1 //===--- SemaOverload.cpp - C++ Overloading -------------------------------===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 // This file provides Sema routines for C++ overloading.
11 //===----------------------------------------------------------------------===//
13 #include "clang/Sema/Overload.h"
14 #include "clang/AST/ASTContext.h"
15 #include "clang/AST/CXXInheritance.h"
16 #include "clang/AST/DeclObjC.h"
17 #include "clang/AST/Expr.h"
18 #include "clang/AST/ExprCXX.h"
19 #include "clang/AST/ExprObjC.h"
20 #include "clang/AST/TypeOrdering.h"
21 #include "clang/Basic/Diagnostic.h"
22 #include "clang/Basic/DiagnosticOptions.h"
23 #include "clang/Basic/PartialDiagnostic.h"
24 #include "clang/Basic/TargetInfo.h"
25 #include "clang/Sema/Initialization.h"
26 #include "clang/Sema/Lookup.h"
27 #include "clang/Sema/SemaInternal.h"
28 #include "clang/Sema/Template.h"
29 #include "clang/Sema/TemplateDeduction.h"
30 #include "llvm/ADT/DenseSet.h"
31 #include "llvm/ADT/Optional.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 const Expr *Base, 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)
66 DeclRefExpr(S.Context, Fn, false, Fn->getType(), VK_LValue, Loc, LocInfo);
67 if (HadMultipleCandidates)
68 DRE->setHadMultipleCandidates(true);
70 S.MarkDeclRefReferenced(DRE, Base);
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] = {
133 ICR_OCL_Scalar_Widening,
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()->isMemberPointerType() ||
226 getFromType()->isObjCObjectPointerType() ||
227 getFromType()->isBlockPointerType() ||
228 getFromType()->isNullPtrType() ||
229 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer))
235 /// isPointerConversionToVoidPointer - Determines whether this
236 /// conversion is a conversion of a pointer to a void pointer. This is
237 /// used as part of the ranking of standard conversion sequences (C++
240 StandardConversionSequence::
241 isPointerConversionToVoidPointer(ASTContext& Context) const {
242 QualType FromType = getFromType();
243 QualType ToType = getToType(1);
245 // Note that FromType has not necessarily been transformed by the
246 // array-to-pointer implicit conversion, so check for its presence
247 // and redo the conversion to get a pointer.
248 if (First == ICK_Array_To_Pointer)
249 FromType = Context.getArrayDecayedType(FromType);
251 if (Second == ICK_Pointer_Conversion && FromType->isAnyPointerType())
252 if (const PointerType* ToPtrType = ToType->getAs<PointerType>())
253 return ToPtrType->getPointeeType()->isVoidType();
258 /// Skip any implicit casts which could be either part of a narrowing conversion
259 /// or after one in an implicit conversion.
260 static const Expr *IgnoreNarrowingConversion(const Expr *Converted) {
261 while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Converted)) {
262 switch (ICE->getCastKind()) {
264 case CK_IntegralCast:
265 case CK_IntegralToBoolean:
266 case CK_IntegralToFloating:
267 case CK_BooleanToSignedIntegral:
268 case CK_FloatingToIntegral:
269 case CK_FloatingToBoolean:
270 case CK_FloatingCast:
271 Converted = ICE->getSubExpr();
282 /// Check if this standard conversion sequence represents a narrowing
283 /// conversion, according to C++11 [dcl.init.list]p7.
285 /// \param Ctx The AST context.
286 /// \param Converted The result of applying this standard conversion sequence.
287 /// \param ConstantValue If this is an NK_Constant_Narrowing conversion, the
288 /// value of the expression prior to the narrowing conversion.
289 /// \param ConstantType If this is an NK_Constant_Narrowing conversion, the
290 /// type of the expression prior to the narrowing conversion.
291 /// \param IgnoreFloatToIntegralConversion If true type-narrowing conversions
292 /// from floating point types to integral types should be ignored.
293 NarrowingKind StandardConversionSequence::getNarrowingKind(
294 ASTContext &Ctx, const Expr *Converted, APValue &ConstantValue,
295 QualType &ConstantType, bool IgnoreFloatToIntegralConversion) const {
296 assert(Ctx.getLangOpts().CPlusPlus && "narrowing check outside C++");
298 // C++11 [dcl.init.list]p7:
299 // A narrowing conversion is an implicit conversion ...
300 QualType FromType = getToType(0);
301 QualType ToType = getToType(1);
303 // A conversion to an enumeration type is narrowing if the conversion to
304 // the underlying type is narrowing. This only arises for expressions of
305 // the form 'Enum{init}'.
306 if (auto *ET = ToType->getAs<EnumType>())
307 ToType = ET->getDecl()->getIntegerType();
310 // 'bool' is an integral type; dispatch to the right place to handle it.
311 case ICK_Boolean_Conversion:
312 if (FromType->isRealFloatingType())
313 goto FloatingIntegralConversion;
314 if (FromType->isIntegralOrUnscopedEnumerationType())
315 goto IntegralConversion;
316 // Boolean conversions can be from pointers and pointers to members
317 // [conv.bool], and those aren't considered narrowing conversions.
318 return NK_Not_Narrowing;
320 // -- from a floating-point type to an integer type, or
322 // -- from an integer type or unscoped enumeration type to a floating-point
323 // type, except where the source is a constant expression and the actual
324 // value after conversion will fit into the target type and will produce
325 // the original value when converted back to the original type, or
326 case ICK_Floating_Integral:
327 FloatingIntegralConversion:
328 if (FromType->isRealFloatingType() && ToType->isIntegralType(Ctx)) {
329 return NK_Type_Narrowing;
330 } else if (FromType->isIntegralOrUnscopedEnumerationType() &&
331 ToType->isRealFloatingType()) {
332 if (IgnoreFloatToIntegralConversion)
333 return NK_Not_Narrowing;
334 llvm::APSInt IntConstantValue;
335 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
336 assert(Initializer && "Unknown conversion expression");
338 // If it's value-dependent, we can't tell whether it's narrowing.
339 if (Initializer->isValueDependent())
340 return NK_Dependent_Narrowing;
342 if (Initializer->isIntegerConstantExpr(IntConstantValue, Ctx)) {
343 // Convert the integer to the floating type.
344 llvm::APFloat Result(Ctx.getFloatTypeSemantics(ToType));
345 Result.convertFromAPInt(IntConstantValue, IntConstantValue.isSigned(),
346 llvm::APFloat::rmNearestTiesToEven);
348 llvm::APSInt ConvertedValue = IntConstantValue;
350 Result.convertToInteger(ConvertedValue,
351 llvm::APFloat::rmTowardZero, &ignored);
352 // If the resulting value is different, this was a narrowing conversion.
353 if (IntConstantValue != ConvertedValue) {
354 ConstantValue = APValue(IntConstantValue);
355 ConstantType = Initializer->getType();
356 return NK_Constant_Narrowing;
359 // Variables are always narrowings.
360 return NK_Variable_Narrowing;
363 return NK_Not_Narrowing;
365 // -- from long double to double or float, or from double to float, except
366 // where the source is a constant expression and the actual value after
367 // conversion is within the range of values that can be represented (even
368 // if it cannot be represented exactly), or
369 case ICK_Floating_Conversion:
370 if (FromType->isRealFloatingType() && ToType->isRealFloatingType() &&
371 Ctx.getFloatingTypeOrder(FromType, ToType) == 1) {
372 // FromType is larger than ToType.
373 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
375 // If it's value-dependent, we can't tell whether it's narrowing.
376 if (Initializer->isValueDependent())
377 return NK_Dependent_Narrowing;
379 if (Initializer->isCXX11ConstantExpr(Ctx, &ConstantValue)) {
381 assert(ConstantValue.isFloat());
382 llvm::APFloat FloatVal = ConstantValue.getFloat();
383 // Convert the source value into the target type.
385 llvm::APFloat::opStatus ConvertStatus = FloatVal.convert(
386 Ctx.getFloatTypeSemantics(ToType),
387 llvm::APFloat::rmNearestTiesToEven, &ignored);
388 // If there was no overflow, the source value is within the range of
389 // values that can be represented.
390 if (ConvertStatus & llvm::APFloat::opOverflow) {
391 ConstantType = Initializer->getType();
392 return NK_Constant_Narrowing;
395 return NK_Variable_Narrowing;
398 return NK_Not_Narrowing;
400 // -- from an integer type or unscoped enumeration type to an integer type
401 // that cannot represent all the values of the original type, except where
402 // the source is a constant expression and the actual value after
403 // conversion will fit into the target type and will produce the original
404 // value when converted back to the original type.
405 case ICK_Integral_Conversion:
406 IntegralConversion: {
407 assert(FromType->isIntegralOrUnscopedEnumerationType());
408 assert(ToType->isIntegralOrUnscopedEnumerationType());
409 const bool FromSigned = FromType->isSignedIntegerOrEnumerationType();
410 const unsigned FromWidth = Ctx.getIntWidth(FromType);
411 const bool ToSigned = ToType->isSignedIntegerOrEnumerationType();
412 const unsigned ToWidth = Ctx.getIntWidth(ToType);
414 if (FromWidth > ToWidth ||
415 (FromWidth == ToWidth && FromSigned != ToSigned) ||
416 (FromSigned && !ToSigned)) {
417 // Not all values of FromType can be represented in ToType.
418 llvm::APSInt InitializerValue;
419 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
421 // If it's value-dependent, we can't tell whether it's narrowing.
422 if (Initializer->isValueDependent())
423 return NK_Dependent_Narrowing;
425 if (!Initializer->isIntegerConstantExpr(InitializerValue, Ctx)) {
426 // Such conversions on variables are always narrowing.
427 return NK_Variable_Narrowing;
429 bool Narrowing = false;
430 if (FromWidth < ToWidth) {
431 // Negative -> unsigned is narrowing. Otherwise, more bits is never
433 if (InitializerValue.isSigned() && InitializerValue.isNegative())
436 // Add a bit to the InitializerValue so we don't have to worry about
437 // signed vs. unsigned comparisons.
438 InitializerValue = InitializerValue.extend(
439 InitializerValue.getBitWidth() + 1);
440 // Convert the initializer to and from the target width and signed-ness.
441 llvm::APSInt ConvertedValue = InitializerValue;
442 ConvertedValue = ConvertedValue.trunc(ToWidth);
443 ConvertedValue.setIsSigned(ToSigned);
444 ConvertedValue = ConvertedValue.extend(InitializerValue.getBitWidth());
445 ConvertedValue.setIsSigned(InitializerValue.isSigned());
446 // If the result is different, this was a narrowing conversion.
447 if (ConvertedValue != InitializerValue)
451 ConstantType = Initializer->getType();
452 ConstantValue = APValue(InitializerValue);
453 return NK_Constant_Narrowing;
456 return NK_Not_Narrowing;
460 // Other kinds of conversions are not narrowings.
461 return NK_Not_Narrowing;
465 /// dump - Print this standard conversion sequence to standard
466 /// error. Useful for debugging overloading issues.
467 LLVM_DUMP_METHOD void StandardConversionSequence::dump() const {
468 raw_ostream &OS = llvm::errs();
469 bool PrintedSomething = false;
470 if (First != ICK_Identity) {
471 OS << GetImplicitConversionName(First);
472 PrintedSomething = true;
475 if (Second != ICK_Identity) {
476 if (PrintedSomething) {
479 OS << GetImplicitConversionName(Second);
481 if (CopyConstructor) {
482 OS << " (by copy constructor)";
483 } else if (DirectBinding) {
484 OS << " (direct reference binding)";
485 } else if (ReferenceBinding) {
486 OS << " (reference binding)";
488 PrintedSomething = true;
491 if (Third != ICK_Identity) {
492 if (PrintedSomething) {
495 OS << GetImplicitConversionName(Third);
496 PrintedSomething = true;
499 if (!PrintedSomething) {
500 OS << "No conversions required";
504 /// dump - Print this user-defined conversion sequence to standard
505 /// error. Useful for debugging overloading issues.
506 void UserDefinedConversionSequence::dump() const {
507 raw_ostream &OS = llvm::errs();
508 if (Before.First || Before.Second || Before.Third) {
512 if (ConversionFunction)
513 OS << '\'' << *ConversionFunction << '\'';
515 OS << "aggregate initialization";
516 if (After.First || After.Second || After.Third) {
522 /// dump - Print this implicit conversion sequence to standard
523 /// error. Useful for debugging overloading issues.
524 void ImplicitConversionSequence::dump() const {
525 raw_ostream &OS = llvm::errs();
526 if (isStdInitializerListElement())
527 OS << "Worst std::initializer_list element conversion: ";
528 switch (ConversionKind) {
529 case StandardConversion:
530 OS << "Standard conversion: ";
533 case UserDefinedConversion:
534 OS << "User-defined conversion: ";
537 case EllipsisConversion:
538 OS << "Ellipsis conversion";
540 case AmbiguousConversion:
541 OS << "Ambiguous conversion";
544 OS << "Bad conversion";
551 void AmbiguousConversionSequence::construct() {
552 new (&conversions()) ConversionSet();
555 void AmbiguousConversionSequence::destruct() {
556 conversions().~ConversionSet();
560 AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) {
561 FromTypePtr = O.FromTypePtr;
562 ToTypePtr = O.ToTypePtr;
563 new (&conversions()) ConversionSet(O.conversions());
567 // Structure used by DeductionFailureInfo to store
568 // template argument information.
569 struct DFIArguments {
570 TemplateArgument FirstArg;
571 TemplateArgument SecondArg;
573 // Structure used by DeductionFailureInfo to store
574 // template parameter and template argument information.
575 struct DFIParamWithArguments : DFIArguments {
576 TemplateParameter Param;
578 // Structure used by DeductionFailureInfo to store template argument
579 // information and the index of the problematic call argument.
580 struct DFIDeducedMismatchArgs : DFIArguments {
581 TemplateArgumentList *TemplateArgs;
582 unsigned CallArgIndex;
586 /// Convert from Sema's representation of template deduction information
587 /// to the form used in overload-candidate information.
589 clang::MakeDeductionFailureInfo(ASTContext &Context,
590 Sema::TemplateDeductionResult TDK,
591 TemplateDeductionInfo &Info) {
592 DeductionFailureInfo Result;
593 Result.Result = static_cast<unsigned>(TDK);
594 Result.HasDiagnostic = false;
596 case Sema::TDK_Invalid:
597 case Sema::TDK_InstantiationDepth:
598 case Sema::TDK_TooManyArguments:
599 case Sema::TDK_TooFewArguments:
600 case Sema::TDK_MiscellaneousDeductionFailure:
601 case Sema::TDK_CUDATargetMismatch:
602 Result.Data = nullptr;
605 case Sema::TDK_Incomplete:
606 case Sema::TDK_InvalidExplicitArguments:
607 Result.Data = Info.Param.getOpaqueValue();
610 case Sema::TDK_DeducedMismatch:
611 case Sema::TDK_DeducedMismatchNested: {
612 // FIXME: Should allocate from normal heap so that we can free this later.
613 auto *Saved = new (Context) DFIDeducedMismatchArgs;
614 Saved->FirstArg = Info.FirstArg;
615 Saved->SecondArg = Info.SecondArg;
616 Saved->TemplateArgs = Info.take();
617 Saved->CallArgIndex = Info.CallArgIndex;
622 case Sema::TDK_NonDeducedMismatch: {
623 // FIXME: Should allocate from normal heap so that we can free this later.
624 DFIArguments *Saved = new (Context) DFIArguments;
625 Saved->FirstArg = Info.FirstArg;
626 Saved->SecondArg = Info.SecondArg;
631 case Sema::TDK_IncompletePack:
632 // FIXME: It's slightly wasteful to allocate two TemplateArguments for this.
633 case Sema::TDK_Inconsistent:
634 case Sema::TDK_Underqualified: {
635 // FIXME: Should allocate from normal heap so that we can free this later.
636 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments;
637 Saved->Param = Info.Param;
638 Saved->FirstArg = Info.FirstArg;
639 Saved->SecondArg = Info.SecondArg;
644 case Sema::TDK_SubstitutionFailure:
645 Result.Data = Info.take();
646 if (Info.hasSFINAEDiagnostic()) {
647 PartialDiagnosticAt *Diag = new (Result.Diagnostic) PartialDiagnosticAt(
648 SourceLocation(), PartialDiagnostic::NullDiagnostic());
649 Info.takeSFINAEDiagnostic(*Diag);
650 Result.HasDiagnostic = true;
654 case Sema::TDK_Success:
655 case Sema::TDK_NonDependentConversionFailure:
656 llvm_unreachable("not a deduction failure");
662 void DeductionFailureInfo::Destroy() {
663 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
664 case Sema::TDK_Success:
665 case Sema::TDK_Invalid:
666 case Sema::TDK_InstantiationDepth:
667 case Sema::TDK_Incomplete:
668 case Sema::TDK_TooManyArguments:
669 case Sema::TDK_TooFewArguments:
670 case Sema::TDK_InvalidExplicitArguments:
671 case Sema::TDK_CUDATargetMismatch:
672 case Sema::TDK_NonDependentConversionFailure:
675 case Sema::TDK_IncompletePack:
676 case Sema::TDK_Inconsistent:
677 case Sema::TDK_Underqualified:
678 case Sema::TDK_DeducedMismatch:
679 case Sema::TDK_DeducedMismatchNested:
680 case Sema::TDK_NonDeducedMismatch:
681 // FIXME: Destroy the data?
685 case Sema::TDK_SubstitutionFailure:
686 // FIXME: Destroy the template argument list?
688 if (PartialDiagnosticAt *Diag = getSFINAEDiagnostic()) {
689 Diag->~PartialDiagnosticAt();
690 HasDiagnostic = false;
695 case Sema::TDK_MiscellaneousDeductionFailure:
700 PartialDiagnosticAt *DeductionFailureInfo::getSFINAEDiagnostic() {
702 return static_cast<PartialDiagnosticAt*>(static_cast<void*>(Diagnostic));
706 TemplateParameter DeductionFailureInfo::getTemplateParameter() {
707 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
708 case Sema::TDK_Success:
709 case Sema::TDK_Invalid:
710 case Sema::TDK_InstantiationDepth:
711 case Sema::TDK_TooManyArguments:
712 case Sema::TDK_TooFewArguments:
713 case Sema::TDK_SubstitutionFailure:
714 case Sema::TDK_DeducedMismatch:
715 case Sema::TDK_DeducedMismatchNested:
716 case Sema::TDK_NonDeducedMismatch:
717 case Sema::TDK_CUDATargetMismatch:
718 case Sema::TDK_NonDependentConversionFailure:
719 return TemplateParameter();
721 case Sema::TDK_Incomplete:
722 case Sema::TDK_InvalidExplicitArguments:
723 return TemplateParameter::getFromOpaqueValue(Data);
725 case Sema::TDK_IncompletePack:
726 case Sema::TDK_Inconsistent:
727 case Sema::TDK_Underqualified:
728 return static_cast<DFIParamWithArguments*>(Data)->Param;
731 case Sema::TDK_MiscellaneousDeductionFailure:
735 return TemplateParameter();
738 TemplateArgumentList *DeductionFailureInfo::getTemplateArgumentList() {
739 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
740 case Sema::TDK_Success:
741 case Sema::TDK_Invalid:
742 case Sema::TDK_InstantiationDepth:
743 case Sema::TDK_TooManyArguments:
744 case Sema::TDK_TooFewArguments:
745 case Sema::TDK_Incomplete:
746 case Sema::TDK_IncompletePack:
747 case Sema::TDK_InvalidExplicitArguments:
748 case Sema::TDK_Inconsistent:
749 case Sema::TDK_Underqualified:
750 case Sema::TDK_NonDeducedMismatch:
751 case Sema::TDK_CUDATargetMismatch:
752 case Sema::TDK_NonDependentConversionFailure:
755 case Sema::TDK_DeducedMismatch:
756 case Sema::TDK_DeducedMismatchNested:
757 return static_cast<DFIDeducedMismatchArgs*>(Data)->TemplateArgs;
759 case Sema::TDK_SubstitutionFailure:
760 return static_cast<TemplateArgumentList*>(Data);
763 case Sema::TDK_MiscellaneousDeductionFailure:
770 const TemplateArgument *DeductionFailureInfo::getFirstArg() {
771 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
772 case Sema::TDK_Success:
773 case Sema::TDK_Invalid:
774 case Sema::TDK_InstantiationDepth:
775 case Sema::TDK_Incomplete:
776 case Sema::TDK_TooManyArguments:
777 case Sema::TDK_TooFewArguments:
778 case Sema::TDK_InvalidExplicitArguments:
779 case Sema::TDK_SubstitutionFailure:
780 case Sema::TDK_CUDATargetMismatch:
781 case Sema::TDK_NonDependentConversionFailure:
784 case Sema::TDK_IncompletePack:
785 case Sema::TDK_Inconsistent:
786 case Sema::TDK_Underqualified:
787 case Sema::TDK_DeducedMismatch:
788 case Sema::TDK_DeducedMismatchNested:
789 case Sema::TDK_NonDeducedMismatch:
790 return &static_cast<DFIArguments*>(Data)->FirstArg;
793 case Sema::TDK_MiscellaneousDeductionFailure:
800 const TemplateArgument *DeductionFailureInfo::getSecondArg() {
801 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
802 case Sema::TDK_Success:
803 case Sema::TDK_Invalid:
804 case Sema::TDK_InstantiationDepth:
805 case Sema::TDK_Incomplete:
806 case Sema::TDK_IncompletePack:
807 case Sema::TDK_TooManyArguments:
808 case Sema::TDK_TooFewArguments:
809 case Sema::TDK_InvalidExplicitArguments:
810 case Sema::TDK_SubstitutionFailure:
811 case Sema::TDK_CUDATargetMismatch:
812 case Sema::TDK_NonDependentConversionFailure:
815 case Sema::TDK_Inconsistent:
816 case Sema::TDK_Underqualified:
817 case Sema::TDK_DeducedMismatch:
818 case Sema::TDK_DeducedMismatchNested:
819 case Sema::TDK_NonDeducedMismatch:
820 return &static_cast<DFIArguments*>(Data)->SecondArg;
823 case Sema::TDK_MiscellaneousDeductionFailure:
830 llvm::Optional<unsigned> DeductionFailureInfo::getCallArgIndex() {
831 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
832 case Sema::TDK_DeducedMismatch:
833 case Sema::TDK_DeducedMismatchNested:
834 return static_cast<DFIDeducedMismatchArgs*>(Data)->CallArgIndex;
841 void OverloadCandidateSet::destroyCandidates() {
842 for (iterator i = begin(), e = end(); i != e; ++i) {
843 for (auto &C : i->Conversions)
844 C.~ImplicitConversionSequence();
845 if (!i->Viable && i->FailureKind == ovl_fail_bad_deduction)
846 i->DeductionFailure.Destroy();
850 void OverloadCandidateSet::clear(CandidateSetKind CSK) {
852 SlabAllocator.Reset();
853 NumInlineBytesUsed = 0;
860 class UnbridgedCastsSet {
865 SmallVector<Entry, 2> Entries;
868 void save(Sema &S, Expr *&E) {
869 assert(E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast));
870 Entry entry = { &E, E };
871 Entries.push_back(entry);
872 E = S.stripARCUnbridgedCast(E);
876 for (SmallVectorImpl<Entry>::iterator
877 i = Entries.begin(), e = Entries.end(); i != e; ++i)
883 /// checkPlaceholderForOverload - Do any interesting placeholder-like
884 /// preprocessing on the given expression.
886 /// \param unbridgedCasts a collection to which to add unbridged casts;
887 /// without this, they will be immediately diagnosed as errors
889 /// Return true on unrecoverable error.
891 checkPlaceholderForOverload(Sema &S, Expr *&E,
892 UnbridgedCastsSet *unbridgedCasts = nullptr) {
893 if (const BuiltinType *placeholder = E->getType()->getAsPlaceholderType()) {
894 // We can't handle overloaded expressions here because overload
895 // resolution might reasonably tweak them.
896 if (placeholder->getKind() == BuiltinType::Overload) return false;
898 // If the context potentially accepts unbridged ARC casts, strip
899 // the unbridged cast and add it to the collection for later restoration.
900 if (placeholder->getKind() == BuiltinType::ARCUnbridgedCast &&
902 unbridgedCasts->save(S, E);
906 // Go ahead and check everything else.
907 ExprResult result = S.CheckPlaceholderExpr(E);
908 if (result.isInvalid())
919 /// checkArgPlaceholdersForOverload - Check a set of call operands for
921 static bool checkArgPlaceholdersForOverload(Sema &S,
923 UnbridgedCastsSet &unbridged) {
924 for (unsigned i = 0, e = Args.size(); i != e; ++i)
925 if (checkPlaceholderForOverload(S, Args[i], &unbridged))
931 /// Determine whether the given New declaration is an overload of the
932 /// declarations in Old. This routine returns Ovl_Match or Ovl_NonFunction if
933 /// New and Old cannot be overloaded, e.g., if New has the same signature as
934 /// some function in Old (C++ 1.3.10) or if the Old declarations aren't
935 /// functions (or function templates) at all. When it does return Ovl_Match or
936 /// Ovl_NonFunction, MatchedDecl will point to the decl that New cannot be
937 /// overloaded with. This decl may be a UsingShadowDecl on top of the underlying
940 /// Example: Given the following input:
942 /// void f(int, float); // #1
943 /// void f(int, int); // #2
944 /// int f(int, int); // #3
946 /// When we process #1, there is no previous declaration of "f", so IsOverload
947 /// will not be used.
949 /// When we process #2, Old contains only the FunctionDecl for #1. By comparing
950 /// the parameter types, we see that #1 and #2 are overloaded (since they have
951 /// different signatures), so this routine returns Ovl_Overload; MatchedDecl is
954 /// When we process #3, Old is an overload set containing #1 and #2. We compare
955 /// the signatures of #3 to #1 (they're overloaded, so we do nothing) and then
956 /// #3 to #2. Since the signatures of #3 and #2 are identical (return types of
957 /// functions are not part of the signature), IsOverload returns Ovl_Match and
958 /// MatchedDecl will be set to point to the FunctionDecl for #2.
960 /// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced into a class
961 /// by a using declaration. The rules for whether to hide shadow declarations
962 /// ignore some properties which otherwise figure into a function template's
965 Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old,
966 NamedDecl *&Match, bool NewIsUsingDecl) {
967 for (LookupResult::iterator I = Old.begin(), E = Old.end();
969 NamedDecl *OldD = *I;
971 bool OldIsUsingDecl = false;
972 if (isa<UsingShadowDecl>(OldD)) {
973 OldIsUsingDecl = true;
975 // We can always introduce two using declarations into the same
976 // context, even if they have identical signatures.
977 if (NewIsUsingDecl) continue;
979 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl();
982 // A using-declaration does not conflict with another declaration
983 // if one of them is hidden.
984 if ((OldIsUsingDecl || NewIsUsingDecl) && !isVisible(*I))
987 // If either declaration was introduced by a using declaration,
988 // we'll need to use slightly different rules for matching.
989 // Essentially, these rules are the normal rules, except that
990 // function templates hide function templates with different
991 // return types or template parameter lists.
992 bool UseMemberUsingDeclRules =
993 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord() &&
994 !New->getFriendObjectKind();
996 if (FunctionDecl *OldF = OldD->getAsFunction()) {
997 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) {
998 if (UseMemberUsingDeclRules && OldIsUsingDecl) {
999 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I));
1003 if (!isa<FunctionTemplateDecl>(OldD) &&
1004 !shouldLinkPossiblyHiddenDecl(*I, New))
1011 // Builtins that have custom typechecking or have a reference should
1012 // not be overloadable or redeclarable.
1013 if (!getASTContext().canBuiltinBeRedeclared(OldF)) {
1015 return Ovl_NonFunction;
1017 } else if (isa<UsingDecl>(OldD) || isa<UsingPackDecl>(OldD)) {
1018 // We can overload with these, which can show up when doing
1019 // redeclaration checks for UsingDecls.
1020 assert(Old.getLookupKind() == LookupUsingDeclName);
1021 } else if (isa<TagDecl>(OldD)) {
1022 // We can always overload with tags by hiding them.
1023 } else if (auto *UUD = dyn_cast<UnresolvedUsingValueDecl>(OldD)) {
1024 // Optimistically assume that an unresolved using decl will
1025 // overload; if it doesn't, we'll have to diagnose during
1026 // template instantiation.
1028 // Exception: if the scope is dependent and this is not a class
1029 // member, the using declaration can only introduce an enumerator.
1030 if (UUD->getQualifier()->isDependent() && !UUD->isCXXClassMember()) {
1032 return Ovl_NonFunction;
1036 // Only function declarations can be overloaded; object and type
1037 // declarations cannot be overloaded.
1039 return Ovl_NonFunction;
1043 // C++ [temp.friend]p1:
1044 // For a friend function declaration that is not a template declaration:
1045 // -- if the name of the friend is a qualified or unqualified template-id,
1047 // -- if the name of the friend is a qualified-id and a matching
1048 // non-template function is found in the specified class or namespace,
1049 // the friend declaration refers to that function, otherwise,
1050 // -- if the name of the friend is a qualified-id and a matching function
1051 // template is found in the specified class or namespace, the friend
1052 // declaration refers to the deduced specialization of that function
1053 // template, otherwise
1054 // -- the name shall be an unqualified-id [...]
1055 // If we get here for a qualified friend declaration, we've just reached the
1056 // third bullet. If the type of the friend is dependent, skip this lookup
1057 // until instantiation.
1058 if (New->getFriendObjectKind() && New->getQualifier() &&
1059 !New->getDescribedFunctionTemplate() &&
1060 !New->getDependentSpecializationInfo() &&
1061 !New->getType()->isDependentType()) {
1062 LookupResult TemplateSpecResult(LookupResult::Temporary, Old);
1063 TemplateSpecResult.addAllDecls(Old);
1064 if (CheckFunctionTemplateSpecialization(New, nullptr, TemplateSpecResult,
1065 /*QualifiedFriend*/true)) {
1066 New->setInvalidDecl();
1067 return Ovl_Overload;
1070 Match = TemplateSpecResult.getAsSingle<FunctionDecl>();
1074 return Ovl_Overload;
1077 bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old,
1078 bool UseMemberUsingDeclRules, bool ConsiderCudaAttrs) {
1079 // C++ [basic.start.main]p2: This function shall not be overloaded.
1083 // MSVCRT user defined entry points cannot be overloaded.
1084 if (New->isMSVCRTEntryPoint())
1087 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate();
1088 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate();
1090 // C++ [temp.fct]p2:
1091 // A function template can be overloaded with other function templates
1092 // and with normal (non-template) functions.
1093 if ((OldTemplate == nullptr) != (NewTemplate == nullptr))
1096 // Is the function New an overload of the function Old?
1097 QualType OldQType = Context.getCanonicalType(Old->getType());
1098 QualType NewQType = Context.getCanonicalType(New->getType());
1100 // Compare the signatures (C++ 1.3.10) of the two functions to
1101 // determine whether they are overloads. If we find any mismatch
1102 // in the signature, they are overloads.
1104 // If either of these functions is a K&R-style function (no
1105 // prototype), then we consider them to have matching signatures.
1106 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) ||
1107 isa<FunctionNoProtoType>(NewQType.getTypePtr()))
1110 const FunctionProtoType *OldType = cast<FunctionProtoType>(OldQType);
1111 const FunctionProtoType *NewType = cast<FunctionProtoType>(NewQType);
1113 // The signature of a function includes the types of its
1114 // parameters (C++ 1.3.10), which includes the presence or absence
1115 // of the ellipsis; see C++ DR 357).
1116 if (OldQType != NewQType &&
1117 (OldType->getNumParams() != NewType->getNumParams() ||
1118 OldType->isVariadic() != NewType->isVariadic() ||
1119 !FunctionParamTypesAreEqual(OldType, NewType)))
1122 // C++ [temp.over.link]p4:
1123 // The signature of a function template consists of its function
1124 // signature, its return type and its template parameter list. The names
1125 // of the template parameters are significant only for establishing the
1126 // relationship between the template parameters and the rest of the
1129 // We check the return type and template parameter lists for function
1130 // templates first; the remaining checks follow.
1132 // However, we don't consider either of these when deciding whether
1133 // a member introduced by a shadow declaration is hidden.
1134 if (!UseMemberUsingDeclRules && NewTemplate &&
1135 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(),
1136 OldTemplate->getTemplateParameters(),
1137 false, TPL_TemplateMatch) ||
1138 !Context.hasSameType(Old->getDeclaredReturnType(),
1139 New->getDeclaredReturnType())))
1142 // If the function is a class member, its signature includes the
1143 // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself.
1145 // As part of this, also check whether one of the member functions
1146 // is static, in which case they are not overloads (C++
1147 // 13.1p2). While not part of the definition of the signature,
1148 // this check is important to determine whether these functions
1149 // can be overloaded.
1150 CXXMethodDecl *OldMethod = dyn_cast<CXXMethodDecl>(Old);
1151 CXXMethodDecl *NewMethod = dyn_cast<CXXMethodDecl>(New);
1152 if (OldMethod && NewMethod &&
1153 !OldMethod->isStatic() && !NewMethod->isStatic()) {
1154 if (OldMethod->getRefQualifier() != NewMethod->getRefQualifier()) {
1155 if (!UseMemberUsingDeclRules &&
1156 (OldMethod->getRefQualifier() == RQ_None ||
1157 NewMethod->getRefQualifier() == RQ_None)) {
1158 // C++0x [over.load]p2:
1159 // - Member function declarations with the same name and the same
1160 // parameter-type-list as well as member function template
1161 // declarations with the same name, the same parameter-type-list, and
1162 // the same template parameter lists cannot be overloaded if any of
1163 // them, but not all, have a ref-qualifier (8.3.5).
1164 Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload)
1165 << NewMethod->getRefQualifier() << OldMethod->getRefQualifier();
1166 Diag(OldMethod->getLocation(), diag::note_previous_declaration);
1171 // We may not have applied the implicit const for a constexpr member
1172 // function yet (because we haven't yet resolved whether this is a static
1173 // or non-static member function). Add it now, on the assumption that this
1174 // is a redeclaration of OldMethod.
1175 auto OldQuals = OldMethod->getMethodQualifiers();
1176 auto NewQuals = NewMethod->getMethodQualifiers();
1177 if (!getLangOpts().CPlusPlus14 && NewMethod->isConstexpr() &&
1178 !isa<CXXConstructorDecl>(NewMethod))
1179 NewQuals.addConst();
1180 // We do not allow overloading based off of '__restrict'.
1181 OldQuals.removeRestrict();
1182 NewQuals.removeRestrict();
1183 if (OldQuals != NewQuals)
1187 // Though pass_object_size is placed on parameters and takes an argument, we
1188 // consider it to be a function-level modifier for the sake of function
1189 // identity. Either the function has one or more parameters with
1190 // pass_object_size or it doesn't.
1191 if (functionHasPassObjectSizeParams(New) !=
1192 functionHasPassObjectSizeParams(Old))
1195 // enable_if attributes are an order-sensitive part of the signature.
1196 for (specific_attr_iterator<EnableIfAttr>
1197 NewI = New->specific_attr_begin<EnableIfAttr>(),
1198 NewE = New->specific_attr_end<EnableIfAttr>(),
1199 OldI = Old->specific_attr_begin<EnableIfAttr>(),
1200 OldE = Old->specific_attr_end<EnableIfAttr>();
1201 NewI != NewE || OldI != OldE; ++NewI, ++OldI) {
1202 if (NewI == NewE || OldI == OldE)
1204 llvm::FoldingSetNodeID NewID, OldID;
1205 NewI->getCond()->Profile(NewID, Context, true);
1206 OldI->getCond()->Profile(OldID, Context, true);
1211 if (getLangOpts().CUDA && ConsiderCudaAttrs) {
1212 // Don't allow overloading of destructors. (In theory we could, but it
1213 // would be a giant change to clang.)
1214 if (isa<CXXDestructorDecl>(New))
1217 CUDAFunctionTarget NewTarget = IdentifyCUDATarget(New),
1218 OldTarget = IdentifyCUDATarget(Old);
1219 if (NewTarget == CFT_InvalidTarget)
1222 assert((OldTarget != CFT_InvalidTarget) && "Unexpected invalid target.");
1224 // Allow overloading of functions with same signature and different CUDA
1225 // target attributes.
1226 return NewTarget != OldTarget;
1229 // The signatures match; this is not an overload.
1233 /// Tries a user-defined conversion from From to ToType.
1235 /// Produces an implicit conversion sequence for when a standard conversion
1236 /// is not an option. See TryImplicitConversion for more information.
1237 static ImplicitConversionSequence
1238 TryUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
1239 bool SuppressUserConversions,
1241 bool InOverloadResolution,
1243 bool AllowObjCWritebackConversion,
1244 bool AllowObjCConversionOnExplicit) {
1245 ImplicitConversionSequence ICS;
1247 if (SuppressUserConversions) {
1248 // We're not in the case above, so there is no conversion that
1250 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1254 // Attempt user-defined conversion.
1255 OverloadCandidateSet Conversions(From->getExprLoc(),
1256 OverloadCandidateSet::CSK_Normal);
1257 switch (IsUserDefinedConversion(S, From, ToType, ICS.UserDefined,
1258 Conversions, AllowExplicit,
1259 AllowObjCConversionOnExplicit)) {
1262 ICS.setUserDefined();
1263 // C++ [over.ics.user]p4:
1264 // A conversion of an expression of class type to the same class
1265 // type is given Exact Match rank, and a conversion of an
1266 // expression of class type to a base class of that type is
1267 // given Conversion rank, in spite of the fact that a copy
1268 // constructor (i.e., a user-defined conversion function) is
1269 // called for those cases.
1270 if (CXXConstructorDecl *Constructor
1271 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) {
1273 = S.Context.getCanonicalType(From->getType().getUnqualifiedType());
1275 = S.Context.getCanonicalType(ToType).getUnqualifiedType();
1276 if (Constructor->isCopyConstructor() &&
1277 (FromCanon == ToCanon ||
1278 S.IsDerivedFrom(From->getBeginLoc(), FromCanon, ToCanon))) {
1279 // Turn this into a "standard" conversion sequence, so that it
1280 // gets ranked with standard conversion sequences.
1281 DeclAccessPair Found = ICS.UserDefined.FoundConversionFunction;
1283 ICS.Standard.setAsIdentityConversion();
1284 ICS.Standard.setFromType(From->getType());
1285 ICS.Standard.setAllToTypes(ToType);
1286 ICS.Standard.CopyConstructor = Constructor;
1287 ICS.Standard.FoundCopyConstructor = Found;
1288 if (ToCanon != FromCanon)
1289 ICS.Standard.Second = ICK_Derived_To_Base;
1296 ICS.Ambiguous.setFromType(From->getType());
1297 ICS.Ambiguous.setToType(ToType);
1298 for (OverloadCandidateSet::iterator Cand = Conversions.begin();
1299 Cand != Conversions.end(); ++Cand)
1301 ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
1305 case OR_No_Viable_Function:
1306 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1313 /// TryImplicitConversion - Attempt to perform an implicit conversion
1314 /// from the given expression (Expr) to the given type (ToType). This
1315 /// function returns an implicit conversion sequence that can be used
1316 /// to perform the initialization. Given
1318 /// void f(float f);
1319 /// void g(int i) { f(i); }
1321 /// this routine would produce an implicit conversion sequence to
1322 /// describe the initialization of f from i, which will be a standard
1323 /// conversion sequence containing an lvalue-to-rvalue conversion (C++
1324 /// 4.1) followed by a floating-integral conversion (C++ 4.9).
1326 /// Note that this routine only determines how the conversion can be
1327 /// performed; it does not actually perform the conversion. As such,
1328 /// it will not produce any diagnostics if no conversion is available,
1329 /// but will instead return an implicit conversion sequence of kind
1330 /// "BadConversion".
1332 /// If @p SuppressUserConversions, then user-defined conversions are
1334 /// If @p AllowExplicit, then explicit user-defined conversions are
1337 /// \param AllowObjCWritebackConversion Whether we allow the Objective-C
1338 /// writeback conversion, which allows __autoreleasing id* parameters to
1339 /// be initialized with __strong id* or __weak id* arguments.
1340 static ImplicitConversionSequence
1341 TryImplicitConversion(Sema &S, Expr *From, QualType ToType,
1342 bool SuppressUserConversions,
1344 bool InOverloadResolution,
1346 bool AllowObjCWritebackConversion,
1347 bool AllowObjCConversionOnExplicit) {
1348 ImplicitConversionSequence ICS;
1349 if (IsStandardConversion(S, From, ToType, InOverloadResolution,
1350 ICS.Standard, CStyle, AllowObjCWritebackConversion)){
1355 if (!S.getLangOpts().CPlusPlus) {
1356 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1360 // C++ [over.ics.user]p4:
1361 // A conversion of an expression of class type to the same class
1362 // type is given Exact Match rank, and a conversion of an
1363 // expression of class type to a base class of that type is
1364 // given Conversion rank, in spite of the fact that a copy/move
1365 // constructor (i.e., a user-defined conversion function) is
1366 // called for those cases.
1367 QualType FromType = From->getType();
1368 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() &&
1369 (S.Context.hasSameUnqualifiedType(FromType, ToType) ||
1370 S.IsDerivedFrom(From->getBeginLoc(), FromType, ToType))) {
1372 ICS.Standard.setAsIdentityConversion();
1373 ICS.Standard.setFromType(FromType);
1374 ICS.Standard.setAllToTypes(ToType);
1376 // We don't actually check at this point whether there is a valid
1377 // copy/move constructor, since overloading just assumes that it
1378 // exists. When we actually perform initialization, we'll find the
1379 // appropriate constructor to copy the returned object, if needed.
1380 ICS.Standard.CopyConstructor = nullptr;
1382 // Determine whether this is considered a derived-to-base conversion.
1383 if (!S.Context.hasSameUnqualifiedType(FromType, ToType))
1384 ICS.Standard.Second = ICK_Derived_To_Base;
1389 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
1390 AllowExplicit, InOverloadResolution, CStyle,
1391 AllowObjCWritebackConversion,
1392 AllowObjCConversionOnExplicit);
1395 ImplicitConversionSequence
1396 Sema::TryImplicitConversion(Expr *From, QualType ToType,
1397 bool SuppressUserConversions,
1399 bool InOverloadResolution,
1401 bool AllowObjCWritebackConversion) {
1402 return ::TryImplicitConversion(*this, From, ToType,
1403 SuppressUserConversions, AllowExplicit,
1404 InOverloadResolution, CStyle,
1405 AllowObjCWritebackConversion,
1406 /*AllowObjCConversionOnExplicit=*/false);
1409 /// PerformImplicitConversion - Perform an implicit conversion of the
1410 /// expression From to the type ToType. Returns the
1411 /// converted expression. Flavor is the kind of conversion we're
1412 /// performing, used in the error message. If @p AllowExplicit,
1413 /// explicit user-defined conversions are permitted.
1415 Sema::PerformImplicitConversion(Expr *From, QualType ToType,
1416 AssignmentAction Action, bool AllowExplicit) {
1417 ImplicitConversionSequence ICS;
1418 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS);
1422 Sema::PerformImplicitConversion(Expr *From, QualType ToType,
1423 AssignmentAction Action, bool AllowExplicit,
1424 ImplicitConversionSequence& ICS) {
1425 if (checkPlaceholderForOverload(*this, From))
1428 // Objective-C ARC: Determine whether we will allow the writeback conversion.
1429 bool AllowObjCWritebackConversion
1430 = getLangOpts().ObjCAutoRefCount &&
1431 (Action == AA_Passing || Action == AA_Sending);
1432 if (getLangOpts().ObjC)
1433 CheckObjCBridgeRelatedConversions(From->getBeginLoc(), ToType,
1434 From->getType(), From);
1435 ICS = ::TryImplicitConversion(*this, From, ToType,
1436 /*SuppressUserConversions=*/false,
1438 /*InOverloadResolution=*/false,
1440 AllowObjCWritebackConversion,
1441 /*AllowObjCConversionOnExplicit=*/false);
1442 return PerformImplicitConversion(From, ToType, ICS, Action);
1445 /// Determine whether the conversion from FromType to ToType is a valid
1446 /// conversion that strips "noexcept" or "noreturn" off the nested function
1448 bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
1449 QualType &ResultTy) {
1450 if (Context.hasSameUnqualifiedType(FromType, ToType))
1453 // Permit the conversion F(t __attribute__((noreturn))) -> F(t)
1454 // or F(t noexcept) -> F(t)
1455 // where F adds one of the following at most once:
1457 // - a member pointer
1458 // - a block pointer
1459 // Changes here need matching changes in FindCompositePointerType.
1460 CanQualType CanTo = Context.getCanonicalType(ToType);
1461 CanQualType CanFrom = Context.getCanonicalType(FromType);
1462 Type::TypeClass TyClass = CanTo->getTypeClass();
1463 if (TyClass != CanFrom->getTypeClass()) return false;
1464 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) {
1465 if (TyClass == Type::Pointer) {
1466 CanTo = CanTo.getAs<PointerType>()->getPointeeType();
1467 CanFrom = CanFrom.getAs<PointerType>()->getPointeeType();
1468 } else if (TyClass == Type::BlockPointer) {
1469 CanTo = CanTo.getAs<BlockPointerType>()->getPointeeType();
1470 CanFrom = CanFrom.getAs<BlockPointerType>()->getPointeeType();
1471 } else if (TyClass == Type::MemberPointer) {
1472 auto ToMPT = CanTo.getAs<MemberPointerType>();
1473 auto FromMPT = CanFrom.getAs<MemberPointerType>();
1474 // A function pointer conversion cannot change the class of the function.
1475 if (ToMPT->getClass() != FromMPT->getClass())
1477 CanTo = ToMPT->getPointeeType();
1478 CanFrom = FromMPT->getPointeeType();
1483 TyClass = CanTo->getTypeClass();
1484 if (TyClass != CanFrom->getTypeClass()) return false;
1485 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto)
1489 const auto *FromFn = cast<FunctionType>(CanFrom);
1490 FunctionType::ExtInfo FromEInfo = FromFn->getExtInfo();
1492 const auto *ToFn = cast<FunctionType>(CanTo);
1493 FunctionType::ExtInfo ToEInfo = ToFn->getExtInfo();
1495 bool Changed = false;
1497 // Drop 'noreturn' if not present in target type.
1498 if (FromEInfo.getNoReturn() && !ToEInfo.getNoReturn()) {
1499 FromFn = Context.adjustFunctionType(FromFn, FromEInfo.withNoReturn(false));
1503 // Drop 'noexcept' if not present in target type.
1504 if (const auto *FromFPT = dyn_cast<FunctionProtoType>(FromFn)) {
1505 const auto *ToFPT = cast<FunctionProtoType>(ToFn);
1506 if (FromFPT->isNothrow() && !ToFPT->isNothrow()) {
1507 FromFn = cast<FunctionType>(
1508 Context.getFunctionTypeWithExceptionSpec(QualType(FromFPT, 0),
1514 // Convert FromFPT's ExtParameterInfo if necessary. The conversion is valid
1515 // only if the ExtParameterInfo lists of the two function prototypes can be
1516 // merged and the merged list is identical to ToFPT's ExtParameterInfo list.
1517 SmallVector<FunctionProtoType::ExtParameterInfo, 4> NewParamInfos;
1518 bool CanUseToFPT, CanUseFromFPT;
1519 if (Context.mergeExtParameterInfo(ToFPT, FromFPT, CanUseToFPT,
1520 CanUseFromFPT, NewParamInfos) &&
1521 CanUseToFPT && !CanUseFromFPT) {
1522 FunctionProtoType::ExtProtoInfo ExtInfo = FromFPT->getExtProtoInfo();
1523 ExtInfo.ExtParameterInfos =
1524 NewParamInfos.empty() ? nullptr : NewParamInfos.data();
1525 QualType QT = Context.getFunctionType(FromFPT->getReturnType(),
1526 FromFPT->getParamTypes(), ExtInfo);
1527 FromFn = QT->getAs<FunctionType>();
1535 assert(QualType(FromFn, 0).isCanonical());
1536 if (QualType(FromFn, 0) != CanTo) return false;
1542 /// Determine whether the conversion from FromType to ToType is a valid
1543 /// vector conversion.
1545 /// \param ICK Will be set to the vector conversion kind, if this is a vector
1547 static bool IsVectorConversion(Sema &S, QualType FromType,
1548 QualType ToType, ImplicitConversionKind &ICK) {
1549 // We need at least one of these types to be a vector type to have a vector
1551 if (!ToType->isVectorType() && !FromType->isVectorType())
1554 // Identical types require no conversions.
1555 if (S.Context.hasSameUnqualifiedType(FromType, ToType))
1558 // There are no conversions between extended vector types, only identity.
1559 if (ToType->isExtVectorType()) {
1560 // There are no conversions between extended vector types other than the
1561 // identity conversion.
1562 if (FromType->isExtVectorType())
1565 // Vector splat from any arithmetic type to a vector.
1566 if (FromType->isArithmeticType()) {
1567 ICK = ICK_Vector_Splat;
1572 // We can perform the conversion between vector types in the following cases:
1573 // 1)vector types are equivalent AltiVec and GCC vector types
1574 // 2)lax vector conversions are permitted and the vector types are of the
1576 if (ToType->isVectorType() && FromType->isVectorType()) {
1577 if (S.Context.areCompatibleVectorTypes(FromType, ToType) ||
1578 S.isLaxVectorConversion(FromType, ToType)) {
1579 ICK = ICK_Vector_Conversion;
1587 static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
1588 bool InOverloadResolution,
1589 StandardConversionSequence &SCS,
1592 /// IsStandardConversion - Determines whether there is a standard
1593 /// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the
1594 /// expression From to the type ToType. Standard conversion sequences
1595 /// only consider non-class types; for conversions that involve class
1596 /// types, use TryImplicitConversion. If a conversion exists, SCS will
1597 /// contain the standard conversion sequence required to perform this
1598 /// conversion and this routine will return true. Otherwise, this
1599 /// routine will return false and the value of SCS is unspecified.
1600 static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
1601 bool InOverloadResolution,
1602 StandardConversionSequence &SCS,
1604 bool AllowObjCWritebackConversion) {
1605 QualType FromType = From->getType();
1607 // Standard conversions (C++ [conv])
1608 SCS.setAsIdentityConversion();
1609 SCS.IncompatibleObjC = false;
1610 SCS.setFromType(FromType);
1611 SCS.CopyConstructor = nullptr;
1613 // There are no standard conversions for class types in C++, so
1614 // abort early. When overloading in C, however, we do permit them.
1615 if (S.getLangOpts().CPlusPlus &&
1616 (FromType->isRecordType() || ToType->isRecordType()))
1619 // The first conversion can be an lvalue-to-rvalue conversion,
1620 // array-to-pointer conversion, or function-to-pointer conversion
1623 if (FromType == S.Context.OverloadTy) {
1624 DeclAccessPair AccessPair;
1625 if (FunctionDecl *Fn
1626 = S.ResolveAddressOfOverloadedFunction(From, ToType, false,
1628 // We were able to resolve the address of the overloaded function,
1629 // so we can convert to the type of that function.
1630 FromType = Fn->getType();
1631 SCS.setFromType(FromType);
1633 // we can sometimes resolve &foo<int> regardless of ToType, so check
1634 // if the type matches (identity) or we are converting to bool
1635 if (!S.Context.hasSameUnqualifiedType(
1636 S.ExtractUnqualifiedFunctionType(ToType), FromType)) {
1638 // if the function type matches except for [[noreturn]], it's ok
1639 if (!S.IsFunctionConversion(FromType,
1640 S.ExtractUnqualifiedFunctionType(ToType), resultTy))
1641 // otherwise, only a boolean conversion is standard
1642 if (!ToType->isBooleanType())
1646 // Check if the "from" expression is taking the address of an overloaded
1647 // function and recompute the FromType accordingly. Take advantage of the
1648 // fact that non-static member functions *must* have such an address-of
1650 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn);
1651 if (Method && !Method->isStatic()) {
1652 assert(isa<UnaryOperator>(From->IgnoreParens()) &&
1653 "Non-unary operator on non-static member address");
1654 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode()
1656 "Non-address-of operator on non-static member address");
1657 const Type *ClassType
1658 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr();
1659 FromType = S.Context.getMemberPointerType(FromType, ClassType);
1660 } else if (isa<UnaryOperator>(From->IgnoreParens())) {
1661 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() ==
1663 "Non-address-of operator for overloaded function expression");
1664 FromType = S.Context.getPointerType(FromType);
1667 // Check that we've computed the proper type after overload resolution.
1668 // FIXME: FixOverloadedFunctionReference has side-effects; we shouldn't
1669 // be calling it from within an NDEBUG block.
1670 assert(S.Context.hasSameType(
1672 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType()));
1677 // Lvalue-to-rvalue conversion (C++11 4.1):
1678 // A glvalue (3.10) of a non-function, non-array type T can
1679 // be converted to a prvalue.
1680 bool argIsLValue = From->isGLValue();
1682 !FromType->isFunctionType() && !FromType->isArrayType() &&
1683 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) {
1684 SCS.First = ICK_Lvalue_To_Rvalue;
1687 // ... if the lvalue has atomic type, the value has the non-atomic version
1688 // of the type of the lvalue ...
1689 if (const AtomicType *Atomic = FromType->getAs<AtomicType>())
1690 FromType = Atomic->getValueType();
1692 // If T is a non-class type, the type of the rvalue is the
1693 // cv-unqualified version of T. Otherwise, the type of the rvalue
1694 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we
1695 // just strip the qualifiers because they don't matter.
1696 FromType = FromType.getUnqualifiedType();
1697 } else if (FromType->isArrayType()) {
1698 // Array-to-pointer conversion (C++ 4.2)
1699 SCS.First = ICK_Array_To_Pointer;
1701 // An lvalue or rvalue of type "array of N T" or "array of unknown
1702 // bound of T" can be converted to an rvalue of type "pointer to
1704 FromType = S.Context.getArrayDecayedType(FromType);
1706 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) {
1707 // This conversion is deprecated in C++03 (D.4)
1708 SCS.DeprecatedStringLiteralToCharPtr = true;
1710 // For the purpose of ranking in overload resolution
1711 // (13.3.3.1.1), this conversion is considered an
1712 // array-to-pointer conversion followed by a qualification
1713 // conversion (4.4). (C++ 4.2p2)
1714 SCS.Second = ICK_Identity;
1715 SCS.Third = ICK_Qualification;
1716 SCS.QualificationIncludesObjCLifetime = false;
1717 SCS.setAllToTypes(FromType);
1720 } else if (FromType->isFunctionType() && argIsLValue) {
1721 // Function-to-pointer conversion (C++ 4.3).
1722 SCS.First = ICK_Function_To_Pointer;
1724 if (auto *DRE = dyn_cast<DeclRefExpr>(From->IgnoreParenCasts()))
1725 if (auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl()))
1726 if (!S.checkAddressOfFunctionIsAvailable(FD))
1729 // An lvalue of function type T can be converted to an rvalue of
1730 // type "pointer to T." The result is a pointer to the
1731 // function. (C++ 4.3p1).
1732 FromType = S.Context.getPointerType(FromType);
1734 // We don't require any conversions for the first step.
1735 SCS.First = ICK_Identity;
1737 SCS.setToType(0, FromType);
1739 // The second conversion can be an integral promotion, floating
1740 // point promotion, integral conversion, floating point conversion,
1741 // floating-integral conversion, pointer conversion,
1742 // pointer-to-member conversion, or boolean conversion (C++ 4p1).
1743 // For overloading in C, this can also be a "compatible-type"
1745 bool IncompatibleObjC = false;
1746 ImplicitConversionKind SecondICK = ICK_Identity;
1747 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) {
1748 // The unqualified versions of the types are the same: there's no
1749 // conversion to do.
1750 SCS.Second = ICK_Identity;
1751 } else if (S.IsIntegralPromotion(From, FromType, ToType)) {
1752 // Integral promotion (C++ 4.5).
1753 SCS.Second = ICK_Integral_Promotion;
1754 FromType = ToType.getUnqualifiedType();
1755 } else if (S.IsFloatingPointPromotion(FromType, ToType)) {
1756 // Floating point promotion (C++ 4.6).
1757 SCS.Second = ICK_Floating_Promotion;
1758 FromType = ToType.getUnqualifiedType();
1759 } else if (S.IsComplexPromotion(FromType, ToType)) {
1760 // Complex promotion (Clang extension)
1761 SCS.Second = ICK_Complex_Promotion;
1762 FromType = ToType.getUnqualifiedType();
1763 } else if (ToType->isBooleanType() &&
1764 (FromType->isArithmeticType() ||
1765 FromType->isAnyPointerType() ||
1766 FromType->isBlockPointerType() ||
1767 FromType->isMemberPointerType() ||
1768 FromType->isNullPtrType())) {
1769 // Boolean conversions (C++ 4.12).
1770 SCS.Second = ICK_Boolean_Conversion;
1771 FromType = S.Context.BoolTy;
1772 } else if (FromType->isIntegralOrUnscopedEnumerationType() &&
1773 ToType->isIntegralType(S.Context)) {
1774 // Integral conversions (C++ 4.7).
1775 SCS.Second = ICK_Integral_Conversion;
1776 FromType = ToType.getUnqualifiedType();
1777 } else if (FromType->isAnyComplexType() && ToType->isAnyComplexType()) {
1778 // Complex conversions (C99 6.3.1.6)
1779 SCS.Second = ICK_Complex_Conversion;
1780 FromType = ToType.getUnqualifiedType();
1781 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) ||
1782 (ToType->isAnyComplexType() && FromType->isArithmeticType())) {
1783 // Complex-real conversions (C99 6.3.1.7)
1784 SCS.Second = ICK_Complex_Real;
1785 FromType = ToType.getUnqualifiedType();
1786 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) {
1787 // FIXME: disable conversions between long double and __float128 if
1788 // their representation is different until there is back end support
1789 // We of course allow this conversion if long double is really double.
1790 if (&S.Context.getFloatTypeSemantics(FromType) !=
1791 &S.Context.getFloatTypeSemantics(ToType)) {
1792 bool Float128AndLongDouble = ((FromType == S.Context.Float128Ty &&
1793 ToType == S.Context.LongDoubleTy) ||
1794 (FromType == S.Context.LongDoubleTy &&
1795 ToType == S.Context.Float128Ty));
1796 if (Float128AndLongDouble &&
1797 (&S.Context.getFloatTypeSemantics(S.Context.LongDoubleTy) ==
1798 &llvm::APFloat::PPCDoubleDouble()))
1801 // Floating point conversions (C++ 4.8).
1802 SCS.Second = ICK_Floating_Conversion;
1803 FromType = ToType.getUnqualifiedType();
1804 } else if ((FromType->isRealFloatingType() &&
1805 ToType->isIntegralType(S.Context)) ||
1806 (FromType->isIntegralOrUnscopedEnumerationType() &&
1807 ToType->isRealFloatingType())) {
1808 // Floating-integral conversions (C++ 4.9).
1809 SCS.Second = ICK_Floating_Integral;
1810 FromType = ToType.getUnqualifiedType();
1811 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) {
1812 SCS.Second = ICK_Block_Pointer_Conversion;
1813 } else if (AllowObjCWritebackConversion &&
1814 S.isObjCWritebackConversion(FromType, ToType, FromType)) {
1815 SCS.Second = ICK_Writeback_Conversion;
1816 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution,
1817 FromType, IncompatibleObjC)) {
1818 // Pointer conversions (C++ 4.10).
1819 SCS.Second = ICK_Pointer_Conversion;
1820 SCS.IncompatibleObjC = IncompatibleObjC;
1821 FromType = FromType.getUnqualifiedType();
1822 } else if (S.IsMemberPointerConversion(From, FromType, ToType,
1823 InOverloadResolution, FromType)) {
1824 // Pointer to member conversions (4.11).
1825 SCS.Second = ICK_Pointer_Member;
1826 } else if (IsVectorConversion(S, FromType, ToType, SecondICK)) {
1827 SCS.Second = SecondICK;
1828 FromType = ToType.getUnqualifiedType();
1829 } else if (!S.getLangOpts().CPlusPlus &&
1830 S.Context.typesAreCompatible(ToType, FromType)) {
1831 // Compatible conversions (Clang extension for C function overloading)
1832 SCS.Second = ICK_Compatible_Conversion;
1833 FromType = ToType.getUnqualifiedType();
1834 } else if (IsTransparentUnionStandardConversion(S, From, ToType,
1835 InOverloadResolution,
1837 SCS.Second = ICK_TransparentUnionConversion;
1839 } else if (tryAtomicConversion(S, From, ToType, InOverloadResolution, SCS,
1841 // tryAtomicConversion has updated the standard conversion sequence
1844 } else if (ToType->isEventT() &&
1845 From->isIntegerConstantExpr(S.getASTContext()) &&
1846 From->EvaluateKnownConstInt(S.getASTContext()) == 0) {
1847 SCS.Second = ICK_Zero_Event_Conversion;
1849 } else if (ToType->isQueueT() &&
1850 From->isIntegerConstantExpr(S.getASTContext()) &&
1851 (From->EvaluateKnownConstInt(S.getASTContext()) == 0)) {
1852 SCS.Second = ICK_Zero_Queue_Conversion;
1854 } else if (ToType->isSamplerT() &&
1855 From->isIntegerConstantExpr(S.getASTContext())) {
1856 SCS.Second = ICK_Compatible_Conversion;
1859 // No second conversion required.
1860 SCS.Second = ICK_Identity;
1862 SCS.setToType(1, FromType);
1864 // The third conversion can be a function pointer conversion or a
1865 // qualification conversion (C++ [conv.fctptr], [conv.qual]).
1866 bool ObjCLifetimeConversion;
1867 if (S.IsFunctionConversion(FromType, ToType, FromType)) {
1868 // Function pointer conversions (removing 'noexcept') including removal of
1869 // 'noreturn' (Clang extension).
1870 SCS.Third = ICK_Function_Conversion;
1871 } else if (S.IsQualificationConversion(FromType, ToType, CStyle,
1872 ObjCLifetimeConversion)) {
1873 SCS.Third = ICK_Qualification;
1874 SCS.QualificationIncludesObjCLifetime = ObjCLifetimeConversion;
1877 // No conversion required
1878 SCS.Third = ICK_Identity;
1881 // C++ [over.best.ics]p6:
1882 // [...] Any difference in top-level cv-qualification is
1883 // subsumed by the initialization itself and does not constitute
1884 // a conversion. [...]
1885 QualType CanonFrom = S.Context.getCanonicalType(FromType);
1886 QualType CanonTo = S.Context.getCanonicalType(ToType);
1887 if (CanonFrom.getLocalUnqualifiedType()
1888 == CanonTo.getLocalUnqualifiedType() &&
1889 CanonFrom.getLocalQualifiers() != CanonTo.getLocalQualifiers()) {
1891 CanonFrom = CanonTo;
1894 SCS.setToType(2, FromType);
1896 if (CanonFrom == CanonTo)
1899 // If we have not converted the argument type to the parameter type,
1900 // this is a bad conversion sequence, unless we're resolving an overload in C.
1901 if (S.getLangOpts().CPlusPlus || !InOverloadResolution)
1904 ExprResult ER = ExprResult{From};
1905 Sema::AssignConvertType Conv =
1906 S.CheckSingleAssignmentConstraints(ToType, ER,
1908 /*DiagnoseCFAudited=*/false,
1909 /*ConvertRHS=*/false);
1910 ImplicitConversionKind SecondConv;
1912 case Sema::Compatible:
1913 SecondConv = ICK_C_Only_Conversion;
1915 // For our purposes, discarding qualifiers is just as bad as using an
1916 // incompatible pointer. Note that an IncompatiblePointer conversion can drop
1917 // qualifiers, as well.
