OO_Equal)
12042 DiagnoseSelfMove(Args[0], Args[1], OpLoc);
12044 checkCall(FnDecl, nullptr, ArgsArray, isa<CXXMethodDecl>(FnDecl), OpLoc,
12045 TheCall->getSourceRange(), VariadicDoesNotApply);
12047 return MaybeBindToTemporary(TheCall);
12049 // We matched a built-in operator. Convert the arguments, then
12050 // break out so that we will build the appropriate built-in
12052 ExprResult ArgsRes0 =
12053 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0],
12054 Best->Conversions[0], AA_Passing);
12055 if (ArgsRes0.isInvalid())
12056 return ExprError();
12057 Args[0] = ArgsRes0.get();
12059 ExprResult ArgsRes1 =
12060 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1],
12061 Best->Conversions[1], AA_Passing);
12062 if (ArgsRes1.isInvalid())
12063 return ExprError();
12064 Args[1] = ArgsRes1.get();
12069 case OR_No_Viable_Function: {
12070 // C++ [over.match.oper]p9:
12071 // If the operator is the operator , [...] and there are no
12072 // viable functions, then the operator is assumed to be the
12073 // built-in operator and interpreted according to clause 5.
12074 if (Opc == BO_Comma)
12077 // For class as left operand for assignment or compound assigment
12078 // operator do not fall through to handling in built-in, but report that
12079 // no overloaded assignment operator found
12080 ExprResult Result = ExprError();
12081 if (Args[0]->getType()->isRecordType() &&
12082 Opc >= BO_Assign && Opc <= BO_OrAssign) {
12083 Diag(OpLoc, diag::err_ovl_no_viable_oper)
12084 << BinaryOperator::getOpcodeStr(Opc)
12085 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12086 if (Args[0]->getType()->isIncompleteType()) {
12087 Diag(OpLoc, diag::note_assign_lhs_incomplete)
12088 << Args[0]->getType()
12089 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12092 // This is an erroneous use of an operator which can be overloaded by
12093 // a non-member function. Check for non-member operators which were
12094 // defined too late to be candidates.
12095 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, Args))
12096 // FIXME: Recover by calling the found function.
12097 return ExprError();
12099 // No viable function; try to create a built-in operation, which will
12100 // produce an error. Then, show the non-viable candidates.
12101 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
12103 assert(Result.isInvalid() &&
12104 "C++ binary operator overloading is missing candidates!");
12105 if (Result.isInvalid())
12106 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args,
12107 BinaryOperator::getOpcodeStr(Opc), OpLoc);
12112 Diag(OpLoc, diag::err_ovl_ambiguous_oper_binary)
12113 << BinaryOperator::getOpcodeStr(Opc)
12114 << Args[0]->getType() << Args[1]->getType()
12115 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12116 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args,
12117 BinaryOperator::getOpcodeStr(Opc), OpLoc);
12118 return ExprError();
12121 if (isImplicitlyDeleted(Best->Function)) {
12122 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
12123 Diag(OpLoc, diag::err_ovl_deleted_special_oper)
12124 << Context.getRecordType(Method->getParent())
12125 << getSpecialMember(Method);
12127 // The user probably meant to call this special member. Just
12128 // explain why it's deleted.
12129 NoteDeletedFunction(Method);
12130 return ExprError();
12132 Diag(OpLoc, diag::err_ovl_deleted_oper)
12133 << Best->Function->isDeleted()
12134 << BinaryOperator::getOpcodeStr(Opc)
12135 << getDeletedOrUnavailableSuffix(Best->Function)
12136 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12138 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args,
12139 BinaryOperator::getOpcodeStr(Opc), OpLoc);
12140 return ExprError();
12143 // We matched a built-in operator; build it.
12144 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
12148 Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc,
12149 SourceLocation RLoc,
12150 Expr *Base, Expr *Idx) {
12151 Expr *Args[2] = { Base, Idx };
12152 DeclarationName OpName =
12153 Context.DeclarationNames.getCXXOperatorName(OO_Subscript);
12155 // If either side is type-dependent, create an appropriate dependent
12157 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) {
12159 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
12160 // CHECKME: no 'operator' keyword?
12161 DeclarationNameInfo OpNameInfo(OpName, LLoc);
12162 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc));
12163 UnresolvedLookupExpr *Fn
12164 = UnresolvedLookupExpr::Create(Context, NamingClass,
12165 NestedNameSpecifierLoc(), OpNameInfo,
12166 /*ADL*/ true, /*Overloaded*/ false,
12167 UnresolvedSetIterator(),
12168 UnresolvedSetIterator());
12169 // Can't add any actual overloads yet
12171 return new (Context)
12172 CXXOperatorCallExpr(Context, OO_Subscript, Fn, Args,
12173 Context.DependentTy, VK_RValue, RLoc, false);
12176 // Handle placeholders on both operands.
12177 if (checkPlaceholderForOverload(*this, Args[0]))
12178 return ExprError();
12179 if (checkPlaceholderForOverload(*this, Args[1]))
12180 return ExprError();
12182 // Build an empty overload set.
12183 OverloadCandidateSet CandidateSet(LLoc, OverloadCandidateSet::CSK_Operator);
12185 // Subscript can only be overloaded as a member function.
12187 // Add operator candidates that are member functions.
12188 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, CandidateSet);
12190 // Add builtin operator candidates.
12191 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, CandidateSet);
12193 bool HadMultipleCandidates = (CandidateSet.size() > 1);
12195 // Perform overload resolution.
12196 OverloadCandidateSet::iterator Best;
12197 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) {
12199 // We found a built-in operator or an overloaded operator.
12200 FunctionDecl *FnDecl = Best->Function;
12203 // We matched an overloaded operator. Build a call to that
12206 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl);
12208 // Convert the arguments.
