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 DeclRefExpr *DRE = new (S.Context)
64 DeclRefExpr(S.Context, Fn, false, Fn->getType(), VK_LValue, Loc, LocInfo);
65 if (HadMultipleCandidates)
66 DRE->setHadMultipleCandidates(true);
68 S.MarkDeclRefReferenced(DRE, Base);
69 if (auto *FPT = DRE->getType()->getAs<FunctionProtoType>()) {
70 if (isUnresolvedExceptionSpec(FPT->getExceptionSpecType())) {
71 S.ResolveExceptionSpec(Loc, FPT);
72 DRE->setType(Fn->getType());
75 return S.ImpCastExprToType(DRE, S.Context.getPointerType(DRE->getType()),
76 CK_FunctionToPointerDecay);
79 static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
80 bool InOverloadResolution,
81 StandardConversionSequence &SCS,
83 bool AllowObjCWritebackConversion);
85 static bool IsTransparentUnionStandardConversion(Sema &S, Expr* From,
87 bool InOverloadResolution,
88 StandardConversionSequence &SCS,
90 static OverloadingResult
91 IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
92 UserDefinedConversionSequence& User,
93 OverloadCandidateSet& Conversions,
95 bool AllowObjCConversionOnExplicit);
98 static ImplicitConversionSequence::CompareKind
99 CompareStandardConversionSequences(Sema &S, SourceLocation Loc,
100 const StandardConversionSequence& SCS1,
101 const StandardConversionSequence& SCS2);
103 static ImplicitConversionSequence::CompareKind
104 CompareQualificationConversions(Sema &S,
105 const StandardConversionSequence& SCS1,
106 const StandardConversionSequence& SCS2);
108 static ImplicitConversionSequence::CompareKind
109 CompareDerivedToBaseConversions(Sema &S, SourceLocation Loc,
110 const StandardConversionSequence& SCS1,
111 const StandardConversionSequence& SCS2);
113 /// GetConversionRank - Retrieve the implicit conversion rank
114 /// corresponding to the given implicit conversion kind.
115 ImplicitConversionRank clang::GetConversionRank(ImplicitConversionKind Kind) {
116 static const ImplicitConversionRank
117 Rank[(int)ICK_Num_Conversion_Kinds] = {
137 ICR_OCL_Scalar_Widening,
138 ICR_Complex_Real_Conversion,
141 ICR_Writeback_Conversion,
142 ICR_Exact_Match, // NOTE(gbiv): This may not be completely right --
143 // it was omitted by the patch that added
144 // ICK_Zero_Event_Conversion
146 ICR_C_Conversion_Extension
148 return Rank[(int)Kind];
151 /// GetImplicitConversionName - Return the name of this kind of
152 /// implicit conversion.
153 static const char* GetImplicitConversionName(ImplicitConversionKind Kind) {
154 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = {
158 "Function-to-pointer",
159 "Function pointer conversion",
161 "Integral promotion",
162 "Floating point promotion",
164 "Integral conversion",
165 "Floating conversion",
166 "Complex conversion",
167 "Floating-integral conversion",
168 "Pointer conversion",
169 "Pointer-to-member conversion",
170 "Boolean conversion",
171 "Compatible-types conversion",
172 "Derived-to-base conversion",
175 "Complex-real conversion",
176 "Block Pointer conversion",
177 "Transparent Union Conversion",
178 "Writeback conversion",
179 "OpenCL Zero Event Conversion",
180 "C specific type conversion",
181 "Incompatible pointer conversion"
186 /// StandardConversionSequence - Set the standard conversion
187 /// sequence to the identity conversion.
188 void StandardConversionSequence::setAsIdentityConversion() {
189 First = ICK_Identity;
190 Second = ICK_Identity;
191 Third = ICK_Identity;
192 DeprecatedStringLiteralToCharPtr = false;
193 QualificationIncludesObjCLifetime = false;
194 ReferenceBinding = false;
195 DirectBinding = false;
196 IsLvalueReference = true;
197 BindsToFunctionLvalue = false;
198 BindsToRvalue = false;
199 BindsImplicitObjectArgumentWithoutRefQualifier = false;
200 ObjCLifetimeConversionBinding = false;
201 CopyConstructor = nullptr;
204 /// getRank - Retrieve the rank of this standard conversion sequence
205 /// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the
206 /// implicit conversions.
207 ImplicitConversionRank StandardConversionSequence::getRank() const {
208 ImplicitConversionRank Rank = ICR_Exact_Match;
209 if (GetConversionRank(First) > Rank)
210 Rank = GetConversionRank(First);
211 if (GetConversionRank(Second) > Rank)
212 Rank = GetConversionRank(Second);
213 if (GetConversionRank(Third) > Rank)
214 Rank = GetConversionRank(Third);
218 /// isPointerConversionToBool - Determines whether this conversion is
219 /// a conversion of a pointer or pointer-to-member to bool. This is
220 /// used as part of the ranking of standard conversion sequences
221 /// (C++ 13.3.3.2p4).
222 bool StandardConversionSequence::isPointerConversionToBool() const {
223 // Note that FromType has not necessarily been transformed by the
224 // array-to-pointer or function-to-pointer implicit conversions, so
225 // check for their presence as well as checking whether FromType is
227 if (getToType(1)->isBooleanType() &&
228 (getFromType()->isPointerType() ||
229 getFromType()->isMemberPointerType() ||
230 getFromType()->isObjCObjectPointerType() ||
231 getFromType()->isBlockPointerType() ||
232 getFromType()->isNullPtrType() ||
233 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer))
239 /// isPointerConversionToVoidPointer - Determines whether this
240 /// conversion is a conversion of a pointer to a void pointer. This is
241 /// used as part of the ranking of standard conversion sequences (C++
244 StandardConversionSequence::
245 isPointerConversionToVoidPointer(ASTContext& Context) const {
246 QualType FromType = getFromType();
247 QualType ToType = getToType(1);
249 // Note that FromType has not necessarily been transformed by the
250 // array-to-pointer implicit conversion, so check for its presence
251 // and redo the conversion to get a pointer.
252 if (First == ICK_Array_To_Pointer)
253 FromType = Context.getArrayDecayedType(FromType);
255 if (Second == ICK_Pointer_Conversion && FromType->isAnyPointerType())
256 if (const PointerType* ToPtrType = ToType->getAs<PointerType>())
257 return ToPtrType->getPointeeType()->isVoidType();
262 /// Skip any implicit casts which could be either part of a narrowing conversion
263 /// or after one in an implicit conversion.
264 static const Expr *IgnoreNarrowingConversion(ASTContext &Ctx,
265 const Expr *Converted) {
266 // We can have cleanups wrapping the converted expression; these need to be
267 // preserved so that destructors run if necessary.
268 if (auto *EWC = dyn_cast<ExprWithCleanups>(Converted)) {
270 const_cast<Expr *>(IgnoreNarrowingConversion(Ctx, EWC->getSubExpr()));
271 return ExprWithCleanups::Create(Ctx, Inner, EWC->cleanupsHaveSideEffects(),
275 while (auto *ICE = dyn_cast<ImplicitCastExpr>(Converted)) {
276 switch (ICE->getCastKind()) {
278 case CK_IntegralCast:
279 case CK_IntegralToBoolean:
280 case CK_IntegralToFloating:
281 case CK_BooleanToSignedIntegral:
282 case CK_FloatingToIntegral:
283 case CK_FloatingToBoolean:
284 case CK_FloatingCast:
285 Converted = ICE->getSubExpr();
296 /// Check if this standard conversion sequence represents a narrowing
297 /// conversion, according to C++11 [dcl.init.list]p7.
299 /// \param Ctx The AST context.
300 /// \param Converted The result of applying this standard conversion sequence.
301 /// \param ConstantValue If this is an NK_Constant_Narrowing conversion, the
302 /// value of the expression prior to the narrowing conversion.
303 /// \param ConstantType If this is an NK_Constant_Narrowing conversion, the
304 /// type of the expression prior to the narrowing conversion.
305 /// \param IgnoreFloatToIntegralConversion If true type-narrowing conversions
306 /// from floating point types to integral types should be ignored.
307 NarrowingKind StandardConversionSequence::getNarrowingKind(
308 ASTContext &Ctx, const Expr *Converted, APValue &ConstantValue,
309 QualType &ConstantType, bool IgnoreFloatToIntegralConversion) const {
310 assert(Ctx.getLangOpts().CPlusPlus && "narrowing check outside C++");
312 // C++11 [dcl.init.list]p7:
313 // A narrowing conversion is an implicit conversion ...
314 QualType FromType = getToType(0);
315 QualType ToType = getToType(1);
317 // A conversion to an enumeration type is narrowing if the conversion to
318 // the underlying type is narrowing. This only arises for expressions of
319 // the form 'Enum{init}'.
320 if (auto *ET = ToType->getAs<EnumType>())
321 ToType = ET->getDecl()->getIntegerType();
324 // 'bool' is an integral type; dispatch to the right place to handle it.
325 case ICK_Boolean_Conversion:
326 if (FromType->isRealFloatingType())
327 goto FloatingIntegralConversion;
328 if (FromType->isIntegralOrUnscopedEnumerationType())
329 goto IntegralConversion;
330 // Boolean conversions can be from pointers and pointers to members
331 // [conv.bool], and those aren't considered narrowing conversions.
332 return NK_Not_Narrowing;
334 // -- from a floating-point type to an integer type, or
336 // -- from an integer type or unscoped enumeration type to a floating-point
337 // type, except where the source is a constant expression and the actual
338 // value after conversion will fit into the target type and will produce
339 // the original value when converted back to the original type, or
340 case ICK_Floating_Integral:
341 FloatingIntegralConversion:
342 if (FromType->isRealFloatingType() && ToType->isIntegralType(Ctx)) {
343 return NK_Type_Narrowing;
344 } else if (FromType->isIntegralOrUnscopedEnumerationType() &&
345 ToType->isRealFloatingType()) {
346 if (IgnoreFloatToIntegralConversion)
347 return NK_Not_Narrowing;
348 llvm::APSInt IntConstantValue;
349 const Expr *Initializer = IgnoreNarrowingConversion(Ctx, Converted);
350 assert(Initializer && "Unknown conversion expression");
352 // If it's value-dependent, we can't tell whether it's narrowing.
353 if (Initializer->isValueDependent())
354 return NK_Dependent_Narrowing;
356 if (Initializer->isIntegerConstantExpr(IntConstantValue, Ctx)) {
357 // Convert the integer to the floating type.
358 llvm::APFloat Result(Ctx.getFloatTypeSemantics(ToType));
359 Result.convertFromAPInt(IntConstantValue, IntConstantValue.isSigned(),
360 llvm::APFloat::rmNearestTiesToEven);
362 llvm::APSInt ConvertedValue = IntConstantValue;
364 Result.convertToInteger(ConvertedValue,
365 llvm::APFloat::rmTowardZero, &ignored);
366 // If the resulting value is different, this was a narrowing conversion.
367 if (IntConstantValue != ConvertedValue) {
368 ConstantValue = APValue(IntConstantValue);
369 ConstantType = Initializer->getType();
370 return NK_Constant_Narrowing;
373 // Variables are always narrowings.
374 return NK_Variable_Narrowing;
377 return NK_Not_Narrowing;
379 // -- from long double to double or float, or from double to float, except
380 // where the source is a constant expression and the actual value after
381 // conversion is within the range of values that can be represented (even
382 // if it cannot be represented exactly), or
383 case ICK_Floating_Conversion:
384 if (FromType->isRealFloatingType() && ToType->isRealFloatingType() &&
385 Ctx.getFloatingTypeOrder(FromType, ToType) == 1) {
386 // FromType is larger than ToType.
387 const Expr *Initializer = IgnoreNarrowingConversion(Ctx, Converted);
389 // If it's value-dependent, we can't tell whether it's narrowing.
390 if (Initializer->isValueDependent())
391 return NK_Dependent_Narrowing;
393 if (Initializer->isCXX11ConstantExpr(Ctx, &ConstantValue)) {
395 assert(ConstantValue.isFloat());
396 llvm::APFloat FloatVal = ConstantValue.getFloat();
397 // Convert the source value into the target type.
399 llvm::APFloat::opStatus ConvertStatus = FloatVal.convert(
400 Ctx.getFloatTypeSemantics(ToType),
401 llvm::APFloat::rmNearestTiesToEven, &ignored);
402 // If there was no overflow, the source value is within the range of
403 // values that can be represented.
404 if (ConvertStatus & llvm::APFloat::opOverflow) {
405 ConstantType = Initializer->getType();
406 return NK_Constant_Narrowing;
409 return NK_Variable_Narrowing;
412 return NK_Not_Narrowing;
414 // -- from an integer type or unscoped enumeration type to an integer type
415 // that cannot represent all the values of the original type, except where
416 // the source is a constant expression and the actual value after
417 // conversion will fit into the target type and will produce the original
418 // value when converted back to the original type.
419 case ICK_Integral_Conversion:
420 IntegralConversion: {
421 assert(FromType->isIntegralOrUnscopedEnumerationType());
422 assert(ToType->isIntegralOrUnscopedEnumerationType());
423 const bool FromSigned = FromType->isSignedIntegerOrEnumerationType();
424 const unsigned FromWidth = Ctx.getIntWidth(FromType);
425 const bool ToSigned = ToType->isSignedIntegerOrEnumerationType();
426 const unsigned ToWidth = Ctx.getIntWidth(ToType);
428 if (FromWidth > ToWidth ||
429 (FromWidth == ToWidth && FromSigned != ToSigned) ||
430 (FromSigned && !ToSigned)) {
431 // Not all values of FromType can be represented in ToType.
432 llvm::APSInt InitializerValue;
433 const Expr *Initializer = IgnoreNarrowingConversion(Ctx, Converted);
435 // If it's value-dependent, we can't tell whether it's narrowing.
436 if (Initializer->isValueDependent())
437 return NK_Dependent_Narrowing;
439 if (!Initializer->isIntegerConstantExpr(InitializerValue, Ctx)) {
440 // Such conversions on variables are always narrowing.
441 return NK_Variable_Narrowing;
443 bool Narrowing = false;
444 if (FromWidth < ToWidth) {
445 // Negative -> unsigned is narrowing. Otherwise, more bits is never
447 if (InitializerValue.isSigned() && InitializerValue.isNegative())
450 // Add a bit to the InitializerValue so we don't have to worry about
451 // signed vs. unsigned comparisons.
452 InitializerValue = InitializerValue.extend(
453 InitializerValue.getBitWidth() + 1);
454 // Convert the initializer to and from the target width and signed-ness.
455 llvm::APSInt ConvertedValue = InitializerValue;
456 ConvertedValue = ConvertedValue.trunc(ToWidth);
457 ConvertedValue.setIsSigned(ToSigned);
458 ConvertedValue = ConvertedValue.extend(InitializerValue.getBitWidth());
459 ConvertedValue.setIsSigned(InitializerValue.isSigned());
460 // If the result is different, this was a narrowing conversion.
461 if (ConvertedValue != InitializerValue)
465 ConstantType = Initializer->getType();
466 ConstantValue = APValue(InitializerValue);
467 return NK_Constant_Narrowing;
470 return NK_Not_Narrowing;
474 // Other kinds of conversions are not narrowings.
475 return NK_Not_Narrowing;
479 /// dump - Print this standard conversion sequence to standard
480 /// error. Useful for debugging overloading issues.
481 LLVM_DUMP_METHOD void StandardConversionSequence::dump() const {
482 raw_ostream &OS = llvm::errs();
483 bool PrintedSomething = false;
484 if (First != ICK_Identity) {
485 OS << GetImplicitConversionName(First);
486 PrintedSomething = true;
489 if (Second != ICK_Identity) {
490 if (PrintedSomething) {
493 OS << GetImplicitConversionName(Second);
495 if (CopyConstructor) {
496 OS << " (by copy constructor)";
497 } else if (DirectBinding) {
498 OS << " (direct reference binding)";
499 } else if (ReferenceBinding) {
500 OS << " (reference binding)";
502 PrintedSomething = true;
505 if (Third != ICK_Identity) {
506 if (PrintedSomething) {
509 OS << GetImplicitConversionName(Third);
510 PrintedSomething = true;
513 if (!PrintedSomething) {
514 OS << "No conversions required";
518 /// dump - Print this user-defined conversion sequence to standard
519 /// error. Useful for debugging overloading issues.
520 void UserDefinedConversionSequence::dump() const {
521 raw_ostream &OS = llvm::errs();
522 if (Before.First || Before.Second || Before.Third) {
526 if (ConversionFunction)
527 OS << '\'' << *ConversionFunction << '\'';
529 OS << "aggregate initialization";
530 if (After.First || After.Second || After.Third) {
536 /// dump - Print this implicit conversion sequence to standard
537 /// error. Useful for debugging overloading issues.
538 void ImplicitConversionSequence::dump() const {
539 raw_ostream &OS = llvm::errs();
540 if (isStdInitializerListElement())
541 OS << "Worst std::initializer_list element conversion: ";
542 switch (ConversionKind) {
543 case StandardConversion:
544 OS << "Standard conversion: ";
547 case UserDefinedConversion:
548 OS << "User-defined conversion: ";
551 case EllipsisConversion:
552 OS << "Ellipsis conversion";
554 case AmbiguousConversion:
555 OS << "Ambiguous conversion";
558 OS << "Bad conversion";
565 void AmbiguousConversionSequence::construct() {
566 new (&conversions()) ConversionSet();
569 void AmbiguousConversionSequence::destruct() {
570 conversions().~ConversionSet();
574 AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) {
575 FromTypePtr = O.FromTypePtr;
576 ToTypePtr = O.ToTypePtr;
577 new (&conversions()) ConversionSet(O.conversions());
581 // Structure used by DeductionFailureInfo to store
582 // template argument information.
583 struct DFIArguments {
584 TemplateArgument FirstArg;
585 TemplateArgument SecondArg;
587 // Structure used by DeductionFailureInfo to store
588 // template parameter and template argument information.
589 struct DFIParamWithArguments : DFIArguments {
590 TemplateParameter Param;
592 // Structure used by DeductionFailureInfo to store template argument
593 // information and the index of the problematic call argument.
594 struct DFIDeducedMismatchArgs : DFIArguments {
595 TemplateArgumentList *TemplateArgs;
596 unsigned CallArgIndex;
598 // Structure used by DeductionFailureInfo to store information about
599 // unsatisfied constraints.
601 TemplateArgumentList *TemplateArgs;
602 ConstraintSatisfaction Satisfaction;
606 /// Convert from Sema's representation of template deduction information
607 /// to the form used in overload-candidate information.
609 clang::MakeDeductionFailureInfo(ASTContext &Context,
610 Sema::TemplateDeductionResult TDK,
611 TemplateDeductionInfo &Info) {
612 DeductionFailureInfo Result;
613 Result.Result = static_cast<unsigned>(TDK);
614 Result.HasDiagnostic = false;
616 case Sema::TDK_Invalid:
617 case Sema::TDK_InstantiationDepth:
618 case Sema::TDK_TooManyArguments:
619 case Sema::TDK_TooFewArguments:
620 case Sema::TDK_MiscellaneousDeductionFailure:
621 case Sema::TDK_CUDATargetMismatch:
622 Result.Data = nullptr;
625 case Sema::TDK_Incomplete:
626 case Sema::TDK_InvalidExplicitArguments:
627 Result.Data = Info.Param.getOpaqueValue();
630 case Sema::TDK_DeducedMismatch:
631 case Sema::TDK_DeducedMismatchNested: {
632 // FIXME: Should allocate from normal heap so that we can free this later.
633 auto *Saved = new (Context) DFIDeducedMismatchArgs;
634 Saved->FirstArg = Info.FirstArg;
635 Saved->SecondArg = Info.SecondArg;
636 Saved->TemplateArgs = Info.take();
637 Saved->CallArgIndex = Info.CallArgIndex;
642 case Sema::TDK_NonDeducedMismatch: {
643 // FIXME: Should allocate from normal heap so that we can free this later.
644 DFIArguments *Saved = new (Context) DFIArguments;
645 Saved->FirstArg = Info.FirstArg;
646 Saved->SecondArg = Info.SecondArg;
651 case Sema::TDK_IncompletePack:
652 // FIXME: It's slightly wasteful to allocate two TemplateArguments for this.
653 case Sema::TDK_Inconsistent:
654 case Sema::TDK_Underqualified: {
655 // FIXME: Should allocate from normal heap so that we can free this later.
656 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments;
657 Saved->Param = Info.Param;
658 Saved->FirstArg = Info.FirstArg;
659 Saved->SecondArg = Info.SecondArg;
664 case Sema::TDK_SubstitutionFailure:
665 Result.Data = Info.take();
666 if (Info.hasSFINAEDiagnostic()) {
667 PartialDiagnosticAt *Diag = new (Result.Diagnostic) PartialDiagnosticAt(
668 SourceLocation(), PartialDiagnostic::NullDiagnostic());
669 Info.takeSFINAEDiagnostic(*Diag);
670 Result.HasDiagnostic = true;
674 case Sema::TDK_ConstraintsNotSatisfied: {
675 CNSInfo *Saved = new (Context) CNSInfo;
676 Saved->TemplateArgs = Info.take();
677 Saved->Satisfaction = Info.AssociatedConstraintsSatisfaction;
682 case Sema::TDK_Success:
683 case Sema::TDK_NonDependentConversionFailure:
684 llvm_unreachable("not a deduction failure");
690 void DeductionFailureInfo::Destroy() {
691 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
692 case Sema::TDK_Success:
693 case Sema::TDK_Invalid:
694 case Sema::TDK_InstantiationDepth:
695 case Sema::TDK_Incomplete:
696 case Sema::TDK_TooManyArguments:
697 case Sema::TDK_TooFewArguments:
698 case Sema::TDK_InvalidExplicitArguments:
699 case Sema::TDK_CUDATargetMismatch:
700 case Sema::TDK_NonDependentConversionFailure:
703 case Sema::TDK_IncompletePack:
704 case Sema::TDK_Inconsistent:
705 case Sema::TDK_Underqualified:
706 case Sema::TDK_DeducedMismatch:
707 case Sema::TDK_DeducedMismatchNested:
708 case Sema::TDK_NonDeducedMismatch:
709 // FIXME: Destroy the data?
713 case Sema::TDK_SubstitutionFailure:
714 // FIXME: Destroy the template argument list?
716 if (PartialDiagnosticAt *Diag = getSFINAEDiagnostic()) {
717 Diag->~PartialDiagnosticAt();
718 HasDiagnostic = false;
722 case Sema::TDK_ConstraintsNotSatisfied:
723 // FIXME: Destroy the template argument list?
725 if (PartialDiagnosticAt *Diag = getSFINAEDiagnostic()) {
726 Diag->~PartialDiagnosticAt();
727 HasDiagnostic = false;
732 case Sema::TDK_MiscellaneousDeductionFailure:
737 PartialDiagnosticAt *DeductionFailureInfo::getSFINAEDiagnostic() {
739 return static_cast<PartialDiagnosticAt*>(static_cast<void*>(Diagnostic));
743 TemplateParameter DeductionFailureInfo::getTemplateParameter() {
744 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
745 case Sema::TDK_Success:
746 case Sema::TDK_Invalid:
747 case Sema::TDK_InstantiationDepth:
748 case Sema::TDK_TooManyArguments:
749 case Sema::TDK_TooFewArguments:
750 case Sema::TDK_SubstitutionFailure:
751 case Sema::TDK_DeducedMismatch:
752 case Sema::TDK_DeducedMismatchNested:
753 case Sema::TDK_NonDeducedMismatch:
754 case Sema::TDK_CUDATargetMismatch:
755 case Sema::TDK_NonDependentConversionFailure:
756 case Sema::TDK_ConstraintsNotSatisfied:
757 return TemplateParameter();
759 case Sema::TDK_Incomplete:
760 case Sema::TDK_InvalidExplicitArguments:
761 return TemplateParameter::getFromOpaqueValue(Data);
763 case Sema::TDK_IncompletePack:
764 case Sema::TDK_Inconsistent:
765 case Sema::TDK_Underqualified:
766 return static_cast<DFIParamWithArguments*>(Data)->Param;
769 case Sema::TDK_MiscellaneousDeductionFailure:
773 return TemplateParameter();
776 TemplateArgumentList *DeductionFailureInfo::getTemplateArgumentList() {
777 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
778 case Sema::TDK_Success:
779 case Sema::TDK_Invalid:
780 case Sema::TDK_InstantiationDepth:
781 case Sema::TDK_TooManyArguments:
782 case Sema::TDK_TooFewArguments:
783 case Sema::TDK_Incomplete:
784 case Sema::TDK_IncompletePack:
785 case Sema::TDK_InvalidExplicitArguments:
786 case Sema::TDK_Inconsistent:
787 case Sema::TDK_Underqualified:
788 case Sema::TDK_NonDeducedMismatch:
789 case Sema::TDK_CUDATargetMismatch:
790 case Sema::TDK_NonDependentConversionFailure:
793 case Sema::TDK_DeducedMismatch:
794 case Sema::TDK_DeducedMismatchNested:
795 return static_cast<DFIDeducedMismatchArgs*>(Data)->TemplateArgs;
797 case Sema::TDK_SubstitutionFailure:
798 return static_cast<TemplateArgumentList*>(Data);
800 case Sema::TDK_ConstraintsNotSatisfied:
801 return static_cast<CNSInfo*>(Data)->TemplateArgs;
804 case Sema::TDK_MiscellaneousDeductionFailure:
811 const TemplateArgument *DeductionFailureInfo::getFirstArg() {
812 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
813 case Sema::TDK_Success:
814 case Sema::TDK_Invalid:
815 case Sema::TDK_InstantiationDepth:
816 case Sema::TDK_Incomplete:
817 case Sema::TDK_TooManyArguments:
818 case Sema::TDK_TooFewArguments:
819 case Sema::TDK_InvalidExplicitArguments:
820 case Sema::TDK_SubstitutionFailure:
821 case Sema::TDK_CUDATargetMismatch:
822 case Sema::TDK_NonDependentConversionFailure:
823 case Sema::TDK_ConstraintsNotSatisfied:
826 case Sema::TDK_IncompletePack:
827 case Sema::TDK_Inconsistent:
828 case Sema::TDK_Underqualified:
829 case Sema::TDK_DeducedMismatch:
830 case Sema::TDK_DeducedMismatchNested:
831 case Sema::TDK_NonDeducedMismatch:
832 return &static_cast<DFIArguments*>(Data)->FirstArg;
835 case Sema::TDK_MiscellaneousDeductionFailure:
842 const TemplateArgument *DeductionFailureInfo::getSecondArg() {
843 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
844 case Sema::TDK_Success:
845 case Sema::TDK_Invalid:
846 case Sema::TDK_InstantiationDepth:
847 case Sema::TDK_Incomplete:
848 case Sema::TDK_IncompletePack:
849 case Sema::TDK_TooManyArguments:
850 case Sema::TDK_TooFewArguments:
851 case Sema::TDK_InvalidExplicitArguments:
852 case Sema::TDK_SubstitutionFailure:
853 case Sema::TDK_CUDATargetMismatch:
854 case Sema::TDK_NonDependentConversionFailure:
855 case Sema::TDK_ConstraintsNotSatisfied:
858 case Sema::TDK_Inconsistent:
859 case Sema::TDK_Underqualified:
860 case Sema::TDK_DeducedMismatch:
861 case Sema::TDK_DeducedMismatchNested:
862 case Sema::TDK_NonDeducedMismatch:
863 return &static_cast<DFIArguments*>(Data)->SecondArg;
866 case Sema::TDK_MiscellaneousDeductionFailure:
873 llvm::Optional<unsigned> DeductionFailureInfo::getCallArgIndex() {
874 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
875 case Sema::TDK_DeducedMismatch:
876 case Sema::TDK_DeducedMismatchNested:
877 return static_cast<DFIDeducedMismatchArgs*>(Data)->CallArgIndex;
884 bool OverloadCandidateSet::OperatorRewriteInfo::shouldAddReversed(
885 OverloadedOperatorKind Op) {
886 if (!AllowRewrittenCandidates)
888 return Op == OO_EqualEqual || Op == OO_Spaceship;
891 bool OverloadCandidateSet::OperatorRewriteInfo::shouldAddReversed(
892 ASTContext &Ctx, const FunctionDecl *FD) {
893 if (!shouldAddReversed(FD->getDeclName().getCXXOverloadedOperator()))
895 // Don't bother adding a reversed candidate that can never be a better
896 // match than the non-reversed version.
897 return FD->getNumParams() != 2 ||
898 !Ctx.hasSameUnqualifiedType(FD->getParamDecl(0)->getType(),
899 FD->getParamDecl(1)->getType()) ||
900 FD->hasAttr<EnableIfAttr>();
903 void OverloadCandidateSet::destroyCandidates() {
904 for (iterator i = begin(), e = end(); i != e; ++i) {
905 for (auto &C : i->Conversions)
906 C.~ImplicitConversionSequence();
907 if (!i->Viable && i->FailureKind == ovl_fail_bad_deduction)
908 i->DeductionFailure.Destroy();
912 void OverloadCandidateSet::clear(CandidateSetKind CSK) {
914 SlabAllocator.Reset();
915 NumInlineBytesUsed = 0;
922 class UnbridgedCastsSet {
927 SmallVector<Entry, 2> Entries;
930 void save(Sema &S, Expr *&E) {
931 assert(E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast));
932 Entry entry = { &E, E };
933 Entries.push_back(entry);
934 E = S.stripARCUnbridgedCast(E);
938 for (SmallVectorImpl<Entry>::iterator
939 i = Entries.begin(), e = Entries.end(); i != e; ++i)
945 /// checkPlaceholderForOverload - Do any interesting placeholder-like
946 /// preprocessing on the given expression.
948 /// \param unbridgedCasts a collection to which to add unbridged casts;
949 /// without this, they will be immediately diagnosed as errors
951 /// Return true on unrecoverable error.
953 checkPlaceholderForOverload(Sema &S, Expr *&E,
954 UnbridgedCastsSet *unbridgedCasts = nullptr) {
955 if (const BuiltinType *placeholder = E->getType()->getAsPlaceholderType()) {
956 // We can't handle overloaded expressions here because overload
957 // resolution might reasonably tweak them.
958 if (placeholder->getKind() == BuiltinType::Overload) return false;
960 // If the context potentially accepts unbridged ARC casts, strip
961 // the unbridged cast and add it to the collection for later restoration.
962 if (placeholder->getKind() == BuiltinType::ARCUnbridgedCast &&
964 unbridgedCasts->save(S, E);
968 // Go ahead and check everything else.
969 ExprResult result = S.CheckPlaceholderExpr(E);
970 if (result.isInvalid())
981 /// checkArgPlaceholdersForOverload - Check a set of call operands for
983 static bool checkArgPlaceholdersForOverload(Sema &S,
985 UnbridgedCastsSet &unbridged) {
986 for (unsigned i = 0, e = Args.size(); i != e; ++i)
987 if (checkPlaceholderForOverload(S, Args[i], &unbridged))
993 /// Determine whether the given New declaration is an overload of the
994 /// declarations in Old. This routine returns Ovl_Match or Ovl_NonFunction if
995 /// New and Old cannot be overloaded, e.g., if New has the same signature as
996 /// some function in Old (C++ 1.3.10) or if the Old declarations aren't
997 /// functions (or function templates) at all. When it does return Ovl_Match or
998 /// Ovl_NonFunction, MatchedDecl will point to the decl that New cannot be
999 /// overloaded with. This decl may be a UsingShadowDecl on top of the underlying
1002 /// Example: Given the following input:
1004 /// void f(int, float); // #1
1005 /// void f(int, int); // #2
1006 /// int f(int, int); // #3
1008 /// When we process #1, there is no previous declaration of "f", so IsOverload
1009 /// will not be used.
1011 /// When we process #2, Old contains only the FunctionDecl for #1. By comparing
1012 /// the parameter types, we see that #1 and #2 are overloaded (since they have
1013 /// different signatures), so this routine returns Ovl_Overload; MatchedDecl is
1016 /// When we process #3, Old is an overload set containing #1 and #2. We compare
1017 /// the signatures of #3 to #1 (they're overloaded, so we do nothing) and then
1018 /// #3 to #2. Since the signatures of #3 and #2 are identical (return types of
1019 /// functions are not part of the signature), IsOverload returns Ovl_Match and
1020 /// MatchedDecl will be set to point to the FunctionDecl for #2.
1022 /// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced into a class
1023 /// by a using declaration. The rules for whether to hide shadow declarations
1024 /// ignore some properties which otherwise figure into a function template's
1027 Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old,
1028 NamedDecl *&Match, bool NewIsUsingDecl) {
1029 for (LookupResult::iterator I = Old.begin(), E = Old.end();
1031 NamedDecl *OldD = *I;
1033 bool OldIsUsingDecl = false;
1034 if (isa<UsingShadowDecl>(OldD)) {
1035 OldIsUsingDecl = true;
1037 // We can always introduce two using declarations into the same
1038 // context, even if they have identical signatures.
1039 if (NewIsUsingDecl) continue;
1041 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl();
1044 // A using-declaration does not conflict with another declaration
1045 // if one of them is hidden.
1046 if ((OldIsUsingDecl || NewIsUsingDecl) && !isVisible(*I))
1049 // If either declaration was introduced by a using declaration,
1050 // we'll need to use slightly different rules for matching.
1051 // Essentially, these rules are the normal rules, except that
1052 // function templates hide function templates with different
1053 // return types or template parameter lists.
1054 bool UseMemberUsingDeclRules =
1055 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord() &&
1056 !New->getFriendObjectKind();
1058 if (FunctionDecl *OldF = OldD->getAsFunction()) {
1059 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) {
1060 if (UseMemberUsingDeclRules && OldIsUsingDecl) {
1061 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I));
1065 if (!isa<FunctionTemplateDecl>(OldD) &&
1066 !shouldLinkPossiblyHiddenDecl(*I, New))
1073 // Builtins that have custom typechecking or have a reference should
1074 // not be overloadable or redeclarable.
1075 if (!getASTContext().canBuiltinBeRedeclared(OldF)) {
1077 return Ovl_NonFunction;
1079 } else if (isa<UsingDecl>(OldD) || isa<UsingPackDecl>(OldD)) {
1080 // We can overload with these, which can show up when doing
1081 // redeclaration checks for UsingDecls.
1082 assert(Old.getLookupKind() == LookupUsingDeclName);
1083 } else if (isa<TagDecl>(OldD)) {
1084 // We can always overload with tags by hiding them.
1085 } else if (auto *UUD = dyn_cast<UnresolvedUsingValueDecl>(OldD)) {
1086 // Optimistically assume that an unresolved using decl will
1087 // overload; if it doesn't, we'll have to diagnose during
1088 // template instantiation.
1090 // Exception: if the scope is dependent and this is not a class
1091 // member, the using declaration can only introduce an enumerator.
1092 if (UUD->getQualifier()->isDependent() && !UUD->isCXXClassMember()) {
1094 return Ovl_NonFunction;
1098 // Only function declarations can be overloaded; object and type
1099 // declarations cannot be overloaded.
1101 return Ovl_NonFunction;
1105 // C++ [temp.friend]p1:
1106 // For a friend function declaration that is not a template declaration:
1107 // -- if the name of the friend is a qualified or unqualified template-id,
1109 // -- if the name of the friend is a qualified-id and a matching
1110 // non-template function is found in the specified class or namespace,
1111 // the friend declaration refers to that function, otherwise,
1112 // -- if the name of the friend is a qualified-id and a matching function
1113 // template is found in the specified class or namespace, the friend
1114 // declaration refers to the deduced specialization of that function
1115 // template, otherwise
1116 // -- the name shall be an unqualified-id [...]
1117 // If we get here for a qualified friend declaration, we've just reached the
1118 // third bullet. If the type of the friend is dependent, skip this lookup
1119 // until instantiation.
1120 if (New->getFriendObjectKind() && New->getQualifier() &&
1121 !New->getDescribedFunctionTemplate() &&
1122 !New->getDependentSpecializationInfo() &&
1123 !New->getType()->isDependentType()) {
1124 LookupResult TemplateSpecResult(LookupResult::Temporary, Old);
1125 TemplateSpecResult.addAllDecls(Old);
1126 if (CheckFunctionTemplateSpecialization(New, nullptr, TemplateSpecResult,
1127 /*QualifiedFriend*/true)) {
1128 New->setInvalidDecl();
1129 return Ovl_Overload;
1132 Match = TemplateSpecResult.getAsSingle<FunctionDecl>();
1136 return Ovl_Overload;
1139 bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old,
1140 bool UseMemberUsingDeclRules, bool ConsiderCudaAttrs,
1141 bool ConsiderRequiresClauses) {
1142 // C++ [basic.start.main]p2: This function shall not be overloaded.
1146 // MSVCRT user defined entry points cannot be overloaded.
1147 if (New->isMSVCRTEntryPoint())
1150 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate();
1151 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate();
1153 // C++ [temp.fct]p2:
1154 // A function template can be overloaded with other function templates
1155 // and with normal (non-template) functions.
1156 if ((OldTemplate == nullptr) != (NewTemplate == nullptr))
1159 // Is the function New an overload of the function Old?
1160 QualType OldQType = Context.getCanonicalType(Old->getType());
1161 QualType NewQType = Context.getCanonicalType(New->getType());
1163 // Compare the signatures (C++ 1.3.10) of the two functions to
1164 // determine whether they are overloads. If we find any mismatch
1165 // in the signature, they are overloads.
1167 // If either of these functions is a K&R-style function (no
1168 // prototype), then we consider them to have matching signatures.
1169 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) ||
1170 isa<FunctionNoProtoType>(NewQType.getTypePtr()))
1173 const FunctionProtoType *OldType = cast<FunctionProtoType>(OldQType);
1174 const FunctionProtoType *NewType = cast<FunctionProtoType>(NewQType);
1176 // The signature of a function includes the types of its
1177 // parameters (C++ 1.3.10), which includes the presence or absence
1178 // of the ellipsis; see C++ DR 357).
1179 if (OldQType != NewQType &&
1180 (OldType->getNumParams() != NewType->getNumParams() ||
1181 OldType->isVariadic() != NewType->isVariadic() ||
1182 !FunctionParamTypesAreEqual(OldType, NewType)))
1185 // C++ [temp.over.link]p4:
1186 // The signature of a function template consists of its function
1187 // signature, its return type and its template parameter list. The names
1188 // of the template parameters are significant only for establishing the
1189 // relationship between the template parameters and the rest of the
1192 // We check the return type and template parameter lists for function
1193 // templates first; the remaining checks follow.
1195 // However, we don't consider either of these when deciding whether
1196 // a member introduced by a shadow declaration is hidden.
1197 if (!UseMemberUsingDeclRules && NewTemplate &&
1198 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(),
1199 OldTemplate->getTemplateParameters(),
1200 false, TPL_TemplateMatch) ||
1201 !Context.hasSameType(Old->getDeclaredReturnType(),
1202 New->getDeclaredReturnType())))
1205 // If the function is a class member, its signature includes the
1206 // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself.
1208 // As part of this, also check whether one of the member functions
1209 // is static, in which case they are not overloads (C++
1210 // 13.1p2). While not part of the definition of the signature,
1211 // this check is important to determine whether these functions
1212 // can be overloaded.
1213 CXXMethodDecl *OldMethod = dyn_cast<CXXMethodDecl>(Old);
1214 CXXMethodDecl *NewMethod = dyn_cast<CXXMethodDecl>(New);
1215 if (OldMethod && NewMethod &&
1216 !OldMethod->isStatic() && !NewMethod->isStatic()) {
1217 if (OldMethod->getRefQualifier() != NewMethod->getRefQualifier()) {
1218 if (!UseMemberUsingDeclRules &&
1219 (OldMethod->getRefQualifier() == RQ_None ||
1220 NewMethod->getRefQualifier() == RQ_None)) {
1221 // C++0x [over.load]p2:
1222 // - Member function declarations with the same name and the same
1223 // parameter-type-list as well as member function template
1224 // declarations with the same name, the same parameter-type-list, and
1225 // the same template parameter lists cannot be overloaded if any of
1226 // them, but not all, have a ref-qualifier (8.3.5).
1227 Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload)
1228 << NewMethod->getRefQualifier() << OldMethod->getRefQualifier();
1229 Diag(OldMethod->getLocation(), diag::note_previous_declaration);
1234 // We may not have applied the implicit const for a constexpr member
1235 // function yet (because we haven't yet resolved whether this is a static
1236 // or non-static member function). Add it now, on the assumption that this
1237 // is a redeclaration of OldMethod.
1238 auto OldQuals = OldMethod->getMethodQualifiers();
1239 auto NewQuals = NewMethod->getMethodQualifiers();
1240 if (!getLangOpts().CPlusPlus14 && NewMethod->isConstexpr() &&
1241 !isa<CXXConstructorDecl>(NewMethod))
1242 NewQuals.addConst();
1243 // We do not allow overloading based off of '__restrict'.
1244 OldQuals.removeRestrict();
1245 NewQuals.removeRestrict();
1246 if (OldQuals != NewQuals)
1250 // Though pass_object_size is placed on parameters and takes an argument, we
1251 // consider it to be a function-level modifier for the sake of function
1252 // identity. Either the function has one or more parameters with
1253 // pass_object_size or it doesn't.
1254 if (functionHasPassObjectSizeParams(New) !=
1255 functionHasPassObjectSizeParams(Old))
1258 // enable_if attributes are an order-sensitive part of the signature.
1259 for (specific_attr_iterator<EnableIfAttr>
1260 NewI = New->specific_attr_begin<EnableIfAttr>(),
1261 NewE = New->specific_attr_end<EnableIfAttr>(),
1262 OldI = Old->specific_attr_begin<EnableIfAttr>(),
1263 OldE = Old->specific_attr_end<EnableIfAttr>();
1264 NewI != NewE || OldI != OldE; ++NewI, ++OldI) {
1265 if (NewI == NewE || OldI == OldE)
1267 llvm::FoldingSetNodeID NewID, OldID;
1268 NewI->getCond()->Profile(NewID, Context, true);
1269 OldI->getCond()->Profile(OldID, Context, true);
1274 if (getLangOpts().CUDA && ConsiderCudaAttrs) {
1275 // Don't allow overloading of destructors. (In theory we could, but it
1276 // would be a giant change to clang.)
1277 if (!isa<CXXDestructorDecl>(New)) {
1278 CUDAFunctionTarget NewTarget = IdentifyCUDATarget(New),
1279 OldTarget = IdentifyCUDATarget(Old);
1280 if (NewTarget != CFT_InvalidTarget) {
1281 assert((OldTarget != CFT_InvalidTarget) &&
1282 "Unexpected invalid target.");
1284 // Allow overloading of functions with same signature and different CUDA
1285 // target attributes.
1286 if (NewTarget != OldTarget)
1292 if (ConsiderRequiresClauses) {
1293 Expr *NewRC = New->getTrailingRequiresClause(),
1294 *OldRC = Old->getTrailingRequiresClause();
1295 if ((NewRC != nullptr) != (OldRC != nullptr))
1296 // RC are most certainly different - these are overloads.
1300 llvm::FoldingSetNodeID NewID, OldID;
1301 NewRC->Profile(NewID, Context, /*Canonical=*/true);
1302 OldRC->Profile(OldID, Context, /*Canonical=*/true);
1304 // RCs are not equivalent - these are overloads.
1309 // The signatures match; this is not an overload.
1313 /// Tries a user-defined conversion from From to ToType.
1315 /// Produces an implicit conversion sequence for when a standard conversion
1316 /// is not an option. See TryImplicitConversion for more information.
1317 static ImplicitConversionSequence
1318 TryUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
1319 bool SuppressUserConversions,
1321 bool InOverloadResolution,
1323 bool AllowObjCWritebackConversion,
1324 bool AllowObjCConversionOnExplicit) {
1325 ImplicitConversionSequence ICS;
1327 if (SuppressUserConversions) {
1328 // We're not in the case above, so there is no conversion that
1330 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1334 // Attempt user-defined conversion.
1335 OverloadCandidateSet Conversions(From->getExprLoc(),
1336 OverloadCandidateSet::CSK_Normal);
1337 switch (IsUserDefinedConversion(S, From, ToType, ICS.UserDefined,
1338 Conversions, AllowExplicit,
1339 AllowObjCConversionOnExplicit)) {
1342 ICS.setUserDefined();
1343 // C++ [over.ics.user]p4:
1344 // A conversion of an expression of class type to the same class
1345 // type is given Exact Match rank, and a conversion of an
1346 // expression of class type to a base class of that type is
1347 // given Conversion rank, in spite of the fact that a copy
1348 // constructor (i.e., a user-defined conversion function) is
1349 // called for those cases.
1350 if (CXXConstructorDecl *Constructor
1351 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) {
1353 = S.Context.getCanonicalType(From->getType().getUnqualifiedType());
1355 = S.Context.getCanonicalType(ToType).getUnqualifiedType();
1356 if (Constructor->isCopyConstructor() &&
1357 (FromCanon == ToCanon ||
1358 S.IsDerivedFrom(From->getBeginLoc(), FromCanon, ToCanon))) {
1359 // Turn this into a "standard" conversion sequence, so that it
1360 // gets ranked with standard conversion sequences.
1361 DeclAccessPair Found = ICS.UserDefined.FoundConversionFunction;
1363 ICS.Standard.setAsIdentityConversion();
1364 ICS.Standard.setFromType(From->getType());
1365 ICS.Standard.setAllToTypes(ToType);
1366 ICS.Standard.CopyConstructor = Constructor;
1367 ICS.Standard.FoundCopyConstructor = Found;
1368 if (ToCanon != FromCanon)
1369 ICS.Standard.Second = ICK_Derived_To_Base;
1376 ICS.Ambiguous.setFromType(From->getType());
1377 ICS.Ambiguous.setToType(ToType);
1378 for (OverloadCandidateSet::iterator Cand = Conversions.begin();
1379 Cand != Conversions.end(); ++Cand)
1381 ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
1385 case OR_No_Viable_Function:
1386 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1393 /// TryImplicitConversion - Attempt to perform an implicit conversion
1394 /// from the given expression (Expr) to the given type (ToType). This
1395 /// function returns an implicit conversion sequence that can be used
1396 /// to perform the initialization. Given
1398 /// void f(float f);
1399 /// void g(int i) { f(i); }
1401 /// this routine would produce an implicit conversion sequence to
1402 /// describe the initialization of f from i, which will be a standard
1403 /// conversion sequence containing an lvalue-to-rvalue conversion (C++
1404 /// 4.1) followed by a floating-integral conversion (C++ 4.9).
1406 /// Note that this routine only determines how the conversion can be
1407 /// performed; it does not actually perform the conversion. As such,
1408 /// it will not produce any diagnostics if no conversion is available,
1409 /// but will instead return an implicit conversion sequence of kind
1410 /// "BadConversion".
1412 /// If @p SuppressUserConversions, then user-defined conversions are
1414 /// If @p AllowExplicit, then explicit user-defined conversions are
1417 /// \param AllowObjCWritebackConversion Whether we allow the Objective-C
1418 /// writeback conversion, which allows __autoreleasing id* parameters to
1419 /// be initialized with __strong id* or __weak id* arguments.
1420 static ImplicitConversionSequence
1421 TryImplicitConversion(Sema &S, Expr *From, QualType ToType,
1422 bool SuppressUserConversions,
1424 bool InOverloadResolution,
1426 bool AllowObjCWritebackConversion,
1427 bool AllowObjCConversionOnExplicit) {
1428 ImplicitConversionSequence ICS;
1429 if (IsStandardConversion(S, From, ToType, InOverloadResolution,
1430 ICS.Standard, CStyle, AllowObjCWritebackConversion)){
1435 if (!S.getLangOpts().CPlusPlus) {
1436 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1440 // C++ [over.ics.user]p4:
1441 // A conversion of an expression of class type to the same class
1442 // type is given Exact Match rank, and a conversion of an
1443 // expression of class type to a base class of that type is
1444 // given Conversion rank, in spite of the fact that a copy/move
1445 // constructor (i.e., a user-defined conversion function) is
1446 // called for those cases.
1447 QualType FromType = From->getType();
1448 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() &&
1449 (S.Context.hasSameUnqualifiedType(FromType, ToType) ||
1450 S.IsDerivedFrom(From->getBeginLoc(), FromType, ToType))) {
1452 ICS.Standard.setAsIdentityConversion();
1453 ICS.Standard.setFromType(FromType);
1454 ICS.Standard.setAllToTypes(ToType);
1456 // We don't actually check at this point whether there is a valid
1457 // copy/move constructor, since overloading just assumes that it
1458 // exists. When we actually perform initialization, we'll find the
1459 // appropriate constructor to copy the returned object, if needed.
1460 ICS.Standard.CopyConstructor = nullptr;
1462 // Determine whether this is considered a derived-to-base conversion.
1463 if (!S.Context.hasSameUnqualifiedType(FromType, ToType))
1464 ICS.Standard.Second = ICK_Derived_To_Base;
1469 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
1470 AllowExplicit, InOverloadResolution, CStyle,
1471 AllowObjCWritebackConversion,
1472 AllowObjCConversionOnExplicit);
1475 ImplicitConversionSequence
1476 Sema::TryImplicitConversion(Expr *From, QualType ToType,
1477 bool SuppressUserConversions,
1479 bool InOverloadResolution,
1481 bool AllowObjCWritebackConversion) {
1482 return ::TryImplicitConversion(*this, From, ToType,
1483 SuppressUserConversions, AllowExplicit,
1484 InOverloadResolution, CStyle,
1485 AllowObjCWritebackConversion,
1486 /*AllowObjCConversionOnExplicit=*/false);
1489 /// PerformImplicitConversion - Perform an implicit conversion of the
1490 /// expression From to the type ToType. Returns the
1491 /// converted expression. Flavor is the kind of conversion we're
1492 /// performing, used in the error message. If @p AllowExplicit,
1493 /// explicit user-defined conversions are permitted.
1495 Sema::PerformImplicitConversion(Expr *From, QualType ToType,
1496 AssignmentAction Action, bool AllowExplicit) {
1497 ImplicitConversionSequence ICS;
1498 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS);
1502 Sema::PerformImplicitConversion(Expr *From, QualType ToType,
1503 AssignmentAction Action, bool AllowExplicit,
1504 ImplicitConversionSequence& ICS) {
1505 if (checkPlaceholderForOverload(*this, From))
1508 // Objective-C ARC: Determine whether we will allow the writeback conversion.
1509 bool AllowObjCWritebackConversion
1510 = getLangOpts().ObjCAutoRefCount &&
1511 (Action == AA_Passing || Action == AA_Sending);
1512 if (getLangOpts().ObjC)
1513 CheckObjCBridgeRelatedConversions(From->getBeginLoc(), ToType,
1514 From->getType(), From);
1515 ICS = ::TryImplicitConversion(*this, From, ToType,
1516 /*SuppressUserConversions=*/false,
1518 /*InOverloadResolution=*/false,
1520 AllowObjCWritebackConversion,
1521 /*AllowObjCConversionOnExplicit=*/false);
1522 return PerformImplicitConversion(From, ToType, ICS, Action);
1525 /// Determine whether the conversion from FromType to ToType is a valid
1526 /// conversion that strips "noexcept" or "noreturn" off the nested function
1528 bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
1529 QualType &ResultTy) {
1530 if (Context.hasSameUnqualifiedType(FromType, ToType))
1533 // Permit the conversion F(t __attribute__((noreturn))) -> F(t)
1534 // or F(t noexcept) -> F(t)
1535 // where F adds one of the following at most once:
1537 // - a member pointer
1538 // - a block pointer
1539 // Changes here need matching changes in FindCompositePointerType.
1540 CanQualType CanTo = Context.getCanonicalType(ToType);
1541 CanQualType CanFrom = Context.getCanonicalType(FromType);
1542 Type::TypeClass TyClass = CanTo->getTypeClass();
1543 if (TyClass != CanFrom->getTypeClass()) return false;
1544 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) {
1545 if (TyClass == Type::Pointer) {
1546 CanTo = CanTo.castAs<PointerType>()->getPointeeType();
1547 CanFrom = CanFrom.castAs<PointerType>()->getPointeeType();
1548 } else if (TyClass == Type::BlockPointer) {
1549 CanTo = CanTo.castAs<BlockPointerType>()->getPointeeType();
1550 CanFrom = CanFrom.castAs<BlockPointerType>()->getPointeeType();
1551 } else if (TyClass == Type::MemberPointer) {
1552 auto ToMPT = CanTo.castAs<MemberPointerType>();
1553 auto FromMPT = CanFrom.castAs<MemberPointerType>();
1554 // A function pointer conversion cannot change the class of the function.
1555 if (ToMPT->getClass() != FromMPT->getClass())
1557 CanTo = ToMPT->getPointeeType();
1558 CanFrom = FromMPT->getPointeeType();
1563 TyClass = CanTo->getTypeClass();
1564 if (TyClass != CanFrom->getTypeClass()) return false;
1565 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto)
1569 const auto *FromFn = cast<FunctionType>(CanFrom);
1570 FunctionType::ExtInfo FromEInfo = FromFn->getExtInfo();
1572 const auto *ToFn = cast<FunctionType>(CanTo);
1573 FunctionType::ExtInfo ToEInfo = ToFn->getExtInfo();
1575 bool Changed = false;
1577 // Drop 'noreturn' if not present in target type.
1578 if (FromEInfo.getNoReturn() && !ToEInfo.getNoReturn()) {
1579 FromFn = Context.adjustFunctionType(FromFn, FromEInfo.withNoReturn(false));
1583 // Drop 'noexcept' if not present in target type.
1584 if (const auto *FromFPT = dyn_cast<FunctionProtoType>(FromFn)) {
1585 const auto *ToFPT = cast<FunctionProtoType>(ToFn);
1586 if (FromFPT->isNothrow() && !ToFPT->isNothrow()) {
1587 FromFn = cast<FunctionType>(
1588 Context.getFunctionTypeWithExceptionSpec(QualType(FromFPT, 0),
1594 // Convert FromFPT's ExtParameterInfo if necessary. The conversion is valid
1595 // only if the ExtParameterInfo lists of the two function prototypes can be
1596 // merged and the merged list is identical to ToFPT's ExtParameterInfo list.
1597 SmallVector<FunctionProtoType::ExtParameterInfo, 4> NewParamInfos;
1598 bool CanUseToFPT, CanUseFromFPT;
1599 if (Context.mergeExtParameterInfo(ToFPT, FromFPT, CanUseToFPT,
1600 CanUseFromFPT, NewParamInfos) &&
1601 CanUseToFPT && !CanUseFromFPT) {
1602 FunctionProtoType::ExtProtoInfo ExtInfo = FromFPT->getExtProtoInfo();
1603 ExtInfo.ExtParameterInfos =
1604 NewParamInfos.empty() ? nullptr : NewParamInfos.data();
1605 QualType QT = Context.getFunctionType(FromFPT->getReturnType(),
1606 FromFPT->getParamTypes(), ExtInfo);
1607 FromFn = QT->getAs<FunctionType>();
1615 assert(QualType(FromFn, 0).isCanonical());
1616 if (QualType(FromFn, 0) != CanTo) return false;
1622 /// Determine whether the conversion from FromType to ToType is a valid
1623 /// vector conversion.
1625 /// \param ICK Will be set to the vector conversion kind, if this is a vector
1627 static bool IsVectorConversion(Sema &S, QualType FromType,
1628 QualType ToType, ImplicitConversionKind &ICK) {
1629 // We need at least one of these types to be a vector type to have a vector
1631 if (!ToType->isVectorType() && !FromType->isVectorType())
1634 // Identical types require no conversions.
1635 if (S.Context.hasSameUnqualifiedType(FromType, ToType))
1638 // There are no conversions between extended vector types, only identity.
1639 if (ToType->isExtVectorType()) {
1640 // There are no conversions between extended vector types other than the
1641 // identity conversion.
1642 if (FromType->isExtVectorType())
1645 // Vector splat from any arithmetic type to a vector.
1646 if (FromType->isArithmeticType()) {
1647 ICK = ICK_Vector_Splat;
1652 // We can perform the conversion between vector types in the following cases:
1653 // 1)vector types are equivalent AltiVec and GCC vector types
1654 // 2)lax vector conversions are permitted and the vector types are of the
1656 if (ToType->isVectorType() && FromType->isVectorType()) {
1657 if (S.Context.areCompatibleVectorTypes(FromType, ToType) ||
1658 S.isLaxVectorConversion(FromType, ToType)) {
1659 ICK = ICK_Vector_Conversion;
1667 static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
1668 bool InOverloadResolution,
1669 StandardConversionSequence &SCS,
1672 /// IsStandardConversion - Determines whether there is a standard
1673 /// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the
1674 /// expression From to the type ToType. Standard conversion sequences
1675 /// only consider non-class types; for conversions that involve class
1676 /// types, use TryImplicitConversion. If a conversion exists, SCS will
1677 /// contain the standard conversion sequence required to perform this
1678 /// conversion and this routine will return true. Otherwise, this
1679 /// routine will return false and the value of SCS is unspecified.
1680 static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
1681 bool InOverloadResolution,
1682 StandardConversionSequence &SCS,
1684 bool AllowObjCWritebackConversion) {
1685 QualType FromType = From->getType();
1687 // Standard conversions (C++ [conv])
1688 SCS.setAsIdentityConversion();
1689 SCS.IncompatibleObjC = false;
1690 SCS.setFromType(FromType);
1691 SCS.CopyConstructor = nullptr;
1693 // There are no standard conversions for class types in C++, so
1694 // abort early. When overloading in C, however, we do permit them.
1695 if (S.getLangOpts().CPlusPlus &&
1696 (FromType->isRecordType() || ToType->isRecordType()))
1699 // The first conversion can be an lvalue-to-rvalue conversion,
1700 // array-to-pointer conversion, or function-to-pointer conversion
1703 if (FromType == S.Context.OverloadTy) {
1704 DeclAccessPair AccessPair;
1705 if (FunctionDecl *Fn
1706 = S.ResolveAddressOfOverloadedFunction(From, ToType, false,
1708 // We were able to resolve the address of the overloaded function,
1709 // so we can convert to the type of that function.
1710 FromType = Fn->getType();
1711 SCS.setFromType(FromType);
1713 // we can sometimes resolve &foo<int> regardless of ToType, so check
1714 // if the type matches (identity) or we are converting to bool
1715 if (!S.Context.hasSameUnqualifiedType(
1716 S.ExtractUnqualifiedFunctionType(ToType), FromType)) {
1718 // if the function type matches except for [[noreturn]], it's ok
1719 if (!S.IsFunctionConversion(FromType,
1720 S.ExtractUnqualifiedFunctionType(ToType), resultTy))
1721 // otherwise, only a boolean conversion is standard
1722 if (!ToType->isBooleanType())
1726 // Check if the "from" expression is taking the address of an overloaded
1727 // function and recompute the FromType accordingly. Take advantage of the
1728 // fact that non-static member functions *must* have such an address-of
1730 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn);
1731 if (Method && !Method->isStatic()) {
1732 assert(isa<UnaryOperator>(From->IgnoreParens()) &&
1733 "Non-unary operator on non-static member address");
1734 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode()
1736 "Non-address-of operator on non-static member address");
1737 const Type *ClassType
1738 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr();
1739 FromType = S.Context.getMemberPointerType(FromType, ClassType);
1740 } else if (isa<UnaryOperator>(From->IgnoreParens())) {
1741 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() ==
1743 "Non-address-of operator for overloaded function expression");
1744 FromType = S.Context.getPointerType(FromType);
1747 // Check that we've computed the proper type after overload resolution.
1748 // FIXME: FixOverloadedFunctionReference has side-effects; we shouldn't
1749 // be calling it from within an NDEBUG block.
1750 assert(S.Context.hasSameType(
1752 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType()));
1757 // Lvalue-to-rvalue conversion (C++11 4.1):
1758 // A glvalue (3.10) of a non-function, non-array type T can
1759 // be converted to a prvalue.
1760 bool argIsLValue = From->isGLValue();
1762 !FromType->isFunctionType() && !FromType->isArrayType() &&
1763 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) {
1764 SCS.First = ICK_Lvalue_To_Rvalue;
1767 // ... if the lvalue has atomic type, the value has the non-atomic version
1768 // of the type of the lvalue ...
1769 if (const AtomicType *Atomic = FromType->getAs<AtomicType>())
1770 FromType = Atomic->getValueType();
1772 // If T is a non-class type, the type of the rvalue is the
1773 // cv-unqualified version of T. Otherwise, the type of the rvalue
1774 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we
1775 // just strip the qualifiers because they don't matter.
1776 FromType = FromType.getUnqualifiedType();
1777 } else if (FromType->isArrayType()) {
1778 // Array-to-pointer conversion (C++ 4.2)
1779 SCS.First = ICK_Array_To_Pointer;
1781 // An lvalue or rvalue of type "array of N T" or "array of unknown
1782 // bound of T" can be converted to an rvalue of type "pointer to
1784 FromType = S.Context.getArrayDecayedType(FromType);
1786 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) {
1787 // This conversion is deprecated in C++03 (D.4)
1788 SCS.DeprecatedStringLiteralToCharPtr = true;
1790 // For the purpose of ranking in overload resolution
1791 // (13.3.3.1.1), this conversion is considered an
1792 // array-to-pointer conversion followed by a qualification
1793 // conversion (4.4). (C++ 4.2p2)
1794 SCS.Second = ICK_Identity;
1795 SCS.Third = ICK_Qualification;
1796 SCS.QualificationIncludesObjCLifetime = false;
1797 SCS.setAllToTypes(FromType);
1800 } else if (FromType->isFunctionType() && argIsLValue) {
1801 // Function-to-pointer conversion (C++ 4.3).
1802 SCS.First = ICK_Function_To_Pointer;
1804 if (auto *DRE = dyn_cast<DeclRefExpr>(From->IgnoreParenCasts()))
1805 if (auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl()))
1806 if (!S.checkAddressOfFunctionIsAvailable(FD))
1809 // An lvalue of function type T can be converted to an rvalue of
1810 // type "pointer to T." The result is a pointer to the
1811 // function. (C++ 4.3p1).
1812 FromType = S.Context.getPointerType(FromType);
1814 // We don't require any conversions for the first step.
1815 SCS.First = ICK_Identity;
1817 SCS.setToType(0, FromType);
1819 // The second conversion can be an integral promotion, floating
1820 // point promotion, integral conversion, floating point conversion,
1821 // floating-integral conversion, pointer conversion,
1822 // pointer-to-member conversion, or boolean conversion (C++ 4p1).
1823 // For overloading in C, this can also be a "compatible-type"
1825 bool IncompatibleObjC = false;
1826 ImplicitConversionKind SecondICK = ICK_Identity;
1827 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) {
1828 // The unqualified versions of the types are the same: there's no
1829 // conversion to do.
1830 SCS.Second = ICK_Identity;
1831 } else if (S.IsIntegralPromotion(From, FromType, ToType)) {
1832 // Integral promotion (C++ 4.5).
1833 SCS.Second = ICK_Integral_Promotion;
1834 FromType = ToType.getUnqualifiedType();
1835 } else if (S.IsFloatingPointPromotion(FromType, ToType)) {
1836 // Floating point promotion (C++ 4.6).
1837 SCS.Second = ICK_Floating_Promotion;
1838 FromType = ToType.getUnqualifiedType();
1839 } else if (S.IsComplexPromotion(FromType, ToType)) {
1840 // Complex promotion (Clang extension)
1841 SCS.Second = ICK_Complex_Promotion;
1842 FromType = ToType.getUnqualifiedType();
1843 } else if (ToType->isBooleanType() &&
1844 (FromType->isArithmeticType() ||
1845 FromType->isAnyPointerType() ||
1846 FromType->isBlockPointerType() ||
1847 FromType->isMemberPointerType() ||
1848 FromType->isNullPtrType())) {
1849 // Boolean conversions (C++ 4.12).
1850 SCS.Second = ICK_Boolean_Conversion;
1851 FromType = S.Context.BoolTy;
1852 } else if (FromType->isIntegralOrUnscopedEnumerationType() &&
1853 ToType->isIntegralType(S.Context)) {
1854 // Integral conversions (C++ 4.7).
1855 SCS.Second = ICK_Integral_Conversion;
1856 FromType = ToType.getUnqualifiedType();
1857 } else if (FromType->isAnyComplexType() && ToType->isAnyComplexType()) {
1858 // Complex conversions (C99 6.3.1.6)
1859 SCS.Second = ICK_Complex_Conversion;
1860 FromType = ToType.getUnqualifiedType();
1861 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) ||
1862 (ToType->isAnyComplexType() && FromType->isArithmeticType())) {
1863 // Complex-real conversions (C99 6.3.1.7)
1864 SCS.Second = ICK_Complex_Real;
1865 FromType = ToType.getUnqualifiedType();
1866 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) {
1867 // FIXME: disable conversions between long double and __float128 if
1868 // their representation is different until there is back end support
1869 // We of course allow this conversion if long double is really double.
1870 if (&S.Context.getFloatTypeSemantics(FromType) !=
1871 &S.Context.getFloatTypeSemantics(ToType)) {
1872 bool Float128AndLongDouble = ((FromType == S.Context.Float128Ty &&
1873 ToType == S.Context.LongDoubleTy) ||
1874 (FromType == S.Context.LongDoubleTy &&
1875 ToType == S.Context.Float128Ty));
1876 if (Float128AndLongDouble &&
1877 (&S.Context.getFloatTypeSemantics(S.Context.LongDoubleTy) ==
1878 &llvm::APFloat::PPCDoubleDouble()))
1881 // Floating point conversions (C++ 4.8).
1882 SCS.Second = ICK_Floating_Conversion;
1883 FromType = ToType.getUnqualifiedType();
1884 } else if ((FromType->isRealFloatingType() &&
1885 ToType->isIntegralType(S.Context)) ||
1886 (FromType->isIntegralOrUnscopedEnumerationType() &&
1887 ToType->isRealFloatingType())) {
1888 // Floating-integral conversions (C++ 4.9).
1889 SCS.Second = ICK_Floating_Integral;
1890 FromType = ToType.getUnqualifiedType();
1891 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) {
1892 SCS.Second = ICK_Block_Pointer_Conversion;
1893 } else if (AllowObjCWritebackConversion &&
1894 S.isObjCWritebackConversion(FromType, ToType, FromType)) {
1895 SCS.Second = ICK_Writeback_Conversion;
1896 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution,
1897 FromType, IncompatibleObjC)) {
1898 // Pointer conversions (C++ 4.10).
1899 SCS.Second = ICK_Pointer_Conversion;
1900 SCS.IncompatibleObjC = IncompatibleObjC;
1901 FromType = FromType.getUnqualifiedType();
1902 } else if (S.IsMemberPointerConversion(From, FromType, ToType,
1903 InOverloadResolution, FromType)) {
1904 // Pointer to member conversions (4.11).
1905 SCS.Second = ICK_Pointer_Member;
1906 } else if (IsVectorConversion(S, FromType, ToType, SecondICK)) {
1907 SCS.Second = SecondICK;
1908 FromType = ToType.getUnqualifiedType();
1909 } else if (!S.getLangOpts().CPlusPlus &&
1910 S.Context.typesAreCompatible(ToType, FromType)) {
1911 // Compatible conversions (Clang extension for C function overloading)
1912 SCS.Second = ICK_Compatible_Conversion;
1913 FromType = ToType.getUnqualifiedType();
1914 } else if (IsTransparentUnionStandardConversion(S, From, ToType,
1915 InOverloadResolution,
1917 SCS.Second = ICK_TransparentUnionConversion;
1919 } else if (tryAtomicConversion(S, From, ToType, InOverloadResolution, SCS,
1921 // tryAtomicConversion has updated the standard conversion sequence
1924 } else if (ToType->isEventT() &&
1925 From->isIntegerConstantExpr(S.getASTContext()) &&
1926 From->EvaluateKnownConstInt(S.getASTContext()) == 0) {
1927 SCS.Second = ICK_Zero_Event_Conversion;
1929 } else if (ToType->isQueueT() &&
1930 From->isIntegerConstantExpr(S.getASTContext()) &&
1931 (From->EvaluateKnownConstInt(S.getASTContext()) == 0)) {
1932 SCS.Second = ICK_Zero_Queue_Conversion;
1934 } else if (ToType->isSamplerT() &&
1935 From->isIntegerConstantExpr(S.getASTContext())) {
1936 SCS.Second = ICK_Compatible_Conversion;
1939 // No second conversion required.
1940 SCS.Second = ICK_Identity;
1942 SCS.setToType(1, FromType);
1944 // The third conversion can be a function pointer conversion or a
1945 // qualification conversion (C++ [conv.fctptr], [conv.qual]).
1946 bool ObjCLifetimeConversion;
1947 if (S.IsFunctionConversion(FromType, ToType, FromType)) {
1948 // Function pointer conversions (removing 'noexcept') including removal of
1949 // 'noreturn' (Clang extension).
