1 //===--- SemaOverload.cpp - C++ Overloading -------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file provides Sema routines for C++ overloading.
12 //===----------------------------------------------------------------------===//
14 #include "clang/Sema/Overload.h"
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/CXXInheritance.h"
17 #include "clang/AST/DeclObjC.h"
18 #include "clang/AST/Expr.h"
19 #include "clang/AST/ExprCXX.h"
20 #include "clang/AST/ExprObjC.h"
21 #include "clang/AST/TypeOrdering.h"
22 #include "clang/Basic/Diagnostic.h"
23 #include "clang/Basic/DiagnosticOptions.h"
24 #include "clang/Basic/PartialDiagnostic.h"
25 #include "clang/Basic/TargetInfo.h"
26 #include "clang/Sema/Initialization.h"
27 #include "clang/Sema/Lookup.h"
28 #include "clang/Sema/SemaInternal.h"
29 #include "clang/Sema/Template.h"
30 #include "clang/Sema/TemplateDeduction.h"
31 #include "llvm/ADT/DenseSet.h"
32 #include "llvm/ADT/Optional.h"
33 #include "llvm/ADT/STLExtras.h"
34 #include "llvm/ADT/SmallPtrSet.h"
35 #include "llvm/ADT/SmallString.h"
39 using namespace clang;
42 static bool functionHasPassObjectSizeParams(const FunctionDecl *FD) {
43 return llvm::any_of(FD->parameters(), [](const ParmVarDecl *P) {
44 return P->hasAttr<PassObjectSizeAttr>();
48 /// A convenience routine for creating a decayed reference to a function.
50 CreateFunctionRefExpr(Sema &S, FunctionDecl *Fn, NamedDecl *FoundDecl,
51 bool HadMultipleCandidates,
52 SourceLocation Loc = SourceLocation(),
53 const DeclarationNameLoc &LocInfo = DeclarationNameLoc()){
54 if (S.DiagnoseUseOfDecl(FoundDecl, Loc))
56 // If FoundDecl is different from Fn (such as if one is a template
57 // and the other a specialization), make sure DiagnoseUseOfDecl is
59 // FIXME: This would be more comprehensively addressed by modifying
60 // DiagnoseUseOfDecl to accept both the FoundDecl and the decl
62 if (FoundDecl != Fn && S.DiagnoseUseOfDecl(Fn, Loc))
64 if (auto *FPT = Fn->getType()->getAs<FunctionProtoType>())
65 S.ResolveExceptionSpec(Loc, FPT);
66 DeclRefExpr *DRE = new (S.Context) DeclRefExpr(Fn, false, Fn->getType(),
67 VK_LValue, Loc, LocInfo);
68 if (HadMultipleCandidates)
69 DRE->setHadMultipleCandidates(true);
71 S.MarkDeclRefReferenced(DRE);
72 return S.ImpCastExprToType(DRE, S.Context.getPointerType(DRE->getType()),
73 CK_FunctionToPointerDecay);
76 static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
77 bool InOverloadResolution,
78 StandardConversionSequence &SCS,
80 bool AllowObjCWritebackConversion);
82 static bool IsTransparentUnionStandardConversion(Sema &S, Expr* From,
84 bool InOverloadResolution,
85 StandardConversionSequence &SCS,
87 static OverloadingResult
88 IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
89 UserDefinedConversionSequence& User,
90 OverloadCandidateSet& Conversions,
92 bool AllowObjCConversionOnExplicit);
95 static ImplicitConversionSequence::CompareKind
96 CompareStandardConversionSequences(Sema &S, SourceLocation Loc,
97 const StandardConversionSequence& SCS1,
98 const StandardConversionSequence& SCS2);
100 static ImplicitConversionSequence::CompareKind
101 CompareQualificationConversions(Sema &S,
102 const StandardConversionSequence& SCS1,
103 const StandardConversionSequence& SCS2);
105 static ImplicitConversionSequence::CompareKind
106 CompareDerivedToBaseConversions(Sema &S, SourceLocation Loc,
107 const StandardConversionSequence& SCS1,
108 const StandardConversionSequence& SCS2);
110 /// GetConversionRank - Retrieve the implicit conversion rank
111 /// corresponding to the given implicit conversion kind.
112 ImplicitConversionRank clang::GetConversionRank(ImplicitConversionKind Kind) {
113 static const ImplicitConversionRank
114 Rank[(int)ICK_Num_Conversion_Kinds] = {
134 ICR_OCL_Scalar_Widening,
135 ICR_Complex_Real_Conversion,
138 ICR_Writeback_Conversion,
139 ICR_Exact_Match, // NOTE(gbiv): This may not be completely right --
140 // it was omitted by the patch that added
141 // ICK_Zero_Event_Conversion
143 ICR_C_Conversion_Extension
145 return Rank[(int)Kind];
148 /// GetImplicitConversionName - Return the name of this kind of
149 /// implicit conversion.
150 static const char* GetImplicitConversionName(ImplicitConversionKind Kind) {
151 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = {
155 "Function-to-pointer",
156 "Function pointer conversion",
158 "Integral promotion",
159 "Floating point promotion",
161 "Integral conversion",
162 "Floating conversion",
163 "Complex conversion",
164 "Floating-integral conversion",
165 "Pointer conversion",
166 "Pointer-to-member conversion",
167 "Boolean conversion",
168 "Compatible-types conversion",
169 "Derived-to-base conversion",
172 "Complex-real conversion",
173 "Block Pointer conversion",
174 "Transparent Union Conversion",
175 "Writeback conversion",
176 "OpenCL Zero Event Conversion",
177 "C specific type conversion",
178 "Incompatible pointer conversion"
183 /// StandardConversionSequence - Set the standard conversion
184 /// sequence to the identity conversion.
185 void StandardConversionSequence::setAsIdentityConversion() {
186 First = ICK_Identity;
187 Second = ICK_Identity;
188 Third = ICK_Identity;
189 DeprecatedStringLiteralToCharPtr = false;
190 QualificationIncludesObjCLifetime = false;
191 ReferenceBinding = false;
192 DirectBinding = false;
193 IsLvalueReference = true;
194 BindsToFunctionLvalue = false;
195 BindsToRvalue = false;
196 BindsImplicitObjectArgumentWithoutRefQualifier = false;
197 ObjCLifetimeConversionBinding = false;
198 CopyConstructor = nullptr;
201 /// getRank - Retrieve the rank of this standard conversion sequence
202 /// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the
203 /// implicit conversions.
204 ImplicitConversionRank StandardConversionSequence::getRank() const {
205 ImplicitConversionRank Rank = ICR_Exact_Match;
206 if (GetConversionRank(First) > Rank)
207 Rank = GetConversionRank(First);
208 if (GetConversionRank(Second) > Rank)
209 Rank = GetConversionRank(Second);
210 if (GetConversionRank(Third) > Rank)
211 Rank = GetConversionRank(Third);
215 /// isPointerConversionToBool - Determines whether this conversion is
216 /// a conversion of a pointer or pointer-to-member to bool. This is
217 /// used as part of the ranking of standard conversion sequences
218 /// (C++ 13.3.3.2p4).
219 bool StandardConversionSequence::isPointerConversionToBool() const {
220 // Note that FromType has not necessarily been transformed by the
221 // array-to-pointer or function-to-pointer implicit conversions, so
222 // check for their presence as well as checking whether FromType is
224 if (getToType(1)->isBooleanType() &&
225 (getFromType()->isPointerType() ||
226 getFromType()->isObjCObjectPointerType() ||
227 getFromType()->isBlockPointerType() ||
228 getFromType()->isNullPtrType() ||
229 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer))
235 /// isPointerConversionToVoidPointer - Determines whether this
236 /// conversion is a conversion of a pointer to a void pointer. This is
237 /// used as part of the ranking of standard conversion sequences (C++
240 StandardConversionSequence::
241 isPointerConversionToVoidPointer(ASTContext& Context) const {
242 QualType FromType = getFromType();
243 QualType ToType = getToType(1);
245 // Note that FromType has not necessarily been transformed by the
246 // array-to-pointer implicit conversion, so check for its presence
247 // and redo the conversion to get a pointer.
248 if (First == ICK_Array_To_Pointer)
249 FromType = Context.getArrayDecayedType(FromType);
251 if (Second == ICK_Pointer_Conversion && FromType->isAnyPointerType())
252 if (const PointerType* ToPtrType = ToType->getAs<PointerType>())
253 return ToPtrType->getPointeeType()->isVoidType();
258 /// Skip any implicit casts which could be either part of a narrowing conversion
259 /// or after one in an implicit conversion.
260 static const Expr *IgnoreNarrowingConversion(const Expr *Converted) {
261 while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Converted)) {
262 switch (ICE->getCastKind()) {
264 case CK_IntegralCast:
265 case CK_IntegralToBoolean:
266 case CK_IntegralToFloating:
267 case CK_BooleanToSignedIntegral:
268 case CK_FloatingToIntegral:
269 case CK_FloatingToBoolean:
270 case CK_FloatingCast:
271 Converted = ICE->getSubExpr();
282 /// Check if this standard conversion sequence represents a narrowing
283 /// conversion, according to C++11 [dcl.init.list]p7.
285 /// \param Ctx The AST context.
286 /// \param Converted The result of applying this standard conversion sequence.
287 /// \param ConstantValue If this is an NK_Constant_Narrowing conversion, the
288 /// value of the expression prior to the narrowing conversion.
289 /// \param ConstantType If this is an NK_Constant_Narrowing conversion, the
290 /// type of the expression prior to the narrowing conversion.
292 StandardConversionSequence::getNarrowingKind(ASTContext &Ctx,
293 const Expr *Converted,
294 APValue &ConstantValue,
295 QualType &ConstantType) const {
296 assert(Ctx.getLangOpts().CPlusPlus && "narrowing check outside C++");
298 // C++11 [dcl.init.list]p7:
299 // A narrowing conversion is an implicit conversion ...
300 QualType FromType = getToType(0);
301 QualType ToType = getToType(1);
303 // A conversion to an enumeration type is narrowing if the conversion to
304 // the underlying type is narrowing. This only arises for expressions of
305 // the form 'Enum{init}'.
306 if (auto *ET = ToType->getAs<EnumType>())
307 ToType = ET->getDecl()->getIntegerType();
310 // 'bool' is an integral type; dispatch to the right place to handle it.
311 case ICK_Boolean_Conversion:
312 if (FromType->isRealFloatingType())
313 goto FloatingIntegralConversion;
314 if (FromType->isIntegralOrUnscopedEnumerationType())
315 goto IntegralConversion;
316 // Boolean conversions can be from pointers and pointers to members
317 // [conv.bool], and those aren't considered narrowing conversions.
318 return NK_Not_Narrowing;
320 // -- from a floating-point type to an integer type, or
322 // -- from an integer type or unscoped enumeration type to a floating-point
323 // type, except where the source is a constant expression and the actual
324 // value after conversion will fit into the target type and will produce
325 // the original value when converted back to the original type, or
326 case ICK_Floating_Integral:
327 FloatingIntegralConversion:
328 if (FromType->isRealFloatingType() && ToType->isIntegralType(Ctx)) {
329 return NK_Type_Narrowing;
330 } else if (FromType->isIntegralType(Ctx) && ToType->isRealFloatingType()) {
331 llvm::APSInt IntConstantValue;
332 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
334 // If it's value-dependent, we can't tell whether it's narrowing.
335 if (Initializer->isValueDependent())
336 return NK_Dependent_Narrowing;
339 Initializer->isIntegerConstantExpr(IntConstantValue, Ctx)) {
340 // Convert the integer to the floating type.
341 llvm::APFloat Result(Ctx.getFloatTypeSemantics(ToType));
342 Result.convertFromAPInt(IntConstantValue, IntConstantValue.isSigned(),
343 llvm::APFloat::rmNearestTiesToEven);
345 llvm::APSInt ConvertedValue = IntConstantValue;
347 Result.convertToInteger(ConvertedValue,
348 llvm::APFloat::rmTowardZero, &ignored);
349 // If the resulting value is different, this was a narrowing conversion.
350 if (IntConstantValue != ConvertedValue) {
351 ConstantValue = APValue(IntConstantValue);
352 ConstantType = Initializer->getType();
353 return NK_Constant_Narrowing;
356 // Variables are always narrowings.
357 return NK_Variable_Narrowing;
360 return NK_Not_Narrowing;
362 // -- from long double to double or float, or from double to float, except
363 // where the source is a constant expression and the actual value after
364 // conversion is within the range of values that can be represented (even
365 // if it cannot be represented exactly), or
366 case ICK_Floating_Conversion:
367 if (FromType->isRealFloatingType() && ToType->isRealFloatingType() &&
368 Ctx.getFloatingTypeOrder(FromType, ToType) == 1) {
369 // FromType is larger than ToType.
370 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
372 // If it's value-dependent, we can't tell whether it's narrowing.
373 if (Initializer->isValueDependent())
374 return NK_Dependent_Narrowing;
376 if (Initializer->isCXX11ConstantExpr(Ctx, &ConstantValue)) {
378 assert(ConstantValue.isFloat());
379 llvm::APFloat FloatVal = ConstantValue.getFloat();
380 // Convert the source value into the target type.
382 llvm::APFloat::opStatus ConvertStatus = FloatVal.convert(
383 Ctx.getFloatTypeSemantics(ToType),
384 llvm::APFloat::rmNearestTiesToEven, &ignored);
385 // If there was no overflow, the source value is within the range of
386 // values that can be represented.
387 if (ConvertStatus & llvm::APFloat::opOverflow) {
388 ConstantType = Initializer->getType();
389 return NK_Constant_Narrowing;
392 return NK_Variable_Narrowing;
395 return NK_Not_Narrowing;
397 // -- from an integer type or unscoped enumeration type to an integer type
398 // that cannot represent all the values of the original type, except where
399 // the source is a constant expression and the actual value after
400 // conversion will fit into the target type and will produce the original
401 // value when converted back to the original type.
402 case ICK_Integral_Conversion:
403 IntegralConversion: {
404 assert(FromType->isIntegralOrUnscopedEnumerationType());
405 assert(ToType->isIntegralOrUnscopedEnumerationType());
406 const bool FromSigned = FromType->isSignedIntegerOrEnumerationType();
407 const unsigned FromWidth = Ctx.getIntWidth(FromType);
408 const bool ToSigned = ToType->isSignedIntegerOrEnumerationType();
409 const unsigned ToWidth = Ctx.getIntWidth(ToType);
411 if (FromWidth > ToWidth ||
412 (FromWidth == ToWidth && FromSigned != ToSigned) ||
413 (FromSigned && !ToSigned)) {
414 // Not all values of FromType can be represented in ToType.
415 llvm::APSInt InitializerValue;
416 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
418 // If it's value-dependent, we can't tell whether it's narrowing.
419 if (Initializer->isValueDependent())
420 return NK_Dependent_Narrowing;
422 if (!Initializer->isIntegerConstantExpr(InitializerValue, Ctx)) {
423 // Such conversions on variables are always narrowing.
424 return NK_Variable_Narrowing;
426 bool Narrowing = false;
427 if (FromWidth < ToWidth) {
428 // Negative -> unsigned is narrowing. Otherwise, more bits is never
430 if (InitializerValue.isSigned() && InitializerValue.isNegative())
433 // Add a bit to the InitializerValue so we don't have to worry about
434 // signed vs. unsigned comparisons.
435 InitializerValue = InitializerValue.extend(
436 InitializerValue.getBitWidth() + 1);
437 // Convert the initializer to and from the target width and signed-ness.
438 llvm::APSInt ConvertedValue = InitializerValue;
439 ConvertedValue = ConvertedValue.trunc(ToWidth);
440 ConvertedValue.setIsSigned(ToSigned);
441 ConvertedValue = ConvertedValue.extend(InitializerValue.getBitWidth());
442 ConvertedValue.setIsSigned(InitializerValue.isSigned());
443 // If the result is different, this was a narrowing conversion.
444 if (ConvertedValue != InitializerValue)
448 ConstantType = Initializer->getType();
449 ConstantValue = APValue(InitializerValue);
450 return NK_Constant_Narrowing;
453 return NK_Not_Narrowing;
457 // Other kinds of conversions are not narrowings.
458 return NK_Not_Narrowing;
462 /// dump - Print this standard conversion sequence to standard
463 /// error. Useful for debugging overloading issues.
464 LLVM_DUMP_METHOD void StandardConversionSequence::dump() const {
465 raw_ostream &OS = llvm::errs();
466 bool PrintedSomething = false;
467 if (First != ICK_Identity) {
468 OS << GetImplicitConversionName(First);
469 PrintedSomething = true;
472 if (Second != ICK_Identity) {
473 if (PrintedSomething) {
476 OS << GetImplicitConversionName(Second);
478 if (CopyConstructor) {
479 OS << " (by copy constructor)";
480 } else if (DirectBinding) {
481 OS << " (direct reference binding)";
482 } else if (ReferenceBinding) {
483 OS << " (reference binding)";
485 PrintedSomething = true;
488 if (Third != ICK_Identity) {
489 if (PrintedSomething) {
492 OS << GetImplicitConversionName(Third);
493 PrintedSomething = true;
496 if (!PrintedSomething) {
497 OS << "No conversions required";
501 /// dump - Print this user-defined conversion sequence to standard
502 /// error. Useful for debugging overloading issues.
503 void UserDefinedConversionSequence::dump() const {
504 raw_ostream &OS = llvm::errs();
505 if (Before.First || Before.Second || Before.Third) {
509 if (ConversionFunction)
510 OS << '\'' << *ConversionFunction << '\'';
512 OS << "aggregate initialization";
513 if (After.First || After.Second || After.Third) {
519 /// dump - Print this implicit conversion sequence to standard
520 /// error. Useful for debugging overloading issues.
521 void ImplicitConversionSequence::dump() const {
522 raw_ostream &OS = llvm::errs();
523 if (isStdInitializerListElement())
524 OS << "Worst std::initializer_list element conversion: ";
525 switch (ConversionKind) {
526 case StandardConversion:
527 OS << "Standard conversion: ";
530 case UserDefinedConversion:
531 OS << "User-defined conversion: ";
534 case EllipsisConversion:
535 OS << "Ellipsis conversion";
537 case AmbiguousConversion:
538 OS << "Ambiguous conversion";
541 OS << "Bad conversion";
548 void AmbiguousConversionSequence::construct() {
549 new (&conversions()) ConversionSet();
552 void AmbiguousConversionSequence::destruct() {
553 conversions().~ConversionSet();
557 AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) {
558 FromTypePtr = O.FromTypePtr;
559 ToTypePtr = O.ToTypePtr;
560 new (&conversions()) ConversionSet(O.conversions());
564 // Structure used by DeductionFailureInfo to store
565 // template argument information.
566 struct DFIArguments {
567 TemplateArgument FirstArg;
568 TemplateArgument SecondArg;
570 // Structure used by DeductionFailureInfo to store
571 // template parameter and template argument information.
572 struct DFIParamWithArguments : DFIArguments {
573 TemplateParameter Param;
575 // Structure used by DeductionFailureInfo to store template argument
576 // information and the index of the problematic call argument.
577 struct DFIDeducedMismatchArgs : DFIArguments {
578 TemplateArgumentList *TemplateArgs;
579 unsigned CallArgIndex;
583 /// \brief Convert from Sema's representation of template deduction information
584 /// to the form used in overload-candidate information.
586 clang::MakeDeductionFailureInfo(ASTContext &Context,
587 Sema::TemplateDeductionResult TDK,
588 TemplateDeductionInfo &Info) {
589 DeductionFailureInfo Result;
590 Result.Result = static_cast<unsigned>(TDK);
591 Result.HasDiagnostic = false;
593 case Sema::TDK_Invalid:
594 case Sema::TDK_InstantiationDepth:
595 case Sema::TDK_TooManyArguments:
596 case Sema::TDK_TooFewArguments:
597 case Sema::TDK_MiscellaneousDeductionFailure:
598 case Sema::TDK_CUDATargetMismatch:
599 Result.Data = nullptr;
602 case Sema::TDK_Incomplete:
603 case Sema::TDK_InvalidExplicitArguments:
604 Result.Data = Info.Param.getOpaqueValue();
607 case Sema::TDK_DeducedMismatch:
608 case Sema::TDK_DeducedMismatchNested: {
609 // FIXME: Should allocate from normal heap so that we can free this later.
610 auto *Saved = new (Context) DFIDeducedMismatchArgs;
611 Saved->FirstArg = Info.FirstArg;
612 Saved->SecondArg = Info.SecondArg;
613 Saved->TemplateArgs = Info.take();
614 Saved->CallArgIndex = Info.CallArgIndex;
619 case Sema::TDK_NonDeducedMismatch: {
620 // FIXME: Should allocate from normal heap so that we can free this later.
621 DFIArguments *Saved = new (Context) DFIArguments;
622 Saved->FirstArg = Info.FirstArg;
623 Saved->SecondArg = Info.SecondArg;
628 case Sema::TDK_Inconsistent:
629 case Sema::TDK_Underqualified: {
630 // FIXME: Should allocate from normal heap so that we can free this later.
631 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments;
632 Saved->Param = Info.Param;
633 Saved->FirstArg = Info.FirstArg;
634 Saved->SecondArg = Info.SecondArg;
639 case Sema::TDK_SubstitutionFailure:
640 Result.Data = Info.take();
641 if (Info.hasSFINAEDiagnostic()) {
642 PartialDiagnosticAt *Diag = new (Result.Diagnostic) PartialDiagnosticAt(
643 SourceLocation(), PartialDiagnostic::NullDiagnostic());
644 Info.takeSFINAEDiagnostic(*Diag);
645 Result.HasDiagnostic = true;
649 case Sema::TDK_Success:
650 case Sema::TDK_NonDependentConversionFailure:
651 llvm_unreachable("not a deduction failure");
657 void DeductionFailureInfo::Destroy() {
658 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
659 case Sema::TDK_Success:
660 case Sema::TDK_Invalid:
661 case Sema::TDK_InstantiationDepth:
662 case Sema::TDK_Incomplete:
663 case Sema::TDK_TooManyArguments:
664 case Sema::TDK_TooFewArguments:
665 case Sema::TDK_InvalidExplicitArguments:
666 case Sema::TDK_CUDATargetMismatch:
667 case Sema::TDK_NonDependentConversionFailure:
670 case Sema::TDK_Inconsistent:
671 case Sema::TDK_Underqualified:
672 case Sema::TDK_DeducedMismatch:
673 case Sema::TDK_DeducedMismatchNested:
674 case Sema::TDK_NonDeducedMismatch:
675 // FIXME: Destroy the data?
679 case Sema::TDK_SubstitutionFailure:
680 // FIXME: Destroy the template argument list?