12209 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl);
12211 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/nullptr,
12212 Best->FoundDecl, Method);
12213 if (Arg0.isInvalid())
12214 return ExprError();
12215 Args[0] = Arg0.get();
12217 // Convert the arguments.
12218 ExprResult InputInit
12219 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
12221 FnDecl->getParamDecl(0)),
12224 if (InputInit.isInvalid())
12225 return ExprError();
12227 Args[1] = InputInit.getAs<Expr>();
12229 // Build the actual expression node.
12230 DeclarationNameInfo OpLocInfo(OpName, LLoc);
12231 OpLocInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc));
12232 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl,
12234 HadMultipleCandidates,
12235 OpLocInfo.getLoc(),
12236 OpLocInfo.getInfo());
12237 if (FnExpr.isInvalid())
12238 return ExprError();
12240 // Determine the result type
12241 QualType ResultTy = FnDecl->getReturnType();
12242 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
12243 ResultTy = ResultTy.getNonLValueExprType(Context);
12245 CXXOperatorCallExpr *TheCall =
12246 new (Context) CXXOperatorCallExpr(Context, OO_Subscript,
12247 FnExpr.get(), Args,
12248 ResultTy, VK, RLoc,
12251 if (CheckCallReturnType(FnDecl->getReturnType(), LLoc, TheCall, FnDecl))
12252 return ExprError();
12254 return MaybeBindToTemporary(TheCall);
12256 // We matched a built-in operator. Convert the arguments, then
12257 // break out so that we will build the appropriate built-in
12259 ExprResult ArgsRes0 =
12260 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0],
12261 Best->Conversions[0], AA_Passing);
12262 if (ArgsRes0.isInvalid())
12263 return ExprError();
12264 Args[0] = ArgsRes0.get();
12266 ExprResult ArgsRes1 =
12267 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1],
12268 Best->Conversions[1], AA_Passing);
12269 if (ArgsRes1.isInvalid())
12270 return ExprError();
12271 Args[1] = ArgsRes1.get();
12277 case OR_No_Viable_Function: {
12278 if (CandidateSet.empty())
12279 Diag(LLoc, diag::err_ovl_no_oper)
12280 << Args[0]->getType() << /*subscript*/ 0
12281 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12283 Diag(LLoc, diag::err_ovl_no_viable_subscript)
12284 << Args[0]->getType()
12285 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12286 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args,
12288 return ExprError();
12292 Diag(LLoc, diag::err_ovl_ambiguous_oper_binary)
12294 << Args[0]->getType() << Args[1]->getType()
12295 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12296 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args,
12298 return ExprError();
12301 Diag(LLoc, diag::err_ovl_deleted_oper)
12302 << Best->Function->isDeleted() << "[]"
12303 << getDeletedOrUnavailableSuffix(Best->Function)
12304 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12305 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args,
12307 return ExprError();
12310 // We matched a built-in operator; build it.
12311 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc);
12314 /// BuildCallToMemberFunction - Build a call to a member
12315 /// function. MemExpr is the expression that refers to the member
12316 /// function (and includes the object parameter), Args/NumArgs are the
12317 /// arguments to the function call (not including the object
12318 /// parameter). The caller needs to validate that the member
12319 /// expression refers to a non-static member function or an overloaded
12320 /// member function.
12322 Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE,
12323 SourceLocation LParenLoc,
12325 SourceLocation RParenLoc) {
12326 assert(MemExprE->getType() == Context.BoundMemberTy ||
12327 MemExprE->getType() == Context.OverloadTy);
12329 // Dig out the member expression. This holds both the object
12330 // argument and the member function we're referring to.
12331 Expr *NakedMemExpr = MemExprE->IgnoreParens();
12333 // Determine whether this is a call to a pointer-to-member function.
12334 if (BinaryOperator *op = dyn_cast<BinaryOperator>(NakedMemExpr)) {
12335 assert(op->getType() == Context.BoundMemberTy);
12336 assert(op->getOpcode() == BO_PtrMemD || op->getOpcode() == BO_PtrMemI);
12339 op->getRHS()->getType()->castAs<MemberPointerType>()->getPointeeType();
12341 const FunctionProtoType *proto = fnType->castAs<FunctionProtoType>();
12342 QualType resultType = proto->getCallResultType(Context);
12343 ExprValueKind valueKind = Expr::getValueKindForType(proto->getReturnType());
12345 // Check that the object type isn't more qualified than the
12346 // member function we're calling.
12347 Qualifiers funcQuals = Qualifiers::fromCVRMask(proto->getTypeQuals());
12349 QualType objectType = op->getLHS()->getType();
12350 if (op->getOpcode() == BO_PtrMemI)
12351 objectType = objectType->castAs<PointerType>()->getPointeeType();
12352 Qualifiers objectQuals = objectType.getQualifiers();
12354 Qualifiers difference = objectQuals - funcQuals;
12355 difference.removeObjCGCAttr();
12356 difference.removeAddressSpace();
12358 std::string qualsString = difference.getAsString();
12359 Diag(LParenLoc, diag::err_pointer_to_member_call_drops_quals)
12360 << fnType.getUnqualifiedType()
12362 << (qualsString.find(' ') == std::string::npos ? 1 : 2);
12365 CXXMemberCallExpr *call
12366 = new (Context) CXXMemberCallExpr(Context, MemExprE, Args,
12367 resultType, valueKind, RParenLoc);
12369 if (CheckCallReturnType(proto->getReturnType(), op->getRHS()->getLocStart(),
12371 return ExprError();
12373 if (ConvertArgumentsForCall(call, op, nullptr, proto, Args, RParenLoc))
12374 return ExprError();
12376 if (CheckOtherCall(call, proto))
12377 return ExprError();
12379 return MaybeBindToTemporary(call);
12382 if (isa<CXXPseudoDestructorExpr>(NakedMemExpr))
12383 return new (Context)
12384 CallExpr(Context, MemExprE, Args, Context.VoidTy, VK_RValue, RParenLoc);
12386 UnbridgedCastsSet UnbridgedCasts;
12387 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts))
12388 return ExprError();
12390 MemberExpr *MemExpr;
12391 CXXMethodDecl *Method = nullptr;
12392 DeclAccessPair FoundDecl = DeclAccessPair::make(nullptr, AS_public);
12393 NestedNameSpecifier *Qualifier = nullptr;
12394 if (isa<MemberExpr>(NakedMemExpr)) {
12395 MemExpr = cast<MemberExpr>(NakedMemExpr);
12396 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl());
12397 FoundDecl = MemExpr->getFoundDecl();
12398 Qualifier = MemExpr->getQualifier();
12399 UnbridgedCasts.restore();
12401 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr);
12402 Qualifier = UnresExpr->getQualifier();
12404 QualType ObjectType = UnresExpr->getBaseType();
12405 Expr::Classification ObjectClassification
12406 = UnresExpr->isArrow()? Expr::Classification::makeSimpleLValue()
12407 : UnresExpr->getBase()->Classify(Context);
12409 // Add overload candidates
12410 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc(),
12411 OverloadCandidateSet::CSK_Normal);
12413 // FIXME: avoid copy.