1950 SCS.Third = ICK_Function_Conversion;
1951 } else if (S.IsQualificationConversion(FromType, ToType, CStyle,
1952 ObjCLifetimeConversion)) {
1953 SCS.Third = ICK_Qualification;
1954 SCS.QualificationIncludesObjCLifetime = ObjCLifetimeConversion;
1957 // No conversion required
1958 SCS.Third = ICK_Identity;
1961 // C++ [over.best.ics]p6:
1962 // [...] Any difference in top-level cv-qualification is
1963 // subsumed by the initialization itself and does not constitute
1964 // a conversion. [...]
1965 QualType CanonFrom = S.Context.getCanonicalType(FromType);
1966 QualType CanonTo = S.Context.getCanonicalType(ToType);
1967 if (CanonFrom.getLocalUnqualifiedType()
1968 == CanonTo.getLocalUnqualifiedType() &&
1969 CanonFrom.getLocalQualifiers() != CanonTo.getLocalQualifiers()) {
1971 CanonFrom = CanonTo;
1974 SCS.setToType(2, FromType);
1976 if (CanonFrom == CanonTo)
1979 // If we have not converted the argument type to the parameter type,
1980 // this is a bad conversion sequence, unless we're resolving an overload in C.
1981 if (S.getLangOpts().CPlusPlus || !InOverloadResolution)
1984 ExprResult ER = ExprResult{From};
1985 Sema::AssignConvertType Conv =
1986 S.CheckSingleAssignmentConstraints(ToType, ER,
1988 /*DiagnoseCFAudited=*/false,
1989 /*ConvertRHS=*/false);
1990 ImplicitConversionKind SecondConv;
1992 case Sema::Compatible:
1993 SecondConv = ICK_C_Only_Conversion;
1995 // For our purposes, discarding qualifiers is just as bad as using an
1996 // incompatible pointer. Note that an IncompatiblePointer conversion can drop
1997 // qualifiers, as well.
1998 case Sema::CompatiblePointerDiscardsQualifiers:
1999 case Sema::IncompatiblePointer:
2000 case Sema::IncompatiblePointerSign:
2001 SecondConv = ICK_Incompatible_Pointer_Conversion;
2007 // First can only be an lvalue conversion, so we pretend that this was the
2008 // second conversion. First should already be valid from earlier in the
2010 SCS.Second = SecondConv;
2011 SCS.setToType(1, ToType);
2013 // Third is Identity, because Second should rank us worse than any other
2014 // conversion. This could also be ICK_Qualification, but it's simpler to just
2015 // lump everything in with the second conversion, and we don't gain anything
2016 // from making this ICK_Qualification.
2017 SCS.Third = ICK_Identity;
2018 SCS.setToType(2, ToType);
2023 IsTransparentUnionStandardConversion(Sema &S, Expr* From,
2025 bool InOverloadResolution,
2026 StandardConversionSequence &SCS,
2029 const RecordType *UT = ToType->getAsUnionType();
2030 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>())
2032 // The field to initialize within the transparent union.
2033 RecordDecl *UD = UT->getDecl();
2034 // It's compatible if the expression matches any of the fields.
2035 for (const auto *it : UD->fields()) {
2036 if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS,
2037 CStyle, /*AllowObjCWritebackConversion=*/false)) {
2038 ToType = it->getType();
2045 /// IsIntegralPromotion - Determines whether the conversion from the
2046 /// expression From (whose potentially-adjusted type is FromType) to
2047 /// ToType is an integral promotion (C++ 4.5). If so, returns true and
2048 /// sets PromotedType to the promoted type.
2049 bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) {
2050 const BuiltinType *To = ToType->getAs<BuiltinType>();
2051 // All integers are built-in.
2056 // An rvalue of type char, signed char, unsigned char, short int, or
2057 // unsigned short int can be converted to an rvalue of type int if
2058 // int can represent all the values of the source type; otherwise,
2059 // the source rvalue can be converted to an rvalue of type unsigned
2061 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() &&
2062 !FromType->isEnumeralType()) {
2063 if (// We can promote any signed, promotable integer type to an int
2064 (FromType->isSignedIntegerType() ||
2065 // We can promote any unsigned integer type whose size is
2066 // less than int to an int.
2067 Context.getTypeSize(FromType) < Context.getTypeSize(ToType))) {
2068 return To->getKind() == BuiltinType::Int;
2071 return To->getKind() == BuiltinType::UInt;
2074 // C++11 [conv.prom]p3:
2075 // A prvalue of an unscoped enumeration type whose underlying type is not
2076 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the
2077 // following types that can represent all the values of the enumeration
2078 // (i.e., the values in the range bmin to bmax as described in 7.2): int,
2079 // unsigned int, long int, unsigned long int, long long int, or unsigned
2080 // long long int. If none of the types in that list can represent all the
2081 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration
2082 // type can be converted to an rvalue a prvalue of the extended integer type
2083 // with lowest integer conversion rank (4.13) greater than the rank of long
2084 // long in which all the values of the enumeration can be represented. If
2085 // there are two such extended types, the signed one is chosen.
2086 // C++11 [conv.prom]p4:
2087 // A prvalue of an unscoped enumeration type whose underlying type is fixed
2088 // can be converted to a prvalue of its underlying type. Moreover, if
2089 // integral promotion can be applied to its underlying type, a prvalue of an
2090 // unscoped enumeration type whose underlying type is fixed can also be
2091 // converted to a prvalue of the promoted underlying type.
2092 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) {
2093 // C++0x 7.2p9: Note that this implicit enum to int conversion is not
2094 // provided for a scoped enumeration.
2095 if (FromEnumType->getDecl()->isScoped())
2098 // We can perform an integral promotion to the underlying type of the enum,
2099 // even if that's not the promoted type. Note that the check for promoting
2100 // the underlying type is based on the type alone, and does not consider
2101 // the bitfield-ness of the actual source expression.
2102 if (FromEnumType->getDecl()->isFixed()) {
2103 QualType Underlying = FromEnumType->getDecl()->getIntegerType();
2104 return Context.hasSameUnqualifiedType(Underlying, ToType) ||
2105 IsIntegralPromotion(nullptr, Underlying, ToType);
2108 // We have already pre-calculated the promotion type, so this is trivial.
2109 if (ToType->isIntegerType() &&
2110 isCompleteType(From->getBeginLoc(), FromType))
2111 return Context.hasSameUnqualifiedType(
2112 ToType, FromEnumType->getDecl()->getPromotionType());
2114 // C++ [conv.prom]p5:
2115 // If the bit-field has an enumerated type, it is treated as any other
2116 // value of that type for promotion purposes.
2118 // ... so do not fall through into the bit-field checks below in C++.
2119 if (getLangOpts().CPlusPlus)
2123 // C++0x [conv.prom]p2:
2124 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted
2125 // to an rvalue a prvalue of the first of the following types that can
2126 // represent all the values of its underlying type: int, unsigned int,
2127 // long int, unsigned long int, long long int, or unsigned long long int.
2128 // If none of the types in that list can represent all the values of its
2129 // underlying type, an rvalue a prvalue of type char16_t, char32_t,
2130 // or wchar_t can be converted to an rvalue a prvalue of its underlying
2132 if (FromType->isAnyCharacterType() && !FromType->isCharType() &&
2133 ToType->isIntegerType()) {
2134 // Determine whether the type we're converting from is signed or
2136 bool FromIsSigned = FromType->isSignedIntegerType();
2137 uint64_t FromSize = Context.getTypeSize(FromType);
2139 // The types we'll try to promote to, in the appropriate
2140 // order. Try each of these types.
2141 QualType PromoteTypes[6] = {
2142 Context.IntTy, Context.UnsignedIntTy,
2143 Context.LongTy, Context.UnsignedLongTy ,
2144 Context.LongLongTy, Context.UnsignedLongLongTy
2146 for (int Idx = 0; Idx < 6; ++Idx) {
2147 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]);
2148 if (FromSize < ToSize ||
2149 (FromSize == ToSize &&
2150 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) {
2151 // We found the type that we can promote to. If this is the
2152 // type we wanted, we have a promotion. Otherwise, no
2154 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]);
2159 // An rvalue for an integral bit-field (9.6) can be converted to an
2160 // rvalue of type int if int can represent all the values of the
2161 // bit-field; otherwise, it can be converted to unsigned int if
2162 // unsigned int can represent all the values of the bit-field. If
2163 // the bit-field is larger yet, no integral promotion applies to
2164 // it. If the bit-field has an enumerated type, it is treated as any
2165 // other value of that type for promotion purposes (C++ 4.5p3).
2166 // FIXME: We should delay checking of bit-fields until we actually perform the
2169 // FIXME: In C, only bit-fields of types _Bool, int, or unsigned int may be
2170 // promoted, per C11 6.3.1.1/2. We promote all bit-fields (including enum
2171 // bit-fields and those whose underlying type is larger than int) for GCC
2174 if (FieldDecl *MemberDecl = From->getSourceBitField()) {
2175 llvm::APSInt BitWidth;
2176 if (FromType->isIntegralType(Context) &&
2177 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) {
2178 llvm::APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned());
2179 ToSize = Context.getTypeSize(ToType);
2181 // Are we promoting to an int from a bitfield that fits in an int?
2182 if (BitWidth < ToSize ||
2183 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) {
2184 return To->getKind() == BuiltinType::Int;
2187 // Are we promoting to an unsigned int from an unsigned bitfield
2188 // that fits into an unsigned int?
2189 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) {
2190 return To->getKind() == BuiltinType::UInt;
2198 // An rvalue of type bool can be converted to an rvalue of type int,
2199 // with false becoming zero and true becoming one (C++ 4.5p4).
2200 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) {
2207 /// IsFloatingPointPromotion - Determines whether the conversion from
2208 /// FromType to ToType is a floating point promotion (C++ 4.6). If so,
2209 /// returns true and sets PromotedType to the promoted type.
2210 bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) {
2211 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>())
2212 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) {
2213 /// An rvalue of type float can be converted to an rvalue of type
2214 /// double. (C++ 4.6p1).
2215 if (FromBuiltin->getKind() == BuiltinType::Float &&
2216 ToBuiltin->getKind() == BuiltinType::Double)
2220 // When a float is promoted to double or long double, or a
2221 // double is promoted to long double [...].
2222 if (!getLangOpts().CPlusPlus &&
2223 (FromBuiltin->getKind() == BuiltinType::Float ||
2224 FromBuiltin->getKind() == BuiltinType::Double) &&
2225 (ToBuiltin->getKind() == BuiltinType::LongDouble ||
2226 ToBuiltin->getKind() == BuiltinType::Float128))
2229 // Half can be promoted to float.
2230 if (!getLangOpts().NativeHalfType &&
2231 FromBuiltin->getKind() == BuiltinType::Half &&
2232 ToBuiltin->getKind() == BuiltinType::Float)
2239 /// Determine if a conversion is a complex promotion.
2241 /// A complex promotion is defined as a complex -> complex conversion
2242 /// where the conversion between the underlying real types is a
2243 /// floating-point or integral promotion.
2244 bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) {
2245 const ComplexType *FromComplex = FromType->getAs<ComplexType>();
2249 const ComplexType *ToComplex = ToType->getAs<ComplexType>();
2253 return IsFloatingPointPromotion(FromComplex->getElementType(),
2254 ToComplex->getElementType()) ||
2255 IsIntegralPromotion(nullptr, FromComplex->getElementType(),
2256 ToComplex->getElementType());
2259 /// BuildSimilarlyQualifiedPointerType - In a pointer conversion from
2260 /// the pointer type FromPtr to a pointer to type ToPointee, with the
2261 /// same type qualifiers as FromPtr has on its pointee type. ToType,
2262 /// if non-empty, will be a pointer to ToType that may or may not have
2263 /// the right set of qualifiers on its pointee.
2266 BuildSimilarlyQualifiedPointerType(const Type *FromPtr,
2267 QualType ToPointee, QualType ToType,
2268 ASTContext &Context,
2269 bool StripObjCLifetime = false) {
2270 assert((FromPtr->getTypeClass() == Type::Pointer ||
2271 FromPtr->getTypeClass() == Type::ObjCObjectPointer) &&
2272 "Invalid similarly-qualified pointer type");
2274 /// Conversions to 'id' subsume cv-qualifier conversions.
2275 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType())
2276 return ToType.getUnqualifiedType();
2278 QualType CanonFromPointee
2279 = Context.getCanonicalType(FromPtr->getPointeeType());
2280 QualType CanonToPointee = Context.getCanonicalType(ToPointee);
2281 Qualifiers Quals = CanonFromPointee.getQualifiers();
2283 if (StripObjCLifetime)
2284 Quals.removeObjCLifetime();
2286 // Exact qualifier match -> return the pointer type we're converting to.
2287 if (CanonToPointee.getLocalQualifiers() == Quals) {
2288 // ToType is exactly what we need. Return it.
2289 if (!ToType.isNull())
2290 return ToType.getUnqualifiedType();
2292 // Build a pointer to ToPointee. It has the right qualifiers
2294 if (isa<ObjCObjectPointerType>(ToType))
2295 return Context.getObjCObjectPointerType(ToPointee);
2296 return Context.getPointerType(ToPointee);
2299 // Just build a canonical type that has the right qualifiers.
2300 QualType QualifiedCanonToPointee
2301 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals);
2303 if (isa<ObjCObjectPointerType>(ToType))
2304 return Context.getObjCObjectPointerType(QualifiedCanonToPointee);
2305 return Context.getPointerType(QualifiedCanonToPointee);
2308 static bool isNullPointerConstantForConversion(Expr *Expr,
2309 bool InOverloadResolution,
2310 ASTContext &Context) {
2311 // Handle value-dependent integral null pointer constants correctly.
2312 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903
2313 if (Expr->isValueDependent() && !Expr->isTypeDependent() &&
2314 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType())
2315 return !InOverloadResolution;
2317 return Expr->isNullPointerConstant(Context,
2318 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
2319 : Expr::NPC_ValueDependentIsNull);
2322 /// IsPointerConversion - Determines whether the conversion of the
2323 /// expression From, which has the (possibly adjusted) type FromType,
2324 /// can be converted to the type ToType via a pointer conversion (C++
2325 /// 4.10). If so, returns true and places the converted type (that
2326 /// might differ from ToType in its cv-qualifiers at some level) into
2329 /// This routine also supports conversions to and from block pointers
2330 /// and conversions with Objective-C's 'id', 'id<protocols...>', and
2331 /// pointers to interfaces. FIXME: Once we've determined the
2332 /// appropriate overloading rules for Objective-C, we may want to
2333 /// split the Objective-C checks into a different routine; however,
2334 /// GCC seems to consider all of these conversions to be pointer
2335 /// conversions, so for now they live here. IncompatibleObjC will be
2336 /// set if the conversion is an allowed Objective-C conversion that
2337 /// should result in a warning.
2338 bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType,
2339 bool InOverloadResolution,
2340 QualType& ConvertedType,
2341 bool &IncompatibleObjC) {
2342 IncompatibleObjC = false;
2343 if (isObjCPointerConversion(FromType, ToType, ConvertedType,
2347 // Conversion from a null pointer constant to any Objective-C pointer type.
2348 if (ToType->isObjCObjectPointerType() &&
2349 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2350 ConvertedType = ToType;
2354 // Blocks: Block pointers can be converted to void*.
2355 if (FromType->isBlockPointerType() && ToType->isPointerType() &&
2356 ToType->castAs<PointerType>()->getPointeeType()->isVoidType()) {
2357 ConvertedType = ToType;
2360 // Blocks: A null pointer constant can be converted to a block
2362 if (ToType->isBlockPointerType() &&
2363 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2364 ConvertedType = ToType;
2368 // If the left-hand-side is nullptr_t, the right side can be a null
2369 // pointer constant.
2370 if (ToType->isNullPtrType() &&
2371 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2372 ConvertedType = ToType;
2376 const PointerType* ToTypePtr = ToType->getAs<PointerType>();
2380 // A null pointer constant can be converted to a pointer type (C++ 4.10p1).
2381 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2382 ConvertedType = ToType;
2386 // Beyond this point, both types need to be pointers
2387 // , including objective-c pointers.
2388 QualType ToPointeeType = ToTypePtr->getPointeeType();
2389 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType() &&
2390 !getLangOpts().ObjCAutoRefCount) {
2391 ConvertedType = BuildSimilarlyQualifiedPointerType(
2392 FromType->getAs<ObjCObjectPointerType>(),
2397 const PointerType *FromTypePtr = FromType->getAs<PointerType>();
2401 QualType FromPointeeType = FromTypePtr->getPointeeType();
2403 // If the unqualified pointee types are the same, this can't be a
2404 // pointer conversion, so don't do all of the work below.
2405 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType))
2408 // An rvalue of type "pointer to cv T," where T is an object type,
2409 // can be converted to an rvalue of type "pointer to cv void" (C++
2411 if (FromPointeeType->isIncompleteOrObjectType() &&
2412 ToPointeeType->isVoidType()) {
2413 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2416 /*StripObjCLifetime=*/true);
2420 // MSVC allows implicit function to void* type conversion.
2421 if (getLangOpts().MSVCCompat && FromPointeeType->isFunctionType() &&
2422 ToPointeeType->isVoidType()) {
2423 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2429 // When we're overloading in C, we allow a special kind of pointer
2430 // conversion for compatible-but-not-identical pointee types.
2431 if (!getLangOpts().CPlusPlus &&
2432 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) {
2433 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2439 // C++ [conv.ptr]p3:
2441 // An rvalue of type "pointer to cv D," where D is a class type,
2442 // can be converted to an rvalue of type "pointer to cv B," where
2443 // B is a base class (clause 10) of D. If B is an inaccessible
2444 // (clause 11) or ambiguous (10.2) base class of D, a program that
2445 // necessitates this conversion is ill-formed. The result of the
2446 // conversion is a pointer to the base class sub-object of the
2447 // derived class object. The null pointer value is converted to
2448 // the null pointer value of the destination type.
2450 // Note that we do not check for ambiguity or inaccessibility
2451 // here. That is handled by CheckPointerConversion.
2452 if (getLangOpts().CPlusPlus && FromPointeeType->isRecordType() &&
2453 ToPointeeType->isRecordType() &&
2454 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) &&
2455 IsDerivedFrom(From->getBeginLoc(), FromPointeeType, ToPointeeType)) {
2456 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2462 if (FromPointeeType->isVectorType() && ToPointeeType->isVectorType() &&
2463 Context.areCompatibleVectorTypes(FromPointeeType, ToPointeeType)) {
2464 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2473 /// Adopt the given qualifiers for the given type.
2474 static QualType AdoptQualifiers(ASTContext &Context, QualType T, Qualifiers Qs){
2475 Qualifiers TQs = T.getQualifiers();
2477 // Check whether qualifiers already match.
2481 if (Qs.compatiblyIncludes(TQs))
2482 return Context.getQualifiedType(T, Qs);
2484 return Context.getQualifiedType(T.getUnqualifiedType(), Qs);
2487 /// isObjCPointerConversion - Determines whether this is an
2488 /// Objective-C pointer conversion. Subroutine of IsPointerConversion,
2489 /// with the same arguments and return values.
2490 bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType,
2491 QualType& ConvertedType,
2492 bool &IncompatibleObjC) {
2493 if (!getLangOpts().ObjC)
2496 // The set of qualifiers on the type we're converting from.
2497 Qualifiers FromQualifiers = FromType.getQualifiers();
2499 // First, we handle all conversions on ObjC object pointer types.
2500 const ObjCObjectPointerType* ToObjCPtr =
2501 ToType->getAs<ObjCObjectPointerType>();
2502 const ObjCObjectPointerType *FromObjCPtr =
2503 FromType->getAs<ObjCObjectPointerType>();
2505 if (ToObjCPtr && FromObjCPtr) {
2506 // If the pointee types are the same (ignoring qualifications),
2507 // then this is not a pointer conversion.
2508 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(),
2509 FromObjCPtr->getPointeeType()))
2512 // Conversion between Objective-C pointers.
2513 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) {
2514 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType();
2515 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType();
2516 if (getLangOpts().CPlusPlus && LHS && RHS &&
2517 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs(
2518 FromObjCPtr->getPointeeType()))
2520 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2521 ToObjCPtr->getPointeeType(),
2523 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2527 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) {
2528 // Okay: this is some kind of implicit downcast of Objective-C
2529 // interfaces, which is permitted. However, we're going to
2530 // complain about it.
2531 IncompatibleObjC = true;
2532 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2533 ToObjCPtr->getPointeeType(),
2535 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2539 // Beyond this point, both types need to be C pointers or block pointers.
2540 QualType ToPointeeType;
2541 if (const PointerType *ToCPtr = ToType->getAs<PointerType>())
2542 ToPointeeType = ToCPtr->getPointeeType();
2543 else if (const BlockPointerType *ToBlockPtr =
2544 ToType->getAs<BlockPointerType>()) {
2545 // Objective C++: We're able to convert from a pointer to any object
2546 // to a block pointer type.
2547 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) {
2548 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2551 ToPointeeType = ToBlockPtr->getPointeeType();
2553 else if (FromType->getAs<BlockPointerType>() &&
2554 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) {
2555 // Objective C++: We're able to convert from a block pointer type to a
2556 // pointer to any object.
2557 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2563 QualType FromPointeeType;
2564 if (const PointerType *FromCPtr = FromType->getAs<PointerType>())
2565 FromPointeeType = FromCPtr->getPointeeType();
2566 else if (const BlockPointerType *FromBlockPtr =
2567 FromType->getAs<BlockPointerType>())
2568 FromPointeeType = FromBlockPtr->getPointeeType();
2572 // If we have pointers to pointers, recursively check whether this
2573 // is an Objective-C conversion.
2574 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() &&
2575 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2576 IncompatibleObjC)) {
2577 // We always complain about this conversion.
2578 IncompatibleObjC = true;
2579 ConvertedType = Context.getPointerType(ConvertedType);
2580 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2583 // Allow conversion of pointee being objective-c pointer to another one;
2585 if (FromPointeeType->getAs<ObjCObjectPointerType>() &&
2586 ToPointeeType->getAs<ObjCObjectPointerType>() &&
2587 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2588 IncompatibleObjC)) {
2590 ConvertedType = Context.getPointerType(ConvertedType);
2591 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2595 // If we have pointers to functions or blocks, check whether the only
2596 // differences in the argument and result types are in Objective-C
2597 // pointer conversions. If so, we permit the conversion (but
2598 // complain about it).
2599 const FunctionProtoType *FromFunctionType
2600 = FromPointeeType->getAs<FunctionProtoType>();
2601 const FunctionProtoType *ToFunctionType
2602 = ToPointeeType->getAs<FunctionProtoType>();
2603 if (FromFunctionType && ToFunctionType) {
2604 // If the function types are exactly the same, this isn't an
2605 // Objective-C pointer conversion.
2606 if (Context.getCanonicalType(FromPointeeType)
2607 == Context.getCanonicalType(ToPointeeType))
2610 // Perform the quick checks that will tell us whether these
2611 // function types are obviously different.
2612 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2613 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() ||
2614 FromFunctionType->getMethodQuals() != ToFunctionType->getMethodQuals())
2617 bool HasObjCConversion = false;
2618 if (Context.getCanonicalType(FromFunctionType->getReturnType()) ==
2619 Context.getCanonicalType(ToFunctionType->getReturnType())) {
2620 // Okay, the types match exactly. Nothing to do.
2621 } else if (isObjCPointerConversion(FromFunctionType->getReturnType(),
2622 ToFunctionType->getReturnType(),
2623 ConvertedType, IncompatibleObjC)) {
2624 // Okay, we have an Objective-C pointer conversion.
2625 HasObjCConversion = true;
2627 // Function types are too different. Abort.
2631 // Check argument types.
2632 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2633 ArgIdx != NumArgs; ++ArgIdx) {
2634 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2635 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2636 if (Context.getCanonicalType(FromArgType)
2637 == Context.getCanonicalType(ToArgType)) {
2638 // Okay, the types match exactly. Nothing to do.
2639 } else if (isObjCPointerConversion(FromArgType, ToArgType,
2640 ConvertedType, IncompatibleObjC)) {
2641 // Okay, we have an Objective-C pointer conversion.
2642 HasObjCConversion = true;
2644 // Argument types are too different. Abort.
2649 if (HasObjCConversion) {
2650 // We had an Objective-C conversion. Allow this pointer
2651 // conversion, but complain about it.
2652 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2653 IncompatibleObjC = true;
2661 /// Determine whether this is an Objective-C writeback conversion,
2662 /// used for parameter passing when performing automatic reference counting.
2664 /// \param FromType The type we're converting form.
2666 /// \param ToType The type we're converting to.
2668 /// \param ConvertedType The type that will be produced after applying
2669 /// this conversion.
2670 bool Sema::isObjCWritebackConversion(QualType FromType, QualType ToType,
2671 QualType &ConvertedType) {
2672 if (!getLangOpts().ObjCAutoRefCount ||
2673 Context.hasSameUnqualifiedType(FromType, ToType))
2676 // Parameter must be a pointer to __autoreleasing (with no other qualifiers).
2678 if (const PointerType *ToPointer = ToType->getAs<PointerType>())
2679 ToPointee = ToPointer->getPointeeType();
2683 Qualifiers ToQuals = ToPointee.getQualifiers();
2684 if (!ToPointee->isObjCLifetimeType() ||
2685 ToQuals.getObjCLifetime() != Qualifiers::OCL_Autoreleasing ||
2686 !ToQuals.withoutObjCLifetime().empty())
2689 // Argument must be a pointer to __strong to __weak.
2690 QualType FromPointee;
2691 if (const PointerType *FromPointer = FromType->getAs<PointerType>())
2692 FromPointee = FromPointer->getPointeeType();
2696 Qualifiers FromQuals = FromPointee.getQualifiers();
2697 if (!FromPointee->isObjCLifetimeType() ||
2698 (FromQuals.getObjCLifetime() != Qualifiers::OCL_Strong &&
2699 FromQuals.getObjCLifetime() != Qualifiers::OCL_Weak))
2702 // Make sure that we have compatible qualifiers.
2703 FromQuals.setObjCLifetime(Qualifiers::OCL_Autoreleasing);
2704 if (!ToQuals.compatiblyIncludes(FromQuals))
2707 // Remove qualifiers from the pointee type we're converting from; they
2708 // aren't used in the compatibility check belong, and we'll be adding back
2709 // qualifiers (with __autoreleasing) if the compatibility check succeeds.
2710 FromPointee = FromPointee.getUnqualifiedType();
2712 // The unqualified form of the pointee types must be compatible.
2713 ToPointee = ToPointee.getUnqualifiedType();
2714 bool IncompatibleObjC;
2715 if (Context.typesAreCompatible(FromPointee, ToPointee))
2716 FromPointee = ToPointee;
2717 else if (!isObjCPointerConversion(FromPointee, ToPointee, FromPointee,
2721 /// Construct the type we're converting to, which is a pointer to
2722 /// __autoreleasing pointee.
2723 FromPointee = Context.getQualifiedType(FromPointee, FromQuals);
2724 ConvertedType = Context.getPointerType(FromPointee);
2728 bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType,
2729 QualType& ConvertedType) {
2730 QualType ToPointeeType;
2731 if (const BlockPointerType *ToBlockPtr =
2732 ToType->getAs<BlockPointerType>())
2733 ToPointeeType = ToBlockPtr->getPointeeType();
2737 QualType FromPointeeType;
2738 if (const BlockPointerType *FromBlockPtr =
2739 FromType->getAs<BlockPointerType>())
2740 FromPointeeType = FromBlockPtr->getPointeeType();
2743 // We have pointer to blocks, check whether the only
2744 // differences in the argument and result types are in Objective-C
2745 // pointer conversions. If so, we permit the conversion.
2747 const FunctionProtoType *FromFunctionType
2748 = FromPointeeType->getAs<FunctionProtoType>();
2749 const FunctionProtoType *ToFunctionType
2750 = ToPointeeType->getAs<FunctionProtoType>();
2752 if (!FromFunctionType || !ToFunctionType)
2755 if (Context.hasSameType(FromPointeeType, ToPointeeType))
2758 // Perform the quick checks that will tell us whether these
2759 // function types are obviously different.
2760 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2761 FromFunctionType->isVariadic() != ToFunctionType->isVariadic())
2764 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo();
2765 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo();
2766 if (FromEInfo != ToEInfo)
2769 bool IncompatibleObjC = false;
2770 if (Context.hasSameType(FromFunctionType->getReturnType(),
2771 ToFunctionType->getReturnType())) {
2772 // Okay, the types match exactly. Nothing to do.
2774 QualType RHS = FromFunctionType->getReturnType();
2775 QualType LHS = ToFunctionType->getReturnType();
2776 if ((!getLangOpts().CPlusPlus || !RHS->isRecordType()) &&
2777 !RHS.hasQualifiers() && LHS.hasQualifiers())
2778 LHS = LHS.getUnqualifiedType();
2780 if (Context.hasSameType(RHS,LHS)) {
2782 } else if (isObjCPointerConversion(RHS, LHS,
2783 ConvertedType, IncompatibleObjC)) {
2784 if (IncompatibleObjC)
2786 // Okay, we have an Objective-C pointer conversion.
2792 // Check argument types.
2793 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2794 ArgIdx != NumArgs; ++ArgIdx) {
2795 IncompatibleObjC = false;
2796 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2797 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2798 if (Context.hasSameType(FromArgType, ToArgType)) {
2799 // Okay, the types match exactly. Nothing to do.
2800 } else if (isObjCPointerConversion(ToArgType, FromArgType,
2801 ConvertedType, IncompatibleObjC)) {
2802 if (IncompatibleObjC)
2804 // Okay, we have an Objective-C pointer conversion.
2806 // Argument types are too different. Abort.
2810 SmallVector<FunctionProtoType::ExtParameterInfo, 4> NewParamInfos;
2811 bool CanUseToFPT, CanUseFromFPT;
2812 if (!Context.mergeExtParameterInfo(ToFunctionType, FromFunctionType,
2813 CanUseToFPT, CanUseFromFPT,
2817 ConvertedType = ToType;
2825 ft_parameter_mismatch,
2827 ft_qualifer_mismatch,
2831 /// Attempts to get the FunctionProtoType from a Type. Handles
2832 /// MemberFunctionPointers properly.
2833 static const FunctionProtoType *tryGetFunctionProtoType(QualType FromType) {
2834 if (auto *FPT = FromType->getAs<FunctionProtoType>())
2837 if (auto *MPT = FromType->getAs<MemberPointerType>())
2838 return MPT->getPointeeType()->getAs<FunctionProtoType>();
2843 /// HandleFunctionTypeMismatch - Gives diagnostic information for differeing
2844 /// function types. Catches different number of parameter, mismatch in
2845 /// parameter types, and different return types.
2846 void Sema::HandleFunctionTypeMismatch(PartialDiagnostic &PDiag,
2847 QualType FromType, QualType ToType) {
2848 // If either type is not valid, include no extra info.
2849 if (FromType.isNull() || ToType.isNull()) {
2850 PDiag << ft_default;
2854 // Get the function type from the pointers.
2855 if (FromType->isMemberPointerType() && ToType->isMemberPointerType()) {
2856 const auto *FromMember = FromType->castAs<MemberPointerType>(),
2857 *ToMember = ToType->castAs<MemberPointerType>();
2858 if (!Context.hasSameType(FromMember->getClass(), ToMember->getClass())) {
2859 PDiag << ft_different_class << QualType(ToMember->getClass(), 0)
2860 << QualType(FromMember->getClass(), 0);
2863 FromType = FromMember->getPointeeType();
2864 ToType = ToMember->getPointeeType();
2867 if (FromType->isPointerType())
2868 FromType = FromType->getPointeeType();
2869 if (ToType->isPointerType())
2870 ToType = ToType->getPointeeType();
2872 // Remove references.
2873 FromType = FromType.getNonReferenceType();
2874 ToType = ToType.getNonReferenceType();
2876 // Don't print extra info for non-specialized template functions.
2877 if (FromType->isInstantiationDependentType() &&
2878 !FromType->getAs<TemplateSpecializationType>()) {
2879 PDiag << ft_default;
2883 // No extra info for same types.
2884 if (Context.hasSameType(FromType, ToType)) {
2885 PDiag << ft_default;
2889 const FunctionProtoType *FromFunction = tryGetFunctionProtoType(FromType),
2890 *ToFunction = tryGetFunctionProtoType(ToType);
2892 // Both types need to be function types.
2893 if (!FromFunction || !ToFunction) {
2894 PDiag << ft_default;
2898 if (FromFunction->getNumParams() != ToFunction->getNumParams()) {
2899 PDiag << ft_parameter_arity << ToFunction->getNumParams()
2900 << FromFunction->getNumParams();
2904 // Handle different parameter types.
2906 if (!FunctionParamTypesAreEqual(FromFunction, ToFunction, &ArgPos)) {
2907 PDiag << ft_parameter_mismatch << ArgPos + 1
2908 << ToFunction->getParamType(ArgPos)
2909 << FromFunction->getParamType(ArgPos);
2913 // Handle different return type.
2914 if (!Context.hasSameType(FromFunction->getReturnType(),
2915 ToFunction->getReturnType())) {
2916 PDiag << ft_return_type << ToFunction->getReturnType()
2917 << FromFunction->getReturnType();
2921 if (FromFunction->getMethodQuals() != ToFunction->getMethodQuals()) {
2922 PDiag << ft_qualifer_mismatch << ToFunction->getMethodQuals()
2923 << FromFunction->getMethodQuals();
2927 // Handle exception specification differences on canonical type (in C++17
2929 if (cast<FunctionProtoType>(FromFunction->getCanonicalTypeUnqualified())
2931 cast<FunctionProtoType>(ToFunction->getCanonicalTypeUnqualified())
2933 PDiag << ft_noexcept;
2937 // Unable to find a difference, so add no extra info.
2938 PDiag << ft_default;
2941 /// FunctionParamTypesAreEqual - This routine checks two function proto types
2942 /// for equality of their argument types. Caller has already checked that
2943 /// they have same number of arguments. If the parameters are different,
2944 /// ArgPos will have the parameter index of the first different parameter.
2945 bool Sema::FunctionParamTypesAreEqual(const FunctionProtoType *OldType,
2946 const FunctionProtoType *NewType,
2948 for (FunctionProtoType::param_type_iterator O = OldType->param_type_begin(),
2949 N = NewType->param_type_begin(),
2950 E = OldType->param_type_end();
2951 O && (O != E); ++O, ++N) {
2952 // Ignore address spaces in pointee type. This is to disallow overloading
2953 // on __ptr32/__ptr64 address spaces.
2954 QualType Old = Context.removePtrSizeAddrSpace(O->getUnqualifiedType());
2955 QualType New = Context.removePtrSizeAddrSpace(N->getUnqualifiedType());
2957 if (!Context.hasSameType(Old, New)) {
2959 *ArgPos = O - OldType->param_type_begin();
2966 /// CheckPointerConversion - Check the pointer conversion from the
2967 /// expression From to the type ToType. This routine checks for
2968 /// ambiguous or inaccessible derived-to-base pointer
2969 /// conversions for which IsPointerConversion has already returned
2970 /// true. It returns true and produces a diagnostic if there was an
2971 /// error, or returns false otherwise.
2972 bool Sema::CheckPointerConversion(Expr *From, QualType ToType,
2974 CXXCastPath& BasePath,
2975 bool IgnoreBaseAccess,
2977 QualType FromType = From->getType();
2978 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess;
2982 if (Diagnose && !IsCStyleOrFunctionalCast && !FromType->isAnyPointerType() &&
2983 From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) ==
2984 Expr::NPCK_ZeroExpression) {
2985 if (Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy))
2986 DiagRuntimeBehavior(From->getExprLoc(), From,
2987 PDiag(diag::warn_impcast_bool_to_null_pointer)
2988 << ToType << From->getSourceRange());
2989 else if (!isUnevaluatedContext())
2990 Diag(From->getExprLoc(), diag::warn_non_literal_null_pointer)
2991 << ToType << From->getSourceRange();
2993 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) {
2994 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) {
2995 QualType FromPointeeType = FromPtrType->getPointeeType(),
2996 ToPointeeType = ToPtrType->getPointeeType();
2998 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() &&
2999 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) {
3000 // We must have a derived-to-base conversion. Check an
3001 // ambiguous or inaccessible conversion.
3002 unsigned InaccessibleID = 0;
3003 unsigned AmbigiousID = 0;
3005 InaccessibleID = diag::err_upcast_to_inaccessible_base;
3006 AmbigiousID = diag::err_ambiguous_derived_to_base_conv;
3008 if (CheckDerivedToBaseConversion(
3009 FromPointeeType, ToPointeeType, InaccessibleID, AmbigiousID,
3010 From->getExprLoc(), From->getSourceRange(), DeclarationName(),
3011 &BasePath, IgnoreBaseAccess))
3014 // The conversion was successful.
3015 Kind = CK_DerivedToBase;
3018 if (Diagnose && !IsCStyleOrFunctionalCast &&
3019 FromPointeeType->isFunctionType() && ToPointeeType->isVoidType()) {
3020 assert(getLangOpts().MSVCCompat &&
3021 "this should only be possible with MSVCCompat!");
3022 Diag(From->getExprLoc(), diag::ext_ms_impcast_fn_obj)
3023 << From->getSourceRange();
3026 } else if (const ObjCObjectPointerType *ToPtrType =
3027 ToType->getAs<ObjCObjectPointerType>()) {
3028 if (const ObjCObjectPointerType *FromPtrType =
3029 FromType->getAs<ObjCObjectPointerType>()) {
3030 // Objective-C++ conversions are always okay.
3031 // FIXME: We should have a different class of conversions for the
3032 // Objective-C++ implicit conversions.
3033 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType())
3035 } else if (FromType->isBlockPointerType()) {
3036 Kind = CK_BlockPointerToObjCPointerCast;
3038 Kind = CK_CPointerToObjCPointerCast;
3040 } else if (ToType->isBlockPointerType()) {
3041 if (!FromType->isBlockPointerType())
3042 Kind = CK_AnyPointerToBlockPointerCast;
3045 // We shouldn't fall into this case unless it's valid for other
3047 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull))
3048 Kind = CK_NullToPointer;
3053 /// IsMemberPointerConversion - Determines whether the conversion of the
3054 /// expression From, which has the (possibly adjusted) type FromType, can be
3055 /// converted to the type ToType via a member pointer conversion (C++ 4.11).
3056 /// If so, returns true and places the converted type (that might differ from
3057 /// ToType in its cv-qualifiers at some level) into ConvertedType.
3058 bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType,
3060 bool InOverloadResolution,
3061 QualType &ConvertedType) {
3062 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>();
3066 // A null pointer constant can be converted to a member pointer (C++ 4.11p1)
3067 if (From->isNullPointerConstant(Context,
3068 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
3069 : Expr::NPC_ValueDependentIsNull)) {
3070 ConvertedType = ToType;
3074 // Otherwise, both types have to be member pointers.
3075 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>();
3079 // A pointer to member of B can be converted to a pointer to member of D,
3080 // where D is derived from B (C++ 4.11p2).
3081 QualType FromClass(FromTypePtr->getClass(), 0);
3082 QualType ToClass(ToTypePtr->getClass(), 0);
3084 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) &&
3085 IsDerivedFrom(From->getBeginLoc(), ToClass, FromClass)) {
3086 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(),
3087 ToClass.getTypePtr());
3094 /// CheckMemberPointerConversion - Check the member pointer conversion from the
3095 /// expression From to the type ToType. This routine checks for ambiguous or
3096 /// virtual or inaccessible base-to-derived member pointer conversions
3097 /// for which IsMemberPointerConversion has already returned true. It returns
3098 /// true and produces a diagnostic if there was an error, or returns false
3100 bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType,
3102 CXXCastPath &BasePath,
3103 bool IgnoreBaseAccess) {
3104 QualType FromType = From->getType();
3105 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>();
3107 // This must be a null pointer to member pointer conversion
3108 assert(From->isNullPointerConstant(Context,
3109 Expr::NPC_ValueDependentIsNull) &&
3110 "Expr must be null pointer constant!");
3111 Kind = CK_NullToMemberPointer;
3115 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>();
3116 assert(ToPtrType && "No member pointer cast has a target type "
3117 "that is not a member pointer.");
3119 QualType FromClass = QualType(FromPtrType->getClass(), 0);
3120 QualType ToClass = QualType(ToPtrType->getClass(), 0);
3122 // FIXME: What about dependent types?
3123 assert(FromClass->isRecordType() && "Pointer into non-class.");
3124 assert(ToClass->isRecordType() && "Pointer into non-class.");
3126 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
3127 /*DetectVirtual=*/true);
3128 bool DerivationOkay =
3129 IsDerivedFrom(From->getBeginLoc(), ToClass, FromClass, Paths);
3130 assert(DerivationOkay &&
3131 "Should not have been called if derivation isn't OK.");
3132 (void)DerivationOkay;
3134 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass).
3135 getUnqualifiedType())) {
3136 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
3137 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv)
3138 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange();
3142 if (const RecordType *VBase = Paths.getDetectedVirtual()) {
3143 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual)
3144 << FromClass << ToClass << QualType(VBase, 0)
3145 << From->getSourceRange();
3149 if (!IgnoreBaseAccess)
3150 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass,
3152 diag::err_downcast_from_inaccessible_base);
3154 // Must be a base to derived member conversion.
3155 BuildBasePathArray(Paths, BasePath);
3156 Kind = CK_BaseToDerivedMemberPointer;
3160 /// Determine whether the lifetime conversion between the two given
3161 /// qualifiers sets is nontrivial.
3162 static bool isNonTrivialObjCLifetimeConversion(Qualifiers FromQuals,
3163 Qualifiers ToQuals) {
3164 // Converting anything to const __unsafe_unretained is trivial.
3165 if (ToQuals.hasConst() &&
3166 ToQuals.getObjCLifetime() == Qualifiers::OCL_ExplicitNone)
3172 /// Perform a single iteration of the loop for checking if a qualification
3173 /// conversion is valid.
3175 /// Specifically, check whether any change between the qualifiers of \p
3176 /// FromType and \p ToType is permissible, given knowledge about whether every
3177 /// outer layer is const-qualified.
3178 static bool isQualificationConversionStep(QualType FromType, QualType ToType,
3180 bool &PreviousToQualsIncludeConst,
3181 bool &ObjCLifetimeConversion) {
3182 Qualifiers FromQuals = FromType.getQualifiers();
3183 Qualifiers ToQuals = ToType.getQualifiers();
3185 // Ignore __unaligned qualifier if this type is void.
3186 if (ToType.getUnqualifiedType()->isVoidType())
3187 FromQuals.removeUnaligned();
3190 // Check Objective-C lifetime conversions.
3191 if (FromQuals.getObjCLifetime() != ToQuals.getObjCLifetime()) {
3192 if (ToQuals.compatiblyIncludesObjCLifetime(FromQuals)) {
3193 if (isNonTrivialObjCLifetimeConversion(FromQuals, ToQuals))
3194 ObjCLifetimeConversion = true;
3195 FromQuals.removeObjCLifetime();
3196 ToQuals.removeObjCLifetime();
3198 // Qualification conversions cannot cast between different
3199 // Objective-C lifetime qualifiers.
3204 // Allow addition/removal of GC attributes but not changing GC attributes.
3205 if (FromQuals.getObjCGCAttr() != ToQuals.getObjCGCAttr() &&
3206 (!FromQuals.hasObjCGCAttr() || !ToQuals.hasObjCGCAttr())) {
3207 FromQuals.removeObjCGCAttr();
3208 ToQuals.removeObjCGCAttr();
3211 // -- for every j > 0, if const is in cv 1,j then const is in cv
3212 // 2,j, and similarly for volatile.
3213 if (!CStyle && !ToQuals.compatiblyIncludes(FromQuals))
3216 // For a C-style cast, just require the address spaces to overlap.
3217 // FIXME: Does "superset" also imply the representation of a pointer is the
3218 // same? We're assuming that it does here and in compatiblyIncludes.
3219 if (CStyle && !ToQuals.isAddressSpaceSupersetOf(FromQuals) &&
3220 !FromQuals.isAddressSpaceSupersetOf(ToQuals))
3223 // -- if the cv 1,j and cv 2,j are different, then const is in
3224 // every cv for 0 < k < j.
3225 if (!CStyle && FromQuals.getCVRQualifiers() != ToQuals.getCVRQualifiers() &&
3226 !PreviousToQualsIncludeConst)
3229 // Keep track of whether all prior cv-qualifiers in the "to" type
3231 PreviousToQualsIncludeConst =
3232 PreviousToQualsIncludeConst && ToQuals.hasConst();
3236 /// IsQualificationConversion - Determines whether the conversion from
3237 /// an rvalue of type FromType to ToType is a qualification conversion
3240 /// \param ObjCLifetimeConversion Output parameter that will be set to indicate
3241 /// when the qualification conversion involves a change in the Objective-C
3242 /// object lifetime.
3244 Sema::IsQualificationConversion(QualType FromType, QualType ToType,
3245 bool CStyle, bool &ObjCLifetimeConversion) {
3246 FromType = Context.getCanonicalType(FromType);
3247 ToType = Context.getCanonicalType(ToType);
3248 ObjCLifetimeConversion = false;
3250 // If FromType and ToType are the same type, this is not a
3251 // qualification conversion.
3252 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType())
3256 // A conversion can add cv-qualifiers at levels other than the first
3257 // in multi-level pointers, subject to the following rules: [...]
3258 bool PreviousToQualsIncludeConst = true;
3259 bool UnwrappedAnyPointer = false;
3260 while (Context.UnwrapSimilarTypes(FromType, ToType)) {
3261 if (!isQualificationConversionStep(FromType, ToType, CStyle,
3262 PreviousToQualsIncludeConst,
3263 ObjCLifetimeConversion))
3265 UnwrappedAnyPointer = true;
3268 // We are left with FromType and ToType being the pointee types
3269 // after unwrapping the original FromType and ToType the same number
3270 // of times. If we unwrapped any pointers, and if FromType and
3271 // ToType have the same unqualified type (since we checked
3272 // qualifiers above), then this is a qualification conversion.
3273 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType);
3276 /// - Determine whether this is a conversion from a scalar type to an
3279 /// If successful, updates \c SCS's second and third steps in the conversion
3280 /// sequence to finish the conversion.
3281 static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
3282 bool InOverloadResolution,
3283 StandardConversionSequence &SCS,
3285 const AtomicType *ToAtomic = ToType->getAs<AtomicType>();
3289 StandardConversionSequence InnerSCS;
3290 if (!IsStandardConversion(S, From, ToAtomic->getValueType(),
3291 InOverloadResolution, InnerSCS,
3292 CStyle, /*AllowObjCWritebackConversion=*/false))
3295 SCS.Second = InnerSCS.Second;
3296 SCS.setToType(1, InnerSCS.getToType(1));
3297 SCS.Third = InnerSCS.Third;
3298 SCS.QualificationIncludesObjCLifetime
3299 = InnerSCS.QualificationIncludesObjCLifetime;
3300 SCS.setToType(2, InnerSCS.getToType(2));
3304 static bool isFirstArgumentCompatibleWithType(ASTContext &Context,
3305 CXXConstructorDecl *Constructor,
3307 const auto *CtorType = Constructor->getType()->castAs<FunctionProtoType>();
3308 if (CtorType->getNumParams() > 0) {
3309 QualType FirstArg = CtorType->getParamType(0);
3310 if (Context.hasSameUnqualifiedType(Type, FirstArg.getNonReferenceType()))
3316 static OverloadingResult
3317 IsInitializerListConstructorConversion(Sema &S, Expr *From, QualType ToType,
3319 UserDefinedConversionSequence &User,
3320 OverloadCandidateSet &CandidateSet,
3321 bool AllowExplicit) {
3322 CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion);
3323 for (auto *D : S.LookupConstructors(To)) {
3324 auto Info = getConstructorInfo(D);
3328 bool Usable = !Info.Constructor->isInvalidDecl() &&
3329 S.isInitListConstructor(Info.Constructor);
3331 // If the first argument is (a reference to) the target type,
3332 // suppress conversions.
3333 bool SuppressUserConversions = isFirstArgumentCompatibleWithType(
3334 S.Context, Info.Constructor, ToType);
3335 if (Info.ConstructorTmpl)
3336 S.AddTemplateOverloadCandidate(Info.ConstructorTmpl, Info.FoundDecl,
3337 /*ExplicitArgs*/ nullptr, From,
3338 CandidateSet, SuppressUserConversions,
3339 /*PartialOverloading*/ false,
3342 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl, From,
3343 CandidateSet, SuppressUserConversions,
3344 /*PartialOverloading*/ false, AllowExplicit);
3348 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3350 OverloadCandidateSet::iterator Best;
3351 switch (auto Result =
3352 CandidateSet.BestViableFunction(S, From->getBeginLoc(), Best)) {
3355 // Record the standard conversion we used and the conversion function.
3356 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function);
3357 QualType ThisType = Constructor->getThisType();
3358 // Initializer lists don't have conversions as such.
3359 User.Before.setAsIdentityConversion();
3360 User.HadMultipleCandidates = HadMultipleCandidates;
3361 User.ConversionFunction = Constructor;
3362 User.FoundConversionFunction = Best->FoundDecl;
3363 User.After.setAsIdentityConversion();
3364 User.After.setFromType(ThisType->castAs<PointerType>()->getPointeeType());
3365 User.After.setAllToTypes(ToType);
3369 case OR_No_Viable_Function:
3370 return OR_No_Viable_Function;
3372 return OR_Ambiguous;
3375 llvm_unreachable("Invalid OverloadResult!");
3378 /// Determines whether there is a user-defined conversion sequence
3379 /// (C++ [over.ics.user]) that converts expression From to the type
3380 /// ToType. If such a conversion exists, User will contain the
3381 /// user-defined conversion sequence that performs such a conversion
3382 /// and this routine will return true. Otherwise, this routine returns
3383 /// false and User is unspecified.
3385 /// \param AllowExplicit true if the conversion should consider C++0x
3386 /// "explicit" conversion functions as well as non-explicit conversion
3387 /// functions (C++0x [class.conv.fct]p2).
3389 /// \param AllowObjCConversionOnExplicit true if the conversion should
3390 /// allow an extra Objective-C pointer conversion on uses of explicit
3391 /// constructors. Requires \c AllowExplicit to also be set.
3392 static OverloadingResult
3393 IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
3394 UserDefinedConversionSequence &User,
3395 OverloadCandidateSet &CandidateSet,
3397 bool AllowObjCConversionOnExplicit) {
3398 assert(AllowExplicit || !AllowObjCConversionOnExplicit);
3399 CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion);
3401 // Whether we will only visit constructors.
3402 bool ConstructorsOnly = false;
3404 // If the type we are conversion to is a class type, enumerate its
3406 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) {
3407 // C++ [over.match.ctor]p1:
3408 // When objects of class type are direct-initialized (8.5), or
3409 // copy-initialized from an expression of the same or a
3410 // derived class type (8.5), overload resolution selects the
3411 // constructor. [...] For copy-initialization, the candidate
3412 // functions are all the converting constructors (12.3.1) of
3413 // that class. The argument list is the expression-list within
3414 // the parentheses of the initializer.
3415 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) ||
3416 (From->getType()->getAs<RecordType>() &&
3417 S.IsDerivedFrom(From->getBeginLoc(), From->getType(), ToType)))
3418 ConstructorsOnly = true;
3420 if (!S.isCompleteType(From->getExprLoc(), ToType)) {
3421 // We're not going to find any constructors.
3422 } else if (CXXRecordDecl *ToRecordDecl
3423 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) {
3425 Expr **Args = &From;
3426 unsigned NumArgs = 1;
3427 bool ListInitializing = false;
3428 if (InitListExpr *InitList = dyn_cast<InitListExpr>(From)) {
3429 // But first, see if there is an init-list-constructor that will work.
3430 OverloadingResult Result = IsInitializerListConstructorConversion(
3431 S, From, ToType, ToRecordDecl, User, CandidateSet, AllowExplicit);
3432 if (Result != OR_No_Viable_Function)
3436 OverloadCandidateSet::CSK_InitByUserDefinedConversion);
3438 // If we're list-initializing, we pass the individual elements as
3439 // arguments, not the entire list.
3440 Args = InitList->getInits();
3441 NumArgs = InitList->getNumInits();
3442 ListInitializing = true;
3445 for (auto *D : S.LookupConstructors(ToRecordDecl)) {
3446 auto Info = getConstructorInfo(D);
3450 bool Usable = !Info.Constructor->isInvalidDecl();
3451 if (!ListInitializing)
3452 Usable = Usable && Info.Constructor->isConvertingConstructor(
3453 /*AllowExplicit*/ true);
3455 bool SuppressUserConversions = !ConstructorsOnly;
3456 if (SuppressUserConversions && ListInitializing) {
3457 SuppressUserConversions = false;
3459 // If the first argument is (a reference to) the target type,
3460 // suppress conversions.
3461 SuppressUserConversions = isFirstArgumentCompatibleWithType(
3462 S.Context, Info.Constructor, ToType);
3465 if (Info.ConstructorTmpl)
3466 S.AddTemplateOverloadCandidate(
3467 Info.ConstructorTmpl, Info.FoundDecl,
3468 /*ExplicitArgs*/ nullptr, llvm::makeArrayRef(Args, NumArgs),
3469 CandidateSet, SuppressUserConversions,
3470 /*PartialOverloading*/ false, AllowExplicit);
3472 // Allow one user-defined conversion when user specifies a
3473 // From->ToType conversion via an static cast (c-style, etc).
3474 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl,
3475 llvm::makeArrayRef(Args, NumArgs),
3476 CandidateSet, SuppressUserConversions,
3477 /*PartialOverloading*/ false, AllowExplicit);
3483 // Enumerate conversion functions, if we're allowed to.
3484 if (ConstructorsOnly || isa<InitListExpr>(From)) {
3485 } else if (!S.isCompleteType(From->getBeginLoc(), From->getType())) {
3486 // No conversion functions from incomplete types.
3487 } else if (const RecordType *FromRecordType =
3488 From->getType()->getAs<RecordType>()) {
3489 if (CXXRecordDecl *FromRecordDecl
3490 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) {
3491 // Add all of the conversion functions as candidates.
3492 const auto &Conversions = FromRecordDecl->getVisibleConversionFunctions();
3493 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
3494 DeclAccessPair FoundDecl = I.getPair();
3495 NamedDecl *D = FoundDecl.getDecl();
3496 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
3497 if (isa<UsingShadowDecl>(D))
3498 D = cast<UsingShadowDecl>(D)->getTargetDecl();
3500 CXXConversionDecl *Conv;
3501 FunctionTemplateDecl *ConvTemplate;
3502 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
3503 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
3505 Conv = cast<CXXConversionDecl>(D);
3508 S.AddTemplateConversionCandidate(
3509 ConvTemplate, FoundDecl, ActingContext, From, ToType,
3510 CandidateSet, AllowObjCConversionOnExplicit, AllowExplicit);
3512 S.AddConversionCandidate(
3513 Conv, FoundDecl, ActingContext, From, ToType, CandidateSet,
3514 AllowObjCConversionOnExplicit, AllowExplicit);
3519 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3521 OverloadCandidateSet::iterator Best;
3522 switch (auto Result =
3523 CandidateSet.BestViableFunction(S, From->getBeginLoc(), Best)) {
3526 // Record the standard conversion we used and the conversion function.
3527 if (CXXConstructorDecl *Constructor
3528 = dyn_cast<CXXConstructorDecl>(Best->Function)) {
3529 // C++ [over.ics.user]p1:
3530 // If the user-defined conversion is specified by a
3531 // constructor (12.3.1), the initial standard conversion
3532 // sequence converts the source type to the type required by
3533 // the argument of the constructor.
3535 QualType ThisType = Constructor->getThisType();
3536 if (isa<InitListExpr>(From)) {
3537 // Initializer lists don't have conversions as such.
3538 User.Before.setAsIdentityConversion();
3540 if (Best->Conversions[0].isEllipsis())
3541 User.EllipsisConversion = true;
3543 User.Before = Best->Conversions[0].Standard;
3544 User.EllipsisConversion = false;
3547 User.HadMultipleCandidates = HadMultipleCandidates;
3548 User.ConversionFunction = Constructor;
3549 User.FoundConversionFunction = Best->FoundDecl;
3550 User.After.setAsIdentityConversion();
3551 User.After.setFromType(ThisType->castAs<PointerType>()->getPointeeType());
3552 User.After.setAllToTypes(ToType);
3555 if (CXXConversionDecl *Conversion
3556 = dyn_cast<CXXConversionDecl>(Best->Function)) {
3557 // C++ [over.ics.user]p1:
3559 // [...] If the user-defined conversion is specified by a
3560 // conversion function (12.3.2), the initial standard
3561 // conversion sequence converts the source type to the
3562 // implicit object parameter of the conversion function.
3563 User.Before = Best->Conversions[0].Standard;
3564 User.HadMultipleCandidates = HadMultipleCandidates;
3565 User.ConversionFunction = Conversion;
3566 User.FoundConversionFunction = Best->FoundDecl;
3567 User.EllipsisConversion = false;
3569 // C++ [over.ics.user]p2:
3570 // The second standard conversion sequence converts the
3571 // result of the user-defined conversion to the target type
3572 // for the sequence. Since an implicit conversion sequence
3573 // is an initialization, the special rules for
3574 // initialization by user-defined conversion apply when
3575 // selecting the best user-defined conversion for a
3576 // user-defined conversion sequence (see 13.3.3 and
3578 User.After = Best->FinalConversion;
3581 llvm_unreachable("Not a constructor or conversion function?");
3583 case OR_No_Viable_Function:
3584 return OR_No_Viable_Function;
3587 return OR_Ambiguous;
3590 llvm_unreachable("Invalid OverloadResult!");
3594 Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) {
3595 ImplicitConversionSequence ICS;
3596 OverloadCandidateSet CandidateSet(From->getExprLoc(),
3597 OverloadCandidateSet::CSK_Normal);
3598 OverloadingResult OvResult =
3599 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined,
3600 CandidateSet, false, false);
3602 if (!(OvResult == OR_Ambiguous ||
3603 (OvResult == OR_No_Viable_Function && !CandidateSet.empty())))
3606 auto Cands = CandidateSet.CompleteCandidates(
3608 OvResult == OR_Ambiguous ? OCD_AmbiguousCandidates : OCD_AllCandidates,
3610 if (OvResult == OR_Ambiguous)
3611 Diag(From->getBeginLoc(), diag::err_typecheck_ambiguous_condition)
3612 << From->getType() << ToType << From->getSourceRange();
3613 else { // OR_No_Viable_Function && !CandidateSet.empty()
3614 if (!RequireCompleteType(From->getBeginLoc(), ToType,
3615 diag::err_typecheck_nonviable_condition_incomplete,
3616 From->getType(), From->getSourceRange()))
3617 Diag(From->getBeginLoc(), diag::err_typecheck_nonviable_condition)
3618 << false << From->getType() << From->getSourceRange() << ToType;
3621 CandidateSet.NoteCandidates(
3622 *this, From, Cands);
3626 /// Compare the user-defined conversion functions or constructors
3627 /// of two user-defined conversion sequences to determine whether any ordering
3629 static ImplicitConversionSequence::CompareKind
3630 compareConversionFunctions(Sema &S, FunctionDecl *Function1,
3631 FunctionDecl *Function2) {
3632 if (!S.getLangOpts().ObjC || !S.getLangOpts().CPlusPlus11)
3633 return ImplicitConversionSequence::Indistinguishable;
3636 // If both conversion functions are implicitly-declared conversions from
3637 // a lambda closure type to a function pointer and a block pointer,
3638 // respectively, always prefer the conversion to a function pointer,
3639 // because the function pointer is more lightweight and is more likely
3640 // to keep code working.
3641 CXXConversionDecl *Conv1 = dyn_cast_or_null<CXXConversionDecl>(Function1);
3643 return ImplicitConversionSequence::Indistinguishable;
3645 CXXConversionDecl *Conv2 = dyn_cast<CXXConversionDecl>(Function2);
3647 return ImplicitConversionSequence::Indistinguishable;
3649 if (Conv1->getParent()->isLambda() && Conv2->getParent()->isLambda()) {
3650 bool Block1 = Conv1->getConversionType()->isBlockPointerType();
3651 bool Block2 = Conv2->getConversionType()->isBlockPointerType();
3652 if (Block1 != Block2)
3653 return Block1 ? ImplicitConversionSequence::Worse
3654 : ImplicitConversionSequence::Better;
3657 return ImplicitConversionSequence::Indistinguishable;
3660 static bool hasDeprecatedStringLiteralToCharPtrConversion(
3661 const ImplicitConversionSequence &ICS) {
3662 return (ICS.isStandard() && ICS.Standard.DeprecatedStringLiteralToCharPtr) ||
3663 (ICS.isUserDefined() &&
3664 ICS.UserDefined.Before.DeprecatedStringLiteralToCharPtr);
3667 /// CompareImplicitConversionSequences - Compare two implicit
3668 /// conversion sequences to determine whether one is better than the
3669 /// other or if they are indistinguishable (C++ 13.3.3.2).
3670 static ImplicitConversionSequence::CompareKind
3671 CompareImplicitConversionSequences(Sema &S, SourceLocation Loc,
3672 const ImplicitConversionSequence& ICS1,
3673 const ImplicitConversionSequence& ICS2)
3675 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit
3676 // conversion sequences (as defined in 13.3.3.1)
3677 // -- a standard conversion sequence (13.3.3.1.1) is a better
3678 // conversion sequence than a user-defined conversion sequence or
3679 // an ellipsis conversion sequence, and
3680 // -- a user-defined conversion sequence (13.3.3.1.2) is a better
3681 // conversion sequence than an ellipsis conversion sequence
3684 // C++0x [over.best.ics]p10:
3685 // For the purpose of ranking implicit conversion sequences as
3686 // described in 13.3.3.2, the ambiguous conversion sequence is
3687 // treated as a user-defined sequence that is indistinguishable
3688 // from any other user-defined conversion sequence.
3690 // String literal to 'char *' conversion has been deprecated in C++03. It has
3691 // been removed from C++11. We still accept this conversion, if it happens at
3692 // the best viable function. Otherwise, this conversion is considered worse
3693 // than ellipsis conversion. Consider this as an extension; this is not in the
3694 // standard. For example:
3696 // int &f(...); // #1
3697 // void f(char*); // #2
3698 // void g() { int &r = f("foo"); }
3700 // In C++03, we pick #2 as the best viable function.
3701 // In C++11, we pick #1 as the best viable function, because ellipsis
3702 // conversion is better than string-literal to char* conversion (since there
3703 // is no such conversion in C++11). If there was no #1 at all or #1 couldn't
3704 // convert arguments, #2 would be the best viable function in C++11.
3705 // If the best viable function has this conversion, a warning will be issued
3706 // in C++03, or an ExtWarn (+SFINAE failure) will be issued in C++11.
3708 if (S.getLangOpts().CPlusPlus11 && !S.getLangOpts().WritableStrings &&
3709 hasDeprecatedStringLiteralToCharPtrConversion(ICS1) !=
3710 hasDeprecatedStringLiteralToCharPtrConversion(ICS2))
3711 return hasDeprecatedStringLiteralToCharPtrConversion(ICS1)
3712 ? ImplicitConversionSequence::Worse
3713 : ImplicitConversionSequence::Better;
3715 if (ICS1.getKindRank() < ICS2.getKindRank())
3716 return ImplicitConversionSequence::Better;
3717 if (ICS2.getKindRank() < ICS1.getKindRank())
3718 return ImplicitConversionSequence::Worse;
3720 // The following checks require both conversion sequences to be of
3722 if (ICS1.getKind() != ICS2.getKind())
3723 return ImplicitConversionSequence::Indistinguishable;
3725 ImplicitConversionSequence::CompareKind Result =
3726 ImplicitConversionSequence::Indistinguishable;
3728 // Two implicit conversion sequences of the same form are
3729 // indistinguishable conversion sequences unless one of the
3730 // following rules apply: (C++ 13.3.3.2p3):
3732 // List-initialization sequence L1 is a better conversion sequence than
3733 // list-initialization sequence L2 if:
3734 // - L1 converts to std::initializer_list<X> for some X and L2 does not, or,
3736 // - L1 converts to type "array of N1 T", L2 converts to type "array of N2 T",
3737 // and N1 is smaller than N2.,
3738 // even if one of the other rules in this paragraph would otherwise apply.
3739 if (!ICS1.isBad()) {
3740 if (ICS1.isStdInitializerListElement() &&
3741 !ICS2.isStdInitializerListElement())
3742 return ImplicitConversionSequence::Better;
3743 if (!ICS1.isStdInitializerListElement() &&
3744 ICS2.isStdInitializerListElement())
3745 return ImplicitConversionSequence::Worse;
3748 if (ICS1.isStandard())
3749 // Standard conversion sequence S1 is a better conversion sequence than
3750 // standard conversion sequence S2 if [...]
3751 Result = CompareStandardConversionSequences(S, Loc,
3752 ICS1.Standard, ICS2.Standard);
3753 else if (ICS1.isUserDefined()) {
3754 // User-defined conversion sequence U1 is a better conversion
3755 // sequence than another user-defined conversion sequence U2 if
3756 // they contain the same user-defined conversion function or
3757 // constructor and if the second standard conversion sequence of
3758 // U1 is better than the second standard conversion sequence of
3759 // U2 (C++ 13.3.3.2p3).
3760 if (ICS1.UserDefined.ConversionFunction ==
3761 ICS2.UserDefined.ConversionFunction)
3762 Result = CompareStandardConversionSequences(S, Loc,
3763 ICS1.UserDefined.After,
3764 ICS2.UserDefined.After);
3766 Result = compareConversionFunctions(S,
3767 ICS1.UserDefined.ConversionFunction,
3768 ICS2.UserDefined.ConversionFunction);
3774 // Per 13.3.3.2p3, compare the given standard conversion sequences to
3775 // determine if one is a proper subset of the other.
3776 static ImplicitConversionSequence::CompareKind
3777 compareStandardConversionSubsets(ASTContext &Context,
3778 const StandardConversionSequence& SCS1,
3779 const StandardConversionSequence& SCS2) {
3780 ImplicitConversionSequence::CompareKind Result
3781 = ImplicitConversionSequence::Indistinguishable;
3783 // the identity conversion sequence is considered to be a subsequence of
3784 // any non-identity conversion sequence
3785 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion())
3786 return ImplicitConversionSequence::Better;
3787 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion())
3788 return ImplicitConversionSequence::Worse;
3790 if (SCS1.Second != SCS2.Second) {
3791 if (SCS1.Second == ICK_Identity)
3792 Result = ImplicitConversionSequence::Better;
3793 else if (SCS2.Second == ICK_Identity)
3794 Result = ImplicitConversionSequence::Worse;
3796 return ImplicitConversionSequence::Indistinguishable;
3797 } else if (!Context.hasSimilarType(SCS1.getToType(1), SCS2.getToType(1)))
3798 return ImplicitConversionSequence::Indistinguishable;
3800 if (SCS1.Third == SCS2.Third) {
3801 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result
3802 : ImplicitConversionSequence::Indistinguishable;
3805 if (SCS1.Third == ICK_Identity)
3806 return Result == ImplicitConversionSequence::Worse
3807 ? ImplicitConversionSequence::Indistinguishable
3808 : ImplicitConversionSequence::Better;
3810 if (SCS2.Third == ICK_Identity)
3811 return Result == ImplicitConversionSequence::Better
3812 ? ImplicitConversionSequence::Indistinguishable
3813 : ImplicitConversionSequence::Worse;
3815 return ImplicitConversionSequence::Indistinguishable;
3818 /// Determine whether one of the given reference bindings is better
3819 /// than the other based on what kind of bindings they are.
3821 isBetterReferenceBindingKind(const StandardConversionSequence &SCS1,
3822 const StandardConversionSequence &SCS2) {
3823 // C++0x [over.ics.rank]p3b4:
3824 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an
3825 // implicit object parameter of a non-static member function declared
3826 // without a ref-qualifier, and *either* S1 binds an rvalue reference
3827 // to an rvalue and S2 binds an lvalue reference *or S1 binds an
3828 // lvalue reference to a function lvalue and S2 binds an rvalue
3831 // FIXME: Rvalue references. We're going rogue with the above edits,
3832 // because the semantics in the current C++0x working paper (N3225 at the
3833 // time of this writing) break the standard definition of std::forward
3834 // and std::reference_wrapper when dealing with references to functions.
3835 // Proposed wording changes submitted to CWG for consideration.
3836 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier ||
3837 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier)
3840 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue &&
3841 SCS2.IsLvalueReference) ||
3842 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue &&
3843 !SCS2.IsLvalueReference && SCS2.BindsToFunctionLvalue);
3846 enum class FixedEnumPromotion {
3849 ToPromotedUnderlyingType
3852 /// Returns kind of fixed enum promotion the \a SCS uses.
