1 //===--- SemaOverload.cpp - C++ Overloading -------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file provides Sema routines for C++ overloading.
12 //===----------------------------------------------------------------------===//
14 #include "clang/Sema/Overload.h"
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/CXXInheritance.h"
17 #include "clang/AST/DeclObjC.h"
18 #include "clang/AST/Expr.h"
19 #include "clang/AST/ExprCXX.h"
20 #include "clang/AST/ExprObjC.h"
21 #include "clang/AST/TypeOrdering.h"
22 #include "clang/Basic/Diagnostic.h"
23 #include "clang/Basic/DiagnosticOptions.h"
24 #include "clang/Basic/PartialDiagnostic.h"
25 #include "clang/Basic/TargetInfo.h"
26 #include "clang/Sema/Initialization.h"
27 #include "clang/Sema/Lookup.h"
28 #include "clang/Sema/SemaInternal.h"
29 #include "clang/Sema/Template.h"
30 #include "clang/Sema/TemplateDeduction.h"
31 #include "llvm/ADT/DenseSet.h"
32 #include "llvm/ADT/STLExtras.h"
33 #include "llvm/ADT/SmallPtrSet.h"
34 #include "llvm/ADT/SmallString.h"
38 using namespace clang;
41 static bool functionHasPassObjectSizeParams(const FunctionDecl *FD) {
42 return llvm::any_of(FD->parameters(),
43 std::mem_fn(&ParmVarDecl::hasAttr<PassObjectSizeAttr>));
46 /// A convenience routine for creating a decayed reference to a function.
48 CreateFunctionRefExpr(Sema &S, FunctionDecl *Fn, NamedDecl *FoundDecl,
49 bool HadMultipleCandidates,
50 SourceLocation Loc = SourceLocation(),
51 const DeclarationNameLoc &LocInfo = DeclarationNameLoc()){
52 if (S.DiagnoseUseOfDecl(FoundDecl, Loc))
54 // If FoundDecl is different from Fn (such as if one is a template
55 // and the other a specialization), make sure DiagnoseUseOfDecl is
57 // FIXME: This would be more comprehensively addressed by modifying
58 // DiagnoseUseOfDecl to accept both the FoundDecl and the decl
60 if (FoundDecl != Fn && S.DiagnoseUseOfDecl(Fn, Loc))
62 DeclRefExpr *DRE = new (S.Context) DeclRefExpr(Fn, false, Fn->getType(),
63 VK_LValue, Loc, LocInfo);
64 if (HadMultipleCandidates)
65 DRE->setHadMultipleCandidates(true);
67 S.MarkDeclRefReferenced(DRE);
68 return S.ImpCastExprToType(DRE, S.Context.getPointerType(DRE->getType()),
69 CK_FunctionToPointerDecay);
72 static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
73 bool InOverloadResolution,
74 StandardConversionSequence &SCS,
76 bool AllowObjCWritebackConversion);
78 static bool IsTransparentUnionStandardConversion(Sema &S, Expr* From,
80 bool InOverloadResolution,
81 StandardConversionSequence &SCS,
83 static OverloadingResult
84 IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
85 UserDefinedConversionSequence& User,
86 OverloadCandidateSet& Conversions,
88 bool AllowObjCConversionOnExplicit);
91 static ImplicitConversionSequence::CompareKind
92 CompareStandardConversionSequences(Sema &S, SourceLocation Loc,
93 const StandardConversionSequence& SCS1,
94 const StandardConversionSequence& SCS2);
96 static ImplicitConversionSequence::CompareKind
97 CompareQualificationConversions(Sema &S,
98 const StandardConversionSequence& SCS1,
99 const StandardConversionSequence& SCS2);
101 static ImplicitConversionSequence::CompareKind
102 CompareDerivedToBaseConversions(Sema &S, SourceLocation Loc,
103 const StandardConversionSequence& SCS1,
104 const StandardConversionSequence& SCS2);
106 /// GetConversionRank - Retrieve the implicit conversion rank
107 /// corresponding to the given implicit conversion kind.
108 ImplicitConversionRank clang::GetConversionRank(ImplicitConversionKind Kind) {
109 static const ImplicitConversionRank
110 Rank[(int)ICK_Num_Conversion_Kinds] = {
131 ICR_Complex_Real_Conversion,
134 ICR_Writeback_Conversion,
135 ICR_Exact_Match, // NOTE(gbiv): This may not be completely right --
136 // it was omitted by the patch that added
137 // ICK_Zero_Event_Conversion
140 return Rank[(int)Kind];
143 /// GetImplicitConversionName - Return the name of this kind of
144 /// implicit conversion.
145 static const char* GetImplicitConversionName(ImplicitConversionKind Kind) {
146 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = {
150 "Function-to-pointer",
151 "Noreturn adjustment",
153 "Integral promotion",
154 "Floating point promotion",
156 "Integral conversion",
157 "Floating conversion",
158 "Complex conversion",
159 "Floating-integral conversion",
160 "Pointer conversion",
161 "Pointer-to-member conversion",
162 "Boolean conversion",
163 "Compatible-types conversion",
164 "Derived-to-base conversion",
167 "Complex-real conversion",
168 "Block Pointer conversion",
169 "Transparent Union Conversion",
170 "Writeback conversion",
171 "OpenCL Zero Event Conversion",
172 "C specific type conversion"
177 /// StandardConversionSequence - Set the standard conversion
178 /// sequence to the identity conversion.
179 void StandardConversionSequence::setAsIdentityConversion() {
180 First = ICK_Identity;
181 Second = ICK_Identity;
182 Third = ICK_Identity;
183 DeprecatedStringLiteralToCharPtr = false;
184 QualificationIncludesObjCLifetime = false;
185 ReferenceBinding = false;
186 DirectBinding = false;
187 IsLvalueReference = true;
188 BindsToFunctionLvalue = false;
189 BindsToRvalue = false;
190 BindsImplicitObjectArgumentWithoutRefQualifier = false;
191 ObjCLifetimeConversionBinding = false;
192 CopyConstructor = nullptr;
195 /// getRank - Retrieve the rank of this standard conversion sequence
196 /// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the
197 /// implicit conversions.
198 ImplicitConversionRank StandardConversionSequence::getRank() const {
199 ImplicitConversionRank Rank = ICR_Exact_Match;
200 if (GetConversionRank(First) > Rank)
201 Rank = GetConversionRank(First);
202 if (GetConversionRank(Second) > Rank)
203 Rank = GetConversionRank(Second);
204 if (GetConversionRank(Third) > Rank)
205 Rank = GetConversionRank(Third);
209 /// isPointerConversionToBool - Determines whether this conversion is
210 /// a conversion of a pointer or pointer-to-member to bool. This is
211 /// used as part of the ranking of standard conversion sequences
212 /// (C++ 13.3.3.2p4).
213 bool StandardConversionSequence::isPointerConversionToBool() const {
214 // Note that FromType has not necessarily been transformed by the
215 // array-to-pointer or function-to-pointer implicit conversions, so
216 // check for their presence as well as checking whether FromType is
218 if (getToType(1)->isBooleanType() &&
219 (getFromType()->isPointerType() ||
220 getFromType()->isObjCObjectPointerType() ||
221 getFromType()->isBlockPointerType() ||
222 getFromType()->isNullPtrType() ||
223 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer))
229 /// isPointerConversionToVoidPointer - Determines whether this
230 /// conversion is a conversion of a pointer to a void pointer. This is
231 /// used as part of the ranking of standard conversion sequences (C++
234 StandardConversionSequence::
235 isPointerConversionToVoidPointer(ASTContext& Context) const {
236 QualType FromType = getFromType();
237 QualType ToType = getToType(1);
239 // Note that FromType has not necessarily been transformed by the
240 // array-to-pointer implicit conversion, so check for its presence
241 // and redo the conversion to get a pointer.
242 if (First == ICK_Array_To_Pointer)
243 FromType = Context.getArrayDecayedType(FromType);
245 if (Second == ICK_Pointer_Conversion && FromType->isAnyPointerType())
246 if (const PointerType* ToPtrType = ToType->getAs<PointerType>())
247 return ToPtrType->getPointeeType()->isVoidType();
252 /// Skip any implicit casts which could be either part of a narrowing conversion
253 /// or after one in an implicit conversion.
254 static const Expr *IgnoreNarrowingConversion(const Expr *Converted) {
255 while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Converted)) {
256 switch (ICE->getCastKind()) {
258 case CK_IntegralCast:
259 case CK_IntegralToBoolean:
260 case CK_IntegralToFloating:
261 case CK_BooleanToSignedIntegral:
262 case CK_FloatingToIntegral:
263 case CK_FloatingToBoolean:
264 case CK_FloatingCast:
265 Converted = ICE->getSubExpr();
276 /// Check if this standard conversion sequence represents a narrowing
277 /// conversion, according to C++11 [dcl.init.list]p7.
279 /// \param Ctx The AST context.
280 /// \param Converted The result of applying this standard conversion sequence.
281 /// \param ConstantValue If this is an NK_Constant_Narrowing conversion, the
282 /// value of the expression prior to the narrowing conversion.
283 /// \param ConstantType If this is an NK_Constant_Narrowing conversion, the
284 /// type of the expression prior to the narrowing conversion.
286 StandardConversionSequence::getNarrowingKind(ASTContext &Ctx,
287 const Expr *Converted,
288 APValue &ConstantValue,
289 QualType &ConstantType) const {
290 assert(Ctx.getLangOpts().CPlusPlus && "narrowing check outside C++");
292 // C++11 [dcl.init.list]p7:
293 // A narrowing conversion is an implicit conversion ...
294 QualType FromType = getToType(0);
295 QualType ToType = getToType(1);
297 // A conversion to an enumeration type is narrowing if the conversion to
298 // the underlying type is narrowing. This only arises for expressions of
299 // the form 'Enum{init}'.
300 if (auto *ET = ToType->getAs<EnumType>())
301 ToType = ET->getDecl()->getIntegerType();
304 // 'bool' is an integral type; dispatch to the right place to handle it.
305 case ICK_Boolean_Conversion:
306 if (FromType->isRealFloatingType())
307 goto FloatingIntegralConversion;
308 if (FromType->isIntegralOrUnscopedEnumerationType())
309 goto IntegralConversion;
310 // Boolean conversions can be from pointers and pointers to members
311 // [conv.bool], and those aren't considered narrowing conversions.
312 return NK_Not_Narrowing;
314 // -- from a floating-point type to an integer type, or
316 // -- from an integer type or unscoped enumeration type to a floating-point
317 // type, except where the source is a constant expression and the actual
318 // value after conversion will fit into the target type and will produce
319 // the original value when converted back to the original type, or
320 case ICK_Floating_Integral:
321 FloatingIntegralConversion:
322 if (FromType->isRealFloatingType() && ToType->isIntegralType(Ctx)) {
323 return NK_Type_Narrowing;
324 } else if (FromType->isIntegralType(Ctx) && ToType->isRealFloatingType()) {
325 llvm::APSInt IntConstantValue;
326 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
328 Initializer->isIntegerConstantExpr(IntConstantValue, Ctx)) {
329 // Convert the integer to the floating type.
330 llvm::APFloat Result(Ctx.getFloatTypeSemantics(ToType));
331 Result.convertFromAPInt(IntConstantValue, IntConstantValue.isSigned(),
332 llvm::APFloat::rmNearestTiesToEven);
334 llvm::APSInt ConvertedValue = IntConstantValue;
336 Result.convertToInteger(ConvertedValue,
337 llvm::APFloat::rmTowardZero, &ignored);
338 // If the resulting value is different, this was a narrowing conversion.
339 if (IntConstantValue != ConvertedValue) {
340 ConstantValue = APValue(IntConstantValue);
341 ConstantType = Initializer->getType();
342 return NK_Constant_Narrowing;
345 // Variables are always narrowings.
346 return NK_Variable_Narrowing;
349 return NK_Not_Narrowing;
351 // -- from long double to double or float, or from double to float, except
352 // where the source is a constant expression and the actual value after
353 // conversion is within the range of values that can be represented (even
354 // if it cannot be represented exactly), or
355 case ICK_Floating_Conversion:
356 if (FromType->isRealFloatingType() && ToType->isRealFloatingType() &&
357 Ctx.getFloatingTypeOrder(FromType, ToType) == 1) {
358 // FromType is larger than ToType.
359 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
360 if (Initializer->isCXX11ConstantExpr(Ctx, &ConstantValue)) {
362 assert(ConstantValue.isFloat());
363 llvm::APFloat FloatVal = ConstantValue.getFloat();
364 // Convert the source value into the target type.
366 llvm::APFloat::opStatus ConvertStatus = FloatVal.convert(
367 Ctx.getFloatTypeSemantics(ToType),
368 llvm::APFloat::rmNearestTiesToEven, &ignored);
369 // If there was no overflow, the source value is within the range of
370 // values that can be represented.
371 if (ConvertStatus & llvm::APFloat::opOverflow) {
372 ConstantType = Initializer->getType();
373 return NK_Constant_Narrowing;
376 return NK_Variable_Narrowing;
379 return NK_Not_Narrowing;
381 // -- from an integer type or unscoped enumeration type to an integer type
382 // that cannot represent all the values of the original type, except where
383 // the source is a constant expression and the actual value after
384 // conversion will fit into the target type and will produce the original
385 // value when converted back to the original type.
386 case ICK_Integral_Conversion:
387 IntegralConversion: {
388 assert(FromType->isIntegralOrUnscopedEnumerationType());
389 assert(ToType->isIntegralOrUnscopedEnumerationType());
390 const bool FromSigned = FromType->isSignedIntegerOrEnumerationType();
391 const unsigned FromWidth = Ctx.getIntWidth(FromType);
392 const bool ToSigned = ToType->isSignedIntegerOrEnumerationType();
393 const unsigned ToWidth = Ctx.getIntWidth(ToType);
395 if (FromWidth > ToWidth ||
396 (FromWidth == ToWidth && FromSigned != ToSigned) ||
397 (FromSigned && !ToSigned)) {
398 // Not all values of FromType can be represented in ToType.
399 llvm::APSInt InitializerValue;
400 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
401 if (!Initializer->isIntegerConstantExpr(InitializerValue, Ctx)) {
402 // Such conversions on variables are always narrowing.
403 return NK_Variable_Narrowing;
405 bool Narrowing = false;
406 if (FromWidth < ToWidth) {
407 // Negative -> unsigned is narrowing. Otherwise, more bits is never
409 if (InitializerValue.isSigned() && InitializerValue.isNegative())
412 // Add a bit to the InitializerValue so we don't have to worry about
413 // signed vs. unsigned comparisons.
414 InitializerValue = InitializerValue.extend(
415 InitializerValue.getBitWidth() + 1);
416 // Convert the initializer to and from the target width and signed-ness.
417 llvm::APSInt ConvertedValue = InitializerValue;
418 ConvertedValue = ConvertedValue.trunc(ToWidth);
419 ConvertedValue.setIsSigned(ToSigned);
420 ConvertedValue = ConvertedValue.extend(InitializerValue.getBitWidth());
421 ConvertedValue.setIsSigned(InitializerValue.isSigned());
422 // If the result is different, this was a narrowing conversion.
423 if (ConvertedValue != InitializerValue)
427 ConstantType = Initializer->getType();
428 ConstantValue = APValue(InitializerValue);
429 return NK_Constant_Narrowing;
432 return NK_Not_Narrowing;
436 // Other kinds of conversions are not narrowings.
437 return NK_Not_Narrowing;
441 /// dump - Print this standard conversion sequence to standard
442 /// error. Useful for debugging overloading issues.
443 LLVM_DUMP_METHOD void StandardConversionSequence::dump() const {
444 raw_ostream &OS = llvm::errs();
445 bool PrintedSomething = false;
446 if (First != ICK_Identity) {
447 OS << GetImplicitConversionName(First);
448 PrintedSomething = true;
451 if (Second != ICK_Identity) {
452 if (PrintedSomething) {
455 OS << GetImplicitConversionName(Second);
457 if (CopyConstructor) {
458 OS << " (by copy constructor)";
459 } else if (DirectBinding) {
460 OS << " (direct reference binding)";
461 } else if (ReferenceBinding) {
462 OS << " (reference binding)";
464 PrintedSomething = true;
467 if (Third != ICK_Identity) {
468 if (PrintedSomething) {
471 OS << GetImplicitConversionName(Third);
472 PrintedSomething = true;
475 if (!PrintedSomething) {
476 OS << "No conversions required";
480 /// dump - Print this user-defined conversion sequence to standard
481 /// error. Useful for debugging overloading issues.
482 void UserDefinedConversionSequence::dump() const {
483 raw_ostream &OS = llvm::errs();
484 if (Before.First || Before.Second || Before.Third) {
488 if (ConversionFunction)
489 OS << '\'' << *ConversionFunction << '\'';
491 OS << "aggregate initialization";
492 if (After.First || After.Second || After.Third) {
498 /// dump - Print this implicit conversion sequence to standard
499 /// error. Useful for debugging overloading issues.
500 void ImplicitConversionSequence::dump() const {
501 raw_ostream &OS = llvm::errs();
502 if (isStdInitializerListElement())
503 OS << "Worst std::initializer_list element conversion: ";
504 switch (ConversionKind) {
505 case StandardConversion:
506 OS << "Standard conversion: ";
509 case UserDefinedConversion:
510 OS << "User-defined conversion: ";
513 case EllipsisConversion:
514 OS << "Ellipsis conversion";
516 case AmbiguousConversion:
517 OS << "Ambiguous conversion";
520 OS << "Bad conversion";
527 void AmbiguousConversionSequence::construct() {
528 new (&conversions()) ConversionSet();
531 void AmbiguousConversionSequence::destruct() {
532 conversions().~ConversionSet();
536 AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) {
537 FromTypePtr = O.FromTypePtr;
538 ToTypePtr = O.ToTypePtr;
539 new (&conversions()) ConversionSet(O.conversions());
543 // Structure used by DeductionFailureInfo to store
544 // template argument information.
545 struct DFIArguments {
546 TemplateArgument FirstArg;
547 TemplateArgument SecondArg;
549 // Structure used by DeductionFailureInfo to store
550 // template parameter and template argument information.
551 struct DFIParamWithArguments : DFIArguments {
552 TemplateParameter Param;
554 // Structure used by DeductionFailureInfo to store template argument
555 // information and the index of the problematic call argument.
556 struct DFIDeducedMismatchArgs : DFIArguments {
557 TemplateArgumentList *TemplateArgs;
558 unsigned CallArgIndex;
562 /// \brief Convert from Sema's representation of template deduction information
563 /// to the form used in overload-candidate information.
565 clang::MakeDeductionFailureInfo(ASTContext &Context,
566 Sema::TemplateDeductionResult TDK,
567 TemplateDeductionInfo &Info) {
568 DeductionFailureInfo Result;
569 Result.Result = static_cast<unsigned>(TDK);
570 Result.HasDiagnostic = false;
572 case Sema::TDK_Success:
573 case Sema::TDK_Invalid:
574 case Sema::TDK_InstantiationDepth:
575 case Sema::TDK_TooManyArguments:
576 case Sema::TDK_TooFewArguments:
577 case Sema::TDK_MiscellaneousDeductionFailure:
578 Result.Data = nullptr;
581 case Sema::TDK_Incomplete:
582 case Sema::TDK_InvalidExplicitArguments:
583 Result.Data = Info.Param.getOpaqueValue();
586 case Sema::TDK_DeducedMismatch: {
587 // FIXME: Should allocate from normal heap so that we can free this later.
588 auto *Saved = new (Context) DFIDeducedMismatchArgs;
589 Saved->FirstArg = Info.FirstArg;
590 Saved->SecondArg = Info.SecondArg;
591 Saved->TemplateArgs = Info.take();
592 Saved->CallArgIndex = Info.CallArgIndex;
597 case Sema::TDK_NonDeducedMismatch: {
598 // FIXME: Should allocate from normal heap so that we can free this later.
599 DFIArguments *Saved = new (Context) DFIArguments;
600 Saved->FirstArg = Info.FirstArg;
601 Saved->SecondArg = Info.SecondArg;
606 case Sema::TDK_Inconsistent:
607 case Sema::TDK_Underqualified: {
608 // FIXME: Should allocate from normal heap so that we can free this later.
609 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments;
610 Saved->Param = Info.Param;
611 Saved->FirstArg = Info.FirstArg;
612 Saved->SecondArg = Info.SecondArg;
617 case Sema::TDK_SubstitutionFailure:
618 Result.Data = Info.take();
619 if (Info.hasSFINAEDiagnostic()) {
620 PartialDiagnosticAt *Diag = new (Result.Diagnostic) PartialDiagnosticAt(
621 SourceLocation(), PartialDiagnostic::NullDiagnostic());
622 Info.takeSFINAEDiagnostic(*Diag);
623 Result.HasDiagnostic = true;
627 case Sema::TDK_FailedOverloadResolution:
628 Result.Data = Info.Expression;
635 void DeductionFailureInfo::Destroy() {
636 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
637 case Sema::TDK_Success:
638 case Sema::TDK_Invalid:
639 case Sema::TDK_InstantiationDepth:
640 case Sema::TDK_Incomplete:
641 case Sema::TDK_TooManyArguments:
642 case Sema::TDK_TooFewArguments:
643 case Sema::TDK_InvalidExplicitArguments:
644 case Sema::TDK_FailedOverloadResolution:
647 case Sema::TDK_Inconsistent:
648 case Sema::TDK_Underqualified:
649 case Sema::TDK_DeducedMismatch:
650 case Sema::TDK_NonDeducedMismatch:
651 // FIXME: Destroy the data?
655 case Sema::TDK_SubstitutionFailure:
656 // FIXME: Destroy the template argument list?
658 if (PartialDiagnosticAt *Diag = getSFINAEDiagnostic()) {
659 Diag->~PartialDiagnosticAt();
660 HasDiagnostic = false;
665 case Sema::TDK_MiscellaneousDeductionFailure:
670 PartialDiagnosticAt *DeductionFailureInfo::getSFINAEDiagnostic() {
672 return static_cast<PartialDiagnosticAt*>(static_cast<void*>(Diagnostic));
676 TemplateParameter DeductionFailureInfo::getTemplateParameter() {
677 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
678 case Sema::TDK_Success:
679 case Sema::TDK_Invalid:
680 case Sema::TDK_InstantiationDepth:
681 case Sema::TDK_TooManyArguments:
682 case Sema::TDK_TooFewArguments:
683 case Sema::TDK_SubstitutionFailure:
684 case Sema::TDK_DeducedMismatch:
685 case Sema::TDK_NonDeducedMismatch:
686 case Sema::TDK_FailedOverloadResolution:
687 return TemplateParameter();
689 case Sema::TDK_Incomplete:
690 case Sema::TDK_InvalidExplicitArguments:
691 return TemplateParameter::getFromOpaqueValue(Data);
693 case Sema::TDK_Inconsistent:
694 case Sema::TDK_Underqualified:
695 return static_cast<DFIParamWithArguments*>(Data)->Param;
698 case Sema::TDK_MiscellaneousDeductionFailure:
702 return TemplateParameter();
705 TemplateArgumentList *DeductionFailureInfo::getTemplateArgumentList() {
706 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
707 case Sema::TDK_Success:
708 case Sema::TDK_Invalid:
709 case Sema::TDK_InstantiationDepth:
710 case Sema::TDK_TooManyArguments:
711 case Sema::TDK_TooFewArguments:
712 case Sema::TDK_Incomplete:
713 case Sema::TDK_InvalidExplicitArguments:
714 case Sema::TDK_Inconsistent:
715 case Sema::TDK_Underqualified:
716 case Sema::TDK_NonDeducedMismatch:
717 case Sema::TDK_FailedOverloadResolution:
720 case Sema::TDK_DeducedMismatch:
721 return static_cast<DFIDeducedMismatchArgs*>(Data)->TemplateArgs;
723 case Sema::TDK_SubstitutionFailure:
724 return static_cast<TemplateArgumentList*>(Data);
727 case Sema::TDK_MiscellaneousDeductionFailure:
734 const TemplateArgument *DeductionFailureInfo::getFirstArg() {
735 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
736 case Sema::TDK_Success:
737 case Sema::TDK_Invalid:
738 case Sema::TDK_InstantiationDepth:
739 case Sema::TDK_Incomplete:
740 case Sema::TDK_TooManyArguments:
741 case Sema::TDK_TooFewArguments:
742 case Sema::TDK_InvalidExplicitArguments:
743 case Sema::TDK_SubstitutionFailure:
744 case Sema::TDK_FailedOverloadResolution:
747 case Sema::TDK_Inconsistent:
748 case Sema::TDK_Underqualified:
749 case Sema::TDK_DeducedMismatch:
750 case Sema::TDK_NonDeducedMismatch:
751 return &static_cast<DFIArguments*>(Data)->FirstArg;
754 case Sema::TDK_MiscellaneousDeductionFailure:
761 const TemplateArgument *DeductionFailureInfo::getSecondArg() {
762 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
763 case Sema::TDK_Success:
764 case Sema::TDK_Invalid:
765 case Sema::TDK_InstantiationDepth:
766 case Sema::TDK_Incomplete:
767 case Sema::TDK_TooManyArguments:
768 case Sema::TDK_TooFewArguments:
769 case Sema::TDK_InvalidExplicitArguments:
770 case Sema::TDK_SubstitutionFailure:
771 case Sema::TDK_FailedOverloadResolution:
774 case Sema::TDK_Inconsistent:
775 case Sema::TDK_Underqualified:
776 case Sema::TDK_DeducedMismatch:
777 case Sema::TDK_NonDeducedMismatch:
778 return &static_cast<DFIArguments*>(Data)->SecondArg;
781 case Sema::TDK_MiscellaneousDeductionFailure:
788 Expr *DeductionFailureInfo::getExpr() {
789 if (static_cast<Sema::TemplateDeductionResult>(Result) ==
790 Sema::TDK_FailedOverloadResolution)
791 return static_cast<Expr*>(Data);
796 llvm::Optional<unsigned> DeductionFailureInfo::getCallArgIndex() {
797 if (static_cast<Sema::TemplateDeductionResult>(Result) ==
798 Sema::TDK_DeducedMismatch)
799 return static_cast<DFIDeducedMismatchArgs*>(Data)->CallArgIndex;
804 void OverloadCandidateSet::destroyCandidates() {
805 for (iterator i = begin(), e = end(); i != e; ++i) {
806 for (unsigned ii = 0, ie = i->NumConversions; ii != ie; ++ii)
807 i->Conversions[ii].~ImplicitConversionSequence();
808 if (!i->Viable && i->FailureKind == ovl_fail_bad_deduction)
809 i->DeductionFailure.Destroy();
813 void OverloadCandidateSet::clear() {
815 NumInlineSequences = 0;
821 class UnbridgedCastsSet {
826 SmallVector<Entry, 2> Entries;
829 void save(Sema &S, Expr *&E) {
830 assert(E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast));
831 Entry entry = { &E, E };
832 Entries.push_back(entry);
833 E = S.stripARCUnbridgedCast(E);
837 for (SmallVectorImpl<Entry>::iterator
838 i = Entries.begin(), e = Entries.end(); i != e; ++i)
844 /// checkPlaceholderForOverload - Do any interesting placeholder-like
845 /// preprocessing on the given expression.
847 /// \param unbridgedCasts a collection to which to add unbridged casts;
848 /// without this, they will be immediately diagnosed as errors
850 /// Return true on unrecoverable error.
852 checkPlaceholderForOverload(Sema &S, Expr *&E,
853 UnbridgedCastsSet *unbridgedCasts = nullptr) {
854 if (const BuiltinType *placeholder = E->getType()->getAsPlaceholderType()) {
855 // We can't handle overloaded expressions here because overload
856 // resolution might reasonably tweak them.
857 if (placeholder->getKind() == BuiltinType::Overload) return false;
859 // If the context potentially accepts unbridged ARC casts, strip
860 // the unbridged cast and add it to the collection for later restoration.
861 if (placeholder->getKind() == BuiltinType::ARCUnbridgedCast &&
863 unbridgedCasts->save(S, E);
867 // Go ahead and check everything else.
868 ExprResult result = S.CheckPlaceholderExpr(E);
869 if (result.isInvalid())
880 /// checkArgPlaceholdersForOverload - Check a set of call operands for
882 static bool checkArgPlaceholdersForOverload(Sema &S,
884 UnbridgedCastsSet &unbridged) {
885 for (unsigned i = 0, e = Args.size(); i != e; ++i)
886 if (checkPlaceholderForOverload(S, Args[i], &unbridged))
892 // IsOverload - Determine whether the given New declaration is an
893 // overload of the declarations in Old. This routine returns false if
894 // New and Old cannot be overloaded, e.g., if New has the same
895 // signature as some function in Old (C++ 1.3.10) or if the Old
896 // declarations aren't functions (or function templates) at all. When
897 // it does return false, MatchedDecl will point to the decl that New
898 // cannot be overloaded with. This decl may be a UsingShadowDecl on
899 // top of the underlying declaration.
901 // Example: Given the following input:
903 // void f(int, float); // #1
904 // void f(int, int); // #2
905 // int f(int, int); // #3
907 // When we process #1, there is no previous declaration of "f",
908 // so IsOverload will not be used.
910 // When we process #2, Old contains only the FunctionDecl for #1. By
911 // comparing the parameter types, we see that #1 and #2 are overloaded
912 // (since they have different signatures), so this routine returns
913 // false; MatchedDecl is unchanged.
915 // When we process #3, Old is an overload set containing #1 and #2. We
916 // compare the signatures of #3 to #1 (they're overloaded, so we do
917 // nothing) and then #3 to #2. Since the signatures of #3 and #2 are
918 // identical (return types of functions are not part of the
919 // signature), IsOverload returns false and MatchedDecl will be set to
920 // point to the FunctionDecl for #2.
922 // 'NewIsUsingShadowDecl' indicates that 'New' is being introduced
923 // into a class by a using declaration. The rules for whether to hide
924 // shadow declarations ignore some properties which otherwise figure
925 // into a function template's signature.
927 Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old,
928 NamedDecl *&Match, bool NewIsUsingDecl) {
929 for (LookupResult::iterator I = Old.begin(), E = Old.end();
931 NamedDecl *OldD = *I;
933 bool OldIsUsingDecl = false;
934 if (isa<UsingShadowDecl>(OldD)) {
935 OldIsUsingDecl = true;
937 // We can always introduce two using declarations into the same
938 // context, even if they have identical signatures.
939 if (NewIsUsingDecl) continue;
941 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl();
944 // A using-declaration does not conflict with another declaration
945 // if one of them is hidden.
946 if ((OldIsUsingDecl || NewIsUsingDecl) && !isVisible(*I))
949 // If either declaration was introduced by a using declaration,
950 // we'll need to use slightly different rules for matching.
951 // Essentially, these rules are the normal rules, except that
952 // function templates hide function templates with different
953 // return types or template parameter lists.
954 bool UseMemberUsingDeclRules =
955 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord() &&
956 !New->getFriendObjectKind();
958 if (FunctionDecl *OldF = OldD->getAsFunction()) {
959 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) {
960 if (UseMemberUsingDeclRules && OldIsUsingDecl) {
961 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I));
965 if (!isa<FunctionTemplateDecl>(OldD) &&
966 !shouldLinkPossiblyHiddenDecl(*I, New))
972 } else if (isa<UsingDecl>(OldD)) {
973 // We can overload with these, which can show up when doing
974 // redeclaration checks for UsingDecls.
975 assert(Old.getLookupKind() == LookupUsingDeclName);
976 } else if (isa<TagDecl>(OldD)) {
977 // We can always overload with tags by hiding them.
978 } else if (isa<UnresolvedUsingValueDecl>(OldD)) {
979 // Optimistically assume that an unresolved using decl will
980 // overload; if it doesn't, we'll have to diagnose during
981 // template instantiation.
984 // Only function declarations can be overloaded; object and type
985 // declarations cannot be overloaded.
987 return Ovl_NonFunction;
994 bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old,
995 bool UseMemberUsingDeclRules, bool ConsiderCudaAttrs) {
996 // C++ [basic.start.main]p2: This function shall not be overloaded.
1000 // MSVCRT user defined entry points cannot be overloaded.
1001 if (New->isMSVCRTEntryPoint())
1004 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate();
1005 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate();
1007 // C++ [temp.fct]p2:
1008 // A function template can be overloaded with other function templates
1009 // and with normal (non-template) functions.
1010 if ((OldTemplate == nullptr) != (NewTemplate == nullptr))
1013 // Is the function New an overload of the function Old?
1014 QualType OldQType = Context.getCanonicalType(Old->getType());
1015 QualType NewQType = Context.getCanonicalType(New->getType());
1017 // Compare the signatures (C++ 1.3.10) of the two functions to
1018 // determine whether they are overloads. If we find any mismatch
1019 // in the signature, they are overloads.
1021 // If either of these functions is a K&R-style function (no
1022 // prototype), then we consider them to have matching signatures.
1023 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) ||
1024 isa<FunctionNoProtoType>(NewQType.getTypePtr()))
1027 const FunctionProtoType *OldType = cast<FunctionProtoType>(OldQType);
1028 const FunctionProtoType *NewType = cast<FunctionProtoType>(NewQType);
1030 // The signature of a function includes the types of its
1031 // parameters (C++ 1.3.10), which includes the presence or absence
1032 // of the ellipsis; see C++ DR 357).
1033 if (OldQType != NewQType &&
1034 (OldType->getNumParams() != NewType->getNumParams() ||
1035 OldType->isVariadic() != NewType->isVariadic() ||
1036 !FunctionParamTypesAreEqual(OldType, NewType)))
1039 // C++ [temp.over.link]p4:
1040 // The signature of a function template consists of its function
1041 // signature, its return type and its template parameter list. The names
1042 // of the template parameters are significant only for establishing the
1043 // relationship between the template parameters and the rest of the
1046 // We check the return type and template parameter lists for function
1047 // templates first; the remaining checks follow.
1049 // However, we don't consider either of these when deciding whether
1050 // a member introduced by a shadow declaration is hidden.
1051 if (!UseMemberUsingDeclRules && NewTemplate &&
1052 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(),
1053 OldTemplate->getTemplateParameters(),
1054 false, TPL_TemplateMatch) ||
1055 OldType->getReturnType() != NewType->getReturnType()))
1058 // If the function is a class member, its signature includes the
1059 // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself.
1061 // As part of this, also check whether one of the member functions
1062 // is static, in which case they are not overloads (C++
1063 // 13.1p2). While not part of the definition of the signature,
1064 // this check is important to determine whether these functions
1065 // can be overloaded.
1066 CXXMethodDecl *OldMethod = dyn_cast<CXXMethodDecl>(Old);
1067 CXXMethodDecl *NewMethod = dyn_cast<CXXMethodDecl>(New);
1068 if (OldMethod && NewMethod &&
1069 !OldMethod->isStatic() && !NewMethod->isStatic()) {
1070 if (OldMethod->getRefQualifier() != NewMethod->getRefQualifier()) {
1071 if (!UseMemberUsingDeclRules &&
1072 (OldMethod->getRefQualifier() == RQ_None ||
1073 NewMethod->getRefQualifier() == RQ_None)) {
1074 // C++0x [over.load]p2:
1075 // - Member function declarations with the same name and the same
1076 // parameter-type-list as well as member function template
1077 // declarations with the same name, the same parameter-type-list, and
1078 // the same template parameter lists cannot be overloaded if any of
1079 // them, but not all, have a ref-qualifier (8.3.5).
1080 Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload)
1081 << NewMethod->getRefQualifier() << OldMethod->getRefQualifier();
1082 Diag(OldMethod->getLocation(), diag::note_previous_declaration);
1087 // We may not have applied the implicit const for a constexpr member
1088 // function yet (because we haven't yet resolved whether this is a static
1089 // or non-static member function). Add it now, on the assumption that this
1090 // is a redeclaration of OldMethod.
1091 unsigned OldQuals = OldMethod->getTypeQualifiers();
1092 unsigned NewQuals = NewMethod->getTypeQualifiers();
1093 if (!getLangOpts().CPlusPlus14 && NewMethod->isConstexpr() &&
1094 !isa<CXXConstructorDecl>(NewMethod))
1095 NewQuals |= Qualifiers::Const;
1097 // We do not allow overloading based off of '__restrict'.
1098 OldQuals &= ~Qualifiers::Restrict;
1099 NewQuals &= ~Qualifiers::Restrict;
1100 if (OldQuals != NewQuals)
1104 // Though pass_object_size is placed on parameters and takes an argument, we
1105 // consider it to be a function-level modifier for the sake of function
1106 // identity. Either the function has one or more parameters with
1107 // pass_object_size or it doesn't.
1108 if (functionHasPassObjectSizeParams(New) !=
1109 functionHasPassObjectSizeParams(Old))
1112 // enable_if attributes are an order-sensitive part of the signature.
1113 for (specific_attr_iterator<EnableIfAttr>
1114 NewI = New->specific_attr_begin<EnableIfAttr>(),
1115 NewE = New->specific_attr_end<EnableIfAttr>(),
1116 OldI = Old->specific_attr_begin<EnableIfAttr>(),
1117 OldE = Old->specific_attr_end<EnableIfAttr>();
1118 NewI != NewE || OldI != OldE; ++NewI, ++OldI) {
1119 if (NewI == NewE || OldI == OldE)
1121 llvm::FoldingSetNodeID NewID, OldID;
1122 NewI->getCond()->Profile(NewID, Context, true);
1123 OldI->getCond()->Profile(OldID, Context, true);
1128 if (getLangOpts().CUDA && ConsiderCudaAttrs) {
1129 CUDAFunctionTarget NewTarget = IdentifyCUDATarget(New),
1130 OldTarget = IdentifyCUDATarget(Old);
1131 if (NewTarget == CFT_InvalidTarget || NewTarget == CFT_Global)
1134 assert((OldTarget != CFT_InvalidTarget) && "Unexpected invalid target.");
1136 // Don't allow mixing of HD with other kinds. This guarantees that
1137 // we have only one viable function with this signature on any
1138 // side of CUDA compilation .
1139 // __global__ functions can't be overloaded based on attribute
1140 // difference because, like HD, they also exist on both sides.
1141 if ((NewTarget == CFT_HostDevice) || (OldTarget == CFT_HostDevice) ||
1142 (NewTarget == CFT_Global) || (OldTarget == CFT_Global))
1145 // Allow overloading of functions with same signature, but
1146 // different CUDA target attributes.
1147 return NewTarget != OldTarget;
1150 // The signatures match; this is not an overload.
1154 /// \brief Checks availability of the function depending on the current
1155 /// function context. Inside an unavailable function, unavailability is ignored.
1157 /// \returns true if \arg FD is unavailable and current context is inside
1158 /// an available function, false otherwise.
1159 bool Sema::isFunctionConsideredUnavailable(FunctionDecl *FD) {
1160 if (!FD->isUnavailable())
1163 // Walk up the context of the caller.
1164 Decl *C = cast<Decl>(CurContext);
1166 if (C->isUnavailable())
1168 } while ((C = cast_or_null<Decl>(C->getDeclContext())));
1172 /// \brief Tries a user-defined conversion from From to ToType.
1174 /// Produces an implicit conversion sequence for when a standard conversion
1175 /// is not an option. See TryImplicitConversion for more information.
1176 static ImplicitConversionSequence
1177 TryUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
1178 bool SuppressUserConversions,
1180 bool InOverloadResolution,
1182 bool AllowObjCWritebackConversion,
1183 bool AllowObjCConversionOnExplicit) {
1184 ImplicitConversionSequence ICS;
1186 if (SuppressUserConversions) {
1187 // We're not in the case above, so there is no conversion that
1189 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1193 // Attempt user-defined conversion.
1194 OverloadCandidateSet Conversions(From->getExprLoc(),
1195 OverloadCandidateSet::CSK_Normal);
1196 switch (IsUserDefinedConversion(S, From, ToType, ICS.UserDefined,
1197 Conversions, AllowExplicit,
1198 AllowObjCConversionOnExplicit)) {
1201 ICS.setUserDefined();
1202 ICS.UserDefined.Before.setAsIdentityConversion();
1203 // C++ [over.ics.user]p4:
1204 // A conversion of an expression of class type to the same class
1205 // type is given Exact Match rank, and a conversion of an
1206 // expression of class type to a base class of that type is
1207 // given Conversion rank, in spite of the fact that a copy
1208 // constructor (i.e., a user-defined conversion function) is
1209 // called for those cases.
1210 if (CXXConstructorDecl *Constructor
1211 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) {
1213 = S.Context.getCanonicalType(From->getType().getUnqualifiedType());
1215 = S.Context.getCanonicalType(ToType).getUnqualifiedType();
1216 if (Constructor->isCopyConstructor() &&
1217 (FromCanon == ToCanon ||
1218 S.IsDerivedFrom(From->getLocStart(), FromCanon, ToCanon))) {
1219 // Turn this into a "standard" conversion sequence, so that it
1220 // gets ranked with standard conversion sequences.
1221 DeclAccessPair Found = ICS.UserDefined.FoundConversionFunction;
1223 ICS.Standard.setAsIdentityConversion();
1224 ICS.Standard.setFromType(From->getType());
1225 ICS.Standard.setAllToTypes(ToType);
1226 ICS.Standard.CopyConstructor = Constructor;
1227 ICS.Standard.FoundCopyConstructor = Found;
1228 if (ToCanon != FromCanon)
1229 ICS.Standard.Second = ICK_Derived_To_Base;
1236 ICS.Ambiguous.setFromType(From->getType());
1237 ICS.Ambiguous.setToType(ToType);
1238 for (OverloadCandidateSet::iterator Cand = Conversions.begin();
1239 Cand != Conversions.end(); ++Cand)
1241 ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
1245 case OR_No_Viable_Function:
1246 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1253 /// TryImplicitConversion - Attempt to perform an implicit conversion
1254 /// from the given expression (Expr) to the given type (ToType). This
1255 /// function returns an implicit conversion sequence that can be used
1256 /// to perform the initialization. Given
1258 /// void f(float f);
1259 /// void g(int i) { f(i); }
1261 /// this routine would produce an implicit conversion sequence to
1262 /// describe the initialization of f from i, which will be a standard
1263 /// conversion sequence containing an lvalue-to-rvalue conversion (C++
1264 /// 4.1) followed by a floating-integral conversion (C++ 4.9).
1266 /// Note that this routine only determines how the conversion can be
1267 /// performed; it does not actually perform the conversion. As such,
1268 /// it will not produce any diagnostics if no conversion is available,
1269 /// but will instead return an implicit conversion sequence of kind
1270 /// "BadConversion".
1272 /// If @p SuppressUserConversions, then user-defined conversions are
1274 /// If @p AllowExplicit, then explicit user-defined conversions are
1277 /// \param AllowObjCWritebackConversion Whether we allow the Objective-C
1278 /// writeback conversion, which allows __autoreleasing id* parameters to
1279 /// be initialized with __strong id* or __weak id* arguments.
1280 static ImplicitConversionSequence
1281 TryImplicitConversion(Sema &S, Expr *From, QualType ToType,
1282 bool SuppressUserConversions,
1284 bool InOverloadResolution,
1286 bool AllowObjCWritebackConversion,
1287 bool AllowObjCConversionOnExplicit) {
1288 ImplicitConversionSequence ICS;
1289 if (IsStandardConversion(S, From, ToType, InOverloadResolution,
1290 ICS.Standard, CStyle, AllowObjCWritebackConversion)){
1295 if (!S.getLangOpts().CPlusPlus) {
1296 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1300 // C++ [over.ics.user]p4:
1301 // A conversion of an expression of class type to the same class
1302 // type is given Exact Match rank, and a conversion of an
1303 // expression of class type to a base class of that type is
1304 // given Conversion rank, in spite of the fact that a copy/move
1305 // constructor (i.e., a user-defined conversion function) is
1306 // called for those cases.
1307 QualType FromType = From->getType();
1308 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() &&
1309 (S.Context.hasSameUnqualifiedType(FromType, ToType) ||
1310 S.IsDerivedFrom(From->getLocStart(), FromType, ToType))) {
1312 ICS.Standard.setAsIdentityConversion();
1313 ICS.Standard.setFromType(FromType);
1314 ICS.Standard.setAllToTypes(ToType);
1316 // We don't actually check at this point whether there is a valid
1317 // copy/move constructor, since overloading just assumes that it
1318 // exists. When we actually perform initialization, we'll find the
1319 // appropriate constructor to copy the returned object, if needed.
1320 ICS.Standard.CopyConstructor = nullptr;
1322 // Determine whether this is considered a derived-to-base conversion.
1323 if (!S.Context.hasSameUnqualifiedType(FromType, ToType))
1324 ICS.Standard.Second = ICK_Derived_To_Base;
1329 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
1330 AllowExplicit, InOverloadResolution, CStyle,
1331 AllowObjCWritebackConversion,
1332 AllowObjCConversionOnExplicit);
1335 ImplicitConversionSequence
1336 Sema::TryImplicitConversion(Expr *From, QualType ToType,
1337 bool SuppressUserConversions,
1339 bool InOverloadResolution,
1341 bool AllowObjCWritebackConversion) {
1342 return ::TryImplicitConversion(*this, From, ToType,
1343 SuppressUserConversions, AllowExplicit,
1344 InOverloadResolution, CStyle,
1345 AllowObjCWritebackConversion,
1346 /*AllowObjCConversionOnExplicit=*/false);
1349 /// PerformImplicitConversion - Perform an implicit conversion of the
1350 /// expression From to the type ToType. Returns the
1351 /// converted expression. Flavor is the kind of conversion we're
1352 /// performing, used in the error message. If @p AllowExplicit,
1353 /// explicit user-defined conversions are permitted.
1355 Sema::PerformImplicitConversion(Expr *From, QualType ToType,
1356 AssignmentAction Action, bool AllowExplicit) {
1357 ImplicitConversionSequence ICS;
1358 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS);
1362 Sema::PerformImplicitConversion(Expr *From, QualType ToType,
1363 AssignmentAction Action, bool AllowExplicit,
1364 ImplicitConversionSequence& ICS) {
1365 if (checkPlaceholderForOverload(*this, From))
1368 // Objective-C ARC: Determine whether we will allow the writeback conversion.
1369 bool AllowObjCWritebackConversion
1370 = getLangOpts().ObjCAutoRefCount &&
1371 (Action == AA_Passing || Action == AA_Sending);
1372 if (getLangOpts().ObjC1)
1373 CheckObjCBridgeRelatedConversions(From->getLocStart(),
1374 ToType, From->getType(), From);
1375 ICS = ::TryImplicitConversion(*this, From, ToType,
1376 /*SuppressUserConversions=*/false,
1378 /*InOverloadResolution=*/false,
1380 AllowObjCWritebackConversion,
1381 /*AllowObjCConversionOnExplicit=*/false);
1382 return PerformImplicitConversion(From, ToType, ICS, Action);
1385 /// \brief Determine whether the conversion from FromType to ToType is a valid
1386 /// conversion that strips "noreturn" off the nested function type.
1387 bool Sema::IsNoReturnConversion(QualType FromType, QualType ToType,
1388 QualType &ResultTy) {
1389 if (Context.hasSameUnqualifiedType(FromType, ToType))
1392 // Permit the conversion F(t __attribute__((noreturn))) -> F(t)
1393 // where F adds one of the following at most once:
1395 // - a member pointer
1396 // - a block pointer
1397 CanQualType CanTo = Context.getCanonicalType(ToType);
1398 CanQualType CanFrom = Context.getCanonicalType(FromType);
1399 Type::TypeClass TyClass = CanTo->getTypeClass();
1400 if (TyClass != CanFrom->getTypeClass()) return false;
1401 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) {
1402 if (TyClass == Type::Pointer) {
1403 CanTo = CanTo.getAs<PointerType>()->getPointeeType();
1404 CanFrom = CanFrom.getAs<PointerType>()->getPointeeType();
1405 } else if (TyClass == Type::BlockPointer) {
1406 CanTo = CanTo.getAs<BlockPointerType>()->getPointeeType();
1407 CanFrom = CanFrom.getAs<BlockPointerType>()->getPointeeType();
1408 } else if (TyClass == Type::MemberPointer) {
1409 CanTo = CanTo.getAs<MemberPointerType>()->getPointeeType();
1410 CanFrom = CanFrom.getAs<MemberPointerType>()->getPointeeType();
1415 TyClass = CanTo->getTypeClass();
1416 if (TyClass != CanFrom->getTypeClass()) return false;
1417 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto)
1421 const FunctionType *FromFn = cast<FunctionType>(CanFrom);
1422 FunctionType::ExtInfo EInfo = FromFn->getExtInfo();
1423 if (!EInfo.getNoReturn()) return false;
1425 FromFn = Context.adjustFunctionType(FromFn, EInfo.withNoReturn(false));
1426 assert(QualType(FromFn, 0).isCanonical());
1427 if (QualType(FromFn, 0) != CanTo) return false;
1433 /// \brief Determine whether the conversion from FromType to ToType is a valid
1434 /// vector conversion.
1436 /// \param ICK Will be set to the vector conversion kind, if this is a vector
1438 static bool IsVectorConversion(Sema &S, QualType FromType,
1439 QualType ToType, ImplicitConversionKind &ICK) {
1440 // We need at least one of these types to be a vector type to have a vector
1442 if (!ToType->isVectorType() && !FromType->isVectorType())
1445 // Identical types require no conversions.
1446 if (S.Context.hasSameUnqualifiedType(FromType, ToType))
1449 // There are no conversions between extended vector types, only identity.
1450 if (ToType->isExtVectorType()) {
1451 // There are no conversions between extended vector types other than the
1452 // identity conversion.
1453 if (FromType->isExtVectorType())
1456 // Vector splat from any arithmetic type to a vector.
1457 if (FromType->isArithmeticType()) {
1458 ICK = ICK_Vector_Splat;
1463 // We can perform the conversion between vector types in the following cases:
1464 // 1)vector types are equivalent AltiVec and GCC vector types
1465 // 2)lax vector conversions are permitted and the vector types are of the
1467 if (ToType->isVectorType() && FromType->isVectorType()) {
1468 if (S.Context.areCompatibleVectorTypes(FromType, ToType) ||
1469 S.isLaxVectorConversion(FromType, ToType)) {
1470 ICK = ICK_Vector_Conversion;
1478 static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
1479 bool InOverloadResolution,
1480 StandardConversionSequence &SCS,
1483 /// IsStandardConversion - Determines whether there is a standard
1484 /// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the
1485 /// expression From to the type ToType. Standard conversion sequences
1486 /// only consider non-class types; for conversions that involve class
1487 /// types, use TryImplicitConversion. If a conversion exists, SCS will
1488 /// contain the standard conversion sequence required to perform this
1489 /// conversion and this routine will return true. Otherwise, this
1490 /// routine will return false and the value of SCS is unspecified.
1491 static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
1492 bool InOverloadResolution,
1493 StandardConversionSequence &SCS,
1495 bool AllowObjCWritebackConversion) {
1496 QualType FromType = From->getType();
1498 // Standard conversions (C++ [conv])
1499 SCS.setAsIdentityConversion();
1500 SCS.IncompatibleObjC = false;
1501 SCS.setFromType(FromType);
1502 SCS.CopyConstructor = nullptr;
1504 // There are no standard conversions for class types in C++, so
1505 // abort early. When overloading in C, however, we do permit them.
1506 if (S.getLangOpts().CPlusPlus &&
1507 (FromType->isRecordType() || ToType->isRecordType()))
1510 // The first conversion can be an lvalue-to-rvalue conversion,
1511 // array-to-pointer conversion, or function-to-pointer conversion
1514 if (FromType == S.Context.OverloadTy) {
1515 DeclAccessPair AccessPair;
1516 if (FunctionDecl *Fn
1517 = S.ResolveAddressOfOverloadedFunction(From, ToType, false,
1519 // We were able to resolve the address of the overloaded function,
1520 // so we can convert to the type of that function.
1521 FromType = Fn->getType();
1522 SCS.setFromType(FromType);
1524 // we can sometimes resolve &foo<int> regardless of ToType, so check
1525 // if the type matches (identity) or we are converting to bool
1526 if (!S.Context.hasSameUnqualifiedType(
1527 S.ExtractUnqualifiedFunctionType(ToType), FromType)) {
1529 // if the function type matches except for [[noreturn]], it's ok
1530 if (!S.IsNoReturnConversion(FromType,
1531 S.ExtractUnqualifiedFunctionType(ToType), resultTy))
1532 // otherwise, only a boolean conversion is standard
1533 if (!ToType->isBooleanType())
1537 // Check if the "from" expression is taking the address of an overloaded
1538 // function and recompute the FromType accordingly. Take advantage of the
1539 // fact that non-static member functions *must* have such an address-of
1541 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn);
1542 if (Method && !Method->isStatic()) {
1543 assert(isa<UnaryOperator>(From->IgnoreParens()) &&
1544 "Non-unary operator on non-static member address");
1545 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode()
1547 "Non-address-of operator on non-static member address");
1548 const Type *ClassType
1549 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr();
1550 FromType = S.Context.getMemberPointerType(FromType, ClassType);
1551 } else if (isa<UnaryOperator>(From->IgnoreParens())) {
1552 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() ==
1554 "Non-address-of operator for overloaded function expression");
1555 FromType = S.Context.getPointerType(FromType);
1558 // Check that we've computed the proper type after overload resolution.
1559 assert(S.Context.hasSameType(
1561 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType()));
1566 // Lvalue-to-rvalue conversion (C++11 4.1):
1567 // A glvalue (3.10) of a non-function, non-array type T can
1568 // be converted to a prvalue.
1569 bool argIsLValue = From->isGLValue();
1571 !FromType->isFunctionType() && !FromType->isArrayType() &&
1572 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) {
1573 SCS.First = ICK_Lvalue_To_Rvalue;
1576 // ... if the lvalue has atomic type, the value has the non-atomic version
1577 // of the type of the lvalue ...
1578 if (const AtomicType *Atomic = FromType->getAs<AtomicType>())
1579 FromType = Atomic->getValueType();
1581 // If T is a non-class type, the type of the rvalue is the
1582 // cv-unqualified version of T. Otherwise, the type of the rvalue
1583 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we
1584 // just strip the qualifiers because they don't matter.
1585 FromType = FromType.getUnqualifiedType();
1586 } else if (FromType->isArrayType()) {
1587 // Array-to-pointer conversion (C++ 4.2)
1588 SCS.First = ICK_Array_To_Pointer;
1590 // An lvalue or rvalue of type "array of N T" or "array of unknown
1591 // bound of T" can be converted to an rvalue of type "pointer to
1593 FromType = S.Context.getArrayDecayedType(FromType);
1595 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) {
1596 // This conversion is deprecated in C++03 (D.4)
1597 SCS.DeprecatedStringLiteralToCharPtr = true;
1599 // For the purpose of ranking in overload resolution
1600 // (13.3.3.1.1), this conversion is considered an
1601 // array-to-pointer conversion followed by a qualification
1602 // conversion (4.4). (C++ 4.2p2)
1603 SCS.Second = ICK_Identity;
1604 SCS.Third = ICK_Qualification;
1605 SCS.QualificationIncludesObjCLifetime = false;
1606 SCS.setAllToTypes(FromType);
1609 } else if (FromType->isFunctionType() && argIsLValue) {
1610 // Function-to-pointer conversion (C++ 4.3).
1611 SCS.First = ICK_Function_To_Pointer;
1613 if (auto *DRE = dyn_cast<DeclRefExpr>(From->IgnoreParenCasts()))
1614 if (auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl()))
1615 if (!S.checkAddressOfFunctionIsAvailable(FD))
1618 // An lvalue of function type T can be converted to an rvalue of
1619 // type "pointer to T." The result is a pointer to the
1620 // function. (C++ 4.3p1).
1621 FromType = S.Context.getPointerType(FromType);
1623 // We don't require any conversions for the first step.
1624 SCS.First = ICK_Identity;
1626 SCS.setToType(0, FromType);
1628 // The second conversion can be an integral promotion, floating
1629 // point promotion, integral conversion, floating point conversion,
1630 // floating-integral conversion, pointer conversion,
1631 // pointer-to-member conversion, or boolean conversion (C++ 4p1).
1632 // For overloading in C, this can also be a "compatible-type"
1634 bool IncompatibleObjC = false;
1635 ImplicitConversionKind SecondICK = ICK_Identity;
1636 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) {
1637 // The unqualified versions of the types are the same: there's no
1638 // conversion to do.
1639 SCS.Second = ICK_Identity;
1640 } else if (S.IsIntegralPromotion(From, FromType, ToType)) {
1641 // Integral promotion (C++ 4.5).
1642 SCS.Second = ICK_Integral_Promotion;
1643 FromType = ToType.getUnqualifiedType();
1644 } else if (S.IsFloatingPointPromotion(FromType, ToType)) {
1645 // Floating point promotion (C++ 4.6).
1646 SCS.Second = ICK_Floating_Promotion;
1647 FromType = ToType.getUnqualifiedType();
1648 } else if (S.IsComplexPromotion(FromType, ToType)) {
1649 // Complex promotion (Clang extension)
1650 SCS.Second = ICK_Complex_Promotion;
1651 FromType = ToType.getUnqualifiedType();
1652 } else if (ToType->isBooleanType() &&
1653 (FromType->isArithmeticType() ||
1654 FromType->isAnyPointerType() ||
1655 FromType->isBlockPointerType() ||
1656 FromType->isMemberPointerType() ||
1657 FromType->isNullPtrType())) {
1658 // Boolean conversions (C++ 4.12).
1659 SCS.Second = ICK_Boolean_Conversion;
1660 FromType = S.Context.BoolTy;
1661 } else if (FromType->isIntegralOrUnscopedEnumerationType() &&
1662 ToType->isIntegralType(S.Context)) {
1663 // Integral conversions (C++ 4.7).
1664 SCS.Second = ICK_Integral_Conversion;
1665 FromType = ToType.getUnqualifiedType();
1666 } else if (FromType->isAnyComplexType() && ToType->isAnyComplexType()) {
1667 // Complex conversions (C99 6.3.1.6)
1668 SCS.Second = ICK_Complex_Conversion;
1669 FromType = ToType.getUnqualifiedType();
1670 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) ||
1671 (ToType->isAnyComplexType() && FromType->isArithmeticType())) {
1672 // Complex-real conversions (C99 6.3.1.7)
1673 SCS.Second = ICK_Complex_Real;
1674 FromType = ToType.getUnqualifiedType();
1675 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) {
1676 // FIXME: disable conversions between long double and __float128 if
1677 // their representation is different until there is back end support
1678 // We of course allow this conversion if long double is really double.
1679 if (&S.Context.getFloatTypeSemantics(FromType) !=
1680 &S.Context.getFloatTypeSemantics(ToType)) {
1681 bool Float128AndLongDouble = ((FromType == S.Context.Float128Ty &&
1682 ToType == S.Context.LongDoubleTy) ||
1683 (FromType == S.Context.LongDoubleTy &&
1684 ToType == S.Context.Float128Ty));
1685 if (Float128AndLongDouble &&
1686 (&S.Context.getFloatTypeSemantics(S.Context.LongDoubleTy) !=
1687 &llvm::APFloat::IEEEdouble))
1690 // Floating point conversions (C++ 4.8).