12414 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
12415 if (UnresExpr->hasExplicitTemplateArgs()) {
12416 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer);
12417 TemplateArgs = &TemplateArgsBuffer;
12420 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(),
12421 E = UnresExpr->decls_end(); I != E; ++I) {
12423 NamedDecl *Func = *I;
12424 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext());
12425 if (isa<UsingShadowDecl>(Func))
12426 Func = cast<UsingShadowDecl>(Func)->getTargetDecl();
12429 // Microsoft supports direct constructor calls.
12430 if (getLangOpts().MicrosoftExt && isa<CXXConstructorDecl>(Func)) {
12431 AddOverloadCandidate(cast<CXXConstructorDecl>(Func), I.getPair(),
12432 Args, CandidateSet);
12433 } else if ((Method = dyn_cast<CXXMethodDecl>(Func))) {
12434 // If explicit template arguments were provided, we can't call a
12435 // non-template member function.
12439 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType,
12440 ObjectClassification, Args, CandidateSet,
12441 /*SuppressUserConversions=*/false);
12443 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func),
12444 I.getPair(), ActingDC, TemplateArgs,
12445 ObjectType, ObjectClassification,
12446 Args, CandidateSet,
12447 /*SuppressUsedConversions=*/false);
12451 DeclarationName DeclName = UnresExpr->getMemberName();
12453 UnbridgedCasts.restore();
12455 OverloadCandidateSet::iterator Best;
12456 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getLocStart(),
12459 Method = cast<CXXMethodDecl>(Best->Function);
12460 FoundDecl = Best->FoundDecl;
12461 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl);
12462 if (DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()))
12463 return ExprError();
12464 // If FoundDecl is different from Method (such as if one is a template
12465 // and the other a specialization), make sure DiagnoseUseOfDecl is
12467 // FIXME: This would be more comprehensively addressed by modifying
12468 // DiagnoseUseOfDecl to accept both the FoundDecl and the decl
12470 if (Method != FoundDecl.getDecl() &&
12471 DiagnoseUseOfDecl(Method, UnresExpr->getNameLoc()))
12472 return ExprError();
12475 case OR_No_Viable_Function:
12476 Diag(UnresExpr->getMemberLoc(),
12477 diag::err_ovl_no_viable_member_function_in_call)
12478 << DeclName << MemExprE->getSourceRange();
12479 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
12480 // FIXME: Leaking incoming expressions!
12481 return ExprError();
12484 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call)
12485 << DeclName << MemExprE->getSourceRange();
12486 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
12487 // FIXME: Leaking incoming expressions!
12488 return ExprError();
12491 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call)
12492 << Best->Function->isDeleted()
12494 << getDeletedOrUnavailableSuffix(Best->Function)
12495 << MemExprE->getSourceRange();
12496 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
12497 // FIXME: Leaking incoming expressions!
12498 return ExprError();
12501 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method);
12503 // If overload resolution picked a static member, build a
12504 // non-member call based on that function.
12505 if (Method->isStatic()) {
12506 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, Args,
12510 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens());
12513 QualType ResultType = Method->getReturnType();
12514 ExprValueKind VK = Expr::getValueKindForType(ResultType);
12515 ResultType = ResultType.getNonLValueExprType(Context);
12517 assert(Method && "Member call to something that isn't a method?");
12518 CXXMemberCallExpr *TheCall =
12519 new (Context) CXXMemberCallExpr(Context, MemExprE, Args,
12520 ResultType, VK, RParenLoc);
12522 // Check for a valid return type.
12523 if (CheckCallReturnType(Method->getReturnType(), MemExpr->getMemberLoc(),
12525 return ExprError();
12527 // Convert the object argument (for a non-static member function call).
12528 // We only need to do this if there was actually an overload; otherwise
12529 // it was done at lookup.
12530 if (!Method->isStatic()) {
12531 ExprResult ObjectArg =
12532 PerformObjectArgumentInitialization(MemExpr->getBase(), Qualifier,
12533 FoundDecl, Method);
12534 if (ObjectArg.isInvalid())
12535 return ExprError();
12536 MemExpr->setBase(ObjectArg.get());
12539 // Convert the rest of the arguments
12540 const FunctionProtoType *Proto =
12541 Method->getType()->getAs<FunctionProtoType>();
12542 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args,
12544 return ExprError();
12546 DiagnoseSentinelCalls(Method, LParenLoc, Args);
12548 if (CheckFunctionCall(Method, TheCall, Proto))
12549 return ExprError();
12551 // In the case the method to call was not selected by the overloading
12552 // resolution process, we still need to handle the enable_if attribute. Do
12553 // that here, so it will not hide previous -- and more relevant -- errors.