682 if (PartialDiagnosticAt *Diag = getSFINAEDiagnostic()) {
683 Diag->~PartialDiagnosticAt();
684 HasDiagnostic = false;
689 case Sema::TDK_MiscellaneousDeductionFailure:
694 PartialDiagnosticAt *DeductionFailureInfo::getSFINAEDiagnostic() {
696 return static_cast<PartialDiagnosticAt*>(static_cast<void*>(Diagnostic));
700 TemplateParameter DeductionFailureInfo::getTemplateParameter() {
701 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
702 case Sema::TDK_Success:
703 case Sema::TDK_Invalid:
704 case Sema::TDK_InstantiationDepth:
705 case Sema::TDK_TooManyArguments:
706 case Sema::TDK_TooFewArguments:
707 case Sema::TDK_SubstitutionFailure:
708 case Sema::TDK_DeducedMismatch:
709 case Sema::TDK_DeducedMismatchNested:
710 case Sema::TDK_NonDeducedMismatch:
711 case Sema::TDK_CUDATargetMismatch:
712 case Sema::TDK_NonDependentConversionFailure:
713 return TemplateParameter();
715 case Sema::TDK_Incomplete:
716 case Sema::TDK_InvalidExplicitArguments:
717 return TemplateParameter::getFromOpaqueValue(Data);
719 case Sema::TDK_Inconsistent:
720 case Sema::TDK_Underqualified:
721 return static_cast<DFIParamWithArguments*>(Data)->Param;
724 case Sema::TDK_MiscellaneousDeductionFailure:
728 return TemplateParameter();
731 TemplateArgumentList *DeductionFailureInfo::getTemplateArgumentList() {
732 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
733 case Sema::TDK_Success:
734 case Sema::TDK_Invalid:
735 case Sema::TDK_InstantiationDepth:
736 case Sema::TDK_TooManyArguments:
737 case Sema::TDK_TooFewArguments:
738 case Sema::TDK_Incomplete:
739 case Sema::TDK_InvalidExplicitArguments:
740 case Sema::TDK_Inconsistent:
741 case Sema::TDK_Underqualified:
742 case Sema::TDK_NonDeducedMismatch:
743 case Sema::TDK_CUDATargetMismatch:
744 case Sema::TDK_NonDependentConversionFailure:
747 case Sema::TDK_DeducedMismatch:
748 case Sema::TDK_DeducedMismatchNested:
749 return static_cast<DFIDeducedMismatchArgs*>(Data)->TemplateArgs;
751 case Sema::TDK_SubstitutionFailure:
752 return static_cast<TemplateArgumentList*>(Data);
755 case Sema::TDK_MiscellaneousDeductionFailure:
762 const TemplateArgument *DeductionFailureInfo::getFirstArg() {
763 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
764 case Sema::TDK_Success:
765 case Sema::TDK_Invalid:
766 case Sema::TDK_InstantiationDepth:
767 case Sema::TDK_Incomplete:
768 case Sema::TDK_TooManyArguments:
769 case Sema::TDK_TooFewArguments:
770 case Sema::TDK_InvalidExplicitArguments:
771 case Sema::TDK_SubstitutionFailure:
772 case Sema::TDK_CUDATargetMismatch:
773 case Sema::TDK_NonDependentConversionFailure:
776 case Sema::TDK_Inconsistent:
777 case Sema::TDK_Underqualified:
778 case Sema::TDK_DeducedMismatch:
779 case Sema::TDK_DeducedMismatchNested:
780 case Sema::TDK_NonDeducedMismatch:
781 return &static_cast<DFIArguments*>(Data)->FirstArg;
784 case Sema::TDK_MiscellaneousDeductionFailure:
791 const TemplateArgument *DeductionFailureInfo::getSecondArg() {
792 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
793 case Sema::TDK_Success:
794 case Sema::TDK_Invalid:
795 case Sema::TDK_InstantiationDepth:
796 case Sema::TDK_Incomplete:
797 case Sema::TDK_TooManyArguments:
798 case Sema::TDK_TooFewArguments:
799 case Sema::TDK_InvalidExplicitArguments:
800 case Sema::TDK_SubstitutionFailure:
801 case Sema::TDK_CUDATargetMismatch:
802 case Sema::TDK_NonDependentConversionFailure:
805 case Sema::TDK_Inconsistent:
806 case Sema::TDK_Underqualified:
807 case Sema::TDK_DeducedMismatch:
808 case Sema::TDK_DeducedMismatchNested:
809 case Sema::TDK_NonDeducedMismatch:
810 return &static_cast<DFIArguments*>(Data)->SecondArg;
813 case Sema::TDK_MiscellaneousDeductionFailure:
820 llvm::Optional<unsigned> DeductionFailureInfo::getCallArgIndex() {
821 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
822 case Sema::TDK_DeducedMismatch:
823 case Sema::TDK_DeducedMismatchNested:
824 return static_cast<DFIDeducedMismatchArgs*>(Data)->CallArgIndex;
831 void OverloadCandidateSet::destroyCandidates() {
832 for (iterator i = begin(), e = end(); i != e; ++i) {
833 for (auto &C : i->Conversions)
834 C.~ImplicitConversionSequence();
835 if (!i->Viable && i->FailureKind == ovl_fail_bad_deduction)
836 i->DeductionFailure.Destroy();
840 void OverloadCandidateSet::clear() {
842 SlabAllocator.Reset();
843 NumInlineBytesUsed = 0;
849 class UnbridgedCastsSet {
854 SmallVector<Entry, 2> Entries;
857 void save(Sema &S, Expr *&E) {
858 assert(E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast));
859 Entry entry = { &E, E };
860 Entries.push_back(entry);
861 E = S.stripARCUnbridgedCast(E);
865 for (SmallVectorImpl<Entry>::iterator
866 i = Entries.begin(), e = Entries.end(); i != e; ++i)
872 /// checkPlaceholderForOverload - Do any interesting placeholder-like
873 /// preprocessing on the given expression.
875 /// \param unbridgedCasts a collection to which to add unbridged casts;
876 /// without this, they will be immediately diagnosed as errors
878 /// Return true on unrecoverable error.
880 checkPlaceholderForOverload(Sema &S, Expr *&E,
881 UnbridgedCastsSet *unbridgedCasts = nullptr) {
882 if (const BuiltinType *placeholder = E->getType()->getAsPlaceholderType()) {
883 // We can't handle overloaded expressions here because overload
884 // resolution might reasonably tweak them.
885 if (placeholder->getKind() == BuiltinType::Overload) return false;
887 // If the context potentially accepts unbridged ARC casts, strip
888 // the unbridged cast and add it to the collection for later restoration.
889 if (placeholder->getKind() == BuiltinType::ARCUnbridgedCast &&
891 unbridgedCasts->save(S, E);
895 // Go ahead and check everything else.
896 ExprResult result = S.CheckPlaceholderExpr(E);
897 if (result.isInvalid())
908 /// checkArgPlaceholdersForOverload - Check a set of call operands for
910 static bool checkArgPlaceholdersForOverload(Sema &S,
912 UnbridgedCastsSet &unbridged) {
913 for (unsigned i = 0, e = Args.size(); i != e; ++i)
914 if (checkPlaceholderForOverload(S, Args[i], &unbridged))
920 /// Determine whether the given New declaration is an overload of the
921 /// declarations in Old. This routine returns Ovl_Match or Ovl_NonFunction if
922 /// New and Old cannot be overloaded, e.g., if New has the same signature as
923 /// some function in Old (C++ 1.3.10) or if the Old declarations aren't
924 /// functions (or function templates) at all. When it does return Ovl_Match or
925 /// Ovl_NonFunction, MatchedDecl will point to the decl that New cannot be
926 /// overloaded with. This decl may be a UsingShadowDecl on top of the underlying
929 /// Example: Given the following input:
931 /// void f(int, float); // #1
932 /// void f(int, int); // #2
933 /// int f(int, int); // #3
935 /// When we process #1, there is no previous declaration of "f", so IsOverload
936 /// will not be used.
938 /// When we process #2, Old contains only the FunctionDecl for #1. By comparing
939 /// the parameter types, we see that #1 and #2 are overloaded (since they have
940 /// different signatures), so this routine returns Ovl_Overload; MatchedDecl is
943 /// When we process #3, Old is an overload set containing #1 and #2. We compare
944 /// the signatures of #3 to #1 (they're overloaded, so we do nothing) and then
945 /// #3 to #2. Since the signatures of #3 and #2 are identical (return types of
946 /// functions are not part of the signature), IsOverload returns Ovl_Match and
947 /// MatchedDecl will be set to point to the FunctionDecl for #2.
949 /// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced into a class
950 /// by a using declaration. The rules for whether to hide shadow declarations
951 /// ignore some properties which otherwise figure into a function template's
954 Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old,
955 NamedDecl *&Match, bool NewIsUsingDecl) {
956 for (LookupResult::iterator I = Old.begin(), E = Old.end();
958 NamedDecl *OldD = *I;
960 bool OldIsUsingDecl = false;
961 if (isa<UsingShadowDecl>(OldD)) {
962 OldIsUsingDecl = true;
964 // We can always introduce two using declarations into the same
965 // context, even if they have identical signatures.
966 if (NewIsUsingDecl) continue;
968 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl();
971 // A using-declaration does not conflict with another declaration
972 // if one of them is hidden.
973 if ((OldIsUsingDecl || NewIsUsingDecl) && !isVisible(*I))
976 // If either declaration was introduced by a using declaration,
977 // we'll need to use slightly different rules for matching.
978 // Essentially, these rules are the normal rules, except that
979 // function templates hide function templates with different
980 // return types or template parameter lists.
981 bool UseMemberUsingDeclRules =
982 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord() &&
983 !New->getFriendObjectKind();
985 if (FunctionDecl *OldF = OldD->getAsFunction()) {
986 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) {
987 if (UseMemberUsingDeclRules && OldIsUsingDecl) {
988 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I));
992 if (!isa<FunctionTemplateDecl>(OldD) &&
993 !shouldLinkPossiblyHiddenDecl(*I, New))
999 } else if (isa<UsingDecl>(OldD) || isa<UsingPackDecl>(OldD)) {
1000 // We can overload with these, which can show up when doing
1001 // redeclaration checks for UsingDecls.
1002 assert(Old.getLookupKind() == LookupUsingDeclName);
1003 } else if (isa<TagDecl>(OldD)) {
1004 // We can always overload with tags by hiding them.
1005 } else if (auto *UUD = dyn_cast<UnresolvedUsingValueDecl>(OldD)) {
1006 // Optimistically assume that an unresolved using decl will
1007 // overload; if it doesn't, we'll have to diagnose during
1008 // template instantiation.
1010 // Exception: if the scope is dependent and this is not a class
1011 // member, the using declaration can only introduce an enumerator.
1012 if (UUD->getQualifier()->isDependent() && !UUD->isCXXClassMember()) {
1014 return Ovl_NonFunction;
1018 // Only function declarations can be overloaded; object and type
1019 // declarations cannot be overloaded.
1021 return Ovl_NonFunction;
1025 return Ovl_Overload;
1028 bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old,
1029 bool UseMemberUsingDeclRules, bool ConsiderCudaAttrs) {
1030 // C++ [basic.start.main]p2: This function shall not be overloaded.
1034 // MSVCRT user defined entry points cannot be overloaded.
1035 if (New->isMSVCRTEntryPoint())
1038 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate();
1039 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate();
1041 // C++ [temp.fct]p2:
1042 // A function template can be overloaded with other function templates
1043 // and with normal (non-template) functions.
1044 if ((OldTemplate == nullptr) != (NewTemplate == nullptr))
1047 // Is the function New an overload of the function Old?
1048 QualType OldQType = Context.getCanonicalType(Old->getType());
1049 QualType NewQType = Context.getCanonicalType(New->getType());
1051 // Compare the signatures (C++ 1.3.10) of the two functions to
1052 // determine whether they are overloads. If we find any mismatch
1053 // in the signature, they are overloads.
1055 // If either of these functions is a K&R-style function (no
1056 // prototype), then we consider them to have matching signatures.
1057 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) ||
1058 isa<FunctionNoProtoType>(NewQType.getTypePtr()))
1061 const FunctionProtoType *OldType = cast<FunctionProtoType>(OldQType);
1062 const FunctionProtoType *NewType = cast<FunctionProtoType>(NewQType);
1064 // The signature of a function includes the types of its
1065 // parameters (C++ 1.3.10), which includes the presence or absence
1066 // of the ellipsis; see C++ DR 357).
1067 if (OldQType != NewQType &&
1068 (OldType->getNumParams() != NewType->getNumParams() ||
1069 OldType->isVariadic() != NewType->isVariadic() ||
1070 !FunctionParamTypesAreEqual(OldType, NewType)))
1073 // C++ [temp.over.link]p4:
1074 // The signature of a function template consists of its function
1075 // signature, its return type and its template parameter list. The names
1076 // of the template parameters are significant only for establishing the
1077 // relationship between the template parameters and the rest of the
1080 // We check the return type and template parameter lists for function
1081 // templates first; the remaining checks follow.
1083 // However, we don't consider either of these when deciding whether
1084 // a member introduced by a shadow declaration is hidden.
1085 if (!UseMemberUsingDeclRules && NewTemplate &&
1086 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(),
1087 OldTemplate->getTemplateParameters(),
1088 false, TPL_TemplateMatch) ||
1089 OldType->getReturnType() != NewType->getReturnType()))
1092 // If the function is a class member, its signature includes the
1093 // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself.
1095 // As part of this, also check whether one of the member functions
1096 // is static, in which case they are not overloads (C++
1097 // 13.1p2). While not part of the definition of the signature,
1098 // this check is important to determine whether these functions
1099 // can be overloaded.
1100 CXXMethodDecl *OldMethod = dyn_cast<CXXMethodDecl>(Old);
1101 CXXMethodDecl *NewMethod = dyn_cast<CXXMethodDecl>(New);
1102 if (OldMethod && NewMethod &&
1103 !OldMethod->isStatic() && !NewMethod->isStatic()) {
1104 if (OldMethod->getRefQualifier() != NewMethod->getRefQualifier()) {
1105 if (!UseMemberUsingDeclRules &&
1106 (OldMethod->getRefQualifier() == RQ_None ||
1107 NewMethod->getRefQualifier() == RQ_None)) {
1108 // C++0x [over.load]p2:
1109 // - Member function declarations with the same name and the same
1110 // parameter-type-list as well as member function template
1111 // declarations with the same name, the same parameter-type-list, and
1112 // the same template parameter lists cannot be overloaded if any of
1113 // them, but not all, have a ref-qualifier (8.3.5).
1114 Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload)
1115 << NewMethod->getRefQualifier() << OldMethod->getRefQualifier();
1116 Diag(OldMethod->getLocation(), diag::note_previous_declaration);
1121 // We may not have applied the implicit const for a constexpr member
1122 // function yet (because we haven't yet resolved whether this is a static
1123 // or non-static member function). Add it now, on the assumption that this
1124 // is a redeclaration of OldMethod.
1125 unsigned OldQuals = OldMethod->getTypeQualifiers();
1126 unsigned NewQuals = NewMethod->getTypeQualifiers();
1127 if (!getLangOpts().CPlusPlus14 && NewMethod->isConstexpr() &&
1128 !isa<CXXConstructorDecl>(NewMethod))
1129 NewQuals |= Qualifiers::Const;
1131 // We do not allow overloading based off of '__restrict'.
1132 OldQuals &= ~Qualifiers::Restrict;
1133 NewQuals &= ~Qualifiers::Restrict;
1134 if (OldQuals != NewQuals)
1138 // Though pass_object_size is placed on parameters and takes an argument, we
1139 // consider it to be a function-level modifier for the sake of function
1140 // identity. Either the function has one or more parameters with
1141 // pass_object_size or it doesn't.
1142 if (functionHasPassObjectSizeParams(New) !=
1143 functionHasPassObjectSizeParams(Old))
1146 // enable_if attributes are an order-sensitive part of the signature.
1147 for (specific_attr_iterator<EnableIfAttr>
1148 NewI = New->specific_attr_begin<EnableIfAttr>(),
1149 NewE = New->specific_attr_end<EnableIfAttr>(),
1150 OldI = Old->specific_attr_begin<EnableIfAttr>(),
1151 OldE = Old->specific_attr_end<EnableIfAttr>();
1152 NewI != NewE || OldI != OldE; ++NewI, ++OldI) {
1153 if (NewI == NewE || OldI == OldE)
1155 llvm::FoldingSetNodeID NewID, OldID;
1156 NewI->getCond()->Profile(NewID, Context, true);
1157 OldI->getCond()->Profile(OldID, Context, true);
1162 if (getLangOpts().CUDA && ConsiderCudaAttrs) {
1163 // Don't allow overloading of destructors. (In theory we could, but it
1164 // would be a giant change to clang.)
1165 if (isa<CXXDestructorDecl>(New))
1168 CUDAFunctionTarget NewTarget = IdentifyCUDATarget(New),
1169 OldTarget = IdentifyCUDATarget(Old);
1170 if (NewTarget == CFT_InvalidTarget)
1173 assert((OldTarget != CFT_InvalidTarget) && "Unexpected invalid target.");
1175 // Allow overloading of functions with same signature and different CUDA
1176 // target attributes.
1177 return NewTarget != OldTarget;
1180 // The signatures match; this is not an overload.
1184 /// \brief Checks availability of the function depending on the current
1185 /// function context. Inside an unavailable function, unavailability is ignored.
1187 /// \returns true if \arg FD is unavailable and current context is inside
1188 /// an available function, false otherwise.
1189 bool Sema::isFunctionConsideredUnavailable(FunctionDecl *FD) {
1190 if (!FD->isUnavailable())
1193 // Walk up the context of the caller.
1194 Decl *C = cast<Decl>(CurContext);
1196 if (C->isUnavailable())
1198 } while ((C = cast_or_null<Decl>(C->getDeclContext())));
1202 /// \brief Tries a user-defined conversion from From to ToType.
1204 /// Produces an implicit conversion sequence for when a standard conversion
1205 /// is not an option. See TryImplicitConversion for more information.
1206 static ImplicitConversionSequence
1207 TryUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
1208 bool SuppressUserConversions,
1210 bool InOverloadResolution,
1212 bool AllowObjCWritebackConversion,
1213 bool AllowObjCConversionOnExplicit) {
1214 ImplicitConversionSequence ICS;
1216 if (SuppressUserConversions) {
1217 // We're not in the case above, so there is no conversion that
1219 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1223 // Attempt user-defined conversion.
1224 OverloadCandidateSet Conversions(From->getExprLoc(),
1225 OverloadCandidateSet::CSK_Normal);
1226 switch (IsUserDefinedConversion(S, From, ToType, ICS.UserDefined,
1227 Conversions, AllowExplicit,
1228 AllowObjCConversionOnExplicit)) {
1231 ICS.setUserDefined();
1232 // C++ [over.ics.user]p4:
1233 // A conversion of an expression of class type to the same class
1234 // type is given Exact Match rank, and a conversion of an
1235 // expression of class type to a base class of that type is
1236 // given Conversion rank, in spite of the fact that a copy
1237 // constructor (i.e., a user-defined conversion function) is
1238 // called for those cases.
1239 if (CXXConstructorDecl *Constructor
1240 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) {
1242 = S.Context.getCanonicalType(From->getType().getUnqualifiedType());
1244 = S.Context.getCanonicalType(ToType).getUnqualifiedType();
1245 if (Constructor->isCopyConstructor() &&
1246 (FromCanon == ToCanon ||
1247 S.IsDerivedFrom(From->getLocStart(), FromCanon, ToCanon))) {
1248 // Turn this into a "standard" conversion sequence, so that it
1249 // gets ranked with standard conversion sequences.
1250 DeclAccessPair Found = ICS.UserDefined.FoundConversionFunction;
1252 ICS.Standard.setAsIdentityConversion();
1253 ICS.Standard.setFromType(From->getType());
1254 ICS.Standard.setAllToTypes(ToType);
1255 ICS.Standard.CopyConstructor = Constructor;
1256 ICS.Standard.FoundCopyConstructor = Found;
1257 if (ToCanon != FromCanon)
1258 ICS.Standard.Second = ICK_Derived_To_Base;
1265 ICS.Ambiguous.setFromType(From->getType());
1266 ICS.Ambiguous.setToType(ToType);
1267 for (OverloadCandidateSet::iterator Cand = Conversions.begin();
1268 Cand != Conversions.end(); ++Cand)
1270 ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
1274 case OR_No_Viable_Function:
1275 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1282 /// TryImplicitConversion - Attempt to perform an implicit conversion
1283 /// from the given expression (Expr) to the given type (ToType). This
1284 /// function returns an implicit conversion sequence that can be used
1285 /// to perform the initialization. Given
1287 /// void f(float f);
1288 /// void g(int i) { f(i); }
1290 /// this routine would produce an implicit conversion sequence to
1291 /// describe the initialization of f from i, which will be a standard
1292 /// conversion sequence containing an lvalue-to-rvalue conversion (C++
1293 /// 4.1) followed by a floating-integral conversion (C++ 4.9).
1295 /// Note that this routine only determines how the conversion can be
1296 /// performed; it does not actually perform the conversion. As such,
1297 /// it will not produce any diagnostics if no conversion is available,
1298 /// but will instead return an implicit conversion sequence of kind
1299 /// "BadConversion".
1301 /// If @p SuppressUserConversions, then user-defined conversions are
1303 /// If @p AllowExplicit, then explicit user-defined conversions are
1306 /// \param AllowObjCWritebackConversion Whether we allow the Objective-C
1307 /// writeback conversion, which allows __autoreleasing id* parameters to
1308 /// be initialized with __strong id* or __weak id* arguments.
1309 static ImplicitConversionSequence
1310 TryImplicitConversion(Sema &S, Expr *From, QualType ToType,
1311 bool SuppressUserConversions,
1313 bool InOverloadResolution,
1315 bool AllowObjCWritebackConversion,
1316 bool AllowObjCConversionOnExplicit) {
1317 ImplicitConversionSequence ICS;
1318 if (IsStandardConversion(S, From, ToType, InOverloadResolution,
1319 ICS.Standard, CStyle, AllowObjCWritebackConversion)){
1324 if (!S.getLangOpts().CPlusPlus) {
1325 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1329 // C++ [over.ics.user]p4:
1330 // A conversion of an expression of class type to the same class
1331 // type is given Exact Match rank, and a conversion of an
1332 // expression of class type to a base class of that type is
1333 // given Conversion rank, in spite of the fact that a copy/move
1334 // constructor (i.e., a user-defined conversion function) is
1335 // called for those cases.