3853 static FixedEnumPromotion
3854 getFixedEnumPromtion(Sema &S, const StandardConversionSequence &SCS) {
3856 if (SCS.Second != ICK_Integral_Promotion)
3857 return FixedEnumPromotion::None;
3859 QualType FromType = SCS.getFromType();
3860 if (!FromType->isEnumeralType())
3861 return FixedEnumPromotion::None;
3863 EnumDecl *Enum = FromType->getAs<EnumType>()->getDecl();
3864 if (!Enum->isFixed())
3865 return FixedEnumPromotion::None;
3867 QualType UnderlyingType = Enum->getIntegerType();
3868 if (S.Context.hasSameType(SCS.getToType(1), UnderlyingType))
3869 return FixedEnumPromotion::ToUnderlyingType;
3871 return FixedEnumPromotion::ToPromotedUnderlyingType;
3874 /// CompareStandardConversionSequences - Compare two standard
3875 /// conversion sequences to determine whether one is better than the
3876 /// other or if they are indistinguishable (C++ 13.3.3.2p3).
3877 static ImplicitConversionSequence::CompareKind
3878 CompareStandardConversionSequences(Sema &S, SourceLocation Loc,
3879 const StandardConversionSequence& SCS1,
3880 const StandardConversionSequence& SCS2)
3882 // Standard conversion sequence S1 is a better conversion sequence
3883 // than standard conversion sequence S2 if (C++ 13.3.3.2p3):
3885 // -- S1 is a proper subsequence of S2 (comparing the conversion
3886 // sequences in the canonical form defined by 13.3.3.1.1,
3887 // excluding any Lvalue Transformation; the identity conversion
3888 // sequence is considered to be a subsequence of any
3889 // non-identity conversion sequence) or, if not that,
3890 if (ImplicitConversionSequence::CompareKind CK
3891 = compareStandardConversionSubsets(S.Context, SCS1, SCS2))
3894 // -- the rank of S1 is better than the rank of S2 (by the rules
3895 // defined below), or, if not that,
3896 ImplicitConversionRank Rank1 = SCS1.getRank();
3897 ImplicitConversionRank Rank2 = SCS2.getRank();
3899 return ImplicitConversionSequence::Better;
3900 else if (Rank2 < Rank1)
3901 return ImplicitConversionSequence::Worse;
3903 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank
3904 // are indistinguishable unless one of the following rules
3907 // A conversion that is not a conversion of a pointer, or
3908 // pointer to member, to bool is better than another conversion
3909 // that is such a conversion.
3910 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool())
3911 return SCS2.isPointerConversionToBool()
3912 ? ImplicitConversionSequence::Better
3913 : ImplicitConversionSequence::Worse;
3915 // C++14 [over.ics.rank]p4b2:
3916 // This is retroactively applied to C++11 by CWG 1601.
3918 // A conversion that promotes an enumeration whose underlying type is fixed
3919 // to its underlying type is better than one that promotes to the promoted
3920 // underlying type, if the two are different.
3921 FixedEnumPromotion FEP1 = getFixedEnumPromtion(S, SCS1);
3922 FixedEnumPromotion FEP2 = getFixedEnumPromtion(S, SCS2);
3923 if (FEP1 != FixedEnumPromotion::None && FEP2 != FixedEnumPromotion::None &&
3925 return FEP1 == FixedEnumPromotion::ToUnderlyingType
3926 ? ImplicitConversionSequence::Better
3927 : ImplicitConversionSequence::Worse;
3929 // C++ [over.ics.rank]p4b2:
3931 // If class B is derived directly or indirectly from class A,
3932 // conversion of B* to A* is better than conversion of B* to
3933 // void*, and conversion of A* to void* is better than conversion
3935 bool SCS1ConvertsToVoid
3936 = SCS1.isPointerConversionToVoidPointer(S.Context);
3937 bool SCS2ConvertsToVoid
3938 = SCS2.isPointerConversionToVoidPointer(S.Context);
3939 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) {
3940 // Exactly one of the conversion sequences is a conversion to
3941 // a void pointer; it's the worse conversion.
3942 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better
3943 : ImplicitConversionSequence::Worse;
3944 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) {
3945 // Neither conversion sequence converts to a void pointer; compare
3946 // their derived-to-base conversions.
3947 if (ImplicitConversionSequence::CompareKind DerivedCK
3948 = CompareDerivedToBaseConversions(S, Loc, SCS1, SCS2))
3950 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid &&
3951 !S.Context.hasSameType(SCS1.getFromType(), SCS2.getFromType())) {
3952 // Both conversion sequences are conversions to void
3953 // pointers. Compare the source types to determine if there's an
3954 // inheritance relationship in their sources.
3955 QualType FromType1 = SCS1.getFromType();
3956 QualType FromType2 = SCS2.getFromType();
3958 // Adjust the types we're converting from via the array-to-pointer
3959 // conversion, if we need to.
3960 if (SCS1.First == ICK_Array_To_Pointer)
3961 FromType1 = S.Context.getArrayDecayedType(FromType1);
3962 if (SCS2.First == ICK_Array_To_Pointer)
3963 FromType2 = S.Context.getArrayDecayedType(FromType2);
3965 QualType FromPointee1 = FromType1->getPointeeType().getUnqualifiedType();
3966 QualType FromPointee2 = FromType2->getPointeeType().getUnqualifiedType();
3968 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
3969 return ImplicitConversionSequence::Better;
3970 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
3971 return ImplicitConversionSequence::Worse;
3973 // Objective-C++: If one interface is more specific than the
3974 // other, it is the better one.
3975 const ObjCObjectPointerType* FromObjCPtr1
3976 = FromType1->getAs<ObjCObjectPointerType>();
3977 const ObjCObjectPointerType* FromObjCPtr2
3978 = FromType2->getAs<ObjCObjectPointerType>();
3979 if (FromObjCPtr1 && FromObjCPtr2) {
3980 bool AssignLeft = S.Context.canAssignObjCInterfaces(FromObjCPtr1,
3982 bool AssignRight = S.Context.canAssignObjCInterfaces(FromObjCPtr2,
3984 if (AssignLeft != AssignRight) {
3985 return AssignLeft? ImplicitConversionSequence::Better
3986 : ImplicitConversionSequence::Worse;
3991 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) {
3992 // Check for a better reference binding based on the kind of bindings.
3993 if (isBetterReferenceBindingKind(SCS1, SCS2))
3994 return ImplicitConversionSequence::Better;
3995 else if (isBetterReferenceBindingKind(SCS2, SCS1))
3996 return ImplicitConversionSequence::Worse;
3999 // Compare based on qualification conversions (C++ 13.3.3.2p3,
4001 if (ImplicitConversionSequence::CompareKind QualCK
4002 = CompareQualificationConversions(S, SCS1, SCS2))
4005 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) {
4006 // C++ [over.ics.rank]p3b4:
4007 // -- S1 and S2 are reference bindings (8.5.3), and the types to
4008 // which the references refer are the same type except for
4009 // top-level cv-qualifiers, and the type to which the reference
4010 // initialized by S2 refers is more cv-qualified than the type
4011 // to which the reference initialized by S1 refers.
4012 QualType T1 = SCS1.getToType(2);
4013 QualType T2 = SCS2.getToType(2);
4014 T1 = S.Context.getCanonicalType(T1);
4015 T2 = S.Context.getCanonicalType(T2);
4016 Qualifiers T1Quals, T2Quals;
4017 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
4018 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
4019 if (UnqualT1 == UnqualT2) {
4020 // Objective-C++ ARC: If the references refer to objects with different
4021 // lifetimes, prefer bindings that don't change lifetime.
4022 if (SCS1.ObjCLifetimeConversionBinding !=
4023 SCS2.ObjCLifetimeConversionBinding) {
4024 return SCS1.ObjCLifetimeConversionBinding
4025 ? ImplicitConversionSequence::Worse
4026 : ImplicitConversionSequence::Better;
4029 // If the type is an array type, promote the element qualifiers to the
4030 // type for comparison.
4031 if (isa<ArrayType>(T1) && T1Quals)
4032 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals);
4033 if (isa<ArrayType>(T2) && T2Quals)
4034 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals);
4035 if (T2.isMoreQualifiedThan(T1))
4036 return ImplicitConversionSequence::Better;
4037 if (T1.isMoreQualifiedThan(T2))
4038 return ImplicitConversionSequence::Worse;
4042 // In Microsoft mode, prefer an integral conversion to a
4043 // floating-to-integral conversion if the integral conversion
4044 // is between types of the same size.
4052 // Here, MSVC will call f(int) instead of generating a compile error
4053 // as clang will do in standard mode.
4054 if (S.getLangOpts().MSVCCompat && SCS1.Second == ICK_Integral_Conversion &&
4055 SCS2.Second == ICK_Floating_Integral &&
4056 S.Context.getTypeSize(SCS1.getFromType()) ==
4057 S.Context.getTypeSize(SCS1.getToType(2)))
4058 return ImplicitConversionSequence::Better;
4060 // Prefer a compatible vector conversion over a lax vector conversion
4063 // typedef float __v4sf __attribute__((__vector_size__(16)));
4064 // void f(vector float);
4065 // void f(vector signed int);
4070 // Here, we'd like to choose f(vector float) and not
4071 // report an ambiguous call error
4072 if (SCS1.Second == ICK_Vector_Conversion &&
4073 SCS2.Second == ICK_Vector_Conversion) {
4074 bool SCS1IsCompatibleVectorConversion = S.Context.areCompatibleVectorTypes(
4075 SCS1.getFromType(), SCS1.getToType(2));
4076 bool SCS2IsCompatibleVectorConversion = S.Context.areCompatibleVectorTypes(
4077 SCS2.getFromType(), SCS2.getToType(2));
4079 if (SCS1IsCompatibleVectorConversion != SCS2IsCompatibleVectorConversion)
4080 return SCS1IsCompatibleVectorConversion
4081 ? ImplicitConversionSequence::Better
4082 : ImplicitConversionSequence::Worse;
4085 return ImplicitConversionSequence::Indistinguishable;
4088 /// CompareQualificationConversions - Compares two standard conversion
4089 /// sequences to determine whether they can be ranked based on their
4090 /// qualification conversions (C++ 13.3.3.2p3 bullet 3).
4091 static ImplicitConversionSequence::CompareKind
4092 CompareQualificationConversions(Sema &S,
4093 const StandardConversionSequence& SCS1,
4094 const StandardConversionSequence& SCS2) {
4096 // -- S1 and S2 differ only in their qualification conversion and
4097 // yield similar types T1 and T2 (C++ 4.4), respectively, and the
4098 // cv-qualification signature of type T1 is a proper subset of
4099 // the cv-qualification signature of type T2, and S1 is not the
4100 // deprecated string literal array-to-pointer conversion (4.2).
4101 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second ||
4102 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification)
4103 return ImplicitConversionSequence::Indistinguishable;
4105 // FIXME: the example in the standard doesn't use a qualification
4107 QualType T1 = SCS1.getToType(2);
4108 QualType T2 = SCS2.getToType(2);
4109 T1 = S.Context.getCanonicalType(T1);
4110 T2 = S.Context.getCanonicalType(T2);
4111 assert(!T1->isReferenceType() && !T2->isReferenceType());
4112 Qualifiers T1Quals, T2Quals;
4113 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
4114 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
4116 // If the types are the same, we won't learn anything by unwrapping
4118 if (UnqualT1 == UnqualT2)
4119 return ImplicitConversionSequence::Indistinguishable;
4121 ImplicitConversionSequence::CompareKind Result
4122 = ImplicitConversionSequence::Indistinguishable;
4124 // Objective-C++ ARC:
4125 // Prefer qualification conversions not involving a change in lifetime
4126 // to qualification conversions that do not change lifetime.
4127 if (SCS1.QualificationIncludesObjCLifetime !=
4128 SCS2.QualificationIncludesObjCLifetime) {
4129 Result = SCS1.QualificationIncludesObjCLifetime
4130 ? ImplicitConversionSequence::Worse
4131 : ImplicitConversionSequence::Better;
4134 while (S.Context.UnwrapSimilarTypes(T1, T2)) {
4135 // Within each iteration of the loop, we check the qualifiers to
4136 // determine if this still looks like a qualification
4137 // conversion. Then, if all is well, we unwrap one more level of
4138 // pointers or pointers-to-members and do it all again
4139 // until there are no more pointers or pointers-to-members left
4140 // to unwrap. This essentially mimics what
4141 // IsQualificationConversion does, but here we're checking for a
4142 // strict subset of qualifiers.
4143 if (T1.getQualifiers().withoutObjCLifetime() ==
4144 T2.getQualifiers().withoutObjCLifetime())
4145 // The qualifiers are the same, so this doesn't tell us anything
4146 // about how the sequences rank.
4147 // ObjC ownership quals are omitted above as they interfere with
4148 // the ARC overload rule.
4150 else if (T2.isMoreQualifiedThan(T1)) {
4151 // T1 has fewer qualifiers, so it could be the better sequence.
4152 if (Result == ImplicitConversionSequence::Worse)
4153 // Neither has qualifiers that are a subset of the other's
4155 return ImplicitConversionSequence::Indistinguishable;
4157 Result = ImplicitConversionSequence::Better;
4158 } else if (T1.isMoreQualifiedThan(T2)) {
4159 // T2 has fewer qualifiers, so it could be the better sequence.
4160 if (Result == ImplicitConversionSequence::Better)
4161 // Neither has qualifiers that are a subset of the other's
4163 return ImplicitConversionSequence::Indistinguishable;
4165 Result = ImplicitConversionSequence::Worse;
4167 // Qualifiers are disjoint.
4168 return ImplicitConversionSequence::Indistinguishable;
4171 // If the types after this point are equivalent, we're done.
4172 if (S.Context.hasSameUnqualifiedType(T1, T2))
4176 // Check that the winning standard conversion sequence isn't using
4177 // the deprecated string literal array to pointer conversion.
4179 case ImplicitConversionSequence::Better:
4180 if (SCS1.DeprecatedStringLiteralToCharPtr)
4181 Result = ImplicitConversionSequence::Indistinguishable;
4184 case ImplicitConversionSequence::Indistinguishable:
4187 case ImplicitConversionSequence::Worse:
4188 if (SCS2.DeprecatedStringLiteralToCharPtr)
4189 Result = ImplicitConversionSequence::Indistinguishable;
4196 /// CompareDerivedToBaseConversions - Compares two standard conversion
4197 /// sequences to determine whether they can be ranked based on their
4198 /// various kinds of derived-to-base conversions (C++
4199 /// [over.ics.rank]p4b3). As part of these checks, we also look at
4200 /// conversions between Objective-C interface types.
4201 static ImplicitConversionSequence::CompareKind
4202 CompareDerivedToBaseConversions(Sema &S, SourceLocation Loc,
4203 const StandardConversionSequence& SCS1,
4204 const StandardConversionSequence& SCS2) {
4205 QualType FromType1 = SCS1.getFromType();
4206 QualType ToType1 = SCS1.getToType(1);
4207 QualType FromType2 = SCS2.getFromType();
4208 QualType ToType2 = SCS2.getToType(1);
4210 // Adjust the types we're converting from via the array-to-pointer
4211 // conversion, if we need to.
4212 if (SCS1.First == ICK_Array_To_Pointer)
4213 FromType1 = S.Context.getArrayDecayedType(FromType1);
4214 if (SCS2.First == ICK_Array_To_Pointer)
4215 FromType2 = S.Context.getArrayDecayedType(FromType2);
4217 // Canonicalize all of the types.
4218 FromType1 = S.Context.getCanonicalType(FromType1);
4219 ToType1 = S.Context.getCanonicalType(ToType1);
4220 FromType2 = S.Context.getCanonicalType(FromType2);
4221 ToType2 = S.Context.getCanonicalType(ToType2);
4223 // C++ [over.ics.rank]p4b3:
4225 // If class B is derived directly or indirectly from class A and
4226 // class C is derived directly or indirectly from B,
4228 // Compare based on pointer conversions.
4229 if (SCS1.Second == ICK_Pointer_Conversion &&
4230 SCS2.Second == ICK_Pointer_Conversion &&
4231 /*FIXME: Remove if Objective-C id conversions get their own rank*/
4232 FromType1->isPointerType() && FromType2->isPointerType() &&
4233 ToType1->isPointerType() && ToType2->isPointerType()) {
4234 QualType FromPointee1 =
4235 FromType1->castAs<PointerType>()->getPointeeType().getUnqualifiedType();
4236 QualType ToPointee1 =
4237 ToType1->castAs<PointerType>()->getPointeeType().getUnqualifiedType();
4238 QualType FromPointee2 =
4239 FromType2->castAs<PointerType>()->getPointeeType().getUnqualifiedType();
4240 QualType ToPointee2 =
4241 ToType2->castAs<PointerType>()->getPointeeType().getUnqualifiedType();
4243 // -- conversion of C* to B* is better than conversion of C* to A*,
4244 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
4245 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
4246 return ImplicitConversionSequence::Better;
4247 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
4248 return ImplicitConversionSequence::Worse;
4251 // -- conversion of B* to A* is better than conversion of C* to A*,
4252 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) {
4253 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
4254 return ImplicitConversionSequence::Better;
4255 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
4256 return ImplicitConversionSequence::Worse;
4258 } else if (SCS1.Second == ICK_Pointer_Conversion &&
4259 SCS2.Second == ICK_Pointer_Conversion) {
4260 const ObjCObjectPointerType *FromPtr1
4261 = FromType1->getAs<ObjCObjectPointerType>();
4262 const ObjCObjectPointerType *FromPtr2
4263 = FromType2->getAs<ObjCObjectPointerType>();
4264 const ObjCObjectPointerType *ToPtr1
4265 = ToType1->getAs<ObjCObjectPointerType>();
4266 const ObjCObjectPointerType *ToPtr2
4267 = ToType2->getAs<ObjCObjectPointerType>();
4269 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) {
4270 // Apply the same conversion ranking rules for Objective-C pointer types
4271 // that we do for C++ pointers to class types. However, we employ the
4272 // Objective-C pseudo-subtyping relationship used for assignment of
4273 // Objective-C pointer types.
4275 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2);
4276 bool FromAssignRight
4277 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1);
4279 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2);
4281 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1);
4283 // A conversion to an a non-id object pointer type or qualified 'id'
4284 // type is better than a conversion to 'id'.
4285 if (ToPtr1->isObjCIdType() &&
4286 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl()))
4287 return ImplicitConversionSequence::Worse;
4288 if (ToPtr2->isObjCIdType() &&
4289 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl()))
4290 return ImplicitConversionSequence::Better;
4292 // A conversion to a non-id object pointer type is better than a
4293 // conversion to a qualified 'id' type
4294 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl())
4295 return ImplicitConversionSequence::Worse;
4296 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl())
4297 return ImplicitConversionSequence::Better;
4299 // A conversion to an a non-Class object pointer type or qualified 'Class'
4300 // type is better than a conversion to 'Class'.
4301 if (ToPtr1->isObjCClassType() &&
4302 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl()))
4303 return ImplicitConversionSequence::Worse;
4304 if (ToPtr2->isObjCClassType() &&
4305 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl()))
4306 return ImplicitConversionSequence::Better;
4308 // A conversion to a non-Class object pointer type is better than a
4309 // conversion to a qualified 'Class' type.
4310 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl())
4311 return ImplicitConversionSequence::Worse;
4312 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl())
4313 return ImplicitConversionSequence::Better;
4315 // -- "conversion of C* to B* is better than conversion of C* to A*,"
4316 if (S.Context.hasSameType(FromType1, FromType2) &&
4317 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() &&
4318 (ToAssignLeft != ToAssignRight)) {
4319 if (FromPtr1->isSpecialized()) {
4320 // "conversion of B<A> * to B * is better than conversion of B * to
4323 FromPtr1->getInterfaceDecl() == ToPtr1->getInterfaceDecl();
4325 FromPtr1->getInterfaceDecl() == ToPtr2->getInterfaceDecl();
4328 return ImplicitConversionSequence::Better;
4329 } else if (IsSecondSame)
4330 return ImplicitConversionSequence::Worse;
4332 return ToAssignLeft? ImplicitConversionSequence::Worse
4333 : ImplicitConversionSequence::Better;
4336 // -- "conversion of B* to A* is better than conversion of C* to A*,"
4337 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) &&
4338 (FromAssignLeft != FromAssignRight))
4339 return FromAssignLeft? ImplicitConversionSequence::Better
4340 : ImplicitConversionSequence::Worse;
4344 // Ranking of member-pointer types.
4345 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member &&
4346 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() &&
4347 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) {
4348 const auto *FromMemPointer1 = FromType1->castAs<MemberPointerType>();
4349 const auto *ToMemPointer1 = ToType1->castAs<MemberPointerType>();
4350 const auto *FromMemPointer2 = FromType2->castAs<MemberPointerType>();
4351 const auto *ToMemPointer2 = ToType2->castAs<MemberPointerType>();
4352 const Type *FromPointeeType1 = FromMemPointer1->getClass();
4353 const Type *ToPointeeType1 = ToMemPointer1->getClass();
4354 const Type *FromPointeeType2 = FromMemPointer2->getClass();
4355 const Type *ToPointeeType2 = ToMemPointer2->getClass();
4356 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType();
4357 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType();
4358 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType();
4359 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType();
4360 // conversion of A::* to B::* is better than conversion of A::* to C::*,
4361 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
4362 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
4363 return ImplicitConversionSequence::Worse;
4364 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
4365 return ImplicitConversionSequence::Better;
4367 // conversion of B::* to C::* is better than conversion of A::* to C::*
4368 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) {
4369 if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
4370 return ImplicitConversionSequence::Better;
4371 else if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
4372 return ImplicitConversionSequence::Worse;
4376 if (SCS1.Second == ICK_Derived_To_Base) {
4377 // -- conversion of C to B is better than conversion of C to A,
4378 // -- binding of an expression of type C to a reference of type
4379 // B& is better than binding an expression of type C to a
4380 // reference of type A&,
4381 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4382 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4383 if (S.IsDerivedFrom(Loc, ToType1, ToType2))
4384 return ImplicitConversionSequence::Better;
4385 else if (S.IsDerivedFrom(Loc, ToType2, ToType1))
4386 return ImplicitConversionSequence::Worse;
4389 // -- conversion of B to A is better than conversion of C to A.
4390 // -- binding of an expression of type B to a reference of type
4391 // A& is better than binding an expression of type C to a
4392 // reference of type A&,
4393 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4394 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4395 if (S.IsDerivedFrom(Loc, FromType2, FromType1))
4396 return ImplicitConversionSequence::Better;
4397 else if (S.IsDerivedFrom(Loc, FromType1, FromType2))
4398 return ImplicitConversionSequence::Worse;
4402 return ImplicitConversionSequence::Indistinguishable;
4405 /// Determine whether the given type is valid, e.g., it is not an invalid
4407 static bool isTypeValid(QualType T) {
4408 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl())
4409 return !Record->isInvalidDecl();
4414 static QualType withoutUnaligned(ASTContext &Ctx, QualType T) {
4415 if (!T.getQualifiers().hasUnaligned())
4419 T = Ctx.getUnqualifiedArrayType(T, Q);
4420 Q.removeUnaligned();
4421 return Ctx.getQualifiedType(T, Q);
4424 /// CompareReferenceRelationship - Compare the two types T1 and T2 to
4425 /// determine whether they are reference-compatible,
4426 /// reference-related, or incompatible, for use in C++ initialization by
4427 /// reference (C++ [dcl.ref.init]p4). Neither type can be a reference
4428 /// type, and the first type (T1) is the pointee type of the reference
4429 /// type being initialized.
4430 Sema::ReferenceCompareResult
4431 Sema::CompareReferenceRelationship(SourceLocation Loc,
4432 QualType OrigT1, QualType OrigT2,
4433 ReferenceConversions *ConvOut) {
4434 assert(!OrigT1->isReferenceType() &&
4435 "T1 must be the pointee type of the reference type");
4436 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type");
4438 QualType T1 = Context.getCanonicalType(OrigT1);
4439 QualType T2 = Context.getCanonicalType(OrigT2);
4440 Qualifiers T1Quals, T2Quals;
4441 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals);
4442 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals);
4444 ReferenceConversions ConvTmp;
4445 ReferenceConversions &Conv = ConvOut ? *ConvOut : ConvTmp;
4446 Conv = ReferenceConversions();
4448 // C++2a [dcl.init.ref]p4:
4449 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is
4450 // reference-related to "cv2 T2" if T1 is similar to T2, or
4451 // T1 is a base class of T2.
4452 // "cv1 T1" is reference-compatible with "cv2 T2" if
4453 // a prvalue of type "pointer to cv2 T2" can be converted to the type
4454 // "pointer to cv1 T1" via a standard conversion sequence.
4456 // Check for standard conversions we can apply to pointers: derived-to-base
4457 // conversions, ObjC pointer conversions, and function pointer conversions.
4458 // (Qualification conversions are checked last.)
4459 QualType ConvertedT2;
4460 if (UnqualT1 == UnqualT2) {
4462 } else if (isCompleteType(Loc, OrigT2) &&
4463 isTypeValid(UnqualT1) && isTypeValid(UnqualT2) &&
4464 IsDerivedFrom(Loc, UnqualT2, UnqualT1))
4465 Conv |= ReferenceConversions::DerivedToBase;
4466 else if (UnqualT1->isObjCObjectOrInterfaceType() &&
4467 UnqualT2->isObjCObjectOrInterfaceType() &&
4468 Context.canBindObjCObjectType(UnqualT1, UnqualT2))
4469 Conv |= ReferenceConversions::ObjC;
4470 else if (UnqualT2->isFunctionType() &&
4471 IsFunctionConversion(UnqualT2, UnqualT1, ConvertedT2)) {
4472 Conv |= ReferenceConversions::Function;
4473 // No need to check qualifiers; function types don't have them.
4474 return Ref_Compatible;
4476 bool ConvertedReferent = Conv != 0;
4478 // We can have a qualification conversion. Compute whether the types are
4479 // similar at the same time.
4480 bool PreviousToQualsIncludeConst = true;
4481 bool TopLevel = true;
4486 // We will need a qualification conversion.
4487 Conv |= ReferenceConversions::Qualification;
4489 // Track whether we performed a qualification conversion anywhere other
4490 // than the top level. This matters for ranking reference bindings in
4491 // overload resolution.
4493 Conv |= ReferenceConversions::NestedQualification;
4495 // MS compiler ignores __unaligned qualifier for references; do the same.
4496 T1 = withoutUnaligned(Context, T1);
4497 T2 = withoutUnaligned(Context, T2);
4499 // If we find a qualifier mismatch, the types are not reference-compatible,
4500 // but are still be reference-related if they're similar.
4501 bool ObjCLifetimeConversion = false;
4502 if (!isQualificationConversionStep(T2, T1, /*CStyle=*/false,
4503 PreviousToQualsIncludeConst,
4504 ObjCLifetimeConversion))
4505 return (ConvertedReferent || Context.hasSimilarType(T1, T2))
4509 // FIXME: Should we track this for any level other than the first?
4510 if (ObjCLifetimeConversion)
4511 Conv |= ReferenceConversions::ObjCLifetime;
4514 } while (Context.UnwrapSimilarTypes(T1, T2));
4516 // At this point, if the types are reference-related, we must either have the
4517 // same inner type (ignoring qualifiers), or must have already worked out how
4518 // to convert the referent.
4519 return (ConvertedReferent || Context.hasSameUnqualifiedType(T1, T2))
4524 /// Look for a user-defined conversion to a value reference-compatible
4525 /// with DeclType. Return true if something definite is found.
4527 FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS,
4528 QualType DeclType, SourceLocation DeclLoc,
4529 Expr *Init, QualType T2, bool AllowRvalues,
4530 bool AllowExplicit) {
4531 assert(T2->isRecordType() && "Can only find conversions of record types.");
4532 auto *T2RecordDecl = cast<CXXRecordDecl>(T2->castAs<RecordType>()->getDecl());
4534 OverloadCandidateSet CandidateSet(
4535 DeclLoc, OverloadCandidateSet::CSK_InitByUserDefinedConversion);
4536 const auto &Conversions = T2RecordDecl->getVisibleConversionFunctions();
4537 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
4539 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
4540 if (isa<UsingShadowDecl>(D))
4541 D = cast<UsingShadowDecl>(D)->getTargetDecl();
4543 FunctionTemplateDecl *ConvTemplate
4544 = dyn_cast<FunctionTemplateDecl>(D);
4545 CXXConversionDecl *Conv;
4547 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
4549 Conv = cast<CXXConversionDecl>(D);
4552 // If we are initializing an rvalue reference, don't permit conversion
4553 // functions that return lvalues.
4554 if (!ConvTemplate && DeclType->isRValueReferenceType()) {
4555 const ReferenceType *RefType
4556 = Conv->getConversionType()->getAs<LValueReferenceType>();
4557 if (RefType && !RefType->getPointeeType()->isFunctionType())
4561 if (!ConvTemplate &&
4562 S.CompareReferenceRelationship(
4564 Conv->getConversionType()
4565 .getNonReferenceType()
4566 .getUnqualifiedType(),
4567 DeclType.getNonReferenceType().getUnqualifiedType()) ==
4568 Sema::Ref_Incompatible)
4571 // If the conversion function doesn't return a reference type,
4572 // it can't be considered for this conversion. An rvalue reference
4573 // is only acceptable if its referencee is a function type.
4575 const ReferenceType *RefType =
4576 Conv->getConversionType()->getAs<ReferenceType>();
4578 (!RefType->isLValueReferenceType() &&
4579 !RefType->getPointeeType()->isFunctionType()))
4584 S.AddTemplateConversionCandidate(
4585 ConvTemplate, I.getPair(), ActingDC, Init, DeclType, CandidateSet,
4586 /*AllowObjCConversionOnExplicit=*/false, AllowExplicit);
4588 S.AddConversionCandidate(
4589 Conv, I.getPair(), ActingDC, Init, DeclType, CandidateSet,
4590 /*AllowObjCConversionOnExplicit=*/false, AllowExplicit);
4593 bool HadMultipleCandidates = (CandidateSet.size() > 1);
4595 OverloadCandidateSet::iterator Best;
4596 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best)) {
4598 // C++ [over.ics.ref]p1:
4600 // [...] If the parameter binds directly to the result of
4601 // applying a conversion function to the argument
4602 // expression, the implicit conversion sequence is a
4603 // user-defined conversion sequence (13.3.3.1.2), with the
4604 // second standard conversion sequence either an identity
4605 // conversion or, if the conversion function returns an
4606 // entity of a type that is a derived class of the parameter
4607 // type, a derived-to-base Conversion.
4608 if (!Best->FinalConversion.DirectBinding)
4611 ICS.setUserDefined();
4612 ICS.UserDefined.Before = Best->Conversions[0].Standard;
4613 ICS.UserDefined.After = Best->FinalConversion;
4614 ICS.UserDefined.HadMultipleCandidates = HadMultipleCandidates;
4615 ICS.UserDefined.ConversionFunction = Best->Function;
4616 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl;
4617 ICS.UserDefined.EllipsisConversion = false;
4618 assert(ICS.UserDefined.After.ReferenceBinding &&
4619 ICS.UserDefined.After.DirectBinding &&
4620 "Expected a direct reference binding!");
4625 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin();
4626 Cand != CandidateSet.end(); ++Cand)
4628 ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
4631 case OR_No_Viable_Function:
4633 // There was no suitable conversion, or we found a deleted
4634 // conversion; continue with other checks.
4638 llvm_unreachable("Invalid OverloadResult!");
4641 /// Compute an implicit conversion sequence for reference
4643 static ImplicitConversionSequence
4644 TryReferenceInit(Sema &S, Expr *Init, QualType DeclType,
4645 SourceLocation DeclLoc,
4646 bool SuppressUserConversions,
4647 bool AllowExplicit) {
4648 assert(DeclType->isReferenceType() && "Reference init needs a reference");
4650 // Most paths end in a failed conversion.
4651 ImplicitConversionSequence ICS;
4652 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4654 QualType T1 = DeclType->castAs<ReferenceType>()->getPointeeType();
4655 QualType T2 = Init->getType();
4657 // If the initializer is the address of an overloaded function, try
4658 // to resolve the overloaded function. If all goes well, T2 is the
4659 // type of the resulting function.
4660 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
4661 DeclAccessPair Found;
4662 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType,
4667 // Compute some basic properties of the types and the initializer.
4668 bool isRValRef = DeclType->isRValueReferenceType();
4669 Expr::Classification InitCategory = Init->Classify(S.Context);
4671 Sema::ReferenceConversions RefConv;
4672 Sema::ReferenceCompareResult RefRelationship =
4673 S.CompareReferenceRelationship(DeclLoc, T1, T2, &RefConv);
4675 auto SetAsReferenceBinding = [&](bool BindsDirectly) {
4677 ICS.Standard.First = ICK_Identity;
4678 // FIXME: A reference binding can be a function conversion too. We should
4679 // consider that when ordering reference-to-function bindings.
4680 ICS.Standard.Second = (RefConv & Sema::ReferenceConversions::DerivedToBase)
4681 ? ICK_Derived_To_Base
4682 : (RefConv & Sema::ReferenceConversions::ObjC)
4683 ? ICK_Compatible_Conversion
4685 // FIXME: As a speculative fix to a defect introduced by CWG2352, we rank
4686 // a reference binding that performs a non-top-level qualification
4687 // conversion as a qualification conversion, not as an identity conversion.
4688 ICS.Standard.Third = (RefConv &
4689 Sema::ReferenceConversions::NestedQualification)
4692 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
4693 ICS.Standard.setToType(0, T2);
4694 ICS.Standard.setToType(1, T1);
4695 ICS.Standard.setToType(2, T1);
4696 ICS.Standard.ReferenceBinding = true;
4697 ICS.Standard.DirectBinding = BindsDirectly;
4698 ICS.Standard.IsLvalueReference = !isRValRef;
4699 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType();
4700 ICS.Standard.BindsToRvalue = InitCategory.isRValue();
4701 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4702 ICS.Standard.ObjCLifetimeConversionBinding =
4703 (RefConv & Sema::ReferenceConversions::ObjCLifetime) != 0;
4704 ICS.Standard.CopyConstructor = nullptr;
4705 ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
4708 // C++0x [dcl.init.ref]p5:
4709 // A reference to type "cv1 T1" is initialized by an expression
4710 // of type "cv2 T2" as follows:
4712 // -- If reference is an lvalue reference and the initializer expression
4714 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is
4715 // reference-compatible with "cv2 T2," or
4717 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here.
4718 if (InitCategory.isLValue() && RefRelationship == Sema::Ref_Compatible) {
4719 // C++ [over.ics.ref]p1:
4720 // When a parameter of reference type binds directly (8.5.3)
4721 // to an argument expression, the implicit conversion sequence
4722 // is the identity conversion, unless the argument expression
4723 // has a type that is a derived class of the parameter type,
4724 // in which case the implicit conversion sequence is a
4725 // derived-to-base Conversion (13.3.3.1).
4726 SetAsReferenceBinding(/*BindsDirectly=*/true);
4728 // Nothing more to do: the inaccessibility/ambiguity check for
4729 // derived-to-base conversions is suppressed when we're
4730 // computing the implicit conversion sequence (C++
4731 // [over.best.ics]p2).
4735 // -- has a class type (i.e., T2 is a class type), where T1 is
4736 // not reference-related to T2, and can be implicitly
4737 // converted to an lvalue of type "cv3 T3," where "cv1 T1"
4738 // is reference-compatible with "cv3 T3" 92) (this
4739 // conversion is selected by enumerating the applicable
4740 // conversion functions (13.3.1.6) and choosing the best
4741 // one through overload resolution (13.3)),
4742 if (!SuppressUserConversions && T2->isRecordType() &&
4743 S.isCompleteType(DeclLoc, T2) &&
4744 RefRelationship == Sema::Ref_Incompatible) {
4745 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4746 Init, T2, /*AllowRvalues=*/false,
4752 // -- Otherwise, the reference shall be an lvalue reference to a
4753 // non-volatile const type (i.e., cv1 shall be const), or the reference
4754 // shall be an rvalue reference.
4755 if (!isRValRef && (!T1.isConstQualified() || T1.isVolatileQualified()))
4758 // -- If the initializer expression
4760 // -- is an xvalue, class prvalue, array prvalue or function
4761 // lvalue and "cv1 T1" is reference-compatible with "cv2 T2", or
4762 if (RefRelationship == Sema::Ref_Compatible &&
4763 (InitCategory.isXValue() ||
4764 (InitCategory.isPRValue() &&
4765 (T2->isRecordType() || T2->isArrayType())) ||
4766 (InitCategory.isLValue() && T2->isFunctionType()))) {
4767 // In C++11, this is always a direct binding. In C++98/03, it's a direct
4768 // binding unless we're binding to a class prvalue.
4769 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we
4770 // allow the use of rvalue references in C++98/03 for the benefit of
4771 // standard library implementors; therefore, we need the xvalue check here.
4772 SetAsReferenceBinding(/*BindsDirectly=*/S.getLangOpts().CPlusPlus11 ||
4773 !(InitCategory.isPRValue() || T2->isRecordType()));
4777 // -- has a class type (i.e., T2 is a class type), where T1 is not
4778 // reference-related to T2, and can be implicitly converted to
4779 // an xvalue, class prvalue, or function lvalue of type
4780 // "cv3 T3", where "cv1 T1" is reference-compatible with
4783 // then the reference is bound to the value of the initializer
4784 // expression in the first case and to the result of the conversion
4785 // in the second case (or, in either case, to an appropriate base
4786 // class subobject).
4787 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4788 T2->isRecordType() && S.isCompleteType(DeclLoc, T2) &&
4789 FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4790 Init, T2, /*AllowRvalues=*/true,
4792 // In the second case, if the reference is an rvalue reference
4793 // and the second standard conversion sequence of the
4794 // user-defined conversion sequence includes an lvalue-to-rvalue
4795 // conversion, the program is ill-formed.
4796 if (ICS.isUserDefined() && isRValRef &&
4797 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue)
4798 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4803 // A temporary of function type cannot be created; don't even try.
4804 if (T1->isFunctionType())
4807 // -- Otherwise, a temporary of type "cv1 T1" is created and
4808 // initialized from the initializer expression using the
4809 // rules for a non-reference copy initialization (8.5). The
4810 // reference is then bound to the temporary. If T1 is
4811 // reference-related to T2, cv1 must be the same
4812 // cv-qualification as, or greater cv-qualification than,
4813 // cv2; otherwise, the program is ill-formed.
4814 if (RefRelationship == Sema::Ref_Related) {
4815 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then
4816 // we would be reference-compatible or reference-compatible with
4817 // added qualification. But that wasn't the case, so the reference
4818 // initialization fails.
4820 // Note that we only want to check address spaces and cvr-qualifiers here.
4821 // ObjC GC, lifetime and unaligned qualifiers aren't important.
4822 Qualifiers T1Quals = T1.getQualifiers();
4823 Qualifiers T2Quals = T2.getQualifiers();
4824 T1Quals.removeObjCGCAttr();
4825 T1Quals.removeObjCLifetime();
4826 T2Quals.removeObjCGCAttr();
4827 T2Quals.removeObjCLifetime();
4828 // MS compiler ignores __unaligned qualifier for references; do the same.
4829 T1Quals.removeUnaligned();
4830 T2Quals.removeUnaligned();
4831 if (!T1Quals.compatiblyIncludes(T2Quals))
4835 // If at least one of the types is a class type, the types are not
4836 // related, and we aren't allowed any user conversions, the
4837 // reference binding fails. This case is important for breaking
4838 // recursion, since TryImplicitConversion below will attempt to
4839 // create a temporary through the use of a copy constructor.
4840 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4841 (T1->isRecordType() || T2->isRecordType()))
4844 // If T1 is reference-related to T2 and the reference is an rvalue
4845 // reference, the initializer expression shall not be an lvalue.
4846 if (RefRelationship >= Sema::Ref_Related &&
4847 isRValRef && Init->Classify(S.Context).isLValue())
4850 // C++ [over.ics.ref]p2:
4851 // When a parameter of reference type is not bound directly to
4852 // an argument expression, the conversion sequence is the one
4853 // required to convert the argument expression to the
4854 // underlying type of the reference according to
4855 // 13.3.3.1. Conceptually, this conversion sequence corresponds
4856 // to copy-initializing a temporary of the underlying type with
4857 // the argument expression. Any difference in top-level
4858 // cv-qualification is subsumed by the initialization itself
4859 // and does not constitute a conversion.
4860 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions,
4861 /*AllowExplicit=*/false,
4862 /*InOverloadResolution=*/false,
4864 /*AllowObjCWritebackConversion=*/false,
4865 /*AllowObjCConversionOnExplicit=*/false);
4867 // Of course, that's still a reference binding.
4868 if (ICS.isStandard()) {
4869 ICS.Standard.ReferenceBinding = true;
4870 ICS.Standard.IsLvalueReference = !isRValRef;
4871 ICS.Standard.BindsToFunctionLvalue = false;
4872 ICS.Standard.BindsToRvalue = true;
4873 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4874 ICS.Standard.ObjCLifetimeConversionBinding = false;
4875 } else if (ICS.isUserDefined()) {
4876 const ReferenceType *LValRefType =
4877 ICS.UserDefined.ConversionFunction->getReturnType()
4878 ->getAs<LValueReferenceType>();
4880 // C++ [over.ics.ref]p3:
4881 // Except for an implicit object parameter, for which see 13.3.1, a
4882 // standard conversion sequence cannot be formed if it requires [...]
4883 // binding an rvalue reference to an lvalue other than a function
4885 // Note that the function case is not possible here.
4886 if (DeclType->isRValueReferenceType() && LValRefType) {
4887 // FIXME: This is the wrong BadConversionSequence. The problem is binding
4888 // an rvalue reference to a (non-function) lvalue, not binding an lvalue
4889 // reference to an rvalue!
4890 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, Init, DeclType);
4894 ICS.UserDefined.After.ReferenceBinding = true;
4895 ICS.UserDefined.After.IsLvalueReference = !isRValRef;
4896 ICS.UserDefined.After.BindsToFunctionLvalue = false;
4897 ICS.UserDefined.After.BindsToRvalue = !LValRefType;
4898 ICS.UserDefined.After.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4899 ICS.UserDefined.After.ObjCLifetimeConversionBinding = false;
4905 static ImplicitConversionSequence
4906 TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
4907 bool SuppressUserConversions,
4908 bool InOverloadResolution,
4909 bool AllowObjCWritebackConversion,
4910 bool AllowExplicit = false);
4912 /// TryListConversion - Try to copy-initialize a value of type ToType from the
4913 /// initializer list From.
4914 static ImplicitConversionSequence
4915 TryListConversion(Sema &S, InitListExpr *From, QualType ToType,
4916 bool SuppressUserConversions,
4917 bool InOverloadResolution,
4918 bool AllowObjCWritebackConversion) {
4919 // C++11 [over.ics.list]p1:
4920 // When an argument is an initializer list, it is not an expression and
4921 // special rules apply for converting it to a parameter type.
4923 ImplicitConversionSequence Result;
4924 Result.setBad(BadConversionSequence::no_conversion, From, ToType);
4926 // We need a complete type for what follows. Incomplete types can never be
4927 // initialized from init lists.
4928 if (!S.isCompleteType(From->getBeginLoc(), ToType))
4932 // If the parameter type is a class X and the initializer list has a single
4933 // element of type cv U, where U is X or a class derived from X, the
4934 // implicit conversion sequence is the one required to convert the element
4935 // to the parameter type.
4937 // Otherwise, if the parameter type is a character array [... ]
4938 // and the initializer list has a single element that is an
4939 // appropriately-typed string literal (8.5.2 [dcl.init.string]), the
4940 // implicit conversion sequence is the identity conversion.
4941 if (From->getNumInits() == 1) {
4942 if (ToType->isRecordType()) {
4943 QualType InitType = From->getInit(0)->getType();
4944 if (S.Context.hasSameUnqualifiedType(InitType, ToType) ||
4945 S.IsDerivedFrom(From->getBeginLoc(), InitType, ToType))
4946 return TryCopyInitialization(S, From->getInit(0), ToType,
4947 SuppressUserConversions,
4948 InOverloadResolution,
4949 AllowObjCWritebackConversion);
4951 // FIXME: Check the other conditions here: array of character type,
4952 // initializer is a string literal.
4953 if (ToType->isArrayType()) {
4954 InitializedEntity Entity =
4955 InitializedEntity::InitializeParameter(S.Context, ToType,
4956 /*Consumed=*/false);
4957 if (S.CanPerformCopyInitialization(Entity, From)) {
4958 Result.setStandard();
4959 Result.Standard.setAsIdentityConversion();
4960 Result.Standard.setFromType(ToType);
4961 Result.Standard.setAllToTypes(ToType);
4967 // C++14 [over.ics.list]p2: Otherwise, if the parameter type [...] (below).
4968 // C++11 [over.ics.list]p2:
4969 // If the parameter type is std::initializer_list<X> or "array of X" and
4970 // all the elements can be implicitly converted to X, the implicit
4971 // conversion sequence is the worst conversion necessary to convert an
4972 // element of the list to X.
4974 // C++14 [over.ics.list]p3:
4975 // Otherwise, if the parameter type is "array of N X", if the initializer
4976 // list has exactly N elements or if it has fewer than N elements and X is
4977 // default-constructible, and if all the elements of the initializer list
4978 // can be implicitly converted to X, the implicit conversion sequence is
4979 // the worst conversion necessary to convert an element of the list to X.
4981 // FIXME: We're missing a lot of these checks.
4982 bool toStdInitializerList = false;
4984 if (ToType->isArrayType())
4985 X = S.Context.getAsArrayType(ToType)->getElementType();
4987 toStdInitializerList = S.isStdInitializerList(ToType, &X);
4989 for (unsigned i = 0, e = From->getNumInits(); i < e; ++i) {
4990 Expr *Init = From->getInit(i);
4991 ImplicitConversionSequence ICS =
4992 TryCopyInitialization(S, Init, X, SuppressUserConversions,
4993 InOverloadResolution,
4994 AllowObjCWritebackConversion);
4995 // If a single element isn't convertible, fail.
5000 // Otherwise, look for the worst conversion.
5001 if (Result.isBad() || CompareImplicitConversionSequences(
5002 S, From->getBeginLoc(), ICS, Result) ==
5003 ImplicitConversionSequence::Worse)
5007 // For an empty list, we won't have computed any conversion sequence.
5008 // Introduce the identity conversion sequence.
5009 if (From->getNumInits() == 0) {
5010 Result.setStandard();
5011 Result.Standard.setAsIdentityConversion();
5012 Result.Standard.setFromType(ToType);
5013 Result.Standard.setAllToTypes(ToType);
5016 Result.setStdInitializerListElement(toStdInitializerList);
5020 // C++14 [over.ics.list]p4:
5021 // C++11 [over.ics.list]p3:
5022 // Otherwise, if the parameter is a non-aggregate class X and overload
5023 // resolution chooses a single best constructor [...] the implicit
5024 // conversion sequence is a user-defined conversion sequence. If multiple
5025 // constructors are viable but none is better than the others, the
5026 // implicit conversion sequence is a user-defined conversion sequence.
5027 if (ToType->isRecordType() && !ToType->isAggregateType()) {
5028 // This function can deal with initializer lists.
5029 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
5030 /*AllowExplicit=*/false,
5031 InOverloadResolution, /*CStyle=*/false,
5032 AllowObjCWritebackConversion,
5033 /*AllowObjCConversionOnExplicit=*/false);
5036 // C++14 [over.ics.list]p5:
5037 // C++11 [over.ics.list]p4:
5038 // Otherwise, if the parameter has an aggregate type which can be
5039 // initialized from the initializer list [...] the implicit conversion
5040 // sequence is a user-defined conversion sequence.
5041 if (ToType->isAggregateType()) {
5042 // Type is an aggregate, argument is an init list. At this point it comes
5043 // down to checking whether the initialization works.
5044 // FIXME: Find out whether this parameter is consumed or not.
5045 InitializedEntity Entity =
5046 InitializedEntity::InitializeParameter(S.Context, ToType,
5047 /*Consumed=*/false);
5048 if (S.CanPerformAggregateInitializationForOverloadResolution(Entity,
5050 Result.setUserDefined();
5051 Result.UserDefined.Before.setAsIdentityConversion();
5052 // Initializer lists don't have a type.
5053 Result.UserDefined.Before.setFromType(QualType());
5054 Result.UserDefined.Before.setAllToTypes(QualType());
5056 Result.UserDefined.After.setAsIdentityConversion();
5057 Result.UserDefined.After.setFromType(ToType);
5058 Result.UserDefined.After.setAllToTypes(ToType);
5059 Result.UserDefined.ConversionFunction = nullptr;
5064 // C++14 [over.ics.list]p6:
5065 // C++11 [over.ics.list]p5:
5066 // Otherwise, if the parameter is a reference, see 13.3.3.1.4.
5067 if (ToType->isReferenceType()) {
5068 // The standard is notoriously unclear here, since 13.3.3.1.4 doesn't
5069 // mention initializer lists in any way. So we go by what list-
5070 // initialization would do and try to extrapolate from that.
5072 QualType T1 = ToType->castAs<ReferenceType>()->getPointeeType();
5074 // If the initializer list has a single element that is reference-related
5075 // to the parameter type, we initialize the reference from that.
5076 if (From->getNumInits() == 1) {
5077 Expr *Init = From->getInit(0);
5079 QualType T2 = Init->getType();
5081 // If the initializer is the address of an overloaded function, try
5082 // to resolve the overloaded function. If all goes well, T2 is the
5083 // type of the resulting function.
5084 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
5085 DeclAccessPair Found;
5086 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(
5087 Init, ToType, false, Found))
5091 // Compute some basic properties of the types and the initializer.
5092 Sema::ReferenceCompareResult RefRelationship =
5093 S.CompareReferenceRelationship(From->getBeginLoc(), T1, T2);
5095 if (RefRelationship >= Sema::Ref_Related) {
5096 return TryReferenceInit(S, Init, ToType, /*FIXME*/ From->getBeginLoc(),
5097 SuppressUserConversions,
5098 /*AllowExplicit=*/false);
5102 // Otherwise, we bind the reference to a temporary created from the
5103 // initializer list.
5104 Result = TryListConversion(S, From, T1, SuppressUserConversions,
5105 InOverloadResolution,
5106 AllowObjCWritebackConversion);
5107 if (Result.isFailure())
5109 assert(!Result.isEllipsis() &&
5110 "Sub-initialization cannot result in ellipsis conversion.");
5112 // Can we even bind to a temporary?
5113 if (ToType->isRValueReferenceType() ||
5114 (T1.isConstQualified() && !T1.isVolatileQualified())) {
5115 StandardConversionSequence &SCS = Result.isStandard() ? Result.Standard :
5116 Result.UserDefined.After;
5117 SCS.ReferenceBinding = true;
5118 SCS.IsLvalueReference = ToType->isLValueReferenceType();
5119 SCS.BindsToRvalue = true;
5120 SCS.BindsToFunctionLvalue = false;
5121 SCS.BindsImplicitObjectArgumentWithoutRefQualifier = false;
5122 SCS.ObjCLifetimeConversionBinding = false;
5124 Result.setBad(BadConversionSequence::lvalue_ref_to_rvalue,
5129 // C++14 [over.ics.list]p7:
5130 // C++11 [over.ics.list]p6:
5131 // Otherwise, if the parameter type is not a class:
5132 if (!ToType->isRecordType()) {
5133 // - if the initializer list has one element that is not itself an
5134 // initializer list, the implicit conversion sequence is the one
5135 // required to convert the element to the parameter type.
5136 unsigned NumInits = From->getNumInits();
5137 if (NumInits == 1 && !isa<InitListExpr>(From->getInit(0)))
5138 Result = TryCopyInitialization(S, From->getInit(0), ToType,
5139 SuppressUserConversions,
5140 InOverloadResolution,
5141 AllowObjCWritebackConversion);
5142 // - if the initializer list has no elements, the implicit conversion
5143 // sequence is the identity conversion.
5144 else if (NumInits == 0) {
5145 Result.setStandard();
5146 Result.Standard.setAsIdentityConversion();
5147 Result.Standard.setFromType(ToType);
5148 Result.Standard.setAllToTypes(ToType);
5153 // C++14 [over.ics.list]p8:
5154 // C++11 [over.ics.list]p7:
5155 // In all cases other than those enumerated above, no conversion is possible
5159 /// TryCopyInitialization - Try to copy-initialize a value of type
5160 /// ToType from the expression From. Return the implicit conversion
5161 /// sequence required to pass this argument, which may be a bad
5162 /// conversion sequence (meaning that the argument cannot be passed to
5163 /// a parameter of this type). If @p SuppressUserConversions, then we
5164 /// do not permit any user-defined conversion sequences.
5165 static ImplicitConversionSequence
5166 TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
5167 bool SuppressUserConversions,
5168 bool InOverloadResolution,
5169 bool AllowObjCWritebackConversion,
5170 bool AllowExplicit) {
5171 if (InitListExpr *FromInitList = dyn_cast<InitListExpr>(From))
5172 return TryListConversion(S, FromInitList, ToType, SuppressUserConversions,
5173 InOverloadResolution,AllowObjCWritebackConversion);
5175 if (ToType->isReferenceType())
5176 return TryReferenceInit(S, From, ToType,
5177 /*FIXME:*/ From->getBeginLoc(),
5178 SuppressUserConversions, AllowExplicit);
5180 return TryImplicitConversion(S, From, ToType,
5181 SuppressUserConversions,
5182 /*AllowExplicit=*/false,
5183 InOverloadResolution,
5185 AllowObjCWritebackConversion,
5186 /*AllowObjCConversionOnExplicit=*/false);
5189 static bool TryCopyInitialization(const CanQualType FromQTy,
5190 const CanQualType ToQTy,
5193 ExprValueKind FromVK) {
5194 OpaqueValueExpr TmpExpr(Loc, FromQTy, FromVK);
5195 ImplicitConversionSequence ICS =
5196 TryCopyInitialization(S, &TmpExpr, ToQTy, true, true, false);
5198 return !ICS.isBad();
5201 /// TryObjectArgumentInitialization - Try to initialize the object
5202 /// parameter of the given member function (@c Method) from the
5203 /// expression @p From.
5204 static ImplicitConversionSequence
5205 TryObjectArgumentInitialization(Sema &S, SourceLocation Loc, QualType FromType,
5206 Expr::Classification FromClassification,
5207 CXXMethodDecl *Method,
5208 CXXRecordDecl *ActingContext) {
5209 QualType ClassType = S.Context.getTypeDeclType(ActingContext);
5210 // [class.dtor]p2: A destructor can be invoked for a const, volatile or
5211 // const volatile object.
5212 Qualifiers Quals = Method->getMethodQualifiers();
5213 if (isa<CXXDestructorDecl>(Method)) {
5215 Quals.addVolatile();
5218 QualType ImplicitParamType = S.Context.getQualifiedType(ClassType, Quals);
5220 // Set up the conversion sequence as a "bad" conversion, to allow us
5222 ImplicitConversionSequence ICS;
5224 // We need to have an object of class type.
5225 if (const PointerType *PT = FromType->getAs<PointerType>()) {
5226 FromType = PT->getPointeeType();
5228 // When we had a pointer, it's implicitly dereferenced, so we
5229 // better have an lvalue.
5230 assert(FromClassification.isLValue());
5233 assert(FromType->isRecordType());
5235 // C++0x [over.match.funcs]p4:
5236 // For non-static member functions, the type of the implicit object
5239 // - "lvalue reference to cv X" for functions declared without a
5240 // ref-qualifier or with the & ref-qualifier
5241 // - "rvalue reference to cv X" for functions declared with the &&
5244 // where X is the class of which the function is a member and cv is the
5245 // cv-qualification on the member function declaration.
5247 // However, when finding an implicit conversion sequence for the argument, we
5248 // are not allowed to perform user-defined conversions
5249 // (C++ [over.match.funcs]p5). We perform a simplified version of
5250 // reference binding here, that allows class rvalues to bind to
5251 // non-constant references.
5253 // First check the qualifiers.
5254 QualType FromTypeCanon = S.Context.getCanonicalType(FromType);
5255 if (ImplicitParamType.getCVRQualifiers()
5256 != FromTypeCanon.getLocalCVRQualifiers() &&
5257 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) {
5258 ICS.setBad(BadConversionSequence::bad_qualifiers,
5259 FromType, ImplicitParamType);
5263 if (FromTypeCanon.hasAddressSpace()) {
5264 Qualifiers QualsImplicitParamType = ImplicitParamType.getQualifiers();
5265 Qualifiers QualsFromType = FromTypeCanon.getQualifiers();
5266 if (!QualsImplicitParamType.isAddressSpaceSupersetOf(QualsFromType)) {
5267 ICS.setBad(BadConversionSequence::bad_qualifiers,
5268 FromType, ImplicitParamType);
5273 // Check that we have either the same type or a derived type. It
5274 // affects the conversion rank.
5275 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType);
5276 ImplicitConversionKind SecondKind;
5277 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) {
5278 SecondKind = ICK_Identity;
5279 } else if (S.IsDerivedFrom(Loc, FromType, ClassType))
5280 SecondKind = ICK_Derived_To_Base;
5282 ICS.setBad(BadConversionSequence::unrelated_class,
5283 FromType, ImplicitParamType);
5287 // Check the ref-qualifier.
5288 switch (Method->getRefQualifier()) {
5290 // Do nothing; we don't care about lvalueness or rvalueness.
5294 if (!FromClassification.isLValue() && !Quals.hasOnlyConst()) {
5295 // non-const lvalue reference cannot bind to an rvalue
5296 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType,
5303 if (!FromClassification.isRValue()) {
5304 // rvalue reference cannot bind to an lvalue
5305 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType,
5312 // Success. Mark this as a reference binding.
5314 ICS.Standard.setAsIdentityConversion();
5315 ICS.Standard.Second = SecondKind;
5316 ICS.Standard.setFromType(FromType);
5317 ICS.Standard.setAllToTypes(ImplicitParamType);
5318 ICS.Standard.ReferenceBinding = true;
5319 ICS.Standard.DirectBinding = true;
5320 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue;
5321 ICS.Standard.BindsToFunctionLvalue = false;
5322 ICS.Standard.BindsToRvalue = FromClassification.isRValue();
5323 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier
5324 = (Method->getRefQualifier() == RQ_None);
5328 /// PerformObjectArgumentInitialization - Perform initialization of
5329 /// the implicit object parameter for the given Method with the given
5332 Sema::PerformObjectArgumentInitialization(Expr *From,
5333 NestedNameSpecifier *Qualifier,
5334 NamedDecl *FoundDecl,
5335 CXXMethodDecl *Method) {
5336 QualType FromRecordType, DestType;
5337 QualType ImplicitParamRecordType =
5338 Method->getThisType()->castAs<PointerType>()->getPointeeType();
5340 Expr::Classification FromClassification;
5341 if (const PointerType *PT = From->getType()->getAs<PointerType>()) {
5342 FromRecordType = PT->getPointeeType();
5343 DestType = Method->getThisType();
5344 FromClassification = Expr::Classification::makeSimpleLValue();
5346 FromRecordType = From->getType();
5347 DestType = ImplicitParamRecordType;
5348 FromClassification = From->Classify(Context);
5350 // When performing member access on an rvalue, materialize a temporary.
5351 if (From->isRValue()) {
5352 From = CreateMaterializeTemporaryExpr(FromRecordType, From,
5353 Method->getRefQualifier() !=
5354 RefQualifierKind::RQ_RValue);
5358 // Note that we always use the true parent context when performing
5359 // the actual argument initialization.
5360 ImplicitConversionSequence ICS = TryObjectArgumentInitialization(
5361 *this, From->getBeginLoc(), From->getType(), FromClassification, Method,
5362 Method->getParent());
5364 switch (ICS.Bad.Kind) {
5365 case BadConversionSequence::bad_qualifiers: {
5366 Qualifiers FromQs = FromRecordType.getQualifiers();
5367 Qualifiers ToQs = DestType.getQualifiers();
5368 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers();
5370 Diag(From->getBeginLoc(), diag::err_member_function_call_bad_cvr)
5371 << Method->getDeclName() << FromRecordType << (CVR - 1)
5372 << From->getSourceRange();
5373 Diag(Method->getLocation(), diag::note_previous_decl)
5374 << Method->getDeclName();
5380 case BadConversionSequence::lvalue_ref_to_rvalue:
5381 case BadConversionSequence::rvalue_ref_to_lvalue: {
5382 bool IsRValueQualified =
5383 Method->getRefQualifier() == RefQualifierKind::RQ_RValue;
5384 Diag(From->getBeginLoc(), diag::err_member_function_call_bad_ref)
5385 << Method->getDeclName() << FromClassification.isRValue()
5386 << IsRValueQualified;
5387 Diag(Method->getLocation(), diag::note_previous_decl)
5388 << Method->getDeclName();
5392 case BadConversionSequence::no_conversion:
5393 case BadConversionSequence::unrelated_class:
5397 return Diag(From->getBeginLoc(), diag::err_member_function_call_bad_type)
5398 << ImplicitParamRecordType << FromRecordType
5399 << From->getSourceRange();
5402 if (ICS.Standard.Second == ICK_Derived_To_Base) {
5403 ExprResult FromRes =
5404 PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method);
5405 if (FromRes.isInvalid())
5407 From = FromRes.get();
5410 if (!Context.hasSameType(From->getType(), DestType)) {
5412 QualType PteeTy = DestType->getPointeeType();
5414 PteeTy.isNull() ? DestType.getAddressSpace() : PteeTy.getAddressSpace();
5415 if (FromRecordType.getAddressSpace() != DestAS)
5416 CK = CK_AddressSpaceConversion;
5419 From = ImpCastExprToType(From, DestType, CK, From->getValueKind()).get();
5424 /// TryContextuallyConvertToBool - Attempt to contextually convert the
5425 /// expression From to bool (C++0x [conv]p3).
5426 static ImplicitConversionSequence
5427 TryContextuallyConvertToBool(Sema &S, Expr *From) {
5428 return TryImplicitConversion(S, From, S.Context.BoolTy,
5429 /*SuppressUserConversions=*/false,
5430 /*AllowExplicit=*/true,
5431 /*InOverloadResolution=*/false,
5433 /*AllowObjCWritebackConversion=*/false,
5434 /*AllowObjCConversionOnExplicit=*/false);
5437 /// PerformContextuallyConvertToBool - Perform a contextual conversion
5438 /// of the expression From to bool (C++0x [conv]p3).
5439 ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) {
5440 if (checkPlaceholderForOverload(*this, From))
5443 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From);
5445 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting);
5447 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy))
5448 return Diag(From->getBeginLoc(), diag::err_typecheck_bool_condition)
5449 << From->getType() << From->getSourceRange();
5453 /// Check that the specified conversion is permitted in a converted constant
5454 /// expression, according to C++11 [expr.const]p3. Return true if the conversion
5456 static bool CheckConvertedConstantConversions(Sema &S,
5457 StandardConversionSequence &SCS) {
5458 // Since we know that the target type is an integral or unscoped enumeration
5459 // type, most conversion kinds are impossible. All possible First and Third
5460 // conversions are fine.
5461 switch (SCS.Second) {
5463 case ICK_Function_Conversion:
5464 case ICK_Integral_Promotion:
5465 case ICK_Integral_Conversion: // Narrowing conversions are checked elsewhere.
5466 case ICK_Zero_Queue_Conversion:
5469 case ICK_Boolean_Conversion:
5470 // Conversion from an integral or unscoped enumeration type to bool is
5471 // classified as ICK_Boolean_Conversion, but it's also arguably an integral
5472 // conversion, so we allow it in a converted constant expression.
5474 // FIXME: Per core issue 1407, we should not allow this, but that breaks
5475 // a lot of popular code. We should at least add a warning for this
5476 // (non-conforming) extension.
5477 return SCS.getFromType()->isIntegralOrUnscopedEnumerationType() &&
5478 SCS.getToType(2)->isBooleanType();
5480 case ICK_Pointer_Conversion:
5481 case ICK_Pointer_Member:
5482 // C++1z: null pointer conversions and null member pointer conversions are
5483 // only permitted if the source type is std::nullptr_t.
5484 return SCS.getFromType()->isNullPtrType();
5486 case ICK_Floating_Promotion:
5487 case ICK_Complex_Promotion:
5488 case ICK_Floating_Conversion:
5489 case ICK_Complex_Conversion:
5490 case ICK_Floating_Integral:
5491 case ICK_Compatible_Conversion:
5492 case ICK_Derived_To_Base:
5493 case ICK_Vector_Conversion:
5494 case ICK_Vector_Splat:
5495 case ICK_Complex_Real:
5496 case ICK_Block_Pointer_Conversion:
5497 case ICK_TransparentUnionConversion:
5498 case ICK_Writeback_Conversion:
5499 case ICK_Zero_Event_Conversion:
5500 case ICK_C_Only_Conversion:
5501 case ICK_Incompatible_Pointer_Conversion:
5504 case ICK_Lvalue_To_Rvalue:
5505 case ICK_Array_To_Pointer:
5506 case ICK_Function_To_Pointer:
5507 llvm_unreachable("found a first conversion kind in Second");
5509 case ICK_Qualification:
5510 llvm_unreachable("found a third conversion kind in Second");
5512 case ICK_Num_Conversion_Kinds:
5516 llvm_unreachable("unknown conversion kind");
5519 /// CheckConvertedConstantExpression - Check that the expression From is a
5520 /// converted constant expression of type T, perform the conversion and produce
5521 /// the converted expression, per C++11 [expr.const]p3.
5522 static ExprResult CheckConvertedConstantExpression(Sema &S, Expr *From,
5523 QualType T, APValue &Value,
5526 assert(S.getLangOpts().CPlusPlus11 &&
5527 "converted constant expression outside C++11");
5529 if (checkPlaceholderForOverload(S, From))
5532 // C++1z [expr.const]p3:
5533 // A converted constant expression of type T is an expression,
5534 // implicitly converted to type T, where the converted
5535 // expression is a constant expression and the implicit conversion
5536 // sequence contains only [... list of conversions ...].
5537 // C++1z [stmt.if]p2:
5538 // If the if statement is of the form if constexpr, the value of the
5539 // condition shall be a contextually converted constant expression of type
5541 ImplicitConversionSequence ICS =
5542 CCE == Sema::CCEK_ConstexprIf || CCE == Sema::CCEK_ExplicitBool
5543 ? TryContextuallyConvertToBool(S, From)
5544 : TryCopyInitialization(S, From, T,
5545 /*SuppressUserConversions=*/false,
5546 /*InOverloadResolution=*/false,
5547 /*AllowObjCWritebackConversion=*/false,
5548 /*AllowExplicit=*/false);
5549 StandardConversionSequence *SCS = nullptr;
5550 switch (ICS.getKind()) {
5551 case ImplicitConversionSequence::StandardConversion:
5552 SCS = &ICS.Standard;
5554 case ImplicitConversionSequence::UserDefinedConversion:
5555 // We are converting to a non-class type, so the Before sequence
5557 SCS = &ICS.UserDefined.After;
5559 case ImplicitConversionSequence::AmbiguousConversion:
5560 case ImplicitConversionSequence::BadConversion:
5561 if (!S.DiagnoseMultipleUserDefinedConversion(From, T))
5562 return S.Diag(From->getBeginLoc(),
5563 diag::err_typecheck_converted_constant_expression)
5564 << From->getType() << From->getSourceRange() << T;
5567 case ImplicitConversionSequence::EllipsisConversion:
5568 llvm_unreachable("ellipsis conversion in converted constant expression");
5571 // Check that we would only use permitted conversions.
5572 if (!CheckConvertedConstantConversions(S, *SCS)) {
5573 return S.Diag(From->getBeginLoc(),
5574 diag::err_typecheck_converted_constant_expression_disallowed)
5575 << From->getType() << From->getSourceRange() << T;
5577 // [...] and where the reference binding (if any) binds directly.
5578 if (SCS->ReferenceBinding && !SCS->DirectBinding) {
5579 return S.Diag(From->getBeginLoc(),
5580 diag::err_typecheck_converted_constant_expression_indirect)
5581 << From->getType() << From->getSourceRange() << T;
5585 S.PerformImplicitConversion(From, T, ICS, Sema::AA_Converting);
5586 if (Result.isInvalid())
5589 // C++2a [intro.execution]p5:
5590 // A full-expression is [...] a constant-expression [...]
5592 S.ActOnFinishFullExpr(Result.get(), From->getExprLoc(),
5593 /*DiscardedValue=*/false, /*IsConstexpr=*/true);
5594 if (Result.isInvalid())
5597 // Check for a narrowing implicit conversion.
5598 APValue PreNarrowingValue;
5599 QualType PreNarrowingType;
5600 switch (SCS->getNarrowingKind(S.Context, Result.get(), PreNarrowingValue,
5601 PreNarrowingType)) {
5602 case NK_Dependent_Narrowing:
5603 // Implicit conversion to a narrower type, but the expression is
5604 // value-dependent so we can't tell whether it's actually narrowing.
5605 case NK_Variable_Narrowing:
5606 // Implicit conversion to a narrower type, and the value is not a constant
5607 // expression. We'll diagnose this in a moment.