1691 SCS.Second = ICK_Floating_Conversion;
1692 FromType = ToType.getUnqualifiedType();
1693 } else if ((FromType->isRealFloatingType() &&
1694 ToType->isIntegralType(S.Context)) ||
1695 (FromType->isIntegralOrUnscopedEnumerationType() &&
1696 ToType->isRealFloatingType())) {
1697 // Floating-integral conversions (C++ 4.9).
1698 SCS.Second = ICK_Floating_Integral;
1699 FromType = ToType.getUnqualifiedType();
1700 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) {
1701 SCS.Second = ICK_Block_Pointer_Conversion;
1702 } else if (AllowObjCWritebackConversion &&
1703 S.isObjCWritebackConversion(FromType, ToType, FromType)) {
1704 SCS.Second = ICK_Writeback_Conversion;
1705 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution,
1706 FromType, IncompatibleObjC)) {
1707 // Pointer conversions (C++ 4.10).
1708 SCS.Second = ICK_Pointer_Conversion;
1709 SCS.IncompatibleObjC = IncompatibleObjC;
1710 FromType = FromType.getUnqualifiedType();
1711 } else if (S.IsMemberPointerConversion(From, FromType, ToType,
1712 InOverloadResolution, FromType)) {
1713 // Pointer to member conversions (4.11).
1714 SCS.Second = ICK_Pointer_Member;
1715 } else if (IsVectorConversion(S, FromType, ToType, SecondICK)) {
1716 SCS.Second = SecondICK;
1717 FromType = ToType.getUnqualifiedType();
1718 } else if (!S.getLangOpts().CPlusPlus &&
1719 S.Context.typesAreCompatible(ToType, FromType)) {
1720 // Compatible conversions (Clang extension for C function overloading)
1721 SCS.Second = ICK_Compatible_Conversion;
1722 FromType = ToType.getUnqualifiedType();
1723 } else if (S.IsNoReturnConversion(FromType, ToType, FromType)) {
1724 // Treat a conversion that strips "noreturn" as an identity conversion.
1725 SCS.Second = ICK_NoReturn_Adjustment;
1726 } else if (IsTransparentUnionStandardConversion(S, From, ToType,
1727 InOverloadResolution,
1729 SCS.Second = ICK_TransparentUnionConversion;
1731 } else if (tryAtomicConversion(S, From, ToType, InOverloadResolution, SCS,
1733 // tryAtomicConversion has updated the standard conversion sequence
1736 } else if (ToType->isEventT() &&
1737 From->isIntegerConstantExpr(S.getASTContext()) &&
1738 From->EvaluateKnownConstInt(S.getASTContext()) == 0) {
1739 SCS.Second = ICK_Zero_Event_Conversion;
1742 // No second conversion required.
1743 SCS.Second = ICK_Identity;
1745 SCS.setToType(1, FromType);
1749 // The third conversion can be a qualification conversion (C++ 4p1).
1750 bool ObjCLifetimeConversion;
1751 if (S.IsQualificationConversion(FromType, ToType, CStyle,
1752 ObjCLifetimeConversion)) {
1753 SCS.Third = ICK_Qualification;
1754 SCS.QualificationIncludesObjCLifetime = ObjCLifetimeConversion;
1756 CanonFrom = S.Context.getCanonicalType(FromType);
1757 CanonTo = S.Context.getCanonicalType(ToType);
1759 // No conversion required
1760 SCS.Third = ICK_Identity;
1762 // C++ [over.best.ics]p6:
1763 // [...] Any difference in top-level cv-qualification is
1764 // subsumed by the initialization itself and does not constitute
1765 // a conversion. [...]
1766 CanonFrom = S.Context.getCanonicalType(FromType);
1767 CanonTo = S.Context.getCanonicalType(ToType);
1768 if (CanonFrom.getLocalUnqualifiedType()
1769 == CanonTo.getLocalUnqualifiedType() &&
1770 CanonFrom.getLocalQualifiers() != CanonTo.getLocalQualifiers()) {
1772 CanonFrom = CanonTo;
1775 SCS.setToType(2, FromType);
1777 if (CanonFrom == CanonTo)
1780 // If we have not converted the argument type to the parameter type,
1781 // this is a bad conversion sequence, unless we're resolving an overload in C.
1782 if (S.getLangOpts().CPlusPlus || !InOverloadResolution)
1785 ExprResult ER = ExprResult{From};
1786 auto Conv = S.CheckSingleAssignmentConstraints(ToType, ER,
1788 /*DiagnoseCFAudited=*/false,
1789 /*ConvertRHS=*/false);
1790 if (Conv != Sema::Compatible)
1793 SCS.setAllToTypes(ToType);
1794 // We need to set all three because we want this conversion to rank terribly,
1795 // and we don't know what conversions it may overlap with.
1796 SCS.First = ICK_C_Only_Conversion;
1797 SCS.Second = ICK_C_Only_Conversion;
1798 SCS.Third = ICK_C_Only_Conversion;
1803 IsTransparentUnionStandardConversion(Sema &S, Expr* From,
1805 bool InOverloadResolution,
1806 StandardConversionSequence &SCS,
1809 const RecordType *UT = ToType->getAsUnionType();
1810 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>())
1812 // The field to initialize within the transparent union.
1813 RecordDecl *UD = UT->getDecl();
1814 // It's compatible if the expression matches any of the fields.
1815 for (const auto *it : UD->fields()) {
1816 if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS,
1817 CStyle, /*ObjCWritebackConversion=*/false)) {
1818 ToType = it->getType();
1825 /// IsIntegralPromotion - Determines whether the conversion from the
1826 /// expression From (whose potentially-adjusted type is FromType) to
1827 /// ToType is an integral promotion (C++ 4.5). If so, returns true and
1828 /// sets PromotedType to the promoted type.
1829 bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) {
1830 const BuiltinType *To = ToType->getAs<BuiltinType>();
1831 // All integers are built-in.
1836 // An rvalue of type char, signed char, unsigned char, short int, or
1837 // unsigned short int can be converted to an rvalue of type int if
1838 // int can represent all the values of the source type; otherwise,
1839 // the source rvalue can be converted to an rvalue of type unsigned
1841 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() &&
1842 !FromType->isEnumeralType()) {
1843 if (// We can promote any signed, promotable integer type to an int
1844 (FromType->isSignedIntegerType() ||
1845 // We can promote any unsigned integer type whose size is
1846 // less than int to an int.
1847 Context.getTypeSize(FromType) < Context.getTypeSize(ToType))) {
1848 return To->getKind() == BuiltinType::Int;
1851 return To->getKind() == BuiltinType::UInt;
1854 // C++11 [conv.prom]p3:
1855 // A prvalue of an unscoped enumeration type whose underlying type is not
1856 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the
1857 // following types that can represent all the values of the enumeration
1858 // (i.e., the values in the range bmin to bmax as described in 7.2): int,
1859 // unsigned int, long int, unsigned long int, long long int, or unsigned
1860 // long long int. If none of the types in that list can represent all the
1861 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration
1862 // type can be converted to an rvalue a prvalue of the extended integer type
1863 // with lowest integer conversion rank (4.13) greater than the rank of long
1864 // long in which all the values of the enumeration can be represented. If
1865 // there are two such extended types, the signed one is chosen.
1866 // C++11 [conv.prom]p4:
1867 // A prvalue of an unscoped enumeration type whose underlying type is fixed
1868 // can be converted to a prvalue of its underlying type. Moreover, if
1869 // integral promotion can be applied to its underlying type, a prvalue of an
1870 // unscoped enumeration type whose underlying type is fixed can also be
1871 // converted to a prvalue of the promoted underlying type.
1872 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) {
1873 // C++0x 7.2p9: Note that this implicit enum to int conversion is not
1874 // provided for a scoped enumeration.
1875 if (FromEnumType->getDecl()->isScoped())
1878 // We can perform an integral promotion to the underlying type of the enum,
1879 // even if that's not the promoted type. Note that the check for promoting
1880 // the underlying type is based on the type alone, and does not consider
1881 // the bitfield-ness of the actual source expression.
1882 if (FromEnumType->getDecl()->isFixed()) {
1883 QualType Underlying = FromEnumType->getDecl()->getIntegerType();
1884 return Context.hasSameUnqualifiedType(Underlying, ToType) ||
1885 IsIntegralPromotion(nullptr, Underlying, ToType);
1888 // We have already pre-calculated the promotion type, so this is trivial.
1889 if (ToType->isIntegerType() &&
1890 isCompleteType(From->getLocStart(), FromType))
1891 return Context.hasSameUnqualifiedType(
1892 ToType, FromEnumType->getDecl()->getPromotionType());
1895 // C++0x [conv.prom]p2:
1896 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted
1897 // to an rvalue a prvalue of the first of the following types that can
1898 // represent all the values of its underlying type: int, unsigned int,
1899 // long int, unsigned long int, long long int, or unsigned long long int.
1900 // If none of the types in that list can represent all the values of its
1901 // underlying type, an rvalue a prvalue of type char16_t, char32_t,
1902 // or wchar_t can be converted to an rvalue a prvalue of its underlying
1904 if (FromType->isAnyCharacterType() && !FromType->isCharType() &&
1905 ToType->isIntegerType()) {
1906 // Determine whether the type we're converting from is signed or
1908 bool FromIsSigned = FromType->isSignedIntegerType();
1909 uint64_t FromSize = Context.getTypeSize(FromType);
1911 // The types we'll try to promote to, in the appropriate
1912 // order. Try each of these types.
1913 QualType PromoteTypes[6] = {
1914 Context.IntTy, Context.UnsignedIntTy,
1915 Context.LongTy, Context.UnsignedLongTy ,
1916 Context.LongLongTy, Context.UnsignedLongLongTy
1918 for (int Idx = 0; Idx < 6; ++Idx) {
1919 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]);
1920 if (FromSize < ToSize ||
1921 (FromSize == ToSize &&
1922 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) {
1923 // We found the type that we can promote to. If this is the
1924 // type we wanted, we have a promotion. Otherwise, no
1926 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]);
1931 // An rvalue for an integral bit-field (9.6) can be converted to an
1932 // rvalue of type int if int can represent all the values of the
1933 // bit-field; otherwise, it can be converted to unsigned int if
1934 // unsigned int can represent all the values of the bit-field. If
1935 // the bit-field is larger yet, no integral promotion applies to
1936 // it. If the bit-field has an enumerated type, it is treated as any
1937 // other value of that type for promotion purposes (C++ 4.5p3).
1938 // FIXME: We should delay checking of bit-fields until we actually perform the
1941 if (FieldDecl *MemberDecl = From->getSourceBitField()) {
1942 llvm::APSInt BitWidth;
1943 if (FromType->isIntegralType(Context) &&
1944 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) {
1945 llvm::APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned());
1946 ToSize = Context.getTypeSize(ToType);
1948 // Are we promoting to an int from a bitfield that fits in an int?
1949 if (BitWidth < ToSize ||
1950 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) {
1951 return To->getKind() == BuiltinType::Int;
1954 // Are we promoting to an unsigned int from an unsigned bitfield
1955 // that fits into an unsigned int?
1956 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) {
1957 return To->getKind() == BuiltinType::UInt;
1965 // An rvalue of type bool can be converted to an rvalue of type int,
1966 // with false becoming zero and true becoming one (C++ 4.5p4).
1967 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) {
1974 /// IsFloatingPointPromotion - Determines whether the conversion from
1975 /// FromType to ToType is a floating point promotion (C++ 4.6). If so,
1976 /// returns true and sets PromotedType to the promoted type.
1977 bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) {
1978 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>())
1979 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) {
1980 /// An rvalue of type float can be converted to an rvalue of type
1981 /// double. (C++ 4.6p1).
1982 if (FromBuiltin->getKind() == BuiltinType::Float &&
1983 ToBuiltin->getKind() == BuiltinType::Double)
1987 // When a float is promoted to double or long double, or a
1988 // double is promoted to long double [...].
1989 if (!getLangOpts().CPlusPlus &&
1990 (FromBuiltin->getKind() == BuiltinType::Float ||
1991 FromBuiltin->getKind() == BuiltinType::Double) &&
1992 (ToBuiltin->getKind() == BuiltinType::LongDouble ||
1993 ToBuiltin->getKind() == BuiltinType::Float128))
1996 // Half can be promoted to float.
1997 if (!getLangOpts().NativeHalfType &&
1998 FromBuiltin->getKind() == BuiltinType::Half &&
1999 ToBuiltin->getKind() == BuiltinType::Float)
2006 /// \brief Determine if a conversion is a complex promotion.
2008 /// A complex promotion is defined as a complex -> complex conversion
2009 /// where the conversion between the underlying real types is a
2010 /// floating-point or integral promotion.
2011 bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) {
2012 const ComplexType *FromComplex = FromType->getAs<ComplexType>();
2016 const ComplexType *ToComplex = ToType->getAs<ComplexType>();
2020 return IsFloatingPointPromotion(FromComplex->getElementType(),
2021 ToComplex->getElementType()) ||
2022 IsIntegralPromotion(nullptr, FromComplex->getElementType(),
2023 ToComplex->getElementType());
2026 /// BuildSimilarlyQualifiedPointerType - In a pointer conversion from
2027 /// the pointer type FromPtr to a pointer to type ToPointee, with the
2028 /// same type qualifiers as FromPtr has on its pointee type. ToType,
2029 /// if non-empty, will be a pointer to ToType that may or may not have
2030 /// the right set of qualifiers on its pointee.
2033 BuildSimilarlyQualifiedPointerType(const Type *FromPtr,
2034 QualType ToPointee, QualType ToType,
2035 ASTContext &Context,
2036 bool StripObjCLifetime = false) {
2037 assert((FromPtr->getTypeClass() == Type::Pointer ||
2038 FromPtr->getTypeClass() == Type::ObjCObjectPointer) &&
2039 "Invalid similarly-qualified pointer type");
2041 /// Conversions to 'id' subsume cv-qualifier conversions.
2042 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType())
2043 return ToType.getUnqualifiedType();
2045 QualType CanonFromPointee
2046 = Context.getCanonicalType(FromPtr->getPointeeType());
2047 QualType CanonToPointee = Context.getCanonicalType(ToPointee);
2048 Qualifiers Quals = CanonFromPointee.getQualifiers();
2050 if (StripObjCLifetime)
2051 Quals.removeObjCLifetime();
2053 // Exact qualifier match -> return the pointer type we're converting to.
2054 if (CanonToPointee.getLocalQualifiers() == Quals) {
2055 // ToType is exactly what we need. Return it.
2056 if (!ToType.isNull())
2057 return ToType.getUnqualifiedType();
2059 // Build a pointer to ToPointee. It has the right qualifiers
2061 if (isa<ObjCObjectPointerType>(ToType))
2062 return Context.getObjCObjectPointerType(ToPointee);
2063 return Context.getPointerType(ToPointee);
2066 // Just build a canonical type that has the right qualifiers.
2067 QualType QualifiedCanonToPointee
2068 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals);
2070 if (isa<ObjCObjectPointerType>(ToType))
2071 return Context.getObjCObjectPointerType(QualifiedCanonToPointee);
2072 return Context.getPointerType(QualifiedCanonToPointee);
2075 static bool isNullPointerConstantForConversion(Expr *Expr,
2076 bool InOverloadResolution,
2077 ASTContext &Context) {
2078 // Handle value-dependent integral null pointer constants correctly.
2079 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903
2080 if (Expr->isValueDependent() && !Expr->isTypeDependent() &&
2081 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType())
2082 return !InOverloadResolution;
2084 return Expr->isNullPointerConstant(Context,
2085 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
2086 : Expr::NPC_ValueDependentIsNull);
2089 /// IsPointerConversion - Determines whether the conversion of the
2090 /// expression From, which has the (possibly adjusted) type FromType,
2091 /// can be converted to the type ToType via a pointer conversion (C++
2092 /// 4.10). If so, returns true and places the converted type (that
2093 /// might differ from ToType in its cv-qualifiers at some level) into
2096 /// This routine also supports conversions to and from block pointers
2097 /// and conversions with Objective-C's 'id', 'id<protocols...>', and
2098 /// pointers to interfaces. FIXME: Once we've determined the
2099 /// appropriate overloading rules for Objective-C, we may want to
2100 /// split the Objective-C checks into a different routine; however,
2101 /// GCC seems to consider all of these conversions to be pointer
2102 /// conversions, so for now they live here. IncompatibleObjC will be
2103 /// set if the conversion is an allowed Objective-C conversion that
2104 /// should result in a warning.
2105 bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType,
2106 bool InOverloadResolution,
2107 QualType& ConvertedType,
2108 bool &IncompatibleObjC) {
2109 IncompatibleObjC = false;
2110 if (isObjCPointerConversion(FromType, ToType, ConvertedType,
2114 // Conversion from a null pointer constant to any Objective-C pointer type.
2115 if (ToType->isObjCObjectPointerType() &&
2116 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2117 ConvertedType = ToType;
2121 // Blocks: Block pointers can be converted to void*.
2122 if (FromType->isBlockPointerType() && ToType->isPointerType() &&
2123 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) {
2124 ConvertedType = ToType;
2127 // Blocks: A null pointer constant can be converted to a block
2129 if (ToType->isBlockPointerType() &&
2130 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2131 ConvertedType = ToType;
2135 // If the left-hand-side is nullptr_t, the right side can be a null
2136 // pointer constant.
2137 if (ToType->isNullPtrType() &&
2138 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2139 ConvertedType = ToType;
2143 const PointerType* ToTypePtr = ToType->getAs<PointerType>();
2147 // A null pointer constant can be converted to a pointer type (C++ 4.10p1).
2148 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2149 ConvertedType = ToType;
2153 // Beyond this point, both types need to be pointers
2154 // , including objective-c pointers.
2155 QualType ToPointeeType = ToTypePtr->getPointeeType();
2156 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType() &&
2157 !getLangOpts().ObjCAutoRefCount) {
2158 ConvertedType = BuildSimilarlyQualifiedPointerType(
2159 FromType->getAs<ObjCObjectPointerType>(),
2164 const PointerType *FromTypePtr = FromType->getAs<PointerType>();
2168 QualType FromPointeeType = FromTypePtr->getPointeeType();
2170 // If the unqualified pointee types are the same, this can't be a
2171 // pointer conversion, so don't do all of the work below.
2172 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType))
2175 // An rvalue of type "pointer to cv T," where T is an object type,
2176 // can be converted to an rvalue of type "pointer to cv void" (C++
2178 if (FromPointeeType->isIncompleteOrObjectType() &&
2179 ToPointeeType->isVoidType()) {
2180 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2183 /*StripObjCLifetime=*/true);
2187 // MSVC allows implicit function to void* type conversion.
2188 if (getLangOpts().MSVCCompat && FromPointeeType->isFunctionType() &&
2189 ToPointeeType->isVoidType()) {
2190 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2196 // When we're overloading in C, we allow a special kind of pointer
2197 // conversion for compatible-but-not-identical pointee types.
2198 if (!getLangOpts().CPlusPlus &&
2199 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) {
2200 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2206 // C++ [conv.ptr]p3:
2208 // An rvalue of type "pointer to cv D," where D is a class type,
2209 // can be converted to an rvalue of type "pointer to cv B," where
2210 // B is a base class (clause 10) of D. If B is an inaccessible
2211 // (clause 11) or ambiguous (10.2) base class of D, a program that
2212 // necessitates this conversion is ill-formed. The result of the
2213 // conversion is a pointer to the base class sub-object of the
2214 // derived class object. The null pointer value is converted to
2215 // the null pointer value of the destination type.
2217 // Note that we do not check for ambiguity or inaccessibility
2218 // here. That is handled by CheckPointerConversion.
2219 if (getLangOpts().CPlusPlus &&
2220 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() &&
2221 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) &&
2222 IsDerivedFrom(From->getLocStart(), FromPointeeType, ToPointeeType)) {
2223 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2229 if (FromPointeeType->isVectorType() && ToPointeeType->isVectorType() &&
2230 Context.areCompatibleVectorTypes(FromPointeeType, ToPointeeType)) {
2231 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2240 /// \brief Adopt the given qualifiers for the given type.
2241 static QualType AdoptQualifiers(ASTContext &Context, QualType T, Qualifiers Qs){
2242 Qualifiers TQs = T.getQualifiers();
2244 // Check whether qualifiers already match.
2248 if (Qs.compatiblyIncludes(TQs))
2249 return Context.getQualifiedType(T, Qs);
2251 return Context.getQualifiedType(T.getUnqualifiedType(), Qs);
2254 /// isObjCPointerConversion - Determines whether this is an
2255 /// Objective-C pointer conversion. Subroutine of IsPointerConversion,
2256 /// with the same arguments and return values.
2257 bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType,
2258 QualType& ConvertedType,
2259 bool &IncompatibleObjC) {
2260 if (!getLangOpts().ObjC1)
2263 // The set of qualifiers on the type we're converting from.
2264 Qualifiers FromQualifiers = FromType.getQualifiers();
2266 // First, we handle all conversions on ObjC object pointer types.
2267 const ObjCObjectPointerType* ToObjCPtr =
2268 ToType->getAs<ObjCObjectPointerType>();
2269 const ObjCObjectPointerType *FromObjCPtr =
2270 FromType->getAs<ObjCObjectPointerType>();
2272 if (ToObjCPtr && FromObjCPtr) {
2273 // If the pointee types are the same (ignoring qualifications),
2274 // then this is not a pointer conversion.
2275 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(),
2276 FromObjCPtr->getPointeeType()))
2279 // Conversion between Objective-C pointers.
2280 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) {
2281 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType();
2282 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType();
2283 if (getLangOpts().CPlusPlus && LHS && RHS &&
2284 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs(
2285 FromObjCPtr->getPointeeType()))
2287 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2288 ToObjCPtr->getPointeeType(),
2290 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2294 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) {
2295 // Okay: this is some kind of implicit downcast of Objective-C
2296 // interfaces, which is permitted. However, we're going to
2297 // complain about it.
2298 IncompatibleObjC = true;
2299 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2300 ToObjCPtr->getPointeeType(),
2302 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2306 // Beyond this point, both types need to be C pointers or block pointers.
2307 QualType ToPointeeType;
2308 if (const PointerType *ToCPtr = ToType->getAs<PointerType>())
2309 ToPointeeType = ToCPtr->getPointeeType();
2310 else if (const BlockPointerType *ToBlockPtr =
2311 ToType->getAs<BlockPointerType>()) {
2312 // Objective C++: We're able to convert from a pointer to any object
2313 // to a block pointer type.
2314 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) {
2315 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2318 ToPointeeType = ToBlockPtr->getPointeeType();
2320 else if (FromType->getAs<BlockPointerType>() &&
2321 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) {
2322 // Objective C++: We're able to convert from a block pointer type to a
2323 // pointer to any object.
2324 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2330 QualType FromPointeeType;
2331 if (const PointerType *FromCPtr = FromType->getAs<PointerType>())
2332 FromPointeeType = FromCPtr->getPointeeType();
2333 else if (const BlockPointerType *FromBlockPtr =
2334 FromType->getAs<BlockPointerType>())
2335 FromPointeeType = FromBlockPtr->getPointeeType();
2339 // If we have pointers to pointers, recursively check whether this
2340 // is an Objective-C conversion.
2341 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() &&
2342 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2343 IncompatibleObjC)) {
2344 // We always complain about this conversion.
2345 IncompatibleObjC = true;
2346 ConvertedType = Context.getPointerType(ConvertedType);
2347 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2350 // Allow conversion of pointee being objective-c pointer to another one;
2352 if (FromPointeeType->getAs<ObjCObjectPointerType>() &&
2353 ToPointeeType->getAs<ObjCObjectPointerType>() &&
2354 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2355 IncompatibleObjC)) {
2357 ConvertedType = Context.getPointerType(ConvertedType);
2358 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2362 // If we have pointers to functions or blocks, check whether the only
2363 // differences in the argument and result types are in Objective-C
2364 // pointer conversions. If so, we permit the conversion (but
2365 // complain about it).
2366 const FunctionProtoType *FromFunctionType
2367 = FromPointeeType->getAs<FunctionProtoType>();
2368 const FunctionProtoType *ToFunctionType
2369 = ToPointeeType->getAs<FunctionProtoType>();
2370 if (FromFunctionType && ToFunctionType) {
2371 // If the function types are exactly the same, this isn't an
2372 // Objective-C pointer conversion.
2373 if (Context.getCanonicalType(FromPointeeType)
2374 == Context.getCanonicalType(ToPointeeType))
2377 // Perform the quick checks that will tell us whether these
2378 // function types are obviously different.
2379 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2380 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() ||
2381 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals())
2384 bool HasObjCConversion = false;
2385 if (Context.getCanonicalType(FromFunctionType->getReturnType()) ==
2386 Context.getCanonicalType(ToFunctionType->getReturnType())) {
2387 // Okay, the types match exactly. Nothing to do.
2388 } else if (isObjCPointerConversion(FromFunctionType->getReturnType(),
2389 ToFunctionType->getReturnType(),
2390 ConvertedType, IncompatibleObjC)) {
2391 // Okay, we have an Objective-C pointer conversion.
2392 HasObjCConversion = true;
2394 // Function types are too different. Abort.
2398 // Check argument types.
2399 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2400 ArgIdx != NumArgs; ++ArgIdx) {
2401 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2402 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2403 if (Context.getCanonicalType(FromArgType)
2404 == Context.getCanonicalType(ToArgType)) {
2405 // Okay, the types match exactly. Nothing to do.
2406 } else if (isObjCPointerConversion(FromArgType, ToArgType,
2407 ConvertedType, IncompatibleObjC)) {
2408 // Okay, we have an Objective-C pointer conversion.
2409 HasObjCConversion = true;
2411 // Argument types are too different. Abort.
2416 if (HasObjCConversion) {
2417 // We had an Objective-C conversion. Allow this pointer
2418 // conversion, but complain about it.
2419 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2420 IncompatibleObjC = true;
2428 /// \brief Determine whether this is an Objective-C writeback conversion,
2429 /// used for parameter passing when performing automatic reference counting.
2431 /// \param FromType The type we're converting form.
2433 /// \param ToType The type we're converting to.
2435 /// \param ConvertedType The type that will be produced after applying
2436 /// this conversion.
2437 bool Sema::isObjCWritebackConversion(QualType FromType, QualType ToType,
2438 QualType &ConvertedType) {
2439 if (!getLangOpts().ObjCAutoRefCount ||
2440 Context.hasSameUnqualifiedType(FromType, ToType))
2443 // Parameter must be a pointer to __autoreleasing (with no other qualifiers).
2445 if (const PointerType *ToPointer = ToType->getAs<PointerType>())
2446 ToPointee = ToPointer->getPointeeType();
2450 Qualifiers ToQuals = ToPointee.getQualifiers();
2451 if (!ToPointee->isObjCLifetimeType() ||
2452 ToQuals.getObjCLifetime() != Qualifiers::OCL_Autoreleasing ||
2453 !ToQuals.withoutObjCLifetime().empty())
2456 // Argument must be a pointer to __strong to __weak.
2457 QualType FromPointee;
2458 if (const PointerType *FromPointer = FromType->getAs<PointerType>())
2459 FromPointee = FromPointer->getPointeeType();
2463 Qualifiers FromQuals = FromPointee.getQualifiers();
2464 if (!FromPointee->isObjCLifetimeType() ||
2465 (FromQuals.getObjCLifetime() != Qualifiers::OCL_Strong &&
2466 FromQuals.getObjCLifetime() != Qualifiers::OCL_Weak))
2469 // Make sure that we have compatible qualifiers.
2470 FromQuals.setObjCLifetime(Qualifiers::OCL_Autoreleasing);
2471 if (!ToQuals.compatiblyIncludes(FromQuals))
2474 // Remove qualifiers from the pointee type we're converting from; they
2475 // aren't used in the compatibility check belong, and we'll be adding back
2476 // qualifiers (with __autoreleasing) if the compatibility check succeeds.
2477 FromPointee = FromPointee.getUnqualifiedType();
2479 // The unqualified form of the pointee types must be compatible.
2480 ToPointee = ToPointee.getUnqualifiedType();
2481 bool IncompatibleObjC;
2482 if (Context.typesAreCompatible(FromPointee, ToPointee))
2483 FromPointee = ToPointee;
2484 else if (!isObjCPointerConversion(FromPointee, ToPointee, FromPointee,
2488 /// \brief Construct the type we're converting to, which is a pointer to
2489 /// __autoreleasing pointee.
2490 FromPointee = Context.getQualifiedType(FromPointee, FromQuals);
2491 ConvertedType = Context.getPointerType(FromPointee);
2495 bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType,
2496 QualType& ConvertedType) {
2497 QualType ToPointeeType;
2498 if (const BlockPointerType *ToBlockPtr =
2499 ToType->getAs<BlockPointerType>())
2500 ToPointeeType = ToBlockPtr->getPointeeType();
2504 QualType FromPointeeType;
2505 if (const BlockPointerType *FromBlockPtr =
2506 FromType->getAs<BlockPointerType>())
2507 FromPointeeType = FromBlockPtr->getPointeeType();
2510 // We have pointer to blocks, check whether the only
2511 // differences in the argument and result types are in Objective-C
2512 // pointer conversions. If so, we permit the conversion.
2514 const FunctionProtoType *FromFunctionType
2515 = FromPointeeType->getAs<FunctionProtoType>();
2516 const FunctionProtoType *ToFunctionType
2517 = ToPointeeType->getAs<FunctionProtoType>();
2519 if (!FromFunctionType || !ToFunctionType)
2522 if (Context.hasSameType(FromPointeeType, ToPointeeType))
2525 // Perform the quick checks that will tell us whether these
2526 // function types are obviously different.
2527 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2528 FromFunctionType->isVariadic() != ToFunctionType->isVariadic())
2531 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo();
2532 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo();
2533 if (FromEInfo != ToEInfo)
2536 bool IncompatibleObjC = false;
2537 if (Context.hasSameType(FromFunctionType->getReturnType(),
2538 ToFunctionType->getReturnType())) {
2539 // Okay, the types match exactly. Nothing to do.
2541 QualType RHS = FromFunctionType->getReturnType();
2542 QualType LHS = ToFunctionType->getReturnType();
2543 if ((!getLangOpts().CPlusPlus || !RHS->isRecordType()) &&
2544 !RHS.hasQualifiers() && LHS.hasQualifiers())
2545 LHS = LHS.getUnqualifiedType();
2547 if (Context.hasSameType(RHS,LHS)) {
2549 } else if (isObjCPointerConversion(RHS, LHS,
2550 ConvertedType, IncompatibleObjC)) {
2551 if (IncompatibleObjC)
2553 // Okay, we have an Objective-C pointer conversion.
2559 // Check argument types.
2560 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2561 ArgIdx != NumArgs; ++ArgIdx) {
2562 IncompatibleObjC = false;
2563 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2564 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2565 if (Context.hasSameType(FromArgType, ToArgType)) {
2566 // Okay, the types match exactly. Nothing to do.
2567 } else if (isObjCPointerConversion(ToArgType, FromArgType,
2568 ConvertedType, IncompatibleObjC)) {
2569 if (IncompatibleObjC)
2571 // Okay, we have an Objective-C pointer conversion.
2573 // Argument types are too different. Abort.
2576 if (!Context.doFunctionTypesMatchOnExtParameterInfos(FromFunctionType,
2580 ConvertedType = ToType;
2588 ft_parameter_mismatch,
2590 ft_qualifer_mismatch
2593 /// Attempts to get the FunctionProtoType from a Type. Handles
2594 /// MemberFunctionPointers properly.
2595 static const FunctionProtoType *tryGetFunctionProtoType(QualType FromType) {
2596 if (auto *FPT = FromType->getAs<FunctionProtoType>())
2599 if (auto *MPT = FromType->getAs<MemberPointerType>())
2600 return MPT->getPointeeType()->getAs<FunctionProtoType>();
2605 /// HandleFunctionTypeMismatch - Gives diagnostic information for differeing
2606 /// function types. Catches different number of parameter, mismatch in
2607 /// parameter types, and different return types.
2608 void Sema::HandleFunctionTypeMismatch(PartialDiagnostic &PDiag,
2609 QualType FromType, QualType ToType) {
2610 // If either type is not valid, include no extra info.
2611 if (FromType.isNull() || ToType.isNull()) {
2612 PDiag << ft_default;
2616 // Get the function type from the pointers.
2617 if (FromType->isMemberPointerType() && ToType->isMemberPointerType()) {
2618 const MemberPointerType *FromMember = FromType->getAs<MemberPointerType>(),
2619 *ToMember = ToType->getAs<MemberPointerType>();
2620 if (!Context.hasSameType(FromMember->getClass(), ToMember->getClass())) {
2621 PDiag << ft_different_class << QualType(ToMember->getClass(), 0)
2622 << QualType(FromMember->getClass(), 0);
2625 FromType = FromMember->getPointeeType();
2626 ToType = ToMember->getPointeeType();
2629 if (FromType->isPointerType())
2630 FromType = FromType->getPointeeType();
2631 if (ToType->isPointerType())
2632 ToType = ToType->getPointeeType();
2634 // Remove references.
2635 FromType = FromType.getNonReferenceType();
2636 ToType = ToType.getNonReferenceType();
2638 // Don't print extra info for non-specialized template functions.
2639 if (FromType->isInstantiationDependentType() &&
2640 !FromType->getAs<TemplateSpecializationType>()) {
2641 PDiag << ft_default;
2645 // No extra info for same types.
2646 if (Context.hasSameType(FromType, ToType)) {
2647 PDiag << ft_default;
2651 const FunctionProtoType *FromFunction = tryGetFunctionProtoType(FromType),
2652 *ToFunction = tryGetFunctionProtoType(ToType);
2654 // Both types need to be function types.
2655 if (!FromFunction || !ToFunction) {
2656 PDiag << ft_default;
2660 if (FromFunction->getNumParams() != ToFunction->getNumParams()) {
2661 PDiag << ft_parameter_arity << ToFunction->getNumParams()
2662 << FromFunction->getNumParams();
2666 // Handle different parameter types.
2668 if (!FunctionParamTypesAreEqual(FromFunction, ToFunction, &ArgPos)) {
2669 PDiag << ft_parameter_mismatch << ArgPos + 1
2670 << ToFunction->getParamType(ArgPos)
2671 << FromFunction->getParamType(ArgPos);
2675 // Handle different return type.
2676 if (!Context.hasSameType(FromFunction->getReturnType(),
2677 ToFunction->getReturnType())) {
2678 PDiag << ft_return_type << ToFunction->getReturnType()
2679 << FromFunction->getReturnType();
2683 unsigned FromQuals = FromFunction->getTypeQuals(),
2684 ToQuals = ToFunction->getTypeQuals();
2685 if (FromQuals != ToQuals) {
2686 PDiag << ft_qualifer_mismatch << ToQuals << FromQuals;
2690 // Unable to find a difference, so add no extra info.
2691 PDiag << ft_default;
2694 /// FunctionParamTypesAreEqual - This routine checks two function proto types
2695 /// for equality of their argument types. Caller has already checked that
2696 /// they have same number of arguments. If the parameters are different,
2697 /// ArgPos will have the parameter index of the first different parameter.
2698 bool Sema::FunctionParamTypesAreEqual(const FunctionProtoType *OldType,
2699 const FunctionProtoType *NewType,
2701 for (FunctionProtoType::param_type_iterator O = OldType->param_type_begin(),
2702 N = NewType->param_type_begin(),
2703 E = OldType->param_type_end();
2704 O && (O != E); ++O, ++N) {
2705 if (!Context.hasSameType(O->getUnqualifiedType(),
2706 N->getUnqualifiedType())) {
2708 *ArgPos = O - OldType->param_type_begin();
2715 /// CheckPointerConversion - Check the pointer conversion from the
2716 /// expression From to the type ToType. This routine checks for
2717 /// ambiguous or inaccessible derived-to-base pointer
2718 /// conversions for which IsPointerConversion has already returned
2719 /// true. It returns true and produces a diagnostic if there was an
2720 /// error, or returns false otherwise.
2721 bool Sema::CheckPointerConversion(Expr *From, QualType ToType,
2723 CXXCastPath& BasePath,
2724 bool IgnoreBaseAccess,
2726 QualType FromType = From->getType();
2727 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess;
2731 if (Diagnose && !IsCStyleOrFunctionalCast && !FromType->isAnyPointerType() &&
2732 From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) ==
2733 Expr::NPCK_ZeroExpression) {
2734 if (Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy))
2735 DiagRuntimeBehavior(From->getExprLoc(), From,
2736 PDiag(diag::warn_impcast_bool_to_null_pointer)
2737 << ToType << From->getSourceRange());
2738 else if (!isUnevaluatedContext())
2739 Diag(From->getExprLoc(), diag::warn_non_literal_null_pointer)
2740 << ToType << From->getSourceRange();
2742 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) {
2743 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) {
2744 QualType FromPointeeType = FromPtrType->getPointeeType(),
2745 ToPointeeType = ToPtrType->getPointeeType();
2747 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() &&
2748 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) {
2749 // We must have a derived-to-base conversion. Check an
2750 // ambiguous or inaccessible conversion.
2751 unsigned InaccessibleID = 0;
2752 unsigned AmbigiousID = 0;
2754 InaccessibleID = diag::err_upcast_to_inaccessible_base;
2755 AmbigiousID = diag::err_ambiguous_derived_to_base_conv;
2757 if (CheckDerivedToBaseConversion(
2758 FromPointeeType, ToPointeeType, InaccessibleID, AmbigiousID,
2759 From->getExprLoc(), From->getSourceRange(), DeclarationName(),
2760 &BasePath, IgnoreBaseAccess))
2763 // The conversion was successful.
2764 Kind = CK_DerivedToBase;
2767 if (Diagnose && !IsCStyleOrFunctionalCast &&
2768 FromPointeeType->isFunctionType() && ToPointeeType->isVoidType()) {
2769 assert(getLangOpts().MSVCCompat &&
2770 "this should only be possible with MSVCCompat!");
2771 Diag(From->getExprLoc(), diag::ext_ms_impcast_fn_obj)
2772 << From->getSourceRange();
2775 } else if (const ObjCObjectPointerType *ToPtrType =
2776 ToType->getAs<ObjCObjectPointerType>()) {
2777 if (const ObjCObjectPointerType *FromPtrType =
2778 FromType->getAs<ObjCObjectPointerType>()) {
2779 // Objective-C++ conversions are always okay.
2780 // FIXME: We should have a different class of conversions for the
2781 // Objective-C++ implicit conversions.
2782 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType())
2784 } else if (FromType->isBlockPointerType()) {
2785 Kind = CK_BlockPointerToObjCPointerCast;
2787 Kind = CK_CPointerToObjCPointerCast;
2789 } else if (ToType->isBlockPointerType()) {
2790 if (!FromType->isBlockPointerType())
2791 Kind = CK_AnyPointerToBlockPointerCast;
2794 // We shouldn't fall into this case unless it's valid for other
2796 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull))
2797 Kind = CK_NullToPointer;
2802 /// IsMemberPointerConversion - Determines whether the conversion of the
2803 /// expression From, which has the (possibly adjusted) type FromType, can be
2804 /// converted to the type ToType via a member pointer conversion (C++ 4.11).
2805 /// If so, returns true and places the converted type (that might differ from
2806 /// ToType in its cv-qualifiers at some level) into ConvertedType.
2807 bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType,
2809 bool InOverloadResolution,
2810 QualType &ConvertedType) {
2811 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>();
2815 // A null pointer constant can be converted to a member pointer (C++ 4.11p1)
2816 if (From->isNullPointerConstant(Context,
2817 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
2818 : Expr::NPC_ValueDependentIsNull)) {
2819 ConvertedType = ToType;
2823 // Otherwise, both types have to be member pointers.
2824 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>();
2828 // A pointer to member of B can be converted to a pointer to member of D,
2829 // where D is derived from B (C++ 4.11p2).
2830 QualType FromClass(FromTypePtr->getClass(), 0);
2831 QualType ToClass(ToTypePtr->getClass(), 0);
2833 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) &&
2834 IsDerivedFrom(From->getLocStart(), ToClass, FromClass)) {
2835 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(),
2836 ToClass.getTypePtr());
2843 /// CheckMemberPointerConversion - Check the member pointer conversion from the
2844 /// expression From to the type ToType. This routine checks for ambiguous or
2845 /// virtual or inaccessible base-to-derived member pointer conversions
2846 /// for which IsMemberPointerConversion has already returned true. It returns
2847 /// true and produces a diagnostic if there was an error, or returns false
2849 bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType,
2851 CXXCastPath &BasePath,
2852 bool IgnoreBaseAccess) {
2853 QualType FromType = From->getType();
2854 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>();
2856 // This must be a null pointer to member pointer conversion
2857 assert(From->isNullPointerConstant(Context,
2858 Expr::NPC_ValueDependentIsNull) &&
2859 "Expr must be null pointer constant!");
2860 Kind = CK_NullToMemberPointer;
2864 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>();
2865 assert(ToPtrType && "No member pointer cast has a target type "
2866 "that is not a member pointer.");
2868 QualType FromClass = QualType(FromPtrType->getClass(), 0);
2869 QualType ToClass = QualType(ToPtrType->getClass(), 0);
2871 // FIXME: What about dependent types?
2872 assert(FromClass->isRecordType() && "Pointer into non-class.");
2873 assert(ToClass->isRecordType() && "Pointer into non-class.");
2875 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2876 /*DetectVirtual=*/true);
2877 bool DerivationOkay =
2878 IsDerivedFrom(From->getLocStart(), ToClass, FromClass, Paths);
2879 assert(DerivationOkay &&
2880 "Should not have been called if derivation isn't OK.");
2881 (void)DerivationOkay;
2883 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass).
2884 getUnqualifiedType())) {
2885 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
2886 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv)
2887 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange();
2891 if (const RecordType *VBase = Paths.getDetectedVirtual()) {
2892 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual)
2893 << FromClass << ToClass << QualType(VBase, 0)
2894 << From->getSourceRange();
2898 if (!IgnoreBaseAccess)
2899 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass,
2901 diag::err_downcast_from_inaccessible_base);
2903 // Must be a base to derived member conversion.
2904 BuildBasePathArray(Paths, BasePath);
2905 Kind = CK_BaseToDerivedMemberPointer;
2909 /// Determine whether the lifetime conversion between the two given
2910 /// qualifiers sets is nontrivial.
2911 static bool isNonTrivialObjCLifetimeConversion(Qualifiers FromQuals,
2912 Qualifiers ToQuals) {
2913 // Converting anything to const __unsafe_unretained is trivial.
2914 if (ToQuals.hasConst() &&
2915 ToQuals.getObjCLifetime() == Qualifiers::OCL_ExplicitNone)
2921 /// IsQualificationConversion - Determines whether the conversion from
2922 /// an rvalue of type FromType to ToType is a qualification conversion
2925 /// \param ObjCLifetimeConversion Output parameter that will be set to indicate
2926 /// when the qualification conversion involves a change in the Objective-C
2927 /// object lifetime.
2929 Sema::IsQualificationConversion(QualType FromType, QualType ToType,
2930 bool CStyle, bool &ObjCLifetimeConversion) {
2931 FromType = Context.getCanonicalType(FromType);
2932 ToType = Context.getCanonicalType(ToType);
2933 ObjCLifetimeConversion = false;
2935 // If FromType and ToType are the same type, this is not a
2936 // qualification conversion.
2937 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType())
2941 // A conversion can add cv-qualifiers at levels other than the first
2942 // in multi-level pointers, subject to the following rules: [...]
2943 bool PreviousToQualsIncludeConst = true;
2944 bool UnwrappedAnyPointer = false;
2945 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) {
2946 // Within each iteration of the loop, we check the qualifiers to
2947 // determine if this still looks like a qualification
2948 // conversion. Then, if all is well, we unwrap one more level of
2949 // pointers or pointers-to-members and do it all again
2950 // until there are no more pointers or pointers-to-members left to
2952 UnwrappedAnyPointer = true;
2954 Qualifiers FromQuals = FromType.getQualifiers();
2955 Qualifiers ToQuals = ToType.getQualifiers();
2957 // Ignore __unaligned qualifier if this type is void.
2958 if (ToType.getUnqualifiedType()->isVoidType())
2959 FromQuals.removeUnaligned();
2962 // Check Objective-C lifetime conversions.
2963 if (FromQuals.getObjCLifetime() != ToQuals.getObjCLifetime() &&
2964 UnwrappedAnyPointer) {
2965 if (ToQuals.compatiblyIncludesObjCLifetime(FromQuals)) {
2966 if (isNonTrivialObjCLifetimeConversion(FromQuals, ToQuals))
2967 ObjCLifetimeConversion = true;
2968 FromQuals.removeObjCLifetime();
2969 ToQuals.removeObjCLifetime();
2971 // Qualification conversions cannot cast between different
2972 // Objective-C lifetime qualifiers.
2977 // Allow addition/removal of GC attributes but not changing GC attributes.
2978 if (FromQuals.getObjCGCAttr() != ToQuals.getObjCGCAttr() &&
2979 (!FromQuals.hasObjCGCAttr() || !ToQuals.hasObjCGCAttr())) {
2980 FromQuals.removeObjCGCAttr();
2981 ToQuals.removeObjCGCAttr();
2984 // -- for every j > 0, if const is in cv 1,j then const is in cv
2985 // 2,j, and similarly for volatile.
2986 if (!CStyle && !ToQuals.compatiblyIncludes(FromQuals))
2989 // -- if the cv 1,j and cv 2,j are different, then const is in
2990 // every cv for 0 < k < j.
2991 if (!CStyle && FromQuals.getCVRQualifiers() != ToQuals.getCVRQualifiers()
2992 && !PreviousToQualsIncludeConst)
2995 // Keep track of whether all prior cv-qualifiers in the "to" type
2997 PreviousToQualsIncludeConst
2998 = PreviousToQualsIncludeConst && ToQuals.hasConst();
3001 // We are left with FromType and ToType being the pointee types
3002 // after unwrapping the original FromType and ToType the same number
3003 // of types. If we unwrapped any pointers, and if FromType and
3004 // ToType have the same unqualified type (since we checked
3005 // qualifiers above), then this is a qualification conversion.
3006 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType);
3009 /// \brief - Determine whether this is a conversion from a scalar type to an
3012 /// If successful, updates \c SCS's second and third steps in the conversion
3013 /// sequence to finish the conversion.
3014 static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
3015 bool InOverloadResolution,
3016 StandardConversionSequence &SCS,
3018 const AtomicType *ToAtomic = ToType->getAs<AtomicType>();
3022 StandardConversionSequence InnerSCS;
3023 if (!IsStandardConversion(S, From, ToAtomic->getValueType(),
3024 InOverloadResolution, InnerSCS,
3025 CStyle, /*AllowObjCWritebackConversion=*/false))
3028 SCS.Second = InnerSCS.Second;
3029 SCS.setToType(1, InnerSCS.getToType(1));
3030 SCS.Third = InnerSCS.Third;
3031 SCS.QualificationIncludesObjCLifetime
3032 = InnerSCS.QualificationIncludesObjCLifetime;
3033 SCS.setToType(2, InnerSCS.getToType(2));
3037 static bool isFirstArgumentCompatibleWithType(ASTContext &Context,
3038 CXXConstructorDecl *Constructor,
3040 const FunctionProtoType *CtorType =
3041 Constructor->getType()->getAs<FunctionProtoType>();
3042 if (CtorType->getNumParams() > 0) {
3043 QualType FirstArg = CtorType->getParamType(0);
3044 if (Context.hasSameUnqualifiedType(Type, FirstArg.getNonReferenceType()))
3050 static OverloadingResult
3051 IsInitializerListConstructorConversion(Sema &S, Expr *From, QualType ToType,
3053 UserDefinedConversionSequence &User,
3054 OverloadCandidateSet &CandidateSet,
3055 bool AllowExplicit) {
3056 for (auto *D : S.LookupConstructors(To)) {
3057 auto Info = getConstructorInfo(D);
3061 bool Usable = !Info.Constructor->isInvalidDecl() &&
3062 S.isInitListConstructor(Info.Constructor) &&
3063 (AllowExplicit || !Info.Constructor->isExplicit());
3065 // If the first argument is (a reference to) the target type,
3066 // suppress conversions.
3067 bool SuppressUserConversions = isFirstArgumentCompatibleWithType(
3068 S.Context, Info.Constructor, ToType);
3069 if (Info.ConstructorTmpl)
3070 S.AddTemplateOverloadCandidate(Info.ConstructorTmpl, Info.FoundDecl,
3071 /*ExplicitArgs*/ nullptr, From,
3072 CandidateSet, SuppressUserConversions);
3074 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl, From,
3075 CandidateSet, SuppressUserConversions);
3079 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3081 OverloadCandidateSet::iterator Best;
3082 switch (auto Result =
3083 CandidateSet.BestViableFunction(S, From->getLocStart(),
3087 // Record the standard conversion we used and the conversion function.
3088 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function);
3089 QualType ThisType = Constructor->getThisType(S.Context);
3090 // Initializer lists don't have conversions as such.
3091 User.Before.setAsIdentityConversion();
3092 User.HadMultipleCandidates = HadMultipleCandidates;
3093 User.ConversionFunction = Constructor;
3094 User.FoundConversionFunction = Best->FoundDecl;
3095 User.After.setAsIdentityConversion();
3096 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType());
3097 User.After.setAllToTypes(ToType);
3101 case OR_No_Viable_Function:
3102 return OR_No_Viable_Function;
3104 return OR_Ambiguous;
3107 llvm_unreachable("Invalid OverloadResult!");
3110 /// Determines whether there is a user-defined conversion sequence
3111 /// (C++ [over.ics.user]) that converts expression From to the type
3112 /// ToType. If such a conversion exists, User will contain the
3113 /// user-defined conversion sequence that performs such a conversion
3114 /// and this routine will return true. Otherwise, this routine returns
3115 /// false and User is unspecified.
3117 /// \param AllowExplicit true if the conversion should consider C++0x
3118 /// "explicit" conversion functions as well as non-explicit conversion
3119 /// functions (C++0x [class.conv.fct]p2).
3121 /// \param AllowObjCConversionOnExplicit true if the conversion should
3122 /// allow an extra Objective-C pointer conversion on uses of explicit
3123 /// constructors. Requires \c AllowExplicit to also be set.
3124 static OverloadingResult
3125 IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
3126 UserDefinedConversionSequence &User,
3127 OverloadCandidateSet &CandidateSet,
3129 bool AllowObjCConversionOnExplicit) {
3130 assert(AllowExplicit || !AllowObjCConversionOnExplicit);
3132 // Whether we will only visit constructors.
3133 bool ConstructorsOnly = false;
3135 // If the type we are conversion to is a class type, enumerate its
3137 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) {
3138 // C++ [over.match.ctor]p1:
3139 // When objects of class type are direct-initialized (8.5), or
3140 // copy-initialized from an expression of the same or a
3141 // derived class type (8.5), overload resolution selects the
3142 // constructor. [...] For copy-initialization, the candidate
3143 // functions are all the converting constructors (12.3.1) of
3144 // that class. The argument list is the expression-list within
3145 // the parentheses of the initializer.
3146 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) ||
3147 (From->getType()->getAs<RecordType>() &&
3148 S.IsDerivedFrom(From->getLocStart(), From->getType(), ToType)))
3149 ConstructorsOnly = true;
3151 if (!S.isCompleteType(From->getExprLoc(), ToType)) {
3152 // We're not going to find any constructors.
3153 } else if (CXXRecordDecl *ToRecordDecl
3154 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) {
3156 Expr **Args = &From;
3157 unsigned NumArgs = 1;
3158 bool ListInitializing = false;
3159 if (InitListExpr *InitList = dyn_cast<InitListExpr>(From)) {
3160 // But first, see if there is an init-list-constructor that will work.
3161 OverloadingResult Result = IsInitializerListConstructorConversion(
3162 S, From, ToType, ToRecordDecl, User, CandidateSet, AllowExplicit);
3163 if (Result != OR_No_Viable_Function)
3166 CandidateSet.clear();
3168 // If we're list-initializing, we pass the individual elements as
3169 // arguments, not the entire list.
3170 Args = InitList->getInits();
3171 NumArgs = InitList->getNumInits();
3172 ListInitializing = true;
3175 for (auto *D : S.LookupConstructors(ToRecordDecl)) {
3176 auto Info = getConstructorInfo(D);
3180 bool Usable = !Info.Constructor->isInvalidDecl();
3181 if (ListInitializing)
3182 Usable = Usable && (AllowExplicit || !Info.Constructor->isExplicit());
3185 Info.Constructor->isConvertingConstructor(AllowExplicit);
3187 bool SuppressUserConversions = !ConstructorsOnly;
3188 if (SuppressUserConversions && ListInitializing) {
3189 SuppressUserConversions = false;
3191 // If the first argument is (a reference to) the target type,
3192 // suppress conversions.
3193 SuppressUserConversions = isFirstArgumentCompatibleWithType(
3194 S.Context, Info.Constructor, ToType);
3197 if (Info.ConstructorTmpl)
3198 S.AddTemplateOverloadCandidate(
3199 Info.ConstructorTmpl, Info.FoundDecl,
3200 /*ExplicitArgs*/ nullptr, llvm::makeArrayRef(Args, NumArgs),
3201 CandidateSet, SuppressUserConversions);
3203 // Allow one user-defined conversion when user specifies a
3204 // From->ToType conversion via an static cast (c-style, etc).
3205 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl,
3206 llvm::makeArrayRef(Args, NumArgs),
3207 CandidateSet, SuppressUserConversions);
3213 // Enumerate conversion functions, if we're allowed to.
3214 if (ConstructorsOnly || isa<InitListExpr>(From)) {
3215 } else if (!S.isCompleteType(From->getLocStart(), From->getType())) {
3216 // No conversion functions from incomplete types.
3217 } else if (const RecordType *FromRecordType
3218 = From->getType()->getAs<RecordType>()) {
3219 if (CXXRecordDecl *FromRecordDecl
3220 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) {
3221 // Add all of the conversion functions as candidates.
3222 const auto &Conversions = FromRecordDecl->getVisibleConversionFunctions();
3223 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
3224 DeclAccessPair FoundDecl = I.getPair();
3225 NamedDecl *D = FoundDecl.getDecl();
3226 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
3227 if (isa<UsingShadowDecl>(D))
3228 D = cast<UsingShadowDecl>(D)->getTargetDecl();
3230 CXXConversionDecl *Conv;
3231 FunctionTemplateDecl *ConvTemplate;
3232 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
3233 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
3235 Conv = cast<CXXConversionDecl>(D);
3237 if (AllowExplicit || !Conv->isExplicit()) {
3239 S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl,
3240 ActingContext, From, ToType,
3242 AllowObjCConversionOnExplicit);
3244 S.AddConversionCandidate(Conv, FoundDecl, ActingContext,
3245 From, ToType, CandidateSet,
3246 AllowObjCConversionOnExplicit);
3252 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3254 OverloadCandidateSet::iterator Best;
3255 switch (auto Result = CandidateSet.BestViableFunction(S, From->getLocStart(),
3259 // Record the standard conversion we used and the conversion function.
3260 if (CXXConstructorDecl *Constructor
3261 = dyn_cast<CXXConstructorDecl>(Best->Function)) {
3262 // C++ [over.ics.user]p1:
3263 // If the user-defined conversion is specified by a
3264 // constructor (12.3.1), the initial standard conversion
3265 // sequence converts the source type to the type required by
3266 // the argument of the constructor.
3268 QualType ThisType = Constructor->getThisType(S.Context);
3269 if (isa<InitListExpr>(From)) {
3270 // Initializer lists don't have conversions as such.
3271 User.Before.setAsIdentityConversion();
3273 if (Best->Conversions[0].isEllipsis())
3274 User.EllipsisConversion = true;
3276 User.Before = Best->Conversions[0].Standard;
3277 User.EllipsisConversion = false;
3280 User.HadMultipleCandidates = HadMultipleCandidates;
3281 User.ConversionFunction = Constructor;
3282 User.FoundConversionFunction = Best->FoundDecl;
3283 User.After.setAsIdentityConversion();
3284 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType());
3285 User.After.setAllToTypes(ToType);
3288 if (CXXConversionDecl *Conversion
3289 = dyn_cast<CXXConversionDecl>(Best->Function)) {
3290 // C++ [over.ics.user]p1:
3292 // [...] If the user-defined conversion is specified by a
3293 // conversion function (12.3.2), the initial standard
3294 // conversion sequence converts the source type to the
3295 // implicit object parameter of the conversion function.
3296 User.Before = Best->Conversions[0].Standard;
3297 User.HadMultipleCandidates = HadMultipleCandidates;
3298 User.ConversionFunction = Conversion;
3299 User.FoundConversionFunction = Best->FoundDecl;
3300 User.EllipsisConversion = false;
3302 // C++ [over.ics.user]p2:
3303 // The second standard conversion sequence converts the
3304 // result of the user-defined conversion to the target type
3305 // for the sequence. Since an implicit conversion sequence
3306 // is an initialization, the special rules for
3307 // initialization by user-defined conversion apply when
3308 // selecting the best user-defined conversion for a
3309 // user-defined conversion sequence (see 13.3.3 and
3311 User.After = Best->FinalConversion;
3314 llvm_unreachable("Not a constructor or conversion function?");
3316 case OR_No_Viable_Function:
3317 return OR_No_Viable_Function;
3320 return OR_Ambiguous;
3323 llvm_unreachable("Invalid OverloadResult!");
3327 Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) {
3328 ImplicitConversionSequence ICS;
3329 OverloadCandidateSet CandidateSet(From->getExprLoc(),
3330 OverloadCandidateSet::CSK_Normal);
3331 OverloadingResult OvResult =
3332 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined,
3333 CandidateSet, false, false);
3334 if (OvResult == OR_Ambiguous)
3335 Diag(From->getLocStart(), diag::err_typecheck_ambiguous_condition)
3336 << From->getType() << ToType << From->getSourceRange();
3337 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) {
3338 if (!RequireCompleteType(From->getLocStart(), ToType,
3339 diag::err_typecheck_nonviable_condition_incomplete,
3340 From->getType(), From->getSourceRange()))
3341 Diag(From->getLocStart(), diag::err_typecheck_nonviable_condition)
3342 << false << From->getType() << From->getSourceRange() << ToType;
3345 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, From);
3349 /// \brief Compare the user-defined conversion functions or constructors
3350 /// of two user-defined conversion sequences to determine whether any ordering
3352 static ImplicitConversionSequence::CompareKind
3353 compareConversionFunctions(Sema &S, FunctionDecl *Function1,
3354 FunctionDecl *Function2) {
3355 if (!S.getLangOpts().ObjC1 || !S.getLangOpts().CPlusPlus11)
3356 return ImplicitConversionSequence::Indistinguishable;
3359 // If both conversion functions are implicitly-declared conversions from
3360 // a lambda closure type to a function pointer and a block pointer,
3361 // respectively, always prefer the conversion to a function pointer,
3362 // because the function pointer is more lightweight and is more likely
3363 // to keep code working.