1336 QualType FromType = From->getType();
1337 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() &&
1338 (S.Context.hasSameUnqualifiedType(FromType, ToType) ||
1339 S.IsDerivedFrom(From->getLocStart(), FromType, ToType))) {
1341 ICS.Standard.setAsIdentityConversion();
1342 ICS.Standard.setFromType(FromType);
1343 ICS.Standard.setAllToTypes(ToType);
1345 // We don't actually check at this point whether there is a valid
1346 // copy/move constructor, since overloading just assumes that it
1347 // exists. When we actually perform initialization, we'll find the
1348 // appropriate constructor to copy the returned object, if needed.
1349 ICS.Standard.CopyConstructor = nullptr;
1351 // Determine whether this is considered a derived-to-base conversion.
1352 if (!S.Context.hasSameUnqualifiedType(FromType, ToType))
1353 ICS.Standard.Second = ICK_Derived_To_Base;
1358 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
1359 AllowExplicit, InOverloadResolution, CStyle,
1360 AllowObjCWritebackConversion,
1361 AllowObjCConversionOnExplicit);
1364 ImplicitConversionSequence
1365 Sema::TryImplicitConversion(Expr *From, QualType ToType,
1366 bool SuppressUserConversions,
1368 bool InOverloadResolution,
1370 bool AllowObjCWritebackConversion) {
1371 return ::TryImplicitConversion(*this, From, ToType,
1372 SuppressUserConversions, AllowExplicit,
1373 InOverloadResolution, CStyle,
1374 AllowObjCWritebackConversion,
1375 /*AllowObjCConversionOnExplicit=*/false);
1378 /// PerformImplicitConversion - Perform an implicit conversion of the
1379 /// expression From to the type ToType. Returns the
1380 /// converted expression. Flavor is the kind of conversion we're
1381 /// performing, used in the error message. If @p AllowExplicit,
1382 /// explicit user-defined conversions are permitted.
1384 Sema::PerformImplicitConversion(Expr *From, QualType ToType,
1385 AssignmentAction Action, bool AllowExplicit) {
1386 ImplicitConversionSequence ICS;
1387 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS);
1391 Sema::PerformImplicitConversion(Expr *From, QualType ToType,
1392 AssignmentAction Action, bool AllowExplicit,
1393 ImplicitConversionSequence& ICS) {
1394 if (checkPlaceholderForOverload(*this, From))
1397 // Objective-C ARC: Determine whether we will allow the writeback conversion.
1398 bool AllowObjCWritebackConversion
1399 = getLangOpts().ObjCAutoRefCount &&
1400 (Action == AA_Passing || Action == AA_Sending);
1401 if (getLangOpts().ObjC1)
1402 CheckObjCBridgeRelatedConversions(From->getLocStart(),
1403 ToType, From->getType(), From);
1404 ICS = ::TryImplicitConversion(*this, From, ToType,
1405 /*SuppressUserConversions=*/false,
1407 /*InOverloadResolution=*/false,
1409 AllowObjCWritebackConversion,
1410 /*AllowObjCConversionOnExplicit=*/false);
1411 return PerformImplicitConversion(From, ToType, ICS, Action);
1414 /// \brief Determine whether the conversion from FromType to ToType is a valid
1415 /// conversion that strips "noexcept" or "noreturn" off the nested function
1417 bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
1418 QualType &ResultTy) {
1419 if (Context.hasSameUnqualifiedType(FromType, ToType))
1422 // Permit the conversion F(t __attribute__((noreturn))) -> F(t)
1423 // or F(t noexcept) -> F(t)
1424 // where F adds one of the following at most once:
1426 // - a member pointer
1427 // - a block pointer
1428 // Changes here need matching changes in FindCompositePointerType.
1429 CanQualType CanTo = Context.getCanonicalType(ToType);
1430 CanQualType CanFrom = Context.getCanonicalType(FromType);
1431 Type::TypeClass TyClass = CanTo->getTypeClass();
1432 if (TyClass != CanFrom->getTypeClass()) return false;
1433 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) {
1434 if (TyClass == Type::Pointer) {
1435 CanTo = CanTo.getAs<PointerType>()->getPointeeType();
1436 CanFrom = CanFrom.getAs<PointerType>()->getPointeeType();
1437 } else if (TyClass == Type::BlockPointer) {
1438 CanTo = CanTo.getAs<BlockPointerType>()->getPointeeType();
1439 CanFrom = CanFrom.getAs<BlockPointerType>()->getPointeeType();
1440 } else if (TyClass == Type::MemberPointer) {
1441 auto ToMPT = CanTo.getAs<MemberPointerType>();
1442 auto FromMPT = CanFrom.getAs<MemberPointerType>();
1443 // A function pointer conversion cannot change the class of the function.
1444 if (ToMPT->getClass() != FromMPT->getClass())
1446 CanTo = ToMPT->getPointeeType();
1447 CanFrom = FromMPT->getPointeeType();
1452 TyClass = CanTo->getTypeClass();
1453 if (TyClass != CanFrom->getTypeClass()) return false;
1454 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto)
1458 const auto *FromFn = cast<FunctionType>(CanFrom);
1459 FunctionType::ExtInfo FromEInfo = FromFn->getExtInfo();
1461 const auto *ToFn = cast<FunctionType>(CanTo);
1462 FunctionType::ExtInfo ToEInfo = ToFn->getExtInfo();
1464 bool Changed = false;
1466 // Drop 'noreturn' if not present in target type.
1467 if (FromEInfo.getNoReturn() && !ToEInfo.getNoReturn()) {
1468 FromFn = Context.adjustFunctionType(FromFn, FromEInfo.withNoReturn(false));
1472 // Drop 'noexcept' if not present in target type.
1473 if (const auto *FromFPT = dyn_cast<FunctionProtoType>(FromFn)) {
1474 const auto *ToFPT = cast<FunctionProtoType>(ToFn);
1475 if (FromFPT->isNothrow(Context) && !ToFPT->isNothrow(Context)) {
1476 FromFn = cast<FunctionType>(
1477 Context.getFunctionType(FromFPT->getReturnType(),
1478 FromFPT->getParamTypes(),
1479 FromFPT->getExtProtoInfo().withExceptionSpec(
1480 FunctionProtoType::ExceptionSpecInfo()))
1489 assert(QualType(FromFn, 0).isCanonical());
1490 if (QualType(FromFn, 0) != CanTo) return false;
1496 /// \brief Determine whether the conversion from FromType to ToType is a valid
1497 /// vector conversion.
1499 /// \param ICK Will be set to the vector conversion kind, if this is a vector
1501 static bool IsVectorConversion(Sema &S, QualType FromType,
1502 QualType ToType, ImplicitConversionKind &ICK) {
1503 // We need at least one of these types to be a vector type to have a vector
1505 if (!ToType->isVectorType() && !FromType->isVectorType())
1508 // Identical types require no conversions.
1509 if (S.Context.hasSameUnqualifiedType(FromType, ToType))
1512 // There are no conversions between extended vector types, only identity.
1513 if (ToType->isExtVectorType()) {
1514 // There are no conversions between extended vector types other than the
1515 // identity conversion.
1516 if (FromType->isExtVectorType())
1519 // Vector splat from any arithmetic type to a vector.
1520 if (FromType->isArithmeticType()) {
1521 ICK = ICK_Vector_Splat;
1526 // We can perform the conversion between vector types in the following cases:
1527 // 1)vector types are equivalent AltiVec and GCC vector types
1528 // 2)lax vector conversions are permitted and the vector types are of the
1530 if (ToType->isVectorType() && FromType->isVectorType()) {
1531 if (S.Context.areCompatibleVectorTypes(FromType, ToType) ||
1532 S.isLaxVectorConversion(FromType, ToType)) {
1533 ICK = ICK_Vector_Conversion;
1541 static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
1542 bool InOverloadResolution,
1543 StandardConversionSequence &SCS,
1546 /// IsStandardConversion - Determines whether there is a standard
1547 /// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the
1548 /// expression From to the type ToType. Standard conversion sequences
1549 /// only consider non-class types; for conversions that involve class
1550 /// types, use TryImplicitConversion. If a conversion exists, SCS will
1551 /// contain the standard conversion sequence required to perform this
1552 /// conversion and this routine will return true. Otherwise, this
1553 /// routine will return false and the value of SCS is unspecified.
1554 static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
1555 bool InOverloadResolution,
1556 StandardConversionSequence &SCS,
1558 bool AllowObjCWritebackConversion) {
1559 QualType FromType = From->getType();
1561 // Standard conversions (C++ [conv])
1562 SCS.setAsIdentityConversion();
1563 SCS.IncompatibleObjC = false;
1564 SCS.setFromType(FromType);
1565 SCS.CopyConstructor = nullptr;
1567 // There are no standard conversions for class types in C++, so
1568 // abort early. When overloading in C, however, we do permit them.
1569 if (S.getLangOpts().CPlusPlus &&
1570 (FromType->isRecordType() || ToType->isRecordType()))
1573 // The first conversion can be an lvalue-to-rvalue conversion,
1574 // array-to-pointer conversion, or function-to-pointer conversion
1577 if (FromType == S.Context.OverloadTy) {
1578 DeclAccessPair AccessPair;
1579 if (FunctionDecl *Fn
1580 = S.ResolveAddressOfOverloadedFunction(From, ToType, false,
1582 // We were able to resolve the address of the overloaded function,
1583 // so we can convert to the type of that function.
1584 FromType = Fn->getType();
1585 SCS.setFromType(FromType);
1587 // we can sometimes resolve &foo<int> regardless of ToType, so check
1588 // if the type matches (identity) or we are converting to bool
1589 if (!S.Context.hasSameUnqualifiedType(
1590 S.ExtractUnqualifiedFunctionType(ToType), FromType)) {
1592 // if the function type matches except for [[noreturn]], it's ok
1593 if (!S.IsFunctionConversion(FromType,
1594 S.ExtractUnqualifiedFunctionType(ToType), resultTy))
1595 // otherwise, only a boolean conversion is standard
1596 if (!ToType->isBooleanType())
1600 // Check if the "from" expression is taking the address of an overloaded
1601 // function and recompute the FromType accordingly. Take advantage of the
1602 // fact that non-static member functions *must* have such an address-of
1604 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn);
1605 if (Method && !Method->isStatic()) {
1606 assert(isa<UnaryOperator>(From->IgnoreParens()) &&
1607 "Non-unary operator on non-static member address");
1608 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode()
1610 "Non-address-of operator on non-static member address");
1611 const Type *ClassType
1612 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr();
1613 FromType = S.Context.getMemberPointerType(FromType, ClassType);
1614 } else if (isa<UnaryOperator>(From->IgnoreParens())) {
1615 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() ==
1617 "Non-address-of operator for overloaded function expression");
1618 FromType = S.Context.getPointerType(FromType);
1621 // Check that we've computed the proper type after overload resolution.
1622 // FIXME: FixOverloadedFunctionReference has side-effects; we shouldn't
1623 // be calling it from within an NDEBUG block.
1624 assert(S.Context.hasSameType(
1626 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType()));
1631 // Lvalue-to-rvalue conversion (C++11 4.1):
1632 // A glvalue (3.10) of a non-function, non-array type T can
1633 // be converted to a prvalue.
1634 bool argIsLValue = From->isGLValue();
1636 !FromType->isFunctionType() && !FromType->isArrayType() &&
1637 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) {
1638 SCS.First = ICK_Lvalue_To_Rvalue;
1641 // ... if the lvalue has atomic type, the value has the non-atomic version
1642 // of the type of the lvalue ...
1643 if (const AtomicType *Atomic = FromType->getAs<AtomicType>())
1644 FromType = Atomic->getValueType();
1646 // If T is a non-class type, the type of the rvalue is the
1647 // cv-unqualified version of T. Otherwise, the type of the rvalue
1648 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we
1649 // just strip the qualifiers because they don't matter.
1650 FromType = FromType.getUnqualifiedType();
1651 } else if (FromType->isArrayType()) {
1652 // Array-to-pointer conversion (C++ 4.2)
1653 SCS.First = ICK_Array_To_Pointer;
1655 // An lvalue or rvalue of type "array of N T" or "array of unknown
1656 // bound of T" can be converted to an rvalue of type "pointer to
1658 FromType = S.Context.getArrayDecayedType(FromType);
1660 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) {
1661 // This conversion is deprecated in C++03 (D.4)
1662 SCS.DeprecatedStringLiteralToCharPtr = true;
1664 // For the purpose of ranking in overload resolution
1665 // (13.3.3.1.1), this conversion is considered an
1666 // array-to-pointer conversion followed by a qualification
1667 // conversion (4.4). (C++ 4.2p2)
1668 SCS.Second = ICK_Identity;
1669 SCS.Third = ICK_Qualification;
1670 SCS.QualificationIncludesObjCLifetime = false;
1671 SCS.setAllToTypes(FromType);
1674 } else if (FromType->isFunctionType() && argIsLValue) {
1675 // Function-to-pointer conversion (C++ 4.3).
1676 SCS.First = ICK_Function_To_Pointer;
1678 if (auto *DRE = dyn_cast<DeclRefExpr>(From->IgnoreParenCasts()))
1679 if (auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl()))
1680 if (!S.checkAddressOfFunctionIsAvailable(FD))
1683 // An lvalue of function type T can be converted to an rvalue of
1684 // type "pointer to T." The result is a pointer to the
1685 // function. (C++ 4.3p1).
1686 FromType = S.Context.getPointerType(FromType);
1688 // We don't require any conversions for the first step.
1689 SCS.First = ICK_Identity;
1691 SCS.setToType(0, FromType);
1693 // The second conversion can be an integral promotion, floating
1694 // point promotion, integral conversion, floating point conversion,
1695 // floating-integral conversion, pointer conversion,
1696 // pointer-to-member conversion, or boolean conversion (C++ 4p1).
1697 // For overloading in C, this can also be a "compatible-type"
1699 bool IncompatibleObjC = false;
1700 ImplicitConversionKind SecondICK = ICK_Identity;
1701 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) {
1702 // The unqualified versions of the types are the same: there's no
1703 // conversion to do.
1704 SCS.Second = ICK_Identity;
1705 } else if (S.IsIntegralPromotion(From, FromType, ToType)) {
1706 // Integral promotion (C++ 4.5).
1707 SCS.Second = ICK_Integral_Promotion;
1708 FromType = ToType.getUnqualifiedType();
1709 } else if (S.IsFloatingPointPromotion(FromType, ToType)) {
1710 // Floating point promotion (C++ 4.6).
1711 SCS.Second = ICK_Floating_Promotion;
1712 FromType = ToType.getUnqualifiedType();
1713 } else if (S.IsComplexPromotion(FromType, ToType)) {
1714 // Complex promotion (Clang extension)
1715 SCS.Second = ICK_Complex_Promotion;
1716 FromType = ToType.getUnqualifiedType();
1717 } else if (ToType->isBooleanType() &&
1718 (FromType->isArithmeticType() ||
1719 FromType->isAnyPointerType() ||
1720 FromType->isBlockPointerType() ||
1721 FromType->isMemberPointerType() ||
1722 FromType->isNullPtrType())) {
1723 // Boolean conversions (C++ 4.12).
1724 SCS.Second = ICK_Boolean_Conversion;
1725 FromType = S.Context.BoolTy;
1726 } else if (FromType->isIntegralOrUnscopedEnumerationType() &&
1727 ToType->isIntegralType(S.Context)) {
1728 // Integral conversions (C++ 4.7).
1729 SCS.Second = ICK_Integral_Conversion;
1730 FromType = ToType.getUnqualifiedType();
1731 } else if (FromType->isAnyComplexType() && ToType->isAnyComplexType()) {
1732 // Complex conversions (C99 6.3.1.6)
1733 SCS.Second = ICK_Complex_Conversion;
1734 FromType = ToType.getUnqualifiedType();
1735 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) ||
1736 (ToType->isAnyComplexType() && FromType->isArithmeticType())) {
1737 // Complex-real conversions (C99 6.3.1.7)
1738 SCS.Second = ICK_Complex_Real;
1739 FromType = ToType.getUnqualifiedType();
1740 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) {
1741 // FIXME: disable conversions between long double and __float128 if
1742 // their representation is different until there is back end support
1743 // We of course allow this conversion if long double is really double.
1744 if (&S.Context.getFloatTypeSemantics(FromType) !=
1745 &S.Context.getFloatTypeSemantics(ToType)) {
1746 bool Float128AndLongDouble = ((FromType == S.Context.Float128Ty &&
1747 ToType == S.Context.LongDoubleTy) ||
1748 (FromType == S.Context.LongDoubleTy &&
1749 ToType == S.Context.Float128Ty));
1750 if (Float128AndLongDouble &&
1751 (&S.Context.getFloatTypeSemantics(S.Context.LongDoubleTy) !=
1752 &llvm::APFloat::IEEEdouble()))
1755 // Floating point conversions (C++ 4.8).
1756 SCS.Second = ICK_Floating_Conversion;
1757 FromType = ToType.getUnqualifiedType();
1758 } else if ((FromType->isRealFloatingType() &&
1759 ToType->isIntegralType(S.Context)) ||
1760 (FromType->isIntegralOrUnscopedEnumerationType() &&
1761 ToType->isRealFloatingType())) {
1762 // Floating-integral conversions (C++ 4.9).
1763 SCS.Second = ICK_Floating_Integral;
1764 FromType = ToType.getUnqualifiedType();
1765 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) {
1766 SCS.Second = ICK_Block_Pointer_Conversion;
1767 } else if (AllowObjCWritebackConversion &&
1768 S.isObjCWritebackConversion(FromType, ToType, FromType)) {
1769 SCS.Second = ICK_Writeback_Conversion;
1770 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution,
1771 FromType, IncompatibleObjC)) {
1772 // Pointer conversions (C++ 4.10).
1773 SCS.Second = ICK_Pointer_Conversion;
1774 SCS.IncompatibleObjC = IncompatibleObjC;
1775 FromType = FromType.getUnqualifiedType();
1776 } else if (S.IsMemberPointerConversion(From, FromType, ToType,
1777 InOverloadResolution, FromType)) {
1778 // Pointer to member conversions (4.11).
1779 SCS.Second = ICK_Pointer_Member;
1780 } else if (IsVectorConversion(S, FromType, ToType, SecondICK)) {
1781 SCS.Second = SecondICK;
1782 FromType = ToType.getUnqualifiedType();
1783 } else if (!S.getLangOpts().CPlusPlus &&
1784 S.Context.typesAreCompatible(ToType, FromType)) {
1785 // Compatible conversions (Clang extension for C function overloading)
1786 SCS.Second = ICK_Compatible_Conversion;
1787 FromType = ToType.getUnqualifiedType();
1788 } else if (IsTransparentUnionStandardConversion(S, From, ToType,
1789 InOverloadResolution,
1791 SCS.Second = ICK_TransparentUnionConversion;
1793 } else if (tryAtomicConversion(S, From, ToType, InOverloadResolution, SCS,
1795 // tryAtomicConversion has updated the standard conversion sequence
1798 } else if (ToType->isEventT() &&
1799 From->isIntegerConstantExpr(S.getASTContext()) &&
1800 From->EvaluateKnownConstInt(S.getASTContext()) == 0) {
1801 SCS.Second = ICK_Zero_Event_Conversion;
1803 } else if (ToType->isQueueT() &&
1804 From->isIntegerConstantExpr(S.getASTContext()) &&
1805 (From->EvaluateKnownConstInt(S.getASTContext()) == 0)) {
1806 SCS.Second = ICK_Zero_Queue_Conversion;
1809 // No second conversion required.
1810 SCS.Second = ICK_Identity;
1812 SCS.setToType(1, FromType);
1814 // The third conversion can be a function pointer conversion or a
1815 // qualification conversion (C++ [conv.fctptr], [conv.qual]).
1816 bool ObjCLifetimeConversion;
1817 if (S.IsFunctionConversion(FromType, ToType, FromType)) {
1818 // Function pointer conversions (removing 'noexcept') including removal of
1819 // 'noreturn' (Clang extension).
1820 SCS.Third = ICK_Function_Conversion;
1821 } else if (S.IsQualificationConversion(FromType, ToType, CStyle,
1822 ObjCLifetimeConversion)) {
1823 SCS.Third = ICK_Qualification;
1824 SCS.QualificationIncludesObjCLifetime = ObjCLifetimeConversion;
1827 // No conversion required
1828 SCS.Third = ICK_Identity;
1831 // C++ [over.best.ics]p6:
1832 // [...] Any difference in top-level cv-qualification is
1833 // subsumed by the initialization itself and does not constitute
1834 // a conversion. [...]
1835 QualType CanonFrom = S.Context.getCanonicalType(FromType);
1836 QualType CanonTo = S.Context.getCanonicalType(ToType);
1837 if (CanonFrom.getLocalUnqualifiedType()
1838 == CanonTo.getLocalUnqualifiedType() &&
1839 CanonFrom.getLocalQualifiers() != CanonTo.getLocalQualifiers()) {
1841 CanonFrom = CanonTo;
1844 SCS.setToType(2, FromType);
1846 if (CanonFrom == CanonTo)
1849 // If we have not converted the argument type to the parameter type,
1850 // this is a bad conversion sequence, unless we're resolving an overload in C.
1851 if (S.getLangOpts().CPlusPlus || !InOverloadResolution)
1854 ExprResult ER = ExprResult{From};
1855 Sema::AssignConvertType Conv =
1856 S.CheckSingleAssignmentConstraints(ToType, ER,
1858 /*DiagnoseCFAudited=*/false,
1859 /*ConvertRHS=*/false);
1860 ImplicitConversionKind SecondConv;
1862 case Sema::Compatible:
1863 SecondConv = ICK_C_Only_Conversion;
1865 // For our purposes, discarding qualifiers is just as bad as using an
1866 // incompatible pointer. Note that an IncompatiblePointer conversion can drop
1867 // qualifiers, as well.
1868 case Sema::CompatiblePointerDiscardsQualifiers:
1869 case Sema::IncompatiblePointer:
1870 case Sema::IncompatiblePointerSign:
1871 SecondConv = ICK_Incompatible_Pointer_Conversion;
1877 // First can only be an lvalue conversion, so we pretend that this was the
1878 // second conversion. First should already be valid from earlier in the
1880 SCS.Second = SecondConv;
1881 SCS.setToType(1, ToType);
1883 // Third is Identity, because Second should rank us worse than any other
1884 // conversion. This could also be ICK_Qualification, but it's simpler to just
1885 // lump everything in with the second conversion, and we don't gain anything
1886 // from making this ICK_Qualification.
1887 SCS.Third = ICK_Identity;
1888 SCS.setToType(2, ToType);
1893 IsTransparentUnionStandardConversion(Sema &S, Expr* From,
1895 bool InOverloadResolution,
1896 StandardConversionSequence &SCS,
1899 const RecordType *UT = ToType->getAsUnionType();
1900 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>())
1902 // The field to initialize within the transparent union.