1918 case Sema::CompatiblePointerDiscardsQualifiers:
1919 case Sema::IncompatiblePointer:
1920 case Sema::IncompatiblePointerSign:
1921 SecondConv = ICK_Incompatible_Pointer_Conversion;
1927 // First can only be an lvalue conversion, so we pretend that this was the
1928 // second conversion. First should already be valid from earlier in the
1930 SCS.Second = SecondConv;
1931 SCS.setToType(1, ToType);
1933 // Third is Identity, because Second should rank us worse than any other
1934 // conversion. This could also be ICK_Qualification, but it's simpler to just
1935 // lump everything in with the second conversion, and we don't gain anything
1936 // from making this ICK_Qualification.
1937 SCS.Third = ICK_Identity;
1938 SCS.setToType(2, ToType);
1943 IsTransparentUnionStandardConversion(Sema &S, Expr* From,
1945 bool InOverloadResolution,
1946 StandardConversionSequence &SCS,
1949 const RecordType *UT = ToType->getAsUnionType();
1950 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>())
1952 // The field to initialize within the transparent union.
1953 RecordDecl *UD = UT->getDecl();
1954 // It's compatible if the expression matches any of the fields.
1955 for (const auto *it : UD->fields()) {
1956 if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS,
1957 CStyle, /*AllowObjCWritebackConversion=*/false)) {
1958 ToType = it->getType();
1965 /// IsIntegralPromotion - Determines whether the conversion from the
1966 /// expression From (whose potentially-adjusted type is FromType) to
1967 /// ToType is an integral promotion (C++ 4.5). If so, returns true and
1968 /// sets PromotedType to the promoted type.
1969 bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) {
1970 const BuiltinType *To = ToType->getAs<BuiltinType>();
1971 // All integers are built-in.
1976 // An rvalue of type char, signed char, unsigned char, short int, or
1977 // unsigned short int can be converted to an rvalue of type int if
1978 // int can represent all the values of the source type; otherwise,
1979 // the source rvalue can be converted to an rvalue of type unsigned
1981 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() &&
1982 !FromType->isEnumeralType()) {
1983 if (// We can promote any signed, promotable integer type to an int
1984 (FromType->isSignedIntegerType() ||
1985 // We can promote any unsigned integer type whose size is
1986 // less than int to an int.
1987 Context.getTypeSize(FromType) < Context.getTypeSize(ToType))) {
1988 return To->getKind() == BuiltinType::Int;
1991 return To->getKind() == BuiltinType::UInt;
1994 // C++11 [conv.prom]p3:
1995 // A prvalue of an unscoped enumeration type whose underlying type is not
1996 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the
1997 // following types that can represent all the values of the enumeration
1998 // (i.e., the values in the range bmin to bmax as described in 7.2): int,
1999 // unsigned int, long int, unsigned long int, long long int, or unsigned
2000 // long long int. If none of the types in that list can represent all the
2001 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration
2002 // type can be converted to an rvalue a prvalue of the extended integer type
2003 // with lowest integer conversion rank (4.13) greater than the rank of long
2004 // long in which all the values of the enumeration can be represented. If
2005 // there are two such extended types, the signed one is chosen.
2006 // C++11 [conv.prom]p4:
2007 // A prvalue of an unscoped enumeration type whose underlying type is fixed
2008 // can be converted to a prvalue of its underlying type. Moreover, if
2009 // integral promotion can be applied to its underlying type, a prvalue of an
2010 // unscoped enumeration type whose underlying type is fixed can also be
2011 // converted to a prvalue of the promoted underlying type.
2012 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) {
2013 // C++0x 7.2p9: Note that this implicit enum to int conversion is not
2014 // provided for a scoped enumeration.
2015 if (FromEnumType->getDecl()->isScoped())
2018 // We can perform an integral promotion to the underlying type of the enum,
2019 // even if that's not the promoted type. Note that the check for promoting
2020 // the underlying type is based on the type alone, and does not consider
2021 // the bitfield-ness of the actual source expression.
2022 if (FromEnumType->getDecl()->isFixed()) {
2023 QualType Underlying = FromEnumType->getDecl()->getIntegerType();
2024 return Context.hasSameUnqualifiedType(Underlying, ToType) ||
2025 IsIntegralPromotion(nullptr, Underlying, ToType);
2028 // We have already pre-calculated the promotion type, so this is trivial.
2029 if (ToType->isIntegerType() &&
2030 isCompleteType(From->getBeginLoc(), FromType))
2031 return Context.hasSameUnqualifiedType(
2032 ToType, FromEnumType->getDecl()->getPromotionType());
2034 // C++ [conv.prom]p5:
2035 // If the bit-field has an enumerated type, it is treated as any other
2036 // value of that type for promotion purposes.
2038 // ... so do not fall through into the bit-field checks below in C++.
2039 if (getLangOpts().CPlusPlus)
2043 // C++0x [conv.prom]p2:
2044 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted
2045 // to an rvalue a prvalue of the first of the following types that can
2046 // represent all the values of its underlying type: int, unsigned int,
2047 // long int, unsigned long int, long long int, or unsigned long long int.
2048 // If none of the types in that list can represent all the values of its
2049 // underlying type, an rvalue a prvalue of type char16_t, char32_t,
2050 // or wchar_t can be converted to an rvalue a prvalue of its underlying
2052 if (FromType->isAnyCharacterType() && !FromType->isCharType() &&
2053 ToType->isIntegerType()) {
2054 // Determine whether the type we're converting from is signed or
2056 bool FromIsSigned = FromType->isSignedIntegerType();
2057 uint64_t FromSize = Context.getTypeSize(FromType);
2059 // The types we'll try to promote to, in the appropriate
2060 // order. Try each of these types.
2061 QualType PromoteTypes[6] = {
2062 Context.IntTy, Context.UnsignedIntTy,
2063 Context.LongTy, Context.UnsignedLongTy ,
2064 Context.LongLongTy, Context.UnsignedLongLongTy
2066 for (int Idx = 0; Idx < 6; ++Idx) {
2067 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]);
2068 if (FromSize < ToSize ||
2069 (FromSize == ToSize &&
2070 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) {
2071 // We found the type that we can promote to. If this is the
2072 // type we wanted, we have a promotion. Otherwise, no
2074 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]);
2079 // An rvalue for an integral bit-field (9.6) can be converted to an
2080 // rvalue of type int if int can represent all the values of the
2081 // bit-field; otherwise, it can be converted to unsigned int if
2082 // unsigned int can represent all the values of the bit-field. If
2083 // the bit-field is larger yet, no integral promotion applies to
2084 // it. If the bit-field has an enumerated type, it is treated as any
2085 // other value of that type for promotion purposes (C++ 4.5p3).
2086 // FIXME: We should delay checking of bit-fields until we actually perform the
2089 // FIXME: In C, only bit-fields of types _Bool, int, or unsigned int may be
2090 // promoted, per C11 6.3.1.1/2. We promote all bit-fields (including enum
2091 // bit-fields and those whose underlying type is larger than int) for GCC
2094 if (FieldDecl *MemberDecl = From->getSourceBitField()) {
2095 llvm::APSInt BitWidth;
2096 if (FromType->isIntegralType(Context) &&
2097 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) {
2098 llvm::APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned());
2099 ToSize = Context.getTypeSize(ToType);
2101 // Are we promoting to an int from a bitfield that fits in an int?
2102 if (BitWidth < ToSize ||
2103 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) {
2104 return To->getKind() == BuiltinType::Int;
2107 // Are we promoting to an unsigned int from an unsigned bitfield
2108 // that fits into an unsigned int?
2109 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) {
2110 return To->getKind() == BuiltinType::UInt;
2118 // An rvalue of type bool can be converted to an rvalue of type int,
2119 // with false becoming zero and true becoming one (C++ 4.5p4).
2120 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) {
2127 /// IsFloatingPointPromotion - Determines whether the conversion from
2128 /// FromType to ToType is a floating point promotion (C++ 4.6). If so,
2129 /// returns true and sets PromotedType to the promoted type.
2130 bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) {
2131 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>())
2132 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) {
2133 /// An rvalue of type float can be converted to an rvalue of type
2134 /// double. (C++ 4.6p1).
2135 if (FromBuiltin->getKind() == BuiltinType::Float &&
2136 ToBuiltin->getKind() == BuiltinType::Double)
2140 // When a float is promoted to double or long double, or a
2141 // double is promoted to long double [...].
2142 if (!getLangOpts().CPlusPlus &&
2143 (FromBuiltin->getKind() == BuiltinType::Float ||
2144 FromBuiltin->getKind() == BuiltinType::Double) &&
2145 (ToBuiltin->getKind() == BuiltinType::LongDouble ||
2146 ToBuiltin->getKind() == BuiltinType::Float128))
2149 // Half can be promoted to float.
2150 if (!getLangOpts().NativeHalfType &&
2151 FromBuiltin->getKind() == BuiltinType::Half &&
2152 ToBuiltin->getKind() == BuiltinType::Float)
2159 /// Determine if a conversion is a complex promotion.
2161 /// A complex promotion is defined as a complex -> complex conversion
2162 /// where the conversion between the underlying real types is a
2163 /// floating-point or integral promotion.
2164 bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) {
2165 const ComplexType *FromComplex = FromType->getAs<ComplexType>();
2169 const ComplexType *ToComplex = ToType->getAs<ComplexType>();
2173 return IsFloatingPointPromotion(FromComplex->getElementType(),
2174 ToComplex->getElementType()) ||
2175 IsIntegralPromotion(nullptr, FromComplex->getElementType(),
2176 ToComplex->getElementType());
2179 /// BuildSimilarlyQualifiedPointerType - In a pointer conversion from
2180 /// the pointer type FromPtr to a pointer to type ToPointee, with the
2181 /// same type qualifiers as FromPtr has on its pointee type. ToType,
2182 /// if non-empty, will be a pointer to ToType that may or may not have
2183 /// the right set of qualifiers on its pointee.
2186 BuildSimilarlyQualifiedPointerType(const Type *FromPtr,
2187 QualType ToPointee, QualType ToType,
2188 ASTContext &Context,
2189 bool StripObjCLifetime = false) {
2190 assert((FromPtr->getTypeClass() == Type::Pointer ||
2191 FromPtr->getTypeClass() == Type::ObjCObjectPointer) &&
2192 "Invalid similarly-qualified pointer type");
2194 /// Conversions to 'id' subsume cv-qualifier conversions.
2195 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType())
2196 return ToType.getUnqualifiedType();
2198 QualType CanonFromPointee
2199 = Context.getCanonicalType(FromPtr->getPointeeType());
2200 QualType CanonToPointee = Context.getCanonicalType(ToPointee);
2201 Qualifiers Quals = CanonFromPointee.getQualifiers();
2203 if (StripObjCLifetime)
2204 Quals.removeObjCLifetime();
2206 // Exact qualifier match -> return the pointer type we're converting to.
2207 if (CanonToPointee.getLocalQualifiers() == Quals) {
2208 // ToType is exactly what we need. Return it.
2209 if (!ToType.isNull())
2210 return ToType.getUnqualifiedType();
2212 // Build a pointer to ToPointee. It has the right qualifiers
2214 if (isa<ObjCObjectPointerType>(ToType))
2215 return Context.getObjCObjectPointerType(ToPointee);
2216 return Context.getPointerType(ToPointee);
2219 // Just build a canonical type that has the right qualifiers.
2220 QualType QualifiedCanonToPointee
2221 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals);
2223 if (isa<ObjCObjectPointerType>(ToType))
2224 return Context.getObjCObjectPointerType(QualifiedCanonToPointee);
2225 return Context.getPointerType(QualifiedCanonToPointee);
2228 static bool isNullPointerConstantForConversion(Expr *Expr,
2229 bool InOverloadResolution,
2230 ASTContext &Context) {
2231 // Handle value-dependent integral null pointer constants correctly.
2232 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903
2233 if (Expr->isValueDependent() && !Expr->isTypeDependent() &&
2234 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType())
2235 return !InOverloadResolution;
2237 return Expr->isNullPointerConstant(Context,
2238 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
2239 : Expr::NPC_ValueDependentIsNull);
2242 /// IsPointerConversion - Determines whether the conversion of the
2243 /// expression From, which has the (possibly adjusted) type FromType,
2244 /// can be converted to the type ToType via a pointer conversion (C++
2245 /// 4.10). If so, returns true and places the converted type (that
2246 /// might differ from ToType in its cv-qualifiers at some level) into
2249 /// This routine also supports conversions to and from block pointers
2250 /// and conversions with Objective-C's 'id', 'id<protocols...>', and
2251 /// pointers to interfaces. FIXME: Once we've determined the
2252 /// appropriate overloading rules for Objective-C, we may want to
2253 /// split the Objective-C checks into a different routine; however,
2254 /// GCC seems to consider all of these conversions to be pointer
2255 /// conversions, so for now they live here. IncompatibleObjC will be
2256 /// set if the conversion is an allowed Objective-C conversion that
2257 /// should result in a warning.
2258 bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType,
2259 bool InOverloadResolution,
2260 QualType& ConvertedType,
2261 bool &IncompatibleObjC) {
2262 IncompatibleObjC = false;
2263 if (isObjCPointerConversion(FromType, ToType, ConvertedType,
2267 // Conversion from a null pointer constant to any Objective-C pointer type.
2268 if (ToType->isObjCObjectPointerType() &&
2269 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2270 ConvertedType = ToType;
2274 // Blocks: Block pointers can be converted to void*.
2275 if (FromType->isBlockPointerType() && ToType->isPointerType() &&
2276 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) {
2277 ConvertedType = ToType;
2280 // Blocks: A null pointer constant can be converted to a block
2282 if (ToType->isBlockPointerType() &&
2283 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2284 ConvertedType = ToType;
2288 // If the left-hand-side is nullptr_t, the right side can be a null
2289 // pointer constant.
2290 if (ToType->isNullPtrType() &&
2291 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2292 ConvertedType = ToType;
2296 const PointerType* ToTypePtr = ToType->getAs<PointerType>();
2300 // A null pointer constant can be converted to a pointer type (C++ 4.10p1).
2301 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2302 ConvertedType = ToType;
2306 // Beyond this point, both types need to be pointers
2307 // , including objective-c pointers.
2308 QualType ToPointeeType = ToTypePtr->getPointeeType();
2309 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType() &&
2310 !getLangOpts().ObjCAutoRefCount) {
2311 ConvertedType = BuildSimilarlyQualifiedPointerType(
2312 FromType->getAs<ObjCObjectPointerType>(),
2317 const PointerType *FromTypePtr = FromType->getAs<PointerType>();
2321 QualType FromPointeeType = FromTypePtr->getPointeeType();
2323 // If the unqualified pointee types are the same, this can't be a
2324 // pointer conversion, so don't do all of the work below.
2325 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType))
2328 // An rvalue of type "pointer to cv T," where T is an object type,
2329 // can be converted to an rvalue of type "pointer to cv void" (C++
2331 if (FromPointeeType->isIncompleteOrObjectType() &&
2332 ToPointeeType->isVoidType()) {
2333 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2336 /*StripObjCLifetime=*/true);
2340 // MSVC allows implicit function to void* type conversion.
2341 if (getLangOpts().MSVCCompat && FromPointeeType->isFunctionType() &&
2342 ToPointeeType->isVoidType()) {
2343 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2349 // When we're overloading in C, we allow a special kind of pointer
2350 // conversion for compatible-but-not-identical pointee types.
2351 if (!getLangOpts().CPlusPlus &&
2352 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) {
2353 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2359 // C++ [conv.ptr]p3:
2361 // An rvalue of type "pointer to cv D," where D is a class type,
2362 // can be converted to an rvalue of type "pointer to cv B," where
2363 // B is a base class (clause 10) of D. If B is an inaccessible
2364 // (clause 11) or ambiguous (10.2) base class of D, a program that
2365 // necessitates this conversion is ill-formed. The result of the
2366 // conversion is a pointer to the base class sub-object of the
2367 // derived class object. The null pointer value is converted to
2368 // the null pointer value of the destination type.
2370 // Note that we do not check for ambiguity or inaccessibility
2371 // here. That is handled by CheckPointerConversion.
2372 if (getLangOpts().CPlusPlus && FromPointeeType->isRecordType() &&
2373 ToPointeeType->isRecordType() &&
2374 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) &&
2375 IsDerivedFrom(From->getBeginLoc(), FromPointeeType, ToPointeeType)) {
2376 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2382 if (FromPointeeType->isVectorType() && ToPointeeType->isVectorType() &&
2383 Context.areCompatibleVectorTypes(FromPointeeType, ToPointeeType)) {
2384 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2393 /// Adopt the given qualifiers for the given type.
2394 static QualType AdoptQualifiers(ASTContext &Context, QualType T, Qualifiers Qs){
2395 Qualifiers TQs = T.getQualifiers();
2397 // Check whether qualifiers already match.
2401 if (Qs.compatiblyIncludes(TQs))
2402 return Context.getQualifiedType(T, Qs);
2404 return Context.getQualifiedType(T.getUnqualifiedType(), Qs);
2407 /// isObjCPointerConversion - Determines whether this is an
2408 /// Objective-C pointer conversion. Subroutine of IsPointerConversion,
2409 /// with the same arguments and return values.
2410 bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType,
2411 QualType& ConvertedType,
2412 bool &IncompatibleObjC) {
2413 if (!getLangOpts().ObjC)
2416 // The set of qualifiers on the type we're converting from.
2417 Qualifiers FromQualifiers = FromType.getQualifiers();
2419 // First, we handle all conversions on ObjC object pointer types.
2420 const ObjCObjectPointerType* ToObjCPtr =
2421 ToType->getAs<ObjCObjectPointerType>();
2422 const ObjCObjectPointerType *FromObjCPtr =
2423 FromType->getAs<ObjCObjectPointerType>();
2425 if (ToObjCPtr && FromObjCPtr) {
2426 // If the pointee types are the same (ignoring qualifications),
2427 // then this is not a pointer conversion.
2428 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(),
2429 FromObjCPtr->getPointeeType()))
2432 // Conversion between Objective-C pointers.
2433 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) {
2434 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType();
2435 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType();
2436 if (getLangOpts().CPlusPlus && LHS && RHS &&
2437 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs(
2438 FromObjCPtr->getPointeeType()))
2440 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2441 ToObjCPtr->getPointeeType(),
2443 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2447 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) {
2448 // Okay: this is some kind of implicit downcast of Objective-C
2449 // interfaces, which is permitted. However, we're going to
2450 // complain about it.
2451 IncompatibleObjC = true;
2452 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2453 ToObjCPtr->getPointeeType(),
2455 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2459 // Beyond this point, both types need to be C pointers or block pointers.
2460 QualType ToPointeeType;
2461 if (const PointerType *ToCPtr = ToType->getAs<PointerType>())
2462 ToPointeeType = ToCPtr->getPointeeType();
2463 else if (const BlockPointerType *ToBlockPtr =
2464 ToType->getAs<BlockPointerType>()) {
2465 // Objective C++: We're able to convert from a pointer to any object
2466 // to a block pointer type.
2467 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) {
2468 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2471 ToPointeeType = ToBlockPtr->getPointeeType();
2473 else if (FromType->getAs<BlockPointerType>() &&
2474 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) {
2475 // Objective C++: We're able to convert from a block pointer type to a
2476 // pointer to any object.
2477 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2483 QualType FromPointeeType;
2484 if (const PointerType *FromCPtr = FromType->getAs<PointerType>())
2485 FromPointeeType = FromCPtr->getPointeeType();
2486 else if (const BlockPointerType *FromBlockPtr =
2487 FromType->getAs<BlockPointerType>())
2488 FromPointeeType = FromBlockPtr->getPointeeType();
2492 // If we have pointers to pointers, recursively check whether this
2493 // is an Objective-C conversion.
2494 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() &&
2495 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2496 IncompatibleObjC)) {
2497 // We always complain about this conversion.
2498 IncompatibleObjC = true;
2499 ConvertedType = Context.getPointerType(ConvertedType);
2500 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2503 // Allow conversion of pointee being objective-c pointer to another one;
2505 if (FromPointeeType->getAs<ObjCObjectPointerType>() &&
2506 ToPointeeType->getAs<ObjCObjectPointerType>() &&
2507 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2508 IncompatibleObjC)) {
2510 ConvertedType = Context.getPointerType(ConvertedType);
2511 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2515 // If we have pointers to functions or blocks, check whether the only
2516 // differences in the argument and result types are in Objective-C
2517 // pointer conversions. If so, we permit the conversion (but
2518 // complain about it).
2519 const FunctionProtoType *FromFunctionType
2520 = FromPointeeType->getAs<FunctionProtoType>();
2521 const FunctionProtoType *ToFunctionType
2522 = ToPointeeType->getAs<FunctionProtoType>();
2523 if (FromFunctionType && ToFunctionType) {
2524 // If the function types are exactly the same, this isn't an
2525 // Objective-C pointer conversion.
2526 if (Context.getCanonicalType(FromPointeeType)
2527 == Context.getCanonicalType(ToPointeeType))
2530 // Perform the quick checks that will tell us whether these
2531 // function types are obviously different.
2532 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2533 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() ||
2534 FromFunctionType->getMethodQuals() != ToFunctionType->getMethodQuals())
2537 bool HasObjCConversion = false;
2538 if (Context.getCanonicalType(FromFunctionType->getReturnType()) ==
2539 Context.getCanonicalType(ToFunctionType->getReturnType())) {
2540 // Okay, the types match exactly. Nothing to do.
2541 } else if (isObjCPointerConversion(FromFunctionType->getReturnType(),
2542 ToFunctionType->getReturnType(),
2543 ConvertedType, IncompatibleObjC)) {
2544 // Okay, we have an Objective-C pointer conversion.
2545 HasObjCConversion = true;
2547 // Function types are too different. Abort.
2551 // Check argument types.
2552 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2553 ArgIdx != NumArgs; ++ArgIdx) {
2554 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2555 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2556 if (Context.getCanonicalType(FromArgType)
2557 == Context.getCanonicalType(ToArgType)) {
2558 // Okay, the types match exactly. Nothing to do.
2559 } else if (isObjCPointerConversion(FromArgType, ToArgType,
2560 ConvertedType, IncompatibleObjC)) {
2561 // Okay, we have an Objective-C pointer conversion.
2562 HasObjCConversion = true;
2564 // Argument types are too different. Abort.
2569 if (HasObjCConversion) {
2570 // We had an Objective-C conversion. Allow this pointer
2571 // conversion, but complain about it.
2572 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2573 IncompatibleObjC = true;
2581 /// Determine whether this is an Objective-C writeback conversion,
2582 /// used for parameter passing when performing automatic reference counting.
2584 /// \param FromType The type we're converting form.
2586 /// \param ToType The type we're converting to.
2588 /// \param ConvertedType The type that will be produced after applying
2589 /// this conversion.
2590 bool Sema::isObjCWritebackConversion(QualType FromType, QualType ToType,
2591 QualType &ConvertedType) {
2592 if (!getLangOpts().ObjCAutoRefCount ||
2593 Context.hasSameUnqualifiedType(FromType, ToType))
2596 // Parameter must be a pointer to __autoreleasing (with no other qualifiers).
2598 if (const PointerType *ToPointer = ToType->getAs<PointerType>())
2599 ToPointee = ToPointer->getPointeeType();
2603 Qualifiers ToQuals = ToPointee.getQualifiers();
2604 if (!ToPointee->isObjCLifetimeType() ||
2605 ToQuals.getObjCLifetime() != Qualifiers::OCL_Autoreleasing ||
2606 !ToQuals.withoutObjCLifetime().empty())
2609 // Argument must be a pointer to __strong to __weak.
2610 QualType FromPointee;
2611 if (const PointerType *FromPointer = FromType->getAs<PointerType>())
2612 FromPointee = FromPointer->getPointeeType();
2616 Qualifiers FromQuals = FromPointee.getQualifiers();
2617 if (!FromPointee->isObjCLifetimeType() ||
2618 (FromQuals.getObjCLifetime() != Qualifiers::OCL_Strong &&
2619 FromQuals.getObjCLifetime() != Qualifiers::OCL_Weak))
2622 // Make sure that we have compatible qualifiers.
2623 FromQuals.setObjCLifetime(Qualifiers::OCL_Autoreleasing);
2624 if (!ToQuals.compatiblyIncludes(FromQuals))
2627 // Remove qualifiers from the pointee type we're converting from; they
2628 // aren't used in the compatibility check belong, and we'll be adding back
2629 // qualifiers (with __autoreleasing) if the compatibility check succeeds.
2630 FromPointee = FromPointee.getUnqualifiedType();
2632 // The unqualified form of the pointee types must be compatible.
2633 ToPointee = ToPointee.getUnqualifiedType();
2634 bool IncompatibleObjC;
2635 if (Context.typesAreCompatible(FromPointee, ToPointee))
2636 FromPointee = ToPointee;
2637 else if (!isObjCPointerConversion(FromPointee, ToPointee, FromPointee,
2641 /// Construct the type we're converting to, which is a pointer to
2642 /// __autoreleasing pointee.
2643 FromPointee = Context.getQualifiedType(FromPointee, FromQuals);
2644 ConvertedType = Context.getPointerType(FromPointee);
2648 bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType,
2649 QualType& ConvertedType) {
2650 QualType ToPointeeType;
2651 if (const BlockPointerType *ToBlockPtr =
2652 ToType->getAs<BlockPointerType>())
2653 ToPointeeType = ToBlockPtr->getPointeeType();
2657 QualType FromPointeeType;
2658 if (const BlockPointerType *FromBlockPtr =
2659 FromType->getAs<BlockPointerType>())
2660 FromPointeeType = FromBlockPtr->getPointeeType();
2663 // We have pointer to blocks, check whether the only
2664 // differences in the argument and result types are in Objective-C
2665 // pointer conversions. If so, we permit the conversion.
2667 const FunctionProtoType *FromFunctionType
2668 = FromPointeeType->getAs<FunctionProtoType>();
2669 const FunctionProtoType *ToFunctionType
2670 = ToPointeeType->getAs<FunctionProtoType>();
2672 if (!FromFunctionType || !ToFunctionType)
2675 if (Context.hasSameType(FromPointeeType, ToPointeeType))
2678 // Perform the quick checks that will tell us whether these
2679 // function types are obviously different.
2680 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2681 FromFunctionType->isVariadic() != ToFunctionType->isVariadic())
2684 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo();
2685 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo();
2686 if (FromEInfo != ToEInfo)
2689 bool IncompatibleObjC = false;
2690 if (Context.hasSameType(FromFunctionType->getReturnType(),
2691 ToFunctionType->getReturnType())) {
2692 // Okay, the types match exactly. Nothing to do.
2694 QualType RHS = FromFunctionType->getReturnType();
2695 QualType LHS = ToFunctionType->getReturnType();
2696 if ((!getLangOpts().CPlusPlus || !RHS->isRecordType()) &&
2697 !RHS.hasQualifiers() && LHS.hasQualifiers())
2698 LHS = LHS.getUnqualifiedType();
2700 if (Context.hasSameType(RHS,LHS)) {
2702 } else if (isObjCPointerConversion(RHS, LHS,
2703 ConvertedType, IncompatibleObjC)) {
2704 if (IncompatibleObjC)
2706 // Okay, we have an Objective-C pointer conversion.
2712 // Check argument types.
2713 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2714 ArgIdx != NumArgs; ++ArgIdx) {
2715 IncompatibleObjC = false;
2716 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2717 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2718 if (Context.hasSameType(FromArgType, ToArgType)) {
2719 // Okay, the types match exactly. Nothing to do.
2720 } else if (isObjCPointerConversion(ToArgType, FromArgType,
2721 ConvertedType, IncompatibleObjC)) {
2722 if (IncompatibleObjC)
2724 // Okay, we have an Objective-C pointer conversion.
2726 // Argument types are too different. Abort.
2730 SmallVector<FunctionProtoType::ExtParameterInfo, 4> NewParamInfos;
2731 bool CanUseToFPT, CanUseFromFPT;
2732 if (!Context.mergeExtParameterInfo(ToFunctionType, FromFunctionType,
2733 CanUseToFPT, CanUseFromFPT,
2737 ConvertedType = ToType;
2745 ft_parameter_mismatch,
2747 ft_qualifer_mismatch,
2751 /// Attempts to get the FunctionProtoType from a Type. Handles
2752 /// MemberFunctionPointers properly.
2753 static const FunctionProtoType *tryGetFunctionProtoType(QualType FromType) {
2754 if (auto *FPT = FromType->getAs<FunctionProtoType>())
2757 if (auto *MPT = FromType->getAs<MemberPointerType>())
2758 return MPT->getPointeeType()->getAs<FunctionProtoType>();
2763 /// HandleFunctionTypeMismatch - Gives diagnostic information for differeing
2764 /// function types. Catches different number of parameter, mismatch in
2765 /// parameter types, and different return types.
2766 void Sema::HandleFunctionTypeMismatch(PartialDiagnostic &PDiag,
2767 QualType FromType, QualType ToType) {
2768 // If either type is not valid, include no extra info.
2769 if (FromType.isNull() || ToType.isNull()) {
2770 PDiag << ft_default;
2774 // Get the function type from the pointers.
2775 if (FromType->isMemberPointerType() && ToType->isMemberPointerType()) {
2776 const MemberPointerType *FromMember = FromType->getAs<MemberPointerType>(),
2777 *ToMember = ToType->getAs<MemberPointerType>();
2778 if (!Context.hasSameType(FromMember->getClass(), ToMember->getClass())) {
2779 PDiag << ft_different_class << QualType(ToMember->getClass(), 0)
2780 << QualType(FromMember->getClass(), 0);
2783 FromType = FromMember->getPointeeType();
2784 ToType = ToMember->getPointeeType();
2787 if (FromType->isPointerType())
2788 FromType = FromType->getPointeeType();
2789 if (ToType->isPointerType())
2790 ToType = ToType->getPointeeType();
2792 // Remove references.
2793 FromType = FromType.getNonReferenceType();
2794 ToType = ToType.getNonReferenceType();
2796 // Don't print extra info for non-specialized template functions.
2797 if (FromType->isInstantiationDependentType() &&
2798 !FromType->getAs<TemplateSpecializationType>()) {
2799 PDiag << ft_default;
2803 // No extra info for same types.
2804 if (Context.hasSameType(FromType, ToType)) {
2805 PDiag << ft_default;
2809 const FunctionProtoType *FromFunction = tryGetFunctionProtoType(FromType),
2810 *ToFunction = tryGetFunctionProtoType(ToType);
2812 // Both types need to be function types.
2813 if (!FromFunction || !ToFunction) {
2814 PDiag << ft_default;
2818 if (FromFunction->getNumParams() != ToFunction->getNumParams()) {
2819 PDiag << ft_parameter_arity << ToFunction->getNumParams()
2820 << FromFunction->getNumParams();
2824 // Handle different parameter types.
2826 if (!FunctionParamTypesAreEqual(FromFunction, ToFunction, &ArgPos)) {
2827 PDiag << ft_parameter_mismatch << ArgPos + 1
2828 << ToFunction->getParamType(ArgPos)
2829 << FromFunction->getParamType(ArgPos);
2833 // Handle different return type.
2834 if (!Context.hasSameType(FromFunction->getReturnType(),
2835 ToFunction->getReturnType())) {
2836 PDiag << ft_return_type << ToFunction->getReturnType()
2837 << FromFunction->getReturnType();
2841 if (FromFunction->getMethodQuals() != ToFunction->getMethodQuals()) {
2842 PDiag << ft_qualifer_mismatch << ToFunction->getMethodQuals()
2843 << FromFunction->getMethodQuals();
2847 // Handle exception specification differences on canonical type (in C++17
2849 if (cast<FunctionProtoType>(FromFunction->getCanonicalTypeUnqualified())
2851 cast<FunctionProtoType>(ToFunction->getCanonicalTypeUnqualified())
2853 PDiag << ft_noexcept;
2857 // Unable to find a difference, so add no extra info.
2858 PDiag << ft_default;
2861 /// FunctionParamTypesAreEqual - This routine checks two function proto types
2862 /// for equality of their argument types. Caller has already checked that
2863 /// they have same number of arguments. If the parameters are different,
2864 /// ArgPos will have the parameter index of the first different parameter.
2865 bool Sema::FunctionParamTypesAreEqual(const FunctionProtoType *OldType,
2866 const FunctionProtoType *NewType,
2868 for (FunctionProtoType::param_type_iterator O = OldType->param_type_begin(),
2869 N = NewType->param_type_begin(),
2870 E = OldType->param_type_end();
2871 O && (O != E); ++O, ++N) {
2872 if (!Context.hasSameType(O->getUnqualifiedType(),
2873 N->getUnqualifiedType())) {
2875 *ArgPos = O - OldType->param_type_begin();
2882 /// CheckPointerConversion - Check the pointer conversion from the
2883 /// expression From to the type ToType. This routine checks for
2884 /// ambiguous or inaccessible derived-to-base pointer
2885 /// conversions for which IsPointerConversion has already returned
2886 /// true. It returns true and produces a diagnostic if there was an
2887 /// error, or returns false otherwise.
2888 bool Sema::CheckPointerConversion(Expr *From, QualType ToType,
2890 CXXCastPath& BasePath,
2891 bool IgnoreBaseAccess,
2893 QualType FromType = From->getType();
2894 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess;
2898 if (Diagnose && !IsCStyleOrFunctionalCast && !FromType->isAnyPointerType() &&
2899 From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) ==
2900 Expr::NPCK_ZeroExpression) {
2901 if (Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy))
2902 DiagRuntimeBehavior(From->getExprLoc(), From,
2903 PDiag(diag::warn_impcast_bool_to_null_pointer)
2904 << ToType << From->getSourceRange());
2905 else if (!isUnevaluatedContext())
2906 Diag(From->getExprLoc(), diag::warn_non_literal_null_pointer)
2907 << ToType << From->getSourceRange();
2909 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) {
2910 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) {
2911 QualType FromPointeeType = FromPtrType->getPointeeType(),
2912 ToPointeeType = ToPtrType->getPointeeType();
2914 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() &&
2915 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) {
2916 // We must have a derived-to-base conversion. Check an
2917 // ambiguous or inaccessible conversion.
2918 unsigned InaccessibleID = 0;
2919 unsigned AmbigiousID = 0;
2921 InaccessibleID = diag::err_upcast_to_inaccessible_base;
2922 AmbigiousID = diag::err_ambiguous_derived_to_base_conv;
2924 if (CheckDerivedToBaseConversion(
2925 FromPointeeType, ToPointeeType, InaccessibleID, AmbigiousID,
2926 From->getExprLoc(), From->getSourceRange(), DeclarationName(),
2927 &BasePath, IgnoreBaseAccess))
2930 // The conversion was successful.
2931 Kind = CK_DerivedToBase;
2934 if (Diagnose && !IsCStyleOrFunctionalCast &&
2935 FromPointeeType->isFunctionType() && ToPointeeType->isVoidType()) {
2936 assert(getLangOpts().MSVCCompat &&
2937 "this should only be possible with MSVCCompat!");
2938 Diag(From->getExprLoc(), diag::ext_ms_impcast_fn_obj)
2939 << From->getSourceRange();
2942 } else if (const ObjCObjectPointerType *ToPtrType =
2943 ToType->getAs<ObjCObjectPointerType>()) {
2944 if (const ObjCObjectPointerType *FromPtrType =
2945 FromType->getAs<ObjCObjectPointerType>()) {
2946 // Objective-C++ conversions are always okay.
2947 // FIXME: We should have a different class of conversions for the
2948 // Objective-C++ implicit conversions.
2949 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType())
2951 } else if (FromType->isBlockPointerType()) {
2952 Kind = CK_BlockPointerToObjCPointerCast;
2954 Kind = CK_CPointerToObjCPointerCast;
2956 } else if (ToType->isBlockPointerType()) {
2957 if (!FromType->isBlockPointerType())
2958 Kind = CK_AnyPointerToBlockPointerCast;
2961 // We shouldn't fall into this case unless it's valid for other
2963 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull))
2964 Kind = CK_NullToPointer;
2969 /// IsMemberPointerConversion - Determines whether the conversion of the
2970 /// expression From, which has the (possibly adjusted) type FromType, can be
2971 /// converted to the type ToType via a member pointer conversion (C++ 4.11).
2972 /// If so, returns true and places the converted type (that might differ from
2973 /// ToType in its cv-qualifiers at some level) into ConvertedType.
2974 bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType,
2976 bool InOverloadResolution,
2977 QualType &ConvertedType) {
2978 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>();
2982 // A null pointer constant can be converted to a member pointer (C++ 4.11p1)
2983 if (From->isNullPointerConstant(Context,
2984 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
2985 : Expr::NPC_ValueDependentIsNull)) {
2986 ConvertedType = ToType;
2990 // Otherwise, both types have to be member pointers.
2991 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>();
2995 // A pointer to member of B can be converted to a pointer to member of D,
2996 // where D is derived from B (C++ 4.11p2).
2997 QualType FromClass(FromTypePtr->getClass(), 0);
2998 QualType ToClass(ToTypePtr->getClass(), 0);
3000 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) &&
3001 IsDerivedFrom(From->getBeginLoc(), ToClass, FromClass)) {
3002 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(),
3003 ToClass.getTypePtr());
3010 /// CheckMemberPointerConversion - Check the member pointer conversion from the
3011 /// expression From to the type ToType. This routine checks for ambiguous or
3012 /// virtual or inaccessible base-to-derived member pointer conversions
3013 /// for which IsMemberPointerConversion has already returned true. It returns
3014 /// true and produces a diagnostic if there was an error, or returns false
3016 bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType,
3018 CXXCastPath &BasePath,
3019 bool IgnoreBaseAccess) {
3020 QualType FromType = From->getType();
3021 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>();
3023 // This must be a null pointer to member pointer conversion
3024 assert(From->isNullPointerConstant(Context,
3025 Expr::NPC_ValueDependentIsNull) &&
3026 "Expr must be null pointer constant!");
3027 Kind = CK_NullToMemberPointer;
3031 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>();
3032 assert(ToPtrType && "No member pointer cast has a target type "
3033 "that is not a member pointer.");
3035 QualType FromClass = QualType(FromPtrType->getClass(), 0);
3036 QualType ToClass = QualType(ToPtrType->getClass(), 0);
3038 // FIXME: What about dependent types?
3039 assert(FromClass->isRecordType() && "Pointer into non-class.");
3040 assert(ToClass->isRecordType() && "Pointer into non-class.");
3042 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
3043 /*DetectVirtual=*/true);
3044 bool DerivationOkay =
3045 IsDerivedFrom(From->getBeginLoc(), ToClass, FromClass, Paths);
3046 assert(DerivationOkay &&
3047 "Should not have been called if derivation isn't OK.");
3048 (void)DerivationOkay;
3050 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass).
3051 getUnqualifiedType())) {
3052 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
3053 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv)
3054 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange();
3058 if (const RecordType *VBase = Paths.getDetectedVirtual()) {
3059 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual)
3060 << FromClass << ToClass << QualType(VBase, 0)
3061 << From->getSourceRange();
3065 if (!IgnoreBaseAccess)
3066 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass,
3068 diag::err_downcast_from_inaccessible_base);
3070 // Must be a base to derived member conversion.
3071 BuildBasePathArray(Paths, BasePath);
3072 Kind = CK_BaseToDerivedMemberPointer;
3076 /// Determine whether the lifetime conversion between the two given
3077 /// qualifiers sets is nontrivial.
3078 static bool isNonTrivialObjCLifetimeConversion(Qualifiers FromQuals,
3079 Qualifiers ToQuals) {
3080 // Converting anything to const __unsafe_unretained is trivial.
3081 if (ToQuals.hasConst() &&
3082 ToQuals.getObjCLifetime() == Qualifiers::OCL_ExplicitNone)
3088 /// IsQualificationConversion - Determines whether the conversion from
3089 /// an rvalue of type FromType to ToType is a qualification conversion
3092 /// \param ObjCLifetimeConversion Output parameter that will be set to indicate
3093 /// when the qualification conversion involves a change in the Objective-C
3094 /// object lifetime.
3096 Sema::IsQualificationConversion(QualType FromType, QualType ToType,
3097 bool CStyle, bool &ObjCLifetimeConversion) {
3098 FromType = Context.getCanonicalType(FromType);
3099 ToType = Context.getCanonicalType(ToType);
3100 ObjCLifetimeConversion = false;
3102 // If FromType and ToType are the same type, this is not a
3103 // qualification conversion.
3104 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType())
3108 // A conversion can add cv-qualifiers at levels other than the first
3109 // in multi-level pointers, subject to the following rules: [...]
3110 bool PreviousToQualsIncludeConst = true;
3111 bool UnwrappedAnyPointer = false;
3112 while (Context.UnwrapSimilarTypes(FromType, ToType)) {
3113 // Within each iteration of the loop, we check the qualifiers to
3114 // determine if this still looks like a qualification
3115 // conversion. Then, if all is well, we unwrap one more level of
3116 // pointers or pointers-to-members and do it all again
3117 // until there are no more pointers or pointers-to-members left to
3119 UnwrappedAnyPointer = true;
3121 Qualifiers FromQuals = FromType.getQualifiers();
3122 Qualifiers ToQuals = ToType.getQualifiers();
3124 // Ignore __unaligned qualifier if this type is void.
3125 if (ToType.getUnqualifiedType()->isVoidType())
3126 FromQuals.removeUnaligned();
3129 // Check Objective-C lifetime conversions.
3130 if (FromQuals.getObjCLifetime() != ToQuals.getObjCLifetime() &&
3131 UnwrappedAnyPointer) {
3132 if (ToQuals.compatiblyIncludesObjCLifetime(FromQuals)) {
3133 if (isNonTrivialObjCLifetimeConversion(FromQuals, ToQuals))
3134 ObjCLifetimeConversion = true;
3135 FromQuals.removeObjCLifetime();
3136 ToQuals.removeObjCLifetime();
3138 // Qualification conversions cannot cast between different
3139 // Objective-C lifetime qualifiers.
3144 // Allow addition/removal of GC attributes but not changing GC attributes.
3145 if (FromQuals.getObjCGCAttr() != ToQuals.getObjCGCAttr() &&
3146 (!FromQuals.hasObjCGCAttr() || !ToQuals.hasObjCGCAttr())) {
3147 FromQuals.removeObjCGCAttr();
3148 ToQuals.removeObjCGCAttr();
3151 // -- for every j > 0, if const is in cv 1,j then const is in cv
3152 // 2,j, and similarly for volatile.
3153 if (!CStyle && !ToQuals.compatiblyIncludes(FromQuals))
3156 // -- if the cv 1,j and cv 2,j are different, then const is in
3157 // every cv for 0 < k < j.
3158 if (!CStyle && FromQuals.getCVRQualifiers() != ToQuals.getCVRQualifiers()
3159 && !PreviousToQualsIncludeConst)
3162 // Keep track of whether all prior cv-qualifiers in the "to" type
3164 PreviousToQualsIncludeConst
3165 = PreviousToQualsIncludeConst && ToQuals.hasConst();
3168 // Allows address space promotion by language rules implemented in
3169 // Type::Qualifiers::isAddressSpaceSupersetOf.
3170 Qualifiers FromQuals = FromType.getQualifiers();
3171 Qualifiers ToQuals = ToType.getQualifiers();
3172 if (!ToQuals.isAddressSpaceSupersetOf(FromQuals) &&
3173 !FromQuals.isAddressSpaceSupersetOf(ToQuals)) {
3177 // We are left with FromType and ToType being the pointee types
3178 // after unwrapping the original FromType and ToType the same number
3179 // of types. If we unwrapped any pointers, and if FromType and
3180 // ToType have the same unqualified type (since we checked
3181 // qualifiers above), then this is a qualification conversion.
3182 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType);
3185 /// - Determine whether this is a conversion from a scalar type to an
3188 /// If successful, updates \c SCS's second and third steps in the conversion
3189 /// sequence to finish the conversion.
3190 static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
3191 bool InOverloadResolution,
3192 StandardConversionSequence &SCS,
3194 const AtomicType *ToAtomic = ToType->getAs<AtomicType>();
3198 StandardConversionSequence InnerSCS;
3199 if (!IsStandardConversion(S, From, ToAtomic->getValueType(),
3200 InOverloadResolution, InnerSCS,
3201 CStyle, /*AllowObjCWritebackConversion=*/false))
3204 SCS.Second = InnerSCS.Second;
3205 SCS.setToType(1, InnerSCS.getToType(1));
3206 SCS.Third = InnerSCS.Third;
3207 SCS.QualificationIncludesObjCLifetime
3208 = InnerSCS.QualificationIncludesObjCLifetime;
3209 SCS.setToType(2, InnerSCS.getToType(2));
3213 static bool isFirstArgumentCompatibleWithType(ASTContext &Context,
3214 CXXConstructorDecl *Constructor,
3216 const FunctionProtoType *CtorType =
3217 Constructor->getType()->getAs<FunctionProtoType>();
3218 if (CtorType->getNumParams() > 0) {
3219 QualType FirstArg = CtorType->getParamType(0);
3220 if (Context.hasSameUnqualifiedType(Type, FirstArg.getNonReferenceType()))
3226 static OverloadingResult
3227 IsInitializerListConstructorConversion(Sema &S, Expr *From, QualType ToType,
3229 UserDefinedConversionSequence &User,
3230 OverloadCandidateSet &CandidateSet,
3231 bool AllowExplicit) {
3232 CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion);
3233 for (auto *D : S.LookupConstructors(To)) {
3234 auto Info = getConstructorInfo(D);
3238 bool Usable = !Info.Constructor->isInvalidDecl() &&
3239 S.isInitListConstructor(Info.Constructor) &&
3240 (AllowExplicit || !Info.Constructor->isExplicit());
3242 // If the first argument is (a reference to) the target type,
3243 // suppress conversions.
3244 bool SuppressUserConversions = isFirstArgumentCompatibleWithType(
3245 S.Context, Info.Constructor, ToType);
3246 if (Info.ConstructorTmpl)
3247 S.AddTemplateOverloadCandidate(Info.ConstructorTmpl, Info.FoundDecl,
3248 /*ExplicitArgs*/ nullptr, From,
3249 CandidateSet, SuppressUserConversions,
3250 /*PartialOverloading*/ false,
3253 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl, From,
3254 CandidateSet, SuppressUserConversions,
3255 /*PartialOverloading*/ false, AllowExplicit);
3259 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3261 OverloadCandidateSet::iterator Best;
3262 switch (auto Result =
3263 CandidateSet.BestViableFunction(S, From->getBeginLoc(), Best)) {
3266 // Record the standard conversion we used and the conversion function.
3267 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function);
3268 QualType ThisType = Constructor->getThisType();
3269 // Initializer lists don't have conversions as such.
3270 User.Before.setAsIdentityConversion();
3271 User.HadMultipleCandidates = HadMultipleCandidates;
3272 User.ConversionFunction = Constructor;
3273 User.FoundConversionFunction = Best->FoundDecl;
3274 User.After.setAsIdentityConversion();
3275 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType());
3276 User.After.setAllToTypes(ToType);
3280 case OR_No_Viable_Function:
3281 return OR_No_Viable_Function;
3283 return OR_Ambiguous;
3286 llvm_unreachable("Invalid OverloadResult!");
3289 /// Determines whether there is a user-defined conversion sequence
3290 /// (C++ [over.ics.user]) that converts expression From to the type
3291 /// ToType. If such a conversion exists, User will contain the
3292 /// user-defined conversion sequence that performs such a conversion
3293 /// and this routine will return true. Otherwise, this routine returns
3294 /// false and User is unspecified.
3296 /// \param AllowExplicit true if the conversion should consider C++0x
3297 /// "explicit" conversion functions as well as non-explicit conversion
3298 /// functions (C++0x [class.conv.fct]p2).
3300 /// \param AllowObjCConversionOnExplicit true if the conversion should
3301 /// allow an extra Objective-C pointer conversion on uses of explicit
3302 /// constructors. Requires \c AllowExplicit to also be set.
3303 static OverloadingResult
3304 IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
3305 UserDefinedConversionSequence &User,
3306 OverloadCandidateSet &CandidateSet,
3308 bool AllowObjCConversionOnExplicit) {
3309 assert(AllowExplicit || !AllowObjCConversionOnExplicit);
3310 CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion);
3312 // Whether we will only visit constructors.
3313 bool ConstructorsOnly = false;
3315 // If the type we are conversion to is a class type, enumerate its
3317 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) {
3318 // C++ [over.match.ctor]p1:
3319 // When objects of class type are direct-initialized (8.5), or
3320 // copy-initialized from an expression of the same or a
3321 // derived class type (8.5), overload resolution selects the
3322 // constructor. [...] For copy-initialization, the candidate
3323 // functions are all the converting constructors (12.3.1) of
3324 // that class. The argument list is the expression-list within
3325 // the parentheses of the initializer.
3326 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) ||
3327 (From->getType()->getAs<RecordType>() &&
3328 S.IsDerivedFrom(From->getBeginLoc(), From->getType(), ToType)))
3329 ConstructorsOnly = true;
3331 if (!S.isCompleteType(From->getExprLoc(), ToType)) {
3332 // We're not going to find any constructors.
3333 } else if (CXXRecordDecl *ToRecordDecl
3334 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) {
3336 Expr **Args = &From;
3337 unsigned NumArgs = 1;
3338 bool ListInitializing = false;
3339 if (InitListExpr *InitList = dyn_cast<InitListExpr>(From)) {
3340 // But first, see if there is an init-list-constructor that will work.
3341 OverloadingResult Result = IsInitializerListConstructorConversion(
3342 S, From, ToType, ToRecordDecl, User, CandidateSet, AllowExplicit);
3343 if (Result != OR_No_Viable_Function)
3347 OverloadCandidateSet::CSK_InitByUserDefinedConversion);
3349 // If we're list-initializing, we pass the individual elements as
3350 // arguments, not the entire list.
3351 Args = InitList->getInits();
3352 NumArgs = InitList->getNumInits();
3353 ListInitializing = true;
3356 for (auto *D : S.LookupConstructors(ToRecordDecl)) {
3357 auto Info = getConstructorInfo(D);
3361 bool Usable = !Info.Constructor->isInvalidDecl();
3362 if (ListInitializing)
3363 Usable = Usable && (AllowExplicit || !Info.Constructor->isExplicit());
3366 Info.Constructor->isConvertingConstructor(AllowExplicit);
3368 bool SuppressUserConversions = !ConstructorsOnly;
3369 if (SuppressUserConversions && ListInitializing) {
3370 SuppressUserConversions = false;
3372 // If the first argument is (a reference to) the target type,
3373 // suppress conversions.
3374 SuppressUserConversions = isFirstArgumentCompatibleWithType(
3375 S.Context, Info.Constructor, ToType);
3378 if (Info.ConstructorTmpl)
3379 S.AddTemplateOverloadCandidate(
3380 Info.ConstructorTmpl, Info.FoundDecl,
3381 /*ExplicitArgs*/ nullptr, llvm::makeArrayRef(Args, NumArgs),
3382 CandidateSet, SuppressUserConversions,
3383 /*PartialOverloading*/ false, AllowExplicit);
3385 // Allow one user-defined conversion when user specifies a
3386 // From->ToType conversion via an static cast (c-style, etc).
3387 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl,
3388 llvm::makeArrayRef(Args, NumArgs),
3389 CandidateSet, SuppressUserConversions,
3390 /*PartialOverloading*/ false, AllowExplicit);
3396 // Enumerate conversion functions, if we're allowed to.
3397 if (ConstructorsOnly || isa<InitListExpr>(From)) {
3398 } else if (!S.isCompleteType(From->getBeginLoc(), From->getType())) {
3399 // No conversion functions from incomplete types.
3400 } else if (const RecordType *FromRecordType =
3401 From->getType()->getAs<RecordType>()) {
3402 if (CXXRecordDecl *FromRecordDecl
3403 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) {
3404 // Add all of the conversion functions as candidates.
3405 const auto &Conversions = FromRecordDecl->getVisibleConversionFunctions();
3406 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
3407 DeclAccessPair FoundDecl = I.getPair();
3408 NamedDecl *D = FoundDecl.getDecl();
3409 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
3410 if (isa<UsingShadowDecl>(D))
3411 D = cast<UsingShadowDecl>(D)->getTargetDecl();
3413 CXXConversionDecl *Conv;
3414 FunctionTemplateDecl *ConvTemplate;
3415 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
3416 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
3418 Conv = cast<CXXConversionDecl>(D);
3420 if (AllowExplicit || !Conv->isExplicit()) {
3422 S.AddTemplateConversionCandidate(
3423 ConvTemplate, FoundDecl, ActingContext, From, ToType,
3424 CandidateSet, AllowObjCConversionOnExplicit, AllowExplicit);
3426 S.AddConversionCandidate(
3427 Conv, FoundDecl, ActingContext, From, ToType, CandidateSet,
3428 AllowObjCConversionOnExplicit, AllowExplicit);
3434 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3436 OverloadCandidateSet::iterator Best;
3437 switch (auto Result =
3438 CandidateSet.BestViableFunction(S, From->getBeginLoc(), Best)) {
3441 // Record the standard conversion we used and the conversion function.
3442 if (CXXConstructorDecl *Constructor
3443 = dyn_cast<CXXConstructorDecl>(Best->Function)) {
3444 // C++ [over.ics.user]p1:
3445 // If the user-defined conversion is specified by a
3446 // constructor (12.3.1), the initial standard conversion
3447 // sequence converts the source type to the type required by
3448 // the argument of the constructor.
3450 QualType ThisType = Constructor->getThisType();
3451 if (isa<InitListExpr>(From)) {
3452 // Initializer lists don't have conversions as such.
3453 User.Before.setAsIdentityConversion();
3455 if (Best->Conversions[0].isEllipsis())
3456 User.EllipsisConversion = true;
3458 User.Before = Best->Conversions[0].Standard;
3459 User.EllipsisConversion = false;
3462 User.HadMultipleCandidates = HadMultipleCandidates;
3463 User.ConversionFunction = Constructor;
3464 User.FoundConversionFunction = Best->FoundDecl;
3465 User.After.setAsIdentityConversion();
3466 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType());
3467 User.After.setAllToTypes(ToType);
3470 if (CXXConversionDecl *Conversion
3471 = dyn_cast<CXXConversionDecl>(Best->Function)) {
3472 // C++ [over.ics.user]p1:
3474 // [...] If the user-defined conversion is specified by a
3475 // conversion function (12.3.2), the initial standard
3476 // conversion sequence converts the source type to the
3477 // implicit object parameter of the conversion function.
3478 User.Before = Best->Conversions[0].Standard;
3479 User.HadMultipleCandidates = HadMultipleCandidates;
3480 User.ConversionFunction = Conversion;
3481 User.FoundConversionFunction = Best->FoundDecl;
3482 User.EllipsisConversion = false;
3484 // C++ [over.ics.user]p2:
3485 // The second standard conversion sequence converts the
3486 // result of the user-defined conversion to the target type
3487 // for the sequence. Since an implicit conversion sequence
3488 // is an initialization, the special rules for
3489 // initialization by user-defined conversion apply when
3490 // selecting the best user-defined conversion for a
3491 // user-defined conversion sequence (see 13.3.3 and
3493 User.After = Best->FinalConversion;
3496 llvm_unreachable("Not a constructor or conversion function?");
3498 case OR_No_Viable_Function:
3499 return OR_No_Viable_Function;
3502 return OR_Ambiguous;
3505 llvm_unreachable("Invalid OverloadResult!");
3509 Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) {
3510 ImplicitConversionSequence ICS;
3511 OverloadCandidateSet CandidateSet(From->getExprLoc(),
3512 OverloadCandidateSet::CSK_Normal);
3513 OverloadingResult OvResult =
3514 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined,
3515 CandidateSet, false, false);
3517 if (!(OvResult == OR_Ambiguous ||
3518 (OvResult == OR_No_Viable_Function && !CandidateSet.empty())))
3521 auto Cands = CandidateSet.CompleteCandidates(*this, OCD_AllCandidates, From);
3522 if (OvResult == OR_Ambiguous)
3523 Diag(From->getBeginLoc(), diag::err_typecheck_ambiguous_condition)
3524 << From->getType() << ToType << From->getSourceRange();
3525 else { // OR_No_Viable_Function && !CandidateSet.empty()
3526 if (!RequireCompleteType(From->getBeginLoc(), ToType,
3527 diag::err_typecheck_nonviable_condition_incomplete,
3528 From->getType(), From->getSourceRange()))
3529 Diag(From->getBeginLoc(), diag::err_typecheck_nonviable_condition)
3530 << false << From->getType() << From->getSourceRange() << ToType;
3533 CandidateSet.NoteCandidates(
3534 *this, From, Cands);
3538 /// Compare the user-defined conversion functions or constructors
3539 /// of two user-defined conversion sequences to determine whether any ordering
3541 static ImplicitConversionSequence::CompareKind
3542 compareConversionFunctions(Sema &S, FunctionDecl *Function1,
3543 FunctionDecl *Function2) {
3544 if (!S.getLangOpts().ObjC || !S.getLangOpts().CPlusPlus11)
3545 return ImplicitConversionSequence::Indistinguishable;
3548 // If both conversion functions are implicitly-declared conversions from
3549 // a lambda closure type to a function pointer and a block pointer,
3550 // respectively, always prefer the conversion to a function pointer,
3551 // because the function pointer is more lightweight and is more likely
3552 // to keep code working.
3553 CXXConversionDecl *Conv1 = dyn_cast_or_null<CXXConversionDecl>(Function1);
3555 return ImplicitConversionSequence::Indistinguishable;
3557 CXXConversionDecl *Conv2 = dyn_cast<CXXConversionDecl>(Function2);
3559 return ImplicitConversionSequence::Indistinguishable;
3561 if (Conv1->getParent()->isLambda() && Conv2->getParent()->isLambda()) {
3562 bool Block1 = Conv1->getConversionType()->isBlockPointerType();
3563 bool Block2 = Conv2->getConversionType()->isBlockPointerType();
3564 if (Block1 != Block2)
3565 return Block1 ? ImplicitConversionSequence::Worse
3566 : ImplicitConversionSequence::Better;
3569 return ImplicitConversionSequence::Indistinguishable;
3572 static bool hasDeprecatedStringLiteralToCharPtrConversion(
3573 const ImplicitConversionSequence &ICS) {
3574 return (ICS.isStandard() && ICS.Standard.DeprecatedStringLiteralToCharPtr) ||
3575 (ICS.isUserDefined() &&
3576 ICS.UserDefined.Before.DeprecatedStringLiteralToCharPtr);
3579 /// CompareImplicitConversionSequences - Compare two implicit
3580 /// conversion sequences to determine whether one is better than the
3581 /// other or if they are indistinguishable (C++ 13.3.3.2).
3582 static ImplicitConversionSequence::CompareKind
3583 CompareImplicitConversionSequences(Sema &S, SourceLocation Loc,
3584 const ImplicitConversionSequence& ICS1,
3585 const ImplicitConversionSequence& ICS2)
3587 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit
3588 // conversion sequences (as defined in 13.3.3.1)
3589 // -- a standard conversion sequence (13.3.3.1.1) is a better
3590 // conversion sequence than a user-defined conversion sequence or
3591 // an ellipsis conversion sequence, and
3592 // -- a user-defined conversion sequence (13.3.3.1.2) is a better
3593 // conversion sequence than an ellipsis conversion sequence
3596 // C++0x [over.best.ics]p10:
3597 // For the purpose of ranking implicit conversion sequences as
3598 // described in 13.3.3.2, the ambiguous conversion sequence is
3599 // treated as a user-defined sequence that is indistinguishable
3600 // from any other user-defined conversion sequence.
3602 // String literal to 'char *' conversion has been deprecated in C++03. It has
3603 // been removed from C++11. We still accept this conversion, if it happens at
3604 // the best viable function. Otherwise, this conversion is considered worse
3605 // than ellipsis conversion. Consider this as an extension; this is not in the
3606 // standard. For example:
3608 // int &f(...); // #1
3609 // void f(char*); // #2
3610 // void g() { int &r = f("foo"); }
3612 // In C++03, we pick #2 as the best viable function.
3613 // In C++11, we pick #1 as the best viable function, because ellipsis
3614 // conversion is better than string-literal to char* conversion (since there
3615 // is no such conversion in C++11). If there was no #1 at all or #1 couldn't
3616 // convert arguments, #2 would be the best viable function in C++11.
3617 // If the best viable function has this conversion, a warning will be issued
3618 // in C++03, or an ExtWarn (+SFINAE failure) will be issued in C++11.
3620 if (S.getLangOpts().CPlusPlus11 && !S.getLangOpts().WritableStrings &&
3621 hasDeprecatedStringLiteralToCharPtrConversion(ICS1) !=
3622 hasDeprecatedStringLiteralToCharPtrConversion(ICS2))
3623 return hasDeprecatedStringLiteralToCharPtrConversion(ICS1)
3624 ? ImplicitConversionSequence::Worse
3625 : ImplicitConversionSequence::Better;
3627 if (ICS1.getKindRank() < ICS2.getKindRank())
3628 return ImplicitConversionSequence::Better;
3629 if (ICS2.getKindRank() < ICS1.getKindRank())
3630 return ImplicitConversionSequence::Worse;
3632 // The following checks require both conversion sequences to be of
3634 if (ICS1.getKind() != ICS2.getKind())
3635 return ImplicitConversionSequence::Indistinguishable;
3637 ImplicitConversionSequence::CompareKind Result =
3638 ImplicitConversionSequence::Indistinguishable;
3640 // Two implicit conversion sequences of the same form are
3641 // indistinguishable conversion sequences unless one of the
3642 // following rules apply: (C++ 13.3.3.2p3):
3644 // List-initialization sequence L1 is a better conversion sequence than
3645 // list-initialization sequence L2 if:
3646 // - L1 converts to std::initializer_list<X> for some X and L2 does not, or,
3648 // - L1 converts to type "array of N1 T", L2 converts to type "array of N2 T",
3649 // and N1 is smaller than N2.,
3650 // even if one of the other rules in this paragraph would otherwise apply.
3651 if (!ICS1.isBad()) {
3652 if (ICS1.isStdInitializerListElement() &&
3653 !ICS2.isStdInitializerListElement())
3654 return ImplicitConversionSequence::Better;
3655 if (!ICS1.isStdInitializerListElement() &&
3656 ICS2.isStdInitializerListElement())
3657 return ImplicitConversionSequence::Worse;
3660 if (ICS1.isStandard())
3661 // Standard conversion sequence S1 is a better conversion sequence than
3662 // standard conversion sequence S2 if [...]
3663 Result = CompareStandardConversionSequences(S, Loc,
3664 ICS1.Standard, ICS2.Standard);
3665 else if (ICS1.isUserDefined()) {
3666 // User-defined conversion sequence U1 is a better conversion
3667 // sequence than another user-defined conversion sequence U2 if
3668 // they contain the same user-defined conversion function or
3669 // constructor and if the second standard conversion sequence of
3670 // U1 is better than the second standard conversion sequence of
3671 // U2 (C++ 13.3.3.2p3).
3672 if (ICS1.UserDefined.ConversionFunction ==
3673 ICS2.UserDefined.ConversionFunction)
3674 Result = CompareStandardConversionSequences(S, Loc,
3675 ICS1.UserDefined.After,
3676 ICS2.UserDefined.After);
3678 Result = compareConversionFunctions(S,
3679 ICS1.UserDefined.ConversionFunction,
3680 ICS2.UserDefined.ConversionFunction);
3686 // Per 13.3.3.2p3, compare the given standard conversion sequences to
3687 // determine if one is a proper subset of the other.