3364 CXXConversionDecl *Conv1 = dyn_cast_or_null<CXXConversionDecl>(Function1);
3366 return ImplicitConversionSequence::Indistinguishable;
3368 CXXConversionDecl *Conv2 = dyn_cast<CXXConversionDecl>(Function2);
3370 return ImplicitConversionSequence::Indistinguishable;
3372 if (Conv1->getParent()->isLambda() && Conv2->getParent()->isLambda()) {
3373 bool Block1 = Conv1->getConversionType()->isBlockPointerType();
3374 bool Block2 = Conv2->getConversionType()->isBlockPointerType();
3375 if (Block1 != Block2)
3376 return Block1 ? ImplicitConversionSequence::Worse
3377 : ImplicitConversionSequence::Better;
3380 return ImplicitConversionSequence::Indistinguishable;
3383 static bool hasDeprecatedStringLiteralToCharPtrConversion(
3384 const ImplicitConversionSequence &ICS) {
3385 return (ICS.isStandard() && ICS.Standard.DeprecatedStringLiteralToCharPtr) ||
3386 (ICS.isUserDefined() &&
3387 ICS.UserDefined.Before.DeprecatedStringLiteralToCharPtr);
3390 /// CompareImplicitConversionSequences - Compare two implicit
3391 /// conversion sequences to determine whether one is better than the
3392 /// other or if they are indistinguishable (C++ 13.3.3.2).
3393 static ImplicitConversionSequence::CompareKind
3394 CompareImplicitConversionSequences(Sema &S, SourceLocation Loc,
3395 const ImplicitConversionSequence& ICS1,
3396 const ImplicitConversionSequence& ICS2)
3398 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit
3399 // conversion sequences (as defined in 13.3.3.1)
3400 // -- a standard conversion sequence (13.3.3.1.1) is a better
3401 // conversion sequence than a user-defined conversion sequence or
3402 // an ellipsis conversion sequence, and
3403 // -- a user-defined conversion sequence (13.3.3.1.2) is a better
3404 // conversion sequence than an ellipsis conversion sequence
3407 // C++0x [over.best.ics]p10:
3408 // For the purpose of ranking implicit conversion sequences as
3409 // described in 13.3.3.2, the ambiguous conversion sequence is
3410 // treated as a user-defined sequence that is indistinguishable
3411 // from any other user-defined conversion sequence.
3413 // String literal to 'char *' conversion has been deprecated in C++03. It has
3414 // been removed from C++11. We still accept this conversion, if it happens at
3415 // the best viable function. Otherwise, this conversion is considered worse
3416 // than ellipsis conversion. Consider this as an extension; this is not in the
3417 // standard. For example:
3419 // int &f(...); // #1
3420 // void f(char*); // #2
3421 // void g() { int &r = f("foo"); }
3423 // In C++03, we pick #2 as the best viable function.
3424 // In C++11, we pick #1 as the best viable function, because ellipsis
3425 // conversion is better than string-literal to char* conversion (since there
3426 // is no such conversion in C++11). If there was no #1 at all or #1 couldn't
3427 // convert arguments, #2 would be the best viable function in C++11.
3428 // If the best viable function has this conversion, a warning will be issued
3429 // in C++03, or an ExtWarn (+SFINAE failure) will be issued in C++11.
3431 if (S.getLangOpts().CPlusPlus11 && !S.getLangOpts().WritableStrings &&
3432 hasDeprecatedStringLiteralToCharPtrConversion(ICS1) !=
3433 hasDeprecatedStringLiteralToCharPtrConversion(ICS2))
3434 return hasDeprecatedStringLiteralToCharPtrConversion(ICS1)
3435 ? ImplicitConversionSequence::Worse
3436 : ImplicitConversionSequence::Better;
3438 if (ICS1.getKindRank() < ICS2.getKindRank())
3439 return ImplicitConversionSequence::Better;
3440 if (ICS2.getKindRank() < ICS1.getKindRank())
3441 return ImplicitConversionSequence::Worse;
3443 // The following checks require both conversion sequences to be of
3445 if (ICS1.getKind() != ICS2.getKind())
3446 return ImplicitConversionSequence::Indistinguishable;
3448 ImplicitConversionSequence::CompareKind Result =
3449 ImplicitConversionSequence::Indistinguishable;
3451 // Two implicit conversion sequences of the same form are
3452 // indistinguishable conversion sequences unless one of the
3453 // following rules apply: (C++ 13.3.3.2p3):
3455 // List-initialization sequence L1 is a better conversion sequence than
3456 // list-initialization sequence L2 if:
3457 // - L1 converts to std::initializer_list<X> for some X and L2 does not, or,
3459 // - L1 converts to type "array of N1 T", L2 converts to type "array of N2 T",
3460 // and N1 is smaller than N2.,
3461 // even if one of the other rules in this paragraph would otherwise apply.
3462 if (!ICS1.isBad()) {
3463 if (ICS1.isStdInitializerListElement() &&
3464 !ICS2.isStdInitializerListElement())
3465 return ImplicitConversionSequence::Better;
3466 if (!ICS1.isStdInitializerListElement() &&
3467 ICS2.isStdInitializerListElement())
3468 return ImplicitConversionSequence::Worse;
3471 if (ICS1.isStandard())
3472 // Standard conversion sequence S1 is a better conversion sequence than
3473 // standard conversion sequence S2 if [...]
3474 Result = CompareStandardConversionSequences(S, Loc,
3475 ICS1.Standard, ICS2.Standard);
3476 else if (ICS1.isUserDefined()) {
3477 // User-defined conversion sequence U1 is a better conversion
3478 // sequence than another user-defined conversion sequence U2 if
3479 // they contain the same user-defined conversion function or
3480 // constructor and if the second standard conversion sequence of
3481 // U1 is better than the second standard conversion sequence of
3482 // U2 (C++ 13.3.3.2p3).
3483 if (ICS1.UserDefined.ConversionFunction ==
3484 ICS2.UserDefined.ConversionFunction)
3485 Result = CompareStandardConversionSequences(S, Loc,
3486 ICS1.UserDefined.After,
3487 ICS2.UserDefined.After);
3489 Result = compareConversionFunctions(S,
3490 ICS1.UserDefined.ConversionFunction,
3491 ICS2.UserDefined.ConversionFunction);
3497 static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) {
3498 while (Context.UnwrapSimilarPointerTypes(T1, T2)) {
3500 T1 = Context.getUnqualifiedArrayType(T1, Quals);
3501 T2 = Context.getUnqualifiedArrayType(T2, Quals);
3504 return Context.hasSameUnqualifiedType(T1, T2);
3507 // Per 13.3.3.2p3, compare the given standard conversion sequences to
3508 // determine if one is a proper subset of the other.
3509 static ImplicitConversionSequence::CompareKind
3510 compareStandardConversionSubsets(ASTContext &Context,
3511 const StandardConversionSequence& SCS1,
3512 const StandardConversionSequence& SCS2) {
3513 ImplicitConversionSequence::CompareKind Result
3514 = ImplicitConversionSequence::Indistinguishable;
3516 // the identity conversion sequence is considered to be a subsequence of
3517 // any non-identity conversion sequence
3518 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion())
3519 return ImplicitConversionSequence::Better;
3520 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion())
3521 return ImplicitConversionSequence::Worse;
3523 if (SCS1.Second != SCS2.Second) {
3524 if (SCS1.Second == ICK_Identity)
3525 Result = ImplicitConversionSequence::Better;
3526 else if (SCS2.Second == ICK_Identity)
3527 Result = ImplicitConversionSequence::Worse;
3529 return ImplicitConversionSequence::Indistinguishable;
3530 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1)))
3531 return ImplicitConversionSequence::Indistinguishable;
3533 if (SCS1.Third == SCS2.Third) {
3534 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result
3535 : ImplicitConversionSequence::Indistinguishable;
3538 if (SCS1.Third == ICK_Identity)
3539 return Result == ImplicitConversionSequence::Worse
3540 ? ImplicitConversionSequence::Indistinguishable
3541 : ImplicitConversionSequence::Better;
3543 if (SCS2.Third == ICK_Identity)
3544 return Result == ImplicitConversionSequence::Better
3545 ? ImplicitConversionSequence::Indistinguishable
3546 : ImplicitConversionSequence::Worse;
3548 return ImplicitConversionSequence::Indistinguishable;
3551 /// \brief Determine whether one of the given reference bindings is better
3552 /// than the other based on what kind of bindings they are.
3554 isBetterReferenceBindingKind(const StandardConversionSequence &SCS1,
3555 const StandardConversionSequence &SCS2) {
3556 // C++0x [over.ics.rank]p3b4:
3557 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an
3558 // implicit object parameter of a non-static member function declared
3559 // without a ref-qualifier, and *either* S1 binds an rvalue reference
3560 // to an rvalue and S2 binds an lvalue reference *or S1 binds an
3561 // lvalue reference to a function lvalue and S2 binds an rvalue
3564 // FIXME: Rvalue references. We're going rogue with the above edits,
3565 // because the semantics in the current C++0x working paper (N3225 at the
3566 // time of this writing) break the standard definition of std::forward
3567 // and std::reference_wrapper when dealing with references to functions.
3568 // Proposed wording changes submitted to CWG for consideration.
3569 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier ||
3570 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier)
3573 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue &&
3574 SCS2.IsLvalueReference) ||
3575 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue &&
3576 !SCS2.IsLvalueReference && SCS2.BindsToFunctionLvalue);
3579 /// CompareStandardConversionSequences - Compare two standard
3580 /// conversion sequences to determine whether one is better than the
3581 /// other or if they are indistinguishable (C++ 13.3.3.2p3).
3582 static ImplicitConversionSequence::CompareKind
3583 CompareStandardConversionSequences(Sema &S, SourceLocation Loc,
3584 const StandardConversionSequence& SCS1,
3585 const StandardConversionSequence& SCS2)
3587 // Standard conversion sequence S1 is a better conversion sequence
3588 // than standard conversion sequence S2 if (C++ 13.3.3.2p3):
3590 // -- S1 is a proper subsequence of S2 (comparing the conversion
3591 // sequences in the canonical form defined by 13.3.3.1.1,
3592 // excluding any Lvalue Transformation; the identity conversion
3593 // sequence is considered to be a subsequence of any
3594 // non-identity conversion sequence) or, if not that,
3595 if (ImplicitConversionSequence::CompareKind CK
3596 = compareStandardConversionSubsets(S.Context, SCS1, SCS2))
3599 // -- the rank of S1 is better than the rank of S2 (by the rules
3600 // defined below), or, if not that,
3601 ImplicitConversionRank Rank1 = SCS1.getRank();
3602 ImplicitConversionRank Rank2 = SCS2.getRank();
3604 return ImplicitConversionSequence::Better;
3605 else if (Rank2 < Rank1)
3606 return ImplicitConversionSequence::Worse;
3608 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank
3609 // are indistinguishable unless one of the following rules
3612 // A conversion that is not a conversion of a pointer, or
3613 // pointer to member, to bool is better than another conversion
3614 // that is such a conversion.
3615 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool())
3616 return SCS2.isPointerConversionToBool()
3617 ? ImplicitConversionSequence::Better
3618 : ImplicitConversionSequence::Worse;
3620 // C++ [over.ics.rank]p4b2:
3622 // If class B is derived directly or indirectly from class A,
3623 // conversion of B* to A* is better than conversion of B* to
3624 // void*, and conversion of A* to void* is better than conversion
3626 bool SCS1ConvertsToVoid
3627 = SCS1.isPointerConversionToVoidPointer(S.Context);
3628 bool SCS2ConvertsToVoid
3629 = SCS2.isPointerConversionToVoidPointer(S.Context);
3630 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) {
3631 // Exactly one of the conversion sequences is a conversion to
3632 // a void pointer; it's the worse conversion.
3633 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better
3634 : ImplicitConversionSequence::Worse;
3635 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) {
3636 // Neither conversion sequence converts to a void pointer; compare
3637 // their derived-to-base conversions.
3638 if (ImplicitConversionSequence::CompareKind DerivedCK
3639 = CompareDerivedToBaseConversions(S, Loc, SCS1, SCS2))
3641 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid &&
3642 !S.Context.hasSameType(SCS1.getFromType(), SCS2.getFromType())) {
3643 // Both conversion sequences are conversions to void
3644 // pointers. Compare the source types to determine if there's an
3645 // inheritance relationship in their sources.
3646 QualType FromType1 = SCS1.getFromType();
3647 QualType FromType2 = SCS2.getFromType();
3649 // Adjust the types we're converting from via the array-to-pointer
3650 // conversion, if we need to.
3651 if (SCS1.First == ICK_Array_To_Pointer)
3652 FromType1 = S.Context.getArrayDecayedType(FromType1);
3653 if (SCS2.First == ICK_Array_To_Pointer)
3654 FromType2 = S.Context.getArrayDecayedType(FromType2);
3656 QualType FromPointee1 = FromType1->getPointeeType().getUnqualifiedType();
3657 QualType FromPointee2 = FromType2->getPointeeType().getUnqualifiedType();
3659 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
3660 return ImplicitConversionSequence::Better;
3661 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
3662 return ImplicitConversionSequence::Worse;
3664 // Objective-C++: If one interface is more specific than the
3665 // other, it is the better one.
3666 const ObjCObjectPointerType* FromObjCPtr1
3667 = FromType1->getAs<ObjCObjectPointerType>();
3668 const ObjCObjectPointerType* FromObjCPtr2
3669 = FromType2->getAs<ObjCObjectPointerType>();
3670 if (FromObjCPtr1 && FromObjCPtr2) {
3671 bool AssignLeft = S.Context.canAssignObjCInterfaces(FromObjCPtr1,
3673 bool AssignRight = S.Context.canAssignObjCInterfaces(FromObjCPtr2,
3675 if (AssignLeft != AssignRight) {
3676 return AssignLeft? ImplicitConversionSequence::Better
3677 : ImplicitConversionSequence::Worse;
3682 // Compare based on qualification conversions (C++ 13.3.3.2p3,
3684 if (ImplicitConversionSequence::CompareKind QualCK
3685 = CompareQualificationConversions(S, SCS1, SCS2))
3688 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) {
3689 // Check for a better reference binding based on the kind of bindings.
3690 if (isBetterReferenceBindingKind(SCS1, SCS2))
3691 return ImplicitConversionSequence::Better;
3692 else if (isBetterReferenceBindingKind(SCS2, SCS1))
3693 return ImplicitConversionSequence::Worse;
3695 // C++ [over.ics.rank]p3b4:
3696 // -- S1 and S2 are reference bindings (8.5.3), and the types to
3697 // which the references refer are the same type except for
3698 // top-level cv-qualifiers, and the type to which the reference
3699 // initialized by S2 refers is more cv-qualified than the type
3700 // to which the reference initialized by S1 refers.
3701 QualType T1 = SCS1.getToType(2);
3702 QualType T2 = SCS2.getToType(2);
3703 T1 = S.Context.getCanonicalType(T1);
3704 T2 = S.Context.getCanonicalType(T2);
3705 Qualifiers T1Quals, T2Quals;
3706 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
3707 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
3708 if (UnqualT1 == UnqualT2) {
3709 // Objective-C++ ARC: If the references refer to objects with different
3710 // lifetimes, prefer bindings that don't change lifetime.
3711 if (SCS1.ObjCLifetimeConversionBinding !=
3712 SCS2.ObjCLifetimeConversionBinding) {
3713 return SCS1.ObjCLifetimeConversionBinding
3714 ? ImplicitConversionSequence::Worse
3715 : ImplicitConversionSequence::Better;
3718 // If the type is an array type, promote the element qualifiers to the
3719 // type for comparison.
3720 if (isa<ArrayType>(T1) && T1Quals)
3721 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals);
3722 if (isa<ArrayType>(T2) && T2Quals)
3723 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals);
3724 if (T2.isMoreQualifiedThan(T1))
3725 return ImplicitConversionSequence::Better;
3726 else if (T1.isMoreQualifiedThan(T2))
3727 return ImplicitConversionSequence::Worse;
3731 // In Microsoft mode, prefer an integral conversion to a
3732 // floating-to-integral conversion if the integral conversion
3733 // is between types of the same size.
3741 // Here, MSVC will call f(int) instead of generating a compile error
3742 // as clang will do in standard mode.
3743 if (S.getLangOpts().MSVCCompat && SCS1.Second == ICK_Integral_Conversion &&
3744 SCS2.Second == ICK_Floating_Integral &&
3745 S.Context.getTypeSize(SCS1.getFromType()) ==
3746 S.Context.getTypeSize(SCS1.getToType(2)))
3747 return ImplicitConversionSequence::Better;
3749 return ImplicitConversionSequence::Indistinguishable;
3752 /// CompareQualificationConversions - Compares two standard conversion
3753 /// sequences to determine whether they can be ranked based on their
3754 /// qualification conversions (C++ 13.3.3.2p3 bullet 3).
3755 static ImplicitConversionSequence::CompareKind
3756 CompareQualificationConversions(Sema &S,
3757 const StandardConversionSequence& SCS1,
3758 const StandardConversionSequence& SCS2) {
3760 // -- S1 and S2 differ only in their qualification conversion and
3761 // yield similar types T1 and T2 (C++ 4.4), respectively, and the
3762 // cv-qualification signature of type T1 is a proper subset of
3763 // the cv-qualification signature of type T2, and S1 is not the
3764 // deprecated string literal array-to-pointer conversion (4.2).
3765 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second ||
3766 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification)
3767 return ImplicitConversionSequence::Indistinguishable;
3769 // FIXME: the example in the standard doesn't use a qualification
3771 QualType T1 = SCS1.getToType(2);
3772 QualType T2 = SCS2.getToType(2);
3773 T1 = S.Context.getCanonicalType(T1);
3774 T2 = S.Context.getCanonicalType(T2);
3775 Qualifiers T1Quals, T2Quals;
3776 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
3777 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
3779 // If the types are the same, we won't learn anything by unwrapped
3781 if (UnqualT1 == UnqualT2)
3782 return ImplicitConversionSequence::Indistinguishable;
3784 // If the type is an array type, promote the element qualifiers to the type
3786 if (isa<ArrayType>(T1) && T1Quals)
3787 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals);
3788 if (isa<ArrayType>(T2) && T2Quals)
3789 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals);
3791 ImplicitConversionSequence::CompareKind Result
3792 = ImplicitConversionSequence::Indistinguishable;
3794 // Objective-C++ ARC:
3795 // Prefer qualification conversions not involving a change in lifetime
3796 // to qualification conversions that do not change lifetime.
3797 if (SCS1.QualificationIncludesObjCLifetime !=
3798 SCS2.QualificationIncludesObjCLifetime) {
3799 Result = SCS1.QualificationIncludesObjCLifetime
3800 ? ImplicitConversionSequence::Worse
3801 : ImplicitConversionSequence::Better;
3804 while (S.Context.UnwrapSimilarPointerTypes(T1, T2)) {
3805 // Within each iteration of the loop, we check the qualifiers to
3806 // determine if this still looks like a qualification
3807 // conversion. Then, if all is well, we unwrap one more level of
3808 // pointers or pointers-to-members and do it all again
3809 // until there are no more pointers or pointers-to-members left
3810 // to unwrap. This essentially mimics what
3811 // IsQualificationConversion does, but here we're checking for a
3812 // strict subset of qualifiers.
3813 if (T1.getCVRQualifiers() == T2.getCVRQualifiers())
3814 // The qualifiers are the same, so this doesn't tell us anything
3815 // about how the sequences rank.
3817 else if (T2.isMoreQualifiedThan(T1)) {
3818 // T1 has fewer qualifiers, so it could be the better sequence.
3819 if (Result == ImplicitConversionSequence::Worse)
3820 // Neither has qualifiers that are a subset of the other's
3822 return ImplicitConversionSequence::Indistinguishable;
3824 Result = ImplicitConversionSequence::Better;
3825 } else if (T1.isMoreQualifiedThan(T2)) {
3826 // T2 has fewer qualifiers, so it could be the better sequence.
3827 if (Result == ImplicitConversionSequence::Better)
3828 // Neither has qualifiers that are a subset of the other's
3830 return ImplicitConversionSequence::Indistinguishable;
3832 Result = ImplicitConversionSequence::Worse;
3834 // Qualifiers are disjoint.
3835 return ImplicitConversionSequence::Indistinguishable;
3838 // If the types after this point are equivalent, we're done.
3839 if (S.Context.hasSameUnqualifiedType(T1, T2))
3843 // Check that the winning standard conversion sequence isn't using
3844 // the deprecated string literal array to pointer conversion.
3846 case ImplicitConversionSequence::Better:
3847 if (SCS1.DeprecatedStringLiteralToCharPtr)
3848 Result = ImplicitConversionSequence::Indistinguishable;
3851 case ImplicitConversionSequence::Indistinguishable:
3854 case ImplicitConversionSequence::Worse:
3855 if (SCS2.DeprecatedStringLiteralToCharPtr)
3856 Result = ImplicitConversionSequence::Indistinguishable;
3863 /// CompareDerivedToBaseConversions - Compares two standard conversion
3864 /// sequences to determine whether they can be ranked based on their
3865 /// various kinds of derived-to-base conversions (C++
3866 /// [over.ics.rank]p4b3). As part of these checks, we also look at
3867 /// conversions between Objective-C interface types.
3868 static ImplicitConversionSequence::CompareKind
3869 CompareDerivedToBaseConversions(Sema &S, SourceLocation Loc,
3870 const StandardConversionSequence& SCS1,
3871 const StandardConversionSequence& SCS2) {
3872 QualType FromType1 = SCS1.getFromType();
3873 QualType ToType1 = SCS1.getToType(1);
3874 QualType FromType2 = SCS2.getFromType();
3875 QualType ToType2 = SCS2.getToType(1);
3877 // Adjust the types we're converting from via the array-to-pointer
3878 // conversion, if we need to.
3879 if (SCS1.First == ICK_Array_To_Pointer)
3880 FromType1 = S.Context.getArrayDecayedType(FromType1);
3881 if (SCS2.First == ICK_Array_To_Pointer)
3882 FromType2 = S.Context.getArrayDecayedType(FromType2);
3884 // Canonicalize all of the types.
3885 FromType1 = S.Context.getCanonicalType(FromType1);
3886 ToType1 = S.Context.getCanonicalType(ToType1);
3887 FromType2 = S.Context.getCanonicalType(FromType2);
3888 ToType2 = S.Context.getCanonicalType(ToType2);
3890 // C++ [over.ics.rank]p4b3:
3892 // If class B is derived directly or indirectly from class A and
3893 // class C is derived directly or indirectly from B,
3895 // Compare based on pointer conversions.
3896 if (SCS1.Second == ICK_Pointer_Conversion &&
3897 SCS2.Second == ICK_Pointer_Conversion &&
3898 /*FIXME: Remove if Objective-C id conversions get their own rank*/
3899 FromType1->isPointerType() && FromType2->isPointerType() &&
3900 ToType1->isPointerType() && ToType2->isPointerType()) {
3901 QualType FromPointee1
3902 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
3904 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
3905 QualType FromPointee2
3906 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
3908 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
3910 // -- conversion of C* to B* is better than conversion of C* to A*,
3911 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
3912 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
3913 return ImplicitConversionSequence::Better;
3914 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
3915 return ImplicitConversionSequence::Worse;
3918 // -- conversion of B* to A* is better than conversion of C* to A*,
3919 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) {
3920 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
3921 return ImplicitConversionSequence::Better;
3922 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
3923 return ImplicitConversionSequence::Worse;
3925 } else if (SCS1.Second == ICK_Pointer_Conversion &&
3926 SCS2.Second == ICK_Pointer_Conversion) {
3927 const ObjCObjectPointerType *FromPtr1
3928 = FromType1->getAs<ObjCObjectPointerType>();
3929 const ObjCObjectPointerType *FromPtr2
3930 = FromType2->getAs<ObjCObjectPointerType>();
3931 const ObjCObjectPointerType *ToPtr1
3932 = ToType1->getAs<ObjCObjectPointerType>();
3933 const ObjCObjectPointerType *ToPtr2
3934 = ToType2->getAs<ObjCObjectPointerType>();
3936 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) {
3937 // Apply the same conversion ranking rules for Objective-C pointer types
3938 // that we do for C++ pointers to class types. However, we employ the
3939 // Objective-C pseudo-subtyping relationship used for assignment of
3940 // Objective-C pointer types.
3942 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2);
3943 bool FromAssignRight
3944 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1);
3946 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2);
3948 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1);
3950 // A conversion to an a non-id object pointer type or qualified 'id'
3951 // type is better than a conversion to 'id'.
3952 if (ToPtr1->isObjCIdType() &&
3953 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl()))
3954 return ImplicitConversionSequence::Worse;
3955 if (ToPtr2->isObjCIdType() &&
3956 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl()))
3957 return ImplicitConversionSequence::Better;
3959 // A conversion to a non-id object pointer type is better than a
3960 // conversion to a qualified 'id' type
3961 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl())
3962 return ImplicitConversionSequence::Worse;
3963 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl())
3964 return ImplicitConversionSequence::Better;
3966 // A conversion to an a non-Class object pointer type or qualified 'Class'
3967 // type is better than a conversion to 'Class'.
3968 if (ToPtr1->isObjCClassType() &&
3969 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl()))
3970 return ImplicitConversionSequence::Worse;
3971 if (ToPtr2->isObjCClassType() &&
3972 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl()))
3973 return ImplicitConversionSequence::Better;
3975 // A conversion to a non-Class object pointer type is better than a
3976 // conversion to a qualified 'Class' type.
3977 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl())
3978 return ImplicitConversionSequence::Worse;
3979 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl())
3980 return ImplicitConversionSequence::Better;
3982 // -- "conversion of C* to B* is better than conversion of C* to A*,"
3983 if (S.Context.hasSameType(FromType1, FromType2) &&
3984 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() &&
3985 (ToAssignLeft != ToAssignRight))
3986 return ToAssignLeft? ImplicitConversionSequence::Worse
3987 : ImplicitConversionSequence::Better;
3989 // -- "conversion of B* to A* is better than conversion of C* to A*,"
3990 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) &&
3991 (FromAssignLeft != FromAssignRight))
3992 return FromAssignLeft? ImplicitConversionSequence::Better
3993 : ImplicitConversionSequence::Worse;
3997 // Ranking of member-pointer types.
3998 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member &&
3999 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() &&
4000 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) {
4001 const MemberPointerType * FromMemPointer1 =
4002 FromType1->getAs<MemberPointerType>();
4003 const MemberPointerType * ToMemPointer1 =
4004 ToType1->getAs<MemberPointerType>();
4005 const MemberPointerType * FromMemPointer2 =
4006 FromType2->getAs<MemberPointerType>();
4007 const MemberPointerType * ToMemPointer2 =
4008 ToType2->getAs<MemberPointerType>();
4009 const Type *FromPointeeType1 = FromMemPointer1->getClass();
4010 const Type *ToPointeeType1 = ToMemPointer1->getClass();
4011 const Type *FromPointeeType2 = FromMemPointer2->getClass();
4012 const Type *ToPointeeType2 = ToMemPointer2->getClass();
4013 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType();
4014 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType();
4015 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType();
4016 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType();
4017 // conversion of A::* to B::* is better than conversion of A::* to C::*,
4018 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
4019 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
4020 return ImplicitConversionSequence::Worse;
4021 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
4022 return ImplicitConversionSequence::Better;
4024 // conversion of B::* to C::* is better than conversion of A::* to C::*
4025 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) {
4026 if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
4027 return ImplicitConversionSequence::Better;
4028 else if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
4029 return ImplicitConversionSequence::Worse;
4033 if (SCS1.Second == ICK_Derived_To_Base) {
4034 // -- conversion of C to B is better than conversion of C to A,
4035 // -- binding of an expression of type C to a reference of type
4036 // B& is better than binding an expression of type C to a
4037 // reference of type A&,
4038 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4039 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4040 if (S.IsDerivedFrom(Loc, ToType1, ToType2))
4041 return ImplicitConversionSequence::Better;
4042 else if (S.IsDerivedFrom(Loc, ToType2, ToType1))
4043 return ImplicitConversionSequence::Worse;
4046 // -- conversion of B to A is better than conversion of C to A.
4047 // -- binding of an expression of type B to a reference of type
4048 // A& is better than binding an expression of type C to a
4049 // reference of type A&,
4050 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4051 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4052 if (S.IsDerivedFrom(Loc, FromType2, FromType1))
4053 return ImplicitConversionSequence::Better;
4054 else if (S.IsDerivedFrom(Loc, FromType1, FromType2))
4055 return ImplicitConversionSequence::Worse;
4059 return ImplicitConversionSequence::Indistinguishable;
4062 /// \brief Determine whether the given type is valid, e.g., it is not an invalid
4064 static bool isTypeValid(QualType T) {
4065 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl())
4066 return !Record->isInvalidDecl();
4071 /// CompareReferenceRelationship - Compare the two types T1 and T2 to
4072 /// determine whether they are reference-related,
4073 /// reference-compatible, reference-compatible with added
4074 /// qualification, or incompatible, for use in C++ initialization by
4075 /// reference (C++ [dcl.ref.init]p4). Neither type can be a reference
4076 /// type, and the first type (T1) is the pointee type of the reference
4077 /// type being initialized.
4078 Sema::ReferenceCompareResult
4079 Sema::CompareReferenceRelationship(SourceLocation Loc,
4080 QualType OrigT1, QualType OrigT2,
4081 bool &DerivedToBase,
4082 bool &ObjCConversion,
4083 bool &ObjCLifetimeConversion) {
4084 assert(!OrigT1->isReferenceType() &&
4085 "T1 must be the pointee type of the reference type");
4086 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type");
4088 QualType T1 = Context.getCanonicalType(OrigT1);
4089 QualType T2 = Context.getCanonicalType(OrigT2);
4090 Qualifiers T1Quals, T2Quals;
4091 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals);
4092 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals);
4094 // C++ [dcl.init.ref]p4:
4095 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is
4096 // reference-related to "cv2 T2" if T1 is the same type as T2, or
4097 // T1 is a base class of T2.
4098 DerivedToBase = false;
4099 ObjCConversion = false;
4100 ObjCLifetimeConversion = false;
4101 if (UnqualT1 == UnqualT2) {
4103 } else if (isCompleteType(Loc, OrigT2) &&
4104 isTypeValid(UnqualT1) && isTypeValid(UnqualT2) &&
4105 IsDerivedFrom(Loc, UnqualT2, UnqualT1))
4106 DerivedToBase = true;
4107 else if (UnqualT1->isObjCObjectOrInterfaceType() &&
4108 UnqualT2->isObjCObjectOrInterfaceType() &&
4109 Context.canBindObjCObjectType(UnqualT1, UnqualT2))
4110 ObjCConversion = true;
4112 return Ref_Incompatible;
4114 // At this point, we know that T1 and T2 are reference-related (at
4117 // If the type is an array type, promote the element qualifiers to the type
4119 if (isa<ArrayType>(T1) && T1Quals)
4120 T1 = Context.getQualifiedType(UnqualT1, T1Quals);
4121 if (isa<ArrayType>(T2) && T2Quals)
4122 T2 = Context.getQualifiedType(UnqualT2, T2Quals);
4124 // C++ [dcl.init.ref]p4:
4125 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is
4126 // reference-related to T2 and cv1 is the same cv-qualification
4127 // as, or greater cv-qualification than, cv2. For purposes of
4128 // overload resolution, cases for which cv1 is greater
4129 // cv-qualification than cv2 are identified as
4130 // reference-compatible with added qualification (see 13.3.3.2).
4132 // Note that we also require equivalence of Objective-C GC and address-space
4133 // qualifiers when performing these computations, so that e.g., an int in
4134 // address space 1 is not reference-compatible with an int in address
4136 if (T1Quals.getObjCLifetime() != T2Quals.getObjCLifetime() &&
4137 T1Quals.compatiblyIncludesObjCLifetime(T2Quals)) {
4138 if (isNonTrivialObjCLifetimeConversion(T2Quals, T1Quals))
4139 ObjCLifetimeConversion = true;
4141 T1Quals.removeObjCLifetime();
4142 T2Quals.removeObjCLifetime();
4145 // MS compiler ignores __unaligned qualifier for references; do the same.
4146 T1Quals.removeUnaligned();
4147 T2Quals.removeUnaligned();
4149 if (T1Quals == T2Quals)
4150 return Ref_Compatible;
4151 else if (T1Quals.compatiblyIncludes(T2Quals))
4152 return Ref_Compatible_With_Added_Qualification;
4157 /// \brief Look for a user-defined conversion to an value reference-compatible
4158 /// with DeclType. Return true if something definite is found.
4160 FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS,
4161 QualType DeclType, SourceLocation DeclLoc,
4162 Expr *Init, QualType T2, bool AllowRvalues,
4163 bool AllowExplicit) {
4164 assert(T2->isRecordType() && "Can only find conversions of record types.");
4165 CXXRecordDecl *T2RecordDecl
4166 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl());
4168 OverloadCandidateSet CandidateSet(DeclLoc, OverloadCandidateSet::CSK_Normal);
4169 const auto &Conversions = T2RecordDecl->getVisibleConversionFunctions();
4170 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
4172 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
4173 if (isa<UsingShadowDecl>(D))
4174 D = cast<UsingShadowDecl>(D)->getTargetDecl();
4176 FunctionTemplateDecl *ConvTemplate
4177 = dyn_cast<FunctionTemplateDecl>(D);
4178 CXXConversionDecl *Conv;
4180 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
4182 Conv = cast<CXXConversionDecl>(D);
4184 // If this is an explicit conversion, and we're not allowed to consider
4185 // explicit conversions, skip it.
4186 if (!AllowExplicit && Conv->isExplicit())
4190 bool DerivedToBase = false;
4191 bool ObjCConversion = false;
4192 bool ObjCLifetimeConversion = false;
4194 // If we are initializing an rvalue reference, don't permit conversion
4195 // functions that return lvalues.
4196 if (!ConvTemplate && DeclType->isRValueReferenceType()) {
4197 const ReferenceType *RefType
4198 = Conv->getConversionType()->getAs<LValueReferenceType>();
4199 if (RefType && !RefType->getPointeeType()->isFunctionType())
4203 if (!ConvTemplate &&
4204 S.CompareReferenceRelationship(
4206 Conv->getConversionType().getNonReferenceType()
4207 .getUnqualifiedType(),
4208 DeclType.getNonReferenceType().getUnqualifiedType(),
4209 DerivedToBase, ObjCConversion, ObjCLifetimeConversion) ==
4210 Sema::Ref_Incompatible)
4213 // If the conversion function doesn't return a reference type,
4214 // it can't be considered for this conversion. An rvalue reference
4215 // is only acceptable if its referencee is a function type.
4217 const ReferenceType *RefType =
4218 Conv->getConversionType()->getAs<ReferenceType>();
4220 (!RefType->isLValueReferenceType() &&
4221 !RefType->getPointeeType()->isFunctionType()))
4226 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC,
4227 Init, DeclType, CandidateSet,
4228 /*AllowObjCConversionOnExplicit=*/false);
4230 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init,
4231 DeclType, CandidateSet,
4232 /*AllowObjCConversionOnExplicit=*/false);
4235 bool HadMultipleCandidates = (CandidateSet.size() > 1);
4237 OverloadCandidateSet::iterator Best;
4238 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) {
4240 // C++ [over.ics.ref]p1:
4242 // [...] If the parameter binds directly to the result of
4243 // applying a conversion function to the argument
4244 // expression, the implicit conversion sequence is a
4245 // user-defined conversion sequence (13.3.3.1.2), with the
4246 // second standard conversion sequence either an identity
4247 // conversion or, if the conversion function returns an
4248 // entity of a type that is a derived class of the parameter
4249 // type, a derived-to-base Conversion.
4250 if (!Best->FinalConversion.DirectBinding)
4253 ICS.setUserDefined();
4254 ICS.UserDefined.Before = Best->Conversions[0].Standard;
4255 ICS.UserDefined.After = Best->FinalConversion;
4256 ICS.UserDefined.HadMultipleCandidates = HadMultipleCandidates;
4257 ICS.UserDefined.ConversionFunction = Best->Function;
4258 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl;
4259 ICS.UserDefined.EllipsisConversion = false;
4260 assert(ICS.UserDefined.After.ReferenceBinding &&
4261 ICS.UserDefined.After.DirectBinding &&
4262 "Expected a direct reference binding!");
4267 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin();
4268 Cand != CandidateSet.end(); ++Cand)
4270 ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
4273 case OR_No_Viable_Function:
4275 // There was no suitable conversion, or we found a deleted
4276 // conversion; continue with other checks.
4280 llvm_unreachable("Invalid OverloadResult!");
4283 /// \brief Compute an implicit conversion sequence for reference
4285 static ImplicitConversionSequence
4286 TryReferenceInit(Sema &S, Expr *Init, QualType DeclType,
4287 SourceLocation DeclLoc,
4288 bool SuppressUserConversions,
4289 bool AllowExplicit) {
4290 assert(DeclType->isReferenceType() && "Reference init needs a reference");
4292 // Most paths end in a failed conversion.
4293 ImplicitConversionSequence ICS;
4294 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4296 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType();
4297 QualType T2 = Init->getType();
4299 // If the initializer is the address of an overloaded function, try
4300 // to resolve the overloaded function. If all goes well, T2 is the
4301 // type of the resulting function.
4302 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
4303 DeclAccessPair Found;
4304 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType,
4309 // Compute some basic properties of the types and the initializer.
4310 bool isRValRef = DeclType->isRValueReferenceType();
4311 bool DerivedToBase = false;
4312 bool ObjCConversion = false;
4313 bool ObjCLifetimeConversion = false;
4314 Expr::Classification InitCategory = Init->Classify(S.Context);
4315 Sema::ReferenceCompareResult RefRelationship
4316 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase,
4317 ObjCConversion, ObjCLifetimeConversion);
4320 // C++0x [dcl.init.ref]p5:
4321 // A reference to type "cv1 T1" is initialized by an expression
4322 // of type "cv2 T2" as follows:
4324 // -- If reference is an lvalue reference and the initializer expression
4326 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is
4327 // reference-compatible with "cv2 T2," or
4329 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here.
4330 if (InitCategory.isLValue() &&
4331 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) {
4332 // C++ [over.ics.ref]p1:
4333 // When a parameter of reference type binds directly (8.5.3)
4334 // to an argument expression, the implicit conversion sequence
4335 // is the identity conversion, unless the argument expression
4336 // has a type that is a derived class of the parameter type,
4337 // in which case the implicit conversion sequence is a
4338 // derived-to-base Conversion (13.3.3.1).
4340 ICS.Standard.First = ICK_Identity;
4341 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base
4342 : ObjCConversion? ICK_Compatible_Conversion
4344 ICS.Standard.Third = ICK_Identity;
4345 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
4346 ICS.Standard.setToType(0, T2);
4347 ICS.Standard.setToType(1, T1);
4348 ICS.Standard.setToType(2, T1);
4349 ICS.Standard.ReferenceBinding = true;
4350 ICS.Standard.DirectBinding = true;
4351 ICS.Standard.IsLvalueReference = !isRValRef;
4352 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType();
4353 ICS.Standard.BindsToRvalue = false;
4354 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4355 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion;
4356 ICS.Standard.CopyConstructor = nullptr;
4357 ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
4359 // Nothing more to do: the inaccessibility/ambiguity check for
4360 // derived-to-base conversions is suppressed when we're
4361 // computing the implicit conversion sequence (C++
4362 // [over.best.ics]p2).
4366 // -- has a class type (i.e., T2 is a class type), where T1 is
4367 // not reference-related to T2, and can be implicitly
4368 // converted to an lvalue of type "cv3 T3," where "cv1 T1"
4369 // is reference-compatible with "cv3 T3" 92) (this
4370 // conversion is selected by enumerating the applicable
4371 // conversion functions (13.3.1.6) and choosing the best
4372 // one through overload resolution (13.3)),
4373 if (!SuppressUserConversions && T2->isRecordType() &&
4374 S.isCompleteType(DeclLoc, T2) &&
4375 RefRelationship == Sema::Ref_Incompatible) {
4376 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4377 Init, T2, /*AllowRvalues=*/false,
4383 // -- Otherwise, the reference shall be an lvalue reference to a
4384 // non-volatile const type (i.e., cv1 shall be const), or the reference
4385 // shall be an rvalue reference.
4386 if (!isRValRef && (!T1.isConstQualified() || T1.isVolatileQualified()))
4389 // -- If the initializer expression
4391 // -- is an xvalue, class prvalue, array prvalue or function
4392 // lvalue and "cv1 T1" is reference-compatible with "cv2 T2", or
4393 if (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification &&
4394 (InitCategory.isXValue() ||
4395 (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) ||
4396 (InitCategory.isLValue() && T2->isFunctionType()))) {
4398 ICS.Standard.First = ICK_Identity;
4399 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base
4400 : ObjCConversion? ICK_Compatible_Conversion
4402 ICS.Standard.Third = ICK_Identity;
4403 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
4404 ICS.Standard.setToType(0, T2);
4405 ICS.Standard.setToType(1, T1);
4406 ICS.Standard.setToType(2, T1);
4407 ICS.Standard.ReferenceBinding = true;
4408 // In C++0x, this is always a direct binding. In C++98/03, it's a direct
4409 // binding unless we're binding to a class prvalue.
4410 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we
4411 // allow the use of rvalue references in C++98/03 for the benefit of
4412 // standard library implementors; therefore, we need the xvalue check here.
4413 ICS.Standard.DirectBinding =
4414 S.getLangOpts().CPlusPlus11 ||
4415 !(InitCategory.isPRValue() || T2->isRecordType());
4416 ICS.Standard.IsLvalueReference = !isRValRef;
4417 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType();
4418 ICS.Standard.BindsToRvalue = InitCategory.isRValue();
4419 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4420 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion;
4421 ICS.Standard.CopyConstructor = nullptr;
4422 ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
4426 // -- has a class type (i.e., T2 is a class type), where T1 is not
4427 // reference-related to T2, and can be implicitly converted to
4428 // an xvalue, class prvalue, or function lvalue of type
4429 // "cv3 T3", where "cv1 T1" is reference-compatible with
4432 // then the reference is bound to the value of the initializer
4433 // expression in the first case and to the result of the conversion
4434 // in the second case (or, in either case, to an appropriate base
4435 // class subobject).
4436 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4437 T2->isRecordType() && S.isCompleteType(DeclLoc, T2) &&
4438 FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4439 Init, T2, /*AllowRvalues=*/true,
4441 // In the second case, if the reference is an rvalue reference
4442 // and the second standard conversion sequence of the
4443 // user-defined conversion sequence includes an lvalue-to-rvalue
4444 // conversion, the program is ill-formed.
4445 if (ICS.isUserDefined() && isRValRef &&
4446 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue)
4447 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4452 // A temporary of function type cannot be created; don't even try.
4453 if (T1->isFunctionType())
4456 // -- Otherwise, a temporary of type "cv1 T1" is created and
4457 // initialized from the initializer expression using the
4458 // rules for a non-reference copy initialization (8.5). The
4459 // reference is then bound to the temporary. If T1 is
4460 // reference-related to T2, cv1 must be the same
4461 // cv-qualification as, or greater cv-qualification than,
4462 // cv2; otherwise, the program is ill-formed.
4463 if (RefRelationship == Sema::Ref_Related) {
4464 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then
4465 // we would be reference-compatible or reference-compatible with
4466 // added qualification. But that wasn't the case, so the reference
4467 // initialization fails.
4469 // Note that we only want to check address spaces and cvr-qualifiers here.
4470 // ObjC GC, lifetime and unaligned qualifiers aren't important.
4471 Qualifiers T1Quals = T1.getQualifiers();
4472 Qualifiers T2Quals = T2.getQualifiers();
4473 T1Quals.removeObjCGCAttr();
4474 T1Quals.removeObjCLifetime();
4475 T2Quals.removeObjCGCAttr();
4476 T2Quals.removeObjCLifetime();
4477 // MS compiler ignores __unaligned qualifier for references; do the same.
4478 T1Quals.removeUnaligned();
4479 T2Quals.removeUnaligned();
4480 if (!T1Quals.compatiblyIncludes(T2Quals))
4484 // If at least one of the types is a class type, the types are not
4485 // related, and we aren't allowed any user conversions, the
4486 // reference binding fails. This case is important for breaking
4487 // recursion, since TryImplicitConversion below will attempt to
4488 // create a temporary through the use of a copy constructor.
4489 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4490 (T1->isRecordType() || T2->isRecordType()))
4493 // If T1 is reference-related to T2 and the reference is an rvalue
4494 // reference, the initializer expression shall not be an lvalue.
4495 if (RefRelationship >= Sema::Ref_Related &&
4496 isRValRef && Init->Classify(S.Context).isLValue())
4499 // C++ [over.ics.ref]p2:
4500 // When a parameter of reference type is not bound directly to
4501 // an argument expression, the conversion sequence is the one
4502 // required to convert the argument expression to the
4503 // underlying type of the reference according to
4504 // 13.3.3.1. Conceptually, this conversion sequence corresponds
4505 // to copy-initializing a temporary of the underlying type with
4506 // the argument expression. Any difference in top-level
4507 // cv-qualification is subsumed by the initialization itself
4508 // and does not constitute a conversion.
4509 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions,
4510 /*AllowExplicit=*/false,
4511 /*InOverloadResolution=*/false,
4513 /*AllowObjCWritebackConversion=*/false,
4514 /*AllowObjCConversionOnExplicit=*/false);
4516 // Of course, that's still a reference binding.
4517 if (ICS.isStandard()) {
4518 ICS.Standard.ReferenceBinding = true;
4519 ICS.Standard.IsLvalueReference = !isRValRef;
4520 ICS.Standard.BindsToFunctionLvalue = false;
4521 ICS.Standard.BindsToRvalue = true;
4522 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4523 ICS.Standard.ObjCLifetimeConversionBinding = false;
4524 } else if (ICS.isUserDefined()) {
4525 const ReferenceType *LValRefType =
4526 ICS.UserDefined.ConversionFunction->getReturnType()
4527 ->getAs<LValueReferenceType>();
4529 // C++ [over.ics.ref]p3:
4530 // Except for an implicit object parameter, for which see 13.3.1, a
4531 // standard conversion sequence cannot be formed if it requires [...]
4532 // binding an rvalue reference to an lvalue other than a function
4534 // Note that the function case is not possible here.
4535 if (DeclType->isRValueReferenceType() && LValRefType) {
4536 // FIXME: This is the wrong BadConversionSequence. The problem is binding
4537 // an rvalue reference to a (non-function) lvalue, not binding an lvalue
4538 // reference to an rvalue!
4539 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, Init, DeclType);
4543 ICS.UserDefined.Before.setAsIdentityConversion();
4544 ICS.UserDefined.After.ReferenceBinding = true;
4545 ICS.UserDefined.After.IsLvalueReference = !isRValRef;
4546 ICS.UserDefined.After.BindsToFunctionLvalue = false;
4547 ICS.UserDefined.After.BindsToRvalue = !LValRefType;
4548 ICS.UserDefined.After.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4549 ICS.UserDefined.After.ObjCLifetimeConversionBinding = false;
4555 static ImplicitConversionSequence
4556 TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
4557 bool SuppressUserConversions,
4558 bool InOverloadResolution,
4559 bool AllowObjCWritebackConversion,
4560 bool AllowExplicit = false);
4562 /// TryListConversion - Try to copy-initialize a value of type ToType from the
4563 /// initializer list From.
4564 static ImplicitConversionSequence
4565 TryListConversion(Sema &S, InitListExpr *From, QualType ToType,
4566 bool SuppressUserConversions,
4567 bool InOverloadResolution,
4568 bool AllowObjCWritebackConversion) {
4569 // C++11 [over.ics.list]p1:
4570 // When an argument is an initializer list, it is not an expression and
4571 // special rules apply for converting it to a parameter type.
4573 ImplicitConversionSequence Result;
4574 Result.setBad(BadConversionSequence::no_conversion, From, ToType);
4576 // We need a complete type for what follows. Incomplete types can never be
4577 // initialized from init lists.
4578 if (!S.isCompleteType(From->getLocStart(), ToType))
4582 // If the parameter type is a class X and the initializer list has a single
4583 // element of type cv U, where U is X or a class derived from X, the
4584 // implicit conversion sequence is the one required to convert the element
4585 // to the parameter type.
4587 // Otherwise, if the parameter type is a character array [... ]
4588 // and the initializer list has a single element that is an
4589 // appropriately-typed string literal (8.5.2 [dcl.init.string]), the
4590 // implicit conversion sequence is the identity conversion.
4591 if (From->getNumInits() == 1) {
4592 if (ToType->isRecordType()) {
4593 QualType InitType = From->getInit(0)->getType();
4594 if (S.Context.hasSameUnqualifiedType(InitType, ToType) ||
4595 S.IsDerivedFrom(From->getLocStart(), InitType, ToType))
4596 return TryCopyInitialization(S, From->getInit(0), ToType,
4597 SuppressUserConversions,
4598 InOverloadResolution,
4599 AllowObjCWritebackConversion);
4601 // FIXME: Check the other conditions here: array of character type,
4602 // initializer is a string literal.
4603 if (ToType->isArrayType()) {
4604 InitializedEntity Entity =
4605 InitializedEntity::InitializeParameter(S.Context, ToType,
4606 /*Consumed=*/false);
4607 if (S.CanPerformCopyInitialization(Entity, From)) {
4608 Result.setStandard();
4609 Result.Standard.setAsIdentityConversion();
4610 Result.Standard.setFromType(ToType);
4611 Result.Standard.setAllToTypes(ToType);
4617 // C++14 [over.ics.list]p2: Otherwise, if the parameter type [...] (below).
4618 // C++11 [over.ics.list]p2:
4619 // If the parameter type is std::initializer_list<X> or "array of X" and
4620 // all the elements can be implicitly converted to X, the implicit
4621 // conversion sequence is the worst conversion necessary to convert an
4622 // element of the list to X.
4624 // C++14 [over.ics.list]p3:
4625 // Otherwise, if the parameter type is "array of N X", if the initializer
4626 // list has exactly N elements or if it has fewer than N elements and X is
4627 // default-constructible, and if all the elements of the initializer list
4628 // can be implicitly converted to X, the implicit conversion sequence is
4629 // the worst conversion necessary to convert an element of the list to X.
4631 // FIXME: We're missing a lot of these checks.
4632 bool toStdInitializerList = false;
4634 if (ToType->isArrayType())
4635 X = S.Context.getAsArrayType(ToType)->getElementType();
4637 toStdInitializerList = S.isStdInitializerList(ToType, &X);
4639 for (unsigned i = 0, e = From->getNumInits(); i < e; ++i) {
4640 Expr *Init = From->getInit(i);
4641 ImplicitConversionSequence ICS =
4642 TryCopyInitialization(S, Init, X, SuppressUserConversions,
4643 InOverloadResolution,
4644 AllowObjCWritebackConversion);
4645 // If a single element isn't convertible, fail.
4650 // Otherwise, look for the worst conversion.
4651 if (Result.isBad() ||
4652 CompareImplicitConversionSequences(S, From->getLocStart(), ICS,
4654 ImplicitConversionSequence::Worse)
4658 // For an empty list, we won't have computed any conversion sequence.
4659 // Introduce the identity conversion sequence.
4660 if (From->getNumInits() == 0) {
4661 Result.setStandard();
4662 Result.Standard.setAsIdentityConversion();
4663 Result.Standard.setFromType(ToType);
4664 Result.Standard.setAllToTypes(ToType);
4667 Result.setStdInitializerListElement(toStdInitializerList);
4671 // C++14 [over.ics.list]p4:
4672 // C++11 [over.ics.list]p3:
4673 // Otherwise, if the parameter is a non-aggregate class X and overload
4674 // resolution chooses a single best constructor [...] the implicit
4675 // conversion sequence is a user-defined conversion sequence. If multiple
4676 // constructors are viable but none is better than the others, the
4677 // implicit conversion sequence is a user-defined conversion sequence.
4678 if (ToType->isRecordType() && !ToType->isAggregateType()) {
4679 // This function can deal with initializer lists.
4680 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
4681 /*AllowExplicit=*/false,
4682 InOverloadResolution, /*CStyle=*/false,
4683 AllowObjCWritebackConversion,
4684 /*AllowObjCConversionOnExplicit=*/false);
4687 // C++14 [over.ics.list]p5:
4688 // C++11 [over.ics.list]p4:
4689 // Otherwise, if the parameter has an aggregate type which can be
4690 // initialized from the initializer list [...] the implicit conversion
4691 // sequence is a user-defined conversion sequence.
4692 if (ToType->isAggregateType()) {
4693 // Type is an aggregate, argument is an init list. At this point it comes
4694 // down to checking whether the initialization works.
4695 // FIXME: Find out whether this parameter is consumed or not.
4696 InitializedEntity Entity =
4697 InitializedEntity::InitializeParameter(S.Context, ToType,
4698 /*Consumed=*/false);
4699 if (S.CanPerformCopyInitialization(Entity, From)) {
4700 Result.setUserDefined();
4701 Result.UserDefined.Before.setAsIdentityConversion();
4702 // Initializer lists don't have a type.
4703 Result.UserDefined.Before.setFromType(QualType());
4704 Result.UserDefined.Before.setAllToTypes(QualType());
4706 Result.UserDefined.After.setAsIdentityConversion();
4707 Result.UserDefined.After.setFromType(ToType);
4708 Result.UserDefined.After.setAllToTypes(ToType);
4709 Result.UserDefined.ConversionFunction = nullptr;
4714 // C++14 [over.ics.list]p6:
4715 // C++11 [over.ics.list]p5:
4716 // Otherwise, if the parameter is a reference, see 13.3.3.1.4.
4717 if (ToType->isReferenceType()) {
4718 // The standard is notoriously unclear here, since 13.3.3.1.4 doesn't
4719 // mention initializer lists in any way. So we go by what list-
4720 // initialization would do and try to extrapolate from that.
4722 QualType T1 = ToType->getAs<ReferenceType>()->getPointeeType();
4724 // If the initializer list has a single element that is reference-related
4725 // to the parameter type, we initialize the reference from that.
4726 if (From->getNumInits() == 1) {
4727 Expr *Init = From->getInit(0);
4729 QualType T2 = Init->getType();
4731 // If the initializer is the address of an overloaded function, try
4732 // to resolve the overloaded function. If all goes well, T2 is the
4733 // type of the resulting function.
4734 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
4735 DeclAccessPair Found;
4736 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(
4737 Init, ToType, false, Found))
4741 // Compute some basic properties of the types and the initializer.
4742 bool dummy1 = false;
4743 bool dummy2 = false;
4744 bool dummy3 = false;
4745 Sema::ReferenceCompareResult RefRelationship
4746 = S.CompareReferenceRelationship(From->getLocStart(), T1, T2, dummy1,
4749 if (RefRelationship >= Sema::Ref_Related) {
4750 return TryReferenceInit(S, Init, ToType, /*FIXME*/From->getLocStart(),
4751 SuppressUserConversions,
4752 /*AllowExplicit=*/false);
4756 // Otherwise, we bind the reference to a temporary created from the
4757 // initializer list.
4758 Result = TryListConversion(S, From, T1, SuppressUserConversions,
4759 InOverloadResolution,
4760 AllowObjCWritebackConversion);
4761 if (Result.isFailure())
4763 assert(!Result.isEllipsis() &&
4764 "Sub-initialization cannot result in ellipsis conversion.");
4766 // Can we even bind to a temporary?
4767 if (ToType->isRValueReferenceType() ||
4768 (T1.isConstQualified() && !T1.isVolatileQualified())) {
4769 StandardConversionSequence &SCS = Result.isStandard() ? Result.Standard :
4770 Result.UserDefined.After;
4771 SCS.ReferenceBinding = true;
4772 SCS.IsLvalueReference = ToType->isLValueReferenceType();
4773 SCS.BindsToRvalue = true;
4774 SCS.BindsToFunctionLvalue = false;
4775 SCS.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4776 SCS.ObjCLifetimeConversionBinding = false;
4778 Result.setBad(BadConversionSequence::lvalue_ref_to_rvalue,
4783 // C++14 [over.ics.list]p7:
4784 // C++11 [over.ics.list]p6:
4785 // Otherwise, if the parameter type is not a class:
4786 if (!ToType->isRecordType()) {
4787 // - if the initializer list has one element that is not itself an
4788 // initializer list, the implicit conversion sequence is the one
4789 // required to convert the element to the parameter type.
4790 unsigned NumInits = From->getNumInits();
4791 if (NumInits == 1 && !isa<InitListExpr>(From->getInit(0)))
4792 Result = TryCopyInitialization(S, From->getInit(0), ToType,
4793 SuppressUserConversions,
4794 InOverloadResolution,
4795 AllowObjCWritebackConversion);
4796 // - if the initializer list has no elements, the implicit conversion
4797 // sequence is the identity conversion.
4798 else if (NumInits == 0) {
4799 Result.setStandard();
4800 Result.Standard.setAsIdentityConversion();
4801 Result.Standard.setFromType(ToType);
4802 Result.Standard.setAllToTypes(ToType);
4807 // C++14 [over.ics.list]p8:
4808 // C++11 [over.ics.list]p7:
4809 // In all cases other than those enumerated above, no conversion is possible
4813 /// TryCopyInitialization - Try to copy-initialize a value of type
4814 /// ToType from the expression From. Return the implicit conversion
4815 /// sequence required to pass this argument, which may be a bad
4816 /// conversion sequence (meaning that the argument cannot be passed to
4817 /// a parameter of this type). If @p SuppressUserConversions, then we
4818 /// do not permit any user-defined conversion sequences.
4819 static ImplicitConversionSequence
4820 TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
4821 bool SuppressUserConversions,
4822 bool InOverloadResolution,
4823 bool AllowObjCWritebackConversion,
4824 bool AllowExplicit) {
4825 if (InitListExpr *FromInitList = dyn_cast<InitListExpr>(From))
4826 return TryListConversion(S, FromInitList, ToType, SuppressUserConversions,
4827 InOverloadResolution,AllowObjCWritebackConversion);
4829 if (ToType->isReferenceType())
4830 return TryReferenceInit(S, From, ToType,
4831 /*FIXME:*/From->getLocStart(),
4832 SuppressUserConversions,
4835 return TryImplicitConversion(S, From, ToType,
4836 SuppressUserConversions,
4837 /*AllowExplicit=*/false,
4838 InOverloadResolution,
4840 AllowObjCWritebackConversion,
4841 /*AllowObjCConversionOnExplicit=*/false);
4844 static bool TryCopyInitialization(const CanQualType FromQTy,
4845 const CanQualType ToQTy,
4848 ExprValueKind FromVK) {
4849 OpaqueValueExpr TmpExpr(Loc, FromQTy, FromVK);
4850 ImplicitConversionSequence ICS =
4851 TryCopyInitialization(S, &TmpExpr, ToQTy, true, true, false);
4853 return !ICS.isBad();
4856 /// TryObjectArgumentInitialization - Try to initialize the object
4857 /// parameter of the given member function (@c Method) from the
4858 /// expression @p From.
4859 static ImplicitConversionSequence
4860 TryObjectArgumentInitialization(Sema &S, SourceLocation Loc, QualType FromType,
4861 Expr::Classification FromClassification,
4862 CXXMethodDecl *Method,
4863 CXXRecordDecl *ActingContext) {
4864 QualType ClassType = S.Context.getTypeDeclType(ActingContext);
4865 // [class.dtor]p2: A destructor can be invoked for a const, volatile or
4866 // const volatile object.