1903 RecordDecl *UD = UT->getDecl();
1904 // It's compatible if the expression matches any of the fields.
1905 for (const auto *it : UD->fields()) {
1906 if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS,
1907 CStyle, /*ObjCWritebackConversion=*/false)) {
1908 ToType = it->getType();
1915 /// IsIntegralPromotion - Determines whether the conversion from the
1916 /// expression From (whose potentially-adjusted type is FromType) to
1917 /// ToType is an integral promotion (C++ 4.5). If so, returns true and
1918 /// sets PromotedType to the promoted type.
1919 bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) {
1920 const BuiltinType *To = ToType->getAs<BuiltinType>();
1921 // All integers are built-in.
1926 // An rvalue of type char, signed char, unsigned char, short int, or
1927 // unsigned short int can be converted to an rvalue of type int if
1928 // int can represent all the values of the source type; otherwise,
1929 // the source rvalue can be converted to an rvalue of type unsigned
1931 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() &&
1932 !FromType->isEnumeralType()) {
1933 if (// We can promote any signed, promotable integer type to an int
1934 (FromType->isSignedIntegerType() ||
1935 // We can promote any unsigned integer type whose size is
1936 // less than int to an int.
1937 Context.getTypeSize(FromType) < Context.getTypeSize(ToType))) {
1938 return To->getKind() == BuiltinType::Int;
1941 return To->getKind() == BuiltinType::UInt;
1944 // C++11 [conv.prom]p3:
1945 // A prvalue of an unscoped enumeration type whose underlying type is not
1946 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the
1947 // following types that can represent all the values of the enumeration
1948 // (i.e., the values in the range bmin to bmax as described in 7.2): int,
1949 // unsigned int, long int, unsigned long int, long long int, or unsigned
1950 // long long int. If none of the types in that list can represent all the
1951 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration
1952 // type can be converted to an rvalue a prvalue of the extended integer type
1953 // with lowest integer conversion rank (4.13) greater than the rank of long
1954 // long in which all the values of the enumeration can be represented. If
1955 // there are two such extended types, the signed one is chosen.
1956 // C++11 [conv.prom]p4:
1957 // A prvalue of an unscoped enumeration type whose underlying type is fixed
1958 // can be converted to a prvalue of its underlying type. Moreover, if
1959 // integral promotion can be applied to its underlying type, a prvalue of an
1960 // unscoped enumeration type whose underlying type is fixed can also be
1961 // converted to a prvalue of the promoted underlying type.
1962 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) {
1963 // C++0x 7.2p9: Note that this implicit enum to int conversion is not
1964 // provided for a scoped enumeration.
1965 if (FromEnumType->getDecl()->isScoped())
1968 // We can perform an integral promotion to the underlying type of the enum,
1969 // even if that's not the promoted type. Note that the check for promoting
1970 // the underlying type is based on the type alone, and does not consider
1971 // the bitfield-ness of the actual source expression.
1972 if (FromEnumType->getDecl()->isFixed()) {
1973 QualType Underlying = FromEnumType->getDecl()->getIntegerType();
1974 return Context.hasSameUnqualifiedType(Underlying, ToType) ||
1975 IsIntegralPromotion(nullptr, Underlying, ToType);
1978 // We have already pre-calculated the promotion type, so this is trivial.
1979 if (ToType->isIntegerType() &&
1980 isCompleteType(From->getLocStart(), FromType))
1981 return Context.hasSameUnqualifiedType(
1982 ToType, FromEnumType->getDecl()->getPromotionType());
1985 // C++0x [conv.prom]p2:
1986 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted
1987 // to an rvalue a prvalue of the first of the following types that can
1988 // represent all the values of its underlying type: int, unsigned int,
1989 // long int, unsigned long int, long long int, or unsigned long long int.
1990 // If none of the types in that list can represent all the values of its
1991 // underlying type, an rvalue a prvalue of type char16_t, char32_t,
1992 // or wchar_t can be converted to an rvalue a prvalue of its underlying
1994 if (FromType->isAnyCharacterType() && !FromType->isCharType() &&
1995 ToType->isIntegerType()) {
1996 // Determine whether the type we're converting from is signed or
1998 bool FromIsSigned = FromType->isSignedIntegerType();
1999 uint64_t FromSize = Context.getTypeSize(FromType);
2001 // The types we'll try to promote to, in the appropriate
2002 // order. Try each of these types.
2003 QualType PromoteTypes[6] = {
2004 Context.IntTy, Context.UnsignedIntTy,
2005 Context.LongTy, Context.UnsignedLongTy ,
2006 Context.LongLongTy, Context.UnsignedLongLongTy
2008 for (int Idx = 0; Idx < 6; ++Idx) {
2009 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]);
2010 if (FromSize < ToSize ||
2011 (FromSize == ToSize &&
2012 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) {
2013 // We found the type that we can promote to. If this is the
2014 // type we wanted, we have a promotion. Otherwise, no
2016 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]);
2021 // An rvalue for an integral bit-field (9.6) can be converted to an
2022 // rvalue of type int if int can represent all the values of the
2023 // bit-field; otherwise, it can be converted to unsigned int if
2024 // unsigned int can represent all the values of the bit-field. If
2025 // the bit-field is larger yet, no integral promotion applies to
2026 // it. If the bit-field has an enumerated type, it is treated as any
2027 // other value of that type for promotion purposes (C++ 4.5p3).
2028 // FIXME: We should delay checking of bit-fields until we actually perform the
2031 if (FieldDecl *MemberDecl = From->getSourceBitField()) {
2032 llvm::APSInt BitWidth;
2033 if (FromType->isIntegralType(Context) &&
2034 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) {
2035 llvm::APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned());
2036 ToSize = Context.getTypeSize(ToType);
2038 // Are we promoting to an int from a bitfield that fits in an int?
2039 if (BitWidth < ToSize ||
2040 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) {
2041 return To->getKind() == BuiltinType::Int;
2044 // Are we promoting to an unsigned int from an unsigned bitfield
2045 // that fits into an unsigned int?
2046 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) {
2047 return To->getKind() == BuiltinType::UInt;
2055 // An rvalue of type bool can be converted to an rvalue of type int,
2056 // with false becoming zero and true becoming one (C++ 4.5p4).
2057 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) {
2064 /// IsFloatingPointPromotion - Determines whether the conversion from
2065 /// FromType to ToType is a floating point promotion (C++ 4.6). If so,
2066 /// returns true and sets PromotedType to the promoted type.
2067 bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) {
2068 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>())
2069 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) {
2070 /// An rvalue of type float can be converted to an rvalue of type
2071 /// double. (C++ 4.6p1).
2072 if (FromBuiltin->getKind() == BuiltinType::Float &&
2073 ToBuiltin->getKind() == BuiltinType::Double)
2077 // When a float is promoted to double or long double, or a
2078 // double is promoted to long double [...].
2079 if (!getLangOpts().CPlusPlus &&
2080 (FromBuiltin->getKind() == BuiltinType::Float ||
2081 FromBuiltin->getKind() == BuiltinType::Double) &&
2082 (ToBuiltin->getKind() == BuiltinType::LongDouble ||
2083 ToBuiltin->getKind() == BuiltinType::Float128))
2086 // Half can be promoted to float.
2087 if (!getLangOpts().NativeHalfType &&
2088 FromBuiltin->getKind() == BuiltinType::Half &&
2089 ToBuiltin->getKind() == BuiltinType::Float)
2096 /// \brief Determine if a conversion is a complex promotion.
2098 /// A complex promotion is defined as a complex -> complex conversion
2099 /// where the conversion between the underlying real types is a
2100 /// floating-point or integral promotion.
2101 bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) {
2102 const ComplexType *FromComplex = FromType->getAs<ComplexType>();
2106 const ComplexType *ToComplex = ToType->getAs<ComplexType>();
2110 return IsFloatingPointPromotion(FromComplex->getElementType(),
2111 ToComplex->getElementType()) ||
2112 IsIntegralPromotion(nullptr, FromComplex->getElementType(),
2113 ToComplex->getElementType());
2116 /// BuildSimilarlyQualifiedPointerType - In a pointer conversion from
2117 /// the pointer type FromPtr to a pointer to type ToPointee, with the
2118 /// same type qualifiers as FromPtr has on its pointee type. ToType,
2119 /// if non-empty, will be a pointer to ToType that may or may not have
2120 /// the right set of qualifiers on its pointee.
2123 BuildSimilarlyQualifiedPointerType(const Type *FromPtr,
2124 QualType ToPointee, QualType ToType,
2125 ASTContext &Context,
2126 bool StripObjCLifetime = false) {
2127 assert((FromPtr->getTypeClass() == Type::Pointer ||
2128 FromPtr->getTypeClass() == Type::ObjCObjectPointer) &&
2129 "Invalid similarly-qualified pointer type");
2131 /// Conversions to 'id' subsume cv-qualifier conversions.
2132 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType())
2133 return ToType.getUnqualifiedType();
2135 QualType CanonFromPointee
2136 = Context.getCanonicalType(FromPtr->getPointeeType());
2137 QualType CanonToPointee = Context.getCanonicalType(ToPointee);
2138 Qualifiers Quals = CanonFromPointee.getQualifiers();
2140 if (StripObjCLifetime)
2141 Quals.removeObjCLifetime();
2143 // Exact qualifier match -> return the pointer type we're converting to.
2144 if (CanonToPointee.getLocalQualifiers() == Quals) {
2145 // ToType is exactly what we need. Return it.
2146 if (!ToType.isNull())
2147 return ToType.getUnqualifiedType();
2149 // Build a pointer to ToPointee. It has the right qualifiers
2151 if (isa<ObjCObjectPointerType>(ToType))
2152 return Context.getObjCObjectPointerType(ToPointee);
2153 return Context.getPointerType(ToPointee);
2156 // Just build a canonical type that has the right qualifiers.
2157 QualType QualifiedCanonToPointee
2158 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals);
2160 if (isa<ObjCObjectPointerType>(ToType))
2161 return Context.getObjCObjectPointerType(QualifiedCanonToPointee);
2162 return Context.getPointerType(QualifiedCanonToPointee);
2165 static bool isNullPointerConstantForConversion(Expr *Expr,
2166 bool InOverloadResolution,
2167 ASTContext &Context) {
2168 // Handle value-dependent integral null pointer constants correctly.
2169 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903
2170 if (Expr->isValueDependent() && !Expr->isTypeDependent() &&
2171 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType())
2172 return !InOverloadResolution;
2174 return Expr->isNullPointerConstant(Context,
2175 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
2176 : Expr::NPC_ValueDependentIsNull);
2179 /// IsPointerConversion - Determines whether the conversion of the
2180 /// expression From, which has the (possibly adjusted) type FromType,
2181 /// can be converted to the type ToType via a pointer conversion (C++
2182 /// 4.10). If so, returns true and places the converted type (that
2183 /// might differ from ToType in its cv-qualifiers at some level) into
2186 /// This routine also supports conversions to and from block pointers
2187 /// and conversions with Objective-C's 'id', 'id<protocols...>', and
2188 /// pointers to interfaces. FIXME: Once we've determined the
2189 /// appropriate overloading rules for Objective-C, we may want to
2190 /// split the Objective-C checks into a different routine; however,
2191 /// GCC seems to consider all of these conversions to be pointer
2192 /// conversions, so for now they live here. IncompatibleObjC will be
2193 /// set if the conversion is an allowed Objective-C conversion that
2194 /// should result in a warning.
2195 bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType,
2196 bool InOverloadResolution,
2197 QualType& ConvertedType,
2198 bool &IncompatibleObjC) {
2199 IncompatibleObjC = false;
2200 if (isObjCPointerConversion(FromType, ToType, ConvertedType,
2204 // Conversion from a null pointer constant to any Objective-C pointer type.
2205 if (ToType->isObjCObjectPointerType() &&
2206 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2207 ConvertedType = ToType;
2211 // Blocks: Block pointers can be converted to void*.
2212 if (FromType->isBlockPointerType() && ToType->isPointerType() &&
2213 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) {
2214 ConvertedType = ToType;
2217 // Blocks: A null pointer constant can be converted to a block
2219 if (ToType->isBlockPointerType() &&
2220 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2221 ConvertedType = ToType;
2225 // If the left-hand-side is nullptr_t, the right side can be a null
2226 // pointer constant.
2227 if (ToType->isNullPtrType() &&
2228 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2229 ConvertedType = ToType;
2233 const PointerType* ToTypePtr = ToType->getAs<PointerType>();
2237 // A null pointer constant can be converted to a pointer type (C++ 4.10p1).
2238 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2239 ConvertedType = ToType;
2243 // Beyond this point, both types need to be pointers
2244 // , including objective-c pointers.
2245 QualType ToPointeeType = ToTypePtr->getPointeeType();
2246 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType() &&
2247 !getLangOpts().ObjCAutoRefCount) {
2248 ConvertedType = BuildSimilarlyQualifiedPointerType(
2249 FromType->getAs<ObjCObjectPointerType>(),
2254 const PointerType *FromTypePtr = FromType->getAs<PointerType>();
2258 QualType FromPointeeType = FromTypePtr->getPointeeType();
2260 // If the unqualified pointee types are the same, this can't be a
2261 // pointer conversion, so don't do all of the work below.
2262 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType))
2265 // An rvalue of type "pointer to cv T," where T is an object type,
2266 // can be converted to an rvalue of type "pointer to cv void" (C++
2268 if (FromPointeeType->isIncompleteOrObjectType() &&
2269 ToPointeeType->isVoidType()) {
2270 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2273 /*StripObjCLifetime=*/true);
2277 // MSVC allows implicit function to void* type conversion.
2278 if (getLangOpts().MSVCCompat && FromPointeeType->isFunctionType() &&
2279 ToPointeeType->isVoidType()) {
2280 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2286 // When we're overloading in C, we allow a special kind of pointer
2287 // conversion for compatible-but-not-identical pointee types.
2288 if (!getLangOpts().CPlusPlus &&
2289 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) {
2290 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2296 // C++ [conv.ptr]p3:
2298 // An rvalue of type "pointer to cv D," where D is a class type,
2299 // can be converted to an rvalue of type "pointer to cv B," where
2300 // B is a base class (clause 10) of D. If B is an inaccessible
2301 // (clause 11) or ambiguous (10.2) base class of D, a program that
2302 // necessitates this conversion is ill-formed. The result of the
2303 // conversion is a pointer to the base class sub-object of the
2304 // derived class object. The null pointer value is converted to
2305 // the null pointer value of the destination type.
2307 // Note that we do not check for ambiguity or inaccessibility
2308 // here. That is handled by CheckPointerConversion.
2309 if (getLangOpts().CPlusPlus &&
2310 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() &&
2311 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) &&
2312 IsDerivedFrom(From->getLocStart(), FromPointeeType, ToPointeeType)) {
2313 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2319 if (FromPointeeType->isVectorType() && ToPointeeType->isVectorType() &&
2320 Context.areCompatibleVectorTypes(FromPointeeType, ToPointeeType)) {
2321 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2330 /// \brief Adopt the given qualifiers for the given type.
2331 static QualType AdoptQualifiers(ASTContext &Context, QualType T, Qualifiers Qs){
2332 Qualifiers TQs = T.getQualifiers();
2334 // Check whether qualifiers already match.
2338 if (Qs.compatiblyIncludes(TQs))
2339 return Context.getQualifiedType(T, Qs);
2341 return Context.getQualifiedType(T.getUnqualifiedType(), Qs);
2344 /// isObjCPointerConversion - Determines whether this is an
2345 /// Objective-C pointer conversion. Subroutine of IsPointerConversion,
2346 /// with the same arguments and return values.
2347 bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType,
2348 QualType& ConvertedType,
2349 bool &IncompatibleObjC) {
2350 if (!getLangOpts().ObjC1)
2353 // The set of qualifiers on the type we're converting from.
2354 Qualifiers FromQualifiers = FromType.getQualifiers();
2356 // First, we handle all conversions on ObjC object pointer types.
2357 const ObjCObjectPointerType* ToObjCPtr =
2358 ToType->getAs<ObjCObjectPointerType>();
2359 const ObjCObjectPointerType *FromObjCPtr =
2360 FromType->getAs<ObjCObjectPointerType>();
2362 if (ToObjCPtr && FromObjCPtr) {
2363 // If the pointee types are the same (ignoring qualifications),
2364 // then this is not a pointer conversion.
2365 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(),
2366 FromObjCPtr->getPointeeType()))
2369 // Conversion between Objective-C pointers.
2370 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) {
2371 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType();
2372 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType();
2373 if (getLangOpts().CPlusPlus && LHS && RHS &&
2374 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs(
2375 FromObjCPtr->getPointeeType()))
2377 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2378 ToObjCPtr->getPointeeType(),
2380 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2384 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) {
2385 // Okay: this is some kind of implicit downcast of Objective-C
2386 // interfaces, which is permitted. However, we're going to
2387 // complain about it.
2388 IncompatibleObjC = true;
2389 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2390 ToObjCPtr->getPointeeType(),
2392 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2396 // Beyond this point, both types need to be C pointers or block pointers.
2397 QualType ToPointeeType;
2398 if (const PointerType *ToCPtr = ToType->getAs<PointerType>())
2399 ToPointeeType = ToCPtr->getPointeeType();
2400 else if (const BlockPointerType *ToBlockPtr =
2401 ToType->getAs<BlockPointerType>()) {
2402 // Objective C++: We're able to convert from a pointer to any object
2403 // to a block pointer type.
2404 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) {
2405 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2408 ToPointeeType = ToBlockPtr->getPointeeType();
2410 else if (FromType->getAs<BlockPointerType>() &&
2411 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) {
2412 // Objective C++: We're able to convert from a block pointer type to a
2413 // pointer to any object.
2414 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2420 QualType FromPointeeType;
2421 if (const PointerType *FromCPtr = FromType->getAs<PointerType>())
2422 FromPointeeType = FromCPtr->getPointeeType();
2423 else if (const BlockPointerType *FromBlockPtr =
2424 FromType->getAs<BlockPointerType>())
2425 FromPointeeType = FromBlockPtr->getPointeeType();
2429 // If we have pointers to pointers, recursively check whether this
2430 // is an Objective-C conversion.
2431 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() &&
2432 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2433 IncompatibleObjC)) {
2434 // We always complain about this conversion.
2435 IncompatibleObjC = true;
2436 ConvertedType = Context.getPointerType(ConvertedType);
2437 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2440 // Allow conversion of pointee being objective-c pointer to another one;
2442 if (FromPointeeType->getAs<ObjCObjectPointerType>() &&
2443 ToPointeeType->getAs<ObjCObjectPointerType>() &&
2444 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2445 IncompatibleObjC)) {
2447 ConvertedType = Context.getPointerType(ConvertedType);
2448 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2452 // If we have pointers to functions or blocks, check whether the only
2453 // differences in the argument and result types are in Objective-C
2454 // pointer conversions. If so, we permit the conversion (but
2455 // complain about it).
2456 const FunctionProtoType *FromFunctionType
2457 = FromPointeeType->getAs<FunctionProtoType>();
2458 const FunctionProtoType *ToFunctionType
2459 = ToPointeeType->getAs<FunctionProtoType>();
2460 if (FromFunctionType && ToFunctionType) {
2461 // If the function types are exactly the same, this isn't an
2462 // Objective-C pointer conversion.
2463 if (Context.getCanonicalType(FromPointeeType)
2464 == Context.getCanonicalType(ToPointeeType))
2467 // Perform the quick checks that will tell us whether these
2468 // function types are obviously different.
2469 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2470 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() ||
2471 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals())
2474 bool HasObjCConversion = false;
2475 if (Context.getCanonicalType(FromFunctionType->getReturnType()) ==
2476 Context.getCanonicalType(ToFunctionType->getReturnType())) {
2477 // Okay, the types match exactly. Nothing to do.
2478 } else if (isObjCPointerConversion(FromFunctionType->getReturnType(),
2479 ToFunctionType->getReturnType(),
2480 ConvertedType, IncompatibleObjC)) {
2481 // Okay, we have an Objective-C pointer conversion.
2482 HasObjCConversion = true;
2484 // Function types are too different. Abort.
2488 // Check argument types.
2489 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2490 ArgIdx != NumArgs; ++ArgIdx) {
2491 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2492 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2493 if (Context.getCanonicalType(FromArgType)
2494 == Context.getCanonicalType(ToArgType)) {
2495 // Okay, the types match exactly. Nothing to do.
2496 } else if (isObjCPointerConversion(FromArgType, ToArgType,
2497 ConvertedType, IncompatibleObjC)) {
2498 // Okay, we have an Objective-C pointer conversion.
2499 HasObjCConversion = true;
2501 // Argument types are too different. Abort.
2506 if (HasObjCConversion) {
2507 // We had an Objective-C conversion. Allow this pointer
2508 // conversion, but complain about it.
2509 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2510 IncompatibleObjC = true;
2518 /// \brief Determine whether this is an Objective-C writeback conversion,
2519 /// used for parameter passing when performing automatic reference counting.
2521 /// \param FromType The type we're converting form.
2523 /// \param ToType The type we're converting to.
2525 /// \param ConvertedType The type that will be produced after applying
2526 /// this conversion.
2527 bool Sema::isObjCWritebackConversion(QualType FromType, QualType ToType,
2528 QualType &ConvertedType) {
2529 if (!getLangOpts().ObjCAutoRefCount ||
2530 Context.hasSameUnqualifiedType(FromType, ToType))
2533 // Parameter must be a pointer to __autoreleasing (with no other qualifiers).
2535 if (const PointerType *ToPointer = ToType->getAs<PointerType>())
2536 ToPointee = ToPointer->getPointeeType();
2540 Qualifiers ToQuals = ToPointee.getQualifiers();
2541 if (!ToPointee->isObjCLifetimeType() ||
2542 ToQuals.getObjCLifetime() != Qualifiers::OCL_Autoreleasing ||
2543 !ToQuals.withoutObjCLifetime().empty())
2546 // Argument must be a pointer to __strong to __weak.
2547 QualType FromPointee;
2548 if (const PointerType *FromPointer = FromType->getAs<PointerType>())
2549 FromPointee = FromPointer->getPointeeType();
2553 Qualifiers FromQuals = FromPointee.getQualifiers();
2554 if (!FromPointee->isObjCLifetimeType() ||
2555 (FromQuals.getObjCLifetime() != Qualifiers::OCL_Strong &&
2556 FromQuals.getObjCLifetime() != Qualifiers::OCL_Weak))
2559 // Make sure that we have compatible qualifiers.
2560 FromQuals.setObjCLifetime(Qualifiers::OCL_Autoreleasing);
2561 if (!ToQuals.compatiblyIncludes(FromQuals))
2564 // Remove qualifiers from the pointee type we're converting from; they
2565 // aren't used in the compatibility check belong, and we'll be adding back
2566 // qualifiers (with __autoreleasing) if the compatibility check succeeds.