3688 static ImplicitConversionSequence::CompareKind
3689 compareStandardConversionSubsets(ASTContext &Context,
3690 const StandardConversionSequence& SCS1,
3691 const StandardConversionSequence& SCS2) {
3692 ImplicitConversionSequence::CompareKind Result
3693 = ImplicitConversionSequence::Indistinguishable;
3695 // the identity conversion sequence is considered to be a subsequence of
3696 // any non-identity conversion sequence
3697 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion())
3698 return ImplicitConversionSequence::Better;
3699 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion())
3700 return ImplicitConversionSequence::Worse;
3702 if (SCS1.Second != SCS2.Second) {
3703 if (SCS1.Second == ICK_Identity)
3704 Result = ImplicitConversionSequence::Better;
3705 else if (SCS2.Second == ICK_Identity)
3706 Result = ImplicitConversionSequence::Worse;
3708 return ImplicitConversionSequence::Indistinguishable;
3709 } else if (!Context.hasSimilarType(SCS1.getToType(1), SCS2.getToType(1)))
3710 return ImplicitConversionSequence::Indistinguishable;
3712 if (SCS1.Third == SCS2.Third) {
3713 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result
3714 : ImplicitConversionSequence::Indistinguishable;
3717 if (SCS1.Third == ICK_Identity)
3718 return Result == ImplicitConversionSequence::Worse
3719 ? ImplicitConversionSequence::Indistinguishable
3720 : ImplicitConversionSequence::Better;
3722 if (SCS2.Third == ICK_Identity)
3723 return Result == ImplicitConversionSequence::Better
3724 ? ImplicitConversionSequence::Indistinguishable
3725 : ImplicitConversionSequence::Worse;
3727 return ImplicitConversionSequence::Indistinguishable;
3730 /// Determine whether one of the given reference bindings is better
3731 /// than the other based on what kind of bindings they are.
3733 isBetterReferenceBindingKind(const StandardConversionSequence &SCS1,
3734 const StandardConversionSequence &SCS2) {
3735 // C++0x [over.ics.rank]p3b4:
3736 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an
3737 // implicit object parameter of a non-static member function declared
3738 // without a ref-qualifier, and *either* S1 binds an rvalue reference
3739 // to an rvalue and S2 binds an lvalue reference *or S1 binds an
3740 // lvalue reference to a function lvalue and S2 binds an rvalue
3743 // FIXME: Rvalue references. We're going rogue with the above edits,
3744 // because the semantics in the current C++0x working paper (N3225 at the
3745 // time of this writing) break the standard definition of std::forward
3746 // and std::reference_wrapper when dealing with references to functions.
3747 // Proposed wording changes submitted to CWG for consideration.
3748 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier ||
3749 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier)
3752 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue &&
3753 SCS2.IsLvalueReference) ||
3754 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue &&
3755 !SCS2.IsLvalueReference && SCS2.BindsToFunctionLvalue);
3758 /// CompareStandardConversionSequences - Compare two standard
3759 /// conversion sequences to determine whether one is better than the
3760 /// other or if they are indistinguishable (C++ 13.3.3.2p3).
3761 static ImplicitConversionSequence::CompareKind
3762 CompareStandardConversionSequences(Sema &S, SourceLocation Loc,
3763 const StandardConversionSequence& SCS1,
3764 const StandardConversionSequence& SCS2)
3766 // Standard conversion sequence S1 is a better conversion sequence
3767 // than standard conversion sequence S2 if (C++ 13.3.3.2p3):
3769 // -- S1 is a proper subsequence of S2 (comparing the conversion
3770 // sequences in the canonical form defined by 13.3.3.1.1,
3771 // excluding any Lvalue Transformation; the identity conversion
3772 // sequence is considered to be a subsequence of any
3773 // non-identity conversion sequence) or, if not that,
3774 if (ImplicitConversionSequence::CompareKind CK
3775 = compareStandardConversionSubsets(S.Context, SCS1, SCS2))
3778 // -- the rank of S1 is better than the rank of S2 (by the rules
3779 // defined below), or, if not that,
3780 ImplicitConversionRank Rank1 = SCS1.getRank();
3781 ImplicitConversionRank Rank2 = SCS2.getRank();
3783 return ImplicitConversionSequence::Better;
3784 else if (Rank2 < Rank1)
3785 return ImplicitConversionSequence::Worse;
3787 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank
3788 // are indistinguishable unless one of the following rules
3791 // A conversion that is not a conversion of a pointer, or
3792 // pointer to member, to bool is better than another conversion
3793 // that is such a conversion.
3794 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool())
3795 return SCS2.isPointerConversionToBool()
3796 ? ImplicitConversionSequence::Better
3797 : ImplicitConversionSequence::Worse;
3799 // C++ [over.ics.rank]p4b2:
3801 // If class B is derived directly or indirectly from class A,
3802 // conversion of B* to A* is better than conversion of B* to
3803 // void*, and conversion of A* to void* is better than conversion
3805 bool SCS1ConvertsToVoid
3806 = SCS1.isPointerConversionToVoidPointer(S.Context);
3807 bool SCS2ConvertsToVoid
3808 = SCS2.isPointerConversionToVoidPointer(S.Context);
3809 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) {
3810 // Exactly one of the conversion sequences is a conversion to
3811 // a void pointer; it's the worse conversion.
3812 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better
3813 : ImplicitConversionSequence::Worse;
3814 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) {
3815 // Neither conversion sequence converts to a void pointer; compare
3816 // their derived-to-base conversions.
3817 if (ImplicitConversionSequence::CompareKind DerivedCK
3818 = CompareDerivedToBaseConversions(S, Loc, SCS1, SCS2))
3820 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid &&
3821 !S.Context.hasSameType(SCS1.getFromType(), SCS2.getFromType())) {
3822 // Both conversion sequences are conversions to void
3823 // pointers. Compare the source types to determine if there's an
3824 // inheritance relationship in their sources.
3825 QualType FromType1 = SCS1.getFromType();
3826 QualType FromType2 = SCS2.getFromType();
3828 // Adjust the types we're converting from via the array-to-pointer
3829 // conversion, if we need to.
3830 if (SCS1.First == ICK_Array_To_Pointer)
3831 FromType1 = S.Context.getArrayDecayedType(FromType1);
3832 if (SCS2.First == ICK_Array_To_Pointer)
3833 FromType2 = S.Context.getArrayDecayedType(FromType2);
3835 QualType FromPointee1 = FromType1->getPointeeType().getUnqualifiedType();
3836 QualType FromPointee2 = FromType2->getPointeeType().getUnqualifiedType();
3838 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
3839 return ImplicitConversionSequence::Better;
3840 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
3841 return ImplicitConversionSequence::Worse;
3843 // Objective-C++: If one interface is more specific than the
3844 // other, it is the better one.
3845 const ObjCObjectPointerType* FromObjCPtr1
3846 = FromType1->getAs<ObjCObjectPointerType>();
3847 const ObjCObjectPointerType* FromObjCPtr2
3848 = FromType2->getAs<ObjCObjectPointerType>();
3849 if (FromObjCPtr1 && FromObjCPtr2) {
3850 bool AssignLeft = S.Context.canAssignObjCInterfaces(FromObjCPtr1,
3852 bool AssignRight = S.Context.canAssignObjCInterfaces(FromObjCPtr2,
3854 if (AssignLeft != AssignRight) {
3855 return AssignLeft? ImplicitConversionSequence::Better
3856 : ImplicitConversionSequence::Worse;
3861 // Compare based on qualification conversions (C++ 13.3.3.2p3,
3863 if (ImplicitConversionSequence::CompareKind QualCK
3864 = CompareQualificationConversions(S, SCS1, SCS2))
3867 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) {
3868 // Check for a better reference binding based on the kind of bindings.
3869 if (isBetterReferenceBindingKind(SCS1, SCS2))
3870 return ImplicitConversionSequence::Better;
3871 else if (isBetterReferenceBindingKind(SCS2, SCS1))
3872 return ImplicitConversionSequence::Worse;
3874 // C++ [over.ics.rank]p3b4:
3875 // -- S1 and S2 are reference bindings (8.5.3), and the types to
3876 // which the references refer are the same type except for
3877 // top-level cv-qualifiers, and the type to which the reference
3878 // initialized by S2 refers is more cv-qualified than the type
3879 // to which the reference initialized by S1 refers.
3880 QualType T1 = SCS1.getToType(2);
3881 QualType T2 = SCS2.getToType(2);
3882 T1 = S.Context.getCanonicalType(T1);
3883 T2 = S.Context.getCanonicalType(T2);
3884 Qualifiers T1Quals, T2Quals;
3885 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
3886 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
3887 if (UnqualT1 == UnqualT2) {
3888 // Objective-C++ ARC: If the references refer to objects with different
3889 // lifetimes, prefer bindings that don't change lifetime.
3890 if (SCS1.ObjCLifetimeConversionBinding !=
3891 SCS2.ObjCLifetimeConversionBinding) {
3892 return SCS1.ObjCLifetimeConversionBinding
3893 ? ImplicitConversionSequence::Worse
3894 : ImplicitConversionSequence::Better;
3897 // If the type is an array type, promote the element qualifiers to the
3898 // type for comparison.
3899 if (isa<ArrayType>(T1) && T1Quals)
3900 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals);
3901 if (isa<ArrayType>(T2) && T2Quals)
3902 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals);
3903 if (T2.isMoreQualifiedThan(T1))
3904 return ImplicitConversionSequence::Better;
3905 else if (T1.isMoreQualifiedThan(T2))
3906 return ImplicitConversionSequence::Worse;
3910 // In Microsoft mode, prefer an integral conversion to a
3911 // floating-to-integral conversion if the integral conversion
3912 // is between types of the same size.
3920 // Here, MSVC will call f(int) instead of generating a compile error
3921 // as clang will do in standard mode.
3922 if (S.getLangOpts().MSVCCompat && SCS1.Second == ICK_Integral_Conversion &&
3923 SCS2.Second == ICK_Floating_Integral &&
3924 S.Context.getTypeSize(SCS1.getFromType()) ==
3925 S.Context.getTypeSize(SCS1.getToType(2)))
3926 return ImplicitConversionSequence::Better;
3928 // Prefer a compatible vector conversion over a lax vector conversion
3931 // typedef float __v4sf __attribute__((__vector_size__(16)));
3932 // void f(vector float);
3933 // void f(vector signed int);
3938 // Here, we'd like to choose f(vector float) and not
3939 // report an ambiguous call error
3940 if (SCS1.Second == ICK_Vector_Conversion &&
3941 SCS2.Second == ICK_Vector_Conversion) {
3942 bool SCS1IsCompatibleVectorConversion = S.Context.areCompatibleVectorTypes(
3943 SCS1.getFromType(), SCS1.getToType(2));
3944 bool SCS2IsCompatibleVectorConversion = S.Context.areCompatibleVectorTypes(
3945 SCS2.getFromType(), SCS2.getToType(2));
3947 if (SCS1IsCompatibleVectorConversion != SCS2IsCompatibleVectorConversion)
3948 return SCS1IsCompatibleVectorConversion
3949 ? ImplicitConversionSequence::Better
3950 : ImplicitConversionSequence::Worse;
3953 return ImplicitConversionSequence::Indistinguishable;
3956 /// CompareQualificationConversions - Compares two standard conversion
3957 /// sequences to determine whether they can be ranked based on their
3958 /// qualification conversions (C++ 13.3.3.2p3 bullet 3).
3959 static ImplicitConversionSequence::CompareKind
3960 CompareQualificationConversions(Sema &S,
3961 const StandardConversionSequence& SCS1,
3962 const StandardConversionSequence& SCS2) {
3964 // -- S1 and S2 differ only in their qualification conversion and
3965 // yield similar types T1 and T2 (C++ 4.4), respectively, and the
3966 // cv-qualification signature of type T1 is a proper subset of
3967 // the cv-qualification signature of type T2, and S1 is not the
3968 // deprecated string literal array-to-pointer conversion (4.2).
3969 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second ||
3970 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification)
3971 return ImplicitConversionSequence::Indistinguishable;
3973 // FIXME: the example in the standard doesn't use a qualification
3975 QualType T1 = SCS1.getToType(2);
3976 QualType T2 = SCS2.getToType(2);
3977 T1 = S.Context.getCanonicalType(T1);
3978 T2 = S.Context.getCanonicalType(T2);
3979 Qualifiers T1Quals, T2Quals;
3980 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
3981 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
3983 // If the types are the same, we won't learn anything by unwrapped
3985 if (UnqualT1 == UnqualT2)
3986 return ImplicitConversionSequence::Indistinguishable;
3988 // If the type is an array type, promote the element qualifiers to the type
3990 if (isa<ArrayType>(T1) && T1Quals)
3991 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals);
3992 if (isa<ArrayType>(T2) && T2Quals)
3993 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals);
3995 ImplicitConversionSequence::CompareKind Result
3996 = ImplicitConversionSequence::Indistinguishable;
3998 // Objective-C++ ARC:
3999 // Prefer qualification conversions not involving a change in lifetime
4000 // to qualification conversions that do not change lifetime.
4001 if (SCS1.QualificationIncludesObjCLifetime !=
4002 SCS2.QualificationIncludesObjCLifetime) {
4003 Result = SCS1.QualificationIncludesObjCLifetime
4004 ? ImplicitConversionSequence::Worse
4005 : ImplicitConversionSequence::Better;
4008 while (S.Context.UnwrapSimilarTypes(T1, T2)) {
4009 // Within each iteration of the loop, we check the qualifiers to
4010 // determine if this still looks like a qualification
4011 // conversion. Then, if all is well, we unwrap one more level of
4012 // pointers or pointers-to-members and do it all again
4013 // until there are no more pointers or pointers-to-members left
4014 // to unwrap. This essentially mimics what
4015 // IsQualificationConversion does, but here we're checking for a
4016 // strict subset of qualifiers.
4017 if (T1.getQualifiers().withoutObjCLifetime() ==
4018 T2.getQualifiers().withoutObjCLifetime())
4019 // The qualifiers are the same, so this doesn't tell us anything
4020 // about how the sequences rank.
4021 // ObjC ownership quals are omitted above as they interfere with
4022 // the ARC overload rule.
4024 else if (T2.isMoreQualifiedThan(T1)) {
4025 // T1 has fewer qualifiers, so it could be the better sequence.
4026 if (Result == ImplicitConversionSequence::Worse)
4027 // Neither has qualifiers that are a subset of the other's
4029 return ImplicitConversionSequence::Indistinguishable;
4031 Result = ImplicitConversionSequence::Better;
4032 } else if (T1.isMoreQualifiedThan(T2)) {
4033 // T2 has fewer qualifiers, so it could be the better sequence.
4034 if (Result == ImplicitConversionSequence::Better)
4035 // Neither has qualifiers that are a subset of the other's
4037 return ImplicitConversionSequence::Indistinguishable;
4039 Result = ImplicitConversionSequence::Worse;
4041 // Qualifiers are disjoint.
4042 return ImplicitConversionSequence::Indistinguishable;
4045 // If the types after this point are equivalent, we're done.
4046 if (S.Context.hasSameUnqualifiedType(T1, T2))
4050 // Check that the winning standard conversion sequence isn't using
4051 // the deprecated string literal array to pointer conversion.
4053 case ImplicitConversionSequence::Better:
4054 if (SCS1.DeprecatedStringLiteralToCharPtr)
4055 Result = ImplicitConversionSequence::Indistinguishable;
4058 case ImplicitConversionSequence::Indistinguishable:
4061 case ImplicitConversionSequence::Worse:
4062 if (SCS2.DeprecatedStringLiteralToCharPtr)
4063 Result = ImplicitConversionSequence::Indistinguishable;
4070 /// CompareDerivedToBaseConversions - Compares two standard conversion
4071 /// sequences to determine whether they can be ranked based on their
4072 /// various kinds of derived-to-base conversions (C++
4073 /// [over.ics.rank]p4b3). As part of these checks, we also look at
4074 /// conversions between Objective-C interface types.
4075 static ImplicitConversionSequence::CompareKind
4076 CompareDerivedToBaseConversions(Sema &S, SourceLocation Loc,
4077 const StandardConversionSequence& SCS1,
4078 const StandardConversionSequence& SCS2) {
4079 QualType FromType1 = SCS1.getFromType();
4080 QualType ToType1 = SCS1.getToType(1);
4081 QualType FromType2 = SCS2.getFromType();
4082 QualType ToType2 = SCS2.getToType(1);
4084 // Adjust the types we're converting from via the array-to-pointer
4085 // conversion, if we need to.
4086 if (SCS1.First == ICK_Array_To_Pointer)
4087 FromType1 = S.Context.getArrayDecayedType(FromType1);
4088 if (SCS2.First == ICK_Array_To_Pointer)
4089 FromType2 = S.Context.getArrayDecayedType(FromType2);
4091 // Canonicalize all of the types.
4092 FromType1 = S.Context.getCanonicalType(FromType1);
4093 ToType1 = S.Context.getCanonicalType(ToType1);
4094 FromType2 = S.Context.getCanonicalType(FromType2);
4095 ToType2 = S.Context.getCanonicalType(ToType2);
4097 // C++ [over.ics.rank]p4b3:
4099 // If class B is derived directly or indirectly from class A and
4100 // class C is derived directly or indirectly from B,
4102 // Compare based on pointer conversions.
4103 if (SCS1.Second == ICK_Pointer_Conversion &&
4104 SCS2.Second == ICK_Pointer_Conversion &&
4105 /*FIXME: Remove if Objective-C id conversions get their own rank*/
4106 FromType1->isPointerType() && FromType2->isPointerType() &&
4107 ToType1->isPointerType() && ToType2->isPointerType()) {
4108 QualType FromPointee1
4109 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4111 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4112 QualType FromPointee2
4113 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4115 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4117 // -- conversion of C* to B* is better than conversion of C* to A*,
4118 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
4119 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
4120 return ImplicitConversionSequence::Better;
4121 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
4122 return ImplicitConversionSequence::Worse;
4125 // -- conversion of B* to A* is better than conversion of C* to A*,
4126 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) {
4127 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
4128 return ImplicitConversionSequence::Better;
4129 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
4130 return ImplicitConversionSequence::Worse;
4132 } else if (SCS1.Second == ICK_Pointer_Conversion &&
4133 SCS2.Second == ICK_Pointer_Conversion) {
4134 const ObjCObjectPointerType *FromPtr1
4135 = FromType1->getAs<ObjCObjectPointerType>();
4136 const ObjCObjectPointerType *FromPtr2
4137 = FromType2->getAs<ObjCObjectPointerType>();
4138 const ObjCObjectPointerType *ToPtr1
4139 = ToType1->getAs<ObjCObjectPointerType>();
4140 const ObjCObjectPointerType *ToPtr2
4141 = ToType2->getAs<ObjCObjectPointerType>();
4143 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) {
4144 // Apply the same conversion ranking rules for Objective-C pointer types
4145 // that we do for C++ pointers to class types. However, we employ the
4146 // Objective-C pseudo-subtyping relationship used for assignment of
4147 // Objective-C pointer types.
4149 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2);
4150 bool FromAssignRight
4151 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1);
4153 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2);
4155 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1);
4157 // A conversion to an a non-id object pointer type or qualified 'id'
4158 // type is better than a conversion to 'id'.
4159 if (ToPtr1->isObjCIdType() &&
4160 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl()))
4161 return ImplicitConversionSequence::Worse;
4162 if (ToPtr2->isObjCIdType() &&
4163 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl()))
4164 return ImplicitConversionSequence::Better;
4166 // A conversion to a non-id object pointer type is better than a
4167 // conversion to a qualified 'id' type
4168 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl())
4169 return ImplicitConversionSequence::Worse;
4170 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl())
4171 return ImplicitConversionSequence::Better;
4173 // A conversion to an a non-Class object pointer type or qualified 'Class'
4174 // type is better than a conversion to 'Class'.
4175 if (ToPtr1->isObjCClassType() &&
4176 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl()))
4177 return ImplicitConversionSequence::Worse;
4178 if (ToPtr2->isObjCClassType() &&
4179 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl()))
4180 return ImplicitConversionSequence::Better;
4182 // A conversion to a non-Class object pointer type is better than a
4183 // conversion to a qualified 'Class' type.
4184 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl())
4185 return ImplicitConversionSequence::Worse;
4186 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl())
4187 return ImplicitConversionSequence::Better;
4189 // -- "conversion of C* to B* is better than conversion of C* to A*,"
4190 if (S.Context.hasSameType(FromType1, FromType2) &&
4191 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() &&
4192 (ToAssignLeft != ToAssignRight)) {
4193 if (FromPtr1->isSpecialized()) {
4194 // "conversion of B<A> * to B * is better than conversion of B * to
4197 FromPtr1->getInterfaceDecl() == ToPtr1->getInterfaceDecl();
4199 FromPtr1->getInterfaceDecl() == ToPtr2->getInterfaceDecl();
4202 return ImplicitConversionSequence::Better;
4203 } else if (IsSecondSame)
4204 return ImplicitConversionSequence::Worse;
4206 return ToAssignLeft? ImplicitConversionSequence::Worse
4207 : ImplicitConversionSequence::Better;
4210 // -- "conversion of B* to A* is better than conversion of C* to A*,"
4211 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) &&
4212 (FromAssignLeft != FromAssignRight))
4213 return FromAssignLeft? ImplicitConversionSequence::Better
4214 : ImplicitConversionSequence::Worse;
4218 // Ranking of member-pointer types.
4219 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member &&
4220 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() &&
4221 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) {
4222 const MemberPointerType * FromMemPointer1 =
4223 FromType1->getAs<MemberPointerType>();
4224 const MemberPointerType * ToMemPointer1 =
4225 ToType1->getAs<MemberPointerType>();
4226 const MemberPointerType * FromMemPointer2 =
4227 FromType2->getAs<MemberPointerType>();
4228 const MemberPointerType * ToMemPointer2 =
4229 ToType2->getAs<MemberPointerType>();
4230 const Type *FromPointeeType1 = FromMemPointer1->getClass();
4231 const Type *ToPointeeType1 = ToMemPointer1->getClass();
4232 const Type *FromPointeeType2 = FromMemPointer2->getClass();
4233 const Type *ToPointeeType2 = ToMemPointer2->getClass();
4234 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType();
4235 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType();
4236 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType();
4237 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType();
4238 // conversion of A::* to B::* is better than conversion of A::* to C::*,
4239 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
4240 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
4241 return ImplicitConversionSequence::Worse;
4242 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
4243 return ImplicitConversionSequence::Better;
4245 // conversion of B::* to C::* is better than conversion of A::* to C::*
4246 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) {
4247 if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
4248 return ImplicitConversionSequence::Better;
4249 else if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
4250 return ImplicitConversionSequence::Worse;
4254 if (SCS1.Second == ICK_Derived_To_Base) {
4255 // -- conversion of C to B is better than conversion of C to A,
4256 // -- binding of an expression of type C to a reference of type
4257 // B& is better than binding an expression of type C to a
4258 // reference of type A&,
4259 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4260 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4261 if (S.IsDerivedFrom(Loc, ToType1, ToType2))
4262 return ImplicitConversionSequence::Better;
4263 else if (S.IsDerivedFrom(Loc, ToType2, ToType1))
4264 return ImplicitConversionSequence::Worse;
4267 // -- conversion of B to A is better than conversion of C to A.
4268 // -- binding of an expression of type B to a reference of type
4269 // A& is better than binding an expression of type C to a
4270 // reference of type A&,
4271 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4272 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4273 if (S.IsDerivedFrom(Loc, FromType2, FromType1))
4274 return ImplicitConversionSequence::Better;
4275 else if (S.IsDerivedFrom(Loc, FromType1, FromType2))
4276 return ImplicitConversionSequence::Worse;
4280 return ImplicitConversionSequence::Indistinguishable;
4283 /// Determine whether the given type is valid, e.g., it is not an invalid
4285 static bool isTypeValid(QualType T) {
4286 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl())
4287 return !Record->isInvalidDecl();
4292 /// CompareReferenceRelationship - Compare the two types T1 and T2 to
4293 /// determine whether they are reference-related,
4294 /// reference-compatible, reference-compatible with added
4295 /// qualification, or incompatible, for use in C++ initialization by
4296 /// reference (C++ [dcl.ref.init]p4). Neither type can be a reference
4297 /// type, and the first type (T1) is the pointee type of the reference
4298 /// type being initialized.
4299 Sema::ReferenceCompareResult
4300 Sema::CompareReferenceRelationship(SourceLocation Loc,
4301 QualType OrigT1, QualType OrigT2,
4302 bool &DerivedToBase,
4303 bool &ObjCConversion,
4304 bool &ObjCLifetimeConversion) {
4305 assert(!OrigT1->isReferenceType() &&
4306 "T1 must be the pointee type of the reference type");
4307 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type");
4309 QualType T1 = Context.getCanonicalType(OrigT1);
4310 QualType T2 = Context.getCanonicalType(OrigT2);
4311 Qualifiers T1Quals, T2Quals;
4312 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals);
4313 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals);
4315 // C++ [dcl.init.ref]p4:
4316 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is
4317 // reference-related to "cv2 T2" if T1 is the same type as T2, or
4318 // T1 is a base class of T2.
4319 DerivedToBase = false;
4320 ObjCConversion = false;
4321 ObjCLifetimeConversion = false;
4322 QualType ConvertedT2;
4323 if (UnqualT1 == UnqualT2) {
4325 } else if (isCompleteType(Loc, OrigT2) &&
4326 isTypeValid(UnqualT1) && isTypeValid(UnqualT2) &&
4327 IsDerivedFrom(Loc, UnqualT2, UnqualT1))
4328 DerivedToBase = true;
4329 else if (UnqualT1->isObjCObjectOrInterfaceType() &&
4330 UnqualT2->isObjCObjectOrInterfaceType() &&
4331 Context.canBindObjCObjectType(UnqualT1, UnqualT2))
4332 ObjCConversion = true;
4333 else if (UnqualT2->isFunctionType() &&
4334 IsFunctionConversion(UnqualT2, UnqualT1, ConvertedT2))
4335 // C++1z [dcl.init.ref]p4:
4336 // cv1 T1" is reference-compatible with "cv2 T2" if [...] T2 is "noexcept
4337 // function" and T1 is "function"
4339 // We extend this to also apply to 'noreturn', so allow any function
4340 // conversion between function types.
4341 return Ref_Compatible;
4343 return Ref_Incompatible;
4345 // At this point, we know that T1 and T2 are reference-related (at
4348 // If the type is an array type, promote the element qualifiers to the type
4350 if (isa<ArrayType>(T1) && T1Quals)
4351 T1 = Context.getQualifiedType(UnqualT1, T1Quals);
4352 if (isa<ArrayType>(T2) && T2Quals)
4353 T2 = Context.getQualifiedType(UnqualT2, T2Quals);
4355 // C++ [dcl.init.ref]p4:
4356 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is
4357 // reference-related to T2 and cv1 is the same cv-qualification
4358 // as, or greater cv-qualification than, cv2. For purposes of
4359 // overload resolution, cases for which cv1 is greater
4360 // cv-qualification than cv2 are identified as
4361 // reference-compatible with added qualification (see 13.3.3.2).
4363 // Note that we also require equivalence of Objective-C GC and address-space
4364 // qualifiers when performing these computations, so that e.g., an int in
4365 // address space 1 is not reference-compatible with an int in address
4367 if (T1Quals.getObjCLifetime() != T2Quals.getObjCLifetime() &&
4368 T1Quals.compatiblyIncludesObjCLifetime(T2Quals)) {
4369 if (isNonTrivialObjCLifetimeConversion(T2Quals, T1Quals))
4370 ObjCLifetimeConversion = true;
4372 T1Quals.removeObjCLifetime();
4373 T2Quals.removeObjCLifetime();
4376 // MS compiler ignores __unaligned qualifier for references; do the same.
4377 T1Quals.removeUnaligned();
4378 T2Quals.removeUnaligned();
4380 if (T1Quals.compatiblyIncludes(T2Quals))
4381 return Ref_Compatible;
4386 /// Look for a user-defined conversion to a value reference-compatible
4387 /// with DeclType. Return true if something definite is found.
4389 FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS,
4390 QualType DeclType, SourceLocation DeclLoc,
4391 Expr *Init, QualType T2, bool AllowRvalues,
4392 bool AllowExplicit) {
4393 assert(T2->isRecordType() && "Can only find conversions of record types.");
4394 CXXRecordDecl *T2RecordDecl
4395 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl());
4397 OverloadCandidateSet CandidateSet(
4398 DeclLoc, OverloadCandidateSet::CSK_InitByUserDefinedConversion);
4399 const auto &Conversions = T2RecordDecl->getVisibleConversionFunctions();
4400 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
4402 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
4403 if (isa<UsingShadowDecl>(D))
4404 D = cast<UsingShadowDecl>(D)->getTargetDecl();
4406 FunctionTemplateDecl *ConvTemplate
4407 = dyn_cast<FunctionTemplateDecl>(D);
4408 CXXConversionDecl *Conv;
4410 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
4412 Conv = cast<CXXConversionDecl>(D);
4414 // If this is an explicit conversion, and we're not allowed to consider
4415 // explicit conversions, skip it.
4416 if (!AllowExplicit && Conv->isExplicit())
4420 bool DerivedToBase = false;
4421 bool ObjCConversion = false;
4422 bool ObjCLifetimeConversion = false;
4424 // If we are initializing an rvalue reference, don't permit conversion
4425 // functions that return lvalues.
4426 if (!ConvTemplate && DeclType->isRValueReferenceType()) {
4427 const ReferenceType *RefType
4428 = Conv->getConversionType()->getAs<LValueReferenceType>();
4429 if (RefType && !RefType->getPointeeType()->isFunctionType())
4433 if (!ConvTemplate &&
4434 S.CompareReferenceRelationship(
4436 Conv->getConversionType().getNonReferenceType()
4437 .getUnqualifiedType(),
4438 DeclType.getNonReferenceType().getUnqualifiedType(),
4439 DerivedToBase, ObjCConversion, ObjCLifetimeConversion) ==
4440 Sema::Ref_Incompatible)
4443 // If the conversion function doesn't return a reference type,
4444 // it can't be considered for this conversion. An rvalue reference
4445 // is only acceptable if its referencee is a function type.
4447 const ReferenceType *RefType =
4448 Conv->getConversionType()->getAs<ReferenceType>();
4450 (!RefType->isLValueReferenceType() &&
4451 !RefType->getPointeeType()->isFunctionType()))
4456 S.AddTemplateConversionCandidate(
4457 ConvTemplate, I.getPair(), ActingDC, Init, DeclType, CandidateSet,
4458 /*AllowObjCConversionOnExplicit=*/false, AllowExplicit);
4460 S.AddConversionCandidate(
4461 Conv, I.getPair(), ActingDC, Init, DeclType, CandidateSet,
4462 /*AllowObjCConversionOnExplicit=*/false, AllowExplicit);
4465 bool HadMultipleCandidates = (CandidateSet.size() > 1);
4467 OverloadCandidateSet::iterator Best;
4468 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best)) {
4470 // C++ [over.ics.ref]p1:
4472 // [...] If the parameter binds directly to the result of
4473 // applying a conversion function to the argument
4474 // expression, the implicit conversion sequence is a
4475 // user-defined conversion sequence (13.3.3.1.2), with the
4476 // second standard conversion sequence either an identity
4477 // conversion or, if the conversion function returns an
4478 // entity of a type that is a derived class of the parameter
4479 // type, a derived-to-base Conversion.
4480 if (!Best->FinalConversion.DirectBinding)
4483 ICS.setUserDefined();
4484 ICS.UserDefined.Before = Best->Conversions[0].Standard;
4485 ICS.UserDefined.After = Best->FinalConversion;
4486 ICS.UserDefined.HadMultipleCandidates = HadMultipleCandidates;
4487 ICS.UserDefined.ConversionFunction = Best->Function;
4488 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl;
4489 ICS.UserDefined.EllipsisConversion = false;
4490 assert(ICS.UserDefined.After.ReferenceBinding &&
4491 ICS.UserDefined.After.DirectBinding &&
4492 "Expected a direct reference binding!");
4497 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin();
4498 Cand != CandidateSet.end(); ++Cand)
4500 ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
4503 case OR_No_Viable_Function:
4505 // There was no suitable conversion, or we found a deleted
4506 // conversion; continue with other checks.
4510 llvm_unreachable("Invalid OverloadResult!");
4513 /// Compute an implicit conversion sequence for reference
4515 static ImplicitConversionSequence
4516 TryReferenceInit(Sema &S, Expr *Init, QualType DeclType,
4517 SourceLocation DeclLoc,
4518 bool SuppressUserConversions,
4519 bool AllowExplicit) {
4520 assert(DeclType->isReferenceType() && "Reference init needs a reference");
4522 // Most paths end in a failed conversion.
4523 ImplicitConversionSequence ICS;
4524 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4526 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType();
4527 QualType T2 = Init->getType();
4529 // If the initializer is the address of an overloaded function, try
4530 // to resolve the overloaded function. If all goes well, T2 is the
4531 // type of the resulting function.
4532 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
4533 DeclAccessPair Found;
4534 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType,
4539 // Compute some basic properties of the types and the initializer.
4540 bool isRValRef = DeclType->isRValueReferenceType();
4541 bool DerivedToBase = false;
4542 bool ObjCConversion = false;
4543 bool ObjCLifetimeConversion = false;
4544 Expr::Classification InitCategory = Init->Classify(S.Context);
4545 Sema::ReferenceCompareResult RefRelationship
4546 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase,
4547 ObjCConversion, ObjCLifetimeConversion);
4550 // C++0x [dcl.init.ref]p5:
4551 // A reference to type "cv1 T1" is initialized by an expression
4552 // of type "cv2 T2" as follows:
4554 // -- If reference is an lvalue reference and the initializer expression
4556 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is
4557 // reference-compatible with "cv2 T2," or
4559 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here.
4560 if (InitCategory.isLValue() && RefRelationship == Sema::Ref_Compatible) {
4561 // C++ [over.ics.ref]p1:
4562 // When a parameter of reference type binds directly (8.5.3)
4563 // to an argument expression, the implicit conversion sequence
4564 // is the identity conversion, unless the argument expression
4565 // has a type that is a derived class of the parameter type,
4566 // in which case the implicit conversion sequence is a
4567 // derived-to-base Conversion (13.3.3.1).
4569 ICS.Standard.First = ICK_Identity;
4570 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base
4571 : ObjCConversion? ICK_Compatible_Conversion
4573 ICS.Standard.Third = ICK_Identity;
4574 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
4575 ICS.Standard.setToType(0, T2);
4576 ICS.Standard.setToType(1, T1);
4577 ICS.Standard.setToType(2, T1);
4578 ICS.Standard.ReferenceBinding = true;
4579 ICS.Standard.DirectBinding = true;
4580 ICS.Standard.IsLvalueReference = !isRValRef;
4581 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType();
4582 ICS.Standard.BindsToRvalue = false;
4583 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4584 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion;
4585 ICS.Standard.CopyConstructor = nullptr;
4586 ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
4588 // Nothing more to do: the inaccessibility/ambiguity check for
4589 // derived-to-base conversions is suppressed when we're
4590 // computing the implicit conversion sequence (C++
4591 // [over.best.ics]p2).
4595 // -- has a class type (i.e., T2 is a class type), where T1 is
4596 // not reference-related to T2, and can be implicitly
4597 // converted to an lvalue of type "cv3 T3," where "cv1 T1"
4598 // is reference-compatible with "cv3 T3" 92) (this
4599 // conversion is selected by enumerating the applicable
4600 // conversion functions (13.3.1.6) and choosing the best
4601 // one through overload resolution (13.3)),
4602 if (!SuppressUserConversions && T2->isRecordType() &&
4603 S.isCompleteType(DeclLoc, T2) &&
4604 RefRelationship == Sema::Ref_Incompatible) {
4605 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4606 Init, T2, /*AllowRvalues=*/false,
4612 // -- Otherwise, the reference shall be an lvalue reference to a
4613 // non-volatile const type (i.e., cv1 shall be const), or the reference
4614 // shall be an rvalue reference.
4615 if (!isRValRef && (!T1.isConstQualified() || T1.isVolatileQualified()))
4618 // -- If the initializer expression
4620 // -- is an xvalue, class prvalue, array prvalue or function
4621 // lvalue and "cv1 T1" is reference-compatible with "cv2 T2", or
4622 if (RefRelationship == Sema::Ref_Compatible &&
4623 (InitCategory.isXValue() ||
4624 (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) ||
4625 (InitCategory.isLValue() && T2->isFunctionType()))) {
4627 ICS.Standard.First = ICK_Identity;
4628 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base
4629 : ObjCConversion? ICK_Compatible_Conversion
4631 ICS.Standard.Third = ICK_Identity;
4632 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
4633 ICS.Standard.setToType(0, T2);
4634 ICS.Standard.setToType(1, T1);
4635 ICS.Standard.setToType(2, T1);
4636 ICS.Standard.ReferenceBinding = true;
4637 // In C++0x, this is always a direct binding. In C++98/03, it's a direct
4638 // binding unless we're binding to a class prvalue.
4639 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we
4640 // allow the use of rvalue references in C++98/03 for the benefit of
4641 // standard library implementors; therefore, we need the xvalue check here.
4642 ICS.Standard.DirectBinding =
4643 S.getLangOpts().CPlusPlus11 ||
4644 !(InitCategory.isPRValue() || T2->isRecordType());
4645 ICS.Standard.IsLvalueReference = !isRValRef;
4646 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType();
4647 ICS.Standard.BindsToRvalue = InitCategory.isRValue();
4648 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4649 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion;
4650 ICS.Standard.CopyConstructor = nullptr;
4651 ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
4655 // -- has a class type (i.e., T2 is a class type), where T1 is not
4656 // reference-related to T2, and can be implicitly converted to
4657 // an xvalue, class prvalue, or function lvalue of type
4658 // "cv3 T3", where "cv1 T1" is reference-compatible with
4661 // then the reference is bound to the value of the initializer
4662 // expression in the first case and to the result of the conversion
4663 // in the second case (or, in either case, to an appropriate base
4664 // class subobject).
4665 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4666 T2->isRecordType() && S.isCompleteType(DeclLoc, T2) &&
4667 FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4668 Init, T2, /*AllowRvalues=*/true,
4670 // In the second case, if the reference is an rvalue reference
4671 // and the second standard conversion sequence of the
4672 // user-defined conversion sequence includes an lvalue-to-rvalue
4673 // conversion, the program is ill-formed.
4674 if (ICS.isUserDefined() && isRValRef &&
4675 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue)
4676 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4681 // A temporary of function type cannot be created; don't even try.
4682 if (T1->isFunctionType())
4685 // -- Otherwise, a temporary of type "cv1 T1" is created and
4686 // initialized from the initializer expression using the
4687 // rules for a non-reference copy initialization (8.5). The
4688 // reference is then bound to the temporary. If T1 is
4689 // reference-related to T2, cv1 must be the same
4690 // cv-qualification as, or greater cv-qualification than,
4691 // cv2; otherwise, the program is ill-formed.
4692 if (RefRelationship == Sema::Ref_Related) {
4693 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then
4694 // we would be reference-compatible or reference-compatible with
4695 // added qualification. But that wasn't the case, so the reference
4696 // initialization fails.
4698 // Note that we only want to check address spaces and cvr-qualifiers here.
4699 // ObjC GC, lifetime and unaligned qualifiers aren't important.
4700 Qualifiers T1Quals = T1.getQualifiers();
4701 Qualifiers T2Quals = T2.getQualifiers();
4702 T1Quals.removeObjCGCAttr();
4703 T1Quals.removeObjCLifetime();
4704 T2Quals.removeObjCGCAttr();
4705 T2Quals.removeObjCLifetime();
4706 // MS compiler ignores __unaligned qualifier for references; do the same.
4707 T1Quals.removeUnaligned();
4708 T2Quals.removeUnaligned();
4709 if (!T1Quals.compatiblyIncludes(T2Quals))
4713 // If at least one of the types is a class type, the types are not
4714 // related, and we aren't allowed any user conversions, the
4715 // reference binding fails. This case is important for breaking
4716 // recursion, since TryImplicitConversion below will attempt to
4717 // create a temporary through the use of a copy constructor.
4718 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4719 (T1->isRecordType() || T2->isRecordType()))
4722 // If T1 is reference-related to T2 and the reference is an rvalue
4723 // reference, the initializer expression shall not be an lvalue.
4724 if (RefRelationship >= Sema::Ref_Related &&
4725 isRValRef && Init->Classify(S.Context).isLValue())
4728 // C++ [over.ics.ref]p2:
4729 // When a parameter of reference type is not bound directly to
4730 // an argument expression, the conversion sequence is the one
4731 // required to convert the argument expression to the
4732 // underlying type of the reference according to
4733 // 13.3.3.1. Conceptually, this conversion sequence corresponds
4734 // to copy-initializing a temporary of the underlying type with
4735 // the argument expression. Any difference in top-level
4736 // cv-qualification is subsumed by the initialization itself
4737 // and does not constitute a conversion.
4738 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions,
4739 /*AllowExplicit=*/false,
4740 /*InOverloadResolution=*/false,
4742 /*AllowObjCWritebackConversion=*/false,
4743 /*AllowObjCConversionOnExplicit=*/false);
4745 // Of course, that's still a reference binding.
4746 if (ICS.isStandard()) {
4747 ICS.Standard.ReferenceBinding = true;
4748 ICS.Standard.IsLvalueReference = !isRValRef;
4749 ICS.Standard.BindsToFunctionLvalue = false;
4750 ICS.Standard.BindsToRvalue = true;
4751 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4752 ICS.Standard.ObjCLifetimeConversionBinding = false;
4753 } else if (ICS.isUserDefined()) {
4754 const ReferenceType *LValRefType =
4755 ICS.UserDefined.ConversionFunction->getReturnType()
4756 ->getAs<LValueReferenceType>();
4758 // C++ [over.ics.ref]p3:
4759 // Except for an implicit object parameter, for which see 13.3.1, a
4760 // standard conversion sequence cannot be formed if it requires [...]
4761 // binding an rvalue reference to an lvalue other than a function
4763 // Note that the function case is not possible here.
4764 if (DeclType->isRValueReferenceType() && LValRefType) {
4765 // FIXME: This is the wrong BadConversionSequence. The problem is binding
4766 // an rvalue reference to a (non-function) lvalue, not binding an lvalue
4767 // reference to an rvalue!
4768 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, Init, DeclType);
4772 ICS.UserDefined.After.ReferenceBinding = true;
4773 ICS.UserDefined.After.IsLvalueReference = !isRValRef;
4774 ICS.UserDefined.After.BindsToFunctionLvalue = false;
4775 ICS.UserDefined.After.BindsToRvalue = !LValRefType;
4776 ICS.UserDefined.After.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4777 ICS.UserDefined.After.ObjCLifetimeConversionBinding = false;
4783 static ImplicitConversionSequence
4784 TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
4785 bool SuppressUserConversions,
4786 bool InOverloadResolution,
4787 bool AllowObjCWritebackConversion,
4788 bool AllowExplicit = false);
4790 /// TryListConversion - Try to copy-initialize a value of type ToType from the
4791 /// initializer list From.
4792 static ImplicitConversionSequence
4793 TryListConversion(Sema &S, InitListExpr *From, QualType ToType,
4794 bool SuppressUserConversions,
4795 bool InOverloadResolution,
4796 bool AllowObjCWritebackConversion) {
4797 // C++11 [over.ics.list]p1:
4798 // When an argument is an initializer list, it is not an expression and
4799 // special rules apply for converting it to a parameter type.
4801 ImplicitConversionSequence Result;
4802 Result.setBad(BadConversionSequence::no_conversion, From, ToType);
4804 // We need a complete type for what follows. Incomplete types can never be
4805 // initialized from init lists.
4806 if (!S.isCompleteType(From->getBeginLoc(), ToType))
4810 // If the parameter type is a class X and the initializer list has a single
4811 // element of type cv U, where U is X or a class derived from X, the
4812 // implicit conversion sequence is the one required to convert the element
4813 // to the parameter type.
4815 // Otherwise, if the parameter type is a character array [... ]
4816 // and the initializer list has a single element that is an
4817 // appropriately-typed string literal (8.5.2 [dcl.init.string]), the
4818 // implicit conversion sequence is the identity conversion.
4819 if (From->getNumInits() == 1) {
4820 if (ToType->isRecordType()) {
4821 QualType InitType = From->getInit(0)->getType();
4822 if (S.Context.hasSameUnqualifiedType(InitType, ToType) ||
4823 S.IsDerivedFrom(From->getBeginLoc(), InitType, ToType))
4824 return TryCopyInitialization(S, From->getInit(0), ToType,
4825 SuppressUserConversions,
4826 InOverloadResolution,
4827 AllowObjCWritebackConversion);
4829 // FIXME: Check the other conditions here: array of character type,
4830 // initializer is a string literal.
4831 if (ToType->isArrayType()) {
4832 InitializedEntity Entity =
4833 InitializedEntity::InitializeParameter(S.Context, ToType,
4834 /*Consumed=*/false);
4835 if (S.CanPerformCopyInitialization(Entity, From)) {
4836 Result.setStandard();
4837 Result.Standard.setAsIdentityConversion();
4838 Result.Standard.setFromType(ToType);
4839 Result.Standard.setAllToTypes(ToType);
4845 // C++14 [over.ics.list]p2: Otherwise, if the parameter type [...] (below).
4846 // C++11 [over.ics.list]p2:
4847 // If the parameter type is std::initializer_list<X> or "array of X" and
4848 // all the elements can be implicitly converted to X, the implicit
4849 // conversion sequence is the worst conversion necessary to convert an
4850 // element of the list to X.
4852 // C++14 [over.ics.list]p3:
4853 // Otherwise, if the parameter type is "array of N X", if the initializer
4854 // list has exactly N elements or if it has fewer than N elements and X is
4855 // default-constructible, and if all the elements of the initializer list
4856 // can be implicitly converted to X, the implicit conversion sequence is
4857 // the worst conversion necessary to convert an element of the list to X.
4859 // FIXME: We're missing a lot of these checks.
4860 bool toStdInitializerList = false;
4862 if (ToType->isArrayType())
4863 X = S.Context.getAsArrayType(ToType)->getElementType();
4865 toStdInitializerList = S.isStdInitializerList(ToType, &X);
4867 for (unsigned i = 0, e = From->getNumInits(); i < e; ++i) {
4868 Expr *Init = From->getInit(i);
4869 ImplicitConversionSequence ICS =
4870 TryCopyInitialization(S, Init, X, SuppressUserConversions,
4871 InOverloadResolution,
4872 AllowObjCWritebackConversion);
4873 // If a single element isn't convertible, fail.
4878 // Otherwise, look for the worst conversion.
4879 if (Result.isBad() || CompareImplicitConversionSequences(
4880 S, From->getBeginLoc(), ICS, Result) ==
4881 ImplicitConversionSequence::Worse)
4885 // For an empty list, we won't have computed any conversion sequence.
4886 // Introduce the identity conversion sequence.
4887 if (From->getNumInits() == 0) {
4888 Result.setStandard();
4889 Result.Standard.setAsIdentityConversion();
4890 Result.Standard.setFromType(ToType);
4891 Result.Standard.setAllToTypes(ToType);
4894 Result.setStdInitializerListElement(toStdInitializerList);
4898 // C++14 [over.ics.list]p4:
4899 // C++11 [over.ics.list]p3:
4900 // Otherwise, if the parameter is a non-aggregate class X and overload
4901 // resolution chooses a single best constructor [...] the implicit
4902 // conversion sequence is a user-defined conversion sequence. If multiple
4903 // constructors are viable but none is better than the others, the
4904 // implicit conversion sequence is a user-defined conversion sequence.
4905 if (ToType->isRecordType() && !ToType->isAggregateType()) {
4906 // This function can deal with initializer lists.
4907 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
4908 /*AllowExplicit=*/false,
4909 InOverloadResolution, /*CStyle=*/false,
4910 AllowObjCWritebackConversion,
4911 /*AllowObjCConversionOnExplicit=*/false);
4914 // C++14 [over.ics.list]p5:
4915 // C++11 [over.ics.list]p4:
4916 // Otherwise, if the parameter has an aggregate type which can be
4917 // initialized from the initializer list [...] the implicit conversion
4918 // sequence is a user-defined conversion sequence.
4919 if (ToType->isAggregateType()) {
4920 // Type is an aggregate, argument is an init list. At this point it comes
4921 // down to checking whether the initialization works.
4922 // FIXME: Find out whether this parameter is consumed or not.
4923 // FIXME: Expose SemaInit's aggregate initialization code so that we don't
4924 // need to call into the initialization code here; overload resolution
4925 // should not be doing that.
4926 InitializedEntity Entity =
4927 InitializedEntity::InitializeParameter(S.Context, ToType,
4928 /*Consumed=*/false);
4929 if (S.CanPerformCopyInitialization(Entity, From)) {
4930 Result.setUserDefined();
4931 Result.UserDefined.Before.setAsIdentityConversion();
4932 // Initializer lists don't have a type.
4933 Result.UserDefined.Before.setFromType(QualType());
4934 Result.UserDefined.Before.setAllToTypes(QualType());
4936 Result.UserDefined.After.setAsIdentityConversion();
4937 Result.UserDefined.After.setFromType(ToType);
4938 Result.UserDefined.After.setAllToTypes(ToType);
4939 Result.UserDefined.ConversionFunction = nullptr;
4944 // C++14 [over.ics.list]p6:
4945 // C++11 [over.ics.list]p5:
4946 // Otherwise, if the parameter is a reference, see 13.3.3.1.4.
4947 if (ToType->isReferenceType()) {
4948 // The standard is notoriously unclear here, since 13.3.3.1.4 doesn't
4949 // mention initializer lists in any way. So we go by what list-
4950 // initialization would do and try to extrapolate from that.
4952 QualType T1 = ToType->getAs<ReferenceType>()->getPointeeType();
4954 // If the initializer list has a single element that is reference-related
4955 // to the parameter type, we initialize the reference from that.
4956 if (From->getNumInits() == 1) {
4957 Expr *Init = From->getInit(0);
4959 QualType T2 = Init->getType();
4961 // If the initializer is the address of an overloaded function, try
4962 // to resolve the overloaded function. If all goes well, T2 is the
4963 // type of the resulting function.
4964 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
4965 DeclAccessPair Found;
4966 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(
4967 Init, ToType, false, Found))
4971 // Compute some basic properties of the types and the initializer.
4972 bool dummy1 = false;
4973 bool dummy2 = false;
4974 bool dummy3 = false;
4975 Sema::ReferenceCompareResult RefRelationship =
4976 S.CompareReferenceRelationship(From->getBeginLoc(), T1, T2, dummy1,
4979 if (RefRelationship >= Sema::Ref_Related) {
4980 return TryReferenceInit(S, Init, ToType, /*FIXME*/ From->getBeginLoc(),
4981 SuppressUserConversions,
4982 /*AllowExplicit=*/false);
4986 // Otherwise, we bind the reference to a temporary created from the
4987 // initializer list.
4988 Result = TryListConversion(S, From, T1, SuppressUserConversions,
4989 InOverloadResolution,
4990 AllowObjCWritebackConversion);
4991 if (Result.isFailure())
4993 assert(!Result.isEllipsis() &&
4994 "Sub-initialization cannot result in ellipsis conversion.");
4996 // Can we even bind to a temporary?
4997 if (ToType->isRValueReferenceType() ||
4998 (T1.isConstQualified() && !T1.isVolatileQualified())) {
4999 StandardConversionSequence &SCS = Result.isStandard() ? Result.Standard :
5000 Result.UserDefined.After;
5001 SCS.ReferenceBinding = true;
5002 SCS.IsLvalueReference = ToType->isLValueReferenceType();
5003 SCS.BindsToRvalue = true;
5004 SCS.BindsToFunctionLvalue = false;
5005 SCS.BindsImplicitObjectArgumentWithoutRefQualifier = false;
5006 SCS.ObjCLifetimeConversionBinding = false;
5008 Result.setBad(BadConversionSequence::lvalue_ref_to_rvalue,
5013 // C++14 [over.ics.list]p7:
5014 // C++11 [over.ics.list]p6:
5015 // Otherwise, if the parameter type is not a class:
5016 if (!ToType->isRecordType()) {
5017 // - if the initializer list has one element that is not itself an
5018 // initializer list, the implicit conversion sequence is the one
5019 // required to convert the element to the parameter type.
5020 unsigned NumInits = From->getNumInits();
5021 if (NumInits == 1 && !isa<InitListExpr>(From->getInit(0)))
5022 Result = TryCopyInitialization(S, From->getInit(0), ToType,
5023 SuppressUserConversions,
5024 InOverloadResolution,
5025 AllowObjCWritebackConversion);
5026 // - if the initializer list has no elements, the implicit conversion
5027 // sequence is the identity conversion.
5028 else if (NumInits == 0) {
5029 Result.setStandard();
5030 Result.Standard.setAsIdentityConversion();
5031 Result.Standard.setFromType(ToType);
5032 Result.Standard.setAllToTypes(ToType);
5037 // C++14 [over.ics.list]p8:
5038 // C++11 [over.ics.list]p7:
5039 // In all cases other than those enumerated above, no conversion is possible
5043 /// TryCopyInitialization - Try to copy-initialize a value of type
5044 /// ToType from the expression From. Return the implicit conversion
5045 /// sequence required to pass this argument, which may be a bad
5046 /// conversion sequence (meaning that the argument cannot be passed to
5047 /// a parameter of this type). If @p SuppressUserConversions, then we
5048 /// do not permit any user-defined conversion sequences.
5049 static ImplicitConversionSequence
5050 TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
5051 bool SuppressUserConversions,
5052 bool InOverloadResolution,
5053 bool AllowObjCWritebackConversion,
5054 bool AllowExplicit) {
5055 if (InitListExpr *FromInitList = dyn_cast<InitListExpr>(From))
5056 return TryListConversion(S, FromInitList, ToType, SuppressUserConversions,
5057 InOverloadResolution,AllowObjCWritebackConversion);
5059 if (ToType->isReferenceType())
5060 return TryReferenceInit(S, From, ToType,
5061 /*FIXME:*/ From->getBeginLoc(),
5062 SuppressUserConversions, AllowExplicit);
5064 return TryImplicitConversion(S, From, ToType,
5065 SuppressUserConversions,
5066 /*AllowExplicit=*/false,
5067 InOverloadResolution,
5069 AllowObjCWritebackConversion,
5070 /*AllowObjCConversionOnExplicit=*/false);
5073 static bool TryCopyInitialization(const CanQualType FromQTy,
5074 const CanQualType ToQTy,
5077 ExprValueKind FromVK) {
5078 OpaqueValueExpr TmpExpr(Loc, FromQTy, FromVK);
5079 ImplicitConversionSequence ICS =
5080 TryCopyInitialization(S, &TmpExpr, ToQTy, true, true, false);
5082 return !ICS.isBad();
5085 /// TryObjectArgumentInitialization - Try to initialize the object
5086 /// parameter of the given member function (@c Method) from the
5087 /// expression @p From.
5088 static ImplicitConversionSequence
5089 TryObjectArgumentInitialization(Sema &S, SourceLocation Loc, QualType FromType,
5090 Expr::Classification FromClassification,
5091 CXXMethodDecl *Method,
5092 CXXRecordDecl *ActingContext) {
5093 QualType ClassType = S.Context.getTypeDeclType(ActingContext);
5094 // [class.dtor]p2: A destructor can be invoked for a const, volatile or
5095 // const volatile object.
5096 Qualifiers Quals = Method->getMethodQualifiers();
5097 if (isa<CXXDestructorDecl>(Method)) {
5099 Quals.addVolatile();
5102 QualType ImplicitParamType = S.Context.getQualifiedType(ClassType, Quals);
5104 // Set up the conversion sequence as a "bad" conversion, to allow us
5106 ImplicitConversionSequence ICS;
5108 // We need to have an object of class type.
5109 if (const PointerType *PT = FromType->getAs<PointerType>()) {
5110 FromType = PT->getPointeeType();
5112 // When we had a pointer, it's implicitly dereferenced, so we
5113 // better have an lvalue.
5114 assert(FromClassification.isLValue());
5117 assert(FromType->isRecordType());
5119 // C++0x [over.match.funcs]p4:
5120 // For non-static member functions, the type of the implicit object
5123 // - "lvalue reference to cv X" for functions declared without a
5124 // ref-qualifier or with the & ref-qualifier
5125 // - "rvalue reference to cv X" for functions declared with the &&
5128 // where X is the class of which the function is a member and cv is the
5129 // cv-qualification on the member function declaration.
5131 // However, when finding an implicit conversion sequence for the argument, we
5132 // are not allowed to perform user-defined conversions
5133 // (C++ [over.match.funcs]p5). We perform a simplified version of
5134 // reference binding here, that allows class rvalues to bind to
5135 // non-constant references.
5137 // First check the qualifiers.
5138 QualType FromTypeCanon = S.Context.getCanonicalType(FromType);
5139 if (ImplicitParamType.getCVRQualifiers()
5140 != FromTypeCanon.getLocalCVRQualifiers() &&
5141 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) {
5142 ICS.setBad(BadConversionSequence::bad_qualifiers,
5143 FromType, ImplicitParamType);
5147 if (FromTypeCanon.getQualifiers().hasAddressSpace()) {
5148 Qualifiers QualsImplicitParamType = ImplicitParamType.getQualifiers();
5149 Qualifiers QualsFromType = FromTypeCanon.getQualifiers();
5150 if (!QualsImplicitParamType.isAddressSpaceSupersetOf(QualsFromType)) {
5151 ICS.setBad(BadConversionSequence::bad_qualifiers,
5152 FromType, ImplicitParamType);
5157 // Check that we have either the same type or a derived type. It
5158 // affects the conversion rank.
5159 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType);
5160 ImplicitConversionKind SecondKind;
5161 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) {
5162 SecondKind = ICK_Identity;
5163 } else if (S.IsDerivedFrom(Loc, FromType, ClassType))
5164 SecondKind = ICK_Derived_To_Base;
5166 ICS.setBad(BadConversionSequence::unrelated_class,
5167 FromType, ImplicitParamType);
5171 // Check the ref-qualifier.
5172 switch (Method->getRefQualifier()) {
5174 // Do nothing; we don't care about lvalueness or rvalueness.
5178 if (!FromClassification.isLValue() && !Quals.hasOnlyConst()) {
5179 // non-const lvalue reference cannot bind to an rvalue
5180 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType,
5187 if (!FromClassification.isRValue()) {
5188 // rvalue reference cannot bind to an lvalue
5189 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType,
5196 // Success. Mark this as a reference binding.
5198 ICS.Standard.setAsIdentityConversion();
5199 ICS.Standard.Second = SecondKind;
5200 ICS.Standard.setFromType(FromType);
5201 ICS.Standard.setAllToTypes(ImplicitParamType);
5202 ICS.Standard.ReferenceBinding = true;
5203 ICS.Standard.DirectBinding = true;
5204 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue;
5205 ICS.Standard.BindsToFunctionLvalue = false;
5206 ICS.Standard.BindsToRvalue = FromClassification.isRValue();
5207 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier
5208 = (Method->getRefQualifier() == RQ_None);
5212 /// PerformObjectArgumentInitialization - Perform initialization of
5213 /// the implicit object parameter for the given Method with the given
5216 Sema::PerformObjectArgumentInitialization(Expr *From,
5217 NestedNameSpecifier *Qualifier,
5218 NamedDecl *FoundDecl,
5219 CXXMethodDecl *Method) {
5220 QualType FromRecordType, DestType;
5221 QualType ImplicitParamRecordType =
5222 Method->getThisType()->getAs<PointerType>()->getPointeeType();
5224 Expr::Classification FromClassification;
5225 if (const PointerType *PT = From->getType()->getAs<PointerType>()) {
5226 FromRecordType = PT->getPointeeType();
5227 DestType = Method->getThisType();
5228 FromClassification = Expr::Classification::makeSimpleLValue();
5230 FromRecordType = From->getType();
5231 DestType = ImplicitParamRecordType;
5232 FromClassification = From->Classify(Context);
5234 // When performing member access on an rvalue, materialize a temporary.
5235 if (From->isRValue()) {
5236 From = CreateMaterializeTemporaryExpr(FromRecordType, From,
5237 Method->getRefQualifier() !=
5238 RefQualifierKind::RQ_RValue);
5242 // Note that we always use the true parent context when performing
5243 // the actual argument initialization.
5244 ImplicitConversionSequence ICS = TryObjectArgumentInitialization(
5245 *this, From->getBeginLoc(), From->getType(), FromClassification, Method,
5246 Method->getParent());
5248 switch (ICS.Bad.Kind) {
5249 case BadConversionSequence::bad_qualifiers: {
5250 Qualifiers FromQs = FromRecordType.getQualifiers();
5251 Qualifiers ToQs = DestType.getQualifiers();
5252 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers();
5254 Diag(From->getBeginLoc(), diag::err_member_function_call_bad_cvr)
5255 << Method->getDeclName() << FromRecordType << (CVR - 1)
5256 << From->getSourceRange();
5257 Diag(Method->getLocation(), diag::note_previous_decl)
5258 << Method->getDeclName();
5264 case BadConversionSequence::lvalue_ref_to_rvalue:
5265 case BadConversionSequence::rvalue_ref_to_lvalue: {
5266 bool IsRValueQualified =
5267 Method->getRefQualifier() == RefQualifierKind::RQ_RValue;
5268 Diag(From->getBeginLoc(), diag::err_member_function_call_bad_ref)
5269 << Method->getDeclName() << FromClassification.isRValue()
5270 << IsRValueQualified;
5271 Diag(Method->getLocation(), diag::note_previous_decl)
5272 << Method->getDeclName();
5276 case BadConversionSequence::no_conversion:
5277 case BadConversionSequence::unrelated_class:
5281 return Diag(From->getBeginLoc(), diag::err_member_function_call_bad_type)
5282 << ImplicitParamRecordType << FromRecordType
5283 << From->getSourceRange();
5286 if (ICS.Standard.Second == ICK_Derived_To_Base) {
5287 ExprResult FromRes =
5288 PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method);
5289 if (FromRes.isInvalid())
5291 From = FromRes.get();
5294 if (!Context.hasSameType(From->getType(), DestType)) {
5296 if (FromRecordType.getAddressSpace() != DestType.getAddressSpace())
5297 CK = CK_AddressSpaceConversion;
5300 From = ImpCastExprToType(From, DestType, CK, From->getValueKind()).get();
5305 /// TryContextuallyConvertToBool - Attempt to contextually convert the
5306 /// expression From to bool (C++0x [conv]p3).
5307 static ImplicitConversionSequence
5308 TryContextuallyConvertToBool(Sema &S, Expr *From) {
5309 return TryImplicitConversion(S, From, S.Context.BoolTy,
5310 /*SuppressUserConversions=*/false,
5311 /*AllowExplicit=*/true,
5312 /*InOverloadResolution=*/false,
5314 /*AllowObjCWritebackConversion=*/false,
5315 /*AllowObjCConversionOnExplicit=*/false);
5318 /// PerformContextuallyConvertToBool - Perform a contextual conversion
5319 /// of the expression From to bool (C++0x [conv]p3).
5320 ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) {
5321 if (checkPlaceholderForOverload(*this, From))
5324 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From);
5326 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting);
5328 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy))
5329 return Diag(From->getBeginLoc(), diag::err_typecheck_bool_condition)
5330 << From->getType() << From->getSourceRange();
5334 /// Check that the specified conversion is permitted in a converted constant
5335 /// expression, according to C++11 [expr.const]p3. Return true if the conversion
5337 static bool CheckConvertedConstantConversions(Sema &S,
5338 StandardConversionSequence &SCS) {
5339 // Since we know that the target type is an integral or unscoped enumeration
5340 // type, most conversion kinds are impossible. All possible First and Third
5341 // conversions are fine.
5342 switch (SCS.Second) {
5344 case ICK_Function_Conversion:
5345 case ICK_Integral_Promotion:
5346 case ICK_Integral_Conversion: // Narrowing conversions are checked elsewhere.
5347 case ICK_Zero_Queue_Conversion:
5350 case ICK_Boolean_Conversion:
5351 // Conversion from an integral or unscoped enumeration type to bool is
5352 // classified as ICK_Boolean_Conversion, but it's also arguably an integral
5353 // conversion, so we allow it in a converted constant expression.
5355 // FIXME: Per core issue 1407, we should not allow this, but that breaks
5356 // a lot of popular code. We should at least add a warning for this
5357 // (non-conforming) extension.