12554 if (auto *MemE = dyn_cast<MemberExpr>(NakedMemExpr)) {
12555 if (const EnableIfAttr *Attr = CheckEnableIf(Method, Args, true)) {
12556 Diag(MemE->getMemberLoc(),
12557 diag::err_ovl_no_viable_member_function_in_call)
12558 << Method << Method->getSourceRange();
12559 Diag(Method->getLocation(),
12560 diag::note_ovl_candidate_disabled_by_enable_if_attr)
12561 << Attr->getCond()->getSourceRange() << Attr->getMessage();
12562 return ExprError();
12566 if ((isa<CXXConstructorDecl>(CurContext) ||
12567 isa<CXXDestructorDecl>(CurContext)) &&
12568 TheCall->getMethodDecl()->isPure()) {
12569 const CXXMethodDecl *MD = TheCall->getMethodDecl();
12571 if (isa<CXXThisExpr>(MemExpr->getBase()->IgnoreParenCasts()) &&
12572 MemExpr->performsVirtualDispatch(getLangOpts())) {
12573 Diag(MemExpr->getLocStart(),
12574 diag::warn_call_to_pure_virtual_member_function_from_ctor_dtor)
12575 << MD->getDeclName() << isa<CXXDestructorDecl>(CurContext)
12576 << MD->getParent()->getDeclName();
12578 Diag(MD->getLocStart(), diag::note_previous_decl) << MD->getDeclName();
12579 if (getLangOpts().AppleKext)
12580 Diag(MemExpr->getLocStart(),
12581 diag::note_pure_qualified_call_kext)
12582 << MD->getParent()->getDeclName()
12583 << MD->getDeclName();
12587 if (CXXDestructorDecl *DD =
12588 dyn_cast<CXXDestructorDecl>(TheCall->getMethodDecl())) {
12589 // a->A::f() doesn't go through the vtable, except in AppleKext mode.
12590 bool CallCanBeVirtual = !MemExpr->hasQualifier() || getLangOpts().AppleKext;
12591 CheckVirtualDtorCall(DD, MemExpr->getLocStart(), /*IsDelete=*/false,
12592 CallCanBeVirtual, /*WarnOnNonAbstractTypes=*/true,
12593 MemExpr->getMemberLoc());
12596 return MaybeBindToTemporary(TheCall);
12599 /// BuildCallToObjectOfClassType - Build a call to an object of class
12600 /// type (C++ [over.call.object]), which can end up invoking an
12601 /// overloaded function call operator (@c operator()) or performing a
12602 /// user-defined conversion on the object argument.
12604 Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj,
12605 SourceLocation LParenLoc,
12607 SourceLocation RParenLoc) {
12608 if (checkPlaceholderForOverload(*this, Obj))
12609 return ExprError();
12610 ExprResult Object = Obj;
12612 UnbridgedCastsSet UnbridgedCasts;
12613 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts))
12614 return ExprError();
12616 assert(Object.get()->getType()->isRecordType() &&
12617 "Requires object type argument");
12618 const RecordType *Record = Object.get()->getType()->getAs<RecordType>();
12620 // C++ [over.call.object]p1:
12621 // If the primary-expression E in the function call syntax
12622 // evaluates to a class object of type "cv T", then the set of
12623 // candidate functions includes at least the function call
12624 // operators of T. The function call operators of T are obtained by
12625 // ordinary lookup of the name operator() in the context of
12627 OverloadCandidateSet CandidateSet(LParenLoc,
12628 OverloadCandidateSet::CSK_Operator);
12629 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call);
12631 if (RequireCompleteType(LParenLoc, Object.get()->getType(),
12632 diag::err_incomplete_object_call, Object.get()))
12635 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName);
12636 LookupQualifiedName(R, Record->getDecl());
12637 R.suppressDiagnostics();
12639 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end();
12640 Oper != OperEnd; ++Oper) {
12641 AddMethodCandidate(Oper.getPair(), Object.get()->getType(),
12642 Object.get()->Classify(Context),
12643 Args, CandidateSet,
12644 /*SuppressUserConversions=*/ false);
12647 // C++ [over.call.object]p2:
12648 // In addition, for each (non-explicit in C++0x) conversion function
12649 // declared in T of the form
12651 // operator conversion-type-id () cv-qualifier;
12653 // where cv-qualifier is the same cv-qualification as, or a
12654 // greater cv-qualification than, cv, and where conversion-type-id
12655 // denotes the type "pointer to function of (P1,...,Pn) returning
12656 // R", or the type "reference to pointer to function of
12657 // (P1,...,Pn) returning R", or the type "reference to function
12658 // of (P1,...,Pn) returning R", a surrogate call function [...]
12659 // is also considered as a candidate function. Similarly,
12660 // surrogate call functions are added to the set of candidate
12661 // functions for each conversion function declared in an
12662 // accessible base class provided the function is not hidden
12663 // within T by another intervening declaration.
12664 const auto &Conversions =
12665 cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions();
12666 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
12668 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
12669 if (isa<UsingShadowDecl>(D))
12670 D = cast<UsingShadowDecl>(D)->getTargetDecl();
12672 // Skip over templated conversion functions; they aren't
12674 if (isa<FunctionTemplateDecl>(D))
12677 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D);
12678 if (!Conv->isExplicit()) {
12679 // Strip the reference type (if any) and then the pointer type (if
12680 // any) to get down to what might be a function type.
12681 QualType ConvType = Conv->getConversionType().getNonReferenceType();
12682 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
12683 ConvType = ConvPtrType->getPointeeType();
12685 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>())
12687 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto,
12688 Object.get(), Args, CandidateSet);
12693 bool HadMultipleCandidates = (CandidateSet.size() > 1);
12695 // Perform overload resolution.