4867 unsigned Quals = isa<CXXDestructorDecl>(Method) ?
4868 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers();
4869 QualType ImplicitParamType = S.Context.getCVRQualifiedType(ClassType, Quals);
4871 // Set up the conversion sequence as a "bad" conversion, to allow us
4873 ImplicitConversionSequence ICS;
4875 // We need to have an object of class type.
4876 if (const PointerType *PT = FromType->getAs<PointerType>()) {
4877 FromType = PT->getPointeeType();
4879 // When we had a pointer, it's implicitly dereferenced, so we
4880 // better have an lvalue.
4881 assert(FromClassification.isLValue());
4884 assert(FromType->isRecordType());
4886 // C++0x [over.match.funcs]p4:
4887 // For non-static member functions, the type of the implicit object
4890 // - "lvalue reference to cv X" for functions declared without a
4891 // ref-qualifier or with the & ref-qualifier
4892 // - "rvalue reference to cv X" for functions declared with the &&
4895 // where X is the class of which the function is a member and cv is the
4896 // cv-qualification on the member function declaration.
4898 // However, when finding an implicit conversion sequence for the argument, we
4899 // are not allowed to create temporaries or perform user-defined conversions
4900 // (C++ [over.match.funcs]p5). We perform a simplified version of
4901 // reference binding here, that allows class rvalues to bind to
4902 // non-constant references.
4904 // First check the qualifiers.
4905 QualType FromTypeCanon = S.Context.getCanonicalType(FromType);
4906 if (ImplicitParamType.getCVRQualifiers()
4907 != FromTypeCanon.getLocalCVRQualifiers() &&
4908 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) {
4909 ICS.setBad(BadConversionSequence::bad_qualifiers,
4910 FromType, ImplicitParamType);
4914 // Check that we have either the same type or a derived type. It
4915 // affects the conversion rank.
4916 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType);
4917 ImplicitConversionKind SecondKind;
4918 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) {
4919 SecondKind = ICK_Identity;
4920 } else if (S.IsDerivedFrom(Loc, FromType, ClassType))
4921 SecondKind = ICK_Derived_To_Base;
4923 ICS.setBad(BadConversionSequence::unrelated_class,
4924 FromType, ImplicitParamType);
4928 // Check the ref-qualifier.
4929 switch (Method->getRefQualifier()) {
4931 // Do nothing; we don't care about lvalueness or rvalueness.
4935 if (!FromClassification.isLValue() && Quals != Qualifiers::Const) {
4936 // non-const lvalue reference cannot bind to an rvalue
4937 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType,
4944 if (!FromClassification.isRValue()) {
4945 // rvalue reference cannot bind to an lvalue
4946 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType,
4953 // Success. Mark this as a reference binding.
4955 ICS.Standard.setAsIdentityConversion();
4956 ICS.Standard.Second = SecondKind;
4957 ICS.Standard.setFromType(FromType);
4958 ICS.Standard.setAllToTypes(ImplicitParamType);
4959 ICS.Standard.ReferenceBinding = true;
4960 ICS.Standard.DirectBinding = true;
4961 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue;
4962 ICS.Standard.BindsToFunctionLvalue = false;
4963 ICS.Standard.BindsToRvalue = FromClassification.isRValue();
4964 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier
4965 = (Method->getRefQualifier() == RQ_None);
4969 /// PerformObjectArgumentInitialization - Perform initialization of
4970 /// the implicit object parameter for the given Method with the given
4973 Sema::PerformObjectArgumentInitialization(Expr *From,
4974 NestedNameSpecifier *Qualifier,
4975 NamedDecl *FoundDecl,
4976 CXXMethodDecl *Method) {
4977 QualType FromRecordType, DestType;
4978 QualType ImplicitParamRecordType =
4979 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType();
4981 Expr::Classification FromClassification;
4982 if (const PointerType *PT = From->getType()->getAs<PointerType>()) {
4983 FromRecordType = PT->getPointeeType();
4984 DestType = Method->getThisType(Context);
4985 FromClassification = Expr::Classification::makeSimpleLValue();
4987 FromRecordType = From->getType();
4988 DestType = ImplicitParamRecordType;
4989 FromClassification = From->Classify(Context);
4992 // Note that we always use the true parent context when performing
4993 // the actual argument initialization.
4994 ImplicitConversionSequence ICS = TryObjectArgumentInitialization(
4995 *this, From->getLocStart(), From->getType(), FromClassification, Method,
4996 Method->getParent());
4998 if (ICS.Bad.Kind == BadConversionSequence::bad_qualifiers) {
4999 Qualifiers FromQs = FromRecordType.getQualifiers();
5000 Qualifiers ToQs = DestType.getQualifiers();
5001 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers();
5003 Diag(From->getLocStart(),
5004 diag::err_member_function_call_bad_cvr)
5005 << Method->getDeclName() << FromRecordType << (CVR - 1)
5006 << From->getSourceRange();
5007 Diag(Method->getLocation(), diag::note_previous_decl)
5008 << Method->getDeclName();
5013 return Diag(From->getLocStart(),
5014 diag::err_implicit_object_parameter_init)
5015 << ImplicitParamRecordType << FromRecordType << From->getSourceRange();
5018 if (ICS.Standard.Second == ICK_Derived_To_Base) {
5019 ExprResult FromRes =
5020 PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method);
5021 if (FromRes.isInvalid())
5023 From = FromRes.get();
5026 if (!Context.hasSameType(From->getType(), DestType))
5027 From = ImpCastExprToType(From, DestType, CK_NoOp,
5028 From->getValueKind()).get();
5032 /// TryContextuallyConvertToBool - Attempt to contextually convert the
5033 /// expression From to bool (C++0x [conv]p3).
5034 static ImplicitConversionSequence
5035 TryContextuallyConvertToBool(Sema &S, Expr *From) {
5036 return TryImplicitConversion(S, From, S.Context.BoolTy,
5037 /*SuppressUserConversions=*/false,
5038 /*AllowExplicit=*/true,
5039 /*InOverloadResolution=*/false,
5041 /*AllowObjCWritebackConversion=*/false,
5042 /*AllowObjCConversionOnExplicit=*/false);
5045 /// PerformContextuallyConvertToBool - Perform a contextual conversion
5046 /// of the expression From to bool (C++0x [conv]p3).
5047 ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) {
5048 if (checkPlaceholderForOverload(*this, From))
5051 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From);
5053 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting);
5055 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy))
5056 return Diag(From->getLocStart(),
5057 diag::err_typecheck_bool_condition)
5058 << From->getType() << From->getSourceRange();
5062 /// Check that the specified conversion is permitted in a converted constant
5063 /// expression, according to C++11 [expr.const]p3. Return true if the conversion
5065 static bool CheckConvertedConstantConversions(Sema &S,
5066 StandardConversionSequence &SCS) {
5067 // Since we know that the target type is an integral or unscoped enumeration
5068 // type, most conversion kinds are impossible. All possible First and Third
5069 // conversions are fine.
5070 switch (SCS.Second) {
5072 case ICK_NoReturn_Adjustment:
5073 case ICK_Integral_Promotion:
5074 case ICK_Integral_Conversion: // Narrowing conversions are checked elsewhere.
5077 case ICK_Boolean_Conversion:
5078 // Conversion from an integral or unscoped enumeration type to bool is
5079 // classified as ICK_Boolean_Conversion, but it's also arguably an integral
5080 // conversion, so we allow it in a converted constant expression.
5082 // FIXME: Per core issue 1407, we should not allow this, but that breaks
5083 // a lot of popular code. We should at least add a warning for this
5084 // (non-conforming) extension.
5085 return SCS.getFromType()->isIntegralOrUnscopedEnumerationType() &&
5086 SCS.getToType(2)->isBooleanType();
5088 case ICK_Pointer_Conversion:
5089 case ICK_Pointer_Member:
5090 // C++1z: null pointer conversions and null member pointer conversions are
5091 // only permitted if the source type is std::nullptr_t.
5092 return SCS.getFromType()->isNullPtrType();
5094 case ICK_Floating_Promotion:
5095 case ICK_Complex_Promotion:
5096 case ICK_Floating_Conversion:
5097 case ICK_Complex_Conversion:
5098 case ICK_Floating_Integral:
5099 case ICK_Compatible_Conversion:
5100 case ICK_Derived_To_Base:
5101 case ICK_Vector_Conversion:
5102 case ICK_Vector_Splat:
5103 case ICK_Complex_Real:
5104 case ICK_Block_Pointer_Conversion:
5105 case ICK_TransparentUnionConversion:
5106 case ICK_Writeback_Conversion:
5107 case ICK_Zero_Event_Conversion:
5108 case ICK_C_Only_Conversion:
5111 case ICK_Lvalue_To_Rvalue:
5112 case ICK_Array_To_Pointer:
5113 case ICK_Function_To_Pointer:
5114 llvm_unreachable("found a first conversion kind in Second");
5116 case ICK_Qualification:
5117 llvm_unreachable("found a third conversion kind in Second");
5119 case ICK_Num_Conversion_Kinds:
5123 llvm_unreachable("unknown conversion kind");
5126 /// CheckConvertedConstantExpression - Check that the expression From is a
5127 /// converted constant expression of type T, perform the conversion and produce
5128 /// the converted expression, per C++11 [expr.const]p3.
5129 static ExprResult CheckConvertedConstantExpression(Sema &S, Expr *From,
5130 QualType T, APValue &Value,
5133 assert(S.getLangOpts().CPlusPlus11 &&
5134 "converted constant expression outside C++11");
5136 if (checkPlaceholderForOverload(S, From))
5139 // C++1z [expr.const]p3:
5140 // A converted constant expression of type T is an expression,
5141 // implicitly converted to type T, where the converted
5142 // expression is a constant expression and the implicit conversion
5143 // sequence contains only [... list of conversions ...].
5144 ImplicitConversionSequence ICS =
5145 TryCopyInitialization(S, From, T,
5146 /*SuppressUserConversions=*/false,
5147 /*InOverloadResolution=*/false,
5148 /*AllowObjcWritebackConversion=*/false,
5149 /*AllowExplicit=*/false);
5150 StandardConversionSequence *SCS = nullptr;
5151 switch (ICS.getKind()) {
5152 case ImplicitConversionSequence::StandardConversion:
5153 SCS = &ICS.Standard;
5155 case ImplicitConversionSequence::UserDefinedConversion:
5156 // We are converting to a non-class type, so the Before sequence
5158 SCS = &ICS.UserDefined.After;
5160 case ImplicitConversionSequence::AmbiguousConversion:
5161 case ImplicitConversionSequence::BadConversion:
5162 if (!S.DiagnoseMultipleUserDefinedConversion(From, T))
5163 return S.Diag(From->getLocStart(),
5164 diag::err_typecheck_converted_constant_expression)
5165 << From->getType() << From->getSourceRange() << T;
5168 case ImplicitConversionSequence::EllipsisConversion:
5169 llvm_unreachable("ellipsis conversion in converted constant expression");
5172 // Check that we would only use permitted conversions.
5173 if (!CheckConvertedConstantConversions(S, *SCS)) {
5174 return S.Diag(From->getLocStart(),
5175 diag::err_typecheck_converted_constant_expression_disallowed)
5176 << From->getType() << From->getSourceRange() << T;
5178 // [...] and where the reference binding (if any) binds directly.
5179 if (SCS->ReferenceBinding && !SCS->DirectBinding) {
5180 return S.Diag(From->getLocStart(),
5181 diag::err_typecheck_converted_constant_expression_indirect)
5182 << From->getType() << From->getSourceRange() << T;
5186 S.PerformImplicitConversion(From, T, ICS, Sema::AA_Converting);
5187 if (Result.isInvalid())
5190 // Check for a narrowing implicit conversion.
5191 APValue PreNarrowingValue;
5192 QualType PreNarrowingType;
5193 switch (SCS->getNarrowingKind(S.Context, Result.get(), PreNarrowingValue,
5194 PreNarrowingType)) {
5195 case NK_Variable_Narrowing:
5196 // Implicit conversion to a narrower type, and the value is not a constant
5197 // expression. We'll diagnose this in a moment.
5198 case NK_Not_Narrowing:
5201 case NK_Constant_Narrowing:
5202 S.Diag(From->getLocStart(), diag::ext_cce_narrowing)
5203 << CCE << /*Constant*/1
5204 << PreNarrowingValue.getAsString(S.Context, PreNarrowingType) << T;
5207 case NK_Type_Narrowing:
5208 S.Diag(From->getLocStart(), diag::ext_cce_narrowing)
5209 << CCE << /*Constant*/0 << From->getType() << T;
5213 // Check the expression is a constant expression.
5214 SmallVector<PartialDiagnosticAt, 8> Notes;
5215 Expr::EvalResult Eval;
5218 if ((T->isReferenceType()
5219 ? !Result.get()->EvaluateAsLValue(Eval, S.Context)
5220 : !Result.get()->EvaluateAsRValue(Eval, S.Context)) ||
5221 (RequireInt && !Eval.Val.isInt())) {
5222 // The expression can't be folded, so we can't keep it at this position in
5224 Result = ExprError();
5228 if (Notes.empty()) {
5229 // It's a constant expression.
5234 // It's not a constant expression. Produce an appropriate diagnostic.
5235 if (Notes.size() == 1 &&
5236 Notes[0].second.getDiagID() == diag::note_invalid_subexpr_in_const_expr)
5237 S.Diag(Notes[0].first, diag::err_expr_not_cce) << CCE;
5239 S.Diag(From->getLocStart(), diag::err_expr_not_cce)
5240 << CCE << From->getSourceRange();
5241 for (unsigned I = 0; I < Notes.size(); ++I)
5242 S.Diag(Notes[I].first, Notes[I].second);
5247 ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5248 APValue &Value, CCEKind CCE) {
5249 return ::CheckConvertedConstantExpression(*this, From, T, Value, CCE, false);
5252 ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5253 llvm::APSInt &Value,
5255 assert(T->isIntegralOrEnumerationType() && "unexpected converted const type");
5258 auto R = ::CheckConvertedConstantExpression(*this, From, T, V, CCE, true);
5265 /// dropPointerConversions - If the given standard conversion sequence
5266 /// involves any pointer conversions, remove them. This may change
5267 /// the result type of the conversion sequence.
5268 static void dropPointerConversion(StandardConversionSequence &SCS) {
5269 if (SCS.Second == ICK_Pointer_Conversion) {
5270 SCS.Second = ICK_Identity;
5271 SCS.Third = ICK_Identity;
5272 SCS.ToTypePtrs[2] = SCS.ToTypePtrs[1] = SCS.ToTypePtrs[0];
5276 /// TryContextuallyConvertToObjCPointer - Attempt to contextually
5277 /// convert the expression From to an Objective-C pointer type.
5278 static ImplicitConversionSequence
5279 TryContextuallyConvertToObjCPointer(Sema &S, Expr *From) {
5280 // Do an implicit conversion to 'id'.
5281 QualType Ty = S.Context.getObjCIdType();
5282 ImplicitConversionSequence ICS
5283 = TryImplicitConversion(S, From, Ty,
5284 // FIXME: Are these flags correct?
5285 /*SuppressUserConversions=*/false,
5286 /*AllowExplicit=*/true,
5287 /*InOverloadResolution=*/false,
5289 /*AllowObjCWritebackConversion=*/false,
5290 /*AllowObjCConversionOnExplicit=*/true);
5292 // Strip off any final conversions to 'id'.
5293 switch (ICS.getKind()) {
5294 case ImplicitConversionSequence::BadConversion:
5295 case ImplicitConversionSequence::AmbiguousConversion:
5296 case ImplicitConversionSequence::EllipsisConversion:
5299 case ImplicitConversionSequence::UserDefinedConversion:
5300 dropPointerConversion(ICS.UserDefined.After);
5303 case ImplicitConversionSequence::StandardConversion:
5304 dropPointerConversion(ICS.Standard);
5311 /// PerformContextuallyConvertToObjCPointer - Perform a contextual
5312 /// conversion of the expression From to an Objective-C pointer type.
5313 ExprResult Sema::PerformContextuallyConvertToObjCPointer(Expr *From) {
5314 if (checkPlaceholderForOverload(*this, From))
5317 QualType Ty = Context.getObjCIdType();
5318 ImplicitConversionSequence ICS =
5319 TryContextuallyConvertToObjCPointer(*this, From);
5321 return PerformImplicitConversion(From, Ty, ICS, AA_Converting);
5325 /// Determine whether the provided type is an integral type, or an enumeration
5326 /// type of a permitted flavor.
5327 bool Sema::ICEConvertDiagnoser::match(QualType T) {
5328 return AllowScopedEnumerations ? T->isIntegralOrEnumerationType()
5329 : T->isIntegralOrUnscopedEnumerationType();
5333 diagnoseAmbiguousConversion(Sema &SemaRef, SourceLocation Loc, Expr *From,
5334 Sema::ContextualImplicitConverter &Converter,
5335 QualType T, UnresolvedSetImpl &ViableConversions) {
5337 if (Converter.Suppress)
5340 Converter.diagnoseAmbiguous(SemaRef, Loc, T) << From->getSourceRange();
5341 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5342 CXXConversionDecl *Conv =
5343 cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl());
5344 QualType ConvTy = Conv->getConversionType().getNonReferenceType();
5345 Converter.noteAmbiguous(SemaRef, Conv, ConvTy);
5351 diagnoseNoViableConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5352 Sema::ContextualImplicitConverter &Converter,
5353 QualType T, bool HadMultipleCandidates,
5354 UnresolvedSetImpl &ExplicitConversions) {
5355 if (ExplicitConversions.size() == 1 && !Converter.Suppress) {
5356 DeclAccessPair Found = ExplicitConversions[0];
5357 CXXConversionDecl *Conversion =
5358 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5360 // The user probably meant to invoke the given explicit
5361 // conversion; use it.
5362 QualType ConvTy = Conversion->getConversionType().getNonReferenceType();
5363 std::string TypeStr;
5364 ConvTy.getAsStringInternal(TypeStr, SemaRef.getPrintingPolicy());
5366 Converter.diagnoseExplicitConv(SemaRef, Loc, T, ConvTy)
5367 << FixItHint::CreateInsertion(From->getLocStart(),
5368 "static_cast<" + TypeStr + ">(")
5369 << FixItHint::CreateInsertion(
5370 SemaRef.getLocForEndOfToken(From->getLocEnd()), ")");
5371 Converter.noteExplicitConv(SemaRef, Conversion, ConvTy);
5373 // If we aren't in a SFINAE context, build a call to the
5374 // explicit conversion function.
5375 if (SemaRef.isSFINAEContext())
5378 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5379 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5380 HadMultipleCandidates);
5381 if (Result.isInvalid())
5383 // Record usage of conversion in an implicit cast.
5384 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5385 CK_UserDefinedConversion, Result.get(),
5386 nullptr, Result.get()->getValueKind());
5391 static bool recordConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5392 Sema::ContextualImplicitConverter &Converter,
5393 QualType T, bool HadMultipleCandidates,
5394 DeclAccessPair &Found) {
5395 CXXConversionDecl *Conversion =
5396 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5397 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5399 QualType ToType = Conversion->getConversionType().getNonReferenceType();
5400 if (!Converter.SuppressConversion) {
5401 if (SemaRef.isSFINAEContext())
5404 Converter.diagnoseConversion(SemaRef, Loc, T, ToType)
5405 << From->getSourceRange();
5408 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5409 HadMultipleCandidates);
5410 if (Result.isInvalid())
5412 // Record usage of conversion in an implicit cast.
5413 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5414 CK_UserDefinedConversion, Result.get(),
5415 nullptr, Result.get()->getValueKind());
5419 static ExprResult finishContextualImplicitConversion(
5420 Sema &SemaRef, SourceLocation Loc, Expr *From,
5421 Sema::ContextualImplicitConverter &Converter) {
5422 if (!Converter.match(From->getType()) && !Converter.Suppress)
5423 Converter.diagnoseNoMatch(SemaRef, Loc, From->getType())
5424 << From->getSourceRange();
5426 return SemaRef.DefaultLvalueConversion(From);
5430 collectViableConversionCandidates(Sema &SemaRef, Expr *From, QualType ToType,
5431 UnresolvedSetImpl &ViableConversions,
5432 OverloadCandidateSet &CandidateSet) {
5433 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5434 DeclAccessPair FoundDecl = ViableConversions[I];
5435 NamedDecl *D = FoundDecl.getDecl();
5436 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
5437 if (isa<UsingShadowDecl>(D))
5438 D = cast<UsingShadowDecl>(D)->getTargetDecl();
5440 CXXConversionDecl *Conv;
5441 FunctionTemplateDecl *ConvTemplate;
5442 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
5443 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5445 Conv = cast<CXXConversionDecl>(D);
5448 SemaRef.AddTemplateConversionCandidate(
5449 ConvTemplate, FoundDecl, ActingContext, From, ToType, CandidateSet,
5450 /*AllowObjCConversionOnExplicit=*/false);
5452 SemaRef.AddConversionCandidate(Conv, FoundDecl, ActingContext, From,
5453 ToType, CandidateSet,
5454 /*AllowObjCConversionOnExplicit=*/false);
5458 /// \brief Attempt to convert the given expression to a type which is accepted
5459 /// by the given converter.
5461 /// This routine will attempt to convert an expression of class type to a
5462 /// type accepted by the specified converter. In C++11 and before, the class
5463 /// must have a single non-explicit conversion function converting to a matching
5464 /// type. In C++1y, there can be multiple such conversion functions, but only
5465 /// one target type.
5467 /// \param Loc The source location of the construct that requires the
5470 /// \param From The expression we're converting from.
5472 /// \param Converter Used to control and diagnose the conversion process.
5474 /// \returns The expression, converted to an integral or enumeration type if
5476 ExprResult Sema::PerformContextualImplicitConversion(
5477 SourceLocation Loc, Expr *From, ContextualImplicitConverter &Converter) {
5478 // We can't perform any more checking for type-dependent expressions.
5479 if (From->isTypeDependent())
5482 // Process placeholders immediately.
5483 if (From->hasPlaceholderType()) {
5484 ExprResult result = CheckPlaceholderExpr(From);
5485 if (result.isInvalid())
5487 From = result.get();
5490 // If the expression already has a matching type, we're golden.
5491 QualType T = From->getType();
5492 if (Converter.match(T))
5493 return DefaultLvalueConversion(From);
5495 // FIXME: Check for missing '()' if T is a function type?
5497 // We can only perform contextual implicit conversions on objects of class
5499 const RecordType *RecordTy = T->getAs<RecordType>();
5500 if (!RecordTy || !getLangOpts().CPlusPlus) {
5501 if (!Converter.Suppress)
5502 Converter.diagnoseNoMatch(*this, Loc, T) << From->getSourceRange();
5506 // We must have a complete class type.
5507 struct TypeDiagnoserPartialDiag : TypeDiagnoser {
5508 ContextualImplicitConverter &Converter;
5511 TypeDiagnoserPartialDiag(ContextualImplicitConverter &Converter, Expr *From)
5512 : Converter(Converter), From(From) {}
5514 void diagnose(Sema &S, SourceLocation Loc, QualType T) override {
5515 Converter.diagnoseIncomplete(S, Loc, T) << From->getSourceRange();
5517 } IncompleteDiagnoser(Converter, From);
5519 if (Converter.Suppress ? !isCompleteType(Loc, T)
5520 : RequireCompleteType(Loc, T, IncompleteDiagnoser))
5523 // Look for a conversion to an integral or enumeration type.
5525 ViableConversions; // These are *potentially* viable in C++1y.
5526 UnresolvedSet<4> ExplicitConversions;
5527 const auto &Conversions =
5528 cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions();
5530 bool HadMultipleCandidates =
5531 (std::distance(Conversions.begin(), Conversions.end()) > 1);
5533 // To check that there is only one target type, in C++1y:
5535 bool HasUniqueTargetType = true;
5537 // Collect explicit or viable (potentially in C++1y) conversions.
5538 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
5539 NamedDecl *D = (*I)->getUnderlyingDecl();
5540 CXXConversionDecl *Conversion;
5541 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
5543 if (getLangOpts().CPlusPlus14)
5544 Conversion = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5546 continue; // C++11 does not consider conversion operator templates(?).
5548 Conversion = cast<CXXConversionDecl>(D);
5550 assert((!ConvTemplate || getLangOpts().CPlusPlus14) &&
5551 "Conversion operator templates are considered potentially "
5554 QualType CurToType = Conversion->getConversionType().getNonReferenceType();
5555 if (Converter.match(CurToType) || ConvTemplate) {
5557 if (Conversion->isExplicit()) {
5558 // FIXME: For C++1y, do we need this restriction?
5559 // cf. diagnoseNoViableConversion()
5561 ExplicitConversions.addDecl(I.getDecl(), I.getAccess());
5563 if (!ConvTemplate && getLangOpts().CPlusPlus14) {
5564 if (ToType.isNull())
5565 ToType = CurToType.getUnqualifiedType();
5566 else if (HasUniqueTargetType &&
5567 (CurToType.getUnqualifiedType() != ToType))
5568 HasUniqueTargetType = false;
5570 ViableConversions.addDecl(I.getDecl(), I.getAccess());
5575 if (getLangOpts().CPlusPlus14) {
5577 // ... An expression e of class type E appearing in such a context
5578 // is said to be contextually implicitly converted to a specified
5579 // type T and is well-formed if and only if e can be implicitly
5580 // converted to a type T that is determined as follows: E is searched
5581 // for conversion functions whose return type is cv T or reference to
5582 // cv T such that T is allowed by the context. There shall be
5583 // exactly one such T.
5585 // If no unique T is found:
5586 if (ToType.isNull()) {
5587 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5588 HadMultipleCandidates,
5589 ExplicitConversions))
5591 return finishContextualImplicitConversion(*this, Loc, From, Converter);
5594 // If more than one unique Ts are found:
5595 if (!HasUniqueTargetType)
5596 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5599 // If one unique T is found:
5600 // First, build a candidate set from the previously recorded
5601 // potentially viable conversions.
5602 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Normal);
5603 collectViableConversionCandidates(*this, From, ToType, ViableConversions,
5606 // Then, perform overload resolution over the candidate set.
5607 OverloadCandidateSet::iterator Best;
5608 switch (CandidateSet.BestViableFunction(*this, Loc, Best)) {
5610 // Apply this conversion.
5611 DeclAccessPair Found =
5612 DeclAccessPair::make(Best->Function, Best->FoundDecl.getAccess());
5613 if (recordConversion(*this, Loc, From, Converter, T,
5614 HadMultipleCandidates, Found))
5619 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5621 case OR_No_Viable_Function:
5622 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5623 HadMultipleCandidates,
5624 ExplicitConversions))
5626 // fall through 'OR_Deleted' case.
5628 // We'll complain below about a non-integral condition type.
5632 switch (ViableConversions.size()) {
5634 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5635 HadMultipleCandidates,
5636 ExplicitConversions))
5639 // We'll complain below about a non-integral condition type.
5643 // Apply this conversion.
5644 DeclAccessPair Found = ViableConversions[0];
5645 if (recordConversion(*this, Loc, From, Converter, T,
5646 HadMultipleCandidates, Found))
5651 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5656 return finishContextualImplicitConversion(*this, Loc, From, Converter);
5659 /// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is
5660 /// an acceptable non-member overloaded operator for a call whose
5661 /// arguments have types T1 (and, if non-empty, T2). This routine
5662 /// implements the check in C++ [over.match.oper]p3b2 concerning
5663 /// enumeration types.
5664 static bool IsAcceptableNonMemberOperatorCandidate(ASTContext &Context,
5666 ArrayRef<Expr *> Args) {
5667 QualType T1 = Args[0]->getType();
5668 QualType T2 = Args.size() > 1 ? Args[1]->getType() : QualType();
5670 if (T1->isDependentType() || (!T2.isNull() && T2->isDependentType()))
5673 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType()))
5676 const FunctionProtoType *Proto = Fn->getType()->getAs<FunctionProtoType>();
5677 if (Proto->getNumParams() < 1)
5680 if (T1->isEnumeralType()) {
5681 QualType ArgType = Proto->getParamType(0).getNonReferenceType();
5682 if (Context.hasSameUnqualifiedType(T1, ArgType))
5686 if (Proto->getNumParams() < 2)
5689 if (!T2.isNull() && T2->isEnumeralType()) {
5690 QualType ArgType = Proto->getParamType(1).getNonReferenceType();
5691 if (Context.hasSameUnqualifiedType(T2, ArgType))
5698 /// AddOverloadCandidate - Adds the given function to the set of
5699 /// candidate functions, using the given function call arguments. If
5700 /// @p SuppressUserConversions, then don't allow user-defined
5701 /// conversions via constructors or conversion operators.
5703 /// \param PartialOverloading true if we are performing "partial" overloading
5704 /// based on an incomplete set of function arguments. This feature is used by
5705 /// code completion.
5707 Sema::AddOverloadCandidate(FunctionDecl *Function,
5708 DeclAccessPair FoundDecl,
5709 ArrayRef<Expr *> Args,
5710 OverloadCandidateSet &CandidateSet,
5711 bool SuppressUserConversions,
5712 bool PartialOverloading,
5713 bool AllowExplicit) {
5714 const FunctionProtoType *Proto
5715 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>());
5716 assert(Proto && "Functions without a prototype cannot be overloaded");
5717 assert(!Function->getDescribedFunctionTemplate() &&
5718 "Use AddTemplateOverloadCandidate for function templates");
5720 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) {
5721 if (!isa<CXXConstructorDecl>(Method)) {
5722 // If we get here, it's because we're calling a member function
5723 // that is named without a member access expression (e.g.,
5724 // "this->f") that was either written explicitly or created
5725 // implicitly. This can happen with a qualified call to a member
5726 // function, e.g., X::f(). We use an empty type for the implied
5727 // object argument (C++ [over.call.func]p3), and the acting context
5729 AddMethodCandidate(Method, FoundDecl, Method->getParent(),
5730 QualType(), Expr::Classification::makeSimpleLValue(),
5731 Args, CandidateSet, SuppressUserConversions,
5732 PartialOverloading);
5735 // We treat a constructor like a non-member function, since its object
5736 // argument doesn't participate in overload resolution.
5739 if (!CandidateSet.isNewCandidate(Function))
5742 // C++ [over.match.oper]p3:
5743 // if no operand has a class type, only those non-member functions in the
5744 // lookup set that have a first parameter of type T1 or "reference to
5745 // (possibly cv-qualified) T1", when T1 is an enumeration type, or (if there
5746 // is a right operand) a second parameter of type T2 or "reference to
5747 // (possibly cv-qualified) T2", when T2 is an enumeration type, are
5748 // candidate functions.
5749 if (CandidateSet.getKind() == OverloadCandidateSet::CSK_Operator &&
5750 !IsAcceptableNonMemberOperatorCandidate(Context, Function, Args))
5753 // C++11 [class.copy]p11: [DR1402]
5754 // A defaulted move constructor that is defined as deleted is ignored by
5755 // overload resolution.
5756 CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function);
5757 if (Constructor && Constructor->isDefaulted() && Constructor->isDeleted() &&
5758 Constructor->isMoveConstructor())
5761 // Overload resolution is always an unevaluated context.
5762 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated);
5764 // Add this candidate
5765 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size());
5766 Candidate.FoundDecl = FoundDecl;
5767 Candidate.Function = Function;
5768 Candidate.Viable = true;
5769 Candidate.IsSurrogate = false;
5770 Candidate.IgnoreObjectArgument = false;
5771 Candidate.ExplicitCallArguments = Args.size();
5774 // C++ [class.copy]p3:
5775 // A member function template is never instantiated to perform the copy
5776 // of a class object to an object of its class type.
5777 QualType ClassType = Context.getTypeDeclType(Constructor->getParent());
5778 if (Args.size() == 1 && Constructor->isSpecializationCopyingObject() &&
5779 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) ||
5780 IsDerivedFrom(Args[0]->getLocStart(), Args[0]->getType(),
5782 Candidate.Viable = false;
5783 Candidate.FailureKind = ovl_fail_illegal_constructor;
5788 unsigned NumParams = Proto->getNumParams();
5790 // (C++ 13.3.2p2): A candidate function having fewer than m
5791 // parameters is viable only if it has an ellipsis in its parameter
5793 if (TooManyArguments(NumParams, Args.size(), PartialOverloading) &&
5794 !Proto->isVariadic()) {
5795 Candidate.Viable = false;
5796 Candidate.FailureKind = ovl_fail_too_many_arguments;
5800 // (C++ 13.3.2p2): A candidate function having more than m parameters
5801 // is viable only if the (m+1)st parameter has a default argument
5802 // (8.3.6). For the purposes of overload resolution, the
5803 // parameter list is truncated on the right, so that there are
5804 // exactly m parameters.
5805 unsigned MinRequiredArgs = Function->getMinRequiredArguments();
5806 if (Args.size() < MinRequiredArgs && !PartialOverloading) {
5807 // Not enough arguments.
5808 Candidate.Viable = false;
5809 Candidate.FailureKind = ovl_fail_too_few_arguments;
5813 // (CUDA B.1): Check for invalid calls between targets.
5814 if (getLangOpts().CUDA)
5815 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext))
5816 // Skip the check for callers that are implicit members, because in this
5817 // case we may not yet know what the member's target is; the target is
5818 // inferred for the member automatically, based on the bases and fields of
5820 if (!Caller->isImplicit() && CheckCUDATarget(Caller, Function)) {
5821 Candidate.Viable = false;
5822 Candidate.FailureKind = ovl_fail_bad_target;
5826 // Determine the implicit conversion sequences for each of the
5828 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) {
5829 if (ArgIdx < NumParams) {
5830 // (C++ 13.3.2p3): for F to be a viable function, there shall
5831 // exist for each argument an implicit conversion sequence
5832 // (13.3.3.1) that converts that argument to the corresponding
5834 QualType ParamType = Proto->getParamType(ArgIdx);
5835 Candidate.Conversions[ArgIdx]
5836 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
5837 SuppressUserConversions,
5838 /*InOverloadResolution=*/true,
5839 /*AllowObjCWritebackConversion=*/
5840 getLangOpts().ObjCAutoRefCount,
5842 if (Candidate.Conversions[ArgIdx].isBad()) {
5843 Candidate.Viable = false;
5844 Candidate.FailureKind = ovl_fail_bad_conversion;
5848 // (C++ 13.3.2p2): For the purposes of overload resolution, any
5849 // argument for which there is no corresponding parameter is
5850 // considered to ""match the ellipsis" (C+ 13.3.3.1.3).
5851 Candidate.Conversions[ArgIdx].setEllipsis();
5855 if (EnableIfAttr *FailedAttr = CheckEnableIf(Function, Args)) {
5856 Candidate.Viable = false;
5857 Candidate.FailureKind = ovl_fail_enable_if;
5858 Candidate.DeductionFailure.Data = FailedAttr;
5864 Sema::SelectBestMethod(Selector Sel, MultiExprArg Args, bool IsInstance,
5865 SmallVectorImpl<ObjCMethodDecl *> &Methods) {
5866 if (Methods.size() <= 1)
5869 for (unsigned b = 0, e = Methods.size(); b < e; b++) {
5871 ObjCMethodDecl *Method = Methods[b];
5872 unsigned NumNamedArgs = Sel.getNumArgs();
5873 // Method might have more arguments than selector indicates. This is due
5874 // to addition of c-style arguments in method.
5875 if (Method->param_size() > NumNamedArgs)
5876 NumNamedArgs = Method->param_size();
5877 if (Args.size() < NumNamedArgs)
5880 for (unsigned i = 0; i < NumNamedArgs; i++) {
5881 // We can't do any type-checking on a type-dependent argument.
5882 if (Args[i]->isTypeDependent()) {
5887 ParmVarDecl *param = Method->parameters()[i];
5888 Expr *argExpr = Args[i];
5889 assert(argExpr && "SelectBestMethod(): missing expression");
5891 // Strip the unbridged-cast placeholder expression off unless it's
5892 // a consumed argument.
5893 if (argExpr->hasPlaceholderType(BuiltinType::ARCUnbridgedCast) &&
5894 !param->hasAttr<CFConsumedAttr>())
5895 argExpr = stripARCUnbridgedCast(argExpr);
5897 // If the parameter is __unknown_anytype, move on to the next method.
5898 if (param->getType() == Context.UnknownAnyTy) {
5903 ImplicitConversionSequence ConversionState
5904 = TryCopyInitialization(*this, argExpr, param->getType(),
5905 /*SuppressUserConversions*/false,
5906 /*InOverloadResolution=*/true,
5907 /*AllowObjCWritebackConversion=*/
5908 getLangOpts().ObjCAutoRefCount,
5909 /*AllowExplicit*/false);
5910 if (ConversionState.isBad()) {
5915 // Promote additional arguments to variadic methods.
5916 if (Match && Method->isVariadic()) {
5917 for (unsigned i = NumNamedArgs, e = Args.size(); i < e; ++i) {
5918 if (Args[i]->isTypeDependent()) {
5922 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod,
5924 if (Arg.isInvalid()) {
5930 // Check for extra arguments to non-variadic methods.
5931 if (Args.size() != NumNamedArgs)
5933 else if (Match && NumNamedArgs == 0 && Methods.size() > 1) {
5934 // Special case when selectors have no argument. In this case, select
5935 // one with the most general result type of 'id'.
5936 for (unsigned b = 0, e = Methods.size(); b < e; b++) {
5937 QualType ReturnT = Methods[b]->getReturnType();
5938 if (ReturnT->isObjCIdType())
5950 // specific_attr_iterator iterates over enable_if attributes in reverse, and
5951 // enable_if is order-sensitive. As a result, we need to reverse things
5952 // sometimes. Size of 4 elements is arbitrary.
5953 static SmallVector<EnableIfAttr *, 4>
5954 getOrderedEnableIfAttrs(const FunctionDecl *Function) {
5955 SmallVector<EnableIfAttr *, 4> Result;
5956 if (!Function->hasAttrs())
5959 const auto &FuncAttrs = Function->getAttrs();
5960 for (Attr *Attr : FuncAttrs)
5961 if (auto *EnableIf = dyn_cast<EnableIfAttr>(Attr))
5962 Result.push_back(EnableIf);
5964 std::reverse(Result.begin(), Result.end());
5968 EnableIfAttr *Sema::CheckEnableIf(FunctionDecl *Function, ArrayRef<Expr *> Args,
5969 bool MissingImplicitThis) {
5970 auto EnableIfAttrs = getOrderedEnableIfAttrs(Function);
5971 if (EnableIfAttrs.empty())
5974 SFINAETrap Trap(*this);
5975 SmallVector<Expr *, 16> ConvertedArgs;
5976 bool InitializationFailed = false;
5978 // Ignore any variadic parameters. Converting them is pointless, since the
5979 // user can't refer to them in the enable_if condition.
5980 unsigned ArgSizeNoVarargs = std::min(Function->param_size(), Args.size());
5982 // Convert the arguments.
5983 for (unsigned I = 0; I != ArgSizeNoVarargs; ++I) {
5985 if (I == 0 && !MissingImplicitThis && isa<CXXMethodDecl>(Function) &&
5986 !cast<CXXMethodDecl>(Function)->isStatic() &&
5987 !isa<CXXConstructorDecl>(Function)) {
5988 CXXMethodDecl *Method = cast<CXXMethodDecl>(Function);
5989 R = PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/nullptr,
5992 R = PerformCopyInitialization(InitializedEntity::InitializeParameter(
5993 Context, Function->getParamDecl(I)),
5994 SourceLocation(), Args[I]);
5997 if (R.isInvalid()) {
5998 InitializationFailed = true;
6002 ConvertedArgs.push_back(R.get());
6005 if (InitializationFailed || Trap.hasErrorOccurred())
6006 return EnableIfAttrs[0];
6008 // Push default arguments if needed.
6009 if (!Function->isVariadic() && Args.size() < Function->getNumParams()) {
6010 for (unsigned i = Args.size(), e = Function->getNumParams(); i != e; ++i) {
6011 ParmVarDecl *P = Function->getParamDecl(i);
6012 ExprResult R = PerformCopyInitialization(
6013 InitializedEntity::InitializeParameter(Context,
6014 Function->getParamDecl(i)),
6016 P->hasUninstantiatedDefaultArg() ? P->getUninstantiatedDefaultArg()
6017 : P->getDefaultArg());
6018 if (R.isInvalid()) {
6019 InitializationFailed = true;
6022 ConvertedArgs.push_back(R.get());
6025 if (InitializationFailed || Trap.hasErrorOccurred())
6026 return EnableIfAttrs[0];
6029 for (auto *EIA : EnableIfAttrs) {
6031 // FIXME: This doesn't consider value-dependent cases, because doing so is
6032 // very difficult. Ideally, we should handle them more gracefully.
6033 if (!EIA->getCond()->EvaluateWithSubstitution(
6034 Result, Context, Function, llvm::makeArrayRef(ConvertedArgs)))
6037 if (!Result.isInt() || !Result.getInt().getBoolValue())
6043 /// \brief Add all of the function declarations in the given function set to
6044 /// the overload candidate set.
6045 void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns,
6046 ArrayRef<Expr *> Args,
6047 OverloadCandidateSet& CandidateSet,
6048 TemplateArgumentListInfo *ExplicitTemplateArgs,
6049 bool SuppressUserConversions,
6050 bool PartialOverloading) {
6051 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) {
6052 NamedDecl *D = F.getDecl()->getUnderlyingDecl();
6053 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
6054 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic())
6055 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(),
6056 cast<CXXMethodDecl>(FD)->getParent(),
6057 Args[0]->getType(), Args[0]->Classify(Context),
6058 Args.slice(1), CandidateSet,
6059 SuppressUserConversions, PartialOverloading);
6061 AddOverloadCandidate(FD, F.getPair(), Args, CandidateSet,
6062 SuppressUserConversions, PartialOverloading);
6064 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D);
6065 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) &&
6066 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic())
6067 AddMethodTemplateCandidate(FunTmpl, F.getPair(),
6068 cast<CXXRecordDecl>(FunTmpl->getDeclContext()),
6069 ExplicitTemplateArgs,
6071 Args[0]->Classify(Context), Args.slice(1),
6072 CandidateSet, SuppressUserConversions,
6073 PartialOverloading);
6075 AddTemplateOverloadCandidate(FunTmpl, F.getPair(),
6076 ExplicitTemplateArgs, Args,
6077 CandidateSet, SuppressUserConversions,
6078 PartialOverloading);
6083 /// AddMethodCandidate - Adds a named decl (which is some kind of
6084 /// method) as a method candidate to the given overload set.
6085 void Sema::AddMethodCandidate(DeclAccessPair FoundDecl,
6086 QualType ObjectType,
6087 Expr::Classification ObjectClassification,
6088 ArrayRef<Expr *> Args,
6089 OverloadCandidateSet& CandidateSet,
6090 bool SuppressUserConversions) {
6091 NamedDecl *Decl = FoundDecl.getDecl();
6092 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext());
6094 if (isa<UsingShadowDecl>(Decl))
6095 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl();
6097 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) {
6098 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) &&
6099 "Expected a member function template");
6100 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext,
6101 /*ExplicitArgs*/ nullptr,
6102 ObjectType, ObjectClassification,
6104 SuppressUserConversions);
6106 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext,
6107 ObjectType, ObjectClassification,
6109 CandidateSet, SuppressUserConversions);
6113 /// AddMethodCandidate - Adds the given C++ member function to the set
6114 /// of candidate functions, using the given function call arguments
6115 /// and the object argument (@c Object). For example, in a call
6116 /// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain
6117 /// both @c a1 and @c a2. If @p SuppressUserConversions, then don't
6118 /// allow user-defined conversions via constructors or conversion
6121 Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl,
6122 CXXRecordDecl *ActingContext, QualType ObjectType,
6123 Expr::Classification ObjectClassification,
6124 ArrayRef<Expr *> Args,
6125 OverloadCandidateSet &CandidateSet,
6126 bool SuppressUserConversions,
6127 bool PartialOverloading) {
6128 const FunctionProtoType *Proto
6129 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>());
6130 assert(Proto && "Methods without a prototype cannot be overloaded");
6131 assert(!isa<CXXConstructorDecl>(Method) &&
6132 "Use AddOverloadCandidate for constructors");
6134 if (!CandidateSet.isNewCandidate(Method))
6137 // C++11 [class.copy]p23: [DR1402]
6138 // A defaulted move assignment operator that is defined as deleted is
6139 // ignored by overload resolution.
6140 if (Method->isDefaulted() && Method->isDeleted() &&
6141 Method->isMoveAssignmentOperator())
6144 // Overload resolution is always an unevaluated context.
6145 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated);
6147 // Add this candidate
6148 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1);
6149 Candidate.FoundDecl = FoundDecl;
6150 Candidate.Function = Method;
6151 Candidate.IsSurrogate = false;
6152 Candidate.IgnoreObjectArgument = false;
6153 Candidate.ExplicitCallArguments = Args.size();
6155 unsigned NumParams = Proto->getNumParams();
6157 // (C++ 13.3.2p2): A candidate function having fewer than m
6158 // parameters is viable only if it has an ellipsis in its parameter
6160 if (TooManyArguments(NumParams, Args.size(), PartialOverloading) &&
6161 !Proto->isVariadic()) {
6162 Candidate.Viable = false;
6163 Candidate.FailureKind = ovl_fail_too_many_arguments;
6167 // (C++ 13.3.2p2): A candidate function having more than m parameters
6168 // is viable only if the (m+1)st parameter has a default argument
6169 // (8.3.6). For the purposes of overload resolution, the
6170 // parameter list is truncated on the right, so that there are
6171 // exactly m parameters.
6172 unsigned MinRequiredArgs = Method->getMinRequiredArguments();
6173 if (Args.size() < MinRequiredArgs && !PartialOverloading) {
6174 // Not enough arguments.
6175 Candidate.Viable = false;
6176 Candidate.FailureKind = ovl_fail_too_few_arguments;
6180 Candidate.Viable = true;
6182 if (Method->isStatic() || ObjectType.isNull())
6183 // The implicit object argument is ignored.
6184 Candidate.IgnoreObjectArgument = true;
6186 // Determine the implicit conversion sequence for the object
6188 Candidate.Conversions[0] = TryObjectArgumentInitialization(
6189 *this, CandidateSet.getLocation(), ObjectType, ObjectClassification,
6190 Method, ActingContext);
6191 if (Candidate.Conversions[0].isBad()) {
6192 Candidate.Viable = false;
6193 Candidate.FailureKind = ovl_fail_bad_conversion;
6198 // (CUDA B.1): Check for invalid calls between targets.
6199 if (getLangOpts().CUDA)
6200 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext))
6201 if (CheckCUDATarget(Caller, Method)) {
6202 Candidate.Viable = false;
6203 Candidate.FailureKind = ovl_fail_bad_target;
6207 // Determine the implicit conversion sequences for each of the
6209 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) {
6210 if (ArgIdx < NumParams) {
6211 // (C++ 13.3.2p3): for F to be a viable function, there shall
6212 // exist for each argument an implicit conversion sequence
6213 // (13.3.3.1) that converts that argument to the corresponding
6215 QualType ParamType = Proto->getParamType(ArgIdx);
6216 Candidate.Conversions[ArgIdx + 1]
6217 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
6218 SuppressUserConversions,
6219 /*InOverloadResolution=*/true,
6220 /*AllowObjCWritebackConversion=*/
6221 getLangOpts().ObjCAutoRefCount);
6222 if (Candidate.Conversions[ArgIdx + 1].isBad()) {
6223 Candidate.Viable = false;
6224 Candidate.FailureKind = ovl_fail_bad_conversion;
6228 // (C++ 13.3.2p2): For the purposes of overload resolution, any
6229 // argument for which there is no corresponding parameter is
6230 // considered to "match the ellipsis" (C+ 13.3.3.1.3).
6231 Candidate.Conversions[ArgIdx + 1].setEllipsis();
6235 if (EnableIfAttr *FailedAttr = CheckEnableIf(Method, Args, true)) {
6236 Candidate.Viable = false;
6237 Candidate.FailureKind = ovl_fail_enable_if;
6238 Candidate.DeductionFailure.Data = FailedAttr;
6243 /// \brief Add a C++ member function template as a candidate to the candidate
6244 /// set, using template argument deduction to produce an appropriate member
6245 /// function template specialization.
6247 Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl,
6248 DeclAccessPair FoundDecl,
6249 CXXRecordDecl *ActingContext,
6250 TemplateArgumentListInfo *ExplicitTemplateArgs,
6251 QualType ObjectType,
6252 Expr::Classification ObjectClassification,
6253 ArrayRef<Expr *> Args,
6254 OverloadCandidateSet& CandidateSet,
6255 bool SuppressUserConversions,
6256 bool PartialOverloading) {
6257 if (!CandidateSet.isNewCandidate(MethodTmpl))
6260 // C++ [over.match.funcs]p7:
6261 // In each case where a candidate is a function template, candidate
6262 // function template specializations are generated using template argument
6263 // deduction (14.8.3, 14.8.2). Those candidates are then handled as
6264 // candidate functions in the usual way.113) A given name can refer to one
6265 // or more function templates and also to a set of overloaded non-template
6266 // functions. In such a case, the candidate functions generated from each
6267 // function template are combined with the set of non-template candidate
6269 TemplateDeductionInfo Info(CandidateSet.getLocation());
6270 FunctionDecl *Specialization = nullptr;
6271 if (TemplateDeductionResult Result
6272 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, Args,
6273 Specialization, Info, PartialOverloading)) {
6274 OverloadCandidate &Candidate = CandidateSet.addCandidate();
6275 Candidate.FoundDecl = FoundDecl;
6276 Candidate.Function = MethodTmpl->getTemplatedDecl();
6277 Candidate.Viable = false;
6278 Candidate.FailureKind = ovl_fail_bad_deduction;
6279 Candidate.IsSurrogate = false;
6280 Candidate.IgnoreObjectArgument = false;
6281 Candidate.ExplicitCallArguments = Args.size();
6282 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
6287 // Add the function template specialization produced by template argument
6288 // deduction as a candidate.
6289 assert(Specialization && "Missing member function template specialization?");
6290 assert(isa<CXXMethodDecl>(Specialization) &&
6291 "Specialization is not a member function?");
6292 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl,
6293 ActingContext, ObjectType, ObjectClassification, Args,
6294 CandidateSet, SuppressUserConversions, PartialOverloading);
6297 /// \brief Add a C++ function template specialization as a candidate
6298 /// in the candidate set, using template argument deduction to produce
6299 /// an appropriate function template specialization.
6301 Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate,
6302 DeclAccessPair FoundDecl,
6303 TemplateArgumentListInfo *ExplicitTemplateArgs,
6304 ArrayRef<Expr *> Args,
6305 OverloadCandidateSet& CandidateSet,
6306 bool SuppressUserConversions,
6307 bool PartialOverloading) {
6308 if (!CandidateSet.isNewCandidate(FunctionTemplate))
6311 // C++ [over.match.funcs]p7:
6312 // In each case where a candidate is a function template, candidate
6313 // function template specializations are generated using template argument
6314 // deduction (14.8.3, 14.8.2). Those candidates are then handled as
6315 // candidate functions in the usual way.113) A given name can refer to one
6316 // or more function templates and also to a set of overloaded non-template
6317 // functions. In such a case, the candidate functions generated from each
6318 // function template are combined with the set of non-template candidate
6320 TemplateDeductionInfo Info(CandidateSet.getLocation());
6321 FunctionDecl *Specialization = nullptr;
6322 if (TemplateDeductionResult Result
6323 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, Args,
6324 Specialization, Info, PartialOverloading)) {
6325 OverloadCandidate &Candidate = CandidateSet.addCandidate();
6326 Candidate.FoundDecl = FoundDecl;
6327 Candidate.Function = FunctionTemplate->getTemplatedDecl();
6328 Candidate.Viable = false;
6329 Candidate.FailureKind = ovl_fail_bad_deduction;
6330 Candidate.IsSurrogate = false;
6331 Candidate.IgnoreObjectArgument = false;
6332 Candidate.ExplicitCallArguments = Args.size();
6333 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
6338 // Add the function template specialization produced by template argument
6339 // deduction as a candidate.
6340 assert(Specialization && "Missing function template specialization?");
6341 AddOverloadCandidate(Specialization, FoundDecl, Args, CandidateSet,
6342 SuppressUserConversions, PartialOverloading);
6345 /// Determine whether this is an allowable conversion from the result
6346 /// of an explicit conversion operator to the expected type, per C++
6347 /// [over.match.conv]p1 and [over.match.ref]p1.
6349 /// \param ConvType The return type of the conversion function.
6351 /// \param ToType The type we are converting to.
6353 /// \param AllowObjCPointerConversion Allow a conversion from one
6354 /// Objective-C pointer to another.
6356 /// \returns true if the conversion is allowable, false otherwise.
6357 static bool isAllowableExplicitConversion(Sema &S,
6358 QualType ConvType, QualType ToType,
6359 bool AllowObjCPointerConversion) {
6360 QualType ToNonRefType = ToType.getNonReferenceType();
6362 // Easy case: the types are the same.
6363 if (S.Context.hasSameUnqualifiedType(ConvType, ToNonRefType))
6366 // Allow qualification conversions.
6367 bool ObjCLifetimeConversion;
6368 if (S.IsQualificationConversion(ConvType, ToNonRefType, /*CStyle*/false,
6369 ObjCLifetimeConversion))
6372 // If we're not allowed to consider Objective-C pointer conversions,
6374 if (!AllowObjCPointerConversion)
6377 // Is this an Objective-C pointer conversion?
6378 bool IncompatibleObjC = false;
6379 QualType ConvertedType;
6380 return S.isObjCPointerConversion(ConvType, ToNonRefType, ConvertedType,
6384 /// AddConversionCandidate - Add a C++ conversion function as a
6385 /// candidate in the candidate set (C++ [over.match.conv],
6386 /// C++ [over.match.copy]). From is the expression we're converting from,
6387 /// and ToType is the type that we're eventually trying to convert to
6388 /// (which may or may not be the same type as the type that the
6389 /// conversion function produces).
6391 Sema::AddConversionCandidate(CXXConversionDecl *Conversion,
6392 DeclAccessPair FoundDecl,
6393 CXXRecordDecl *ActingContext,
6394 Expr *From, QualType ToType,
6395 OverloadCandidateSet& CandidateSet,
6396 bool AllowObjCConversionOnExplicit) {
6397 assert(!Conversion->getDescribedFunctionTemplate() &&
6398 "Conversion function templates use AddTemplateConversionCandidate");
6399 QualType ConvType = Conversion->getConversionType().getNonReferenceType();
6400 if (!CandidateSet.isNewCandidate(Conversion))
6403 // If the conversion function has an undeduced return type, trigger its
6405 if (getLangOpts().CPlusPlus14 && ConvType->isUndeducedType()) {
6406 if (DeduceReturnType(Conversion, From->getExprLoc()))
6408 ConvType = Conversion->getConversionType().getNonReferenceType();
6411 // Per C++ [over.match.conv]p1, [over.match.ref]p1, an explicit conversion
6412 // operator is only a candidate if its return type is the target type or
6413 // can be converted to the target type with a qualification conversion.
6414 if (Conversion->isExplicit() &&
6415 !isAllowableExplicitConversion(*this, ConvType, ToType,
6416 AllowObjCConversionOnExplicit))
6419 // Overload resolution is always an unevaluated context.
6420 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated);
6422 // Add this candidate
6423 OverloadCandidate &Candidate = CandidateSet.addCandidate(1);
6424 Candidate.FoundDecl = FoundDecl;
6425 Candidate.Function = Conversion;
6426 Candidate.IsSurrogate = false;
6427 Candidate.IgnoreObjectArgument = false;
6428 Candidate.FinalConversion.setAsIdentityConversion();
6429 Candidate.FinalConversion.setFromType(ConvType);
6430 Candidate.FinalConversion.setAllToTypes(ToType);
6431 Candidate.Viable = true;
6432 Candidate.ExplicitCallArguments = 1;
6434 // C++ [over.match.funcs]p4:
6435 // For conversion functions, the function is considered to be a member of
6436 // the class of the implicit implied object argument for the purpose of
6437 // defining the type of the implicit object parameter.
6439 // Determine the implicit conversion sequence for the implicit
6440 // object parameter.
6441 QualType ImplicitParamType = From->getType();
6442 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>())
6443 ImplicitParamType = FromPtrType->getPointeeType();
6444 CXXRecordDecl *ConversionContext
6445 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl());
6447 Candidate.Conversions[0] = TryObjectArgumentInitialization(
6448 *this, CandidateSet.getLocation(), From->getType(),
6449 From->Classify(Context), Conversion, ConversionContext);
6451 if (Candidate.Conversions[0].isBad()) {
6452 Candidate.Viable = false;
6453 Candidate.FailureKind = ovl_fail_bad_conversion;
6457 // We won't go through a user-defined type conversion function to convert a
6458 // derived to base as such conversions are given Conversion Rank. They only
6459 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user]
6461 = Context.getCanonicalType(From->getType().getUnqualifiedType());
6462 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType();
6463 if (FromCanon == ToCanon ||
6464 IsDerivedFrom(CandidateSet.getLocation(), FromCanon, ToCanon)) {
6465 Candidate.Viable = false;
6466 Candidate.FailureKind = ovl_fail_trivial_conversion;
6470 // To determine what the conversion from the result of calling the
6471 // conversion function to the type we're eventually trying to
6472 // convert to (ToType), we need to synthesize a call to the
6473 // conversion function and attempt copy initialization from it. This
6474 // makes sure that we get the right semantics with respect to
6475 // lvalues/rvalues and the type. Fortunately, we can allocate this
6476 // call on the stack and we don't need its arguments to be
6478 DeclRefExpr ConversionRef(Conversion, false, Conversion->getType(),
6479 VK_LValue, From->getLocStart());
6480 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack,
6481 Context.getPointerType(Conversion->getType()),
6482 CK_FunctionToPointerDecay,
6483 &ConversionRef, VK_RValue);
6485 QualType ConversionType = Conversion->getConversionType();
6486 if (!isCompleteType(From->getLocStart(), ConversionType)) {
6487 Candidate.Viable = false;
6488 Candidate.FailureKind = ovl_fail_bad_final_conversion;
6492 ExprValueKind VK = Expr::getValueKindForType(ConversionType);
6494 // Note that it is safe to allocate CallExpr on the stack here because
6495 // there are 0 arguments (i.e., nothing is allocated using ASTContext's
6497 QualType CallResultType = ConversionType.getNonLValueExprType(Context);
6498 CallExpr Call(Context, &ConversionFn, None, CallResultType, VK,
6499 From->getLocStart());
6500 ImplicitConversionSequence ICS =
6501 TryCopyInitialization(*this, &Call, ToType,
6502 /*SuppressUserConversions=*/true,
6503 /*InOverloadResolution=*/false,
6504 /*AllowObjCWritebackConversion=*/false);
6506 switch (ICS.getKind()) {
6507 case ImplicitConversionSequence::StandardConversion:
6508 Candidate.FinalConversion = ICS.Standard;
6510 // C++ [over.ics.user]p3:
6511 // If the user-defined conversion is specified by a specialization of a
6512 // conversion function template, the second standard conversion sequence
6513 // shall have exact match rank.