5358 return SCS.getFromType()->isIntegralOrUnscopedEnumerationType() &&
5359 SCS.getToType(2)->isBooleanType();
5361 case ICK_Pointer_Conversion:
5362 case ICK_Pointer_Member:
5363 // C++1z: null pointer conversions and null member pointer conversions are
5364 // only permitted if the source type is std::nullptr_t.
5365 return SCS.getFromType()->isNullPtrType();
5367 case ICK_Floating_Promotion:
5368 case ICK_Complex_Promotion:
5369 case ICK_Floating_Conversion:
5370 case ICK_Complex_Conversion:
5371 case ICK_Floating_Integral:
5372 case ICK_Compatible_Conversion:
5373 case ICK_Derived_To_Base:
5374 case ICK_Vector_Conversion:
5375 case ICK_Vector_Splat:
5376 case ICK_Complex_Real:
5377 case ICK_Block_Pointer_Conversion:
5378 case ICK_TransparentUnionConversion:
5379 case ICK_Writeback_Conversion:
5380 case ICK_Zero_Event_Conversion:
5381 case ICK_C_Only_Conversion:
5382 case ICK_Incompatible_Pointer_Conversion:
5385 case ICK_Lvalue_To_Rvalue:
5386 case ICK_Array_To_Pointer:
5387 case ICK_Function_To_Pointer:
5388 llvm_unreachable("found a first conversion kind in Second");
5390 case ICK_Qualification:
5391 llvm_unreachable("found a third conversion kind in Second");
5393 case ICK_Num_Conversion_Kinds:
5397 llvm_unreachable("unknown conversion kind");
5400 /// CheckConvertedConstantExpression - Check that the expression From is a
5401 /// converted constant expression of type T, perform the conversion and produce
5402 /// the converted expression, per C++11 [expr.const]p3.
5403 static ExprResult CheckConvertedConstantExpression(Sema &S, Expr *From,
5404 QualType T, APValue &Value,
5407 assert(S.getLangOpts().CPlusPlus11 &&
5408 "converted constant expression outside C++11");
5410 if (checkPlaceholderForOverload(S, From))
5413 // C++1z [expr.const]p3:
5414 // A converted constant expression of type T is an expression,
5415 // implicitly converted to type T, where the converted
5416 // expression is a constant expression and the implicit conversion
5417 // sequence contains only [... list of conversions ...].
5418 // C++1z [stmt.if]p2:
5419 // If the if statement is of the form if constexpr, the value of the
5420 // condition shall be a contextually converted constant expression of type
5422 ImplicitConversionSequence ICS =
5423 CCE == Sema::CCEK_ConstexprIf || CCE == Sema::CCEK_ExplicitBool
5424 ? TryContextuallyConvertToBool(S, From)
5425 : TryCopyInitialization(S, From, T,
5426 /*SuppressUserConversions=*/false,
5427 /*InOverloadResolution=*/false,
5428 /*AllowObjCWritebackConversion=*/false,
5429 /*AllowExplicit=*/false);
5430 StandardConversionSequence *SCS = nullptr;
5431 switch (ICS.getKind()) {
5432 case ImplicitConversionSequence::StandardConversion:
5433 SCS = &ICS.Standard;
5435 case ImplicitConversionSequence::UserDefinedConversion:
5436 // We are converting to a non-class type, so the Before sequence
5438 SCS = &ICS.UserDefined.After;
5440 case ImplicitConversionSequence::AmbiguousConversion:
5441 case ImplicitConversionSequence::BadConversion:
5442 if (!S.DiagnoseMultipleUserDefinedConversion(From, T))
5443 return S.Diag(From->getBeginLoc(),
5444 diag::err_typecheck_converted_constant_expression)
5445 << From->getType() << From->getSourceRange() << T;
5448 case ImplicitConversionSequence::EllipsisConversion:
5449 llvm_unreachable("ellipsis conversion in converted constant expression");
5452 // Check that we would only use permitted conversions.
5453 if (!CheckConvertedConstantConversions(S, *SCS)) {
5454 return S.Diag(From->getBeginLoc(),
5455 diag::err_typecheck_converted_constant_expression_disallowed)
5456 << From->getType() << From->getSourceRange() << T;
5458 // [...] and where the reference binding (if any) binds directly.
5459 if (SCS->ReferenceBinding && !SCS->DirectBinding) {
5460 return S.Diag(From->getBeginLoc(),
5461 diag::err_typecheck_converted_constant_expression_indirect)
5462 << From->getType() << From->getSourceRange() << T;
5466 S.PerformImplicitConversion(From, T, ICS, Sema::AA_Converting);
5467 if (Result.isInvalid())
5470 // Check for a narrowing implicit conversion.
5471 APValue PreNarrowingValue;
5472 QualType PreNarrowingType;
5473 switch (SCS->getNarrowingKind(S.Context, Result.get(), PreNarrowingValue,
5474 PreNarrowingType)) {
5475 case NK_Dependent_Narrowing:
5476 // Implicit conversion to a narrower type, but the expression is
5477 // value-dependent so we can't tell whether it's actually narrowing.
5478 case NK_Variable_Narrowing:
5479 // Implicit conversion to a narrower type, and the value is not a constant
5480 // expression. We'll diagnose this in a moment.
5481 case NK_Not_Narrowing:
5484 case NK_Constant_Narrowing:
5485 S.Diag(From->getBeginLoc(), diag::ext_cce_narrowing)
5486 << CCE << /*Constant*/ 1
5487 << PreNarrowingValue.getAsString(S.Context, PreNarrowingType) << T;
5490 case NK_Type_Narrowing:
5491 S.Diag(From->getBeginLoc(), diag::ext_cce_narrowing)
5492 << CCE << /*Constant*/ 0 << From->getType() << T;
5496 if (Result.get()->isValueDependent()) {
5501 // Check the expression is a constant expression.
5502 SmallVector<PartialDiagnosticAt, 8> Notes;
5503 Expr::EvalResult Eval;
5505 Expr::ConstExprUsage Usage = CCE == Sema::CCEK_TemplateArg
5506 ? Expr::EvaluateForMangling
5507 : Expr::EvaluateForCodeGen;
5509 if (!Result.get()->EvaluateAsConstantExpr(Eval, Usage, S.Context) ||
5510 (RequireInt && !Eval.Val.isInt())) {
5511 // The expression can't be folded, so we can't keep it at this position in
5513 Result = ExprError();
5517 if (Notes.empty()) {
5518 // It's a constant expression.
5519 return ConstantExpr::Create(S.Context, Result.get(), Value);
5523 // It's not a constant expression. Produce an appropriate diagnostic.
5524 if (Notes.size() == 1 &&
5525 Notes[0].second.getDiagID() == diag::note_invalid_subexpr_in_const_expr)
5526 S.Diag(Notes[0].first, diag::err_expr_not_cce) << CCE;
5528 S.Diag(From->getBeginLoc(), diag::err_expr_not_cce)
5529 << CCE << From->getSourceRange();
5530 for (unsigned I = 0; I < Notes.size(); ++I)
5531 S.Diag(Notes[I].first, Notes[I].second);
5536 ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5537 APValue &Value, CCEKind CCE) {
5538 return ::CheckConvertedConstantExpression(*this, From, T, Value, CCE, false);
5541 ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5542 llvm::APSInt &Value,
5544 assert(T->isIntegralOrEnumerationType() && "unexpected converted const type");
5547 auto R = ::CheckConvertedConstantExpression(*this, From, T, V, CCE, true);
5548 if (!R.isInvalid() && !R.get()->isValueDependent())
5554 /// dropPointerConversions - If the given standard conversion sequence
5555 /// involves any pointer conversions, remove them. This may change
5556 /// the result type of the conversion sequence.
5557 static void dropPointerConversion(StandardConversionSequence &SCS) {
5558 if (SCS.Second == ICK_Pointer_Conversion) {
5559 SCS.Second = ICK_Identity;
5560 SCS.Third = ICK_Identity;
5561 SCS.ToTypePtrs[2] = SCS.ToTypePtrs[1] = SCS.ToTypePtrs[0];
5565 /// TryContextuallyConvertToObjCPointer - Attempt to contextually
5566 /// convert the expression From to an Objective-C pointer type.
5567 static ImplicitConversionSequence
5568 TryContextuallyConvertToObjCPointer(Sema &S, Expr *From) {
5569 // Do an implicit conversion to 'id'.
5570 QualType Ty = S.Context.getObjCIdType();
5571 ImplicitConversionSequence ICS
5572 = TryImplicitConversion(S, From, Ty,
5573 // FIXME: Are these flags correct?
5574 /*SuppressUserConversions=*/false,
5575 /*AllowExplicit=*/true,
5576 /*InOverloadResolution=*/false,
5578 /*AllowObjCWritebackConversion=*/false,
5579 /*AllowObjCConversionOnExplicit=*/true);
5581 // Strip off any final conversions to 'id'.
5582 switch (ICS.getKind()) {
5583 case ImplicitConversionSequence::BadConversion:
5584 case ImplicitConversionSequence::AmbiguousConversion:
5585 case ImplicitConversionSequence::EllipsisConversion:
5588 case ImplicitConversionSequence::UserDefinedConversion:
5589 dropPointerConversion(ICS.UserDefined.After);
5592 case ImplicitConversionSequence::StandardConversion:
5593 dropPointerConversion(ICS.Standard);
5600 /// PerformContextuallyConvertToObjCPointer - Perform a contextual
5601 /// conversion of the expression From to an Objective-C pointer type.
5602 /// Returns a valid but null ExprResult if no conversion sequence exists.
5603 ExprResult Sema::PerformContextuallyConvertToObjCPointer(Expr *From) {
5604 if (checkPlaceholderForOverload(*this, From))
5607 QualType Ty = Context.getObjCIdType();
5608 ImplicitConversionSequence ICS =
5609 TryContextuallyConvertToObjCPointer(*this, From);
5611 return PerformImplicitConversion(From, Ty, ICS, AA_Converting);
5612 return ExprResult();
5615 /// Determine whether the provided type is an integral type, or an enumeration
5616 /// type of a permitted flavor.
5617 bool Sema::ICEConvertDiagnoser::match(QualType T) {
5618 return AllowScopedEnumerations ? T->isIntegralOrEnumerationType()
5619 : T->isIntegralOrUnscopedEnumerationType();
5623 diagnoseAmbiguousConversion(Sema &SemaRef, SourceLocation Loc, Expr *From,
5624 Sema::ContextualImplicitConverter &Converter,
5625 QualType T, UnresolvedSetImpl &ViableConversions) {
5627 if (Converter.Suppress)
5630 Converter.diagnoseAmbiguous(SemaRef, Loc, T) << From->getSourceRange();
5631 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5632 CXXConversionDecl *Conv =
5633 cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl());
5634 QualType ConvTy = Conv->getConversionType().getNonReferenceType();
5635 Converter.noteAmbiguous(SemaRef, Conv, ConvTy);
5641 diagnoseNoViableConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5642 Sema::ContextualImplicitConverter &Converter,
5643 QualType T, bool HadMultipleCandidates,
5644 UnresolvedSetImpl &ExplicitConversions) {
5645 if (ExplicitConversions.size() == 1 && !Converter.Suppress) {
5646 DeclAccessPair Found = ExplicitConversions[0];
5647 CXXConversionDecl *Conversion =
5648 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5650 // The user probably meant to invoke the given explicit
5651 // conversion; use it.
5652 QualType ConvTy = Conversion->getConversionType().getNonReferenceType();
5653 std::string TypeStr;
5654 ConvTy.getAsStringInternal(TypeStr, SemaRef.getPrintingPolicy());
5656 Converter.diagnoseExplicitConv(SemaRef, Loc, T, ConvTy)
5657 << FixItHint::CreateInsertion(From->getBeginLoc(),
5658 "static_cast<" + TypeStr + ">(")
5659 << FixItHint::CreateInsertion(
5660 SemaRef.getLocForEndOfToken(From->getEndLoc()), ")");
5661 Converter.noteExplicitConv(SemaRef, Conversion, ConvTy);
5663 // If we aren't in a SFINAE context, build a call to the
5664 // explicit conversion function.
5665 if (SemaRef.isSFINAEContext())
5668 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5669 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5670 HadMultipleCandidates);
5671 if (Result.isInvalid())
5673 // Record usage of conversion in an implicit cast.
5674 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5675 CK_UserDefinedConversion, Result.get(),
5676 nullptr, Result.get()->getValueKind());
5681 static bool recordConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5682 Sema::ContextualImplicitConverter &Converter,
5683 QualType T, bool HadMultipleCandidates,
5684 DeclAccessPair &Found) {
5685 CXXConversionDecl *Conversion =
5686 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5687 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5689 QualType ToType = Conversion->getConversionType().getNonReferenceType();
5690 if (!Converter.SuppressConversion) {
5691 if (SemaRef.isSFINAEContext())
5694 Converter.diagnoseConversion(SemaRef, Loc, T, ToType)
5695 << From->getSourceRange();
5698 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5699 HadMultipleCandidates);
5700 if (Result.isInvalid())
5702 // Record usage of conversion in an implicit cast.
5703 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5704 CK_UserDefinedConversion, Result.get(),
5705 nullptr, Result.get()->getValueKind());
5709 static ExprResult finishContextualImplicitConversion(
5710 Sema &SemaRef, SourceLocation Loc, Expr *From,
5711 Sema::ContextualImplicitConverter &Converter) {
5712 if (!Converter.match(From->getType()) && !Converter.Suppress)
5713 Converter.diagnoseNoMatch(SemaRef, Loc, From->getType())
5714 << From->getSourceRange();
5716 return SemaRef.DefaultLvalueConversion(From);
5720 collectViableConversionCandidates(Sema &SemaRef, Expr *From, QualType ToType,
5721 UnresolvedSetImpl &ViableConversions,
5722 OverloadCandidateSet &CandidateSet) {
5723 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5724 DeclAccessPair FoundDecl = ViableConversions[I];
5725 NamedDecl *D = FoundDecl.getDecl();
5726 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
5727 if (isa<UsingShadowDecl>(D))
5728 D = cast<UsingShadowDecl>(D)->getTargetDecl();
5730 CXXConversionDecl *Conv;
5731 FunctionTemplateDecl *ConvTemplate;
5732 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
5733 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5735 Conv = cast<CXXConversionDecl>(D);
5738 SemaRef.AddTemplateConversionCandidate(
5739 ConvTemplate, FoundDecl, ActingContext, From, ToType, CandidateSet,
5740 /*AllowObjCConversionOnExplicit=*/false, /*AllowExplicit*/ true);
5742 SemaRef.AddConversionCandidate(Conv, FoundDecl, ActingContext, From,
5743 ToType, CandidateSet,
5744 /*AllowObjCConversionOnExplicit=*/false,
5745 /*AllowExplicit*/ true);
5749 /// Attempt to convert the given expression to a type which is accepted
5750 /// by the given converter.
5752 /// This routine will attempt to convert an expression of class type to a
5753 /// type accepted by the specified converter. In C++11 and before, the class
5754 /// must have a single non-explicit conversion function converting to a matching
5755 /// type. In C++1y, there can be multiple such conversion functions, but only
5756 /// one target type.
5758 /// \param Loc The source location of the construct that requires the
5761 /// \param From The expression we're converting from.
5763 /// \param Converter Used to control and diagnose the conversion process.
5765 /// \returns The expression, converted to an integral or enumeration type if
5767 ExprResult Sema::PerformContextualImplicitConversion(
5768 SourceLocation Loc, Expr *From, ContextualImplicitConverter &Converter) {
5769 // We can't perform any more checking for type-dependent expressions.
5770 if (From->isTypeDependent())
5773 // Process placeholders immediately.
5774 if (From->hasPlaceholderType()) {
5775 ExprResult result = CheckPlaceholderExpr(From);
5776 if (result.isInvalid())
5778 From = result.get();
5781 // If the expression already has a matching type, we're golden.
5782 QualType T = From->getType();
5783 if (Converter.match(T))
5784 return DefaultLvalueConversion(From);
5786 // FIXME: Check for missing '()' if T is a function type?
5788 // We can only perform contextual implicit conversions on objects of class
5790 const RecordType *RecordTy = T->getAs<RecordType>();
5791 if (!RecordTy || !getLangOpts().CPlusPlus) {
5792 if (!Converter.Suppress)
5793 Converter.diagnoseNoMatch(*this, Loc, T) << From->getSourceRange();
5797 // We must have a complete class type.
5798 struct TypeDiagnoserPartialDiag : TypeDiagnoser {
5799 ContextualImplicitConverter &Converter;
5802 TypeDiagnoserPartialDiag(ContextualImplicitConverter &Converter, Expr *From)
5803 : Converter(Converter), From(From) {}
5805 void diagnose(Sema &S, SourceLocation Loc, QualType T) override {
5806 Converter.diagnoseIncomplete(S, Loc, T) << From->getSourceRange();
5808 } IncompleteDiagnoser(Converter, From);
5810 if (Converter.Suppress ? !isCompleteType(Loc, T)
5811 : RequireCompleteType(Loc, T, IncompleteDiagnoser))
5814 // Look for a conversion to an integral or enumeration type.
5816 ViableConversions; // These are *potentially* viable in C++1y.
5817 UnresolvedSet<4> ExplicitConversions;
5818 const auto &Conversions =
5819 cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions();
5821 bool HadMultipleCandidates =
5822 (std::distance(Conversions.begin(), Conversions.end()) > 1);
5824 // To check that there is only one target type, in C++1y:
5826 bool HasUniqueTargetType = true;
5828 // Collect explicit or viable (potentially in C++1y) conversions.
5829 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
5830 NamedDecl *D = (*I)->getUnderlyingDecl();
5831 CXXConversionDecl *Conversion;
5832 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
5834 if (getLangOpts().CPlusPlus14)
5835 Conversion = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5837 continue; // C++11 does not consider conversion operator templates(?).
5839 Conversion = cast<CXXConversionDecl>(D);
5841 assert((!ConvTemplate || getLangOpts().CPlusPlus14) &&
5842 "Conversion operator templates are considered potentially "
5845 QualType CurToType = Conversion->getConversionType().getNonReferenceType();
5846 if (Converter.match(CurToType) || ConvTemplate) {
5848 if (Conversion->isExplicit()) {
5849 // FIXME: For C++1y, do we need this restriction?
5850 // cf. diagnoseNoViableConversion()
5852 ExplicitConversions.addDecl(I.getDecl(), I.getAccess());
5854 if (!ConvTemplate && getLangOpts().CPlusPlus14) {
5855 if (ToType.isNull())
5856 ToType = CurToType.getUnqualifiedType();
5857 else if (HasUniqueTargetType &&
5858 (CurToType.getUnqualifiedType() != ToType))
5859 HasUniqueTargetType = false;
5861 ViableConversions.addDecl(I.getDecl(), I.getAccess());
5866 if (getLangOpts().CPlusPlus14) {
5868 // ... An expression e of class type E appearing in such a context
5869 // is said to be contextually implicitly converted to a specified
5870 // type T and is well-formed if and only if e can be implicitly
5871 // converted to a type T that is determined as follows: E is searched
5872 // for conversion functions whose return type is cv T or reference to
5873 // cv T such that T is allowed by the context. There shall be
5874 // exactly one such T.
5876 // If no unique T is found:
5877 if (ToType.isNull()) {
5878 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5879 HadMultipleCandidates,
5880 ExplicitConversions))
5882 return finishContextualImplicitConversion(*this, Loc, From, Converter);
5885 // If more than one unique Ts are found:
5886 if (!HasUniqueTargetType)
5887 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5890 // If one unique T is found:
5891 // First, build a candidate set from the previously recorded
5892 // potentially viable conversions.
5893 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Normal);
5894 collectViableConversionCandidates(*this, From, ToType, ViableConversions,
5897 // Then, perform overload resolution over the candidate set.
5898 OverloadCandidateSet::iterator Best;
5899 switch (CandidateSet.BestViableFunction(*this, Loc, Best)) {
5901 // Apply this conversion.
5902 DeclAccessPair Found =
5903 DeclAccessPair::make(Best->Function, Best->FoundDecl.getAccess());
5904 if (recordConversion(*this, Loc, From, Converter, T,
5905 HadMultipleCandidates, Found))
5910 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5912 case OR_No_Viable_Function:
5913 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5914 HadMultipleCandidates,
5915 ExplicitConversions))
5919 // We'll complain below about a non-integral condition type.
5923 switch (ViableConversions.size()) {
5925 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5926 HadMultipleCandidates,
5927 ExplicitConversions))
5930 // We'll complain below about a non-integral condition type.
5934 // Apply this conversion.
5935 DeclAccessPair Found = ViableConversions[0];
5936 if (recordConversion(*this, Loc, From, Converter, T,
5937 HadMultipleCandidates, Found))
5942 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5947 return finishContextualImplicitConversion(*this, Loc, From, Converter);
5950 /// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is
5951 /// an acceptable non-member overloaded operator for a call whose
5952 /// arguments have types T1 (and, if non-empty, T2). This routine
5953 /// implements the check in C++ [over.match.oper]p3b2 concerning
5954 /// enumeration types.
5955 static bool IsAcceptableNonMemberOperatorCandidate(ASTContext &Context,
5957 ArrayRef<Expr *> Args) {
5958 QualType T1 = Args[0]->getType();
5959 QualType T2 = Args.size() > 1 ? Args[1]->getType() : QualType();
5961 if (T1->isDependentType() || (!T2.isNull() && T2->isDependentType()))
5964 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType()))
5967 const FunctionProtoType *Proto = Fn->getType()->getAs<FunctionProtoType>();
5968 if (Proto->getNumParams() < 1)
5971 if (T1->isEnumeralType()) {
5972 QualType ArgType = Proto->getParamType(0).getNonReferenceType();
5973 if (Context.hasSameUnqualifiedType(T1, ArgType))
5977 if (Proto->getNumParams() < 2)
5980 if (!T2.isNull() && T2->isEnumeralType()) {
5981 QualType ArgType = Proto->getParamType(1).getNonReferenceType();
5982 if (Context.hasSameUnqualifiedType(T2, ArgType))
5989 /// AddOverloadCandidate - Adds the given function to the set of
5990 /// candidate functions, using the given function call arguments. If
5991 /// @p SuppressUserConversions, then don't allow user-defined
5992 /// conversions via constructors or conversion operators.
5994 /// \param PartialOverloading true if we are performing "partial" overloading
5995 /// based on an incomplete set of function arguments. This feature is used by
5996 /// code completion.
5997 void Sema::AddOverloadCandidate(
5998 FunctionDecl *Function, DeclAccessPair FoundDecl, ArrayRef<Expr *> Args,
5999 OverloadCandidateSet &CandidateSet, bool SuppressUserConversions,
6000 bool PartialOverloading, bool AllowExplicit, bool AllowExplicitConversions,
6001 ADLCallKind IsADLCandidate, ConversionSequenceList EarlyConversions) {
6002 const FunctionProtoType *Proto
6003 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>());
6004 assert(Proto && "Functions without a prototype cannot be overloaded");
6005 assert(!Function->getDescribedFunctionTemplate() &&
6006 "Use AddTemplateOverloadCandidate for function templates");
6008 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) {
6009 if (!isa<CXXConstructorDecl>(Method)) {
6010 // If we get here, it's because we're calling a member function
6011 // that is named without a member access expression (e.g.,
6012 // "this->f") that was either written explicitly or created
6013 // implicitly. This can happen with a qualified call to a member
6014 // function, e.g., X::f(). We use an empty type for the implied
6015 // object argument (C++ [over.call.func]p3), and the acting context
6017 AddMethodCandidate(Method, FoundDecl, Method->getParent(), QualType(),
6018 Expr::Classification::makeSimpleLValue(), Args,
6019 CandidateSet, SuppressUserConversions,
6020 PartialOverloading, EarlyConversions);
6023 // We treat a constructor like a non-member function, since its object
6024 // argument doesn't participate in overload resolution.
6027 if (!CandidateSet.isNewCandidate(Function))
6030 // C++ [over.match.oper]p3:
6031 // if no operand has a class type, only those non-member functions in the
6032 // lookup set that have a first parameter of type T1 or "reference to
6033 // (possibly cv-qualified) T1", when T1 is an enumeration type, or (if there
6034 // is a right operand) a second parameter of type T2 or "reference to
6035 // (possibly cv-qualified) T2", when T2 is an enumeration type, are
6036 // candidate functions.
6037 if (CandidateSet.getKind() == OverloadCandidateSet::CSK_Operator &&
6038 !IsAcceptableNonMemberOperatorCandidate(Context, Function, Args))
6041 // C++11 [class.copy]p11: [DR1402]
6042 // A defaulted move constructor that is defined as deleted is ignored by
6043 // overload resolution.
6044 CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function);
6045 if (Constructor && Constructor->isDefaulted() && Constructor->isDeleted() &&
6046 Constructor->isMoveConstructor())
6049 // Overload resolution is always an unevaluated context.
6050 EnterExpressionEvaluationContext Unevaluated(
6051 *this, Sema::ExpressionEvaluationContext::Unevaluated);
6053 // Add this candidate
6054 OverloadCandidate &Candidate =
6055 CandidateSet.addCandidate(Args.size(), EarlyConversions);
6056 Candidate.FoundDecl = FoundDecl;
6057 Candidate.Function = Function;
6058 Candidate.Viable = true;
6059 Candidate.IsSurrogate = false;
6060 Candidate.IsADLCandidate = IsADLCandidate;
6061 Candidate.IgnoreObjectArgument = false;
6062 Candidate.ExplicitCallArguments = Args.size();
6064 if (Function->isMultiVersion() && Function->hasAttr<TargetAttr>() &&
6065 !Function->getAttr<TargetAttr>()->isDefaultVersion()) {
6066 Candidate.Viable = false;
6067 Candidate.FailureKind = ovl_non_default_multiversion_function;
6072 // C++ [class.copy]p3:
6073 // A member function template is never instantiated to perform the copy
6074 // of a class object to an object of its class type.
6075 QualType ClassType = Context.getTypeDeclType(Constructor->getParent());
6076 if (Args.size() == 1 && Constructor->isSpecializationCopyingObject() &&
6077 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) ||
6078 IsDerivedFrom(Args[0]->getBeginLoc(), Args[0]->getType(),
6080 Candidate.Viable = false;
6081 Candidate.FailureKind = ovl_fail_illegal_constructor;
6085 // C++ [over.match.funcs]p8: (proposed DR resolution)
6086 // A constructor inherited from class type C that has a first parameter
6087 // of type "reference to P" (including such a constructor instantiated
6088 // from a template) is excluded from the set of candidate functions when
6089 // constructing an object of type cv D if the argument list has exactly
6090 // one argument and D is reference-related to P and P is reference-related
6092 auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(FoundDecl.getDecl());
6093 if (Shadow && Args.size() == 1 && Constructor->getNumParams() >= 1 &&
6094 Constructor->getParamDecl(0)->getType()->isReferenceType()) {
6095 QualType P = Constructor->getParamDecl(0)->getType()->getPointeeType();
6096 QualType C = Context.getRecordType(Constructor->getParent());
6097 QualType D = Context.getRecordType(Shadow->getParent());
6098 SourceLocation Loc = Args.front()->getExprLoc();
6099 if ((Context.hasSameUnqualifiedType(P, C) || IsDerivedFrom(Loc, P, C)) &&
6100 (Context.hasSameUnqualifiedType(D, P) || IsDerivedFrom(Loc, D, P))) {
6101 Candidate.Viable = false;
6102 Candidate.FailureKind = ovl_fail_inhctor_slice;
6107 // Check that the constructor is capable of constructing an object in the
6108 // destination address space.
6109 if (!Qualifiers::isAddressSpaceSupersetOf(
6110 Constructor->getMethodQualifiers().getAddressSpace(),
6111 CandidateSet.getDestAS())) {
6112 Candidate.Viable = false;
6113 Candidate.FailureKind = ovl_fail_object_addrspace_mismatch;
6117 unsigned NumParams = Proto->getNumParams();
6119 // (C++ 13.3.2p2): A candidate function having fewer than m
6120 // parameters is viable only if it has an ellipsis in its parameter
6122 if (TooManyArguments(NumParams, Args.size(), PartialOverloading) &&
6123 !Proto->isVariadic()) {
6124 Candidate.Viable = false;
6125 Candidate.FailureKind = ovl_fail_too_many_arguments;
6129 // (C++ 13.3.2p2): A candidate function having more than m parameters
6130 // is viable only if the (m+1)st parameter has a default argument
6131 // (8.3.6). For the purposes of overload resolution, the
6132 // parameter list is truncated on the right, so that there are
6133 // exactly m parameters.
6134 unsigned MinRequiredArgs = Function->getMinRequiredArguments();
6135 if (Args.size() < MinRequiredArgs && !PartialOverloading) {
6136 // Not enough arguments.
6137 Candidate.Viable = false;
6138 Candidate.FailureKind = ovl_fail_too_few_arguments;
6142 // (CUDA B.1): Check for invalid calls between targets.
6143 if (getLangOpts().CUDA)
6144 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext))
6145 // Skip the check for callers that are implicit members, because in this
6146 // case we may not yet know what the member's target is; the target is
6147 // inferred for the member automatically, based on the bases and fields of
6149 if (!Caller->isImplicit() && !IsAllowedCUDACall(Caller, Function)) {
6150 Candidate.Viable = false;
6151 Candidate.FailureKind = ovl_fail_bad_target;
6155 // Determine the implicit conversion sequences for each of the
6157 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) {
6158 if (Candidate.Conversions[ArgIdx].isInitialized()) {
6159 // We already formed a conversion sequence for this parameter during
6160 // template argument deduction.
6161 } else if (ArgIdx < NumParams) {
6162 // (C++ 13.3.2p3): for F to be a viable function, there shall
6163 // exist for each argument an implicit conversion sequence
6164 // (13.3.3.1) that converts that argument to the corresponding
6166 QualType ParamType = Proto->getParamType(ArgIdx);
6167 Candidate.Conversions[ArgIdx] = TryCopyInitialization(
6168 *this, Args[ArgIdx], ParamType, SuppressUserConversions,
6169 /*InOverloadResolution=*/true,
6170 /*AllowObjCWritebackConversion=*/
6171 getLangOpts().ObjCAutoRefCount, AllowExplicitConversions);
6172 if (Candidate.Conversions[ArgIdx].isBad()) {
6173 Candidate.Viable = false;
6174 Candidate.FailureKind = ovl_fail_bad_conversion;
6178 // (C++ 13.3.2p2): For the purposes of overload resolution, any
6179 // argument for which there is no corresponding parameter is
6180 // considered to ""match the ellipsis" (C+ 13.3.3.1.3).
6181 Candidate.Conversions[ArgIdx].setEllipsis();
6185 if (!AllowExplicit) {
6186 ExplicitSpecifier ES = ExplicitSpecifier::getFromDecl(Function);
6187 if (ES.getKind() != ExplicitSpecKind::ResolvedFalse) {
6188 Candidate.Viable = false;
6189 Candidate.FailureKind = ovl_fail_explicit_resolved;
6194 if (EnableIfAttr *FailedAttr = CheckEnableIf(Function, Args)) {
6195 Candidate.Viable = false;
6196 Candidate.FailureKind = ovl_fail_enable_if;
6197 Candidate.DeductionFailure.Data = FailedAttr;
6201 if (LangOpts.OpenCL && isOpenCLDisabledDecl(Function)) {
6202 Candidate.Viable = false;
6203 Candidate.FailureKind = ovl_fail_ext_disabled;
6209 Sema::SelectBestMethod(Selector Sel, MultiExprArg Args, bool IsInstance,
6210 SmallVectorImpl<ObjCMethodDecl *> &Methods) {
6211 if (Methods.size() <= 1)
6214 for (unsigned b = 0, e = Methods.size(); b < e; b++) {
6216 ObjCMethodDecl *Method = Methods[b];
6217 unsigned NumNamedArgs = Sel.getNumArgs();
6218 // Method might have more arguments than selector indicates. This is due
6219 // to addition of c-style arguments in method.
6220 if (Method->param_size() > NumNamedArgs)
6221 NumNamedArgs = Method->param_size();
6222 if (Args.size() < NumNamedArgs)
6225 for (unsigned i = 0; i < NumNamedArgs; i++) {
6226 // We can't do any type-checking on a type-dependent argument.
6227 if (Args[i]->isTypeDependent()) {
6232 ParmVarDecl *param = Method->parameters()[i];
6233 Expr *argExpr = Args[i];
6234 assert(argExpr && "SelectBestMethod(): missing expression");
6236 // Strip the unbridged-cast placeholder expression off unless it's
6237 // a consumed argument.
6238 if (argExpr->hasPlaceholderType(BuiltinType::ARCUnbridgedCast) &&
6239 !param->hasAttr<CFConsumedAttr>())
6240 argExpr = stripARCUnbridgedCast(argExpr);
6242 // If the parameter is __unknown_anytype, move on to the next method.
6243 if (param->getType() == Context.UnknownAnyTy) {
6248 ImplicitConversionSequence ConversionState
6249 = TryCopyInitialization(*this, argExpr, param->getType(),
6250 /*SuppressUserConversions*/false,
6251 /*InOverloadResolution=*/true,
6252 /*AllowObjCWritebackConversion=*/
6253 getLangOpts().ObjCAutoRefCount,
6254 /*AllowExplicit*/false);
6255 // This function looks for a reasonably-exact match, so we consider
6256 // incompatible pointer conversions to be a failure here.
6257 if (ConversionState.isBad() ||
6258 (ConversionState.isStandard() &&
6259 ConversionState.Standard.Second ==
6260 ICK_Incompatible_Pointer_Conversion)) {
6265 // Promote additional arguments to variadic methods.
6266 if (Match && Method->isVariadic()) {
6267 for (unsigned i = NumNamedArgs, e = Args.size(); i < e; ++i) {
6268 if (Args[i]->isTypeDependent()) {
6272 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod,
6274 if (Arg.isInvalid()) {
6280 // Check for extra arguments to non-variadic methods.
6281 if (Args.size() != NumNamedArgs)
6283 else if (Match && NumNamedArgs == 0 && Methods.size() > 1) {
6284 // Special case when selectors have no argument. In this case, select
6285 // one with the most general result type of 'id'.
6286 for (unsigned b = 0, e = Methods.size(); b < e; b++) {
6287 QualType ReturnT = Methods[b]->getReturnType();
6288 if (ReturnT->isObjCIdType())
6301 convertArgsForAvailabilityChecks(Sema &S, FunctionDecl *Function, Expr *ThisArg,
6302 ArrayRef<Expr *> Args, Sema::SFINAETrap &Trap,
6303 bool MissingImplicitThis, Expr *&ConvertedThis,
6304 SmallVectorImpl<Expr *> &ConvertedArgs) {
6306 CXXMethodDecl *Method = cast<CXXMethodDecl>(Function);
6307 assert(!isa<CXXConstructorDecl>(Method) &&
6308 "Shouldn't have `this` for ctors!");
6309 assert(!Method->isStatic() && "Shouldn't have `this` for static methods!");
6310 ExprResult R = S.PerformObjectArgumentInitialization(
6311 ThisArg, /*Qualifier=*/nullptr, Method, Method);
6314 ConvertedThis = R.get();
6316 if (auto *MD = dyn_cast<CXXMethodDecl>(Function)) {
6318 assert((MissingImplicitThis || MD->isStatic() ||
6319 isa<CXXConstructorDecl>(MD)) &&
6320 "Expected `this` for non-ctor instance methods");
6322 ConvertedThis = nullptr;
6325 // Ignore any variadic arguments. Converting them is pointless, since the
6326 // user can't refer to them in the function condition.
6327 unsigned ArgSizeNoVarargs = std::min(Function->param_size(), Args.size());
6329 // Convert the arguments.
6330 for (unsigned I = 0; I != ArgSizeNoVarargs; ++I) {
6332 R = S.PerformCopyInitialization(InitializedEntity::InitializeParameter(
6333 S.Context, Function->getParamDecl(I)),
6334 SourceLocation(), Args[I]);
6339 ConvertedArgs.push_back(R.get());
6342 if (Trap.hasErrorOccurred())
6345 // Push default arguments if needed.
6346 if (!Function->isVariadic() && Args.size() < Function->getNumParams()) {
6347 for (unsigned i = Args.size(), e = Function->getNumParams(); i != e; ++i) {
6348 ParmVarDecl *P = Function->getParamDecl(i);
6349 Expr *DefArg = P->hasUninstantiatedDefaultArg()
6350 ? P->getUninstantiatedDefaultArg()
6351 : P->getDefaultArg();
6352 // This can only happen in code completion, i.e. when PartialOverloading
6357 S.PerformCopyInitialization(InitializedEntity::InitializeParameter(
6358 S.Context, Function->getParamDecl(i)),
6359 SourceLocation(), DefArg);
6362 ConvertedArgs.push_back(R.get());
6365 if (Trap.hasErrorOccurred())
6371 EnableIfAttr *Sema::CheckEnableIf(FunctionDecl *Function, ArrayRef<Expr *> Args,
6372 bool MissingImplicitThis) {
6373 auto EnableIfAttrs = Function->specific_attrs<EnableIfAttr>();
6374 if (EnableIfAttrs.begin() == EnableIfAttrs.end())
6377 SFINAETrap Trap(*this);
6378 SmallVector<Expr *, 16> ConvertedArgs;
6379 // FIXME: We should look into making enable_if late-parsed.
6380 Expr *DiscardedThis;
6381 if (!convertArgsForAvailabilityChecks(
6382 *this, Function, /*ThisArg=*/nullptr, Args, Trap,
6383 /*MissingImplicitThis=*/true, DiscardedThis, ConvertedArgs))
6384 return *EnableIfAttrs.begin();
6386 for (auto *EIA : EnableIfAttrs) {
6388 // FIXME: This doesn't consider value-dependent cases, because doing so is
6389 // very difficult. Ideally, we should handle them more gracefully.
6390 if (EIA->getCond()->isValueDependent() ||
6391 !EIA->getCond()->EvaluateWithSubstitution(
6392 Result, Context, Function, llvm::makeArrayRef(ConvertedArgs)))
6395 if (!Result.isInt() || !Result.getInt().getBoolValue())
6401 template <typename CheckFn>
6402 static bool diagnoseDiagnoseIfAttrsWith(Sema &S, const NamedDecl *ND,
6403 bool ArgDependent, SourceLocation Loc,
6404 CheckFn &&IsSuccessful) {
6405 SmallVector<const DiagnoseIfAttr *, 8> Attrs;
6406 for (const auto *DIA : ND->specific_attrs<DiagnoseIfAttr>()) {
6407 if (ArgDependent == DIA->getArgDependent())
6408 Attrs.push_back(DIA);
6411 // Common case: No diagnose_if attributes, so we can quit early.
6415 auto WarningBegin = std::stable_partition(
6416 Attrs.begin(), Attrs.end(),
6417 [](const DiagnoseIfAttr *DIA) { return DIA->isError(); });
6419 // Note that diagnose_if attributes are late-parsed, so they appear in the
6420 // correct order (unlike enable_if attributes).
6421 auto ErrAttr = llvm::find_if(llvm::make_range(Attrs.begin(), WarningBegin),
6423 if (ErrAttr != WarningBegin) {
6424 const DiagnoseIfAttr *DIA = *ErrAttr;
6425 S.Diag(Loc, diag::err_diagnose_if_succeeded) << DIA->getMessage();
6426 S.Diag(DIA->getLocation(), diag::note_from_diagnose_if)
6427 << DIA->getParent() << DIA->getCond()->getSourceRange();
6431 for (const auto *DIA : llvm::make_range(WarningBegin, Attrs.end()))
6432 if (IsSuccessful(DIA)) {
6433 S.Diag(Loc, diag::warn_diagnose_if_succeeded) << DIA->getMessage();
6434 S.Diag(DIA->getLocation(), diag::note_from_diagnose_if)
6435 << DIA->getParent() << DIA->getCond()->getSourceRange();
6441 bool Sema::diagnoseArgDependentDiagnoseIfAttrs(const FunctionDecl *Function,
6442 const Expr *ThisArg,
6443 ArrayRef<const Expr *> Args,
6444 SourceLocation Loc) {
6445 return diagnoseDiagnoseIfAttrsWith(
6446 *this, Function, /*ArgDependent=*/true, Loc,
6447 [&](const DiagnoseIfAttr *DIA) {
6449 // It's sane to use the same Args for any redecl of this function, since
6450 // EvaluateWithSubstitution only cares about the position of each
6451 // argument in the arg list, not the ParmVarDecl* it maps to.
6452 if (!DIA->getCond()->EvaluateWithSubstitution(
6453 Result, Context, cast<FunctionDecl>(DIA->getParent()), Args, ThisArg))
6455 return Result.isInt() && Result.getInt().getBoolValue();
6459 bool Sema::diagnoseArgIndependentDiagnoseIfAttrs(const NamedDecl *ND,
6460 SourceLocation Loc) {
6461 return diagnoseDiagnoseIfAttrsWith(
6462 *this, ND, /*ArgDependent=*/false, Loc,
6463 [&](const DiagnoseIfAttr *DIA) {
6465 return DIA->getCond()->EvaluateAsBooleanCondition(Result, Context) &&
6470 /// Add all of the function declarations in the given function set to
6471 /// the overload candidate set.
6472 void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns,
6473 ArrayRef<Expr *> Args,
6474 OverloadCandidateSet &CandidateSet,
6475 TemplateArgumentListInfo *ExplicitTemplateArgs,
6476 bool SuppressUserConversions,
6477 bool PartialOverloading,
6478 bool FirstArgumentIsBase) {
6479 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) {
6480 NamedDecl *D = F.getDecl()->getUnderlyingDecl();
6481 ArrayRef<Expr *> FunctionArgs = Args;
6483 FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(D);
6485 FunTmpl ? FunTmpl->getTemplatedDecl() : cast<FunctionDecl>(D);
6487 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) {
6488 QualType ObjectType;
6489 Expr::Classification ObjectClassification;
6490 if (Args.size() > 0) {
6491 if (Expr *E = Args[0]) {
6492 // Use the explicit base to restrict the lookup:
6493 ObjectType = E->getType();
6494 // Pointers in the object arguments are implicitly dereferenced, so we
6495 // always classify them as l-values.
6496 if (!ObjectType.isNull() && ObjectType->isPointerType())
6497 ObjectClassification = Expr::Classification::makeSimpleLValue();
6499 ObjectClassification = E->Classify(Context);
6500 } // .. else there is an implicit base.
6501 FunctionArgs = Args.slice(1);
6504 AddMethodTemplateCandidate(
6505 FunTmpl, F.getPair(),
6506 cast<CXXRecordDecl>(FunTmpl->getDeclContext()),
6507 ExplicitTemplateArgs, ObjectType, ObjectClassification,
6508 FunctionArgs, CandidateSet, SuppressUserConversions,
6509 PartialOverloading);
6511 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(),
6512 cast<CXXMethodDecl>(FD)->getParent(), ObjectType,
6513 ObjectClassification, FunctionArgs, CandidateSet,
6514 SuppressUserConversions, PartialOverloading);
6517 // This branch handles both standalone functions and static methods.
6519 // Slice the first argument (which is the base) when we access
6520 // static method as non-static.
6521 if (Args.size() > 0 &&
6522 (!Args[0] || (FirstArgumentIsBase && isa<CXXMethodDecl>(FD) &&
6523 !isa<CXXConstructorDecl>(FD)))) {
6524 assert(cast<CXXMethodDecl>(FD)->isStatic());
6525 FunctionArgs = Args.slice(1);
6528 AddTemplateOverloadCandidate(
6529 FunTmpl, F.getPair(), ExplicitTemplateArgs, FunctionArgs,
6530 CandidateSet, SuppressUserConversions, PartialOverloading);
6532 AddOverloadCandidate(FD, F.getPair(), FunctionArgs, CandidateSet,
6533 SuppressUserConversions, PartialOverloading);
6539 /// AddMethodCandidate - Adds a named decl (which is some kind of
6540 /// method) as a method candidate to the given overload set.
6541 void Sema::AddMethodCandidate(DeclAccessPair FoundDecl,
6542 QualType ObjectType,
6543 Expr::Classification ObjectClassification,
6544 ArrayRef<Expr *> Args,
6545 OverloadCandidateSet& CandidateSet,
6546 bool SuppressUserConversions) {
6547 NamedDecl *Decl = FoundDecl.getDecl();
6548 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext());
6550 if (isa<UsingShadowDecl>(Decl))
6551 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl();
6553 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) {
6554 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) &&
6555 "Expected a member function template");
6556 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext,
6557 /*ExplicitArgs*/ nullptr, ObjectType,
6558 ObjectClassification, Args, CandidateSet,
6559 SuppressUserConversions);
6561 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext,
6562 ObjectType, ObjectClassification, Args, CandidateSet,
6563 SuppressUserConversions);
6567 /// AddMethodCandidate - Adds the given C++ member function to the set
6568 /// of candidate functions, using the given function call arguments
6569 /// and the object argument (@c Object). For example, in a call
6570 /// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain
6571 /// both @c a1 and @c a2. If @p SuppressUserConversions, then don't
6572 /// allow user-defined conversions via constructors or conversion
6575 Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl,
6576 CXXRecordDecl *ActingContext, QualType ObjectType,
6577 Expr::Classification ObjectClassification,
6578 ArrayRef<Expr *> Args,
6579 OverloadCandidateSet &CandidateSet,
6580 bool SuppressUserConversions,
6581 bool PartialOverloading,
6582 ConversionSequenceList EarlyConversions) {
6583 const FunctionProtoType *Proto
6584 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>());
6585 assert(Proto && "Methods without a prototype cannot be overloaded");
6586 assert(!isa<CXXConstructorDecl>(Method) &&
6587 "Use AddOverloadCandidate for constructors");
6589 if (!CandidateSet.isNewCandidate(Method))
6592 // C++11 [class.copy]p23: [DR1402]
6593 // A defaulted move assignment operator that is defined as deleted is
6594 // ignored by overload resolution.
6595 if (Method->isDefaulted() && Method->isDeleted() &&
6596 Method->isMoveAssignmentOperator())
6599 // Overload resolution is always an unevaluated context.
6600 EnterExpressionEvaluationContext Unevaluated(
6601 *this, Sema::ExpressionEvaluationContext::Unevaluated);
6603 // Add this candidate
6604 OverloadCandidate &Candidate =
6605 CandidateSet.addCandidate(Args.size() + 1, EarlyConversions);
6606 Candidate.FoundDecl = FoundDecl;
6607 Candidate.Function = Method;
6608 Candidate.IsSurrogate = false;
6609 Candidate.IgnoreObjectArgument = false;
6610 Candidate.ExplicitCallArguments = Args.size();
6612 unsigned NumParams = Proto->getNumParams();
6614 // (C++ 13.3.2p2): A candidate function having fewer than m
6615 // parameters is viable only if it has an ellipsis in its parameter
6617 if (TooManyArguments(NumParams, Args.size(), PartialOverloading) &&
6618 !Proto->isVariadic()) {
6619 Candidate.Viable = false;
6620 Candidate.FailureKind = ovl_fail_too_many_arguments;
6624 // (C++ 13.3.2p2): A candidate function having more than m parameters
6625 // is viable only if the (m+1)st parameter has a default argument
6626 // (8.3.6). For the purposes of overload resolution, the
6627 // parameter list is truncated on the right, so that there are
6628 // exactly m parameters.
6629 unsigned MinRequiredArgs = Method->getMinRequiredArguments();
6630 if (Args.size() < MinRequiredArgs && !PartialOverloading) {
6631 // Not enough arguments.
6632 Candidate.Viable = false;
6633 Candidate.FailureKind = ovl_fail_too_few_arguments;
6637 Candidate.Viable = true;
6639 if (Method->isStatic() || ObjectType.isNull())
6640 // The implicit object argument is ignored.
6641 Candidate.IgnoreObjectArgument = true;
6643 // Determine the implicit conversion sequence for the object
6645 Candidate.Conversions[0] = TryObjectArgumentInitialization(
6646 *this, CandidateSet.getLocation(), ObjectType, ObjectClassification,
6647 Method, ActingContext);
6648 if (Candidate.Conversions[0].isBad()) {
6649 Candidate.Viable = false;
6650 Candidate.FailureKind = ovl_fail_bad_conversion;
6655 // (CUDA B.1): Check for invalid calls between targets.
6656 if (getLangOpts().CUDA)
6657 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext))
6658 if (!IsAllowedCUDACall(Caller, Method)) {
6659 Candidate.Viable = false;
6660 Candidate.FailureKind = ovl_fail_bad_target;
6664 // Determine the implicit conversion sequences for each of the
6666 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) {
6667 if (Candidate.Conversions[ArgIdx + 1].isInitialized()) {
6668 // We already formed a conversion sequence for this parameter during
6669 // template argument deduction.
6670 } else if (ArgIdx < NumParams) {
6671 // (C++ 13.3.2p3): for F to be a viable function, there shall
6672 // exist for each argument an implicit conversion sequence
6673 // (13.3.3.1) that converts that argument to the corresponding
6675 QualType ParamType = Proto->getParamType(ArgIdx);
6676 Candidate.Conversions[ArgIdx + 1]
6677 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
6678 SuppressUserConversions,
6679 /*InOverloadResolution=*/true,
6680 /*AllowObjCWritebackConversion=*/
6681 getLangOpts().ObjCAutoRefCount);
6682 if (Candidate.Conversions[ArgIdx + 1].isBad()) {
6683 Candidate.Viable = false;
6684 Candidate.FailureKind = ovl_fail_bad_conversion;
6688 // (C++ 13.3.2p2): For the purposes of overload resolution, any
6689 // argument for which there is no corresponding parameter is
6690 // considered to "match the ellipsis" (C+ 13.3.3.1.3).
6691 Candidate.Conversions[ArgIdx + 1].setEllipsis();
6695 if (EnableIfAttr *FailedAttr = CheckEnableIf(Method, Args, true)) {
6696 Candidate.Viable = false;
6697 Candidate.FailureKind = ovl_fail_enable_if;
6698 Candidate.DeductionFailure.Data = FailedAttr;
6702 if (Method->isMultiVersion() && Method->hasAttr<TargetAttr>() &&
6703 !Method->getAttr<TargetAttr>()->isDefaultVersion()) {
6704 Candidate.Viable = false;
6705 Candidate.FailureKind = ovl_non_default_multiversion_function;
6709 /// Add a C++ member function template as a candidate to the candidate
6710 /// set, using template argument deduction to produce an appropriate member
6711 /// function template specialization.
6713 Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl,
6714 DeclAccessPair FoundDecl,
6715 CXXRecordDecl *ActingContext,
6716 TemplateArgumentListInfo *ExplicitTemplateArgs,
6717 QualType ObjectType,
6718 Expr::Classification ObjectClassification,
6719 ArrayRef<Expr *> Args,
6720 OverloadCandidateSet& CandidateSet,
6721 bool SuppressUserConversions,
6722 bool PartialOverloading) {
6723 if (!CandidateSet.isNewCandidate(MethodTmpl))
6726 // C++ [over.match.funcs]p7:
6727 // In each case where a candidate is a function template, candidate
6728 // function template specializations are generated using template argument
6729 // deduction (14.8.3, 14.8.2). Those candidates are then handled as
6730 // candidate functions in the usual way.113) A given name can refer to one
6731 // or more function templates and also to a set of overloaded non-template
6732 // functions. In such a case, the candidate functions generated from each
6733 // function template are combined with the set of non-template candidate
6735 TemplateDeductionInfo Info(CandidateSet.getLocation());
6736 FunctionDecl *Specialization = nullptr;
6737 ConversionSequenceList Conversions;
6738 if (TemplateDeductionResult Result = DeduceTemplateArguments(
6739 MethodTmpl, ExplicitTemplateArgs, Args, Specialization, Info,
6740 PartialOverloading, [&](ArrayRef<QualType> ParamTypes) {
6741 return CheckNonDependentConversions(
6742 MethodTmpl, ParamTypes, Args, CandidateSet, Conversions,
6743 SuppressUserConversions, ActingContext, ObjectType,
6744 ObjectClassification);
6746 OverloadCandidate &Candidate =
6747 CandidateSet.addCandidate(Conversions.size(), Conversions);
6748 Candidate.FoundDecl = FoundDecl;
6749 Candidate.Function = MethodTmpl->getTemplatedDecl();
6750 Candidate.Viable = false;
6751 Candidate.IsSurrogate = false;
6752 Candidate.IgnoreObjectArgument =
6753 cast<CXXMethodDecl>(Candidate.Function)->isStatic() ||
6754 ObjectType.isNull();
6755 Candidate.ExplicitCallArguments = Args.size();
6756 if (Result == TDK_NonDependentConversionFailure)
6757 Candidate.FailureKind = ovl_fail_bad_conversion;
6759 Candidate.FailureKind = ovl_fail_bad_deduction;
6760 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
6766 // Add the function template specialization produced by template argument
6767 // deduction as a candidate.
6768 assert(Specialization && "Missing member function template specialization?");
6769 assert(isa<CXXMethodDecl>(Specialization) &&
6770 "Specialization is not a member function?");
6771 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl,
6772 ActingContext, ObjectType, ObjectClassification, Args,
6773 CandidateSet, SuppressUserConversions, PartialOverloading,
6777 /// Add a C++ function template specialization as a candidate
6778 /// in the candidate set, using template argument deduction to produce
6779 /// an appropriate function template specialization.
6780 void Sema::AddTemplateOverloadCandidate(
6781 FunctionTemplateDecl *FunctionTemplate, DeclAccessPair FoundDecl,
6782 TemplateArgumentListInfo *ExplicitTemplateArgs, ArrayRef<Expr *> Args,
6783 OverloadCandidateSet &CandidateSet, bool SuppressUserConversions,
6784 bool PartialOverloading, bool AllowExplicit, ADLCallKind IsADLCandidate) {
6785 if (!CandidateSet.isNewCandidate(FunctionTemplate))
6788 // C++ [over.match.funcs]p7:
6789 // In each case where a candidate is a function template, candidate
6790 // function template specializations are generated using template argument
6791 // deduction (14.8.3, 14.8.2). Those candidates are then handled as
6792 // candidate functions in the usual way.113) A given name can refer to one
6793 // or more function templates and also to a set of overloaded non-template
6794 // functions. In such a case, the candidate functions generated from each
6795 // function template are combined with the set of non-template candidate
6797 TemplateDeductionInfo Info(CandidateSet.getLocation());
6798 FunctionDecl *Specialization = nullptr;
6799 ConversionSequenceList Conversions;
6800 if (TemplateDeductionResult Result = DeduceTemplateArguments(
6801 FunctionTemplate, ExplicitTemplateArgs, Args, Specialization, Info,
6802 PartialOverloading, [&](ArrayRef<QualType> ParamTypes) {
6803 return CheckNonDependentConversions(FunctionTemplate, ParamTypes,
6804 Args, CandidateSet, Conversions,
6805 SuppressUserConversions);
6807 OverloadCandidate &Candidate =
6808 CandidateSet.addCandidate(Conversions.size(), Conversions);
6809 Candidate.FoundDecl = FoundDecl;
6810 Candidate.Function = FunctionTemplate->getTemplatedDecl();
6811 Candidate.Viable = false;
6812 Candidate.IsSurrogate = false;
6813 Candidate.IsADLCandidate = IsADLCandidate;
6814 // Ignore the object argument if there is one, since we don't have an object
6816 Candidate.IgnoreObjectArgument =
6817 isa<CXXMethodDecl>(Candidate.Function) &&
6818 !isa<CXXConstructorDecl>(Candidate.Function);
6819 Candidate.ExplicitCallArguments = Args.size();
6820 if (Result == TDK_NonDependentConversionFailure)
6821 Candidate.FailureKind = ovl_fail_bad_conversion;
6823 Candidate.FailureKind = ovl_fail_bad_deduction;
6824 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
6830 // Add the function template specialization produced by template argument
6831 // deduction as a candidate.
6832 assert(Specialization && "Missing function template specialization?");
6833 AddOverloadCandidate(
6834 Specialization, FoundDecl, Args, CandidateSet, SuppressUserConversions,
6835 PartialOverloading, AllowExplicit,
6836 /*AllowExplicitConversions*/ false, IsADLCandidate, Conversions);
6839 /// Check that implicit conversion sequences can be formed for each argument
6840 /// whose corresponding parameter has a non-dependent type, per DR1391's
6841 /// [temp.deduct.call]p10.
6842 bool Sema::CheckNonDependentConversions(
6843 FunctionTemplateDecl *FunctionTemplate, ArrayRef<QualType> ParamTypes,
6844 ArrayRef<Expr *> Args, OverloadCandidateSet &CandidateSet,
6845 ConversionSequenceList &Conversions, bool SuppressUserConversions,
6846 CXXRecordDecl *ActingContext, QualType ObjectType,
6847 Expr::Classification ObjectClassification) {
6848 // FIXME: The cases in which we allow explicit conversions for constructor
6849 // arguments never consider calling a constructor template. It's not clear
6851 const bool AllowExplicit = false;
6853 auto *FD = FunctionTemplate->getTemplatedDecl();
6854 auto *Method = dyn_cast<CXXMethodDecl>(FD);
6855 bool HasThisConversion = Method && !isa<CXXConstructorDecl>(Method);
6856 unsigned ThisConversions = HasThisConversion ? 1 : 0;
6859 CandidateSet.allocateConversionSequences(ThisConversions + Args.size());
6861 // Overload resolution is always an unevaluated context.
6862 EnterExpressionEvaluationContext Unevaluated(
6863 *this, Sema::ExpressionEvaluationContext::Unevaluated);
6865 // For a method call, check the 'this' conversion here too. DR1391 doesn't
6866 // require that, but this check should never result in a hard error, and
6867 // overload resolution is permitted to sidestep instantiations.
6868 if (HasThisConversion && !cast<CXXMethodDecl>(FD)->isStatic() &&
6869 !ObjectType.isNull()) {
6870 Conversions[0] = TryObjectArgumentInitialization(
6871 *this, CandidateSet.getLocation(), ObjectType, ObjectClassification,
6872 Method, ActingContext);
6873 if (Conversions[0].isBad())
6877 for (unsigned I = 0, N = std::min(ParamTypes.size(), Args.size()); I != N;
6879 QualType ParamType = ParamTypes[I];
6880 if (!ParamType->isDependentType()) {
6881 Conversions[ThisConversions + I]
6882 = TryCopyInitialization(*this, Args[I], ParamType,
6883 SuppressUserConversions,
6884 /*InOverloadResolution=*/true,
6885 /*AllowObjCWritebackConversion=*/
6886 getLangOpts().ObjCAutoRefCount,
6888 if (Conversions[ThisConversions + I].isBad())
6896 /// Determine whether this is an allowable conversion from the result
6897 /// of an explicit conversion operator to the expected type, per C++
6898 /// [over.match.conv]p1 and [over.match.ref]p1.
6900 /// \param ConvType The return type of the conversion function.
6902 /// \param ToType The type we are converting to.
6904 /// \param AllowObjCPointerConversion Allow a conversion from one
6905 /// Objective-C pointer to another.
6907 /// \returns true if the conversion is allowable, false otherwise.
6908 static bool isAllowableExplicitConversion(Sema &S,
6909 QualType ConvType, QualType ToType,
6910 bool AllowObjCPointerConversion) {
6911 QualType ToNonRefType = ToType.getNonReferenceType();
6913 // Easy case: the types are the same.
6914 if (S.Context.hasSameUnqualifiedType(ConvType, ToNonRefType))
6917 // Allow qualification conversions.
6918 bool ObjCLifetimeConversion;
6919 if (S.IsQualificationConversion(ConvType, ToNonRefType, /*CStyle*/false,
6920 ObjCLifetimeConversion))
6923 // If we're not allowed to consider Objective-C pointer conversions,
6925 if (!AllowObjCPointerConversion)
6928 // Is this an Objective-C pointer conversion?
6929 bool IncompatibleObjC = false;
6930 QualType ConvertedType;
6931 return S.isObjCPointerConversion(ConvType, ToNonRefType, ConvertedType,
6935 /// AddConversionCandidate - Add a C++ conversion function as a
6936 /// candidate in the candidate set (C++ [over.match.conv],
6937 /// C++ [over.match.copy]). From is the expression we're converting from,
6938 /// and ToType is the type that we're eventually trying to convert to
6939 /// (which may or may not be the same type as the type that the
6940 /// conversion function produces).
6941 void Sema::AddConversionCandidate(
6942 CXXConversionDecl *Conversion, DeclAccessPair FoundDecl,
6943 CXXRecordDecl *ActingContext, Expr *From, QualType ToType,
6944 OverloadCandidateSet &CandidateSet, bool AllowObjCConversionOnExplicit,
6945 bool AllowExplicit, bool AllowResultConversion) {
6946 assert(!Conversion->getDescribedFunctionTemplate() &&
6947 "Conversion function templates use AddTemplateConversionCandidate");
6948 QualType ConvType = Conversion->getConversionType().getNonReferenceType();
6949 if (!CandidateSet.isNewCandidate(Conversion))
6952 // If the conversion function has an undeduced return type, trigger its
6954 if (getLangOpts().CPlusPlus14 && ConvType->isUndeducedType()) {
6955 if (DeduceReturnType(Conversion, From->getExprLoc()))
6957 ConvType = Conversion->getConversionType().getNonReferenceType();
6960 // If we don't allow any conversion of the result type, ignore conversion
6961 // functions that don't convert to exactly (possibly cv-qualified) T.
6962 if (!AllowResultConversion &&
6963 !Context.hasSameUnqualifiedType(Conversion->getConversionType(), ToType))
6966 // Per C++ [over.match.conv]p1, [over.match.ref]p1, an explicit conversion
6967 // operator is only a candidate if its return type is the target type or
6968 // can be converted to the target type with a qualification conversion.
6969 if (Conversion->isExplicit() &&
6970 !isAllowableExplicitConversion(*this, ConvType, ToType,
6971 AllowObjCConversionOnExplicit))
6974 // Overload resolution is always an unevaluated context.
6975 EnterExpressionEvaluationContext Unevaluated(
6976 *this, Sema::ExpressionEvaluationContext::Unevaluated);
6978 // Add this candidate
6979 OverloadCandidate &Candidate = CandidateSet.addCandidate(1);
6980 Candidate.FoundDecl = FoundDecl;
6981 Candidate.Function = Conversion;
6982 Candidate.IsSurrogate = false;
6983 Candidate.IgnoreObjectArgument = false;
6984 Candidate.FinalConversion.setAsIdentityConversion();
6985 Candidate.FinalConversion.setFromType(ConvType);
6986 Candidate.FinalConversion.setAllToTypes(ToType);
6987 Candidate.Viable = true;
6988 Candidate.ExplicitCallArguments = 1;
6990 // C++ [over.match.funcs]p4:
6991 // For conversion functions, the function is considered to be a member of
6992 // the class of the implicit implied object argument for the purpose of
6993 // defining the type of the implicit object parameter.
6995 // Determine the implicit conversion sequence for the implicit
6996 // object parameter.