2567 FromPointee = FromPointee.getUnqualifiedType();
2569 // The unqualified form of the pointee types must be compatible.
2570 ToPointee = ToPointee.getUnqualifiedType();
2571 bool IncompatibleObjC;
2572 if (Context.typesAreCompatible(FromPointee, ToPointee))
2573 FromPointee = ToPointee;
2574 else if (!isObjCPointerConversion(FromPointee, ToPointee, FromPointee,
2578 /// \brief Construct the type we're converting to, which is a pointer to
2579 /// __autoreleasing pointee.
2580 FromPointee = Context.getQualifiedType(FromPointee, FromQuals);
2581 ConvertedType = Context.getPointerType(FromPointee);
2585 bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType,
2586 QualType& ConvertedType) {
2587 QualType ToPointeeType;
2588 if (const BlockPointerType *ToBlockPtr =
2589 ToType->getAs<BlockPointerType>())
2590 ToPointeeType = ToBlockPtr->getPointeeType();
2594 QualType FromPointeeType;
2595 if (const BlockPointerType *FromBlockPtr =
2596 FromType->getAs<BlockPointerType>())
2597 FromPointeeType = FromBlockPtr->getPointeeType();
2600 // We have pointer to blocks, check whether the only
2601 // differences in the argument and result types are in Objective-C
2602 // pointer conversions. If so, we permit the conversion.
2604 const FunctionProtoType *FromFunctionType
2605 = FromPointeeType->getAs<FunctionProtoType>();
2606 const FunctionProtoType *ToFunctionType
2607 = ToPointeeType->getAs<FunctionProtoType>();
2609 if (!FromFunctionType || !ToFunctionType)
2612 if (Context.hasSameType(FromPointeeType, ToPointeeType))
2615 // Perform the quick checks that will tell us whether these
2616 // function types are obviously different.
2617 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2618 FromFunctionType->isVariadic() != ToFunctionType->isVariadic())
2621 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo();
2622 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo();
2623 if (FromEInfo != ToEInfo)
2626 bool IncompatibleObjC = false;
2627 if (Context.hasSameType(FromFunctionType->getReturnType(),
2628 ToFunctionType->getReturnType())) {
2629 // Okay, the types match exactly. Nothing to do.
2631 QualType RHS = FromFunctionType->getReturnType();
2632 QualType LHS = ToFunctionType->getReturnType();
2633 if ((!getLangOpts().CPlusPlus || !RHS->isRecordType()) &&
2634 !RHS.hasQualifiers() && LHS.hasQualifiers())
2635 LHS = LHS.getUnqualifiedType();
2637 if (Context.hasSameType(RHS,LHS)) {
2639 } else if (isObjCPointerConversion(RHS, LHS,
2640 ConvertedType, IncompatibleObjC)) {
2641 if (IncompatibleObjC)
2643 // Okay, we have an Objective-C pointer conversion.
2649 // Check argument types.
2650 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2651 ArgIdx != NumArgs; ++ArgIdx) {
2652 IncompatibleObjC = false;
2653 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2654 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2655 if (Context.hasSameType(FromArgType, ToArgType)) {
2656 // Okay, the types match exactly. Nothing to do.
2657 } else if (isObjCPointerConversion(ToArgType, FromArgType,
2658 ConvertedType, IncompatibleObjC)) {
2659 if (IncompatibleObjC)
2661 // Okay, we have an Objective-C pointer conversion.
2663 // Argument types are too different. Abort.
2666 if (!Context.doFunctionTypesMatchOnExtParameterInfos(FromFunctionType,
2670 ConvertedType = ToType;
2678 ft_parameter_mismatch,
2680 ft_qualifer_mismatch,
2684 /// Attempts to get the FunctionProtoType from a Type. Handles
2685 /// MemberFunctionPointers properly.
2686 static const FunctionProtoType *tryGetFunctionProtoType(QualType FromType) {
2687 if (auto *FPT = FromType->getAs<FunctionProtoType>())
2690 if (auto *MPT = FromType->getAs<MemberPointerType>())
2691 return MPT->getPointeeType()->getAs<FunctionProtoType>();
2696 /// HandleFunctionTypeMismatch - Gives diagnostic information for differeing
2697 /// function types. Catches different number of parameter, mismatch in
2698 /// parameter types, and different return types.
2699 void Sema::HandleFunctionTypeMismatch(PartialDiagnostic &PDiag,
2700 QualType FromType, QualType ToType) {
2701 // If either type is not valid, include no extra info.
2702 if (FromType.isNull() || ToType.isNull()) {
2703 PDiag << ft_default;
2707 // Get the function type from the pointers.
2708 if (FromType->isMemberPointerType() && ToType->isMemberPointerType()) {
2709 const MemberPointerType *FromMember = FromType->getAs<MemberPointerType>(),
2710 *ToMember = ToType->getAs<MemberPointerType>();
2711 if (!Context.hasSameType(FromMember->getClass(), ToMember->getClass())) {
2712 PDiag << ft_different_class << QualType(ToMember->getClass(), 0)
2713 << QualType(FromMember->getClass(), 0);
2716 FromType = FromMember->getPointeeType();
2717 ToType = ToMember->getPointeeType();
2720 if (FromType->isPointerType())
2721 FromType = FromType->getPointeeType();
2722 if (ToType->isPointerType())
2723 ToType = ToType->getPointeeType();
2725 // Remove references.
2726 FromType = FromType.getNonReferenceType();
2727 ToType = ToType.getNonReferenceType();
2729 // Don't print extra info for non-specialized template functions.
2730 if (FromType->isInstantiationDependentType() &&
2731 !FromType->getAs<TemplateSpecializationType>()) {
2732 PDiag << ft_default;
2736 // No extra info for same types.
2737 if (Context.hasSameType(FromType, ToType)) {
2738 PDiag << ft_default;
2742 const FunctionProtoType *FromFunction = tryGetFunctionProtoType(FromType),
2743 *ToFunction = tryGetFunctionProtoType(ToType);
2745 // Both types need to be function types.
2746 if (!FromFunction || !ToFunction) {
2747 PDiag << ft_default;
2751 if (FromFunction->getNumParams() != ToFunction->getNumParams()) {
2752 PDiag << ft_parameter_arity << ToFunction->getNumParams()
2753 << FromFunction->getNumParams();
2757 // Handle different parameter types.
2759 if (!FunctionParamTypesAreEqual(FromFunction, ToFunction, &ArgPos)) {
2760 PDiag << ft_parameter_mismatch << ArgPos + 1
2761 << ToFunction->getParamType(ArgPos)
2762 << FromFunction->getParamType(ArgPos);
2766 // Handle different return type.
2767 if (!Context.hasSameType(FromFunction->getReturnType(),
2768 ToFunction->getReturnType())) {
2769 PDiag << ft_return_type << ToFunction->getReturnType()
2770 << FromFunction->getReturnType();
2774 unsigned FromQuals = FromFunction->getTypeQuals(),
2775 ToQuals = ToFunction->getTypeQuals();
2776 if (FromQuals != ToQuals) {
2777 PDiag << ft_qualifer_mismatch << ToQuals << FromQuals;
2781 // Handle exception specification differences on canonical type (in C++17
2783 if (cast<FunctionProtoType>(FromFunction->getCanonicalTypeUnqualified())
2784 ->isNothrow(Context) !=
2785 cast<FunctionProtoType>(ToFunction->getCanonicalTypeUnqualified())
2786 ->isNothrow(Context)) {
2787 PDiag << ft_noexcept;
2791 // Unable to find a difference, so add no extra info.
2792 PDiag << ft_default;
2795 /// FunctionParamTypesAreEqual - This routine checks two function proto types
2796 /// for equality of their argument types. Caller has already checked that
2797 /// they have same number of arguments. If the parameters are different,
2798 /// ArgPos will have the parameter index of the first different parameter.
2799 bool Sema::FunctionParamTypesAreEqual(const FunctionProtoType *OldType,
2800 const FunctionProtoType *NewType,
2802 for (FunctionProtoType::param_type_iterator O = OldType->param_type_begin(),
2803 N = NewType->param_type_begin(),
2804 E = OldType->param_type_end();
2805 O && (O != E); ++O, ++N) {
2806 if (!Context.hasSameType(O->getUnqualifiedType(),
2807 N->getUnqualifiedType())) {
2809 *ArgPos = O - OldType->param_type_begin();
2816 /// CheckPointerConversion - Check the pointer conversion from the
2817 /// expression From to the type ToType. This routine checks for
2818 /// ambiguous or inaccessible derived-to-base pointer
2819 /// conversions for which IsPointerConversion has already returned
2820 /// true. It returns true and produces a diagnostic if there was an
2821 /// error, or returns false otherwise.
2822 bool Sema::CheckPointerConversion(Expr *From, QualType ToType,
2824 CXXCastPath& BasePath,
2825 bool IgnoreBaseAccess,
2827 QualType FromType = From->getType();
2828 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess;
2832 if (Diagnose && !IsCStyleOrFunctionalCast && !FromType->isAnyPointerType() &&
2833 From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) ==
2834 Expr::NPCK_ZeroExpression) {
2835 if (Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy))
2836 DiagRuntimeBehavior(From->getExprLoc(), From,
2837 PDiag(diag::warn_impcast_bool_to_null_pointer)
2838 << ToType << From->getSourceRange());
2839 else if (!isUnevaluatedContext())
2840 Diag(From->getExprLoc(), diag::warn_non_literal_null_pointer)
2841 << ToType << From->getSourceRange();
2843 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) {
2844 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) {
2845 QualType FromPointeeType = FromPtrType->getPointeeType(),
2846 ToPointeeType = ToPtrType->getPointeeType();
2848 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() &&
2849 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) {
2850 // We must have a derived-to-base conversion. Check an
2851 // ambiguous or inaccessible conversion.
2852 unsigned InaccessibleID = 0;
2853 unsigned AmbigiousID = 0;
2855 InaccessibleID = diag::err_upcast_to_inaccessible_base;
2856 AmbigiousID = diag::err_ambiguous_derived_to_base_conv;
2858 if (CheckDerivedToBaseConversion(
2859 FromPointeeType, ToPointeeType, InaccessibleID, AmbigiousID,
2860 From->getExprLoc(), From->getSourceRange(), DeclarationName(),
2861 &BasePath, IgnoreBaseAccess))
2864 // The conversion was successful.
2865 Kind = CK_DerivedToBase;
2868 if (Diagnose && !IsCStyleOrFunctionalCast &&
2869 FromPointeeType->isFunctionType() && ToPointeeType->isVoidType()) {
2870 assert(getLangOpts().MSVCCompat &&
2871 "this should only be possible with MSVCCompat!");
2872 Diag(From->getExprLoc(), diag::ext_ms_impcast_fn_obj)
2873 << From->getSourceRange();
2876 } else if (const ObjCObjectPointerType *ToPtrType =
2877 ToType->getAs<ObjCObjectPointerType>()) {
2878 if (const ObjCObjectPointerType *FromPtrType =
2879 FromType->getAs<ObjCObjectPointerType>()) {
2880 // Objective-C++ conversions are always okay.
2881 // FIXME: We should have a different class of conversions for the
2882 // Objective-C++ implicit conversions.
2883 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType())
2885 } else if (FromType->isBlockPointerType()) {
2886 Kind = CK_BlockPointerToObjCPointerCast;
2888 Kind = CK_CPointerToObjCPointerCast;
2890 } else if (ToType->isBlockPointerType()) {
2891 if (!FromType->isBlockPointerType())
2892 Kind = CK_AnyPointerToBlockPointerCast;
2895 // We shouldn't fall into this case unless it's valid for other
2897 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull))
2898 Kind = CK_NullToPointer;
2903 /// IsMemberPointerConversion - Determines whether the conversion of the
2904 /// expression From, which has the (possibly adjusted) type FromType, can be
2905 /// converted to the type ToType via a member pointer conversion (C++ 4.11).
2906 /// If so, returns true and places the converted type (that might differ from
2907 /// ToType in its cv-qualifiers at some level) into ConvertedType.
2908 bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType,
2910 bool InOverloadResolution,
2911 QualType &ConvertedType) {
2912 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>();
2916 // A null pointer constant can be converted to a member pointer (C++ 4.11p1)
2917 if (From->isNullPointerConstant(Context,
2918 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
2919 : Expr::NPC_ValueDependentIsNull)) {
2920 ConvertedType = ToType;
2924 // Otherwise, both types have to be member pointers.
2925 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>();
2929 // A pointer to member of B can be converted to a pointer to member of D,
2930 // where D is derived from B (C++ 4.11p2).
2931 QualType FromClass(FromTypePtr->getClass(), 0);
2932 QualType ToClass(ToTypePtr->getClass(), 0);
2934 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) &&
2935 IsDerivedFrom(From->getLocStart(), ToClass, FromClass)) {
2936 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(),
2937 ToClass.getTypePtr());
2944 /// CheckMemberPointerConversion - Check the member pointer conversion from the
2945 /// expression From to the type ToType. This routine checks for ambiguous or
2946 /// virtual or inaccessible base-to-derived member pointer conversions
2947 /// for which IsMemberPointerConversion has already returned true. It returns
2948 /// true and produces a diagnostic if there was an error, or returns false
2950 bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType,
2952 CXXCastPath &BasePath,
2953 bool IgnoreBaseAccess) {
2954 QualType FromType = From->getType();
2955 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>();
2957 // This must be a null pointer to member pointer conversion
2958 assert(From->isNullPointerConstant(Context,
2959 Expr::NPC_ValueDependentIsNull) &&
2960 "Expr must be null pointer constant!");
2961 Kind = CK_NullToMemberPointer;
2965 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>();
2966 assert(ToPtrType && "No member pointer cast has a target type "
2967 "that is not a member pointer.");
2969 QualType FromClass = QualType(FromPtrType->getClass(), 0);
2970 QualType ToClass = QualType(ToPtrType->getClass(), 0);
2972 // FIXME: What about dependent types?
2973 assert(FromClass->isRecordType() && "Pointer into non-class.");
2974 assert(ToClass->isRecordType() && "Pointer into non-class.");
2976 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2977 /*DetectVirtual=*/true);
2978 bool DerivationOkay =
2979 IsDerivedFrom(From->getLocStart(), ToClass, FromClass, Paths);
2980 assert(DerivationOkay &&
2981 "Should not have been called if derivation isn't OK.");
2982 (void)DerivationOkay;
2984 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass).
2985 getUnqualifiedType())) {
2986 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
2987 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv)
2988 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange();
2992 if (const RecordType *VBase = Paths.getDetectedVirtual()) {
2993 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual)
2994 << FromClass << ToClass << QualType(VBase, 0)
2995 << From->getSourceRange();
2999 if (!IgnoreBaseAccess)
3000 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass,
3002 diag::err_downcast_from_inaccessible_base);
3004 // Must be a base to derived member conversion.
3005 BuildBasePathArray(Paths, BasePath);
3006 Kind = CK_BaseToDerivedMemberPointer;
3010 /// Determine whether the lifetime conversion between the two given
3011 /// qualifiers sets is nontrivial.
3012 static bool isNonTrivialObjCLifetimeConversion(Qualifiers FromQuals,
3013 Qualifiers ToQuals) {
3014 // Converting anything to const __unsafe_unretained is trivial.
3015 if (ToQuals.hasConst() &&
3016 ToQuals.getObjCLifetime() == Qualifiers::OCL_ExplicitNone)
3022 /// IsQualificationConversion - Determines whether the conversion from
3023 /// an rvalue of type FromType to ToType is a qualification conversion
3026 /// \param ObjCLifetimeConversion Output parameter that will be set to indicate
3027 /// when the qualification conversion involves a change in the Objective-C
3028 /// object lifetime.
3030 Sema::IsQualificationConversion(QualType FromType, QualType ToType,
3031 bool CStyle, bool &ObjCLifetimeConversion) {
3032 FromType = Context.getCanonicalType(FromType);
3033 ToType = Context.getCanonicalType(ToType);
3034 ObjCLifetimeConversion = false;
3036 // If FromType and ToType are the same type, this is not a
3037 // qualification conversion.
3038 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType())
3042 // A conversion can add cv-qualifiers at levels other than the first
3043 // in multi-level pointers, subject to the following rules: [...]
3044 bool PreviousToQualsIncludeConst = true;
3045 bool UnwrappedAnyPointer = false;
3046 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) {
3047 // Within each iteration of the loop, we check the qualifiers to
3048 // determine if this still looks like a qualification
3049 // conversion. Then, if all is well, we unwrap one more level of
3050 // pointers or pointers-to-members and do it all again
3051 // until there are no more pointers or pointers-to-members left to
3053 UnwrappedAnyPointer = true;
3055 Qualifiers FromQuals = FromType.getQualifiers();
3056 Qualifiers ToQuals = ToType.getQualifiers();
3058 // Ignore __unaligned qualifier if this type is void.
3059 if (ToType.getUnqualifiedType()->isVoidType())
3060 FromQuals.removeUnaligned();
3063 // Check Objective-C lifetime conversions.
3064 if (FromQuals.getObjCLifetime() != ToQuals.getObjCLifetime() &&
3065 UnwrappedAnyPointer) {
3066 if (ToQuals.compatiblyIncludesObjCLifetime(FromQuals)) {
3067 if (isNonTrivialObjCLifetimeConversion(FromQuals, ToQuals))
3068 ObjCLifetimeConversion = true;
3069 FromQuals.removeObjCLifetime();
3070 ToQuals.removeObjCLifetime();
3072 // Qualification conversions cannot cast between different
3073 // Objective-C lifetime qualifiers.
3078 // Allow addition/removal of GC attributes but not changing GC attributes.
3079 if (FromQuals.getObjCGCAttr() != ToQuals.getObjCGCAttr() &&
3080 (!FromQuals.hasObjCGCAttr() || !ToQuals.hasObjCGCAttr())) {
3081 FromQuals.removeObjCGCAttr();
3082 ToQuals.removeObjCGCAttr();
3085 // -- for every j > 0, if const is in cv 1,j then const is in cv
3086 // 2,j, and similarly for volatile.
3087 if (!CStyle && !ToQuals.compatiblyIncludes(FromQuals))
3090 // -- if the cv 1,j and cv 2,j are different, then const is in
3091 // every cv for 0 < k < j.
3092 if (!CStyle && FromQuals.getCVRQualifiers() != ToQuals.getCVRQualifiers()
3093 && !PreviousToQualsIncludeConst)
3096 // Keep track of whether all prior cv-qualifiers in the "to" type
3098 PreviousToQualsIncludeConst
3099 = PreviousToQualsIncludeConst && ToQuals.hasConst();
3102 // We are left with FromType and ToType being the pointee types
3103 // after unwrapping the original FromType and ToType the same number
3104 // of types. If we unwrapped any pointers, and if FromType and
3105 // ToType have the same unqualified type (since we checked
3106 // qualifiers above), then this is a qualification conversion.
3107 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType);
3110 /// \brief - Determine whether this is a conversion from a scalar type to an
3113 /// If successful, updates \c SCS's second and third steps in the conversion
3114 /// sequence to finish the conversion.
3115 static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
3116 bool InOverloadResolution,
3117 StandardConversionSequence &SCS,
3119 const AtomicType *ToAtomic = ToType->getAs<AtomicType>();
3123 StandardConversionSequence InnerSCS;
3124 if (!IsStandardConversion(S, From, ToAtomic->getValueType(),
3125 InOverloadResolution, InnerSCS,
3126 CStyle, /*AllowObjCWritebackConversion=*/false))
3129 SCS.Second = InnerSCS.Second;
3130 SCS.setToType(1, InnerSCS.getToType(1));
3131 SCS.Third = InnerSCS.Third;
3132 SCS.QualificationIncludesObjCLifetime
3133 = InnerSCS.QualificationIncludesObjCLifetime;
3134 SCS.setToType(2, InnerSCS.getToType(2));
3138 static bool isFirstArgumentCompatibleWithType(ASTContext &Context,
3139 CXXConstructorDecl *Constructor,
3141 const FunctionProtoType *CtorType =
3142 Constructor->getType()->getAs<FunctionProtoType>();
3143 if (CtorType->getNumParams() > 0) {
3144 QualType FirstArg = CtorType->getParamType(0);
3145 if (Context.hasSameUnqualifiedType(Type, FirstArg.getNonReferenceType()))
3151 static OverloadingResult
3152 IsInitializerListConstructorConversion(Sema &S, Expr *From, QualType ToType,
3154 UserDefinedConversionSequence &User,
3155 OverloadCandidateSet &CandidateSet,
3156 bool AllowExplicit) {
3157 for (auto *D : S.LookupConstructors(To)) {
3158 auto Info = getConstructorInfo(D);
3162 bool Usable = !Info.Constructor->isInvalidDecl() &&
3163 S.isInitListConstructor(Info.Constructor) &&
3164 (AllowExplicit || !Info.Constructor->isExplicit());
3166 // If the first argument is (a reference to) the target type,
3167 // suppress conversions.
3168 bool SuppressUserConversions = isFirstArgumentCompatibleWithType(
3169 S.Context, Info.Constructor, ToType);
3170 if (Info.ConstructorTmpl)
3171 S.AddTemplateOverloadCandidate(Info.ConstructorTmpl, Info.FoundDecl,
3172 /*ExplicitArgs*/ nullptr, From,
3173 CandidateSet, SuppressUserConversions);
3175 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl, From,
3176 CandidateSet, SuppressUserConversions);
3180 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3182 OverloadCandidateSet::iterator Best;
3183 switch (auto Result =
3184 CandidateSet.BestViableFunction(S, From->getLocStart(),
3188 // Record the standard conversion we used and the conversion function.
3189 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function);
3190 QualType ThisType = Constructor->getThisType(S.Context);
3191 // Initializer lists don't have conversions as such.
3192 User.Before.setAsIdentityConversion();
3193 User.HadMultipleCandidates = HadMultipleCandidates;
3194 User.ConversionFunction = Constructor;
3195 User.FoundConversionFunction = Best->FoundDecl;
3196 User.After.setAsIdentityConversion();
3197 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType());
3198 User.After.setAllToTypes(ToType);
3202 case OR_No_Viable_Function:
3203 return OR_No_Viable_Function;
3205 return OR_Ambiguous;
3208 llvm_unreachable("Invalid OverloadResult!");
3211 /// Determines whether there is a user-defined conversion sequence
3212 /// (C++ [over.ics.user]) that converts expression From to the type
3213 /// ToType. If such a conversion exists, User will contain the
3214 /// user-defined conversion sequence that performs such a conversion
3215 /// and this routine will return true. Otherwise, this routine returns
3216 /// false and User is unspecified.