12696 OverloadCandidateSet::iterator Best;
12697 switch (CandidateSet.BestViableFunction(*this, Object.get()->getLocStart(),
12700 // Overload resolution succeeded; we'll build the appropriate call
12704 case OR_No_Viable_Function:
12705 if (CandidateSet.empty())
12706 Diag(Object.get()->getLocStart(), diag::err_ovl_no_oper)
12707 << Object.get()->getType() << /*call*/ 1
12708 << Object.get()->getSourceRange();
12710 Diag(Object.get()->getLocStart(),
12711 diag::err_ovl_no_viable_object_call)
12712 << Object.get()->getType() << Object.get()->getSourceRange();
12713 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
12717 Diag(Object.get()->getLocStart(),
12718 diag::err_ovl_ambiguous_object_call)
12719 << Object.get()->getType() << Object.get()->getSourceRange();
12720 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args);
12724 Diag(Object.get()->getLocStart(),
12725 diag::err_ovl_deleted_object_call)
12726 << Best->Function->isDeleted()
12727 << Object.get()->getType()
12728 << getDeletedOrUnavailableSuffix(Best->Function)
12729 << Object.get()->getSourceRange();
12730 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
12734 if (Best == CandidateSet.end())
12737 UnbridgedCasts.restore();
12739 if (Best->Function == nullptr) {
12740 // Since there is no function declaration, this is one of the
12741 // surrogate candidates. Dig out the conversion function.
12742 CXXConversionDecl *Conv
12743 = cast<CXXConversionDecl>(
12744 Best->Conversions[0].UserDefined.ConversionFunction);
12746 CheckMemberOperatorAccess(LParenLoc, Object.get(), nullptr,
12748 if (DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc))
12749 return ExprError();
12750 assert(Conv == Best->FoundDecl.getDecl() &&
12751 "Found Decl & conversion-to-functionptr should be same, right?!");
12752 // We selected one of the surrogate functions that converts the
12753 // object parameter to a function pointer. Perform the conversion
12754 // on the object argument, then let ActOnCallExpr finish the job.
12756 // Create an implicit member expr to refer to the conversion operator.
12757 // and then call it.
12758 ExprResult Call = BuildCXXMemberCallExpr(Object.get(), Best->FoundDecl,
12759 Conv, HadMultipleCandidates);
12760 if (Call.isInvalid())
12761 return ExprError();
12762 // Record usage of conversion in an implicit cast.
12763 Call = ImplicitCastExpr::Create(Context, Call.get()->getType(),
12764 CK_UserDefinedConversion, Call.get(),
12765 nullptr, VK_RValue);
12767 return ActOnCallExpr(S, Call.get(), LParenLoc, Args, RParenLoc);
12770 CheckMemberOperatorAccess(LParenLoc, Object.get(), nullptr, Best->FoundDecl);
12772 // We found an overloaded operator(). Build a CXXOperatorCallExpr
12773 // that calls this method, using Object for the implicit object
12774 // parameter and passing along the remaining arguments.
12775 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
12777 // An error diagnostic has already been printed when parsing the declaration.
12778 if (Method->isInvalidDecl())
12779 return ExprError();
12781 const FunctionProtoType *Proto =
12782 Method->getType()->getAs<FunctionProtoType>();
12784 unsigned NumParams = Proto->getNumParams();
12786 DeclarationNameInfo OpLocInfo(
12787 Context.DeclarationNames.getCXXOperatorName(OO_Call), LParenLoc);
12788 OpLocInfo.setCXXOperatorNameRange(SourceRange(LParenLoc, RParenLoc));
12789 ExprResult NewFn = CreateFunctionRefExpr(*this, Method, Best->FoundDecl,
12790 HadMultipleCandidates,
12791 OpLocInfo.getLoc(),
12792 OpLocInfo.getInfo());
12793 if (NewFn.isInvalid())
12796 // Build the full argument list for the method call (the implicit object
12797 // parameter is placed at the beginning of the list).
12798 SmallVector<Expr *, 8> MethodArgs(Args.size() + 1);
12799 MethodArgs[0] = Object.get();
12800 std::copy(Args.begin(), Args.end(), MethodArgs.begin() + 1);
12802 // Once we've built TheCall, all of the expressions are properly
12804 QualType ResultTy = Method->getReturnType();
12805 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
12806 ResultTy = ResultTy.getNonLValueExprType(Context);
12808 CXXOperatorCallExpr *TheCall = new (Context)
12809 CXXOperatorCallExpr(Context, OO_Call, NewFn.get(), MethodArgs, ResultTy,
12810 VK, RParenLoc, false);
12812 if (CheckCallReturnType(Method->getReturnType(), LParenLoc, TheCall, Method))
12815 // We may have default arguments. If so, we need to allocate more
12816 // slots in the call for them.
12817 if (Args.size() < NumParams)
12818 TheCall->setNumArgs(Context, NumParams + 1);
12820 bool IsError = false;
12822 // Initialize the implicit object parameter.
12823 ExprResult ObjRes =
12824 PerformObjectArgumentInitialization(Object.get(), /*Qualifier=*/nullptr,
12825 Best->FoundDecl, Method);
12826 if (ObjRes.isInvalid())
12830 TheCall->setArg(0, Object.get());
12832 // Check the argument types.
12833 for (unsigned i = 0; i != NumParams; i++) {
12835 if (i < Args.size()) {
12838 // Pass the argument.
12840 ExprResult InputInit
12841 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
12843 Method->getParamDecl(i)),
12844 SourceLocation(), Arg);
12846 IsError |= InputInit.isInvalid();
12847 Arg = InputInit.getAs<Expr>();
12850 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i));
12851 if (DefArg.isInvalid()) {
12856 Arg = DefArg.getAs<Expr>();
12859 TheCall->setArg(i + 1, Arg);
12862 // If this is a variadic call, handle args passed through "...".
12863 if (Proto->isVariadic()) {
12864 // Promote the arguments (C99 6.5.2.2p7).