6997 QualType ImplicitParamType = From->getType();
6998 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>())
6999 ImplicitParamType = FromPtrType->getPointeeType();
7000 CXXRecordDecl *ConversionContext
7001 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl());
7003 Candidate.Conversions[0] = TryObjectArgumentInitialization(
7004 *this, CandidateSet.getLocation(), From->getType(),
7005 From->Classify(Context), Conversion, ConversionContext);
7007 if (Candidate.Conversions[0].isBad()) {
7008 Candidate.Viable = false;
7009 Candidate.FailureKind = ovl_fail_bad_conversion;
7013 // We won't go through a user-defined type conversion function to convert a
7014 // derived to base as such conversions are given Conversion Rank. They only
7015 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user]
7017 = Context.getCanonicalType(From->getType().getUnqualifiedType());
7018 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType();
7019 if (FromCanon == ToCanon ||
7020 IsDerivedFrom(CandidateSet.getLocation(), FromCanon, ToCanon)) {
7021 Candidate.Viable = false;
7022 Candidate.FailureKind = ovl_fail_trivial_conversion;
7026 // To determine what the conversion from the result of calling the
7027 // conversion function to the type we're eventually trying to
7028 // convert to (ToType), we need to synthesize a call to the
7029 // conversion function and attempt copy initialization from it. This
7030 // makes sure that we get the right semantics with respect to
7031 // lvalues/rvalues and the type. Fortunately, we can allocate this
7032 // call on the stack and we don't need its arguments to be
7034 DeclRefExpr ConversionRef(Context, Conversion, false, Conversion->getType(),
7035 VK_LValue, From->getBeginLoc());
7036 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack,
7037 Context.getPointerType(Conversion->getType()),
7038 CK_FunctionToPointerDecay,
7039 &ConversionRef, VK_RValue);
7041 QualType ConversionType = Conversion->getConversionType();
7042 if (!isCompleteType(From->getBeginLoc(), ConversionType)) {
7043 Candidate.Viable = false;
7044 Candidate.FailureKind = ovl_fail_bad_final_conversion;
7048 ExprValueKind VK = Expr::getValueKindForType(ConversionType);
7050 // Note that it is safe to allocate CallExpr on the stack here because
7051 // there are 0 arguments (i.e., nothing is allocated using ASTContext's
7053 QualType CallResultType = ConversionType.getNonLValueExprType(Context);
7055 llvm::AlignedCharArray<alignof(CallExpr), sizeof(CallExpr) + sizeof(Stmt *)>
7057 CallExpr *TheTemporaryCall = CallExpr::CreateTemporary(
7058 Buffer.buffer, &ConversionFn, CallResultType, VK, From->getBeginLoc());
7060 ImplicitConversionSequence ICS =
7061 TryCopyInitialization(*this, TheTemporaryCall, ToType,
7062 /*SuppressUserConversions=*/true,
7063 /*InOverloadResolution=*/false,
7064 /*AllowObjCWritebackConversion=*/false);
7066 switch (ICS.getKind()) {
7067 case ImplicitConversionSequence::StandardConversion:
7068 Candidate.FinalConversion = ICS.Standard;
7070 // C++ [over.ics.user]p3:
7071 // If the user-defined conversion is specified by a specialization of a
7072 // conversion function template, the second standard conversion sequence
7073 // shall have exact match rank.
7074 if (Conversion->getPrimaryTemplate() &&
7075 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) {
7076 Candidate.Viable = false;
7077 Candidate.FailureKind = ovl_fail_final_conversion_not_exact;
7081 // C++0x [dcl.init.ref]p5:
7082 // In the second case, if the reference is an rvalue reference and
7083 // the second standard conversion sequence of the user-defined
7084 // conversion sequence includes an lvalue-to-rvalue conversion, the
7085 // program is ill-formed.
7086 if (ToType->isRValueReferenceType() &&
7087 ICS.Standard.First == ICK_Lvalue_To_Rvalue) {
7088 Candidate.Viable = false;
7089 Candidate.FailureKind = ovl_fail_bad_final_conversion;
7094 case ImplicitConversionSequence::BadConversion:
7095 Candidate.Viable = false;
7096 Candidate.FailureKind = ovl_fail_bad_final_conversion;
7101 "Can only end up with a standard conversion sequence or failure");
7104 if (!AllowExplicit && Conversion->getExplicitSpecifier().getKind() !=
7105 ExplicitSpecKind::ResolvedFalse) {
7106 Candidate.Viable = false;
7107 Candidate.FailureKind = ovl_fail_explicit_resolved;
7111 if (EnableIfAttr *FailedAttr = CheckEnableIf(Conversion, None)) {
7112 Candidate.Viable = false;
7113 Candidate.FailureKind = ovl_fail_enable_if;
7114 Candidate.DeductionFailure.Data = FailedAttr;
7118 if (Conversion->isMultiVersion() && Conversion->hasAttr<TargetAttr>() &&
7119 !Conversion->getAttr<TargetAttr>()->isDefaultVersion()) {
7120 Candidate.Viable = false;
7121 Candidate.FailureKind = ovl_non_default_multiversion_function;
7125 /// Adds a conversion function template specialization
7126 /// candidate to the overload set, using template argument deduction
7127 /// to deduce the template arguments of the conversion function
7128 /// template from the type that we are converting to (C++
7129 /// [temp.deduct.conv]).
7130 void Sema::AddTemplateConversionCandidate(
7131 FunctionTemplateDecl *FunctionTemplate, DeclAccessPair FoundDecl,
7132 CXXRecordDecl *ActingDC, Expr *From, QualType ToType,
7133 OverloadCandidateSet &CandidateSet, bool AllowObjCConversionOnExplicit,
7134 bool AllowExplicit, bool AllowResultConversion) {
7135 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) &&
7136 "Only conversion function templates permitted here");
7138 if (!CandidateSet.isNewCandidate(FunctionTemplate))
7141 TemplateDeductionInfo Info(CandidateSet.getLocation());
7142 CXXConversionDecl *Specialization = nullptr;
7143 if (TemplateDeductionResult Result
7144 = DeduceTemplateArguments(FunctionTemplate, ToType,
7145 Specialization, Info)) {
7146 OverloadCandidate &Candidate = CandidateSet.addCandidate();
7147 Candidate.FoundDecl = FoundDecl;
7148 Candidate.Function = FunctionTemplate->getTemplatedDecl();
7149 Candidate.Viable = false;
7150 Candidate.FailureKind = ovl_fail_bad_deduction;
7151 Candidate.IsSurrogate = false;
7152 Candidate.IgnoreObjectArgument = false;
7153 Candidate.ExplicitCallArguments = 1;
7154 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
7159 // Add the conversion function template specialization produced by
7160 // template argument deduction as a candidate.
7161 assert(Specialization && "Missing function template specialization?");
7162 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType,
7163 CandidateSet, AllowObjCConversionOnExplicit,
7164 AllowExplicit, AllowResultConversion);
7167 /// AddSurrogateCandidate - Adds a "surrogate" candidate function that
7168 /// converts the given @c Object to a function pointer via the
7169 /// conversion function @c Conversion, and then attempts to call it
7170 /// with the given arguments (C++ [over.call.object]p2-4). Proto is
7171 /// the type of function that we'll eventually be calling.
7172 void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion,
7173 DeclAccessPair FoundDecl,
7174 CXXRecordDecl *ActingContext,
7175 const FunctionProtoType *Proto,
7177 ArrayRef<Expr *> Args,
7178 OverloadCandidateSet& CandidateSet) {
7179 if (!CandidateSet.isNewCandidate(Conversion))
7182 // Overload resolution is always an unevaluated context.
7183 EnterExpressionEvaluationContext Unevaluated(
7184 *this, Sema::ExpressionEvaluationContext::Unevaluated);
7186 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1);
7187 Candidate.FoundDecl = FoundDecl;
7188 Candidate.Function = nullptr;
7189 Candidate.Surrogate = Conversion;
7190 Candidate.Viable = true;
7191 Candidate.IsSurrogate = true;
7192 Candidate.IgnoreObjectArgument = false;
7193 Candidate.ExplicitCallArguments = Args.size();
7195 // Determine the implicit conversion sequence for the implicit
7196 // object parameter.
7197 ImplicitConversionSequence ObjectInit = TryObjectArgumentInitialization(
7198 *this, CandidateSet.getLocation(), Object->getType(),
7199 Object->Classify(Context), Conversion, ActingContext);
7200 if (ObjectInit.isBad()) {
7201 Candidate.Viable = false;
7202 Candidate.FailureKind = ovl_fail_bad_conversion;
7203 Candidate.Conversions[0] = ObjectInit;
7207 // The first conversion is actually a user-defined conversion whose
7208 // first conversion is ObjectInit's standard conversion (which is
7209 // effectively a reference binding). Record it as such.
7210 Candidate.Conversions[0].setUserDefined();
7211 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard;
7212 Candidate.Conversions[0].UserDefined.EllipsisConversion = false;
7213 Candidate.Conversions[0].UserDefined.HadMultipleCandidates = false;
7214 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion;
7215 Candidate.Conversions[0].UserDefined.FoundConversionFunction = FoundDecl;
7216 Candidate.Conversions[0].UserDefined.After
7217 = Candidate.Conversions[0].UserDefined.Before;
7218 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion();
7221 unsigned NumParams = Proto->getNumParams();
7223 // (C++ 13.3.2p2): A candidate function having fewer than m
7224 // parameters is viable only if it has an ellipsis in its parameter
7226 if (Args.size() > NumParams && !Proto->isVariadic()) {
7227 Candidate.Viable = false;
7228 Candidate.FailureKind = ovl_fail_too_many_arguments;
7232 // Function types don't have any default arguments, so just check if
7233 // we have enough arguments.
7234 if (Args.size() < NumParams) {
7235 // Not enough arguments.
7236 Candidate.Viable = false;
7237 Candidate.FailureKind = ovl_fail_too_few_arguments;
7241 // Determine the implicit conversion sequences for each of the
7243 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7244 if (ArgIdx < NumParams) {
7245 // (C++ 13.3.2p3): for F to be a viable function, there shall
7246 // exist for each argument an implicit conversion sequence
7247 // (13.3.3.1) that converts that argument to the corresponding
7249 QualType ParamType = Proto->getParamType(ArgIdx);
7250 Candidate.Conversions[ArgIdx + 1]
7251 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
7252 /*SuppressUserConversions=*/false,
7253 /*InOverloadResolution=*/false,
7254 /*AllowObjCWritebackConversion=*/
7255 getLangOpts().ObjCAutoRefCount);
7256 if (Candidate.Conversions[ArgIdx + 1].isBad()) {
7257 Candidate.Viable = false;
7258 Candidate.FailureKind = ovl_fail_bad_conversion;
7262 // (C++ 13.3.2p2): For the purposes of overload resolution, any
7263 // argument for which there is no corresponding parameter is
7264 // considered to ""match the ellipsis" (C+ 13.3.3.1.3).
7265 Candidate.Conversions[ArgIdx + 1].setEllipsis();
7269 if (EnableIfAttr *FailedAttr = CheckEnableIf(Conversion, None)) {
7270 Candidate.Viable = false;
7271 Candidate.FailureKind = ovl_fail_enable_if;
7272 Candidate.DeductionFailure.Data = FailedAttr;
7277 /// Add overload candidates for overloaded operators that are
7278 /// member functions.
7280 /// Add the overloaded operator candidates that are member functions
7281 /// for the operator Op that was used in an operator expression such
7282 /// as "x Op y". , Args/NumArgs provides the operator arguments, and
7283 /// CandidateSet will store the added overload candidates. (C++
7284 /// [over.match.oper]).
7285 void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op,
7286 SourceLocation OpLoc,
7287 ArrayRef<Expr *> Args,
7288 OverloadCandidateSet& CandidateSet,
7289 SourceRange OpRange) {
7290 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
7292 // C++ [over.match.oper]p3:
7293 // For a unary operator @ with an operand of a type whose
7294 // cv-unqualified version is T1, and for a binary operator @ with
7295 // a left operand of a type whose cv-unqualified version is T1 and
7296 // a right operand of a type whose cv-unqualified version is T2,
7297 // three sets of candidate functions, designated member
7298 // candidates, non-member candidates and built-in candidates, are
7299 // constructed as follows:
7300 QualType T1 = Args[0]->getType();
7302 // -- If T1 is a complete class type or a class currently being
7303 // defined, the set of member candidates is the result of the
7304 // qualified lookup of T1::operator@ (13.3.1.1.1); otherwise,
7305 // the set of member candidates is empty.
7306 if (const RecordType *T1Rec = T1->getAs<RecordType>()) {
7307 // Complete the type if it can be completed.
7308 if (!isCompleteType(OpLoc, T1) && !T1Rec->isBeingDefined())
7310 // If the type is neither complete nor being defined, bail out now.
7311 if (!T1Rec->getDecl()->getDefinition())
7314 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName);
7315 LookupQualifiedName(Operators, T1Rec->getDecl());
7316 Operators.suppressDiagnostics();
7318 for (LookupResult::iterator Oper = Operators.begin(),
7319 OperEnd = Operators.end();
7322 AddMethodCandidate(Oper.getPair(), Args[0]->getType(),
7323 Args[0]->Classify(Context), Args.slice(1),
7324 CandidateSet, /*SuppressUserConversion=*/false);
7328 /// AddBuiltinCandidate - Add a candidate for a built-in
7329 /// operator. ResultTy and ParamTys are the result and parameter types
7330 /// of the built-in candidate, respectively. Args and NumArgs are the
7331 /// arguments being passed to the candidate. IsAssignmentOperator
7332 /// should be true when this built-in candidate is an assignment
7333 /// operator. NumContextualBoolArguments is the number of arguments
7334 /// (at the beginning of the argument list) that will be contextually
7335 /// converted to bool.
7336 void Sema::AddBuiltinCandidate(QualType *ParamTys, ArrayRef<Expr *> Args,
7337 OverloadCandidateSet& CandidateSet,
7338 bool IsAssignmentOperator,
7339 unsigned NumContextualBoolArguments) {
7340 // Overload resolution is always an unevaluated context.
7341 EnterExpressionEvaluationContext Unevaluated(
7342 *this, Sema::ExpressionEvaluationContext::Unevaluated);
7344 // Add this candidate
7345 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size());
7346 Candidate.FoundDecl = DeclAccessPair::make(nullptr, AS_none);
7347 Candidate.Function = nullptr;
7348 Candidate.IsSurrogate = false;
7349 Candidate.IgnoreObjectArgument = false;
7350 std::copy(ParamTys, ParamTys + Args.size(), Candidate.BuiltinParamTypes);
7352 // Determine the implicit conversion sequences for each of the
7354 Candidate.Viable = true;
7355 Candidate.ExplicitCallArguments = Args.size();
7356 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7357 // C++ [over.match.oper]p4:
7358 // For the built-in assignment operators, conversions of the
7359 // left operand are restricted as follows:
7360 // -- no temporaries are introduced to hold the left operand, and
7361 // -- no user-defined conversions are applied to the left
7362 // operand to achieve a type match with the left-most
7363 // parameter of a built-in candidate.
7365 // We block these conversions by turning off user-defined
7366 // conversions, since that is the only way that initialization of
7367 // a reference to a non-class type can occur from something that
7368 // is not of the same type.
7369 if (ArgIdx < NumContextualBoolArguments) {
7370 assert(ParamTys[ArgIdx] == Context.BoolTy &&
7371 "Contextual conversion to bool requires bool type");
7372 Candidate.Conversions[ArgIdx]
7373 = TryContextuallyConvertToBool(*this, Args[ArgIdx]);
7375 Candidate.Conversions[ArgIdx]
7376 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx],
7377 ArgIdx == 0 && IsAssignmentOperator,
7378 /*InOverloadResolution=*/false,
7379 /*AllowObjCWritebackConversion=*/
7380 getLangOpts().ObjCAutoRefCount);
7382 if (Candidate.Conversions[ArgIdx].isBad()) {
7383 Candidate.Viable = false;
7384 Candidate.FailureKind = ovl_fail_bad_conversion;
7392 /// BuiltinCandidateTypeSet - A set of types that will be used for the
7393 /// candidate operator functions for built-in operators (C++
7394 /// [over.built]). The types are separated into pointer types and
7395 /// enumeration types.
7396 class BuiltinCandidateTypeSet {
7397 /// TypeSet - A set of types.
7398 typedef llvm::SetVector<QualType, SmallVector<QualType, 8>,
7399 llvm::SmallPtrSet<QualType, 8>> TypeSet;
7401 /// PointerTypes - The set of pointer types that will be used in the
7402 /// built-in candidates.
7403 TypeSet PointerTypes;
7405 /// MemberPointerTypes - The set of member pointer types that will be
7406 /// used in the built-in candidates.
7407 TypeSet MemberPointerTypes;
7409 /// EnumerationTypes - The set of enumeration types that will be
7410 /// used in the built-in candidates.
7411 TypeSet EnumerationTypes;
7413 /// The set of vector types that will be used in the built-in
7415 TypeSet VectorTypes;
7417 /// A flag indicating non-record types are viable candidates
7418 bool HasNonRecordTypes;
7420 /// A flag indicating whether either arithmetic or enumeration types
7421 /// were present in the candidate set.
7422 bool HasArithmeticOrEnumeralTypes;
7424 /// A flag indicating whether the nullptr type was present in the
7426 bool HasNullPtrType;
7428 /// Sema - The semantic analysis instance where we are building the
7429 /// candidate type set.
7432 /// Context - The AST context in which we will build the type sets.
7433 ASTContext &Context;
7435 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
7436 const Qualifiers &VisibleQuals);
7437 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty);
7440 /// iterator - Iterates through the types that are part of the set.
7441 typedef TypeSet::iterator iterator;
7443 BuiltinCandidateTypeSet(Sema &SemaRef)
7444 : HasNonRecordTypes(false),
7445 HasArithmeticOrEnumeralTypes(false),
7446 HasNullPtrType(false),
7448 Context(SemaRef.Context) { }
7450 void AddTypesConvertedFrom(QualType Ty,
7452 bool AllowUserConversions,
7453 bool AllowExplicitConversions,
7454 const Qualifiers &VisibleTypeConversionsQuals);
7456 /// pointer_begin - First pointer type found;
7457 iterator pointer_begin() { return PointerTypes.begin(); }
7459 /// pointer_end - Past the last pointer type found;
7460 iterator pointer_end() { return PointerTypes.end(); }
7462 /// member_pointer_begin - First member pointer type found;
7463 iterator member_pointer_begin() { return MemberPointerTypes.begin(); }
7465 /// member_pointer_end - Past the last member pointer type found;
7466 iterator member_pointer_end() { return MemberPointerTypes.end(); }
7468 /// enumeration_begin - First enumeration type found;
7469 iterator enumeration_begin() { return EnumerationTypes.begin(); }
7471 /// enumeration_end - Past the last enumeration type found;
7472 iterator enumeration_end() { return EnumerationTypes.end(); }
7474 iterator vector_begin() { return VectorTypes.begin(); }
7475 iterator vector_end() { return VectorTypes.end(); }
7477 bool hasNonRecordTypes() { return HasNonRecordTypes; }
7478 bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; }
7479 bool hasNullPtrType() const { return HasNullPtrType; }
7482 } // end anonymous namespace
7484 /// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to
7485 /// the set of pointer types along with any more-qualified variants of
7486 /// that type. For example, if @p Ty is "int const *", this routine
7487 /// will add "int const *", "int const volatile *", "int const
7488 /// restrict *", and "int const volatile restrict *" to the set of
7489 /// pointer types. Returns true if the add of @p Ty itself succeeded,
7490 /// false otherwise.
7492 /// FIXME: what to do about extended qualifiers?
7494 BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
7495 const Qualifiers &VisibleQuals) {
7497 // Insert this type.
7498 if (!PointerTypes.insert(Ty))
7502 const PointerType *PointerTy = Ty->getAs<PointerType>();
7503 bool buildObjCPtr = false;
7505 const ObjCObjectPointerType *PTy = Ty->castAs<ObjCObjectPointerType>();
7506 PointeeTy = PTy->getPointeeType();
7507 buildObjCPtr = true;
7509 PointeeTy = PointerTy->getPointeeType();
7512 // Don't add qualified variants of arrays. For one, they're not allowed
7513 // (the qualifier would sink to the element type), and for another, the
7514 // only overload situation where it matters is subscript or pointer +- int,
7515 // and those shouldn't have qualifier variants anyway.
7516 if (PointeeTy->isArrayType())
7519 unsigned BaseCVR = PointeeTy.getCVRQualifiers();
7520 bool hasVolatile = VisibleQuals.hasVolatile();
7521 bool hasRestrict = VisibleQuals.hasRestrict();
7523 // Iterate through all strict supersets of BaseCVR.
7524 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) {
7525 if ((CVR | BaseCVR) != CVR) continue;
7526 // Skip over volatile if no volatile found anywhere in the types.
7527 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue;
7529 // Skip over restrict if no restrict found anywhere in the types, or if
7530 // the type cannot be restrict-qualified.
7531 if ((CVR & Qualifiers::Restrict) &&
7533 (!(PointeeTy->isAnyPointerType() || PointeeTy->isReferenceType()))))
7536 // Build qualified pointee type.
7537 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR);
7539 // Build qualified pointer type.
7540 QualType QPointerTy;
7542 QPointerTy = Context.getPointerType(QPointeeTy);
7544 QPointerTy = Context.getObjCObjectPointerType(QPointeeTy);
7546 // Insert qualified pointer type.
7547 PointerTypes.insert(QPointerTy);
7553 /// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty
7554 /// to the set of pointer types along with any more-qualified variants of
7555 /// that type. For example, if @p Ty is "int const *", this routine
7556 /// will add "int const *", "int const volatile *", "int const
7557 /// restrict *", and "int const volatile restrict *" to the set of
7558 /// pointer types. Returns true if the add of @p Ty itself succeeded,
7559 /// false otherwise.
7561 /// FIXME: what to do about extended qualifiers?
7563 BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants(
7565 // Insert this type.
7566 if (!MemberPointerTypes.insert(Ty))
7569 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>();
7570 assert(PointerTy && "type was not a member pointer type!");
7572 QualType PointeeTy = PointerTy->getPointeeType();
7573 // Don't add qualified variants of arrays. For one, they're not allowed
7574 // (the qualifier would sink to the element type), and for another, the
7575 // only overload situation where it matters is subscript or pointer +- int,
7576 // and those shouldn't have qualifier variants anyway.
7577 if (PointeeTy->isArrayType())
7579 const Type *ClassTy = PointerTy->getClass();
7581 // Iterate through all strict supersets of the pointee type's CVR
7583 unsigned BaseCVR = PointeeTy.getCVRQualifiers();
7584 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) {
7585 if ((CVR | BaseCVR) != CVR) continue;
7587 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR);
7588 MemberPointerTypes.insert(
7589 Context.getMemberPointerType(QPointeeTy, ClassTy));
7595 /// AddTypesConvertedFrom - Add each of the types to which the type @p
7596 /// Ty can be implicit converted to the given set of @p Types. We're
7597 /// primarily interested in pointer types and enumeration types. We also
7598 /// take member pointer types, for the conditional operator.
7599 /// AllowUserConversions is true if we should look at the conversion
7600 /// functions of a class type, and AllowExplicitConversions if we
7601 /// should also include the explicit conversion functions of a class
7604 BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty,
7606 bool AllowUserConversions,
7607 bool AllowExplicitConversions,
7608 const Qualifiers &VisibleQuals) {
7609 // Only deal with canonical types.
7610 Ty = Context.getCanonicalType(Ty);
7612 // Look through reference types; they aren't part of the type of an
7613 // expression for the purposes of conversions.
7614 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>())
7615 Ty = RefTy->getPointeeType();
7617 // If we're dealing with an array type, decay to the pointer.
7618 if (Ty->isArrayType())
7619 Ty = SemaRef.Context.getArrayDecayedType(Ty);
7621 // Otherwise, we don't care about qualifiers on the type.
7622 Ty = Ty.getLocalUnqualifiedType();
7624 // Flag if we ever add a non-record type.
7625 const RecordType *TyRec = Ty->getAs<RecordType>();
7626 HasNonRecordTypes = HasNonRecordTypes || !TyRec;
7628 // Flag if we encounter an arithmetic type.
7629 HasArithmeticOrEnumeralTypes =
7630 HasArithmeticOrEnumeralTypes || Ty->isArithmeticType();
7632 if (Ty->isObjCIdType() || Ty->isObjCClassType())
7633 PointerTypes.insert(Ty);
7634 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) {
7635 // Insert our type, and its more-qualified variants, into the set
7637 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals))
7639 } else if (Ty->isMemberPointerType()) {
7640 // Member pointers are far easier, since the pointee can't be converted.
7641 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty))
7643 } else if (Ty->isEnumeralType()) {
7644 HasArithmeticOrEnumeralTypes = true;
7645 EnumerationTypes.insert(Ty);
7646 } else if (Ty->isVectorType()) {
7647 // We treat vector types as arithmetic types in many contexts as an
7649 HasArithmeticOrEnumeralTypes = true;
7650 VectorTypes.insert(Ty);
7651 } else if (Ty->isNullPtrType()) {
7652 HasNullPtrType = true;
7653 } else if (AllowUserConversions && TyRec) {
7654 // No conversion functions in incomplete types.
7655 if (!SemaRef.isCompleteType(Loc, Ty))
7658 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl());
7659 for (NamedDecl *D : ClassDecl->getVisibleConversionFunctions()) {
7660 if (isa<UsingShadowDecl>(D))
7661 D = cast<UsingShadowDecl>(D)->getTargetDecl();
7663 // Skip conversion function templates; they don't tell us anything
7664 // about which builtin types we can convert to.
7665 if (isa<FunctionTemplateDecl>(D))
7668 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D);
7669 if (AllowExplicitConversions || !Conv->isExplicit()) {
7670 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false,
7676 /// Helper function for adjusting address spaces for the pointer or reference
7677 /// operands of builtin operators depending on the argument.
7678 static QualType AdjustAddressSpaceForBuiltinOperandType(Sema &S, QualType T,
7680 return S.Context.getAddrSpaceQualType(T, Arg->getType().getAddressSpace());
7683 /// Helper function for AddBuiltinOperatorCandidates() that adds
7684 /// the volatile- and non-volatile-qualified assignment operators for the
7685 /// given type to the candidate set.
7686 static void AddBuiltinAssignmentOperatorCandidates(Sema &S,
7688 ArrayRef<Expr *> Args,
7689 OverloadCandidateSet &CandidateSet) {
7690 QualType ParamTypes[2];
7692 // T& operator=(T&, T)
7693 ParamTypes[0] = S.Context.getLValueReferenceType(
7694 AdjustAddressSpaceForBuiltinOperandType(S, T, Args[0]));
7696 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
7697 /*IsAssignmentOperator=*/true);
7699 if (!S.Context.getCanonicalType(T).isVolatileQualified()) {
7700 // volatile T& operator=(volatile T&, T)
7701 ParamTypes[0] = S.Context.getLValueReferenceType(
7702 AdjustAddressSpaceForBuiltinOperandType(S, S.Context.getVolatileType(T),
7705 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
7706 /*IsAssignmentOperator=*/true);
7710 /// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers,
7711 /// if any, found in visible type conversion functions found in ArgExpr's type.
7712 static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) {
7714 const RecordType *TyRec;
7715 if (const MemberPointerType *RHSMPType =
7716 ArgExpr->getType()->getAs<MemberPointerType>())
7717 TyRec = RHSMPType->getClass()->getAs<RecordType>();
7719 TyRec = ArgExpr->getType()->getAs<RecordType>();
7721 // Just to be safe, assume the worst case.
7722 VRQuals.addVolatile();
7723 VRQuals.addRestrict();
7727 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl());
7728 if (!ClassDecl->hasDefinition())
7731 for (NamedDecl *D : ClassDecl->getVisibleConversionFunctions()) {
7732 if (isa<UsingShadowDecl>(D))
7733 D = cast<UsingShadowDecl>(D)->getTargetDecl();
7734 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) {
7735 QualType CanTy = Context.getCanonicalType(Conv->getConversionType());
7736 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>())
7737 CanTy = ResTypeRef->getPointeeType();
7738 // Need to go down the pointer/mempointer chain and add qualifiers
7742 if (CanTy.isRestrictQualified())
7743 VRQuals.addRestrict();
7744 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>())
7745 CanTy = ResTypePtr->getPointeeType();
7746 else if (const MemberPointerType *ResTypeMPtr =
7747 CanTy->getAs<MemberPointerType>())
7748 CanTy = ResTypeMPtr->getPointeeType();
7751 if (CanTy.isVolatileQualified())
7752 VRQuals.addVolatile();
7753 if (VRQuals.hasRestrict() && VRQuals.hasVolatile())
7763 /// Helper class to manage the addition of builtin operator overload
7764 /// candidates. It provides shared state and utility methods used throughout
7765 /// the process, as well as a helper method to add each group of builtin
7766 /// operator overloads from the standard to a candidate set.
7767 class BuiltinOperatorOverloadBuilder {
7768 // Common instance state available to all overload candidate addition methods.
7770 ArrayRef<Expr *> Args;
7771 Qualifiers VisibleTypeConversionsQuals;
7772 bool HasArithmeticOrEnumeralCandidateType;
7773 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes;
7774 OverloadCandidateSet &CandidateSet;
7776 static constexpr int ArithmeticTypesCap = 24;
7777 SmallVector<CanQualType, ArithmeticTypesCap> ArithmeticTypes;
7779 // Define some indices used to iterate over the arithemetic types in
7780 // ArithmeticTypes. The "promoted arithmetic types" are the arithmetic
7781 // types are that preserved by promotion (C++ [over.built]p2).
7782 unsigned FirstIntegralType,
7784 unsigned FirstPromotedIntegralType,
7785 LastPromotedIntegralType;
7786 unsigned FirstPromotedArithmeticType,
7787 LastPromotedArithmeticType;
7788 unsigned NumArithmeticTypes;
7790 void InitArithmeticTypes() {
7791 // Start of promoted types.
7792 FirstPromotedArithmeticType = 0;
7793 ArithmeticTypes.push_back(S.Context.FloatTy);
7794 ArithmeticTypes.push_back(S.Context.DoubleTy);
7795 ArithmeticTypes.push_back(S.Context.LongDoubleTy);
7796 if (S.Context.getTargetInfo().hasFloat128Type())
7797 ArithmeticTypes.push_back(S.Context.Float128Ty);
7799 // Start of integral types.
7800 FirstIntegralType = ArithmeticTypes.size();
7801 FirstPromotedIntegralType = ArithmeticTypes.size();
7802 ArithmeticTypes.push_back(S.Context.IntTy);
7803 ArithmeticTypes.push_back(S.Context.LongTy);
7804 ArithmeticTypes.push_back(S.Context.LongLongTy);
7805 if (S.Context.getTargetInfo().hasInt128Type())
7806 ArithmeticTypes.push_back(S.Context.Int128Ty);
7807 ArithmeticTypes.push_back(S.Context.UnsignedIntTy);
7808 ArithmeticTypes.push_back(S.Context.UnsignedLongTy);
7809 ArithmeticTypes.push_back(S.Context.UnsignedLongLongTy);
7810 if (S.Context.getTargetInfo().hasInt128Type())
7811 ArithmeticTypes.push_back(S.Context.UnsignedInt128Ty);
7812 LastPromotedIntegralType = ArithmeticTypes.size();
7813 LastPromotedArithmeticType = ArithmeticTypes.size();
7814 // End of promoted types.
7816 ArithmeticTypes.push_back(S.Context.BoolTy);
7817 ArithmeticTypes.push_back(S.Context.CharTy);
7818 ArithmeticTypes.push_back(S.Context.WCharTy);
7819 if (S.Context.getLangOpts().Char8)
7820 ArithmeticTypes.push_back(S.Context.Char8Ty);
7821 ArithmeticTypes.push_back(S.Context.Char16Ty);
7822 ArithmeticTypes.push_back(S.Context.Char32Ty);
7823 ArithmeticTypes.push_back(S.Context.SignedCharTy);
7824 ArithmeticTypes.push_back(S.Context.ShortTy);
7825 ArithmeticTypes.push_back(S.Context.UnsignedCharTy);
7826 ArithmeticTypes.push_back(S.Context.UnsignedShortTy);
7827 LastIntegralType = ArithmeticTypes.size();
7828 NumArithmeticTypes = ArithmeticTypes.size();
7829 // End of integral types.
7830 // FIXME: What about complex? What about half?
7832 assert(ArithmeticTypes.size() <= ArithmeticTypesCap &&
7833 "Enough inline storage for all arithmetic types.");
7836 /// Helper method to factor out the common pattern of adding overloads
7837 /// for '++' and '--' builtin operators.
7838 void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy,
7841 QualType ParamTypes[2] = {
7842 S.Context.getLValueReferenceType(CandidateTy),
7846 // Non-volatile version.
7847 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
7849 // Use a heuristic to reduce number of builtin candidates in the set:
7850 // add volatile version only if there are conversions to a volatile type.
7853 S.Context.getLValueReferenceType(
7854 S.Context.getVolatileType(CandidateTy));
7855 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
7858 // Add restrict version only if there are conversions to a restrict type
7859 // and our candidate type is a non-restrict-qualified pointer.
7860 if (HasRestrict && CandidateTy->isAnyPointerType() &&
7861 !CandidateTy.isRestrictQualified()) {
7863 = S.Context.getLValueReferenceType(
7864 S.Context.getCVRQualifiedType(CandidateTy, Qualifiers::Restrict));
7865 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
7869 = S.Context.getLValueReferenceType(
7870 S.Context.getCVRQualifiedType(CandidateTy,
7871 (Qualifiers::Volatile |
7872 Qualifiers::Restrict)));
7873 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
7880 BuiltinOperatorOverloadBuilder(
7881 Sema &S, ArrayRef<Expr *> Args,
7882 Qualifiers VisibleTypeConversionsQuals,
7883 bool HasArithmeticOrEnumeralCandidateType,
7884 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes,
7885 OverloadCandidateSet &CandidateSet)
7887 VisibleTypeConversionsQuals(VisibleTypeConversionsQuals),
7888 HasArithmeticOrEnumeralCandidateType(
7889 HasArithmeticOrEnumeralCandidateType),
7890 CandidateTypes(CandidateTypes),
7891 CandidateSet(CandidateSet) {
7893 InitArithmeticTypes();
7896 // Increment is deprecated for bool since C++17.
7898 // C++ [over.built]p3:
7900 // For every pair (T, VQ), where T is an arithmetic type other
7901 // than bool, and VQ is either volatile or empty, there exist
7902 // candidate operator functions of the form
7904 // VQ T& operator++(VQ T&);
7905 // T operator++(VQ T&, int);
7907 // C++ [over.built]p4:
7909 // For every pair (T, VQ), where T is an arithmetic type other
7910 // than bool, and VQ is either volatile or empty, there exist
7911 // candidate operator functions of the form
7913 // VQ T& operator--(VQ T&);
7914 // T operator--(VQ T&, int);
7915 void addPlusPlusMinusMinusArithmeticOverloads(OverloadedOperatorKind Op) {
7916 if (!HasArithmeticOrEnumeralCandidateType)
7919 for (unsigned Arith = 0; Arith < NumArithmeticTypes; ++Arith) {
7920 const auto TypeOfT = ArithmeticTypes[Arith];
7921 if (TypeOfT == S.Context.BoolTy) {
7922 if (Op == OO_MinusMinus)
7924 if (Op == OO_PlusPlus && S.getLangOpts().CPlusPlus17)
7927 addPlusPlusMinusMinusStyleOverloads(
7929 VisibleTypeConversionsQuals.hasVolatile(),
7930 VisibleTypeConversionsQuals.hasRestrict());
7934 // C++ [over.built]p5:
7936 // For every pair (T, VQ), where T is a cv-qualified or
7937 // cv-unqualified object type, and VQ is either volatile or
7938 // empty, there exist candidate operator functions of the form
7940 // T*VQ& operator++(T*VQ&);
7941 // T*VQ& operator--(T*VQ&);
7942 // T* operator++(T*VQ&, int);
7943 // T* operator--(T*VQ&, int);
7944 void addPlusPlusMinusMinusPointerOverloads() {
7945 for (BuiltinCandidateTypeSet::iterator
7946 Ptr = CandidateTypes[0].pointer_begin(),
7947 PtrEnd = CandidateTypes[0].pointer_end();
7948 Ptr != PtrEnd; ++Ptr) {
7949 // Skip pointer types that aren't pointers to object types.
7950 if (!(*Ptr)->getPointeeType()->isObjectType())
7953 addPlusPlusMinusMinusStyleOverloads(*Ptr,
7954 (!(*Ptr).isVolatileQualified() &&
7955 VisibleTypeConversionsQuals.hasVolatile()),
7956 (!(*Ptr).isRestrictQualified() &&
7957 VisibleTypeConversionsQuals.hasRestrict()));
7961 // C++ [over.built]p6:
7962 // For every cv-qualified or cv-unqualified object type T, there
7963 // exist candidate operator functions of the form
7965 // T& operator*(T*);
7967 // C++ [over.built]p7:
7968 // For every function type T that does not have cv-qualifiers or a
7969 // ref-qualifier, there exist candidate operator functions of the form
7970 // T& operator*(T*);
7971 void addUnaryStarPointerOverloads() {
7972 for (BuiltinCandidateTypeSet::iterator
7973 Ptr = CandidateTypes[0].pointer_begin(),
7974 PtrEnd = CandidateTypes[0].pointer_end();
7975 Ptr != PtrEnd; ++Ptr) {
7976 QualType ParamTy = *Ptr;
7977 QualType PointeeTy = ParamTy->getPointeeType();
7978 if (!PointeeTy->isObjectType() && !PointeeTy->isFunctionType())
7981 if (const FunctionProtoType *Proto =PointeeTy->getAs<FunctionProtoType>())
7982 if (Proto->getMethodQuals() || Proto->getRefQualifier())
7985 S.AddBuiltinCandidate(&ParamTy, Args, CandidateSet);
7989 // C++ [over.built]p9:
7990 // For every promoted arithmetic type T, there exist candidate
7991 // operator functions of the form
7995 void addUnaryPlusOrMinusArithmeticOverloads() {
7996 if (!HasArithmeticOrEnumeralCandidateType)
7999 for (unsigned Arith = FirstPromotedArithmeticType;
8000 Arith < LastPromotedArithmeticType; ++Arith) {
8001 QualType ArithTy = ArithmeticTypes[Arith];
8002 S.AddBuiltinCandidate(&ArithTy, Args, CandidateSet);
8005 // Extension: We also add these operators for vector types.
8006 for (BuiltinCandidateTypeSet::iterator
8007 Vec = CandidateTypes[0].vector_begin(),
8008 VecEnd = CandidateTypes[0].vector_end();
8009 Vec != VecEnd; ++Vec) {
8010 QualType VecTy = *Vec;
8011 S.AddBuiltinCandidate(&VecTy, Args, CandidateSet);
8015 // C++ [over.built]p8:
8016 // For every type T, there exist candidate operator functions of
8019 // T* operator+(T*);
8020 void addUnaryPlusPointerOverloads() {
8021 for (BuiltinCandidateTypeSet::iterator
8022 Ptr = CandidateTypes[0].pointer_begin(),
8023 PtrEnd = CandidateTypes[0].pointer_end();
8024 Ptr != PtrEnd; ++Ptr) {
8025 QualType ParamTy = *Ptr;
8026 S.AddBuiltinCandidate(&ParamTy, Args, CandidateSet);
8030 // C++ [over.built]p10:
8031 // For every promoted integral type T, there exist candidate
8032 // operator functions of the form
8035 void addUnaryTildePromotedIntegralOverloads() {
8036 if (!HasArithmeticOrEnumeralCandidateType)
8039 for (unsigned Int = FirstPromotedIntegralType;
8040 Int < LastPromotedIntegralType; ++Int) {
8041 QualType IntTy = ArithmeticTypes[Int];
8042 S.AddBuiltinCandidate(&IntTy, Args, CandidateSet);
8045 // Extension: We also add this operator for vector types.
8046 for (BuiltinCandidateTypeSet::iterator
8047 Vec = CandidateTypes[0].vector_begin(),
8048 VecEnd = CandidateTypes[0].vector_end();
8049 Vec != VecEnd; ++Vec) {
8050 QualType VecTy = *Vec;
8051 S.AddBuiltinCandidate(&VecTy, Args, CandidateSet);
8055 // C++ [over.match.oper]p16:
8056 // For every pointer to member type T or type std::nullptr_t, there
8057 // exist candidate operator functions of the form
8059 // bool operator==(T,T);
8060 // bool operator!=(T,T);
8061 void addEqualEqualOrNotEqualMemberPointerOrNullptrOverloads() {
8062 /// Set of (canonical) types that we've already handled.
8063 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8065 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
8066 for (BuiltinCandidateTypeSet::iterator
8067 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(),
8068 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end();
8069 MemPtr != MemPtrEnd;
8071 // Don't add the same builtin candidate twice.
8072 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr)).second)
8075 QualType ParamTypes[2] = { *MemPtr, *MemPtr };
8076 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8079 if (CandidateTypes[ArgIdx].hasNullPtrType()) {
8080 CanQualType NullPtrTy = S.Context.getCanonicalType(S.Context.NullPtrTy);
8081 if (AddedTypes.insert(NullPtrTy).second) {
8082 QualType ParamTypes[2] = { NullPtrTy, NullPtrTy };
8083 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8089 // C++ [over.built]p15:
8091 // For every T, where T is an enumeration type or a pointer type,
8092 // there exist candidate operator functions of the form
8094 // bool operator<(T, T);
8095 // bool operator>(T, T);
8096 // bool operator<=(T, T);
8097 // bool operator>=(T, T);
8098 // bool operator==(T, T);
8099 // bool operator!=(T, T);
8100 // R operator<=>(T, T)
8101 void addGenericBinaryPointerOrEnumeralOverloads() {
8102 // C++ [over.match.oper]p3:
8103 // [...]the built-in candidates include all of the candidate operator
8104 // functions defined in 13.6 that, compared to the given operator, [...]
8105 // do not have the same parameter-type-list as any non-template non-member
8108 // Note that in practice, this only affects enumeration types because there
8109 // aren't any built-in candidates of record type, and a user-defined operator
8110 // must have an operand of record or enumeration type. Also, the only other
8111 // overloaded operator with enumeration arguments, operator=,
8112 // cannot be overloaded for enumeration types, so this is the only place
8113 // where we must suppress candidates like this.
8114 llvm::DenseSet<std::pair<CanQualType, CanQualType> >
8115 UserDefinedBinaryOperators;
8117 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
8118 if (CandidateTypes[ArgIdx].enumeration_begin() !=
8119 CandidateTypes[ArgIdx].enumeration_end()) {
8120 for (OverloadCandidateSet::iterator C = CandidateSet.begin(),
8121 CEnd = CandidateSet.end();
8123 if (!C->Viable || !C->Function || C->Function->getNumParams() != 2)
8126 if (C->Function->isFunctionTemplateSpecialization())
8129 QualType FirstParamType =
8130 C->Function->getParamDecl(0)->getType().getUnqualifiedType();
8131 QualType SecondParamType =
8132 C->Function->getParamDecl(1)->getType().getUnqualifiedType();
8134 // Skip if either parameter isn't of enumeral type.
8135 if (!FirstParamType->isEnumeralType() ||
8136 !SecondParamType->isEnumeralType())
8139 // Add this operator to the set of known user-defined operators.
8140 UserDefinedBinaryOperators.insert(
8141 std::make_pair(S.Context.getCanonicalType(FirstParamType),
8142 S.Context.getCanonicalType(SecondParamType)));
8147 /// Set of (canonical) types that we've already handled.
8148 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8150 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
8151 for (BuiltinCandidateTypeSet::iterator
8152 Ptr = CandidateTypes[ArgIdx].pointer_begin(),
8153 PtrEnd = CandidateTypes[ArgIdx].pointer_end();
8154 Ptr != PtrEnd; ++Ptr) {
8155 // Don't add the same builtin candidate twice.
8156 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
8159 QualType ParamTypes[2] = { *Ptr, *Ptr };
8160 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8162 for (BuiltinCandidateTypeSet::iterator
8163 Enum = CandidateTypes[ArgIdx].enumeration_begin(),
8164 EnumEnd = CandidateTypes[ArgIdx].enumeration_end();
8165 Enum != EnumEnd; ++Enum) {
8166 CanQualType CanonType = S.Context.getCanonicalType(*Enum);
8168 // Don't add the same builtin candidate twice, or if a user defined
8169 // candidate exists.
8170 if (!AddedTypes.insert(CanonType).second ||
8171 UserDefinedBinaryOperators.count(std::make_pair(CanonType,
8174 QualType ParamTypes[2] = { *Enum, *Enum };
8175 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8180 // C++ [over.built]p13:
8182 // For every cv-qualified or cv-unqualified object type T
8183 // there exist candidate operator functions of the form
8185 // T* operator+(T*, ptrdiff_t);
8186 // T& operator[](T*, ptrdiff_t); [BELOW]
8187 // T* operator-(T*, ptrdiff_t);
8188 // T* operator+(ptrdiff_t, T*);
8189 // T& operator[](ptrdiff_t, T*); [BELOW]
8191 // C++ [over.built]p14:
8193 // For every T, where T is a pointer to object type, there
8194 // exist candidate operator functions of the form
8196 // ptrdiff_t operator-(T, T);
8197 void addBinaryPlusOrMinusPointerOverloads(OverloadedOperatorKind Op) {
8198 /// Set of (canonical) types that we've already handled.
8199 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8201 for (int Arg = 0; Arg < 2; ++Arg) {
8202 QualType AsymmetricParamTypes[2] = {
8203 S.Context.getPointerDiffType(),
8204 S.Context.getPointerDiffType(),
8206 for (BuiltinCandidateTypeSet::iterator
8207 Ptr = CandidateTypes[Arg].pointer_begin(),
8208 PtrEnd = CandidateTypes[Arg].pointer_end();
8209 Ptr != PtrEnd; ++Ptr) {
8210 QualType PointeeTy = (*Ptr)->getPointeeType();
8211 if (!PointeeTy->isObjectType())
8214 AsymmetricParamTypes[Arg] = *Ptr;
8215 if (Arg == 0 || Op == OO_Plus) {
8216 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t)
8217 // T* operator+(ptrdiff_t, T*);
8218 S.AddBuiltinCandidate(AsymmetricParamTypes, Args, CandidateSet);
8220 if (Op == OO_Minus) {
8221 // ptrdiff_t operator-(T, T);
8222 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
8225 QualType ParamTypes[2] = { *Ptr, *Ptr };
8226 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8232 // C++ [over.built]p12:
8234 // For every pair of promoted arithmetic types L and R, there
8235 // exist candidate operator functions of the form
8237 // LR operator*(L, R);
8238 // LR operator/(L, R);
8239 // LR operator+(L, R);
8240 // LR operator-(L, R);
8241 // bool operator<(L, R);
8242 // bool operator>(L, R);
8243 // bool operator<=(L, R);
8244 // bool operator>=(L, R);
8245 // bool operator==(L, R);
8246 // bool operator!=(L, R);
8248 // where LR is the result of the usual arithmetic conversions
8249 // between types L and R.
8251 // C++ [over.built]p24:
8253 // For every pair of promoted arithmetic types L and R, there exist
8254 // candidate operator functions of the form
8256 // LR operator?(bool, L, R);
8258 // where LR is the result of the usual arithmetic conversions
8259 // between types L and R.
8260 // Our candidates ignore the first parameter.
8261 void addGenericBinaryArithmeticOverloads() {
8262 if (!HasArithmeticOrEnumeralCandidateType)
8265 for (unsigned Left = FirstPromotedArithmeticType;
8266 Left < LastPromotedArithmeticType; ++Left) {
8267 for (unsigned Right = FirstPromotedArithmeticType;
8268 Right < LastPromotedArithmeticType; ++Right) {
8269 QualType LandR[2] = { ArithmeticTypes[Left],
8270 ArithmeticTypes[Right] };
8271 S.AddBuiltinCandidate(LandR, Args, CandidateSet);
8275 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the
8276 // conditional operator for vector types.
8277 for (BuiltinCandidateTypeSet::iterator
8278 Vec1 = CandidateTypes[0].vector_begin(),
8279 Vec1End = CandidateTypes[0].vector_end();
8280 Vec1 != Vec1End; ++Vec1) {
8281 for (BuiltinCandidateTypeSet::iterator
8282 Vec2 = CandidateTypes[1].vector_begin(),
8283 Vec2End = CandidateTypes[1].vector_end();
8284 Vec2 != Vec2End; ++Vec2) {
8285 QualType LandR[2] = { *Vec1, *Vec2 };
8286 S.AddBuiltinCandidate(LandR, Args, CandidateSet);
8291 // C++2a [over.built]p14:
8293 // For every integral type T there exists a candidate operator function
8296 // std::strong_ordering operator<=>(T, T)
8298 // C++2a [over.built]p15:
8300 // For every pair of floating-point types L and R, there exists a candidate
8301 // operator function of the form
8303 // std::partial_ordering operator<=>(L, R);
8305 // FIXME: The current specification for integral types doesn't play nice with
8306 // the direction of p0946r0, which allows mixed integral and unscoped-enum
8307 // comparisons. Under the current spec this can lead to ambiguity during
8308 // overload resolution. For example:
8310 // enum A : int {a};
8311 // auto x = (a <=> (long)42);
8313 // error: call is ambiguous for arguments 'A' and 'long'.
8314 // note: candidate operator<=>(int, int)
8315 // note: candidate operator<=>(long, long)
8317 // To avoid this error, this function deviates from the specification and adds
8318 // the mixed overloads `operator<=>(L, R)` where L and R are promoted
8319 // arithmetic types (the same as the generic relational overloads).
8321 // For now this function acts as a placeholder.
8322 void addThreeWayArithmeticOverloads() {
8323 addGenericBinaryArithmeticOverloads();
8326 // C++ [over.built]p17:
8328 // For every pair of promoted integral types L and R, there
8329 // exist candidate operator functions of the form
8331 // LR operator%(L, R);
8332 // LR operator&(L, R);
8333 // LR operator^(L, R);
8334 // LR operator|(L, R);
8335 // L operator<<(L, R);
8336 // L operator>>(L, R);
8338 // where LR is the result of the usual arithmetic conversions
8339 // between types L and R.
8340 void addBinaryBitwiseArithmeticOverloads(OverloadedOperatorKind Op) {
8341 if (!HasArithmeticOrEnumeralCandidateType)
8344 for (unsigned Left = FirstPromotedIntegralType;
8345 Left < LastPromotedIntegralType; ++Left) {
8346 for (unsigned Right = FirstPromotedIntegralType;
8347 Right < LastPromotedIntegralType; ++Right) {
8348 QualType LandR[2] = { ArithmeticTypes[Left],
8349 ArithmeticTypes[Right] };
8350 S.AddBuiltinCandidate(LandR, Args, CandidateSet);
8355 // C++ [over.built]p20:
8357 // For every pair (T, VQ), where T is an enumeration or
8358 // pointer to member type and VQ is either volatile or
8359 // empty, there exist candidate operator functions of the form
8361 // VQ T& operator=(VQ T&, T);
8362 void addAssignmentMemberPointerOrEnumeralOverloads() {
8363 /// Set of (canonical) types that we've already handled.
8364 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8366 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) {
8367 for (BuiltinCandidateTypeSet::iterator
8368 Enum = CandidateTypes[ArgIdx].enumeration_begin(),
8369 EnumEnd = CandidateTypes[ArgIdx].enumeration_end();
8370 Enum != EnumEnd; ++Enum) {
8371 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum)).second)
8374 AddBuiltinAssignmentOperatorCandidates(S, *Enum, Args, CandidateSet);
8377 for (BuiltinCandidateTypeSet::iterator
8378 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(),
8379 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end();
8380 MemPtr != MemPtrEnd; ++MemPtr) {
8381 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr)).second)
8384 AddBuiltinAssignmentOperatorCandidates(S, *MemPtr, Args, CandidateSet);
8389 // C++ [over.built]p19:
8391 // For every pair (T, VQ), where T is any type and VQ is either
8392 // volatile or empty, there exist candidate operator functions
8395 // T*VQ& operator=(T*VQ&, T*);
8397 // C++ [over.built]p21:
8399 // For every pair (T, VQ), where T is a cv-qualified or
8400 // cv-unqualified object type and VQ is either volatile or
8401 // empty, there exist candidate operator functions of the form
8403 // T*VQ& operator+=(T*VQ&, ptrdiff_t);
8404 // T*VQ& operator-=(T*VQ&, ptrdiff_t);
8405 void addAssignmentPointerOverloads(bool isEqualOp) {
8406 /// Set of (canonical) types that we've already handled.
8407 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8409 for (BuiltinCandidateTypeSet::iterator
8410 Ptr = CandidateTypes[0].pointer_begin(),
8411 PtrEnd = CandidateTypes[0].pointer_end();
8412 Ptr != PtrEnd; ++Ptr) {
8413 // If this is operator=, keep track of the builtin candidates we added.
8415 AddedTypes.insert(S.Context.getCanonicalType(*Ptr));
8416 else if (!(*Ptr)->getPointeeType()->isObjectType())
8419 // non-volatile version
8420 QualType ParamTypes[2] = {
8421 S.Context.getLValueReferenceType(*Ptr),
8422 isEqualOp ? *Ptr : S.Context.getPointerDiffType(),
8424 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8425 /*IsAssignmentOperator=*/ isEqualOp);
8427 bool NeedVolatile = !(*Ptr).isVolatileQualified() &&
8428 VisibleTypeConversionsQuals.hasVolatile();
8432 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr));
8433 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8434 /*IsAssignmentOperator=*/isEqualOp);
8437 if (!(*Ptr).isRestrictQualified() &&
8438 VisibleTypeConversionsQuals.hasRestrict()) {
8441 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr));
8442 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8443 /*IsAssignmentOperator=*/isEqualOp);
8446 // volatile restrict version
8448 = S.Context.getLValueReferenceType(
8449 S.Context.getCVRQualifiedType(*Ptr,
8450 (Qualifiers::Volatile |
8451 Qualifiers::Restrict)));
8452 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8453 /*IsAssignmentOperator=*/isEqualOp);
8459 for (BuiltinCandidateTypeSet::iterator
8460 Ptr = CandidateTypes[1].pointer_begin(),
8461 PtrEnd = CandidateTypes[1].pointer_end();
8462 Ptr != PtrEnd; ++Ptr) {
8463 // Make sure we don't add the same candidate twice.
8464 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
8467 QualType ParamTypes[2] = {
8468 S.Context.getLValueReferenceType(*Ptr),
8472 // non-volatile version
8473 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8474 /*IsAssignmentOperator=*/true);
8476 bool NeedVolatile = !(*Ptr).isVolatileQualified() &&
8477 VisibleTypeConversionsQuals.hasVolatile();
8481 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr));
8482 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8483 /*IsAssignmentOperator=*/true);
8486 if (!(*Ptr).isRestrictQualified() &&
8487 VisibleTypeConversionsQuals.hasRestrict()) {
8490 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr));
8491 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8492 /*IsAssignmentOperator=*/true);
8495 // volatile restrict version
8497 = S.Context.getLValueReferenceType(
8498 S.Context.getCVRQualifiedType(*Ptr,
8499 (Qualifiers::Volatile |
8500 Qualifiers::Restrict)));
8501 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8502 /*IsAssignmentOperator=*/true);
8509 // C++ [over.built]p18:
8511 // For every triple (L, VQ, R), where L is an arithmetic type,
8512 // VQ is either volatile or empty, and R is a promoted
8513 // arithmetic type, there exist candidate operator functions of
8516 // VQ L& operator=(VQ L&, R);
8517 // VQ L& operator*=(VQ L&, R);
8518 // VQ L& operator/=(VQ L&, R);
8519 // VQ L& operator+=(VQ L&, R);
8520 // VQ L& operator-=(VQ L&, R);
8521 void addAssignmentArithmeticOverloads(bool isEqualOp) {
8522 if (!HasArithmeticOrEnumeralCandidateType)
8525 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) {
8526 for (unsigned Right = FirstPromotedArithmeticType;
8527 Right < LastPromotedArithmeticType; ++Right) {
8528 QualType ParamTypes[2];
8529 ParamTypes[1] = ArithmeticTypes[Right];
8530 auto LeftBaseTy = AdjustAddressSpaceForBuiltinOperandType(
8531 S, ArithmeticTypes[Left], Args[0]);
8532 // Add this built-in operator as a candidate (VQ is empty).
8533 ParamTypes[0] = S.Context.getLValueReferenceType(LeftBaseTy);
8534 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8535 /*IsAssignmentOperator=*/isEqualOp);
8537 // Add this built-in operator as a candidate (VQ is 'volatile').
8538 if (VisibleTypeConversionsQuals.hasVolatile()) {
8539 ParamTypes[0] = S.Context.getVolatileType(LeftBaseTy);
8540 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
8541 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8542 /*IsAssignmentOperator=*/isEqualOp);
8547 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types.
8548 for (BuiltinCandidateTypeSet::iterator
8549 Vec1 = CandidateTypes[0].vector_begin(),
8550 Vec1End = CandidateTypes[0].vector_end();
8551 Vec1 != Vec1End; ++Vec1) {
8552 for (BuiltinCandidateTypeSet::iterator
8553 Vec2 = CandidateTypes[1].vector_begin(),
8554 Vec2End = CandidateTypes[1].vector_end();
8555 Vec2 != Vec2End; ++Vec2) {
8556 QualType ParamTypes[2];
8557 ParamTypes[1] = *Vec2;
8558 // Add this built-in operator as a candidate (VQ is empty).
8559 ParamTypes[0] = S.Context.getLValueReferenceType(*Vec1);
8560 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8561 /*IsAssignmentOperator=*/isEqualOp);
8563 // Add this built-in operator as a candidate (VQ is 'volatile').
8564 if (VisibleTypeConversionsQuals.hasVolatile()) {
8565 ParamTypes[0] = S.Context.getVolatileType(*Vec1);
8566 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
8567 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8568 /*IsAssignmentOperator=*/isEqualOp);
8574 // C++ [over.built]p22:
8576 // For every triple (L, VQ, R), where L is an integral type, VQ
8577 // is either volatile or empty, and R is a promoted integral
8578 // type, there exist candidate operator functions of the form
8580 // VQ L& operator%=(VQ L&, R);
8581 // VQ L& operator<<=(VQ L&, R);
8582 // VQ L& operator>>=(VQ L&, R);
8583 // VQ L& operator&=(VQ L&, R);
8584 // VQ L& operator^=(VQ L&, R);
8585 // VQ L& operator|=(VQ L&, R);
8586 void addAssignmentIntegralOverloads() {
8587 if (!HasArithmeticOrEnumeralCandidateType)
8590 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) {
8591 for (unsigned Right = FirstPromotedIntegralType;
8592 Right < LastPromotedIntegralType; ++Right) {
8593 QualType ParamTypes[2];
8594 ParamTypes[1] = ArithmeticTypes[Right];
8595 auto LeftBaseTy = AdjustAddressSpaceForBuiltinOperandType(
8596 S, ArithmeticTypes[Left], Args[0]);
8597 // Add this built-in operator as a candidate (VQ is empty).
8598 ParamTypes[0] = S.Context.getLValueReferenceType(LeftBaseTy);
8599 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8600 if (VisibleTypeConversionsQuals.hasVolatile()) {
8601 // Add this built-in operator as a candidate (VQ is 'volatile').
8602 ParamTypes[0] = LeftBaseTy;
8603 ParamTypes[0] = S.Context.getVolatileType(ParamTypes[0]);
8604 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
8605 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8611 // C++ [over.operator]p23:
8613 // There also exist candidate operator functions of the form
8615 // bool operator!(bool);
8616 // bool operator&&(bool, bool);
8617 // bool operator||(bool, bool);
8618 void addExclaimOverload() {
8619 QualType ParamTy = S.Context.BoolTy;
8620 S.AddBuiltinCandidate(&ParamTy, Args, CandidateSet,
8621 /*IsAssignmentOperator=*/false,
8622 /*NumContextualBoolArguments=*/1);
8624 void addAmpAmpOrPipePipeOverload() {
8625 QualType ParamTypes[2] = { S.Context.BoolTy, S.Context.BoolTy };
8626 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8627 /*IsAssignmentOperator=*/false,
8628 /*NumContextualBoolArguments=*/2);
8631 // C++ [over.built]p13:
8633 // For every cv-qualified or cv-unqualified object type T there
8634 // exist candidate operator functions of the form
8636 // T* operator+(T*, ptrdiff_t); [ABOVE]
8637 // T& operator[](T*, ptrdiff_t);
8638 // T* operator-(T*, ptrdiff_t); [ABOVE]
8639 // T* operator+(ptrdiff_t, T*); [ABOVE]
8640 // T& operator[](ptrdiff_t, T*);
8641 void addSubscriptOverloads() {
8642 for (BuiltinCandidateTypeSet::iterator
8643 Ptr = CandidateTypes[0].pointer_begin(),
8644 PtrEnd = CandidateTypes[0].pointer_end();
8645 Ptr != PtrEnd; ++Ptr) {
8646 QualType ParamTypes[2] = { *Ptr, S.Context.getPointerDiffType() };
8647 QualType PointeeType = (*Ptr)->getPointeeType();
8648 if (!PointeeType->isObjectType())
8651 // T& operator[](T*, ptrdiff_t)
8652 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8655 for (BuiltinCandidateTypeSet::iterator
8656 Ptr = CandidateTypes[1].pointer_begin(),
8657 PtrEnd = CandidateTypes[1].pointer_end();
8658 Ptr != PtrEnd; ++Ptr) {
8659 QualType ParamTypes[2] = { S.Context.getPointerDiffType(), *Ptr };
8660 QualType PointeeType = (*Ptr)->getPointeeType();
8661 if (!PointeeType->isObjectType())
8664 // T& operator[](ptrdiff_t, T*)
8665 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8669 // C++ [over.built]p11:
8670 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type,
8671 // C1 is the same type as C2 or is a derived class of C2, T is an object
8672 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
8673 // there exist candidate operator functions of the form
8675 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
8677 // where CV12 is the union of CV1 and CV2.
8678 void addArrowStarOverloads() {
8679 for (BuiltinCandidateTypeSet::iterator
8680 Ptr = CandidateTypes[0].pointer_begin(),
8681 PtrEnd = CandidateTypes[0].pointer_end();
8682 Ptr != PtrEnd; ++Ptr) {
8683 QualType C1Ty = (*Ptr);
8685 QualifierCollector Q1;
8686 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0);
8687 if (!isa<RecordType>(C1))
8689 // heuristic to reduce number of builtin candidates in the set.
8690 // Add volatile/restrict version only if there are conversions to a
8691 // volatile/restrict type.
8692 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile())
8694 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict())
8696 for (BuiltinCandidateTypeSet::iterator
8697 MemPtr = CandidateTypes[1].member_pointer_begin(),
8698 MemPtrEnd = CandidateTypes[1].member_pointer_end();
8699 MemPtr != MemPtrEnd; ++MemPtr) {
8700 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr);
8701 QualType C2 = QualType(mptr->getClass(), 0);
8702 C2 = C2.getUnqualifiedType();
8703 if (C1 != C2 && !S.IsDerivedFrom(CandidateSet.getLocation(), C1, C2))
8705 QualType ParamTypes[2] = { *Ptr, *MemPtr };
8707 QualType T = mptr->getPointeeType();
8708 if (!VisibleTypeConversionsQuals.hasVolatile() &&
8709 T.isVolatileQualified())
8711 if (!VisibleTypeConversionsQuals.hasRestrict() &&
8712 T.isRestrictQualified())
8714 T = Q1.apply(S.Context, T);
8715 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8720 // Note that we don't consider the first argument, since it has been
8721 // contextually converted to bool long ago. The candidates below are
8722 // therefore added as binary.
8724 // C++ [over.built]p25:
8725 // For every type T, where T is a pointer, pointer-to-member, or scoped
8726 // enumeration type, there exist candidate operator functions of the form
8728 // T operator?(bool, T, T);
8730 void addConditionalOperatorOverloads() {
8731 /// Set of (canonical) types that we've already handled.
8732 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8734 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) {
8735 for (BuiltinCandidateTypeSet::iterator
8736 Ptr = CandidateTypes[ArgIdx].pointer_begin(),
8737 PtrEnd = CandidateTypes[ArgIdx].pointer_end();
8738 Ptr != PtrEnd; ++Ptr) {
8739 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
8742 QualType ParamTypes[2] = { *Ptr, *Ptr };
8743 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8746 for (BuiltinCandidateTypeSet::iterator
8747 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(),
8748 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end();
8749 MemPtr != MemPtrEnd; ++MemPtr) {
8750 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr)).second)
8753 QualType ParamTypes[2] = { *MemPtr, *MemPtr };
8754 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8757 if (S.getLangOpts().CPlusPlus11) {
8758 for (BuiltinCandidateTypeSet::iterator
8759 Enum = CandidateTypes[ArgIdx].enumeration_begin(),
8760 EnumEnd = CandidateTypes[ArgIdx].enumeration_end();
8761 Enum != EnumEnd; ++Enum) {
8762 if (!(*Enum)->getAs<EnumType>()->getDecl()->isScoped())
8765 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum)).second)
8768 QualType ParamTypes[2] = { *Enum, *Enum };
8769 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8776 } // end anonymous namespace
8778 /// AddBuiltinOperatorCandidates - Add the appropriate built-in
8779 /// operator overloads to the candidate set (C++ [over.built]), based
8780 /// on the operator @p Op and the arguments given. For example, if the
8781 /// operator is a binary '+', this routine might add "int
8782 /// operator+(int, int)" to cover integer addition.