6514 if (Conversion->getPrimaryTemplate() &&
6515 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) {
6516 Candidate.Viable = false;
6517 Candidate.FailureKind = ovl_fail_final_conversion_not_exact;
6521 // C++0x [dcl.init.ref]p5:
6522 // In the second case, if the reference is an rvalue reference and
6523 // the second standard conversion sequence of the user-defined
6524 // conversion sequence includes an lvalue-to-rvalue conversion, the
6525 // program is ill-formed.
6526 if (ToType->isRValueReferenceType() &&
6527 ICS.Standard.First == ICK_Lvalue_To_Rvalue) {
6528 Candidate.Viable = false;
6529 Candidate.FailureKind = ovl_fail_bad_final_conversion;
6534 case ImplicitConversionSequence::BadConversion:
6535 Candidate.Viable = false;
6536 Candidate.FailureKind = ovl_fail_bad_final_conversion;
6541 "Can only end up with a standard conversion sequence or failure");
6544 if (EnableIfAttr *FailedAttr = CheckEnableIf(Conversion, None)) {
6545 Candidate.Viable = false;
6546 Candidate.FailureKind = ovl_fail_enable_if;
6547 Candidate.DeductionFailure.Data = FailedAttr;
6552 /// \brief Adds a conversion function template specialization
6553 /// candidate to the overload set, using template argument deduction
6554 /// to deduce the template arguments of the conversion function
6555 /// template from the type that we are converting to (C++
6556 /// [temp.deduct.conv]).
6558 Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate,
6559 DeclAccessPair FoundDecl,
6560 CXXRecordDecl *ActingDC,
6561 Expr *From, QualType ToType,
6562 OverloadCandidateSet &CandidateSet,
6563 bool AllowObjCConversionOnExplicit) {
6564 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) &&
6565 "Only conversion function templates permitted here");
6567 if (!CandidateSet.isNewCandidate(FunctionTemplate))
6570 TemplateDeductionInfo Info(CandidateSet.getLocation());
6571 CXXConversionDecl *Specialization = nullptr;
6572 if (TemplateDeductionResult Result
6573 = DeduceTemplateArguments(FunctionTemplate, ToType,
6574 Specialization, Info)) {
6575 OverloadCandidate &Candidate = CandidateSet.addCandidate();
6576 Candidate.FoundDecl = FoundDecl;
6577 Candidate.Function = FunctionTemplate->getTemplatedDecl();
6578 Candidate.Viable = false;
6579 Candidate.FailureKind = ovl_fail_bad_deduction;
6580 Candidate.IsSurrogate = false;
6581 Candidate.IgnoreObjectArgument = false;
6582 Candidate.ExplicitCallArguments = 1;
6583 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
6588 // Add the conversion function template specialization produced by
6589 // template argument deduction as a candidate.
6590 assert(Specialization && "Missing function template specialization?");
6591 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType,
6592 CandidateSet, AllowObjCConversionOnExplicit);
6595 /// AddSurrogateCandidate - Adds a "surrogate" candidate function that
6596 /// converts the given @c Object to a function pointer via the
6597 /// conversion function @c Conversion, and then attempts to call it
6598 /// with the given arguments (C++ [over.call.object]p2-4). Proto is
6599 /// the type of function that we'll eventually be calling.
6600 void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion,
6601 DeclAccessPair FoundDecl,
6602 CXXRecordDecl *ActingContext,
6603 const FunctionProtoType *Proto,
6605 ArrayRef<Expr *> Args,
6606 OverloadCandidateSet& CandidateSet) {
6607 if (!CandidateSet.isNewCandidate(Conversion))
6610 // Overload resolution is always an unevaluated context.
6611 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated);
6613 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1);
6614 Candidate.FoundDecl = FoundDecl;
6615 Candidate.Function = nullptr;
6616 Candidate.Surrogate = Conversion;
6617 Candidate.Viable = true;
6618 Candidate.IsSurrogate = true;
6619 Candidate.IgnoreObjectArgument = false;
6620 Candidate.ExplicitCallArguments = Args.size();
6622 // Determine the implicit conversion sequence for the implicit
6623 // object parameter.
6624 ImplicitConversionSequence ObjectInit = TryObjectArgumentInitialization(
6625 *this, CandidateSet.getLocation(), Object->getType(),
6626 Object->Classify(Context), Conversion, ActingContext);
6627 if (ObjectInit.isBad()) {
6628 Candidate.Viable = false;
6629 Candidate.FailureKind = ovl_fail_bad_conversion;
6630 Candidate.Conversions[0] = ObjectInit;
6634 // The first conversion is actually a user-defined conversion whose
6635 // first conversion is ObjectInit's standard conversion (which is
6636 // effectively a reference binding). Record it as such.
6637 Candidate.Conversions[0].setUserDefined();
6638 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard;
6639 Candidate.Conversions[0].UserDefined.EllipsisConversion = false;
6640 Candidate.Conversions[0].UserDefined.HadMultipleCandidates = false;
6641 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion;
6642 Candidate.Conversions[0].UserDefined.FoundConversionFunction = FoundDecl;
6643 Candidate.Conversions[0].UserDefined.After
6644 = Candidate.Conversions[0].UserDefined.Before;
6645 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion();
6648 unsigned NumParams = Proto->getNumParams();
6650 // (C++ 13.3.2p2): A candidate function having fewer than m
6651 // parameters is viable only if it has an ellipsis in its parameter
6653 if (Args.size() > NumParams && !Proto->isVariadic()) {
6654 Candidate.Viable = false;
6655 Candidate.FailureKind = ovl_fail_too_many_arguments;
6659 // Function types don't have any default arguments, so just check if
6660 // we have enough arguments.
6661 if (Args.size() < NumParams) {
6662 // Not enough arguments.
6663 Candidate.Viable = false;
6664 Candidate.FailureKind = ovl_fail_too_few_arguments;
6668 // Determine the implicit conversion sequences for each of the
6670 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
6671 if (ArgIdx < NumParams) {
6672 // (C++ 13.3.2p3): for F to be a viable function, there shall
6673 // exist for each argument an implicit conversion sequence
6674 // (13.3.3.1) that converts that argument to the corresponding
6676 QualType ParamType = Proto->getParamType(ArgIdx);
6677 Candidate.Conversions[ArgIdx + 1]
6678 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
6679 /*SuppressUserConversions=*/false,
6680 /*InOverloadResolution=*/false,
6681 /*AllowObjCWritebackConversion=*/
6682 getLangOpts().ObjCAutoRefCount);
6683 if (Candidate.Conversions[ArgIdx + 1].isBad()) {
6684 Candidate.Viable = false;
6685 Candidate.FailureKind = ovl_fail_bad_conversion;
6689 // (C++ 13.3.2p2): For the purposes of overload resolution, any
6690 // argument for which there is no corresponding parameter is
6691 // considered to ""match the ellipsis" (C+ 13.3.3.1.3).
6692 Candidate.Conversions[ArgIdx + 1].setEllipsis();
6696 if (EnableIfAttr *FailedAttr = CheckEnableIf(Conversion, None)) {
6697 Candidate.Viable = false;
6698 Candidate.FailureKind = ovl_fail_enable_if;
6699 Candidate.DeductionFailure.Data = FailedAttr;
6704 /// \brief Add overload candidates for overloaded operators that are
6705 /// member functions.
6707 /// Add the overloaded operator candidates that are member functions
6708 /// for the operator Op that was used in an operator expression such
6709 /// as "x Op y". , Args/NumArgs provides the operator arguments, and
6710 /// CandidateSet will store the added overload candidates. (C++
6711 /// [over.match.oper]).
6712 void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op,
6713 SourceLocation OpLoc,
6714 ArrayRef<Expr *> Args,
6715 OverloadCandidateSet& CandidateSet,
6716 SourceRange OpRange) {
6717 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
6719 // C++ [over.match.oper]p3:
6720 // For a unary operator @ with an operand of a type whose
6721 // cv-unqualified version is T1, and for a binary operator @ with
6722 // a left operand of a type whose cv-unqualified version is T1 and
6723 // a right operand of a type whose cv-unqualified version is T2,
6724 // three sets of candidate functions, designated member
6725 // candidates, non-member candidates and built-in candidates, are
6726 // constructed as follows:
6727 QualType T1 = Args[0]->getType();
6729 // -- If T1 is a complete class type or a class currently being
6730 // defined, the set of member candidates is the result of the
6731 // qualified lookup of T1::operator@ (13.3.1.1.1); otherwise,
6732 // the set of member candidates is empty.
6733 if (const RecordType *T1Rec = T1->getAs<RecordType>()) {
6734 // Complete the type if it can be completed.
6735 if (!isCompleteType(OpLoc, T1) && !T1Rec->isBeingDefined())
6737 // If the type is neither complete nor being defined, bail out now.
6738 if (!T1Rec->getDecl()->getDefinition())
6741 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName);
6742 LookupQualifiedName(Operators, T1Rec->getDecl());
6743 Operators.suppressDiagnostics();
6745 for (LookupResult::iterator Oper = Operators.begin(),
6746 OperEnd = Operators.end();
6749 AddMethodCandidate(Oper.getPair(), Args[0]->getType(),
6750 Args[0]->Classify(Context),
6753 /* SuppressUserConversions = */ false);
6757 /// AddBuiltinCandidate - Add a candidate for a built-in
6758 /// operator. ResultTy and ParamTys are the result and parameter types
6759 /// of the built-in candidate, respectively. Args and NumArgs are the
6760 /// arguments being passed to the candidate. IsAssignmentOperator
6761 /// should be true when this built-in candidate is an assignment
6762 /// operator. NumContextualBoolArguments is the number of arguments
6763 /// (at the beginning of the argument list) that will be contextually
6764 /// converted to bool.
6765 void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys,
6766 ArrayRef<Expr *> Args,
6767 OverloadCandidateSet& CandidateSet,
6768 bool IsAssignmentOperator,
6769 unsigned NumContextualBoolArguments) {
6770 // Overload resolution is always an unevaluated context.
6771 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated);
6773 // Add this candidate
6774 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size());
6775 Candidate.FoundDecl = DeclAccessPair::make(nullptr, AS_none);
6776 Candidate.Function = nullptr;
6777 Candidate.IsSurrogate = false;
6778 Candidate.IgnoreObjectArgument = false;
6779 Candidate.BuiltinTypes.ResultTy = ResultTy;
6780 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx)
6781 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx];
6783 // Determine the implicit conversion sequences for each of the
6785 Candidate.Viable = true;
6786 Candidate.ExplicitCallArguments = Args.size();
6787 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
6788 // C++ [over.match.oper]p4:
6789 // For the built-in assignment operators, conversions of the
6790 // left operand are restricted as follows:
6791 // -- no temporaries are introduced to hold the left operand, and
6792 // -- no user-defined conversions are applied to the left
6793 // operand to achieve a type match with the left-most
6794 // parameter of a built-in candidate.
6796 // We block these conversions by turning off user-defined
6797 // conversions, since that is the only way that initialization of
6798 // a reference to a non-class type can occur from something that
6799 // is not of the same type.
6800 if (ArgIdx < NumContextualBoolArguments) {
6801 assert(ParamTys[ArgIdx] == Context.BoolTy &&
6802 "Contextual conversion to bool requires bool type");
6803 Candidate.Conversions[ArgIdx]
6804 = TryContextuallyConvertToBool(*this, Args[ArgIdx]);
6806 Candidate.Conversions[ArgIdx]
6807 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx],
6808 ArgIdx == 0 && IsAssignmentOperator,
6809 /*InOverloadResolution=*/false,
6810 /*AllowObjCWritebackConversion=*/
6811 getLangOpts().ObjCAutoRefCount);
6813 if (Candidate.Conversions[ArgIdx].isBad()) {
6814 Candidate.Viable = false;
6815 Candidate.FailureKind = ovl_fail_bad_conversion;
6823 /// BuiltinCandidateTypeSet - A set of types that will be used for the
6824 /// candidate operator functions for built-in operators (C++
6825 /// [over.built]). The types are separated into pointer types and
6826 /// enumeration types.
6827 class BuiltinCandidateTypeSet {
6828 /// TypeSet - A set of types.
6829 typedef llvm::SetVector<QualType, SmallVector<QualType, 8>,
6830 llvm::SmallPtrSet<QualType, 8>> TypeSet;
6832 /// PointerTypes - The set of pointer types that will be used in the
6833 /// built-in candidates.
6834 TypeSet PointerTypes;
6836 /// MemberPointerTypes - The set of member pointer types that will be
6837 /// used in the built-in candidates.
6838 TypeSet MemberPointerTypes;
6840 /// EnumerationTypes - The set of enumeration types that will be
6841 /// used in the built-in candidates.
6842 TypeSet EnumerationTypes;
6844 /// \brief The set of vector types that will be used in the built-in
6846 TypeSet VectorTypes;
6848 /// \brief A flag indicating non-record types are viable candidates
6849 bool HasNonRecordTypes;
6851 /// \brief A flag indicating whether either arithmetic or enumeration types
6852 /// were present in the candidate set.
6853 bool HasArithmeticOrEnumeralTypes;
6855 /// \brief A flag indicating whether the nullptr type was present in the
6857 bool HasNullPtrType;
6859 /// Sema - The semantic analysis instance where we are building the
6860 /// candidate type set.
6863 /// Context - The AST context in which we will build the type sets.
6864 ASTContext &Context;
6866 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
6867 const Qualifiers &VisibleQuals);
6868 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty);
6871 /// iterator - Iterates through the types that are part of the set.
6872 typedef TypeSet::iterator iterator;
6874 BuiltinCandidateTypeSet(Sema &SemaRef)
6875 : HasNonRecordTypes(false),
6876 HasArithmeticOrEnumeralTypes(false),
6877 HasNullPtrType(false),
6879 Context(SemaRef.Context) { }
6881 void AddTypesConvertedFrom(QualType Ty,
6883 bool AllowUserConversions,
6884 bool AllowExplicitConversions,
6885 const Qualifiers &VisibleTypeConversionsQuals);
6887 /// pointer_begin - First pointer type found;
6888 iterator pointer_begin() { return PointerTypes.begin(); }
6890 /// pointer_end - Past the last pointer type found;
6891 iterator pointer_end() { return PointerTypes.end(); }
6893 /// member_pointer_begin - First member pointer type found;
6894 iterator member_pointer_begin() { return MemberPointerTypes.begin(); }
6896 /// member_pointer_end - Past the last member pointer type found;
6897 iterator member_pointer_end() { return MemberPointerTypes.end(); }
6899 /// enumeration_begin - First enumeration type found;
6900 iterator enumeration_begin() { return EnumerationTypes.begin(); }
6902 /// enumeration_end - Past the last enumeration type found;
6903 iterator enumeration_end() { return EnumerationTypes.end(); }
6905 iterator vector_begin() { return VectorTypes.begin(); }
6906 iterator vector_end() { return VectorTypes.end(); }
6908 bool hasNonRecordTypes() { return HasNonRecordTypes; }
6909 bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; }
6910 bool hasNullPtrType() const { return HasNullPtrType; }
6913 } // end anonymous namespace
6915 /// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to
6916 /// the set of pointer types along with any more-qualified variants of
6917 /// that type. For example, if @p Ty is "int const *", this routine
6918 /// will add "int const *", "int const volatile *", "int const
6919 /// restrict *", and "int const volatile restrict *" to the set of
6920 /// pointer types. Returns true if the add of @p Ty itself succeeded,
6921 /// false otherwise.
6923 /// FIXME: what to do about extended qualifiers?
6925 BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
6926 const Qualifiers &VisibleQuals) {
6928 // Insert this type.
6929 if (!PointerTypes.insert(Ty))
6933 const PointerType *PointerTy = Ty->getAs<PointerType>();
6934 bool buildObjCPtr = false;
6936 const ObjCObjectPointerType *PTy = Ty->castAs<ObjCObjectPointerType>();
6937 PointeeTy = PTy->getPointeeType();
6938 buildObjCPtr = true;
6940 PointeeTy = PointerTy->getPointeeType();
6943 // Don't add qualified variants of arrays. For one, they're not allowed
6944 // (the qualifier would sink to the element type), and for another, the
6945 // only overload situation where it matters is subscript or pointer +- int,
6946 // and those shouldn't have qualifier variants anyway.
6947 if (PointeeTy->isArrayType())
6950 unsigned BaseCVR = PointeeTy.getCVRQualifiers();
6951 bool hasVolatile = VisibleQuals.hasVolatile();
6952 bool hasRestrict = VisibleQuals.hasRestrict();
6954 // Iterate through all strict supersets of BaseCVR.
6955 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) {
6956 if ((CVR | BaseCVR) != CVR) continue;
6957 // Skip over volatile if no volatile found anywhere in the types.
6958 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue;
6960 // Skip over restrict if no restrict found anywhere in the types, or if
6961 // the type cannot be restrict-qualified.
6962 if ((CVR & Qualifiers::Restrict) &&
6964 (!(PointeeTy->isAnyPointerType() || PointeeTy->isReferenceType()))))
6967 // Build qualified pointee type.
6968 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR);
6970 // Build qualified pointer type.
6971 QualType QPointerTy;
6973 QPointerTy = Context.getPointerType(QPointeeTy);
6975 QPointerTy = Context.getObjCObjectPointerType(QPointeeTy);
6977 // Insert qualified pointer type.
6978 PointerTypes.insert(QPointerTy);
6984 /// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty
6985 /// to the set of pointer types along with any more-qualified variants of
6986 /// that type. For example, if @p Ty is "int const *", this routine
6987 /// will add "int const *", "int const volatile *", "int const
6988 /// restrict *", and "int const volatile restrict *" to the set of
6989 /// pointer types. Returns true if the add of @p Ty itself succeeded,
6990 /// false otherwise.
6992 /// FIXME: what to do about extended qualifiers?
6994 BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants(
6996 // Insert this type.
6997 if (!MemberPointerTypes.insert(Ty))
7000 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>();
7001 assert(PointerTy && "type was not a member pointer type!");
7003 QualType PointeeTy = PointerTy->getPointeeType();
7004 // Don't add qualified variants of arrays. For one, they're not allowed
7005 // (the qualifier would sink to the element type), and for another, the
7006 // only overload situation where it matters is subscript or pointer +- int,
7007 // and those shouldn't have qualifier variants anyway.
7008 if (PointeeTy->isArrayType())
7010 const Type *ClassTy = PointerTy->getClass();
7012 // Iterate through all strict supersets of the pointee type's CVR
7014 unsigned BaseCVR = PointeeTy.getCVRQualifiers();
7015 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) {
7016 if ((CVR | BaseCVR) != CVR) continue;
7018 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR);
7019 MemberPointerTypes.insert(
7020 Context.getMemberPointerType(QPointeeTy, ClassTy));
7026 /// AddTypesConvertedFrom - Add each of the types to which the type @p
7027 /// Ty can be implicit converted to the given set of @p Types. We're
7028 /// primarily interested in pointer types and enumeration types. We also
7029 /// take member pointer types, for the conditional operator.
7030 /// AllowUserConversions is true if we should look at the conversion
7031 /// functions of a class type, and AllowExplicitConversions if we
7032 /// should also include the explicit conversion functions of a class
7035 BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty,
7037 bool AllowUserConversions,
7038 bool AllowExplicitConversions,
7039 const Qualifiers &VisibleQuals) {
7040 // Only deal with canonical types.
7041 Ty = Context.getCanonicalType(Ty);
7043 // Look through reference types; they aren't part of the type of an
7044 // expression for the purposes of conversions.
7045 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>())
7046 Ty = RefTy->getPointeeType();
7048 // If we're dealing with an array type, decay to the pointer.
7049 if (Ty->isArrayType())
7050 Ty = SemaRef.Context.getArrayDecayedType(Ty);
7052 // Otherwise, we don't care about qualifiers on the type.
7053 Ty = Ty.getLocalUnqualifiedType();
7055 // Flag if we ever add a non-record type.
7056 const RecordType *TyRec = Ty->getAs<RecordType>();
7057 HasNonRecordTypes = HasNonRecordTypes || !TyRec;
7059 // Flag if we encounter an arithmetic type.
7060 HasArithmeticOrEnumeralTypes =
7061 HasArithmeticOrEnumeralTypes || Ty->isArithmeticType();
7063 if (Ty->isObjCIdType() || Ty->isObjCClassType())
7064 PointerTypes.insert(Ty);
7065 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) {
7066 // Insert our type, and its more-qualified variants, into the set
7068 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals))
7070 } else if (Ty->isMemberPointerType()) {
7071 // Member pointers are far easier, since the pointee can't be converted.
7072 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty))
7074 } else if (Ty->isEnumeralType()) {
7075 HasArithmeticOrEnumeralTypes = true;
7076 EnumerationTypes.insert(Ty);
7077 } else if (Ty->isVectorType()) {
7078 // We treat vector types as arithmetic types in many contexts as an
7080 HasArithmeticOrEnumeralTypes = true;
7081 VectorTypes.insert(Ty);
7082 } else if (Ty->isNullPtrType()) {
7083 HasNullPtrType = true;
7084 } else if (AllowUserConversions && TyRec) {
7085 // No conversion functions in incomplete types.
7086 if (!SemaRef.isCompleteType(Loc, Ty))
7089 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl());
7090 for (NamedDecl *D : ClassDecl->getVisibleConversionFunctions()) {
7091 if (isa<UsingShadowDecl>(D))
7092 D = cast<UsingShadowDecl>(D)->getTargetDecl();
7094 // Skip conversion function templates; they don't tell us anything
7095 // about which builtin types we can convert to.
7096 if (isa<FunctionTemplateDecl>(D))
7099 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D);
7100 if (AllowExplicitConversions || !Conv->isExplicit()) {
7101 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false,
7108 /// \brief Helper function for AddBuiltinOperatorCandidates() that adds
7109 /// the volatile- and non-volatile-qualified assignment operators for the
7110 /// given type to the candidate set.
7111 static void AddBuiltinAssignmentOperatorCandidates(Sema &S,
7113 ArrayRef<Expr *> Args,
7114 OverloadCandidateSet &CandidateSet) {
7115 QualType ParamTypes[2];
7117 // T& operator=(T&, T)
7118 ParamTypes[0] = S.Context.getLValueReferenceType(T);
7120 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7121 /*IsAssignmentOperator=*/true);
7123 if (!S.Context.getCanonicalType(T).isVolatileQualified()) {
7124 // volatile T& operator=(volatile T&, T)
7126 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T));
7128 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7129 /*IsAssignmentOperator=*/true);
7133 /// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers,
7134 /// if any, found in visible type conversion functions found in ArgExpr's type.
7135 static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) {
7137 const RecordType *TyRec;
7138 if (const MemberPointerType *RHSMPType =
7139 ArgExpr->getType()->getAs<MemberPointerType>())
7140 TyRec = RHSMPType->getClass()->getAs<RecordType>();
7142 TyRec = ArgExpr->getType()->getAs<RecordType>();
7144 // Just to be safe, assume the worst case.
7145 VRQuals.addVolatile();
7146 VRQuals.addRestrict();
7150 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl());
7151 if (!ClassDecl->hasDefinition())
7154 for (NamedDecl *D : ClassDecl->getVisibleConversionFunctions()) {
7155 if (isa<UsingShadowDecl>(D))
7156 D = cast<UsingShadowDecl>(D)->getTargetDecl();
7157 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) {
7158 QualType CanTy = Context.getCanonicalType(Conv->getConversionType());
7159 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>())
7160 CanTy = ResTypeRef->getPointeeType();
7161 // Need to go down the pointer/mempointer chain and add qualifiers
7165 if (CanTy.isRestrictQualified())
7166 VRQuals.addRestrict();
7167 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>())
7168 CanTy = ResTypePtr->getPointeeType();
7169 else if (const MemberPointerType *ResTypeMPtr =
7170 CanTy->getAs<MemberPointerType>())
7171 CanTy = ResTypeMPtr->getPointeeType();
7174 if (CanTy.isVolatileQualified())
7175 VRQuals.addVolatile();
7176 if (VRQuals.hasRestrict() && VRQuals.hasVolatile())
7186 /// \brief Helper class to manage the addition of builtin operator overload
7187 /// candidates. It provides shared state and utility methods used throughout
7188 /// the process, as well as a helper method to add each group of builtin
7189 /// operator overloads from the standard to a candidate set.
7190 class BuiltinOperatorOverloadBuilder {
7191 // Common instance state available to all overload candidate addition methods.
7193 ArrayRef<Expr *> Args;
7194 Qualifiers VisibleTypeConversionsQuals;
7195 bool HasArithmeticOrEnumeralCandidateType;
7196 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes;
7197 OverloadCandidateSet &CandidateSet;
7199 // Define some constants used to index and iterate over the arithemetic types
7200 // provided via the getArithmeticType() method below.
7201 // The "promoted arithmetic types" are the arithmetic
7202 // types are that preserved by promotion (C++ [over.built]p2).
7203 static const unsigned FirstIntegralType = 4;
7204 static const unsigned LastIntegralType = 21;
7205 static const unsigned FirstPromotedIntegralType = 4,
7206 LastPromotedIntegralType = 12;
7207 static const unsigned FirstPromotedArithmeticType = 0,
7208 LastPromotedArithmeticType = 12;
7209 static const unsigned NumArithmeticTypes = 21;
7211 /// \brief Get the canonical type for a given arithmetic type index.
7212 CanQualType getArithmeticType(unsigned index) {
7213 assert(index < NumArithmeticTypes);
7214 static CanQualType ASTContext::* const
7215 ArithmeticTypes[NumArithmeticTypes] = {
7216 // Start of promoted types.
7217 &ASTContext::FloatTy,
7218 &ASTContext::DoubleTy,
7219 &ASTContext::LongDoubleTy,
7220 &ASTContext::Float128Ty,
7222 // Start of integral types.
7224 &ASTContext::LongTy,
7225 &ASTContext::LongLongTy,
7226 &ASTContext::Int128Ty,
7227 &ASTContext::UnsignedIntTy,
7228 &ASTContext::UnsignedLongTy,
7229 &ASTContext::UnsignedLongLongTy,
7230 &ASTContext::UnsignedInt128Ty,
7231 // End of promoted types.
7233 &ASTContext::BoolTy,
7234 &ASTContext::CharTy,
7235 &ASTContext::WCharTy,
7236 &ASTContext::Char16Ty,
7237 &ASTContext::Char32Ty,
7238 &ASTContext::SignedCharTy,
7239 &ASTContext::ShortTy,
7240 &ASTContext::UnsignedCharTy,
7241 &ASTContext::UnsignedShortTy,
7242 // End of integral types.
7243 // FIXME: What about complex? What about half?
7245 return S.Context.*ArithmeticTypes[index];
7248 /// \brief Gets the canonical type resulting from the usual arithemetic
7249 /// converions for the given arithmetic types.
7250 CanQualType getUsualArithmeticConversions(unsigned L, unsigned R) {
7251 // Accelerator table for performing the usual arithmetic conversions.
7252 // The rules are basically:
7253 // - if either is floating-point, use the wider floating-point
7254 // - if same signedness, use the higher rank
7255 // - if same size, use unsigned of the higher rank
7256 // - use the larger type
7257 // These rules, together with the axiom that higher ranks are
7258 // never smaller, are sufficient to precompute all of these results
7259 // *except* when dealing with signed types of higher rank.
7260 // (we could precompute SLL x UI for all known platforms, but it's
7261 // better not to make any assumptions).
7262 // We assume that int128 has a higher rank than long long on all platforms.
7263 enum PromotedType : int8_t {
7265 Flt, Dbl, LDbl, SI, SL, SLL, S128, UI, UL, ULL, U128
7267 static const PromotedType ConversionsTable[LastPromotedArithmeticType]
7268 [LastPromotedArithmeticType] = {
7269 /* Flt*/ { Flt, Dbl, LDbl, Flt, Flt, Flt, Flt, Flt, Flt, Flt, Flt },
7270 /* Dbl*/ { Dbl, Dbl, LDbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl },
7271 /*LDbl*/ { LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl },
7272 /* SI*/ { Flt, Dbl, LDbl, SI, SL, SLL, S128, UI, UL, ULL, U128 },
7273 /* SL*/ { Flt, Dbl, LDbl, SL, SL, SLL, S128, Dep, UL, ULL, U128 },
7274 /* SLL*/ { Flt, Dbl, LDbl, SLL, SLL, SLL, S128, Dep, Dep, ULL, U128 },
7275 /*S128*/ { Flt, Dbl, LDbl, S128, S128, S128, S128, S128, S128, S128, U128 },
7276 /* UI*/ { Flt, Dbl, LDbl, UI, Dep, Dep, S128, UI, UL, ULL, U128 },
7277 /* UL*/ { Flt, Dbl, LDbl, UL, UL, Dep, S128, UL, UL, ULL, U128 },
7278 /* ULL*/ { Flt, Dbl, LDbl, ULL, ULL, ULL, S128, ULL, ULL, ULL, U128 },
7279 /*U128*/ { Flt, Dbl, LDbl, U128, U128, U128, U128, U128, U128, U128, U128 },
7282 assert(L < LastPromotedArithmeticType);
7283 assert(R < LastPromotedArithmeticType);
7284 int Idx = ConversionsTable[L][R];
7286 // Fast path: the table gives us a concrete answer.
7287 if (Idx != Dep) return getArithmeticType(Idx);
7289 // Slow path: we need to compare widths.
7290 // An invariant is that the signed type has higher rank.
7291 CanQualType LT = getArithmeticType(L),
7292 RT = getArithmeticType(R);
7293 unsigned LW = S.Context.getIntWidth(LT),
7294 RW = S.Context.getIntWidth(RT);
7296 // If they're different widths, use the signed type.
7297 if (LW > RW) return LT;
7298 else if (LW < RW) return RT;
7300 // Otherwise, use the unsigned type of the signed type's rank.
7301 if (L == SL || R == SL) return S.Context.UnsignedLongTy;
7302 assert(L == SLL || R == SLL);
7303 return S.Context.UnsignedLongLongTy;
7306 /// \brief Helper method to factor out the common pattern of adding overloads
7307 /// for '++' and '--' builtin operators.
7308 void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy,
7311 QualType ParamTypes[2] = {
7312 S.Context.getLValueReferenceType(CandidateTy),
7316 // Non-volatile version.
7317 if (Args.size() == 1)
7318 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
7320 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet);
7322 // Use a heuristic to reduce number of builtin candidates in the set:
7323 // add volatile version only if there are conversions to a volatile type.
7326 S.Context.getLValueReferenceType(
7327 S.Context.getVolatileType(CandidateTy));
7328 if (Args.size() == 1)
7329 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
7331 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet);
7334 // Add restrict version only if there are conversions to a restrict type
7335 // and our candidate type is a non-restrict-qualified pointer.
7336 if (HasRestrict && CandidateTy->isAnyPointerType() &&
7337 !CandidateTy.isRestrictQualified()) {
7339 = S.Context.getLValueReferenceType(
7340 S.Context.getCVRQualifiedType(CandidateTy, Qualifiers::Restrict));
7341 if (Args.size() == 1)
7342 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
7344 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet);
7348 = S.Context.getLValueReferenceType(
7349 S.Context.getCVRQualifiedType(CandidateTy,
7350 (Qualifiers::Volatile |
7351 Qualifiers::Restrict)));
7352 if (Args.size() == 1)
7353 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
7355 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet);
7362 BuiltinOperatorOverloadBuilder(
7363 Sema &S, ArrayRef<Expr *> Args,
7364 Qualifiers VisibleTypeConversionsQuals,
7365 bool HasArithmeticOrEnumeralCandidateType,
7366 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes,
7367 OverloadCandidateSet &CandidateSet)
7369 VisibleTypeConversionsQuals(VisibleTypeConversionsQuals),
7370 HasArithmeticOrEnumeralCandidateType(
7371 HasArithmeticOrEnumeralCandidateType),
7372 CandidateTypes(CandidateTypes),
7373 CandidateSet(CandidateSet) {
7374 // Validate some of our static helper constants in debug builds.
7375 assert(getArithmeticType(FirstPromotedIntegralType) == S.Context.IntTy &&
7376 "Invalid first promoted integral type");
7377 assert(getArithmeticType(LastPromotedIntegralType - 1)
7378 == S.Context.UnsignedInt128Ty &&
7379 "Invalid last promoted integral type");
7380 assert(getArithmeticType(FirstPromotedArithmeticType)
7381 == S.Context.FloatTy &&
7382 "Invalid first promoted arithmetic type");
7383 assert(getArithmeticType(LastPromotedArithmeticType - 1)
7384 == S.Context.UnsignedInt128Ty &&
7385 "Invalid last promoted arithmetic type");
7388 // C++ [over.built]p3:
7390 // For every pair (T, VQ), where T is an arithmetic type, and VQ
7391 // is either volatile or empty, there exist candidate operator
7392 // functions of the form
7394 // VQ T& operator++(VQ T&);
7395 // T operator++(VQ T&, int);
7397 // C++ [over.built]p4:
7399 // For every pair (T, VQ), where T is an arithmetic type other
7400 // than bool, and VQ is either volatile or empty, there exist
7401 // candidate operator functions of the form
7403 // VQ T& operator--(VQ T&);
7404 // T operator--(VQ T&, int);
7405 void addPlusPlusMinusMinusArithmeticOverloads(OverloadedOperatorKind Op) {
7406 if (!HasArithmeticOrEnumeralCandidateType)
7409 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1);
7410 Arith < NumArithmeticTypes; ++Arith) {
7411 addPlusPlusMinusMinusStyleOverloads(
7412 getArithmeticType(Arith),
7413 VisibleTypeConversionsQuals.hasVolatile(),
7414 VisibleTypeConversionsQuals.hasRestrict());
7418 // C++ [over.built]p5:
7420 // For every pair (T, VQ), where T is a cv-qualified or
7421 // cv-unqualified object type, and VQ is either volatile or
7422 // empty, there exist candidate operator functions of the form
7424 // T*VQ& operator++(T*VQ&);
7425 // T*VQ& operator--(T*VQ&);
7426 // T* operator++(T*VQ&, int);
7427 // T* operator--(T*VQ&, int);
7428 void addPlusPlusMinusMinusPointerOverloads() {
7429 for (BuiltinCandidateTypeSet::iterator
7430 Ptr = CandidateTypes[0].pointer_begin(),
7431 PtrEnd = CandidateTypes[0].pointer_end();
7432 Ptr != PtrEnd; ++Ptr) {
7433 // Skip pointer types that aren't pointers to object types.
7434 if (!(*Ptr)->getPointeeType()->isObjectType())
7437 addPlusPlusMinusMinusStyleOverloads(*Ptr,
7438 (!(*Ptr).isVolatileQualified() &&
7439 VisibleTypeConversionsQuals.hasVolatile()),
7440 (!(*Ptr).isRestrictQualified() &&
7441 VisibleTypeConversionsQuals.hasRestrict()));
7445 // C++ [over.built]p6:
7446 // For every cv-qualified or cv-unqualified object type T, there
7447 // exist candidate operator functions of the form
7449 // T& operator*(T*);
7451 // C++ [over.built]p7:
7452 // For every function type T that does not have cv-qualifiers or a
7453 // ref-qualifier, there exist candidate operator functions of the form
7454 // T& operator*(T*);
7455 void addUnaryStarPointerOverloads() {
7456 for (BuiltinCandidateTypeSet::iterator
7457 Ptr = CandidateTypes[0].pointer_begin(),
7458 PtrEnd = CandidateTypes[0].pointer_end();
7459 Ptr != PtrEnd; ++Ptr) {
7460 QualType ParamTy = *Ptr;
7461 QualType PointeeTy = ParamTy->getPointeeType();
7462 if (!PointeeTy->isObjectType() && !PointeeTy->isFunctionType())
7465 if (const FunctionProtoType *Proto =PointeeTy->getAs<FunctionProtoType>())
7466 if (Proto->getTypeQuals() || Proto->getRefQualifier())
7469 S.AddBuiltinCandidate(S.Context.getLValueReferenceType(PointeeTy),
7470 &ParamTy, Args, CandidateSet);
7474 // C++ [over.built]p9:
7475 // For every promoted arithmetic type T, there exist candidate
7476 // operator functions of the form
7480 void addUnaryPlusOrMinusArithmeticOverloads() {
7481 if (!HasArithmeticOrEnumeralCandidateType)
7484 for (unsigned Arith = FirstPromotedArithmeticType;
7485 Arith < LastPromotedArithmeticType; ++Arith) {
7486 QualType ArithTy = getArithmeticType(Arith);
7487 S.AddBuiltinCandidate(ArithTy, &ArithTy, Args, CandidateSet);
7490 // Extension: We also add these operators for vector types.
7491 for (BuiltinCandidateTypeSet::iterator
7492 Vec = CandidateTypes[0].vector_begin(),
7493 VecEnd = CandidateTypes[0].vector_end();
7494 Vec != VecEnd; ++Vec) {
7495 QualType VecTy = *Vec;
7496 S.AddBuiltinCandidate(VecTy, &VecTy, Args, CandidateSet);
7500 // C++ [over.built]p8:
7501 // For every type T, there exist candidate operator functions of
7504 // T* operator+(T*);
7505 void addUnaryPlusPointerOverloads() {
7506 for (BuiltinCandidateTypeSet::iterator
7507 Ptr = CandidateTypes[0].pointer_begin(),
7508 PtrEnd = CandidateTypes[0].pointer_end();
7509 Ptr != PtrEnd; ++Ptr) {
7510 QualType ParamTy = *Ptr;
7511 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, CandidateSet);
7515 // C++ [over.built]p10:
7516 // For every promoted integral type T, there exist candidate
7517 // operator functions of the form
7520 void addUnaryTildePromotedIntegralOverloads() {
7521 if (!HasArithmeticOrEnumeralCandidateType)
7524 for (unsigned Int = FirstPromotedIntegralType;
7525 Int < LastPromotedIntegralType; ++Int) {
7526 QualType IntTy = getArithmeticType(Int);
7527 S.AddBuiltinCandidate(IntTy, &IntTy, Args, CandidateSet);
7530 // Extension: We also add this operator for vector types.
7531 for (BuiltinCandidateTypeSet::iterator
7532 Vec = CandidateTypes[0].vector_begin(),
7533 VecEnd = CandidateTypes[0].vector_end();
7534 Vec != VecEnd; ++Vec) {
7535 QualType VecTy = *Vec;
7536 S.AddBuiltinCandidate(VecTy, &VecTy, Args, CandidateSet);
7540 // C++ [over.match.oper]p16:
7541 // For every pointer to member type T, there exist candidate operator
7542 // functions of the form
7544 // bool operator==(T,T);
7545 // bool operator!=(T,T);
7546 void addEqualEqualOrNotEqualMemberPointerOverloads() {
7547 /// Set of (canonical) types that we've already handled.
7548 llvm::SmallPtrSet<QualType, 8> AddedTypes;
7550 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7551 for (BuiltinCandidateTypeSet::iterator
7552 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(),
7553 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end();
7554 MemPtr != MemPtrEnd;
7556 // Don't add the same builtin candidate twice.
7557 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr)).second)
7560 QualType ParamTypes[2] = { *MemPtr, *MemPtr };
7561 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet);
7566 // C++ [over.built]p15:
7568 // For every T, where T is an enumeration type, a pointer type, or
7569 // std::nullptr_t, there exist candidate operator functions of the form
7571 // bool operator<(T, T);
7572 // bool operator>(T, T);
7573 // bool operator<=(T, T);
7574 // bool operator>=(T, T);
7575 // bool operator==(T, T);
7576 // bool operator!=(T, T);
7577 void addRelationalPointerOrEnumeralOverloads() {
7578 // C++ [over.match.oper]p3:
7579 // [...]the built-in candidates include all of the candidate operator
7580 // functions defined in 13.6 that, compared to the given operator, [...]
7581 // do not have the same parameter-type-list as any non-template non-member
7584 // Note that in practice, this only affects enumeration types because there
7585 // aren't any built-in candidates of record type, and a user-defined operator
7586 // must have an operand of record or enumeration type. Also, the only other
7587 // overloaded operator with enumeration arguments, operator=,
7588 // cannot be overloaded for enumeration types, so this is the only place
7589 // where we must suppress candidates like this.
7590 llvm::DenseSet<std::pair<CanQualType, CanQualType> >
7591 UserDefinedBinaryOperators;
7593 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7594 if (CandidateTypes[ArgIdx].enumeration_begin() !=
7595 CandidateTypes[ArgIdx].enumeration_end()) {
7596 for (OverloadCandidateSet::iterator C = CandidateSet.begin(),
7597 CEnd = CandidateSet.end();
7599 if (!C->Viable || !C->Function || C->Function->getNumParams() != 2)
7602 if (C->Function->isFunctionTemplateSpecialization())
7605 QualType FirstParamType =
7606 C->Function->getParamDecl(0)->getType().getUnqualifiedType();
7607 QualType SecondParamType =
7608 C->Function->getParamDecl(1)->getType().getUnqualifiedType();
7610 // Skip if either parameter isn't of enumeral type.
7611 if (!FirstParamType->isEnumeralType() ||
7612 !SecondParamType->isEnumeralType())
7615 // Add this operator to the set of known user-defined operators.
7616 UserDefinedBinaryOperators.insert(
7617 std::make_pair(S.Context.getCanonicalType(FirstParamType),
7618 S.Context.getCanonicalType(SecondParamType)));
7623 /// Set of (canonical) types that we've already handled.
7624 llvm::SmallPtrSet<QualType, 8> AddedTypes;
7626 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7627 for (BuiltinCandidateTypeSet::iterator
7628 Ptr = CandidateTypes[ArgIdx].pointer_begin(),
7629 PtrEnd = CandidateTypes[ArgIdx].pointer_end();
7630 Ptr != PtrEnd; ++Ptr) {
7631 // Don't add the same builtin candidate twice.
7632 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
7635 QualType ParamTypes[2] = { *Ptr, *Ptr };
7636 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet);
7638 for (BuiltinCandidateTypeSet::iterator
7639 Enum = CandidateTypes[ArgIdx].enumeration_begin(),
7640 EnumEnd = CandidateTypes[ArgIdx].enumeration_end();
7641 Enum != EnumEnd; ++Enum) {
7642 CanQualType CanonType = S.Context.getCanonicalType(*Enum);
7644 // Don't add the same builtin candidate twice, or if a user defined
7645 // candidate exists.
7646 if (!AddedTypes.insert(CanonType).second ||
7647 UserDefinedBinaryOperators.count(std::make_pair(CanonType,
7651 QualType ParamTypes[2] = { *Enum, *Enum };
7652 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet);
7655 if (CandidateTypes[ArgIdx].hasNullPtrType()) {
7656 CanQualType NullPtrTy = S.Context.getCanonicalType(S.Context.NullPtrTy);
7657 if (AddedTypes.insert(NullPtrTy).second &&
7658 !UserDefinedBinaryOperators.count(std::make_pair(NullPtrTy,
7660 QualType ParamTypes[2] = { NullPtrTy, NullPtrTy };
7661 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args,
7668 // C++ [over.built]p13:
7670 // For every cv-qualified or cv-unqualified object type T
7671 // there exist candidate operator functions of the form
7673 // T* operator+(T*, ptrdiff_t);
7674 // T& operator[](T*, ptrdiff_t); [BELOW]
7675 // T* operator-(T*, ptrdiff_t);
7676 // T* operator+(ptrdiff_t, T*);
7677 // T& operator[](ptrdiff_t, T*); [BELOW]
7679 // C++ [over.built]p14:
7681 // For every T, where T is a pointer to object type, there
7682 // exist candidate operator functions of the form
7684 // ptrdiff_t operator-(T, T);
7685 void addBinaryPlusOrMinusPointerOverloads(OverloadedOperatorKind Op) {
7686 /// Set of (canonical) types that we've already handled.
7687 llvm::SmallPtrSet<QualType, 8> AddedTypes;
7689 for (int Arg = 0; Arg < 2; ++Arg) {
7690 QualType AsymmetricParamTypes[2] = {
7691 S.Context.getPointerDiffType(),
7692 S.Context.getPointerDiffType(),
7694 for (BuiltinCandidateTypeSet::iterator
7695 Ptr = CandidateTypes[Arg].pointer_begin(),
7696 PtrEnd = CandidateTypes[Arg].pointer_end();
7697 Ptr != PtrEnd; ++Ptr) {
7698 QualType PointeeTy = (*Ptr)->getPointeeType();
7699 if (!PointeeTy->isObjectType())
7702 AsymmetricParamTypes[Arg] = *Ptr;
7703 if (Arg == 0 || Op == OO_Plus) {
7704 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t)
7705 // T* operator+(ptrdiff_t, T*);
7706 S.AddBuiltinCandidate(*Ptr, AsymmetricParamTypes, Args, CandidateSet);
7708 if (Op == OO_Minus) {
7709 // ptrdiff_t operator-(T, T);
7710 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
7713 QualType ParamTypes[2] = { *Ptr, *Ptr };
7714 S.AddBuiltinCandidate(S.Context.getPointerDiffType(), ParamTypes,
7715 Args, CandidateSet);
7721 // C++ [over.built]p12:
7723 // For every pair of promoted arithmetic types L and R, there
7724 // exist candidate operator functions of the form
7726 // LR operator*(L, R);
7727 // LR operator/(L, R);
7728 // LR operator+(L, R);
7729 // LR operator-(L, R);
7730 // bool operator<(L, R);
7731 // bool operator>(L, R);
7732 // bool operator<=(L, R);
7733 // bool operator>=(L, R);
7734 // bool operator==(L, R);
7735 // bool operator!=(L, R);
7737 // where LR is the result of the usual arithmetic conversions
7738 // between types L and R.
7740 // C++ [over.built]p24:
7742 // For every pair of promoted arithmetic types L and R, there exist
7743 // candidate operator functions of the form
7745 // LR operator?(bool, L, R);
7747 // where LR is the result of the usual arithmetic conversions
7748 // between types L and R.
7749 // Our candidates ignore the first parameter.
7750 void addGenericBinaryArithmeticOverloads(bool isComparison) {
7751 if (!HasArithmeticOrEnumeralCandidateType)
7754 for (unsigned Left = FirstPromotedArithmeticType;
7755 Left < LastPromotedArithmeticType; ++Left) {
7756 for (unsigned Right = FirstPromotedArithmeticType;
7757 Right < LastPromotedArithmeticType; ++Right) {
7758 QualType LandR[2] = { getArithmeticType(Left),
7759 getArithmeticType(Right) };
7761 isComparison ? S.Context.BoolTy
7762 : getUsualArithmeticConversions(Left, Right);
7763 S.AddBuiltinCandidate(Result, LandR, Args, CandidateSet);
7767 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the
7768 // conditional operator for vector types.
7769 for (BuiltinCandidateTypeSet::iterator
7770 Vec1 = CandidateTypes[0].vector_begin(),
7771 Vec1End = CandidateTypes[0].vector_end();
7772 Vec1 != Vec1End; ++Vec1) {
7773 for (BuiltinCandidateTypeSet::iterator
7774 Vec2 = CandidateTypes[1].vector_begin(),
7775 Vec2End = CandidateTypes[1].vector_end();
7776 Vec2 != Vec2End; ++Vec2) {
7777 QualType LandR[2] = { *Vec1, *Vec2 };
7778 QualType Result = S.Context.BoolTy;
7779 if (!isComparison) {
7780 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType())
7786 S.AddBuiltinCandidate(Result, LandR, Args, CandidateSet);
7791 // C++ [over.built]p17:
7793 // For every pair of promoted integral types L and R, there
7794 // exist candidate operator functions of the form
7796 // LR operator%(L, R);
7797 // LR operator&(L, R);
7798 // LR operator^(L, R);
7799 // LR operator|(L, R);
7800 // L operator<<(L, R);
7801 // L operator>>(L, R);
7803 // where LR is the result of the usual arithmetic conversions
7804 // between types L and R.
7805 void addBinaryBitwiseArithmeticOverloads(OverloadedOperatorKind Op) {
7806 if (!HasArithmeticOrEnumeralCandidateType)
7809 for (unsigned Left = FirstPromotedIntegralType;
7810 Left < LastPromotedIntegralType; ++Left) {
7811 for (unsigned Right = FirstPromotedIntegralType;
7812 Right < LastPromotedIntegralType; ++Right) {
7813 QualType LandR[2] = { getArithmeticType(Left),
7814 getArithmeticType(Right) };
7815 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater)
7817 : getUsualArithmeticConversions(Left, Right);
7818 S.AddBuiltinCandidate(Result, LandR, Args, CandidateSet);
7823 // C++ [over.built]p20:
7825 // For every pair (T, VQ), where T is an enumeration or
7826 // pointer to member type and VQ is either volatile or
7827 // empty, there exist candidate operator functions of the form
7829 // VQ T& operator=(VQ T&, T);
7830 void addAssignmentMemberPointerOrEnumeralOverloads() {
7831 /// Set of (canonical) types that we've already handled.
7832 llvm::SmallPtrSet<QualType, 8> AddedTypes;
7834 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) {
7835 for (BuiltinCandidateTypeSet::iterator
7836 Enum = CandidateTypes[ArgIdx].enumeration_begin(),
7837 EnumEnd = CandidateTypes[ArgIdx].enumeration_end();
7838 Enum != EnumEnd; ++Enum) {
7839 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum)).second)
7842 AddBuiltinAssignmentOperatorCandidates(S, *Enum, Args, CandidateSet);
7845 for (BuiltinCandidateTypeSet::iterator
7846 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(),
7847 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end();
7848 MemPtr != MemPtrEnd; ++MemPtr) {
7849 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr)).second)
7852 AddBuiltinAssignmentOperatorCandidates(S, *MemPtr, Args, CandidateSet);
7857 // C++ [over.built]p19:
7859 // For every pair (T, VQ), where T is any type and VQ is either
7860 // volatile or empty, there exist candidate operator functions
7863 // T*VQ& operator=(T*VQ&, T*);
7865 // C++ [over.built]p21:
7867 // For every pair (T, VQ), where T is a cv-qualified or
7868 // cv-unqualified object type and VQ is either volatile or
7869 // empty, there exist candidate operator functions of the form
7871 // T*VQ& operator+=(T*VQ&, ptrdiff_t);
7872 // T*VQ& operator-=(T*VQ&, ptrdiff_t);
7873 void addAssignmentPointerOverloads(bool isEqualOp) {
7874 /// Set of (canonical) types that we've already handled.
7875 llvm::SmallPtrSet<QualType, 8> AddedTypes;
7877 for (BuiltinCandidateTypeSet::iterator
7878 Ptr = CandidateTypes[0].pointer_begin(),
7879 PtrEnd = CandidateTypes[0].pointer_end();
7880 Ptr != PtrEnd; ++Ptr) {
7881 // If this is operator=, keep track of the builtin candidates we added.
7883 AddedTypes.insert(S.Context.getCanonicalType(*Ptr));
7884 else if (!(*Ptr)->getPointeeType()->isObjectType())
7887 // non-volatile version
7888 QualType ParamTypes[2] = {
7889 S.Context.getLValueReferenceType(*Ptr),
7890 isEqualOp ? *Ptr : S.Context.getPointerDiffType(),
7892 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7893 /*IsAssigmentOperator=*/ isEqualOp);
7895 bool NeedVolatile = !(*Ptr).isVolatileQualified() &&
7896 VisibleTypeConversionsQuals.hasVolatile();
7900 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr));
7901 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7902 /*IsAssigmentOperator=*/isEqualOp);
7905 if (!(*Ptr).isRestrictQualified() &&
7906 VisibleTypeConversionsQuals.hasRestrict()) {
7909 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr));
7910 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7911 /*IsAssigmentOperator=*/isEqualOp);
7914 // volatile restrict version
7916 = S.Context.getLValueReferenceType(
7917 S.Context.getCVRQualifiedType(*Ptr,
7918 (Qualifiers::Volatile |
7919 Qualifiers::Restrict)));
7920 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7921 /*IsAssigmentOperator=*/isEqualOp);
7927 for (BuiltinCandidateTypeSet::iterator
7928 Ptr = CandidateTypes[1].pointer_begin(),
7929 PtrEnd = CandidateTypes[1].pointer_end();
7930 Ptr != PtrEnd; ++Ptr) {
7931 // Make sure we don't add the same candidate twice.
7932 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
7935 QualType ParamTypes[2] = {
7936 S.Context.getLValueReferenceType(*Ptr),
7940 // non-volatile version
7941 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7942 /*IsAssigmentOperator=*/true);
7944 bool NeedVolatile = !(*Ptr).isVolatileQualified() &&
7945 VisibleTypeConversionsQuals.hasVolatile();
7949 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr));
7950 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7951 /*IsAssigmentOperator=*/true);
7954 if (!(*Ptr).isRestrictQualified() &&
7955 VisibleTypeConversionsQuals.hasRestrict()) {
7958 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr));
7959 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7960 /*IsAssigmentOperator=*/true);
7963 // volatile restrict version
7965 = S.Context.getLValueReferenceType(
7966 S.Context.getCVRQualifiedType(*Ptr,
7967 (Qualifiers::Volatile |
7968 Qualifiers::Restrict)));
7969 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7970 /*IsAssigmentOperator=*/true);
7977 // C++ [over.built]p18:
7979 // For every triple (L, VQ, R), where L is an arithmetic type,
7980 // VQ is either volatile or empty, and R is a promoted
7981 // arithmetic type, there exist candidate operator functions of
7984 // VQ L& operator=(VQ L&, R);
7985 // VQ L& operator*=(VQ L&, R);
7986 // VQ L& operator/=(VQ L&, R);
7987 // VQ L& operator+=(VQ L&, R);
7988 // VQ L& operator-=(VQ L&, R);
7989 void addAssignmentArithmeticOverloads(bool isEqualOp) {
7990 if (!HasArithmeticOrEnumeralCandidateType)
7993 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) {
7994 for (unsigned Right = FirstPromotedArithmeticType;
7995 Right < LastPromotedArithmeticType; ++Right) {
7996 QualType ParamTypes[2];
7997 ParamTypes[1] = getArithmeticType(Right);
7999 // Add this built-in operator as a candidate (VQ is empty).
8001 S.Context.getLValueReferenceType(getArithmeticType(Left));
8002 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8003 /*IsAssigmentOperator=*/isEqualOp);
8005 // Add this built-in operator as a candidate (VQ is 'volatile').
8006 if (VisibleTypeConversionsQuals.hasVolatile()) {
8008 S.Context.getVolatileType(getArithmeticType(Left));
8009 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
8010 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8011 /*IsAssigmentOperator=*/isEqualOp);
8016 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types.
8017 for (BuiltinCandidateTypeSet::iterator
8018 Vec1 = CandidateTypes[0].vector_begin(),
8019 Vec1End = CandidateTypes[0].vector_end();
8020 Vec1 != Vec1End; ++Vec1) {
8021 for (BuiltinCandidateTypeSet::iterator
8022 Vec2 = CandidateTypes[1].vector_begin(),
8023 Vec2End = CandidateTypes[1].vector_end();
8024 Vec2 != Vec2End; ++Vec2) {
8025 QualType ParamTypes[2];
8026 ParamTypes[1] = *Vec2;
8027 // Add this built-in operator as a candidate (VQ is empty).
8028 ParamTypes[0] = S.Context.getLValueReferenceType(*Vec1);
8029 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8030 /*IsAssigmentOperator=*/isEqualOp);
8032 // Add this built-in operator as a candidate (VQ is 'volatile').
8033 if (VisibleTypeConversionsQuals.hasVolatile()) {
8034 ParamTypes[0] = S.Context.getVolatileType(*Vec1);
8035 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
8036 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8037 /*IsAssigmentOperator=*/isEqualOp);
8043 // C++ [over.built]p22:
8045 // For every triple (L, VQ, R), where L is an integral type, VQ
8046 // is either volatile or empty, and R is a promoted integral
8047 // type, there exist candidate operator functions of the form
8049 // VQ L& operator%=(VQ L&, R);
8050 // VQ L& operator<<=(VQ L&, R);
8051 // VQ L& operator>>=(VQ L&, R);
8052 // VQ L& operator&=(VQ L&, R);
8053 // VQ L& operator^=(VQ L&, R);
8054 // VQ L& operator|=(VQ L&, R);
8055 void addAssignmentIntegralOverloads() {
8056 if (!HasArithmeticOrEnumeralCandidateType)
8059 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) {
8060 for (unsigned Right = FirstPromotedIntegralType;
8061 Right < LastPromotedIntegralType; ++Right) {
8062 QualType ParamTypes[2];
8063 ParamTypes[1] = getArithmeticType(Right);
8065 // Add this built-in operator as a candidate (VQ is empty).
8067 S.Context.getLValueReferenceType(getArithmeticType(Left));
8068 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
8069 if (VisibleTypeConversionsQuals.hasVolatile()) {
8070 // Add this built-in operator as a candidate (VQ is 'volatile').
8071 ParamTypes[0] = getArithmeticType(Left);
8072 ParamTypes[0] = S.Context.getVolatileType(ParamTypes[0]);
8073 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
8074 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
8080 // C++ [over.operator]p23:
8082 // There also exist candidate operator functions of the form
8084 // bool operator!(bool);
8085 // bool operator&&(bool, bool);
8086 // bool operator||(bool, bool);
8087 void addExclaimOverload() {
8088 QualType ParamTy = S.Context.BoolTy;
8089 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, CandidateSet,
8090 /*IsAssignmentOperator=*/false,
8091 /*NumContextualBoolArguments=*/1);
8093 void addAmpAmpOrPipePipeOverload() {
8094 QualType ParamTypes[2] = { S.Context.BoolTy, S.Context.BoolTy };
8095 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet,
8096 /*IsAssignmentOperator=*/false,
8097 /*NumContextualBoolArguments=*/2);
8100 // C++ [over.built]p13:
8102 // For every cv-qualified or cv-unqualified object type T there
8103 // exist candidate operator functions of the form
8105 // T* operator+(T*, ptrdiff_t); [ABOVE]
8106 // T& operator[](T*, ptrdiff_t);
8107 // T* operator-(T*, ptrdiff_t); [ABOVE]
8108 // T* operator+(ptrdiff_t, T*); [ABOVE]
8109 // T& operator[](ptrdiff_t, T*);
8110 void addSubscriptOverloads() {
8111 for (BuiltinCandidateTypeSet::iterator
8112 Ptr = CandidateTypes[0].pointer_begin(),
8113 PtrEnd = CandidateTypes[0].pointer_end();
8114 Ptr != PtrEnd; ++Ptr) {
8115 QualType ParamTypes[2] = { *Ptr, S.Context.getPointerDiffType() };
8116 QualType PointeeType = (*Ptr)->getPointeeType();
8117 if (!PointeeType->isObjectType())
8120 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType);
8122 // T& operator[](T*, ptrdiff_t)
8123 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, CandidateSet);
8126 for (BuiltinCandidateTypeSet::iterator
8127 Ptr = CandidateTypes[1].pointer_begin(),
8128 PtrEnd = CandidateTypes[1].pointer_end();
8129 Ptr != PtrEnd; ++Ptr) {
8130 QualType ParamTypes[2] = { S.Context.getPointerDiffType(), *Ptr };
8131 QualType PointeeType = (*Ptr)->getPointeeType();
8132 if (!PointeeType->isObjectType())
8135 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType);
8137 // T& operator[](ptrdiff_t, T*)
8138 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, CandidateSet);
8142 // C++ [over.built]p11:
8143 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type,
8144 // C1 is the same type as C2 or is a derived class of C2, T is an object
8145 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
8146 // there exist candidate operator functions of the form
8148 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
8150 // where CV12 is the union of CV1 and CV2.