12865 for (unsigned i = NumParams, e = Args.size(); i < e; i++) {
12866 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod,
12868 IsError |= Arg.isInvalid();
12869 TheCall->setArg(i + 1, Arg.get());
12873 if (IsError) return true;
12875 DiagnoseSentinelCalls(Method, LParenLoc, Args);
12877 if (CheckFunctionCall(Method, TheCall, Proto))
12880 return MaybeBindToTemporary(TheCall);
12883 /// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator->
12884 /// (if one exists), where @c Base is an expression of class type and
12885 /// @c Member is the name of the member we're trying to find.
12887 Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc,
12888 bool *NoArrowOperatorFound) {
12889 assert(Base->getType()->isRecordType() &&
12890 "left-hand side must have class type");
12892 if (checkPlaceholderForOverload(*this, Base))
12893 return ExprError();
12895 SourceLocation Loc = Base->getExprLoc();
12897 // C++ [over.ref]p1:
12899 // [...] An expression x->m is interpreted as (x.operator->())->m
12900 // for a class object x of type T if T::operator->() exists and if
12901 // the operator is selected as the best match function by the
12902 // overload resolution mechanism (13.3).
12903 DeclarationName OpName =
12904 Context.DeclarationNames.getCXXOperatorName(OO_Arrow);
12905 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Operator);
12906 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>();
12908 if (RequireCompleteType(Loc, Base->getType(),
12909 diag::err_typecheck_incomplete_tag, Base))
12910 return ExprError();
12912 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName);
12913 LookupQualifiedName(R, BaseRecord->getDecl());
12914 R.suppressDiagnostics();
12916 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end();
12917 Oper != OperEnd; ++Oper) {
12918 AddMethodCandidate(Oper.getPair(), Base->getType(), Base->Classify(Context),
12919 None, CandidateSet, /*SuppressUserConversions=*/false);
12922 bool HadMultipleCandidates = (CandidateSet.size() > 1);
12924 // Perform overload resolution.
12925 OverloadCandidateSet::iterator Best;
12926 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
12928 // Overload resolution succeeded; we'll build the call below.
12931 case OR_No_Viable_Function:
12932 if (CandidateSet.empty()) {
12933 QualType BaseType = Base->getType();
12934 if (NoArrowOperatorFound) {
12935 // Report this specific error to the caller instead of emitting a
12936 // diagnostic, as requested.
12937 *NoArrowOperatorFound = true;
12938 return ExprError();
12940 Diag(OpLoc, diag::err_typecheck_member_reference_arrow)
12941 << BaseType << Base->getSourceRange();
12942 if (BaseType->isRecordType() && !BaseType->isPointerType()) {
12943 Diag(OpLoc, diag::note_typecheck_member_reference_suggestion)
12944 << FixItHint::CreateReplacement(OpLoc, ".");
12947 Diag(OpLoc, diag::err_ovl_no_viable_oper)
12948 << "operator->" << Base->getSourceRange();
12949 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Base);
12950 return ExprError();
12953 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary)
12954 << "->" << Base->getType() << Base->getSourceRange();
12955 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Base);
12956 return ExprError();
12959 Diag(OpLoc, diag::err_ovl_deleted_oper)
12960 << Best->Function->isDeleted()
12962 << getDeletedOrUnavailableSuffix(Best->Function)
12963 << Base->getSourceRange();
12964 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Base);
12965 return ExprError();
12968 CheckMemberOperatorAccess(OpLoc, Base, nullptr, Best->FoundDecl);
12970 // Convert the object parameter.
12971 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
12972 ExprResult BaseResult =
12973 PerformObjectArgumentInitialization(Base, /*Qualifier=*/nullptr,
12974 Best->FoundDecl, Method);
12975 if (BaseResult.isInvalid())
12976 return ExprError();
12977 Base = BaseResult.get();
12979 // Build the operator call.
12980 ExprResult FnExpr = CreateFunctionRefExpr(*this, Method, Best->FoundDecl,
12981 HadMultipleCandidates, OpLoc);
12982 if (FnExpr.isInvalid())
12983 return ExprError();
12985 QualType ResultTy = Method->getReturnType();
12986 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
12987 ResultTy = ResultTy.getNonLValueExprType(Context);
12988 CXXOperatorCallExpr *TheCall =
12989 new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr.get(),
12990 Base, ResultTy, VK, OpLoc, false);
12992 if (CheckCallReturnType(Method->getReturnType(), OpLoc, TheCall, Method))
12993 return ExprError();
12995 return MaybeBindToTemporary(TheCall);
12998 /// BuildLiteralOperatorCall - Build a UserDefinedLiteral by creating a call to
12999 /// a literal operator described by the provided lookup results.
13000 ExprResult Sema::BuildLiteralOperatorCall(LookupResult &R,
13001 DeclarationNameInfo &SuffixInfo,
13002 ArrayRef<Expr*> Args,
13003 SourceLocation LitEndLoc,
13004 TemplateArgumentListInfo *TemplateArgs) {
13005 SourceLocation UDSuffixLoc = SuffixInfo.getCXXLiteralOperatorNameLoc();
13007 OverloadCandidateSet CandidateSet(UDSuffixLoc,
13008 OverloadCandidateSet::CSK_Normal);
13009 AddFunctionCandidates(R.asUnresolvedSet(), Args, CandidateSet, TemplateArgs,
13010 /*SuppressUserConversions=*/true);
13012 bool HadMultipleCandidates = (CandidateSet.size() > 1);
13014 // Perform overload resolution. This will usually be trivial, but might need
13015 // to perform substitutions for a literal operator template.