8783 void Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op,
8784 SourceLocation OpLoc,
8785 ArrayRef<Expr *> Args,
8786 OverloadCandidateSet &CandidateSet) {
8787 // Find all of the types that the arguments can convert to, but only
8788 // if the operator we're looking at has built-in operator candidates
8789 // that make use of these types. Also record whether we encounter non-record
8790 // candidate types or either arithmetic or enumeral candidate types.
8791 Qualifiers VisibleTypeConversionsQuals;
8792 VisibleTypeConversionsQuals.addConst();
8793 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx)
8794 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]);
8796 bool HasNonRecordCandidateType = false;
8797 bool HasArithmeticOrEnumeralCandidateType = false;
8798 SmallVector<BuiltinCandidateTypeSet, 2> CandidateTypes;
8799 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
8800 CandidateTypes.emplace_back(*this);
8801 CandidateTypes[ArgIdx].AddTypesConvertedFrom(Args[ArgIdx]->getType(),
8804 (Op == OO_Exclaim ||
8807 VisibleTypeConversionsQuals);
8808 HasNonRecordCandidateType = HasNonRecordCandidateType ||
8809 CandidateTypes[ArgIdx].hasNonRecordTypes();
8810 HasArithmeticOrEnumeralCandidateType =
8811 HasArithmeticOrEnumeralCandidateType ||
8812 CandidateTypes[ArgIdx].hasArithmeticOrEnumeralTypes();
8815 // Exit early when no non-record types have been added to the candidate set
8816 // for any of the arguments to the operator.
8818 // We can't exit early for !, ||, or &&, since there we have always have
8819 // 'bool' overloads.
8820 if (!HasNonRecordCandidateType &&
8821 !(Op == OO_Exclaim || Op == OO_AmpAmp || Op == OO_PipePipe))
8824 // Setup an object to manage the common state for building overloads.
8825 BuiltinOperatorOverloadBuilder OpBuilder(*this, Args,
8826 VisibleTypeConversionsQuals,
8827 HasArithmeticOrEnumeralCandidateType,
8828 CandidateTypes, CandidateSet);
8830 // Dispatch over the operation to add in only those overloads which apply.
8833 case NUM_OVERLOADED_OPERATORS:
8834 llvm_unreachable("Expected an overloaded operator");
8839 case OO_Array_Delete:
8842 "Special operators don't use AddBuiltinOperatorCandidates");
8847 // C++ [over.match.oper]p3:
8848 // -- For the operator ',', the unary operator '&', the
8849 // operator '->', or the operator 'co_await', the
8850 // built-in candidates set is empty.
8853 case OO_Plus: // '+' is either unary or binary
8854 if (Args.size() == 1)
8855 OpBuilder.addUnaryPlusPointerOverloads();
8858 case OO_Minus: // '-' is either unary or binary
8859 if (Args.size() == 1) {
8860 OpBuilder.addUnaryPlusOrMinusArithmeticOverloads();
8862 OpBuilder.addBinaryPlusOrMinusPointerOverloads(Op);
8863 OpBuilder.addGenericBinaryArithmeticOverloads();
8867 case OO_Star: // '*' is either unary or binary
8868 if (Args.size() == 1)
8869 OpBuilder.addUnaryStarPointerOverloads();
8871 OpBuilder.addGenericBinaryArithmeticOverloads();
8875 OpBuilder.addGenericBinaryArithmeticOverloads();
8880 OpBuilder.addPlusPlusMinusMinusArithmeticOverloads(Op);
8881 OpBuilder.addPlusPlusMinusMinusPointerOverloads();
8885 case OO_ExclaimEqual:
8886 OpBuilder.addEqualEqualOrNotEqualMemberPointerOrNullptrOverloads();
8892 case OO_GreaterEqual:
8893 OpBuilder.addGenericBinaryPointerOrEnumeralOverloads();
8894 OpBuilder.addGenericBinaryArithmeticOverloads();
8898 OpBuilder.addGenericBinaryPointerOrEnumeralOverloads();
8899 OpBuilder.addThreeWayArithmeticOverloads();
8906 case OO_GreaterGreater:
8907 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op);
8910 case OO_Amp: // '&' is either unary or binary
8911 if (Args.size() == 1)
8912 // C++ [over.match.oper]p3:
8913 // -- For the operator ',', the unary operator '&', or the
8914 // operator '->', the built-in candidates set is empty.
8917 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op);
8921 OpBuilder.addUnaryTildePromotedIntegralOverloads();
8925 OpBuilder.addAssignmentMemberPointerOrEnumeralOverloads();
8930 OpBuilder.addAssignmentPointerOverloads(Op == OO_Equal);
8935 OpBuilder.addAssignmentArithmeticOverloads(Op == OO_Equal);
8938 case OO_PercentEqual:
8939 case OO_LessLessEqual:
8940 case OO_GreaterGreaterEqual:
8944 OpBuilder.addAssignmentIntegralOverloads();
8948 OpBuilder.addExclaimOverload();
8953 OpBuilder.addAmpAmpOrPipePipeOverload();
8957 OpBuilder.addSubscriptOverloads();
8961 OpBuilder.addArrowStarOverloads();
8964 case OO_Conditional:
8965 OpBuilder.addConditionalOperatorOverloads();
8966 OpBuilder.addGenericBinaryArithmeticOverloads();
8971 /// Add function candidates found via argument-dependent lookup
8972 /// to the set of overloading candidates.
8974 /// This routine performs argument-dependent name lookup based on the
8975 /// given function name (which may also be an operator name) and adds
8976 /// all of the overload candidates found by ADL to the overload
8977 /// candidate set (C++ [basic.lookup.argdep]).
8979 Sema::AddArgumentDependentLookupCandidates(DeclarationName Name,
8981 ArrayRef<Expr *> Args,
8982 TemplateArgumentListInfo *ExplicitTemplateArgs,
8983 OverloadCandidateSet& CandidateSet,
8984 bool PartialOverloading) {
8987 // FIXME: This approach for uniquing ADL results (and removing
8988 // redundant candidates from the set) relies on pointer-equality,
8989 // which means we need to key off the canonical decl. However,
8990 // always going back to the canonical decl might not get us the
8991 // right set of default arguments. What default arguments are
8992 // we supposed to consider on ADL candidates, anyway?
8994 // FIXME: Pass in the explicit template arguments?
8995 ArgumentDependentLookup(Name, Loc, Args, Fns);
8997 // Erase all of the candidates we already knew about.
8998 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(),
8999 CandEnd = CandidateSet.end();
9000 Cand != CandEnd; ++Cand)
9001 if (Cand->Function) {
9002 Fns.erase(Cand->Function);
9003 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate())
9007 // For each of the ADL candidates we found, add it to the overload
9009 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) {
9010 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none);
9012 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) {
9013 if (ExplicitTemplateArgs)
9016 AddOverloadCandidate(FD, FoundDecl, Args, CandidateSet,
9017 /*SuppressUserConversions=*/false, PartialOverloading,
9018 /*AllowExplicit*/ true,
9019 /*AllowExplicitConversions*/ false,
9020 ADLCallKind::UsesADL);
9022 AddTemplateOverloadCandidate(
9023 cast<FunctionTemplateDecl>(*I), FoundDecl, ExplicitTemplateArgs, Args,
9025 /*SuppressUserConversions=*/false, PartialOverloading,
9026 /*AllowExplicit*/true, ADLCallKind::UsesADL);
9032 enum class Comparison { Equal, Better, Worse };
9035 /// Compares the enable_if attributes of two FunctionDecls, for the purposes of
9036 /// overload resolution.
9038 /// Cand1's set of enable_if attributes are said to be "better" than Cand2's iff
9039 /// Cand1's first N enable_if attributes have precisely the same conditions as
9040 /// Cand2's first N enable_if attributes (where N = the number of enable_if
9041 /// attributes on Cand2), and Cand1 has more than N enable_if attributes.
9043 /// Note that you can have a pair of candidates such that Cand1's enable_if
9044 /// attributes are worse than Cand2's, and Cand2's enable_if attributes are
9045 /// worse than Cand1's.
9046 static Comparison compareEnableIfAttrs(const Sema &S, const FunctionDecl *Cand1,
9047 const FunctionDecl *Cand2) {
9048 // Common case: One (or both) decls don't have enable_if attrs.
9049 bool Cand1Attr = Cand1->hasAttr<EnableIfAttr>();
9050 bool Cand2Attr = Cand2->hasAttr<EnableIfAttr>();
9051 if (!Cand1Attr || !Cand2Attr) {
9052 if (Cand1Attr == Cand2Attr)
9053 return Comparison::Equal;
9054 return Cand1Attr ? Comparison::Better : Comparison::Worse;
9057 auto Cand1Attrs = Cand1->specific_attrs<EnableIfAttr>();
9058 auto Cand2Attrs = Cand2->specific_attrs<EnableIfAttr>();
9060 llvm::FoldingSetNodeID Cand1ID, Cand2ID;
9061 for (auto Pair : zip_longest(Cand1Attrs, Cand2Attrs)) {
9062 Optional<EnableIfAttr *> Cand1A = std::get<0>(Pair);
9063 Optional<EnableIfAttr *> Cand2A = std::get<1>(Pair);
9065 // It's impossible for Cand1 to be better than (or equal to) Cand2 if Cand1
9066 // has fewer enable_if attributes than Cand2, and vice versa.
9068 return Comparison::Worse;
9070 return Comparison::Better;
9075 (*Cand1A)->getCond()->Profile(Cand1ID, S.getASTContext(), true);
9076 (*Cand2A)->getCond()->Profile(Cand2ID, S.getASTContext(), true);
9077 if (Cand1ID != Cand2ID)
9078 return Comparison::Worse;
9081 return Comparison::Equal;
9084 static bool isBetterMultiversionCandidate(const OverloadCandidate &Cand1,
9085 const OverloadCandidate &Cand2) {
9086 if (!Cand1.Function || !Cand1.Function->isMultiVersion() || !Cand2.Function ||
9087 !Cand2.Function->isMultiVersion())
9090 // If Cand1 is invalid, it cannot be a better match, if Cand2 is invalid, this
9091 // is obviously better.
9092 if (Cand1.Function->isInvalidDecl()) return false;
9093 if (Cand2.Function->isInvalidDecl()) return true;
9095 // If this is a cpu_dispatch/cpu_specific multiversion situation, prefer
9096 // cpu_dispatch, else arbitrarily based on the identifiers.
9097 bool Cand1CPUDisp = Cand1.Function->hasAttr<CPUDispatchAttr>();
9098 bool Cand2CPUDisp = Cand2.Function->hasAttr<CPUDispatchAttr>();
9099 const auto *Cand1CPUSpec = Cand1.Function->getAttr<CPUSpecificAttr>();
9100 const auto *Cand2CPUSpec = Cand2.Function->getAttr<CPUSpecificAttr>();
9102 if (!Cand1CPUDisp && !Cand2CPUDisp && !Cand1CPUSpec && !Cand2CPUSpec)
9105 if (Cand1CPUDisp && !Cand2CPUDisp)
9107 if (Cand2CPUDisp && !Cand1CPUDisp)
9110 if (Cand1CPUSpec && Cand2CPUSpec) {
9111 if (Cand1CPUSpec->cpus_size() != Cand2CPUSpec->cpus_size())
9112 return Cand1CPUSpec->cpus_size() < Cand2CPUSpec->cpus_size();
9114 std::pair<CPUSpecificAttr::cpus_iterator, CPUSpecificAttr::cpus_iterator>
9115 FirstDiff = std::mismatch(
9116 Cand1CPUSpec->cpus_begin(), Cand1CPUSpec->cpus_end(),
9117 Cand2CPUSpec->cpus_begin(),
9118 [](const IdentifierInfo *LHS, const IdentifierInfo *RHS) {
9119 return LHS->getName() == RHS->getName();
9122 assert(FirstDiff.first != Cand1CPUSpec->cpus_end() &&
9123 "Two different cpu-specific versions should not have the same "
9124 "identifier list, otherwise they'd be the same decl!");
9125 return (*FirstDiff.first)->getName() < (*FirstDiff.second)->getName();
9127 llvm_unreachable("No way to get here unless both had cpu_dispatch");
9130 /// isBetterOverloadCandidate - Determines whether the first overload
9131 /// candidate is a better candidate than the second (C++ 13.3.3p1).
9132 bool clang::isBetterOverloadCandidate(
9133 Sema &S, const OverloadCandidate &Cand1, const OverloadCandidate &Cand2,
9134 SourceLocation Loc, OverloadCandidateSet::CandidateSetKind Kind) {
9135 // Define viable functions to be better candidates than non-viable
9138 return Cand1.Viable;
9139 else if (!Cand1.Viable)
9142 // C++ [over.match.best]p1:
9144 // -- if F is a static member function, ICS1(F) is defined such
9145 // that ICS1(F) is neither better nor worse than ICS1(G) for
9146 // any function G, and, symmetrically, ICS1(G) is neither
9147 // better nor worse than ICS1(F).
9148 unsigned StartArg = 0;
9149 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument)
9152 auto IsIllFormedConversion = [&](const ImplicitConversionSequence &ICS) {
9153 // We don't allow incompatible pointer conversions in C++.
9154 if (!S.getLangOpts().CPlusPlus)
9155 return ICS.isStandard() &&
9156 ICS.Standard.Second == ICK_Incompatible_Pointer_Conversion;
9158 // The only ill-formed conversion we allow in C++ is the string literal to
9159 // char* conversion, which is only considered ill-formed after C++11.
9160 return S.getLangOpts().CPlusPlus11 && !S.getLangOpts().WritableStrings &&
9161 hasDeprecatedStringLiteralToCharPtrConversion(ICS);
9164 // Define functions that don't require ill-formed conversions for a given
9165 // argument to be better candidates than functions that do.
9166 unsigned NumArgs = Cand1.Conversions.size();
9167 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch");
9168 bool HasBetterConversion = false;
9169 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) {
9170 bool Cand1Bad = IsIllFormedConversion(Cand1.Conversions[ArgIdx]);
9171 bool Cand2Bad = IsIllFormedConversion(Cand2.Conversions[ArgIdx]);
9172 if (Cand1Bad != Cand2Bad) {
9175 HasBetterConversion = true;
9179 if (HasBetterConversion)
9182 // C++ [over.match.best]p1:
9183 // A viable function F1 is defined to be a better function than another
9184 // viable function F2 if for all arguments i, ICSi(F1) is not a worse
9185 // conversion sequence than ICSi(F2), and then...
9186 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) {
9187 switch (CompareImplicitConversionSequences(S, Loc,
9188 Cand1.Conversions[ArgIdx],
9189 Cand2.Conversions[ArgIdx])) {
9190 case ImplicitConversionSequence::Better:
9191 // Cand1 has a better conversion sequence.
9192 HasBetterConversion = true;
9195 case ImplicitConversionSequence::Worse:
9196 // Cand1 can't be better than Cand2.
9199 case ImplicitConversionSequence::Indistinguishable:
9205 // -- for some argument j, ICSj(F1) is a better conversion sequence than
9206 // ICSj(F2), or, if not that,
9207 if (HasBetterConversion)
9210 // -- the context is an initialization by user-defined conversion
9211 // (see 8.5, 13.3.1.5) and the standard conversion sequence
9212 // from the return type of F1 to the destination type (i.e.,
9213 // the type of the entity being initialized) is a better
9214 // conversion sequence than the standard conversion sequence
9215 // from the return type of F2 to the destination type.
9216 if (Kind == OverloadCandidateSet::CSK_InitByUserDefinedConversion &&
9217 Cand1.Function && Cand2.Function &&
9218 isa<CXXConversionDecl>(Cand1.Function) &&
9219 isa<CXXConversionDecl>(Cand2.Function)) {
9220 // First check whether we prefer one of the conversion functions over the
9221 // other. This only distinguishes the results in non-standard, extension
9222 // cases such as the conversion from a lambda closure type to a function
9223 // pointer or block.
9224 ImplicitConversionSequence::CompareKind Result =
9225 compareConversionFunctions(S, Cand1.Function, Cand2.Function);
9226 if (Result == ImplicitConversionSequence::Indistinguishable)
9227 Result = CompareStandardConversionSequences(S, Loc,
9228 Cand1.FinalConversion,
9229 Cand2.FinalConversion);
9231 if (Result != ImplicitConversionSequence::Indistinguishable)
9232 return Result == ImplicitConversionSequence::Better;
9234 // FIXME: Compare kind of reference binding if conversion functions
9235 // convert to a reference type used in direct reference binding, per
9236 // C++14 [over.match.best]p1 section 2 bullet 3.
9239 // FIXME: Work around a defect in the C++17 guaranteed copy elision wording,
9240 // as combined with the resolution to CWG issue 243.
9242 // When the context is initialization by constructor ([over.match.ctor] or
9243 // either phase of [over.match.list]), a constructor is preferred over
9244 // a conversion function.
9245 if (Kind == OverloadCandidateSet::CSK_InitByConstructor && NumArgs == 1 &&
9246 Cand1.Function && Cand2.Function &&
9247 isa<CXXConstructorDecl>(Cand1.Function) !=
9248 isa<CXXConstructorDecl>(Cand2.Function))
9249 return isa<CXXConstructorDecl>(Cand1.Function);
9251 // -- F1 is a non-template function and F2 is a function template
9252 // specialization, or, if not that,
9253 bool Cand1IsSpecialization = Cand1.Function &&
9254 Cand1.Function->getPrimaryTemplate();
9255 bool Cand2IsSpecialization = Cand2.Function &&
9256 Cand2.Function->getPrimaryTemplate();
9257 if (Cand1IsSpecialization != Cand2IsSpecialization)
9258 return Cand2IsSpecialization;
9260 // -- F1 and F2 are function template specializations, and the function
9261 // template for F1 is more specialized than the template for F2
9262 // according to the partial ordering rules described in 14.5.5.2, or,
9264 if (Cand1IsSpecialization && Cand2IsSpecialization) {
9265 if (FunctionTemplateDecl *BetterTemplate
9266 = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(),
9267 Cand2.Function->getPrimaryTemplate(),
9269 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion
9271 Cand1.ExplicitCallArguments,
9272 Cand2.ExplicitCallArguments))
9273 return BetterTemplate == Cand1.Function->getPrimaryTemplate();
9276 // FIXME: Work around a defect in the C++17 inheriting constructor wording.
9277 // A derived-class constructor beats an (inherited) base class constructor.
9278 bool Cand1IsInherited =
9279 dyn_cast_or_null<ConstructorUsingShadowDecl>(Cand1.FoundDecl.getDecl());
9280 bool Cand2IsInherited =
9281 dyn_cast_or_null<ConstructorUsingShadowDecl>(Cand2.FoundDecl.getDecl());
9282 if (Cand1IsInherited != Cand2IsInherited)
9283 return Cand2IsInherited;
9284 else if (Cand1IsInherited) {
9285 assert(Cand2IsInherited);
9286 auto *Cand1Class = cast<CXXRecordDecl>(Cand1.Function->getDeclContext());
9287 auto *Cand2Class = cast<CXXRecordDecl>(Cand2.Function->getDeclContext());
9288 if (Cand1Class->isDerivedFrom(Cand2Class))
9290 if (Cand2Class->isDerivedFrom(Cand1Class))
9292 // Inherited from sibling base classes: still ambiguous.
9295 // Check C++17 tie-breakers for deduction guides.
9297 auto *Guide1 = dyn_cast_or_null<CXXDeductionGuideDecl>(Cand1.Function);
9298 auto *Guide2 = dyn_cast_or_null<CXXDeductionGuideDecl>(Cand2.Function);
9299 if (Guide1 && Guide2) {
9300 // -- F1 is generated from a deduction-guide and F2 is not
9301 if (Guide1->isImplicit() != Guide2->isImplicit())
9302 return Guide2->isImplicit();
9304 // -- F1 is the copy deduction candidate(16.3.1.8) and F2 is not
9305 if (Guide1->isCopyDeductionCandidate())
9310 // Check for enable_if value-based overload resolution.
9311 if (Cand1.Function && Cand2.Function) {
9312 Comparison Cmp = compareEnableIfAttrs(S, Cand1.Function, Cand2.Function);
9313 if (Cmp != Comparison::Equal)
9314 return Cmp == Comparison::Better;
9317 if (S.getLangOpts().CUDA && Cand1.Function && Cand2.Function) {
9318 FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext);
9319 return S.IdentifyCUDAPreference(Caller, Cand1.Function) >
9320 S.IdentifyCUDAPreference(Caller, Cand2.Function);
9323 bool HasPS1 = Cand1.Function != nullptr &&
9324 functionHasPassObjectSizeParams(Cand1.Function);
9325 bool HasPS2 = Cand2.Function != nullptr &&
9326 functionHasPassObjectSizeParams(Cand2.Function);
9327 if (HasPS1 != HasPS2 && HasPS1)
9330 return isBetterMultiversionCandidate(Cand1, Cand2);
9333 /// Determine whether two declarations are "equivalent" for the purposes of
9334 /// name lookup and overload resolution. This applies when the same internal/no
9335 /// linkage entity is defined by two modules (probably by textually including
9336 /// the same header). In such a case, we don't consider the declarations to
9337 /// declare the same entity, but we also don't want lookups with both
9338 /// declarations visible to be ambiguous in some cases (this happens when using
9339 /// a modularized libstdc++).
9340 bool Sema::isEquivalentInternalLinkageDeclaration(const NamedDecl *A,
9341 const NamedDecl *B) {
9342 auto *VA = dyn_cast_or_null<ValueDecl>(A);
9343 auto *VB = dyn_cast_or_null<ValueDecl>(B);
9347 // The declarations must be declaring the same name as an internal linkage
9348 // entity in different modules.
9349 if (!VA->getDeclContext()->getRedeclContext()->Equals(
9350 VB->getDeclContext()->getRedeclContext()) ||
9351 getOwningModule(const_cast<ValueDecl *>(VA)) ==
9352 getOwningModule(const_cast<ValueDecl *>(VB)) ||
9353 VA->isExternallyVisible() || VB->isExternallyVisible())
9356 // Check that the declarations appear to be equivalent.
9358 // FIXME: Checking the type isn't really enough to resolve the ambiguity.
9359 // For constants and functions, we should check the initializer or body is
9360 // the same. For non-constant variables, we shouldn't allow it at all.
9361 if (Context.hasSameType(VA->getType(), VB->getType()))
9364 // Enum constants within unnamed enumerations will have different types, but
9365 // may still be similar enough to be interchangeable for our purposes.
9366 if (auto *EA = dyn_cast<EnumConstantDecl>(VA)) {
9367 if (auto *EB = dyn_cast<EnumConstantDecl>(VB)) {
9368 // Only handle anonymous enums. If the enumerations were named and
9369 // equivalent, they would have been merged to the same type.
9370 auto *EnumA = cast<EnumDecl>(EA->getDeclContext());
9371 auto *EnumB = cast<EnumDecl>(EB->getDeclContext());
9372 if (EnumA->hasNameForLinkage() || EnumB->hasNameForLinkage() ||
9373 !Context.hasSameType(EnumA->getIntegerType(),
9374 EnumB->getIntegerType()))
9376 // Allow this only if the value is the same for both enumerators.
9377 return llvm::APSInt::isSameValue(EA->getInitVal(), EB->getInitVal());
9381 // Nothing else is sufficiently similar.
9385 void Sema::diagnoseEquivalentInternalLinkageDeclarations(
9386 SourceLocation Loc, const NamedDecl *D, ArrayRef<const NamedDecl *> Equiv) {
9387 Diag(Loc, diag::ext_equivalent_internal_linkage_decl_in_modules) << D;
9389 Module *M = getOwningModule(const_cast<NamedDecl*>(D));
9390 Diag(D->getLocation(), diag::note_equivalent_internal_linkage_decl)
9391 << !M << (M ? M->getFullModuleName() : "");
9393 for (auto *E : Equiv) {
9394 Module *M = getOwningModule(const_cast<NamedDecl*>(E));
9395 Diag(E->getLocation(), diag::note_equivalent_internal_linkage_decl)
9396 << !M << (M ? M->getFullModuleName() : "");
9400 /// Computes the best viable function (C++ 13.3.3)
9401 /// within an overload candidate set.
9403 /// \param Loc The location of the function name (or operator symbol) for
9404 /// which overload resolution occurs.
9406 /// \param Best If overload resolution was successful or found a deleted
9407 /// function, \p Best points to the candidate function found.
9409 /// \returns The result of overload resolution.
9411 OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc,
9413 llvm::SmallVector<OverloadCandidate *, 16> Candidates;
9414 std::transform(begin(), end(), std::back_inserter(Candidates),
9415 [](OverloadCandidate &Cand) { return &Cand; });
9417 // [CUDA] HD->H or HD->D calls are technically not allowed by CUDA but
9418 // are accepted by both clang and NVCC. However, during a particular
9419 // compilation mode only one call variant is viable. We need to
9420 // exclude non-viable overload candidates from consideration based
9421 // only on their host/device attributes. Specifically, if one
9422 // candidate call is WrongSide and the other is SameSide, we ignore
9423 // the WrongSide candidate.
9424 if (S.getLangOpts().CUDA) {
9425 const FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext);
9426 bool ContainsSameSideCandidate =
9427 llvm::any_of(Candidates, [&](OverloadCandidate *Cand) {
9428 return Cand->Function &&
9429 S.IdentifyCUDAPreference(Caller, Cand->Function) ==
9432 if (ContainsSameSideCandidate) {
9433 auto IsWrongSideCandidate = [&](OverloadCandidate *Cand) {
9434 return Cand->Function &&
9435 S.IdentifyCUDAPreference(Caller, Cand->Function) ==
9436 Sema::CFP_WrongSide;
9438 llvm::erase_if(Candidates, IsWrongSideCandidate);
9442 // Find the best viable function.
9444 for (auto *Cand : Candidates)
9446 if (Best == end() ||
9447 isBetterOverloadCandidate(S, *Cand, *Best, Loc, Kind))
9450 // If we didn't find any viable functions, abort.
9452 return OR_No_Viable_Function;
9454 llvm::SmallVector<const NamedDecl *, 4> EquivalentCands;
9456 // Make sure that this function is better than every other viable
9457 // function. If not, we have an ambiguity.
9458 for (auto *Cand : Candidates) {
9459 if (Cand->Viable && Cand != Best &&
9460 !isBetterOverloadCandidate(S, *Best, *Cand, Loc, Kind)) {
9461 if (S.isEquivalentInternalLinkageDeclaration(Best->Function,
9463 EquivalentCands.push_back(Cand->Function);
9468 return OR_Ambiguous;
9472 // Best is the best viable function.
9473 if (Best->Function && Best->Function->isDeleted())
9476 if (!EquivalentCands.empty())
9477 S.diagnoseEquivalentInternalLinkageDeclarations(Loc, Best->Function,
9485 enum OverloadCandidateKind {
9489 oc_implicit_default_constructor,
9490 oc_implicit_copy_constructor,
9491 oc_implicit_move_constructor,
9492 oc_implicit_copy_assignment,
9493 oc_implicit_move_assignment,
9494 oc_inherited_constructor
9497 enum OverloadCandidateSelect {
9500 ocs_described_template,
9503 static std::pair<OverloadCandidateKind, OverloadCandidateSelect>
9504 ClassifyOverloadCandidate(Sema &S, NamedDecl *Found, FunctionDecl *Fn,
9505 std::string &Description) {
9507 bool isTemplate = Fn->isTemplateDecl() || Found->isTemplateDecl();
9508 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) {
9510 Description = S.getTemplateArgumentBindingsText(
9511 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs());
9514 OverloadCandidateSelect Select = [&]() {
9515 if (!Description.empty())
9516 return ocs_described_template;
9517 return isTemplate ? ocs_template : ocs_non_template;
9520 OverloadCandidateKind Kind = [&]() {
9521 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) {
9522 if (!Ctor->isImplicit()) {
9523 if (isa<ConstructorUsingShadowDecl>(Found))
9524 return oc_inherited_constructor;
9526 return oc_constructor;
9529 if (Ctor->isDefaultConstructor())
9530 return oc_implicit_default_constructor;
9532 if (Ctor->isMoveConstructor())
9533 return oc_implicit_move_constructor;
9535 assert(Ctor->isCopyConstructor() &&
9536 "unexpected sort of implicit constructor");
9537 return oc_implicit_copy_constructor;
9540 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) {
9541 // This actually gets spelled 'candidate function' for now, but
9542 // it doesn't hurt to split it out.
9543 if (!Meth->isImplicit())
9546 if (Meth->isMoveAssignmentOperator())
9547 return oc_implicit_move_assignment;
9549 if (Meth->isCopyAssignmentOperator())
9550 return oc_implicit_copy_assignment;
9552 assert(isa<CXXConversionDecl>(Meth) && "expected conversion");
9559 return std::make_pair(Kind, Select);
9562 void MaybeEmitInheritedConstructorNote(Sema &S, Decl *FoundDecl) {
9563 // FIXME: It'd be nice to only emit a note once per using-decl per overload
9565 if (auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(FoundDecl))
9566 S.Diag(FoundDecl->getLocation(),
9567 diag::note_ovl_candidate_inherited_constructor)
9568 << Shadow->getNominatedBaseClass();
9571 } // end anonymous namespace
9573 static bool isFunctionAlwaysEnabled(const ASTContext &Ctx,
9574 const FunctionDecl *FD) {
9575 for (auto *EnableIf : FD->specific_attrs<EnableIfAttr>()) {
9577 if (EnableIf->getCond()->isValueDependent() ||
9578 !EnableIf->getCond()->EvaluateAsBooleanCondition(AlwaysTrue, Ctx))
9586 /// Returns true if we can take the address of the function.
9588 /// \param Complain - If true, we'll emit a diagnostic
9589 /// \param InOverloadResolution - For the purposes of emitting a diagnostic, are
9590 /// we in overload resolution?
9591 /// \param Loc - The location of the statement we're complaining about. Ignored
9592 /// if we're not complaining, or if we're in overload resolution.
9593 static bool checkAddressOfFunctionIsAvailable(Sema &S, const FunctionDecl *FD,
9595 bool InOverloadResolution,
9596 SourceLocation Loc) {
9597 if (!isFunctionAlwaysEnabled(S.Context, FD)) {
9599 if (InOverloadResolution)
9600 S.Diag(FD->getBeginLoc(),
9601 diag::note_addrof_ovl_candidate_disabled_by_enable_if_attr);
9603 S.Diag(Loc, diag::err_addrof_function_disabled_by_enable_if_attr) << FD;
9608 auto I = llvm::find_if(FD->parameters(), [](const ParmVarDecl *P) {
9609 return P->hasAttr<PassObjectSizeAttr>();
9611 if (I == FD->param_end())
9615 // Add one to ParamNo because it's user-facing
9616 unsigned ParamNo = std::distance(FD->param_begin(), I) + 1;
9617 if (InOverloadResolution)
9618 S.Diag(FD->getLocation(),
9619 diag::note_ovl_candidate_has_pass_object_size_params)
9622 S.Diag(Loc, diag::err_address_of_function_with_pass_object_size_params)
9628 static bool checkAddressOfCandidateIsAvailable(Sema &S,
9629 const FunctionDecl *FD) {
9630 return checkAddressOfFunctionIsAvailable(S, FD, /*Complain=*/true,
9631 /*InOverloadResolution=*/true,
9632 /*Loc=*/SourceLocation());
9635 bool Sema::checkAddressOfFunctionIsAvailable(const FunctionDecl *Function,
9637 SourceLocation Loc) {
9638 return ::checkAddressOfFunctionIsAvailable(*this, Function, Complain,
9639 /*InOverloadResolution=*/false,
9643 // Notes the location of an overload candidate.
9644 void Sema::NoteOverloadCandidate(NamedDecl *Found, FunctionDecl *Fn,
9645 QualType DestType, bool TakingAddress) {
9646 if (TakingAddress && !checkAddressOfCandidateIsAvailable(*this, Fn))
9648 if (Fn->isMultiVersion() && Fn->hasAttr<TargetAttr>() &&
9649 !Fn->getAttr<TargetAttr>()->isDefaultVersion())
9653 std::pair<OverloadCandidateKind, OverloadCandidateSelect> KSPair =
9654 ClassifyOverloadCandidate(*this, Found, Fn, FnDesc);
9655 PartialDiagnostic PD = PDiag(diag::note_ovl_candidate)
9656 << (unsigned)KSPair.first << (unsigned)KSPair.second
9659 HandleFunctionTypeMismatch(PD, Fn->getType(), DestType);
9660 Diag(Fn->getLocation(), PD);
9661 MaybeEmitInheritedConstructorNote(*this, Found);
9664 // Notes the location of all overload candidates designated through
9666 void Sema::NoteAllOverloadCandidates(Expr *OverloadedExpr, QualType DestType,
9667 bool TakingAddress) {
9668 assert(OverloadedExpr->getType() == Context.OverloadTy);
9670 OverloadExpr::FindResult Ovl = OverloadExpr::find(OverloadedExpr);
9671 OverloadExpr *OvlExpr = Ovl.Expression;
9673 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
9674 IEnd = OvlExpr->decls_end();
9676 if (FunctionTemplateDecl *FunTmpl =
9677 dyn_cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()) ) {
9678 NoteOverloadCandidate(*I, FunTmpl->getTemplatedDecl(), DestType,
9680 } else if (FunctionDecl *Fun
9681 = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()) ) {
9682 NoteOverloadCandidate(*I, Fun, DestType, TakingAddress);
9687 /// Diagnoses an ambiguous conversion. The partial diagnostic is the
9688 /// "lead" diagnostic; it will be given two arguments, the source and
9689 /// target types of the conversion.
9690 void ImplicitConversionSequence::DiagnoseAmbiguousConversion(
9692 SourceLocation CaretLoc,
9693 const PartialDiagnostic &PDiag) const {
9694 S.Diag(CaretLoc, PDiag)
9695 << Ambiguous.getFromType() << Ambiguous.getToType();
9696 // FIXME: The note limiting machinery is borrowed from
9697 // OverloadCandidateSet::NoteCandidates; there's an opportunity for
9698 // refactoring here.
9699 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
9700 unsigned CandsShown = 0;
9701 AmbiguousConversionSequence::const_iterator I, E;
9702 for (I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) {
9703 if (CandsShown >= 4 && ShowOverloads == Ovl_Best)
9706 S.NoteOverloadCandidate(I->first, I->second);
9709 S.Diag(SourceLocation(), diag::note_ovl_too_many_candidates) << int(E - I);
9712 static void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand,
9713 unsigned I, bool TakingCandidateAddress) {
9714 const ImplicitConversionSequence &Conv = Cand->Conversions[I];
9715 assert(Conv.isBad());
9716 assert(Cand->Function && "for now, candidate must be a function");
9717 FunctionDecl *Fn = Cand->Function;
9719 // There's a conversion slot for the object argument if this is a
9720 // non-constructor method. Note that 'I' corresponds the
9721 // conversion-slot index.
9722 bool isObjectArgument = false;
9723 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) {
9725 isObjectArgument = true;
9731 std::pair<OverloadCandidateKind, OverloadCandidateSelect> FnKindPair =
9732 ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn, FnDesc);
9734 Expr *FromExpr = Conv.Bad.FromExpr;
9735 QualType FromTy = Conv.Bad.getFromType();
9736 QualType ToTy = Conv.Bad.getToType();
9738 if (FromTy == S.Context.OverloadTy) {
9739 assert(FromExpr && "overload set argument came from implicit argument?");
9740 Expr *E = FromExpr->IgnoreParens();
9741 if (isa<UnaryOperator>(E))
9742 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens();
9743 DeclarationName Name = cast<OverloadExpr>(E)->getName();
9745 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload)
9746 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9747 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << ToTy
9749 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9753 // Do some hand-waving analysis to see if the non-viability is due
9754 // to a qualifier mismatch.
9755 CanQualType CFromTy = S.Context.getCanonicalType(FromTy);
9756 CanQualType CToTy = S.Context.getCanonicalType(ToTy);
9757 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>())
9758 CToTy = RT->getPointeeType();
9760 // TODO: detect and diagnose the full richness of const mismatches.
9761 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>())
9762 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) {
9763 CFromTy = FromPT->getPointeeType();
9764 CToTy = ToPT->getPointeeType();
9768 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() &&
9769 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) {
9770 Qualifiers FromQs = CFromTy.getQualifiers();
9771 Qualifiers ToQs = CToTy.getQualifiers();
9773 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) {
9774 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace)
9775 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9776 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
9777 << ToTy << (unsigned)isObjectArgument << I + 1;
9778 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9782 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) {
9783 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_ownership)
9784 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9785 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
9786 << FromQs.getObjCLifetime() << ToQs.getObjCLifetime()
9787 << (unsigned)isObjectArgument << I + 1;
9788 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9792 if (FromQs.getObjCGCAttr() != ToQs.getObjCGCAttr()) {
9793 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_gc)
9794 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9795 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
9796 << FromQs.getObjCGCAttr() << ToQs.getObjCGCAttr()
9797 << (unsigned)isObjectArgument << I + 1;
9798 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9802 if (FromQs.hasUnaligned() != ToQs.hasUnaligned()) {
9803 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_unaligned)
9804 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9805 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
9806 << FromQs.hasUnaligned() << I + 1;
9807 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9811 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers();
9812 assert(CVR && "unexpected qualifiers mismatch");
9814 if (isObjectArgument) {
9815 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this)
9816 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9817 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
9820 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr)
9821 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9822 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
9823 << (CVR - 1) << I + 1;
9825 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9829 // Special diagnostic for failure to convert an initializer list, since
9830 // telling the user that it has type void is not useful.
9831 if (FromExpr && isa<InitListExpr>(FromExpr)) {
9832 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_list_argument)
9833 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9834 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
9835 << ToTy << (unsigned)isObjectArgument << I + 1;
9836 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9840 // Diagnose references or pointers to incomplete types differently,
9841 // since it's far from impossible that the incompleteness triggered
9843 QualType TempFromTy = FromTy.getNonReferenceType();
9844 if (const PointerType *PTy = TempFromTy->getAs<PointerType>())
9845 TempFromTy = PTy->getPointeeType();
9846 if (TempFromTy->isIncompleteType()) {
9847 // Emit the generic diagnostic and, optionally, add the hints to it.
9848 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete)
9849 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9850 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
9851 << ToTy << (unsigned)isObjectArgument << I + 1
9852 << (unsigned)(Cand->Fix.Kind);
9854 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9858 // Diagnose base -> derived pointer conversions.
9859 unsigned BaseToDerivedConversion = 0;
9860 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) {
9861 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) {
9862 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs(
9863 FromPtrTy->getPointeeType()) &&
9864 !FromPtrTy->getPointeeType()->isIncompleteType() &&
9865 !ToPtrTy->getPointeeType()->isIncompleteType() &&
9866 S.IsDerivedFrom(SourceLocation(), ToPtrTy->getPointeeType(),
9867 FromPtrTy->getPointeeType()))
9868 BaseToDerivedConversion = 1;
9870 } else if (const ObjCObjectPointerType *FromPtrTy
9871 = FromTy->getAs<ObjCObjectPointerType>()) {
9872 if (const ObjCObjectPointerType *ToPtrTy
9873 = ToTy->getAs<ObjCObjectPointerType>())
9874 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl())
9875 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl())
9876 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs(
9877 FromPtrTy->getPointeeType()) &&
9878 FromIface->isSuperClassOf(ToIface))
9879 BaseToDerivedConversion = 2;
9880 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) {
9881 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) &&
9882 !FromTy->isIncompleteType() &&
9883 !ToRefTy->getPointeeType()->isIncompleteType() &&
9884 S.IsDerivedFrom(SourceLocation(), ToRefTy->getPointeeType(), FromTy)) {
9885 BaseToDerivedConversion = 3;
9886 } else if (ToTy->isLValueReferenceType() && !FromExpr->isLValue() &&
9887 ToTy.getNonReferenceType().getCanonicalType() ==
9888 FromTy.getNonReferenceType().getCanonicalType()) {
9889 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_lvalue)
9890 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9891 << (unsigned)isObjectArgument << I + 1
9892 << (FromExpr ? FromExpr->getSourceRange() : SourceRange());
9893 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9898 if (BaseToDerivedConversion) {
9899 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_base_to_derived_conv)
9900 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9901 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9902 << (BaseToDerivedConversion - 1) << FromTy << ToTy << I + 1;
9903 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9907 if (isa<ObjCObjectPointerType>(CFromTy) &&
9908 isa<PointerType>(CToTy)) {
9909 Qualifiers FromQs = CFromTy.getQualifiers();
9910 Qualifiers ToQs = CToTy.getQualifiers();
9911 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) {
9912 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_arc_conv)
9913 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second
9914 << FnDesc << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9915 << FromTy << ToTy << (unsigned)isObjectArgument << I + 1;
9916 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9921 if (TakingCandidateAddress &&
9922 !checkAddressOfCandidateIsAvailable(S, Cand->Function))
9925 // Emit the generic diagnostic and, optionally, add the hints to it.
9926 PartialDiagnostic FDiag = S.PDiag(diag::note_ovl_candidate_bad_conv);
9927 FDiag << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
9928 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
9929 << ToTy << (unsigned)isObjectArgument << I + 1
9930 << (unsigned)(Cand->Fix.Kind);
9932 // If we can fix the conversion, suggest the FixIts.
9933 for (std::vector<FixItHint>::iterator HI = Cand->Fix.Hints.begin(),
9934 HE = Cand->Fix.Hints.end(); HI != HE; ++HI)
9936 S.Diag(Fn->getLocation(), FDiag);
9938 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9941 /// Additional arity mismatch diagnosis specific to a function overload
9942 /// candidates. This is not covered by the more general DiagnoseArityMismatch()
9943 /// over a candidate in any candidate set.
9944 static bool CheckArityMismatch(Sema &S, OverloadCandidate *Cand,
9946 FunctionDecl *Fn = Cand->Function;
9947 unsigned MinParams = Fn->getMinRequiredArguments();
9949 // With invalid overloaded operators, it's possible that we think we
9950 // have an arity mismatch when in fact it looks like we have the
9951 // right number of arguments, because only overloaded operators have
9952 // the weird behavior of overloading member and non-member functions.
9953 // Just don't report anything.
9954 if (Fn->isInvalidDecl() &&
9955 Fn->getDeclName().getNameKind() == DeclarationName::CXXOperatorName)
9958 if (NumArgs < MinParams) {
9959 assert((Cand->FailureKind == ovl_fail_too_few_arguments) ||
9960 (Cand->FailureKind == ovl_fail_bad_deduction &&
9961 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments));
9963 assert((Cand->FailureKind == ovl_fail_too_many_arguments) ||
9964 (Cand->FailureKind == ovl_fail_bad_deduction &&
9965 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments));
9971 /// General arity mismatch diagnosis over a candidate in a candidate set.
9972 static void DiagnoseArityMismatch(Sema &S, NamedDecl *Found, Decl *D,
9973 unsigned NumFormalArgs) {
9974 assert(isa<FunctionDecl>(D) &&
9975 "The templated declaration should at least be a function"
9976 " when diagnosing bad template argument deduction due to too many"
9977 " or too few arguments");
9979 FunctionDecl *Fn = cast<FunctionDecl>(D);
9981 // TODO: treat calls to a missing default constructor as a special case
9982 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>();
9983 unsigned MinParams = Fn->getMinRequiredArguments();
9985 // at least / at most / exactly
9986 unsigned mode, modeCount;
9987 if (NumFormalArgs < MinParams) {
9988 if (MinParams != FnTy->getNumParams() || FnTy->isVariadic() ||
9989 FnTy->isTemplateVariadic())
9990 mode = 0; // "at least"
9992 mode = 2; // "exactly"
9993 modeCount = MinParams;
9995 if (MinParams != FnTy->getNumParams())
9996 mode = 1; // "at most"
9998 mode = 2; // "exactly"
9999 modeCount = FnTy->getNumParams();
10002 std::string Description;
10003 std::pair<OverloadCandidateKind, OverloadCandidateSelect> FnKindPair =
10004 ClassifyOverloadCandidate(S, Found, Fn, Description);
10006 if (modeCount == 1 && Fn->getParamDecl(0)->getDeclName())
10007 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity_one)
10008 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second
10009 << Description << mode << Fn->getParamDecl(0) << NumFormalArgs;
10011 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity)
10012 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second
10013 << Description << mode << modeCount << NumFormalArgs;
10015 MaybeEmitInheritedConstructorNote(S, Found);
10018 /// Arity mismatch diagnosis specific to a function overload candidate.
10019 static void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand,
10020 unsigned NumFormalArgs) {
10021 if (!CheckArityMismatch(S, Cand, NumFormalArgs))
10022 DiagnoseArityMismatch(S, Cand->FoundDecl, Cand->Function, NumFormalArgs);
10025 static TemplateDecl *getDescribedTemplate(Decl *Templated) {
10026 if (TemplateDecl *TD = Templated->getDescribedTemplate())
10028 llvm_unreachable("Unsupported: Getting the described template declaration"
10029 " for bad deduction diagnosis");
10032 /// Diagnose a failed template-argument deduction.
10033 static void DiagnoseBadDeduction(Sema &S, NamedDecl *Found, Decl *Templated,
10034 DeductionFailureInfo &DeductionFailure,
10036 bool TakingCandidateAddress) {
10037 TemplateParameter Param = DeductionFailure.getTemplateParameter();
10039 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) ||
10040 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) ||
10041 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>());
10042 switch (DeductionFailure.Result) {
10043 case Sema::TDK_Success:
10044 llvm_unreachable("TDK_success while diagnosing bad deduction");
10046 case Sema::TDK_Incomplete: {
10047 assert(ParamD && "no parameter found for incomplete deduction result");
10048 S.Diag(Templated->getLocation(),
10049 diag::note_ovl_candidate_incomplete_deduction)
10050 << ParamD->getDeclName();
10051 MaybeEmitInheritedConstructorNote(S, Found);
10055 case Sema::TDK_IncompletePack: {
10056 assert(ParamD && "no parameter found for incomplete deduction result");
10057 S.Diag(Templated->getLocation(),
10058 diag::note_ovl_candidate_incomplete_deduction_pack)
10059 << ParamD->getDeclName()
10060 << (DeductionFailure.getFirstArg()->pack_size() + 1)
10061 << *DeductionFailure.getFirstArg();
10062 MaybeEmitInheritedConstructorNote(S, Found);
10066 case Sema::TDK_Underqualified: {
10067 assert(ParamD && "no parameter found for bad qualifiers deduction result");
10068 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD);
10070 QualType Param = DeductionFailure.getFirstArg()->getAsType();
10072 // Param will have been canonicalized, but it should just be a
10073 // qualified version of ParamD, so move the qualifiers to that.
10074 QualifierCollector Qs;
10076 QualType NonCanonParam = Qs.apply(S.Context, TParam->getTypeForDecl());
10077 assert(S.Context.hasSameType(Param, NonCanonParam));
10079 // Arg has also been canonicalized, but there's nothing we can do
10080 // about that. It also doesn't matter as much, because it won't
10081 // have any template parameters in it (because deduction isn't
10082 // done on dependent types).
10083 QualType Arg = DeductionFailure.getSecondArg()->getAsType();
10085 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_underqualified)
10086 << ParamD->getDeclName() << Arg << NonCanonParam;
10087 MaybeEmitInheritedConstructorNote(S, Found);
10091 case Sema::TDK_Inconsistent: {
10092 assert(ParamD && "no parameter found for inconsistent deduction result");
10094 if (isa<TemplateTypeParmDecl>(ParamD))
10096 else if (isa<NonTypeTemplateParmDecl>(ParamD)) {
10097 // Deduction might have failed because we deduced arguments of two
10098 // different types for a non-type template parameter.
10099 // FIXME: Use a different TDK value for this.
10101 DeductionFailure.getFirstArg()->getNonTypeTemplateArgumentType();
10103 DeductionFailure.getSecondArg()->getNonTypeTemplateArgumentType();
10104 if (!T1.isNull() && !T2.isNull() && !S.Context.hasSameType(T1, T2)) {
10105 S.Diag(Templated->getLocation(),
10106 diag::note_ovl_candidate_inconsistent_deduction_types)
10107 << ParamD->getDeclName() << *DeductionFailure.getFirstArg() << T1
10108 << *DeductionFailure.getSecondArg() << T2;
10109 MaybeEmitInheritedConstructorNote(S, Found);
10118 S.Diag(Templated->getLocation(),
10119 diag::note_ovl_candidate_inconsistent_deduction)
10120 << which << ParamD->getDeclName() << *DeductionFailure.getFirstArg()
10121 << *DeductionFailure.getSecondArg();
10122 MaybeEmitInheritedConstructorNote(S, Found);
10126 case Sema::TDK_InvalidExplicitArguments:
10127 assert(ParamD && "no parameter found for invalid explicit arguments");
10128 if (ParamD->getDeclName())
10129 S.Diag(Templated->getLocation(),
10130 diag::note_ovl_candidate_explicit_arg_mismatch_named)
10131 << ParamD->getDeclName();
10134 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD))
10135 index = TTP->getIndex();
10136 else if (NonTypeTemplateParmDecl *NTTP
10137 = dyn_cast<NonTypeTemplateParmDecl>(ParamD))
10138 index = NTTP->getIndex();
10140 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex();
10141 S.Diag(Templated->getLocation(),
10142 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed)
10145 MaybeEmitInheritedConstructorNote(S, Found);
10148 case Sema::TDK_TooManyArguments:
10149 case Sema::TDK_TooFewArguments:
10150 DiagnoseArityMismatch(S, Found, Templated, NumArgs);
10153 case Sema::TDK_InstantiationDepth:
10154 S.Diag(Templated->getLocation(),
10155 diag::note_ovl_candidate_instantiation_depth);
10156 MaybeEmitInheritedConstructorNote(S, Found);
10159 case Sema::TDK_SubstitutionFailure: {
10160 // Format the template argument list into the argument string.
10161 SmallString<128> TemplateArgString;
10162 if (TemplateArgumentList *Args =
10163 DeductionFailure.getTemplateArgumentList()) {
10164 TemplateArgString = " ";
10165 TemplateArgString += S.getTemplateArgumentBindingsText(
10166 getDescribedTemplate(Templated)->getTemplateParameters(), *Args);
10169 // If this candidate was disabled by enable_if, say so.
10170 PartialDiagnosticAt *PDiag = DeductionFailure.getSFINAEDiagnostic();
10171 if (PDiag && PDiag->second.getDiagID() ==
10172 diag::err_typename_nested_not_found_enable_if) {
10173 // FIXME: Use the source range of the condition, and the fully-qualified
10174 // name of the enable_if template. These are both present in PDiag.
10175 S.Diag(PDiag->first, diag::note_ovl_candidate_disabled_by_enable_if)
10176 << "'enable_if'" << TemplateArgString;
10180 // We found a specific requirement that disabled the enable_if.
10181 if (PDiag && PDiag->second.getDiagID() ==
10182 diag::err_typename_nested_not_found_requirement) {
10183 S.Diag(Templated->getLocation(),
10184 diag::note_ovl_candidate_disabled_by_requirement)
10185 << PDiag->second.getStringArg(0) << TemplateArgString;
10189 // Format the SFINAE diagnostic into the argument string.
10190 // FIXME: Add a general mechanism to include a PartialDiagnostic *'s
10191 // formatted message in another diagnostic.
10192 SmallString<128> SFINAEArgString;
10195 SFINAEArgString = ": ";
10196 R = SourceRange(PDiag->first, PDiag->first);
10197 PDiag->second.EmitToString(S.getDiagnostics(), SFINAEArgString);
10200 S.Diag(Templated->getLocation(),
10201 diag::note_ovl_candidate_substitution_failure)
10202 << TemplateArgString << SFINAEArgString << R;
10203 MaybeEmitInheritedConstructorNote(S, Found);
10207 case Sema::TDK_DeducedMismatch:
10208 case Sema::TDK_DeducedMismatchNested: {
10209 // Format the template argument list into the argument string.
10210 SmallString<128> TemplateArgString;
10211 if (TemplateArgumentList *Args =
10212 DeductionFailure.getTemplateArgumentList()) {
10213 TemplateArgString = " ";
10214 TemplateArgString += S.getTemplateArgumentBindingsText(
10215 getDescribedTemplate(Templated)->getTemplateParameters(), *Args);
10218 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_deduced_mismatch)
10219 << (*DeductionFailure.getCallArgIndex() + 1)
10220 << *DeductionFailure.getFirstArg() << *DeductionFailure.getSecondArg()
10221 << TemplateArgString
10222 << (DeductionFailure.Result == Sema::TDK_DeducedMismatchNested);
10226 case Sema::TDK_NonDeducedMismatch: {
10227 // FIXME: Provide a source location to indicate what we couldn't match.
10228 TemplateArgument FirstTA = *DeductionFailure.getFirstArg();
10229 TemplateArgument SecondTA = *DeductionFailure.getSecondArg();
10230 if (FirstTA.getKind() == TemplateArgument::Template &&
10231 SecondTA.getKind() == TemplateArgument::Template) {
10232 TemplateName FirstTN = FirstTA.getAsTemplate();
10233 TemplateName SecondTN = SecondTA.getAsTemplate();
10234 if (FirstTN.getKind() == TemplateName::Template &&
10235 SecondTN.getKind() == TemplateName::Template) {
10236 if (FirstTN.getAsTemplateDecl()->getName() ==
10237 SecondTN.getAsTemplateDecl()->getName()) {
10238 // FIXME: This fixes a bad diagnostic where both templates are named
10239 // the same. This particular case is a bit difficult since:
10240 // 1) It is passed as a string to the diagnostic printer.
10241 // 2) The diagnostic printer only attempts to find a better
10242 // name for types, not decls.
10243 // Ideally, this should folded into the diagnostic printer.
10244 S.Diag(Templated->getLocation(),
10245 diag::note_ovl_candidate_non_deduced_mismatch_qualified)
10246 << FirstTN.getAsTemplateDecl() << SecondTN.getAsTemplateDecl();
10252 if (TakingCandidateAddress && isa<FunctionDecl>(Templated) &&
10253 !checkAddressOfCandidateIsAvailable(S, cast<FunctionDecl>(Templated)))
10256 // FIXME: For generic lambda parameters, check if the function is a lambda
10257 // call operator, and if so, emit a prettier and more informative
10258 // diagnostic that mentions 'auto' and lambda in addition to
10259 // (or instead of?) the canonical template type parameters.
10260 S.Diag(Templated->getLocation(),
10261 diag::note_ovl_candidate_non_deduced_mismatch)
10262 << FirstTA << SecondTA;
10265 // TODO: diagnose these individually, then kill off
10266 // note_ovl_candidate_bad_deduction, which is uselessly vague.
10267 case Sema::TDK_MiscellaneousDeductionFailure:
10268 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_bad_deduction);
10269 MaybeEmitInheritedConstructorNote(S, Found);
10271 case Sema::TDK_CUDATargetMismatch:
10272 S.Diag(Templated->getLocation(),
10273 diag::note_cuda_ovl_candidate_target_mismatch);
10278 /// Diagnose a failed template-argument deduction, for function calls.
10279 static void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand,
10281 bool TakingCandidateAddress) {
10282 unsigned TDK = Cand->DeductionFailure.Result;
10283 if (TDK == Sema::TDK_TooFewArguments || TDK == Sema::TDK_TooManyArguments) {
10284 if (CheckArityMismatch(S, Cand, NumArgs))
10287 DiagnoseBadDeduction(S, Cand->FoundDecl, Cand->Function, // pattern
10288 Cand->DeductionFailure, NumArgs, TakingCandidateAddress);
10291 /// CUDA: diagnose an invalid call across targets.
10292 static void DiagnoseBadTarget(Sema &S, OverloadCandidate *Cand) {
10293 FunctionDecl *Caller = cast<FunctionDecl>(S.CurContext);
10294 FunctionDecl *Callee = Cand->Function;
10296 Sema::CUDAFunctionTarget CallerTarget = S.IdentifyCUDATarget(Caller),
10297 CalleeTarget = S.IdentifyCUDATarget(Callee);
10299 std::string FnDesc;
10300 std::pair<OverloadCandidateKind, OverloadCandidateSelect> FnKindPair =
10301 ClassifyOverloadCandidate(S, Cand->FoundDecl, Callee, FnDesc);
10303 S.Diag(Callee->getLocation(), diag::note_ovl_candidate_bad_target)
10304 << (unsigned)FnKindPair.first << (unsigned)ocs_non_template
10305 << FnDesc /* Ignored */
10306 << CalleeTarget << CallerTarget;
10308 // This could be an implicit constructor for which we could not infer the
10309 // target due to a collsion. Diagnose that case.
10310 CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Callee);
10311 if (Meth != nullptr && Meth->isImplicit()) {
10312 CXXRecordDecl *ParentClass = Meth->getParent();
10313 Sema::CXXSpecialMember CSM;
10315 switch (FnKindPair.first) {
10318 case oc_implicit_default_constructor:
10319 CSM = Sema::CXXDefaultConstructor;
10321 case oc_implicit_copy_constructor:
10322 CSM = Sema::CXXCopyConstructor;
10324 case oc_implicit_move_constructor:
10325 CSM = Sema::CXXMoveConstructor;
10327 case oc_implicit_copy_assignment:
10328 CSM = Sema::CXXCopyAssignment;
10330 case oc_implicit_move_assignment:
10331 CSM = Sema::CXXMoveAssignment;
10335 bool ConstRHS = false;
10336 if (Meth->getNumParams()) {
10337 if (const ReferenceType *RT =
10338 Meth->getParamDecl(0)->getType()->getAs<ReferenceType>()) {
10339 ConstRHS = RT->getPointeeType().isConstQualified();
10343 S.inferCUDATargetForImplicitSpecialMember(ParentClass, CSM, Meth,
10344 /* ConstRHS */ ConstRHS,
10345 /* Diagnose */ true);
10349 static void DiagnoseFailedEnableIfAttr(Sema &S, OverloadCandidate *Cand) {
10350 FunctionDecl *Callee = Cand->Function;
10351 EnableIfAttr *Attr = static_cast<EnableIfAttr*>(Cand->DeductionFailure.Data);
10353 S.Diag(Callee->getLocation(),
10354 diag::note_ovl_candidate_disabled_by_function_cond_attr)
10355 << Attr->getCond()->getSourceRange() << Attr->getMessage();
10358 static void DiagnoseFailedExplicitSpec(Sema &S, OverloadCandidate *Cand) {
10359 ExplicitSpecifier ES;
10360 const char *DeclName;
10361 switch (Cand->Function->getDeclKind()) {
10362 case Decl::Kind::CXXConstructor:
10363 ES = cast<CXXConstructorDecl>(Cand->Function)->getExplicitSpecifier();
10364 DeclName = "constructor";
10366 case Decl::Kind::CXXConversion:
10367 ES = cast<CXXConversionDecl>(Cand->Function)->getExplicitSpecifier();
10368 DeclName = "conversion operator";
10370 case Decl::Kind::CXXDeductionGuide:
10371 ES = cast<CXXDeductionGuideDecl>(Cand->Function)->getExplicitSpecifier();
10372 DeclName = "deductiong guide";
10375 llvm_unreachable("invalid Decl");
10377 assert(ES.getExpr() && "null expression should be handled before");
10378 S.Diag(Cand->Function->getLocation(),
10379 diag::note_ovl_candidate_explicit_forbidden)
10381 S.Diag(ES.getExpr()->getBeginLoc(),
10382 diag::note_explicit_bool_resolved_to_true);
10385 static void DiagnoseOpenCLExtensionDisabled(Sema &S, OverloadCandidate *Cand) {
10386 FunctionDecl *Callee = Cand->Function;
10388 S.Diag(Callee->getLocation(),
10389 diag::note_ovl_candidate_disabled_by_extension)
10390 << S.getOpenCLExtensionsFromDeclExtMap(Callee);
10393 /// Generates a 'note' diagnostic for an overload candidate. We've
10394 /// already generated a primary error at the call site.
10396 /// It really does need to be a single diagnostic with its caret
10397 /// pointed at the candidate declaration. Yes, this creates some
10398 /// major challenges of technical writing. Yes, this makes pointing
10399 /// out problems with specific arguments quite awkward. It's still
10400 /// better than generating twenty screens of text for every failed
10403 /// It would be great to be able to express per-candidate problems
10404 /// more richly for those diagnostic clients that cared, but we'd
10405 /// still have to be just as careful with the default diagnostics.
10406 /// \param CtorDestAS Addr space of object being constructed (for ctor
10407 /// candidates only).
10408 static void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand,
10410 bool TakingCandidateAddress,
10411 LangAS CtorDestAS = LangAS::Default) {
10412 FunctionDecl *Fn = Cand->Function;
10414 // Note deleted candidates, but only if they're viable.
10415 if (Cand->Viable) {
10416 if (Fn->isDeleted()) {
10417 std::string FnDesc;
10418 std::pair<OverloadCandidateKind, OverloadCandidateSelect> FnKindPair =
10419 ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn, FnDesc);
10421 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted)
10422 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10423 << (Fn->isDeleted() ? (Fn->isDeletedAsWritten() ? 1 : 2) : 0);
10424 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10428 // We don't really have anything else to say about viable candidates.
10429 S.NoteOverloadCandidate(Cand->FoundDecl, Fn);
10433 switch (Cand->FailureKind) {
10434 case ovl_fail_too_many_arguments:
10435 case ovl_fail_too_few_arguments:
10436 return DiagnoseArityMismatch(S, Cand, NumArgs);
10438 case ovl_fail_bad_deduction:
10439 return DiagnoseBadDeduction(S, Cand, NumArgs,
10440 TakingCandidateAddress);
10442 case ovl_fail_illegal_constructor: {
10443 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_illegal_constructor)
10444 << (Fn->getPrimaryTemplate() ? 1 : 0);
10445 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10449 case ovl_fail_object_addrspace_mismatch: {
10450 Qualifiers QualsForPrinting;
10451 QualsForPrinting.setAddressSpace(CtorDestAS);
10452 S.Diag(Fn->getLocation(),
10453 diag::note_ovl_candidate_illegal_constructor_adrspace_mismatch)
10454 << QualsForPrinting;
10455 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10459 case ovl_fail_trivial_conversion:
10460 case ovl_fail_bad_final_conversion:
10461 case ovl_fail_final_conversion_not_exact:
10462 return S.NoteOverloadCandidate(Cand->FoundDecl, Fn);
10464 case ovl_fail_bad_conversion: {
10465 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0);
10466 for (unsigned N = Cand->Conversions.size(); I != N; ++I)
10467 if (Cand->Conversions[I].isBad())
10468 return DiagnoseBadConversion(S, Cand, I, TakingCandidateAddress);
10470 // FIXME: this currently happens when we're called from SemaInit
10471 // when user-conversion overload fails. Figure out how to handle
10472 // those conditions and diagnose them well.
10473 return S.NoteOverloadCandidate(Cand->FoundDecl, Fn);
10476 case ovl_fail_bad_target:
10477 return DiagnoseBadTarget(S, Cand);
10479 case ovl_fail_enable_if:
10480 return DiagnoseFailedEnableIfAttr(S, Cand);
10482 case ovl_fail_explicit_resolved:
10483 return DiagnoseFailedExplicitSpec(S, Cand);
10485 case ovl_fail_ext_disabled:
10486 return DiagnoseOpenCLExtensionDisabled(S, Cand);
10488 case ovl_fail_inhctor_slice:
10489 // It's generally not interesting to note copy/move constructors here.