5608 case NK_Not_Narrowing:
5611 case NK_Constant_Narrowing:
5612 S.Diag(From->getBeginLoc(), diag::ext_cce_narrowing)
5613 << CCE << /*Constant*/ 1
5614 << PreNarrowingValue.getAsString(S.Context, PreNarrowingType) << T;
5617 case NK_Type_Narrowing:
5618 S.Diag(From->getBeginLoc(), diag::ext_cce_narrowing)
5619 << CCE << /*Constant*/ 0 << From->getType() << T;
5623 if (Result.get()->isValueDependent()) {
5628 // Check the expression is a constant expression.
5629 SmallVector<PartialDiagnosticAt, 8> Notes;
5630 Expr::EvalResult Eval;
5632 Expr::ConstExprUsage Usage = CCE == Sema::CCEK_TemplateArg
5633 ? Expr::EvaluateForMangling
5634 : Expr::EvaluateForCodeGen;
5636 if (!Result.get()->EvaluateAsConstantExpr(Eval, Usage, S.Context) ||
5637 (RequireInt && !Eval.Val.isInt())) {
5638 // The expression can't be folded, so we can't keep it at this position in
5640 Result = ExprError();
5644 if (Notes.empty()) {
5645 // It's a constant expression.
5646 return ConstantExpr::Create(S.Context, Result.get(), Value);
5650 // It's not a constant expression. Produce an appropriate diagnostic.
5651 if (Notes.size() == 1 &&
5652 Notes[0].second.getDiagID() == diag::note_invalid_subexpr_in_const_expr)
5653 S.Diag(Notes[0].first, diag::err_expr_not_cce) << CCE;
5655 S.Diag(From->getBeginLoc(), diag::err_expr_not_cce)
5656 << CCE << From->getSourceRange();
5657 for (unsigned I = 0; I < Notes.size(); ++I)
5658 S.Diag(Notes[I].first, Notes[I].second);
5663 ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5664 APValue &Value, CCEKind CCE) {
5665 return ::CheckConvertedConstantExpression(*this, From, T, Value, CCE, false);
5668 ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5669 llvm::APSInt &Value,
5671 assert(T->isIntegralOrEnumerationType() && "unexpected converted const type");
5674 auto R = ::CheckConvertedConstantExpression(*this, From, T, V, CCE, true);
5675 if (!R.isInvalid() && !R.get()->isValueDependent())
5681 /// dropPointerConversions - If the given standard conversion sequence
5682 /// involves any pointer conversions, remove them. This may change
5683 /// the result type of the conversion sequence.
5684 static void dropPointerConversion(StandardConversionSequence &SCS) {
5685 if (SCS.Second == ICK_Pointer_Conversion) {
5686 SCS.Second = ICK_Identity;
5687 SCS.Third = ICK_Identity;
5688 SCS.ToTypePtrs[2] = SCS.ToTypePtrs[1] = SCS.ToTypePtrs[0];
5692 /// TryContextuallyConvertToObjCPointer - Attempt to contextually
5693 /// convert the expression From to an Objective-C pointer type.
5694 static ImplicitConversionSequence
5695 TryContextuallyConvertToObjCPointer(Sema &S, Expr *From) {
5696 // Do an implicit conversion to 'id'.
5697 QualType Ty = S.Context.getObjCIdType();
5698 ImplicitConversionSequence ICS
5699 = TryImplicitConversion(S, From, Ty,
5700 // FIXME: Are these flags correct?
5701 /*SuppressUserConversions=*/false,
5702 /*AllowExplicit=*/true,
5703 /*InOverloadResolution=*/false,
5705 /*AllowObjCWritebackConversion=*/false,
5706 /*AllowObjCConversionOnExplicit=*/true);
5708 // Strip off any final conversions to 'id'.
5709 switch (ICS.getKind()) {
5710 case ImplicitConversionSequence::BadConversion:
5711 case ImplicitConversionSequence::AmbiguousConversion:
5712 case ImplicitConversionSequence::EllipsisConversion:
5715 case ImplicitConversionSequence::UserDefinedConversion:
5716 dropPointerConversion(ICS.UserDefined.After);
5719 case ImplicitConversionSequence::StandardConversion:
5720 dropPointerConversion(ICS.Standard);
5727 /// PerformContextuallyConvertToObjCPointer - Perform a contextual
5728 /// conversion of the expression From to an Objective-C pointer type.
5729 /// Returns a valid but null ExprResult if no conversion sequence exists.
5730 ExprResult Sema::PerformContextuallyConvertToObjCPointer(Expr *From) {
5731 if (checkPlaceholderForOverload(*this, From))
5734 QualType Ty = Context.getObjCIdType();
5735 ImplicitConversionSequence ICS =
5736 TryContextuallyConvertToObjCPointer(*this, From);
5738 return PerformImplicitConversion(From, Ty, ICS, AA_Converting);
5739 return ExprResult();
5742 /// Determine whether the provided type is an integral type, or an enumeration
5743 /// type of a permitted flavor.
5744 bool Sema::ICEConvertDiagnoser::match(QualType T) {
5745 return AllowScopedEnumerations ? T->isIntegralOrEnumerationType()
5746 : T->isIntegralOrUnscopedEnumerationType();
5750 diagnoseAmbiguousConversion(Sema &SemaRef, SourceLocation Loc, Expr *From,
5751 Sema::ContextualImplicitConverter &Converter,
5752 QualType T, UnresolvedSetImpl &ViableConversions) {
5754 if (Converter.Suppress)
5757 Converter.diagnoseAmbiguous(SemaRef, Loc, T) << From->getSourceRange();
5758 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5759 CXXConversionDecl *Conv =
5760 cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl());
5761 QualType ConvTy = Conv->getConversionType().getNonReferenceType();
5762 Converter.noteAmbiguous(SemaRef, Conv, ConvTy);
5768 diagnoseNoViableConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5769 Sema::ContextualImplicitConverter &Converter,
5770 QualType T, bool HadMultipleCandidates,
5771 UnresolvedSetImpl &ExplicitConversions) {
5772 if (ExplicitConversions.size() == 1 && !Converter.Suppress) {
5773 DeclAccessPair Found = ExplicitConversions[0];
5774 CXXConversionDecl *Conversion =
5775 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5777 // The user probably meant to invoke the given explicit
5778 // conversion; use it.
5779 QualType ConvTy = Conversion->getConversionType().getNonReferenceType();
5780 std::string TypeStr;
5781 ConvTy.getAsStringInternal(TypeStr, SemaRef.getPrintingPolicy());
5783 Converter.diagnoseExplicitConv(SemaRef, Loc, T, ConvTy)
5784 << FixItHint::CreateInsertion(From->getBeginLoc(),
5785 "static_cast<" + TypeStr + ">(")
5786 << FixItHint::CreateInsertion(
5787 SemaRef.getLocForEndOfToken(From->getEndLoc()), ")");
5788 Converter.noteExplicitConv(SemaRef, Conversion, ConvTy);
5790 // If we aren't in a SFINAE context, build a call to the
5791 // explicit conversion function.
5792 if (SemaRef.isSFINAEContext())
5795 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5796 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5797 HadMultipleCandidates);
5798 if (Result.isInvalid())
5800 // Record usage of conversion in an implicit cast.
5801 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5802 CK_UserDefinedConversion, Result.get(),
5803 nullptr, Result.get()->getValueKind());
5808 static bool recordConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5809 Sema::ContextualImplicitConverter &Converter,
5810 QualType T, bool HadMultipleCandidates,
5811 DeclAccessPair &Found) {
5812 CXXConversionDecl *Conversion =
5813 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5814 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5816 QualType ToType = Conversion->getConversionType().getNonReferenceType();
5817 if (!Converter.SuppressConversion) {
5818 if (SemaRef.isSFINAEContext())
5821 Converter.diagnoseConversion(SemaRef, Loc, T, ToType)
5822 << From->getSourceRange();
5825 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5826 HadMultipleCandidates);
5827 if (Result.isInvalid())
5829 // Record usage of conversion in an implicit cast.
5830 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5831 CK_UserDefinedConversion, Result.get(),
5832 nullptr, Result.get()->getValueKind());
5836 static ExprResult finishContextualImplicitConversion(
5837 Sema &SemaRef, SourceLocation Loc, Expr *From,
5838 Sema::ContextualImplicitConverter &Converter) {
5839 if (!Converter.match(From->getType()) && !Converter.Suppress)
5840 Converter.diagnoseNoMatch(SemaRef, Loc, From->getType())
5841 << From->getSourceRange();
5843 return SemaRef.DefaultLvalueConversion(From);
5847 collectViableConversionCandidates(Sema &SemaRef, Expr *From, QualType ToType,
5848 UnresolvedSetImpl &ViableConversions,
5849 OverloadCandidateSet &CandidateSet) {
5850 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5851 DeclAccessPair FoundDecl = ViableConversions[I];
5852 NamedDecl *D = FoundDecl.getDecl();
5853 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
5854 if (isa<UsingShadowDecl>(D))
5855 D = cast<UsingShadowDecl>(D)->getTargetDecl();
5857 CXXConversionDecl *Conv;
5858 FunctionTemplateDecl *ConvTemplate;
5859 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
5860 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5862 Conv = cast<CXXConversionDecl>(D);
5865 SemaRef.AddTemplateConversionCandidate(
5866 ConvTemplate, FoundDecl, ActingContext, From, ToType, CandidateSet,
5867 /*AllowObjCConversionOnExplicit=*/false, /*AllowExplicit*/ true);
5869 SemaRef.AddConversionCandidate(Conv, FoundDecl, ActingContext, From,
5870 ToType, CandidateSet,
5871 /*AllowObjCConversionOnExplicit=*/false,
5872 /*AllowExplicit*/ true);
5876 /// Attempt to convert the given expression to a type which is accepted
5877 /// by the given converter.
5879 /// This routine will attempt to convert an expression of class type to a
5880 /// type accepted by the specified converter. In C++11 and before, the class
5881 /// must have a single non-explicit conversion function converting to a matching
5882 /// type. In C++1y, there can be multiple such conversion functions, but only
5883 /// one target type.
5885 /// \param Loc The source location of the construct that requires the
5888 /// \param From The expression we're converting from.
5890 /// \param Converter Used to control and diagnose the conversion process.
5892 /// \returns The expression, converted to an integral or enumeration type if
5894 ExprResult Sema::PerformContextualImplicitConversion(
5895 SourceLocation Loc, Expr *From, ContextualImplicitConverter &Converter) {
5896 // We can't perform any more checking for type-dependent expressions.
5897 if (From->isTypeDependent())
5900 // Process placeholders immediately.
5901 if (From->hasPlaceholderType()) {
5902 ExprResult result = CheckPlaceholderExpr(From);
5903 if (result.isInvalid())
5905 From = result.get();
5908 // If the expression already has a matching type, we're golden.
5909 QualType T = From->getType();
5910 if (Converter.match(T))
5911 return DefaultLvalueConversion(From);
5913 // FIXME: Check for missing '()' if T is a function type?
5915 // We can only perform contextual implicit conversions on objects of class
5917 const RecordType *RecordTy = T->getAs<RecordType>();
5918 if (!RecordTy || !getLangOpts().CPlusPlus) {
5919 if (!Converter.Suppress)
5920 Converter.diagnoseNoMatch(*this, Loc, T) << From->getSourceRange();
5924 // We must have a complete class type.
5925 struct TypeDiagnoserPartialDiag : TypeDiagnoser {
5926 ContextualImplicitConverter &Converter;
5929 TypeDiagnoserPartialDiag(ContextualImplicitConverter &Converter, Expr *From)
5930 : Converter(Converter), From(From) {}
5932 void diagnose(Sema &S, SourceLocation Loc, QualType T) override {
5933 Converter.diagnoseIncomplete(S, Loc, T) << From->getSourceRange();
5935 } IncompleteDiagnoser(Converter, From);
5937 if (Converter.Suppress ? !isCompleteType(Loc, T)
5938 : RequireCompleteType(Loc, T, IncompleteDiagnoser))
5941 // Look for a conversion to an integral or enumeration type.
5943 ViableConversions; // These are *potentially* viable in C++1y.
5944 UnresolvedSet<4> ExplicitConversions;
5945 const auto &Conversions =
5946 cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions();
5948 bool HadMultipleCandidates =
5949 (std::distance(Conversions.begin(), Conversions.end()) > 1);
5951 // To check that there is only one target type, in C++1y:
5953 bool HasUniqueTargetType = true;
5955 // Collect explicit or viable (potentially in C++1y) conversions.
5956 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
5957 NamedDecl *D = (*I)->getUnderlyingDecl();
5958 CXXConversionDecl *Conversion;
5959 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
5961 if (getLangOpts().CPlusPlus14)
5962 Conversion = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5964 continue; // C++11 does not consider conversion operator templates(?).
5966 Conversion = cast<CXXConversionDecl>(D);
5968 assert((!ConvTemplate || getLangOpts().CPlusPlus14) &&
5969 "Conversion operator templates are considered potentially "
5972 QualType CurToType = Conversion->getConversionType().getNonReferenceType();
5973 if (Converter.match(CurToType) || ConvTemplate) {
5975 if (Conversion->isExplicit()) {
5976 // FIXME: For C++1y, do we need this restriction?
5977 // cf. diagnoseNoViableConversion()
5979 ExplicitConversions.addDecl(I.getDecl(), I.getAccess());
5981 if (!ConvTemplate && getLangOpts().CPlusPlus14) {
5982 if (ToType.isNull())
5983 ToType = CurToType.getUnqualifiedType();
5984 else if (HasUniqueTargetType &&
5985 (CurToType.getUnqualifiedType() != ToType))
5986 HasUniqueTargetType = false;
5988 ViableConversions.addDecl(I.getDecl(), I.getAccess());
5993 if (getLangOpts().CPlusPlus14) {
5995 // ... An expression e of class type E appearing in such a context
5996 // is said to be contextually implicitly converted to a specified
5997 // type T and is well-formed if and only if e can be implicitly
5998 // converted to a type T that is determined as follows: E is searched
5999 // for conversion functions whose return type is cv T or reference to
6000 // cv T such that T is allowed by the context. There shall be
6001 // exactly one such T.
6003 // If no unique T is found:
6004 if (ToType.isNull()) {
6005 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
6006 HadMultipleCandidates,
6007 ExplicitConversions))
6009 return finishContextualImplicitConversion(*this, Loc, From, Converter);
6012 // If more than one unique Ts are found:
6013 if (!HasUniqueTargetType)
6014 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
6017 // If one unique T is found:
6018 // First, build a candidate set from the previously recorded
6019 // potentially viable conversions.
6020 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Normal);
6021 collectViableConversionCandidates(*this, From, ToType, ViableConversions,
6024 // Then, perform overload resolution over the candidate set.
6025 OverloadCandidateSet::iterator Best;
6026 switch (CandidateSet.BestViableFunction(*this, Loc, Best)) {
6028 // Apply this conversion.
6029 DeclAccessPair Found =
6030 DeclAccessPair::make(Best->Function, Best->FoundDecl.getAccess());
6031 if (recordConversion(*this, Loc, From, Converter, T,
6032 HadMultipleCandidates, Found))
6037 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
6039 case OR_No_Viable_Function:
6040 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
6041 HadMultipleCandidates,
6042 ExplicitConversions))
6046 // We'll complain below about a non-integral condition type.
6050 switch (ViableConversions.size()) {
6052 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
6053 HadMultipleCandidates,
6054 ExplicitConversions))
6057 // We'll complain below about a non-integral condition type.
6061 // Apply this conversion.
6062 DeclAccessPair Found = ViableConversions[0];
6063 if (recordConversion(*this, Loc, From, Converter, T,
6064 HadMultipleCandidates, Found))
6069 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
6074 return finishContextualImplicitConversion(*this, Loc, From, Converter);
6077 /// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is
6078 /// an acceptable non-member overloaded operator for a call whose
6079 /// arguments have types T1 (and, if non-empty, T2). This routine
6080 /// implements the check in C++ [over.match.oper]p3b2 concerning
6081 /// enumeration types.
6082 static bool IsAcceptableNonMemberOperatorCandidate(ASTContext &Context,
6084 ArrayRef<Expr *> Args) {
6085 QualType T1 = Args[0]->getType();
6086 QualType T2 = Args.size() > 1 ? Args[1]->getType() : QualType();
6088 if (T1->isDependentType() || (!T2.isNull() && T2->isDependentType()))
6091 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType()))
6094 const auto *Proto = Fn->getType()->castAs<FunctionProtoType>();
6095 if (Proto->getNumParams() < 1)
6098 if (T1->isEnumeralType()) {
6099 QualType ArgType = Proto->getParamType(0).getNonReferenceType();
6100 if (Context.hasSameUnqualifiedType(T1, ArgType))
6104 if (Proto->getNumParams() < 2)
6107 if (!T2.isNull() && T2->isEnumeralType()) {
6108 QualType ArgType = Proto->getParamType(1).getNonReferenceType();
6109 if (Context.hasSameUnqualifiedType(T2, ArgType))
6116 /// AddOverloadCandidate - Adds the given function to the set of
6117 /// candidate functions, using the given function call arguments. If
6118 /// @p SuppressUserConversions, then don't allow user-defined
6119 /// conversions via constructors or conversion operators.
6121 /// \param PartialOverloading true if we are performing "partial" overloading
6122 /// based on an incomplete set of function arguments. This feature is used by
6123 /// code completion.
6124 void Sema::AddOverloadCandidate(
6125 FunctionDecl *Function, DeclAccessPair FoundDecl, ArrayRef<Expr *> Args,
6126 OverloadCandidateSet &CandidateSet, bool SuppressUserConversions,
6127 bool PartialOverloading, bool AllowExplicit, bool AllowExplicitConversions,
6128 ADLCallKind IsADLCandidate, ConversionSequenceList EarlyConversions,
6129 OverloadCandidateParamOrder PO) {
6130 const FunctionProtoType *Proto
6131 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>());
6132 assert(Proto && "Functions without a prototype cannot be overloaded");
6133 assert(!Function->getDescribedFunctionTemplate() &&
6134 "Use AddTemplateOverloadCandidate for function templates");
6136 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) {
6137 if (!isa<CXXConstructorDecl>(Method)) {
6138 // If we get here, it's because we're calling a member function
6139 // that is named without a member access expression (e.g.,
6140 // "this->f") that was either written explicitly or created
6141 // implicitly. This can happen with a qualified call to a member
6142 // function, e.g., X::f(). We use an empty type for the implied
6143 // object argument (C++ [over.call.func]p3), and the acting context
6145 AddMethodCandidate(Method, FoundDecl, Method->getParent(), QualType(),
6146 Expr::Classification::makeSimpleLValue(), Args,
6147 CandidateSet, SuppressUserConversions,
6148 PartialOverloading, EarlyConversions, PO);
6151 // We treat a constructor like a non-member function, since its object
6152 // argument doesn't participate in overload resolution.
6155 if (!CandidateSet.isNewCandidate(Function, PO))
6158 // C++11 [class.copy]p11: [DR1402]
6159 // A defaulted move constructor that is defined as deleted is ignored by
6160 // overload resolution.
6161 CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function);
6162 if (Constructor && Constructor->isDefaulted() && Constructor->isDeleted() &&
6163 Constructor->isMoveConstructor())
6166 // Overload resolution is always an unevaluated context.
6167 EnterExpressionEvaluationContext Unevaluated(
6168 *this, Sema::ExpressionEvaluationContext::Unevaluated);
6170 // C++ [over.match.oper]p3:
6171 // if no operand has a class type, only those non-member functions in the
6172 // lookup set that have a first parameter of type T1 or "reference to
6173 // (possibly cv-qualified) T1", when T1 is an enumeration type, or (if there
6174 // is a right operand) a second parameter of type T2 or "reference to
6175 // (possibly cv-qualified) T2", when T2 is an enumeration type, are
6176 // candidate functions.
6177 if (CandidateSet.getKind() == OverloadCandidateSet::CSK_Operator &&
6178 !IsAcceptableNonMemberOperatorCandidate(Context, Function, Args))
6181 // Add this candidate
6182 OverloadCandidate &Candidate =
6183 CandidateSet.addCandidate(Args.size(), EarlyConversions);
6184 Candidate.FoundDecl = FoundDecl;
6185 Candidate.Function = Function;
6186 Candidate.Viable = true;
6187 Candidate.RewriteKind =
6188 CandidateSet.getRewriteInfo().getRewriteKind(Function, PO);
6189 Candidate.IsSurrogate = false;
6190 Candidate.IsADLCandidate = IsADLCandidate;
6191 Candidate.IgnoreObjectArgument = false;
6192 Candidate.ExplicitCallArguments = Args.size();
6194 // Explicit functions are not actually candidates at all if we're not
6195 // allowing them in this context, but keep them around so we can point
6196 // to them in diagnostics.
6197 if (!AllowExplicit && ExplicitSpecifier::getFromDecl(Function).isExplicit()) {
6198 Candidate.Viable = false;
6199 Candidate.FailureKind = ovl_fail_explicit;
6203 if (Function->isMultiVersion() && Function->hasAttr<TargetAttr>() &&
6204 !Function->getAttr<TargetAttr>()->isDefaultVersion()) {
6205 Candidate.Viable = false;
6206 Candidate.FailureKind = ovl_non_default_multiversion_function;
6211 // C++ [class.copy]p3:
6212 // A member function template is never instantiated to perform the copy
6213 // of a class object to an object of its class type.
6214 QualType ClassType = Context.getTypeDeclType(Constructor->getParent());
6215 if (Args.size() == 1 && Constructor->isSpecializationCopyingObject() &&
6216 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) ||
6217 IsDerivedFrom(Args[0]->getBeginLoc(), Args[0]->getType(),
6219 Candidate.Viable = false;
6220 Candidate.FailureKind = ovl_fail_illegal_constructor;
6224 // C++ [over.match.funcs]p8: (proposed DR resolution)
6225 // A constructor inherited from class type C that has a first parameter
6226 // of type "reference to P" (including such a constructor instantiated
6227 // from a template) is excluded from the set of candidate functions when
6228 // constructing an object of type cv D if the argument list has exactly
6229 // one argument and D is reference-related to P and P is reference-related
6231 auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(FoundDecl.getDecl());
6232 if (Shadow && Args.size() == 1 && Constructor->getNumParams() >= 1 &&
6233 Constructor->getParamDecl(0)->getType()->isReferenceType()) {
6234 QualType P = Constructor->getParamDecl(0)->getType()->getPointeeType();
6235 QualType C = Context.getRecordType(Constructor->getParent());
6236 QualType D = Context.getRecordType(Shadow->getParent());
6237 SourceLocation Loc = Args.front()->getExprLoc();
6238 if ((Context.hasSameUnqualifiedType(P, C) || IsDerivedFrom(Loc, P, C)) &&
6239 (Context.hasSameUnqualifiedType(D, P) || IsDerivedFrom(Loc, D, P))) {
6240 Candidate.Viable = false;
6241 Candidate.FailureKind = ovl_fail_inhctor_slice;
6246 // Check that the constructor is capable of constructing an object in the
6247 // destination address space.
6248 if (!Qualifiers::isAddressSpaceSupersetOf(
6249 Constructor->getMethodQualifiers().getAddressSpace(),
6250 CandidateSet.getDestAS())) {
6251 Candidate.Viable = false;
6252 Candidate.FailureKind = ovl_fail_object_addrspace_mismatch;
6256 unsigned NumParams = Proto->getNumParams();
6258 // (C++ 13.3.2p2): A candidate function having fewer than m
6259 // parameters is viable only if it has an ellipsis in its parameter
6261 if (TooManyArguments(NumParams, Args.size(), PartialOverloading) &&
6262 !Proto->isVariadic()) {
6263 Candidate.Viable = false;
6264 Candidate.FailureKind = ovl_fail_too_many_arguments;
6268 // (C++ 13.3.2p2): A candidate function having more than m parameters
6269 // is viable only if the (m+1)st parameter has a default argument
6270 // (8.3.6). For the purposes of overload resolution, the
6271 // parameter list is truncated on the right, so that there are
6272 // exactly m parameters.
6273 unsigned MinRequiredArgs = Function->getMinRequiredArguments();
6274 if (Args.size() < MinRequiredArgs && !PartialOverloading) {
6275 // Not enough arguments.
6276 Candidate.Viable = false;
6277 Candidate.FailureKind = ovl_fail_too_few_arguments;
6281 // (CUDA B.1): Check for invalid calls between targets.
6282 if (getLangOpts().CUDA)
6283 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext))
6284 // Skip the check for callers that are implicit members, because in this
6285 // case we may not yet know what the member's target is; the target is
6286 // inferred for the member automatically, based on the bases and fields of
6288 if (!Caller->isImplicit() && !IsAllowedCUDACall(Caller, Function)) {
6289 Candidate.Viable = false;
6290 Candidate.FailureKind = ovl_fail_bad_target;
6294 if (Expr *RequiresClause = Function->getTrailingRequiresClause()) {
6295 ConstraintSatisfaction Satisfaction;
6296 if (CheckConstraintSatisfaction(RequiresClause, Satisfaction) ||
6297 !Satisfaction.IsSatisfied) {
6298 Candidate.Viable = false;
6299 Candidate.FailureKind = ovl_fail_constraints_not_satisfied;
6304 // Determine the implicit conversion sequences for each of the
6306 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) {
6308 PO == OverloadCandidateParamOrder::Reversed ? 1 - ArgIdx : ArgIdx;
6309 if (Candidate.Conversions[ConvIdx].isInitialized()) {
6310 // We already formed a conversion sequence for this parameter during
6311 // template argument deduction.
6312 } else if (ArgIdx < NumParams) {
6313 // (C++ 13.3.2p3): for F to be a viable function, there shall
6314 // exist for each argument an implicit conversion sequence
6315 // (13.3.3.1) that converts that argument to the corresponding
6317 QualType ParamType = Proto->getParamType(ArgIdx);
6318 Candidate.Conversions[ConvIdx] = TryCopyInitialization(
6319 *this, Args[ArgIdx], ParamType, SuppressUserConversions,
6320 /*InOverloadResolution=*/true,
6321 /*AllowObjCWritebackConversion=*/
6322 getLangOpts().ObjCAutoRefCount, AllowExplicitConversions);
6323 if (Candidate.Conversions[ConvIdx].isBad()) {
6324 Candidate.Viable = false;
6325 Candidate.FailureKind = ovl_fail_bad_conversion;
6329 // (C++ 13.3.2p2): For the purposes of overload resolution, any
6330 // argument for which there is no corresponding parameter is
6331 // considered to ""match the ellipsis" (C+ 13.3.3.1.3).
6332 Candidate.Conversions[ConvIdx].setEllipsis();
6336 if (EnableIfAttr *FailedAttr = CheckEnableIf(Function, Args)) {
6337 Candidate.Viable = false;
6338 Candidate.FailureKind = ovl_fail_enable_if;
6339 Candidate.DeductionFailure.Data = FailedAttr;
6343 if (LangOpts.OpenCL && isOpenCLDisabledDecl(Function)) {
6344 Candidate.Viable = false;
6345 Candidate.FailureKind = ovl_fail_ext_disabled;
6351 Sema::SelectBestMethod(Selector Sel, MultiExprArg Args, bool IsInstance,
6352 SmallVectorImpl<ObjCMethodDecl *> &Methods) {
6353 if (Methods.size() <= 1)
6356 for (unsigned b = 0, e = Methods.size(); b < e; b++) {
6358 ObjCMethodDecl *Method = Methods[b];
6359 unsigned NumNamedArgs = Sel.getNumArgs();
6360 // Method might have more arguments than selector indicates. This is due
6361 // to addition of c-style arguments in method.
6362 if (Method->param_size() > NumNamedArgs)
6363 NumNamedArgs = Method->param_size();
6364 if (Args.size() < NumNamedArgs)
6367 for (unsigned i = 0; i < NumNamedArgs; i++) {
6368 // We can't do any type-checking on a type-dependent argument.
6369 if (Args[i]->isTypeDependent()) {
6374 ParmVarDecl *param = Method->parameters()[i];
6375 Expr *argExpr = Args[i];
6376 assert(argExpr && "SelectBestMethod(): missing expression");
6378 // Strip the unbridged-cast placeholder expression off unless it's
6379 // a consumed argument.
6380 if (argExpr->hasPlaceholderType(BuiltinType::ARCUnbridgedCast) &&
6381 !param->hasAttr<CFConsumedAttr>())
6382 argExpr = stripARCUnbridgedCast(argExpr);
6384 // If the parameter is __unknown_anytype, move on to the next method.
6385 if (param->getType() == Context.UnknownAnyTy) {
6390 ImplicitConversionSequence ConversionState
6391 = TryCopyInitialization(*this, argExpr, param->getType(),
6392 /*SuppressUserConversions*/false,
6393 /*InOverloadResolution=*/true,
6394 /*AllowObjCWritebackConversion=*/
6395 getLangOpts().ObjCAutoRefCount,
6396 /*AllowExplicit*/false);
6397 // This function looks for a reasonably-exact match, so we consider
6398 // incompatible pointer conversions to be a failure here.
6399 if (ConversionState.isBad() ||
6400 (ConversionState.isStandard() &&
6401 ConversionState.Standard.Second ==
6402 ICK_Incompatible_Pointer_Conversion)) {
6407 // Promote additional arguments to variadic methods.
6408 if (Match && Method->isVariadic()) {
6409 for (unsigned i = NumNamedArgs, e = Args.size(); i < e; ++i) {
6410 if (Args[i]->isTypeDependent()) {
6414 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod,
6416 if (Arg.isInvalid()) {
6422 // Check for extra arguments to non-variadic methods.
6423 if (Args.size() != NumNamedArgs)
6425 else if (Match && NumNamedArgs == 0 && Methods.size() > 1) {
6426 // Special case when selectors have no argument. In this case, select
6427 // one with the most general result type of 'id'.
6428 for (unsigned b = 0, e = Methods.size(); b < e; b++) {
6429 QualType ReturnT = Methods[b]->getReturnType();
6430 if (ReturnT->isObjCIdType())
6443 convertArgsForAvailabilityChecks(Sema &S, FunctionDecl *Function, Expr *ThisArg,
6444 ArrayRef<Expr *> Args, Sema::SFINAETrap &Trap,
6445 bool MissingImplicitThis, Expr *&ConvertedThis,
6446 SmallVectorImpl<Expr *> &ConvertedArgs) {
6448 CXXMethodDecl *Method = cast<CXXMethodDecl>(Function);
6449 assert(!isa<CXXConstructorDecl>(Method) &&
6450 "Shouldn't have `this` for ctors!");
6451 assert(!Method->isStatic() && "Shouldn't have `this` for static methods!");
6452 ExprResult R = S.PerformObjectArgumentInitialization(
6453 ThisArg, /*Qualifier=*/nullptr, Method, Method);
6456 ConvertedThis = R.get();
6458 if (auto *MD = dyn_cast<CXXMethodDecl>(Function)) {
6460 assert((MissingImplicitThis || MD->isStatic() ||
6461 isa<CXXConstructorDecl>(MD)) &&
6462 "Expected `this` for non-ctor instance methods");
6464 ConvertedThis = nullptr;
6467 // Ignore any variadic arguments. Converting them is pointless, since the
6468 // user can't refer to them in the function condition.
6469 unsigned ArgSizeNoVarargs = std::min(Function->param_size(), Args.size());
6471 // Convert the arguments.
6472 for (unsigned I = 0; I != ArgSizeNoVarargs; ++I) {
6474 R = S.PerformCopyInitialization(InitializedEntity::InitializeParameter(
6475 S.Context, Function->getParamDecl(I)),
6476 SourceLocation(), Args[I]);
6481 ConvertedArgs.push_back(R.get());
6484 if (Trap.hasErrorOccurred())
6487 // Push default arguments if needed.
6488 if (!Function->isVariadic() && Args.size() < Function->getNumParams()) {
6489 for (unsigned i = Args.size(), e = Function->getNumParams(); i != e; ++i) {
6490 ParmVarDecl *P = Function->getParamDecl(i);
6491 Expr *DefArg = P->hasUninstantiatedDefaultArg()
6492 ? P->getUninstantiatedDefaultArg()
6493 : P->getDefaultArg();
6494 // This can only happen in code completion, i.e. when PartialOverloading
6499 S.PerformCopyInitialization(InitializedEntity::InitializeParameter(
6500 S.Context, Function->getParamDecl(i)),
6501 SourceLocation(), DefArg);
6504 ConvertedArgs.push_back(R.get());
6507 if (Trap.hasErrorOccurred())
6513 EnableIfAttr *Sema::CheckEnableIf(FunctionDecl *Function, ArrayRef<Expr *> Args,
6514 bool MissingImplicitThis) {
6515 auto EnableIfAttrs = Function->specific_attrs<EnableIfAttr>();
6516 if (EnableIfAttrs.begin() == EnableIfAttrs.end())
6519 SFINAETrap Trap(*this);
6520 SmallVector<Expr *, 16> ConvertedArgs;
6521 // FIXME: We should look into making enable_if late-parsed.
6522 Expr *DiscardedThis;
6523 if (!convertArgsForAvailabilityChecks(
6524 *this, Function, /*ThisArg=*/nullptr, Args, Trap,
6525 /*MissingImplicitThis=*/true, DiscardedThis, ConvertedArgs))
6526 return *EnableIfAttrs.begin();
6528 for (auto *EIA : EnableIfAttrs) {
6530 // FIXME: This doesn't consider value-dependent cases, because doing so is
6531 // very difficult. Ideally, we should handle them more gracefully.
6532 if (EIA->getCond()->isValueDependent() ||
6533 !EIA->getCond()->EvaluateWithSubstitution(
6534 Result, Context, Function, llvm::makeArrayRef(ConvertedArgs)))
6537 if (!Result.isInt() || !Result.getInt().getBoolValue())
6543 template <typename CheckFn>
6544 static bool diagnoseDiagnoseIfAttrsWith(Sema &S, const NamedDecl *ND,
6545 bool ArgDependent, SourceLocation Loc,
6546 CheckFn &&IsSuccessful) {
6547 SmallVector<const DiagnoseIfAttr *, 8> Attrs;
6548 for (const auto *DIA : ND->specific_attrs<DiagnoseIfAttr>()) {
6549 if (ArgDependent == DIA->getArgDependent())
6550 Attrs.push_back(DIA);
6553 // Common case: No diagnose_if attributes, so we can quit early.
6557 auto WarningBegin = std::stable_partition(
6558 Attrs.begin(), Attrs.end(),
6559 [](const DiagnoseIfAttr *DIA) { return DIA->isError(); });
6561 // Note that diagnose_if attributes are late-parsed, so they appear in the
6562 // correct order (unlike enable_if attributes).
6563 auto ErrAttr = llvm::find_if(llvm::make_range(Attrs.begin(), WarningBegin),
6565 if (ErrAttr != WarningBegin) {
6566 const DiagnoseIfAttr *DIA = *ErrAttr;
6567 S.Diag(Loc, diag::err_diagnose_if_succeeded) << DIA->getMessage();
6568 S.Diag(DIA->getLocation(), diag::note_from_diagnose_if)
6569 << DIA->getParent() << DIA->getCond()->getSourceRange();
6573 for (const auto *DIA : llvm::make_range(WarningBegin, Attrs.end()))
6574 if (IsSuccessful(DIA)) {
6575 S.Diag(Loc, diag::warn_diagnose_if_succeeded) << DIA->getMessage();
6576 S.Diag(DIA->getLocation(), diag::note_from_diagnose_if)
6577 << DIA->getParent() << DIA->getCond()->getSourceRange();
6583 bool Sema::diagnoseArgDependentDiagnoseIfAttrs(const FunctionDecl *Function,
6584 const Expr *ThisArg,
6585 ArrayRef<const Expr *> Args,
6586 SourceLocation Loc) {
6587 return diagnoseDiagnoseIfAttrsWith(
6588 *this, Function, /*ArgDependent=*/true, Loc,
6589 [&](const DiagnoseIfAttr *DIA) {
6591 // It's sane to use the same Args for any redecl of this function, since
6592 // EvaluateWithSubstitution only cares about the position of each
6593 // argument in the arg list, not the ParmVarDecl* it maps to.
6594 if (!DIA->getCond()->EvaluateWithSubstitution(
6595 Result, Context, cast<FunctionDecl>(DIA->getParent()), Args, ThisArg))
6597 return Result.isInt() && Result.getInt().getBoolValue();
6601 bool Sema::diagnoseArgIndependentDiagnoseIfAttrs(const NamedDecl *ND,
6602 SourceLocation Loc) {
6603 return diagnoseDiagnoseIfAttrsWith(
6604 *this, ND, /*ArgDependent=*/false, Loc,
6605 [&](const DiagnoseIfAttr *DIA) {
6607 return DIA->getCond()->EvaluateAsBooleanCondition(Result, Context) &&
6612 /// Add all of the function declarations in the given function set to
6613 /// the overload candidate set.
6614 void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns,
6615 ArrayRef<Expr *> Args,
6616 OverloadCandidateSet &CandidateSet,
6617 TemplateArgumentListInfo *ExplicitTemplateArgs,
6618 bool SuppressUserConversions,
6619 bool PartialOverloading,
6620 bool FirstArgumentIsBase) {
6621 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) {
6622 NamedDecl *D = F.getDecl()->getUnderlyingDecl();
6623 ArrayRef<Expr *> FunctionArgs = Args;
6625 FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(D);
6627 FunTmpl ? FunTmpl->getTemplatedDecl() : cast<FunctionDecl>(D);
6629 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) {
6630 QualType ObjectType;
6631 Expr::Classification ObjectClassification;
6632 if (Args.size() > 0) {
6633 if (Expr *E = Args[0]) {
6634 // Use the explicit base to restrict the lookup:
6635 ObjectType = E->getType();
6636 // Pointers in the object arguments are implicitly dereferenced, so we
6637 // always classify them as l-values.
6638 if (!ObjectType.isNull() && ObjectType->isPointerType())
6639 ObjectClassification = Expr::Classification::makeSimpleLValue();
6641 ObjectClassification = E->Classify(Context);
6642 } // .. else there is an implicit base.
6643 FunctionArgs = Args.slice(1);
6646 AddMethodTemplateCandidate(
6647 FunTmpl, F.getPair(),
6648 cast<CXXRecordDecl>(FunTmpl->getDeclContext()),
6649 ExplicitTemplateArgs, ObjectType, ObjectClassification,
6650 FunctionArgs, CandidateSet, SuppressUserConversions,
6651 PartialOverloading);
6653 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(),
6654 cast<CXXMethodDecl>(FD)->getParent(), ObjectType,
6655 ObjectClassification, FunctionArgs, CandidateSet,
6656 SuppressUserConversions, PartialOverloading);
6659 // This branch handles both standalone functions and static methods.
6661 // Slice the first argument (which is the base) when we access
6662 // static method as non-static.
6663 if (Args.size() > 0 &&
6664 (!Args[0] || (FirstArgumentIsBase && isa<CXXMethodDecl>(FD) &&
6665 !isa<CXXConstructorDecl>(FD)))) {
6666 assert(cast<CXXMethodDecl>(FD)->isStatic());
6667 FunctionArgs = Args.slice(1);
6670 AddTemplateOverloadCandidate(FunTmpl, F.getPair(),
6671 ExplicitTemplateArgs, FunctionArgs,
6672 CandidateSet, SuppressUserConversions,
6673 PartialOverloading);
6675 AddOverloadCandidate(FD, F.getPair(), FunctionArgs, CandidateSet,
6676 SuppressUserConversions, PartialOverloading);
6682 /// AddMethodCandidate - Adds a named decl (which is some kind of
6683 /// method) as a method candidate to the given overload set.
6684 void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, QualType ObjectType,
6685 Expr::Classification ObjectClassification,
6686 ArrayRef<Expr *> Args,
6687 OverloadCandidateSet &CandidateSet,
6688 bool SuppressUserConversions,
6689 OverloadCandidateParamOrder PO) {
6690 NamedDecl *Decl = FoundDecl.getDecl();
6691 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext());
6693 if (isa<UsingShadowDecl>(Decl))
6694 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl();
6696 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) {
6697 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) &&
6698 "Expected a member function template");
6699 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext,
6700 /*ExplicitArgs*/ nullptr, ObjectType,
6701 ObjectClassification, Args, CandidateSet,
6702 SuppressUserConversions, false, PO);
6704 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext,
6705 ObjectType, ObjectClassification, Args, CandidateSet,
6706 SuppressUserConversions, false, None, PO);
6710 /// AddMethodCandidate - Adds the given C++ member function to the set
6711 /// of candidate functions, using the given function call arguments
6712 /// and the object argument (@c Object). For example, in a call
6713 /// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain
6714 /// both @c a1 and @c a2. If @p SuppressUserConversions, then don't
6715 /// allow user-defined conversions via constructors or conversion
6718 Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl,
6719 CXXRecordDecl *ActingContext, QualType ObjectType,
6720 Expr::Classification ObjectClassification,
6721 ArrayRef<Expr *> Args,
6722 OverloadCandidateSet &CandidateSet,
6723 bool SuppressUserConversions,
6724 bool PartialOverloading,
6725 ConversionSequenceList EarlyConversions,
6726 OverloadCandidateParamOrder PO) {
6727 const FunctionProtoType *Proto
6728 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>());
6729 assert(Proto && "Methods without a prototype cannot be overloaded");
6730 assert(!isa<CXXConstructorDecl>(Method) &&
6731 "Use AddOverloadCandidate for constructors");
6733 if (!CandidateSet.isNewCandidate(Method, PO))
6736 // C++11 [class.copy]p23: [DR1402]
6737 // A defaulted move assignment operator that is defined as deleted is
6738 // ignored by overload resolution.
6739 if (Method->isDefaulted() && Method->isDeleted() &&
6740 Method->isMoveAssignmentOperator())
6743 // Overload resolution is always an unevaluated context.
6744 EnterExpressionEvaluationContext Unevaluated(
6745 *this, Sema::ExpressionEvaluationContext::Unevaluated);
6747 // Add this candidate
6748 OverloadCandidate &Candidate =
6749 CandidateSet.addCandidate(Args.size() + 1, EarlyConversions);
6750 Candidate.FoundDecl = FoundDecl;
6751 Candidate.Function = Method;
6752 Candidate.RewriteKind =
6753 CandidateSet.getRewriteInfo().getRewriteKind(Method, PO);
6754 Candidate.IsSurrogate = false;
6755 Candidate.IgnoreObjectArgument = false;
6756 Candidate.ExplicitCallArguments = Args.size();
6758 unsigned NumParams = Proto->getNumParams();
6760 // (C++ 13.3.2p2): A candidate function having fewer than m
6761 // parameters is viable only if it has an ellipsis in its parameter
6763 if (TooManyArguments(NumParams, Args.size(), PartialOverloading) &&
6764 !Proto->isVariadic()) {
6765 Candidate.Viable = false;
6766 Candidate.FailureKind = ovl_fail_too_many_arguments;
6770 // (C++ 13.3.2p2): A candidate function having more than m parameters
6771 // is viable only if the (m+1)st parameter has a default argument
6772 // (8.3.6). For the purposes of overload resolution, the
6773 // parameter list is truncated on the right, so that there are
6774 // exactly m parameters.
6775 unsigned MinRequiredArgs = Method->getMinRequiredArguments();
6776 if (Args.size() < MinRequiredArgs && !PartialOverloading) {
6777 // Not enough arguments.
6778 Candidate.Viable = false;
6779 Candidate.FailureKind = ovl_fail_too_few_arguments;
6783 Candidate.Viable = true;
6785 if (Method->isStatic() || ObjectType.isNull())
6786 // The implicit object argument is ignored.
6787 Candidate.IgnoreObjectArgument = true;
6789 unsigned ConvIdx = PO == OverloadCandidateParamOrder::Reversed ? 1 : 0;
6790 // Determine the implicit conversion sequence for the object
6792 Candidate.Conversions[ConvIdx] = TryObjectArgumentInitialization(
6793 *this, CandidateSet.getLocation(), ObjectType, ObjectClassification,
6794 Method, ActingContext);
6795 if (Candidate.Conversions[ConvIdx].isBad()) {
6796 Candidate.Viable = false;
6797 Candidate.FailureKind = ovl_fail_bad_conversion;
6802 // (CUDA B.1): Check for invalid calls between targets.
6803 if (getLangOpts().CUDA)
6804 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext))
6805 if (!IsAllowedCUDACall(Caller, Method)) {
6806 Candidate.Viable = false;
6807 Candidate.FailureKind = ovl_fail_bad_target;
6811 if (Expr *RequiresClause = Method->getTrailingRequiresClause()) {
6812 ConstraintSatisfaction Satisfaction;
6813 if (CheckConstraintSatisfaction(RequiresClause, Satisfaction) ||
6814 !Satisfaction.IsSatisfied) {
6815 Candidate.Viable = false;
6816 Candidate.FailureKind = ovl_fail_constraints_not_satisfied;
6821 // Determine the implicit conversion sequences for each of the
6823 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) {
6825 PO == OverloadCandidateParamOrder::Reversed ? 0 : (ArgIdx + 1);
6826 if (Candidate.Conversions[ConvIdx].isInitialized()) {
6827 // We already formed a conversion sequence for this parameter during
6828 // template argument deduction.
6829 } else if (ArgIdx < NumParams) {
6830 // (C++ 13.3.2p3): for F to be a viable function, there shall
6831 // exist for each argument an implicit conversion sequence
6832 // (13.3.3.1) that converts that argument to the corresponding
6834 QualType ParamType = Proto->getParamType(ArgIdx);
6835 Candidate.Conversions[ConvIdx]
6836 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
6837 SuppressUserConversions,
6838 /*InOverloadResolution=*/true,
6839 /*AllowObjCWritebackConversion=*/
6840 getLangOpts().ObjCAutoRefCount);
6841 if (Candidate.Conversions[ConvIdx].isBad()) {
6842 Candidate.Viable = false;
6843 Candidate.FailureKind = ovl_fail_bad_conversion;
6847 // (C++ 13.3.2p2): For the purposes of overload resolution, any
6848 // argument for which there is no corresponding parameter is
6849 // considered to "match the ellipsis" (C+ 13.3.3.1.3).
6850 Candidate.Conversions[ConvIdx].setEllipsis();
6854 if (EnableIfAttr *FailedAttr = CheckEnableIf(Method, Args, true)) {
6855 Candidate.Viable = false;
6856 Candidate.FailureKind = ovl_fail_enable_if;
6857 Candidate.DeductionFailure.Data = FailedAttr;
6861 if (Method->isMultiVersion() && Method->hasAttr<TargetAttr>() &&
6862 !Method->getAttr<TargetAttr>()->isDefaultVersion()) {
6863 Candidate.Viable = false;
6864 Candidate.FailureKind = ovl_non_default_multiversion_function;
6868 /// Add a C++ member function template as a candidate to the candidate
6869 /// set, using template argument deduction to produce an appropriate member
6870 /// function template specialization.
6871 void Sema::AddMethodTemplateCandidate(
6872 FunctionTemplateDecl *MethodTmpl, DeclAccessPair FoundDecl,
6873 CXXRecordDecl *ActingContext,
6874 TemplateArgumentListInfo *ExplicitTemplateArgs, QualType ObjectType,
6875 Expr::Classification ObjectClassification, ArrayRef<Expr *> Args,
6876 OverloadCandidateSet &CandidateSet, bool SuppressUserConversions,
6877 bool PartialOverloading, OverloadCandidateParamOrder PO) {
6878 if (!CandidateSet.isNewCandidate(MethodTmpl, PO))
6881 // C++ [over.match.funcs]p7:
6882 // In each case where a candidate is a function template, candidate
6883 // function template specializations are generated using template argument
6884 // deduction (14.8.3, 14.8.2). Those candidates are then handled as
6885 // candidate functions in the usual way.113) A given name can refer to one
6886 // or more function templates and also to a set of overloaded non-template
6887 // functions. In such a case, the candidate functions generated from each
6888 // function template are combined with the set of non-template candidate
6890 TemplateDeductionInfo Info(CandidateSet.getLocation());
6891 FunctionDecl *Specialization = nullptr;
6892 ConversionSequenceList Conversions;
6893 if (TemplateDeductionResult Result = DeduceTemplateArguments(
6894 MethodTmpl, ExplicitTemplateArgs, Args, Specialization, Info,
6895 PartialOverloading, [&](ArrayRef<QualType> ParamTypes) {
6896 return CheckNonDependentConversions(
6897 MethodTmpl, ParamTypes, Args, CandidateSet, Conversions,
6898 SuppressUserConversions, ActingContext, ObjectType,
6899 ObjectClassification, PO);
6901 OverloadCandidate &Candidate =
6902 CandidateSet.addCandidate(Conversions.size(), Conversions);
6903 Candidate.FoundDecl = FoundDecl;
6904 Candidate.Function = MethodTmpl->getTemplatedDecl();
6905 Candidate.Viable = false;
6906 Candidate.RewriteKind =
6907 CandidateSet.getRewriteInfo().getRewriteKind(Candidate.Function, PO);
6908 Candidate.IsSurrogate = false;
6909 Candidate.IgnoreObjectArgument =
6910 cast<CXXMethodDecl>(Candidate.Function)->isStatic() ||
6911 ObjectType.isNull();
6912 Candidate.ExplicitCallArguments = Args.size();
6913 if (Result == TDK_NonDependentConversionFailure)
6914 Candidate.FailureKind = ovl_fail_bad_conversion;
6916 Candidate.FailureKind = ovl_fail_bad_deduction;
6917 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
6923 // Add the function template specialization produced by template argument
6924 // deduction as a candidate.
6925 assert(Specialization && "Missing member function template specialization?");
6926 assert(isa<CXXMethodDecl>(Specialization) &&
6927 "Specialization is not a member function?");
6928 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl,
6929 ActingContext, ObjectType, ObjectClassification, Args,
6930 CandidateSet, SuppressUserConversions, PartialOverloading,
6934 /// Determine whether a given function template has a simple explicit specifier
6935 /// or a non-value-dependent explicit-specification that evaluates to true.
6936 static bool isNonDependentlyExplicit(FunctionTemplateDecl *FTD) {
6937 return ExplicitSpecifier::getFromDecl(FTD->getTemplatedDecl()).isExplicit();
6940 /// Add a C++ function template specialization as a candidate
6941 /// in the candidate set, using template argument deduction to produce
6942 /// an appropriate function template specialization.
6943 void Sema::AddTemplateOverloadCandidate(
6944 FunctionTemplateDecl *FunctionTemplate, DeclAccessPair FoundDecl,
6945 TemplateArgumentListInfo *ExplicitTemplateArgs, ArrayRef<Expr *> Args,
6946 OverloadCandidateSet &CandidateSet, bool SuppressUserConversions,
6947 bool PartialOverloading, bool AllowExplicit, ADLCallKind IsADLCandidate,
6948 OverloadCandidateParamOrder PO) {
6949 if (!CandidateSet.isNewCandidate(FunctionTemplate, PO))
6952 // If the function template has a non-dependent explicit specification,
6953 // exclude it now if appropriate; we are not permitted to perform deduction
6954 // and substitution in this case.
6955 if (!AllowExplicit && isNonDependentlyExplicit(FunctionTemplate)) {
6956 OverloadCandidate &Candidate = CandidateSet.addCandidate();
6957 Candidate.FoundDecl = FoundDecl;
6958 Candidate.Function = FunctionTemplate->getTemplatedDecl();
6959 Candidate.Viable = false;
6960 Candidate.FailureKind = ovl_fail_explicit;
6964 // C++ [over.match.funcs]p7:
6965 // In each case where a candidate is a function template, candidate
6966 // function template specializations are generated using template argument
6967 // deduction (14.8.3, 14.8.2). Those candidates are then handled as
6968 // candidate functions in the usual way.113) A given name can refer to one
6969 // or more function templates and also to a set of overloaded non-template
6970 // functions. In such a case, the candidate functions generated from each
6971 // function template are combined with the set of non-template candidate
6973 TemplateDeductionInfo Info(CandidateSet.getLocation());
6974 FunctionDecl *Specialization = nullptr;
6975 ConversionSequenceList Conversions;
6976 if (TemplateDeductionResult Result = DeduceTemplateArguments(
6977 FunctionTemplate, ExplicitTemplateArgs, Args, Specialization, Info,
6978 PartialOverloading, [&](ArrayRef<QualType> ParamTypes) {
6979 return CheckNonDependentConversions(
6980 FunctionTemplate, ParamTypes, Args, CandidateSet, Conversions,
6981 SuppressUserConversions, nullptr, QualType(), {}, PO);
6983 OverloadCandidate &Candidate =
6984 CandidateSet.addCandidate(Conversions.size(), Conversions);
6985 Candidate.FoundDecl = FoundDecl;
6986 Candidate.Function = FunctionTemplate->getTemplatedDecl();
6987 Candidate.Viable = false;
6988 Candidate.RewriteKind =
6989 CandidateSet.getRewriteInfo().getRewriteKind(Candidate.Function, PO);
6990 Candidate.IsSurrogate = false;
6991 Candidate.IsADLCandidate = IsADLCandidate;
6992 // Ignore the object argument if there is one, since we don't have an object
6994 Candidate.IgnoreObjectArgument =
6995 isa<CXXMethodDecl>(Candidate.Function) &&
6996 !isa<CXXConstructorDecl>(Candidate.Function);
6997 Candidate.ExplicitCallArguments = Args.size();
6998 if (Result == TDK_NonDependentConversionFailure)
6999 Candidate.FailureKind = ovl_fail_bad_conversion;
7001 Candidate.FailureKind = ovl_fail_bad_deduction;
7002 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
7008 // Add the function template specialization produced by template argument
7009 // deduction as a candidate.
7010 assert(Specialization && "Missing function template specialization?");
7011 AddOverloadCandidate(
7012 Specialization, FoundDecl, Args, CandidateSet, SuppressUserConversions,
7013 PartialOverloading, AllowExplicit,
7014 /*AllowExplicitConversions*/ false, IsADLCandidate, Conversions, PO);
7017 /// Check that implicit conversion sequences can be formed for each argument
7018 /// whose corresponding parameter has a non-dependent type, per DR1391's
7019 /// [temp.deduct.call]p10.
7020 bool Sema::CheckNonDependentConversions(
7021 FunctionTemplateDecl *FunctionTemplate, ArrayRef<QualType> ParamTypes,
7022 ArrayRef<Expr *> Args, OverloadCandidateSet &CandidateSet,
7023 ConversionSequenceList &Conversions, bool SuppressUserConversions,
7024 CXXRecordDecl *ActingContext, QualType ObjectType,
7025 Expr::Classification ObjectClassification, OverloadCandidateParamOrder PO) {
7026 // FIXME: The cases in which we allow explicit conversions for constructor
7027 // arguments never consider calling a constructor template. It's not clear
7029 const bool AllowExplicit = false;
7031 auto *FD = FunctionTemplate->getTemplatedDecl();
7032 auto *Method = dyn_cast<CXXMethodDecl>(FD);
7033 bool HasThisConversion = Method && !isa<CXXConstructorDecl>(Method);
7034 unsigned ThisConversions = HasThisConversion ? 1 : 0;
7037 CandidateSet.allocateConversionSequences(ThisConversions + Args.size());
7039 // Overload resolution is always an unevaluated context.
7040 EnterExpressionEvaluationContext Unevaluated(
7041 *this, Sema::ExpressionEvaluationContext::Unevaluated);
7043 // For a method call, check the 'this' conversion here too. DR1391 doesn't
7044 // require that, but this check should never result in a hard error, and
7045 // overload resolution is permitted to sidestep instantiations.
7046 if (HasThisConversion && !cast<CXXMethodDecl>(FD)->isStatic() &&
7047 !ObjectType.isNull()) {
7048 unsigned ConvIdx = PO == OverloadCandidateParamOrder::Reversed ? 1 : 0;
7049 Conversions[ConvIdx] = TryObjectArgumentInitialization(
7050 *this, CandidateSet.getLocation(), ObjectType, ObjectClassification,
7051 Method, ActingContext);
7052 if (Conversions[ConvIdx].isBad())
7056 for (unsigned I = 0, N = std::min(ParamTypes.size(), Args.size()); I != N;
7058 QualType ParamType = ParamTypes[I];
7059 if (!ParamType->isDependentType()) {
7060 unsigned ConvIdx = PO == OverloadCandidateParamOrder::Reversed
7062 : (ThisConversions + I);
7063 Conversions[ConvIdx]
7064 = TryCopyInitialization(*this, Args[I], ParamType,
7065 SuppressUserConversions,
7066 /*InOverloadResolution=*/true,
7067 /*AllowObjCWritebackConversion=*/
7068 getLangOpts().ObjCAutoRefCount,
7070 if (Conversions[ConvIdx].isBad())
7078 /// Determine whether this is an allowable conversion from the result
7079 /// of an explicit conversion operator to the expected type, per C++
7080 /// [over.match.conv]p1 and [over.match.ref]p1.
7082 /// \param ConvType The return type of the conversion function.
7084 /// \param ToType The type we are converting to.
7086 /// \param AllowObjCPointerConversion Allow a conversion from one
7087 /// Objective-C pointer to another.
7089 /// \returns true if the conversion is allowable, false otherwise.
7090 static bool isAllowableExplicitConversion(Sema &S,
7091 QualType ConvType, QualType ToType,
7092 bool AllowObjCPointerConversion) {
7093 QualType ToNonRefType = ToType.getNonReferenceType();
7095 // Easy case: the types are the same.
7096 if (S.Context.hasSameUnqualifiedType(ConvType, ToNonRefType))
7099 // Allow qualification conversions.
7100 bool ObjCLifetimeConversion;
7101 if (S.IsQualificationConversion(ConvType, ToNonRefType, /*CStyle*/false,
7102 ObjCLifetimeConversion))
7105 // If we're not allowed to consider Objective-C pointer conversions,
7107 if (!AllowObjCPointerConversion)
7110 // Is this an Objective-C pointer conversion?
7111 bool IncompatibleObjC = false;
7112 QualType ConvertedType;
7113 return S.isObjCPointerConversion(ConvType, ToNonRefType, ConvertedType,
7117 /// AddConversionCandidate - Add a C++ conversion function as a
7118 /// candidate in the candidate set (C++ [over.match.conv],
7119 /// C++ [over.match.copy]). From is the expression we're converting from,
7120 /// and ToType is the type that we're eventually trying to convert to
7121 /// (which may or may not be the same type as the type that the
7122 /// conversion function produces).
7123 void Sema::AddConversionCandidate(
7124 CXXConversionDecl *Conversion, DeclAccessPair FoundDecl,
7125 CXXRecordDecl *ActingContext, Expr *From, QualType ToType,
7126 OverloadCandidateSet &CandidateSet, bool AllowObjCConversionOnExplicit,
7127 bool AllowExplicit, bool AllowResultConversion) {
7128 assert(!Conversion->getDescribedFunctionTemplate() &&
7129 "Conversion function templates use AddTemplateConversionCandidate");
7130 QualType ConvType = Conversion->getConversionType().getNonReferenceType();
7131 if (!CandidateSet.isNewCandidate(Conversion))
7134 // If the conversion function has an undeduced return type, trigger its
7136 if (getLangOpts().CPlusPlus14 && ConvType->isUndeducedType()) {
7137 if (DeduceReturnType(Conversion, From->getExprLoc()))
7139 ConvType = Conversion->getConversionType().getNonReferenceType();
7142 // If we don't allow any conversion of the result type, ignore conversion
7143 // functions that don't convert to exactly (possibly cv-qualified) T.
7144 if (!AllowResultConversion &&
7145 !Context.hasSameUnqualifiedType(Conversion->getConversionType(), ToType))
7148 // Per C++ [over.match.conv]p1, [over.match.ref]p1, an explicit conversion
7149 // operator is only a candidate if its return type is the target type or
7150 // can be converted to the target type with a qualification conversion.
7152 // FIXME: Include such functions in the candidate list and explain why we
7153 // can't select them.
7154 if (Conversion->isExplicit() &&
7155 !isAllowableExplicitConversion(*this, ConvType, ToType,
7156 AllowObjCConversionOnExplicit))
7159 // Overload resolution is always an unevaluated context.
7160 EnterExpressionEvaluationContext Unevaluated(
7161 *this, Sema::ExpressionEvaluationContext::Unevaluated);
7163 // Add this candidate
7164 OverloadCandidate &Candidate = CandidateSet.addCandidate(1);
7165 Candidate.FoundDecl = FoundDecl;
7166 Candidate.Function = Conversion;
7167 Candidate.IsSurrogate = false;
7168 Candidate.IgnoreObjectArgument = false;
7169 Candidate.FinalConversion.setAsIdentityConversion();
7170 Candidate.FinalConversion.setFromType(ConvType);
7171 Candidate.FinalConversion.setAllToTypes(ToType);
7172 Candidate.Viable = true;
7173 Candidate.ExplicitCallArguments = 1;
7175 // Explicit functions are not actually candidates at all if we're not
7176 // allowing them in this context, but keep them around so we can point
7177 // to them in diagnostics.
7178 if (!AllowExplicit && Conversion->isExplicit()) {
7179 Candidate.Viable = false;
7180 Candidate.FailureKind = ovl_fail_explicit;
7184 // C++ [over.match.funcs]p4:
7185 // For conversion functions, the function is considered to be a member of
7186 // the class of the implicit implied object argument for the purpose of
7187 // defining the type of the implicit object parameter.
7189 // Determine the implicit conversion sequence for the implicit
7190 // object parameter.
7191 QualType ImplicitParamType = From->getType();
7192 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>())
7193 ImplicitParamType = FromPtrType->getPointeeType();
7194 CXXRecordDecl *ConversionContext
7195 = cast<CXXRecordDecl>(ImplicitParamType->castAs<RecordType>()->getDecl());
7197 Candidate.Conversions[0] = TryObjectArgumentInitialization(
7198 *this, CandidateSet.getLocation(), From->getType(),
7199 From->Classify(Context), Conversion, ConversionContext);
7201 if (Candidate.Conversions[0].isBad()) {
7202 Candidate.Viable = false;
7203 Candidate.FailureKind = ovl_fail_bad_conversion;
7207 Expr *RequiresClause = Conversion->getTrailingRequiresClause();
7208 if (RequiresClause) {
7209 ConstraintSatisfaction Satisfaction;
7210 if (CheckConstraintSatisfaction(RequiresClause, Satisfaction) ||
7211 !Satisfaction.IsSatisfied) {
7212 Candidate.Viable = false;
7213 Candidate.FailureKind = ovl_fail_constraints_not_satisfied;
7218 // We won't go through a user-defined type conversion function to convert a
7219 // derived to base as such conversions are given Conversion Rank. They only
7220 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user]
7222 = Context.getCanonicalType(From->getType().getUnqualifiedType());
7223 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType();
7224 if (FromCanon == ToCanon ||
7225 IsDerivedFrom(CandidateSet.getLocation(), FromCanon, ToCanon)) {
7226 Candidate.Viable = false;
7227 Candidate.FailureKind = ovl_fail_trivial_conversion;
7231 // To determine what the conversion from the result of calling the
7232 // conversion function to the type we're eventually trying to
7233 // convert to (ToType), we need to synthesize a call to the
7234 // conversion function and attempt copy initialization from it. This
7235 // makes sure that we get the right semantics with respect to
7236 // lvalues/rvalues and the type. Fortunately, we can allocate this
7237 // call on the stack and we don't need its arguments to be
7239 DeclRefExpr ConversionRef(Context, Conversion, false, Conversion->getType(),
7240 VK_LValue, From->getBeginLoc());
7241 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack,
7242 Context.getPointerType(Conversion->getType()),
7243 CK_FunctionToPointerDecay,
7244 &ConversionRef, VK_RValue);
7246 QualType ConversionType = Conversion->getConversionType();
7247 if (!isCompleteType(From->getBeginLoc(), ConversionType)) {
7248 Candidate.Viable = false;
7249 Candidate.FailureKind = ovl_fail_bad_final_conversion;
7253 ExprValueKind VK = Expr::getValueKindForType(ConversionType);
7255 // Note that it is safe to allocate CallExpr on the stack here because
7256 // there are 0 arguments (i.e., nothing is allocated using ASTContext's
7258 QualType CallResultType = ConversionType.getNonLValueExprType(Context);
7260 alignas(CallExpr) char Buffer[sizeof(CallExpr) + sizeof(Stmt *)];
7261 CallExpr *TheTemporaryCall = CallExpr::CreateTemporary(
7262 Buffer, &ConversionFn, CallResultType, VK, From->getBeginLoc());
7264 ImplicitConversionSequence ICS =
7265 TryCopyInitialization(*this, TheTemporaryCall, ToType,
7266 /*SuppressUserConversions=*/true,
7267 /*InOverloadResolution=*/false,
7268 /*AllowObjCWritebackConversion=*/false);
7270 switch (ICS.getKind()) {
7271 case ImplicitConversionSequence::StandardConversion:
7272 Candidate.FinalConversion = ICS.Standard;
7274 // C++ [over.ics.user]p3:
7275 // If the user-defined conversion is specified by a specialization of a
7276 // conversion function template, the second standard conversion sequence
7277 // shall have exact match rank.
7278 if (Conversion->getPrimaryTemplate() &&
7279 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) {
7280 Candidate.Viable = false;
7281 Candidate.FailureKind = ovl_fail_final_conversion_not_exact;
7285 // C++0x [dcl.init.ref]p5:
7286 // In the second case, if the reference is an rvalue reference and
7287 // the second standard conversion sequence of the user-defined
7288 // conversion sequence includes an lvalue-to-rvalue conversion, the
7289 // program is ill-formed.
7290 if (ToType->isRValueReferenceType() &&
7291 ICS.Standard.First == ICK_Lvalue_To_Rvalue) {
7292 Candidate.Viable = false;
7293 Candidate.FailureKind = ovl_fail_bad_final_conversion;
7298 case ImplicitConversionSequence::BadConversion:
7299 Candidate.Viable = false;
7300 Candidate.FailureKind = ovl_fail_bad_final_conversion;
7305 "Can only end up with a standard conversion sequence or failure");
7308 if (EnableIfAttr *FailedAttr = CheckEnableIf(Conversion, None)) {
7309 Candidate.Viable = false;
7310 Candidate.FailureKind = ovl_fail_enable_if;
7311 Candidate.DeductionFailure.Data = FailedAttr;
7315 if (Conversion->isMultiVersion() && Conversion->hasAttr<TargetAttr>() &&
7316 !Conversion->getAttr<TargetAttr>()->isDefaultVersion()) {
7317 Candidate.Viable = false;
7318 Candidate.FailureKind = ovl_non_default_multiversion_function;
7322 /// Adds a conversion function template specialization
7323 /// candidate to the overload set, using template argument deduction
7324 /// to deduce the template arguments of the conversion function
7325 /// template from the type that we are converting to (C++
7326 /// [temp.deduct.conv]).
7327 void Sema::AddTemplateConversionCandidate(
7328 FunctionTemplateDecl *FunctionTemplate, DeclAccessPair FoundDecl,
7329 CXXRecordDecl *ActingDC, Expr *From, QualType ToType,
7330 OverloadCandidateSet &CandidateSet, bool AllowObjCConversionOnExplicit,
7331 bool AllowExplicit, bool AllowResultConversion) {
7332 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) &&
7333 "Only conversion function templates permitted here");
7335 if (!CandidateSet.isNewCandidate(FunctionTemplate))
7338 // If the function template has a non-dependent explicit specification,
7339 // exclude it now if appropriate; we are not permitted to perform deduction
7340 // and substitution in this case.
7341 if (!AllowExplicit && isNonDependentlyExplicit(FunctionTemplate)) {
7342 OverloadCandidate &Candidate = CandidateSet.addCandidate();
7343 Candidate.FoundDecl = FoundDecl;
7344 Candidate.Function = FunctionTemplate->getTemplatedDecl();
7345 Candidate.Viable = false;
7346 Candidate.FailureKind = ovl_fail_explicit;
7350 TemplateDeductionInfo Info(CandidateSet.getLocation());
7351 CXXConversionDecl *Specialization = nullptr;
7352 if (TemplateDeductionResult Result
7353 = DeduceTemplateArguments(FunctionTemplate, ToType,
7354 Specialization, Info)) {
7355 OverloadCandidate &Candidate = CandidateSet.addCandidate();
7356 Candidate.FoundDecl = FoundDecl;
7357 Candidate.Function = FunctionTemplate->getTemplatedDecl();
7358 Candidate.Viable = false;
7359 Candidate.FailureKind = ovl_fail_bad_deduction;
7360 Candidate.IsSurrogate = false;
7361 Candidate.IgnoreObjectArgument = false;
7362 Candidate.ExplicitCallArguments = 1;
7363 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
7368 // Add the conversion function template specialization produced by
7369 // template argument deduction as a candidate.
7370 assert(Specialization && "Missing function template specialization?");
7371 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType,
7372 CandidateSet, AllowObjCConversionOnExplicit,
7373 AllowExplicit, AllowResultConversion);
7376 /// AddSurrogateCandidate - Adds a "surrogate" candidate function that
7377 /// converts the given @c Object to a function pointer via the
7378 /// conversion function @c Conversion, and then attempts to call it
7379 /// with the given arguments (C++ [over.call.object]p2-4). Proto is
7380 /// the type of function that we'll eventually be calling.