8151 void addArrowStarOverloads() {
8152 for (BuiltinCandidateTypeSet::iterator
8153 Ptr = CandidateTypes[0].pointer_begin(),
8154 PtrEnd = CandidateTypes[0].pointer_end();
8155 Ptr != PtrEnd; ++Ptr) {
8156 QualType C1Ty = (*Ptr);
8158 QualifierCollector Q1;
8159 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0);
8160 if (!isa<RecordType>(C1))
8162 // heuristic to reduce number of builtin candidates in the set.
8163 // Add volatile/restrict version only if there are conversions to a
8164 // volatile/restrict type.
8165 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile())
8167 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict())
8169 for (BuiltinCandidateTypeSet::iterator
8170 MemPtr = CandidateTypes[1].member_pointer_begin(),
8171 MemPtrEnd = CandidateTypes[1].member_pointer_end();
8172 MemPtr != MemPtrEnd; ++MemPtr) {
8173 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr);
8174 QualType C2 = QualType(mptr->getClass(), 0);
8175 C2 = C2.getUnqualifiedType();
8176 if (C1 != C2 && !S.IsDerivedFrom(CandidateSet.getLocation(), C1, C2))
8178 QualType ParamTypes[2] = { *Ptr, *MemPtr };
8180 QualType T = mptr->getPointeeType();
8181 if (!VisibleTypeConversionsQuals.hasVolatile() &&
8182 T.isVolatileQualified())
8184 if (!VisibleTypeConversionsQuals.hasRestrict() &&
8185 T.isRestrictQualified())
8187 T = Q1.apply(S.Context, T);
8188 QualType ResultTy = S.Context.getLValueReferenceType(T);
8189 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, CandidateSet);
8194 // Note that we don't consider the first argument, since it has been
8195 // contextually converted to bool long ago. The candidates below are
8196 // therefore added as binary.
8198 // C++ [over.built]p25:
8199 // For every type T, where T is a pointer, pointer-to-member, or scoped
8200 // enumeration type, there exist candidate operator functions of the form
8202 // T operator?(bool, T, T);
8204 void addConditionalOperatorOverloads() {
8205 /// Set of (canonical) types that we've already handled.
8206 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8208 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) {
8209 for (BuiltinCandidateTypeSet::iterator
8210 Ptr = CandidateTypes[ArgIdx].pointer_begin(),
8211 PtrEnd = CandidateTypes[ArgIdx].pointer_end();
8212 Ptr != PtrEnd; ++Ptr) {
8213 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
8216 QualType ParamTypes[2] = { *Ptr, *Ptr };
8217 S.AddBuiltinCandidate(*Ptr, ParamTypes, Args, CandidateSet);
8220 for (BuiltinCandidateTypeSet::iterator
8221 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(),
8222 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end();
8223 MemPtr != MemPtrEnd; ++MemPtr) {
8224 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr)).second)
8227 QualType ParamTypes[2] = { *MemPtr, *MemPtr };
8228 S.AddBuiltinCandidate(*MemPtr, ParamTypes, Args, CandidateSet);
8231 if (S.getLangOpts().CPlusPlus11) {
8232 for (BuiltinCandidateTypeSet::iterator
8233 Enum = CandidateTypes[ArgIdx].enumeration_begin(),
8234 EnumEnd = CandidateTypes[ArgIdx].enumeration_end();
8235 Enum != EnumEnd; ++Enum) {
8236 if (!(*Enum)->getAs<EnumType>()->getDecl()->isScoped())
8239 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum)).second)
8242 QualType ParamTypes[2] = { *Enum, *Enum };
8243 S.AddBuiltinCandidate(*Enum, ParamTypes, Args, CandidateSet);
8250 } // end anonymous namespace
8252 /// AddBuiltinOperatorCandidates - Add the appropriate built-in
8253 /// operator overloads to the candidate set (C++ [over.built]), based
8254 /// on the operator @p Op and the arguments given. For example, if the
8255 /// operator is a binary '+', this routine might add "int
8256 /// operator+(int, int)" to cover integer addition.
8257 void Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op,
8258 SourceLocation OpLoc,
8259 ArrayRef<Expr *> Args,
8260 OverloadCandidateSet &CandidateSet) {
8261 // Find all of the types that the arguments can convert to, but only
8262 // if the operator we're looking at has built-in operator candidates
8263 // that make use of these types. Also record whether we encounter non-record
8264 // candidate types or either arithmetic or enumeral candidate types.
8265 Qualifiers VisibleTypeConversionsQuals;
8266 VisibleTypeConversionsQuals.addConst();
8267 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx)
8268 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]);
8270 bool HasNonRecordCandidateType = false;
8271 bool HasArithmeticOrEnumeralCandidateType = false;
8272 SmallVector<BuiltinCandidateTypeSet, 2> CandidateTypes;
8273 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
8274 CandidateTypes.emplace_back(*this);
8275 CandidateTypes[ArgIdx].AddTypesConvertedFrom(Args[ArgIdx]->getType(),
8278 (Op == OO_Exclaim ||
8281 VisibleTypeConversionsQuals);
8282 HasNonRecordCandidateType = HasNonRecordCandidateType ||
8283 CandidateTypes[ArgIdx].hasNonRecordTypes();
8284 HasArithmeticOrEnumeralCandidateType =
8285 HasArithmeticOrEnumeralCandidateType ||
8286 CandidateTypes[ArgIdx].hasArithmeticOrEnumeralTypes();
8289 // Exit early when no non-record types have been added to the candidate set
8290 // for any of the arguments to the operator.
8292 // We can't exit early for !, ||, or &&, since there we have always have
8293 // 'bool' overloads.
8294 if (!HasNonRecordCandidateType &&
8295 !(Op == OO_Exclaim || Op == OO_AmpAmp || Op == OO_PipePipe))
8298 // Setup an object to manage the common state for building overloads.
8299 BuiltinOperatorOverloadBuilder OpBuilder(*this, Args,
8300 VisibleTypeConversionsQuals,
8301 HasArithmeticOrEnumeralCandidateType,
8302 CandidateTypes, CandidateSet);
8304 // Dispatch over the operation to add in only those overloads which apply.
8307 case NUM_OVERLOADED_OPERATORS:
8308 llvm_unreachable("Expected an overloaded operator");
8313 case OO_Array_Delete:
8316 "Special operators don't use AddBuiltinOperatorCandidates");
8321 // C++ [over.match.oper]p3:
8322 // -- For the operator ',', the unary operator '&', the
8323 // operator '->', or the operator 'co_await', the
8324 // built-in candidates set is empty.
8327 case OO_Plus: // '+' is either unary or binary
8328 if (Args.size() == 1)
8329 OpBuilder.addUnaryPlusPointerOverloads();
8332 case OO_Minus: // '-' is either unary or binary
8333 if (Args.size() == 1) {
8334 OpBuilder.addUnaryPlusOrMinusArithmeticOverloads();
8336 OpBuilder.addBinaryPlusOrMinusPointerOverloads(Op);
8337 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false);
8341 case OO_Star: // '*' is either unary or binary
8342 if (Args.size() == 1)
8343 OpBuilder.addUnaryStarPointerOverloads();
8345 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false);
8349 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false);
8354 OpBuilder.addPlusPlusMinusMinusArithmeticOverloads(Op);
8355 OpBuilder.addPlusPlusMinusMinusPointerOverloads();
8359 case OO_ExclaimEqual:
8360 OpBuilder.addEqualEqualOrNotEqualMemberPointerOverloads();
8366 case OO_GreaterEqual:
8367 OpBuilder.addRelationalPointerOrEnumeralOverloads();
8368 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/true);
8375 case OO_GreaterGreater:
8376 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op);
8379 case OO_Amp: // '&' is either unary or binary
8380 if (Args.size() == 1)
8381 // C++ [over.match.oper]p3:
8382 // -- For the operator ',', the unary operator '&', or the
8383 // operator '->', the built-in candidates set is empty.
8386 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op);
8390 OpBuilder.addUnaryTildePromotedIntegralOverloads();
8394 OpBuilder.addAssignmentMemberPointerOrEnumeralOverloads();
8399 OpBuilder.addAssignmentPointerOverloads(Op == OO_Equal);
8404 OpBuilder.addAssignmentArithmeticOverloads(Op == OO_Equal);
8407 case OO_PercentEqual:
8408 case OO_LessLessEqual:
8409 case OO_GreaterGreaterEqual:
8413 OpBuilder.addAssignmentIntegralOverloads();
8417 OpBuilder.addExclaimOverload();
8422 OpBuilder.addAmpAmpOrPipePipeOverload();
8426 OpBuilder.addSubscriptOverloads();
8430 OpBuilder.addArrowStarOverloads();
8433 case OO_Conditional:
8434 OpBuilder.addConditionalOperatorOverloads();
8435 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false);
8440 /// \brief Add function candidates found via argument-dependent lookup
8441 /// to the set of overloading candidates.
8443 /// This routine performs argument-dependent name lookup based on the
8444 /// given function name (which may also be an operator name) and adds
8445 /// all of the overload candidates found by ADL to the overload
8446 /// candidate set (C++ [basic.lookup.argdep]).
8448 Sema::AddArgumentDependentLookupCandidates(DeclarationName Name,
8450 ArrayRef<Expr *> Args,
8451 TemplateArgumentListInfo *ExplicitTemplateArgs,
8452 OverloadCandidateSet& CandidateSet,
8453 bool PartialOverloading) {
8456 // FIXME: This approach for uniquing ADL results (and removing
8457 // redundant candidates from the set) relies on pointer-equality,
8458 // which means we need to key off the canonical decl. However,
8459 // always going back to the canonical decl might not get us the
8460 // right set of default arguments. What default arguments are
8461 // we supposed to consider on ADL candidates, anyway?
8463 // FIXME: Pass in the explicit template arguments?
8464 ArgumentDependentLookup(Name, Loc, Args, Fns);
8466 // Erase all of the candidates we already knew about.
8467 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(),
8468 CandEnd = CandidateSet.end();
8469 Cand != CandEnd; ++Cand)
8470 if (Cand->Function) {
8471 Fns.erase(Cand->Function);
8472 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate())
8476 // For each of the ADL candidates we found, add it to the overload
8478 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) {
8479 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none);
8480 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) {
8481 if (ExplicitTemplateArgs)
8484 AddOverloadCandidate(FD, FoundDecl, Args, CandidateSet, false,
8485 PartialOverloading);
8487 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I),
8488 FoundDecl, ExplicitTemplateArgs,
8489 Args, CandidateSet, PartialOverloading);
8494 enum class Comparison { Equal, Better, Worse };
8497 /// Compares the enable_if attributes of two FunctionDecls, for the purposes of
8498 /// overload resolution.
8500 /// Cand1's set of enable_if attributes are said to be "better" than Cand2's iff
8501 /// Cand1's first N enable_if attributes have precisely the same conditions as
8502 /// Cand2's first N enable_if attributes (where N = the number of enable_if
8503 /// attributes on Cand2), and Cand1 has more than N enable_if attributes.
8505 /// Note that you can have a pair of candidates such that Cand1's enable_if
8506 /// attributes are worse than Cand2's, and Cand2's enable_if attributes are
8507 /// worse than Cand1's.
8508 static Comparison compareEnableIfAttrs(const Sema &S, const FunctionDecl *Cand1,
8509 const FunctionDecl *Cand2) {
8510 // Common case: One (or both) decls don't have enable_if attrs.
8511 bool Cand1Attr = Cand1->hasAttr<EnableIfAttr>();
8512 bool Cand2Attr = Cand2->hasAttr<EnableIfAttr>();
8513 if (!Cand1Attr || !Cand2Attr) {
8514 if (Cand1Attr == Cand2Attr)
8515 return Comparison::Equal;
8516 return Cand1Attr ? Comparison::Better : Comparison::Worse;
8519 // FIXME: The next several lines are just
8520 // specific_attr_iterator<EnableIfAttr> but going in declaration order,
8521 // instead of reverse order which is how they're stored in the AST.
8522 auto Cand1Attrs = getOrderedEnableIfAttrs(Cand1);
8523 auto Cand2Attrs = getOrderedEnableIfAttrs(Cand2);
8525 // It's impossible for Cand1 to be better than (or equal to) Cand2 if Cand1
8526 // has fewer enable_if attributes than Cand2.
8527 if (Cand1Attrs.size() < Cand2Attrs.size())
8528 return Comparison::Worse;
8530 auto Cand1I = Cand1Attrs.begin();
8531 llvm::FoldingSetNodeID Cand1ID, Cand2ID;
8532 for (auto &Cand2A : Cand2Attrs) {
8536 auto &Cand1A = *Cand1I++;
8537 Cand1A->getCond()->Profile(Cand1ID, S.getASTContext(), true);
8538 Cand2A->getCond()->Profile(Cand2ID, S.getASTContext(), true);
8539 if (Cand1ID != Cand2ID)
8540 return Comparison::Worse;
8543 return Cand1I == Cand1Attrs.end() ? Comparison::Equal : Comparison::Better;
8546 /// isBetterOverloadCandidate - Determines whether the first overload
8547 /// candidate is a better candidate than the second (C++ 13.3.3p1).
8548 bool clang::isBetterOverloadCandidate(Sema &S, const OverloadCandidate &Cand1,
8549 const OverloadCandidate &Cand2,
8551 bool UserDefinedConversion) {
8552 // Define viable functions to be better candidates than non-viable
8555 return Cand1.Viable;
8556 else if (!Cand1.Viable)
8559 // C++ [over.match.best]p1:
8561 // -- if F is a static member function, ICS1(F) is defined such
8562 // that ICS1(F) is neither better nor worse than ICS1(G) for
8563 // any function G, and, symmetrically, ICS1(G) is neither
8564 // better nor worse than ICS1(F).
8565 unsigned StartArg = 0;
8566 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument)
8569 // C++ [over.match.best]p1:
8570 // A viable function F1 is defined to be a better function than another
8571 // viable function F2 if for all arguments i, ICSi(F1) is not a worse
8572 // conversion sequence than ICSi(F2), and then...
8573 unsigned NumArgs = Cand1.NumConversions;
8574 assert(Cand2.NumConversions == NumArgs && "Overload candidate mismatch");
8575 bool HasBetterConversion = false;
8576 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) {
8577 switch (CompareImplicitConversionSequences(S, Loc,
8578 Cand1.Conversions[ArgIdx],
8579 Cand2.Conversions[ArgIdx])) {
8580 case ImplicitConversionSequence::Better:
8581 // Cand1 has a better conversion sequence.
8582 HasBetterConversion = true;
8585 case ImplicitConversionSequence::Worse:
8586 // Cand1 can't be better than Cand2.
8589 case ImplicitConversionSequence::Indistinguishable:
8595 // -- for some argument j, ICSj(F1) is a better conversion sequence than
8596 // ICSj(F2), or, if not that,
8597 if (HasBetterConversion)
8600 // -- the context is an initialization by user-defined conversion
8601 // (see 8.5, 13.3.1.5) and the standard conversion sequence
8602 // from the return type of F1 to the destination type (i.e.,
8603 // the type of the entity being initialized) is a better
8604 // conversion sequence than the standard conversion sequence
8605 // from the return type of F2 to the destination type.
8606 if (UserDefinedConversion && Cand1.Function && Cand2.Function &&
8607 isa<CXXConversionDecl>(Cand1.Function) &&
8608 isa<CXXConversionDecl>(Cand2.Function)) {
8609 // First check whether we prefer one of the conversion functions over the
8610 // other. This only distinguishes the results in non-standard, extension
8611 // cases such as the conversion from a lambda closure type to a function
8612 // pointer or block.
8613 ImplicitConversionSequence::CompareKind Result =
8614 compareConversionFunctions(S, Cand1.Function, Cand2.Function);
8615 if (Result == ImplicitConversionSequence::Indistinguishable)
8616 Result = CompareStandardConversionSequences(S, Loc,
8617 Cand1.FinalConversion,
8618 Cand2.FinalConversion);
8620 if (Result != ImplicitConversionSequence::Indistinguishable)
8621 return Result == ImplicitConversionSequence::Better;
8623 // FIXME: Compare kind of reference binding if conversion functions
8624 // convert to a reference type used in direct reference binding, per
8625 // C++14 [over.match.best]p1 section 2 bullet 3.
8628 // -- F1 is a non-template function and F2 is a function template
8629 // specialization, or, if not that,
8630 bool Cand1IsSpecialization = Cand1.Function &&
8631 Cand1.Function->getPrimaryTemplate();
8632 bool Cand2IsSpecialization = Cand2.Function &&
8633 Cand2.Function->getPrimaryTemplate();
8634 if (Cand1IsSpecialization != Cand2IsSpecialization)
8635 return Cand2IsSpecialization;
8637 // -- F1 and F2 are function template specializations, and the function
8638 // template for F1 is more specialized than the template for F2
8639 // according to the partial ordering rules described in 14.5.5.2, or,
8641 if (Cand1IsSpecialization && Cand2IsSpecialization) {
8642 if (FunctionTemplateDecl *BetterTemplate
8643 = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(),
8644 Cand2.Function->getPrimaryTemplate(),
8646 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion
8648 Cand1.ExplicitCallArguments,
8649 Cand2.ExplicitCallArguments))
8650 return BetterTemplate == Cand1.Function->getPrimaryTemplate();
8653 // FIXME: Work around a defect in the C++17 inheriting constructor wording.
8654 // A derived-class constructor beats an (inherited) base class constructor.
8655 bool Cand1IsInherited =
8656 dyn_cast_or_null<ConstructorUsingShadowDecl>(Cand1.FoundDecl.getDecl());
8657 bool Cand2IsInherited =
8658 dyn_cast_or_null<ConstructorUsingShadowDecl>(Cand2.FoundDecl.getDecl());
8659 if (Cand1IsInherited != Cand2IsInherited)
8660 return Cand2IsInherited;
8661 else if (Cand1IsInherited) {
8662 assert(Cand2IsInherited);
8663 auto *Cand1Class = cast<CXXRecordDecl>(Cand1.Function->getDeclContext());
8664 auto *Cand2Class = cast<CXXRecordDecl>(Cand2.Function->getDeclContext());
8665 if (Cand1Class->isDerivedFrom(Cand2Class))
8667 if (Cand2Class->isDerivedFrom(Cand1Class))
8669 // Inherited from sibling base classes: still ambiguous.
8672 // Check for enable_if value-based overload resolution.
8673 if (Cand1.Function && Cand2.Function) {
8674 Comparison Cmp = compareEnableIfAttrs(S, Cand1.Function, Cand2.Function);
8675 if (Cmp != Comparison::Equal)
8676 return Cmp == Comparison::Better;
8679 if (S.getLangOpts().CUDA && Cand1.Function && Cand2.Function) {
8680 FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext);
8681 return S.IdentifyCUDAPreference(Caller, Cand1.Function) >
8682 S.IdentifyCUDAPreference(Caller, Cand2.Function);
8685 bool HasPS1 = Cand1.Function != nullptr &&
8686 functionHasPassObjectSizeParams(Cand1.Function);
8687 bool HasPS2 = Cand2.Function != nullptr &&
8688 functionHasPassObjectSizeParams(Cand2.Function);
8689 return HasPS1 != HasPS2 && HasPS1;
8692 /// Determine whether two declarations are "equivalent" for the purposes of
8693 /// name lookup and overload resolution. This applies when the same internal/no
8694 /// linkage entity is defined by two modules (probably by textually including
8695 /// the same header). In such a case, we don't consider the declarations to
8696 /// declare the same entity, but we also don't want lookups with both
8697 /// declarations visible to be ambiguous in some cases (this happens when using
8698 /// a modularized libstdc++).
8699 bool Sema::isEquivalentInternalLinkageDeclaration(const NamedDecl *A,
8700 const NamedDecl *B) {
8701 auto *VA = dyn_cast_or_null<ValueDecl>(A);
8702 auto *VB = dyn_cast_or_null<ValueDecl>(B);
8706 // The declarations must be declaring the same name as an internal linkage
8707 // entity in different modules.
8708 if (!VA->getDeclContext()->getRedeclContext()->Equals(
8709 VB->getDeclContext()->getRedeclContext()) ||
8710 getOwningModule(const_cast<ValueDecl *>(VA)) ==
8711 getOwningModule(const_cast<ValueDecl *>(VB)) ||
8712 VA->isExternallyVisible() || VB->isExternallyVisible())
8715 // Check that the declarations appear to be equivalent.
8717 // FIXME: Checking the type isn't really enough to resolve the ambiguity.
8718 // For constants and functions, we should check the initializer or body is
8719 // the same. For non-constant variables, we shouldn't allow it at all.
8720 if (Context.hasSameType(VA->getType(), VB->getType()))
8723 // Enum constants within unnamed enumerations will have different types, but
8724 // may still be similar enough to be interchangeable for our purposes.
8725 if (auto *EA = dyn_cast<EnumConstantDecl>(VA)) {
8726 if (auto *EB = dyn_cast<EnumConstantDecl>(VB)) {
8727 // Only handle anonymous enums. If the enumerations were named and
8728 // equivalent, they would have been merged to the same type.
8729 auto *EnumA = cast<EnumDecl>(EA->getDeclContext());
8730 auto *EnumB = cast<EnumDecl>(EB->getDeclContext());
8731 if (EnumA->hasNameForLinkage() || EnumB->hasNameForLinkage() ||
8732 !Context.hasSameType(EnumA->getIntegerType(),
8733 EnumB->getIntegerType()))
8735 // Allow this only if the value is the same for both enumerators.
8736 return llvm::APSInt::isSameValue(EA->getInitVal(), EB->getInitVal());
8740 // Nothing else is sufficiently similar.
8744 void Sema::diagnoseEquivalentInternalLinkageDeclarations(
8745 SourceLocation Loc, const NamedDecl *D, ArrayRef<const NamedDecl *> Equiv) {
8746 Diag(Loc, diag::ext_equivalent_internal_linkage_decl_in_modules) << D;
8748 Module *M = getOwningModule(const_cast<NamedDecl*>(D));
8749 Diag(D->getLocation(), diag::note_equivalent_internal_linkage_decl)
8750 << !M << (M ? M->getFullModuleName() : "");
8752 for (auto *E : Equiv) {
8753 Module *M = getOwningModule(const_cast<NamedDecl*>(E));
8754 Diag(E->getLocation(), diag::note_equivalent_internal_linkage_decl)
8755 << !M << (M ? M->getFullModuleName() : "");
8759 /// \brief Computes the best viable function (C++ 13.3.3)
8760 /// within an overload candidate set.
8762 /// \param Loc The location of the function name (or operator symbol) for
8763 /// which overload resolution occurs.
8765 /// \param Best If overload resolution was successful or found a deleted
8766 /// function, \p Best points to the candidate function found.
8768 /// \returns The result of overload resolution.
8770 OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc,
8772 bool UserDefinedConversion) {
8773 llvm::SmallVector<OverloadCandidate *, 16> Candidates;
8774 std::transform(begin(), end(), std::back_inserter(Candidates),
8775 [](OverloadCandidate &Cand) { return &Cand; });
8777 // [CUDA] HD->H or HD->D calls are technically not allowed by CUDA
8778 // but accepted by both clang and NVCC. However during a particular
8779 // compilation mode only one call variant is viable. We need to
8780 // exclude non-viable overload candidates from consideration based
8781 // only on their host/device attributes. Specifically, if one
8782 // candidate call is WrongSide and the other is SameSide, we ignore
8783 // the WrongSide candidate.
8784 if (S.getLangOpts().CUDA) {
8785 const FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext);
8786 bool ContainsSameSideCandidate =
8787 llvm::any_of(Candidates, [&](OverloadCandidate *Cand) {
8788 return Cand->Function &&
8789 S.IdentifyCUDAPreference(Caller, Cand->Function) ==
8792 if (ContainsSameSideCandidate) {
8793 auto IsWrongSideCandidate = [&](OverloadCandidate *Cand) {
8794 return Cand->Function &&
8795 S.IdentifyCUDAPreference(Caller, Cand->Function) ==
8796 Sema::CFP_WrongSide;
8798 Candidates.erase(std::remove_if(Candidates.begin(), Candidates.end(),
8799 IsWrongSideCandidate),
8804 // Find the best viable function.
8806 for (auto *Cand : Candidates)
8808 if (Best == end() || isBetterOverloadCandidate(S, *Cand, *Best, Loc,
8809 UserDefinedConversion))
8812 // If we didn't find any viable functions, abort.
8814 return OR_No_Viable_Function;
8816 llvm::SmallVector<const NamedDecl *, 4> EquivalentCands;
8818 // Make sure that this function is better than every other viable
8819 // function. If not, we have an ambiguity.
8820 for (auto *Cand : Candidates) {
8823 !isBetterOverloadCandidate(S, *Best, *Cand, Loc,
8824 UserDefinedConversion)) {
8825 if (S.isEquivalentInternalLinkageDeclaration(Best->Function,
8827 EquivalentCands.push_back(Cand->Function);
8832 return OR_Ambiguous;
8836 // Best is the best viable function.
8837 if (Best->Function &&
8838 (Best->Function->isDeleted() ||
8839 S.isFunctionConsideredUnavailable(Best->Function)))
8842 if (!EquivalentCands.empty())
8843 S.diagnoseEquivalentInternalLinkageDeclarations(Loc, Best->Function,
8851 enum OverloadCandidateKind {
8855 oc_function_template,
8857 oc_constructor_template,
8858 oc_implicit_default_constructor,
8859 oc_implicit_copy_constructor,
8860 oc_implicit_move_constructor,
8861 oc_implicit_copy_assignment,
8862 oc_implicit_move_assignment,
8863 oc_inherited_constructor,
8864 oc_inherited_constructor_template
8867 OverloadCandidateKind ClassifyOverloadCandidate(Sema &S,
8870 std::string &Description) {
8871 bool isTemplate = false;
8873 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) {
8875 Description = S.getTemplateArgumentBindingsText(
8876 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs());
8879 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) {
8880 if (!Ctor->isImplicit()) {
8881 if (isa<ConstructorUsingShadowDecl>(Found))
8882 return isTemplate ? oc_inherited_constructor_template
8883 : oc_inherited_constructor;
8885 return isTemplate ? oc_constructor_template : oc_constructor;
8888 if (Ctor->isDefaultConstructor())
8889 return oc_implicit_default_constructor;
8891 if (Ctor->isMoveConstructor())
8892 return oc_implicit_move_constructor;
8894 assert(Ctor->isCopyConstructor() &&
8895 "unexpected sort of implicit constructor");
8896 return oc_implicit_copy_constructor;
8899 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) {
8900 // This actually gets spelled 'candidate function' for now, but
8901 // it doesn't hurt to split it out.
8902 if (!Meth->isImplicit())
8903 return isTemplate ? oc_method_template : oc_method;
8905 if (Meth->isMoveAssignmentOperator())
8906 return oc_implicit_move_assignment;
8908 if (Meth->isCopyAssignmentOperator())
8909 return oc_implicit_copy_assignment;
8911 assert(isa<CXXConversionDecl>(Meth) && "expected conversion");
8915 return isTemplate ? oc_function_template : oc_function;
8918 void MaybeEmitInheritedConstructorNote(Sema &S, Decl *FoundDecl) {
8919 // FIXME: It'd be nice to only emit a note once per using-decl per overload
8921 if (auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(FoundDecl))
8922 S.Diag(FoundDecl->getLocation(),
8923 diag::note_ovl_candidate_inherited_constructor)
8924 << Shadow->getNominatedBaseClass();
8927 } // end anonymous namespace
8929 static bool isFunctionAlwaysEnabled(const ASTContext &Ctx,
8930 const FunctionDecl *FD) {
8931 for (auto *EnableIf : FD->specific_attrs<EnableIfAttr>()) {
8933 if (!EnableIf->getCond()->EvaluateAsBooleanCondition(AlwaysTrue, Ctx))
8941 /// \brief Returns true if we can take the address of the function.
8943 /// \param Complain - If true, we'll emit a diagnostic
8944 /// \param InOverloadResolution - For the purposes of emitting a diagnostic, are
8945 /// we in overload resolution?
8946 /// \param Loc - The location of the statement we're complaining about. Ignored
8947 /// if we're not complaining, or if we're in overload resolution.
8948 static bool checkAddressOfFunctionIsAvailable(Sema &S, const FunctionDecl *FD,
8950 bool InOverloadResolution,
8951 SourceLocation Loc) {
8952 if (!isFunctionAlwaysEnabled(S.Context, FD)) {
8954 if (InOverloadResolution)
8955 S.Diag(FD->getLocStart(),
8956 diag::note_addrof_ovl_candidate_disabled_by_enable_if_attr);
8958 S.Diag(Loc, diag::err_addrof_function_disabled_by_enable_if_attr) << FD;
8963 auto I = llvm::find_if(
8964 FD->parameters(), std::mem_fn(&ParmVarDecl::hasAttr<PassObjectSizeAttr>));
8965 if (I == FD->param_end())
8969 // Add one to ParamNo because it's user-facing
8970 unsigned ParamNo = std::distance(FD->param_begin(), I) + 1;
8971 if (InOverloadResolution)
8972 S.Diag(FD->getLocation(),
8973 diag::note_ovl_candidate_has_pass_object_size_params)
8976 S.Diag(Loc, diag::err_address_of_function_with_pass_object_size_params)
8982 static bool checkAddressOfCandidateIsAvailable(Sema &S,
8983 const FunctionDecl *FD) {
8984 return checkAddressOfFunctionIsAvailable(S, FD, /*Complain=*/true,
8985 /*InOverloadResolution=*/true,
8986 /*Loc=*/SourceLocation());
8989 bool Sema::checkAddressOfFunctionIsAvailable(const FunctionDecl *Function,
8991 SourceLocation Loc) {
8992 return ::checkAddressOfFunctionIsAvailable(*this, Function, Complain,
8993 /*InOverloadResolution=*/false,
8997 // Notes the location of an overload candidate.
8998 void Sema::NoteOverloadCandidate(NamedDecl *Found, FunctionDecl *Fn,
8999 QualType DestType, bool TakingAddress) {
9000 if (TakingAddress && !checkAddressOfCandidateIsAvailable(*this, Fn))
9004 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Found, Fn, FnDesc);
9005 PartialDiagnostic PD = PDiag(diag::note_ovl_candidate)
9006 << (unsigned) K << FnDesc;
9008 HandleFunctionTypeMismatch(PD, Fn->getType(), DestType);
9009 Diag(Fn->getLocation(), PD);
9010 MaybeEmitInheritedConstructorNote(*this, Found);
9013 // Notes the location of all overload candidates designated through
9015 void Sema::NoteAllOverloadCandidates(Expr *OverloadedExpr, QualType DestType,
9016 bool TakingAddress) {
9017 assert(OverloadedExpr->getType() == Context.OverloadTy);
9019 OverloadExpr::FindResult Ovl = OverloadExpr::find(OverloadedExpr);
9020 OverloadExpr *OvlExpr = Ovl.Expression;
9022 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
9023 IEnd = OvlExpr->decls_end();
9025 if (FunctionTemplateDecl *FunTmpl =
9026 dyn_cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()) ) {
9027 NoteOverloadCandidate(*I, FunTmpl->getTemplatedDecl(), DestType,
9029 } else if (FunctionDecl *Fun
9030 = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()) ) {
9031 NoteOverloadCandidate(*I, Fun, DestType, TakingAddress);
9036 /// Diagnoses an ambiguous conversion. The partial diagnostic is the
9037 /// "lead" diagnostic; it will be given two arguments, the source and
9038 /// target types of the conversion.
9039 void ImplicitConversionSequence::DiagnoseAmbiguousConversion(
9041 SourceLocation CaretLoc,
9042 const PartialDiagnostic &PDiag) const {
9043 S.Diag(CaretLoc, PDiag)
9044 << Ambiguous.getFromType() << Ambiguous.getToType();
9045 // FIXME: The note limiting machinery is borrowed from
9046 // OverloadCandidateSet::NoteCandidates; there's an opportunity for
9047 // refactoring here.
9048 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
9049 unsigned CandsShown = 0;
9050 AmbiguousConversionSequence::const_iterator I, E;
9051 for (I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) {
9052 if (CandsShown >= 4 && ShowOverloads == Ovl_Best)
9055 S.NoteOverloadCandidate(I->first, I->second);
9058 S.Diag(SourceLocation(), diag::note_ovl_too_many_candidates) << int(E - I);
9061 static void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand,
9062 unsigned I, bool TakingCandidateAddress) {
9063 const ImplicitConversionSequence &Conv = Cand->Conversions[I];
9064 assert(Conv.isBad());
9065 assert(Cand->Function && "for now, candidate must be a function");
9066 FunctionDecl *Fn = Cand->Function;
9068 // There's a conversion slot for the object argument if this is a
9069 // non-constructor method. Note that 'I' corresponds the
9070 // conversion-slot index.
9071 bool isObjectArgument = false;
9072 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) {
9074 isObjectArgument = true;
9080 OverloadCandidateKind FnKind =
9081 ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn, FnDesc);
9083 Expr *FromExpr = Conv.Bad.FromExpr;
9084 QualType FromTy = Conv.Bad.getFromType();
9085 QualType ToTy = Conv.Bad.getToType();
9087 if (FromTy == S.Context.OverloadTy) {
9088 assert(FromExpr && "overload set argument came from implicit argument?");
9089 Expr *E = FromExpr->IgnoreParens();
9090 if (isa<UnaryOperator>(E))
9091 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens();
9092 DeclarationName Name = cast<OverloadExpr>(E)->getName();
9094 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload)
9095 << (unsigned) FnKind << FnDesc
9096 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9097 << ToTy << Name << I+1;
9098 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9102 // Do some hand-waving analysis to see if the non-viability is due
9103 // to a qualifier mismatch.
9104 CanQualType CFromTy = S.Context.getCanonicalType(FromTy);
9105 CanQualType CToTy = S.Context.getCanonicalType(ToTy);
9106 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>())
9107 CToTy = RT->getPointeeType();
9109 // TODO: detect and diagnose the full richness of const mismatches.
9110 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>())
9111 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) {
9112 CFromTy = FromPT->getPointeeType();
9113 CToTy = ToPT->getPointeeType();
9117 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() &&
9118 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) {
9119 Qualifiers FromQs = CFromTy.getQualifiers();
9120 Qualifiers ToQs = CToTy.getQualifiers();
9122 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) {
9123 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace)
9124 << (unsigned) FnKind << FnDesc
9125 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9127 << FromQs.getAddressSpace() << ToQs.getAddressSpace()
9128 << (unsigned) isObjectArgument << I+1;
9129 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9133 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) {
9134 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_ownership)
9135 << (unsigned) FnKind << FnDesc
9136 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9138 << FromQs.getObjCLifetime() << ToQs.getObjCLifetime()
9139 << (unsigned) isObjectArgument << I+1;
9140 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9144 if (FromQs.getObjCGCAttr() != ToQs.getObjCGCAttr()) {
9145 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_gc)
9146 << (unsigned) FnKind << FnDesc
9147 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9149 << FromQs.getObjCGCAttr() << ToQs.getObjCGCAttr()
9150 << (unsigned) isObjectArgument << I+1;
9151 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9155 if (FromQs.hasUnaligned() != ToQs.hasUnaligned()) {
9156 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_unaligned)
9157 << (unsigned) FnKind << FnDesc
9158 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9159 << FromTy << FromQs.hasUnaligned() << I+1;
9160 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9164 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers();
9165 assert(CVR && "unexpected qualifiers mismatch");
9167 if (isObjectArgument) {
9168 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this)
9169 << (unsigned) FnKind << FnDesc
9170 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9171 << FromTy << (CVR - 1);
9173 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr)
9174 << (unsigned) FnKind << FnDesc
9175 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9176 << FromTy << (CVR - 1) << I+1;
9178 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9182 // Special diagnostic for failure to convert an initializer list, since
9183 // telling the user that it has type void is not useful.
9184 if (FromExpr && isa<InitListExpr>(FromExpr)) {
9185 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_list_argument)
9186 << (unsigned) FnKind << FnDesc
9187 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9188 << FromTy << ToTy << (unsigned) isObjectArgument << I+1;
9189 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9193 // Diagnose references or pointers to incomplete types differently,
9194 // since it's far from impossible that the incompleteness triggered
9196 QualType TempFromTy = FromTy.getNonReferenceType();
9197 if (const PointerType *PTy = TempFromTy->getAs<PointerType>())
9198 TempFromTy = PTy->getPointeeType();
9199 if (TempFromTy->isIncompleteType()) {
9200 // Emit the generic diagnostic and, optionally, add the hints to it.
9201 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete)
9202 << (unsigned) FnKind << FnDesc
9203 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9204 << FromTy << ToTy << (unsigned) isObjectArgument << I+1
9205 << (unsigned) (Cand->Fix.Kind);
9207 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9211 // Diagnose base -> derived pointer conversions.
9212 unsigned BaseToDerivedConversion = 0;
9213 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) {
9214 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) {
9215 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs(
9216 FromPtrTy->getPointeeType()) &&
9217 !FromPtrTy->getPointeeType()->isIncompleteType() &&
9218 !ToPtrTy->getPointeeType()->isIncompleteType() &&
9219 S.IsDerivedFrom(SourceLocation(), ToPtrTy->getPointeeType(),
9220 FromPtrTy->getPointeeType()))
9221 BaseToDerivedConversion = 1;
9223 } else if (const ObjCObjectPointerType *FromPtrTy
9224 = FromTy->getAs<ObjCObjectPointerType>()) {
9225 if (const ObjCObjectPointerType *ToPtrTy
9226 = ToTy->getAs<ObjCObjectPointerType>())
9227 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl())
9228 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl())
9229 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs(
9230 FromPtrTy->getPointeeType()) &&
9231 FromIface->isSuperClassOf(ToIface))
9232 BaseToDerivedConversion = 2;
9233 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) {
9234 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) &&
9235 !FromTy->isIncompleteType() &&
9236 !ToRefTy->getPointeeType()->isIncompleteType() &&
9237 S.IsDerivedFrom(SourceLocation(), ToRefTy->getPointeeType(), FromTy)) {
9238 BaseToDerivedConversion = 3;
9239 } else if (ToTy->isLValueReferenceType() && !FromExpr->isLValue() &&
9240 ToTy.getNonReferenceType().getCanonicalType() ==
9241 FromTy.getNonReferenceType().getCanonicalType()) {
9242 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_lvalue)
9243 << (unsigned) FnKind << FnDesc
9244 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9245 << (unsigned) isObjectArgument << I + 1;
9246 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9251 if (BaseToDerivedConversion) {
9252 S.Diag(Fn->getLocation(),
9253 diag::note_ovl_candidate_bad_base_to_derived_conv)
9254 << (unsigned) FnKind << FnDesc
9255 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9256 << (BaseToDerivedConversion - 1)
9257 << FromTy << ToTy << I+1;
9258 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9262 if (isa<ObjCObjectPointerType>(CFromTy) &&
9263 isa<PointerType>(CToTy)) {
9264 Qualifiers FromQs = CFromTy.getQualifiers();
9265 Qualifiers ToQs = CToTy.getQualifiers();
9266 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) {
9267 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_arc_conv)
9268 << (unsigned) FnKind << FnDesc
9269 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9270 << FromTy << ToTy << (unsigned) isObjectArgument << I+1;
9271 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9276 if (TakingCandidateAddress &&
9277 !checkAddressOfCandidateIsAvailable(S, Cand->Function))
9280 // Emit the generic diagnostic and, optionally, add the hints to it.
9281 PartialDiagnostic FDiag = S.PDiag(diag::note_ovl_candidate_bad_conv);
9282 FDiag << (unsigned) FnKind << FnDesc
9283 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9284 << FromTy << ToTy << (unsigned) isObjectArgument << I + 1
9285 << (unsigned) (Cand->Fix.Kind);
9287 // If we can fix the conversion, suggest the FixIts.
9288 for (std::vector<FixItHint>::iterator HI = Cand->Fix.Hints.begin(),
9289 HE = Cand->Fix.Hints.end(); HI != HE; ++HI)
9291 S.Diag(Fn->getLocation(), FDiag);
9293 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9296 /// Additional arity mismatch diagnosis specific to a function overload
9297 /// candidates. This is not covered by the more general DiagnoseArityMismatch()
9298 /// over a candidate in any candidate set.
9299 static bool CheckArityMismatch(Sema &S, OverloadCandidate *Cand,
9301 FunctionDecl *Fn = Cand->Function;
9302 unsigned MinParams = Fn->getMinRequiredArguments();
9304 // With invalid overloaded operators, it's possible that we think we
9305 // have an arity mismatch when in fact it looks like we have the
9306 // right number of arguments, because only overloaded operators have
9307 // the weird behavior of overloading member and non-member functions.
9308 // Just don't report anything.
9309 if (Fn->isInvalidDecl() &&
9310 Fn->getDeclName().getNameKind() == DeclarationName::CXXOperatorName)
9313 if (NumArgs < MinParams) {
9314 assert((Cand->FailureKind == ovl_fail_too_few_arguments) ||
9315 (Cand->FailureKind == ovl_fail_bad_deduction &&
9316 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments));
9318 assert((Cand->FailureKind == ovl_fail_too_many_arguments) ||
9319 (Cand->FailureKind == ovl_fail_bad_deduction &&
9320 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments));
9326 /// General arity mismatch diagnosis over a candidate in a candidate set.
9327 static void DiagnoseArityMismatch(Sema &S, NamedDecl *Found, Decl *D,
9328 unsigned NumFormalArgs) {
9329 assert(isa<FunctionDecl>(D) &&
9330 "The templated declaration should at least be a function"
9331 " when diagnosing bad template argument deduction due to too many"
9332 " or too few arguments");
9334 FunctionDecl *Fn = cast<FunctionDecl>(D);
9336 // TODO: treat calls to a missing default constructor as a special case
9337 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>();
9338 unsigned MinParams = Fn->getMinRequiredArguments();
9340 // at least / at most / exactly
9341 unsigned mode, modeCount;
9342 if (NumFormalArgs < MinParams) {
9343 if (MinParams != FnTy->getNumParams() || FnTy->isVariadic() ||
9344 FnTy->isTemplateVariadic())
9345 mode = 0; // "at least"
9347 mode = 2; // "exactly"
9348 modeCount = MinParams;
9350 if (MinParams != FnTy->getNumParams())
9351 mode = 1; // "at most"
9353 mode = 2; // "exactly"
9354 modeCount = FnTy->getNumParams();
9357 std::string Description;
9358 OverloadCandidateKind FnKind =
9359 ClassifyOverloadCandidate(S, Found, Fn, Description);
9361 if (modeCount == 1 && Fn->getParamDecl(0)->getDeclName())
9362 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity_one)
9363 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != nullptr)
9364 << mode << Fn->getParamDecl(0) << NumFormalArgs;
9366 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity)
9367 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != nullptr)
9368 << mode << modeCount << NumFormalArgs;
9369 MaybeEmitInheritedConstructorNote(S, Found);
9372 /// Arity mismatch diagnosis specific to a function overload candidate.
9373 static void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand,
9374 unsigned NumFormalArgs) {
9375 if (!CheckArityMismatch(S, Cand, NumFormalArgs))
9376 DiagnoseArityMismatch(S, Cand->FoundDecl, Cand->Function, NumFormalArgs);
9379 static TemplateDecl *getDescribedTemplate(Decl *Templated) {
9380 if (TemplateDecl *TD = Templated->getDescribedTemplate())
9382 llvm_unreachable("Unsupported: Getting the described template declaration"
9383 " for bad deduction diagnosis");
9386 /// Diagnose a failed template-argument deduction.
9387 static void DiagnoseBadDeduction(Sema &S, NamedDecl *Found, Decl *Templated,
9388 DeductionFailureInfo &DeductionFailure,
9390 bool TakingCandidateAddress) {
9391 TemplateParameter Param = DeductionFailure.getTemplateParameter();
9393 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) ||
9394 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) ||
9395 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>());
9396 switch (DeductionFailure.Result) {
9397 case Sema::TDK_Success:
9398 llvm_unreachable("TDK_success while diagnosing bad deduction");
9400 case Sema::TDK_Incomplete: {
9401 assert(ParamD && "no parameter found for incomplete deduction result");
9402 S.Diag(Templated->getLocation(),
9403 diag::note_ovl_candidate_incomplete_deduction)
9404 << ParamD->getDeclName();
9405 MaybeEmitInheritedConstructorNote(S, Found);
9409 case Sema::TDK_Underqualified: {
9410 assert(ParamD && "no parameter found for bad qualifiers deduction result");
9411 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD);
9413 QualType Param = DeductionFailure.getFirstArg()->getAsType();
9415 // Param will have been canonicalized, but it should just be a
9416 // qualified version of ParamD, so move the qualifiers to that.
9417 QualifierCollector Qs;
9419 QualType NonCanonParam = Qs.apply(S.Context, TParam->getTypeForDecl());
9420 assert(S.Context.hasSameType(Param, NonCanonParam));
9422 // Arg has also been canonicalized, but there's nothing we can do
9423 // about that. It also doesn't matter as much, because it won't
9424 // have any template parameters in it (because deduction isn't
9425 // done on dependent types).
9426 QualType Arg = DeductionFailure.getSecondArg()->getAsType();
9428 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_underqualified)
9429 << ParamD->getDeclName() << Arg << NonCanonParam;
9430 MaybeEmitInheritedConstructorNote(S, Found);
9434 case Sema::TDK_Inconsistent: {
9435 assert(ParamD && "no parameter found for inconsistent deduction result");
9437 if (isa<TemplateTypeParmDecl>(ParamD))
9439 else if (isa<NonTypeTemplateParmDecl>(ParamD))
9445 S.Diag(Templated->getLocation(),
9446 diag::note_ovl_candidate_inconsistent_deduction)
9447 << which << ParamD->getDeclName() << *DeductionFailure.getFirstArg()
9448 << *DeductionFailure.getSecondArg();
9449 MaybeEmitInheritedConstructorNote(S, Found);
9453 case Sema::TDK_InvalidExplicitArguments:
9454 assert(ParamD && "no parameter found for invalid explicit arguments");
9455 if (ParamD->getDeclName())
9456 S.Diag(Templated->getLocation(),
9457 diag::note_ovl_candidate_explicit_arg_mismatch_named)
9458 << ParamD->getDeclName();
9461 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD))
9462 index = TTP->getIndex();
9463 else if (NonTypeTemplateParmDecl *NTTP
9464 = dyn_cast<NonTypeTemplateParmDecl>(ParamD))
9465 index = NTTP->getIndex();
9467 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex();
9468 S.Diag(Templated->getLocation(),
9469 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed)
9472 MaybeEmitInheritedConstructorNote(S, Found);
9475 case Sema::TDK_TooManyArguments:
9476 case Sema::TDK_TooFewArguments:
9477 DiagnoseArityMismatch(S, Found, Templated, NumArgs);
9480 case Sema::TDK_InstantiationDepth:
9481 S.Diag(Templated->getLocation(),
9482 diag::note_ovl_candidate_instantiation_depth);
9483 MaybeEmitInheritedConstructorNote(S, Found);
9486 case Sema::TDK_SubstitutionFailure: {
9487 // Format the template argument list into the argument string.
9488 SmallString<128> TemplateArgString;
9489 if (TemplateArgumentList *Args =
9490 DeductionFailure.getTemplateArgumentList()) {
9491 TemplateArgString = " ";
9492 TemplateArgString += S.getTemplateArgumentBindingsText(
9493 getDescribedTemplate(Templated)->getTemplateParameters(), *Args);
9496 // If this candidate was disabled by enable_if, say so.
9497 PartialDiagnosticAt *PDiag = DeductionFailure.getSFINAEDiagnostic();
9498 if (PDiag && PDiag->second.getDiagID() ==
9499 diag::err_typename_nested_not_found_enable_if) {
9500 // FIXME: Use the source range of the condition, and the fully-qualified
9501 // name of the enable_if template. These are both present in PDiag.
9502 S.Diag(PDiag->first, diag::note_ovl_candidate_disabled_by_enable_if)
9503 << "'enable_if'" << TemplateArgString;
9507 // Format the SFINAE diagnostic into the argument string.
9508 // FIXME: Add a general mechanism to include a PartialDiagnostic *'s
9509 // formatted message in another diagnostic.
9510 SmallString<128> SFINAEArgString;
9513 SFINAEArgString = ": ";
9514 R = SourceRange(PDiag->first, PDiag->first);
9515 PDiag->second.EmitToString(S.getDiagnostics(), SFINAEArgString);
9518 S.Diag(Templated->getLocation(),
9519 diag::note_ovl_candidate_substitution_failure)
9520 << TemplateArgString << SFINAEArgString << R;
9521 MaybeEmitInheritedConstructorNote(S, Found);
9525 case Sema::TDK_FailedOverloadResolution: {
9526 OverloadExpr::FindResult R = OverloadExpr::find(DeductionFailure.getExpr());
9527 S.Diag(Templated->getLocation(),
9528 diag::note_ovl_candidate_failed_overload_resolution)
9529 << R.Expression->getName();
9533 case Sema::TDK_DeducedMismatch: {
9534 // Format the template argument list into the argument string.
9535 SmallString<128> TemplateArgString;
9536 if (TemplateArgumentList *Args =
9537 DeductionFailure.getTemplateArgumentList()) {
9538 TemplateArgString = " ";
9539 TemplateArgString += S.getTemplateArgumentBindingsText(
9540 getDescribedTemplate(Templated)->getTemplateParameters(), *Args);
9543 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_deduced_mismatch)
9544 << (*DeductionFailure.getCallArgIndex() + 1)
9545 << *DeductionFailure.getFirstArg() << *DeductionFailure.getSecondArg()
9546 << TemplateArgString;
9550 case Sema::TDK_NonDeducedMismatch: {
9551 // FIXME: Provide a source location to indicate what we couldn't match.
9552 TemplateArgument FirstTA = *DeductionFailure.getFirstArg();
9553 TemplateArgument SecondTA = *DeductionFailure.getSecondArg();
9554 if (FirstTA.getKind() == TemplateArgument::Template &&
9555 SecondTA.getKind() == TemplateArgument::Template) {
9556 TemplateName FirstTN = FirstTA.getAsTemplate();
9557 TemplateName SecondTN = SecondTA.getAsTemplate();
9558 if (FirstTN.getKind() == TemplateName::Template &&
9559 SecondTN.getKind() == TemplateName::Template) {
9560 if (FirstTN.getAsTemplateDecl()->getName() ==
9561 SecondTN.getAsTemplateDecl()->getName()) {
9562 // FIXME: This fixes a bad diagnostic where both templates are named
9563 // the same. This particular case is a bit difficult since:
9564 // 1) It is passed as a string to the diagnostic printer.
9565 // 2) The diagnostic printer only attempts to find a better
9566 // name for types, not decls.
9567 // Ideally, this should folded into the diagnostic printer.
9568 S.Diag(Templated->getLocation(),
9569 diag::note_ovl_candidate_non_deduced_mismatch_qualified)
9570 << FirstTN.getAsTemplateDecl() << SecondTN.getAsTemplateDecl();
9576 if (TakingCandidateAddress && isa<FunctionDecl>(Templated) &&
9577 !checkAddressOfCandidateIsAvailable(S, cast<FunctionDecl>(Templated)))
9580 // FIXME: For generic lambda parameters, check if the function is a lambda
9581 // call operator, and if so, emit a prettier and more informative
9582 // diagnostic that mentions 'auto' and lambda in addition to
9583 // (or instead of?) the canonical template type parameters.
9584 S.Diag(Templated->getLocation(),
9585 diag::note_ovl_candidate_non_deduced_mismatch)
9586 << FirstTA << SecondTA;
9589 // TODO: diagnose these individually, then kill off
9590 // note_ovl_candidate_bad_deduction, which is uselessly vague.
9591 case Sema::TDK_MiscellaneousDeductionFailure:
9592 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_bad_deduction);
9593 MaybeEmitInheritedConstructorNote(S, Found);
9598 /// Diagnose a failed template-argument deduction, for function calls.
9599 static void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand,
9601 bool TakingCandidateAddress) {
9602 unsigned TDK = Cand->DeductionFailure.Result;
9603 if (TDK == Sema::TDK_TooFewArguments || TDK == Sema::TDK_TooManyArguments) {
9604 if (CheckArityMismatch(S, Cand, NumArgs))
9607 DiagnoseBadDeduction(S, Cand->FoundDecl, Cand->Function, // pattern
9608 Cand->DeductionFailure, NumArgs, TakingCandidateAddress);
9611 /// CUDA: diagnose an invalid call across targets.
9612 static void DiagnoseBadTarget(Sema &S, OverloadCandidate *Cand) {
9613 FunctionDecl *Caller = cast<FunctionDecl>(S.CurContext);
9614 FunctionDecl *Callee = Cand->Function;
9616 Sema::CUDAFunctionTarget CallerTarget = S.IdentifyCUDATarget(Caller),
9617 CalleeTarget = S.IdentifyCUDATarget(Callee);
9620 OverloadCandidateKind FnKind =
9621 ClassifyOverloadCandidate(S, Cand->FoundDecl, Callee, FnDesc);
9623 S.Diag(Callee->getLocation(), diag::note_ovl_candidate_bad_target)
9624 << (unsigned)FnKind << CalleeTarget << CallerTarget;
9626 // This could be an implicit constructor for which we could not infer the
9627 // target due to a collsion. Diagnose that case.
9628 CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Callee);
9629 if (Meth != nullptr && Meth->isImplicit()) {
9630 CXXRecordDecl *ParentClass = Meth->getParent();
9631 Sema::CXXSpecialMember CSM;
9636 case oc_implicit_default_constructor:
9637 CSM = Sema::CXXDefaultConstructor;
9639 case oc_implicit_copy_constructor:
9640 CSM = Sema::CXXCopyConstructor;
9642 case oc_implicit_move_constructor:
9643 CSM = Sema::CXXMoveConstructor;
9645 case oc_implicit_copy_assignment:
9646 CSM = Sema::CXXCopyAssignment;
9648 case oc_implicit_move_assignment:
9649 CSM = Sema::CXXMoveAssignment;
9653 bool ConstRHS = false;
9654 if (Meth->getNumParams()) {
9655 if (const ReferenceType *RT =
9656 Meth->getParamDecl(0)->getType()->getAs<ReferenceType>()) {
9657 ConstRHS = RT->getPointeeType().isConstQualified();
9661 S.inferCUDATargetForImplicitSpecialMember(ParentClass, CSM, Meth,
9662 /* ConstRHS */ ConstRHS,
9663 /* Diagnose */ true);
9667 static void DiagnoseFailedEnableIfAttr(Sema &S, OverloadCandidate *Cand) {
9668 FunctionDecl *Callee = Cand->Function;
9669 EnableIfAttr *Attr = static_cast<EnableIfAttr*>(Cand->DeductionFailure.Data);
9671 S.Diag(Callee->getLocation(),
9672 diag::note_ovl_candidate_disabled_by_enable_if_attr)
9673 << Attr->getCond()->getSourceRange() << Attr->getMessage();
9676 /// Generates a 'note' diagnostic for an overload candidate. We've
9677 /// already generated a primary error at the call site.
9679 /// It really does need to be a single diagnostic with its caret
9680 /// pointed at the candidate declaration. Yes, this creates some
9681 /// major challenges of technical writing. Yes, this makes pointing
9682 /// out problems with specific arguments quite awkward. It's still
9683 /// better than generating twenty screens of text for every failed
9686 /// It would be great to be able to express per-candidate problems
9687 /// more richly for those diagnostic clients that cared, but we'd
9688 /// still have to be just as careful with the default diagnostics.
9689 static void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand,
9691 bool TakingCandidateAddress) {
9692 FunctionDecl *Fn = Cand->Function;
9694 // Note deleted candidates, but only if they're viable.
9695 if (Cand->Viable && (Fn->isDeleted() ||
9696 S.isFunctionConsideredUnavailable(Fn))) {
9698 OverloadCandidateKind FnKind =
9699 ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn, FnDesc);
9701 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted)
9703 << (Fn->isDeleted() ? (Fn->isDeletedAsWritten() ? 1 : 2) : 0);
9704 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9708 // We don't really have anything else to say about viable candidates.
9710 S.NoteOverloadCandidate(Cand->FoundDecl, Fn);
9714 switch (Cand->FailureKind) {
9715 case ovl_fail_too_many_arguments:
9716 case ovl_fail_too_few_arguments:
9717 return DiagnoseArityMismatch(S, Cand, NumArgs);
9719 case ovl_fail_bad_deduction:
9720 return DiagnoseBadDeduction(S, Cand, NumArgs,
9721 TakingCandidateAddress);
9723 case ovl_fail_illegal_constructor: {
9724 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_illegal_constructor)
9725 << (Fn->getPrimaryTemplate() ? 1 : 0);
9726 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9730 case ovl_fail_trivial_conversion:
9731 case ovl_fail_bad_final_conversion:
9732 case ovl_fail_final_conversion_not_exact:
9733 return S.NoteOverloadCandidate(Cand->FoundDecl, Fn);
9735 case ovl_fail_bad_conversion: {
9736 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0);
9737 for (unsigned N = Cand->NumConversions; I != N; ++I)
9738 if (Cand->Conversions[I].isBad())
9739 return DiagnoseBadConversion(S, Cand, I, TakingCandidateAddress);
9741 // FIXME: this currently happens when we're called from SemaInit
9742 // when user-conversion overload fails. Figure out how to handle
9743 // those conditions and diagnose them well.
9744 return S.NoteOverloadCandidate(Cand->FoundDecl, Fn);
9747 case ovl_fail_bad_target:
9748 return DiagnoseBadTarget(S, Cand);
9750 case ovl_fail_enable_if:
9751 return DiagnoseFailedEnableIfAttr(S, Cand);
9753 case ovl_fail_addr_not_available: {
9754 bool Available = checkAddressOfCandidateIsAvailable(S, Cand->Function);
9762 static void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) {
9763 // Desugar the type of the surrogate down to a function type,
9764 // retaining as many typedefs as possible while still showing
9765 // the function type (and, therefore, its parameter types).
9766 QualType FnType = Cand->Surrogate->getConversionType();
9767 bool isLValueReference = false;
9768 bool isRValueReference = false;
9769 bool isPointer = false;
9770 if (const LValueReferenceType *FnTypeRef =
9771 FnType->getAs<LValueReferenceType>()) {
9772 FnType = FnTypeRef->getPointeeType();
9773 isLValueReference = true;
9774 } else if (const RValueReferenceType *FnTypeRef =
9775 FnType->getAs<RValueReferenceType>()) {
9776 FnType = FnTypeRef->getPointeeType();
9777 isRValueReference = true;
9779 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) {
9780 FnType = FnTypePtr->getPointeeType();
9783 // Desugar down to a function type.
9784 FnType = QualType(FnType->getAs<FunctionType>(), 0);
9785 // Reconstruct the pointer/reference as appropriate.