10490 if (cast<CXXConstructorDecl>(Fn)->isCopyOrMoveConstructor())
10492 S.Diag(Fn->getLocation(),
10493 diag::note_ovl_candidate_inherited_constructor_slice)
10494 << (Fn->getPrimaryTemplate() ? 1 : 0)
10495 << Fn->getParamDecl(0)->getType()->isRValueReferenceType();
10496 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10499 case ovl_fail_addr_not_available: {
10500 bool Available = checkAddressOfCandidateIsAvailable(S, Cand->Function);
10502 assert(!Available);
10505 case ovl_non_default_multiversion_function:
10506 // Do nothing, these should simply be ignored.
10511 static void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) {
10512 // Desugar the type of the surrogate down to a function type,
10513 // retaining as many typedefs as possible while still showing
10514 // the function type (and, therefore, its parameter types).
10515 QualType FnType = Cand->Surrogate->getConversionType();
10516 bool isLValueReference = false;
10517 bool isRValueReference = false;
10518 bool isPointer = false;
10519 if (const LValueReferenceType *FnTypeRef =
10520 FnType->getAs<LValueReferenceType>()) {
10521 FnType = FnTypeRef->getPointeeType();
10522 isLValueReference = true;
10523 } else if (const RValueReferenceType *FnTypeRef =
10524 FnType->getAs<RValueReferenceType>()) {
10525 FnType = FnTypeRef->getPointeeType();
10526 isRValueReference = true;
10528 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) {
10529 FnType = FnTypePtr->getPointeeType();
10532 // Desugar down to a function type.
10533 FnType = QualType(FnType->getAs<FunctionType>(), 0);
10534 // Reconstruct the pointer/reference as appropriate.
10535 if (isPointer) FnType = S.Context.getPointerType(FnType);
10536 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType);
10537 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType);
10539 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand)
10543 static void NoteBuiltinOperatorCandidate(Sema &S, StringRef Opc,
10544 SourceLocation OpLoc,
10545 OverloadCandidate *Cand) {
10546 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary");
10547 std::string TypeStr("operator");
10550 TypeStr += Cand->BuiltinParamTypes[0].getAsString();
10551 if (Cand->Conversions.size() == 1) {
10553 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr;
10556 TypeStr += Cand->BuiltinParamTypes[1].getAsString();
10558 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr;
10562 static void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc,
10563 OverloadCandidate *Cand) {
10564 for (const ImplicitConversionSequence &ICS : Cand->Conversions) {
10565 if (ICS.isBad()) break; // all meaningless after first invalid
10566 if (!ICS.isAmbiguous()) continue;
10568 ICS.DiagnoseAmbiguousConversion(
10569 S, OpLoc, S.PDiag(diag::note_ambiguous_type_conversion));
10573 static SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) {
10574 if (Cand->Function)
10575 return Cand->Function->getLocation();
10576 if (Cand->IsSurrogate)
10577 return Cand->Surrogate->getLocation();
10578 return SourceLocation();
10581 static unsigned RankDeductionFailure(const DeductionFailureInfo &DFI) {
10582 switch ((Sema::TemplateDeductionResult)DFI.Result) {
10583 case Sema::TDK_Success:
10584 case Sema::TDK_NonDependentConversionFailure:
10585 llvm_unreachable("non-deduction failure while diagnosing bad deduction");
10587 case Sema::TDK_Invalid:
10588 case Sema::TDK_Incomplete:
10589 case Sema::TDK_IncompletePack:
10592 case Sema::TDK_Underqualified:
10593 case Sema::TDK_Inconsistent:
10596 case Sema::TDK_SubstitutionFailure:
10597 case Sema::TDK_DeducedMismatch:
10598 case Sema::TDK_DeducedMismatchNested:
10599 case Sema::TDK_NonDeducedMismatch:
10600 case Sema::TDK_MiscellaneousDeductionFailure:
10601 case Sema::TDK_CUDATargetMismatch:
10604 case Sema::TDK_InstantiationDepth:
10607 case Sema::TDK_InvalidExplicitArguments:
10610 case Sema::TDK_TooManyArguments:
10611 case Sema::TDK_TooFewArguments:
10614 llvm_unreachable("Unhandled deduction result");
10618 struct CompareOverloadCandidatesForDisplay {
10620 SourceLocation Loc;
10622 OverloadCandidateSet::CandidateSetKind CSK;
10624 CompareOverloadCandidatesForDisplay(
10625 Sema &S, SourceLocation Loc, size_t NArgs,
10626 OverloadCandidateSet::CandidateSetKind CSK)
10627 : S(S), NumArgs(NArgs), CSK(CSK) {}
10629 bool operator()(const OverloadCandidate *L,
10630 const OverloadCandidate *R) {
10631 // Fast-path this check.
10632 if (L == R) return false;
10634 // Order first by viability.
10636 if (!R->Viable) return true;
10638 // TODO: introduce a tri-valued comparison for overload
10639 // candidates. Would be more worthwhile if we had a sort
10640 // that could exploit it.
10641 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation(), CSK))
10643 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation(), CSK))
10645 } else if (R->Viable)
10648 assert(L->Viable == R->Viable);
10650 // Criteria by which we can sort non-viable candidates:
10652 // 1. Arity mismatches come after other candidates.
10653 if (L->FailureKind == ovl_fail_too_many_arguments ||
10654 L->FailureKind == ovl_fail_too_few_arguments) {
10655 if (R->FailureKind == ovl_fail_too_many_arguments ||
10656 R->FailureKind == ovl_fail_too_few_arguments) {
10657 int LDist = std::abs((int)L->getNumParams() - (int)NumArgs);
10658 int RDist = std::abs((int)R->getNumParams() - (int)NumArgs);
10659 if (LDist == RDist) {
10660 if (L->FailureKind == R->FailureKind)
10661 // Sort non-surrogates before surrogates.
10662 return !L->IsSurrogate && R->IsSurrogate;
10663 // Sort candidates requiring fewer parameters than there were
10664 // arguments given after candidates requiring more parameters
10665 // than there were arguments given.
10666 return L->FailureKind == ovl_fail_too_many_arguments;
10668 return LDist < RDist;
10672 if (R->FailureKind == ovl_fail_too_many_arguments ||
10673 R->FailureKind == ovl_fail_too_few_arguments)
10676 // 2. Bad conversions come first and are ordered by the number
10677 // of bad conversions and quality of good conversions.
10678 if (L->FailureKind == ovl_fail_bad_conversion) {
10679 if (R->FailureKind != ovl_fail_bad_conversion)
10682 // The conversion that can be fixed with a smaller number of changes,
10684 unsigned numLFixes = L->Fix.NumConversionsFixed;
10685 unsigned numRFixes = R->Fix.NumConversionsFixed;
10686 numLFixes = (numLFixes == 0) ? UINT_MAX : numLFixes;
10687 numRFixes = (numRFixes == 0) ? UINT_MAX : numRFixes;
10688 if (numLFixes != numRFixes) {
10689 return numLFixes < numRFixes;
10692 // If there's any ordering between the defined conversions...
10693 // FIXME: this might not be transitive.
10694 assert(L->Conversions.size() == R->Conversions.size());
10696 int leftBetter = 0;
10697 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument);
10698 for (unsigned E = L->Conversions.size(); I != E; ++I) {
10699 switch (CompareImplicitConversionSequences(S, Loc,
10701 R->Conversions[I])) {
10702 case ImplicitConversionSequence::Better:
10706 case ImplicitConversionSequence::Worse:
10710 case ImplicitConversionSequence::Indistinguishable:
10714 if (leftBetter > 0) return true;
10715 if (leftBetter < 0) return false;
10717 } else if (R->FailureKind == ovl_fail_bad_conversion)
10720 if (L->FailureKind == ovl_fail_bad_deduction) {
10721 if (R->FailureKind != ovl_fail_bad_deduction)
10724 if (L->DeductionFailure.Result != R->DeductionFailure.Result)
10725 return RankDeductionFailure(L->DeductionFailure)
10726 < RankDeductionFailure(R->DeductionFailure);
10727 } else if (R->FailureKind == ovl_fail_bad_deduction)
10733 // Sort everything else by location.
10734 SourceLocation LLoc = GetLocationForCandidate(L);
10735 SourceLocation RLoc = GetLocationForCandidate(R);
10737 // Put candidates without locations (e.g. builtins) at the end.
10738 if (LLoc.isInvalid()) return false;
10739 if (RLoc.isInvalid()) return true;
10741 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc);
10746 /// CompleteNonViableCandidate - Normally, overload resolution only
10747 /// computes up to the first bad conversion. Produces the FixIt set if
10749 static void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand,
10750 ArrayRef<Expr *> Args) {
10751 assert(!Cand->Viable);
10753 // Don't do anything on failures other than bad conversion.
10754 if (Cand->FailureKind != ovl_fail_bad_conversion) return;
10756 // We only want the FixIts if all the arguments can be corrected.
10757 bool Unfixable = false;
10758 // Use a implicit copy initialization to check conversion fixes.
10759 Cand->Fix.setConversionChecker(TryCopyInitialization);
10761 // Attempt to fix the bad conversion.
10762 unsigned ConvCount = Cand->Conversions.size();
10763 for (unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); /**/;
10765 assert(ConvIdx != ConvCount && "no bad conversion in candidate");
10766 if (Cand->Conversions[ConvIdx].isInitialized() &&
10767 Cand->Conversions[ConvIdx].isBad()) {
10768 Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S);
10773 // FIXME: this should probably be preserved from the overload
10774 // operation somehow.
10775 bool SuppressUserConversions = false;
10777 unsigned ConvIdx = 0;
10778 ArrayRef<QualType> ParamTypes;
10780 if (Cand->IsSurrogate) {
10782 = Cand->Surrogate->getConversionType().getNonReferenceType();
10783 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
10784 ConvType = ConvPtrType->getPointeeType();
10785 ParamTypes = ConvType->getAs<FunctionProtoType>()->getParamTypes();
10786 // Conversion 0 is 'this', which doesn't have a corresponding argument.
10788 } else if (Cand->Function) {
10790 Cand->Function->getType()->getAs<FunctionProtoType>()->getParamTypes();
10791 if (isa<CXXMethodDecl>(Cand->Function) &&
10792 !isa<CXXConstructorDecl>(Cand->Function)) {
10793 // Conversion 0 is 'this', which doesn't have a corresponding argument.
10797 // Builtin operator.
10798 assert(ConvCount <= 3);
10799 ParamTypes = Cand->BuiltinParamTypes;
10802 // Fill in the rest of the conversions.
10803 for (unsigned ArgIdx = 0; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) {
10804 if (Cand->Conversions[ConvIdx].isInitialized()) {
10805 // We've already checked this conversion.
10806 } else if (ArgIdx < ParamTypes.size()) {
10807 if (ParamTypes[ArgIdx]->isDependentType())
10808 Cand->Conversions[ConvIdx].setAsIdentityConversion(
10809 Args[ArgIdx]->getType());
10811 Cand->Conversions[ConvIdx] =
10812 TryCopyInitialization(S, Args[ArgIdx], ParamTypes[ArgIdx],
10813 SuppressUserConversions,
10814 /*InOverloadResolution=*/true,
10815 /*AllowObjCWritebackConversion=*/
10816 S.getLangOpts().ObjCAutoRefCount);
10817 // Store the FixIt in the candidate if it exists.
10818 if (!Unfixable && Cand->Conversions[ConvIdx].isBad())
10819 Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S);
10822 Cand->Conversions[ConvIdx].setEllipsis();
10826 SmallVector<OverloadCandidate *, 32> OverloadCandidateSet::CompleteCandidates(
10827 Sema &S, OverloadCandidateDisplayKind OCD, ArrayRef<Expr *> Args,
10828 SourceLocation OpLoc,
10829 llvm::function_ref<bool(OverloadCandidate &)> Filter) {
10830 // Sort the candidates by viability and position. Sorting directly would
10831 // be prohibitive, so we make a set of pointers and sort those.
10832 SmallVector<OverloadCandidate*, 32> Cands;
10833 if (OCD == OCD_AllCandidates) Cands.reserve(size());
10834 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) {
10835 if (!Filter(*Cand))
10838 Cands.push_back(Cand);
10839 else if (OCD == OCD_AllCandidates) {
10840 CompleteNonViableCandidate(S, Cand, Args);
10841 if (Cand->Function || Cand->IsSurrogate)
10842 Cands.push_back(Cand);
10843 // Otherwise, this a non-viable builtin candidate. We do not, in general,
10844 // want to list every possible builtin candidate.
10849 Cands, CompareOverloadCandidatesForDisplay(S, OpLoc, Args.size(), Kind));
10854 /// When overload resolution fails, prints diagnostic messages containing the
10855 /// candidates in the candidate set.
10856 void OverloadCandidateSet::NoteCandidates(PartialDiagnosticAt PD,
10857 Sema &S, OverloadCandidateDisplayKind OCD, ArrayRef<Expr *> Args,
10858 StringRef Opc, SourceLocation OpLoc,
10859 llvm::function_ref<bool(OverloadCandidate &)> Filter) {
10861 auto Cands = CompleteCandidates(S, OCD, Args, OpLoc, Filter);
10863 S.Diag(PD.first, PD.second);
10865 NoteCandidates(S, Args, Cands, Opc, OpLoc);
10868 void OverloadCandidateSet::NoteCandidates(Sema &S, ArrayRef<Expr *> Args,
10869 ArrayRef<OverloadCandidate *> Cands,
10870 StringRef Opc, SourceLocation OpLoc) {
10871 bool ReportedAmbiguousConversions = false;
10873 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
10874 unsigned CandsShown = 0;
10875 auto I = Cands.begin(), E = Cands.end();
10876 for (; I != E; ++I) {
10877 OverloadCandidate *Cand = *I;
10879 // Set an arbitrary limit on the number of candidate functions we'll spam
10880 // the user with. FIXME: This limit should depend on details of the
10882 if (CandsShown >= 4 && ShowOverloads == Ovl_Best) {
10887 if (Cand->Function)
10888 NoteFunctionCandidate(S, Cand, Args.size(),
10889 /*TakingCandidateAddress=*/false, DestAS);
10890 else if (Cand->IsSurrogate)
10891 NoteSurrogateCandidate(S, Cand);
10893 assert(Cand->Viable &&
10894 "Non-viable built-in candidates are not added to Cands.");
10895 // Generally we only see ambiguities including viable builtin
10896 // operators if overload resolution got screwed up by an
10897 // ambiguous user-defined conversion.
10899 // FIXME: It's quite possible for different conversions to see
10900 // different ambiguities, though.
10901 if (!ReportedAmbiguousConversions) {
10902 NoteAmbiguousUserConversions(S, OpLoc, Cand);
10903 ReportedAmbiguousConversions = true;
10906 // If this is a viable builtin, print it.
10907 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand);
10912 S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I);
10915 static SourceLocation
10916 GetLocationForCandidate(const TemplateSpecCandidate *Cand) {
10917 return Cand->Specialization ? Cand->Specialization->getLocation()
10918 : SourceLocation();
10922 struct CompareTemplateSpecCandidatesForDisplay {
10924 CompareTemplateSpecCandidatesForDisplay(Sema &S) : S(S) {}
10926 bool operator()(const TemplateSpecCandidate *L,
10927 const TemplateSpecCandidate *R) {
10928 // Fast-path this check.
10932 // Assuming that both candidates are not matches...
10934 // Sort by the ranking of deduction failures.
10935 if (L->DeductionFailure.Result != R->DeductionFailure.Result)
10936 return RankDeductionFailure(L->DeductionFailure) <
10937 RankDeductionFailure(R->DeductionFailure);
10939 // Sort everything else by location.
10940 SourceLocation LLoc = GetLocationForCandidate(L);
10941 SourceLocation RLoc = GetLocationForCandidate(R);
10943 // Put candidates without locations (e.g. builtins) at the end.
10944 if (LLoc.isInvalid())
10946 if (RLoc.isInvalid())
10949 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc);
10954 /// Diagnose a template argument deduction failure.
10955 /// We are treating these failures as overload failures due to bad
10957 void TemplateSpecCandidate::NoteDeductionFailure(Sema &S,
10958 bool ForTakingAddress) {
10959 DiagnoseBadDeduction(S, FoundDecl, Specialization, // pattern
10960 DeductionFailure, /*NumArgs=*/0, ForTakingAddress);
10963 void TemplateSpecCandidateSet::destroyCandidates() {
10964 for (iterator i = begin(), e = end(); i != e; ++i) {
10965 i->DeductionFailure.Destroy();
10969 void TemplateSpecCandidateSet::clear() {
10970 destroyCandidates();
10971 Candidates.clear();
10974 /// NoteCandidates - When no template specialization match is found, prints
10975 /// diagnostic messages containing the non-matching specializations that form
10976 /// the candidate set.
10977 /// This is analoguous to OverloadCandidateSet::NoteCandidates() with
10978 /// OCD == OCD_AllCandidates and Cand->Viable == false.
10979 void TemplateSpecCandidateSet::NoteCandidates(Sema &S, SourceLocation Loc) {
10980 // Sort the candidates by position (assuming no candidate is a match).
10981 // Sorting directly would be prohibitive, so we make a set of pointers
10983 SmallVector<TemplateSpecCandidate *, 32> Cands;
10984 Cands.reserve(size());
10985 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) {
10986 if (Cand->Specialization)
10987 Cands.push_back(Cand);
10988 // Otherwise, this is a non-matching builtin candidate. We do not,
10989 // in general, want to list every possible builtin candidate.
10992 llvm::sort(Cands, CompareTemplateSpecCandidatesForDisplay(S));
10994 // FIXME: Perhaps rename OverloadsShown and getShowOverloads()
10995 // for generalization purposes (?).
10996 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
10998 SmallVectorImpl<TemplateSpecCandidate *>::iterator I, E;
10999 unsigned CandsShown = 0;
11000 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) {
11001 TemplateSpecCandidate *Cand = *I;
11003 // Set an arbitrary limit on the number of candidates we'll spam
11004 // the user with. FIXME: This limit should depend on details of the
11006 if (CandsShown >= 4 && ShowOverloads == Ovl_Best)
11010 assert(Cand->Specialization &&
11011 "Non-matching built-in candidates are not added to Cands.");
11012 Cand->NoteDeductionFailure(S, ForTakingAddress);
11016 S.Diag(Loc, diag::note_ovl_too_many_candidates) << int(E - I);
11019 // [PossiblyAFunctionType] --> [Return]
11020 // NonFunctionType --> NonFunctionType
11022 // R (*)(A) --> R (A)
11023 // R (&)(A) --> R (A)
11024 // R (S::*)(A) --> R (A)
11025 QualType Sema::ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType) {
11026 QualType Ret = PossiblyAFunctionType;
11027 if (const PointerType *ToTypePtr =
11028 PossiblyAFunctionType->getAs<PointerType>())
11029 Ret = ToTypePtr->getPointeeType();
11030 else if (const ReferenceType *ToTypeRef =
11031 PossiblyAFunctionType->getAs<ReferenceType>())
11032 Ret = ToTypeRef->getPointeeType();
11033 else if (const MemberPointerType *MemTypePtr =
11034 PossiblyAFunctionType->getAs<MemberPointerType>())
11035 Ret = MemTypePtr->getPointeeType();
11037 Context.getCanonicalType(Ret).getUnqualifiedType();
11041 static bool completeFunctionType(Sema &S, FunctionDecl *FD, SourceLocation Loc,
11042 bool Complain = true) {
11043 if (S.getLangOpts().CPlusPlus14 && FD->getReturnType()->isUndeducedType() &&
11044 S.DeduceReturnType(FD, Loc, Complain))
11047 auto *FPT = FD->getType()->castAs<FunctionProtoType>();
11048 if (S.getLangOpts().CPlusPlus17 &&
11049 isUnresolvedExceptionSpec(FPT->getExceptionSpecType()) &&
11050 !S.ResolveExceptionSpec(Loc, FPT))
11057 // A helper class to help with address of function resolution
11058 // - allows us to avoid passing around all those ugly parameters
11059 class AddressOfFunctionResolver {
11062 const QualType& TargetType;
11063 QualType TargetFunctionType; // Extracted function type from target type
11066 //DeclAccessPair& ResultFunctionAccessPair;
11067 ASTContext& Context;
11069 bool TargetTypeIsNonStaticMemberFunction;
11070 bool FoundNonTemplateFunction;
11071 bool StaticMemberFunctionFromBoundPointer;
11072 bool HasComplained;
11074 OverloadExpr::FindResult OvlExprInfo;
11075 OverloadExpr *OvlExpr;
11076 TemplateArgumentListInfo OvlExplicitTemplateArgs;
11077 SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches;
11078 TemplateSpecCandidateSet FailedCandidates;
11081 AddressOfFunctionResolver(Sema &S, Expr *SourceExpr,
11082 const QualType &TargetType, bool Complain)
11083 : S(S), SourceExpr(SourceExpr), TargetType(TargetType),
11084 Complain(Complain), Context(S.getASTContext()),
11085 TargetTypeIsNonStaticMemberFunction(
11086 !!TargetType->getAs<MemberPointerType>()),
11087 FoundNonTemplateFunction(false),
11088 StaticMemberFunctionFromBoundPointer(false),
11089 HasComplained(false),
11090 OvlExprInfo(OverloadExpr::find(SourceExpr)),
11091 OvlExpr(OvlExprInfo.Expression),
11092 FailedCandidates(OvlExpr->getNameLoc(), /*ForTakingAddress=*/true) {
11093 ExtractUnqualifiedFunctionTypeFromTargetType();
11095 if (TargetFunctionType->isFunctionType()) {
11096 if (UnresolvedMemberExpr *UME = dyn_cast<UnresolvedMemberExpr>(OvlExpr))
11097 if (!UME->isImplicitAccess() &&
11098 !S.ResolveSingleFunctionTemplateSpecialization(UME))
11099 StaticMemberFunctionFromBoundPointer = true;
11100 } else if (OvlExpr->hasExplicitTemplateArgs()) {
11101 DeclAccessPair dap;
11102 if (FunctionDecl *Fn = S.ResolveSingleFunctionTemplateSpecialization(
11103 OvlExpr, false, &dap)) {
11104 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn))
11105 if (!Method->isStatic()) {
11106 // If the target type is a non-function type and the function found
11107 // is a non-static member function, pretend as if that was the
11108 // target, it's the only possible type to end up with.
11109 TargetTypeIsNonStaticMemberFunction = true;
11111 // And skip adding the function if its not in the proper form.
11112 // We'll diagnose this due to an empty set of functions.
11113 if (!OvlExprInfo.HasFormOfMemberPointer)
11117 Matches.push_back(std::make_pair(dap, Fn));
11122 if (OvlExpr->hasExplicitTemplateArgs())
11123 OvlExpr->copyTemplateArgumentsInto(OvlExplicitTemplateArgs);
11125 if (FindAllFunctionsThatMatchTargetTypeExactly()) {
11126 // C++ [over.over]p4:
11127 // If more than one function is selected, [...]
11128 if (Matches.size() > 1 && !eliminiateSuboptimalOverloadCandidates()) {
11129 if (FoundNonTemplateFunction)
11130 EliminateAllTemplateMatches();
11132 EliminateAllExceptMostSpecializedTemplate();
11136 if (S.getLangOpts().CUDA && Matches.size() > 1)
11137 EliminateSuboptimalCudaMatches();
11140 bool hasComplained() const { return HasComplained; }
11143 bool candidateHasExactlyCorrectType(const FunctionDecl *FD) {
11145 return Context.hasSameUnqualifiedType(TargetFunctionType, FD->getType()) ||
11146 S.IsFunctionConversion(FD->getType(), TargetFunctionType, Discard);
11149 /// \return true if A is considered a better overload candidate for the
11150 /// desired type than B.
11151 bool isBetterCandidate(const FunctionDecl *A, const FunctionDecl *B) {
11152 // If A doesn't have exactly the correct type, we don't want to classify it
11153 // as "better" than anything else. This way, the user is required to
11154 // disambiguate for us if there are multiple candidates and no exact match.
11155 return candidateHasExactlyCorrectType(A) &&
11156 (!candidateHasExactlyCorrectType(B) ||
11157 compareEnableIfAttrs(S, A, B) == Comparison::Better);
11160 /// \return true if we were able to eliminate all but one overload candidate,
11161 /// false otherwise.
11162 bool eliminiateSuboptimalOverloadCandidates() {
11163 // Same algorithm as overload resolution -- one pass to pick the "best",
11164 // another pass to be sure that nothing is better than the best.
11165 auto Best = Matches.begin();
11166 for (auto I = Matches.begin()+1, E = Matches.end(); I != E; ++I)
11167 if (isBetterCandidate(I->second, Best->second))
11170 const FunctionDecl *BestFn = Best->second;
11171 auto IsBestOrInferiorToBest = [this, BestFn](
11172 const std::pair<DeclAccessPair, FunctionDecl *> &Pair) {
11173 return BestFn == Pair.second || isBetterCandidate(BestFn, Pair.second);
11176 // Note: We explicitly leave Matches unmodified if there isn't a clear best
11177 // option, so we can potentially give the user a better error
11178 if (!llvm::all_of(Matches, IsBestOrInferiorToBest))
11180 Matches[0] = *Best;
11185 bool isTargetTypeAFunction() const {
11186 return TargetFunctionType->isFunctionType();
11189 // [ToType] [Return]
11191 // R (*)(A) --> R (A), IsNonStaticMemberFunction = false
11192 // R (&)(A) --> R (A), IsNonStaticMemberFunction = false
11193 // R (S::*)(A) --> R (A), IsNonStaticMemberFunction = true
11194 void inline ExtractUnqualifiedFunctionTypeFromTargetType() {
11195 TargetFunctionType = S.ExtractUnqualifiedFunctionType(TargetType);
11198 // return true if any matching specializations were found
11199 bool AddMatchingTemplateFunction(FunctionTemplateDecl* FunctionTemplate,
11200 const DeclAccessPair& CurAccessFunPair) {
11201 if (CXXMethodDecl *Method
11202 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) {
11203 // Skip non-static function templates when converting to pointer, and
11204 // static when converting to member pointer.
11205 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction)
11208 else if (TargetTypeIsNonStaticMemberFunction)
11211 // C++ [over.over]p2:
11212 // If the name is a function template, template argument deduction is
11213 // done (14.8.2.2), and if the argument deduction succeeds, the
11214 // resulting template argument list is used to generate a single
11215 // function template specialization, which is added to the set of
11216 // overloaded functions considered.
11217 FunctionDecl *Specialization = nullptr;
11218 TemplateDeductionInfo Info(FailedCandidates.getLocation());
11219 if (Sema::TemplateDeductionResult Result
11220 = S.DeduceTemplateArguments(FunctionTemplate,
11221 &OvlExplicitTemplateArgs,
11222 TargetFunctionType, Specialization,
11223 Info, /*IsAddressOfFunction*/true)) {
11224 // Make a note of the failed deduction for diagnostics.
11225 FailedCandidates.addCandidate()
11226 .set(CurAccessFunPair, FunctionTemplate->getTemplatedDecl(),
11227 MakeDeductionFailureInfo(Context, Result, Info));
11231 // Template argument deduction ensures that we have an exact match or
11232 // compatible pointer-to-function arguments that would be adjusted by ICS.
11233 // This function template specicalization works.
11234 assert(S.isSameOrCompatibleFunctionType(
11235 Context.getCanonicalType(Specialization->getType()),
11236 Context.getCanonicalType(TargetFunctionType)));
11238 if (!S.checkAddressOfFunctionIsAvailable(Specialization))
11241 Matches.push_back(std::make_pair(CurAccessFunPair, Specialization));
11245 bool AddMatchingNonTemplateFunction(NamedDecl* Fn,
11246 const DeclAccessPair& CurAccessFunPair) {
11247 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) {
11248 // Skip non-static functions when converting to pointer, and static
11249 // when converting to member pointer.
11250 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction)
11253 else if (TargetTypeIsNonStaticMemberFunction)
11256 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) {
11257 if (S.getLangOpts().CUDA)
11258 if (FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext))
11259 if (!Caller->isImplicit() && !S.IsAllowedCUDACall(Caller, FunDecl))
11261 if (FunDecl->isMultiVersion()) {
11262 const auto *TA = FunDecl->getAttr<TargetAttr>();
11263 if (TA && !TA->isDefaultVersion())
11267 // If any candidate has a placeholder return type, trigger its deduction
11269 if (completeFunctionType(S, FunDecl, SourceExpr->getBeginLoc(),
11271 HasComplained |= Complain;
11275 if (!S.checkAddressOfFunctionIsAvailable(FunDecl))
11278 // If we're in C, we need to support types that aren't exactly identical.
11279 if (!S.getLangOpts().CPlusPlus ||
11280 candidateHasExactlyCorrectType(FunDecl)) {
11281 Matches.push_back(std::make_pair(
11282 CurAccessFunPair, cast<FunctionDecl>(FunDecl->getCanonicalDecl())));
11283 FoundNonTemplateFunction = true;
11291 bool FindAllFunctionsThatMatchTargetTypeExactly() {
11294 // If the overload expression doesn't have the form of a pointer to
11295 // member, don't try to convert it to a pointer-to-member type.
11296 if (IsInvalidFormOfPointerToMemberFunction())
11299 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
11300 E = OvlExpr->decls_end();
11302 // Look through any using declarations to find the underlying function.
11303 NamedDecl *Fn = (*I)->getUnderlyingDecl();
11305 // C++ [over.over]p3:
11306 // Non-member functions and static member functions match
11307 // targets of type "pointer-to-function" or "reference-to-function."
11308 // Nonstatic member functions match targets of
11309 // type "pointer-to-member-function."
11310 // Note that according to DR 247, the containing class does not matter.
11311 if (FunctionTemplateDecl *FunctionTemplate
11312 = dyn_cast<FunctionTemplateDecl>(Fn)) {
11313 if (AddMatchingTemplateFunction(FunctionTemplate, I.getPair()))
11316 // If we have explicit template arguments supplied, skip non-templates.
11317 else if (!OvlExpr->hasExplicitTemplateArgs() &&
11318 AddMatchingNonTemplateFunction(Fn, I.getPair()))
11321 assert(Ret || Matches.empty());
11325 void EliminateAllExceptMostSpecializedTemplate() {
11326 // [...] and any given function template specialization F1 is
11327 // eliminated if the set contains a second function template
11328 // specialization whose function template is more specialized
11329 // than the function template of F1 according to the partial
11330 // ordering rules of 14.5.5.2.
11332 // The algorithm specified above is quadratic. We instead use a
11333 // two-pass algorithm (similar to the one used to identify the
11334 // best viable function in an overload set) that identifies the
11335 // best function template (if it exists).
11337 UnresolvedSet<4> MatchesCopy; // TODO: avoid!
11338 for (unsigned I = 0, E = Matches.size(); I != E; ++I)
11339 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess());
11341 // TODO: It looks like FailedCandidates does not serve much purpose
11342 // here, since the no_viable diagnostic has index 0.
11343 UnresolvedSetIterator Result = S.getMostSpecialized(
11344 MatchesCopy.begin(), MatchesCopy.end(), FailedCandidates,
11345 SourceExpr->getBeginLoc(), S.PDiag(),
11346 S.PDiag(diag::err_addr_ovl_ambiguous)
11347 << Matches[0].second->getDeclName(),
11348 S.PDiag(diag::note_ovl_candidate)
11349 << (unsigned)oc_function << (unsigned)ocs_described_template,
11350 Complain, TargetFunctionType);
11352 if (Result != MatchesCopy.end()) {
11353 // Make it the first and only element
11354 Matches[0].first = Matches[Result - MatchesCopy.begin()].first;
11355 Matches[0].second = cast<FunctionDecl>(*Result);
11358 HasComplained |= Complain;
11361 void EliminateAllTemplateMatches() {
11362 // [...] any function template specializations in the set are
11363 // eliminated if the set also contains a non-template function, [...]
11364 for (unsigned I = 0, N = Matches.size(); I != N; ) {
11365 if (Matches[I].second->getPrimaryTemplate() == nullptr)
11368 Matches[I] = Matches[--N];
11374 void EliminateSuboptimalCudaMatches() {
11375 S.EraseUnwantedCUDAMatches(dyn_cast<FunctionDecl>(S.CurContext), Matches);
11379 void ComplainNoMatchesFound() const {
11380 assert(Matches.empty());
11381 S.Diag(OvlExpr->getBeginLoc(), diag::err_addr_ovl_no_viable)
11382 << OvlExpr->getName() << TargetFunctionType
11383 << OvlExpr->getSourceRange();
11384 if (FailedCandidates.empty())
11385 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType,
11386 /*TakingAddress=*/true);
11388 // We have some deduction failure messages. Use them to diagnose
11389 // the function templates, and diagnose the non-template candidates
11391 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
11392 IEnd = OvlExpr->decls_end();
11394 if (FunctionDecl *Fun =
11395 dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()))
11396 if (!functionHasPassObjectSizeParams(Fun))
11397 S.NoteOverloadCandidate(*I, Fun, TargetFunctionType,
11398 /*TakingAddress=*/true);
11399 FailedCandidates.NoteCandidates(S, OvlExpr->getBeginLoc());
11403 bool IsInvalidFormOfPointerToMemberFunction() const {
11404 return TargetTypeIsNonStaticMemberFunction &&
11405 !OvlExprInfo.HasFormOfMemberPointer;
11408 void ComplainIsInvalidFormOfPointerToMemberFunction() const {
11409 // TODO: Should we condition this on whether any functions might
11410 // have matched, or is it more appropriate to do that in callers?
11411 // TODO: a fixit wouldn't hurt.
11412 S.Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier)
11413 << TargetType << OvlExpr->getSourceRange();
11416 bool IsStaticMemberFunctionFromBoundPointer() const {
11417 return StaticMemberFunctionFromBoundPointer;
11420 void ComplainIsStaticMemberFunctionFromBoundPointer() const {
11421 S.Diag(OvlExpr->getBeginLoc(),
11422 diag::err_invalid_form_pointer_member_function)
11423 << OvlExpr->getSourceRange();
11426 void ComplainOfInvalidConversion() const {
11427 S.Diag(OvlExpr->getBeginLoc(), diag::err_addr_ovl_not_func_ptrref)
11428 << OvlExpr->getName() << TargetType;
11431 void ComplainMultipleMatchesFound() const {
11432 assert(Matches.size() > 1);
11433 S.Diag(OvlExpr->getBeginLoc(), diag::err_addr_ovl_ambiguous)
11434 << OvlExpr->getName() << OvlExpr->getSourceRange();
11435 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType,
11436 /*TakingAddress=*/true);
11439 bool hadMultipleCandidates() const { return (OvlExpr->getNumDecls() > 1); }
11441 int getNumMatches() const { return Matches.size(); }
11443 FunctionDecl* getMatchingFunctionDecl() const {
11444 if (Matches.size() != 1) return nullptr;
11445 return Matches[0].second;
11448 const DeclAccessPair* getMatchingFunctionAccessPair() const {
11449 if (Matches.size() != 1) return nullptr;
11450 return &Matches[0].first;
11455 /// ResolveAddressOfOverloadedFunction - Try to resolve the address of
11456 /// an overloaded function (C++ [over.over]), where @p From is an
11457 /// expression with overloaded function type and @p ToType is the type
11458 /// we're trying to resolve to. For example:
11464 /// int (*pfd)(double) = f; // selects f(double)
11467 /// This routine returns the resulting FunctionDecl if it could be
11468 /// resolved, and NULL otherwise. When @p Complain is true, this
11469 /// routine will emit diagnostics if there is an error.
11471 Sema::ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr,
11472 QualType TargetType,
11474 DeclAccessPair &FoundResult,
11475 bool *pHadMultipleCandidates) {
11476 assert(AddressOfExpr->getType() == Context.OverloadTy);
11478 AddressOfFunctionResolver Resolver(*this, AddressOfExpr, TargetType,
11480 int NumMatches = Resolver.getNumMatches();
11481 FunctionDecl *Fn = nullptr;
11482 bool ShouldComplain = Complain && !Resolver.hasComplained();
11483 if (NumMatches == 0 && ShouldComplain) {
11484 if (Resolver.IsInvalidFormOfPointerToMemberFunction())
11485 Resolver.ComplainIsInvalidFormOfPointerToMemberFunction();
11487 Resolver.ComplainNoMatchesFound();
11489 else if (NumMatches > 1 && ShouldComplain)
11490 Resolver.ComplainMultipleMatchesFound();
11491 else if (NumMatches == 1) {
11492 Fn = Resolver.getMatchingFunctionDecl();
11494 if (auto *FPT = Fn->getType()->getAs<FunctionProtoType>())
11495 ResolveExceptionSpec(AddressOfExpr->getExprLoc(), FPT);
11496 FoundResult = *Resolver.getMatchingFunctionAccessPair();
11498 if (Resolver.IsStaticMemberFunctionFromBoundPointer())
11499 Resolver.ComplainIsStaticMemberFunctionFromBoundPointer();
11501 CheckAddressOfMemberAccess(AddressOfExpr, FoundResult);
11505 if (pHadMultipleCandidates)
11506 *pHadMultipleCandidates = Resolver.hadMultipleCandidates();
11510 /// Given an expression that refers to an overloaded function, try to
11511 /// resolve that function to a single function that can have its address taken.
11512 /// This will modify `Pair` iff it returns non-null.
11514 /// This routine can only realistically succeed if all but one candidates in the
11515 /// overload set for SrcExpr cannot have their addresses taken.
11517 Sema::resolveAddressOfOnlyViableOverloadCandidate(Expr *E,
11518 DeclAccessPair &Pair) {
11519 OverloadExpr::FindResult R = OverloadExpr::find(E);
11520 OverloadExpr *Ovl = R.Expression;
11521 FunctionDecl *Result = nullptr;
11522 DeclAccessPair DAP;
11523 // Don't use the AddressOfResolver because we're specifically looking for
11524 // cases where we have one overload candidate that lacks
11525 // enable_if/pass_object_size/...
11526 for (auto I = Ovl->decls_begin(), E = Ovl->decls_end(); I != E; ++I) {
11527 auto *FD = dyn_cast<FunctionDecl>(I->getUnderlyingDecl());
11531 if (!checkAddressOfFunctionIsAvailable(FD))
11534 // We have more than one result; quit.
11546 /// Given an overloaded function, tries to turn it into a non-overloaded
11547 /// function reference using resolveAddressOfOnlyViableOverloadCandidate. This
11548 /// will perform access checks, diagnose the use of the resultant decl, and, if
11549 /// requested, potentially perform a function-to-pointer decay.
11551 /// Returns false if resolveAddressOfOnlyViableOverloadCandidate fails.
11552 /// Otherwise, returns true. This may emit diagnostics and return true.
11553 bool Sema::resolveAndFixAddressOfOnlyViableOverloadCandidate(
11554 ExprResult &SrcExpr, bool DoFunctionPointerConverion) {
11555 Expr *E = SrcExpr.get();
11556 assert(E->getType() == Context.OverloadTy && "SrcExpr must be an overload");
11558 DeclAccessPair DAP;
11559 FunctionDecl *Found = resolveAddressOfOnlyViableOverloadCandidate(E, DAP);
11560 if (!Found || Found->isCPUDispatchMultiVersion() ||
11561 Found->isCPUSpecificMultiVersion())
11564 // Emitting multiple diagnostics for a function that is both inaccessible and
11565 // unavailable is consistent with our behavior elsewhere. So, always check
11567 DiagnoseUseOfDecl(Found, E->getExprLoc());
11568 CheckAddressOfMemberAccess(E, DAP);
11569 Expr *Fixed = FixOverloadedFunctionReference(E, DAP, Found);
11570 if (DoFunctionPointerConverion && Fixed->getType()->isFunctionType())
11571 SrcExpr = DefaultFunctionArrayConversion(Fixed, /*Diagnose=*/false);
11577 /// Given an expression that refers to an overloaded function, try to
11578 /// resolve that overloaded function expression down to a single function.
11580 /// This routine can only resolve template-ids that refer to a single function
11581 /// template, where that template-id refers to a single template whose template
11582 /// arguments are either provided by the template-id or have defaults,
11583 /// as described in C++0x [temp.arg.explicit]p3.
11585 /// If no template-ids are found, no diagnostics are emitted and NULL is
11588 Sema::ResolveSingleFunctionTemplateSpecialization(OverloadExpr *ovl,
11590 DeclAccessPair *FoundResult) {
11591 // C++ [over.over]p1:
11592 // [...] [Note: any redundant set of parentheses surrounding the
11593 // overloaded function name is ignored (5.1). ]
11594 // C++ [over.over]p1:
11595 // [...] The overloaded function name can be preceded by the &
11598 // If we didn't actually find any template-ids, we're done.
11599 if (!ovl->hasExplicitTemplateArgs())
11602 TemplateArgumentListInfo ExplicitTemplateArgs;
11603 ovl->copyTemplateArgumentsInto(ExplicitTemplateArgs);
11604 TemplateSpecCandidateSet FailedCandidates(ovl->getNameLoc());
11606 // Look through all of the overloaded functions, searching for one
11607 // whose type matches exactly.
11608 FunctionDecl *Matched = nullptr;
11609 for (UnresolvedSetIterator I = ovl->decls_begin(),
11610 E = ovl->decls_end(); I != E; ++I) {
11611 // C++0x [temp.arg.explicit]p3:
11612 // [...] In contexts where deduction is done and fails, or in contexts
11613 // where deduction is not done, if a template argument list is
11614 // specified and it, along with any default template arguments,
11615 // identifies a single function template specialization, then the
11616 // template-id is an lvalue for the function template specialization.
11617 FunctionTemplateDecl *FunctionTemplate
11618 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl());
11620 // C++ [over.over]p2:
11621 // If the name is a function template, template argument deduction is
11622 // done (14.8.2.2), and if the argument deduction succeeds, the
11623 // resulting template argument list is used to generate a single
11624 // function template specialization, which is added to the set of
11625 // overloaded functions considered.
11626 FunctionDecl *Specialization = nullptr;
11627 TemplateDeductionInfo Info(FailedCandidates.getLocation());
11628 if (TemplateDeductionResult Result
11629 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs,
11630 Specialization, Info,
11631 /*IsAddressOfFunction*/true)) {
11632 // Make a note of the failed deduction for diagnostics.
11633 // TODO: Actually use the failed-deduction info?
11634 FailedCandidates.addCandidate()
11635 .set(I.getPair(), FunctionTemplate->getTemplatedDecl(),
11636 MakeDeductionFailureInfo(Context, Result, Info));
11640 assert(Specialization && "no specialization and no error?");
11642 // Multiple matches; we can't resolve to a single declaration.
11645 Diag(ovl->getExprLoc(), diag::err_addr_ovl_ambiguous)
11647 NoteAllOverloadCandidates(ovl);
11652 Matched = Specialization;
11653 if (FoundResult) *FoundResult = I.getPair();
11657 completeFunctionType(*this, Matched, ovl->getExprLoc(), Complain))
11663 // Resolve and fix an overloaded expression that can be resolved
11664 // because it identifies a single function template specialization.
11666 // Last three arguments should only be supplied if Complain = true
11668 // Return true if it was logically possible to so resolve the
11669 // expression, regardless of whether or not it succeeded. Always
11670 // returns true if 'complain' is set.
11671 bool Sema::ResolveAndFixSingleFunctionTemplateSpecialization(
11672 ExprResult &SrcExpr, bool doFunctionPointerConverion,
11673 bool complain, SourceRange OpRangeForComplaining,
11674 QualType DestTypeForComplaining,
11675 unsigned DiagIDForComplaining) {
11676 assert(SrcExpr.get()->getType() == Context.OverloadTy);
11678 OverloadExpr::FindResult ovl = OverloadExpr::find(SrcExpr.get());
11680 DeclAccessPair found;
11681 ExprResult SingleFunctionExpression;
11682 if (FunctionDecl *fn = ResolveSingleFunctionTemplateSpecialization(
11683 ovl.Expression, /*complain*/ false, &found)) {
11684 if (DiagnoseUseOfDecl(fn, SrcExpr.get()->getBeginLoc())) {
11685 SrcExpr = ExprError();
11689 // It is only correct to resolve to an instance method if we're
11690 // resolving a form that's permitted to be a pointer to member.
11691 // Otherwise we'll end up making a bound member expression, which
11692 // is illegal in all the contexts we resolve like this.
11693 if (!ovl.HasFormOfMemberPointer &&
11694 isa<CXXMethodDecl>(fn) &&
11695 cast<CXXMethodDecl>(fn)->isInstance()) {
11696 if (!complain) return false;
11698 Diag(ovl.Expression->getExprLoc(),
11699 diag::err_bound_member_function)
11700 << 0 << ovl.Expression->getSourceRange();
11702 // TODO: I believe we only end up here if there's a mix of
11703 // static and non-static candidates (otherwise the expression
11704 // would have 'bound member' type, not 'overload' type).
11705 // Ideally we would note which candidate was chosen and why
11706 // the static candidates were rejected.
11707 SrcExpr = ExprError();
11711 // Fix the expression to refer to 'fn'.
11712 SingleFunctionExpression =
11713 FixOverloadedFunctionReference(SrcExpr.get(), found, fn);
11715 // If desired, do function-to-pointer decay.
11716 if (doFunctionPointerConverion) {
11717 SingleFunctionExpression =
11718 DefaultFunctionArrayLvalueConversion(SingleFunctionExpression.get());
11719 if (SingleFunctionExpression.isInvalid()) {
11720 SrcExpr = ExprError();
11726 if (!SingleFunctionExpression.isUsable()) {
11728 Diag(OpRangeForComplaining.getBegin(), DiagIDForComplaining)
11729 << ovl.Expression->getName()
11730 << DestTypeForComplaining
11731 << OpRangeForComplaining
11732 << ovl.Expression->getQualifierLoc().getSourceRange();
11733 NoteAllOverloadCandidates(SrcExpr.get());
11735 SrcExpr = ExprError();
11742 SrcExpr = SingleFunctionExpression;
11746 /// Add a single candidate to the overload set.
11747 static void AddOverloadedCallCandidate(Sema &S,
11748 DeclAccessPair FoundDecl,
11749 TemplateArgumentListInfo *ExplicitTemplateArgs,
11750 ArrayRef<Expr *> Args,
11751 OverloadCandidateSet &CandidateSet,
11752 bool PartialOverloading,
11754 NamedDecl *Callee = FoundDecl.getDecl();
11755 if (isa<UsingShadowDecl>(Callee))
11756 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl();
11758 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) {
11759 if (ExplicitTemplateArgs) {
11760 assert(!KnownValid && "Explicit template arguments?");
11763 // Prevent ill-formed function decls to be added as overload candidates.
11764 if (!dyn_cast<FunctionProtoType>(Func->getType()->getAs<FunctionType>()))
11767 S.AddOverloadCandidate(Func, FoundDecl, Args, CandidateSet,
11768 /*SuppressUserConversions=*/false,
11769 PartialOverloading);
11773 if (FunctionTemplateDecl *FuncTemplate
11774 = dyn_cast<FunctionTemplateDecl>(Callee)) {
11775 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl,
11776 ExplicitTemplateArgs, Args, CandidateSet,
11777 /*SuppressUserConversions=*/false,
11778 PartialOverloading);
11782 assert(!KnownValid && "unhandled case in overloaded call candidate");
11785 /// Add the overload candidates named by callee and/or found by argument
11786 /// dependent lookup to the given overload set.
11787 void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE,
11788 ArrayRef<Expr *> Args,
11789 OverloadCandidateSet &CandidateSet,
11790 bool PartialOverloading) {
11793 // Verify that ArgumentDependentLookup is consistent with the rules
11794 // in C++0x [basic.lookup.argdep]p3:
11796 // Let X be the lookup set produced by unqualified lookup (3.4.1)
11797 // and let Y be the lookup set produced by argument dependent
11798 // lookup (defined as follows). If X contains
11800 // -- a declaration of a class member, or
11802 // -- a block-scope function declaration that is not a
11803 // using-declaration, or
11805 // -- a declaration that is neither a function or a function
11808 // then Y is empty.
11810 if (ULE->requiresADL()) {
11811 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(),
11812 E = ULE->decls_end(); I != E; ++I) {
11813 assert(!(*I)->getDeclContext()->isRecord());
11814 assert(isa<UsingShadowDecl>(*I) ||
11815 !(*I)->getDeclContext()->isFunctionOrMethod());
11816 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate());
11821 // It would be nice to avoid this copy.
11822 TemplateArgumentListInfo TABuffer;
11823 TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr;
11824 if (ULE->hasExplicitTemplateArgs()) {
11825 ULE->copyTemplateArgumentsInto(TABuffer);
11826 ExplicitTemplateArgs = &TABuffer;
11829 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(),
11830 E = ULE->decls_end(); I != E; ++I)
11831 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, Args,
11832 CandidateSet, PartialOverloading,
11833 /*KnownValid*/ true);
11835 if (ULE->requiresADL())
11836 AddArgumentDependentLookupCandidates(ULE->getName(), ULE->getExprLoc(),
11837 Args, ExplicitTemplateArgs,
11838 CandidateSet, PartialOverloading);
11841 /// Determine whether a declaration with the specified name could be moved into
11842 /// a different namespace.
11843 static bool canBeDeclaredInNamespace(const DeclarationName &Name) {
11844 switch (Name.getCXXOverloadedOperator()) {
11845 case OO_New: case OO_Array_New:
11846 case OO_Delete: case OO_Array_Delete:
11854 /// Attempt to recover from an ill-formed use of a non-dependent name in a
11855 /// template, where the non-dependent name was declared after the template
11856 /// was defined. This is common in code written for a compilers which do not
11857 /// correctly implement two-stage name lookup.
11859 /// Returns true if a viable candidate was found and a diagnostic was issued.
11861 DiagnoseTwoPhaseLookup(Sema &SemaRef, SourceLocation FnLoc,
11862 const CXXScopeSpec &SS, LookupResult &R,
11863 OverloadCandidateSet::CandidateSetKind CSK,
11864 TemplateArgumentListInfo *ExplicitTemplateArgs,
11865 ArrayRef<Expr *> Args,
11866 bool *DoDiagnoseEmptyLookup = nullptr) {
11867 if (!SemaRef.inTemplateInstantiation() || !SS.isEmpty())
11870 for (DeclContext *DC = SemaRef.CurContext; DC; DC = DC->getParent()) {
11871 if (DC->isTransparentContext())
11874 SemaRef.LookupQualifiedName(R, DC);
11877 R.suppressDiagnostics();
11879 if (isa<CXXRecordDecl>(DC)) {
11880 // Don't diagnose names we find in classes; we get much better
11881 // diagnostics for these from DiagnoseEmptyLookup.
11883 if (DoDiagnoseEmptyLookup)
11884 *DoDiagnoseEmptyLookup = true;
11888 OverloadCandidateSet Candidates(FnLoc, CSK);
11889 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
11890 AddOverloadedCallCandidate(SemaRef, I.getPair(),
11891 ExplicitTemplateArgs, Args,
11892 Candidates, false, /*KnownValid*/ false);
11894 OverloadCandidateSet::iterator Best;
11895 if (Candidates.BestViableFunction(SemaRef, FnLoc, Best) != OR_Success) {
11896 // No viable functions. Don't bother the user with notes for functions
11897 // which don't work and shouldn't be found anyway.
11902 // Find the namespaces where ADL would have looked, and suggest
11903 // declaring the function there instead.
11904 Sema::AssociatedNamespaceSet AssociatedNamespaces;
11905 Sema::AssociatedClassSet AssociatedClasses;
11906 SemaRef.FindAssociatedClassesAndNamespaces(FnLoc, Args,
11907 AssociatedNamespaces,
11908 AssociatedClasses);
11909 Sema::AssociatedNamespaceSet SuggestedNamespaces;
11910 if (canBeDeclaredInNamespace(R.getLookupName())) {
11911 DeclContext *Std = SemaRef.getStdNamespace();
11912 for (Sema::AssociatedNamespaceSet::iterator
11913 it = AssociatedNamespaces.begin(),
11914 end = AssociatedNamespaces.end(); it != end; ++it) {
11915 // Never suggest declaring a function within namespace 'std'.
11916 if (Std && Std->Encloses(*it))
11919 // Never suggest declaring a function within a namespace with a
11920 // reserved name, like __gnu_cxx.
11921 NamespaceDecl *NS = dyn_cast<NamespaceDecl>(*it);
11923 NS->getQualifiedNameAsString().find("__") != std::string::npos)
11926 SuggestedNamespaces.insert(*it);
11930 SemaRef.Diag(R.getNameLoc(), diag::err_not_found_by_two_phase_lookup)
11931 << R.getLookupName();
11932 if (SuggestedNamespaces.empty()) {
11933 SemaRef.Diag(Best->Function->getLocation(),
11934 diag::note_not_found_by_two_phase_lookup)
11935 << R.getLookupName() << 0;
11936 } else if (SuggestedNamespaces.size() == 1) {
11937 SemaRef.Diag(Best->Function->getLocation(),
11938 diag::note_not_found_by_two_phase_lookup)
11939 << R.getLookupName() << 1 << *SuggestedNamespaces.begin();
11941 // FIXME: It would be useful to list the associated namespaces here,
11942 // but the diagnostics infrastructure doesn't provide a way to produce
11943 // a localized representation of a list of items.
11944 SemaRef.Diag(Best->Function->getLocation(),
11945 diag::note_not_found_by_two_phase_lookup)
11946 << R.getLookupName() << 2;
11949 // Try to recover by calling this function.
11959 /// Attempt to recover from ill-formed use of a non-dependent operator in a
11960 /// template, where the non-dependent operator was declared after the template
11963 /// Returns true if a viable candidate was found and a diagnostic was issued.
11965 DiagnoseTwoPhaseOperatorLookup(Sema &SemaRef, OverloadedOperatorKind Op,
11966 SourceLocation OpLoc,
11967 ArrayRef<Expr *> Args) {
11968 DeclarationName OpName =
11969 SemaRef.Context.DeclarationNames.getCXXOperatorName(Op);
11970 LookupResult R(SemaRef, OpName, OpLoc, Sema::LookupOperatorName);
11971 return DiagnoseTwoPhaseLookup(SemaRef, OpLoc, CXXScopeSpec(), R,
11972 OverloadCandidateSet::CSK_Operator,
11973 /*ExplicitTemplateArgs=*/nullptr, Args);
11977 class BuildRecoveryCallExprRAII {
11980 BuildRecoveryCallExprRAII(Sema &S) : SemaRef(S) {
11981 assert(SemaRef.IsBuildingRecoveryCallExpr == false);
11982 SemaRef.IsBuildingRecoveryCallExpr = true;
11985 ~BuildRecoveryCallExprRAII() {
11986 SemaRef.IsBuildingRecoveryCallExpr = false;
11992 /// Attempts to recover from a call where no functions were found.
11994 /// Returns true if new candidates were found.
11996 BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn,
11997 UnresolvedLookupExpr *ULE,
11998 SourceLocation LParenLoc,
11999 MutableArrayRef<Expr *> Args,
12000 SourceLocation RParenLoc,
12001 bool EmptyLookup, bool AllowTypoCorrection) {
12002 // Do not try to recover if it is already building a recovery call.
12003 // This stops infinite loops for template instantiations like
12005 // template <typename T> auto foo(T t) -> decltype(foo(t)) {}
12006 // template <typename T> auto foo(T t) -> decltype(foo(&t)) {}
12008 if (SemaRef.IsBuildingRecoveryCallExpr)
12009 return ExprError();
12010 BuildRecoveryCallExprRAII RCE(SemaRef);
12013 SS.Adopt(ULE->getQualifierLoc());
12014 SourceLocation TemplateKWLoc = ULE->getTemplateKeywordLoc();
12016 TemplateArgumentListInfo TABuffer;
12017 TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr;
12018 if (ULE->hasExplicitTemplateArgs()) {
12019 ULE->copyTemplateArgumentsInto(TABuffer);
12020 ExplicitTemplateArgs = &TABuffer;
12023 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(),
12024 Sema::LookupOrdinaryName);
12025 bool DoDiagnoseEmptyLookup = EmptyLookup;
12026 if (!DiagnoseTwoPhaseLookup(
12027 SemaRef, Fn->getExprLoc(), SS, R, OverloadCandidateSet::CSK_Normal,
12028 ExplicitTemplateArgs, Args, &DoDiagnoseEmptyLookup)) {
12029 NoTypoCorrectionCCC NoTypoValidator{};
12030 FunctionCallFilterCCC FunctionCallValidator(SemaRef, Args.size(),
12031 ExplicitTemplateArgs != nullptr,
12032 dyn_cast<MemberExpr>(Fn));
12033 CorrectionCandidateCallback &Validator =
12034 AllowTypoCorrection
12035 ? static_cast<CorrectionCandidateCallback &>(FunctionCallValidator)
12036 : static_cast<CorrectionCandidateCallback &>(NoTypoValidator);
12037 if (!DoDiagnoseEmptyLookup ||
12038 SemaRef.DiagnoseEmptyLookup(S, SS, R, Validator, ExplicitTemplateArgs,
12040 return ExprError();
12043 assert(!R.empty() && "lookup results empty despite recovery");
12045 // If recovery created an ambiguity, just bail out.
12046 if (R.isAmbiguous()) {
12047 R.suppressDiagnostics();
12048 return ExprError();
12051 // Build an implicit member call if appropriate. Just drop the
12052 // casts and such from the call, we don't really care.
12053 ExprResult NewFn = ExprError();
12054 if ((*R.begin())->isCXXClassMember())
12055 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, TemplateKWLoc, R,
12056 ExplicitTemplateArgs, S);
12057 else if (ExplicitTemplateArgs || TemplateKWLoc.isValid())
12058 NewFn = SemaRef.BuildTemplateIdExpr(SS, TemplateKWLoc, R, false,
12059 ExplicitTemplateArgs);
12061 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false);
12063 if (NewFn.isInvalid())
12064 return ExprError();
12066 // This shouldn't cause an infinite loop because we're giving it
12067 // an expression with viable lookup results, which should never
12069 return SemaRef.BuildCallExpr(/*Scope*/ nullptr, NewFn.get(), LParenLoc,
12070 MultiExprArg(Args.data(), Args.size()),
12074 /// Constructs and populates an OverloadedCandidateSet from
12075 /// the given function.
12076 /// \returns true when an the ExprResult output parameter has been set.
12077 bool Sema::buildOverloadedCallSet(Scope *S, Expr *Fn,
12078 UnresolvedLookupExpr *ULE,
12080 SourceLocation RParenLoc,
12081 OverloadCandidateSet *CandidateSet,
12082 ExprResult *Result) {
12084 if (ULE->requiresADL()) {
12085 // To do ADL, we must have found an unqualified name.
12086 assert(!ULE->getQualifier() && "qualified name with ADL");
12088 // We don't perform ADL for implicit declarations of builtins.
12089 // Verify that this was correctly set up.
12091 if (ULE->decls_begin() != ULE->decls_end() &&
12092 ULE->decls_begin() + 1 == ULE->decls_end() &&
12093 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) &&
12094 F->getBuiltinID() && F->isImplicit())
12095 llvm_unreachable("performing ADL for builtin");
12097 // We don't perform ADL in C.
12098 assert(getLangOpts().CPlusPlus && "ADL enabled in C");
12102 UnbridgedCastsSet UnbridgedCasts;
12103 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts)) {
12104 *Result = ExprError();
12108 // Add the functions denoted by the callee to the set of candidate
12109 // functions, including those from argument-dependent lookup.
12110 AddOverloadedCallCandidates(ULE, Args, *CandidateSet);
12112 if (getLangOpts().MSVCCompat &&
12113 CurContext->isDependentContext() && !isSFINAEContext() &&
12114 (isa<FunctionDecl>(CurContext) || isa<CXXRecordDecl>(CurContext))) {
12116 OverloadCandidateSet::iterator Best;
12117 if (CandidateSet->empty() ||
12118 CandidateSet->BestViableFunction(*this, Fn->getBeginLoc(), Best) ==
12119 OR_No_Viable_Function) {
12120 // In Microsoft mode, if we are inside a template class member function
12121 // then create a type dependent CallExpr. The goal is to postpone name
12122 // lookup to instantiation time to be able to search into type dependent
12124 CallExpr *CE = CallExpr::Create(Context, Fn, Args, Context.DependentTy,
12125 VK_RValue, RParenLoc);
12126 CE->setTypeDependent(true);
12127 CE->setValueDependent(true);
12128 CE->setInstantiationDependent(true);
12134 if (CandidateSet->empty())
12137 UnbridgedCasts.restore();
12141 /// FinishOverloadedCallExpr - given an OverloadCandidateSet, builds and returns
12142 /// the completed call expression. If overload resolution fails, emits
12143 /// diagnostics and returns ExprError()
12144 static ExprResult FinishOverloadedCallExpr(Sema &SemaRef, Scope *S, Expr *Fn,
12145 UnresolvedLookupExpr *ULE,
12146 SourceLocation LParenLoc,
12148 SourceLocation RParenLoc,
12150 OverloadCandidateSet *CandidateSet,
12151 OverloadCandidateSet::iterator *Best,
12152 OverloadingResult OverloadResult,
12153 bool AllowTypoCorrection) {
12154 if (CandidateSet->empty())
12155 return BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc, Args,
12156 RParenLoc, /*EmptyLookup=*/true,
12157 AllowTypoCorrection);
12159 switch (OverloadResult) {
12161 FunctionDecl *FDecl = (*Best)->Function;
12162 SemaRef.CheckUnresolvedLookupAccess(ULE, (*Best)->FoundDecl);
12163 if (SemaRef.DiagnoseUseOfDecl(FDecl, ULE->getNameLoc()))
12164 return ExprError();
12165 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl);
12166 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, RParenLoc,
12167 ExecConfig, /*IsExecConfig=*/false,
12168 (*Best)->IsADLCandidate);
12171 case OR_No_Viable_Function: {
12172 // Try to recover by looking for viable functions which the user might
12173 // have meant to call.
12174 ExprResult Recovery = BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc,
12176 /*EmptyLookup=*/false,
12177 AllowTypoCorrection);
12178 if (!Recovery.isInvalid())
12181 // If the user passes in a function that we can't take the address of, we
12182 // generally end up emitting really bad error messages. Here, we attempt to
12183 // emit better ones.
12184 for (const Expr *Arg : Args) {
12185 if (!Arg->getType()->isFunctionType())
12187 if (auto *DRE = dyn_cast<DeclRefExpr>(Arg->IgnoreParenImpCasts())) {
12188 auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl());
12190 !SemaRef.checkAddressOfFunctionIsAvailable(FD, /*Complain=*/true,
12191 Arg->getExprLoc()))
12192 return ExprError();
12196 CandidateSet->NoteCandidates(
12197 PartialDiagnosticAt(
12199 SemaRef.PDiag(diag::err_ovl_no_viable_function_in_call)
12200 << ULE->getName() << Fn->getSourceRange()),
12201 SemaRef, OCD_AllCandidates, Args);
12206 CandidateSet->NoteCandidates(
12207 PartialDiagnosticAt(Fn->getBeginLoc(),
12208 SemaRef.PDiag(diag::err_ovl_ambiguous_call)
12209 << ULE->getName() << Fn->getSourceRange()),
12210 SemaRef, OCD_ViableCandidates, Args);
12214 CandidateSet->NoteCandidates(
12215 PartialDiagnosticAt(Fn->getBeginLoc(),
12216 SemaRef.PDiag(diag::err_ovl_deleted_call)
12217 << ULE->getName() << Fn->getSourceRange()),
12218 SemaRef, OCD_AllCandidates, Args);
12220 // We emitted an error for the unavailable/deleted function call but keep
12221 // the call in the AST.
12222 FunctionDecl *FDecl = (*Best)->Function;
12223 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl);
12224 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, RParenLoc,
12225 ExecConfig, /*IsExecConfig=*/false,
12226 (*Best)->IsADLCandidate);
12230 // Overload resolution failed.