3218 /// \param AllowExplicit true if the conversion should consider C++0x
3219 /// "explicit" conversion functions as well as non-explicit conversion
3220 /// functions (C++0x [class.conv.fct]p2).
3222 /// \param AllowObjCConversionOnExplicit true if the conversion should
3223 /// allow an extra Objective-C pointer conversion on uses of explicit
3224 /// constructors. Requires \c AllowExplicit to also be set.
3225 static OverloadingResult
3226 IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
3227 UserDefinedConversionSequence &User,
3228 OverloadCandidateSet &CandidateSet,
3230 bool AllowObjCConversionOnExplicit) {
3231 assert(AllowExplicit || !AllowObjCConversionOnExplicit);
3233 // Whether we will only visit constructors.
3234 bool ConstructorsOnly = false;
3236 // If the type we are conversion to is a class type, enumerate its
3238 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) {
3239 // C++ [over.match.ctor]p1:
3240 // When objects of class type are direct-initialized (8.5), or
3241 // copy-initialized from an expression of the same or a
3242 // derived class type (8.5), overload resolution selects the
3243 // constructor. [...] For copy-initialization, the candidate
3244 // functions are all the converting constructors (12.3.1) of
3245 // that class. The argument list is the expression-list within
3246 // the parentheses of the initializer.
3247 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) ||
3248 (From->getType()->getAs<RecordType>() &&
3249 S.IsDerivedFrom(From->getLocStart(), From->getType(), ToType)))
3250 ConstructorsOnly = true;
3252 if (!S.isCompleteType(From->getExprLoc(), ToType)) {
3253 // We're not going to find any constructors.
3254 } else if (CXXRecordDecl *ToRecordDecl
3255 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) {
3257 Expr **Args = &From;
3258 unsigned NumArgs = 1;
3259 bool ListInitializing = false;
3260 if (InitListExpr *InitList = dyn_cast<InitListExpr>(From)) {
3261 // But first, see if there is an init-list-constructor that will work.
3262 OverloadingResult Result = IsInitializerListConstructorConversion(
3263 S, From, ToType, ToRecordDecl, User, CandidateSet, AllowExplicit);
3264 if (Result != OR_No_Viable_Function)
3267 CandidateSet.clear();
3269 // If we're list-initializing, we pass the individual elements as
3270 // arguments, not the entire list.
3271 Args = InitList->getInits();
3272 NumArgs = InitList->getNumInits();
3273 ListInitializing = true;
3276 for (auto *D : S.LookupConstructors(ToRecordDecl)) {
3277 auto Info = getConstructorInfo(D);
3281 bool Usable = !Info.Constructor->isInvalidDecl();
3282 if (ListInitializing)
3283 Usable = Usable && (AllowExplicit || !Info.Constructor->isExplicit());
3286 Info.Constructor->isConvertingConstructor(AllowExplicit);
3288 bool SuppressUserConversions = !ConstructorsOnly;
3289 if (SuppressUserConversions && ListInitializing) {
3290 SuppressUserConversions = false;
3292 // If the first argument is (a reference to) the target type,
3293 // suppress conversions.
3294 SuppressUserConversions = isFirstArgumentCompatibleWithType(
3295 S.Context, Info.Constructor, ToType);
3298 if (Info.ConstructorTmpl)
3299 S.AddTemplateOverloadCandidate(
3300 Info.ConstructorTmpl, Info.FoundDecl,
3301 /*ExplicitArgs*/ nullptr, llvm::makeArrayRef(Args, NumArgs),
3302 CandidateSet, SuppressUserConversions);
3304 // Allow one user-defined conversion when user specifies a
3305 // From->ToType conversion via an static cast (c-style, etc).
3306 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl,
3307 llvm::makeArrayRef(Args, NumArgs),
3308 CandidateSet, SuppressUserConversions);
3314 // Enumerate conversion functions, if we're allowed to.
3315 if (ConstructorsOnly || isa<InitListExpr>(From)) {
3316 } else if (!S.isCompleteType(From->getLocStart(), From->getType())) {
3317 // No conversion functions from incomplete types.
3318 } else if (const RecordType *FromRecordType
3319 = From->getType()->getAs<RecordType>()) {
3320 if (CXXRecordDecl *FromRecordDecl
3321 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) {
3322 // Add all of the conversion functions as candidates.
3323 const auto &Conversions = FromRecordDecl->getVisibleConversionFunctions();
3324 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
3325 DeclAccessPair FoundDecl = I.getPair();
3326 NamedDecl *D = FoundDecl.getDecl();
3327 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
3328 if (isa<UsingShadowDecl>(D))
3329 D = cast<UsingShadowDecl>(D)->getTargetDecl();
3331 CXXConversionDecl *Conv;
3332 FunctionTemplateDecl *ConvTemplate;
3333 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
3334 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
3336 Conv = cast<CXXConversionDecl>(D);
3338 if (AllowExplicit || !Conv->isExplicit()) {
3340 S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl,
3341 ActingContext, From, ToType,
3343 AllowObjCConversionOnExplicit);
3345 S.AddConversionCandidate(Conv, FoundDecl, ActingContext,
3346 From, ToType, CandidateSet,
3347 AllowObjCConversionOnExplicit);
3353 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3355 OverloadCandidateSet::iterator Best;
3356 switch (auto Result = CandidateSet.BestViableFunction(S, From->getLocStart(),
3360 // Record the standard conversion we used and the conversion function.
3361 if (CXXConstructorDecl *Constructor
3362 = dyn_cast<CXXConstructorDecl>(Best->Function)) {
3363 // C++ [over.ics.user]p1:
3364 // If the user-defined conversion is specified by a
3365 // constructor (12.3.1), the initial standard conversion
3366 // sequence converts the source type to the type required by
3367 // the argument of the constructor.
3369 QualType ThisType = Constructor->getThisType(S.Context);
3370 if (isa<InitListExpr>(From)) {
3371 // Initializer lists don't have conversions as such.
3372 User.Before.setAsIdentityConversion();
3374 if (Best->Conversions[0].isEllipsis())
3375 User.EllipsisConversion = true;
3377 User.Before = Best->Conversions[0].Standard;
3378 User.EllipsisConversion = false;
3381 User.HadMultipleCandidates = HadMultipleCandidates;
3382 User.ConversionFunction = Constructor;
3383 User.FoundConversionFunction = Best->FoundDecl;
3384 User.After.setAsIdentityConversion();
3385 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType());
3386 User.After.setAllToTypes(ToType);
3389 if (CXXConversionDecl *Conversion
3390 = dyn_cast<CXXConversionDecl>(Best->Function)) {
3391 // C++ [over.ics.user]p1:
3393 // [...] If the user-defined conversion is specified by a
3394 // conversion function (12.3.2), the initial standard
3395 // conversion sequence converts the source type to the
3396 // implicit object parameter of the conversion function.
3397 User.Before = Best->Conversions[0].Standard;
3398 User.HadMultipleCandidates = HadMultipleCandidates;
3399 User.ConversionFunction = Conversion;
3400 User.FoundConversionFunction = Best->FoundDecl;
3401 User.EllipsisConversion = false;
3403 // C++ [over.ics.user]p2:
3404 // The second standard conversion sequence converts the
3405 // result of the user-defined conversion to the target type
3406 // for the sequence. Since an implicit conversion sequence
3407 // is an initialization, the special rules for
3408 // initialization by user-defined conversion apply when
3409 // selecting the best user-defined conversion for a
3410 // user-defined conversion sequence (see 13.3.3 and
3412 User.After = Best->FinalConversion;
3415 llvm_unreachable("Not a constructor or conversion function?");
3417 case OR_No_Viable_Function:
3418 return OR_No_Viable_Function;
3421 return OR_Ambiguous;
3424 llvm_unreachable("Invalid OverloadResult!");
3428 Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) {
3429 ImplicitConversionSequence ICS;
3430 OverloadCandidateSet CandidateSet(From->getExprLoc(),
3431 OverloadCandidateSet::CSK_Normal);
3432 OverloadingResult OvResult =
3433 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined,
3434 CandidateSet, false, false);
3435 if (OvResult == OR_Ambiguous)
3436 Diag(From->getLocStart(), diag::err_typecheck_ambiguous_condition)
3437 << From->getType() << ToType << From->getSourceRange();
3438 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) {
3439 if (!RequireCompleteType(From->getLocStart(), ToType,
3440 diag::err_typecheck_nonviable_condition_incomplete,
3441 From->getType(), From->getSourceRange()))
3442 Diag(From->getLocStart(), diag::err_typecheck_nonviable_condition)
3443 << false << From->getType() << From->getSourceRange() << ToType;
3446 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, From);
3450 /// \brief Compare the user-defined conversion functions or constructors
3451 /// of two user-defined conversion sequences to determine whether any ordering
3453 static ImplicitConversionSequence::CompareKind
3454 compareConversionFunctions(Sema &S, FunctionDecl *Function1,
3455 FunctionDecl *Function2) {
3456 if (!S.getLangOpts().ObjC1 || !S.getLangOpts().CPlusPlus11)
3457 return ImplicitConversionSequence::Indistinguishable;
3460 // If both conversion functions are implicitly-declared conversions from
3461 // a lambda closure type to a function pointer and a block pointer,
3462 // respectively, always prefer the conversion to a function pointer,
3463 // because the function pointer is more lightweight and is more likely
3464 // to keep code working.
3465 CXXConversionDecl *Conv1 = dyn_cast_or_null<CXXConversionDecl>(Function1);
3467 return ImplicitConversionSequence::Indistinguishable;
3469 CXXConversionDecl *Conv2 = dyn_cast<CXXConversionDecl>(Function2);
3471 return ImplicitConversionSequence::Indistinguishable;
3473 if (Conv1->getParent()->isLambda() && Conv2->getParent()->isLambda()) {
3474 bool Block1 = Conv1->getConversionType()->isBlockPointerType();
3475 bool Block2 = Conv2->getConversionType()->isBlockPointerType();
3476 if (Block1 != Block2)
3477 return Block1 ? ImplicitConversionSequence::Worse
3478 : ImplicitConversionSequence::Better;
3481 return ImplicitConversionSequence::Indistinguishable;
3484 static bool hasDeprecatedStringLiteralToCharPtrConversion(
3485 const ImplicitConversionSequence &ICS) {
3486 return (ICS.isStandard() && ICS.Standard.DeprecatedStringLiteralToCharPtr) ||
3487 (ICS.isUserDefined() &&
3488 ICS.UserDefined.Before.DeprecatedStringLiteralToCharPtr);
3491 /// CompareImplicitConversionSequences - Compare two implicit
3492 /// conversion sequences to determine whether one is better than the
3493 /// other or if they are indistinguishable (C++ 13.3.3.2).
3494 static ImplicitConversionSequence::CompareKind
3495 CompareImplicitConversionSequences(Sema &S, SourceLocation Loc,
3496 const ImplicitConversionSequence& ICS1,
3497 const ImplicitConversionSequence& ICS2)
3499 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit
3500 // conversion sequences (as defined in 13.3.3.1)
3501 // -- a standard conversion sequence (13.3.3.1.1) is a better
3502 // conversion sequence than a user-defined conversion sequence or
3503 // an ellipsis conversion sequence, and
3504 // -- a user-defined conversion sequence (13.3.3.1.2) is a better
3505 // conversion sequence than an ellipsis conversion sequence
3508 // C++0x [over.best.ics]p10:
3509 // For the purpose of ranking implicit conversion sequences as
3510 // described in 13.3.3.2, the ambiguous conversion sequence is
3511 // treated as a user-defined sequence that is indistinguishable
3512 // from any other user-defined conversion sequence.
3514 // String literal to 'char *' conversion has been deprecated in C++03. It has
3515 // been removed from C++11. We still accept this conversion, if it happens at
3516 // the best viable function. Otherwise, this conversion is considered worse
3517 // than ellipsis conversion. Consider this as an extension; this is not in the
3518 // standard. For example:
3520 // int &f(...); // #1
3521 // void f(char*); // #2
3522 // void g() { int &r = f("foo"); }
3524 // In C++03, we pick #2 as the best viable function.
3525 // In C++11, we pick #1 as the best viable function, because ellipsis
3526 // conversion is better than string-literal to char* conversion (since there
3527 // is no such conversion in C++11). If there was no #1 at all or #1 couldn't
3528 // convert arguments, #2 would be the best viable function in C++11.
3529 // If the best viable function has this conversion, a warning will be issued
3530 // in C++03, or an ExtWarn (+SFINAE failure) will be issued in C++11.
3532 if (S.getLangOpts().CPlusPlus11 && !S.getLangOpts().WritableStrings &&
3533 hasDeprecatedStringLiteralToCharPtrConversion(ICS1) !=
3534 hasDeprecatedStringLiteralToCharPtrConversion(ICS2))
3535 return hasDeprecatedStringLiteralToCharPtrConversion(ICS1)
3536 ? ImplicitConversionSequence::Worse
3537 : ImplicitConversionSequence::Better;
3539 if (ICS1.getKindRank() < ICS2.getKindRank())
3540 return ImplicitConversionSequence::Better;
3541 if (ICS2.getKindRank() < ICS1.getKindRank())
3542 return ImplicitConversionSequence::Worse;
3544 // The following checks require both conversion sequences to be of
3546 if (ICS1.getKind() != ICS2.getKind())
3547 return ImplicitConversionSequence::Indistinguishable;
3549 ImplicitConversionSequence::CompareKind Result =
3550 ImplicitConversionSequence::Indistinguishable;
3552 // Two implicit conversion sequences of the same form are
3553 // indistinguishable conversion sequences unless one of the
3554 // following rules apply: (C++ 13.3.3.2p3):
3556 // List-initialization sequence L1 is a better conversion sequence than
3557 // list-initialization sequence L2 if:
3558 // - L1 converts to std::initializer_list<X> for some X and L2 does not, or,
3560 // - L1 converts to type "array of N1 T", L2 converts to type "array of N2 T",
3561 // and N1 is smaller than N2.,
3562 // even if one of the other rules in this paragraph would otherwise apply.
3563 if (!ICS1.isBad()) {
3564 if (ICS1.isStdInitializerListElement() &&
3565 !ICS2.isStdInitializerListElement())
3566 return ImplicitConversionSequence::Better;
3567 if (!ICS1.isStdInitializerListElement() &&
3568 ICS2.isStdInitializerListElement())
3569 return ImplicitConversionSequence::Worse;
3572 if (ICS1.isStandard())
3573 // Standard conversion sequence S1 is a better conversion sequence than
3574 // standard conversion sequence S2 if [...]
3575 Result = CompareStandardConversionSequences(S, Loc,
3576 ICS1.Standard, ICS2.Standard);
3577 else if (ICS1.isUserDefined()) {
3578 // User-defined conversion sequence U1 is a better conversion
3579 // sequence than another user-defined conversion sequence U2 if
3580 // they contain the same user-defined conversion function or
3581 // constructor and if the second standard conversion sequence of
3582 // U1 is better than the second standard conversion sequence of
3583 // U2 (C++ 13.3.3.2p3).
3584 if (ICS1.UserDefined.ConversionFunction ==
3585 ICS2.UserDefined.ConversionFunction)
3586 Result = CompareStandardConversionSequences(S, Loc,
3587 ICS1.UserDefined.After,
3588 ICS2.UserDefined.After);
3590 Result = compareConversionFunctions(S,
3591 ICS1.UserDefined.ConversionFunction,
3592 ICS2.UserDefined.ConversionFunction);
3598 static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) {
3599 while (Context.UnwrapSimilarPointerTypes(T1, T2)) {
3601 T1 = Context.getUnqualifiedArrayType(T1, Quals);
3602 T2 = Context.getUnqualifiedArrayType(T2, Quals);
3605 return Context.hasSameUnqualifiedType(T1, T2);
3608 // Per 13.3.3.2p3, compare the given standard conversion sequences to
3609 // determine if one is a proper subset of the other.
3610 static ImplicitConversionSequence::CompareKind
3611 compareStandardConversionSubsets(ASTContext &Context,
3612 const StandardConversionSequence& SCS1,
3613 const StandardConversionSequence& SCS2) {
3614 ImplicitConversionSequence::CompareKind Result
3615 = ImplicitConversionSequence::Indistinguishable;
3617 // the identity conversion sequence is considered to be a subsequence of
3618 // any non-identity conversion sequence
3619 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion())
3620 return ImplicitConversionSequence::Better;
3621 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion())
3622 return ImplicitConversionSequence::Worse;
3624 if (SCS1.Second != SCS2.Second) {
3625 if (SCS1.Second == ICK_Identity)
3626 Result = ImplicitConversionSequence::Better;
3627 else if (SCS2.Second == ICK_Identity)
3628 Result = ImplicitConversionSequence::Worse;
3630 return ImplicitConversionSequence::Indistinguishable;
3631 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1)))
3632 return ImplicitConversionSequence::Indistinguishable;
3634 if (SCS1.Third == SCS2.Third) {
3635 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result
3636 : ImplicitConversionSequence::Indistinguishable;
3639 if (SCS1.Third == ICK_Identity)
3640 return Result == ImplicitConversionSequence::Worse
3641 ? ImplicitConversionSequence::Indistinguishable
3642 : ImplicitConversionSequence::Better;
3644 if (SCS2.Third == ICK_Identity)
3645 return Result == ImplicitConversionSequence::Better
3646 ? ImplicitConversionSequence::Indistinguishable
3647 : ImplicitConversionSequence::Worse;
3649 return ImplicitConversionSequence::Indistinguishable;
3652 /// \brief Determine whether one of the given reference bindings is better
3653 /// than the other based on what kind of bindings they are.
3655 isBetterReferenceBindingKind(const StandardConversionSequence &SCS1,
3656 const StandardConversionSequence &SCS2) {
3657 // C++0x [over.ics.rank]p3b4:
3658 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an
3659 // implicit object parameter of a non-static member function declared
3660 // without a ref-qualifier, and *either* S1 binds an rvalue reference
3661 // to an rvalue and S2 binds an lvalue reference *or S1 binds an
3662 // lvalue reference to a function lvalue and S2 binds an rvalue
3665 // FIXME: Rvalue references. We're going rogue with the above edits,
3666 // because the semantics in the current C++0x working paper (N3225 at the
3667 // time of this writing) break the standard definition of std::forward
3668 // and std::reference_wrapper when dealing with references to functions.
3669 // Proposed wording changes submitted to CWG for consideration.
3670 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier ||
3671 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier)
3674 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue &&
3675 SCS2.IsLvalueReference) ||
3676 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue &&
3677 !SCS2.IsLvalueReference && SCS2.BindsToFunctionLvalue);
3680 /// CompareStandardConversionSequences - Compare two standard
3681 /// conversion sequences to determine whether one is better than the
3682 /// other or if they are indistinguishable (C++ 13.3.3.2p3).
3683 static ImplicitConversionSequence::CompareKind
3684 CompareStandardConversionSequences(Sema &S, SourceLocation Loc,
3685 const StandardConversionSequence& SCS1,
3686 const StandardConversionSequence& SCS2)
3688 // Standard conversion sequence S1 is a better conversion sequence
3689 // than standard conversion sequence S2 if (C++ 13.3.3.2p3):
3691 // -- S1 is a proper subsequence of S2 (comparing the conversion
3692 // sequences in the canonical form defined by 13.3.3.1.1,
3693 // excluding any Lvalue Transformation; the identity conversion
3694 // sequence is considered to be a subsequence of any
3695 // non-identity conversion sequence) or, if not that,
3696 if (ImplicitConversionSequence::CompareKind CK
3697 = compareStandardConversionSubsets(S.Context, SCS1, SCS2))
3700 // -- the rank of S1 is better than the rank of S2 (by the rules
3701 // defined below), or, if not that,
3702 ImplicitConversionRank Rank1 = SCS1.getRank();
3703 ImplicitConversionRank Rank2 = SCS2.getRank();
3705 return ImplicitConversionSequence::Better;
3706 else if (Rank2 < Rank1)
3707 return ImplicitConversionSequence::Worse;
3709 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank
3710 // are indistinguishable unless one of the following rules
3713 // A conversion that is not a conversion of a pointer, or
3714 // pointer to member, to bool is better than another conversion
3715 // that is such a conversion.
3716 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool())
3717 return SCS2.isPointerConversionToBool()
3718 ? ImplicitConversionSequence::Better
3719 : ImplicitConversionSequence::Worse;
3721 // C++ [over.ics.rank]p4b2:
3723 // If class B is derived directly or indirectly from class A,
3724 // conversion of B* to A* is better than conversion of B* to
3725 // void*, and conversion of A* to void* is better than conversion
3727 bool SCS1ConvertsToVoid
3728 = SCS1.isPointerConversionToVoidPointer(S.Context);
3729 bool SCS2ConvertsToVoid
3730 = SCS2.isPointerConversionToVoidPointer(S.Context);
3731 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) {
3732 // Exactly one of the conversion sequences is a conversion to
3733 // a void pointer; it's the worse conversion.
3734 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better
3735 : ImplicitConversionSequence::Worse;
3736 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) {
3737 // Neither conversion sequence converts to a void pointer; compare
3738 // their derived-to-base conversions.
3739 if (ImplicitConversionSequence::CompareKind DerivedCK
3740 = CompareDerivedToBaseConversions(S, Loc, SCS1, SCS2))
3742 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid &&
3743 !S.Context.hasSameType(SCS1.getFromType(), SCS2.getFromType())) {
3744 // Both conversion sequences are conversions to void
3745 // pointers. Compare the source types to determine if there's an
3746 // inheritance relationship in their sources.
3747 QualType FromType1 = SCS1.getFromType();
3748 QualType FromType2 = SCS2.getFromType();
3750 // Adjust the types we're converting from via the array-to-pointer
3751 // conversion, if we need to.
3752 if (SCS1.First == ICK_Array_To_Pointer)
3753 FromType1 = S.Context.getArrayDecayedType(FromType1);
3754 if (SCS2.First == ICK_Array_To_Pointer)
3755 FromType2 = S.Context.getArrayDecayedType(FromType2);
3757 QualType FromPointee1 = FromType1->getPointeeType().getUnqualifiedType();
3758 QualType FromPointee2 = FromType2->getPointeeType().getUnqualifiedType();
3760 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
3761 return ImplicitConversionSequence::Better;
3762 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
3763 return ImplicitConversionSequence::Worse;
3765 // Objective-C++: If one interface is more specific than the
3766 // other, it is the better one.