7381 void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion,
7382 DeclAccessPair FoundDecl,
7383 CXXRecordDecl *ActingContext,
7384 const FunctionProtoType *Proto,
7386 ArrayRef<Expr *> Args,
7387 OverloadCandidateSet& CandidateSet) {
7388 if (!CandidateSet.isNewCandidate(Conversion))
7391 // Overload resolution is always an unevaluated context.
7392 EnterExpressionEvaluationContext Unevaluated(
7393 *this, Sema::ExpressionEvaluationContext::Unevaluated);
7395 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1);
7396 Candidate.FoundDecl = FoundDecl;
7397 Candidate.Function = nullptr;
7398 Candidate.Surrogate = Conversion;
7399 Candidate.Viable = true;
7400 Candidate.IsSurrogate = true;
7401 Candidate.IgnoreObjectArgument = false;
7402 Candidate.ExplicitCallArguments = Args.size();
7404 // Determine the implicit conversion sequence for the implicit
7405 // object parameter.
7406 ImplicitConversionSequence ObjectInit = TryObjectArgumentInitialization(
7407 *this, CandidateSet.getLocation(), Object->getType(),
7408 Object->Classify(Context), Conversion, ActingContext);
7409 if (ObjectInit.isBad()) {
7410 Candidate.Viable = false;
7411 Candidate.FailureKind = ovl_fail_bad_conversion;
7412 Candidate.Conversions[0] = ObjectInit;
7416 // The first conversion is actually a user-defined conversion whose
7417 // first conversion is ObjectInit's standard conversion (which is
7418 // effectively a reference binding). Record it as such.
7419 Candidate.Conversions[0].setUserDefined();
7420 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard;
7421 Candidate.Conversions[0].UserDefined.EllipsisConversion = false;
7422 Candidate.Conversions[0].UserDefined.HadMultipleCandidates = false;
7423 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion;
7424 Candidate.Conversions[0].UserDefined.FoundConversionFunction = FoundDecl;
7425 Candidate.Conversions[0].UserDefined.After
7426 = Candidate.Conversions[0].UserDefined.Before;
7427 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion();
7430 unsigned NumParams = Proto->getNumParams();
7432 // (C++ 13.3.2p2): A candidate function having fewer than m
7433 // parameters is viable only if it has an ellipsis in its parameter
7435 if (Args.size() > NumParams && !Proto->isVariadic()) {
7436 Candidate.Viable = false;
7437 Candidate.FailureKind = ovl_fail_too_many_arguments;
7441 // Function types don't have any default arguments, so just check if
7442 // we have enough arguments.
7443 if (Args.size() < NumParams) {
7444 // Not enough arguments.
7445 Candidate.Viable = false;
7446 Candidate.FailureKind = ovl_fail_too_few_arguments;
7450 // Determine the implicit conversion sequences for each of the
7452 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7453 if (ArgIdx < NumParams) {
7454 // (C++ 13.3.2p3): for F to be a viable function, there shall
7455 // exist for each argument an implicit conversion sequence
7456 // (13.3.3.1) that converts that argument to the corresponding
7458 QualType ParamType = Proto->getParamType(ArgIdx);
7459 Candidate.Conversions[ArgIdx + 1]
7460 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
7461 /*SuppressUserConversions=*/false,
7462 /*InOverloadResolution=*/false,
7463 /*AllowObjCWritebackConversion=*/
7464 getLangOpts().ObjCAutoRefCount);
7465 if (Candidate.Conversions[ArgIdx + 1].isBad()) {
7466 Candidate.Viable = false;
7467 Candidate.FailureKind = ovl_fail_bad_conversion;
7471 // (C++ 13.3.2p2): For the purposes of overload resolution, any
7472 // argument for which there is no corresponding parameter is
7473 // considered to ""match the ellipsis" (C+ 13.3.3.1.3).
7474 Candidate.Conversions[ArgIdx + 1].setEllipsis();
7478 if (EnableIfAttr *FailedAttr = CheckEnableIf(Conversion, None)) {
7479 Candidate.Viable = false;
7480 Candidate.FailureKind = ovl_fail_enable_if;
7481 Candidate.DeductionFailure.Data = FailedAttr;
7486 /// Add all of the non-member operator function declarations in the given
7487 /// function set to the overload candidate set.
7488 void Sema::AddNonMemberOperatorCandidates(
7489 const UnresolvedSetImpl &Fns, ArrayRef<Expr *> Args,
7490 OverloadCandidateSet &CandidateSet,
7491 TemplateArgumentListInfo *ExplicitTemplateArgs) {
7492 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) {
7493 NamedDecl *D = F.getDecl()->getUnderlyingDecl();
7494 ArrayRef<Expr *> FunctionArgs = Args;
7496 FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(D);
7498 FunTmpl ? FunTmpl->getTemplatedDecl() : cast<FunctionDecl>(D);
7500 // Don't consider rewritten functions if we're not rewriting.
7501 if (!CandidateSet.getRewriteInfo().isAcceptableCandidate(FD))
7504 assert(!isa<CXXMethodDecl>(FD) &&
7505 "unqualified operator lookup found a member function");
7508 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), ExplicitTemplateArgs,
7509 FunctionArgs, CandidateSet);
7510 if (CandidateSet.getRewriteInfo().shouldAddReversed(Context, FD))
7511 AddTemplateOverloadCandidate(
7512 FunTmpl, F.getPair(), ExplicitTemplateArgs,
7513 {FunctionArgs[1], FunctionArgs[0]}, CandidateSet, false, false,
7514 true, ADLCallKind::NotADL, OverloadCandidateParamOrder::Reversed);
7516 if (ExplicitTemplateArgs)
7518 AddOverloadCandidate(FD, F.getPair(), FunctionArgs, CandidateSet);
7519 if (CandidateSet.getRewriteInfo().shouldAddReversed(Context, FD))
7520 AddOverloadCandidate(FD, F.getPair(),
7521 {FunctionArgs[1], FunctionArgs[0]}, CandidateSet,
7522 false, false, true, false, ADLCallKind::NotADL,
7523 None, OverloadCandidateParamOrder::Reversed);
7528 /// Add overload candidates for overloaded operators that are
7529 /// member functions.
7531 /// Add the overloaded operator candidates that are member functions
7532 /// for the operator Op that was used in an operator expression such
7533 /// as "x Op y". , Args/NumArgs provides the operator arguments, and
7534 /// CandidateSet will store the added overload candidates. (C++
7535 /// [over.match.oper]).
7536 void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op,
7537 SourceLocation OpLoc,
7538 ArrayRef<Expr *> Args,
7539 OverloadCandidateSet &CandidateSet,
7540 OverloadCandidateParamOrder PO) {
7541 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
7543 // C++ [over.match.oper]p3:
7544 // For a unary operator @ with an operand of a type whose
7545 // cv-unqualified version is T1, and for a binary operator @ with
7546 // a left operand of a type whose cv-unqualified version is T1 and
7547 // a right operand of a type whose cv-unqualified version is T2,
7548 // three sets of candidate functions, designated member
7549 // candidates, non-member candidates and built-in candidates, are
7550 // constructed as follows:
7551 QualType T1 = Args[0]->getType();
7553 // -- If T1 is a complete class type or a class currently being
7554 // defined, the set of member candidates is the result of the
7555 // qualified lookup of T1::operator@ (13.3.1.1.1); otherwise,
7556 // the set of member candidates is empty.
7557 if (const RecordType *T1Rec = T1->getAs<RecordType>()) {
7558 // Complete the type if it can be completed.
7559 if (!isCompleteType(OpLoc, T1) && !T1Rec->isBeingDefined())
7561 // If the type is neither complete nor being defined, bail out now.
7562 if (!T1Rec->getDecl()->getDefinition())
7565 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName);
7566 LookupQualifiedName(Operators, T1Rec->getDecl());
7567 Operators.suppressDiagnostics();
7569 for (LookupResult::iterator Oper = Operators.begin(),
7570 OperEnd = Operators.end();
7573 AddMethodCandidate(Oper.getPair(), Args[0]->getType(),
7574 Args[0]->Classify(Context), Args.slice(1),
7575 CandidateSet, /*SuppressUserConversion=*/false, PO);
7579 /// AddBuiltinCandidate - Add a candidate for a built-in
7580 /// operator. ResultTy and ParamTys are the result and parameter types
7581 /// of the built-in candidate, respectively. Args and NumArgs are the
7582 /// arguments being passed to the candidate. IsAssignmentOperator
7583 /// should be true when this built-in candidate is an assignment
7584 /// operator. NumContextualBoolArguments is the number of arguments
7585 /// (at the beginning of the argument list) that will be contextually
7586 /// converted to bool.
7587 void Sema::AddBuiltinCandidate(QualType *ParamTys, ArrayRef<Expr *> Args,
7588 OverloadCandidateSet& CandidateSet,
7589 bool IsAssignmentOperator,
7590 unsigned NumContextualBoolArguments) {
7591 // Overload resolution is always an unevaluated context.
7592 EnterExpressionEvaluationContext Unevaluated(
7593 *this, Sema::ExpressionEvaluationContext::Unevaluated);
7595 // Add this candidate
7596 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size());
7597 Candidate.FoundDecl = DeclAccessPair::make(nullptr, AS_none);
7598 Candidate.Function = nullptr;
7599 Candidate.IsSurrogate = false;
7600 Candidate.IgnoreObjectArgument = false;
7601 std::copy(ParamTys, ParamTys + Args.size(), Candidate.BuiltinParamTypes);
7603 // Determine the implicit conversion sequences for each of the
7605 Candidate.Viable = true;
7606 Candidate.ExplicitCallArguments = Args.size();
7607 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7608 // C++ [over.match.oper]p4:
7609 // For the built-in assignment operators, conversions of the
7610 // left operand are restricted as follows:
7611 // -- no temporaries are introduced to hold the left operand, and
7612 // -- no user-defined conversions are applied to the left
7613 // operand to achieve a type match with the left-most
7614 // parameter of a built-in candidate.
7616 // We block these conversions by turning off user-defined
7617 // conversions, since that is the only way that initialization of
7618 // a reference to a non-class type can occur from something that
7619 // is not of the same type.
7620 if (ArgIdx < NumContextualBoolArguments) {
7621 assert(ParamTys[ArgIdx] == Context.BoolTy &&
7622 "Contextual conversion to bool requires bool type");
7623 Candidate.Conversions[ArgIdx]
7624 = TryContextuallyConvertToBool(*this, Args[ArgIdx]);
7626 Candidate.Conversions[ArgIdx]
7627 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx],
7628 ArgIdx == 0 && IsAssignmentOperator,
7629 /*InOverloadResolution=*/false,
7630 /*AllowObjCWritebackConversion=*/
7631 getLangOpts().ObjCAutoRefCount);
7633 if (Candidate.Conversions[ArgIdx].isBad()) {
7634 Candidate.Viable = false;
7635 Candidate.FailureKind = ovl_fail_bad_conversion;
7643 /// BuiltinCandidateTypeSet - A set of types that will be used for the
7644 /// candidate operator functions for built-in operators (C++
7645 /// [over.built]). The types are separated into pointer types and
7646 /// enumeration types.
7647 class BuiltinCandidateTypeSet {
7648 /// TypeSet - A set of types.
7649 typedef llvm::SetVector<QualType, SmallVector<QualType, 8>,
7650 llvm::SmallPtrSet<QualType, 8>> TypeSet;
7652 /// PointerTypes - The set of pointer types that will be used in the
7653 /// built-in candidates.
7654 TypeSet PointerTypes;
7656 /// MemberPointerTypes - The set of member pointer types that will be
7657 /// used in the built-in candidates.
7658 TypeSet MemberPointerTypes;
7660 /// EnumerationTypes - The set of enumeration types that will be
7661 /// used in the built-in candidates.
7662 TypeSet EnumerationTypes;
7664 /// The set of vector types that will be used in the built-in
7666 TypeSet VectorTypes;
7668 /// A flag indicating non-record types are viable candidates
7669 bool HasNonRecordTypes;
7671 /// A flag indicating whether either arithmetic or enumeration types
7672 /// were present in the candidate set.
7673 bool HasArithmeticOrEnumeralTypes;
7675 /// A flag indicating whether the nullptr type was present in the
7677 bool HasNullPtrType;
7679 /// Sema - The semantic analysis instance where we are building the
7680 /// candidate type set.
7683 /// Context - The AST context in which we will build the type sets.
7684 ASTContext &Context;
7686 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
7687 const Qualifiers &VisibleQuals);
7688 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty);
7691 /// iterator - Iterates through the types that are part of the set.
7692 typedef TypeSet::iterator iterator;
7694 BuiltinCandidateTypeSet(Sema &SemaRef)
7695 : HasNonRecordTypes(false),
7696 HasArithmeticOrEnumeralTypes(false),
7697 HasNullPtrType(false),
7699 Context(SemaRef.Context) { }
7701 void AddTypesConvertedFrom(QualType Ty,
7703 bool AllowUserConversions,
7704 bool AllowExplicitConversions,
7705 const Qualifiers &VisibleTypeConversionsQuals);
7707 /// pointer_begin - First pointer type found;
7708 iterator pointer_begin() { return PointerTypes.begin(); }
7710 /// pointer_end - Past the last pointer type found;
7711 iterator pointer_end() { return PointerTypes.end(); }
7713 /// member_pointer_begin - First member pointer type found;
7714 iterator member_pointer_begin() { return MemberPointerTypes.begin(); }
7716 /// member_pointer_end - Past the last member pointer type found;
7717 iterator member_pointer_end() { return MemberPointerTypes.end(); }
7719 /// enumeration_begin - First enumeration type found;
7720 iterator enumeration_begin() { return EnumerationTypes.begin(); }
7722 /// enumeration_end - Past the last enumeration type found;
7723 iterator enumeration_end() { return EnumerationTypes.end(); }
7725 iterator vector_begin() { return VectorTypes.begin(); }
7726 iterator vector_end() { return VectorTypes.end(); }
7728 bool hasNonRecordTypes() { return HasNonRecordTypes; }
7729 bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; }
7730 bool hasNullPtrType() const { return HasNullPtrType; }
7733 } // end anonymous namespace
7735 /// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to
7736 /// the set of pointer types along with any more-qualified variants of
7737 /// that type. For example, if @p Ty is "int const *", this routine
7738 /// will add "int const *", "int const volatile *", "int const
7739 /// restrict *", and "int const volatile restrict *" to the set of
7740 /// pointer types. Returns true if the add of @p Ty itself succeeded,
7741 /// false otherwise.
7743 /// FIXME: what to do about extended qualifiers?
7745 BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
7746 const Qualifiers &VisibleQuals) {
7748 // Insert this type.
7749 if (!PointerTypes.insert(Ty))
7753 const PointerType *PointerTy = Ty->getAs<PointerType>();
7754 bool buildObjCPtr = false;
7756 const ObjCObjectPointerType *PTy = Ty->castAs<ObjCObjectPointerType>();
7757 PointeeTy = PTy->getPointeeType();
7758 buildObjCPtr = true;
7760 PointeeTy = PointerTy->getPointeeType();
7763 // Don't add qualified variants of arrays. For one, they're not allowed
7764 // (the qualifier would sink to the element type), and for another, the
7765 // only overload situation where it matters is subscript or pointer +- int,
7766 // and those shouldn't have qualifier variants anyway.
7767 if (PointeeTy->isArrayType())
7770 unsigned BaseCVR = PointeeTy.getCVRQualifiers();
7771 bool hasVolatile = VisibleQuals.hasVolatile();
7772 bool hasRestrict = VisibleQuals.hasRestrict();
7774 // Iterate through all strict supersets of BaseCVR.
7775 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) {
7776 if ((CVR | BaseCVR) != CVR) continue;
7777 // Skip over volatile if no volatile found anywhere in the types.
7778 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue;
7780 // Skip over restrict if no restrict found anywhere in the types, or if
7781 // the type cannot be restrict-qualified.
7782 if ((CVR & Qualifiers::Restrict) &&
7784 (!(PointeeTy->isAnyPointerType() || PointeeTy->isReferenceType()))))
7787 // Build qualified pointee type.
7788 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR);
7790 // Build qualified pointer type.
7791 QualType QPointerTy;
7793 QPointerTy = Context.getPointerType(QPointeeTy);
7795 QPointerTy = Context.getObjCObjectPointerType(QPointeeTy);
7797 // Insert qualified pointer type.
7798 PointerTypes.insert(QPointerTy);
7804 /// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty
7805 /// to the set of pointer types along with any more-qualified variants of
7806 /// that type. For example, if @p Ty is "int const *", this routine
7807 /// will add "int const *", "int const volatile *", "int const
7808 /// restrict *", and "int const volatile restrict *" to the set of
7809 /// pointer types. Returns true if the add of @p Ty itself succeeded,
7810 /// false otherwise.
7812 /// FIXME: what to do about extended qualifiers?
7814 BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants(
7816 // Insert this type.
7817 if (!MemberPointerTypes.insert(Ty))
7820 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>();
7821 assert(PointerTy && "type was not a member pointer type!");
7823 QualType PointeeTy = PointerTy->getPointeeType();
7824 // Don't add qualified variants of arrays. For one, they're not allowed
7825 // (the qualifier would sink to the element type), and for another, the
7826 // only overload situation where it matters is subscript or pointer +- int,
7827 // and those shouldn't have qualifier variants anyway.
7828 if (PointeeTy->isArrayType())
7830 const Type *ClassTy = PointerTy->getClass();
7832 // Iterate through all strict supersets of the pointee type's CVR
7834 unsigned BaseCVR = PointeeTy.getCVRQualifiers();
7835 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) {
7836 if ((CVR | BaseCVR) != CVR) continue;
7838 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR);
7839 MemberPointerTypes.insert(
7840 Context.getMemberPointerType(QPointeeTy, ClassTy));
7846 /// AddTypesConvertedFrom - Add each of the types to which the type @p
7847 /// Ty can be implicit converted to the given set of @p Types. We're
7848 /// primarily interested in pointer types and enumeration types. We also
7849 /// take member pointer types, for the conditional operator.
7850 /// AllowUserConversions is true if we should look at the conversion
7851 /// functions of a class type, and AllowExplicitConversions if we
7852 /// should also include the explicit conversion functions of a class
7855 BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty,
7857 bool AllowUserConversions,
7858 bool AllowExplicitConversions,
7859 const Qualifiers &VisibleQuals) {
7860 // Only deal with canonical types.
7861 Ty = Context.getCanonicalType(Ty);
7863 // Look through reference types; they aren't part of the type of an
7864 // expression for the purposes of conversions.
7865 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>())
7866 Ty = RefTy->getPointeeType();
7868 // If we're dealing with an array type, decay to the pointer.
7869 if (Ty->isArrayType())
7870 Ty = SemaRef.Context.getArrayDecayedType(Ty);
7872 // Otherwise, we don't care about qualifiers on the type.
7873 Ty = Ty.getLocalUnqualifiedType();
7875 // Flag if we ever add a non-record type.
7876 const RecordType *TyRec = Ty->getAs<RecordType>();
7877 HasNonRecordTypes = HasNonRecordTypes || !TyRec;
7879 // Flag if we encounter an arithmetic type.
7880 HasArithmeticOrEnumeralTypes =
7881 HasArithmeticOrEnumeralTypes || Ty->isArithmeticType();
7883 if (Ty->isObjCIdType() || Ty->isObjCClassType())
7884 PointerTypes.insert(Ty);
7885 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) {
7886 // Insert our type, and its more-qualified variants, into the set
7888 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals))
7890 } else if (Ty->isMemberPointerType()) {
7891 // Member pointers are far easier, since the pointee can't be converted.
7892 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty))
7894 } else if (Ty->isEnumeralType()) {
7895 HasArithmeticOrEnumeralTypes = true;
7896 EnumerationTypes.insert(Ty);
7897 } else if (Ty->isVectorType()) {
7898 // We treat vector types as arithmetic types in many contexts as an
7900 HasArithmeticOrEnumeralTypes = true;
7901 VectorTypes.insert(Ty);
7902 } else if (Ty->isNullPtrType()) {
7903 HasNullPtrType = true;
7904 } else if (AllowUserConversions && TyRec) {
7905 // No conversion functions in incomplete types.
7906 if (!SemaRef.isCompleteType(Loc, Ty))
7909 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl());
7910 for (NamedDecl *D : ClassDecl->getVisibleConversionFunctions()) {
7911 if (isa<UsingShadowDecl>(D))
7912 D = cast<UsingShadowDecl>(D)->getTargetDecl();
7914 // Skip conversion function templates; they don't tell us anything
7915 // about which builtin types we can convert to.
7916 if (isa<FunctionTemplateDecl>(D))
7919 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D);
7920 if (AllowExplicitConversions || !Conv->isExplicit()) {
7921 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false,
7927 /// Helper function for adjusting address spaces for the pointer or reference
7928 /// operands of builtin operators depending on the argument.
7929 static QualType AdjustAddressSpaceForBuiltinOperandType(Sema &S, QualType T,
7931 return S.Context.getAddrSpaceQualType(T, Arg->getType().getAddressSpace());
7934 /// Helper function for AddBuiltinOperatorCandidates() that adds
7935 /// the volatile- and non-volatile-qualified assignment operators for the
7936 /// given type to the candidate set.
7937 static void AddBuiltinAssignmentOperatorCandidates(Sema &S,
7939 ArrayRef<Expr *> Args,
7940 OverloadCandidateSet &CandidateSet) {
7941 QualType ParamTypes[2];
7943 // T& operator=(T&, T)
7944 ParamTypes[0] = S.Context.getLValueReferenceType(
7945 AdjustAddressSpaceForBuiltinOperandType(S, T, Args[0]));
7947 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
7948 /*IsAssignmentOperator=*/true);
7950 if (!S.Context.getCanonicalType(T).isVolatileQualified()) {
7951 // volatile T& operator=(volatile T&, T)
7952 ParamTypes[0] = S.Context.getLValueReferenceType(
7953 AdjustAddressSpaceForBuiltinOperandType(S, S.Context.getVolatileType(T),
7956 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
7957 /*IsAssignmentOperator=*/true);
7961 /// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers,
7962 /// if any, found in visible type conversion functions found in ArgExpr's type.
7963 static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) {
7965 const RecordType *TyRec;
7966 if (const MemberPointerType *RHSMPType =
7967 ArgExpr->getType()->getAs<MemberPointerType>())
7968 TyRec = RHSMPType->getClass()->getAs<RecordType>();
7970 TyRec = ArgExpr->getType()->getAs<RecordType>();
7972 // Just to be safe, assume the worst case.
7973 VRQuals.addVolatile();
7974 VRQuals.addRestrict();
7978 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl());
7979 if (!ClassDecl->hasDefinition())
7982 for (NamedDecl *D : ClassDecl->getVisibleConversionFunctions()) {
7983 if (isa<UsingShadowDecl>(D))
7984 D = cast<UsingShadowDecl>(D)->getTargetDecl();
7985 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) {
7986 QualType CanTy = Context.getCanonicalType(Conv->getConversionType());
7987 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>())
7988 CanTy = ResTypeRef->getPointeeType();
7989 // Need to go down the pointer/mempointer chain and add qualifiers
7993 if (CanTy.isRestrictQualified())
7994 VRQuals.addRestrict();
7995 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>())
7996 CanTy = ResTypePtr->getPointeeType();
7997 else if (const MemberPointerType *ResTypeMPtr =
7998 CanTy->getAs<MemberPointerType>())
7999 CanTy = ResTypeMPtr->getPointeeType();
8002 if (CanTy.isVolatileQualified())
8003 VRQuals.addVolatile();
8004 if (VRQuals.hasRestrict() && VRQuals.hasVolatile())
8014 /// Helper class to manage the addition of builtin operator overload
8015 /// candidates. It provides shared state and utility methods used throughout
8016 /// the process, as well as a helper method to add each group of builtin
8017 /// operator overloads from the standard to a candidate set.
8018 class BuiltinOperatorOverloadBuilder {
8019 // Common instance state available to all overload candidate addition methods.
8021 ArrayRef<Expr *> Args;
8022 Qualifiers VisibleTypeConversionsQuals;
8023 bool HasArithmeticOrEnumeralCandidateType;
8024 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes;
8025 OverloadCandidateSet &CandidateSet;
8027 static constexpr int ArithmeticTypesCap = 24;
8028 SmallVector<CanQualType, ArithmeticTypesCap> ArithmeticTypes;
8030 // Define some indices used to iterate over the arithmetic types in
8031 // ArithmeticTypes. The "promoted arithmetic types" are the arithmetic
8032 // types are that preserved by promotion (C++ [over.built]p2).
8033 unsigned FirstIntegralType,
8035 unsigned FirstPromotedIntegralType,
8036 LastPromotedIntegralType;
8037 unsigned FirstPromotedArithmeticType,
8038 LastPromotedArithmeticType;
8039 unsigned NumArithmeticTypes;
8041 void InitArithmeticTypes() {
8042 // Start of promoted types.
8043 FirstPromotedArithmeticType = 0;
8044 ArithmeticTypes.push_back(S.Context.FloatTy);
8045 ArithmeticTypes.push_back(S.Context.DoubleTy);
8046 ArithmeticTypes.push_back(S.Context.LongDoubleTy);
8047 if (S.Context.getTargetInfo().hasFloat128Type())
8048 ArithmeticTypes.push_back(S.Context.Float128Ty);
8050 // Start of integral types.
8051 FirstIntegralType = ArithmeticTypes.size();
8052 FirstPromotedIntegralType = ArithmeticTypes.size();
8053 ArithmeticTypes.push_back(S.Context.IntTy);
8054 ArithmeticTypes.push_back(S.Context.LongTy);
8055 ArithmeticTypes.push_back(S.Context.LongLongTy);
8056 if (S.Context.getTargetInfo().hasInt128Type())
8057 ArithmeticTypes.push_back(S.Context.Int128Ty);
8058 ArithmeticTypes.push_back(S.Context.UnsignedIntTy);
8059 ArithmeticTypes.push_back(S.Context.UnsignedLongTy);
8060 ArithmeticTypes.push_back(S.Context.UnsignedLongLongTy);
8061 if (S.Context.getTargetInfo().hasInt128Type())
8062 ArithmeticTypes.push_back(S.Context.UnsignedInt128Ty);
8063 LastPromotedIntegralType = ArithmeticTypes.size();
8064 LastPromotedArithmeticType = ArithmeticTypes.size();
8065 // End of promoted types.
8067 ArithmeticTypes.push_back(S.Context.BoolTy);
8068 ArithmeticTypes.push_back(S.Context.CharTy);
8069 ArithmeticTypes.push_back(S.Context.WCharTy);
8070 if (S.Context.getLangOpts().Char8)
8071 ArithmeticTypes.push_back(S.Context.Char8Ty);
8072 ArithmeticTypes.push_back(S.Context.Char16Ty);
8073 ArithmeticTypes.push_back(S.Context.Char32Ty);
8074 ArithmeticTypes.push_back(S.Context.SignedCharTy);
8075 ArithmeticTypes.push_back(S.Context.ShortTy);
8076 ArithmeticTypes.push_back(S.Context.UnsignedCharTy);
8077 ArithmeticTypes.push_back(S.Context.UnsignedShortTy);
8078 LastIntegralType = ArithmeticTypes.size();
8079 NumArithmeticTypes = ArithmeticTypes.size();
8080 // End of integral types.
8081 // FIXME: What about complex? What about half?
8083 assert(ArithmeticTypes.size() <= ArithmeticTypesCap &&
8084 "Enough inline storage for all arithmetic types.");
8087 /// Helper method to factor out the common pattern of adding overloads
8088 /// for '++' and '--' builtin operators.
8089 void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy,
8092 QualType ParamTypes[2] = {
8093 S.Context.getLValueReferenceType(CandidateTy),
8097 // Non-volatile version.
8098 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8100 // Use a heuristic to reduce number of builtin candidates in the set:
8101 // add volatile version only if there are conversions to a volatile type.
8104 S.Context.getLValueReferenceType(
8105 S.Context.getVolatileType(CandidateTy));
8106 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8109 // Add restrict version only if there are conversions to a restrict type
8110 // and our candidate type is a non-restrict-qualified pointer.
8111 if (HasRestrict && CandidateTy->isAnyPointerType() &&
8112 !CandidateTy.isRestrictQualified()) {
8114 = S.Context.getLValueReferenceType(
8115 S.Context.getCVRQualifiedType(CandidateTy, Qualifiers::Restrict));
8116 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8120 = S.Context.getLValueReferenceType(
8121 S.Context.getCVRQualifiedType(CandidateTy,
8122 (Qualifiers::Volatile |
8123 Qualifiers::Restrict)));
8124 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8131 BuiltinOperatorOverloadBuilder(
8132 Sema &S, ArrayRef<Expr *> Args,
8133 Qualifiers VisibleTypeConversionsQuals,
8134 bool HasArithmeticOrEnumeralCandidateType,
8135 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes,
8136 OverloadCandidateSet &CandidateSet)
8138 VisibleTypeConversionsQuals(VisibleTypeConversionsQuals),
8139 HasArithmeticOrEnumeralCandidateType(
8140 HasArithmeticOrEnumeralCandidateType),
8141 CandidateTypes(CandidateTypes),
8142 CandidateSet(CandidateSet) {
8144 InitArithmeticTypes();
8147 // Increment is deprecated for bool since C++17.
8149 // C++ [over.built]p3:
8151 // For every pair (T, VQ), where T is an arithmetic type other
8152 // than bool, and VQ is either volatile or empty, there exist
8153 // candidate operator functions of the form
8155 // VQ T& operator++(VQ T&);
8156 // T operator++(VQ T&, int);
8158 // C++ [over.built]p4:
8160 // For every pair (T, VQ), where T is an arithmetic type other
8161 // than bool, and VQ is either volatile or empty, there exist
8162 // candidate operator functions of the form
8164 // VQ T& operator--(VQ T&);
8165 // T operator--(VQ T&, int);
8166 void addPlusPlusMinusMinusArithmeticOverloads(OverloadedOperatorKind Op) {
8167 if (!HasArithmeticOrEnumeralCandidateType)
8170 for (unsigned Arith = 0; Arith < NumArithmeticTypes; ++Arith) {
8171 const auto TypeOfT = ArithmeticTypes[Arith];
8172 if (TypeOfT == S.Context.BoolTy) {
8173 if (Op == OO_MinusMinus)
8175 if (Op == OO_PlusPlus && S.getLangOpts().CPlusPlus17)
8178 addPlusPlusMinusMinusStyleOverloads(
8180 VisibleTypeConversionsQuals.hasVolatile(),
8181 VisibleTypeConversionsQuals.hasRestrict());
8185 // C++ [over.built]p5:
8187 // For every pair (T, VQ), where T is a cv-qualified or
8188 // cv-unqualified object type, and VQ is either volatile or
8189 // empty, there exist candidate operator functions of the form
8191 // T*VQ& operator++(T*VQ&);
8192 // T*VQ& operator--(T*VQ&);
8193 // T* operator++(T*VQ&, int);
8194 // T* operator--(T*VQ&, int);
8195 void addPlusPlusMinusMinusPointerOverloads() {
8196 for (BuiltinCandidateTypeSet::iterator
8197 Ptr = CandidateTypes[0].pointer_begin(),
8198 PtrEnd = CandidateTypes[0].pointer_end();
8199 Ptr != PtrEnd; ++Ptr) {
8200 // Skip pointer types that aren't pointers to object types.
8201 if (!(*Ptr)->getPointeeType()->isObjectType())
8204 addPlusPlusMinusMinusStyleOverloads(*Ptr,
8205 (!(*Ptr).isVolatileQualified() &&
8206 VisibleTypeConversionsQuals.hasVolatile()),
8207 (!(*Ptr).isRestrictQualified() &&
8208 VisibleTypeConversionsQuals.hasRestrict()));
8212 // C++ [over.built]p6:
8213 // For every cv-qualified or cv-unqualified object type T, there
8214 // exist candidate operator functions of the form
8216 // T& operator*(T*);
8218 // C++ [over.built]p7:
8219 // For every function type T that does not have cv-qualifiers or a
8220 // ref-qualifier, there exist candidate operator functions of the form
8221 // T& operator*(T*);
8222 void addUnaryStarPointerOverloads() {
8223 for (BuiltinCandidateTypeSet::iterator
8224 Ptr = CandidateTypes[0].pointer_begin(),
8225 PtrEnd = CandidateTypes[0].pointer_end();
8226 Ptr != PtrEnd; ++Ptr) {
8227 QualType ParamTy = *Ptr;
8228 QualType PointeeTy = ParamTy->getPointeeType();
8229 if (!PointeeTy->isObjectType() && !PointeeTy->isFunctionType())
8232 if (const FunctionProtoType *Proto =PointeeTy->getAs<FunctionProtoType>())
8233 if (Proto->getMethodQuals() || Proto->getRefQualifier())
8236 S.AddBuiltinCandidate(&ParamTy, Args, CandidateSet);
8240 // C++ [over.built]p9:
8241 // For every promoted arithmetic type T, there exist candidate
8242 // operator functions of the form
8246 void addUnaryPlusOrMinusArithmeticOverloads() {
8247 if (!HasArithmeticOrEnumeralCandidateType)
8250 for (unsigned Arith = FirstPromotedArithmeticType;
8251 Arith < LastPromotedArithmeticType; ++Arith) {
8252 QualType ArithTy = ArithmeticTypes[Arith];
8253 S.AddBuiltinCandidate(&ArithTy, Args, CandidateSet);
8256 // Extension: We also add these operators for vector types.
8257 for (BuiltinCandidateTypeSet::iterator
8258 Vec = CandidateTypes[0].vector_begin(),
8259 VecEnd = CandidateTypes[0].vector_end();
8260 Vec != VecEnd; ++Vec) {
8261 QualType VecTy = *Vec;
8262 S.AddBuiltinCandidate(&VecTy, Args, CandidateSet);
8266 // C++ [over.built]p8:
8267 // For every type T, there exist candidate operator functions of
8270 // T* operator+(T*);
8271 void addUnaryPlusPointerOverloads() {
8272 for (BuiltinCandidateTypeSet::iterator
8273 Ptr = CandidateTypes[0].pointer_begin(),
8274 PtrEnd = CandidateTypes[0].pointer_end();
8275 Ptr != PtrEnd; ++Ptr) {
8276 QualType ParamTy = *Ptr;
8277 S.AddBuiltinCandidate(&ParamTy, Args, CandidateSet);
8281 // C++ [over.built]p10:
8282 // For every promoted integral type T, there exist candidate
8283 // operator functions of the form
8286 void addUnaryTildePromotedIntegralOverloads() {
8287 if (!HasArithmeticOrEnumeralCandidateType)
8290 for (unsigned Int = FirstPromotedIntegralType;
8291 Int < LastPromotedIntegralType; ++Int) {
8292 QualType IntTy = ArithmeticTypes[Int];
8293 S.AddBuiltinCandidate(&IntTy, Args, CandidateSet);
8296 // Extension: We also add this operator for vector types.
8297 for (BuiltinCandidateTypeSet::iterator
8298 Vec = CandidateTypes[0].vector_begin(),
8299 VecEnd = CandidateTypes[0].vector_end();
8300 Vec != VecEnd; ++Vec) {
8301 QualType VecTy = *Vec;
8302 S.AddBuiltinCandidate(&VecTy, Args, CandidateSet);
8306 // C++ [over.match.oper]p16:
8307 // For every pointer to member type T or type std::nullptr_t, there
8308 // exist candidate operator functions of the form
8310 // bool operator==(T,T);
8311 // bool operator!=(T,T);
8312 void addEqualEqualOrNotEqualMemberPointerOrNullptrOverloads() {
8313 /// Set of (canonical) types that we've already handled.
8314 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8316 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
8317 for (BuiltinCandidateTypeSet::iterator
8318 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(),
8319 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end();
8320 MemPtr != MemPtrEnd;
8322 // Don't add the same builtin candidate twice.
8323 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr)).second)
8326 QualType ParamTypes[2] = { *MemPtr, *MemPtr };
8327 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8330 if (CandidateTypes[ArgIdx].hasNullPtrType()) {
8331 CanQualType NullPtrTy = S.Context.getCanonicalType(S.Context.NullPtrTy);
8332 if (AddedTypes.insert(NullPtrTy).second) {
8333 QualType ParamTypes[2] = { NullPtrTy, NullPtrTy };
8334 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8340 // C++ [over.built]p15:
8342 // For every T, where T is an enumeration type or a pointer type,
8343 // there exist candidate operator functions of the form
8345 // bool operator<(T, T);
8346 // bool operator>(T, T);
8347 // bool operator<=(T, T);
8348 // bool operator>=(T, T);
8349 // bool operator==(T, T);
8350 // bool operator!=(T, T);
8351 // R operator<=>(T, T)
8352 void addGenericBinaryPointerOrEnumeralOverloads() {
8353 // C++ [over.match.oper]p3:
8354 // [...]the built-in candidates include all of the candidate operator
8355 // functions defined in 13.6 that, compared to the given operator, [...]
8356 // do not have the same parameter-type-list as any non-template non-member
8359 // Note that in practice, this only affects enumeration types because there
8360 // aren't any built-in candidates of record type, and a user-defined operator
8361 // must have an operand of record or enumeration type. Also, the only other
8362 // overloaded operator with enumeration arguments, operator=,
8363 // cannot be overloaded for enumeration types, so this is the only place
8364 // where we must suppress candidates like this.
8365 llvm::DenseSet<std::pair<CanQualType, CanQualType> >
8366 UserDefinedBinaryOperators;
8368 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
8369 if (CandidateTypes[ArgIdx].enumeration_begin() !=
8370 CandidateTypes[ArgIdx].enumeration_end()) {
8371 for (OverloadCandidateSet::iterator C = CandidateSet.begin(),
8372 CEnd = CandidateSet.end();
8374 if (!C->Viable || !C->Function || C->Function->getNumParams() != 2)
8377 if (C->Function->isFunctionTemplateSpecialization())
8380 // We interpret "same parameter-type-list" as applying to the
8381 // "synthesized candidate, with the order of the two parameters
8382 // reversed", not to the original function.
8383 bool Reversed = C->RewriteKind & CRK_Reversed;
8384 QualType FirstParamType = C->Function->getParamDecl(Reversed ? 1 : 0)
8386 .getUnqualifiedType();
8387 QualType SecondParamType = C->Function->getParamDecl(Reversed ? 0 : 1)
8389 .getUnqualifiedType();
8391 // Skip if either parameter isn't of enumeral type.
8392 if (!FirstParamType->isEnumeralType() ||
8393 !SecondParamType->isEnumeralType())
8396 // Add this operator to the set of known user-defined operators.
8397 UserDefinedBinaryOperators.insert(
8398 std::make_pair(S.Context.getCanonicalType(FirstParamType),
8399 S.Context.getCanonicalType(SecondParamType)));
8404 /// Set of (canonical) types that we've already handled.
8405 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8407 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
8408 for (BuiltinCandidateTypeSet::iterator
8409 Ptr = CandidateTypes[ArgIdx].pointer_begin(),
8410 PtrEnd = CandidateTypes[ArgIdx].pointer_end();
8411 Ptr != PtrEnd; ++Ptr) {
8412 // Don't add the same builtin candidate twice.
8413 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
8416 QualType ParamTypes[2] = { *Ptr, *Ptr };
8417 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8419 for (BuiltinCandidateTypeSet::iterator
8420 Enum = CandidateTypes[ArgIdx].enumeration_begin(),
8421 EnumEnd = CandidateTypes[ArgIdx].enumeration_end();
8422 Enum != EnumEnd; ++Enum) {
8423 CanQualType CanonType = S.Context.getCanonicalType(*Enum);
8425 // Don't add the same builtin candidate twice, or if a user defined
8426 // candidate exists.
8427 if (!AddedTypes.insert(CanonType).second ||
8428 UserDefinedBinaryOperators.count(std::make_pair(CanonType,
8431 QualType ParamTypes[2] = { *Enum, *Enum };
8432 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8437 // C++ [over.built]p13:
8439 // For every cv-qualified or cv-unqualified object type T
8440 // there exist candidate operator functions of the form
8442 // T* operator+(T*, ptrdiff_t);
8443 // T& operator[](T*, ptrdiff_t); [BELOW]
8444 // T* operator-(T*, ptrdiff_t);
8445 // T* operator+(ptrdiff_t, T*);
8446 // T& operator[](ptrdiff_t, T*); [BELOW]
8448 // C++ [over.built]p14:
8450 // For every T, where T is a pointer to object type, there
8451 // exist candidate operator functions of the form
8453 // ptrdiff_t operator-(T, T);
8454 void addBinaryPlusOrMinusPointerOverloads(OverloadedOperatorKind Op) {
8455 /// Set of (canonical) types that we've already handled.
8456 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8458 for (int Arg = 0; Arg < 2; ++Arg) {
8459 QualType AsymmetricParamTypes[2] = {
8460 S.Context.getPointerDiffType(),
8461 S.Context.getPointerDiffType(),
8463 for (BuiltinCandidateTypeSet::iterator
8464 Ptr = CandidateTypes[Arg].pointer_begin(),
8465 PtrEnd = CandidateTypes[Arg].pointer_end();
8466 Ptr != PtrEnd; ++Ptr) {
8467 QualType PointeeTy = (*Ptr)->getPointeeType();
8468 if (!PointeeTy->isObjectType())
8471 AsymmetricParamTypes[Arg] = *Ptr;
8472 if (Arg == 0 || Op == OO_Plus) {
8473 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t)
8474 // T* operator+(ptrdiff_t, T*);
8475 S.AddBuiltinCandidate(AsymmetricParamTypes, Args, CandidateSet);
8477 if (Op == OO_Minus) {
8478 // ptrdiff_t operator-(T, T);
8479 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
8482 QualType ParamTypes[2] = { *Ptr, *Ptr };
8483 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8489 // C++ [over.built]p12:
8491 // For every pair of promoted arithmetic types L and R, there
8492 // exist candidate operator functions of the form
8494 // LR operator*(L, R);
8495 // LR operator/(L, R);
8496 // LR operator+(L, R);
8497 // LR operator-(L, R);
8498 // bool operator<(L, R);
8499 // bool operator>(L, R);
8500 // bool operator<=(L, R);
8501 // bool operator>=(L, R);
8502 // bool operator==(L, R);
8503 // bool operator!=(L, R);
8505 // where LR is the result of the usual arithmetic conversions
8506 // between types L and R.
8508 // C++ [over.built]p24:
8510 // For every pair of promoted arithmetic types L and R, there exist
8511 // candidate operator functions of the form
8513 // LR operator?(bool, L, R);
8515 // where LR is the result of the usual arithmetic conversions
8516 // between types L and R.
8517 // Our candidates ignore the first parameter.
8518 void addGenericBinaryArithmeticOverloads() {
8519 if (!HasArithmeticOrEnumeralCandidateType)
8522 for (unsigned Left = FirstPromotedArithmeticType;
8523 Left < LastPromotedArithmeticType; ++Left) {
8524 for (unsigned Right = FirstPromotedArithmeticType;
8525 Right < LastPromotedArithmeticType; ++Right) {
8526 QualType LandR[2] = { ArithmeticTypes[Left],
8527 ArithmeticTypes[Right] };
8528 S.AddBuiltinCandidate(LandR, Args, CandidateSet);
8532 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the
8533 // conditional operator for vector types.
8534 for (BuiltinCandidateTypeSet::iterator
8535 Vec1 = CandidateTypes[0].vector_begin(),
8536 Vec1End = CandidateTypes[0].vector_end();
8537 Vec1 != Vec1End; ++Vec1) {
8538 for (BuiltinCandidateTypeSet::iterator
8539 Vec2 = CandidateTypes[1].vector_begin(),
8540 Vec2End = CandidateTypes[1].vector_end();
8541 Vec2 != Vec2End; ++Vec2) {
8542 QualType LandR[2] = { *Vec1, *Vec2 };
8543 S.AddBuiltinCandidate(LandR, Args, CandidateSet);
8548 // C++2a [over.built]p14:
8550 // For every integral type T there exists a candidate operator function
8553 // std::strong_ordering operator<=>(T, T)
8555 // C++2a [over.built]p15:
8557 // For every pair of floating-point types L and R, there exists a candidate
8558 // operator function of the form
8560 // std::partial_ordering operator<=>(L, R);
8562 // FIXME: The current specification for integral types doesn't play nice with
8563 // the direction of p0946r0, which allows mixed integral and unscoped-enum
8564 // comparisons. Under the current spec this can lead to ambiguity during
8565 // overload resolution. For example:
8567 // enum A : int {a};
8568 // auto x = (a <=> (long)42);
8570 // error: call is ambiguous for arguments 'A' and 'long'.
8571 // note: candidate operator<=>(int, int)
8572 // note: candidate operator<=>(long, long)
8574 // To avoid this error, this function deviates from the specification and adds
8575 // the mixed overloads `operator<=>(L, R)` where L and R are promoted
8576 // arithmetic types (the same as the generic relational overloads).
8578 // For now this function acts as a placeholder.
8579 void addThreeWayArithmeticOverloads() {
8580 addGenericBinaryArithmeticOverloads();
8583 // C++ [over.built]p17:
8585 // For every pair of promoted integral types L and R, there
8586 // exist candidate operator functions of the form
8588 // LR operator%(L, R);
8589 // LR operator&(L, R);
8590 // LR operator^(L, R);
8591 // LR operator|(L, R);
8592 // L operator<<(L, R);
8593 // L operator>>(L, R);
8595 // where LR is the result of the usual arithmetic conversions
8596 // between types L and R.
8597 void addBinaryBitwiseArithmeticOverloads(OverloadedOperatorKind Op) {
8598 if (!HasArithmeticOrEnumeralCandidateType)
8601 for (unsigned Left = FirstPromotedIntegralType;
8602 Left < LastPromotedIntegralType; ++Left) {
8603 for (unsigned Right = FirstPromotedIntegralType;
8604 Right < LastPromotedIntegralType; ++Right) {
8605 QualType LandR[2] = { ArithmeticTypes[Left],
8606 ArithmeticTypes[Right] };
8607 S.AddBuiltinCandidate(LandR, Args, CandidateSet);
8612 // C++ [over.built]p20:
8614 // For every pair (T, VQ), where T is an enumeration or
8615 // pointer to member type and VQ is either volatile or
8616 // empty, there exist candidate operator functions of the form
8618 // VQ T& operator=(VQ T&, T);
8619 void addAssignmentMemberPointerOrEnumeralOverloads() {
8620 /// Set of (canonical) types that we've already handled.
8621 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8623 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) {
8624 for (BuiltinCandidateTypeSet::iterator
8625 Enum = CandidateTypes[ArgIdx].enumeration_begin(),
8626 EnumEnd = CandidateTypes[ArgIdx].enumeration_end();
8627 Enum != EnumEnd; ++Enum) {
8628 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum)).second)
8631 AddBuiltinAssignmentOperatorCandidates(S, *Enum, Args, CandidateSet);
8634 for (BuiltinCandidateTypeSet::iterator
8635 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(),
8636 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end();
8637 MemPtr != MemPtrEnd; ++MemPtr) {
8638 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr)).second)
8641 AddBuiltinAssignmentOperatorCandidates(S, *MemPtr, Args, CandidateSet);
8646 // C++ [over.built]p19:
8648 // For every pair (T, VQ), where T is any type and VQ is either
8649 // volatile or empty, there exist candidate operator functions
8652 // T*VQ& operator=(T*VQ&, T*);
8654 // C++ [over.built]p21:
8656 // For every pair (T, VQ), where T is a cv-qualified or
8657 // cv-unqualified object type and VQ is either volatile or
8658 // empty, there exist candidate operator functions of the form
8660 // T*VQ& operator+=(T*VQ&, ptrdiff_t);
8661 // T*VQ& operator-=(T*VQ&, ptrdiff_t);
8662 void addAssignmentPointerOverloads(bool isEqualOp) {
8663 /// Set of (canonical) types that we've already handled.
8664 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8666 for (BuiltinCandidateTypeSet::iterator
8667 Ptr = CandidateTypes[0].pointer_begin(),
8668 PtrEnd = CandidateTypes[0].pointer_end();
8669 Ptr != PtrEnd; ++Ptr) {
8670 // If this is operator=, keep track of the builtin candidates we added.
8672 AddedTypes.insert(S.Context.getCanonicalType(*Ptr));
8673 else if (!(*Ptr)->getPointeeType()->isObjectType())
8676 // non-volatile version
8677 QualType ParamTypes[2] = {
8678 S.Context.getLValueReferenceType(*Ptr),
8679 isEqualOp ? *Ptr : S.Context.getPointerDiffType(),
8681 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8682 /*IsAssignmentOperator=*/ isEqualOp);
8684 bool NeedVolatile = !(*Ptr).isVolatileQualified() &&
8685 VisibleTypeConversionsQuals.hasVolatile();
8689 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr));
8690 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8691 /*IsAssignmentOperator=*/isEqualOp);
8694 if (!(*Ptr).isRestrictQualified() &&
8695 VisibleTypeConversionsQuals.hasRestrict()) {
8698 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr));
8699 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8700 /*IsAssignmentOperator=*/isEqualOp);
8703 // volatile restrict version
8705 = S.Context.getLValueReferenceType(
8706 S.Context.getCVRQualifiedType(*Ptr,
8707 (Qualifiers::Volatile |
8708 Qualifiers::Restrict)));
8709 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8710 /*IsAssignmentOperator=*/isEqualOp);
8716 for (BuiltinCandidateTypeSet::iterator
8717 Ptr = CandidateTypes[1].pointer_begin(),
8718 PtrEnd = CandidateTypes[1].pointer_end();
8719 Ptr != PtrEnd; ++Ptr) {
8720 // Make sure we don't add the same candidate twice.
8721 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
8724 QualType ParamTypes[2] = {
8725 S.Context.getLValueReferenceType(*Ptr),
8729 // non-volatile version
8730 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8731 /*IsAssignmentOperator=*/true);
8733 bool NeedVolatile = !(*Ptr).isVolatileQualified() &&
8734 VisibleTypeConversionsQuals.hasVolatile();
8738 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr));
8739 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8740 /*IsAssignmentOperator=*/true);
8743 if (!(*Ptr).isRestrictQualified() &&
8744 VisibleTypeConversionsQuals.hasRestrict()) {
8747 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr));
8748 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8749 /*IsAssignmentOperator=*/true);
8752 // volatile restrict version
8754 = S.Context.getLValueReferenceType(
8755 S.Context.getCVRQualifiedType(*Ptr,
8756 (Qualifiers::Volatile |
8757 Qualifiers::Restrict)));
8758 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8759 /*IsAssignmentOperator=*/true);
8766 // C++ [over.built]p18:
8768 // For every triple (L, VQ, R), where L is an arithmetic type,
8769 // VQ is either volatile or empty, and R is a promoted
8770 // arithmetic type, there exist candidate operator functions of
8773 // VQ L& operator=(VQ L&, R);
8774 // VQ L& operator*=(VQ L&, R);
8775 // VQ L& operator/=(VQ L&, R);
8776 // VQ L& operator+=(VQ L&, R);
8777 // VQ L& operator-=(VQ L&, R);
8778 void addAssignmentArithmeticOverloads(bool isEqualOp) {
8779 if (!HasArithmeticOrEnumeralCandidateType)
8782 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) {
8783 for (unsigned Right = FirstPromotedArithmeticType;
8784 Right < LastPromotedArithmeticType; ++Right) {
8785 QualType ParamTypes[2];
8786 ParamTypes[1] = ArithmeticTypes[Right];
8787 auto LeftBaseTy = AdjustAddressSpaceForBuiltinOperandType(
8788 S, ArithmeticTypes[Left], Args[0]);
8789 // Add this built-in operator as a candidate (VQ is empty).
8790 ParamTypes[0] = S.Context.getLValueReferenceType(LeftBaseTy);
8791 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8792 /*IsAssignmentOperator=*/isEqualOp);
8794 // Add this built-in operator as a candidate (VQ is 'volatile').
8795 if (VisibleTypeConversionsQuals.hasVolatile()) {
8796 ParamTypes[0] = S.Context.getVolatileType(LeftBaseTy);
8797 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
8798 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8799 /*IsAssignmentOperator=*/isEqualOp);
8804 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types.
8805 for (BuiltinCandidateTypeSet::iterator
8806 Vec1 = CandidateTypes[0].vector_begin(),
8807 Vec1End = CandidateTypes[0].vector_end();
8808 Vec1 != Vec1End; ++Vec1) {
8809 for (BuiltinCandidateTypeSet::iterator
8810 Vec2 = CandidateTypes[1].vector_begin(),
8811 Vec2End = CandidateTypes[1].vector_end();
8812 Vec2 != Vec2End; ++Vec2) {
8813 QualType ParamTypes[2];
8814 ParamTypes[1] = *Vec2;
8815 // Add this built-in operator as a candidate (VQ is empty).
8816 ParamTypes[0] = S.Context.getLValueReferenceType(*Vec1);
8817 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8818 /*IsAssignmentOperator=*/isEqualOp);
8820 // Add this built-in operator as a candidate (VQ is 'volatile').
8821 if (VisibleTypeConversionsQuals.hasVolatile()) {
8822 ParamTypes[0] = S.Context.getVolatileType(*Vec1);
8823 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
8824 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8825 /*IsAssignmentOperator=*/isEqualOp);
8831 // C++ [over.built]p22:
8833 // For every triple (L, VQ, R), where L is an integral type, VQ
8834 // is either volatile or empty, and R is a promoted integral
8835 // type, there exist candidate operator functions of the form
8837 // VQ L& operator%=(VQ L&, R);
8838 // VQ L& operator<<=(VQ L&, R);
8839 // VQ L& operator>>=(VQ L&, R);
8840 // VQ L& operator&=(VQ L&, R);
8841 // VQ L& operator^=(VQ L&, R);
8842 // VQ L& operator|=(VQ L&, R);
8843 void addAssignmentIntegralOverloads() {
8844 if (!HasArithmeticOrEnumeralCandidateType)
8847 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) {
8848 for (unsigned Right = FirstPromotedIntegralType;
8849 Right < LastPromotedIntegralType; ++Right) {
8850 QualType ParamTypes[2];
8851 ParamTypes[1] = ArithmeticTypes[Right];
8852 auto LeftBaseTy = AdjustAddressSpaceForBuiltinOperandType(
8853 S, ArithmeticTypes[Left], Args[0]);
8854 // Add this built-in operator as a candidate (VQ is empty).
8855 ParamTypes[0] = S.Context.getLValueReferenceType(LeftBaseTy);
8856 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8857 if (VisibleTypeConversionsQuals.hasVolatile()) {
8858 // Add this built-in operator as a candidate (VQ is 'volatile').
8859 ParamTypes[0] = LeftBaseTy;
8860 ParamTypes[0] = S.Context.getVolatileType(ParamTypes[0]);
8861 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
8862 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8868 // C++ [over.operator]p23:
8870 // There also exist candidate operator functions of the form
8872 // bool operator!(bool);
8873 // bool operator&&(bool, bool);
8874 // bool operator||(bool, bool);
8875 void addExclaimOverload() {
8876 QualType ParamTy = S.Context.BoolTy;
8877 S.AddBuiltinCandidate(&ParamTy, Args, CandidateSet,
8878 /*IsAssignmentOperator=*/false,
8879 /*NumContextualBoolArguments=*/1);
8881 void addAmpAmpOrPipePipeOverload() {
8882 QualType ParamTypes[2] = { S.Context.BoolTy, S.Context.BoolTy };
8883 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet,
8884 /*IsAssignmentOperator=*/false,
8885 /*NumContextualBoolArguments=*/2);
8888 // C++ [over.built]p13:
8890 // For every cv-qualified or cv-unqualified object type T there
8891 // exist candidate operator functions of the form
8893 // T* operator+(T*, ptrdiff_t); [ABOVE]
8894 // T& operator[](T*, ptrdiff_t);
8895 // T* operator-(T*, ptrdiff_t); [ABOVE]
8896 // T* operator+(ptrdiff_t, T*); [ABOVE]
8897 // T& operator[](ptrdiff_t, T*);
8898 void addSubscriptOverloads() {
8899 for (BuiltinCandidateTypeSet::iterator
8900 Ptr = CandidateTypes[0].pointer_begin(),
8901 PtrEnd = CandidateTypes[0].pointer_end();
8902 Ptr != PtrEnd; ++Ptr) {
8903 QualType ParamTypes[2] = { *Ptr, S.Context.getPointerDiffType() };
8904 QualType PointeeType = (*Ptr)->getPointeeType();
8905 if (!PointeeType->isObjectType())
8908 // T& operator[](T*, ptrdiff_t)
8909 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8912 for (BuiltinCandidateTypeSet::iterator
8913 Ptr = CandidateTypes[1].pointer_begin(),
8914 PtrEnd = CandidateTypes[1].pointer_end();
8915 Ptr != PtrEnd; ++Ptr) {
8916 QualType ParamTypes[2] = { S.Context.getPointerDiffType(), *Ptr };
8917 QualType PointeeType = (*Ptr)->getPointeeType();
8918 if (!PointeeType->isObjectType())
8921 // T& operator[](ptrdiff_t, T*)
8922 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8926 // C++ [over.built]p11:
8927 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type,
8928 // C1 is the same type as C2 or is a derived class of C2, T is an object
8929 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
8930 // there exist candidate operator functions of the form
8932 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
8934 // where CV12 is the union of CV1 and CV2.
8935 void addArrowStarOverloads() {
8936 for (BuiltinCandidateTypeSet::iterator
8937 Ptr = CandidateTypes[0].pointer_begin(),
8938 PtrEnd = CandidateTypes[0].pointer_end();
8939 Ptr != PtrEnd; ++Ptr) {
8940 QualType C1Ty = (*Ptr);
8942 QualifierCollector Q1;
8943 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0);
8944 if (!isa<RecordType>(C1))
8946 // heuristic to reduce number of builtin candidates in the set.
8947 // Add volatile/restrict version only if there are conversions to a
8948 // volatile/restrict type.
8949 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile())
8951 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict())
8953 for (BuiltinCandidateTypeSet::iterator
8954 MemPtr = CandidateTypes[1].member_pointer_begin(),
8955 MemPtrEnd = CandidateTypes[1].member_pointer_end();
8956 MemPtr != MemPtrEnd; ++MemPtr) {
8957 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr);
8958 QualType C2 = QualType(mptr->getClass(), 0);
8959 C2 = C2.getUnqualifiedType();
8960 if (C1 != C2 && !S.IsDerivedFrom(CandidateSet.getLocation(), C1, C2))
8962 QualType ParamTypes[2] = { *Ptr, *MemPtr };
8964 QualType T = mptr->getPointeeType();
8965 if (!VisibleTypeConversionsQuals.hasVolatile() &&
8966 T.isVolatileQualified())
8968 if (!VisibleTypeConversionsQuals.hasRestrict() &&
8969 T.isRestrictQualified())
8971 T = Q1.apply(S.Context, T);
8972 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
8977 // Note that we don't consider the first argument, since it has been
8978 // contextually converted to bool long ago. The candidates below are
8979 // therefore added as binary.
8981 // C++ [over.built]p25:
8982 // For every type T, where T is a pointer, pointer-to-member, or scoped
8983 // enumeration type, there exist candidate operator functions of the form
8985 // T operator?(bool, T, T);
8987 void addConditionalOperatorOverloads() {
8988 /// Set of (canonical) types that we've already handled.
8989 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8991 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) {
8992 for (BuiltinCandidateTypeSet::iterator
8993 Ptr = CandidateTypes[ArgIdx].pointer_begin(),
8994 PtrEnd = CandidateTypes[ArgIdx].pointer_end();
8995 Ptr != PtrEnd; ++Ptr) {
8996 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
8999 QualType ParamTypes[2] = { *Ptr, *Ptr };
9000 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
9003 for (BuiltinCandidateTypeSet::iterator
9004 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(),
9005 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end();
9006 MemPtr != MemPtrEnd; ++MemPtr) {
9007 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr)).second)
9010 QualType ParamTypes[2] = { *MemPtr, *MemPtr };
9011 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
9014 if (S.getLangOpts().CPlusPlus11) {
9015 for (BuiltinCandidateTypeSet::iterator
9016 Enum = CandidateTypes[ArgIdx].enumeration_begin(),
9017 EnumEnd = CandidateTypes[ArgIdx].enumeration_end();
9018 Enum != EnumEnd; ++Enum) {
9019 if (!(*Enum)->castAs<EnumType>()->getDecl()->isScoped())
9022 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum)).second)
9025 QualType ParamTypes[2] = { *Enum, *Enum };
9026 S.AddBuiltinCandidate(ParamTypes, Args, CandidateSet);
9033 } // end anonymous namespace
9035 /// AddBuiltinOperatorCandidates - Add the appropriate built-in
9036 /// operator overloads to the candidate set (C++ [over.built]), based
9037 /// on the operator @p Op and the arguments given. For example, if the
9038 /// operator is a binary '+', this routine might add "int
9039 /// operator+(int, int)" to cover integer addition.
9040 void Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op,
9041 SourceLocation OpLoc,
9042 ArrayRef<Expr *> Args,
9043 OverloadCandidateSet &CandidateSet) {
9044 // Find all of the types that the arguments can convert to, but only
9045 // if the operator we're looking at has built-in operator candidates
9046 // that make use of these types. Also record whether we encounter non-record
9047 // candidate types or either arithmetic or enumeral candidate types.
9048 Qualifiers VisibleTypeConversionsQuals;
9049 VisibleTypeConversionsQuals.addConst();
9050 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx)
9051 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]);
9053 bool HasNonRecordCandidateType = false;
9054 bool HasArithmeticOrEnumeralCandidateType = false;
9055 SmallVector<BuiltinCandidateTypeSet, 2> CandidateTypes;
9056 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
9057 CandidateTypes.emplace_back(*this);
9058 CandidateTypes[ArgIdx].AddTypesConvertedFrom(Args[ArgIdx]->getType(),
9061 (Op == OO_Exclaim ||
9064 VisibleTypeConversionsQuals);
9065 HasNonRecordCandidateType = HasNonRecordCandidateType ||
9066 CandidateTypes[ArgIdx].hasNonRecordTypes();
9067 HasArithmeticOrEnumeralCandidateType =
9068 HasArithmeticOrEnumeralCandidateType ||
9069 CandidateTypes[ArgIdx].hasArithmeticOrEnumeralTypes();
9072 // Exit early when no non-record types have been added to the candidate set
9073 // for any of the arguments to the operator.
9075 // We can't exit early for !, ||, or &&, since there we have always have
9076 // 'bool' overloads.
9077 if (!HasNonRecordCandidateType &&
9078 !(Op == OO_Exclaim || Op == OO_AmpAmp || Op == OO_PipePipe))
9081 // Setup an object to manage the common state for building overloads.
9082 BuiltinOperatorOverloadBuilder OpBuilder(*this, Args,
9083 VisibleTypeConversionsQuals,
9084 HasArithmeticOrEnumeralCandidateType,
9085 CandidateTypes, CandidateSet);
9087 // Dispatch over the operation to add in only those overloads which apply.
9090 case NUM_OVERLOADED_OPERATORS:
9091 llvm_unreachable("Expected an overloaded operator");
9096 case OO_Array_Delete:
9099 "Special operators don't use AddBuiltinOperatorCandidates");
9104 // C++ [over.match.oper]p3:
9105 // -- For the operator ',', the unary operator '&', the
9106 // operator '->', or the operator 'co_await', the
9107 // built-in candidates set is empty.
9110 case OO_Plus: // '+' is either unary or binary
9111 if (Args.size() == 1)
9112 OpBuilder.addUnaryPlusPointerOverloads();
9115 case OO_Minus: // '-' is either unary or binary
9116 if (Args.size() == 1) {
9117 OpBuilder.addUnaryPlusOrMinusArithmeticOverloads();
9119 OpBuilder.addBinaryPlusOrMinusPointerOverloads(Op);
9120 OpBuilder.addGenericBinaryArithmeticOverloads();
9124 case OO_Star: // '*' is either unary or binary
9125 if (Args.size() == 1)
9126 OpBuilder.addUnaryStarPointerOverloads();
9128 OpBuilder.addGenericBinaryArithmeticOverloads();
9132 OpBuilder.addGenericBinaryArithmeticOverloads();
9137 OpBuilder.addPlusPlusMinusMinusArithmeticOverloads(Op);
9138 OpBuilder.addPlusPlusMinusMinusPointerOverloads();
9142 case OO_ExclaimEqual:
9143 OpBuilder.addEqualEqualOrNotEqualMemberPointerOrNullptrOverloads();
9149 case OO_GreaterEqual:
9150 OpBuilder.addGenericBinaryPointerOrEnumeralOverloads();
9151 OpBuilder.addGenericBinaryArithmeticOverloads();
9155 OpBuilder.addGenericBinaryPointerOrEnumeralOverloads();
9156 OpBuilder.addThreeWayArithmeticOverloads();
9163 case OO_GreaterGreater:
9164 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op);
9167 case OO_Amp: // '&' is either unary or binary
9168 if (Args.size() == 1)
9169 // C++ [over.match.oper]p3:
9170 // -- For the operator ',', the unary operator '&', or the
9171 // operator '->', the built-in candidates set is empty.
9174 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op);
9178 OpBuilder.addUnaryTildePromotedIntegralOverloads();
9182 OpBuilder.addAssignmentMemberPointerOrEnumeralOverloads();
9187 OpBuilder.addAssignmentPointerOverloads(Op == OO_Equal);
9192 OpBuilder.addAssignmentArithmeticOverloads(Op == OO_Equal);
9195 case OO_PercentEqual:
9196 case OO_LessLessEqual:
9197 case OO_GreaterGreaterEqual:
9201 OpBuilder.addAssignmentIntegralOverloads();
9205 OpBuilder.addExclaimOverload();
9210 OpBuilder.addAmpAmpOrPipePipeOverload();
9214 OpBuilder.addSubscriptOverloads();
9218 OpBuilder.addArrowStarOverloads();
9221 case OO_Conditional:
9222 OpBuilder.addConditionalOperatorOverloads();
9223 OpBuilder.addGenericBinaryArithmeticOverloads();
9228 /// Add function candidates found via argument-dependent lookup
9229 /// to the set of overloading candidates.
9231 /// This routine performs argument-dependent name lookup based on the
9232 /// given function name (which may also be an operator name) and adds
9233 /// all of the overload candidates found by ADL to the overload
9234 /// candidate set (C++ [basic.lookup.argdep]).
9236 Sema::AddArgumentDependentLookupCandidates(DeclarationName Name,
9238 ArrayRef<Expr *> Args,
9239 TemplateArgumentListInfo *ExplicitTemplateArgs,
9240 OverloadCandidateSet& CandidateSet,
9241 bool PartialOverloading) {
9244 // FIXME: This approach for uniquing ADL results (and removing
9245 // redundant candidates from the set) relies on pointer-equality,
9246 // which means we need to key off the canonical decl. However,
9247 // always going back to the canonical decl might not get us the
9248 // right set of default arguments. What default arguments are
9249 // we supposed to consider on ADL candidates, anyway?
9251 // FIXME: Pass in the explicit template arguments?
9252 ArgumentDependentLookup(Name, Loc, Args, Fns);
9254 // Erase all of the candidates we already knew about.
9255 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(),
9256 CandEnd = CandidateSet.end();
9257 Cand != CandEnd; ++Cand)
9258 if (Cand->Function) {
9259 Fns.erase(Cand->Function);
9260 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate())
9264 // For each of the ADL candidates we found, add it to the overload
9266 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) {
9267 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none);
9269 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) {
9270 if (ExplicitTemplateArgs)
9273 AddOverloadCandidate(FD, FoundDecl, Args, CandidateSet,
9274 /*SuppressUserConversions=*/false, PartialOverloading,
9275 /*AllowExplicit*/ true,
9276 /*AllowExplicitConversions*/ false,
9277 ADLCallKind::UsesADL);
9279 AddTemplateOverloadCandidate(
9280 cast<FunctionTemplateDecl>(*I), FoundDecl, ExplicitTemplateArgs, Args,
9282 /*SuppressUserConversions=*/false, PartialOverloading,
9283 /*AllowExplicit*/true, ADLCallKind::UsesADL);
9289 enum class Comparison { Equal, Better, Worse };
9292 /// Compares the enable_if attributes of two FunctionDecls, for the purposes of
9293 /// overload resolution.
9295 /// Cand1's set of enable_if attributes are said to be "better" than Cand2's iff
9296 /// Cand1's first N enable_if attributes have precisely the same conditions as
9297 /// Cand2's first N enable_if attributes (where N = the number of enable_if
9298 /// attributes on Cand2), and Cand1 has more than N enable_if attributes.
9300 /// Note that you can have a pair of candidates such that Cand1's enable_if
9301 /// attributes are worse than Cand2's, and Cand2's enable_if attributes are
9302 /// worse than Cand1's.
9303 static Comparison compareEnableIfAttrs(const Sema &S, const FunctionDecl *Cand1,
9304 const FunctionDecl *Cand2) {
9305 // Common case: One (or both) decls don't have enable_if attrs.