12231 return ExprError();
12234 static void markUnaddressableCandidatesUnviable(Sema &S,
12235 OverloadCandidateSet &CS) {
12236 for (auto I = CS.begin(), E = CS.end(); I != E; ++I) {
12238 !S.checkAddressOfFunctionIsAvailable(I->Function, /*Complain=*/false)) {
12240 I->FailureKind = ovl_fail_addr_not_available;
12245 /// BuildOverloadedCallExpr - Given the call expression that calls Fn
12246 /// (which eventually refers to the declaration Func) and the call
12247 /// arguments Args/NumArgs, attempt to resolve the function call down
12248 /// to a specific function. If overload resolution succeeds, returns
12249 /// the call expression produced by overload resolution.
12250 /// Otherwise, emits diagnostics and returns ExprError.
12251 ExprResult Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn,
12252 UnresolvedLookupExpr *ULE,
12253 SourceLocation LParenLoc,
12255 SourceLocation RParenLoc,
12257 bool AllowTypoCorrection,
12258 bool CalleesAddressIsTaken) {
12259 OverloadCandidateSet CandidateSet(Fn->getExprLoc(),
12260 OverloadCandidateSet::CSK_Normal);
12263 if (buildOverloadedCallSet(S, Fn, ULE, Args, LParenLoc, &CandidateSet,
12267 // If the user handed us something like `(&Foo)(Bar)`, we need to ensure that
12268 // functions that aren't addressible are considered unviable.
12269 if (CalleesAddressIsTaken)
12270 markUnaddressableCandidatesUnviable(*this, CandidateSet);
12272 OverloadCandidateSet::iterator Best;
12273 OverloadingResult OverloadResult =
12274 CandidateSet.BestViableFunction(*this, Fn->getBeginLoc(), Best);
12276 return FinishOverloadedCallExpr(*this, S, Fn, ULE, LParenLoc, Args, RParenLoc,
12277 ExecConfig, &CandidateSet, &Best,
12278 OverloadResult, AllowTypoCorrection);
12281 static bool IsOverloaded(const UnresolvedSetImpl &Functions) {
12282 return Functions.size() > 1 ||
12283 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin()));
12286 /// Create a unary operation that may resolve to an overloaded
12289 /// \param OpLoc The location of the operator itself (e.g., '*').
12291 /// \param Opc The UnaryOperatorKind that describes this operator.
12293 /// \param Fns The set of non-member functions that will be
12294 /// considered by overload resolution. The caller needs to build this
12295 /// set based on the context using, e.g.,
12296 /// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This
12297 /// set should not contain any member functions; those will be added
12298 /// by CreateOverloadedUnaryOp().
12300 /// \param Input The input argument.
12302 Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, UnaryOperatorKind Opc,
12303 const UnresolvedSetImpl &Fns,
12304 Expr *Input, bool PerformADL) {
12305 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc);
12306 assert(Op != OO_None && "Invalid opcode for overloaded unary operator");
12307 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
12308 // TODO: provide better source location info.
12309 DeclarationNameInfo OpNameInfo(OpName, OpLoc);
12311 if (checkPlaceholderForOverload(*this, Input))
12312 return ExprError();
12314 Expr *Args[2] = { Input, nullptr };
12315 unsigned NumArgs = 1;
12317 // For post-increment and post-decrement, add the implicit '0' as
12318 // the second argument, so that we know this is a post-increment or
12320 if (Opc == UO_PostInc || Opc == UO_PostDec) {
12321 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false);
12322 Args[1] = IntegerLiteral::Create(Context, Zero, Context.IntTy,
12327 ArrayRef<Expr *> ArgsArray(Args, NumArgs);
12329 if (Input->isTypeDependent()) {
12331 return new (Context) UnaryOperator(Input, Opc, Context.DependentTy,
12332 VK_RValue, OK_Ordinary, OpLoc, false);
12334 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
12335 UnresolvedLookupExpr *Fn = UnresolvedLookupExpr::Create(
12336 Context, NamingClass, NestedNameSpecifierLoc(), OpNameInfo,
12337 /*ADL*/ true, IsOverloaded(Fns), Fns.begin(), Fns.end());
12338 return CXXOperatorCallExpr::Create(Context, Op, Fn, ArgsArray,
12339 Context.DependentTy, VK_RValue, OpLoc,
12343 // Build an empty overload set.
12344 OverloadCandidateSet CandidateSet(OpLoc, OverloadCandidateSet::CSK_Operator);
12346 // Add the candidates from the given function set.
12347 AddFunctionCandidates(Fns, ArgsArray, CandidateSet);
12349 // Add operator candidates that are member functions.
12350 AddMemberOperatorCandidates(Op, OpLoc, ArgsArray, CandidateSet);
12352 // Add candidates from ADL.
12354 AddArgumentDependentLookupCandidates(OpName, OpLoc, ArgsArray,
12355 /*ExplicitTemplateArgs*/nullptr,
12359 // Add builtin operator candidates.
12360 AddBuiltinOperatorCandidates(Op, OpLoc, ArgsArray, CandidateSet);
12362 bool HadMultipleCandidates = (CandidateSet.size() > 1);
12364 // Perform overload resolution.
12365 OverloadCandidateSet::iterator Best;
12366 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
12368 // We found a built-in operator or an overloaded operator.
12369 FunctionDecl *FnDecl = Best->Function;
12372 Expr *Base = nullptr;
12373 // We matched an overloaded operator. Build a call to that
12376 // Convert the arguments.
12377 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) {
12378 CheckMemberOperatorAccess(OpLoc, Args[0], nullptr, Best->FoundDecl);
12380 ExprResult InputRes =
12381 PerformObjectArgumentInitialization(Input, /*Qualifier=*/nullptr,
12382 Best->FoundDecl, Method);
12383 if (InputRes.isInvalid())
12384 return ExprError();
12385 Base = Input = InputRes.get();
12387 // Convert the arguments.
12388 ExprResult InputInit
12389 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
12391 FnDecl->getParamDecl(0)),
12394 if (InputInit.isInvalid())
12395 return ExprError();
12396 Input = InputInit.get();
12399 // Build the actual expression node.
12400 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, Best->FoundDecl,
12401 Base, HadMultipleCandidates,
12403 if (FnExpr.isInvalid())
12404 return ExprError();
12406 // Determine the result type.
12407 QualType ResultTy = FnDecl->getReturnType();
12408 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
12409 ResultTy = ResultTy.getNonLValueExprType(Context);
12412 CallExpr *TheCall = CXXOperatorCallExpr::Create(
12413 Context, Op, FnExpr.get(), ArgsArray, ResultTy, VK, OpLoc,
12414 FPOptions(), Best->IsADLCandidate);
12416 if (CheckCallReturnType(FnDecl->getReturnType(), OpLoc, TheCall, FnDecl))
12417 return ExprError();
12419 if (CheckFunctionCall(FnDecl, TheCall,
12420 FnDecl->getType()->castAs<FunctionProtoType>()))
12421 return ExprError();
12423 return MaybeBindToTemporary(TheCall);
12425 // We matched a built-in operator. Convert the arguments, then
12426 // break out so that we will build the appropriate built-in
12428 ExprResult InputRes = PerformImplicitConversion(
12429 Input, Best->BuiltinParamTypes[0], Best->Conversions[0], AA_Passing,
12430 CCK_ForBuiltinOverloadedOp);
12431 if (InputRes.isInvalid())
12432 return ExprError();
12433 Input = InputRes.get();
12438 case OR_No_Viable_Function:
12439 // This is an erroneous use of an operator which can be overloaded by
12440 // a non-member function. Check for non-member operators which were
12441 // defined too late to be candidates.
12442 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, ArgsArray))
12443 // FIXME: Recover by calling the found function.
12444 return ExprError();
12446 // No viable function; fall through to handling this as a
12447 // built-in operator, which will produce an error message for us.
12451 CandidateSet.NoteCandidates(
12452 PartialDiagnosticAt(OpLoc,
12453 PDiag(diag::err_ovl_ambiguous_oper_unary)
12454 << UnaryOperator::getOpcodeStr(Opc)
12455 << Input->getType() << Input->getSourceRange()),
12456 *this, OCD_ViableCandidates, ArgsArray,
12457 UnaryOperator::getOpcodeStr(Opc), OpLoc);
12458 return ExprError();
12461 CandidateSet.NoteCandidates(
12462 PartialDiagnosticAt(OpLoc, PDiag(diag::err_ovl_deleted_oper)
12463 << UnaryOperator::getOpcodeStr(Opc)
12464 << Input->getSourceRange()),
12465 *this, OCD_AllCandidates, ArgsArray, UnaryOperator::getOpcodeStr(Opc),
12467 return ExprError();
12470 // Either we found no viable overloaded operator or we matched a
12471 // built-in operator. In either case, fall through to trying to
12472 // build a built-in operation.
12473 return CreateBuiltinUnaryOp(OpLoc, Opc, Input);
12476 /// Create a binary operation that may resolve to an overloaded
12479 /// \param OpLoc The location of the operator itself (e.g., '+').
12481 /// \param Opc The BinaryOperatorKind that describes this operator.
12483 /// \param Fns The set of non-member functions that will be
12484 /// considered by overload resolution. The caller needs to build this
12485 /// set based on the context using, e.g.,
12486 /// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This
12487 /// set should not contain any member functions; those will be added
12488 /// by CreateOverloadedBinOp().
12490 /// \param LHS Left-hand argument.
12491 /// \param RHS Right-hand argument.
12493 Sema::CreateOverloadedBinOp(SourceLocation OpLoc,
12494 BinaryOperatorKind Opc,
12495 const UnresolvedSetImpl &Fns,
12496 Expr *LHS, Expr *RHS, bool PerformADL) {
12497 Expr *Args[2] = { LHS, RHS };
12498 LHS=RHS=nullptr; // Please use only Args instead of LHS/RHS couple
12500 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc);
12501 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
12503 // If either side is type-dependent, create an appropriate dependent
12505 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) {
12507 // If there are no functions to store, just build a dependent
12508 // BinaryOperator or CompoundAssignment.
12509 if (Opc <= BO_Assign || Opc > BO_OrAssign)
12510 return new (Context) BinaryOperator(
12511 Args[0], Args[1], Opc, Context.DependentTy, VK_RValue, OK_Ordinary,
12512 OpLoc, FPFeatures);
12514 return new (Context) CompoundAssignOperator(
12515 Args[0], Args[1], Opc, Context.DependentTy, VK_LValue, OK_Ordinary,
12516 Context.DependentTy, Context.DependentTy, OpLoc,
12520 // FIXME: save results of ADL from here?
12521 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
12522 // TODO: provide better source location info in DNLoc component.
12523 DeclarationNameInfo OpNameInfo(OpName, OpLoc);
12524 UnresolvedLookupExpr *Fn = UnresolvedLookupExpr::Create(
12525 Context, NamingClass, NestedNameSpecifierLoc(), OpNameInfo,
12526 /*ADL*/ PerformADL, IsOverloaded(Fns), Fns.begin(), Fns.end());
12527 return CXXOperatorCallExpr::Create(Context, Op, Fn, Args,
12528 Context.DependentTy, VK_RValue, OpLoc,
12532 // Always do placeholder-like conversions on the RHS.
12533 if (checkPlaceholderForOverload(*this, Args[1]))
12534 return ExprError();
12536 // Do placeholder-like conversion on the LHS; note that we should
12537 // not get here with a PseudoObject LHS.
12538 assert(Args[0]->getObjectKind() != OK_ObjCProperty);
12539 if (checkPlaceholderForOverload(*this, Args[0]))
12540 return ExprError();
12542 // If this is the assignment operator, we only perform overload resolution
12543 // if the left-hand side is a class or enumeration type. This is actually
12544 // a hack. The standard requires that we do overload resolution between the
12545 // various built-in candidates, but as DR507 points out, this can lead to
12546 // problems. So we do it this way, which pretty much follows what GCC does.
12547 // Note that we go the traditional code path for compound assignment forms.
12548 if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType())
12549 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
12551 // If this is the .* operator, which is not overloadable, just
12552 // create a built-in binary operator.
12553 if (Opc == BO_PtrMemD)
12554 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
12556 // Build an empty overload set.
12557 OverloadCandidateSet CandidateSet(OpLoc, OverloadCandidateSet::CSK_Operator);
12559 // Add the candidates from the given function set.
12560 AddFunctionCandidates(Fns, Args, CandidateSet);
12562 // Add operator candidates that are member functions.
12563 AddMemberOperatorCandidates(Op, OpLoc, Args, CandidateSet);
12565 // Add candidates from ADL. Per [over.match.oper]p2, this lookup is not
12566 // performed for an assignment operator (nor for operator[] nor operator->,
12567 // which don't get here).
12568 if (Opc != BO_Assign && PerformADL)
12569 AddArgumentDependentLookupCandidates(OpName, OpLoc, Args,
12570 /*ExplicitTemplateArgs*/ nullptr,
12573 // Add builtin operator candidates.
12574 AddBuiltinOperatorCandidates(Op, OpLoc, Args, CandidateSet);
12576 bool HadMultipleCandidates = (CandidateSet.size() > 1);
12578 // Perform overload resolution.
12579 OverloadCandidateSet::iterator Best;
12580 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
12582 // We found a built-in operator or an overloaded operator.
12583 FunctionDecl *FnDecl = Best->Function;
12586 Expr *Base = nullptr;
12587 // We matched an overloaded operator. Build a call to that
12590 // Convert the arguments.
12591 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) {
12592 // Best->Access is only meaningful for class members.
12593 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl);
12596 PerformCopyInitialization(
12597 InitializedEntity::InitializeParameter(Context,
12598 FnDecl->getParamDecl(0)),
12599 SourceLocation(), Args[1]);
12600 if (Arg1.isInvalid())
12601 return ExprError();
12604 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/nullptr,
12605 Best->FoundDecl, Method);
12606 if (Arg0.isInvalid())
12607 return ExprError();
12608 Base = Args[0] = Arg0.getAs<Expr>();
12609 Args[1] = RHS = Arg1.getAs<Expr>();
12611 // Convert the arguments.
12612 ExprResult Arg0 = PerformCopyInitialization(
12613 InitializedEntity::InitializeParameter(Context,
12614 FnDecl->getParamDecl(0)),
12615 SourceLocation(), Args[0]);
12616 if (Arg0.isInvalid())
12617 return ExprError();
12620 PerformCopyInitialization(
12621 InitializedEntity::InitializeParameter(Context,
12622 FnDecl->getParamDecl(1)),
12623 SourceLocation(), Args[1]);
12624 if (Arg1.isInvalid())
12625 return ExprError();
12626 Args[0] = LHS = Arg0.getAs<Expr>();
12627 Args[1] = RHS = Arg1.getAs<Expr>();
12630 // Build the actual expression node.
12631 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl,
12632 Best->FoundDecl, Base,
12633 HadMultipleCandidates, OpLoc);
12634 if (FnExpr.isInvalid())
12635 return ExprError();
12637 // Determine the result type.
12638 QualType ResultTy = FnDecl->getReturnType();
12639 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
12640 ResultTy = ResultTy.getNonLValueExprType(Context);
12642 CXXOperatorCallExpr *TheCall = CXXOperatorCallExpr::Create(
12643 Context, Op, FnExpr.get(), Args, ResultTy, VK, OpLoc, FPFeatures,
12644 Best->IsADLCandidate);
12646 if (CheckCallReturnType(FnDecl->getReturnType(), OpLoc, TheCall,
12648 return ExprError();
12650 ArrayRef<const Expr *> ArgsArray(Args, 2);
12651 const Expr *ImplicitThis = nullptr;
12652 // Cut off the implicit 'this'.
12653 if (isa<CXXMethodDecl>(FnDecl)) {
12654 ImplicitThis = ArgsArray[0];
12655 ArgsArray = ArgsArray.slice(1);
12658 // Check for a self move.
12659 if (Op == OO_Equal)
12660 DiagnoseSelfMove(Args[0], Args[1], OpLoc);
12662 checkCall(FnDecl, nullptr, ImplicitThis, ArgsArray,
12663 isa<CXXMethodDecl>(FnDecl), OpLoc, TheCall->getSourceRange(),
12664 VariadicDoesNotApply);
12666 return MaybeBindToTemporary(TheCall);
12668 // We matched a built-in operator. Convert the arguments, then
12669 // break out so that we will build the appropriate built-in
12671 ExprResult ArgsRes0 = PerformImplicitConversion(
12672 Args[0], Best->BuiltinParamTypes[0], Best->Conversions[0],
12673 AA_Passing, CCK_ForBuiltinOverloadedOp);
12674 if (ArgsRes0.isInvalid())
12675 return ExprError();
12676 Args[0] = ArgsRes0.get();
12678 ExprResult ArgsRes1 = PerformImplicitConversion(
12679 Args[1], Best->BuiltinParamTypes[1], Best->Conversions[1],
12680 AA_Passing, CCK_ForBuiltinOverloadedOp);
12681 if (ArgsRes1.isInvalid())
12682 return ExprError();
12683 Args[1] = ArgsRes1.get();
12688 case OR_No_Viable_Function: {
12689 // C++ [over.match.oper]p9:
12690 // If the operator is the operator , [...] and there are no
12691 // viable functions, then the operator is assumed to be the
12692 // built-in operator and interpreted according to clause 5.
12693 if (Opc == BO_Comma)
12696 // For class as left operand for assignment or compound assignment
12697 // operator do not fall through to handling in built-in, but report that
12698 // no overloaded assignment operator found
12699 ExprResult Result = ExprError();
12700 StringRef OpcStr = BinaryOperator::getOpcodeStr(Opc);
12701 auto Cands = CandidateSet.CompleteCandidates(*this, OCD_AllCandidates,
12703 if (Args[0]->getType()->isRecordType() &&
12704 Opc >= BO_Assign && Opc <= BO_OrAssign) {
12705 Diag(OpLoc, diag::err_ovl_no_viable_oper)
12706 << BinaryOperator::getOpcodeStr(Opc)
12707 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12708 if (Args[0]->getType()->isIncompleteType()) {
12709 Diag(OpLoc, diag::note_assign_lhs_incomplete)
12710 << Args[0]->getType()
12711 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12714 // This is an erroneous use of an operator which can be overloaded by
12715 // a non-member function. Check for non-member operators which were
12716 // defined too late to be candidates.
12717 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, Args))
12718 // FIXME: Recover by calling the found function.
12719 return ExprError();
12721 // No viable function; try to create a built-in operation, which will
12722 // produce an error. Then, show the non-viable candidates.
12723 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
12725 assert(Result.isInvalid() &&
12726 "C++ binary operator overloading is missing candidates!");
12727 CandidateSet.NoteCandidates(*this, Args, Cands, OpcStr, OpLoc);
12732 CandidateSet.NoteCandidates(
12733 PartialDiagnosticAt(OpLoc, PDiag(diag::err_ovl_ambiguous_oper_binary)
12734 << BinaryOperator::getOpcodeStr(Opc)
12735 << Args[0]->getType()
12736 << Args[1]->getType()
12737 << Args[0]->getSourceRange()
12738 << Args[1]->getSourceRange()),
12739 *this, OCD_ViableCandidates, Args, BinaryOperator::getOpcodeStr(Opc),
12741 return ExprError();
12744 if (isImplicitlyDeleted(Best->Function)) {
12745 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
12746 Diag(OpLoc, diag::err_ovl_deleted_special_oper)
12747 << Context.getRecordType(Method->getParent())
12748 << getSpecialMember(Method);
12750 // The user probably meant to call this special member. Just
12751 // explain why it's deleted.
12752 NoteDeletedFunction(Method);
12753 return ExprError();
12755 CandidateSet.NoteCandidates(
12756 PartialDiagnosticAt(OpLoc, PDiag(diag::err_ovl_deleted_oper)
12757 << BinaryOperator::getOpcodeStr(Opc)
12758 << Args[0]->getSourceRange()
12759 << Args[1]->getSourceRange()),
12760 *this, OCD_AllCandidates, Args, BinaryOperator::getOpcodeStr(Opc),
12762 return ExprError();
12765 // We matched a built-in operator; build it.
12766 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
12770 Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc,
12771 SourceLocation RLoc,
12772 Expr *Base, Expr *Idx) {
12773 Expr *Args[2] = { Base, Idx };
12774 DeclarationName OpName =
12775 Context.DeclarationNames.getCXXOperatorName(OO_Subscript);
12777 // If either side is type-dependent, create an appropriate dependent
12779 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) {
12781 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
12782 // CHECKME: no 'operator' keyword?
12783 DeclarationNameInfo OpNameInfo(OpName, LLoc);
12784 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc));
12785 UnresolvedLookupExpr *Fn
12786 = UnresolvedLookupExpr::Create(Context, NamingClass,
12787 NestedNameSpecifierLoc(), OpNameInfo,
12788 /*ADL*/ true, /*Overloaded*/ false,
12789 UnresolvedSetIterator(),
12790 UnresolvedSetIterator());
12791 // Can't add any actual overloads yet
12793 return CXXOperatorCallExpr::Create(Context, OO_Subscript, Fn, Args,
12794 Context.DependentTy, VK_RValue, RLoc,
12798 // Handle placeholders on both operands.
12799 if (checkPlaceholderForOverload(*this, Args[0]))
12800 return ExprError();
12801 if (checkPlaceholderForOverload(*this, Args[1]))
12802 return ExprError();
12804 // Build an empty overload set.
12805 OverloadCandidateSet CandidateSet(LLoc, OverloadCandidateSet::CSK_Operator);
12807 // Subscript can only be overloaded as a member function.
12809 // Add operator candidates that are member functions.
12810 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, CandidateSet);
12812 // Add builtin operator candidates.
12813 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, CandidateSet);
12815 bool HadMultipleCandidates = (CandidateSet.size() > 1);
12817 // Perform overload resolution.
12818 OverloadCandidateSet::iterator Best;
12819 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) {
12821 // We found a built-in operator or an overloaded operator.
12822 FunctionDecl *FnDecl = Best->Function;
12825 // We matched an overloaded operator. Build a call to that
12828 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl);
12830 // Convert the arguments.
12831 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl);
12833 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/nullptr,
12834 Best->FoundDecl, Method);
12835 if (Arg0.isInvalid())
12836 return ExprError();
12837 Args[0] = Arg0.get();
12839 // Convert the arguments.
12840 ExprResult InputInit
12841 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
12843 FnDecl->getParamDecl(0)),
12846 if (InputInit.isInvalid())
12847 return ExprError();
12849 Args[1] = InputInit.getAs<Expr>();
12851 // Build the actual expression node.
12852 DeclarationNameInfo OpLocInfo(OpName, LLoc);
12853 OpLocInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc));
12854 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl,
12857 HadMultipleCandidates,
12858 OpLocInfo.getLoc(),
12859 OpLocInfo.getInfo());
12860 if (FnExpr.isInvalid())
12861 return ExprError();
12863 // Determine the result type
12864 QualType ResultTy = FnDecl->getReturnType();
12865 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
12866 ResultTy = ResultTy.getNonLValueExprType(Context);
12868 CXXOperatorCallExpr *TheCall =
12869 CXXOperatorCallExpr::Create(Context, OO_Subscript, FnExpr.get(),
12870 Args, ResultTy, VK, RLoc, FPOptions());
12872 if (CheckCallReturnType(FnDecl->getReturnType(), LLoc, TheCall, FnDecl))
12873 return ExprError();
12875 if (CheckFunctionCall(Method, TheCall,
12876 Method->getType()->castAs<FunctionProtoType>()))
12877 return ExprError();
12879 return MaybeBindToTemporary(TheCall);
12881 // We matched a built-in operator. Convert the arguments, then
12882 // break out so that we will build the appropriate built-in
12884 ExprResult ArgsRes0 = PerformImplicitConversion(
12885 Args[0], Best->BuiltinParamTypes[0], Best->Conversions[0],
12886 AA_Passing, CCK_ForBuiltinOverloadedOp);
12887 if (ArgsRes0.isInvalid())
12888 return ExprError();
12889 Args[0] = ArgsRes0.get();
12891 ExprResult ArgsRes1 = PerformImplicitConversion(
12892 Args[1], Best->BuiltinParamTypes[1], Best->Conversions[1],
12893 AA_Passing, CCK_ForBuiltinOverloadedOp);
12894 if (ArgsRes1.isInvalid())
12895 return ExprError();
12896 Args[1] = ArgsRes1.get();
12902 case OR_No_Viable_Function: {
12903 PartialDiagnostic PD = CandidateSet.empty()
12904 ? (PDiag(diag::err_ovl_no_oper)
12905 << Args[0]->getType() << /*subscript*/ 0
12906 << Args[0]->getSourceRange() << Args[1]->getSourceRange())
12907 : (PDiag(diag::err_ovl_no_viable_subscript)
12908 << Args[0]->getType() << Args[0]->getSourceRange()
12909 << Args[1]->getSourceRange());
12910 CandidateSet.NoteCandidates(PartialDiagnosticAt(LLoc, PD), *this,
12911 OCD_AllCandidates, Args, "[]", LLoc);
12912 return ExprError();
12916 CandidateSet.NoteCandidates(
12917 PartialDiagnosticAt(LLoc, PDiag(diag::err_ovl_ambiguous_oper_binary)
12918 << "[]" << Args[0]->getType()
12919 << Args[1]->getType()
12920 << Args[0]->getSourceRange()
12921 << Args[1]->getSourceRange()),
12922 *this, OCD_ViableCandidates, Args, "[]", LLoc);
12923 return ExprError();
12926 CandidateSet.NoteCandidates(
12927 PartialDiagnosticAt(LLoc, PDiag(diag::err_ovl_deleted_oper)
12928 << "[]" << Args[0]->getSourceRange()
12929 << Args[1]->getSourceRange()),
12930 *this, OCD_AllCandidates, Args, "[]", LLoc);
12931 return ExprError();
12934 // We matched a built-in operator; build it.
12935 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc);
12938 /// BuildCallToMemberFunction - Build a call to a member
12939 /// function. MemExpr is the expression that refers to the member
12940 /// function (and includes the object parameter), Args/NumArgs are the
12941 /// arguments to the function call (not including the object
12942 /// parameter). The caller needs to validate that the member
12943 /// expression refers to a non-static member function or an overloaded
12944 /// member function.
12946 Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE,
12947 SourceLocation LParenLoc,
12949 SourceLocation RParenLoc) {
12950 assert(MemExprE->getType() == Context.BoundMemberTy ||
12951 MemExprE->getType() == Context.OverloadTy);
12953 // Dig out the member expression. This holds both the object
12954 // argument and the member function we're referring to.
12955 Expr *NakedMemExpr = MemExprE->IgnoreParens();
12957 // Determine whether this is a call to a pointer-to-member function.
12958 if (BinaryOperator *op = dyn_cast<BinaryOperator>(NakedMemExpr)) {
12959 assert(op->getType() == Context.BoundMemberTy);
12960 assert(op->getOpcode() == BO_PtrMemD || op->getOpcode() == BO_PtrMemI);
12963 op->getRHS()->getType()->castAs<MemberPointerType>()->getPointeeType();
12965 const FunctionProtoType *proto = fnType->castAs<FunctionProtoType>();
12966 QualType resultType = proto->getCallResultType(Context);
12967 ExprValueKind valueKind = Expr::getValueKindForType(proto->getReturnType());
12969 // Check that the object type isn't more qualified than the
12970 // member function we're calling.
12971 Qualifiers funcQuals = proto->getMethodQuals();
12973 QualType objectType = op->getLHS()->getType();
12974 if (op->getOpcode() == BO_PtrMemI)
12975 objectType = objectType->castAs<PointerType>()->getPointeeType();
12976 Qualifiers objectQuals = objectType.getQualifiers();
12978 Qualifiers difference = objectQuals - funcQuals;
12979 difference.removeObjCGCAttr();
12980 difference.removeAddressSpace();
12982 std::string qualsString = difference.getAsString();
12983 Diag(LParenLoc, diag::err_pointer_to_member_call_drops_quals)
12984 << fnType.getUnqualifiedType()
12986 << (qualsString.find(' ') == std::string::npos ? 1 : 2);
12989 CXXMemberCallExpr *call =
12990 CXXMemberCallExpr::Create(Context, MemExprE, Args, resultType,
12991 valueKind, RParenLoc, proto->getNumParams());
12993 if (CheckCallReturnType(proto->getReturnType(), op->getRHS()->getBeginLoc(),
12995 return ExprError();
12997 if (ConvertArgumentsForCall(call, op, nullptr, proto, Args, RParenLoc))
12998 return ExprError();
13000 if (CheckOtherCall(call, proto))
13001 return ExprError();
13003 return MaybeBindToTemporary(call);
13006 if (isa<CXXPseudoDestructorExpr>(NakedMemExpr))
13007 return CallExpr::Create(Context, MemExprE, Args, Context.VoidTy, VK_RValue,
13010 UnbridgedCastsSet UnbridgedCasts;
13011 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts))
13012 return ExprError();
13014 MemberExpr *MemExpr;
13015 CXXMethodDecl *Method = nullptr;
13016 DeclAccessPair FoundDecl = DeclAccessPair::make(nullptr, AS_public);
13017 NestedNameSpecifier *Qualifier = nullptr;
13018 if (isa<MemberExpr>(NakedMemExpr)) {
13019 MemExpr = cast<MemberExpr>(NakedMemExpr);
13020 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl());
13021 FoundDecl = MemExpr->getFoundDecl();
13022 Qualifier = MemExpr->getQualifier();
13023 UnbridgedCasts.restore();
13025 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr);
13026 Qualifier = UnresExpr->getQualifier();
13028 QualType ObjectType = UnresExpr->getBaseType();
13029 Expr::Classification ObjectClassification
13030 = UnresExpr->isArrow()? Expr::Classification::makeSimpleLValue()
13031 : UnresExpr->getBase()->Classify(Context);
13033 // Add overload candidates
13034 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc(),
13035 OverloadCandidateSet::CSK_Normal);
13037 // FIXME: avoid copy.
13038 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
13039 if (UnresExpr->hasExplicitTemplateArgs()) {
13040 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer);
13041 TemplateArgs = &TemplateArgsBuffer;
13044 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(),
13045 E = UnresExpr->decls_end(); I != E; ++I) {
13047 NamedDecl *Func = *I;
13048 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext());
13049 if (isa<UsingShadowDecl>(Func))
13050 Func = cast<UsingShadowDecl>(Func)->getTargetDecl();
13053 // Microsoft supports direct constructor calls.
13054 if (getLangOpts().MicrosoftExt && isa<CXXConstructorDecl>(Func)) {
13055 AddOverloadCandidate(cast<CXXConstructorDecl>(Func), I.getPair(), Args,
13057 /*SuppressUserConversions*/ false);
13058 } else if ((Method = dyn_cast<CXXMethodDecl>(Func))) {
13059 // If explicit template arguments were provided, we can't call a
13060 // non-template member function.
13064 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType,
13065 ObjectClassification, Args, CandidateSet,
13066 /*SuppressUserConversions=*/false);
13068 AddMethodTemplateCandidate(
13069 cast<FunctionTemplateDecl>(Func), I.getPair(), ActingDC,
13070 TemplateArgs, ObjectType, ObjectClassification, Args, CandidateSet,
13071 /*SuppressUserConversions=*/false);
13075 DeclarationName DeclName = UnresExpr->getMemberName();
13077 UnbridgedCasts.restore();
13079 OverloadCandidateSet::iterator Best;
13080 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getBeginLoc(),
13083 Method = cast<CXXMethodDecl>(Best->Function);
13084 FoundDecl = Best->FoundDecl;
13085 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl);
13086 if (DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()))
13087 return ExprError();
13088 // If FoundDecl is different from Method (such as if one is a template
13089 // and the other a specialization), make sure DiagnoseUseOfDecl is
13091 // FIXME: This would be more comprehensively addressed by modifying
13092 // DiagnoseUseOfDecl to accept both the FoundDecl and the decl
13094 if (Method != FoundDecl.getDecl() &&
13095 DiagnoseUseOfDecl(Method, UnresExpr->getNameLoc()))
13096 return ExprError();
13099 case OR_No_Viable_Function:
13100 CandidateSet.NoteCandidates(
13101 PartialDiagnosticAt(
13102 UnresExpr->getMemberLoc(),
13103 PDiag(diag::err_ovl_no_viable_member_function_in_call)
13104 << DeclName << MemExprE->getSourceRange()),
13105 *this, OCD_AllCandidates, Args);
13106 // FIXME: Leaking incoming expressions!
13107 return ExprError();
13110 CandidateSet.NoteCandidates(
13111 PartialDiagnosticAt(UnresExpr->getMemberLoc(),
13112 PDiag(diag::err_ovl_ambiguous_member_call)
13113 << DeclName << MemExprE->getSourceRange()),
13114 *this, OCD_AllCandidates, Args);
13115 // FIXME: Leaking incoming expressions!
13116 return ExprError();
13119 CandidateSet.NoteCandidates(
13120 PartialDiagnosticAt(UnresExpr->getMemberLoc(),
13121 PDiag(diag::err_ovl_deleted_member_call)
13122 << DeclName << MemExprE->getSourceRange()),
13123 *this, OCD_AllCandidates, Args);
13124 // FIXME: Leaking incoming expressions!
13125 return ExprError();
13128 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method);
13130 // If overload resolution picked a static member, build a
13131 // non-member call based on that function.
13132 if (Method->isStatic()) {
13133 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, Args,
13137 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens());
13140 QualType ResultType = Method->getReturnType();
13141 ExprValueKind VK = Expr::getValueKindForType(ResultType);
13142 ResultType = ResultType.getNonLValueExprType(Context);
13144 assert(Method && "Member call to something that isn't a method?");
13145 const auto *Proto = Method->getType()->getAs<FunctionProtoType>();
13146 CXXMemberCallExpr *TheCall =
13147 CXXMemberCallExpr::Create(Context, MemExprE, Args, ResultType, VK,
13148 RParenLoc, Proto->getNumParams());
13150 // Check for a valid return type.
13151 if (CheckCallReturnType(Method->getReturnType(), MemExpr->getMemberLoc(),
13153 return ExprError();
13155 // Convert the object argument (for a non-static member function call).
13156 // We only need to do this if there was actually an overload; otherwise
13157 // it was done at lookup.
13158 if (!Method->isStatic()) {
13159 ExprResult ObjectArg =
13160 PerformObjectArgumentInitialization(MemExpr->getBase(), Qualifier,
13161 FoundDecl, Method);
13162 if (ObjectArg.isInvalid())
13163 return ExprError();
13164 MemExpr->setBase(ObjectArg.get());
13167 // Convert the rest of the arguments
13168 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args,
13170 return ExprError();
13172 DiagnoseSentinelCalls(Method, LParenLoc, Args);
13174 if (CheckFunctionCall(Method, TheCall, Proto))
13175 return ExprError();
13177 // In the case the method to call was not selected by the overloading
13178 // resolution process, we still need to handle the enable_if attribute. Do
13179 // that here, so it will not hide previous -- and more relevant -- errors.
13180 if (auto *MemE = dyn_cast<MemberExpr>(NakedMemExpr)) {
13181 if (const EnableIfAttr *Attr = CheckEnableIf(Method, Args, true)) {
13182 Diag(MemE->getMemberLoc(),
13183 diag::err_ovl_no_viable_member_function_in_call)
13184 << Method << Method->getSourceRange();
13185 Diag(Method->getLocation(),
13186 diag::note_ovl_candidate_disabled_by_function_cond_attr)
13187 << Attr->getCond()->getSourceRange() << Attr->getMessage();
13188 return ExprError();
13192 if ((isa<CXXConstructorDecl>(CurContext) ||
13193 isa<CXXDestructorDecl>(CurContext)) &&
13194 TheCall->getMethodDecl()->isPure()) {
13195 const CXXMethodDecl *MD = TheCall->getMethodDecl();
13197 if (isa<CXXThisExpr>(MemExpr->getBase()->IgnoreParenCasts()) &&
13198 MemExpr->performsVirtualDispatch(getLangOpts())) {
13199 Diag(MemExpr->getBeginLoc(),
13200 diag::warn_call_to_pure_virtual_member_function_from_ctor_dtor)
13201 << MD->getDeclName() << isa<CXXDestructorDecl>(CurContext)
13202 << MD->getParent()->getDeclName();
13204 Diag(MD->getBeginLoc(), diag::note_previous_decl) << MD->getDeclName();
13205 if (getLangOpts().AppleKext)
13206 Diag(MemExpr->getBeginLoc(), diag::note_pure_qualified_call_kext)
13207 << MD->getParent()->getDeclName() << MD->getDeclName();
13211 if (CXXDestructorDecl *DD =
13212 dyn_cast<CXXDestructorDecl>(TheCall->getMethodDecl())) {
13213 // a->A::f() doesn't go through the vtable, except in AppleKext mode.
13214 bool CallCanBeVirtual = !MemExpr->hasQualifier() || getLangOpts().AppleKext;
13215 CheckVirtualDtorCall(DD, MemExpr->getBeginLoc(), /*IsDelete=*/false,
13216 CallCanBeVirtual, /*WarnOnNonAbstractTypes=*/true,
13217 MemExpr->getMemberLoc());
13220 return MaybeBindToTemporary(TheCall);
13223 /// BuildCallToObjectOfClassType - Build a call to an object of class
13224 /// type (C++ [over.call.object]), which can end up invoking an
13225 /// overloaded function call operator (@c operator()) or performing a
13226 /// user-defined conversion on the object argument.
13228 Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj,
13229 SourceLocation LParenLoc,
13231 SourceLocation RParenLoc) {
13232 if (checkPlaceholderForOverload(*this, Obj))
13233 return ExprError();
13234 ExprResult Object = Obj;
13236 UnbridgedCastsSet UnbridgedCasts;
13237 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts))
13238 return ExprError();
13240 assert(Object.get()->getType()->isRecordType() &&
13241 "Requires object type argument");
13242 const RecordType *Record = Object.get()->getType()->getAs<RecordType>();
13244 // C++ [over.call.object]p1:
13245 // If the primary-expression E in the function call syntax
13246 // evaluates to a class object of type "cv T", then the set of
13247 // candidate functions includes at least the function call
13248 // operators of T. The function call operators of T are obtained by
13249 // ordinary lookup of the name operator() in the context of
13251 OverloadCandidateSet CandidateSet(LParenLoc,
13252 OverloadCandidateSet::CSK_Operator);
13253 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call);
13255 if (RequireCompleteType(LParenLoc, Object.get()->getType(),
13256 diag::err_incomplete_object_call, Object.get()))
13259 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName);
13260 LookupQualifiedName(R, Record->getDecl());
13261 R.suppressDiagnostics();
13263 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end();
13264 Oper != OperEnd; ++Oper) {
13265 AddMethodCandidate(Oper.getPair(), Object.get()->getType(),
13266 Object.get()->Classify(Context), Args, CandidateSet,
13267 /*SuppressUserConversion=*/false);
13270 // C++ [over.call.object]p2:
13271 // In addition, for each (non-explicit in C++0x) conversion function
13272 // declared in T of the form
13274 // operator conversion-type-id () cv-qualifier;
13276 // where cv-qualifier is the same cv-qualification as, or a
13277 // greater cv-qualification than, cv, and where conversion-type-id
13278 // denotes the type "pointer to function of (P1,...,Pn) returning
13279 // R", or the type "reference to pointer to function of
13280 // (P1,...,Pn) returning R", or the type "reference to function
13281 // of (P1,...,Pn) returning R", a surrogate call function [...]
13282 // is also considered as a candidate function. Similarly,
13283 // surrogate call functions are added to the set of candidate
13284 // functions for each conversion function declared in an
13285 // accessible base class provided the function is not hidden
13286 // within T by another intervening declaration.
13287 const auto &Conversions =
13288 cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions();
13289 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
13291 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
13292 if (isa<UsingShadowDecl>(D))
13293 D = cast<UsingShadowDecl>(D)->getTargetDecl();
13295 // Skip over templated conversion functions; they aren't
13297 if (isa<FunctionTemplateDecl>(D))
13300 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D);
13301 if (!Conv->isExplicit()) {
13302 // Strip the reference type (if any) and then the pointer type (if
13303 // any) to get down to what might be a function type.
13304 QualType ConvType = Conv->getConversionType().getNonReferenceType();
13305 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
13306 ConvType = ConvPtrType->getPointeeType();
13308 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>())
13310 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto,
13311 Object.get(), Args, CandidateSet);
13316 bool HadMultipleCandidates = (CandidateSet.size() > 1);
13318 // Perform overload resolution.
13319 OverloadCandidateSet::iterator Best;
13320 switch (CandidateSet.BestViableFunction(*this, Object.get()->getBeginLoc(),
13323 // Overload resolution succeeded; we'll build the appropriate call
13327 case OR_No_Viable_Function: {
13328 PartialDiagnostic PD =
13329 CandidateSet.empty()
13330 ? (PDiag(diag::err_ovl_no_oper)
13331 << Object.get()->getType() << /*call*/ 1
13332 << Object.get()->getSourceRange())
13333 : (PDiag(diag::err_ovl_no_viable_object_call)
13334 << Object.get()->getType() << Object.get()->getSourceRange());
13335 CandidateSet.NoteCandidates(
13336 PartialDiagnosticAt(Object.get()->getBeginLoc(), PD), *this,
13337 OCD_AllCandidates, Args);
13341 CandidateSet.NoteCandidates(
13342 PartialDiagnosticAt(Object.get()->getBeginLoc(),
13343 PDiag(diag::err_ovl_ambiguous_object_call)
13344 << Object.get()->getType()
13345 << Object.get()->getSourceRange()),
13346 *this, OCD_ViableCandidates, Args);
13350 CandidateSet.NoteCandidates(
13351 PartialDiagnosticAt(Object.get()->getBeginLoc(),
13352 PDiag(diag::err_ovl_deleted_object_call)
13353 << Object.get()->getType()
13354 << Object.get()->getSourceRange()),
13355 *this, OCD_AllCandidates, Args);
13359 if (Best == CandidateSet.end())
13362 UnbridgedCasts.restore();
13364 if (Best->Function == nullptr) {
13365 // Since there is no function declaration, this is one of the
13366 // surrogate candidates. Dig out the conversion function.
13367 CXXConversionDecl *Conv
13368 = cast<CXXConversionDecl>(
13369 Best->Conversions[0].UserDefined.ConversionFunction);
13371 CheckMemberOperatorAccess(LParenLoc, Object.get(), nullptr,
13373 if (DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc))
13374 return ExprError();
13375 assert(Conv == Best->FoundDecl.getDecl() &&
13376 "Found Decl & conversion-to-functionptr should be same, right?!");
13377 // We selected one of the surrogate functions that converts the
13378 // object parameter to a function pointer. Perform the conversion
13379 // on the object argument, then let BuildCallExpr finish the job.
13381 // Create an implicit member expr to refer to the conversion operator.
13382 // and then call it.
13383 ExprResult Call = BuildCXXMemberCallExpr(Object.get(), Best->FoundDecl,
13384 Conv, HadMultipleCandidates);
13385 if (Call.isInvalid())
13386 return ExprError();
13387 // Record usage of conversion in an implicit cast.
13388 Call = ImplicitCastExpr::Create(Context, Call.get()->getType(),
13389 CK_UserDefinedConversion, Call.get(),
13390 nullptr, VK_RValue);
13392 return BuildCallExpr(S, Call.get(), LParenLoc, Args, RParenLoc);
13395 CheckMemberOperatorAccess(LParenLoc, Object.get(), nullptr, Best->FoundDecl);
13397 // We found an overloaded operator(). Build a CXXOperatorCallExpr
13398 // that calls this method, using Object for the implicit object
13399 // parameter and passing along the remaining arguments.
13400 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
13402 // An error diagnostic has already been printed when parsing the declaration.
13403 if (Method->isInvalidDecl())
13404 return ExprError();
13406 const FunctionProtoType *Proto =
13407 Method->getType()->getAs<FunctionProtoType>();
13409 unsigned NumParams = Proto->getNumParams();
13411 DeclarationNameInfo OpLocInfo(
13412 Context.DeclarationNames.getCXXOperatorName(OO_Call), LParenLoc);
13413 OpLocInfo.setCXXOperatorNameRange(SourceRange(LParenLoc, RParenLoc));
13414 ExprResult NewFn = CreateFunctionRefExpr(*this, Method, Best->FoundDecl,
13415 Obj, HadMultipleCandidates,
13416 OpLocInfo.getLoc(),
13417 OpLocInfo.getInfo());
13418 if (NewFn.isInvalid())
13421 // The number of argument slots to allocate in the call. If we have default
13422 // arguments we need to allocate space for them as well. We additionally
13423 // need one more slot for the object parameter.
13424 unsigned NumArgsSlots = 1 + std::max<unsigned>(Args.size(), NumParams);
13426 // Build the full argument list for the method call (the implicit object
13427 // parameter is placed at the beginning of the list).
13428 SmallVector<Expr *, 8> MethodArgs(NumArgsSlots);
13430 bool IsError = false;
13432 // Initialize the implicit object parameter.
13433 ExprResult ObjRes =
13434 PerformObjectArgumentInitialization(Object.get(), /*Qualifier=*/nullptr,
13435 Best->FoundDecl, Method);
13436 if (ObjRes.isInvalid())
13440 MethodArgs[0] = Object.get();
13442 // Check the argument types.
13443 for (unsigned i = 0; i != NumParams; i++) {
13445 if (i < Args.size()) {
13448 // Pass the argument.
13450 ExprResult InputInit
13451 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
13453 Method->getParamDecl(i)),
13454 SourceLocation(), Arg);
13456 IsError |= InputInit.isInvalid();
13457 Arg = InputInit.getAs<Expr>();
13460 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i));
13461 if (DefArg.isInvalid()) {
13466 Arg = DefArg.getAs<Expr>();
13469 MethodArgs[i + 1] = Arg;
13472 // If this is a variadic call, handle args passed through "...".
13473 if (Proto->isVariadic()) {
13474 // Promote the arguments (C99 6.5.2.2p7).
13475 for (unsigned i = NumParams, e = Args.size(); i < e; i++) {
13476 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod,
13478 IsError |= Arg.isInvalid();
13479 MethodArgs[i + 1] = Arg.get();
13486 DiagnoseSentinelCalls(Method, LParenLoc, Args);
13488 // Once we've built TheCall, all of the expressions are properly owned.
13489 QualType ResultTy = Method->getReturnType();
13490 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
13491 ResultTy = ResultTy.getNonLValueExprType(Context);
13493 CXXOperatorCallExpr *TheCall =
13494 CXXOperatorCallExpr::Create(Context, OO_Call, NewFn.get(), MethodArgs,
13495 ResultTy, VK, RParenLoc, FPOptions());
13497 if (CheckCallReturnType(Method->getReturnType(), LParenLoc, TheCall, Method))
13500 if (CheckFunctionCall(Method, TheCall, Proto))
13503 return MaybeBindToTemporary(TheCall);
13506 /// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator->
13507 /// (if one exists), where @c Base is an expression of class type and
13508 /// @c Member is the name of the member we're trying to find.
13510 Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc,
13511 bool *NoArrowOperatorFound) {
13512 assert(Base->getType()->isRecordType() &&
13513 "left-hand side must have class type");
13515 if (checkPlaceholderForOverload(*this, Base))
13516 return ExprError();
13518 SourceLocation Loc = Base->getExprLoc();
13520 // C++ [over.ref]p1:
13522 // [...] An expression x->m is interpreted as (x.operator->())->m
13523 // for a class object x of type T if T::operator->() exists and if
13524 // the operator is selected as the best match function by the
13525 // overload resolution mechanism (13.3).
13526 DeclarationName OpName =
13527 Context.DeclarationNames.getCXXOperatorName(OO_Arrow);
13528 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Operator);
13529 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>();
13531 if (RequireCompleteType(Loc, Base->getType(),
13532 diag::err_typecheck_incomplete_tag, Base))
13533 return ExprError();
13535 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName);
13536 LookupQualifiedName(R, BaseRecord->getDecl());
13537 R.suppressDiagnostics();
13539 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end();
13540 Oper != OperEnd; ++Oper) {
13541 AddMethodCandidate(Oper.getPair(), Base->getType(), Base->Classify(Context),
13542 None, CandidateSet, /*SuppressUserConversion=*/false);
13545 bool HadMultipleCandidates = (CandidateSet.size() > 1);
13547 // Perform overload resolution.
13548 OverloadCandidateSet::iterator Best;
13549 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
13551 // Overload resolution succeeded; we'll build the call below.
13554 case OR_No_Viable_Function: {
13555 auto Cands = CandidateSet.CompleteCandidates(*this, OCD_AllCandidates, Base);
13556 if (CandidateSet.empty()) {
13557 QualType BaseType = Base->getType();
13558 if (NoArrowOperatorFound) {
13559 // Report this specific error to the caller instead of emitting a
13560 // diagnostic, as requested.
13561 *NoArrowOperatorFound = true;
13562 return ExprError();
13564 Diag(OpLoc, diag::err_typecheck_member_reference_arrow)
13565 << BaseType << Base->getSourceRange();
13566 if (BaseType->isRecordType() && !BaseType->isPointerType()) {
13567 Diag(OpLoc, diag::note_typecheck_member_reference_suggestion)
13568 << FixItHint::CreateReplacement(OpLoc, ".");
13571 Diag(OpLoc, diag::err_ovl_no_viable_oper)
13572 << "operator->" << Base->getSourceRange();
13573 CandidateSet.NoteCandidates(*this, Base, Cands);
13574 return ExprError();
13577 CandidateSet.NoteCandidates(
13578 PartialDiagnosticAt(OpLoc, PDiag(diag::err_ovl_ambiguous_oper_unary)
13579 << "->" << Base->getType()
13580 << Base->getSourceRange()),
13581 *this, OCD_ViableCandidates, Base);
13582 return ExprError();
13585 CandidateSet.NoteCandidates(
13586 PartialDiagnosticAt(OpLoc, PDiag(diag::err_ovl_deleted_oper)
13587 << "->" << Base->getSourceRange()),
13588 *this, OCD_AllCandidates, Base);
13589 return ExprError();
13592 CheckMemberOperatorAccess(OpLoc, Base, nullptr, Best->FoundDecl);
13594 // Convert the object parameter.
13595 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
13596 ExprResult BaseResult =
13597 PerformObjectArgumentInitialization(Base, /*Qualifier=*/nullptr,
13598 Best->FoundDecl, Method);
13599 if (BaseResult.isInvalid())
13600 return ExprError();
13601 Base = BaseResult.get();
13603 // Build the operator call.
13604 ExprResult FnExpr = CreateFunctionRefExpr(*this, Method, Best->FoundDecl,
13605 Base, HadMultipleCandidates, OpLoc);
13606 if (FnExpr.isInvalid())
13607 return ExprError();
13609 QualType ResultTy = Method->getReturnType();
13610 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
13611 ResultTy = ResultTy.getNonLValueExprType(Context);
13612 CXXOperatorCallExpr *TheCall = CXXOperatorCallExpr::Create(
13613 Context, OO_Arrow, FnExpr.get(), Base, ResultTy, VK, OpLoc, FPOptions());
13615 if (CheckCallReturnType(Method->getReturnType(), OpLoc, TheCall, Method))
13616 return ExprError();
13618 if (CheckFunctionCall(Method, TheCall,
13619 Method->getType()->castAs<FunctionProtoType>()))
13620 return ExprError();
13622 return MaybeBindToTemporary(TheCall);
13625 /// BuildLiteralOperatorCall - Build a UserDefinedLiteral by creating a call to
13626 /// a literal operator described by the provided lookup results.
13627 ExprResult Sema::BuildLiteralOperatorCall(LookupResult &R,
13628 DeclarationNameInfo &SuffixInfo,
13629 ArrayRef<Expr*> Args,
13630 SourceLocation LitEndLoc,
13631 TemplateArgumentListInfo *TemplateArgs) {
13632 SourceLocation UDSuffixLoc = SuffixInfo.getCXXLiteralOperatorNameLoc();
13634 OverloadCandidateSet CandidateSet(UDSuffixLoc,
13635 OverloadCandidateSet::CSK_Normal);
13636 AddFunctionCandidates(R.asUnresolvedSet(), Args, CandidateSet, TemplateArgs,
13637 /*SuppressUserConversions=*/true);
13639 bool HadMultipleCandidates = (CandidateSet.size() > 1);
13641 // Perform overload resolution. This will usually be trivial, but might need
13642 // to perform substitutions for a literal operator template.
13643 OverloadCandidateSet::iterator Best;
13644 switch (CandidateSet.BestViableFunction(*this, UDSuffixLoc, Best)) {
13649 case OR_No_Viable_Function:
13650 CandidateSet.NoteCandidates(
13651 PartialDiagnosticAt(UDSuffixLoc,
13652 PDiag(diag::err_ovl_no_viable_function_in_call)
13653 << R.getLookupName()),
13654 *this, OCD_AllCandidates, Args);
13655 return ExprError();
13658 CandidateSet.NoteCandidates(
13659 PartialDiagnosticAt(R.getNameLoc(), PDiag(diag::err_ovl_ambiguous_call)
13660 << R.getLookupName()),
13661 *this, OCD_ViableCandidates, Args);
13662 return ExprError();
13665 FunctionDecl *FD = Best->Function;
13666 ExprResult Fn = CreateFunctionRefExpr(*this, FD, Best->FoundDecl,
13667 nullptr, HadMultipleCandidates,
13668 SuffixInfo.getLoc(),
13669 SuffixInfo.getInfo());
13670 if (Fn.isInvalid())
13673 // Check the argument types. This should almost always be a no-op, except
13674 // that array-to-pointer decay is applied to string literals.
13676 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
13677 ExprResult InputInit = PerformCopyInitialization(
13678 InitializedEntity::InitializeParameter(Context, FD->getParamDecl(ArgIdx)),
13679 SourceLocation(), Args[ArgIdx]);
13680 if (InputInit.isInvalid())
13682 ConvArgs[ArgIdx] = InputInit.get();
13685 QualType ResultTy = FD->getReturnType();
13686 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
13687 ResultTy = ResultTy.getNonLValueExprType(Context);
13689 UserDefinedLiteral *UDL = UserDefinedLiteral::Create(
13690 Context, Fn.get(), llvm::makeArrayRef(ConvArgs, Args.size()), ResultTy,
13691 VK, LitEndLoc, UDSuffixLoc);
13693 if (CheckCallReturnType(FD->getReturnType(), UDSuffixLoc, UDL, FD))
13694 return ExprError();
13696 if (CheckFunctionCall(FD, UDL, nullptr))
13697 return ExprError();
13699 return MaybeBindToTemporary(UDL);
13702 /// Build a call to 'begin' or 'end' for a C++11 for-range statement. If the
13703 /// given LookupResult is non-empty, it is assumed to describe a member which
13704 /// will be invoked. Otherwise, the function will be found via argument
13705 /// dependent lookup.
13706 /// CallExpr is set to a valid expression and FRS_Success returned on success,
13707 /// otherwise CallExpr is set to ExprError() and some non-success value
13709 Sema::ForRangeStatus
13710 Sema::BuildForRangeBeginEndCall(SourceLocation Loc,
13711 SourceLocation RangeLoc,
13712 const DeclarationNameInfo &NameInfo,
13713 LookupResult &MemberLookup,
13714 OverloadCandidateSet *CandidateSet,
13715 Expr *Range, ExprResult *CallExpr) {
13716 Scope *S = nullptr;
13718 CandidateSet->clear(OverloadCandidateSet::CSK_Normal);
13719 if (!MemberLookup.empty()) {
13720 ExprResult MemberRef =
13721 BuildMemberReferenceExpr(Range, Range->getType(), Loc,
13722 /*IsPtr=*/false, CXXScopeSpec(),
13723 /*TemplateKWLoc=*/SourceLocation(),
13724 /*FirstQualifierInScope=*/nullptr,
13726 /*TemplateArgs=*/nullptr, S);
13727 if (MemberRef.isInvalid()) {
13728 *CallExpr = ExprError();
13729 return FRS_DiagnosticIssued;
13731 *CallExpr = BuildCallExpr(S, MemberRef.get(), Loc, None, Loc, nullptr);
13732 if (CallExpr->isInvalid()) {
13733 *CallExpr = ExprError();
13734 return FRS_DiagnosticIssued;
13737 UnresolvedSet<0> FoundNames;
13738 UnresolvedLookupExpr *Fn =
13739 UnresolvedLookupExpr::Create(Context, /*NamingClass=*/nullptr,
13740 NestedNameSpecifierLoc(), NameInfo,
13741 /*NeedsADL=*/true, /*Overloaded=*/false,
13742 FoundNames.begin(), FoundNames.end());
13744 bool CandidateSetError = buildOverloadedCallSet(S, Fn, Fn, Range, Loc,
13745 CandidateSet, CallExpr);
13746 if (CandidateSet->empty() || CandidateSetError) {
13747 *CallExpr = ExprError();
13748 return FRS_NoViableFunction;
13750 OverloadCandidateSet::iterator Best;
13751 OverloadingResult OverloadResult =
13752 CandidateSet->BestViableFunction(*this, Fn->getBeginLoc(), Best);
13754 if (OverloadResult == OR_No_Viable_Function) {
13755 *CallExpr = ExprError();
13756 return FRS_NoViableFunction;
13758 *CallExpr = FinishOverloadedCallExpr(*this, S, Fn, Fn, Loc, Range,
13759 Loc, nullptr, CandidateSet, &Best,
13761 /*AllowTypoCorrection=*/false);
13762 if (CallExpr->isInvalid() || OverloadResult != OR_Success) {
13763 *CallExpr = ExprError();
13764 return FRS_DiagnosticIssued;
13767 return FRS_Success;
13771 /// FixOverloadedFunctionReference - E is an expression that refers to
13772 /// a C++ overloaded function (possibly with some parentheses and
13773 /// perhaps a '&' around it). We have resolved the overloaded function
13774 /// to the function declaration Fn, so patch up the expression E to
13775 /// refer (possibly indirectly) to Fn. Returns the new expr.
13776 Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found,
13777 FunctionDecl *Fn) {
13778 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
13779 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(),
13781 if (SubExpr == PE->getSubExpr())
13784 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr);
13787 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
13788 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(),
13790 assert(Context.hasSameType(ICE->getSubExpr()->getType(),
13791 SubExpr->getType()) &&
13792 "Implicit cast type cannot be determined from overload");
13793 assert(ICE->path_empty() && "fixing up hierarchy conversion?");
13794 if (SubExpr == ICE->getSubExpr())
13797 return ImplicitCastExpr::Create(Context, ICE->getType(),
13798 ICE->getCastKind(),
13800 ICE->getValueKind());
13803 if (auto *GSE = dyn_cast<GenericSelectionExpr>(E)) {
13804 if (!GSE->isResultDependent()) {
13806 FixOverloadedFunctionReference(GSE->getResultExpr(), Found, Fn);
13807 if (SubExpr == GSE->getResultExpr())
13810 // Replace the resulting type information before rebuilding the generic
13811 // selection expression.
13812 ArrayRef<Expr *> A = GSE->getAssocExprs();
13813 SmallVector<Expr *, 4> AssocExprs(A.begin(), A.end());
13814 unsigned ResultIdx = GSE->getResultIndex();
13815 AssocExprs[ResultIdx] = SubExpr;
13817 return GenericSelectionExpr::Create(
13818 Context, GSE->getGenericLoc(), GSE->getControllingExpr(),
13819 GSE->getAssocTypeSourceInfos(), AssocExprs, GSE->getDefaultLoc(),
13820 GSE->getRParenLoc(), GSE->containsUnexpandedParameterPack(),
13823 // Rather than fall through to the unreachable, return the original generic
13824 // selection expression.
13828 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) {
13829 assert(UnOp->getOpcode() == UO_AddrOf &&
13830 "Can only take the address of an overloaded function");
13831 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) {
13832 if (Method->isStatic()) {
13833 // Do nothing: static member functions aren't any different
13834 // from non-member functions.
13836 // Fix the subexpression, which really has to be an
13837 // UnresolvedLookupExpr holding an overloaded member function
13839 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(),
13841 if (SubExpr == UnOp->getSubExpr())
13844 assert(isa<DeclRefExpr>(SubExpr)
13845 && "fixed to something other than a decl ref");
13846 assert(cast<DeclRefExpr>(SubExpr)->getQualifier()
13847 && "fixed to a member ref with no nested name qualifier");
13849 // We have taken the address of a pointer to member
13850 // function. Perform the computation here so that we get the
13851 // appropriate pointer to member type.
13853 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext()));
13854 QualType MemPtrType
13855 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr());
13856 // Under the MS ABI, lock down the inheritance model now.
13857 if (Context.getTargetInfo().getCXXABI().isMicrosoft())
13858 (void)isCompleteType(UnOp->getOperatorLoc(), MemPtrType);
13860 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, MemPtrType,
13861 VK_RValue, OK_Ordinary,
13862 UnOp->getOperatorLoc(), false);
13865 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(),
13867 if (SubExpr == UnOp->getSubExpr())
13870 return new (Context) UnaryOperator(SubExpr, UO_AddrOf,
13871 Context.getPointerType(SubExpr->getType()),
13872 VK_RValue, OK_Ordinary,
13873 UnOp->getOperatorLoc(), false);
13876 // C++ [except.spec]p17:
13877 // An exception-specification is considered to be needed when:
13878 // - in an expression the function is the unique lookup result or the
13879 // selected member of a set of overloaded functions
13880 if (auto *FPT = Fn->getType()->getAs<FunctionProtoType>())
13881 ResolveExceptionSpec(E->getExprLoc(), FPT);
13883 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) {
13884 // FIXME: avoid copy.
13885 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
13886 if (ULE->hasExplicitTemplateArgs()) {
13887 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer);
13888 TemplateArgs = &TemplateArgsBuffer;
13892 BuildDeclRefExpr(Fn, Fn->getType(), VK_LValue, ULE->getNameInfo(),
13893 ULE->getQualifierLoc(), Found.getDecl(),
13894 ULE->getTemplateKeywordLoc(), TemplateArgs);
13895 DRE->setHadMultipleCandidates(ULE->getNumDecls() > 1);
13899 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) {
13900 // FIXME: avoid copy.
13901 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
13902 if (MemExpr->hasExplicitTemplateArgs()) {
13903 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer);
13904 TemplateArgs = &TemplateArgsBuffer;
13909 // If we're filling in a static method where we used to have an
13910 // implicit member access, rewrite to a simple decl ref.
13911 if (MemExpr->isImplicitAccess()) {
13912 if (cast<CXXMethodDecl>(Fn)->isStatic()) {
13913 DeclRefExpr *DRE = BuildDeclRefExpr(
13914 Fn, Fn->getType(), VK_LValue, MemExpr->getNameInfo(),
13915 MemExpr->getQualifierLoc(), Found.getDecl(),
13916 MemExpr->getTemplateKeywordLoc(), TemplateArgs);
13917 DRE->setHadMultipleCandidates(MemExpr->getNumDecls() > 1);
13920 SourceLocation Loc = MemExpr->getMemberLoc();
13921 if (MemExpr->getQualifier())
13922 Loc = MemExpr->getQualifierLoc().getBeginLoc();
13924 BuildCXXThisExpr(Loc, MemExpr->getBaseType(), /*IsImplicit=*/true);
13927 Base = MemExpr->getBase();
13929 ExprValueKind valueKind;
13931 if (cast<CXXMethodDecl>(Fn)->isStatic()) {
13932 valueKind = VK_LValue;
13933 type = Fn->getType();
13935 valueKind = VK_RValue;
13936 type = Context.BoundMemberTy;
13939 return BuildMemberExpr(
13940 Base, MemExpr->isArrow(), MemExpr->getOperatorLoc(),
13941 MemExpr->getQualifierLoc(), MemExpr->getTemplateKeywordLoc(), Fn, Found,
13942 /*HadMultipleCandidates=*/true, MemExpr->getMemberNameInfo(),
13943 type, valueKind, OK_Ordinary, TemplateArgs);
13946 llvm_unreachable("Invalid reference to overloaded function");
13949 ExprResult Sema::FixOverloadedFunctionReference(ExprResult E,
13950 DeclAccessPair Found,
13951 FunctionDecl *Fn) {
13952 return FixOverloadedFunctionReference(E.get(), Found, Fn);