3767 const ObjCObjectPointerType* FromObjCPtr1
3768 = FromType1->getAs<ObjCObjectPointerType>();
3769 const ObjCObjectPointerType* FromObjCPtr2
3770 = FromType2->getAs<ObjCObjectPointerType>();
3771 if (FromObjCPtr1 && FromObjCPtr2) {
3772 bool AssignLeft = S.Context.canAssignObjCInterfaces(FromObjCPtr1,
3774 bool AssignRight = S.Context.canAssignObjCInterfaces(FromObjCPtr2,
3776 if (AssignLeft != AssignRight) {
3777 return AssignLeft? ImplicitConversionSequence::Better
3778 : ImplicitConversionSequence::Worse;
3783 // Compare based on qualification conversions (C++ 13.3.3.2p3,
3785 if (ImplicitConversionSequence::CompareKind QualCK
3786 = CompareQualificationConversions(S, SCS1, SCS2))
3789 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) {
3790 // Check for a better reference binding based on the kind of bindings.
3791 if (isBetterReferenceBindingKind(SCS1, SCS2))
3792 return ImplicitConversionSequence::Better;
3793 else if (isBetterReferenceBindingKind(SCS2, SCS1))
3794 return ImplicitConversionSequence::Worse;
3796 // C++ [over.ics.rank]p3b4:
3797 // -- S1 and S2 are reference bindings (8.5.3), and the types to
3798 // which the references refer are the same type except for
3799 // top-level cv-qualifiers, and the type to which the reference
3800 // initialized by S2 refers is more cv-qualified than the type
3801 // to which the reference initialized by S1 refers.
3802 QualType T1 = SCS1.getToType(2);
3803 QualType T2 = SCS2.getToType(2);
3804 T1 = S.Context.getCanonicalType(T1);
3805 T2 = S.Context.getCanonicalType(T2);
3806 Qualifiers T1Quals, T2Quals;
3807 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
3808 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
3809 if (UnqualT1 == UnqualT2) {
3810 // Objective-C++ ARC: If the references refer to objects with different
3811 // lifetimes, prefer bindings that don't change lifetime.
3812 if (SCS1.ObjCLifetimeConversionBinding !=
3813 SCS2.ObjCLifetimeConversionBinding) {
3814 return SCS1.ObjCLifetimeConversionBinding
3815 ? ImplicitConversionSequence::Worse
3816 : ImplicitConversionSequence::Better;
3819 // If the type is an array type, promote the element qualifiers to the
3820 // type for comparison.
3821 if (isa<ArrayType>(T1) && T1Quals)
3822 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals);
3823 if (isa<ArrayType>(T2) && T2Quals)
3824 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals);
3825 if (T2.isMoreQualifiedThan(T1))
3826 return ImplicitConversionSequence::Better;
3827 else if (T1.isMoreQualifiedThan(T2))
3828 return ImplicitConversionSequence::Worse;
3832 // In Microsoft mode, prefer an integral conversion to a
3833 // floating-to-integral conversion if the integral conversion
3834 // is between types of the same size.
3842 // Here, MSVC will call f(int) instead of generating a compile error
3843 // as clang will do in standard mode.
3844 if (S.getLangOpts().MSVCCompat && SCS1.Second == ICK_Integral_Conversion &&
3845 SCS2.Second == ICK_Floating_Integral &&
3846 S.Context.getTypeSize(SCS1.getFromType()) ==
3847 S.Context.getTypeSize(SCS1.getToType(2)))
3848 return ImplicitConversionSequence::Better;
3850 return ImplicitConversionSequence::Indistinguishable;
3853 /// CompareQualificationConversions - Compares two standard conversion
3854 /// sequences to determine whether they can be ranked based on their
3855 /// qualification conversions (C++ 13.3.3.2p3 bullet 3).
3856 static ImplicitConversionSequence::CompareKind
3857 CompareQualificationConversions(Sema &S,
3858 const StandardConversionSequence& SCS1,
3859 const StandardConversionSequence& SCS2) {
3861 // -- S1 and S2 differ only in their qualification conversion and
3862 // yield similar types T1 and T2 (C++ 4.4), respectively, and the
3863 // cv-qualification signature of type T1 is a proper subset of
3864 // the cv-qualification signature of type T2, and S1 is not the
3865 // deprecated string literal array-to-pointer conversion (4.2).
3866 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second ||
3867 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification)
3868 return ImplicitConversionSequence::Indistinguishable;
3870 // FIXME: the example in the standard doesn't use a qualification
3872 QualType T1 = SCS1.getToType(2);
3873 QualType T2 = SCS2.getToType(2);
3874 T1 = S.Context.getCanonicalType(T1);
3875 T2 = S.Context.getCanonicalType(T2);
3876 Qualifiers T1Quals, T2Quals;
3877 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
3878 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
3880 // If the types are the same, we won't learn anything by unwrapped
3882 if (UnqualT1 == UnqualT2)
3883 return ImplicitConversionSequence::Indistinguishable;
3885 // If the type is an array type, promote the element qualifiers to the type
3887 if (isa<ArrayType>(T1) && T1Quals)
3888 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals);
3889 if (isa<ArrayType>(T2) && T2Quals)
3890 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals);
3892 ImplicitConversionSequence::CompareKind Result
3893 = ImplicitConversionSequence::Indistinguishable;
3895 // Objective-C++ ARC:
3896 // Prefer qualification conversions not involving a change in lifetime
3897 // to qualification conversions that do not change lifetime.
3898 if (SCS1.QualificationIncludesObjCLifetime !=
3899 SCS2.QualificationIncludesObjCLifetime) {
3900 Result = SCS1.QualificationIncludesObjCLifetime
3901 ? ImplicitConversionSequence::Worse
3902 : ImplicitConversionSequence::Better;
3905 while (S.Context.UnwrapSimilarPointerTypes(T1, T2)) {
3906 // Within each iteration of the loop, we check the qualifiers to
3907 // determine if this still looks like a qualification
3908 // conversion. Then, if all is well, we unwrap one more level of
3909 // pointers or pointers-to-members and do it all again
3910 // until there are no more pointers or pointers-to-members left
3911 // to unwrap. This essentially mimics what
3912 // IsQualificationConversion does, but here we're checking for a
3913 // strict subset of qualifiers.
3914 if (T1.getCVRQualifiers() == T2.getCVRQualifiers())
3915 // The qualifiers are the same, so this doesn't tell us anything
3916 // about how the sequences rank.
3918 else if (T2.isMoreQualifiedThan(T1)) {
3919 // T1 has fewer qualifiers, so it could be the better sequence.
3920 if (Result == ImplicitConversionSequence::Worse)
3921 // Neither has qualifiers that are a subset of the other's
3923 return ImplicitConversionSequence::Indistinguishable;
3925 Result = ImplicitConversionSequence::Better;
3926 } else if (T1.isMoreQualifiedThan(T2)) {
3927 // T2 has fewer qualifiers, so it could be the better sequence.
3928 if (Result == ImplicitConversionSequence::Better)
3929 // Neither has qualifiers that are a subset of the other's
3931 return ImplicitConversionSequence::Indistinguishable;
3933 Result = ImplicitConversionSequence::Worse;
3935 // Qualifiers are disjoint.
3936 return ImplicitConversionSequence::Indistinguishable;
3939 // If the types after this point are equivalent, we're done.
3940 if (S.Context.hasSameUnqualifiedType(T1, T2))
3944 // Check that the winning standard conversion sequence isn't using
3945 // the deprecated string literal array to pointer conversion.
3947 case ImplicitConversionSequence::Better:
3948 if (SCS1.DeprecatedStringLiteralToCharPtr)
3949 Result = ImplicitConversionSequence::Indistinguishable;
3952 case ImplicitConversionSequence::Indistinguishable:
3955 case ImplicitConversionSequence::Worse:
3956 if (SCS2.DeprecatedStringLiteralToCharPtr)
3957 Result = ImplicitConversionSequence::Indistinguishable;
3964 /// CompareDerivedToBaseConversions - Compares two standard conversion
3965 /// sequences to determine whether they can be ranked based on their
3966 /// various kinds of derived-to-base conversions (C++
3967 /// [over.ics.rank]p4b3). As part of these checks, we also look at
3968 /// conversions between Objective-C interface types.
3969 static ImplicitConversionSequence::CompareKind
3970 CompareDerivedToBaseConversions(Sema &S, SourceLocation Loc,
3971 const StandardConversionSequence& SCS1,
3972 const StandardConversionSequence& SCS2) {
3973 QualType FromType1 = SCS1.getFromType();
3974 QualType ToType1 = SCS1.getToType(1);
3975 QualType FromType2 = SCS2.getFromType();
3976 QualType ToType2 = SCS2.getToType(1);
3978 // Adjust the types we're converting from via the array-to-pointer
3979 // conversion, if we need to.
3980 if (SCS1.First == ICK_Array_To_Pointer)
3981 FromType1 = S.Context.getArrayDecayedType(FromType1);
3982 if (SCS2.First == ICK_Array_To_Pointer)
3983 FromType2 = S.Context.getArrayDecayedType(FromType2);
3985 // Canonicalize all of the types.
3986 FromType1 = S.Context.getCanonicalType(FromType1);
3987 ToType1 = S.Context.getCanonicalType(ToType1);
3988 FromType2 = S.Context.getCanonicalType(FromType2);
3989 ToType2 = S.Context.getCanonicalType(ToType2);
3991 // C++ [over.ics.rank]p4b3:
3993 // If class B is derived directly or indirectly from class A and
3994 // class C is derived directly or indirectly from B,
3996 // Compare based on pointer conversions.
3997 if (SCS1.Second == ICK_Pointer_Conversion &&
3998 SCS2.Second == ICK_Pointer_Conversion &&
3999 /*FIXME: Remove if Objective-C id conversions get their own rank*/
4000 FromType1->isPointerType() && FromType2->isPointerType() &&
4001 ToType1->isPointerType() && ToType2->isPointerType()) {
4002 QualType FromPointee1
4003 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4005 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4006 QualType FromPointee2
4007 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4009 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4011 // -- conversion of C* to B* is better than conversion of C* to A*,
4012 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
4013 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
4014 return ImplicitConversionSequence::Better;
4015 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
4016 return ImplicitConversionSequence::Worse;
4019 // -- conversion of B* to A* is better than conversion of C* to A*,
4020 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) {
4021 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
4022 return ImplicitConversionSequence::Better;
4023 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
4024 return ImplicitConversionSequence::Worse;
4026 } else if (SCS1.Second == ICK_Pointer_Conversion &&
4027 SCS2.Second == ICK_Pointer_Conversion) {
4028 const ObjCObjectPointerType *FromPtr1
4029 = FromType1->getAs<ObjCObjectPointerType>();
4030 const ObjCObjectPointerType *FromPtr2
4031 = FromType2->getAs<ObjCObjectPointerType>();
4032 const ObjCObjectPointerType *ToPtr1
4033 = ToType1->getAs<ObjCObjectPointerType>();
4034 const ObjCObjectPointerType *ToPtr2
4035 = ToType2->getAs<ObjCObjectPointerType>();
4037 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) {
4038 // Apply the same conversion ranking rules for Objective-C pointer types
4039 // that we do for C++ pointers to class types. However, we employ the
4040 // Objective-C pseudo-subtyping relationship used for assignment of
4041 // Objective-C pointer types.
4043 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2);
4044 bool FromAssignRight
4045 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1);
4047 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2);
4049 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1);
4051 // A conversion to an a non-id object pointer type or qualified 'id'
4052 // type is better than a conversion to 'id'.
4053 if (ToPtr1->isObjCIdType() &&
4054 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl()))
4055 return ImplicitConversionSequence::Worse;
4056 if (ToPtr2->isObjCIdType() &&
4057 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl()))
4058 return ImplicitConversionSequence::Better;
4060 // A conversion to a non-id object pointer type is better than a
4061 // conversion to a qualified 'id' type
4062 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl())
4063 return ImplicitConversionSequence::Worse;
4064 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl())
4065 return ImplicitConversionSequence::Better;
4067 // A conversion to an a non-Class object pointer type or qualified 'Class'
4068 // type is better than a conversion to 'Class'.
4069 if (ToPtr1->isObjCClassType() &&
4070 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl()))
4071 return ImplicitConversionSequence::Worse;
4072 if (ToPtr2->isObjCClassType() &&
4073 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl()))
4074 return ImplicitConversionSequence::Better;
4076 // A conversion to a non-Class object pointer type is better than a
4077 // conversion to a qualified 'Class' type.
4078 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl())
4079 return ImplicitConversionSequence::Worse;
4080 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl())
4081 return ImplicitConversionSequence::Better;
4083 // -- "conversion of C* to B* is better than conversion of C* to A*,"
4084 if (S.Context.hasSameType(FromType1, FromType2) &&
4085 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() &&
4086 (ToAssignLeft != ToAssignRight)) {
4087 if (FromPtr1->isSpecialized()) {
4088 // "conversion of B<A> * to B * is better than conversion of B * to
4091 FromPtr1->getInterfaceDecl() == ToPtr1->getInterfaceDecl();
4093 FromPtr1->getInterfaceDecl() == ToPtr2->getInterfaceDecl();
4096 return ImplicitConversionSequence::Better;
4097 } else if (IsSecondSame)
4098 return ImplicitConversionSequence::Worse;
4100 return ToAssignLeft? ImplicitConversionSequence::Worse
4101 : ImplicitConversionSequence::Better;
4104 // -- "conversion of B* to A* is better than conversion of C* to A*,"
4105 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) &&
4106 (FromAssignLeft != FromAssignRight))
4107 return FromAssignLeft? ImplicitConversionSequence::Better
4108 : ImplicitConversionSequence::Worse;
4112 // Ranking of member-pointer types.
4113 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member &&
4114 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() &&
4115 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) {
4116 const MemberPointerType * FromMemPointer1 =
4117 FromType1->getAs<MemberPointerType>();
4118 const MemberPointerType * ToMemPointer1 =
4119 ToType1->getAs<MemberPointerType>();
4120 const MemberPointerType * FromMemPointer2 =
4121 FromType2->getAs<MemberPointerType>();
4122 const MemberPointerType * ToMemPointer2 =
4123 ToType2->getAs<MemberPointerType>();
4124 const Type *FromPointeeType1 = FromMemPointer1->getClass();
4125 const Type *ToPointeeType1 = ToMemPointer1->getClass();
4126 const Type *FromPointeeType2 = FromMemPointer2->getClass();
4127 const Type *ToPointeeType2 = ToMemPointer2->getClass();
4128 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType();
4129 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType();
4130 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType();
4131 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType();
4132 // conversion of A::* to B::* is better than conversion of A::* to C::*,
4133 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
4134 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
4135 return ImplicitConversionSequence::Worse;
4136 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
4137 return ImplicitConversionSequence::Better;
4139 // conversion of B::* to C::* is better than conversion of A::* to C::*
4140 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) {
4141 if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
4142 return ImplicitConversionSequence::Better;
4143 else if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
4144 return ImplicitConversionSequence::Worse;
4148 if (SCS1.Second == ICK_Derived_To_Base) {
4149 // -- conversion of C to B is better than conversion of C to A,
4150 // -- binding of an expression of type C to a reference of type
4151 // B& is better than binding an expression of type C to a
4152 // reference of type A&,
4153 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4154 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4155 if (S.IsDerivedFrom(Loc, ToType1, ToType2))
4156 return ImplicitConversionSequence::Better;
4157 else if (S.IsDerivedFrom(Loc, ToType2, ToType1))
4158 return ImplicitConversionSequence::Worse;
4161 // -- conversion of B to A is better than conversion of C to A.
4162 // -- binding of an expression of type B to a reference of type
4163 // A& is better than binding an expression of type C to a
4164 // reference of type A&,
4165 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4166 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4167 if (S.IsDerivedFrom(Loc, FromType2, FromType1))
4168 return ImplicitConversionSequence::Better;
4169 else if (S.IsDerivedFrom(Loc, FromType1, FromType2))
4170 return ImplicitConversionSequence::Worse;
4174 return ImplicitConversionSequence::Indistinguishable;
4177 /// \brief Determine whether the given type is valid, e.g., it is not an invalid
4179 static bool isTypeValid(QualType T) {
4180 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl())
4181 return !Record->isInvalidDecl();
4186 /// CompareReferenceRelationship - Compare the two types T1 and T2 to
4187 /// determine whether they are reference-related,
4188 /// reference-compatible, reference-compatible with added
4189 /// qualification, or incompatible, for use in C++ initialization by
4190 /// reference (C++ [dcl.ref.init]p4). Neither type can be a reference
4191 /// type, and the first type (T1) is the pointee type of the reference
4192 /// type being initialized.
4193 Sema::ReferenceCompareResult
4194 Sema::CompareReferenceRelationship(SourceLocation Loc,
4195 QualType OrigT1, QualType OrigT2,
4196 bool &DerivedToBase,
4197 bool &ObjCConversion,
4198 bool &ObjCLifetimeConversion) {
4199 assert(!OrigT1->isReferenceType() &&
4200 "T1 must be the pointee type of the reference type");
4201 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type");
4203 QualType T1 = Context.getCanonicalType(OrigT1);
4204 QualType T2 = Context.getCanonicalType(OrigT2);
4205 Qualifiers T1Quals, T2Quals;
4206 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals);
4207 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals);
4209 // C++ [dcl.init.ref]p4:
4210 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is
4211 // reference-related to "cv2 T2" if T1 is the same type as T2, or
4212 // T1 is a base class of T2.
4213 DerivedToBase = false;
4214 ObjCConversion = false;
4215 ObjCLifetimeConversion = false;
4216 QualType ConvertedT2;
4217 if (UnqualT1 == UnqualT2) {
4219 } else if (isCompleteType(Loc, OrigT2) &&
4220 isTypeValid(UnqualT1) && isTypeValid(UnqualT2) &&
4221 IsDerivedFrom(Loc, UnqualT2, UnqualT1))
4222 DerivedToBase = true;
4223 else if (UnqualT1->isObjCObjectOrInterfaceType() &&
4224 UnqualT2->isObjCObjectOrInterfaceType() &&
4225 Context.canBindObjCObjectType(UnqualT1, UnqualT2))
4226 ObjCConversion = true;
4227 else if (UnqualT2->isFunctionType() &&
4228 IsFunctionConversion(UnqualT2, UnqualT1, ConvertedT2))
4229 // C++1z [dcl.init.ref]p4:
4230 // cv1 T1" is reference-compatible with "cv2 T2" if [...] T2 is "noexcept
4231 // function" and T1 is "function"
4233 // We extend this to also apply to 'noreturn', so allow any function
4234 // conversion between function types.
4235 return Ref_Compatible;
4237 return Ref_Incompatible;
4239 // At this point, we know that T1 and T2 are reference-related (at
4242 // If the type is an array type, promote the element qualifiers to the type
4244 if (isa<ArrayType>(T1) && T1Quals)
4245 T1 = Context.getQualifiedType(UnqualT1, T1Quals);
4246 if (isa<ArrayType>(T2) && T2Quals)
4247 T2 = Context.getQualifiedType(UnqualT2, T2Quals);
4249 // C++ [dcl.init.ref]p4:
4250 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is
4251 // reference-related to T2 and cv1 is the same cv-qualification
4252 // as, or greater cv-qualification than, cv2. For purposes of
4253 // overload resolution, cases for which cv1 is greater
4254 // cv-qualification than cv2 are identified as
4255 // reference-compatible with added qualification (see 13.3.3.2).
4257 // Note that we also require equivalence of Objective-C GC and address-space
4258 // qualifiers when performing these computations, so that e.g., an int in
4259 // address space 1 is not reference-compatible with an int in address
4261 if (T1Quals.getObjCLifetime() != T2Quals.getObjCLifetime() &&
4262 T1Quals.compatiblyIncludesObjCLifetime(T2Quals)) {
4263 if (isNonTrivialObjCLifetimeConversion(T2Quals, T1Quals))
4264 ObjCLifetimeConversion = true;
4266 T1Quals.removeObjCLifetime();
4267 T2Quals.removeObjCLifetime();
4270 // MS compiler ignores __unaligned qualifier for references; do the same.
4271 T1Quals.removeUnaligned();
4272 T2Quals.removeUnaligned();
4274 if (T1Quals.compatiblyIncludes(T2Quals))
4275 return Ref_Compatible;
4280 /// \brief Look for a user-defined conversion to a value reference-compatible
4281 /// with DeclType. Return true if something definite is found.
4283 FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS,
4284 QualType DeclType, SourceLocation DeclLoc,
4285 Expr *Init, QualType T2, bool AllowRvalues,
4286 bool AllowExplicit) {
4287 assert(T2->isRecordType() && "Can only find conversions of record types.");
4288 CXXRecordDecl *T2RecordDecl
4289 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl());
4291 OverloadCandidateSet CandidateSet(DeclLoc, OverloadCandidateSet::CSK_Normal);
4292 const auto &Conversions = T2RecordDecl->getVisibleConversionFunctions();
4293 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
4295 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
4296 if (isa<UsingShadowDecl>(D))
4297 D = cast<UsingShadowDecl>(D)->getTargetDecl();
4299 FunctionTemplateDecl *ConvTemplate
4300 = dyn_cast<FunctionTemplateDecl>(D);
4301 CXXConversionDecl *Conv;
4303 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
4305 Conv = cast<CXXConversionDecl>(D);
4307 // If this is an explicit conversion, and we're not allowed to consider
4308 // explicit conversions, skip it.
4309 if (!AllowExplicit && Conv->isExplicit())
4313 bool DerivedToBase = false;
4314 bool ObjCConversion = false;
4315 bool ObjCLifetimeConversion = false;
4317 // If we are initializing an rvalue reference, don't permit conversion
4318 // functions that return lvalues.
4319 if (!ConvTemplate && DeclType->isRValueReferenceType()) {
4320 const ReferenceType *RefType
4321 = Conv->getConversionType()->getAs<LValueReferenceType>();
4322 if (RefType && !RefType->getPointeeType()->isFunctionType())
4326 if (!ConvTemplate &&
4327 S.CompareReferenceRelationship(
4329 Conv->getConversionType().getNonReferenceType()
4330 .getUnqualifiedType(),
4331 DeclType.getNonReferenceType().getUnqualifiedType(),
4332 DerivedToBase, ObjCConversion, ObjCLifetimeConversion) ==
4333 Sema::Ref_Incompatible)
4336 // If the conversion function doesn't return a reference type,
4337 // it can't be considered for this conversion. An rvalue reference
4338 // is only acceptable if its referencee is a function type.
4340 const ReferenceType *RefType =
4341 Conv->getConversionType()->getAs<ReferenceType>();
4343 (!RefType->isLValueReferenceType() &&
4344 !RefType->getPointeeType()->isFunctionType()))
4349 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC,
4350 Init, DeclType, CandidateSet,
4351 /*AllowObjCConversionOnExplicit=*/false);
4353 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init,
4354 DeclType, CandidateSet,
4355 /*AllowObjCConversionOnExplicit=*/false);
4358 bool HadMultipleCandidates = (CandidateSet.size() > 1);
4360 OverloadCandidateSet::iterator Best;
4361 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) {
4363 // C++ [over.ics.ref]p1:
4365 // [...] If the parameter binds directly to the result of
4366 // applying a conversion function to the argument
4367 // expression, the implicit conversion sequence is a
4368 // user-defined conversion sequence (13.3.3.1.2), with the
4369 // second standard conversion sequence either an identity
4370 // conversion or, if the conversion function returns an
4371 // entity of a type that is a derived class of the parameter
4372 // type, a derived-to-base Conversion.