9306 bool Cand1Attr = Cand1->hasAttr<EnableIfAttr>();
9307 bool Cand2Attr = Cand2->hasAttr<EnableIfAttr>();
9308 if (!Cand1Attr || !Cand2Attr) {
9309 if (Cand1Attr == Cand2Attr)
9310 return Comparison::Equal;
9311 return Cand1Attr ? Comparison::Better : Comparison::Worse;
9314 auto Cand1Attrs = Cand1->specific_attrs<EnableIfAttr>();
9315 auto Cand2Attrs = Cand2->specific_attrs<EnableIfAttr>();
9317 llvm::FoldingSetNodeID Cand1ID, Cand2ID;
9318 for (auto Pair : zip_longest(Cand1Attrs, Cand2Attrs)) {
9319 Optional<EnableIfAttr *> Cand1A = std::get<0>(Pair);
9320 Optional<EnableIfAttr *> Cand2A = std::get<1>(Pair);
9322 // It's impossible for Cand1 to be better than (or equal to) Cand2 if Cand1
9323 // has fewer enable_if attributes than Cand2, and vice versa.
9325 return Comparison::Worse;
9327 return Comparison::Better;
9332 (*Cand1A)->getCond()->Profile(Cand1ID, S.getASTContext(), true);
9333 (*Cand2A)->getCond()->Profile(Cand2ID, S.getASTContext(), true);
9334 if (Cand1ID != Cand2ID)
9335 return Comparison::Worse;
9338 return Comparison::Equal;
9341 static bool isBetterMultiversionCandidate(const OverloadCandidate &Cand1,
9342 const OverloadCandidate &Cand2) {
9343 if (!Cand1.Function || !Cand1.Function->isMultiVersion() || !Cand2.Function ||
9344 !Cand2.Function->isMultiVersion())
9347 // If Cand1 is invalid, it cannot be a better match, if Cand2 is invalid, this
9348 // is obviously better.
9349 if (Cand1.Function->isInvalidDecl()) return false;
9350 if (Cand2.Function->isInvalidDecl()) return true;
9352 // If this is a cpu_dispatch/cpu_specific multiversion situation, prefer
9353 // cpu_dispatch, else arbitrarily based on the identifiers.
9354 bool Cand1CPUDisp = Cand1.Function->hasAttr<CPUDispatchAttr>();
9355 bool Cand2CPUDisp = Cand2.Function->hasAttr<CPUDispatchAttr>();
9356 const auto *Cand1CPUSpec = Cand1.Function->getAttr<CPUSpecificAttr>();
9357 const auto *Cand2CPUSpec = Cand2.Function->getAttr<CPUSpecificAttr>();
9359 if (!Cand1CPUDisp && !Cand2CPUDisp && !Cand1CPUSpec && !Cand2CPUSpec)
9362 if (Cand1CPUDisp && !Cand2CPUDisp)
9364 if (Cand2CPUDisp && !Cand1CPUDisp)
9367 if (Cand1CPUSpec && Cand2CPUSpec) {
9368 if (Cand1CPUSpec->cpus_size() != Cand2CPUSpec->cpus_size())
9369 return Cand1CPUSpec->cpus_size() < Cand2CPUSpec->cpus_size();
9371 std::pair<CPUSpecificAttr::cpus_iterator, CPUSpecificAttr::cpus_iterator>
9372 FirstDiff = std::mismatch(
9373 Cand1CPUSpec->cpus_begin(), Cand1CPUSpec->cpus_end(),
9374 Cand2CPUSpec->cpus_begin(),
9375 [](const IdentifierInfo *LHS, const IdentifierInfo *RHS) {
9376 return LHS->getName() == RHS->getName();
9379 assert(FirstDiff.first != Cand1CPUSpec->cpus_end() &&
9380 "Two different cpu-specific versions should not have the same "
9381 "identifier list, otherwise they'd be the same decl!");
9382 return (*FirstDiff.first)->getName() < (*FirstDiff.second)->getName();
9384 llvm_unreachable("No way to get here unless both had cpu_dispatch");
9387 /// isBetterOverloadCandidate - Determines whether the first overload
9388 /// candidate is a better candidate than the second (C++ 13.3.3p1).
9389 bool clang::isBetterOverloadCandidate(
9390 Sema &S, const OverloadCandidate &Cand1, const OverloadCandidate &Cand2,
9391 SourceLocation Loc, OverloadCandidateSet::CandidateSetKind Kind) {
9392 // Define viable functions to be better candidates than non-viable
9395 return Cand1.Viable;
9396 else if (!Cand1.Viable)
9399 // C++ [over.match.best]p1:
9401 // -- if F is a static member function, ICS1(F) is defined such
9402 // that ICS1(F) is neither better nor worse than ICS1(G) for
9403 // any function G, and, symmetrically, ICS1(G) is neither
9404 // better nor worse than ICS1(F).
9405 unsigned StartArg = 0;
9406 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument)
9409 auto IsIllFormedConversion = [&](const ImplicitConversionSequence &ICS) {
9410 // We don't allow incompatible pointer conversions in C++.
9411 if (!S.getLangOpts().CPlusPlus)
9412 return ICS.isStandard() &&
9413 ICS.Standard.Second == ICK_Incompatible_Pointer_Conversion;
9415 // The only ill-formed conversion we allow in C++ is the string literal to
9416 // char* conversion, which is only considered ill-formed after C++11.
9417 return S.getLangOpts().CPlusPlus11 && !S.getLangOpts().WritableStrings &&
9418 hasDeprecatedStringLiteralToCharPtrConversion(ICS);
9421 // Define functions that don't require ill-formed conversions for a given
9422 // argument to be better candidates than functions that do.
9423 unsigned NumArgs = Cand1.Conversions.size();
9424 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch");
9425 bool HasBetterConversion = false;
9426 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) {
9427 bool Cand1Bad = IsIllFormedConversion(Cand1.Conversions[ArgIdx]);
9428 bool Cand2Bad = IsIllFormedConversion(Cand2.Conversions[ArgIdx]);
9429 if (Cand1Bad != Cand2Bad) {
9432 HasBetterConversion = true;
9436 if (HasBetterConversion)
9439 // C++ [over.match.best]p1:
9440 // A viable function F1 is defined to be a better function than another
9441 // viable function F2 if for all arguments i, ICSi(F1) is not a worse
9442 // conversion sequence than ICSi(F2), and then...
9443 bool HasWorseConversion = false;
9444 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) {
9445 switch (CompareImplicitConversionSequences(S, Loc,
9446 Cand1.Conversions[ArgIdx],
9447 Cand2.Conversions[ArgIdx])) {
9448 case ImplicitConversionSequence::Better:
9449 // Cand1 has a better conversion sequence.
9450 HasBetterConversion = true;
9453 case ImplicitConversionSequence::Worse:
9454 if (Cand1.Function && Cand1.Function == Cand2.Function &&
9455 (Cand2.RewriteKind & CRK_Reversed) != 0) {
9456 // Work around large-scale breakage caused by considering reversed
9457 // forms of operator== in C++20:
9459 // When comparing a function against its reversed form, if we have a
9460 // better conversion for one argument and a worse conversion for the
9461 // other, we prefer the non-reversed form.
9463 // This prevents a conversion function from being considered ambiguous
9464 // with its own reversed form in various where it's only incidentally
9467 // We diagnose this as an extension from CreateOverloadedBinOp.
9468 HasWorseConversion = true;
9472 // Cand1 can't be better than Cand2.
9475 case ImplicitConversionSequence::Indistinguishable:
9481 // -- for some argument j, ICSj(F1) is a better conversion sequence than
9482 // ICSj(F2), or, if not that,
9483 if (HasBetterConversion)
9485 if (HasWorseConversion)
9488 // -- the context is an initialization by user-defined conversion
9489 // (see 8.5, 13.3.1.5) and the standard conversion sequence
9490 // from the return type of F1 to the destination type (i.e.,
9491 // the type of the entity being initialized) is a better
9492 // conversion sequence than the standard conversion sequence
9493 // from the return type of F2 to the destination type.
9494 if (Kind == OverloadCandidateSet::CSK_InitByUserDefinedConversion &&
9495 Cand1.Function && Cand2.Function &&
9496 isa<CXXConversionDecl>(Cand1.Function) &&
9497 isa<CXXConversionDecl>(Cand2.Function)) {
9498 // First check whether we prefer one of the conversion functions over the
9499 // other. This only distinguishes the results in non-standard, extension
9500 // cases such as the conversion from a lambda closure type to a function
9501 // pointer or block.
9502 ImplicitConversionSequence::CompareKind Result =
9503 compareConversionFunctions(S, Cand1.Function, Cand2.Function);
9504 if (Result == ImplicitConversionSequence::Indistinguishable)
9505 Result = CompareStandardConversionSequences(S, Loc,
9506 Cand1.FinalConversion,
9507 Cand2.FinalConversion);
9509 if (Result != ImplicitConversionSequence::Indistinguishable)
9510 return Result == ImplicitConversionSequence::Better;
9512 // FIXME: Compare kind of reference binding if conversion functions
9513 // convert to a reference type used in direct reference binding, per
9514 // C++14 [over.match.best]p1 section 2 bullet 3.
9517 // FIXME: Work around a defect in the C++17 guaranteed copy elision wording,
9518 // as combined with the resolution to CWG issue 243.
9520 // When the context is initialization by constructor ([over.match.ctor] or
9521 // either phase of [over.match.list]), a constructor is preferred over
9522 // a conversion function.
9523 if (Kind == OverloadCandidateSet::CSK_InitByConstructor && NumArgs == 1 &&
9524 Cand1.Function && Cand2.Function &&
9525 isa<CXXConstructorDecl>(Cand1.Function) !=
9526 isa<CXXConstructorDecl>(Cand2.Function))
9527 return isa<CXXConstructorDecl>(Cand1.Function);
9529 // -- F1 is a non-template function and F2 is a function template
9530 // specialization, or, if not that,
9531 bool Cand1IsSpecialization = Cand1.Function &&
9532 Cand1.Function->getPrimaryTemplate();
9533 bool Cand2IsSpecialization = Cand2.Function &&
9534 Cand2.Function->getPrimaryTemplate();
9535 if (Cand1IsSpecialization != Cand2IsSpecialization)
9536 return Cand2IsSpecialization;
9538 // -- F1 and F2 are function template specializations, and the function
9539 // template for F1 is more specialized than the template for F2
9540 // according to the partial ordering rules described in 14.5.5.2, or,
9542 if (Cand1IsSpecialization && Cand2IsSpecialization) {
9543 if (FunctionTemplateDecl *BetterTemplate
9544 = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(),
9545 Cand2.Function->getPrimaryTemplate(),
9547 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion
9549 Cand1.ExplicitCallArguments,
9550 Cand2.ExplicitCallArguments))
9551 return BetterTemplate == Cand1.Function->getPrimaryTemplate();
9554 // -— F1 and F2 are non-template functions with the same
9555 // parameter-type-lists, and F1 is more constrained than F2 [...],
9556 if (Cand1.Function && Cand2.Function && !Cand1IsSpecialization &&
9557 !Cand2IsSpecialization && Cand1.Function->hasPrototype() &&
9558 Cand2.Function->hasPrototype()) {
9559 auto *PT1 = cast<FunctionProtoType>(Cand1.Function->getFunctionType());
9560 auto *PT2 = cast<FunctionProtoType>(Cand2.Function->getFunctionType());
9561 if (PT1->getNumParams() == PT2->getNumParams() &&
9562 PT1->isVariadic() == PT2->isVariadic() &&
9563 S.FunctionParamTypesAreEqual(PT1, PT2)) {
9564 Expr *RC1 = Cand1.Function->getTrailingRequiresClause();
9565 Expr *RC2 = Cand2.Function->getTrailingRequiresClause();
9567 bool AtLeastAsConstrained1, AtLeastAsConstrained2;
9568 if (S.IsAtLeastAsConstrained(Cand1.Function, {RC1}, Cand2.Function,
9569 {RC2}, AtLeastAsConstrained1))
9571 if (!AtLeastAsConstrained1)
9573 if (S.IsAtLeastAsConstrained(Cand2.Function, {RC2}, Cand1.Function,
9574 {RC1}, AtLeastAsConstrained2))
9576 if (!AtLeastAsConstrained2)
9578 } else if (RC1 || RC2)
9579 return RC1 != nullptr;
9583 // -- F1 is a constructor for a class D, F2 is a constructor for a base
9584 // class B of D, and for all arguments the corresponding parameters of
9585 // F1 and F2 have the same type.
9586 // FIXME: Implement the "all parameters have the same type" check.
9587 bool Cand1IsInherited =
9588 dyn_cast_or_null<ConstructorUsingShadowDecl>(Cand1.FoundDecl.getDecl());
9589 bool Cand2IsInherited =
9590 dyn_cast_or_null<ConstructorUsingShadowDecl>(Cand2.FoundDecl.getDecl());
9591 if (Cand1IsInherited != Cand2IsInherited)
9592 return Cand2IsInherited;
9593 else if (Cand1IsInherited) {
9594 assert(Cand2IsInherited);
9595 auto *Cand1Class = cast<CXXRecordDecl>(Cand1.Function->getDeclContext());
9596 auto *Cand2Class = cast<CXXRecordDecl>(Cand2.Function->getDeclContext());
9597 if (Cand1Class->isDerivedFrom(Cand2Class))
9599 if (Cand2Class->isDerivedFrom(Cand1Class))
9601 // Inherited from sibling base classes: still ambiguous.
9604 // -- F2 is a rewritten candidate (12.4.1.2) and F1 is not
9605 // -- F1 and F2 are rewritten candidates, and F2 is a synthesized candidate
9606 // with reversed order of parameters and F1 is not
9608 // We rank reversed + different operator as worse than just reversed, but
9609 // that comparison can never happen, because we only consider reversing for
9610 // the maximally-rewritten operator (== or <=>).
9611 if (Cand1.RewriteKind != Cand2.RewriteKind)
9612 return Cand1.RewriteKind < Cand2.RewriteKind;
9614 // Check C++17 tie-breakers for deduction guides.
9616 auto *Guide1 = dyn_cast_or_null<CXXDeductionGuideDecl>(Cand1.Function);
9617 auto *Guide2 = dyn_cast_or_null<CXXDeductionGuideDecl>(Cand2.Function);
9618 if (Guide1 && Guide2) {
9619 // -- F1 is generated from a deduction-guide and F2 is not
9620 if (Guide1->isImplicit() != Guide2->isImplicit())
9621 return Guide2->isImplicit();
9623 // -- F1 is the copy deduction candidate(16.3.1.8) and F2 is not
9624 if (Guide1->isCopyDeductionCandidate())
9629 // Check for enable_if value-based overload resolution.
9630 if (Cand1.Function && Cand2.Function) {
9631 Comparison Cmp = compareEnableIfAttrs(S, Cand1.Function, Cand2.Function);
9632 if (Cmp != Comparison::Equal)
9633 return Cmp == Comparison::Better;
9636 if (S.getLangOpts().CUDA && Cand1.Function && Cand2.Function) {
9637 FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext);
9638 return S.IdentifyCUDAPreference(Caller, Cand1.Function) >
9639 S.IdentifyCUDAPreference(Caller, Cand2.Function);
9642 bool HasPS1 = Cand1.Function != nullptr &&
9643 functionHasPassObjectSizeParams(Cand1.Function);
9644 bool HasPS2 = Cand2.Function != nullptr &&
9645 functionHasPassObjectSizeParams(Cand2.Function);
9646 if (HasPS1 != HasPS2 && HasPS1)
9649 return isBetterMultiversionCandidate(Cand1, Cand2);
9652 /// Determine whether two declarations are "equivalent" for the purposes of
9653 /// name lookup and overload resolution. This applies when the same internal/no
9654 /// linkage entity is defined by two modules (probably by textually including
9655 /// the same header). In such a case, we don't consider the declarations to
9656 /// declare the same entity, but we also don't want lookups with both
9657 /// declarations visible to be ambiguous in some cases (this happens when using
9658 /// a modularized libstdc++).
9659 bool Sema::isEquivalentInternalLinkageDeclaration(const NamedDecl *A,
9660 const NamedDecl *B) {
9661 auto *VA = dyn_cast_or_null<ValueDecl>(A);
9662 auto *VB = dyn_cast_or_null<ValueDecl>(B);
9666 // The declarations must be declaring the same name as an internal linkage
9667 // entity in different modules.
9668 if (!VA->getDeclContext()->getRedeclContext()->Equals(
9669 VB->getDeclContext()->getRedeclContext()) ||
9670 getOwningModule(VA) == getOwningModule(VB) ||
9671 VA->isExternallyVisible() || VB->isExternallyVisible())
9674 // Check that the declarations appear to be equivalent.
9676 // FIXME: Checking the type isn't really enough to resolve the ambiguity.
9677 // For constants and functions, we should check the initializer or body is
9678 // the same. For non-constant variables, we shouldn't allow it at all.
9679 if (Context.hasSameType(VA->getType(), VB->getType()))
9682 // Enum constants within unnamed enumerations will have different types, but
9683 // may still be similar enough to be interchangeable for our purposes.
9684 if (auto *EA = dyn_cast<EnumConstantDecl>(VA)) {
9685 if (auto *EB = dyn_cast<EnumConstantDecl>(VB)) {
9686 // Only handle anonymous enums. If the enumerations were named and
9687 // equivalent, they would have been merged to the same type.
9688 auto *EnumA = cast<EnumDecl>(EA->getDeclContext());
9689 auto *EnumB = cast<EnumDecl>(EB->getDeclContext());
9690 if (EnumA->hasNameForLinkage() || EnumB->hasNameForLinkage() ||
9691 !Context.hasSameType(EnumA->getIntegerType(),
9692 EnumB->getIntegerType()))
9694 // Allow this only if the value is the same for both enumerators.
9695 return llvm::APSInt::isSameValue(EA->getInitVal(), EB->getInitVal());
9699 // Nothing else is sufficiently similar.
9703 void Sema::diagnoseEquivalentInternalLinkageDeclarations(
9704 SourceLocation Loc, const NamedDecl *D, ArrayRef<const NamedDecl *> Equiv) {
9705 Diag(Loc, diag::ext_equivalent_internal_linkage_decl_in_modules) << D;
9707 Module *M = getOwningModule(D);
9708 Diag(D->getLocation(), diag::note_equivalent_internal_linkage_decl)
9709 << !M << (M ? M->getFullModuleName() : "");
9711 for (auto *E : Equiv) {
9712 Module *M = getOwningModule(E);
9713 Diag(E->getLocation(), diag::note_equivalent_internal_linkage_decl)
9714 << !M << (M ? M->getFullModuleName() : "");
9718 /// Computes the best viable function (C++ 13.3.3)
9719 /// within an overload candidate set.
9721 /// \param Loc The location of the function name (or operator symbol) for
9722 /// which overload resolution occurs.
9724 /// \param Best If overload resolution was successful or found a deleted
9725 /// function, \p Best points to the candidate function found.
9727 /// \returns The result of overload resolution.
9729 OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc,
9731 llvm::SmallVector<OverloadCandidate *, 16> Candidates;
9732 std::transform(begin(), end(), std::back_inserter(Candidates),
9733 [](OverloadCandidate &Cand) { return &Cand; });
9735 // [CUDA] HD->H or HD->D calls are technically not allowed by CUDA but
9736 // are accepted by both clang and NVCC. However, during a particular
9737 // compilation mode only one call variant is viable. We need to
9738 // exclude non-viable overload candidates from consideration based
9739 // only on their host/device attributes. Specifically, if one
9740 // candidate call is WrongSide and the other is SameSide, we ignore
9741 // the WrongSide candidate.
9742 if (S.getLangOpts().CUDA) {
9743 const FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext);
9744 bool ContainsSameSideCandidate =
9745 llvm::any_of(Candidates, [&](OverloadCandidate *Cand) {
9746 // Check viable function only.
9747 return Cand->Viable && Cand->Function &&
9748 S.IdentifyCUDAPreference(Caller, Cand->Function) ==
9751 if (ContainsSameSideCandidate) {
9752 auto IsWrongSideCandidate = [&](OverloadCandidate *Cand) {
9753 // Check viable function only to avoid unnecessary data copying/moving.
9754 return Cand->Viable && Cand->Function &&
9755 S.IdentifyCUDAPreference(Caller, Cand->Function) ==
9756 Sema::CFP_WrongSide;
9758 llvm::erase_if(Candidates, IsWrongSideCandidate);
9762 // Find the best viable function.
9764 for (auto *Cand : Candidates) {
9767 if (Best == end() ||
9768 isBetterOverloadCandidate(S, *Cand, *Best, Loc, Kind))
9772 // If we didn't find any viable functions, abort.
9774 return OR_No_Viable_Function;
9776 llvm::SmallVector<const NamedDecl *, 4> EquivalentCands;
9778 llvm::SmallVector<OverloadCandidate*, 4> PendingBest;
9779 PendingBest.push_back(&*Best);
9782 // Make sure that this function is better than every other viable
9783 // function. If not, we have an ambiguity.
9784 while (!PendingBest.empty()) {
9785 auto *Curr = PendingBest.pop_back_val();
9786 for (auto *Cand : Candidates) {
9787 if (Cand->Viable && !Cand->Best &&
9788 !isBetterOverloadCandidate(S, *Curr, *Cand, Loc, Kind)) {
9789 PendingBest.push_back(Cand);
9792 if (S.isEquivalentInternalLinkageDeclaration(Cand->Function,
9794 EquivalentCands.push_back(Cand->Function);
9801 // If we found more than one best candidate, this is ambiguous.
9803 return OR_Ambiguous;
9805 // Best is the best viable function.
9806 if (Best->Function && Best->Function->isDeleted())
9809 if (!EquivalentCands.empty())
9810 S.diagnoseEquivalentInternalLinkageDeclarations(Loc, Best->Function,
9818 enum OverloadCandidateKind {
9821 oc_reversed_binary_operator,
9823 oc_implicit_default_constructor,
9824 oc_implicit_copy_constructor,
9825 oc_implicit_move_constructor,
9826 oc_implicit_copy_assignment,
9827 oc_implicit_move_assignment,
9828 oc_implicit_equality_comparison,
9829 oc_inherited_constructor
9832 enum OverloadCandidateSelect {
9835 ocs_described_template,
9838 static std::pair<OverloadCandidateKind, OverloadCandidateSelect>
9839 ClassifyOverloadCandidate(Sema &S, NamedDecl *Found, FunctionDecl *Fn,
9840 OverloadCandidateRewriteKind CRK,
9841 std::string &Description) {
9843 bool isTemplate = Fn->isTemplateDecl() || Found->isTemplateDecl();
9844 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) {
9846 Description = S.getTemplateArgumentBindingsText(
9847 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs());
9850 OverloadCandidateSelect Select = [&]() {
9851 if (!Description.empty())
9852 return ocs_described_template;
9853 return isTemplate ? ocs_template : ocs_non_template;
9856 OverloadCandidateKind Kind = [&]() {
9857 if (Fn->isImplicit() && Fn->getOverloadedOperator() == OO_EqualEqual)
9858 return oc_implicit_equality_comparison;
9860 if (CRK & CRK_Reversed)
9861 return oc_reversed_binary_operator;
9863 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) {
9864 if (!Ctor->isImplicit()) {
9865 if (isa<ConstructorUsingShadowDecl>(Found))
9866 return oc_inherited_constructor;
9868 return oc_constructor;
9871 if (Ctor->isDefaultConstructor())
9872 return oc_implicit_default_constructor;
9874 if (Ctor->isMoveConstructor())
9875 return oc_implicit_move_constructor;
9877 assert(Ctor->isCopyConstructor() &&
9878 "unexpected sort of implicit constructor");
9879 return oc_implicit_copy_constructor;
9882 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) {
9883 // This actually gets spelled 'candidate function' for now, but
9884 // it doesn't hurt to split it out.
9885 if (!Meth->isImplicit())
9888 if (Meth->isMoveAssignmentOperator())
9889 return oc_implicit_move_assignment;
9891 if (Meth->isCopyAssignmentOperator())
9892 return oc_implicit_copy_assignment;
9894 assert(isa<CXXConversionDecl>(Meth) && "expected conversion");
9901 return std::make_pair(Kind, Select);
9904 void MaybeEmitInheritedConstructorNote(Sema &S, Decl *FoundDecl) {
9905 // FIXME: It'd be nice to only emit a note once per using-decl per overload
9907 if (auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(FoundDecl))
9908 S.Diag(FoundDecl->getLocation(),
9909 diag::note_ovl_candidate_inherited_constructor)
9910 << Shadow->getNominatedBaseClass();
9913 } // end anonymous namespace
9915 static bool isFunctionAlwaysEnabled(const ASTContext &Ctx,
9916 const FunctionDecl *FD) {
9917 for (auto *EnableIf : FD->specific_attrs<EnableIfAttr>()) {
9919 if (EnableIf->getCond()->isValueDependent() ||
9920 !EnableIf->getCond()->EvaluateAsBooleanCondition(AlwaysTrue, Ctx))
9928 /// Returns true if we can take the address of the function.
9930 /// \param Complain - If true, we'll emit a diagnostic
9931 /// \param InOverloadResolution - For the purposes of emitting a diagnostic, are
9932 /// we in overload resolution?
9933 /// \param Loc - The location of the statement we're complaining about. Ignored
9934 /// if we're not complaining, or if we're in overload resolution.
9935 static bool checkAddressOfFunctionIsAvailable(Sema &S, const FunctionDecl *FD,
9937 bool InOverloadResolution,
9938 SourceLocation Loc) {
9939 if (!isFunctionAlwaysEnabled(S.Context, FD)) {
9941 if (InOverloadResolution)
9942 S.Diag(FD->getBeginLoc(),
9943 diag::note_addrof_ovl_candidate_disabled_by_enable_if_attr);
9945 S.Diag(Loc, diag::err_addrof_function_disabled_by_enable_if_attr) << FD;
9950 if (const Expr *RC = FD->getTrailingRequiresClause()) {
9951 ConstraintSatisfaction Satisfaction;
9952 if (S.CheckConstraintSatisfaction(RC, Satisfaction))
9954 if (!Satisfaction.IsSatisfied) {
9956 if (InOverloadResolution)
9957 S.Diag(FD->getBeginLoc(),
9958 diag::note_ovl_candidate_unsatisfied_constraints);
9960 S.Diag(Loc, diag::err_addrof_function_constraints_not_satisfied)
9962 S.DiagnoseUnsatisfiedConstraint(Satisfaction);
9968 auto I = llvm::find_if(FD->parameters(), [](const ParmVarDecl *P) {
9969 return P->hasAttr<PassObjectSizeAttr>();
9971 if (I == FD->param_end())
9975 // Add one to ParamNo because it's user-facing
9976 unsigned ParamNo = std::distance(FD->param_begin(), I) + 1;
9977 if (InOverloadResolution)
9978 S.Diag(FD->getLocation(),
9979 diag::note_ovl_candidate_has_pass_object_size_params)
9982 S.Diag(Loc, diag::err_address_of_function_with_pass_object_size_params)
9988 static bool checkAddressOfCandidateIsAvailable(Sema &S,
9989 const FunctionDecl *FD) {
9990 return checkAddressOfFunctionIsAvailable(S, FD, /*Complain=*/true,
9991 /*InOverloadResolution=*/true,
9992 /*Loc=*/SourceLocation());
9995 bool Sema::checkAddressOfFunctionIsAvailable(const FunctionDecl *Function,
9997 SourceLocation Loc) {
9998 return ::checkAddressOfFunctionIsAvailable(*this, Function, Complain,
9999 /*InOverloadResolution=*/false,
10003 // Notes the location of an overload candidate.
10004 void Sema::NoteOverloadCandidate(NamedDecl *Found, FunctionDecl *Fn,
10005 OverloadCandidateRewriteKind RewriteKind,
10006 QualType DestType, bool TakingAddress) {
10007 if (TakingAddress && !checkAddressOfCandidateIsAvailable(*this, Fn))
10009 if (Fn->isMultiVersion() && Fn->hasAttr<TargetAttr>() &&
10010 !Fn->getAttr<TargetAttr>()->isDefaultVersion())
10013 std::string FnDesc;
10014 std::pair<OverloadCandidateKind, OverloadCandidateSelect> KSPair =
10015 ClassifyOverloadCandidate(*this, Found, Fn, RewriteKind, FnDesc);
10016 PartialDiagnostic PD = PDiag(diag::note_ovl_candidate)
10017 << (unsigned)KSPair.first << (unsigned)KSPair.second
10020 HandleFunctionTypeMismatch(PD, Fn->getType(), DestType);
10021 Diag(Fn->getLocation(), PD);
10022 MaybeEmitInheritedConstructorNote(*this, Found);
10026 MaybeDiagnoseAmbiguousConstraints(Sema &S, ArrayRef<OverloadCandidate> Cands) {
10027 // Perhaps the ambiguity was caused by two atomic constraints that are
10028 // 'identical' but not equivalent:
10030 // void foo() requires (sizeof(T) > 4) { } // #1
10031 // void foo() requires (sizeof(T) > 4) && T::value { } // #2
10033 // The 'sizeof(T) > 4' constraints are seemingly equivalent and should cause
10034 // #2 to subsume #1, but these constraint are not considered equivalent
10035 // according to the subsumption rules because they are not the same
10036 // source-level construct. This behavior is quite confusing and we should try
10037 // to help the user figure out what happened.
10039 SmallVector<const Expr *, 3> FirstAC, SecondAC;
10040 FunctionDecl *FirstCand = nullptr, *SecondCand = nullptr;
10041 for (auto I = Cands.begin(), E = Cands.end(); I != E; ++I) {
10044 SmallVector<const Expr *, 3> AC;
10045 if (auto *Template = I->Function->getPrimaryTemplate())
10046 Template->getAssociatedConstraints(AC);
10048 I->Function->getAssociatedConstraints(AC);
10051 if (FirstCand == nullptr) {
10052 FirstCand = I->Function;
10054 } else if (SecondCand == nullptr) {
10055 SecondCand = I->Function;
10058 // We have more than one pair of constrained functions - this check is
10059 // expensive and we'd rather not try to diagnose it.
10065 // The diagnostic can only happen if there are associated constraints on
10066 // both sides (there needs to be some identical atomic constraint).
10067 if (S.MaybeEmitAmbiguousAtomicConstraintsDiagnostic(FirstCand, FirstAC,
10068 SecondCand, SecondAC))
10069 // Just show the user one diagnostic, they'll probably figure it out
10074 // Notes the location of all overload candidates designated through
10076 void Sema::NoteAllOverloadCandidates(Expr *OverloadedExpr, QualType DestType,
10077 bool TakingAddress) {
10078 assert(OverloadedExpr->getType() == Context.OverloadTy);
10080 OverloadExpr::FindResult Ovl = OverloadExpr::find(OverloadedExpr);
10081 OverloadExpr *OvlExpr = Ovl.Expression;
10083 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
10084 IEnd = OvlExpr->decls_end();
10086 if (FunctionTemplateDecl *FunTmpl =
10087 dyn_cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()) ) {
10088 NoteOverloadCandidate(*I, FunTmpl->getTemplatedDecl(), CRK_None, DestType,
10090 } else if (FunctionDecl *Fun
10091 = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()) ) {
10092 NoteOverloadCandidate(*I, Fun, CRK_None, DestType, TakingAddress);
10097 /// Diagnoses an ambiguous conversion. The partial diagnostic is the
10098 /// "lead" diagnostic; it will be given two arguments, the source and
10099 /// target types of the conversion.
10100 void ImplicitConversionSequence::DiagnoseAmbiguousConversion(
10102 SourceLocation CaretLoc,
10103 const PartialDiagnostic &PDiag) const {
10104 S.Diag(CaretLoc, PDiag)
10105 << Ambiguous.getFromType() << Ambiguous.getToType();
10106 // FIXME: The note limiting machinery is borrowed from
10107 // OverloadCandidateSet::NoteCandidates; there's an opportunity for
10108 // refactoring here.
10109 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
10110 unsigned CandsShown = 0;
10111 AmbiguousConversionSequence::const_iterator I, E;
10112 for (I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) {
10113 if (CandsShown >= 4 && ShowOverloads == Ovl_Best)
10116 S.NoteOverloadCandidate(I->first, I->second);
10119 S.Diag(SourceLocation(), diag::note_ovl_too_many_candidates) << int(E - I);
10122 static void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand,
10123 unsigned I, bool TakingCandidateAddress) {
10124 const ImplicitConversionSequence &Conv = Cand->Conversions[I];
10125 assert(Conv.isBad());
10126 assert(Cand->Function && "for now, candidate must be a function");
10127 FunctionDecl *Fn = Cand->Function;
10129 // There's a conversion slot for the object argument if this is a
10130 // non-constructor method. Note that 'I' corresponds the
10131 // conversion-slot index.
10132 bool isObjectArgument = false;
10133 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) {
10135 isObjectArgument = true;
10140 std::string FnDesc;
10141 std::pair<OverloadCandidateKind, OverloadCandidateSelect> FnKindPair =
10142 ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn, Cand->getRewriteKind(),
10145 Expr *FromExpr = Conv.Bad.FromExpr;
10146 QualType FromTy = Conv.Bad.getFromType();
10147 QualType ToTy = Conv.Bad.getToType();
10149 if (FromTy == S.Context.OverloadTy) {
10150 assert(FromExpr && "overload set argument came from implicit argument?");
10151 Expr *E = FromExpr->IgnoreParens();
10152 if (isa<UnaryOperator>(E))
10153 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens();
10154 DeclarationName Name = cast<OverloadExpr>(E)->getName();
10156 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload)
10157 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10158 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << ToTy
10160 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10164 // Do some hand-waving analysis to see if the non-viability is due
10165 // to a qualifier mismatch.
10166 CanQualType CFromTy = S.Context.getCanonicalType(FromTy);
10167 CanQualType CToTy = S.Context.getCanonicalType(ToTy);
10168 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>())
10169 CToTy = RT->getPointeeType();
10171 // TODO: detect and diagnose the full richness of const mismatches.
10172 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>())
10173 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) {
10174 CFromTy = FromPT->getPointeeType();
10175 CToTy = ToPT->getPointeeType();
10179 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() &&
10180 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) {
10181 Qualifiers FromQs = CFromTy.getQualifiers();
10182 Qualifiers ToQs = CToTy.getQualifiers();
10184 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) {
10185 if (isObjectArgument)
10186 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace_this)
10187 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second
10188 << FnDesc << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
10189 << FromQs.getAddressSpace() << ToQs.getAddressSpace();
10191 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace)
10192 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second
10193 << FnDesc << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
10194 << FromQs.getAddressSpace() << ToQs.getAddressSpace()
10195 << ToTy->isReferenceType() << I + 1;
10196 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10200 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) {
10201 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_ownership)
10202 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10203 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
10204 << FromQs.getObjCLifetime() << ToQs.getObjCLifetime()
10205 << (unsigned)isObjectArgument << I + 1;
10206 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10210 if (FromQs.getObjCGCAttr() != ToQs.getObjCGCAttr()) {
10211 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_gc)
10212 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10213 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
10214 << FromQs.getObjCGCAttr() << ToQs.getObjCGCAttr()
10215 << (unsigned)isObjectArgument << I + 1;
10216 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10220 if (FromQs.hasUnaligned() != ToQs.hasUnaligned()) {
10221 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_unaligned)
10222 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10223 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
10224 << FromQs.hasUnaligned() << I + 1;
10225 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10229 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers();
10230 assert(CVR && "unexpected qualifiers mismatch");
10232 if (isObjectArgument) {
10233 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this)
10234 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10235 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
10238 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr)
10239 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10240 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
10241 << (CVR - 1) << I + 1;
10243 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10247 // Special diagnostic for failure to convert an initializer list, since
10248 // telling the user that it has type void is not useful.
10249 if (FromExpr && isa<InitListExpr>(FromExpr)) {
10250 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_list_argument)
10251 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10252 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
10253 << ToTy << (unsigned)isObjectArgument << I + 1;
10254 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10258 // Diagnose references or pointers to incomplete types differently,
10259 // since it's far from impossible that the incompleteness triggered
10261 QualType TempFromTy = FromTy.getNonReferenceType();
10262 if (const PointerType *PTy = TempFromTy->getAs<PointerType>())
10263 TempFromTy = PTy->getPointeeType();
10264 if (TempFromTy->isIncompleteType()) {
10265 // Emit the generic diagnostic and, optionally, add the hints to it.
10266 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete)
10267 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10268 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
10269 << ToTy << (unsigned)isObjectArgument << I + 1
10270 << (unsigned)(Cand->Fix.Kind);
10272 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10276 // Diagnose base -> derived pointer conversions.
10277 unsigned BaseToDerivedConversion = 0;
10278 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) {
10279 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) {
10280 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs(
10281 FromPtrTy->getPointeeType()) &&
10282 !FromPtrTy->getPointeeType()->isIncompleteType() &&
10283 !ToPtrTy->getPointeeType()->isIncompleteType() &&
10284 S.IsDerivedFrom(SourceLocation(), ToPtrTy->getPointeeType(),
10285 FromPtrTy->getPointeeType()))
10286 BaseToDerivedConversion = 1;
10288 } else if (const ObjCObjectPointerType *FromPtrTy
10289 = FromTy->getAs<ObjCObjectPointerType>()) {
10290 if (const ObjCObjectPointerType *ToPtrTy
10291 = ToTy->getAs<ObjCObjectPointerType>())
10292 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl())
10293 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl())
10294 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs(
10295 FromPtrTy->getPointeeType()) &&
10296 FromIface->isSuperClassOf(ToIface))
10297 BaseToDerivedConversion = 2;
10298 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) {
10299 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) &&
10300 !FromTy->isIncompleteType() &&
10301 !ToRefTy->getPointeeType()->isIncompleteType() &&
10302 S.IsDerivedFrom(SourceLocation(), ToRefTy->getPointeeType(), FromTy)) {
10303 BaseToDerivedConversion = 3;
10304 } else if (ToTy->isLValueReferenceType() && !FromExpr->isLValue() &&
10305 ToTy.getNonReferenceType().getCanonicalType() ==
10306 FromTy.getNonReferenceType().getCanonicalType()) {
10307 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_lvalue)
10308 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10309 << (unsigned)isObjectArgument << I + 1
10310 << (FromExpr ? FromExpr->getSourceRange() : SourceRange());
10311 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10316 if (BaseToDerivedConversion) {
10317 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_base_to_derived_conv)
10318 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10319 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
10320 << (BaseToDerivedConversion - 1) << FromTy << ToTy << I + 1;
10321 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10325 if (isa<ObjCObjectPointerType>(CFromTy) &&
10326 isa<PointerType>(CToTy)) {
10327 Qualifiers FromQs = CFromTy.getQualifiers();
10328 Qualifiers ToQs = CToTy.getQualifiers();
10329 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) {
10330 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_arc_conv)
10331 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second
10332 << FnDesc << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
10333 << FromTy << ToTy << (unsigned)isObjectArgument << I + 1;
10334 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10339 if (TakingCandidateAddress &&
10340 !checkAddressOfCandidateIsAvailable(S, Cand->Function))
10343 // Emit the generic diagnostic and, optionally, add the hints to it.
10344 PartialDiagnostic FDiag = S.PDiag(diag::note_ovl_candidate_bad_conv);
10345 FDiag << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10346 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy
10347 << ToTy << (unsigned)isObjectArgument << I + 1
10348 << (unsigned)(Cand->Fix.Kind);
10350 // If we can fix the conversion, suggest the FixIts.
10351 for (std::vector<FixItHint>::iterator HI = Cand->Fix.Hints.begin(),
10352 HE = Cand->Fix.Hints.end(); HI != HE; ++HI)
10354 S.Diag(Fn->getLocation(), FDiag);
10356 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10359 /// Additional arity mismatch diagnosis specific to a function overload
10360 /// candidates. This is not covered by the more general DiagnoseArityMismatch()
10361 /// over a candidate in any candidate set.
10362 static bool CheckArityMismatch(Sema &S, OverloadCandidate *Cand,
10363 unsigned NumArgs) {
10364 FunctionDecl *Fn = Cand->Function;
10365 unsigned MinParams = Fn->getMinRequiredArguments();
10367 // With invalid overloaded operators, it's possible that we think we
10368 // have an arity mismatch when in fact it looks like we have the
10369 // right number of arguments, because only overloaded operators have
10370 // the weird behavior of overloading member and non-member functions.
10371 // Just don't report anything.
10372 if (Fn->isInvalidDecl() &&
10373 Fn->getDeclName().getNameKind() == DeclarationName::CXXOperatorName)
10376 if (NumArgs < MinParams) {
10377 assert((Cand->FailureKind == ovl_fail_too_few_arguments) ||
10378 (Cand->FailureKind == ovl_fail_bad_deduction &&
10379 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments));
10381 assert((Cand->FailureKind == ovl_fail_too_many_arguments) ||
10382 (Cand->FailureKind == ovl_fail_bad_deduction &&
10383 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments));
10389 /// General arity mismatch diagnosis over a candidate in a candidate set.
10390 static void DiagnoseArityMismatch(Sema &S, NamedDecl *Found, Decl *D,
10391 unsigned NumFormalArgs) {
10392 assert(isa<FunctionDecl>(D) &&
10393 "The templated declaration should at least be a function"
10394 " when diagnosing bad template argument deduction due to too many"
10395 " or too few arguments");
10397 FunctionDecl *Fn = cast<FunctionDecl>(D);
10399 // TODO: treat calls to a missing default constructor as a special case
10400 const auto *FnTy = Fn->getType()->castAs<FunctionProtoType>();
10401 unsigned MinParams = Fn->getMinRequiredArguments();
10403 // at least / at most / exactly
10404 unsigned mode, modeCount;
10405 if (NumFormalArgs < MinParams) {
10406 if (MinParams != FnTy->getNumParams() || FnTy->isVariadic() ||
10407 FnTy->isTemplateVariadic())
10408 mode = 0; // "at least"
10410 mode = 2; // "exactly"
10411 modeCount = MinParams;
10413 if (MinParams != FnTy->getNumParams())
10414 mode = 1; // "at most"
10416 mode = 2; // "exactly"
10417 modeCount = FnTy->getNumParams();
10420 std::string Description;
10421 std::pair<OverloadCandidateKind, OverloadCandidateSelect> FnKindPair =
10422 ClassifyOverloadCandidate(S, Found, Fn, CRK_None, Description);
10424 if (modeCount == 1 && Fn->getParamDecl(0)->getDeclName())
10425 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity_one)
10426 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second
10427 << Description << mode << Fn->getParamDecl(0) << NumFormalArgs;
10429 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity)
10430 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second
10431 << Description << mode << modeCount << NumFormalArgs;
10433 MaybeEmitInheritedConstructorNote(S, Found);
10436 /// Arity mismatch diagnosis specific to a function overload candidate.
10437 static void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand,
10438 unsigned NumFormalArgs) {
10439 if (!CheckArityMismatch(S, Cand, NumFormalArgs))
10440 DiagnoseArityMismatch(S, Cand->FoundDecl, Cand->Function, NumFormalArgs);
10443 static TemplateDecl *getDescribedTemplate(Decl *Templated) {
10444 if (TemplateDecl *TD = Templated->getDescribedTemplate())
10446 llvm_unreachable("Unsupported: Getting the described template declaration"
10447 " for bad deduction diagnosis");
10450 /// Diagnose a failed template-argument deduction.
10451 static void DiagnoseBadDeduction(Sema &S, NamedDecl *Found, Decl *Templated,
10452 DeductionFailureInfo &DeductionFailure,
10454 bool TakingCandidateAddress) {
10455 TemplateParameter Param = DeductionFailure.getTemplateParameter();
10457 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) ||
10458 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) ||
10459 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>());
10460 switch (DeductionFailure.Result) {
10461 case Sema::TDK_Success:
10462 llvm_unreachable("TDK_success while diagnosing bad deduction");
10464 case Sema::TDK_Incomplete: {
10465 assert(ParamD && "no parameter found for incomplete deduction result");
10466 S.Diag(Templated->getLocation(),
10467 diag::note_ovl_candidate_incomplete_deduction)
10468 << ParamD->getDeclName();
10469 MaybeEmitInheritedConstructorNote(S, Found);
10473 case Sema::TDK_IncompletePack: {
10474 assert(ParamD && "no parameter found for incomplete deduction result");
10475 S.Diag(Templated->getLocation(),
10476 diag::note_ovl_candidate_incomplete_deduction_pack)
10477 << ParamD->getDeclName()
10478 << (DeductionFailure.getFirstArg()->pack_size() + 1)
10479 << *DeductionFailure.getFirstArg();
10480 MaybeEmitInheritedConstructorNote(S, Found);
10484 case Sema::TDK_Underqualified: {
10485 assert(ParamD && "no parameter found for bad qualifiers deduction result");
10486 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD);
10488 QualType Param = DeductionFailure.getFirstArg()->getAsType();
10490 // Param will have been canonicalized, but it should just be a
10491 // qualified version of ParamD, so move the qualifiers to that.
10492 QualifierCollector Qs;
10494 QualType NonCanonParam = Qs.apply(S.Context, TParam->getTypeForDecl());
10495 assert(S.Context.hasSameType(Param, NonCanonParam));
10497 // Arg has also been canonicalized, but there's nothing we can do
10498 // about that. It also doesn't matter as much, because it won't
10499 // have any template parameters in it (because deduction isn't
10500 // done on dependent types).
10501 QualType Arg = DeductionFailure.getSecondArg()->getAsType();
10503 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_underqualified)
10504 << ParamD->getDeclName() << Arg << NonCanonParam;
10505 MaybeEmitInheritedConstructorNote(S, Found);
10509 case Sema::TDK_Inconsistent: {
10510 assert(ParamD && "no parameter found for inconsistent deduction result");
10512 if (isa<TemplateTypeParmDecl>(ParamD))
10514 else if (isa<NonTypeTemplateParmDecl>(ParamD)) {
10515 // Deduction might have failed because we deduced arguments of two
10516 // different types for a non-type template parameter.
10517 // FIXME: Use a different TDK value for this.
10519 DeductionFailure.getFirstArg()->getNonTypeTemplateArgumentType();
10521 DeductionFailure.getSecondArg()->getNonTypeTemplateArgumentType();
10522 if (!T1.isNull() && !T2.isNull() && !S.Context.hasSameType(T1, T2)) {
10523 S.Diag(Templated->getLocation(),
10524 diag::note_ovl_candidate_inconsistent_deduction_types)
10525 << ParamD->getDeclName() << *DeductionFailure.getFirstArg() << T1
10526 << *DeductionFailure.getSecondArg() << T2;
10527 MaybeEmitInheritedConstructorNote(S, Found);
10536 // Tweak the diagnostic if the problem is that we deduced packs of
10537 // different arities. We'll print the actual packs anyway in case that
10538 // includes additional useful information.
10539 if (DeductionFailure.getFirstArg()->getKind() == TemplateArgument::Pack &&
10540 DeductionFailure.getSecondArg()->getKind() == TemplateArgument::Pack &&
10541 DeductionFailure.getFirstArg()->pack_size() !=
10542 DeductionFailure.getSecondArg()->pack_size()) {
10546 S.Diag(Templated->getLocation(),
10547 diag::note_ovl_candidate_inconsistent_deduction)
10548 << which << ParamD->getDeclName() << *DeductionFailure.getFirstArg()
10549 << *DeductionFailure.getSecondArg();
10550 MaybeEmitInheritedConstructorNote(S, Found);
10554 case Sema::TDK_InvalidExplicitArguments:
10555 assert(ParamD && "no parameter found for invalid explicit arguments");
10556 if (ParamD->getDeclName())
10557 S.Diag(Templated->getLocation(),
10558 diag::note_ovl_candidate_explicit_arg_mismatch_named)
10559 << ParamD->getDeclName();
10562 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD))
10563 index = TTP->getIndex();
10564 else if (NonTypeTemplateParmDecl *NTTP
10565 = dyn_cast<NonTypeTemplateParmDecl>(ParamD))
10566 index = NTTP->getIndex();
10568 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex();
10569 S.Diag(Templated->getLocation(),
10570 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed)
10573 MaybeEmitInheritedConstructorNote(S, Found);
10576 case Sema::TDK_ConstraintsNotSatisfied: {
10577 // Format the template argument list into the argument string.
10578 SmallString<128> TemplateArgString;
10579 TemplateArgumentList *Args = DeductionFailure.getTemplateArgumentList();
10580 TemplateArgString = " ";
10581 TemplateArgString += S.getTemplateArgumentBindingsText(
10582 getDescribedTemplate(Templated)->getTemplateParameters(), *Args);
10583 if (TemplateArgString.size() == 1)
10584 TemplateArgString.clear();
10585 S.Diag(Templated->getLocation(),
10586 diag::note_ovl_candidate_unsatisfied_constraints)
10587 << TemplateArgString;
10589 S.DiagnoseUnsatisfiedConstraint(
10590 static_cast<CNSInfo*>(DeductionFailure.Data)->Satisfaction);
10593 case Sema::TDK_TooManyArguments:
10594 case Sema::TDK_TooFewArguments:
10595 DiagnoseArityMismatch(S, Found, Templated, NumArgs);
10598 case Sema::TDK_InstantiationDepth:
10599 S.Diag(Templated->getLocation(),
10600 diag::note_ovl_candidate_instantiation_depth);
10601 MaybeEmitInheritedConstructorNote(S, Found);
10604 case Sema::TDK_SubstitutionFailure: {
10605 // Format the template argument list into the argument string.
10606 SmallString<128> TemplateArgString;
10607 if (TemplateArgumentList *Args =
10608 DeductionFailure.getTemplateArgumentList()) {
10609 TemplateArgString = " ";
10610 TemplateArgString += S.getTemplateArgumentBindingsText(
10611 getDescribedTemplate(Templated)->getTemplateParameters(), *Args);
10612 if (TemplateArgString.size() == 1)
10613 TemplateArgString.clear();
10616 // If this candidate was disabled by enable_if, say so.
10617 PartialDiagnosticAt *PDiag = DeductionFailure.getSFINAEDiagnostic();
10618 if (PDiag && PDiag->second.getDiagID() ==
10619 diag::err_typename_nested_not_found_enable_if) {
10620 // FIXME: Use the source range of the condition, and the fully-qualified
10621 // name of the enable_if template. These are both present in PDiag.
10622 S.Diag(PDiag->first, diag::note_ovl_candidate_disabled_by_enable_if)
10623 << "'enable_if'" << TemplateArgString;
10627 // We found a specific requirement that disabled the enable_if.
10628 if (PDiag && PDiag->second.getDiagID() ==
10629 diag::err_typename_nested_not_found_requirement) {
10630 S.Diag(Templated->getLocation(),
10631 diag::note_ovl_candidate_disabled_by_requirement)
10632 << PDiag->second.getStringArg(0) << TemplateArgString;
10636 // Format the SFINAE diagnostic into the argument string.
10637 // FIXME: Add a general mechanism to include a PartialDiagnostic *'s
10638 // formatted message in another diagnostic.
10639 SmallString<128> SFINAEArgString;
10642 SFINAEArgString = ": ";
10643 R = SourceRange(PDiag->first, PDiag->first);
10644 PDiag->second.EmitToString(S.getDiagnostics(), SFINAEArgString);
10647 S.Diag(Templated->getLocation(),
10648 diag::note_ovl_candidate_substitution_failure)
10649 << TemplateArgString << SFINAEArgString << R;
10650 MaybeEmitInheritedConstructorNote(S, Found);
10654 case Sema::TDK_DeducedMismatch:
10655 case Sema::TDK_DeducedMismatchNested: {
10656 // Format the template argument list into the argument string.
10657 SmallString<128> TemplateArgString;
10658 if (TemplateArgumentList *Args =
10659 DeductionFailure.getTemplateArgumentList()) {
10660 TemplateArgString = " ";
10661 TemplateArgString += S.getTemplateArgumentBindingsText(
10662 getDescribedTemplate(Templated)->getTemplateParameters(), *Args);
10663 if (TemplateArgString.size() == 1)
10664 TemplateArgString.clear();
10667 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_deduced_mismatch)
10668 << (*DeductionFailure.getCallArgIndex() + 1)
10669 << *DeductionFailure.getFirstArg() << *DeductionFailure.getSecondArg()
10670 << TemplateArgString
10671 << (DeductionFailure.Result == Sema::TDK_DeducedMismatchNested);
10675 case Sema::TDK_NonDeducedMismatch: {
10676 // FIXME: Provide a source location to indicate what we couldn't match.
10677 TemplateArgument FirstTA = *DeductionFailure.getFirstArg();
10678 TemplateArgument SecondTA = *DeductionFailure.getSecondArg();
10679 if (FirstTA.getKind() == TemplateArgument::Template &&
10680 SecondTA.getKind() == TemplateArgument::Template) {
10681 TemplateName FirstTN = FirstTA.getAsTemplate();
10682 TemplateName SecondTN = SecondTA.getAsTemplate();
10683 if (FirstTN.getKind() == TemplateName::Template &&
10684 SecondTN.getKind() == TemplateName::Template) {
10685 if (FirstTN.getAsTemplateDecl()->getName() ==
10686 SecondTN.getAsTemplateDecl()->getName()) {
10687 // FIXME: This fixes a bad diagnostic where both templates are named
10688 // the same. This particular case is a bit difficult since:
10689 // 1) It is passed as a string to the diagnostic printer.
10690 // 2) The diagnostic printer only attempts to find a better
10691 // name for types, not decls.
10692 // Ideally, this should folded into the diagnostic printer.
10693 S.Diag(Templated->getLocation(),
10694 diag::note_ovl_candidate_non_deduced_mismatch_qualified)
10695 << FirstTN.getAsTemplateDecl() << SecondTN.getAsTemplateDecl();
10701 if (TakingCandidateAddress && isa<FunctionDecl>(Templated) &&
10702 !checkAddressOfCandidateIsAvailable(S, cast<FunctionDecl>(Templated)))
10705 // FIXME: For generic lambda parameters, check if the function is a lambda
10706 // call operator, and if so, emit a prettier and more informative
10707 // diagnostic that mentions 'auto' and lambda in addition to
10708 // (or instead of?) the canonical template type parameters.
10709 S.Diag(Templated->getLocation(),
10710 diag::note_ovl_candidate_non_deduced_mismatch)
10711 << FirstTA << SecondTA;
10714 // TODO: diagnose these individually, then kill off
10715 // note_ovl_candidate_bad_deduction, which is uselessly vague.
10716 case Sema::TDK_MiscellaneousDeductionFailure:
10717 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_bad_deduction);
10718 MaybeEmitInheritedConstructorNote(S, Found);
10720 case Sema::TDK_CUDATargetMismatch:
10721 S.Diag(Templated->getLocation(),
10722 diag::note_cuda_ovl_candidate_target_mismatch);
10727 /// Diagnose a failed template-argument deduction, for function calls.
10728 static void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand,
10730 bool TakingCandidateAddress) {
10731 unsigned TDK = Cand->DeductionFailure.Result;
10732 if (TDK == Sema::TDK_TooFewArguments || TDK == Sema::TDK_TooManyArguments) {
10733 if (CheckArityMismatch(S, Cand, NumArgs))
10736 DiagnoseBadDeduction(S, Cand->FoundDecl, Cand->Function, // pattern
10737 Cand->DeductionFailure, NumArgs, TakingCandidateAddress);
10740 /// CUDA: diagnose an invalid call across targets.
10741 static void DiagnoseBadTarget(Sema &S, OverloadCandidate *Cand) {
10742 FunctionDecl *Caller = cast<FunctionDecl>(S.CurContext);
10743 FunctionDecl *Callee = Cand->Function;
10745 Sema::CUDAFunctionTarget CallerTarget = S.IdentifyCUDATarget(Caller),
10746 CalleeTarget = S.IdentifyCUDATarget(Callee);
10748 std::string FnDesc;
10749 std::pair<OverloadCandidateKind, OverloadCandidateSelect> FnKindPair =
10750 ClassifyOverloadCandidate(S, Cand->FoundDecl, Callee,
10751 Cand->getRewriteKind(), FnDesc);
10753 S.Diag(Callee->getLocation(), diag::note_ovl_candidate_bad_target)
10754 << (unsigned)FnKindPair.first << (unsigned)ocs_non_template
10755 << FnDesc /* Ignored */
10756 << CalleeTarget << CallerTarget;
10758 // This could be an implicit constructor for which we could not infer the
10759 // target due to a collsion. Diagnose that case.
10760 CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Callee);
10761 if (Meth != nullptr && Meth->isImplicit()) {
10762 CXXRecordDecl *ParentClass = Meth->getParent();
10763 Sema::CXXSpecialMember CSM;
10765 switch (FnKindPair.first) {
10768 case oc_implicit_default_constructor:
10769 CSM = Sema::CXXDefaultConstructor;
10771 case oc_implicit_copy_constructor:
10772 CSM = Sema::CXXCopyConstructor;
10774 case oc_implicit_move_constructor:
10775 CSM = Sema::CXXMoveConstructor;
10777 case oc_implicit_copy_assignment:
10778 CSM = Sema::CXXCopyAssignment;
10780 case oc_implicit_move_assignment:
10781 CSM = Sema::CXXMoveAssignment;
10785 bool ConstRHS = false;
10786 if (Meth->getNumParams()) {
10787 if (const ReferenceType *RT =
10788 Meth->getParamDecl(0)->getType()->getAs<ReferenceType>()) {
10789 ConstRHS = RT->getPointeeType().isConstQualified();
10793 S.inferCUDATargetForImplicitSpecialMember(ParentClass, CSM, Meth,
10794 /* ConstRHS */ ConstRHS,
10795 /* Diagnose */ true);
10799 static void DiagnoseFailedEnableIfAttr(Sema &S, OverloadCandidate *Cand) {
10800 FunctionDecl *Callee = Cand->Function;
10801 EnableIfAttr *Attr = static_cast<EnableIfAttr*>(Cand->DeductionFailure.Data);
10803 S.Diag(Callee->getLocation(),
10804 diag::note_ovl_candidate_disabled_by_function_cond_attr)
10805 << Attr->getCond()->getSourceRange() << Attr->getMessage();
10808 static void DiagnoseFailedExplicitSpec(Sema &S, OverloadCandidate *Cand) {
10809 ExplicitSpecifier ES = ExplicitSpecifier::getFromDecl(Cand->Function);
10810 assert(ES.isExplicit() && "not an explicit candidate");
10813 switch (Cand->Function->getDeclKind()) {
10814 case Decl::Kind::CXXConstructor:
10817 case Decl::Kind::CXXConversion:
10820 case Decl::Kind::CXXDeductionGuide:
10821 Kind = Cand->Function->isImplicit() ? 0 : 2;
10824 llvm_unreachable("invalid Decl");
10827 // Note the location of the first (in-class) declaration; a redeclaration
10828 // (particularly an out-of-class definition) will typically lack the
10829 // 'explicit' specifier.
10830 // FIXME: This is probably a good thing to do for all 'candidate' notes.
10831 FunctionDecl *First = Cand->Function->getFirstDecl();
10832 if (FunctionDecl *Pattern = First->getTemplateInstantiationPattern())
10833 First = Pattern->getFirstDecl();
10835 S.Diag(First->getLocation(),
10836 diag::note_ovl_candidate_explicit)
10837 << Kind << (ES.getExpr() ? 1 : 0)
10838 << (ES.getExpr() ? ES.getExpr()->getSourceRange() : SourceRange());
10841 static void DiagnoseOpenCLExtensionDisabled(Sema &S, OverloadCandidate *Cand) {
10842 FunctionDecl *Callee = Cand->Function;
10844 S.Diag(Callee->getLocation(),
10845 diag::note_ovl_candidate_disabled_by_extension)
10846 << S.getOpenCLExtensionsFromDeclExtMap(Callee);
10849 /// Generates a 'note' diagnostic for an overload candidate. We've
10850 /// already generated a primary error at the call site.
10852 /// It really does need to be a single diagnostic with its caret
10853 /// pointed at the candidate declaration. Yes, this creates some
10854 /// major challenges of technical writing. Yes, this makes pointing
10855 /// out problems with specific arguments quite awkward. It's still
10856 /// better than generating twenty screens of text for every failed
10859 /// It would be great to be able to express per-candidate problems
10860 /// more richly for those diagnostic clients that cared, but we'd
10861 /// still have to be just as careful with the default diagnostics.
10862 /// \param CtorDestAS Addr space of object being constructed (for ctor
10863 /// candidates only).
10864 static void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand,
10866 bool TakingCandidateAddress,
10867 LangAS CtorDestAS = LangAS::Default) {
10868 FunctionDecl *Fn = Cand->Function;
10870 // Note deleted candidates, but only if they're viable.
10871 if (Cand->Viable) {
10872 if (Fn->isDeleted()) {
10873 std::string FnDesc;
10874 std::pair<OverloadCandidateKind, OverloadCandidateSelect> FnKindPair =
10875 ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn,
10876 Cand->getRewriteKind(), FnDesc);
10878 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted)
10879 << (unsigned)FnKindPair.first << (unsigned)FnKindPair.second << FnDesc
10880 << (Fn->isDeleted() ? (Fn->isDeletedAsWritten() ? 1 : 2) : 0);
10881 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10885 // We don't really have anything else to say about viable candidates.
10886 S.NoteOverloadCandidate(Cand->FoundDecl, Fn, Cand->getRewriteKind());
10890 switch (Cand->FailureKind) {
10891 case ovl_fail_too_many_arguments:
10892 case ovl_fail_too_few_arguments:
10893 return DiagnoseArityMismatch(S, Cand, NumArgs);
10895 case ovl_fail_bad_deduction:
10896 return DiagnoseBadDeduction(S, Cand, NumArgs,
10897 TakingCandidateAddress);
10899 case ovl_fail_illegal_constructor: {
10900 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_illegal_constructor)
10901 << (Fn->getPrimaryTemplate() ? 1 : 0);
10902 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10906 case ovl_fail_object_addrspace_mismatch: {
10907 Qualifiers QualsForPrinting;
10908 QualsForPrinting.setAddressSpace(CtorDestAS);
10909 S.Diag(Fn->getLocation(),
10910 diag::note_ovl_candidate_illegal_constructor_adrspace_mismatch)
10911 << QualsForPrinting;
10912 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10916 case ovl_fail_trivial_conversion:
10917 case ovl_fail_bad_final_conversion:
10918 case ovl_fail_final_conversion_not_exact:
10919 return S.NoteOverloadCandidate(Cand->FoundDecl, Fn, Cand->getRewriteKind());
10921 case ovl_fail_bad_conversion: {
10922 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0);
10923 for (unsigned N = Cand->Conversions.size(); I != N; ++I)
10924 if (Cand->Conversions[I].isBad())
10925 return DiagnoseBadConversion(S, Cand, I, TakingCandidateAddress);
10927 // FIXME: this currently happens when we're called from SemaInit
10928 // when user-conversion overload fails. Figure out how to handle
10929 // those conditions and diagnose them well.
10930 return S.NoteOverloadCandidate(Cand->FoundDecl, Fn, Cand->getRewriteKind());
10933 case ovl_fail_bad_target:
10934 return DiagnoseBadTarget(S, Cand);
10936 case ovl_fail_enable_if:
10937 return DiagnoseFailedEnableIfAttr(S, Cand);
10939 case ovl_fail_explicit:
10940 return DiagnoseFailedExplicitSpec(S, Cand);
10942 case ovl_fail_ext_disabled:
10943 return DiagnoseOpenCLExtensionDisabled(S, Cand);
10945 case ovl_fail_inhctor_slice:
10946 // It's generally not interesting to note copy/move constructors here.
10947 if (cast<CXXConstructorDecl>(Fn)->isCopyOrMoveConstructor())
10949 S.Diag(Fn->getLocation(),
10950 diag::note_ovl_candidate_inherited_constructor_slice)
10951 << (Fn->getPrimaryTemplate() ? 1 : 0)
10952 << Fn->getParamDecl(0)->getType()->isRValueReferenceType();
10953 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10956 case ovl_fail_addr_not_available: {
10957 bool Available = checkAddressOfCandidateIsAvailable(S, Cand->Function);
10959 assert(!Available);
10962 case ovl_non_default_multiversion_function:
10963 // Do nothing, these should simply be ignored.
10966 case ovl_fail_constraints_not_satisfied: {
10967 std::string FnDesc;
10968 std::pair<OverloadCandidateKind, OverloadCandidateSelect> FnKindPair =
10969 ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn,
10970 Cand->getRewriteKind(), FnDesc);
10972 S.Diag(Fn->getLocation(),
10973 diag::note_ovl_candidate_constraints_not_satisfied)
10974 << (unsigned)FnKindPair.first << (unsigned)ocs_non_template
10975 << FnDesc /* Ignored */;
10976 ConstraintSatisfaction Satisfaction;
10977 if (S.CheckConstraintSatisfaction(Fn->getTrailingRequiresClause(),
10980 S.DiagnoseUnsatisfiedConstraint(Satisfaction);
10985 static void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) {
10986 // Desugar the type of the surrogate down to a function type,
10987 // retaining as many typedefs as possible while still showing
10988 // the function type (and, therefore, its parameter types).
10989 QualType FnType = Cand->Surrogate->getConversionType();
10990 bool isLValueReference = false;
10991 bool isRValueReference = false;
10992 bool isPointer = false;
10993 if (const LValueReferenceType *FnTypeRef =
10994 FnType->getAs<LValueReferenceType>()) {
10995 FnType = FnTypeRef->getPointeeType();
10996 isLValueReference = true;
10997 } else if (const RValueReferenceType *FnTypeRef =
10998 FnType->getAs<RValueReferenceType>()) {
10999 FnType = FnTypeRef->getPointeeType();
11000 isRValueReference = true;
11002 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) {
11003 FnType = FnTypePtr->getPointeeType();
11006 // Desugar down to a function type.
11007 FnType = QualType(FnType->getAs<FunctionType>(), 0);
11008 // Reconstruct the pointer/reference as appropriate.
11009 if (isPointer) FnType = S.Context.getPointerType(FnType);
11010 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType);
11011 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType);
11013 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand)
11017 static void NoteBuiltinOperatorCandidate(Sema &S, StringRef Opc,
11018 SourceLocation OpLoc,
11019 OverloadCandidate *Cand) {
11020 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary");
11021 std::string TypeStr("operator");
11024 TypeStr += Cand->BuiltinParamTypes[0].getAsString();
11025 if (Cand->Conversions.size() == 1) {
11027 S.Diag(OpLoc, diag::note_ovl_builtin_candidate) << TypeStr;
11030 TypeStr += Cand->BuiltinParamTypes[1].getAsString();
11032 S.Diag(OpLoc, diag::note_ovl_builtin_candidate) << TypeStr;
11036 static void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc,
11037 OverloadCandidate *Cand) {
11038 for (const ImplicitConversionSequence &ICS : Cand->Conversions) {
11039 if (ICS.isBad()) break; // all meaningless after first invalid
11040 if (!ICS.isAmbiguous()) continue;
11042 ICS.DiagnoseAmbiguousConversion(
11043 S, OpLoc, S.PDiag(diag::note_ambiguous_type_conversion));
11047 static SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) {
11048 if (Cand->Function)
11049 return Cand->Function->getLocation();
11050 if (Cand->IsSurrogate)
11051 return Cand->Surrogate->getLocation();
11052 return SourceLocation();
11055 static unsigned RankDeductionFailure(const DeductionFailureInfo &DFI) {
11056 switch ((Sema::TemplateDeductionResult)DFI.Result) {
11057 case Sema::TDK_Success:
11058 case Sema::TDK_NonDependentConversionFailure:
11059 llvm_unreachable("non-deduction failure while diagnosing bad deduction");
11061 case Sema::TDK_Invalid:
11062 case Sema::TDK_Incomplete:
11063 case Sema::TDK_IncompletePack:
11066 case Sema::TDK_Underqualified:
11067 case Sema::TDK_Inconsistent:
11070 case Sema::TDK_SubstitutionFailure:
11071 case Sema::TDK_DeducedMismatch:
11072 case Sema::TDK_ConstraintsNotSatisfied:
11073 case Sema::TDK_DeducedMismatchNested:
11074 case Sema::TDK_NonDeducedMismatch:
11075 case Sema::TDK_MiscellaneousDeductionFailure:
11076 case Sema::TDK_CUDATargetMismatch:
11079 case Sema::TDK_InstantiationDepth:
11082 case Sema::TDK_InvalidExplicitArguments:
11085 case Sema::TDK_TooManyArguments:
11086 case Sema::TDK_TooFewArguments:
11089 llvm_unreachable("Unhandled deduction result");
11093 struct CompareOverloadCandidatesForDisplay {
11095 SourceLocation Loc;
11097 OverloadCandidateSet::CandidateSetKind CSK;
11099 CompareOverloadCandidatesForDisplay(
11100 Sema &S, SourceLocation Loc, size_t NArgs,
11101 OverloadCandidateSet::CandidateSetKind CSK)
11102 : S(S), NumArgs(NArgs), CSK(CSK) {}
11104 OverloadFailureKind EffectiveFailureKind(const OverloadCandidate *C) const {
11105 // If there are too many or too few arguments, that's the high-order bit we
11106 // want to sort by, even if the immediate failure kind was something else.