9786 if (isPointer) FnType = S.Context.getPointerType(FnType);
9787 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType);
9788 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType);
9790 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand)
9794 static void NoteBuiltinOperatorCandidate(Sema &S, StringRef Opc,
9795 SourceLocation OpLoc,
9796 OverloadCandidate *Cand) {
9797 assert(Cand->NumConversions <= 2 && "builtin operator is not binary");
9798 std::string TypeStr("operator");
9801 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString();
9802 if (Cand->NumConversions == 1) {
9804 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr;
9807 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString();
9809 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr;
9813 static void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc,
9814 OverloadCandidate *Cand) {
9815 unsigned NoOperands = Cand->NumConversions;
9816 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) {
9817 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx];
9818 if (ICS.isBad()) break; // all meaningless after first invalid
9819 if (!ICS.isAmbiguous()) continue;
9821 ICS.DiagnoseAmbiguousConversion(
9822 S, OpLoc, S.PDiag(diag::note_ambiguous_type_conversion));
9826 static SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) {
9828 return Cand->Function->getLocation();
9829 if (Cand->IsSurrogate)
9830 return Cand->Surrogate->getLocation();
9831 return SourceLocation();
9834 static unsigned RankDeductionFailure(const DeductionFailureInfo &DFI) {
9835 switch ((Sema::TemplateDeductionResult)DFI.Result) {
9836 case Sema::TDK_Success:
9837 llvm_unreachable("TDK_success while diagnosing bad deduction");
9839 case Sema::TDK_Invalid:
9840 case Sema::TDK_Incomplete:
9843 case Sema::TDK_Underqualified:
9844 case Sema::TDK_Inconsistent:
9847 case Sema::TDK_SubstitutionFailure:
9848 case Sema::TDK_DeducedMismatch:
9849 case Sema::TDK_NonDeducedMismatch:
9850 case Sema::TDK_MiscellaneousDeductionFailure:
9853 case Sema::TDK_InstantiationDepth:
9854 case Sema::TDK_FailedOverloadResolution:
9857 case Sema::TDK_InvalidExplicitArguments:
9860 case Sema::TDK_TooManyArguments:
9861 case Sema::TDK_TooFewArguments:
9864 llvm_unreachable("Unhandled deduction result");
9868 struct CompareOverloadCandidatesForDisplay {
9873 CompareOverloadCandidatesForDisplay(Sema &S, SourceLocation Loc, size_t nArgs)
9874 : S(S), NumArgs(nArgs) {}
9876 bool operator()(const OverloadCandidate *L,
9877 const OverloadCandidate *R) {
9878 // Fast-path this check.
9879 if (L == R) return false;
9881 // Order first by viability.
9883 if (!R->Viable) return true;
9885 // TODO: introduce a tri-valued comparison for overload
9886 // candidates. Would be more worthwhile if we had a sort
9887 // that could exploit it.
9888 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation())) return true;
9889 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation())) return false;
9890 } else if (R->Viable)
9893 assert(L->Viable == R->Viable);
9895 // Criteria by which we can sort non-viable candidates:
9897 // 1. Arity mismatches come after other candidates.
9898 if (L->FailureKind == ovl_fail_too_many_arguments ||
9899 L->FailureKind == ovl_fail_too_few_arguments) {
9900 if (R->FailureKind == ovl_fail_too_many_arguments ||
9901 R->FailureKind == ovl_fail_too_few_arguments) {
9902 int LDist = std::abs((int)L->getNumParams() - (int)NumArgs);
9903 int RDist = std::abs((int)R->getNumParams() - (int)NumArgs);
9904 if (LDist == RDist) {
9905 if (L->FailureKind == R->FailureKind)
9906 // Sort non-surrogates before surrogates.
9907 return !L->IsSurrogate && R->IsSurrogate;
9908 // Sort candidates requiring fewer parameters than there were
9909 // arguments given after candidates requiring more parameters
9910 // than there were arguments given.
9911 return L->FailureKind == ovl_fail_too_many_arguments;
9913 return LDist < RDist;
9917 if (R->FailureKind == ovl_fail_too_many_arguments ||
9918 R->FailureKind == ovl_fail_too_few_arguments)
9921 // 2. Bad conversions come first and are ordered by the number
9922 // of bad conversions and quality of good conversions.
9923 if (L->FailureKind == ovl_fail_bad_conversion) {
9924 if (R->FailureKind != ovl_fail_bad_conversion)
9927 // The conversion that can be fixed with a smaller number of changes,
9929 unsigned numLFixes = L->Fix.NumConversionsFixed;
9930 unsigned numRFixes = R->Fix.NumConversionsFixed;
9931 numLFixes = (numLFixes == 0) ? UINT_MAX : numLFixes;
9932 numRFixes = (numRFixes == 0) ? UINT_MAX : numRFixes;
9933 if (numLFixes != numRFixes) {
9934 return numLFixes < numRFixes;
9937 // If there's any ordering between the defined conversions...
9938 // FIXME: this might not be transitive.
9939 assert(L->NumConversions == R->NumConversions);
9942 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument);
9943 for (unsigned E = L->NumConversions; I != E; ++I) {
9944 switch (CompareImplicitConversionSequences(S, Loc,
9946 R->Conversions[I])) {
9947 case ImplicitConversionSequence::Better:
9951 case ImplicitConversionSequence::Worse:
9955 case ImplicitConversionSequence::Indistinguishable:
9959 if (leftBetter > 0) return true;
9960 if (leftBetter < 0) return false;
9962 } else if (R->FailureKind == ovl_fail_bad_conversion)
9965 if (L->FailureKind == ovl_fail_bad_deduction) {
9966 if (R->FailureKind != ovl_fail_bad_deduction)
9969 if (L->DeductionFailure.Result != R->DeductionFailure.Result)
9970 return RankDeductionFailure(L->DeductionFailure)
9971 < RankDeductionFailure(R->DeductionFailure);
9972 } else if (R->FailureKind == ovl_fail_bad_deduction)
9978 // Sort everything else by location.
9979 SourceLocation LLoc = GetLocationForCandidate(L);
9980 SourceLocation RLoc = GetLocationForCandidate(R);
9982 // Put candidates without locations (e.g. builtins) at the end.
9983 if (LLoc.isInvalid()) return false;
9984 if (RLoc.isInvalid()) return true;
9986 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc);
9991 /// CompleteNonViableCandidate - Normally, overload resolution only
9992 /// computes up to the first. Produces the FixIt set if possible.
9993 static void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand,
9994 ArrayRef<Expr *> Args) {
9995 assert(!Cand->Viable);
9997 // Don't do anything on failures other than bad conversion.
9998 if (Cand->FailureKind != ovl_fail_bad_conversion) return;
10000 // We only want the FixIts if all the arguments can be corrected.
10001 bool Unfixable = false;
10002 // Use a implicit copy initialization to check conversion fixes.
10003 Cand->Fix.setConversionChecker(TryCopyInitialization);
10005 // Skip forward to the first bad conversion.
10006 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0);
10007 unsigned ConvCount = Cand->NumConversions;
10009 assert(ConvIdx != ConvCount && "no bad conversion in candidate");
10011 if (Cand->Conversions[ConvIdx - 1].isBad()) {
10012 Unfixable = !Cand->TryToFixBadConversion(ConvIdx - 1, S);
10017 if (ConvIdx == ConvCount)
10020 assert(!Cand->Conversions[ConvIdx].isInitialized() &&
10021 "remaining conversion is initialized?");
10023 // FIXME: this should probably be preserved from the overload
10024 // operation somehow.
10025 bool SuppressUserConversions = false;
10027 const FunctionProtoType* Proto;
10028 unsigned ArgIdx = ConvIdx;
10030 if (Cand->IsSurrogate) {
10032 = Cand->Surrogate->getConversionType().getNonReferenceType();
10033 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
10034 ConvType = ConvPtrType->getPointeeType();
10035 Proto = ConvType->getAs<FunctionProtoType>();
10037 } else if (Cand->Function) {
10038 Proto = Cand->Function->getType()->getAs<FunctionProtoType>();
10039 if (isa<CXXMethodDecl>(Cand->Function) &&
10040 !isa<CXXConstructorDecl>(Cand->Function))
10043 // Builtin binary operator with a bad first conversion.
10044 assert(ConvCount <= 3);
10045 for (; ConvIdx != ConvCount; ++ConvIdx)
10046 Cand->Conversions[ConvIdx]
10047 = TryCopyInitialization(S, Args[ConvIdx],
10048 Cand->BuiltinTypes.ParamTypes[ConvIdx],
10049 SuppressUserConversions,
10050 /*InOverloadResolution*/ true,
10051 /*AllowObjCWritebackConversion=*/
10052 S.getLangOpts().ObjCAutoRefCount);
10056 // Fill in the rest of the conversions.
10057 unsigned NumParams = Proto->getNumParams();
10058 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) {
10059 if (ArgIdx < NumParams) {
10060 Cand->Conversions[ConvIdx] = TryCopyInitialization(
10061 S, Args[ArgIdx], Proto->getParamType(ArgIdx), SuppressUserConversions,
10062 /*InOverloadResolution=*/true,
10063 /*AllowObjCWritebackConversion=*/
10064 S.getLangOpts().ObjCAutoRefCount);
10065 // Store the FixIt in the candidate if it exists.
10066 if (!Unfixable && Cand->Conversions[ConvIdx].isBad())
10067 Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S);
10070 Cand->Conversions[ConvIdx].setEllipsis();
10074 /// PrintOverloadCandidates - When overload resolution fails, prints
10075 /// diagnostic messages containing the candidates in the candidate
10077 void OverloadCandidateSet::NoteCandidates(Sema &S,
10078 OverloadCandidateDisplayKind OCD,
10079 ArrayRef<Expr *> Args,
10081 SourceLocation OpLoc) {
10082 // Sort the candidates by viability and position. Sorting directly would
10083 // be prohibitive, so we make a set of pointers and sort those.
10084 SmallVector<OverloadCandidate*, 32> Cands;
10085 if (OCD == OCD_AllCandidates) Cands.reserve(size());
10086 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) {
10088 Cands.push_back(Cand);
10089 else if (OCD == OCD_AllCandidates) {
10090 CompleteNonViableCandidate(S, Cand, Args);
10091 if (Cand->Function || Cand->IsSurrogate)
10092 Cands.push_back(Cand);
10093 // Otherwise, this a non-viable builtin candidate. We do not, in general,
10094 // want to list every possible builtin candidate.
10098 std::sort(Cands.begin(), Cands.end(),
10099 CompareOverloadCandidatesForDisplay(S, OpLoc, Args.size()));
10101 bool ReportedAmbiguousConversions = false;
10103 SmallVectorImpl<OverloadCandidate*>::iterator I, E;
10104 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
10105 unsigned CandsShown = 0;
10106 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) {
10107 OverloadCandidate *Cand = *I;
10109 // Set an arbitrary limit on the number of candidate functions we'll spam
10110 // the user with. FIXME: This limit should depend on details of the
10112 if (CandsShown >= 4 && ShowOverloads == Ovl_Best) {
10117 if (Cand->Function)
10118 NoteFunctionCandidate(S, Cand, Args.size(),
10119 /*TakingCandidateAddress=*/false);
10120 else if (Cand->IsSurrogate)
10121 NoteSurrogateCandidate(S, Cand);
10123 assert(Cand->Viable &&
10124 "Non-viable built-in candidates are not added to Cands.");
10125 // Generally we only see ambiguities including viable builtin
10126 // operators if overload resolution got screwed up by an
10127 // ambiguous user-defined conversion.
10129 // FIXME: It's quite possible for different conversions to see
10130 // different ambiguities, though.
10131 if (!ReportedAmbiguousConversions) {
10132 NoteAmbiguousUserConversions(S, OpLoc, Cand);
10133 ReportedAmbiguousConversions = true;
10136 // If this is a viable builtin, print it.
10137 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand);
10142 S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I);
10145 static SourceLocation
10146 GetLocationForCandidate(const TemplateSpecCandidate *Cand) {
10147 return Cand->Specialization ? Cand->Specialization->getLocation()
10148 : SourceLocation();
10152 struct CompareTemplateSpecCandidatesForDisplay {
10154 CompareTemplateSpecCandidatesForDisplay(Sema &S) : S(S) {}
10156 bool operator()(const TemplateSpecCandidate *L,
10157 const TemplateSpecCandidate *R) {
10158 // Fast-path this check.
10162 // Assuming that both candidates are not matches...
10164 // Sort by the ranking of deduction failures.
10165 if (L->DeductionFailure.Result != R->DeductionFailure.Result)
10166 return RankDeductionFailure(L->DeductionFailure) <
10167 RankDeductionFailure(R->DeductionFailure);
10169 // Sort everything else by location.
10170 SourceLocation LLoc = GetLocationForCandidate(L);
10171 SourceLocation RLoc = GetLocationForCandidate(R);
10173 // Put candidates without locations (e.g. builtins) at the end.
10174 if (LLoc.isInvalid())
10176 if (RLoc.isInvalid())
10179 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc);
10184 /// Diagnose a template argument deduction failure.
10185 /// We are treating these failures as overload failures due to bad
10187 void TemplateSpecCandidate::NoteDeductionFailure(Sema &S,
10188 bool ForTakingAddress) {
10189 DiagnoseBadDeduction(S, FoundDecl, Specialization, // pattern
10190 DeductionFailure, /*NumArgs=*/0, ForTakingAddress);
10193 void TemplateSpecCandidateSet::destroyCandidates() {
10194 for (iterator i = begin(), e = end(); i != e; ++i) {
10195 i->DeductionFailure.Destroy();
10199 void TemplateSpecCandidateSet::clear() {
10200 destroyCandidates();
10201 Candidates.clear();
10204 /// NoteCandidates - When no template specialization match is found, prints
10205 /// diagnostic messages containing the non-matching specializations that form
10206 /// the candidate set.
10207 /// This is analoguous to OverloadCandidateSet::NoteCandidates() with
10208 /// OCD == OCD_AllCandidates and Cand->Viable == false.
10209 void TemplateSpecCandidateSet::NoteCandidates(Sema &S, SourceLocation Loc) {
10210 // Sort the candidates by position (assuming no candidate is a match).
10211 // Sorting directly would be prohibitive, so we make a set of pointers
10213 SmallVector<TemplateSpecCandidate *, 32> Cands;
10214 Cands.reserve(size());
10215 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) {
10216 if (Cand->Specialization)
10217 Cands.push_back(Cand);
10218 // Otherwise, this is a non-matching builtin candidate. We do not,
10219 // in general, want to list every possible builtin candidate.
10222 std::sort(Cands.begin(), Cands.end(),
10223 CompareTemplateSpecCandidatesForDisplay(S));
10225 // FIXME: Perhaps rename OverloadsShown and getShowOverloads()
10226 // for generalization purposes (?).
10227 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
10229 SmallVectorImpl<TemplateSpecCandidate *>::iterator I, E;
10230 unsigned CandsShown = 0;
10231 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) {
10232 TemplateSpecCandidate *Cand = *I;
10234 // Set an arbitrary limit on the number of candidates we'll spam
10235 // the user with. FIXME: This limit should depend on details of the
10237 if (CandsShown >= 4 && ShowOverloads == Ovl_Best)
10241 assert(Cand->Specialization &&
10242 "Non-matching built-in candidates are not added to Cands.");
10243 Cand->NoteDeductionFailure(S, ForTakingAddress);
10247 S.Diag(Loc, diag::note_ovl_too_many_candidates) << int(E - I);
10250 // [PossiblyAFunctionType] --> [Return]
10251 // NonFunctionType --> NonFunctionType
10253 // R (*)(A) --> R (A)
10254 // R (&)(A) --> R (A)
10255 // R (S::*)(A) --> R (A)
10256 QualType Sema::ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType) {
10257 QualType Ret = PossiblyAFunctionType;
10258 if (const PointerType *ToTypePtr =
10259 PossiblyAFunctionType->getAs<PointerType>())
10260 Ret = ToTypePtr->getPointeeType();
10261 else if (const ReferenceType *ToTypeRef =
10262 PossiblyAFunctionType->getAs<ReferenceType>())
10263 Ret = ToTypeRef->getPointeeType();
10264 else if (const MemberPointerType *MemTypePtr =
10265 PossiblyAFunctionType->getAs<MemberPointerType>())
10266 Ret = MemTypePtr->getPointeeType();
10268 Context.getCanonicalType(Ret).getUnqualifiedType();
10273 // A helper class to help with address of function resolution
10274 // - allows us to avoid passing around all those ugly parameters
10275 class AddressOfFunctionResolver {
10278 const QualType& TargetType;
10279 QualType TargetFunctionType; // Extracted function type from target type
10282 //DeclAccessPair& ResultFunctionAccessPair;
10283 ASTContext& Context;
10285 bool TargetTypeIsNonStaticMemberFunction;
10286 bool FoundNonTemplateFunction;
10287 bool StaticMemberFunctionFromBoundPointer;
10288 bool HasComplained;
10290 OverloadExpr::FindResult OvlExprInfo;
10291 OverloadExpr *OvlExpr;
10292 TemplateArgumentListInfo OvlExplicitTemplateArgs;
10293 SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches;
10294 TemplateSpecCandidateSet FailedCandidates;
10297 AddressOfFunctionResolver(Sema &S, Expr *SourceExpr,
10298 const QualType &TargetType, bool Complain)
10299 : S(S), SourceExpr(SourceExpr), TargetType(TargetType),
10300 Complain(Complain), Context(S.getASTContext()),
10301 TargetTypeIsNonStaticMemberFunction(
10302 !!TargetType->getAs<MemberPointerType>()),
10303 FoundNonTemplateFunction(false),
10304 StaticMemberFunctionFromBoundPointer(false),
10305 HasComplained(false),
10306 OvlExprInfo(OverloadExpr::find(SourceExpr)),
10307 OvlExpr(OvlExprInfo.Expression),
10308 FailedCandidates(OvlExpr->getNameLoc(), /*ForTakingAddress=*/true) {
10309 ExtractUnqualifiedFunctionTypeFromTargetType();
10311 if (TargetFunctionType->isFunctionType()) {
10312 if (UnresolvedMemberExpr *UME = dyn_cast<UnresolvedMemberExpr>(OvlExpr))
10313 if (!UME->isImplicitAccess() &&
10314 !S.ResolveSingleFunctionTemplateSpecialization(UME))
10315 StaticMemberFunctionFromBoundPointer = true;
10316 } else if (OvlExpr->hasExplicitTemplateArgs()) {
10317 DeclAccessPair dap;
10318 if (FunctionDecl *Fn = S.ResolveSingleFunctionTemplateSpecialization(
10319 OvlExpr, false, &dap)) {
10320 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn))
10321 if (!Method->isStatic()) {
10322 // If the target type is a non-function type and the function found
10323 // is a non-static member function, pretend as if that was the
10324 // target, it's the only possible type to end up with.
10325 TargetTypeIsNonStaticMemberFunction = true;
10327 // And skip adding the function if its not in the proper form.
10328 // We'll diagnose this due to an empty set of functions.
10329 if (!OvlExprInfo.HasFormOfMemberPointer)
10333 Matches.push_back(std::make_pair(dap, Fn));
10338 if (OvlExpr->hasExplicitTemplateArgs())
10339 OvlExpr->copyTemplateArgumentsInto(OvlExplicitTemplateArgs);
10341 if (FindAllFunctionsThatMatchTargetTypeExactly()) {
10342 // C++ [over.over]p4:
10343 // If more than one function is selected, [...]
10344 if (Matches.size() > 1 && !eliminiateSuboptimalOverloadCandidates()) {
10345 if (FoundNonTemplateFunction)
10346 EliminateAllTemplateMatches();
10348 EliminateAllExceptMostSpecializedTemplate();
10352 if (S.getLangOpts().CUDA && Matches.size() > 1)
10353 EliminateSuboptimalCudaMatches();
10356 bool hasComplained() const { return HasComplained; }
10359 bool candidateHasExactlyCorrectType(const FunctionDecl *FD) {
10361 return Context.hasSameUnqualifiedType(TargetFunctionType, FD->getType()) ||
10362 S.IsNoReturnConversion(FD->getType(), TargetFunctionType, Discard);
10365 /// \return true if A is considered a better overload candidate for the
10366 /// desired type than B.
10367 bool isBetterCandidate(const FunctionDecl *A, const FunctionDecl *B) {
10368 // If A doesn't have exactly the correct type, we don't want to classify it
10369 // as "better" than anything else. This way, the user is required to
10370 // disambiguate for us if there are multiple candidates and no exact match.
10371 return candidateHasExactlyCorrectType(A) &&
10372 (!candidateHasExactlyCorrectType(B) ||
10373 compareEnableIfAttrs(S, A, B) == Comparison::Better);
10376 /// \return true if we were able to eliminate all but one overload candidate,
10377 /// false otherwise.
10378 bool eliminiateSuboptimalOverloadCandidates() {
10379 // Same algorithm as overload resolution -- one pass to pick the "best",
10380 // another pass to be sure that nothing is better than the best.
10381 auto Best = Matches.begin();
10382 for (auto I = Matches.begin()+1, E = Matches.end(); I != E; ++I)
10383 if (isBetterCandidate(I->second, Best->second))
10386 const FunctionDecl *BestFn = Best->second;
10387 auto IsBestOrInferiorToBest = [this, BestFn](
10388 const std::pair<DeclAccessPair, FunctionDecl *> &Pair) {
10389 return BestFn == Pair.second || isBetterCandidate(BestFn, Pair.second);
10392 // Note: We explicitly leave Matches unmodified if there isn't a clear best
10393 // option, so we can potentially give the user a better error
10394 if (!std::all_of(Matches.begin(), Matches.end(), IsBestOrInferiorToBest))
10396 Matches[0] = *Best;
10401 bool isTargetTypeAFunction() const {
10402 return TargetFunctionType->isFunctionType();
10405 // [ToType] [Return]
10407 // R (*)(A) --> R (A), IsNonStaticMemberFunction = false
10408 // R (&)(A) --> R (A), IsNonStaticMemberFunction = false
10409 // R (S::*)(A) --> R (A), IsNonStaticMemberFunction = true
10410 void inline ExtractUnqualifiedFunctionTypeFromTargetType() {
10411 TargetFunctionType = S.ExtractUnqualifiedFunctionType(TargetType);
10414 // return true if any matching specializations were found
10415 bool AddMatchingTemplateFunction(FunctionTemplateDecl* FunctionTemplate,
10416 const DeclAccessPair& CurAccessFunPair) {
10417 if (CXXMethodDecl *Method
10418 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) {
10419 // Skip non-static function templates when converting to pointer, and
10420 // static when converting to member pointer.
10421 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction)
10424 else if (TargetTypeIsNonStaticMemberFunction)
10427 // C++ [over.over]p2:
10428 // If the name is a function template, template argument deduction is
10429 // done (14.8.2.2), and if the argument deduction succeeds, the
10430 // resulting template argument list is used to generate a single
10431 // function template specialization, which is added to the set of
10432 // overloaded functions considered.
10433 FunctionDecl *Specialization = nullptr;
10434 TemplateDeductionInfo Info(FailedCandidates.getLocation());
10435 if (Sema::TemplateDeductionResult Result
10436 = S.DeduceTemplateArguments(FunctionTemplate,
10437 &OvlExplicitTemplateArgs,
10438 TargetFunctionType, Specialization,
10439 Info, /*InOverloadResolution=*/true)) {
10440 // Make a note of the failed deduction for diagnostics.
10441 FailedCandidates.addCandidate()
10442 .set(CurAccessFunPair, FunctionTemplate->getTemplatedDecl(),
10443 MakeDeductionFailureInfo(Context, Result, Info));
10447 // Template argument deduction ensures that we have an exact match or
10448 // compatible pointer-to-function arguments that would be adjusted by ICS.
10449 // This function template specicalization works.
10450 assert(S.isSameOrCompatibleFunctionType(
10451 Context.getCanonicalType(Specialization->getType()),
10452 Context.getCanonicalType(TargetFunctionType)));
10454 if (!S.checkAddressOfFunctionIsAvailable(Specialization))
10457 Matches.push_back(std::make_pair(CurAccessFunPair, Specialization));
10461 bool AddMatchingNonTemplateFunction(NamedDecl* Fn,
10462 const DeclAccessPair& CurAccessFunPair) {
10463 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) {
10464 // Skip non-static functions when converting to pointer, and static
10465 // when converting to member pointer.
10466 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction)
10469 else if (TargetTypeIsNonStaticMemberFunction)
10472 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) {
10473 if (S.getLangOpts().CUDA)
10474 if (FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext))
10475 if (!Caller->isImplicit() && S.CheckCUDATarget(Caller, FunDecl))
10478 // If any candidate has a placeholder return type, trigger its deduction
10480 if (S.getLangOpts().CPlusPlus14 &&
10481 FunDecl->getReturnType()->isUndeducedType() &&
10482 S.DeduceReturnType(FunDecl, SourceExpr->getLocStart(), Complain)) {
10483 HasComplained |= Complain;
10487 if (!S.checkAddressOfFunctionIsAvailable(FunDecl))
10490 // If we're in C, we need to support types that aren't exactly identical.
10491 if (!S.getLangOpts().CPlusPlus ||
10492 candidateHasExactlyCorrectType(FunDecl)) {
10493 Matches.push_back(std::make_pair(
10494 CurAccessFunPair, cast<FunctionDecl>(FunDecl->getCanonicalDecl())));
10495 FoundNonTemplateFunction = true;
10503 bool FindAllFunctionsThatMatchTargetTypeExactly() {
10506 // If the overload expression doesn't have the form of a pointer to
10507 // member, don't try to convert it to a pointer-to-member type.
10508 if (IsInvalidFormOfPointerToMemberFunction())
10511 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
10512 E = OvlExpr->decls_end();
10514 // Look through any using declarations to find the underlying function.
10515 NamedDecl *Fn = (*I)->getUnderlyingDecl();
10517 // C++ [over.over]p3:
10518 // Non-member functions and static member functions match
10519 // targets of type "pointer-to-function" or "reference-to-function."
10520 // Nonstatic member functions match targets of
10521 // type "pointer-to-member-function."
10522 // Note that according to DR 247, the containing class does not matter.
10523 if (FunctionTemplateDecl *FunctionTemplate
10524 = dyn_cast<FunctionTemplateDecl>(Fn)) {
10525 if (AddMatchingTemplateFunction(FunctionTemplate, I.getPair()))
10528 // If we have explicit template arguments supplied, skip non-templates.
10529 else if (!OvlExpr->hasExplicitTemplateArgs() &&
10530 AddMatchingNonTemplateFunction(Fn, I.getPair()))
10533 assert(Ret || Matches.empty());
10537 void EliminateAllExceptMostSpecializedTemplate() {
10538 // [...] and any given function template specialization F1 is
10539 // eliminated if the set contains a second function template
10540 // specialization whose function template is more specialized
10541 // than the function template of F1 according to the partial
10542 // ordering rules of 14.5.5.2.
10544 // The algorithm specified above is quadratic. We instead use a
10545 // two-pass algorithm (similar to the one used to identify the
10546 // best viable function in an overload set) that identifies the
10547 // best function template (if it exists).
10549 UnresolvedSet<4> MatchesCopy; // TODO: avoid!
10550 for (unsigned I = 0, E = Matches.size(); I != E; ++I)
10551 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess());
10553 // TODO: It looks like FailedCandidates does not serve much purpose
10554 // here, since the no_viable diagnostic has index 0.
10555 UnresolvedSetIterator Result = S.getMostSpecialized(
10556 MatchesCopy.begin(), MatchesCopy.end(), FailedCandidates,
10557 SourceExpr->getLocStart(), S.PDiag(),
10558 S.PDiag(diag::err_addr_ovl_ambiguous)
10559 << Matches[0].second->getDeclName(),
10560 S.PDiag(diag::note_ovl_candidate)
10561 << (unsigned)oc_function_template,
10562 Complain, TargetFunctionType);
10564 if (Result != MatchesCopy.end()) {
10565 // Make it the first and only element
10566 Matches[0].first = Matches[Result - MatchesCopy.begin()].first;
10567 Matches[0].second = cast<FunctionDecl>(*Result);
10570 HasComplained |= Complain;
10573 void EliminateAllTemplateMatches() {
10574 // [...] any function template specializations in the set are
10575 // eliminated if the set also contains a non-template function, [...]
10576 for (unsigned I = 0, N = Matches.size(); I != N; ) {
10577 if (Matches[I].second->getPrimaryTemplate() == nullptr)
10580 Matches[I] = Matches[--N];
10586 void EliminateSuboptimalCudaMatches() {
10587 S.EraseUnwantedCUDAMatches(dyn_cast<FunctionDecl>(S.CurContext), Matches);
10591 void ComplainNoMatchesFound() const {
10592 assert(Matches.empty());
10593 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_no_viable)
10594 << OvlExpr->getName() << TargetFunctionType
10595 << OvlExpr->getSourceRange();
10596 if (FailedCandidates.empty())
10597 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType,
10598 /*TakingAddress=*/true);
10600 // We have some deduction failure messages. Use them to diagnose
10601 // the function templates, and diagnose the non-template candidates
10603 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
10604 IEnd = OvlExpr->decls_end();
10606 if (FunctionDecl *Fun =
10607 dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()))
10608 if (!functionHasPassObjectSizeParams(Fun))
10609 S.NoteOverloadCandidate(*I, Fun, TargetFunctionType,
10610 /*TakingAddress=*/true);
10611 FailedCandidates.NoteCandidates(S, OvlExpr->getLocStart());
10615 bool IsInvalidFormOfPointerToMemberFunction() const {
10616 return TargetTypeIsNonStaticMemberFunction &&
10617 !OvlExprInfo.HasFormOfMemberPointer;
10620 void ComplainIsInvalidFormOfPointerToMemberFunction() const {
10621 // TODO: Should we condition this on whether any functions might
10622 // have matched, or is it more appropriate to do that in callers?
10623 // TODO: a fixit wouldn't hurt.
10624 S.Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier)
10625 << TargetType << OvlExpr->getSourceRange();
10628 bool IsStaticMemberFunctionFromBoundPointer() const {
10629 return StaticMemberFunctionFromBoundPointer;
10632 void ComplainIsStaticMemberFunctionFromBoundPointer() const {
10633 S.Diag(OvlExpr->getLocStart(),
10634 diag::err_invalid_form_pointer_member_function)
10635 << OvlExpr->getSourceRange();
10638 void ComplainOfInvalidConversion() const {
10639 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_not_func_ptrref)
10640 << OvlExpr->getName() << TargetType;
10643 void ComplainMultipleMatchesFound() const {
10644 assert(Matches.size() > 1);
10645 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_ambiguous)
10646 << OvlExpr->getName()
10647 << OvlExpr->getSourceRange();
10648 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType,
10649 /*TakingAddress=*/true);
10652 bool hadMultipleCandidates() const { return (OvlExpr->getNumDecls() > 1); }
10654 int getNumMatches() const { return Matches.size(); }
10656 FunctionDecl* getMatchingFunctionDecl() const {
10657 if (Matches.size() != 1) return nullptr;
10658 return Matches[0].second;
10661 const DeclAccessPair* getMatchingFunctionAccessPair() const {
10662 if (Matches.size() != 1) return nullptr;
10663 return &Matches[0].first;
10668 /// ResolveAddressOfOverloadedFunction - Try to resolve the address of
10669 /// an overloaded function (C++ [over.over]), where @p From is an
10670 /// expression with overloaded function type and @p ToType is the type
10671 /// we're trying to resolve to. For example:
10677 /// int (*pfd)(double) = f; // selects f(double)
10680 /// This routine returns the resulting FunctionDecl if it could be
10681 /// resolved, and NULL otherwise. When @p Complain is true, this
10682 /// routine will emit diagnostics if there is an error.
10684 Sema::ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr,
10685 QualType TargetType,
10687 DeclAccessPair &FoundResult,
10688 bool *pHadMultipleCandidates) {
10689 assert(AddressOfExpr->getType() == Context.OverloadTy);
10691 AddressOfFunctionResolver Resolver(*this, AddressOfExpr, TargetType,
10693 int NumMatches = Resolver.getNumMatches();
10694 FunctionDecl *Fn = nullptr;
10695 bool ShouldComplain = Complain && !Resolver.hasComplained();
10696 if (NumMatches == 0 && ShouldComplain) {
10697 if (Resolver.IsInvalidFormOfPointerToMemberFunction())
10698 Resolver.ComplainIsInvalidFormOfPointerToMemberFunction();
10700 Resolver.ComplainNoMatchesFound();
10702 else if (NumMatches > 1 && ShouldComplain)
10703 Resolver.ComplainMultipleMatchesFound();
10704 else if (NumMatches == 1) {
10705 Fn = Resolver.getMatchingFunctionDecl();
10707 FoundResult = *Resolver.getMatchingFunctionAccessPair();
10709 if (Resolver.IsStaticMemberFunctionFromBoundPointer())
10710 Resolver.ComplainIsStaticMemberFunctionFromBoundPointer();
10712 CheckAddressOfMemberAccess(AddressOfExpr, FoundResult);
10716 if (pHadMultipleCandidates)
10717 *pHadMultipleCandidates = Resolver.hadMultipleCandidates();
10721 /// \brief Given an expression that refers to an overloaded function, try to
10722 /// resolve that function to a single function that can have its address taken.
10723 /// This will modify `Pair` iff it returns non-null.
10725 /// This routine can only realistically succeed if all but one candidates in the
10726 /// overload set for SrcExpr cannot have their addresses taken.
10728 Sema::resolveAddressOfOnlyViableOverloadCandidate(Expr *E,
10729 DeclAccessPair &Pair) {
10730 OverloadExpr::FindResult R = OverloadExpr::find(E);
10731 OverloadExpr *Ovl = R.Expression;
10732 FunctionDecl *Result = nullptr;
10733 DeclAccessPair DAP;
10734 // Don't use the AddressOfResolver because we're specifically looking for
10735 // cases where we have one overload candidate that lacks
10736 // enable_if/pass_object_size/...
10737 for (auto I = Ovl->decls_begin(), E = Ovl->decls_end(); I != E; ++I) {
10738 auto *FD = dyn_cast<FunctionDecl>(I->getUnderlyingDecl());
10742 if (!checkAddressOfFunctionIsAvailable(FD))
10745 // We have more than one result; quit.
10757 /// \brief Given an overloaded function, tries to turn it into a non-overloaded
10758 /// function reference using resolveAddressOfOnlyViableOverloadCandidate. This
10759 /// will perform access checks, diagnose the use of the resultant decl, and, if
10760 /// necessary, perform a function-to-pointer decay.
10762 /// Returns false if resolveAddressOfOnlyViableOverloadCandidate fails.
10763 /// Otherwise, returns true. This may emit diagnostics and return true.
10764 bool Sema::resolveAndFixAddressOfOnlyViableOverloadCandidate(
10765 ExprResult &SrcExpr) {
10766 Expr *E = SrcExpr.get();
10767 assert(E->getType() == Context.OverloadTy && "SrcExpr must be an overload");
10769 DeclAccessPair DAP;
10770 FunctionDecl *Found = resolveAddressOfOnlyViableOverloadCandidate(E, DAP);
10774 // Emitting multiple diagnostics for a function that is both inaccessible and
10775 // unavailable is consistent with our behavior elsewhere. So, always check
10777 DiagnoseUseOfDecl(Found, E->getExprLoc());
10778 CheckAddressOfMemberAccess(E, DAP);
10779 Expr *Fixed = FixOverloadedFunctionReference(E, DAP, Found);
10780 if (Fixed->getType()->isFunctionType())
10781 SrcExpr = DefaultFunctionArrayConversion(Fixed, /*Diagnose=*/false);
10787 /// \brief Given an expression that refers to an overloaded function, try to
10788 /// resolve that overloaded function expression down to a single function.
10790 /// This routine can only resolve template-ids that refer to a single function
10791 /// template, where that template-id refers to a single template whose template
10792 /// arguments are either provided by the template-id or have defaults,
10793 /// as described in C++0x [temp.arg.explicit]p3.
10795 /// If no template-ids are found, no diagnostics are emitted and NULL is
10798 Sema::ResolveSingleFunctionTemplateSpecialization(OverloadExpr *ovl,
10800 DeclAccessPair *FoundResult) {
10801 // C++ [over.over]p1:
10802 // [...] [Note: any redundant set of parentheses surrounding the
10803 // overloaded function name is ignored (5.1). ]
10804 // C++ [over.over]p1:
10805 // [...] The overloaded function name can be preceded by the &
10808 // If we didn't actually find any template-ids, we're done.
10809 if (!ovl->hasExplicitTemplateArgs())
10812 TemplateArgumentListInfo ExplicitTemplateArgs;
10813 ovl->copyTemplateArgumentsInto(ExplicitTemplateArgs);
10814 TemplateSpecCandidateSet FailedCandidates(ovl->getNameLoc());
10816 // Look through all of the overloaded functions, searching for one
10817 // whose type matches exactly.
10818 FunctionDecl *Matched = nullptr;
10819 for (UnresolvedSetIterator I = ovl->decls_begin(),
10820 E = ovl->decls_end(); I != E; ++I) {
10821 // C++0x [temp.arg.explicit]p3:
10822 // [...] In contexts where deduction is done and fails, or in contexts
10823 // where deduction is not done, if a template argument list is
10824 // specified and it, along with any default template arguments,
10825 // identifies a single function template specialization, then the
10826 // template-id is an lvalue for the function template specialization.
10827 FunctionTemplateDecl *FunctionTemplate
10828 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl());
10830 // C++ [over.over]p2:
10831 // If the name is a function template, template argument deduction is
10832 // done (14.8.2.2), and if the argument deduction succeeds, the
10833 // resulting template argument list is used to generate a single
10834 // function template specialization, which is added to the set of
10835 // overloaded functions considered.
10836 FunctionDecl *Specialization = nullptr;
10837 TemplateDeductionInfo Info(FailedCandidates.getLocation());
10838 if (TemplateDeductionResult Result
10839 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs,
10840 Specialization, Info,
10841 /*InOverloadResolution=*/true)) {
10842 // Make a note of the failed deduction for diagnostics.
10843 // TODO: Actually use the failed-deduction info?
10844 FailedCandidates.addCandidate()
10845 .set(I.getPair(), FunctionTemplate->getTemplatedDecl(),
10846 MakeDeductionFailureInfo(Context, Result, Info));
10850 assert(Specialization && "no specialization and no error?");
10852 // Multiple matches; we can't resolve to a single declaration.
10855 Diag(ovl->getExprLoc(), diag::err_addr_ovl_ambiguous)
10857 NoteAllOverloadCandidates(ovl);
10862 Matched = Specialization;
10863 if (FoundResult) *FoundResult = I.getPair();
10866 if (Matched && getLangOpts().CPlusPlus14 &&
10867 Matched->getReturnType()->isUndeducedType() &&
10868 DeduceReturnType(Matched, ovl->getExprLoc(), Complain))
10877 // Resolve and fix an overloaded expression that can be resolved
10878 // because it identifies a single function template specialization.
10880 // Last three arguments should only be supplied if Complain = true
10882 // Return true if it was logically possible to so resolve the
10883 // expression, regardless of whether or not it succeeded. Always
10884 // returns true if 'complain' is set.
10885 bool Sema::ResolveAndFixSingleFunctionTemplateSpecialization(
10886 ExprResult &SrcExpr, bool doFunctionPointerConverion,
10887 bool complain, SourceRange OpRangeForComplaining,
10888 QualType DestTypeForComplaining,
10889 unsigned DiagIDForComplaining) {
10890 assert(SrcExpr.get()->getType() == Context.OverloadTy);
10892 OverloadExpr::FindResult ovl = OverloadExpr::find(SrcExpr.get());
10894 DeclAccessPair found;
10895 ExprResult SingleFunctionExpression;
10896 if (FunctionDecl *fn = ResolveSingleFunctionTemplateSpecialization(
10897 ovl.Expression, /*complain*/ false, &found)) {
10898 if (DiagnoseUseOfDecl(fn, SrcExpr.get()->getLocStart())) {
10899 SrcExpr = ExprError();
10903 // It is only correct to resolve to an instance method if we're
10904 // resolving a form that's permitted to be a pointer to member.
10905 // Otherwise we'll end up making a bound member expression, which
10906 // is illegal in all the contexts we resolve like this.
10907 if (!ovl.HasFormOfMemberPointer &&
10908 isa<CXXMethodDecl>(fn) &&
10909 cast<CXXMethodDecl>(fn)->isInstance()) {
10910 if (!complain) return false;
10912 Diag(ovl.Expression->getExprLoc(),
10913 diag::err_bound_member_function)
10914 << 0 << ovl.Expression->getSourceRange();
10916 // TODO: I believe we only end up here if there's a mix of
10917 // static and non-static candidates (otherwise the expression
10918 // would have 'bound member' type, not 'overload' type).
10919 // Ideally we would note which candidate was chosen and why
10920 // the static candidates were rejected.
10921 SrcExpr = ExprError();
10925 // Fix the expression to refer to 'fn'.
10926 SingleFunctionExpression =
10927 FixOverloadedFunctionReference(SrcExpr.get(), found, fn);
10929 // If desired, do function-to-pointer decay.
10930 if (doFunctionPointerConverion) {
10931 SingleFunctionExpression =
10932 DefaultFunctionArrayLvalueConversion(SingleFunctionExpression.get());
10933 if (SingleFunctionExpression.isInvalid()) {
10934 SrcExpr = ExprError();
10940 if (!SingleFunctionExpression.isUsable()) {
10942 Diag(OpRangeForComplaining.getBegin(), DiagIDForComplaining)
10943 << ovl.Expression->getName()
10944 << DestTypeForComplaining
10945 << OpRangeForComplaining
10946 << ovl.Expression->getQualifierLoc().getSourceRange();
10947 NoteAllOverloadCandidates(SrcExpr.get());
10949 SrcExpr = ExprError();
10956 SrcExpr = SingleFunctionExpression;
10960 /// \brief Add a single candidate to the overload set.
10961 static void AddOverloadedCallCandidate(Sema &S,
10962 DeclAccessPair FoundDecl,
10963 TemplateArgumentListInfo *ExplicitTemplateArgs,
10964 ArrayRef<Expr *> Args,
10965 OverloadCandidateSet &CandidateSet,
10966 bool PartialOverloading,
10968 NamedDecl *Callee = FoundDecl.getDecl();
10969 if (isa<UsingShadowDecl>(Callee))
10970 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl();
10972 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) {
10973 if (ExplicitTemplateArgs) {
10974 assert(!KnownValid && "Explicit template arguments?");
10977 S.AddOverloadCandidate(Func, FoundDecl, Args, CandidateSet,
10978 /*SuppressUsedConversions=*/false,
10979 PartialOverloading);
10983 if (FunctionTemplateDecl *FuncTemplate
10984 = dyn_cast<FunctionTemplateDecl>(Callee)) {
10985 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl,
10986 ExplicitTemplateArgs, Args, CandidateSet,
10987 /*SuppressUsedConversions=*/false,
10988 PartialOverloading);
10992 assert(!KnownValid && "unhandled case in overloaded call candidate");
10995 /// \brief Add the overload candidates named by callee and/or found by argument
10996 /// dependent lookup to the given overload set.
10997 void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE,
10998 ArrayRef<Expr *> Args,
10999 OverloadCandidateSet &CandidateSet,
11000 bool PartialOverloading) {
11003 // Verify that ArgumentDependentLookup is consistent with the rules
11004 // in C++0x [basic.lookup.argdep]p3:
11006 // Let X be the lookup set produced by unqualified lookup (3.4.1)
11007 // and let Y be the lookup set produced by argument dependent
11008 // lookup (defined as follows). If X contains
11010 // -- a declaration of a class member, or
11012 // -- a block-scope function declaration that is not a
11013 // using-declaration, or
11015 // -- a declaration that is neither a function or a function
11018 // then Y is empty.
11020 if (ULE->requiresADL()) {
11021 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(),
11022 E = ULE->decls_end(); I != E; ++I) {
11023 assert(!(*I)->getDeclContext()->isRecord());
11024 assert(isa<UsingShadowDecl>(*I) ||
11025 !(*I)->getDeclContext()->isFunctionOrMethod());
11026 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate());
11031 // It would be nice to avoid this copy.
11032 TemplateArgumentListInfo TABuffer;
11033 TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr;
11034 if (ULE->hasExplicitTemplateArgs()) {
11035 ULE->copyTemplateArgumentsInto(TABuffer);
11036 ExplicitTemplateArgs = &TABuffer;
11039 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(),
11040 E = ULE->decls_end(); I != E; ++I)
11041 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, Args,
11042 CandidateSet, PartialOverloading,
11043 /*KnownValid*/ true);
11045 if (ULE->requiresADL())
11046 AddArgumentDependentLookupCandidates(ULE->getName(), ULE->getExprLoc(),
11047 Args, ExplicitTemplateArgs,
11048 CandidateSet, PartialOverloading);
11051 /// Determine whether a declaration with the specified name could be moved into
11052 /// a different namespace.
11053 static bool canBeDeclaredInNamespace(const DeclarationName &Name) {
11054 switch (Name.getCXXOverloadedOperator()) {
11055 case OO_New: case OO_Array_New:
11056 case OO_Delete: case OO_Array_Delete:
11064 /// Attempt to recover from an ill-formed use of a non-dependent name in a
11065 /// template, where the non-dependent name was declared after the template
11066 /// was defined. This is common in code written for a compilers which do not
11067 /// correctly implement two-stage name lookup.
11069 /// Returns true if a viable candidate was found and a diagnostic was issued.
11071 DiagnoseTwoPhaseLookup(Sema &SemaRef, SourceLocation FnLoc,
11072 const CXXScopeSpec &SS, LookupResult &R,
11073 OverloadCandidateSet::CandidateSetKind CSK,
11074 TemplateArgumentListInfo *ExplicitTemplateArgs,
11075 ArrayRef<Expr *> Args,
11076 bool *DoDiagnoseEmptyLookup = nullptr) {
11077 if (SemaRef.ActiveTemplateInstantiations.empty() || !SS.isEmpty())
11080 for (DeclContext *DC = SemaRef.CurContext; DC; DC = DC->getParent()) {
11081 if (DC->isTransparentContext())
11084 SemaRef.LookupQualifiedName(R, DC);
11087 R.suppressDiagnostics();
11089 if (isa<CXXRecordDecl>(DC)) {
11090 // Don't diagnose names we find in classes; we get much better
11091 // diagnostics for these from DiagnoseEmptyLookup.
11093 if (DoDiagnoseEmptyLookup)
11094 *DoDiagnoseEmptyLookup = true;
11098 OverloadCandidateSet Candidates(FnLoc, CSK);
11099 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
11100 AddOverloadedCallCandidate(SemaRef, I.getPair(),
11101 ExplicitTemplateArgs, Args,
11102 Candidates, false, /*KnownValid*/ false);
11104 OverloadCandidateSet::iterator Best;
11105 if (Candidates.BestViableFunction(SemaRef, FnLoc, Best) != OR_Success) {
11106 // No viable functions. Don't bother the user with notes for functions
11107 // which don't work and shouldn't be found anyway.
11112 // Find the namespaces where ADL would have looked, and suggest
11113 // declaring the function there instead.
11114 Sema::AssociatedNamespaceSet AssociatedNamespaces;
11115 Sema::AssociatedClassSet AssociatedClasses;
11116 SemaRef.FindAssociatedClassesAndNamespaces(FnLoc, Args,
11117 AssociatedNamespaces,
11118 AssociatedClasses);
11119 Sema::AssociatedNamespaceSet SuggestedNamespaces;
11120 if (canBeDeclaredInNamespace(R.getLookupName())) {
11121 DeclContext *Std = SemaRef.getStdNamespace();
11122 for (Sema::AssociatedNamespaceSet::iterator
11123 it = AssociatedNamespaces.begin(),
11124 end = AssociatedNamespaces.end(); it != end; ++it) {
11125 // Never suggest declaring a function within namespace 'std'.
11126 if (Std && Std->Encloses(*it))
11129 // Never suggest declaring a function within a namespace with a
11130 // reserved name, like __gnu_cxx.
11131 NamespaceDecl *NS = dyn_cast<NamespaceDecl>(*it);
11133 NS->getQualifiedNameAsString().find("__") != std::string::npos)
11136 SuggestedNamespaces.insert(*it);
11140 SemaRef.Diag(R.getNameLoc(), diag::err_not_found_by_two_phase_lookup)
11141 << R.getLookupName();
11142 if (SuggestedNamespaces.empty()) {
11143 SemaRef.Diag(Best->Function->getLocation(),
11144 diag::note_not_found_by_two_phase_lookup)
11145 << R.getLookupName() << 0;
11146 } else if (SuggestedNamespaces.size() == 1) {
11147 SemaRef.Diag(Best->Function->getLocation(),
11148 diag::note_not_found_by_two_phase_lookup)
11149 << R.getLookupName() << 1 << *SuggestedNamespaces.begin();
11151 // FIXME: It would be useful to list the associated namespaces here,
11152 // but the diagnostics infrastructure doesn't provide a way to produce
11153 // a localized representation of a list of items.
11154 SemaRef.Diag(Best->Function->getLocation(),
11155 diag::note_not_found_by_two_phase_lookup)
11156 << R.getLookupName() << 2;
11159 // Try to recover by calling this function.
11169 /// Attempt to recover from ill-formed use of a non-dependent operator in a
11170 /// template, where the non-dependent operator was declared after the template
11173 /// Returns true if a viable candidate was found and a diagnostic was issued.
11175 DiagnoseTwoPhaseOperatorLookup(Sema &SemaRef, OverloadedOperatorKind Op,
11176 SourceLocation OpLoc,
11177 ArrayRef<Expr *> Args) {
11178 DeclarationName OpName =
11179 SemaRef.Context.DeclarationNames.getCXXOperatorName(Op);
11180 LookupResult R(SemaRef, OpName, OpLoc, Sema::LookupOperatorName);
11181 return DiagnoseTwoPhaseLookup(SemaRef, OpLoc, CXXScopeSpec(), R,
11182 OverloadCandidateSet::CSK_Operator,
11183 /*ExplicitTemplateArgs=*/nullptr, Args);
11187 class BuildRecoveryCallExprRAII {
11190 BuildRecoveryCallExprRAII(Sema &S) : SemaRef(S) {
11191 assert(SemaRef.IsBuildingRecoveryCallExpr == false);
11192 SemaRef.IsBuildingRecoveryCallExpr = true;
11195 ~BuildRecoveryCallExprRAII() {
11196 SemaRef.IsBuildingRecoveryCallExpr = false;
11202 static std::unique_ptr<CorrectionCandidateCallback>
11203 MakeValidator(Sema &SemaRef, MemberExpr *ME, size_t NumArgs,
11204 bool HasTemplateArgs, bool AllowTypoCorrection) {
11205 if (!AllowTypoCorrection)
11206 return llvm::make_unique<NoTypoCorrectionCCC>();
11207 return llvm::make_unique<FunctionCallFilterCCC>(SemaRef, NumArgs,
11208 HasTemplateArgs, ME);
11211 /// Attempts to recover from a call where no functions were found.
11213 /// Returns true if new candidates were found.
11215 BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn,
11216 UnresolvedLookupExpr *ULE,
11217 SourceLocation LParenLoc,
11218 MutableArrayRef<Expr *> Args,
11219 SourceLocation RParenLoc,
11220 bool EmptyLookup, bool AllowTypoCorrection) {
11221 // Do not try to recover if it is already building a recovery call.
11222 // This stops infinite loops for template instantiations like
11224 // template <typename T> auto foo(T t) -> decltype(foo(t)) {}
11225 // template <typename T> auto foo(T t) -> decltype(foo(&t)) {}
11227 if (SemaRef.IsBuildingRecoveryCallExpr)
11228 return ExprError();
11229 BuildRecoveryCallExprRAII RCE(SemaRef);
11232 SS.Adopt(ULE->getQualifierLoc());
11233 SourceLocation TemplateKWLoc = ULE->getTemplateKeywordLoc();
11235 TemplateArgumentListInfo TABuffer;
11236 TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr;
11237 if (ULE->hasExplicitTemplateArgs()) {
11238 ULE->copyTemplateArgumentsInto(TABuffer);
11239 ExplicitTemplateArgs = &TABuffer;
11242 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(),
11243 Sema::LookupOrdinaryName);
11244 bool DoDiagnoseEmptyLookup = EmptyLookup;
11245 if (!DiagnoseTwoPhaseLookup(SemaRef, Fn->getExprLoc(), SS, R,
11246 OverloadCandidateSet::CSK_Normal,
11247 ExplicitTemplateArgs, Args,
11248 &DoDiagnoseEmptyLookup) &&
11249 (!DoDiagnoseEmptyLookup || SemaRef.DiagnoseEmptyLookup(
11251 MakeValidator(SemaRef, dyn_cast<MemberExpr>(Fn), Args.size(),
11252 ExplicitTemplateArgs != nullptr, AllowTypoCorrection),
11253 ExplicitTemplateArgs, Args)))
11254 return ExprError();
11256 assert(!R.empty() && "lookup results empty despite recovery");
11258 // Build an implicit member call if appropriate. Just drop the
11259 // casts and such from the call, we don't really care.
11260 ExprResult NewFn = ExprError();
11261 if ((*R.begin())->isCXXClassMember())
11262 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, TemplateKWLoc, R,
11263 ExplicitTemplateArgs, S);
11264 else if (ExplicitTemplateArgs || TemplateKWLoc.isValid())
11265 NewFn = SemaRef.BuildTemplateIdExpr(SS, TemplateKWLoc, R, false,
11266 ExplicitTemplateArgs);
11268 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false);
11270 if (NewFn.isInvalid())
11271 return ExprError();
11273 // This shouldn't cause an infinite loop because we're giving it
11274 // an expression with viable lookup results, which should never
11276 return SemaRef.ActOnCallExpr(/*Scope*/ nullptr, NewFn.get(), LParenLoc,
11277 MultiExprArg(Args.data(), Args.size()),
11281 /// \brief Constructs and populates an OverloadedCandidateSet from
11282 /// the given function.
11283 /// \returns true when an the ExprResult output parameter has been set.
11284 bool Sema::buildOverloadedCallSet(Scope *S, Expr *Fn,
11285 UnresolvedLookupExpr *ULE,
11287 SourceLocation RParenLoc,
11288 OverloadCandidateSet *CandidateSet,
11289 ExprResult *Result) {
11291 if (ULE->requiresADL()) {
11292 // To do ADL, we must have found an unqualified name.
11293 assert(!ULE->getQualifier() && "qualified name with ADL");
11295 // We don't perform ADL for implicit declarations of builtins.
11296 // Verify that this was correctly set up.
11298 if (ULE->decls_begin() + 1 == ULE->decls_end() &&
11299 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) &&
11300 F->getBuiltinID() && F->isImplicit())
11301 llvm_unreachable("performing ADL for builtin");
11303 // We don't perform ADL in C.
11304 assert(getLangOpts().CPlusPlus && "ADL enabled in C");
11308 UnbridgedCastsSet UnbridgedCasts;
11309 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts)) {
11310 *Result = ExprError();
11314 // Add the functions denoted by the callee to the set of candidate
11315 // functions, including those from argument-dependent lookup.
11316 AddOverloadedCallCandidates(ULE, Args, *CandidateSet);
11318 if (getLangOpts().MSVCCompat &&
11319 CurContext->isDependentContext() && !isSFINAEContext() &&
11320 (isa<FunctionDecl>(CurContext) || isa<CXXRecordDecl>(CurContext))) {
11322 OverloadCandidateSet::iterator Best;
11323 if (CandidateSet->empty() ||
11324 CandidateSet->BestViableFunction(*this, Fn->getLocStart(), Best) ==
11325 OR_No_Viable_Function) {
11326 // In Microsoft mode, if we are inside a template class member function then
11327 // create a type dependent CallExpr. The goal is to postpone name lookup
11328 // to instantiation time to be able to search into type dependent base
11330 CallExpr *CE = new (Context) CallExpr(
11331 Context, Fn, Args, Context.DependentTy, VK_RValue, RParenLoc);
11332 CE->setTypeDependent(true);
11333 CE->setValueDependent(true);
11334 CE->setInstantiationDependent(true);
11340 if (CandidateSet->empty())
11343 UnbridgedCasts.restore();
11347 /// FinishOverloadedCallExpr - given an OverloadCandidateSet, builds and returns
11348 /// the completed call expression. If overload resolution fails, emits
11349 /// diagnostics and returns ExprError()
11350 static ExprResult FinishOverloadedCallExpr(Sema &SemaRef, Scope *S, Expr *Fn,
11351 UnresolvedLookupExpr *ULE,
11352 SourceLocation LParenLoc,
11354 SourceLocation RParenLoc,
11356 OverloadCandidateSet *CandidateSet,
11357 OverloadCandidateSet::iterator *Best,
11358 OverloadingResult OverloadResult,
11359 bool AllowTypoCorrection) {
11360 if (CandidateSet->empty())
11361 return BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc, Args,
11362 RParenLoc, /*EmptyLookup=*/true,
11363 AllowTypoCorrection);
11365 switch (OverloadResult) {
11367 FunctionDecl *FDecl = (*Best)->Function;
11368 SemaRef.CheckUnresolvedLookupAccess(ULE, (*Best)->FoundDecl);
11369 if (SemaRef.DiagnoseUseOfDecl(FDecl, ULE->getNameLoc()))
11370 return ExprError();
11371 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl);
11372 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, RParenLoc,
11376 case OR_No_Viable_Function: {
11377 // Try to recover by looking for viable functions which the user might
11378 // have meant to call.
11379 ExprResult Recovery = BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc,
11381 /*EmptyLookup=*/false,
11382 AllowTypoCorrection);
11383 if (!Recovery.isInvalid())
11386 // If the user passes in a function that we can't take the address of, we
11387 // generally end up emitting really bad error messages. Here, we attempt to
11388 // emit better ones.
11389 for (const Expr *Arg : Args) {
11390 if (!Arg->getType()->isFunctionType())
11392 if (auto *DRE = dyn_cast<DeclRefExpr>(Arg->IgnoreParenImpCasts())) {
11393 auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl());
11395 !SemaRef.checkAddressOfFunctionIsAvailable(FD, /*Complain=*/true,
11396 Arg->getExprLoc()))
11397 return ExprError();
11401 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_no_viable_function_in_call)
11402 << ULE->getName() << Fn->getSourceRange();
11403 CandidateSet->NoteCandidates(SemaRef, OCD_AllCandidates, Args);
11408 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_ambiguous_call)
11409 << ULE->getName() << Fn->getSourceRange();
11410 CandidateSet->NoteCandidates(SemaRef, OCD_ViableCandidates, Args);
11414 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_deleted_call)
11415 << (*Best)->Function->isDeleted()
11417 << SemaRef.getDeletedOrUnavailableSuffix((*Best)->Function)
11418 << Fn->getSourceRange();
11419 CandidateSet->NoteCandidates(SemaRef, OCD_AllCandidates, Args);
11421 // We emitted an error for the unvailable/deleted function call but keep
11422 // the call in the AST.
11423 FunctionDecl *FDecl = (*Best)->Function;
11424 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl);
11425 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, RParenLoc,
11430 // Overload resolution failed.