13016 OverloadCandidateSet::iterator Best;
13017 switch (CandidateSet.BestViableFunction(*this, UDSuffixLoc, Best)) {
13022 case OR_No_Viable_Function:
13023 Diag(UDSuffixLoc, diag::err_ovl_no_viable_function_in_call)
13024 << R.getLookupName();
13025 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
13026 return ExprError();
13029 Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName();
13030 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args);
13031 return ExprError();
13034 FunctionDecl *FD = Best->Function;
13035 ExprResult Fn = CreateFunctionRefExpr(*this, FD, Best->FoundDecl,
13036 HadMultipleCandidates,
13037 SuffixInfo.getLoc(),
13038 SuffixInfo.getInfo());
13039 if (Fn.isInvalid())
13042 // Check the argument types. This should almost always be a no-op, except
13043 // that array-to-pointer decay is applied to string literals.
13045 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
13046 ExprResult InputInit = PerformCopyInitialization(
13047 InitializedEntity::InitializeParameter(Context, FD->getParamDecl(ArgIdx)),
13048 SourceLocation(), Args[ArgIdx]);
13049 if (InputInit.isInvalid())
13051 ConvArgs[ArgIdx] = InputInit.get();
13054 QualType ResultTy = FD->getReturnType();
13055 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
13056 ResultTy = ResultTy.getNonLValueExprType(Context);
13058 UserDefinedLiteral *UDL =
13059 new (Context) UserDefinedLiteral(Context, Fn.get(),
13060 llvm::makeArrayRef(ConvArgs, Args.size()),
13061 ResultTy, VK, LitEndLoc, UDSuffixLoc);
13063 if (CheckCallReturnType(FD->getReturnType(), UDSuffixLoc, UDL, FD))
13064 return ExprError();
13066 if (CheckFunctionCall(FD, UDL, nullptr))
13067 return ExprError();
13069 return MaybeBindToTemporary(UDL);
13072 /// Build a call to 'begin' or 'end' for a C++11 for-range statement. If the
13073 /// given LookupResult is non-empty, it is assumed to describe a member which
13074 /// will be invoked. Otherwise, the function will be found via argument
13075 /// dependent lookup.
13076 /// CallExpr is set to a valid expression and FRS_Success returned on success,
13077 /// otherwise CallExpr is set to ExprError() and some non-success value
13079 Sema::ForRangeStatus
13080 Sema::BuildForRangeBeginEndCall(SourceLocation Loc,
13081 SourceLocation RangeLoc,
13082 const DeclarationNameInfo &NameInfo,
13083 LookupResult &MemberLookup,
13084 OverloadCandidateSet *CandidateSet,
13085 Expr *Range, ExprResult *CallExpr) {
13086 Scope *S = nullptr;
13088 CandidateSet->clear();
13089 if (!MemberLookup.empty()) {
13090 ExprResult MemberRef =
13091 BuildMemberReferenceExpr(Range, Range->getType(), Loc,
13092 /*IsPtr=*/false, CXXScopeSpec(),
13093 /*TemplateKWLoc=*/SourceLocation(),
13094 /*FirstQualifierInScope=*/nullptr,
13096 /*TemplateArgs=*/nullptr, S);
13097 if (MemberRef.isInvalid()) {
13098 *CallExpr = ExprError();
13099 return FRS_DiagnosticIssued;
13101 *CallExpr = ActOnCallExpr(S, MemberRef.get(), Loc, None, Loc, nullptr);
13102 if (CallExpr->isInvalid()) {
13103 *CallExpr = ExprError();
13104 return FRS_DiagnosticIssued;
13107 UnresolvedSet<0> FoundNames;
13108 UnresolvedLookupExpr *Fn =
13109 UnresolvedLookupExpr::Create(Context, /*NamingClass=*/nullptr,
13110 NestedNameSpecifierLoc(), NameInfo,
13111 /*NeedsADL=*/true, /*Overloaded=*/false,
13112 FoundNames.begin(), FoundNames.end());
13114 bool CandidateSetError = buildOverloadedCallSet(S, Fn, Fn, Range, Loc,
13115 CandidateSet, CallExpr);
13116 if (CandidateSet->empty() || CandidateSetError) {
13117 *CallExpr = ExprError();
13118 return FRS_NoViableFunction;
13120 OverloadCandidateSet::iterator Best;
13121 OverloadingResult OverloadResult =
13122 CandidateSet->BestViableFunction(*this, Fn->getLocStart(), Best);
13124 if (OverloadResult == OR_No_Viable_Function) {
13125 *CallExpr = ExprError();
13126 return FRS_NoViableFunction;
13128 *CallExpr = FinishOverloadedCallExpr(*this, S, Fn, Fn, Loc, Range,
13129 Loc, nullptr, CandidateSet, &Best,
13131 /*AllowTypoCorrection=*/false);
13132 if (CallExpr->isInvalid() || OverloadResult != OR_Success) {
13133 *CallExpr = ExprError();
13134 return FRS_DiagnosticIssued;
13137 return FRS_Success;
13141 /// FixOverloadedFunctionReference - E is an expression that refers to
13142 /// a C++ overloaded function (possibly with some parentheses and
13143 /// perhaps a '&' around it). We have resolved the overloaded function
13144 /// to the function declaration Fn, so patch up the expression E to
13145 /// refer (possibly indirectly) to Fn. Returns the new expr.
13146 Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found,
13147 FunctionDecl *Fn) {
13148 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
13149 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(),
13151 if (SubExpr == PE->getSubExpr())
13154 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr);
13157 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
13158 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(),
13160 assert(Context.hasSameType(ICE->getSubExpr()->getType(),
13161 SubExpr->getType()) &&
13162 "Implicit cast type cannot be determined from overload");
13163 assert(ICE->path_empty() && "fixing up hierarchy conversion?");
13164 if (SubExpr == ICE->getSubExpr())
13167 return ImplicitCastExpr::Create(Context, ICE->getType(),
13168 ICE->getCastKind(),
13170 ICE->getValueKind());
13173 if (auto *GSE = dyn_cast<GenericSelectionExpr>(E)) {
13174 if (!GSE->isResultDependent()) {
13176 FixOverloadedFunctionReference(GSE->getResultExpr(), Found, Fn);
13177 if (SubExpr == GSE->getResultExpr())
13180 // Replace the resulting type information before rebuilding the generic
13181 // selection expression.