11107 if (C->FailureKind == ovl_fail_too_many_arguments ||
11108 C->FailureKind == ovl_fail_too_few_arguments)
11109 return static_cast<OverloadFailureKind>(C->FailureKind);
11112 if (NumArgs > C->Function->getNumParams() && !C->Function->isVariadic())
11113 return ovl_fail_too_many_arguments;
11114 if (NumArgs < C->Function->getMinRequiredArguments())
11115 return ovl_fail_too_few_arguments;
11118 return static_cast<OverloadFailureKind>(C->FailureKind);
11121 bool operator()(const OverloadCandidate *L,
11122 const OverloadCandidate *R) {
11123 // Fast-path this check.
11124 if (L == R) return false;
11126 // Order first by viability.
11128 if (!R->Viable) return true;
11130 // TODO: introduce a tri-valued comparison for overload
11131 // candidates. Would be more worthwhile if we had a sort
11132 // that could exploit it.
11133 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation(), CSK))
11135 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation(), CSK))
11137 } else if (R->Viable)
11140 assert(L->Viable == R->Viable);
11142 // Criteria by which we can sort non-viable candidates:
11144 OverloadFailureKind LFailureKind = EffectiveFailureKind(L);
11145 OverloadFailureKind RFailureKind = EffectiveFailureKind(R);
11147 // 1. Arity mismatches come after other candidates.
11148 if (LFailureKind == ovl_fail_too_many_arguments ||
11149 LFailureKind == ovl_fail_too_few_arguments) {
11150 if (RFailureKind == ovl_fail_too_many_arguments ||
11151 RFailureKind == ovl_fail_too_few_arguments) {
11152 int LDist = std::abs((int)L->getNumParams() - (int)NumArgs);
11153 int RDist = std::abs((int)R->getNumParams() - (int)NumArgs);
11154 if (LDist == RDist) {
11155 if (LFailureKind == RFailureKind)
11156 // Sort non-surrogates before surrogates.
11157 return !L->IsSurrogate && R->IsSurrogate;
11158 // Sort candidates requiring fewer parameters than there were
11159 // arguments given after candidates requiring more parameters
11160 // than there were arguments given.
11161 return LFailureKind == ovl_fail_too_many_arguments;
11163 return LDist < RDist;
11167 if (RFailureKind == ovl_fail_too_many_arguments ||
11168 RFailureKind == ovl_fail_too_few_arguments)
11171 // 2. Bad conversions come first and are ordered by the number
11172 // of bad conversions and quality of good conversions.
11173 if (LFailureKind == ovl_fail_bad_conversion) {
11174 if (RFailureKind != ovl_fail_bad_conversion)
11177 // The conversion that can be fixed with a smaller number of changes,
11179 unsigned numLFixes = L->Fix.NumConversionsFixed;
11180 unsigned numRFixes = R->Fix.NumConversionsFixed;
11181 numLFixes = (numLFixes == 0) ? UINT_MAX : numLFixes;
11182 numRFixes = (numRFixes == 0) ? UINT_MAX : numRFixes;
11183 if (numLFixes != numRFixes) {
11184 return numLFixes < numRFixes;
11187 // If there's any ordering between the defined conversions...
11188 // FIXME: this might not be transitive.
11189 assert(L->Conversions.size() == R->Conversions.size());
11191 int leftBetter = 0;
11192 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument);
11193 for (unsigned E = L->Conversions.size(); I != E; ++I) {
11194 switch (CompareImplicitConversionSequences(S, Loc,
11196 R->Conversions[I])) {
11197 case ImplicitConversionSequence::Better:
11201 case ImplicitConversionSequence::Worse:
11205 case ImplicitConversionSequence::Indistinguishable:
11209 if (leftBetter > 0) return true;
11210 if (leftBetter < 0) return false;
11212 } else if (RFailureKind == ovl_fail_bad_conversion)
11215 if (LFailureKind == ovl_fail_bad_deduction) {
11216 if (RFailureKind != ovl_fail_bad_deduction)
11219 if (L->DeductionFailure.Result != R->DeductionFailure.Result)
11220 return RankDeductionFailure(L->DeductionFailure)
11221 < RankDeductionFailure(R->DeductionFailure);
11222 } else if (RFailureKind == ovl_fail_bad_deduction)
11228 // Sort everything else by location.
11229 SourceLocation LLoc = GetLocationForCandidate(L);
11230 SourceLocation RLoc = GetLocationForCandidate(R);
11232 // Put candidates without locations (e.g. builtins) at the end.
11233 if (LLoc.isInvalid()) return false;
11234 if (RLoc.isInvalid()) return true;
11236 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc);
11241 /// CompleteNonViableCandidate - Normally, overload resolution only
11242 /// computes up to the first bad conversion. Produces the FixIt set if
11245 CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand,
11246 ArrayRef<Expr *> Args,
11247 OverloadCandidateSet::CandidateSetKind CSK) {
11248 assert(!Cand->Viable);
11250 // Don't do anything on failures other than bad conversion.
11251 if (Cand->FailureKind != ovl_fail_bad_conversion)
11254 // We only want the FixIts if all the arguments can be corrected.
11255 bool Unfixable = false;
11256 // Use a implicit copy initialization to check conversion fixes.
11257 Cand->Fix.setConversionChecker(TryCopyInitialization);
11259 // Attempt to fix the bad conversion.
11260 unsigned ConvCount = Cand->Conversions.size();
11261 for (unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); /**/;
11263 assert(ConvIdx != ConvCount && "no bad conversion in candidate");
11264 if (Cand->Conversions[ConvIdx].isInitialized() &&
11265 Cand->Conversions[ConvIdx].isBad()) {
11266 Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S);
11271 // FIXME: this should probably be preserved from the overload
11272 // operation somehow.
11273 bool SuppressUserConversions = false;
11275 unsigned ConvIdx = 0;
11276 unsigned ArgIdx = 0;
11277 ArrayRef<QualType> ParamTypes;
11278 bool Reversed = Cand->RewriteKind & CRK_Reversed;
11280 if (Cand->IsSurrogate) {
11282 = Cand->Surrogate->getConversionType().getNonReferenceType();
11283 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
11284 ConvType = ConvPtrType->getPointeeType();
11285 ParamTypes = ConvType->castAs<FunctionProtoType>()->getParamTypes();
11286 // Conversion 0 is 'this', which doesn't have a corresponding parameter.
11288 } else if (Cand->Function) {
11290 Cand->Function->getType()->castAs<FunctionProtoType>()->getParamTypes();
11291 if (isa<CXXMethodDecl>(Cand->Function) &&
11292 !isa<CXXConstructorDecl>(Cand->Function) && !Reversed) {
11293 // Conversion 0 is 'this', which doesn't have a corresponding parameter.
11295 if (CSK == OverloadCandidateSet::CSK_Operator &&
11296 Cand->Function->getDeclName().getCXXOverloadedOperator() != OO_Call)
11297 // Argument 0 is 'this', which doesn't have a corresponding parameter.
11301 // Builtin operator.
11302 assert(ConvCount <= 3);
11303 ParamTypes = Cand->BuiltinParamTypes;
11306 // Fill in the rest of the conversions.
11307 for (unsigned ParamIdx = Reversed ? ParamTypes.size() - 1 : 0;
11308 ConvIdx != ConvCount;
11309 ++ConvIdx, ++ArgIdx, ParamIdx += (Reversed ? -1 : 1)) {
11310 assert(ArgIdx < Args.size() && "no argument for this arg conversion");
11311 if (Cand->Conversions[ConvIdx].isInitialized()) {
11312 // We've already checked this conversion.
11313 } else if (ParamIdx < ParamTypes.size()) {
11314 if (ParamTypes[ParamIdx]->isDependentType())
11315 Cand->Conversions[ConvIdx].setAsIdentityConversion(
11316 Args[ArgIdx]->getType());
11318 Cand->Conversions[ConvIdx] =
11319 TryCopyInitialization(S, Args[ArgIdx], ParamTypes[ParamIdx],
11320 SuppressUserConversions,
11321 /*InOverloadResolution=*/true,
11322 /*AllowObjCWritebackConversion=*/
11323 S.getLangOpts().ObjCAutoRefCount);
11324 // Store the FixIt in the candidate if it exists.
11325 if (!Unfixable && Cand->Conversions[ConvIdx].isBad())
11326 Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S);
11329 Cand->Conversions[ConvIdx].setEllipsis();
11333 SmallVector<OverloadCandidate *, 32> OverloadCandidateSet::CompleteCandidates(
11334 Sema &S, OverloadCandidateDisplayKind OCD, ArrayRef<Expr *> Args,
11335 SourceLocation OpLoc,
11336 llvm::function_ref<bool(OverloadCandidate &)> Filter) {
11337 // Sort the candidates by viability and position. Sorting directly would
11338 // be prohibitive, so we make a set of pointers and sort those.
11339 SmallVector<OverloadCandidate*, 32> Cands;
11340 if (OCD == OCD_AllCandidates) Cands.reserve(size());
11341 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) {
11342 if (!Filter(*Cand))
11345 case OCD_AllCandidates:
11346 if (!Cand->Viable) {
11347 if (!Cand->Function && !Cand->IsSurrogate) {
11348 // This a non-viable builtin candidate. We do not, in general,
11349 // want to list every possible builtin candidate.
11352 CompleteNonViableCandidate(S, Cand, Args, Kind);
11356 case OCD_ViableCandidates:
11361 case OCD_AmbiguousCandidates:
11367 Cands.push_back(Cand);
11371 Cands, CompareOverloadCandidatesForDisplay(S, OpLoc, Args.size(), Kind));
11376 /// When overload resolution fails, prints diagnostic messages containing the
11377 /// candidates in the candidate set.
11378 void OverloadCandidateSet::NoteCandidates(PartialDiagnosticAt PD,
11379 Sema &S, OverloadCandidateDisplayKind OCD, ArrayRef<Expr *> Args,
11380 StringRef Opc, SourceLocation OpLoc,
11381 llvm::function_ref<bool(OverloadCandidate &)> Filter) {
11383 auto Cands = CompleteCandidates(S, OCD, Args, OpLoc, Filter);
11385 S.Diag(PD.first, PD.second);
11387 NoteCandidates(S, Args, Cands, Opc, OpLoc);
11389 if (OCD == OCD_AmbiguousCandidates)
11390 MaybeDiagnoseAmbiguousConstraints(S, {begin(), end()});
11393 void OverloadCandidateSet::NoteCandidates(Sema &S, ArrayRef<Expr *> Args,
11394 ArrayRef<OverloadCandidate *> Cands,
11395 StringRef Opc, SourceLocation OpLoc) {
11396 bool ReportedAmbiguousConversions = false;
11398 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
11399 unsigned CandsShown = 0;
11400 auto I = Cands.begin(), E = Cands.end();
11401 for (; I != E; ++I) {
11402 OverloadCandidate *Cand = *I;
11404 // Set an arbitrary limit on the number of candidate functions we'll spam
11405 // the user with. FIXME: This limit should depend on details of the
11407 if (CandsShown >= 4 && ShowOverloads == Ovl_Best) {
11412 if (Cand->Function)
11413 NoteFunctionCandidate(S, Cand, Args.size(),
11414 /*TakingCandidateAddress=*/false, DestAS);
11415 else if (Cand->IsSurrogate)
11416 NoteSurrogateCandidate(S, Cand);
11418 assert(Cand->Viable &&
11419 "Non-viable built-in candidates are not added to Cands.");
11420 // Generally we only see ambiguities including viable builtin
11421 // operators if overload resolution got screwed up by an
11422 // ambiguous user-defined conversion.
11424 // FIXME: It's quite possible for different conversions to see
11425 // different ambiguities, though.
11426 if (!ReportedAmbiguousConversions) {
11427 NoteAmbiguousUserConversions(S, OpLoc, Cand);
11428 ReportedAmbiguousConversions = true;
11431 // If this is a viable builtin, print it.
11432 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand);
11437 S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I);
11440 static SourceLocation
11441 GetLocationForCandidate(const TemplateSpecCandidate *Cand) {
11442 return Cand->Specialization ? Cand->Specialization->getLocation()
11443 : SourceLocation();
11447 struct CompareTemplateSpecCandidatesForDisplay {
11449 CompareTemplateSpecCandidatesForDisplay(Sema &S) : S(S) {}
11451 bool operator()(const TemplateSpecCandidate *L,
11452 const TemplateSpecCandidate *R) {
11453 // Fast-path this check.
11457 // Assuming that both candidates are not matches...
11459 // Sort by the ranking of deduction failures.
11460 if (L->DeductionFailure.Result != R->DeductionFailure.Result)
11461 return RankDeductionFailure(L->DeductionFailure) <
11462 RankDeductionFailure(R->DeductionFailure);
11464 // Sort everything else by location.
11465 SourceLocation LLoc = GetLocationForCandidate(L);
11466 SourceLocation RLoc = GetLocationForCandidate(R);
11468 // Put candidates without locations (e.g. builtins) at the end.
11469 if (LLoc.isInvalid())
11471 if (RLoc.isInvalid())
11474 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc);
11479 /// Diagnose a template argument deduction failure.
11480 /// We are treating these failures as overload failures due to bad
11482 void TemplateSpecCandidate::NoteDeductionFailure(Sema &S,
11483 bool ForTakingAddress) {
11484 DiagnoseBadDeduction(S, FoundDecl, Specialization, // pattern
11485 DeductionFailure, /*NumArgs=*/0, ForTakingAddress);
11488 void TemplateSpecCandidateSet::destroyCandidates() {
11489 for (iterator i = begin(), e = end(); i != e; ++i) {
11490 i->DeductionFailure.Destroy();
11494 void TemplateSpecCandidateSet::clear() {
11495 destroyCandidates();
11496 Candidates.clear();
11499 /// NoteCandidates - When no template specialization match is found, prints
11500 /// diagnostic messages containing the non-matching specializations that form
11501 /// the candidate set.
11502 /// This is analoguous to OverloadCandidateSet::NoteCandidates() with
11503 /// OCD == OCD_AllCandidates and Cand->Viable == false.
11504 void TemplateSpecCandidateSet::NoteCandidates(Sema &S, SourceLocation Loc) {
11505 // Sort the candidates by position (assuming no candidate is a match).
11506 // Sorting directly would be prohibitive, so we make a set of pointers
11508 SmallVector<TemplateSpecCandidate *, 32> Cands;
11509 Cands.reserve(size());
11510 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) {
11511 if (Cand->Specialization)
11512 Cands.push_back(Cand);
11513 // Otherwise, this is a non-matching builtin candidate. We do not,
11514 // in general, want to list every possible builtin candidate.
11517 llvm::sort(Cands, CompareTemplateSpecCandidatesForDisplay(S));
11519 // FIXME: Perhaps rename OverloadsShown and getShowOverloads()
11520 // for generalization purposes (?).
11521 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
11523 SmallVectorImpl<TemplateSpecCandidate *>::iterator I, E;
11524 unsigned CandsShown = 0;
11525 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) {
11526 TemplateSpecCandidate *Cand = *I;
11528 // Set an arbitrary limit on the number of candidates we'll spam
11529 // the user with. FIXME: This limit should depend on details of the
11531 if (CandsShown >= 4 && ShowOverloads == Ovl_Best)
11535 assert(Cand->Specialization &&
11536 "Non-matching built-in candidates are not added to Cands.");
11537 Cand->NoteDeductionFailure(S, ForTakingAddress);
11541 S.Diag(Loc, diag::note_ovl_too_many_candidates) << int(E - I);
11544 // [PossiblyAFunctionType] --> [Return]
11545 // NonFunctionType --> NonFunctionType
11547 // R (*)(A) --> R (A)
11548 // R (&)(A) --> R (A)
11549 // R (S::*)(A) --> R (A)
11550 QualType Sema::ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType) {
11551 QualType Ret = PossiblyAFunctionType;
11552 if (const PointerType *ToTypePtr =
11553 PossiblyAFunctionType->getAs<PointerType>())
11554 Ret = ToTypePtr->getPointeeType();
11555 else if (const ReferenceType *ToTypeRef =
11556 PossiblyAFunctionType->getAs<ReferenceType>())
11557 Ret = ToTypeRef->getPointeeType();
11558 else if (const MemberPointerType *MemTypePtr =
11559 PossiblyAFunctionType->getAs<MemberPointerType>())
11560 Ret = MemTypePtr->getPointeeType();
11562 Context.getCanonicalType(Ret).getUnqualifiedType();
11566 static bool completeFunctionType(Sema &S, FunctionDecl *FD, SourceLocation Loc,
11567 bool Complain = true) {
11568 if (S.getLangOpts().CPlusPlus14 && FD->getReturnType()->isUndeducedType() &&
11569 S.DeduceReturnType(FD, Loc, Complain))
11572 auto *FPT = FD->getType()->castAs<FunctionProtoType>();
11573 if (S.getLangOpts().CPlusPlus17 &&
11574 isUnresolvedExceptionSpec(FPT->getExceptionSpecType()) &&
11575 !S.ResolveExceptionSpec(Loc, FPT))
11582 // A helper class to help with address of function resolution
11583 // - allows us to avoid passing around all those ugly parameters
11584 class AddressOfFunctionResolver {
11587 const QualType& TargetType;
11588 QualType TargetFunctionType; // Extracted function type from target type
11591 //DeclAccessPair& ResultFunctionAccessPair;
11592 ASTContext& Context;
11594 bool TargetTypeIsNonStaticMemberFunction;
11595 bool FoundNonTemplateFunction;
11596 bool StaticMemberFunctionFromBoundPointer;
11597 bool HasComplained;
11599 OverloadExpr::FindResult OvlExprInfo;
11600 OverloadExpr *OvlExpr;
11601 TemplateArgumentListInfo OvlExplicitTemplateArgs;
11602 SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches;
11603 TemplateSpecCandidateSet FailedCandidates;
11606 AddressOfFunctionResolver(Sema &S, Expr *SourceExpr,
11607 const QualType &TargetType, bool Complain)
11608 : S(S), SourceExpr(SourceExpr), TargetType(TargetType),
11609 Complain(Complain), Context(S.getASTContext()),
11610 TargetTypeIsNonStaticMemberFunction(
11611 !!TargetType->getAs<MemberPointerType>()),
11612 FoundNonTemplateFunction(false),
11613 StaticMemberFunctionFromBoundPointer(false),
11614 HasComplained(false),
11615 OvlExprInfo(OverloadExpr::find(SourceExpr)),
11616 OvlExpr(OvlExprInfo.Expression),
11617 FailedCandidates(OvlExpr->getNameLoc(), /*ForTakingAddress=*/true) {
11618 ExtractUnqualifiedFunctionTypeFromTargetType();
11620 if (TargetFunctionType->isFunctionType()) {
11621 if (UnresolvedMemberExpr *UME = dyn_cast<UnresolvedMemberExpr>(OvlExpr))
11622 if (!UME->isImplicitAccess() &&
11623 !S.ResolveSingleFunctionTemplateSpecialization(UME))
11624 StaticMemberFunctionFromBoundPointer = true;
11625 } else if (OvlExpr->hasExplicitTemplateArgs()) {
11626 DeclAccessPair dap;
11627 if (FunctionDecl *Fn = S.ResolveSingleFunctionTemplateSpecialization(
11628 OvlExpr, false, &dap)) {
11629 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn))
11630 if (!Method->isStatic()) {
11631 // If the target type is a non-function type and the function found
11632 // is a non-static member function, pretend as if that was the
11633 // target, it's the only possible type to end up with.
11634 TargetTypeIsNonStaticMemberFunction = true;
11636 // And skip adding the function if its not in the proper form.
11637 // We'll diagnose this due to an empty set of functions.
11638 if (!OvlExprInfo.HasFormOfMemberPointer)
11642 Matches.push_back(std::make_pair(dap, Fn));
11647 if (OvlExpr->hasExplicitTemplateArgs())
11648 OvlExpr->copyTemplateArgumentsInto(OvlExplicitTemplateArgs);
11650 if (FindAllFunctionsThatMatchTargetTypeExactly()) {
11651 // C++ [over.over]p4:
11652 // If more than one function is selected, [...]
11653 if (Matches.size() > 1 && !eliminiateSuboptimalOverloadCandidates()) {
11654 if (FoundNonTemplateFunction)
11655 EliminateAllTemplateMatches();
11657 EliminateAllExceptMostSpecializedTemplate();
11661 if (S.getLangOpts().CUDA && Matches.size() > 1)
11662 EliminateSuboptimalCudaMatches();
11665 bool hasComplained() const { return HasComplained; }
11668 bool candidateHasExactlyCorrectType(const FunctionDecl *FD) {
11670 return Context.hasSameUnqualifiedType(TargetFunctionType, FD->getType()) ||
11671 S.IsFunctionConversion(FD->getType(), TargetFunctionType, Discard);
11674 /// \return true if A is considered a better overload candidate for the
11675 /// desired type than B.
11676 bool isBetterCandidate(const FunctionDecl *A, const FunctionDecl *B) {
11677 // If A doesn't have exactly the correct type, we don't want to classify it
11678 // as "better" than anything else. This way, the user is required to
11679 // disambiguate for us if there are multiple candidates and no exact match.
11680 return candidateHasExactlyCorrectType(A) &&
11681 (!candidateHasExactlyCorrectType(B) ||
11682 compareEnableIfAttrs(S, A, B) == Comparison::Better);
11685 /// \return true if we were able to eliminate all but one overload candidate,
11686 /// false otherwise.
11687 bool eliminiateSuboptimalOverloadCandidates() {
11688 // Same algorithm as overload resolution -- one pass to pick the "best",
11689 // another pass to be sure that nothing is better than the best.
11690 auto Best = Matches.begin();
11691 for (auto I = Matches.begin()+1, E = Matches.end(); I != E; ++I)
11692 if (isBetterCandidate(I->second, Best->second))
11695 const FunctionDecl *BestFn = Best->second;
11696 auto IsBestOrInferiorToBest = [this, BestFn](
11697 const std::pair<DeclAccessPair, FunctionDecl *> &Pair) {
11698 return BestFn == Pair.second || isBetterCandidate(BestFn, Pair.second);
11701 // Note: We explicitly leave Matches unmodified if there isn't a clear best
11702 // option, so we can potentially give the user a better error
11703 if (!llvm::all_of(Matches, IsBestOrInferiorToBest))
11705 Matches[0] = *Best;
11710 bool isTargetTypeAFunction() const {
11711 return TargetFunctionType->isFunctionType();
11714 // [ToType] [Return]
11716 // R (*)(A) --> R (A), IsNonStaticMemberFunction = false
11717 // R (&)(A) --> R (A), IsNonStaticMemberFunction = false
11718 // R (S::*)(A) --> R (A), IsNonStaticMemberFunction = true
11719 void inline ExtractUnqualifiedFunctionTypeFromTargetType() {
11720 TargetFunctionType = S.ExtractUnqualifiedFunctionType(TargetType);
11723 // return true if any matching specializations were found
11724 bool AddMatchingTemplateFunction(FunctionTemplateDecl* FunctionTemplate,
11725 const DeclAccessPair& CurAccessFunPair) {
11726 if (CXXMethodDecl *Method
11727 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) {
11728 // Skip non-static function templates when converting to pointer, and
11729 // static when converting to member pointer.
11730 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction)
11733 else if (TargetTypeIsNonStaticMemberFunction)
11736 // C++ [over.over]p2:
11737 // If the name is a function template, template argument deduction is
11738 // done (14.8.2.2), and if the argument deduction succeeds, the
11739 // resulting template argument list is used to generate a single
11740 // function template specialization, which is added to the set of
11741 // overloaded functions considered.
11742 FunctionDecl *Specialization = nullptr;
11743 TemplateDeductionInfo Info(FailedCandidates.getLocation());
11744 if (Sema::TemplateDeductionResult Result
11745 = S.DeduceTemplateArguments(FunctionTemplate,
11746 &OvlExplicitTemplateArgs,
11747 TargetFunctionType, Specialization,
11748 Info, /*IsAddressOfFunction*/true)) {
11749 // Make a note of the failed deduction for diagnostics.
11750 FailedCandidates.addCandidate()
11751 .set(CurAccessFunPair, FunctionTemplate->getTemplatedDecl(),
11752 MakeDeductionFailureInfo(Context, Result, Info));
11756 // Template argument deduction ensures that we have an exact match or
11757 // compatible pointer-to-function arguments that would be adjusted by ICS.
11758 // This function template specicalization works.
11759 assert(S.isSameOrCompatibleFunctionType(
11760 Context.getCanonicalType(Specialization->getType()),
11761 Context.getCanonicalType(TargetFunctionType)));
11763 if (!S.checkAddressOfFunctionIsAvailable(Specialization))
11766 Matches.push_back(std::make_pair(CurAccessFunPair, Specialization));
11770 bool AddMatchingNonTemplateFunction(NamedDecl* Fn,
11771 const DeclAccessPair& CurAccessFunPair) {
11772 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) {
11773 // Skip non-static functions when converting to pointer, and static
11774 // when converting to member pointer.
11775 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction)
11778 else if (TargetTypeIsNonStaticMemberFunction)
11781 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) {
11782 if (S.getLangOpts().CUDA)
11783 if (FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext))
11784 if (!Caller->isImplicit() && !S.IsAllowedCUDACall(Caller, FunDecl))
11786 if (FunDecl->isMultiVersion()) {
11787 const auto *TA = FunDecl->getAttr<TargetAttr>();
11788 if (TA && !TA->isDefaultVersion())
11792 // If any candidate has a placeholder return type, trigger its deduction
11794 if (completeFunctionType(S, FunDecl, SourceExpr->getBeginLoc(),
11796 HasComplained |= Complain;
11800 if (!S.checkAddressOfFunctionIsAvailable(FunDecl))
11803 // If we're in C, we need to support types that aren't exactly identical.
11804 if (!S.getLangOpts().CPlusPlus ||
11805 candidateHasExactlyCorrectType(FunDecl)) {
11806 Matches.push_back(std::make_pair(
11807 CurAccessFunPair, cast<FunctionDecl>(FunDecl->getCanonicalDecl())));
11808 FoundNonTemplateFunction = true;
11816 bool FindAllFunctionsThatMatchTargetTypeExactly() {
11819 // If the overload expression doesn't have the form of a pointer to
11820 // member, don't try to convert it to a pointer-to-member type.
11821 if (IsInvalidFormOfPointerToMemberFunction())
11824 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
11825 E = OvlExpr->decls_end();
11827 // Look through any using declarations to find the underlying function.
11828 NamedDecl *Fn = (*I)->getUnderlyingDecl();
11830 // C++ [over.over]p3:
11831 // Non-member functions and static member functions match
11832 // targets of type "pointer-to-function" or "reference-to-function."
11833 // Nonstatic member functions match targets of
11834 // type "pointer-to-member-function."
11835 // Note that according to DR 247, the containing class does not matter.
11836 if (FunctionTemplateDecl *FunctionTemplate
11837 = dyn_cast<FunctionTemplateDecl>(Fn)) {
11838 if (AddMatchingTemplateFunction(FunctionTemplate, I.getPair()))
11841 // If we have explicit template arguments supplied, skip non-templates.
11842 else if (!OvlExpr->hasExplicitTemplateArgs() &&
11843 AddMatchingNonTemplateFunction(Fn, I.getPair()))
11846 assert(Ret || Matches.empty());
11850 void EliminateAllExceptMostSpecializedTemplate() {
11851 // [...] and any given function template specialization F1 is
11852 // eliminated if the set contains a second function template
11853 // specialization whose function template is more specialized
11854 // than the function template of F1 according to the partial
11855 // ordering rules of 14.5.5.2.
11857 // The algorithm specified above is quadratic. We instead use a
11858 // two-pass algorithm (similar to the one used to identify the
11859 // best viable function in an overload set) that identifies the
11860 // best function template (if it exists).
11862 UnresolvedSet<4> MatchesCopy; // TODO: avoid!
11863 for (unsigned I = 0, E = Matches.size(); I != E; ++I)
11864 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess());
11866 // TODO: It looks like FailedCandidates does not serve much purpose
11867 // here, since the no_viable diagnostic has index 0.
11868 UnresolvedSetIterator Result = S.getMostSpecialized(
11869 MatchesCopy.begin(), MatchesCopy.end(), FailedCandidates,
11870 SourceExpr->getBeginLoc(), S.PDiag(),
11871 S.PDiag(diag::err_addr_ovl_ambiguous)
11872 << Matches[0].second->getDeclName(),
11873 S.PDiag(diag::note_ovl_candidate)
11874 << (unsigned)oc_function << (unsigned)ocs_described_template,
11875 Complain, TargetFunctionType);
11877 if (Result != MatchesCopy.end()) {
11878 // Make it the first and only element
11879 Matches[0].first = Matches[Result - MatchesCopy.begin()].first;
11880 Matches[0].second = cast<FunctionDecl>(*Result);
11883 HasComplained |= Complain;
11886 void EliminateAllTemplateMatches() {
11887 // [...] any function template specializations in the set are
11888 // eliminated if the set also contains a non-template function, [...]
11889 for (unsigned I = 0, N = Matches.size(); I != N; ) {
11890 if (Matches[I].second->getPrimaryTemplate() == nullptr)
11893 Matches[I] = Matches[--N];
11899 void EliminateSuboptimalCudaMatches() {
11900 S.EraseUnwantedCUDAMatches(dyn_cast<FunctionDecl>(S.CurContext), Matches);
11904 void ComplainNoMatchesFound() const {
11905 assert(Matches.empty());
11906 S.Diag(OvlExpr->getBeginLoc(), diag::err_addr_ovl_no_viable)
11907 << OvlExpr->getName() << TargetFunctionType
11908 << OvlExpr->getSourceRange();
11909 if (FailedCandidates.empty())
11910 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType,
11911 /*TakingAddress=*/true);
11913 // We have some deduction failure messages. Use them to diagnose
11914 // the function templates, and diagnose the non-template candidates
11916 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
11917 IEnd = OvlExpr->decls_end();
11919 if (FunctionDecl *Fun =
11920 dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()))
11921 if (!functionHasPassObjectSizeParams(Fun))
11922 S.NoteOverloadCandidate(*I, Fun, CRK_None, TargetFunctionType,
11923 /*TakingAddress=*/true);
11924 FailedCandidates.NoteCandidates(S, OvlExpr->getBeginLoc());
11928 bool IsInvalidFormOfPointerToMemberFunction() const {
11929 return TargetTypeIsNonStaticMemberFunction &&
11930 !OvlExprInfo.HasFormOfMemberPointer;
11933 void ComplainIsInvalidFormOfPointerToMemberFunction() const {
11934 // TODO: Should we condition this on whether any functions might
11935 // have matched, or is it more appropriate to do that in callers?
11936 // TODO: a fixit wouldn't hurt.
11937 S.Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier)
11938 << TargetType << OvlExpr->getSourceRange();
11941 bool IsStaticMemberFunctionFromBoundPointer() const {
11942 return StaticMemberFunctionFromBoundPointer;
11945 void ComplainIsStaticMemberFunctionFromBoundPointer() const {
11946 S.Diag(OvlExpr->getBeginLoc(),
11947 diag::err_invalid_form_pointer_member_function)
11948 << OvlExpr->getSourceRange();
11951 void ComplainOfInvalidConversion() const {
11952 S.Diag(OvlExpr->getBeginLoc(), diag::err_addr_ovl_not_func_ptrref)
11953 << OvlExpr->getName() << TargetType;
11956 void ComplainMultipleMatchesFound() const {
11957 assert(Matches.size() > 1);
11958 S.Diag(OvlExpr->getBeginLoc(), diag::err_addr_ovl_ambiguous)
11959 << OvlExpr->getName() << OvlExpr->getSourceRange();
11960 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType,
11961 /*TakingAddress=*/true);
11964 bool hadMultipleCandidates() const { return (OvlExpr->getNumDecls() > 1); }
11966 int getNumMatches() const { return Matches.size(); }
11968 FunctionDecl* getMatchingFunctionDecl() const {
11969 if (Matches.size() != 1) return nullptr;
11970 return Matches[0].second;
11973 const DeclAccessPair* getMatchingFunctionAccessPair() const {
11974 if (Matches.size() != 1) return nullptr;
11975 return &Matches[0].first;
11980 /// ResolveAddressOfOverloadedFunction - Try to resolve the address of
11981 /// an overloaded function (C++ [over.over]), where @p From is an
11982 /// expression with overloaded function type and @p ToType is the type
11983 /// we're trying to resolve to. For example:
11989 /// int (*pfd)(double) = f; // selects f(double)
11992 /// This routine returns the resulting FunctionDecl if it could be
11993 /// resolved, and NULL otherwise. When @p Complain is true, this
11994 /// routine will emit diagnostics if there is an error.
11996 Sema::ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr,
11997 QualType TargetType,
11999 DeclAccessPair &FoundResult,
12000 bool *pHadMultipleCandidates) {
12001 assert(AddressOfExpr->getType() == Context.OverloadTy);
12003 AddressOfFunctionResolver Resolver(*this, AddressOfExpr, TargetType,
12005 int NumMatches = Resolver.getNumMatches();
12006 FunctionDecl *Fn = nullptr;
12007 bool ShouldComplain = Complain && !Resolver.hasComplained();
12008 if (NumMatches == 0 && ShouldComplain) {
12009 if (Resolver.IsInvalidFormOfPointerToMemberFunction())
12010 Resolver.ComplainIsInvalidFormOfPointerToMemberFunction();
12012 Resolver.ComplainNoMatchesFound();
12014 else if (NumMatches > 1 && ShouldComplain)
12015 Resolver.ComplainMultipleMatchesFound();
12016 else if (NumMatches == 1) {
12017 Fn = Resolver.getMatchingFunctionDecl();
12019 if (auto *FPT = Fn->getType()->getAs<FunctionProtoType>())
12020 ResolveExceptionSpec(AddressOfExpr->getExprLoc(), FPT);
12021 FoundResult = *Resolver.getMatchingFunctionAccessPair();
12023 if (Resolver.IsStaticMemberFunctionFromBoundPointer())
12024 Resolver.ComplainIsStaticMemberFunctionFromBoundPointer();
12026 CheckAddressOfMemberAccess(AddressOfExpr, FoundResult);
12030 if (pHadMultipleCandidates)
12031 *pHadMultipleCandidates = Resolver.hadMultipleCandidates();
12035 /// Given an expression that refers to an overloaded function, try to
12036 /// resolve that function to a single function that can have its address taken.
12037 /// This will modify `Pair` iff it returns non-null.
12039 /// This routine can only succeed if from all of the candidates in the overload
12040 /// set for SrcExpr that can have their addresses taken, there is one candidate
12041 /// that is more constrained than the rest.
12043 Sema::resolveAddressOfSingleOverloadCandidate(Expr *E, DeclAccessPair &Pair) {
12044 OverloadExpr::FindResult R = OverloadExpr::find(E);
12045 OverloadExpr *Ovl = R.Expression;
12046 bool IsResultAmbiguous = false;
12047 FunctionDecl *Result = nullptr;
12048 DeclAccessPair DAP;
12049 SmallVector<FunctionDecl *, 2> AmbiguousDecls;
12051 auto CheckMoreConstrained =
12052 [&] (FunctionDecl *FD1, FunctionDecl *FD2) -> Optional<bool> {
12053 SmallVector<const Expr *, 1> AC1, AC2;
12054 FD1->getAssociatedConstraints(AC1);
12055 FD2->getAssociatedConstraints(AC2);
12056 bool AtLeastAsConstrained1, AtLeastAsConstrained2;
12057 if (IsAtLeastAsConstrained(FD1, AC1, FD2, AC2, AtLeastAsConstrained1))
12059 if (IsAtLeastAsConstrained(FD2, AC2, FD1, AC1, AtLeastAsConstrained2))
12061 if (AtLeastAsConstrained1 == AtLeastAsConstrained2)
12063 return AtLeastAsConstrained1;
12066 // Don't use the AddressOfResolver because we're specifically looking for
12067 // cases where we have one overload candidate that lacks
12068 // enable_if/pass_object_size/...
12069 for (auto I = Ovl->decls_begin(), E = Ovl->decls_end(); I != E; ++I) {
12070 auto *FD = dyn_cast<FunctionDecl>(I->getUnderlyingDecl());
12074 if (!checkAddressOfFunctionIsAvailable(FD))
12077 // We have more than one result - see if it is more constrained than the
12080 Optional<bool> MoreConstrainedThanPrevious = CheckMoreConstrained(FD,
12082 if (!MoreConstrainedThanPrevious) {
12083 IsResultAmbiguous = true;
12084 AmbiguousDecls.push_back(FD);
12087 if (!*MoreConstrainedThanPrevious)
12089 // FD is more constrained - replace Result with it.
12091 IsResultAmbiguous = false;
12096 if (IsResultAmbiguous)
12100 SmallVector<const Expr *, 1> ResultAC;
12101 // We skipped over some ambiguous declarations which might be ambiguous with
12102 // the selected result.
12103 for (FunctionDecl *Skipped : AmbiguousDecls)
12104 if (!CheckMoreConstrained(Skipped, Result).hasValue())
12111 /// Given an overloaded function, tries to turn it into a non-overloaded
12112 /// function reference using resolveAddressOfSingleOverloadCandidate. This
12113 /// will perform access checks, diagnose the use of the resultant decl, and, if
12114 /// requested, potentially perform a function-to-pointer decay.
12116 /// Returns false if resolveAddressOfSingleOverloadCandidate fails.
12117 /// Otherwise, returns true. This may emit diagnostics and return true.
12118 bool Sema::resolveAndFixAddressOfSingleOverloadCandidate(
12119 ExprResult &SrcExpr, bool DoFunctionPointerConverion) {
12120 Expr *E = SrcExpr.get();
12121 assert(E->getType() == Context.OverloadTy && "SrcExpr must be an overload");
12123 DeclAccessPair DAP;
12124 FunctionDecl *Found = resolveAddressOfSingleOverloadCandidate(E, DAP);
12125 if (!Found || Found->isCPUDispatchMultiVersion() ||
12126 Found->isCPUSpecificMultiVersion())
12129 // Emitting multiple diagnostics for a function that is both inaccessible and
12130 // unavailable is consistent with our behavior elsewhere. So, always check
12132 DiagnoseUseOfDecl(Found, E->getExprLoc());
12133 CheckAddressOfMemberAccess(E, DAP);
12134 Expr *Fixed = FixOverloadedFunctionReference(E, DAP, Found);
12135 if (DoFunctionPointerConverion && Fixed->getType()->isFunctionType())
12136 SrcExpr = DefaultFunctionArrayConversion(Fixed, /*Diagnose=*/false);
12142 /// Given an expression that refers to an overloaded function, try to
12143 /// resolve that overloaded function expression down to a single function.
12145 /// This routine can only resolve template-ids that refer to a single function
12146 /// template, where that template-id refers to a single template whose template
12147 /// arguments are either provided by the template-id or have defaults,
12148 /// as described in C++0x [temp.arg.explicit]p3.
12150 /// If no template-ids are found, no diagnostics are emitted and NULL is
12153 Sema::ResolveSingleFunctionTemplateSpecialization(OverloadExpr *ovl,
12155 DeclAccessPair *FoundResult) {
12156 // C++ [over.over]p1:
12157 // [...] [Note: any redundant set of parentheses surrounding the
12158 // overloaded function name is ignored (5.1). ]
12159 // C++ [over.over]p1:
12160 // [...] The overloaded function name can be preceded by the &
12163 // If we didn't actually find any template-ids, we're done.
12164 if (!ovl->hasExplicitTemplateArgs())
12167 TemplateArgumentListInfo ExplicitTemplateArgs;
12168 ovl->copyTemplateArgumentsInto(ExplicitTemplateArgs);
12169 TemplateSpecCandidateSet FailedCandidates(ovl->getNameLoc());
12171 // Look through all of the overloaded functions, searching for one
12172 // whose type matches exactly.
12173 FunctionDecl *Matched = nullptr;
12174 for (UnresolvedSetIterator I = ovl->decls_begin(),
12175 E = ovl->decls_end(); I != E; ++I) {
12176 // C++0x [temp.arg.explicit]p3:
12177 // [...] In contexts where deduction is done and fails, or in contexts
12178 // where deduction is not done, if a template argument list is
12179 // specified and it, along with any default template arguments,
12180 // identifies a single function template specialization, then the
12181 // template-id is an lvalue for the function template specialization.
12182 FunctionTemplateDecl *FunctionTemplate
12183 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl());
12185 // C++ [over.over]p2:
12186 // If the name is a function template, template argument deduction is
12187 // done (14.8.2.2), and if the argument deduction succeeds, the
12188 // resulting template argument list is used to generate a single
12189 // function template specialization, which is added to the set of
12190 // overloaded functions considered.
12191 FunctionDecl *Specialization = nullptr;
12192 TemplateDeductionInfo Info(FailedCandidates.getLocation());
12193 if (TemplateDeductionResult Result
12194 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs,
12195 Specialization, Info,
12196 /*IsAddressOfFunction*/true)) {
12197 // Make a note of the failed deduction for diagnostics.
12198 // TODO: Actually use the failed-deduction info?
12199 FailedCandidates.addCandidate()
12200 .set(I.getPair(), FunctionTemplate->getTemplatedDecl(),
12201 MakeDeductionFailureInfo(Context, Result, Info));
12205 assert(Specialization && "no specialization and no error?");
12207 // Multiple matches; we can't resolve to a single declaration.
12210 Diag(ovl->getExprLoc(), diag::err_addr_ovl_ambiguous)
12212 NoteAllOverloadCandidates(ovl);
12217 Matched = Specialization;
12218 if (FoundResult) *FoundResult = I.getPair();
12222 completeFunctionType(*this, Matched, ovl->getExprLoc(), Complain))
12228 // Resolve and fix an overloaded expression that can be resolved
12229 // because it identifies a single function template specialization.
12231 // Last three arguments should only be supplied if Complain = true
12233 // Return true if it was logically possible to so resolve the
12234 // expression, regardless of whether or not it succeeded. Always
12235 // returns true if 'complain' is set.
12236 bool Sema::ResolveAndFixSingleFunctionTemplateSpecialization(
12237 ExprResult &SrcExpr, bool doFunctionPointerConverion,
12238 bool complain, SourceRange OpRangeForComplaining,
12239 QualType DestTypeForComplaining,
12240 unsigned DiagIDForComplaining) {
12241 assert(SrcExpr.get()->getType() == Context.OverloadTy);
12243 OverloadExpr::FindResult ovl = OverloadExpr::find(SrcExpr.get());
12245 DeclAccessPair found;
12246 ExprResult SingleFunctionExpression;
12247 if (FunctionDecl *fn = ResolveSingleFunctionTemplateSpecialization(
12248 ovl.Expression, /*complain*/ false, &found)) {
12249 if (DiagnoseUseOfDecl(fn, SrcExpr.get()->getBeginLoc())) {
12250 SrcExpr = ExprError();
12254 // It is only correct to resolve to an instance method if we're
12255 // resolving a form that's permitted to be a pointer to member.
12256 // Otherwise we'll end up making a bound member expression, which
12257 // is illegal in all the contexts we resolve like this.
12258 if (!ovl.HasFormOfMemberPointer &&
12259 isa<CXXMethodDecl>(fn) &&
12260 cast<CXXMethodDecl>(fn)->isInstance()) {
12261 if (!complain) return false;
12263 Diag(ovl.Expression->getExprLoc(),
12264 diag::err_bound_member_function)
12265 << 0 << ovl.Expression->getSourceRange();
12267 // TODO: I believe we only end up here if there's a mix of
12268 // static and non-static candidates (otherwise the expression
12269 // would have 'bound member' type, not 'overload' type).
12270 // Ideally we would note which candidate was chosen and why
12271 // the static candidates were rejected.
12272 SrcExpr = ExprError();
12276 // Fix the expression to refer to 'fn'.
12277 SingleFunctionExpression =
12278 FixOverloadedFunctionReference(SrcExpr.get(), found, fn);
12280 // If desired, do function-to-pointer decay.
12281 if (doFunctionPointerConverion) {
12282 SingleFunctionExpression =
12283 DefaultFunctionArrayLvalueConversion(SingleFunctionExpression.get());
12284 if (SingleFunctionExpression.isInvalid()) {
12285 SrcExpr = ExprError();
12291 if (!SingleFunctionExpression.isUsable()) {
12293 Diag(OpRangeForComplaining.getBegin(), DiagIDForComplaining)
12294 << ovl.Expression->getName()
12295 << DestTypeForComplaining
12296 << OpRangeForComplaining
12297 << ovl.Expression->getQualifierLoc().getSourceRange();
12298 NoteAllOverloadCandidates(SrcExpr.get());
12300 SrcExpr = ExprError();
12307 SrcExpr = SingleFunctionExpression;
12311 /// Add a single candidate to the overload set.
12312 static void AddOverloadedCallCandidate(Sema &S,
12313 DeclAccessPair FoundDecl,
12314 TemplateArgumentListInfo *ExplicitTemplateArgs,
12315 ArrayRef<Expr *> Args,
12316 OverloadCandidateSet &CandidateSet,
12317 bool PartialOverloading,
12319 NamedDecl *Callee = FoundDecl.getDecl();
12320 if (isa<UsingShadowDecl>(Callee))
12321 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl();
12323 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) {
12324 if (ExplicitTemplateArgs) {
12325 assert(!KnownValid && "Explicit template arguments?");
12328 // Prevent ill-formed function decls to be added as overload candidates.
12329 if (!dyn_cast<FunctionProtoType>(Func->getType()->getAs<FunctionType>()))
12332 S.AddOverloadCandidate(Func, FoundDecl, Args, CandidateSet,
12333 /*SuppressUserConversions=*/false,
12334 PartialOverloading);
12338 if (FunctionTemplateDecl *FuncTemplate
12339 = dyn_cast<FunctionTemplateDecl>(Callee)) {
12340 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl,
12341 ExplicitTemplateArgs, Args, CandidateSet,
12342 /*SuppressUserConversions=*/false,
12343 PartialOverloading);
12347 assert(!KnownValid && "unhandled case in overloaded call candidate");
12350 /// Add the overload candidates named by callee and/or found by argument
12351 /// dependent lookup to the given overload set.
12352 void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE,
12353 ArrayRef<Expr *> Args,
12354 OverloadCandidateSet &CandidateSet,
12355 bool PartialOverloading) {
12358 // Verify that ArgumentDependentLookup is consistent with the rules
12359 // in C++0x [basic.lookup.argdep]p3:
12361 // Let X be the lookup set produced by unqualified lookup (3.4.1)
12362 // and let Y be the lookup set produced by argument dependent
12363 // lookup (defined as follows). If X contains
12365 // -- a declaration of a class member, or
12367 // -- a block-scope function declaration that is not a
12368 // using-declaration, or
12370 // -- a declaration that is neither a function or a function
12373 // then Y is empty.
12375 if (ULE->requiresADL()) {
12376 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(),
12377 E = ULE->decls_end(); I != E; ++I) {
12378 assert(!(*I)->getDeclContext()->isRecord());
12379 assert(isa<UsingShadowDecl>(*I) ||
12380 !(*I)->getDeclContext()->isFunctionOrMethod());
12381 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate());
12386 // It would be nice to avoid this copy.
12387 TemplateArgumentListInfo TABuffer;
12388 TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr;
12389 if (ULE->hasExplicitTemplateArgs()) {
12390 ULE->copyTemplateArgumentsInto(TABuffer);
12391 ExplicitTemplateArgs = &TABuffer;
12394 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(),
12395 E = ULE->decls_end(); I != E; ++I)
12396 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, Args,
12397 CandidateSet, PartialOverloading,
12398 /*KnownValid*/ true);
12400 if (ULE->requiresADL())
12401 AddArgumentDependentLookupCandidates(ULE->getName(), ULE->getExprLoc(),
12402 Args, ExplicitTemplateArgs,
12403 CandidateSet, PartialOverloading);
12406 /// Determine whether a declaration with the specified name could be moved into
12407 /// a different namespace.
12408 static bool canBeDeclaredInNamespace(const DeclarationName &Name) {
12409 switch (Name.getCXXOverloadedOperator()) {
12410 case OO_New: case OO_Array_New:
12411 case OO_Delete: case OO_Array_Delete:
12419 /// Attempt to recover from an ill-formed use of a non-dependent name in a
12420 /// template, where the non-dependent name was declared after the template
12421 /// was defined. This is common in code written for a compilers which do not
12422 /// correctly implement two-stage name lookup.
12424 /// Returns true if a viable candidate was found and a diagnostic was issued.
12426 DiagnoseTwoPhaseLookup(Sema &SemaRef, SourceLocation FnLoc,
12427 const CXXScopeSpec &SS, LookupResult &R,
12428 OverloadCandidateSet::CandidateSetKind CSK,
12429 TemplateArgumentListInfo *ExplicitTemplateArgs,
12430 ArrayRef<Expr *> Args,
12431 bool *DoDiagnoseEmptyLookup = nullptr) {
12432 if (!SemaRef.inTemplateInstantiation() || !SS.isEmpty())
12435 for (DeclContext *DC = SemaRef.CurContext; DC; DC = DC->getParent()) {
12436 if (DC->isTransparentContext())
12439 SemaRef.LookupQualifiedName(R, DC);
12442 R.suppressDiagnostics();
12444 if (isa<CXXRecordDecl>(DC)) {
12445 // Don't diagnose names we find in classes; we get much better
12446 // diagnostics for these from DiagnoseEmptyLookup.
12448 if (DoDiagnoseEmptyLookup)
12449 *DoDiagnoseEmptyLookup = true;
12453 OverloadCandidateSet Candidates(FnLoc, CSK);
12454 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
12455 AddOverloadedCallCandidate(SemaRef, I.getPair(),
12456 ExplicitTemplateArgs, Args,
12457 Candidates, false, /*KnownValid*/ false);
12459 OverloadCandidateSet::iterator Best;
12460 if (Candidates.BestViableFunction(SemaRef, FnLoc, Best) != OR_Success) {
12461 // No viable functions. Don't bother the user with notes for functions
12462 // which don't work and shouldn't be found anyway.
12467 // Find the namespaces where ADL would have looked, and suggest
12468 // declaring the function there instead.
12469 Sema::AssociatedNamespaceSet AssociatedNamespaces;
12470 Sema::AssociatedClassSet AssociatedClasses;
12471 SemaRef.FindAssociatedClassesAndNamespaces(FnLoc, Args,
12472 AssociatedNamespaces,
12473 AssociatedClasses);
12474 Sema::AssociatedNamespaceSet SuggestedNamespaces;
12475 if (canBeDeclaredInNamespace(R.getLookupName())) {
12476 DeclContext *Std = SemaRef.getStdNamespace();
12477 for (Sema::AssociatedNamespaceSet::iterator
12478 it = AssociatedNamespaces.begin(),
12479 end = AssociatedNamespaces.end(); it != end; ++it) {
12480 // Never suggest declaring a function within namespace 'std'.
12481 if (Std && Std->Encloses(*it))
12484 // Never suggest declaring a function within a namespace with a
12485 // reserved name, like __gnu_cxx.
12486 NamespaceDecl *NS = dyn_cast<NamespaceDecl>(*it);
12488 NS->getQualifiedNameAsString().find("__") != std::string::npos)
12491 SuggestedNamespaces.insert(*it);
12495 SemaRef.Diag(R.getNameLoc(), diag::err_not_found_by_two_phase_lookup)
12496 << R.getLookupName();
12497 if (SuggestedNamespaces.empty()) {
12498 SemaRef.Diag(Best->Function->getLocation(),
12499 diag::note_not_found_by_two_phase_lookup)
12500 << R.getLookupName() << 0;
12501 } else if (SuggestedNamespaces.size() == 1) {
12502 SemaRef.Diag(Best->Function->getLocation(),
12503 diag::note_not_found_by_two_phase_lookup)
12504 << R.getLookupName() << 1 << *SuggestedNamespaces.begin();
12506 // FIXME: It would be useful to list the associated namespaces here,
12507 // but the diagnostics infrastructure doesn't provide a way to produce
12508 // a localized representation of a list of items.
12509 SemaRef.Diag(Best->Function->getLocation(),
12510 diag::note_not_found_by_two_phase_lookup)
12511 << R.getLookupName() << 2;
12514 // Try to recover by calling this function.
12524 /// Attempt to recover from ill-formed use of a non-dependent operator in a
12525 /// template, where the non-dependent operator was declared after the template
12528 /// Returns true if a viable candidate was found and a diagnostic was issued.
12530 DiagnoseTwoPhaseOperatorLookup(Sema &SemaRef, OverloadedOperatorKind Op,
12531 SourceLocation OpLoc,
12532 ArrayRef<Expr *> Args) {
12533 DeclarationName OpName =
12534 SemaRef.Context.DeclarationNames.getCXXOperatorName(Op);
12535 LookupResult R(SemaRef, OpName, OpLoc, Sema::LookupOperatorName);
12536 return DiagnoseTwoPhaseLookup(SemaRef, OpLoc, CXXScopeSpec(), R,
12537 OverloadCandidateSet::CSK_Operator,
12538 /*ExplicitTemplateArgs=*/nullptr, Args);
12542 class BuildRecoveryCallExprRAII {
12545 BuildRecoveryCallExprRAII(Sema &S) : SemaRef(S) {
12546 assert(SemaRef.IsBuildingRecoveryCallExpr == false);
12547 SemaRef.IsBuildingRecoveryCallExpr = true;
12550 ~BuildRecoveryCallExprRAII() {
12551 SemaRef.IsBuildingRecoveryCallExpr = false;
12557 /// Attempts to recover from a call where no functions were found.
12559 /// Returns true if new candidates were found.
12561 BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn,
12562 UnresolvedLookupExpr *ULE,
12563 SourceLocation LParenLoc,
12564 MutableArrayRef<Expr *> Args,
12565 SourceLocation RParenLoc,
12566 bool EmptyLookup, bool AllowTypoCorrection) {
12567 // Do not try to recover if it is already building a recovery call.
12568 // This stops infinite loops for template instantiations like
12570 // template <typename T> auto foo(T t) -> decltype(foo(t)) {}
12571 // template <typename T> auto foo(T t) -> decltype(foo(&t)) {}
12573 if (SemaRef.IsBuildingRecoveryCallExpr)
12574 return ExprError();
12575 BuildRecoveryCallExprRAII RCE(SemaRef);
12578 SS.Adopt(ULE->getQualifierLoc());
12579 SourceLocation TemplateKWLoc = ULE->getTemplateKeywordLoc();
12581 TemplateArgumentListInfo TABuffer;
12582 TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr;
12583 if (ULE->hasExplicitTemplateArgs()) {
12584 ULE->copyTemplateArgumentsInto(TABuffer);
12585 ExplicitTemplateArgs = &TABuffer;
12588 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(),
12589 Sema::LookupOrdinaryName);
12590 bool DoDiagnoseEmptyLookup = EmptyLookup;
12591 if (!DiagnoseTwoPhaseLookup(
12592 SemaRef, Fn->getExprLoc(), SS, R, OverloadCandidateSet::CSK_Normal,
12593 ExplicitTemplateArgs, Args, &DoDiagnoseEmptyLookup)) {
12594 NoTypoCorrectionCCC NoTypoValidator{};
12595 FunctionCallFilterCCC FunctionCallValidator(SemaRef, Args.size(),
12596 ExplicitTemplateArgs != nullptr,
12597 dyn_cast<MemberExpr>(Fn));
12598 CorrectionCandidateCallback &Validator =
12599 AllowTypoCorrection
12600 ? static_cast<CorrectionCandidateCallback &>(FunctionCallValidator)
12601 : static_cast<CorrectionCandidateCallback &>(NoTypoValidator);
12602 if (!DoDiagnoseEmptyLookup ||
12603 SemaRef.DiagnoseEmptyLookup(S, SS, R, Validator, ExplicitTemplateArgs,
12605 return ExprError();
12608 assert(!R.empty() && "lookup results empty despite recovery");
12610 // If recovery created an ambiguity, just bail out.
12611 if (R.isAmbiguous()) {
12612 R.suppressDiagnostics();
12613 return ExprError();
12616 // Build an implicit member call if appropriate. Just drop the
12617 // casts and such from the call, we don't really care.
12618 ExprResult NewFn = ExprError();
12619 if ((*R.begin())->isCXXClassMember())
12620 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, TemplateKWLoc, R,
12621 ExplicitTemplateArgs, S);
12622 else if (ExplicitTemplateArgs || TemplateKWLoc.isValid())
12623 NewFn = SemaRef.BuildTemplateIdExpr(SS, TemplateKWLoc, R, false,
12624 ExplicitTemplateArgs);
12626 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false);
12628 if (NewFn.isInvalid())
12629 return ExprError();
12631 // This shouldn't cause an infinite loop because we're giving it
12632 // an expression with viable lookup results, which should never
12634 return SemaRef.BuildCallExpr(/*Scope*/ nullptr, NewFn.get(), LParenLoc,
12635 MultiExprArg(Args.data(), Args.size()),
12639 /// Constructs and populates an OverloadedCandidateSet from
12640 /// the given function.
12641 /// \returns true when an the ExprResult output parameter has been set.
12642 bool Sema::buildOverloadedCallSet(Scope *S, Expr *Fn,
12643 UnresolvedLookupExpr *ULE,
12645 SourceLocation RParenLoc,
12646 OverloadCandidateSet *CandidateSet,
12647 ExprResult *Result) {
12649 if (ULE->requiresADL()) {
12650 // To do ADL, we must have found an unqualified name.
12651 assert(!ULE->getQualifier() && "qualified name with ADL");
12653 // We don't perform ADL for implicit declarations of builtins.
12654 // Verify that this was correctly set up.
12656 if (ULE->decls_begin() != ULE->decls_end() &&
12657 ULE->decls_begin() + 1 == ULE->decls_end() &&
12658 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) &&
12659 F->getBuiltinID() && F->isImplicit())
12660 llvm_unreachable("performing ADL for builtin");
12662 // We don't perform ADL in C.
12663 assert(getLangOpts().CPlusPlus && "ADL enabled in C");
12667 UnbridgedCastsSet UnbridgedCasts;
12668 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts)) {
12669 *Result = ExprError();
12673 // Add the functions denoted by the callee to the set of candidate
12674 // functions, including those from argument-dependent lookup.
12675 AddOverloadedCallCandidates(ULE, Args, *CandidateSet);
12677 if (getLangOpts().MSVCCompat &&
12678 CurContext->isDependentContext() && !isSFINAEContext() &&
12679 (isa<FunctionDecl>(CurContext) || isa<CXXRecordDecl>(CurContext))) {
12681 OverloadCandidateSet::iterator Best;
12682 if (CandidateSet->empty() ||
12683 CandidateSet->BestViableFunction(*this, Fn->getBeginLoc(), Best) ==
12684 OR_No_Viable_Function) {
12685 // In Microsoft mode, if we are inside a template class member function
12686 // then create a type dependent CallExpr. The goal is to postpone name
12687 // lookup to instantiation time to be able to search into type dependent
12689 CallExpr *CE = CallExpr::Create(Context, Fn, Args, Context.DependentTy,
12690 VK_RValue, RParenLoc);
12691 CE->setTypeDependent(true);
12692 CE->setValueDependent(true);
12693 CE->setInstantiationDependent(true);
12699 if (CandidateSet->empty())
12702 UnbridgedCasts.restore();
12706 /// FinishOverloadedCallExpr - given an OverloadCandidateSet, builds and returns
12707 /// the completed call expression. If overload resolution fails, emits
12708 /// diagnostics and returns ExprError()
12709 static ExprResult FinishOverloadedCallExpr(Sema &SemaRef, Scope *S, Expr *Fn,
12710 UnresolvedLookupExpr *ULE,
12711 SourceLocation LParenLoc,
12713 SourceLocation RParenLoc,
12715 OverloadCandidateSet *CandidateSet,
12716 OverloadCandidateSet::iterator *Best,
12717 OverloadingResult OverloadResult,
12718 bool AllowTypoCorrection) {
12719 if (CandidateSet->empty())
12720 return BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc, Args,
12721 RParenLoc, /*EmptyLookup=*/true,
12722 AllowTypoCorrection);
12724 switch (OverloadResult) {
12726 FunctionDecl *FDecl = (*Best)->Function;
12727 SemaRef.CheckUnresolvedLookupAccess(ULE, (*Best)->FoundDecl);
12728 if (SemaRef.DiagnoseUseOfDecl(FDecl, ULE->getNameLoc()))
12729 return ExprError();
12730 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl);
12731 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, RParenLoc,
12732 ExecConfig, /*IsExecConfig=*/false,
12733 (*Best)->IsADLCandidate);
12736 case OR_No_Viable_Function: {
12737 // Try to recover by looking for viable functions which the user might
12738 // have meant to call.
12739 ExprResult Recovery = BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc,
12741 /*EmptyLookup=*/false,
12742 AllowTypoCorrection);
12743 if (!Recovery.isInvalid())
12746 // If the user passes in a function that we can't take the address of, we
12747 // generally end up emitting really bad error messages. Here, we attempt to
12748 // emit better ones.
12749 for (const Expr *Arg : Args) {
12750 if (!Arg->getType()->isFunctionType())
12752 if (auto *DRE = dyn_cast<DeclRefExpr>(Arg->IgnoreParenImpCasts())) {
12753 auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl());
12755 !SemaRef.checkAddressOfFunctionIsAvailable(FD, /*Complain=*/true,
12756 Arg->getExprLoc()))
12757 return ExprError();
12761 CandidateSet->NoteCandidates(
12762 PartialDiagnosticAt(
12764 SemaRef.PDiag(diag::err_ovl_no_viable_function_in_call)
12765 << ULE->getName() << Fn->getSourceRange()),
12766 SemaRef, OCD_AllCandidates, Args);
12771 CandidateSet->NoteCandidates(
12772 PartialDiagnosticAt(Fn->getBeginLoc(),
12773 SemaRef.PDiag(diag::err_ovl_ambiguous_call)
12774 << ULE->getName() << Fn->getSourceRange()),
12775 SemaRef, OCD_AmbiguousCandidates, Args);
12779 CandidateSet->NoteCandidates(
12780 PartialDiagnosticAt(Fn->getBeginLoc(),
12781 SemaRef.PDiag(diag::err_ovl_deleted_call)
12782 << ULE->getName() << Fn->getSourceRange()),
12783 SemaRef, OCD_AllCandidates, Args);
12785 // We emitted an error for the unavailable/deleted function call but keep
12786 // the call in the AST.
12787 FunctionDecl *FDecl = (*Best)->Function;
12788 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl);
12789 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, RParenLoc,
12790 ExecConfig, /*IsExecConfig=*/false,
12791 (*Best)->IsADLCandidate);
12795 // Overload resolution failed.
12796 return ExprError();
12799 static void markUnaddressableCandidatesUnviable(Sema &S,
12800 OverloadCandidateSet &CS) {
12801 for (auto I = CS.begin(), E = CS.end(); I != E; ++I) {
12803 !S.checkAddressOfFunctionIsAvailable(I->Function, /*Complain=*/false)) {
12805 I->FailureKind = ovl_fail_addr_not_available;
12810 /// BuildOverloadedCallExpr - Given the call expression that calls Fn
12811 /// (which eventually refers to the declaration Func) and the call
12812 /// arguments Args/NumArgs, attempt to resolve the function call down
12813 /// to a specific function. If overload resolution succeeds, returns
12814 /// the call expression produced by overload resolution.
12815 /// Otherwise, emits diagnostics and returns ExprError.
12816 ExprResult Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn,
12817 UnresolvedLookupExpr *ULE,
12818 SourceLocation LParenLoc,
12820 SourceLocation RParenLoc,
12822 bool AllowTypoCorrection,
12823 bool CalleesAddressIsTaken) {
12824 OverloadCandidateSet CandidateSet(Fn->getExprLoc(),
12825 OverloadCandidateSet::CSK_Normal);
12828 if (buildOverloadedCallSet(S, Fn, ULE, Args, LParenLoc, &CandidateSet,
12832 // If the user handed us something like `(&Foo)(Bar)`, we need to ensure that
12833 // functions that aren't addressible are considered unviable.
12834 if (CalleesAddressIsTaken)
12835 markUnaddressableCandidatesUnviable(*this, CandidateSet);
12837 OverloadCandidateSet::iterator Best;
12838 OverloadingResult OverloadResult =
12839 CandidateSet.BestViableFunction(*this, Fn->getBeginLoc(), Best);
12841 return FinishOverloadedCallExpr(*this, S, Fn, ULE, LParenLoc, Args, RParenLoc,
12842 ExecConfig, &CandidateSet, &Best,
12843 OverloadResult, AllowTypoCorrection);
12846 static bool IsOverloaded(const UnresolvedSetImpl &Functions) {
12847 return Functions.size() > 1 ||
12848 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin()));
12851 /// Create a unary operation that may resolve to an overloaded
12854 /// \param OpLoc The location of the operator itself (e.g., '*').
12856 /// \param Opc The UnaryOperatorKind that describes this operator.
12858 /// \param Fns The set of non-member functions that will be
12859 /// considered by overload resolution. The caller needs to build this
12860 /// set based on the context using, e.g.,
12861 /// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This
12862 /// set should not contain any member functions; those will be added
12863 /// by CreateOverloadedUnaryOp().
12865 /// \param Input The input argument.
12867 Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, UnaryOperatorKind Opc,
12868 const UnresolvedSetImpl &Fns,
12869 Expr *Input, bool PerformADL) {
12870 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc);
12871 assert(Op != OO_None && "Invalid opcode for overloaded unary operator");
12872 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
12873 // TODO: provide better source location info.
12874 DeclarationNameInfo OpNameInfo(OpName, OpLoc);
12876 if (checkPlaceholderForOverload(*this, Input))
12877 return ExprError();
12879 Expr *Args[2] = { Input, nullptr };
12880 unsigned NumArgs = 1;
12882 // For post-increment and post-decrement, add the implicit '0' as
12883 // the second argument, so that we know this is a post-increment or
12885 if (Opc == UO_PostInc || Opc == UO_PostDec) {
12886 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false);
12887 Args[1] = IntegerLiteral::Create(Context, Zero, Context.IntTy,
12892 ArrayRef<Expr *> ArgsArray(Args, NumArgs);
12894 if (Input->isTypeDependent()) {
12896 return new (Context) UnaryOperator(Input, Opc, Context.DependentTy,
12897 VK_RValue, OK_Ordinary, OpLoc, false);
12899 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
12900 UnresolvedLookupExpr *Fn = UnresolvedLookupExpr::Create(
12901 Context, NamingClass, NestedNameSpecifierLoc(), OpNameInfo,
12902 /*ADL*/ true, IsOverloaded(Fns), Fns.begin(), Fns.end());
12903 return CXXOperatorCallExpr::Create(Context, Op, Fn, ArgsArray,
12904 Context.DependentTy, VK_RValue, OpLoc,
12908 // Build an empty overload set.
12909 OverloadCandidateSet CandidateSet(OpLoc, OverloadCandidateSet::CSK_Operator);
12911 // Add the candidates from the given function set.
12912 AddNonMemberOperatorCandidates(Fns, ArgsArray, CandidateSet);
12914 // Add operator candidates that are member functions.
12915 AddMemberOperatorCandidates(Op, OpLoc, ArgsArray, CandidateSet);
12917 // Add candidates from ADL.
12919 AddArgumentDependentLookupCandidates(OpName, OpLoc, ArgsArray,
12920 /*ExplicitTemplateArgs*/nullptr,
12924 // Add builtin operator candidates.
12925 AddBuiltinOperatorCandidates(Op, OpLoc, ArgsArray, CandidateSet);
12927 bool HadMultipleCandidates = (CandidateSet.size() > 1);
12929 // Perform overload resolution.
12930 OverloadCandidateSet::iterator Best;
12931 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
12933 // We found a built-in operator or an overloaded operator.
12934 FunctionDecl *FnDecl = Best->Function;
12937 Expr *Base = nullptr;
12938 // We matched an overloaded operator. Build a call to that
12941 // Convert the arguments.
12942 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) {
12943 CheckMemberOperatorAccess(OpLoc, Args[0], nullptr, Best->FoundDecl);
12945 ExprResult InputRes =
12946 PerformObjectArgumentInitialization(Input, /*Qualifier=*/nullptr,
12947 Best->FoundDecl, Method);
12948 if (InputRes.isInvalid())
12949 return ExprError();
12950 Base = Input = InputRes.get();
12952 // Convert the arguments.
12953 ExprResult InputInit
12954 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
12956 FnDecl->getParamDecl(0)),
12959 if (InputInit.isInvalid())
12960 return ExprError();
12961 Input = InputInit.get();
12964 // Build the actual expression node.
12965 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, Best->FoundDecl,
12966 Base, HadMultipleCandidates,
12968 if (FnExpr.isInvalid())
12969 return ExprError();
12971 // Determine the result type.