11431 return ExprError();
11434 static void markUnaddressableCandidatesUnviable(Sema &S,
11435 OverloadCandidateSet &CS) {
11436 for (auto I = CS.begin(), E = CS.end(); I != E; ++I) {
11438 !S.checkAddressOfFunctionIsAvailable(I->Function, /*Complain=*/false)) {
11440 I->FailureKind = ovl_fail_addr_not_available;
11445 /// BuildOverloadedCallExpr - Given the call expression that calls Fn
11446 /// (which eventually refers to the declaration Func) and the call
11447 /// arguments Args/NumArgs, attempt to resolve the function call down
11448 /// to a specific function. If overload resolution succeeds, returns
11449 /// the call expression produced by overload resolution.
11450 /// Otherwise, emits diagnostics and returns ExprError.
11451 ExprResult Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn,
11452 UnresolvedLookupExpr *ULE,
11453 SourceLocation LParenLoc,
11455 SourceLocation RParenLoc,
11457 bool AllowTypoCorrection,
11458 bool CalleesAddressIsTaken) {
11459 OverloadCandidateSet CandidateSet(Fn->getExprLoc(),
11460 OverloadCandidateSet::CSK_Normal);
11463 if (buildOverloadedCallSet(S, Fn, ULE, Args, LParenLoc, &CandidateSet,
11467 // If the user handed us something like `(&Foo)(Bar)`, we need to ensure that
11468 // functions that aren't addressible are considered unviable.
11469 if (CalleesAddressIsTaken)
11470 markUnaddressableCandidatesUnviable(*this, CandidateSet);
11472 OverloadCandidateSet::iterator Best;
11473 OverloadingResult OverloadResult =
11474 CandidateSet.BestViableFunction(*this, Fn->getLocStart(), Best);
11476 return FinishOverloadedCallExpr(*this, S, Fn, ULE, LParenLoc, Args,
11477 RParenLoc, ExecConfig, &CandidateSet,
11478 &Best, OverloadResult,
11479 AllowTypoCorrection);
11482 static bool IsOverloaded(const UnresolvedSetImpl &Functions) {
11483 return Functions.size() > 1 ||
11484 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin()));
11487 /// \brief Create a unary operation that may resolve to an overloaded
11490 /// \param OpLoc The location of the operator itself (e.g., '*').
11492 /// \param Opc The UnaryOperatorKind that describes this operator.
11494 /// \param Fns The set of non-member functions that will be
11495 /// considered by overload resolution. The caller needs to build this
11496 /// set based on the context using, e.g.,
11497 /// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This
11498 /// set should not contain any member functions; those will be added
11499 /// by CreateOverloadedUnaryOp().
11501 /// \param Input The input argument.
11503 Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, UnaryOperatorKind Opc,
11504 const UnresolvedSetImpl &Fns,
11506 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc);
11507 assert(Op != OO_None && "Invalid opcode for overloaded unary operator");
11508 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
11509 // TODO: provide better source location info.
11510 DeclarationNameInfo OpNameInfo(OpName, OpLoc);
11512 if (checkPlaceholderForOverload(*this, Input))
11513 return ExprError();
11515 Expr *Args[2] = { Input, nullptr };
11516 unsigned NumArgs = 1;
11518 // For post-increment and post-decrement, add the implicit '0' as
11519 // the second argument, so that we know this is a post-increment or
11521 if (Opc == UO_PostInc || Opc == UO_PostDec) {
11522 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false);
11523 Args[1] = IntegerLiteral::Create(Context, Zero, Context.IntTy,
11528 ArrayRef<Expr *> ArgsArray(Args, NumArgs);
11530 if (Input->isTypeDependent()) {
11532 return new (Context) UnaryOperator(Input, Opc, Context.DependentTy,
11533 VK_RValue, OK_Ordinary, OpLoc);
11535 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
11536 UnresolvedLookupExpr *Fn
11537 = UnresolvedLookupExpr::Create(Context, NamingClass,
11538 NestedNameSpecifierLoc(), OpNameInfo,
11539 /*ADL*/ true, IsOverloaded(Fns),
11540 Fns.begin(), Fns.end());
11541 return new (Context)
11542 CXXOperatorCallExpr(Context, Op, Fn, ArgsArray, Context.DependentTy,
11543 VK_RValue, OpLoc, false);
11546 // Build an empty overload set.
11547 OverloadCandidateSet CandidateSet(OpLoc, OverloadCandidateSet::CSK_Operator);
11549 // Add the candidates from the given function set.
11550 AddFunctionCandidates(Fns, ArgsArray, CandidateSet);
11552 // Add operator candidates that are member functions.
11553 AddMemberOperatorCandidates(Op, OpLoc, ArgsArray, CandidateSet);
11555 // Add candidates from ADL.
11556 AddArgumentDependentLookupCandidates(OpName, OpLoc, ArgsArray,
11557 /*ExplicitTemplateArgs*/nullptr,
11560 // Add builtin operator candidates.
11561 AddBuiltinOperatorCandidates(Op, OpLoc, ArgsArray, CandidateSet);
11563 bool HadMultipleCandidates = (CandidateSet.size() > 1);
11565 // Perform overload resolution.
11566 OverloadCandidateSet::iterator Best;
11567 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
11569 // We found a built-in operator or an overloaded operator.
11570 FunctionDecl *FnDecl = Best->Function;
11573 // We matched an overloaded operator. Build a call to that
11576 // Convert the arguments.
11577 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) {
11578 CheckMemberOperatorAccess(OpLoc, Args[0], nullptr, Best->FoundDecl);
11580 ExprResult InputRes =
11581 PerformObjectArgumentInitialization(Input, /*Qualifier=*/nullptr,
11582 Best->FoundDecl, Method);
11583 if (InputRes.isInvalid())
11584 return ExprError();
11585 Input = InputRes.get();
11587 // Convert the arguments.
11588 ExprResult InputInit
11589 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
11591 FnDecl->getParamDecl(0)),
11594 if (InputInit.isInvalid())
11595 return ExprError();
11596 Input = InputInit.get();
11599 // Build the actual expression node.
11600 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, Best->FoundDecl,
11601 HadMultipleCandidates, OpLoc);
11602 if (FnExpr.isInvalid())
11603 return ExprError();
11605 // Determine the result type.
11606 QualType ResultTy = FnDecl->getReturnType();
11607 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
11608 ResultTy = ResultTy.getNonLValueExprType(Context);
11611 CallExpr *TheCall =
11612 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.get(), ArgsArray,
11613 ResultTy, VK, OpLoc, false);
11615 if (CheckCallReturnType(FnDecl->getReturnType(), OpLoc, TheCall, FnDecl))
11616 return ExprError();
11618 return MaybeBindToTemporary(TheCall);
11620 // We matched a built-in operator. Convert the arguments, then
11621 // break out so that we will build the appropriate built-in
11623 ExprResult InputRes =
11624 PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0],
11625 Best->Conversions[0], AA_Passing);
11626 if (InputRes.isInvalid())
11627 return ExprError();
11628 Input = InputRes.get();
11633 case OR_No_Viable_Function:
11634 // This is an erroneous use of an operator which can be overloaded by
11635 // a non-member function. Check for non-member operators which were
11636 // defined too late to be candidates.
11637 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, ArgsArray))
11638 // FIXME: Recover by calling the found function.
11639 return ExprError();
11641 // No viable function; fall through to handling this as a
11642 // built-in operator, which will produce an error message for us.
11646 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary)
11647 << UnaryOperator::getOpcodeStr(Opc)
11648 << Input->getType()
11649 << Input->getSourceRange();
11650 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, ArgsArray,
11651 UnaryOperator::getOpcodeStr(Opc), OpLoc);
11652 return ExprError();
11655 Diag(OpLoc, diag::err_ovl_deleted_oper)
11656 << Best->Function->isDeleted()
11657 << UnaryOperator::getOpcodeStr(Opc)
11658 << getDeletedOrUnavailableSuffix(Best->Function)
11659 << Input->getSourceRange();
11660 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, ArgsArray,
11661 UnaryOperator::getOpcodeStr(Opc), OpLoc);
11662 return ExprError();
11665 // Either we found no viable overloaded operator or we matched a
11666 // built-in operator. In either case, fall through to trying to
11667 // build a built-in operation.
11668 return CreateBuiltinUnaryOp(OpLoc, Opc, Input);
11671 /// \brief Create a binary operation that may resolve to an overloaded
11674 /// \param OpLoc The location of the operator itself (e.g., '+').
11676 /// \param Opc The BinaryOperatorKind that describes this operator.
11678 /// \param Fns The set of non-member functions that will be
11679 /// considered by overload resolution. The caller needs to build this
11680 /// set based on the context using, e.g.,
11681 /// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This
11682 /// set should not contain any member functions; those will be added
11683 /// by CreateOverloadedBinOp().
11685 /// \param LHS Left-hand argument.
11686 /// \param RHS Right-hand argument.
11688 Sema::CreateOverloadedBinOp(SourceLocation OpLoc,
11689 BinaryOperatorKind Opc,
11690 const UnresolvedSetImpl &Fns,
11691 Expr *LHS, Expr *RHS) {
11692 Expr *Args[2] = { LHS, RHS };
11693 LHS=RHS=nullptr; // Please use only Args instead of LHS/RHS couple
11695 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc);
11696 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
11698 // If either side is type-dependent, create an appropriate dependent
11700 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) {
11702 // If there are no functions to store, just build a dependent
11703 // BinaryOperator or CompoundAssignment.
11704 if (Opc <= BO_Assign || Opc > BO_OrAssign)
11705 return new (Context) BinaryOperator(
11706 Args[0], Args[1], Opc, Context.DependentTy, VK_RValue, OK_Ordinary,
11707 OpLoc, FPFeatures.fp_contract);
11709 return new (Context) CompoundAssignOperator(
11710 Args[0], Args[1], Opc, Context.DependentTy, VK_LValue, OK_Ordinary,
11711 Context.DependentTy, Context.DependentTy, OpLoc,
11712 FPFeatures.fp_contract);
11715 // FIXME: save results of ADL from here?
11716 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
11717 // TODO: provide better source location info in DNLoc component.
11718 DeclarationNameInfo OpNameInfo(OpName, OpLoc);
11719 UnresolvedLookupExpr *Fn
11720 = UnresolvedLookupExpr::Create(Context, NamingClass,
11721 NestedNameSpecifierLoc(), OpNameInfo,
11722 /*ADL*/ true, IsOverloaded(Fns),
11723 Fns.begin(), Fns.end());
11724 return new (Context)
11725 CXXOperatorCallExpr(Context, Op, Fn, Args, Context.DependentTy,
11726 VK_RValue, OpLoc, FPFeatures.fp_contract);
11729 // Always do placeholder-like conversions on the RHS.
11730 if (checkPlaceholderForOverload(*this, Args[1]))
11731 return ExprError();
11733 // Do placeholder-like conversion on the LHS; note that we should
11734 // not get here with a PseudoObject LHS.
11735 assert(Args[0]->getObjectKind() != OK_ObjCProperty);
11736 if (checkPlaceholderForOverload(*this, Args[0]))
11737 return ExprError();
11739 // If this is the assignment operator, we only perform overload resolution
11740 // if the left-hand side is a class or enumeration type. This is actually
11741 // a hack. The standard requires that we do overload resolution between the
11742 // various built-in candidates, but as DR507 points out, this can lead to
11743 // problems. So we do it this way, which pretty much follows what GCC does.
11744 // Note that we go the traditional code path for compound assignment forms.
11745 if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType())
11746 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
11748 // If this is the .* operator, which is not overloadable, just
11749 // create a built-in binary operator.
11750 if (Opc == BO_PtrMemD)
11751 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
11753 // Build an empty overload set.
11754 OverloadCandidateSet CandidateSet(OpLoc, OverloadCandidateSet::CSK_Operator);
11756 // Add the candidates from the given function set.
11757 AddFunctionCandidates(Fns, Args, CandidateSet);
11759 // Add operator candidates that are member functions.
11760 AddMemberOperatorCandidates(Op, OpLoc, Args, CandidateSet);
11762 // Add candidates from ADL. Per [over.match.oper]p2, this lookup is not
11763 // performed for an assignment operator (nor for operator[] nor operator->,
11764 // which don't get here).
11765 if (Opc != BO_Assign)
11766 AddArgumentDependentLookupCandidates(OpName, OpLoc, Args,
11767 /*ExplicitTemplateArgs*/ nullptr,
11770 // Add builtin operator candidates.
11771 AddBuiltinOperatorCandidates(Op, OpLoc, Args, CandidateSet);
11773 bool HadMultipleCandidates = (CandidateSet.size() > 1);
11775 // Perform overload resolution.
11776 OverloadCandidateSet::iterator Best;
11777 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
11779 // We found a built-in operator or an overloaded operator.
11780 FunctionDecl *FnDecl = Best->Function;
11783 // We matched an overloaded operator. Build a call to that
11786 // Convert the arguments.
11787 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) {
11788 // Best->Access is only meaningful for class members.
11789 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl);
11792 PerformCopyInitialization(
11793 InitializedEntity::InitializeParameter(Context,
11794 FnDecl->getParamDecl(0)),
11795 SourceLocation(), Args[1]);
11796 if (Arg1.isInvalid())
11797 return ExprError();
11800 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/nullptr,
11801 Best->FoundDecl, Method);
11802 if (Arg0.isInvalid())
11803 return ExprError();
11804 Args[0] = Arg0.getAs<Expr>();
11805 Args[1] = RHS = Arg1.getAs<Expr>();
11807 // Convert the arguments.
11808 ExprResult Arg0 = PerformCopyInitialization(
11809 InitializedEntity::InitializeParameter(Context,
11810 FnDecl->getParamDecl(0)),
11811 SourceLocation(), Args[0]);
11812 if (Arg0.isInvalid())
11813 return ExprError();
11816 PerformCopyInitialization(
11817 InitializedEntity::InitializeParameter(Context,
11818 FnDecl->getParamDecl(1)),
11819 SourceLocation(), Args[1]);
11820 if (Arg1.isInvalid())
11821 return ExprError();
11822 Args[0] = LHS = Arg0.getAs<Expr>();
11823 Args[1] = RHS = Arg1.getAs<Expr>();
11826 // Build the actual expression node.
11827 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl,
11829 HadMultipleCandidates, OpLoc);
11830 if (FnExpr.isInvalid())
11831 return ExprError();
11833 // Determine the result type.
11834 QualType ResultTy = FnDecl->getReturnType();
11835 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
11836 ResultTy = ResultTy.getNonLValueExprType(Context);
11838 CXXOperatorCallExpr *TheCall =
11839 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.get(),
11840 Args, ResultTy, VK, OpLoc,
11841 FPFeatures.fp_contract);
11843 if (CheckCallReturnType(FnDecl->getReturnType(), OpLoc, TheCall,
11845 return ExprError();
11847 ArrayRef<const Expr *> ArgsArray(Args, 2);
11848 // Cut off the implicit 'this'.
11849 if (isa<CXXMethodDecl>(FnDecl))
11850 ArgsArray = ArgsArray.slice(1);
11852 // Check for a self move.
11853 if (Op == OO_Equal)
11854 DiagnoseSelfMove(Args[0], Args[1], OpLoc);
11856 checkCall(FnDecl, nullptr, ArgsArray, isa<CXXMethodDecl>(FnDecl), OpLoc,
11857 TheCall->getSourceRange(), VariadicDoesNotApply);
11859 return MaybeBindToTemporary(TheCall);
11861 // We matched a built-in operator. Convert the arguments, then
11862 // break out so that we will build the appropriate built-in
11864 ExprResult ArgsRes0 =
11865 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0],
11866 Best->Conversions[0], AA_Passing);
11867 if (ArgsRes0.isInvalid())
11868 return ExprError();
11869 Args[0] = ArgsRes0.get();
11871 ExprResult ArgsRes1 =
11872 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1],
11873 Best->Conversions[1], AA_Passing);
11874 if (ArgsRes1.isInvalid())
11875 return ExprError();
11876 Args[1] = ArgsRes1.get();
11881 case OR_No_Viable_Function: {
11882 // C++ [over.match.oper]p9:
11883 // If the operator is the operator , [...] and there are no
11884 // viable functions, then the operator is assumed to be the
11885 // built-in operator and interpreted according to clause 5.
11886 if (Opc == BO_Comma)
11889 // For class as left operand for assignment or compound assigment
11890 // operator do not fall through to handling in built-in, but report that
11891 // no overloaded assignment operator found
11892 ExprResult Result = ExprError();
11893 if (Args[0]->getType()->isRecordType() &&
11894 Opc >= BO_Assign && Opc <= BO_OrAssign) {
11895 Diag(OpLoc, diag::err_ovl_no_viable_oper)
11896 << BinaryOperator::getOpcodeStr(Opc)
11897 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
11898 if (Args[0]->getType()->isIncompleteType()) {
11899 Diag(OpLoc, diag::note_assign_lhs_incomplete)
11900 << Args[0]->getType()
11901 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
11904 // This is an erroneous use of an operator which can be overloaded by
11905 // a non-member function. Check for non-member operators which were
11906 // defined too late to be candidates.
11907 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, Args))
11908 // FIXME: Recover by calling the found function.
11909 return ExprError();
11911 // No viable function; try to create a built-in operation, which will
11912 // produce an error. Then, show the non-viable candidates.
11913 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
11915 assert(Result.isInvalid() &&
11916 "C++ binary operator overloading is missing candidates!");
11917 if (Result.isInvalid())
11918 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args,
11919 BinaryOperator::getOpcodeStr(Opc), OpLoc);
11924 Diag(OpLoc, diag::err_ovl_ambiguous_oper_binary)
11925 << BinaryOperator::getOpcodeStr(Opc)
11926 << Args[0]->getType() << Args[1]->getType()
11927 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
11928 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args,
11929 BinaryOperator::getOpcodeStr(Opc), OpLoc);
11930 return ExprError();
11933 if (isImplicitlyDeleted(Best->Function)) {
11934 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
11935 Diag(OpLoc, diag::err_ovl_deleted_special_oper)
11936 << Context.getRecordType(Method->getParent())
11937 << getSpecialMember(Method);
11939 // The user probably meant to call this special member. Just
11940 // explain why it's deleted.
11941 NoteDeletedFunction(Method);
11942 return ExprError();
11944 Diag(OpLoc, diag::err_ovl_deleted_oper)
11945 << Best->Function->isDeleted()
11946 << BinaryOperator::getOpcodeStr(Opc)
11947 << getDeletedOrUnavailableSuffix(Best->Function)
11948 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
11950 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args,
11951 BinaryOperator::getOpcodeStr(Opc), OpLoc);
11952 return ExprError();
11955 // We matched a built-in operator; build it.
11956 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
11960 Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc,
11961 SourceLocation RLoc,
11962 Expr *Base, Expr *Idx) {
11963 Expr *Args[2] = { Base, Idx };
11964 DeclarationName OpName =
11965 Context.DeclarationNames.getCXXOperatorName(OO_Subscript);
11967 // If either side is type-dependent, create an appropriate dependent
11969 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) {
11971 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
11972 // CHECKME: no 'operator' keyword?
11973 DeclarationNameInfo OpNameInfo(OpName, LLoc);
11974 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc));
11975 UnresolvedLookupExpr *Fn
11976 = UnresolvedLookupExpr::Create(Context, NamingClass,
11977 NestedNameSpecifierLoc(), OpNameInfo,
11978 /*ADL*/ true, /*Overloaded*/ false,
11979 UnresolvedSetIterator(),
11980 UnresolvedSetIterator());
11981 // Can't add any actual overloads yet
11983 return new (Context)
11984 CXXOperatorCallExpr(Context, OO_Subscript, Fn, Args,
11985 Context.DependentTy, VK_RValue, RLoc, false);
11988 // Handle placeholders on both operands.
11989 if (checkPlaceholderForOverload(*this, Args[0]))
11990 return ExprError();
11991 if (checkPlaceholderForOverload(*this, Args[1]))
11992 return ExprError();
11994 // Build an empty overload set.
11995 OverloadCandidateSet CandidateSet(LLoc, OverloadCandidateSet::CSK_Operator);
11997 // Subscript can only be overloaded as a member function.
11999 // Add operator candidates that are member functions.
12000 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, CandidateSet);
12002 // Add builtin operator candidates.
12003 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, CandidateSet);
12005 bool HadMultipleCandidates = (CandidateSet.size() > 1);
12007 // Perform overload resolution.
12008 OverloadCandidateSet::iterator Best;
12009 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) {
12011 // We found a built-in operator or an overloaded operator.
12012 FunctionDecl *FnDecl = Best->Function;
12015 // We matched an overloaded operator. Build a call to that
12018 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl);
12020 // Convert the arguments.
12021 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl);
12023 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/nullptr,
12024 Best->FoundDecl, Method);
12025 if (Arg0.isInvalid())
12026 return ExprError();
12027 Args[0] = Arg0.get();
12029 // Convert the arguments.
12030 ExprResult InputInit
12031 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
12033 FnDecl->getParamDecl(0)),
12036 if (InputInit.isInvalid())
12037 return ExprError();
12039 Args[1] = InputInit.getAs<Expr>();
12041 // Build the actual expression node.
12042 DeclarationNameInfo OpLocInfo(OpName, LLoc);
12043 OpLocInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc));
12044 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl,
12046 HadMultipleCandidates,
12047 OpLocInfo.getLoc(),
12048 OpLocInfo.getInfo());
12049 if (FnExpr.isInvalid())
12050 return ExprError();
12052 // Determine the result type
12053 QualType ResultTy = FnDecl->getReturnType();
12054 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
12055 ResultTy = ResultTy.getNonLValueExprType(Context);
12057 CXXOperatorCallExpr *TheCall =
12058 new (Context) CXXOperatorCallExpr(Context, OO_Subscript,
12059 FnExpr.get(), Args,
12060 ResultTy, VK, RLoc,
12063 if (CheckCallReturnType(FnDecl->getReturnType(), LLoc, TheCall, FnDecl))
12064 return ExprError();
12066 return MaybeBindToTemporary(TheCall);
12068 // We matched a built-in operator. Convert the arguments, then
12069 // break out so that we will build the appropriate built-in
12071 ExprResult ArgsRes0 =
12072 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0],
12073 Best->Conversions[0], AA_Passing);
12074 if (ArgsRes0.isInvalid())
12075 return ExprError();
12076 Args[0] = ArgsRes0.get();
12078 ExprResult ArgsRes1 =
12079 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1],
12080 Best->Conversions[1], AA_Passing);
12081 if (ArgsRes1.isInvalid())
12082 return ExprError();
12083 Args[1] = ArgsRes1.get();
12089 case OR_No_Viable_Function: {
12090 if (CandidateSet.empty())
12091 Diag(LLoc, diag::err_ovl_no_oper)
12092 << Args[0]->getType() << /*subscript*/ 0
12093 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12095 Diag(LLoc, diag::err_ovl_no_viable_subscript)
12096 << Args[0]->getType()
12097 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12098 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args,
12100 return ExprError();
12104 Diag(LLoc, diag::err_ovl_ambiguous_oper_binary)
12106 << Args[0]->getType() << Args[1]->getType()
12107 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12108 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args,
12110 return ExprError();
12113 Diag(LLoc, diag::err_ovl_deleted_oper)
12114 << Best->Function->isDeleted() << "[]"
12115 << getDeletedOrUnavailableSuffix(Best->Function)
12116 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12117 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args,
12119 return ExprError();
12122 // We matched a built-in operator; build it.
12123 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc);
12126 /// BuildCallToMemberFunction - Build a call to a member
12127 /// function. MemExpr is the expression that refers to the member
12128 /// function (and includes the object parameter), Args/NumArgs are the
12129 /// arguments to the function call (not including the object
12130 /// parameter). The caller needs to validate that the member
12131 /// expression refers to a non-static member function or an overloaded
12132 /// member function.
12134 Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE,
12135 SourceLocation LParenLoc,
12137 SourceLocation RParenLoc) {
12138 assert(MemExprE->getType() == Context.BoundMemberTy ||
12139 MemExprE->getType() == Context.OverloadTy);
12141 // Dig out the member expression. This holds both the object
12142 // argument and the member function we're referring to.
12143 Expr *NakedMemExpr = MemExprE->IgnoreParens();
12145 // Determine whether this is a call to a pointer-to-member function.
12146 if (BinaryOperator *op = dyn_cast<BinaryOperator>(NakedMemExpr)) {
12147 assert(op->getType() == Context.BoundMemberTy);
12148 assert(op->getOpcode() == BO_PtrMemD || op->getOpcode() == BO_PtrMemI);
12151 op->getRHS()->getType()->castAs<MemberPointerType>()->getPointeeType();
12153 const FunctionProtoType *proto = fnType->castAs<FunctionProtoType>();
12154 QualType resultType = proto->getCallResultType(Context);
12155 ExprValueKind valueKind = Expr::getValueKindForType(proto->getReturnType());
12157 // Check that the object type isn't more qualified than the
12158 // member function we're calling.
12159 Qualifiers funcQuals = Qualifiers::fromCVRMask(proto->getTypeQuals());
12161 QualType objectType = op->getLHS()->getType();
12162 if (op->getOpcode() == BO_PtrMemI)
12163 objectType = objectType->castAs<PointerType>()->getPointeeType();
12164 Qualifiers objectQuals = objectType.getQualifiers();
12166 Qualifiers difference = objectQuals - funcQuals;
12167 difference.removeObjCGCAttr();
12168 difference.removeAddressSpace();
12170 std::string qualsString = difference.getAsString();
12171 Diag(LParenLoc, diag::err_pointer_to_member_call_drops_quals)
12172 << fnType.getUnqualifiedType()
12174 << (qualsString.find(' ') == std::string::npos ? 1 : 2);
12177 CXXMemberCallExpr *call
12178 = new (Context) CXXMemberCallExpr(Context, MemExprE, Args,
12179 resultType, valueKind, RParenLoc);
12181 if (CheckCallReturnType(proto->getReturnType(), op->getRHS()->getLocStart(),
12183 return ExprError();
12185 if (ConvertArgumentsForCall(call, op, nullptr, proto, Args, RParenLoc))
12186 return ExprError();
12188 if (CheckOtherCall(call, proto))
12189 return ExprError();
12191 return MaybeBindToTemporary(call);
12194 if (isa<CXXPseudoDestructorExpr>(NakedMemExpr))
12195 return new (Context)
12196 CallExpr(Context, MemExprE, Args, Context.VoidTy, VK_RValue, RParenLoc);
12198 UnbridgedCastsSet UnbridgedCasts;
12199 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts))
12200 return ExprError();
12202 MemberExpr *MemExpr;
12203 CXXMethodDecl *Method = nullptr;
12204 DeclAccessPair FoundDecl = DeclAccessPair::make(nullptr, AS_public);
12205 NestedNameSpecifier *Qualifier = nullptr;
12206 if (isa<MemberExpr>(NakedMemExpr)) {
12207 MemExpr = cast<MemberExpr>(NakedMemExpr);
12208 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl());
12209 FoundDecl = MemExpr->getFoundDecl();
12210 Qualifier = MemExpr->getQualifier();
12211 UnbridgedCasts.restore();
12213 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr);
12214 Qualifier = UnresExpr->getQualifier();
12216 QualType ObjectType = UnresExpr->getBaseType();
12217 Expr::Classification ObjectClassification
12218 = UnresExpr->isArrow()? Expr::Classification::makeSimpleLValue()
12219 : UnresExpr->getBase()->Classify(Context);
12221 // Add overload candidates
12222 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc(),
12223 OverloadCandidateSet::CSK_Normal);
12225 // FIXME: avoid copy.
12226 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
12227 if (UnresExpr->hasExplicitTemplateArgs()) {
12228 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer);
12229 TemplateArgs = &TemplateArgsBuffer;
12232 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(),
12233 E = UnresExpr->decls_end(); I != E; ++I) {
12235 NamedDecl *Func = *I;
12236 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext());
12237 if (isa<UsingShadowDecl>(Func))
12238 Func = cast<UsingShadowDecl>(Func)->getTargetDecl();
12241 // Microsoft supports direct constructor calls.
12242 if (getLangOpts().MicrosoftExt && isa<CXXConstructorDecl>(Func)) {
12243 AddOverloadCandidate(cast<CXXConstructorDecl>(Func), I.getPair(),
12244 Args, CandidateSet);
12245 } else if ((Method = dyn_cast<CXXMethodDecl>(Func))) {
12246 // If explicit template arguments were provided, we can't call a
12247 // non-template member function.
12251 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType,
12252 ObjectClassification, Args, CandidateSet,
12253 /*SuppressUserConversions=*/false);
12255 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func),
12256 I.getPair(), ActingDC, TemplateArgs,
12257 ObjectType, ObjectClassification,
12258 Args, CandidateSet,
12259 /*SuppressUsedConversions=*/false);
12263 DeclarationName DeclName = UnresExpr->getMemberName();
12265 UnbridgedCasts.restore();
12267 OverloadCandidateSet::iterator Best;
12268 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getLocStart(),
12271 Method = cast<CXXMethodDecl>(Best->Function);
12272 FoundDecl = Best->FoundDecl;
12273 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl);
12274 if (DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()))
12275 return ExprError();
12276 // If FoundDecl is different from Method (such as if one is a template
12277 // and the other a specialization), make sure DiagnoseUseOfDecl is
12279 // FIXME: This would be more comprehensively addressed by modifying
12280 // DiagnoseUseOfDecl to accept both the FoundDecl and the decl
12282 if (Method != FoundDecl.getDecl() &&
12283 DiagnoseUseOfDecl(Method, UnresExpr->getNameLoc()))
12284 return ExprError();
12287 case OR_No_Viable_Function:
12288 Diag(UnresExpr->getMemberLoc(),
12289 diag::err_ovl_no_viable_member_function_in_call)
12290 << DeclName << MemExprE->getSourceRange();
12291 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
12292 // FIXME: Leaking incoming expressions!
12293 return ExprError();
12296 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call)
12297 << DeclName << MemExprE->getSourceRange();
12298 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
12299 // FIXME: Leaking incoming expressions!
12300 return ExprError();
12303 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call)
12304 << Best->Function->isDeleted()
12306 << getDeletedOrUnavailableSuffix(Best->Function)
12307 << MemExprE->getSourceRange();
12308 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
12309 // FIXME: Leaking incoming expressions!
12310 return ExprError();
12313 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method);
12315 // If overload resolution picked a static member, build a
12316 // non-member call based on that function.
12317 if (Method->isStatic()) {
12318 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, Args,
12322 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens());
12325 QualType ResultType = Method->getReturnType();
12326 ExprValueKind VK = Expr::getValueKindForType(ResultType);
12327 ResultType = ResultType.getNonLValueExprType(Context);
12329 assert(Method && "Member call to something that isn't a method?");
12330 CXXMemberCallExpr *TheCall =
12331 new (Context) CXXMemberCallExpr(Context, MemExprE, Args,
12332 ResultType, VK, RParenLoc);
12334 // (CUDA B.1): Check for invalid calls between targets.
12335 if (getLangOpts().CUDA) {
12336 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext)) {
12337 if (CheckCUDATarget(Caller, Method)) {
12338 Diag(MemExpr->getMemberLoc(), diag::err_ref_bad_target)
12339 << IdentifyCUDATarget(Method) << Method->getIdentifier()
12340 << IdentifyCUDATarget(Caller);
12341 return ExprError();
12346 // Check for a valid return type.
12347 if (CheckCallReturnType(Method->getReturnType(), MemExpr->getMemberLoc(),
12349 return ExprError();
12351 // Convert the object argument (for a non-static member function call).
12352 // We only need to do this if there was actually an overload; otherwise
12353 // it was done at lookup.
12354 if (!Method->isStatic()) {
12355 ExprResult ObjectArg =
12356 PerformObjectArgumentInitialization(MemExpr->getBase(), Qualifier,
12357 FoundDecl, Method);
12358 if (ObjectArg.isInvalid())
12359 return ExprError();
12360 MemExpr->setBase(ObjectArg.get());
12363 // Convert the rest of the arguments
12364 const FunctionProtoType *Proto =
12365 Method->getType()->getAs<FunctionProtoType>();
12366 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args,
12368 return ExprError();
12370 DiagnoseSentinelCalls(Method, LParenLoc, Args);
12372 if (CheckFunctionCall(Method, TheCall, Proto))
12373 return ExprError();
12375 // In the case the method to call was not selected by the overloading
12376 // resolution process, we still need to handle the enable_if attribute. Do
12377 // that here, so it will not hide previous -- and more relevant -- errors
12378 if (isa<MemberExpr>(NakedMemExpr)) {
12379 if (const EnableIfAttr *Attr = CheckEnableIf(Method, Args, true)) {
12380 Diag(MemExprE->getLocStart(),
12381 diag::err_ovl_no_viable_member_function_in_call)
12382 << Method << Method->getSourceRange();
12383 Diag(Method->getLocation(),
12384 diag::note_ovl_candidate_disabled_by_enable_if_attr)
12385 << Attr->getCond()->getSourceRange() << Attr->getMessage();
12386 return ExprError();
12390 if ((isa<CXXConstructorDecl>(CurContext) ||
12391 isa<CXXDestructorDecl>(CurContext)) &&
12392 TheCall->getMethodDecl()->isPure()) {
12393 const CXXMethodDecl *MD = TheCall->getMethodDecl();
12395 if (isa<CXXThisExpr>(MemExpr->getBase()->IgnoreParenCasts()) &&
12396 MemExpr->performsVirtualDispatch(getLangOpts())) {
12397 Diag(MemExpr->getLocStart(),
12398 diag::warn_call_to_pure_virtual_member_function_from_ctor_dtor)
12399 << MD->getDeclName() << isa<CXXDestructorDecl>(CurContext)
12400 << MD->getParent()->getDeclName();
12402 Diag(MD->getLocStart(), diag::note_previous_decl) << MD->getDeclName();
12403 if (getLangOpts().AppleKext)
12404 Diag(MemExpr->getLocStart(),
12405 diag::note_pure_qualified_call_kext)
12406 << MD->getParent()->getDeclName()
12407 << MD->getDeclName();
12411 if (CXXDestructorDecl *DD =
12412 dyn_cast<CXXDestructorDecl>(TheCall->getMethodDecl())) {
12413 // a->A::f() doesn't go through the vtable, except in AppleKext mode.
12414 bool CallCanBeVirtual = !MemExpr->hasQualifier() || getLangOpts().AppleKext;
12415 CheckVirtualDtorCall(DD, MemExpr->getLocStart(), /*IsDelete=*/false,
12416 CallCanBeVirtual, /*WarnOnNonAbstractTypes=*/true,
12417 MemExpr->getMemberLoc());
12420 return MaybeBindToTemporary(TheCall);
12423 /// BuildCallToObjectOfClassType - Build a call to an object of class
12424 /// type (C++ [over.call.object]), which can end up invoking an
12425 /// overloaded function call operator (@c operator()) or performing a
12426 /// user-defined conversion on the object argument.
12428 Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj,
12429 SourceLocation LParenLoc,
12431 SourceLocation RParenLoc) {
12432 if (checkPlaceholderForOverload(*this, Obj))
12433 return ExprError();
12434 ExprResult Object = Obj;
12436 UnbridgedCastsSet UnbridgedCasts;
12437 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts))
12438 return ExprError();
12440 assert(Object.get()->getType()->isRecordType() &&
12441 "Requires object type argument");
12442 const RecordType *Record = Object.get()->getType()->getAs<RecordType>();
12444 // C++ [over.call.object]p1:
12445 // If the primary-expression E in the function call syntax
12446 // evaluates to a class object of type "cv T", then the set of
12447 // candidate functions includes at least the function call
12448 // operators of T. The function call operators of T are obtained by
12449 // ordinary lookup of the name operator() in the context of
12451 OverloadCandidateSet CandidateSet(LParenLoc,
12452 OverloadCandidateSet::CSK_Operator);
12453 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call);
12455 if (RequireCompleteType(LParenLoc, Object.get()->getType(),
12456 diag::err_incomplete_object_call, Object.get()))
12459 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName);
12460 LookupQualifiedName(R, Record->getDecl());
12461 R.suppressDiagnostics();
12463 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end();
12464 Oper != OperEnd; ++Oper) {
12465 AddMethodCandidate(Oper.getPair(), Object.get()->getType(),
12466 Object.get()->Classify(Context),
12467 Args, CandidateSet,
12468 /*SuppressUserConversions=*/ false);
12471 // C++ [over.call.object]p2:
12472 // In addition, for each (non-explicit in C++0x) conversion function
12473 // declared in T of the form
12475 // operator conversion-type-id () cv-qualifier;
12477 // where cv-qualifier is the same cv-qualification as, or a
12478 // greater cv-qualification than, cv, and where conversion-type-id
12479 // denotes the type "pointer to function of (P1,...,Pn) returning
12480 // R", or the type "reference to pointer to function of
12481 // (P1,...,Pn) returning R", or the type "reference to function
12482 // of (P1,...,Pn) returning R", a surrogate call function [...]
12483 // is also considered as a candidate function. Similarly,
12484 // surrogate call functions are added to the set of candidate
12485 // functions for each conversion function declared in an
12486 // accessible base class provided the function is not hidden
12487 // within T by another intervening declaration.
12488 const auto &Conversions =
12489 cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions();
12490 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
12492 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
12493 if (isa<UsingShadowDecl>(D))
12494 D = cast<UsingShadowDecl>(D)->getTargetDecl();
12496 // Skip over templated conversion functions; they aren't
12498 if (isa<FunctionTemplateDecl>(D))
12501 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D);
12502 if (!Conv->isExplicit()) {
12503 // Strip the reference type (if any) and then the pointer type (if
12504 // any) to get down to what might be a function type.
12505 QualType ConvType = Conv->getConversionType().getNonReferenceType();
12506 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
12507 ConvType = ConvPtrType->getPointeeType();
12509 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>())
12511 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto,
12512 Object.get(), Args, CandidateSet);
12517 bool HadMultipleCandidates = (CandidateSet.size() > 1);
12519 // Perform overload resolution.
12520 OverloadCandidateSet::iterator Best;
12521 switch (CandidateSet.BestViableFunction(*this, Object.get()->getLocStart(),
12524 // Overload resolution succeeded; we'll build the appropriate call
12528 case OR_No_Viable_Function:
12529 if (CandidateSet.empty())
12530 Diag(Object.get()->getLocStart(), diag::err_ovl_no_oper)
12531 << Object.get()->getType() << /*call*/ 1
12532 << Object.get()->getSourceRange();
12534 Diag(Object.get()->getLocStart(),
12535 diag::err_ovl_no_viable_object_call)
12536 << Object.get()->getType() << Object.get()->getSourceRange();
12537 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
12541 Diag(Object.get()->getLocStart(),
12542 diag::err_ovl_ambiguous_object_call)
12543 << Object.get()->getType() << Object.get()->getSourceRange();
12544 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args);
12548 Diag(Object.get()->getLocStart(),
12549 diag::err_ovl_deleted_object_call)
12550 << Best->Function->isDeleted()
12551 << Object.get()->getType()
12552 << getDeletedOrUnavailableSuffix(Best->Function)
12553 << Object.get()->getSourceRange();
12554 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
12558 if (Best == CandidateSet.end())
12561 UnbridgedCasts.restore();
12563 if (Best->Function == nullptr) {
12564 // Since there is no function declaration, this is one of the
12565 // surrogate candidates. Dig out the conversion function.
12566 CXXConversionDecl *Conv
12567 = cast<CXXConversionDecl>(
12568 Best->Conversions[0].UserDefined.ConversionFunction);
12570 CheckMemberOperatorAccess(LParenLoc, Object.get(), nullptr,
12572 if (DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc))
12573 return ExprError();
12574 assert(Conv == Best->FoundDecl.getDecl() &&
12575 "Found Decl & conversion-to-functionptr should be same, right?!");
12576 // We selected one of the surrogate functions that converts the
12577 // object parameter to a function pointer. Perform the conversion
12578 // on the object argument, then let ActOnCallExpr finish the job.
12580 // Create an implicit member expr to refer to the conversion operator.
12581 // and then call it.
12582 ExprResult Call = BuildCXXMemberCallExpr(Object.get(), Best->FoundDecl,
12583 Conv, HadMultipleCandidates);
12584 if (Call.isInvalid())
12585 return ExprError();
12586 // Record usage of conversion in an implicit cast.
12587 Call = ImplicitCastExpr::Create(Context, Call.get()->getType(),
12588 CK_UserDefinedConversion, Call.get(),
12589 nullptr, VK_RValue);
12591 return ActOnCallExpr(S, Call.get(), LParenLoc, Args, RParenLoc);
12594 CheckMemberOperatorAccess(LParenLoc, Object.get(), nullptr, Best->FoundDecl);
12596 // We found an overloaded operator(). Build a CXXOperatorCallExpr
12597 // that calls this method, using Object for the implicit object
12598 // parameter and passing along the remaining arguments.
12599 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
12601 // An error diagnostic has already been printed when parsing the declaration.
12602 if (Method->isInvalidDecl())
12603 return ExprError();
12605 const FunctionProtoType *Proto =
12606 Method->getType()->getAs<FunctionProtoType>();
12608 unsigned NumParams = Proto->getNumParams();
12610 DeclarationNameInfo OpLocInfo(
12611 Context.DeclarationNames.getCXXOperatorName(OO_Call), LParenLoc);
12612 OpLocInfo.setCXXOperatorNameRange(SourceRange(LParenLoc, RParenLoc));
12613 ExprResult NewFn = CreateFunctionRefExpr(*this, Method, Best->FoundDecl,
12614 HadMultipleCandidates,
12615 OpLocInfo.getLoc(),
12616 OpLocInfo.getInfo());
12617 if (NewFn.isInvalid())
12620 // Build the full argument list for the method call (the implicit object
12621 // parameter is placed at the beginning of the list).
12622 std::unique_ptr<Expr * []> MethodArgs(new Expr *[Args.size() + 1]);
12623 MethodArgs[0] = Object.get();
12624 std::copy(Args.begin(), Args.end(), &MethodArgs[1]);
12626 // Once we've built TheCall, all of the expressions are properly
12628 QualType ResultTy = Method->getReturnType();
12629 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
12630 ResultTy = ResultTy.getNonLValueExprType(Context);
12632 CXXOperatorCallExpr *TheCall = new (Context)
12633 CXXOperatorCallExpr(Context, OO_Call, NewFn.get(),
12634 llvm::makeArrayRef(MethodArgs.get(), Args.size() + 1),
12635 ResultTy, VK, RParenLoc, false);
12636 MethodArgs.reset();
12638 if (CheckCallReturnType(Method->getReturnType(), LParenLoc, TheCall, Method))
12641 // We may have default arguments. If so, we need to allocate more
12642 // slots in the call for them.
12643 if (Args.size() < NumParams)
12644 TheCall->setNumArgs(Context, NumParams + 1);
12646 bool IsError = false;
12648 // Initialize the implicit object parameter.
12649 ExprResult ObjRes =
12650 PerformObjectArgumentInitialization(Object.get(), /*Qualifier=*/nullptr,
12651 Best->FoundDecl, Method);
12652 if (ObjRes.isInvalid())
12656 TheCall->setArg(0, Object.get());
12658 // Check the argument types.
12659 for (unsigned i = 0; i != NumParams; i++) {
12661 if (i < Args.size()) {
12664 // Pass the argument.
12666 ExprResult InputInit
12667 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
12669 Method->getParamDecl(i)),
12670 SourceLocation(), Arg);
12672 IsError |= InputInit.isInvalid();
12673 Arg = InputInit.getAs<Expr>();
12676 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i));
12677 if (DefArg.isInvalid()) {
12682 Arg = DefArg.getAs<Expr>();
12685 TheCall->setArg(i + 1, Arg);
12688 // If this is a variadic call, handle args passed through "...".
12689 if (Proto->isVariadic()) {
12690 // Promote the arguments (C99 6.5.2.2p7).
12691 for (unsigned i = NumParams, e = Args.size(); i < e; i++) {
12692 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod,
12694 IsError |= Arg.isInvalid();
12695 TheCall->setArg(i + 1, Arg.get());
12699 if (IsError) return true;
12701 DiagnoseSentinelCalls(Method, LParenLoc, Args);
12703 if (CheckFunctionCall(Method, TheCall, Proto))
12706 return MaybeBindToTemporary(TheCall);
12709 /// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator->
12710 /// (if one exists), where @c Base is an expression of class type and
12711 /// @c Member is the name of the member we're trying to find.
12713 Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc,
12714 bool *NoArrowOperatorFound) {
12715 assert(Base->getType()->isRecordType() &&
12716 "left-hand side must have class type");
12718 if (checkPlaceholderForOverload(*this, Base))
12719 return ExprError();
12721 SourceLocation Loc = Base->getExprLoc();
12723 // C++ [over.ref]p1:
12725 // [...] An expression x->m is interpreted as (x.operator->())->m
12726 // for a class object x of type T if T::operator->() exists and if
12727 // the operator is selected as the best match function by the
12728 // overload resolution mechanism (13.3).
12729 DeclarationName OpName =
12730 Context.DeclarationNames.getCXXOperatorName(OO_Arrow);
12731 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Operator);
12732 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>();
12734 if (RequireCompleteType(Loc, Base->getType(),
12735 diag::err_typecheck_incomplete_tag, Base))
12736 return ExprError();
12738 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName);
12739 LookupQualifiedName(R, BaseRecord->getDecl());
12740 R.suppressDiagnostics();
12742 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end();
12743 Oper != OperEnd; ++Oper) {
12744 AddMethodCandidate(Oper.getPair(), Base->getType(), Base->Classify(Context),
12745 None, CandidateSet, /*SuppressUserConversions=*/false);
12748 bool HadMultipleCandidates = (CandidateSet.size() > 1);
12750 // Perform overload resolution.
12751 OverloadCandidateSet::iterator Best;
12752 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
12754 // Overload resolution succeeded; we'll build the call below.
12757 case OR_No_Viable_Function:
12758 if (CandidateSet.empty()) {
12759 QualType BaseType = Base->getType();
12760 if (NoArrowOperatorFound) {
12761 // Report this specific error to the caller instead of emitting a
12762 // diagnostic, as requested.
12763 *NoArrowOperatorFound = true;
12764 return ExprError();
12766 Diag(OpLoc, diag::err_typecheck_member_reference_arrow)
12767 << BaseType << Base->getSourceRange();
12768 if (BaseType->isRecordType() && !BaseType->isPointerType()) {
12769 Diag(OpLoc, diag::note_typecheck_member_reference_suggestion)
12770 << FixItHint::CreateReplacement(OpLoc, ".");
12773 Diag(OpLoc, diag::err_ovl_no_viable_oper)
12774 << "operator->" << Base->getSourceRange();
12775 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Base);
12776 return ExprError();
12779 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary)
12780 << "->" << Base->getType() << Base->getSourceRange();
12781 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Base);
12782 return ExprError();
12785 Diag(OpLoc, diag::err_ovl_deleted_oper)
12786 << Best->Function->isDeleted()
12788 << getDeletedOrUnavailableSuffix(Best->Function)
12789 << Base->getSourceRange();
12790 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Base);
12791 return ExprError();
12794 CheckMemberOperatorAccess(OpLoc, Base, nullptr, Best->FoundDecl);
12796 // Convert the object parameter.
12797 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
12798 ExprResult BaseResult =
12799 PerformObjectArgumentInitialization(Base, /*Qualifier=*/nullptr,
12800 Best->FoundDecl, Method);
12801 if (BaseResult.isInvalid())
12802 return ExprError();
12803 Base = BaseResult.get();
12805 // Build the operator call.
12806 ExprResult FnExpr = CreateFunctionRefExpr(*this, Method, Best->FoundDecl,
12807 HadMultipleCandidates, OpLoc);
12808 if (FnExpr.isInvalid())
12809 return ExprError();
12811 QualType ResultTy = Method->getReturnType();
12812 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
12813 ResultTy = ResultTy.getNonLValueExprType(Context);
12814 CXXOperatorCallExpr *TheCall =
12815 new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr.get(),
12816 Base, ResultTy, VK, OpLoc, false);
12818 if (CheckCallReturnType(Method->getReturnType(), OpLoc, TheCall, Method))
12819 return ExprError();
12821 return MaybeBindToTemporary(TheCall);
12824 /// BuildLiteralOperatorCall - Build a UserDefinedLiteral by creating a call to
12825 /// a literal operator described by the provided lookup results.
12826 ExprResult Sema::BuildLiteralOperatorCall(LookupResult &R,
12827 DeclarationNameInfo &SuffixInfo,
12828 ArrayRef<Expr*> Args,
12829 SourceLocation LitEndLoc,
12830 TemplateArgumentListInfo *TemplateArgs) {
12831 SourceLocation UDSuffixLoc = SuffixInfo.getCXXLiteralOperatorNameLoc();
12833 OverloadCandidateSet CandidateSet(UDSuffixLoc,
12834 OverloadCandidateSet::CSK_Normal);
12835 AddFunctionCandidates(R.asUnresolvedSet(), Args, CandidateSet, TemplateArgs,
12836 /*SuppressUserConversions=*/true);
12838 bool HadMultipleCandidates = (CandidateSet.size() > 1);
12840 // Perform overload resolution. This will usually be trivial, but might need
12841 // to perform substitutions for a literal operator template.
12842 OverloadCandidateSet::iterator Best;
12843 switch (CandidateSet.BestViableFunction(*this, UDSuffixLoc, Best)) {
12848 case OR_No_Viable_Function:
12849 Diag(UDSuffixLoc, diag::err_ovl_no_viable_function_in_call)
12850 << R.getLookupName();
12851 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
12852 return ExprError();
12855 Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName();
12856 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args);
12857 return ExprError();
12860 FunctionDecl *FD = Best->Function;
12861 ExprResult Fn = CreateFunctionRefExpr(*this, FD, Best->FoundDecl,
12862 HadMultipleCandidates,
12863 SuffixInfo.getLoc(),
12864 SuffixInfo.getInfo());
12865 if (Fn.isInvalid())
12868 // Check the argument types. This should almost always be a no-op, except
12869 // that array-to-pointer decay is applied to string literals.
12871 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
12872 ExprResult InputInit = PerformCopyInitialization(
12873 InitializedEntity::InitializeParameter(Context, FD->getParamDecl(ArgIdx)),
12874 SourceLocation(), Args[ArgIdx]);
12875 if (InputInit.isInvalid())
12877 ConvArgs[ArgIdx] = InputInit.get();
12880 QualType ResultTy = FD->getReturnType();
12881 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
12882 ResultTy = ResultTy.getNonLValueExprType(Context);
12884 UserDefinedLiteral *UDL =
12885 new (Context) UserDefinedLiteral(Context, Fn.get(),
12886 llvm::makeArrayRef(ConvArgs, Args.size()),
12887 ResultTy, VK, LitEndLoc, UDSuffixLoc);
12889 if (CheckCallReturnType(FD->getReturnType(), UDSuffixLoc, UDL, FD))
12890 return ExprError();
12892 if (CheckFunctionCall(FD, UDL, nullptr))
12893 return ExprError();
12895 return MaybeBindToTemporary(UDL);
12898 /// Build a call to 'begin' or 'end' for a C++11 for-range statement. If the
12899 /// given LookupResult is non-empty, it is assumed to describe a member which
12900 /// will be invoked. Otherwise, the function will be found via argument
12901 /// dependent lookup.
12902 /// CallExpr is set to a valid expression and FRS_Success returned on success,
12903 /// otherwise CallExpr is set to ExprError() and some non-success value
12905 Sema::ForRangeStatus
12906 Sema::BuildForRangeBeginEndCall(SourceLocation Loc,
12907 SourceLocation RangeLoc,
12908 const DeclarationNameInfo &NameInfo,
12909 LookupResult &MemberLookup,
12910 OverloadCandidateSet *CandidateSet,
12911 Expr *Range, ExprResult *CallExpr) {
12912 Scope *S = nullptr;
12914 CandidateSet->clear();
12915 if (!MemberLookup.empty()) {
12916 ExprResult MemberRef =
12917 BuildMemberReferenceExpr(Range, Range->getType(), Loc,
12918 /*IsPtr=*/false, CXXScopeSpec(),
12919 /*TemplateKWLoc=*/SourceLocation(),
12920 /*FirstQualifierInScope=*/nullptr,
12922 /*TemplateArgs=*/nullptr, S);
12923 if (MemberRef.isInvalid()) {
12924 *CallExpr = ExprError();
12925 return FRS_DiagnosticIssued;
12927 *CallExpr = ActOnCallExpr(S, MemberRef.get(), Loc, None, Loc, nullptr);
12928 if (CallExpr->isInvalid()) {
12929 *CallExpr = ExprError();
12930 return FRS_DiagnosticIssued;
12933 UnresolvedSet<0> FoundNames;
12934 UnresolvedLookupExpr *Fn =
12935 UnresolvedLookupExpr::Create(Context, /*NamingClass=*/nullptr,
12936 NestedNameSpecifierLoc(), NameInfo,
12937 /*NeedsADL=*/true, /*Overloaded=*/false,
12938 FoundNames.begin(), FoundNames.end());
12940 bool CandidateSetError = buildOverloadedCallSet(S, Fn, Fn, Range, Loc,
12941 CandidateSet, CallExpr);
12942 if (CandidateSet->empty() || CandidateSetError) {
12943 *CallExpr = ExprError();
12944 return FRS_NoViableFunction;
12946 OverloadCandidateSet::iterator Best;
12947 OverloadingResult OverloadResult =
12948 CandidateSet->BestViableFunction(*this, Fn->getLocStart(), Best);
12950 if (OverloadResult == OR_No_Viable_Function) {
12951 *CallExpr = ExprError();
12952 return FRS_NoViableFunction;
12954 *CallExpr = FinishOverloadedCallExpr(*this, S, Fn, Fn, Loc, Range,
12955 Loc, nullptr, CandidateSet, &Best,
12957 /*AllowTypoCorrection=*/false);
12958 if (CallExpr->isInvalid() || OverloadResult != OR_Success) {
12959 *CallExpr = ExprError();
12960 return FRS_DiagnosticIssued;
12963 return FRS_Success;
12967 /// FixOverloadedFunctionReference - E is an expression that refers to
12968 /// a C++ overloaded function (possibly with some parentheses and
12969 /// perhaps a '&' around it). We have resolved the overloaded function
12970 /// to the function declaration Fn, so patch up the expression E to
12971 /// refer (possibly indirectly) to Fn. Returns the new expr.
12972 Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found,
12973 FunctionDecl *Fn) {
12974 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
12975 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(),
12977 if (SubExpr == PE->getSubExpr())
12980 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr);
12983 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
12984 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(),
12986 assert(Context.hasSameType(ICE->getSubExpr()->getType(),
12987 SubExpr->getType()) &&
12988 "Implicit cast type cannot be determined from overload");
12989 assert(ICE->path_empty() && "fixing up hierarchy conversion?");
12990 if (SubExpr == ICE->getSubExpr())
12993 return ImplicitCastExpr::Create(Context, ICE->getType(),
12994 ICE->getCastKind(),
12996 ICE->getValueKind());
12999 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) {
13000 assert(UnOp->getOpcode() == UO_AddrOf &&
13001 "Can only take the address of an overloaded function");
13002 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) {
13003 if (Method->isStatic()) {
13004 // Do nothing: static member functions aren't any different
13005 // from non-member functions.
13007 // Fix the subexpression, which really has to be an
13008 // UnresolvedLookupExpr holding an overloaded member function
13010 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(),
13012 if (SubExpr == UnOp->getSubExpr())
13015 assert(isa<DeclRefExpr>(SubExpr)
13016 && "fixed to something other than a decl ref");
13017 assert(cast<DeclRefExpr>(SubExpr)->getQualifier()
13018 && "fixed to a member ref with no nested name qualifier");
13020 // We have taken the address of a pointer to member
13021 // function. Perform the computation here so that we get the
13022 // appropriate pointer to member type.
13024 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext()));
13025 QualType MemPtrType
13026 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr());
13027 // Under the MS ABI, lock down the inheritance model now.
13028 if (Context.getTargetInfo().getCXXABI().isMicrosoft())
13029 (void)isCompleteType(UnOp->getOperatorLoc(), MemPtrType);
13031 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, MemPtrType,
13032 VK_RValue, OK_Ordinary,
13033 UnOp->getOperatorLoc());
13036 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(),
13038 if (SubExpr == UnOp->getSubExpr())
13041 return new (Context) UnaryOperator(SubExpr, UO_AddrOf,
13042 Context.getPointerType(SubExpr->getType()),
13043 VK_RValue, OK_Ordinary,
13044 UnOp->getOperatorLoc());
13047 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) {
13048 // FIXME: avoid copy.
13049 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
13050 if (ULE->hasExplicitTemplateArgs()) {
13051 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer);
13052 TemplateArgs = &TemplateArgsBuffer;
13055 DeclRefExpr *DRE = DeclRefExpr::Create(Context,
13056 ULE->getQualifierLoc(),
13057 ULE->getTemplateKeywordLoc(),
13059 /*enclosing*/ false, // FIXME?
13065 MarkDeclRefReferenced(DRE);
13066 DRE->setHadMultipleCandidates(ULE->getNumDecls() > 1);
13070 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) {
13071 // FIXME: avoid copy.
13072 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
13073 if (MemExpr->hasExplicitTemplateArgs()) {
13074 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer);
13075 TemplateArgs = &TemplateArgsBuffer;
13080 // If we're filling in a static method where we used to have an
13081 // implicit member access, rewrite to a simple decl ref.
13082 if (MemExpr->isImplicitAccess()) {
13083 if (cast<CXXMethodDecl>(Fn)->isStatic()) {
13084 DeclRefExpr *DRE = DeclRefExpr::Create(Context,
13085 MemExpr->getQualifierLoc(),
13086 MemExpr->getTemplateKeywordLoc(),
13088 /*enclosing*/ false,
13089 MemExpr->getMemberLoc(),
13094 MarkDeclRefReferenced(DRE);
13095 DRE->setHadMultipleCandidates(MemExpr->getNumDecls() > 1);
13098 SourceLocation Loc = MemExpr->getMemberLoc();
13099 if (MemExpr->getQualifier())
13100 Loc = MemExpr->getQualifierLoc().getBeginLoc();
13101 CheckCXXThisCapture(Loc);
13102 Base = new (Context) CXXThisExpr(Loc,
13103 MemExpr->getBaseType(),
13104 /*isImplicit=*/true);
13107 Base = MemExpr->getBase();
13109 ExprValueKind valueKind;
13111 if (cast<CXXMethodDecl>(Fn)->isStatic()) {
13112 valueKind = VK_LValue;
13113 type = Fn->getType();
13115 valueKind = VK_RValue;
13116 type = Context.BoundMemberTy;
13119 MemberExpr *ME = MemberExpr::Create(
13120 Context, Base, MemExpr->isArrow(), MemExpr->getOperatorLoc(),
13121 MemExpr->getQualifierLoc(), MemExpr->getTemplateKeywordLoc(), Fn, Found,
13122 MemExpr->getMemberNameInfo(), TemplateArgs, type, valueKind,
13124 ME->setHadMultipleCandidates(true);
13125 MarkMemberReferenced(ME);
13129 llvm_unreachable("Invalid reference to overloaded function");
13132 ExprResult Sema::FixOverloadedFunctionReference(ExprResult E,
13133 DeclAccessPair Found,
13134 FunctionDecl *Fn) {
13135 return FixOverloadedFunctionReference(E.get(), Found, Fn);