13182 ArrayRef<Expr *> A = GSE->getAssocExprs();
13183 SmallVector<Expr *, 4> AssocExprs(A.begin(), A.end());
13184 unsigned ResultIdx = GSE->getResultIndex();
13185 AssocExprs[ResultIdx] = SubExpr;
13187 return new (Context) GenericSelectionExpr(
13188 Context, GSE->getGenericLoc(), GSE->getControllingExpr(),
13189 GSE->getAssocTypeSourceInfos(), AssocExprs, GSE->getDefaultLoc(),
13190 GSE->getRParenLoc(), GSE->containsUnexpandedParameterPack(),
13193 // Rather than fall through to the unreachable, return the original generic
13194 // selection expression.
13198 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) {
13199 assert(UnOp->getOpcode() == UO_AddrOf &&
13200 "Can only take the address of an overloaded function");
13201 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) {
13202 if (Method->isStatic()) {
13203 // Do nothing: static member functions aren't any different
13204 // from non-member functions.
13206 // Fix the subexpression, which really has to be an
13207 // UnresolvedLookupExpr holding an overloaded member function
13209 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(),
13211 if (SubExpr == UnOp->getSubExpr())
13214 assert(isa<DeclRefExpr>(SubExpr)
13215 && "fixed to something other than a decl ref");
13216 assert(cast<DeclRefExpr>(SubExpr)->getQualifier()
13217 && "fixed to a member ref with no nested name qualifier");
13219 // We have taken the address of a pointer to member
13220 // function. Perform the computation here so that we get the
13221 // appropriate pointer to member type.
13223 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext()));
13224 QualType MemPtrType
13225 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr());
13226 // Under the MS ABI, lock down the inheritance model now.
13227 if (Context.getTargetInfo().getCXXABI().isMicrosoft())
13228 (void)isCompleteType(UnOp->getOperatorLoc(), MemPtrType);
13230 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, MemPtrType,
13231 VK_RValue, OK_Ordinary,
13232 UnOp->getOperatorLoc());
13235 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(),
13237 if (SubExpr == UnOp->getSubExpr())
13240 return new (Context) UnaryOperator(SubExpr, UO_AddrOf,
13241 Context.getPointerType(SubExpr->getType()),
13242 VK_RValue, OK_Ordinary,
13243 UnOp->getOperatorLoc());
13246 // C++ [except.spec]p17:
13247 // An exception-specification is considered to be needed when:
13248 // - in an expression the function is the unique lookup result or the
13249 // selected member of a set of overloaded functions
13250 if (auto *FPT = Fn->getType()->getAs<FunctionProtoType>())
13251 ResolveExceptionSpec(E->getExprLoc(), FPT);
13253 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) {
13254 // FIXME: avoid copy.
13255 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
13256 if (ULE->hasExplicitTemplateArgs()) {
13257 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer);
13258 TemplateArgs = &TemplateArgsBuffer;
13261 DeclRefExpr *DRE = DeclRefExpr::Create(Context,
13262 ULE->getQualifierLoc(),
13263 ULE->getTemplateKeywordLoc(),
13265 /*enclosing*/ false, // FIXME?
13271 MarkDeclRefReferenced(DRE);
13272 DRE->setHadMultipleCandidates(ULE->getNumDecls() > 1);
13276 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) {
13277 // FIXME: avoid copy.
13278 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
13279 if (MemExpr->hasExplicitTemplateArgs()) {
13280 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer);
13281 TemplateArgs = &TemplateArgsBuffer;
13286 // If we're filling in a static method where we used to have an
13287 // implicit member access, rewrite to a simple decl ref.
13288 if (MemExpr->isImplicitAccess()) {
13289 if (cast<CXXMethodDecl>(Fn)->isStatic()) {
13290 DeclRefExpr *DRE = DeclRefExpr::Create(Context,
13291 MemExpr->getQualifierLoc(),
13292 MemExpr->getTemplateKeywordLoc(),
13294 /*enclosing*/ false,
13295 MemExpr->getMemberLoc(),
13300 MarkDeclRefReferenced(DRE);
13301 DRE->setHadMultipleCandidates(MemExpr->getNumDecls() > 1);
13304 SourceLocation Loc = MemExpr->getMemberLoc();
13305 if (MemExpr->getQualifier())
13306 Loc = MemExpr->getQualifierLoc().getBeginLoc();
13307 CheckCXXThisCapture(Loc);
13308 Base = new (Context) CXXThisExpr(Loc,
13309 MemExpr->getBaseType(),
13310 /*isImplicit=*/true);
13313 Base = MemExpr->getBase();
13315 ExprValueKind valueKind;
13317 if (cast<CXXMethodDecl>(Fn)->isStatic()) {
13318 valueKind = VK_LValue;
13319 type = Fn->getType();
13321 valueKind = VK_RValue;
13322 type = Context.BoundMemberTy;
13325 MemberExpr *ME = MemberExpr::Create(
13326 Context, Base, MemExpr->isArrow(), MemExpr->getOperatorLoc(),
13327 MemExpr->getQualifierLoc(), MemExpr->getTemplateKeywordLoc(), Fn, Found,
13328 MemExpr->getMemberNameInfo(), TemplateArgs, type, valueKind,
13330 ME->setHadMultipleCandidates(true);
13331 MarkMemberReferenced(ME);
13335 llvm_unreachable("Invalid reference to overloaded function");
13338 ExprResult Sema::FixOverloadedFunctionReference(ExprResult E,
13339 DeclAccessPair Found,
13340 FunctionDecl *Fn) {
13341 return FixOverloadedFunctionReference(E.get(), Found, Fn);