12972 QualType ResultTy = FnDecl->getReturnType();
12973 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
12974 ResultTy = ResultTy.getNonLValueExprType(Context);
12977 CallExpr *TheCall = CXXOperatorCallExpr::Create(
12978 Context, Op, FnExpr.get(), ArgsArray, ResultTy, VK, OpLoc,
12979 FPOptions(), Best->IsADLCandidate);
12981 if (CheckCallReturnType(FnDecl->getReturnType(), OpLoc, TheCall, FnDecl))
12982 return ExprError();
12984 if (CheckFunctionCall(FnDecl, TheCall,
12985 FnDecl->getType()->castAs<FunctionProtoType>()))
12986 return ExprError();
12988 return MaybeBindToTemporary(TheCall);
12990 // We matched a built-in operator. Convert the arguments, then
12991 // break out so that we will build the appropriate built-in
12993 ExprResult InputRes = PerformImplicitConversion(
12994 Input, Best->BuiltinParamTypes[0], Best->Conversions[0], AA_Passing,
12995 CCK_ForBuiltinOverloadedOp);
12996 if (InputRes.isInvalid())
12997 return ExprError();
12998 Input = InputRes.get();
13003 case OR_No_Viable_Function:
13004 // This is an erroneous use of an operator which can be overloaded by
13005 // a non-member function. Check for non-member operators which were
13006 // defined too late to be candidates.
13007 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, ArgsArray))
13008 // FIXME: Recover by calling the found function.
13009 return ExprError();
13011 // No viable function; fall through to handling this as a
13012 // built-in operator, which will produce an error message for us.
13016 CandidateSet.NoteCandidates(
13017 PartialDiagnosticAt(OpLoc,
13018 PDiag(diag::err_ovl_ambiguous_oper_unary)
13019 << UnaryOperator::getOpcodeStr(Opc)
13020 << Input->getType() << Input->getSourceRange()),
13021 *this, OCD_AmbiguousCandidates, ArgsArray,
13022 UnaryOperator::getOpcodeStr(Opc), OpLoc);
13023 return ExprError();
13026 CandidateSet.NoteCandidates(
13027 PartialDiagnosticAt(OpLoc, PDiag(diag::err_ovl_deleted_oper)
13028 << UnaryOperator::getOpcodeStr(Opc)
13029 << Input->getSourceRange()),
13030 *this, OCD_AllCandidates, ArgsArray, UnaryOperator::getOpcodeStr(Opc),
13032 return ExprError();
13035 // Either we found no viable overloaded operator or we matched a
13036 // built-in operator. In either case, fall through to trying to
13037 // build a built-in operation.
13038 return CreateBuiltinUnaryOp(OpLoc, Opc, Input);
13041 /// Perform lookup for an overloaded binary operator.
13042 void Sema::LookupOverloadedBinOp(OverloadCandidateSet &CandidateSet,
13043 OverloadedOperatorKind Op,
13044 const UnresolvedSetImpl &Fns,
13045 ArrayRef<Expr *> Args, bool PerformADL) {
13046 SourceLocation OpLoc = CandidateSet.getLocation();
13048 OverloadedOperatorKind ExtraOp =
13049 CandidateSet.getRewriteInfo().AllowRewrittenCandidates
13050 ? getRewrittenOverloadedOperator(Op)
13053 // Add the candidates from the given function set. This also adds the
13054 // rewritten candidates using these functions if necessary.
13055 AddNonMemberOperatorCandidates(Fns, Args, CandidateSet);
13057 // Add operator candidates that are member functions.
13058 AddMemberOperatorCandidates(Op, OpLoc, Args, CandidateSet);
13059 if (CandidateSet.getRewriteInfo().shouldAddReversed(Op))
13060 AddMemberOperatorCandidates(Op, OpLoc, {Args[1], Args[0]}, CandidateSet,
13061 OverloadCandidateParamOrder::Reversed);
13063 // In C++20, also add any rewritten member candidates.
13065 AddMemberOperatorCandidates(ExtraOp, OpLoc, Args, CandidateSet);
13066 if (CandidateSet.getRewriteInfo().shouldAddReversed(ExtraOp))
13067 AddMemberOperatorCandidates(ExtraOp, OpLoc, {Args[1], Args[0]},
13069 OverloadCandidateParamOrder::Reversed);
13072 // Add candidates from ADL. Per [over.match.oper]p2, this lookup is not
13073 // performed for an assignment operator (nor for operator[] nor operator->,
13074 // which don't get here).
13075 if (Op != OO_Equal && PerformADL) {
13076 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
13077 AddArgumentDependentLookupCandidates(OpName, OpLoc, Args,
13078 /*ExplicitTemplateArgs*/ nullptr,
13081 DeclarationName ExtraOpName =
13082 Context.DeclarationNames.getCXXOperatorName(ExtraOp);
13083 AddArgumentDependentLookupCandidates(ExtraOpName, OpLoc, Args,
13084 /*ExplicitTemplateArgs*/ nullptr,
13089 // Add builtin operator candidates.
13091 // FIXME: We don't add any rewritten candidates here. This is strictly
13092 // incorrect; a builtin candidate could be hidden by a non-viable candidate,
13093 // resulting in our selecting a rewritten builtin candidate. For example:
13095 // enum class E { e };
13096 // bool operator!=(E, E) requires false;
13097 // bool k = E::e != E::e;
13099 // ... should select the rewritten builtin candidate 'operator==(E, E)'. But
13100 // it seems unreasonable to consider rewritten builtin candidates. A core
13101 // issue has been filed proposing to removed this requirement.
13102 AddBuiltinOperatorCandidates(Op, OpLoc, Args, CandidateSet);
13105 /// Create a binary operation that may resolve to an overloaded
13108 /// \param OpLoc The location of the operator itself (e.g., '+').
13110 /// \param Opc The BinaryOperatorKind that describes this operator.
13112 /// \param Fns The set of non-member functions that will be
13113 /// considered by overload resolution. The caller needs to build this
13114 /// set based on the context using, e.g.,
13115 /// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This
13116 /// set should not contain any member functions; those will be added
13117 /// by CreateOverloadedBinOp().
13119 /// \param LHS Left-hand argument.
13120 /// \param RHS Right-hand argument.
13121 /// \param PerformADL Whether to consider operator candidates found by ADL.
13122 /// \param AllowRewrittenCandidates Whether to consider candidates found by
13123 /// C++20 operator rewrites.
13124 /// \param DefaultedFn If we are synthesizing a defaulted operator function,
13125 /// the function in question. Such a function is never a candidate in
13126 /// our overload resolution. This also enables synthesizing a three-way
13127 /// comparison from < and == as described in C++20 [class.spaceship]p1.
13128 ExprResult Sema::CreateOverloadedBinOp(SourceLocation OpLoc,
13129 BinaryOperatorKind Opc,
13130 const UnresolvedSetImpl &Fns, Expr *LHS,
13131 Expr *RHS, bool PerformADL,
13132 bool AllowRewrittenCandidates,
13133 FunctionDecl *DefaultedFn) {
13134 Expr *Args[2] = { LHS, RHS };
13135 LHS=RHS=nullptr; // Please use only Args instead of LHS/RHS couple
13137 if (!getLangOpts().CPlusPlus2a)
13138 AllowRewrittenCandidates = false;
13140 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc);
13142 // If either side is type-dependent, create an appropriate dependent
13144 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) {
13146 // If there are no functions to store, just build a dependent
13147 // BinaryOperator or CompoundAssignment.
13148 if (Opc <= BO_Assign || Opc > BO_OrAssign)
13149 return new (Context) BinaryOperator(
13150 Args[0], Args[1], Opc, Context.DependentTy, VK_RValue, OK_Ordinary,
13151 OpLoc, FPFeatures);
13153 return new (Context) CompoundAssignOperator(
13154 Args[0], Args[1], Opc, Context.DependentTy, VK_LValue, OK_Ordinary,
13155 Context.DependentTy, Context.DependentTy, OpLoc,
13159 // FIXME: save results of ADL from here?
13160 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
13161 // TODO: provide better source location info in DNLoc component.
13162 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
13163 DeclarationNameInfo OpNameInfo(OpName, OpLoc);
13164 UnresolvedLookupExpr *Fn = UnresolvedLookupExpr::Create(
13165 Context, NamingClass, NestedNameSpecifierLoc(), OpNameInfo,
13166 /*ADL*/ PerformADL, IsOverloaded(Fns), Fns.begin(), Fns.end());
13167 return CXXOperatorCallExpr::Create(Context, Op, Fn, Args,
13168 Context.DependentTy, VK_RValue, OpLoc,
13172 // Always do placeholder-like conversions on the RHS.
13173 if (checkPlaceholderForOverload(*this, Args[1]))
13174 return ExprError();
13176 // Do placeholder-like conversion on the LHS; note that we should
13177 // not get here with a PseudoObject LHS.
13178 assert(Args[0]->getObjectKind() != OK_ObjCProperty);
13179 if (checkPlaceholderForOverload(*this, Args[0]))
13180 return ExprError();
13182 // If this is the assignment operator, we only perform overload resolution
13183 // if the left-hand side is a class or enumeration type. This is actually
13184 // a hack. The standard requires that we do overload resolution between the
13185 // various built-in candidates, but as DR507 points out, this can lead to
13186 // problems. So we do it this way, which pretty much follows what GCC does.
13187 // Note that we go the traditional code path for compound assignment forms.
13188 if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType())
13189 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
13191 // If this is the .* operator, which is not overloadable, just
13192 // create a built-in binary operator.
13193 if (Opc == BO_PtrMemD)
13194 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
13196 // Build the overload set.
13197 OverloadCandidateSet CandidateSet(
13198 OpLoc, OverloadCandidateSet::CSK_Operator,
13199 OverloadCandidateSet::OperatorRewriteInfo(Op, AllowRewrittenCandidates));
13201 CandidateSet.exclude(DefaultedFn);
13202 LookupOverloadedBinOp(CandidateSet, Op, Fns, Args, PerformADL);
13204 bool HadMultipleCandidates = (CandidateSet.size() > 1);
13206 // Perform overload resolution.
13207 OverloadCandidateSet::iterator Best;
13208 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
13210 // We found a built-in operator or an overloaded operator.
13211 FunctionDecl *FnDecl = Best->Function;
13213 bool IsReversed = (Best->RewriteKind & CRK_Reversed);
13215 std::swap(Args[0], Args[1]);
13218 Expr *Base = nullptr;
13219 // We matched an overloaded operator. Build a call to that
13222 OverloadedOperatorKind ChosenOp =
13223 FnDecl->getDeclName().getCXXOverloadedOperator();
13225 // C++2a [over.match.oper]p9:
13226 // If a rewritten operator== candidate is selected by overload
13227 // resolution for an operator@, its return type shall be cv bool
13228 if (Best->RewriteKind && ChosenOp == OO_EqualEqual &&
13229 !FnDecl->getReturnType()->isBooleanType()) {
13230 Diag(OpLoc, diag::err_ovl_rewrite_equalequal_not_bool)
13231 << FnDecl->getReturnType() << BinaryOperator::getOpcodeStr(Opc)
13232 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
13233 Diag(FnDecl->getLocation(), diag::note_declared_at);
13234 return ExprError();
13237 if (AllowRewrittenCandidates && !IsReversed &&
13238 CandidateSet.getRewriteInfo().shouldAddReversed(ChosenOp)) {
13239 // We could have reversed this operator, but didn't. Check if the
13240 // reversed form was a viable candidate, and if so, if it had a
13241 // better conversion for either parameter. If so, this call is
13242 // formally ambiguous, and allowing it is an extension.
13243 for (OverloadCandidate &Cand : CandidateSet) {
13244 if (Cand.Viable && Cand.Function == FnDecl &&
13245 Cand.RewriteKind & CRK_Reversed) {
13246 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) {
13247 if (CompareImplicitConversionSequences(
13248 *this, OpLoc, Cand.Conversions[ArgIdx],
13249 Best->Conversions[ArgIdx]) ==
13250 ImplicitConversionSequence::Better) {
13251 Diag(OpLoc, diag::ext_ovl_ambiguous_oper_binary_reversed)
13252 << BinaryOperator::getOpcodeStr(Opc)
13253 << Args[0]->getType() << Args[1]->getType()
13254 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
13255 Diag(FnDecl->getLocation(),
13256 diag::note_ovl_ambiguous_oper_binary_reversed_candidate);
13264 // Convert the arguments.
13265 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) {
13266 // Best->Access is only meaningful for class members.
13267 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl);
13270 PerformCopyInitialization(
13271 InitializedEntity::InitializeParameter(Context,
13272 FnDecl->getParamDecl(0)),
13273 SourceLocation(), Args[1]);
13274 if (Arg1.isInvalid())
13275 return ExprError();
13278 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/nullptr,
13279 Best->FoundDecl, Method);
13280 if (Arg0.isInvalid())
13281 return ExprError();
13282 Base = Args[0] = Arg0.getAs<Expr>();
13283 Args[1] = RHS = Arg1.getAs<Expr>();
13285 // Convert the arguments.
13286 ExprResult Arg0 = PerformCopyInitialization(
13287 InitializedEntity::InitializeParameter(Context,
13288 FnDecl->getParamDecl(0)),
13289 SourceLocation(), Args[0]);
13290 if (Arg0.isInvalid())
13291 return ExprError();
13294 PerformCopyInitialization(
13295 InitializedEntity::InitializeParameter(Context,
13296 FnDecl->getParamDecl(1)),
13297 SourceLocation(), Args[1]);
13298 if (Arg1.isInvalid())
13299 return ExprError();
13300 Args[0] = LHS = Arg0.getAs<Expr>();
13301 Args[1] = RHS = Arg1.getAs<Expr>();
13304 // Build the actual expression node.
13305 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl,
13306 Best->FoundDecl, Base,
13307 HadMultipleCandidates, OpLoc);
13308 if (FnExpr.isInvalid())
13309 return ExprError();
13311 // Determine the result type.
13312 QualType ResultTy = FnDecl->getReturnType();
13313 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
13314 ResultTy = ResultTy.getNonLValueExprType(Context);
13316 CXXOperatorCallExpr *TheCall = CXXOperatorCallExpr::Create(
13317 Context, ChosenOp, FnExpr.get(), Args, ResultTy, VK, OpLoc,
13318 FPFeatures, Best->IsADLCandidate);
13320 if (CheckCallReturnType(FnDecl->getReturnType(), OpLoc, TheCall,
13322 return ExprError();
13324 ArrayRef<const Expr *> ArgsArray(Args, 2);
13325 const Expr *ImplicitThis = nullptr;
13326 // Cut off the implicit 'this'.
13327 if (isa<CXXMethodDecl>(FnDecl)) {
13328 ImplicitThis = ArgsArray[0];
13329 ArgsArray = ArgsArray.slice(1);
13332 // Check for a self move.
13333 if (Op == OO_Equal)
13334 DiagnoseSelfMove(Args[0], Args[1], OpLoc);
13336 checkCall(FnDecl, nullptr, ImplicitThis, ArgsArray,
13337 isa<CXXMethodDecl>(FnDecl), OpLoc, TheCall->getSourceRange(),
13338 VariadicDoesNotApply);
13340 ExprResult R = MaybeBindToTemporary(TheCall);
13342 return ExprError();
13344 // For a rewritten candidate, we've already reversed the arguments
13345 // if needed. Perform the rest of the rewrite now.
13346 if ((Best->RewriteKind & CRK_DifferentOperator) ||
13347 (Op == OO_Spaceship && IsReversed)) {
13348 if (Op == OO_ExclaimEqual) {
13349 assert(ChosenOp == OO_EqualEqual && "unexpected operator name");
13350 R = CreateBuiltinUnaryOp(OpLoc, UO_LNot, R.get());
13352 assert(ChosenOp == OO_Spaceship && "unexpected operator name");
13353 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false);
13354 Expr *ZeroLiteral =
13355 IntegerLiteral::Create(Context, Zero, Context.IntTy, OpLoc);
13357 Sema::CodeSynthesisContext Ctx;
13358 Ctx.Kind = Sema::CodeSynthesisContext::RewritingOperatorAsSpaceship;
13359 Ctx.Entity = FnDecl;
13360 pushCodeSynthesisContext(Ctx);
13362 R = CreateOverloadedBinOp(
13363 OpLoc, Opc, Fns, IsReversed ? ZeroLiteral : R.get(),
13364 IsReversed ? R.get() : ZeroLiteral, PerformADL,
13365 /*AllowRewrittenCandidates=*/false);
13367 popCodeSynthesisContext();
13370 return ExprError();
13372 assert(ChosenOp == Op && "unexpected operator name");
13375 // Make a note in the AST if we did any rewriting.
13376 if (Best->RewriteKind != CRK_None)
13377 R = new (Context) CXXRewrittenBinaryOperator(R.get(), IsReversed);
13381 // We matched a built-in operator. Convert the arguments, then
13382 // break out so that we will build the appropriate built-in
13384 ExprResult ArgsRes0 = PerformImplicitConversion(
13385 Args[0], Best->BuiltinParamTypes[0], Best->Conversions[0],
13386 AA_Passing, CCK_ForBuiltinOverloadedOp);
13387 if (ArgsRes0.isInvalid())
13388 return ExprError();
13389 Args[0] = ArgsRes0.get();
13391 ExprResult ArgsRes1 = PerformImplicitConversion(
13392 Args[1], Best->BuiltinParamTypes[1], Best->Conversions[1],
13393 AA_Passing, CCK_ForBuiltinOverloadedOp);
13394 if (ArgsRes1.isInvalid())
13395 return ExprError();
13396 Args[1] = ArgsRes1.get();
13401 case OR_No_Viable_Function: {
13402 // C++ [over.match.oper]p9:
13403 // If the operator is the operator , [...] and there are no
13404 // viable functions, then the operator is assumed to be the
13405 // built-in operator and interpreted according to clause 5.
13406 if (Opc == BO_Comma)
13409 // When defaulting an 'operator<=>', we can try to synthesize a three-way
13410 // compare result using '==' and '<'.
13411 if (DefaultedFn && Opc == BO_Cmp) {
13412 ExprResult E = BuildSynthesizedThreeWayComparison(OpLoc, Fns, Args[0],
13413 Args[1], DefaultedFn);
13414 if (E.isInvalid() || E.isUsable())
13418 // For class as left operand for assignment or compound assignment
13419 // operator do not fall through to handling in built-in, but report that
13420 // no overloaded assignment operator found
13421 ExprResult Result = ExprError();
13422 StringRef OpcStr = BinaryOperator::getOpcodeStr(Opc);
13423 auto Cands = CandidateSet.CompleteCandidates(*this, OCD_AllCandidates,
13425 if (Args[0]->getType()->isRecordType() &&
13426 Opc >= BO_Assign && Opc <= BO_OrAssign) {
13427 Diag(OpLoc, diag::err_ovl_no_viable_oper)
13428 << BinaryOperator::getOpcodeStr(Opc)
13429 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
13430 if (Args[0]->getType()->isIncompleteType()) {
13431 Diag(OpLoc, diag::note_assign_lhs_incomplete)
13432 << Args[0]->getType()
13433 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
13436 // This is an erroneous use of an operator which can be overloaded by
13437 // a non-member function. Check for non-member operators which were
13438 // defined too late to be candidates.
13439 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, Args))
13440 // FIXME: Recover by calling the found function.
13441 return ExprError();
13443 // No viable function; try to create a built-in operation, which will
13444 // produce an error. Then, show the non-viable candidates.
13445 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
13447 assert(Result.isInvalid() &&
13448 "C++ binary operator overloading is missing candidates!");
13449 CandidateSet.NoteCandidates(*this, Args, Cands, OpcStr, OpLoc);
13454 CandidateSet.NoteCandidates(
13455 PartialDiagnosticAt(OpLoc, PDiag(diag::err_ovl_ambiguous_oper_binary)
13456 << BinaryOperator::getOpcodeStr(Opc)
13457 << Args[0]->getType()
13458 << Args[1]->getType()
13459 << Args[0]->getSourceRange()
13460 << Args[1]->getSourceRange()),
13461 *this, OCD_AmbiguousCandidates, Args, BinaryOperator::getOpcodeStr(Opc),
13463 return ExprError();
13466 if (isImplicitlyDeleted(Best->Function)) {
13467 FunctionDecl *DeletedFD = Best->Function;
13468 DefaultedFunctionKind DFK = getDefaultedFunctionKind(DeletedFD);
13469 if (DFK.isSpecialMember()) {
13470 Diag(OpLoc, diag::err_ovl_deleted_special_oper)
13471 << Args[0]->getType() << DFK.asSpecialMember();
13473 assert(DFK.isComparison());
13474 Diag(OpLoc, diag::err_ovl_deleted_comparison)
13475 << Args[0]->getType() << DeletedFD;
13478 // The user probably meant to call this special member. Just
13479 // explain why it's deleted.
13480 NoteDeletedFunction(DeletedFD);
13481 return ExprError();
13483 CandidateSet.NoteCandidates(
13484 PartialDiagnosticAt(
13485 OpLoc, PDiag(diag::err_ovl_deleted_oper)
13486 << getOperatorSpelling(Best->Function->getDeclName()
13487 .getCXXOverloadedOperator())
13488 << Args[0]->getSourceRange()
13489 << Args[1]->getSourceRange()),
13490 *this, OCD_AllCandidates, Args, BinaryOperator::getOpcodeStr(Opc),
13492 return ExprError();
13495 // We matched a built-in operator; build it.
13496 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
13499 ExprResult Sema::BuildSynthesizedThreeWayComparison(
13500 SourceLocation OpLoc, const UnresolvedSetImpl &Fns, Expr *LHS, Expr *RHS,
13501 FunctionDecl *DefaultedFn) {
13502 const ComparisonCategoryInfo *Info =
13503 Context.CompCategories.lookupInfoForType(DefaultedFn->getReturnType());
13504 // If we're not producing a known comparison category type, we can't
13505 // synthesize a three-way comparison. Let the caller diagnose this.
13507 return ExprResult((Expr*)nullptr);
13509 // If we ever want to perform this synthesis more generally, we will need to
13510 // apply the temporary materialization conversion to the operands.
13511 assert(LHS->isGLValue() && RHS->isGLValue() &&
13512 "cannot use prvalue expressions more than once");
13513 Expr *OrigLHS = LHS;
13514 Expr *OrigRHS = RHS;
13516 // Replace the LHS and RHS with OpaqueValueExprs; we're going to refer to
13517 // each of them multiple times below.
13518 LHS = new (Context)
13519 OpaqueValueExpr(LHS->getExprLoc(), LHS->getType(), LHS->getValueKind(),
13520 LHS->getObjectKind(), LHS);
13521 RHS = new (Context)
13522 OpaqueValueExpr(RHS->getExprLoc(), RHS->getType(), RHS->getValueKind(),
13523 RHS->getObjectKind(), RHS);
13525 ExprResult Eq = CreateOverloadedBinOp(OpLoc, BO_EQ, Fns, LHS, RHS, true, true,
13527 if (Eq.isInvalid())
13528 return ExprError();
13530 ExprResult Less = CreateOverloadedBinOp(OpLoc, BO_LT, Fns, LHS, RHS, true,
13531 true, DefaultedFn);
13532 if (Less.isInvalid())
13533 return ExprError();
13535 ExprResult Greater;
13536 if (Info->isPartial()) {
13537 Greater = CreateOverloadedBinOp(OpLoc, BO_LT, Fns, RHS, LHS, true, true,
13539 if (Greater.isInvalid())
13540 return ExprError();
13543 // Form the list of comparisons we're going to perform.
13544 struct Comparison {
13546 ComparisonCategoryResult Result;
13548 { {Eq, Info->isStrong() ? ComparisonCategoryResult::Equal
13549 : ComparisonCategoryResult::Equivalent},
13550 {Less, ComparisonCategoryResult::Less},
13551 {Greater, ComparisonCategoryResult::Greater},
13552 {ExprResult(), ComparisonCategoryResult::Unordered},
13555 int I = Info->isPartial() ? 3 : 2;
13557 // Combine the comparisons with suitable conditional expressions.
13559 for (; I >= 0; --I) {
13560 // Build a reference to the comparison category constant.
13561 auto *VI = Info->lookupValueInfo(Comparisons[I].Result);
13562 // FIXME: Missing a constant for a comparison category. Diagnose this?
13564 return ExprResult((Expr*)nullptr);
13565 ExprResult ThisResult =
13566 BuildDeclarationNameExpr(CXXScopeSpec(), DeclarationNameInfo(), VI->VD);
13567 if (ThisResult.isInvalid())
13568 return ExprError();
13570 // Build a conditional unless this is the final case.
13571 if (Result.get()) {
13572 Result = ActOnConditionalOp(OpLoc, OpLoc, Comparisons[I].Cmp.get(),
13573 ThisResult.get(), Result.get());
13574 if (Result.isInvalid())
13575 return ExprError();
13577 Result = ThisResult;
13581 // Build a PseudoObjectExpr to model the rewriting of an <=> operator, and to
13582 // bind the OpaqueValueExprs before they're (repeatedly) used.
13583 Expr *SyntacticForm = new (Context)
13584 BinaryOperator(OrigLHS, OrigRHS, BO_Cmp, Result.get()->getType(),
13585 Result.get()->getValueKind(),
13586 Result.get()->getObjectKind(), OpLoc, FPFeatures);
13587 Expr *SemanticForm[] = {LHS, RHS, Result.get()};
13588 return PseudoObjectExpr::Create(Context, SyntacticForm, SemanticForm, 2);
13592 Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc,
13593 SourceLocation RLoc,
13594 Expr *Base, Expr *Idx) {
13595 Expr *Args[2] = { Base, Idx };
13596 DeclarationName OpName =
13597 Context.DeclarationNames.getCXXOperatorName(OO_Subscript);
13599 // If either side is type-dependent, create an appropriate dependent
13601 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) {
13603 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
13604 // CHECKME: no 'operator' keyword?
13605 DeclarationNameInfo OpNameInfo(OpName, LLoc);
13606 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc));
13607 UnresolvedLookupExpr *Fn
13608 = UnresolvedLookupExpr::Create(Context, NamingClass,
13609 NestedNameSpecifierLoc(), OpNameInfo,
13610 /*ADL*/ true, /*Overloaded*/ false,
13611 UnresolvedSetIterator(),
13612 UnresolvedSetIterator());
13613 // Can't add any actual overloads yet
13615 return CXXOperatorCallExpr::Create(Context, OO_Subscript, Fn, Args,
13616 Context.DependentTy, VK_RValue, RLoc,
13620 // Handle placeholders on both operands.
13621 if (checkPlaceholderForOverload(*this, Args[0]))
13622 return ExprError();
13623 if (checkPlaceholderForOverload(*this, Args[1]))
13624 return ExprError();
13626 // Build an empty overload set.
13627 OverloadCandidateSet CandidateSet(LLoc, OverloadCandidateSet::CSK_Operator);
13629 // Subscript can only be overloaded as a member function.
13631 // Add operator candidates that are member functions.
13632 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, CandidateSet);
13634 // Add builtin operator candidates.
13635 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, CandidateSet);
13637 bool HadMultipleCandidates = (CandidateSet.size() > 1);
13639 // Perform overload resolution.
13640 OverloadCandidateSet::iterator Best;
13641 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) {
13643 // We found a built-in operator or an overloaded operator.
13644 FunctionDecl *FnDecl = Best->Function;
13647 // We matched an overloaded operator. Build a call to that
13650 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl);
13652 // Convert the arguments.
13653 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl);
13655 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/nullptr,
13656 Best->FoundDecl, Method);
13657 if (Arg0.isInvalid())
13658 return ExprError();
13659 Args[0] = Arg0.get();
13661 // Convert the arguments.
13662 ExprResult InputInit
13663 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
13665 FnDecl->getParamDecl(0)),
13668 if (InputInit.isInvalid())
13669 return ExprError();
13671 Args[1] = InputInit.getAs<Expr>();
13673 // Build the actual expression node.
13674 DeclarationNameInfo OpLocInfo(OpName, LLoc);
13675 OpLocInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc));
13676 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl,
13679 HadMultipleCandidates,
13680 OpLocInfo.getLoc(),
13681 OpLocInfo.getInfo());
13682 if (FnExpr.isInvalid())
13683 return ExprError();
13685 // Determine the result type
13686 QualType ResultTy = FnDecl->getReturnType();
13687 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
13688 ResultTy = ResultTy.getNonLValueExprType(Context);
13690 CXXOperatorCallExpr *TheCall =
13691 CXXOperatorCallExpr::Create(Context, OO_Subscript, FnExpr.get(),
13692 Args, ResultTy, VK, RLoc, FPOptions());
13694 if (CheckCallReturnType(FnDecl->getReturnType(), LLoc, TheCall, FnDecl))
13695 return ExprError();
13697 if (CheckFunctionCall(Method, TheCall,
13698 Method->getType()->castAs<FunctionProtoType>()))
13699 return ExprError();
13701 return MaybeBindToTemporary(TheCall);
13703 // We matched a built-in operator. Convert the arguments, then
13704 // break out so that we will build the appropriate built-in
13706 ExprResult ArgsRes0 = PerformImplicitConversion(
13707 Args[0], Best->BuiltinParamTypes[0], Best->Conversions[0],
13708 AA_Passing, CCK_ForBuiltinOverloadedOp);
13709 if (ArgsRes0.isInvalid())
13710 return ExprError();
13711 Args[0] = ArgsRes0.get();
13713 ExprResult ArgsRes1 = PerformImplicitConversion(
13714 Args[1], Best->BuiltinParamTypes[1], Best->Conversions[1],
13715 AA_Passing, CCK_ForBuiltinOverloadedOp);
13716 if (ArgsRes1.isInvalid())
13717 return ExprError();
13718 Args[1] = ArgsRes1.get();
13724 case OR_No_Viable_Function: {
13725 PartialDiagnostic PD = CandidateSet.empty()
13726 ? (PDiag(diag::err_ovl_no_oper)
13727 << Args[0]->getType() << /*subscript*/ 0
13728 << Args[0]->getSourceRange() << Args[1]->getSourceRange())
13729 : (PDiag(diag::err_ovl_no_viable_subscript)
13730 << Args[0]->getType() << Args[0]->getSourceRange()
13731 << Args[1]->getSourceRange());
13732 CandidateSet.NoteCandidates(PartialDiagnosticAt(LLoc, PD), *this,
13733 OCD_AllCandidates, Args, "[]", LLoc);
13734 return ExprError();
13738 CandidateSet.NoteCandidates(
13739 PartialDiagnosticAt(LLoc, PDiag(diag::err_ovl_ambiguous_oper_binary)
13740 << "[]" << Args[0]->getType()
13741 << Args[1]->getType()
13742 << Args[0]->getSourceRange()
13743 << Args[1]->getSourceRange()),
13744 *this, OCD_AmbiguousCandidates, Args, "[]", LLoc);
13745 return ExprError();
13748 CandidateSet.NoteCandidates(
13749 PartialDiagnosticAt(LLoc, PDiag(diag::err_ovl_deleted_oper)
13750 << "[]" << Args[0]->getSourceRange()
13751 << Args[1]->getSourceRange()),
13752 *this, OCD_AllCandidates, Args, "[]", LLoc);
13753 return ExprError();
13756 // We matched a built-in operator; build it.
13757 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc);
13760 /// BuildCallToMemberFunction - Build a call to a member
13761 /// function. MemExpr is the expression that refers to the member
13762 /// function (and includes the object parameter), Args/NumArgs are the
13763 /// arguments to the function call (not including the object
13764 /// parameter). The caller needs to validate that the member
13765 /// expression refers to a non-static member function or an overloaded
13766 /// member function.
13768 Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE,
13769 SourceLocation LParenLoc,
13771 SourceLocation RParenLoc) {
13772 assert(MemExprE->getType() == Context.BoundMemberTy ||
13773 MemExprE->getType() == Context.OverloadTy);
13775 // Dig out the member expression. This holds both the object
13776 // argument and the member function we're referring to.
13777 Expr *NakedMemExpr = MemExprE->IgnoreParens();
13779 // Determine whether this is a call to a pointer-to-member function.
13780 if (BinaryOperator *op = dyn_cast<BinaryOperator>(NakedMemExpr)) {
13781 assert(op->getType() == Context.BoundMemberTy);
13782 assert(op->getOpcode() == BO_PtrMemD || op->getOpcode() == BO_PtrMemI);
13785 op->getRHS()->getType()->castAs<MemberPointerType>()->getPointeeType();
13787 const FunctionProtoType *proto = fnType->castAs<FunctionProtoType>();
13788 QualType resultType = proto->getCallResultType(Context);
13789 ExprValueKind valueKind = Expr::getValueKindForType(proto->getReturnType());
13791 // Check that the object type isn't more qualified than the
13792 // member function we're calling.
13793 Qualifiers funcQuals = proto->getMethodQuals();
13795 QualType objectType = op->getLHS()->getType();
13796 if (op->getOpcode() == BO_PtrMemI)
13797 objectType = objectType->castAs<PointerType>()->getPointeeType();
13798 Qualifiers objectQuals = objectType.getQualifiers();
13800 Qualifiers difference = objectQuals - funcQuals;
13801 difference.removeObjCGCAttr();
13802 difference.removeAddressSpace();
13804 std::string qualsString = difference.getAsString();
13805 Diag(LParenLoc, diag::err_pointer_to_member_call_drops_quals)
13806 << fnType.getUnqualifiedType()
13808 << (qualsString.find(' ') == std::string::npos ? 1 : 2);
13811 CXXMemberCallExpr *call =
13812 CXXMemberCallExpr::Create(Context, MemExprE, Args, resultType,
13813 valueKind, RParenLoc, proto->getNumParams());
13815 if (CheckCallReturnType(proto->getReturnType(), op->getRHS()->getBeginLoc(),
13817 return ExprError();
13819 if (ConvertArgumentsForCall(call, op, nullptr, proto, Args, RParenLoc))
13820 return ExprError();
13822 if (CheckOtherCall(call, proto))
13823 return ExprError();
13825 return MaybeBindToTemporary(call);
13828 if (isa<CXXPseudoDestructorExpr>(NakedMemExpr))
13829 return CallExpr::Create(Context, MemExprE, Args, Context.VoidTy, VK_RValue,
13832 UnbridgedCastsSet UnbridgedCasts;
13833 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts))
13834 return ExprError();
13836 MemberExpr *MemExpr;
13837 CXXMethodDecl *Method = nullptr;
13838 DeclAccessPair FoundDecl = DeclAccessPair::make(nullptr, AS_public);
13839 NestedNameSpecifier *Qualifier = nullptr;
13840 if (isa<MemberExpr>(NakedMemExpr)) {
13841 MemExpr = cast<MemberExpr>(NakedMemExpr);
13842 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl());
13843 FoundDecl = MemExpr->getFoundDecl();
13844 Qualifier = MemExpr->getQualifier();
13845 UnbridgedCasts.restore();
13847 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr);
13848 Qualifier = UnresExpr->getQualifier();
13850 QualType ObjectType = UnresExpr->getBaseType();
13851 Expr::Classification ObjectClassification
13852 = UnresExpr->isArrow()? Expr::Classification::makeSimpleLValue()
13853 : UnresExpr->getBase()->Classify(Context);
13855 // Add overload candidates
13856 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc(),
13857 OverloadCandidateSet::CSK_Normal);
13859 // FIXME: avoid copy.
13860 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
13861 if (UnresExpr->hasExplicitTemplateArgs()) {
13862 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer);
13863 TemplateArgs = &TemplateArgsBuffer;
13866 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(),
13867 E = UnresExpr->decls_end(); I != E; ++I) {
13869 NamedDecl *Func = *I;
13870 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext());
13871 if (isa<UsingShadowDecl>(Func))
13872 Func = cast<UsingShadowDecl>(Func)->getTargetDecl();
13875 // Microsoft supports direct constructor calls.
13876 if (getLangOpts().MicrosoftExt && isa<CXXConstructorDecl>(Func)) {
13877 AddOverloadCandidate(cast<CXXConstructorDecl>(Func), I.getPair(), Args,
13879 /*SuppressUserConversions*/ false);
13880 } else if ((Method = dyn_cast<CXXMethodDecl>(Func))) {
13881 // If explicit template arguments were provided, we can't call a
13882 // non-template member function.
13886 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType,
13887 ObjectClassification, Args, CandidateSet,
13888 /*SuppressUserConversions=*/false);
13890 AddMethodTemplateCandidate(
13891 cast<FunctionTemplateDecl>(Func), I.getPair(), ActingDC,
13892 TemplateArgs, ObjectType, ObjectClassification, Args, CandidateSet,
13893 /*SuppressUserConversions=*/false);
13897 DeclarationName DeclName = UnresExpr->getMemberName();
13899 UnbridgedCasts.restore();
13901 OverloadCandidateSet::iterator Best;
13902 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getBeginLoc(),
13905 Method = cast<CXXMethodDecl>(Best->Function);
13906 FoundDecl = Best->FoundDecl;
13907 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl);
13908 if (DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()))
13909 return ExprError();
13910 // If FoundDecl is different from Method (such as if one is a template
13911 // and the other a specialization), make sure DiagnoseUseOfDecl is
13913 // FIXME: This would be more comprehensively addressed by modifying
13914 // DiagnoseUseOfDecl to accept both the FoundDecl and the decl
13916 if (Method != FoundDecl.getDecl() &&
13917 DiagnoseUseOfDecl(Method, UnresExpr->getNameLoc()))
13918 return ExprError();
13921 case OR_No_Viable_Function:
13922 CandidateSet.NoteCandidates(
13923 PartialDiagnosticAt(
13924 UnresExpr->getMemberLoc(),
13925 PDiag(diag::err_ovl_no_viable_member_function_in_call)
13926 << DeclName << MemExprE->getSourceRange()),
13927 *this, OCD_AllCandidates, Args);
13928 // FIXME: Leaking incoming expressions!
13929 return ExprError();
13932 CandidateSet.NoteCandidates(
13933 PartialDiagnosticAt(UnresExpr->getMemberLoc(),
13934 PDiag(diag::err_ovl_ambiguous_member_call)
13935 << DeclName << MemExprE->getSourceRange()),
13936 *this, OCD_AmbiguousCandidates, Args);
13937 // FIXME: Leaking incoming expressions!
13938 return ExprError();
13941 CandidateSet.NoteCandidates(
13942 PartialDiagnosticAt(UnresExpr->getMemberLoc(),
13943 PDiag(diag::err_ovl_deleted_member_call)
13944 << DeclName << MemExprE->getSourceRange()),
13945 *this, OCD_AllCandidates, Args);
13946 // FIXME: Leaking incoming expressions!
13947 return ExprError();
13950 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method);
13952 // If overload resolution picked a static member, build a
13953 // non-member call based on that function.
13954 if (Method->isStatic()) {
13955 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, Args,
13959 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens());
13962 QualType ResultType = Method->getReturnType();
13963 ExprValueKind VK = Expr::getValueKindForType(ResultType);
13964 ResultType = ResultType.getNonLValueExprType(Context);
13966 assert(Method && "Member call to something that isn't a method?");
13967 const auto *Proto = Method->getType()->castAs<FunctionProtoType>();
13968 CXXMemberCallExpr *TheCall =
13969 CXXMemberCallExpr::Create(Context, MemExprE, Args, ResultType, VK,
13970 RParenLoc, Proto->getNumParams());
13972 // Check for a valid return type.
13973 if (CheckCallReturnType(Method->getReturnType(), MemExpr->getMemberLoc(),
13975 return ExprError();
13977 // Convert the object argument (for a non-static member function call).
13978 // We only need to do this if there was actually an overload; otherwise
13979 // it was done at lookup.
13980 if (!Method->isStatic()) {
13981 ExprResult ObjectArg =
13982 PerformObjectArgumentInitialization(MemExpr->getBase(), Qualifier,
13983 FoundDecl, Method);
13984 if (ObjectArg.isInvalid())
13985 return ExprError();
13986 MemExpr->setBase(ObjectArg.get());
13989 // Convert the rest of the arguments
13990 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args,
13992 return ExprError();
13994 DiagnoseSentinelCalls(Method, LParenLoc, Args);
13996 if (CheckFunctionCall(Method, TheCall, Proto))
13997 return ExprError();
13999 // In the case the method to call was not selected by the overloading
14000 // resolution process, we still need to handle the enable_if attribute. Do
14001 // that here, so it will not hide previous -- and more relevant -- errors.
14002 if (auto *MemE = dyn_cast<MemberExpr>(NakedMemExpr)) {
14003 if (const EnableIfAttr *Attr = CheckEnableIf(Method, Args, true)) {
14004 Diag(MemE->getMemberLoc(),
14005 diag::err_ovl_no_viable_member_function_in_call)
14006 << Method << Method->getSourceRange();
14007 Diag(Method->getLocation(),
14008 diag::note_ovl_candidate_disabled_by_function_cond_attr)
14009 << Attr->getCond()->getSourceRange() << Attr->getMessage();
14010 return ExprError();
14014 if ((isa<CXXConstructorDecl>(CurContext) ||
14015 isa<CXXDestructorDecl>(CurContext)) &&
14016 TheCall->getMethodDecl()->isPure()) {
14017 const CXXMethodDecl *MD = TheCall->getMethodDecl();
14019 if (isa<CXXThisExpr>(MemExpr->getBase()->IgnoreParenCasts()) &&
14020 MemExpr->performsVirtualDispatch(getLangOpts())) {
14021 Diag(MemExpr->getBeginLoc(),
14022 diag::warn_call_to_pure_virtual_member_function_from_ctor_dtor)
14023 << MD->getDeclName() << isa<CXXDestructorDecl>(CurContext)
14024 << MD->getParent()->getDeclName();
14026 Diag(MD->getBeginLoc(), diag::note_previous_decl) << MD->getDeclName();
14027 if (getLangOpts().AppleKext)
14028 Diag(MemExpr->getBeginLoc(), diag::note_pure_qualified_call_kext)
14029 << MD->getParent()->getDeclName() << MD->getDeclName();
14033 if (CXXDestructorDecl *DD =
14034 dyn_cast<CXXDestructorDecl>(TheCall->getMethodDecl())) {
14035 // a->A::f() doesn't go through the vtable, except in AppleKext mode.
14036 bool CallCanBeVirtual = !MemExpr->hasQualifier() || getLangOpts().AppleKext;
14037 CheckVirtualDtorCall(DD, MemExpr->getBeginLoc(), /*IsDelete=*/false,
14038 CallCanBeVirtual, /*WarnOnNonAbstractTypes=*/true,
14039 MemExpr->getMemberLoc());
14042 return MaybeBindToTemporary(TheCall);
14045 /// BuildCallToObjectOfClassType - Build a call to an object of class
14046 /// type (C++ [over.call.object]), which can end up invoking an
14047 /// overloaded function call operator (@c operator()) or performing a
14048 /// user-defined conversion on the object argument.
14050 Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj,
14051 SourceLocation LParenLoc,
14053 SourceLocation RParenLoc) {
14054 if (checkPlaceholderForOverload(*this, Obj))
14055 return ExprError();
14056 ExprResult Object = Obj;
14058 UnbridgedCastsSet UnbridgedCasts;
14059 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts))
14060 return ExprError();
14062 assert(Object.get()->getType()->isRecordType() &&
14063 "Requires object type argument");
14065 // C++ [over.call.object]p1:
14066 // If the primary-expression E in the function call syntax
14067 // evaluates to a class object of type "cv T", then the set of
14068 // candidate functions includes at least the function call
14069 // operators of T. The function call operators of T are obtained by
14070 // ordinary lookup of the name operator() in the context of
14072 OverloadCandidateSet CandidateSet(LParenLoc,
14073 OverloadCandidateSet::CSK_Operator);
14074 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call);
14076 if (RequireCompleteType(LParenLoc, Object.get()->getType(),
14077 diag::err_incomplete_object_call, Object.get()))
14080 const auto *Record = Object.get()->getType()->castAs<RecordType>();
14081 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName);
14082 LookupQualifiedName(R, Record->getDecl());
14083 R.suppressDiagnostics();
14085 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end();
14086 Oper != OperEnd; ++Oper) {
14087 AddMethodCandidate(Oper.getPair(), Object.get()->getType(),
14088 Object.get()->Classify(Context), Args, CandidateSet,
14089 /*SuppressUserConversion=*/false);
14092 // C++ [over.call.object]p2:
14093 // In addition, for each (non-explicit in C++0x) conversion function
14094 // declared in T of the form
14096 // operator conversion-type-id () cv-qualifier;
14098 // where cv-qualifier is the same cv-qualification as, or a
14099 // greater cv-qualification than, cv, and where conversion-type-id
14100 // denotes the type "pointer to function of (P1,...,Pn) returning
14101 // R", or the type "reference to pointer to function of
14102 // (P1,...,Pn) returning R", or the type "reference to function
14103 // of (P1,...,Pn) returning R", a surrogate call function [...]
14104 // is also considered as a candidate function. Similarly,
14105 // surrogate call functions are added to the set of candidate
14106 // functions for each conversion function declared in an
14107 // accessible base class provided the function is not hidden
14108 // within T by another intervening declaration.
14109 const auto &Conversions =
14110 cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions();
14111 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
14113 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
14114 if (isa<UsingShadowDecl>(D))
14115 D = cast<UsingShadowDecl>(D)->getTargetDecl();
14117 // Skip over templated conversion functions; they aren't
14119 if (isa<FunctionTemplateDecl>(D))
14122 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D);
14123 if (!Conv->isExplicit()) {
14124 // Strip the reference type (if any) and then the pointer type (if
14125 // any) to get down to what might be a function type.
14126 QualType ConvType = Conv->getConversionType().getNonReferenceType();
14127 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
14128 ConvType = ConvPtrType->getPointeeType();
14130 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>())
14132 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto,
14133 Object.get(), Args, CandidateSet);
14138 bool HadMultipleCandidates = (CandidateSet.size() > 1);
14140 // Perform overload resolution.
14141 OverloadCandidateSet::iterator Best;
14142 switch (CandidateSet.BestViableFunction(*this, Object.get()->getBeginLoc(),
14145 // Overload resolution succeeded; we'll build the appropriate call
14149 case OR_No_Viable_Function: {
14150 PartialDiagnostic PD =
14151 CandidateSet.empty()
14152 ? (PDiag(diag::err_ovl_no_oper)
14153 << Object.get()->getType() << /*call*/ 1
14154 << Object.get()->getSourceRange())
14155 : (PDiag(diag::err_ovl_no_viable_object_call)
14156 << Object.get()->getType() << Object.get()->getSourceRange());
14157 CandidateSet.NoteCandidates(
14158 PartialDiagnosticAt(Object.get()->getBeginLoc(), PD), *this,
14159 OCD_AllCandidates, Args);
14163 CandidateSet.NoteCandidates(
14164 PartialDiagnosticAt(Object.get()->getBeginLoc(),
14165 PDiag(diag::err_ovl_ambiguous_object_call)
14166 << Object.get()->getType()
14167 << Object.get()->getSourceRange()),
14168 *this, OCD_AmbiguousCandidates, Args);
14172 CandidateSet.NoteCandidates(
14173 PartialDiagnosticAt(Object.get()->getBeginLoc(),
14174 PDiag(diag::err_ovl_deleted_object_call)
14175 << Object.get()->getType()
14176 << Object.get()->getSourceRange()),
14177 *this, OCD_AllCandidates, Args);
14181 if (Best == CandidateSet.end())
14184 UnbridgedCasts.restore();
14186 if (Best->Function == nullptr) {
14187 // Since there is no function declaration, this is one of the
14188 // surrogate candidates. Dig out the conversion function.
14189 CXXConversionDecl *Conv
14190 = cast<CXXConversionDecl>(
14191 Best->Conversions[0].UserDefined.ConversionFunction);
14193 CheckMemberOperatorAccess(LParenLoc, Object.get(), nullptr,
14195 if (DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc))
14196 return ExprError();
14197 assert(Conv == Best->FoundDecl.getDecl() &&
14198 "Found Decl & conversion-to-functionptr should be same, right?!");
14199 // We selected one of the surrogate functions that converts the
14200 // object parameter to a function pointer. Perform the conversion
14201 // on the object argument, then let BuildCallExpr finish the job.
14203 // Create an implicit member expr to refer to the conversion operator.
14204 // and then call it.
14205 ExprResult Call = BuildCXXMemberCallExpr(Object.get(), Best->FoundDecl,
14206 Conv, HadMultipleCandidates);
14207 if (Call.isInvalid())
14208 return ExprError();
14209 // Record usage of conversion in an implicit cast.
14210 Call = ImplicitCastExpr::Create(Context, Call.get()->getType(),
14211 CK_UserDefinedConversion, Call.get(),
14212 nullptr, VK_RValue);
14214 return BuildCallExpr(S, Call.get(), LParenLoc, Args, RParenLoc);
14217 CheckMemberOperatorAccess(LParenLoc, Object.get(), nullptr, Best->FoundDecl);
14219 // We found an overloaded operator(). Build a CXXOperatorCallExpr
14220 // that calls this method, using Object for the implicit object
14221 // parameter and passing along the remaining arguments.
14222 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
14224 // An error diagnostic has already been printed when parsing the declaration.
14225 if (Method->isInvalidDecl())
14226 return ExprError();
14228 const auto *Proto = Method->getType()->castAs<FunctionProtoType>();
14229 unsigned NumParams = Proto->getNumParams();
14231 DeclarationNameInfo OpLocInfo(
14232 Context.DeclarationNames.getCXXOperatorName(OO_Call), LParenLoc);
14233 OpLocInfo.setCXXOperatorNameRange(SourceRange(LParenLoc, RParenLoc));
14234 ExprResult NewFn = CreateFunctionRefExpr(*this, Method, Best->FoundDecl,
14235 Obj, HadMultipleCandidates,
14236 OpLocInfo.getLoc(),
14237 OpLocInfo.getInfo());
14238 if (NewFn.isInvalid())
14241 // The number of argument slots to allocate in the call. If we have default
14242 // arguments we need to allocate space for them as well. We additionally
14243 // need one more slot for the object parameter.
14244 unsigned NumArgsSlots = 1 + std::max<unsigned>(Args.size(), NumParams);
14246 // Build the full argument list for the method call (the implicit object
14247 // parameter is placed at the beginning of the list).
14248 SmallVector<Expr *, 8> MethodArgs(NumArgsSlots);
14250 bool IsError = false;
14252 // Initialize the implicit object parameter.
14253 ExprResult ObjRes =
14254 PerformObjectArgumentInitialization(Object.get(), /*Qualifier=*/nullptr,
14255 Best->FoundDecl, Method);
14256 if (ObjRes.isInvalid())
14260 MethodArgs[0] = Object.get();
14262 // Check the argument types.
14263 for (unsigned i = 0; i != NumParams; i++) {
14265 if (i < Args.size()) {
14268 // Pass the argument.
14270 ExprResult InputInit
14271 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
14273 Method->getParamDecl(i)),
14274 SourceLocation(), Arg);
14276 IsError |= InputInit.isInvalid();
14277 Arg = InputInit.getAs<Expr>();
14280 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i));
14281 if (DefArg.isInvalid()) {
14286 Arg = DefArg.getAs<Expr>();
14289 MethodArgs[i + 1] = Arg;
14292 // If this is a variadic call, handle args passed through "...".
14293 if (Proto->isVariadic()) {
14294 // Promote the arguments (C99 6.5.2.2p7).
14295 for (unsigned i = NumParams, e = Args.size(); i < e; i++) {
14296 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod,
14298 IsError |= Arg.isInvalid();
14299 MethodArgs[i + 1] = Arg.get();
14306 DiagnoseSentinelCalls(Method, LParenLoc, Args);
14308 // Once we've built TheCall, all of the expressions are properly owned.
14309 QualType ResultTy = Method->getReturnType();
14310 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
14311 ResultTy = ResultTy.getNonLValueExprType(Context);
14313 CXXOperatorCallExpr *TheCall =
14314 CXXOperatorCallExpr::Create(Context, OO_Call, NewFn.get(), MethodArgs,
14315 ResultTy, VK, RParenLoc, FPOptions());
14317 if (CheckCallReturnType(Method->getReturnType(), LParenLoc, TheCall, Method))
14320 if (CheckFunctionCall(Method, TheCall, Proto))
14323 return MaybeBindToTemporary(TheCall);
14326 /// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator->
14327 /// (if one exists), where @c Base is an expression of class type and
14328 /// @c Member is the name of the member we're trying to find.
14330 Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc,
14331 bool *NoArrowOperatorFound) {
14332 assert(Base->getType()->isRecordType() &&
14333 "left-hand side must have class type");
14335 if (checkPlaceholderForOverload(*this, Base))
14336 return ExprError();
14338 SourceLocation Loc = Base->getExprLoc();
14340 // C++ [over.ref]p1:
14342 // [...] An expression x->m is interpreted as (x.operator->())->m
14343 // for a class object x of type T if T::operator->() exists and if
14344 // the operator is selected as the best match function by the
14345 // overload resolution mechanism (13.3).
14346 DeclarationName OpName =
14347 Context.DeclarationNames.getCXXOperatorName(OO_Arrow);
14348 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Operator);
14350 if (RequireCompleteType(Loc, Base->getType(),
14351 diag::err_typecheck_incomplete_tag, Base))
14352 return ExprError();
14354 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName);
14355 LookupQualifiedName(R, Base->getType()->castAs<RecordType>()->getDecl());
14356 R.suppressDiagnostics();
14358 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end();
14359 Oper != OperEnd; ++Oper) {
14360 AddMethodCandidate(Oper.getPair(), Base->getType(), Base->Classify(Context),
14361 None, CandidateSet, /*SuppressUserConversion=*/false);
14364 bool HadMultipleCandidates = (CandidateSet.size() > 1);
14366 // Perform overload resolution.
14367 OverloadCandidateSet::iterator Best;
14368 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
14370 // Overload resolution succeeded; we'll build the call below.
14373 case OR_No_Viable_Function: {
14374 auto Cands = CandidateSet.CompleteCandidates(*this, OCD_AllCandidates, Base);
14375 if (CandidateSet.empty()) {
14376 QualType BaseType = Base->getType();
14377 if (NoArrowOperatorFound) {
14378 // Report this specific error to the caller instead of emitting a
14379 // diagnostic, as requested.
14380 *NoArrowOperatorFound = true;
14381 return ExprError();
14383 Diag(OpLoc, diag::err_typecheck_member_reference_arrow)
14384 << BaseType << Base->getSourceRange();
14385 if (BaseType->isRecordType() && !BaseType->isPointerType()) {
14386 Diag(OpLoc, diag::note_typecheck_member_reference_suggestion)
14387 << FixItHint::CreateReplacement(OpLoc, ".");
14390 Diag(OpLoc, diag::err_ovl_no_viable_oper)
14391 << "operator->" << Base->getSourceRange();
14392 CandidateSet.NoteCandidates(*this, Base, Cands);
14393 return ExprError();
14396 CandidateSet.NoteCandidates(
14397 PartialDiagnosticAt(OpLoc, PDiag(diag::err_ovl_ambiguous_oper_unary)
14398 << "->" << Base->getType()
14399 << Base->getSourceRange()),
14400 *this, OCD_AmbiguousCandidates, Base);
14401 return ExprError();
14404 CandidateSet.NoteCandidates(
14405 PartialDiagnosticAt(OpLoc, PDiag(diag::err_ovl_deleted_oper)
14406 << "->" << Base->getSourceRange()),
14407 *this, OCD_AllCandidates, Base);
14408 return ExprError();
14411 CheckMemberOperatorAccess(OpLoc, Base, nullptr, Best->FoundDecl);
14413 // Convert the object parameter.
14414 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
14415 ExprResult BaseResult =
14416 PerformObjectArgumentInitialization(Base, /*Qualifier=*/nullptr,
14417 Best->FoundDecl, Method);
14418 if (BaseResult.isInvalid())
14419 return ExprError();
14420 Base = BaseResult.get();
14422 // Build the operator call.
14423 ExprResult FnExpr = CreateFunctionRefExpr(*this, Method, Best->FoundDecl,
14424 Base, HadMultipleCandidates, OpLoc);
14425 if (FnExpr.isInvalid())
14426 return ExprError();
14428 QualType ResultTy = Method->getReturnType();
14429 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
14430 ResultTy = ResultTy.getNonLValueExprType(Context);
14431 CXXOperatorCallExpr *TheCall = CXXOperatorCallExpr::Create(
14432 Context, OO_Arrow, FnExpr.get(), Base, ResultTy, VK, OpLoc, FPOptions());
14434 if (CheckCallReturnType(Method->getReturnType(), OpLoc, TheCall, Method))
14435 return ExprError();
14437 if (CheckFunctionCall(Method, TheCall,
14438 Method->getType()->castAs<FunctionProtoType>()))
14439 return ExprError();
14441 return MaybeBindToTemporary(TheCall);
14444 /// BuildLiteralOperatorCall - Build a UserDefinedLiteral by creating a call to
14445 /// a literal operator described by the provided lookup results.
14446 ExprResult Sema::BuildLiteralOperatorCall(LookupResult &R,
14447 DeclarationNameInfo &SuffixInfo,
14448 ArrayRef<Expr*> Args,
14449 SourceLocation LitEndLoc,
14450 TemplateArgumentListInfo *TemplateArgs) {
14451 SourceLocation UDSuffixLoc = SuffixInfo.getCXXLiteralOperatorNameLoc();
14453 OverloadCandidateSet CandidateSet(UDSuffixLoc,
14454 OverloadCandidateSet::CSK_Normal);
14455 AddNonMemberOperatorCandidates(R.asUnresolvedSet(), Args, CandidateSet,
14458 bool HadMultipleCandidates = (CandidateSet.size() > 1);
14460 // Perform overload resolution. This will usually be trivial, but might need
14461 // to perform substitutions for a literal operator template.
14462 OverloadCandidateSet::iterator Best;
14463 switch (CandidateSet.BestViableFunction(*this, UDSuffixLoc, Best)) {
14468 case OR_No_Viable_Function:
14469 CandidateSet.NoteCandidates(
14470 PartialDiagnosticAt(UDSuffixLoc,
14471 PDiag(diag::err_ovl_no_viable_function_in_call)
14472 << R.getLookupName()),
14473 *this, OCD_AllCandidates, Args);
14474 return ExprError();
14477 CandidateSet.NoteCandidates(
14478 PartialDiagnosticAt(R.getNameLoc(), PDiag(diag::err_ovl_ambiguous_call)
14479 << R.getLookupName()),
14480 *this, OCD_AmbiguousCandidates, Args);
14481 return ExprError();
14484 FunctionDecl *FD = Best->Function;
14485 ExprResult Fn = CreateFunctionRefExpr(*this, FD, Best->FoundDecl,
14486 nullptr, HadMultipleCandidates,
14487 SuffixInfo.getLoc(),
14488 SuffixInfo.getInfo());
14489 if (Fn.isInvalid())
14492 // Check the argument types. This should almost always be a no-op, except
14493 // that array-to-pointer decay is applied to string literals.
14495 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
14496 ExprResult InputInit = PerformCopyInitialization(
14497 InitializedEntity::InitializeParameter(Context, FD->getParamDecl(ArgIdx)),
14498 SourceLocation(), Args[ArgIdx]);
14499 if (InputInit.isInvalid())
14501 ConvArgs[ArgIdx] = InputInit.get();
14504 QualType ResultTy = FD->getReturnType();
14505 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
14506 ResultTy = ResultTy.getNonLValueExprType(Context);
14508 UserDefinedLiteral *UDL = UserDefinedLiteral::Create(
14509 Context, Fn.get(), llvm::makeArrayRef(ConvArgs, Args.size()), ResultTy,
14510 VK, LitEndLoc, UDSuffixLoc);
14512 if (CheckCallReturnType(FD->getReturnType(), UDSuffixLoc, UDL, FD))
14513 return ExprError();
14515 if (CheckFunctionCall(FD, UDL, nullptr))
14516 return ExprError();
14518 return MaybeBindToTemporary(UDL);
14521 /// Build a call to 'begin' or 'end' for a C++11 for-range statement. If the
14522 /// given LookupResult is non-empty, it is assumed to describe a member which
14523 /// will be invoked. Otherwise, the function will be found via argument
14524 /// dependent lookup.
14525 /// CallExpr is set to a valid expression and FRS_Success returned on success,
14526 /// otherwise CallExpr is set to ExprError() and some non-success value
14528 Sema::ForRangeStatus
14529 Sema::BuildForRangeBeginEndCall(SourceLocation Loc,
14530 SourceLocation RangeLoc,
14531 const DeclarationNameInfo &NameInfo,
14532 LookupResult &MemberLookup,
14533 OverloadCandidateSet *CandidateSet,
14534 Expr *Range, ExprResult *CallExpr) {
14535 Scope *S = nullptr;
14537 CandidateSet->clear(OverloadCandidateSet::CSK_Normal);
14538 if (!MemberLookup.empty()) {
14539 ExprResult MemberRef =
14540 BuildMemberReferenceExpr(Range, Range->getType(), Loc,
14541 /*IsPtr=*/false, CXXScopeSpec(),
14542 /*TemplateKWLoc=*/SourceLocation(),
14543 /*FirstQualifierInScope=*/nullptr,
14545 /*TemplateArgs=*/nullptr, S);
14546 if (MemberRef.isInvalid()) {
14547 *CallExpr = ExprError();
14548 return FRS_DiagnosticIssued;
14550 *CallExpr = BuildCallExpr(S, MemberRef.get(), Loc, None, Loc, nullptr);
14551 if (CallExpr->isInvalid()) {
14552 *CallExpr = ExprError();
14553 return FRS_DiagnosticIssued;
14556 UnresolvedSet<0> FoundNames;
14557 UnresolvedLookupExpr *Fn =
14558 UnresolvedLookupExpr::Create(Context, /*NamingClass=*/nullptr,
14559 NestedNameSpecifierLoc(), NameInfo,
14560 /*NeedsADL=*/true, /*Overloaded=*/false,
14561 FoundNames.begin(), FoundNames.end());
14563 bool CandidateSetError = buildOverloadedCallSet(S, Fn, Fn, Range, Loc,
14564 CandidateSet, CallExpr);
14565 if (CandidateSet->empty() || CandidateSetError) {
14566 *CallExpr = ExprError();
14567 return FRS_NoViableFunction;
14569 OverloadCandidateSet::iterator Best;
14570 OverloadingResult OverloadResult =
14571 CandidateSet->BestViableFunction(*this, Fn->getBeginLoc(), Best);
14573 if (OverloadResult == OR_No_Viable_Function) {
14574 *CallExpr = ExprError();
14575 return FRS_NoViableFunction;
14577 *CallExpr = FinishOverloadedCallExpr(*this, S, Fn, Fn, Loc, Range,
14578 Loc, nullptr, CandidateSet, &Best,
14580 /*AllowTypoCorrection=*/false);
14581 if (CallExpr->isInvalid() || OverloadResult != OR_Success) {
14582 *CallExpr = ExprError();
14583 return FRS_DiagnosticIssued;
14586 return FRS_Success;
14590 /// FixOverloadedFunctionReference - E is an expression that refers to
14591 /// a C++ overloaded function (possibly with some parentheses and
14592 /// perhaps a '&' around it). We have resolved the overloaded function
14593 /// to the function declaration Fn, so patch up the expression E to
14594 /// refer (possibly indirectly) to Fn. Returns the new expr.
14595 Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found,
14596 FunctionDecl *Fn) {
14597 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
14598 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(),
14600 if (SubExpr == PE->getSubExpr())
14603 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr);
14606 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
14607 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(),
14609 assert(Context.hasSameType(ICE->getSubExpr()->getType(),
14610 SubExpr->getType()) &&
14611 "Implicit cast type cannot be determined from overload");
14612 assert(ICE->path_empty() && "fixing up hierarchy conversion?");
14613 if (SubExpr == ICE->getSubExpr())
14616 return ImplicitCastExpr::Create(Context, ICE->getType(),
14617 ICE->getCastKind(),
14619 ICE->getValueKind());
14622 if (auto *GSE = dyn_cast<GenericSelectionExpr>(E)) {
14623 if (!GSE->isResultDependent()) {
14625 FixOverloadedFunctionReference(GSE->getResultExpr(), Found, Fn);
14626 if (SubExpr == GSE->getResultExpr())
14629 // Replace the resulting type information before rebuilding the generic
14630 // selection expression.
14631 ArrayRef<Expr *> A = GSE->getAssocExprs();
14632 SmallVector<Expr *, 4> AssocExprs(A.begin(), A.end());
14633 unsigned ResultIdx = GSE->getResultIndex();
14634 AssocExprs[ResultIdx] = SubExpr;
14636 return GenericSelectionExpr::Create(
14637 Context, GSE->getGenericLoc(), GSE->getControllingExpr(),
14638 GSE->getAssocTypeSourceInfos(), AssocExprs, GSE->getDefaultLoc(),
14639 GSE->getRParenLoc(), GSE->containsUnexpandedParameterPack(),
14642 // Rather than fall through to the unreachable, return the original generic
14643 // selection expression.
14647 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) {
14648 assert(UnOp->getOpcode() == UO_AddrOf &&
14649 "Can only take the address of an overloaded function");
14650 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) {
14651 if (Method->isStatic()) {
14652 // Do nothing: static member functions aren't any different
14653 // from non-member functions.
14655 // Fix the subexpression, which really has to be an
14656 // UnresolvedLookupExpr holding an overloaded member function
14658 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(),
14660 if (SubExpr == UnOp->getSubExpr())
14663 assert(isa<DeclRefExpr>(SubExpr)
14664 && "fixed to something other than a decl ref");
14665 assert(cast<DeclRefExpr>(SubExpr)->getQualifier()
14666 && "fixed to a member ref with no nested name qualifier");
14668 // We have taken the address of a pointer to member
14669 // function. Perform the computation here so that we get the
14670 // appropriate pointer to member type.
14672 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext()));
14673 QualType MemPtrType
14674 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr());
14675 // Under the MS ABI, lock down the inheritance model now.
14676 if (Context.getTargetInfo().getCXXABI().isMicrosoft())
14677 (void)isCompleteType(UnOp->getOperatorLoc(), MemPtrType);
14679 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, MemPtrType,
14680 VK_RValue, OK_Ordinary,
14681 UnOp->getOperatorLoc(), false);
14684 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(),
14686 if (SubExpr == UnOp->getSubExpr())
14689 return new (Context) UnaryOperator(SubExpr, UO_AddrOf,
14690 Context.getPointerType(SubExpr->getType()),
14691 VK_RValue, OK_Ordinary,
14692 UnOp->getOperatorLoc(), false);
14695 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) {
14696 // FIXME: avoid copy.
14697 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
14698 if (ULE->hasExplicitTemplateArgs()) {
14699 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer);
14700 TemplateArgs = &TemplateArgsBuffer;
14704 BuildDeclRefExpr(Fn, Fn->getType(), VK_LValue, ULE->getNameInfo(),
14705 ULE->getQualifierLoc(), Found.getDecl(),
14706 ULE->getTemplateKeywordLoc(), TemplateArgs);
14707 DRE->setHadMultipleCandidates(ULE->getNumDecls() > 1);
14711 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) {
14712 // FIXME: avoid copy.
14713 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
14714 if (MemExpr->hasExplicitTemplateArgs()) {
14715 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer);
14716 TemplateArgs = &TemplateArgsBuffer;
14721 // If we're filling in a static method where we used to have an
14722 // implicit member access, rewrite to a simple decl ref.
14723 if (MemExpr->isImplicitAccess()) {
14724 if (cast<CXXMethodDecl>(Fn)->isStatic()) {
14725 DeclRefExpr *DRE = BuildDeclRefExpr(
14726 Fn, Fn->getType(), VK_LValue, MemExpr->getNameInfo(),
14727 MemExpr->getQualifierLoc(), Found.getDecl(),
14728 MemExpr->getTemplateKeywordLoc(), TemplateArgs);
14729 DRE->setHadMultipleCandidates(MemExpr->getNumDecls() > 1);
14732 SourceLocation Loc = MemExpr->getMemberLoc();
14733 if (MemExpr->getQualifier())
14734 Loc = MemExpr->getQualifierLoc().getBeginLoc();
14736 BuildCXXThisExpr(Loc, MemExpr->getBaseType(), /*IsImplicit=*/true);
14739 Base = MemExpr->getBase();
14741 ExprValueKind valueKind;
14743 if (cast<CXXMethodDecl>(Fn)->isStatic()) {
14744 valueKind = VK_LValue;
14745 type = Fn->getType();
14747 valueKind = VK_RValue;
14748 type = Context.BoundMemberTy;
14751 return BuildMemberExpr(
14752 Base, MemExpr->isArrow(), MemExpr->getOperatorLoc(),
14753 MemExpr->getQualifierLoc(), MemExpr->getTemplateKeywordLoc(), Fn, Found,
14754 /*HadMultipleCandidates=*/true, MemExpr->getMemberNameInfo(),
14755 type, valueKind, OK_Ordinary, TemplateArgs);
14758 llvm_unreachable("Invalid reference to overloaded function");
14761 ExprResult Sema::FixOverloadedFunctionReference(ExprResult E,
14762 DeclAccessPair Found,
14763 FunctionDecl *Fn) {
14764 return FixOverloadedFunctionReference(E.get(), Found, Fn);