4373 if (!Best->FinalConversion.DirectBinding)
4376 ICS.setUserDefined();
4377 ICS.UserDefined.Before = Best->Conversions[0].Standard;
4378 ICS.UserDefined.After = Best->FinalConversion;
4379 ICS.UserDefined.HadMultipleCandidates = HadMultipleCandidates;
4380 ICS.UserDefined.ConversionFunction = Best->Function;
4381 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl;
4382 ICS.UserDefined.EllipsisConversion = false;
4383 assert(ICS.UserDefined.After.ReferenceBinding &&
4384 ICS.UserDefined.After.DirectBinding &&
4385 "Expected a direct reference binding!");
4390 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin();
4391 Cand != CandidateSet.end(); ++Cand)
4393 ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
4396 case OR_No_Viable_Function:
4398 // There was no suitable conversion, or we found a deleted
4399 // conversion; continue with other checks.
4403 llvm_unreachable("Invalid OverloadResult!");
4406 /// \brief Compute an implicit conversion sequence for reference
4408 static ImplicitConversionSequence
4409 TryReferenceInit(Sema &S, Expr *Init, QualType DeclType,
4410 SourceLocation DeclLoc,
4411 bool SuppressUserConversions,
4412 bool AllowExplicit) {
4413 assert(DeclType->isReferenceType() && "Reference init needs a reference");
4415 // Most paths end in a failed conversion.
4416 ImplicitConversionSequence ICS;
4417 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4419 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType();
4420 QualType T2 = Init->getType();
4422 // If the initializer is the address of an overloaded function, try
4423 // to resolve the overloaded function. If all goes well, T2 is the
4424 // type of the resulting function.
4425 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
4426 DeclAccessPair Found;
4427 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType,
4432 // Compute some basic properties of the types and the initializer.
4433 bool isRValRef = DeclType->isRValueReferenceType();
4434 bool DerivedToBase = false;
4435 bool ObjCConversion = false;
4436 bool ObjCLifetimeConversion = false;
4437 Expr::Classification InitCategory = Init->Classify(S.Context);
4438 Sema::ReferenceCompareResult RefRelationship
4439 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase,
4440 ObjCConversion, ObjCLifetimeConversion);
4443 // C++0x [dcl.init.ref]p5:
4444 // A reference to type "cv1 T1" is initialized by an expression
4445 // of type "cv2 T2" as follows:
4447 // -- If reference is an lvalue reference and the initializer expression
4449 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is
4450 // reference-compatible with "cv2 T2," or
4452 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here.
4453 if (InitCategory.isLValue() && RefRelationship == Sema::Ref_Compatible) {
4454 // C++ [over.ics.ref]p1:
4455 // When a parameter of reference type binds directly (8.5.3)
4456 // to an argument expression, the implicit conversion sequence
4457 // is the identity conversion, unless the argument expression
4458 // has a type that is a derived class of the parameter type,
4459 // in which case the implicit conversion sequence is a
4460 // derived-to-base Conversion (13.3.3.1).
4462 ICS.Standard.First = ICK_Identity;
4463 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base
4464 : ObjCConversion? ICK_Compatible_Conversion
4466 ICS.Standard.Third = ICK_Identity;
4467 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
4468 ICS.Standard.setToType(0, T2);
4469 ICS.Standard.setToType(1, T1);
4470 ICS.Standard.setToType(2, T1);
4471 ICS.Standard.ReferenceBinding = true;
4472 ICS.Standard.DirectBinding = true;
4473 ICS.Standard.IsLvalueReference = !isRValRef;
4474 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType();
4475 ICS.Standard.BindsToRvalue = false;
4476 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4477 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion;
4478 ICS.Standard.CopyConstructor = nullptr;
4479 ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
4481 // Nothing more to do: the inaccessibility/ambiguity check for
4482 // derived-to-base conversions is suppressed when we're
4483 // computing the implicit conversion sequence (C++
4484 // [over.best.ics]p2).
4488 // -- has a class type (i.e., T2 is a class type), where T1 is
4489 // not reference-related to T2, and can be implicitly
4490 // converted to an lvalue of type "cv3 T3," where "cv1 T1"
4491 // is reference-compatible with "cv3 T3" 92) (this
4492 // conversion is selected by enumerating the applicable
4493 // conversion functions (13.3.1.6) and choosing the best
4494 // one through overload resolution (13.3)),
4495 if (!SuppressUserConversions && T2->isRecordType() &&
4496 S.isCompleteType(DeclLoc, T2) &&
4497 RefRelationship == Sema::Ref_Incompatible) {
4498 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4499 Init, T2, /*AllowRvalues=*/false,
4505 // -- Otherwise, the reference shall be an lvalue reference to a
4506 // non-volatile const type (i.e., cv1 shall be const), or the reference
4507 // shall be an rvalue reference.
4508 if (!isRValRef && (!T1.isConstQualified() || T1.isVolatileQualified()))
4511 // -- If the initializer expression
4513 // -- is an xvalue, class prvalue, array prvalue or function
4514 // lvalue and "cv1 T1" is reference-compatible with "cv2 T2", or
4515 if (RefRelationship == Sema::Ref_Compatible &&
4516 (InitCategory.isXValue() ||
4517 (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) ||
4518 (InitCategory.isLValue() && T2->isFunctionType()))) {
4520 ICS.Standard.First = ICK_Identity;
4521 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base
4522 : ObjCConversion? ICK_Compatible_Conversion
4524 ICS.Standard.Third = ICK_Identity;
4525 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
4526 ICS.Standard.setToType(0, T2);
4527 ICS.Standard.setToType(1, T1);
4528 ICS.Standard.setToType(2, T1);
4529 ICS.Standard.ReferenceBinding = true;
4530 // In C++0x, this is always a direct binding. In C++98/03, it's a direct
4531 // binding unless we're binding to a class prvalue.
4532 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we
4533 // allow the use of rvalue references in C++98/03 for the benefit of
4534 // standard library implementors; therefore, we need the xvalue check here.
4535 ICS.Standard.DirectBinding =
4536 S.getLangOpts().CPlusPlus11 ||
4537 !(InitCategory.isPRValue() || T2->isRecordType());
4538 ICS.Standard.IsLvalueReference = !isRValRef;
4539 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType();
4540 ICS.Standard.BindsToRvalue = InitCategory.isRValue();
4541 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4542 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion;
4543 ICS.Standard.CopyConstructor = nullptr;
4544 ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
4548 // -- has a class type (i.e., T2 is a class type), where T1 is not
4549 // reference-related to T2, and can be implicitly converted to
4550 // an xvalue, class prvalue, or function lvalue of type
4551 // "cv3 T3", where "cv1 T1" is reference-compatible with
4554 // then the reference is bound to the value of the initializer
4555 // expression in the first case and to the result of the conversion
4556 // in the second case (or, in either case, to an appropriate base
4557 // class subobject).
4558 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4559 T2->isRecordType() && S.isCompleteType(DeclLoc, T2) &&
4560 FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4561 Init, T2, /*AllowRvalues=*/true,
4563 // In the second case, if the reference is an rvalue reference
4564 // and the second standard conversion sequence of the
4565 // user-defined conversion sequence includes an lvalue-to-rvalue
4566 // conversion, the program is ill-formed.
4567 if (ICS.isUserDefined() && isRValRef &&
4568 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue)
4569 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4574 // A temporary of function type cannot be created; don't even try.
4575 if (T1->isFunctionType())
4578 // -- Otherwise, a temporary of type "cv1 T1" is created and
4579 // initialized from the initializer expression using the
4580 // rules for a non-reference copy initialization (8.5). The
4581 // reference is then bound to the temporary. If T1 is
4582 // reference-related to T2, cv1 must be the same
4583 // cv-qualification as, or greater cv-qualification than,
4584 // cv2; otherwise, the program is ill-formed.
4585 if (RefRelationship == Sema::Ref_Related) {
4586 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then
4587 // we would be reference-compatible or reference-compatible with
4588 // added qualification. But that wasn't the case, so the reference
4589 // initialization fails.
4591 // Note that we only want to check address spaces and cvr-qualifiers here.
4592 // ObjC GC, lifetime and unaligned qualifiers aren't important.
4593 Qualifiers T1Quals = T1.getQualifiers();
4594 Qualifiers T2Quals = T2.getQualifiers();
4595 T1Quals.removeObjCGCAttr();
4596 T1Quals.removeObjCLifetime();
4597 T2Quals.removeObjCGCAttr();
4598 T2Quals.removeObjCLifetime();
4599 // MS compiler ignores __unaligned qualifier for references; do the same.
4600 T1Quals.removeUnaligned();
4601 T2Quals.removeUnaligned();
4602 if (!T1Quals.compatiblyIncludes(T2Quals))
4606 // If at least one of the types is a class type, the types are not
4607 // related, and we aren't allowed any user conversions, the
4608 // reference binding fails. This case is important for breaking
4609 // recursion, since TryImplicitConversion below will attempt to
4610 // create a temporary through the use of a copy constructor.
4611 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4612 (T1->isRecordType() || T2->isRecordType()))
4615 // If T1 is reference-related to T2 and the reference is an rvalue
4616 // reference, the initializer expression shall not be an lvalue.
4617 if (RefRelationship >= Sema::Ref_Related &&
4618 isRValRef && Init->Classify(S.Context).isLValue())
4621 // C++ [over.ics.ref]p2:
4622 // When a parameter of reference type is not bound directly to
4623 // an argument expression, the conversion sequence is the one
4624 // required to convert the argument expression to the
4625 // underlying type of the reference according to
4626 // 13.3.3.1. Conceptually, this conversion sequence corresponds
4627 // to copy-initializing a temporary of the underlying type with
4628 // the argument expression. Any difference in top-level
4629 // cv-qualification is subsumed by the initialization itself
4630 // and does not constitute a conversion.
4631 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions,
4632 /*AllowExplicit=*/false,
4633 /*InOverloadResolution=*/false,
4635 /*AllowObjCWritebackConversion=*/false,
4636 /*AllowObjCConversionOnExplicit=*/false);
4638 // Of course, that's still a reference binding.
4639 if (ICS.isStandard()) {
4640 ICS.Standard.ReferenceBinding = true;
4641 ICS.Standard.IsLvalueReference = !isRValRef;
4642 ICS.Standard.BindsToFunctionLvalue = false;
4643 ICS.Standard.BindsToRvalue = true;
4644 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4645 ICS.Standard.ObjCLifetimeConversionBinding = false;
4646 } else if (ICS.isUserDefined()) {
4647 const ReferenceType *LValRefType =
4648 ICS.UserDefined.ConversionFunction->getReturnType()
4649 ->getAs<LValueReferenceType>();
4651 // C++ [over.ics.ref]p3:
4652 // Except for an implicit object parameter, for which see 13.3.1, a
4653 // standard conversion sequence cannot be formed if it requires [...]
4654 // binding an rvalue reference to an lvalue other than a function
4656 // Note that the function case is not possible here.
4657 if (DeclType->isRValueReferenceType() && LValRefType) {
4658 // FIXME: This is the wrong BadConversionSequence. The problem is binding
4659 // an rvalue reference to a (non-function) lvalue, not binding an lvalue
4660 // reference to an rvalue!
4661 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, Init, DeclType);
4665 ICS.UserDefined.After.ReferenceBinding = true;
4666 ICS.UserDefined.After.IsLvalueReference = !isRValRef;
4667 ICS.UserDefined.After.BindsToFunctionLvalue = false;
4668 ICS.UserDefined.After.BindsToRvalue = !LValRefType;
4669 ICS.UserDefined.After.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4670 ICS.UserDefined.After.ObjCLifetimeConversionBinding = false;
4676 static ImplicitConversionSequence
4677 TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
4678 bool SuppressUserConversions,
4679 bool InOverloadResolution,
4680 bool AllowObjCWritebackConversion,
4681 bool AllowExplicit = false);
4683 /// TryListConversion - Try to copy-initialize a value of type ToType from the
4684 /// initializer list From.
4685 static ImplicitConversionSequence
4686 TryListConversion(Sema &S, InitListExpr *From, QualType ToType,
4687 bool SuppressUserConversions,
4688 bool InOverloadResolution,
4689 bool AllowObjCWritebackConversion) {
4690 // C++11 [over.ics.list]p1:
4691 // When an argument is an initializer list, it is not an expression and
4692 // special rules apply for converting it to a parameter type.
4694 ImplicitConversionSequence Result;
4695 Result.setBad(BadConversionSequence::no_conversion, From, ToType);
4697 // We need a complete type for what follows. Incomplete types can never be
4698 // initialized from init lists.
4699 if (!S.isCompleteType(From->getLocStart(), ToType))
4703 // If the parameter type is a class X and the initializer list has a single
4704 // element of type cv U, where U is X or a class derived from X, the
4705 // implicit conversion sequence is the one required to convert the element
4706 // to the parameter type.
4708 // Otherwise, if the parameter type is a character array [... ]
4709 // and the initializer list has a single element that is an
4710 // appropriately-typed string literal (8.5.2 [dcl.init.string]), the
4711 // implicit conversion sequence is the identity conversion.
4712 if (From->getNumInits() == 1) {
4713 if (ToType->isRecordType()) {
4714 QualType InitType = From->getInit(0)->getType();
4715 if (S.Context.hasSameUnqualifiedType(InitType, ToType) ||
4716 S.IsDerivedFrom(From->getLocStart(), InitType, ToType))
4717 return TryCopyInitialization(S, From->getInit(0), ToType,
4718 SuppressUserConversions,
4719 InOverloadResolution,
4720 AllowObjCWritebackConversion);
4722 // FIXME: Check the other conditions here: array of character type,
4723 // initializer is a string literal.
4724 if (ToType->isArrayType()) {
4725 InitializedEntity Entity =
4726 InitializedEntity::InitializeParameter(S.Context, ToType,
4727 /*Consumed=*/false);
4728 if (S.CanPerformCopyInitialization(Entity, From)) {
4729 Result.setStandard();
4730 Result.Standard.setAsIdentityConversion();
4731 Result.Standard.setFromType(ToType);
4732 Result.Standard.setAllToTypes(ToType);
4738 // C++14 [over.ics.list]p2: Otherwise, if the parameter type [...] (below).
4739 // C++11 [over.ics.list]p2:
4740 // If the parameter type is std::initializer_list<X> or "array of X" and
4741 // all the elements can be implicitly converted to X, the implicit
4742 // conversion sequence is the worst conversion necessary to convert an
4743 // element of the list to X.
4745 // C++14 [over.ics.list]p3:
4746 // Otherwise, if the parameter type is "array of N X", if the initializer
4747 // list has exactly N elements or if it has fewer than N elements and X is
4748 // default-constructible, and if all the elements of the initializer list
4749 // can be implicitly converted to X, the implicit conversion sequence is
4750 // the worst conversion necessary to convert an element of the list to X.
4752 // FIXME: We're missing a lot of these checks.
4753 bool toStdInitializerList = false;
4755 if (ToType->isArrayType())
4756 X = S.Context.getAsArrayType(ToType)->getElementType();
4758 toStdInitializerList = S.isStdInitializerList(ToType, &X);
4760 for (unsigned i = 0, e = From->getNumInits(); i < e; ++i) {
4761 Expr *Init = From->getInit(i);
4762 ImplicitConversionSequence ICS =
4763 TryCopyInitialization(S, Init, X, SuppressUserConversions,
4764 InOverloadResolution,
4765 AllowObjCWritebackConversion);
4766 // If a single element isn't convertible, fail.
4771 // Otherwise, look for the worst conversion.
4772 if (Result.isBad() ||
4773 CompareImplicitConversionSequences(S, From->getLocStart(), ICS,
4775 ImplicitConversionSequence::Worse)
4779 // For an empty list, we won't have computed any conversion sequence.
4780 // Introduce the identity conversion sequence.
4781 if (From->getNumInits() == 0) {
4782 Result.setStandard();
4783 Result.Standard.setAsIdentityConversion();
4784 Result.Standard.setFromType(ToType);
4785 Result.Standard.setAllToTypes(ToType);
4788 Result.setStdInitializerListElement(toStdInitializerList);
4792 // C++14 [over.ics.list]p4:
4793 // C++11 [over.ics.list]p3:
4794 // Otherwise, if the parameter is a non-aggregate class X and overload
4795 // resolution chooses a single best constructor [...] the implicit
4796 // conversion sequence is a user-defined conversion sequence. If multiple
4797 // constructors are viable but none is better than the others, the
4798 // implicit conversion sequence is a user-defined conversion sequence.
4799 if (ToType->isRecordType() && !ToType->isAggregateType()) {
4800 // This function can deal with initializer lists.
4801 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
4802 /*AllowExplicit=*/false,
4803 InOverloadResolution, /*CStyle=*/false,
4804 AllowObjCWritebackConversion,
4805 /*AllowObjCConversionOnExplicit=*/false);
4808 // C++14 [over.ics.list]p5:
4809 // C++11 [over.ics.list]p4:
4810 // Otherwise, if the parameter has an aggregate type which can be
4811 // initialized from the initializer list [...] the implicit conversion
4812 // sequence is a user-defined conversion sequence.
4813 if (ToType->isAggregateType()) {
4814 // Type is an aggregate, argument is an init list. At this point it comes
4815 // down to checking whether the initialization works.
4816 // FIXME: Find out whether this parameter is consumed or not.
4817 // FIXME: Expose SemaInit's aggregate initialization code so that we don't
4818 // need to call into the initialization code here; overload resolution
4819 // should not be doing that.
4820 InitializedEntity Entity =
4821 InitializedEntity::InitializeParameter(S.Context, ToType,
4822 /*Consumed=*/false);
4823 if (S.CanPerformCopyInitialization(Entity, From)) {
4824 Result.setUserDefined();
4825 Result.UserDefined.Before.setAsIdentityConversion();
4826 // Initializer lists don't have a type.
4827 Result.UserDefined.Before.setFromType(QualType());
4828 Result.UserDefined.Before.setAllToTypes(QualType());
4830 Result.UserDefined.After.setAsIdentityConversion();
4831 Result.UserDefined.After.setFromType(ToType);
4832 Result.UserDefined.After.setAllToTypes(ToType);
4833 Result.UserDefined.ConversionFunction = nullptr;
4838 // C++14 [over.ics.list]p6:
4839 // C++11 [over.ics.list]p5:
4840 // Otherwise, if the parameter is a reference, see 13.3.3.1.4.
4841 if (ToType->isReferenceType()) {
4842 // The standard is notoriously unclear here, since 13.3.3.1.4 doesn't
4843 // mention initializer lists in any way. So we go by what list-
4844 // initialization would do and try to extrapolate from that.
4846 QualType T1 = ToType->getAs<ReferenceType>()->getPointeeType();
4848 // If the initializer list has a single element that is reference-related
4849 // to the parameter type, we initialize the reference from that.
4850 if (From->getNumInits() == 1) {
4851 Expr *Init = From->getInit(0);
4853 QualType T2 = Init->getType();
4855 // If the initializer is the address of an overloaded function, try
4856 // to resolve the overloaded function. If all goes well, T2 is the
4857 // type of the resulting function.
4858 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
4859 DeclAccessPair Found;
4860 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(
4861 Init, ToType, false, Found))
4865 // Compute some basic properties of the types and the initializer.
4866 bool dummy1 = false;
4867 bool dummy2 = false;
4868 bool dummy3 = false;
4869 Sema::ReferenceCompareResult RefRelationship
4870 = S.CompareReferenceRelationship(From->getLocStart(), T1, T2, dummy1,
4873 if (RefRelationship >= Sema::Ref_Related) {
4874 return TryReferenceInit(S, Init, ToType, /*FIXME*/From->getLocStart(),
4875 SuppressUserConversions,
4876 /*AllowExplicit=*/false);
4880 // Otherwise, we bind the reference to a temporary created from the
4881 // initializer list.
4882 Result = TryListConversion(S, From, T1, SuppressUserConversions,
4883 InOverloadResolution,
4884 AllowObjCWritebackConversion);
4885 if (Result.isFailure())
4887 assert(!Result.isEllipsis() &&
4888 "Sub-initialization cannot result in ellipsis conversion.");
4890 // Can we even bind to a temporary?
4891 if (ToType->isRValueReferenceType() ||
4892 (T1.isConstQualified() && !T1.isVolatileQualified())) {
4893 StandardConversionSequence &SCS = Result.isStandard() ? Result.Standard :
4894 Result.UserDefined.After;
4895 SCS.ReferenceBinding = true;
4896 SCS.IsLvalueReference = ToType->isLValueReferenceType();
4897 SCS.BindsToRvalue = true;
4898 SCS.BindsToFunctionLvalue = false;
4899 SCS.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4900 SCS.ObjCLifetimeConversionBinding = false;
4902 Result.setBad(BadConversionSequence::lvalue_ref_to_rvalue,
4907 // C++14 [over.ics.list]p7:
4908 // C++11 [over.ics.list]p6:
4909 // Otherwise, if the parameter type is not a class:
4910 if (!ToType->isRecordType()) {
4911 // - if the initializer list has one element that is not itself an
4912 // initializer list, the implicit conversion sequence is the one
4913 // required to convert the element to the parameter type.
4914 unsigned NumInits = From->getNumInits();
4915 if (NumInits == 1 && !isa<InitListExpr>(From->getInit(0)))
4916 Result = TryCopyInitialization(S, From->getInit(0), ToType,
4917 SuppressUserConversions,
4918 InOverloadResolution,
4919 AllowObjCWritebackConversion);
4920 // - if the initializer list has no elements, the implicit conversion
4921 // sequence is the identity conversion.
4922 else if (NumInits == 0) {
4923 Result.setStandard();
4924 Result.Standard.setAsIdentityConversion();
4925 Result.Standard.setFromType(ToType);
4926 Result.Standard.setAllToTypes(ToType);
4931 // C++14 [over.ics.list]p8:
4932 // C++11 [over.ics.list]p7:
4933 // In all cases other than those enumerated above, no conversion is possible
4937 /// TryCopyInitialization - Try to copy-initialize a value of type
4938 /// ToType from the expression From. Return the implicit conversion
4939 /// sequence required to pass this argument, which may be a bad
4940 /// conversion sequence (meaning that the argument cannot be passed to
4941 /// a parameter of this type). If @p SuppressUserConversions, then we
4942 /// do not permit any user-defined conversion sequences.
4943 static ImplicitConversionSequence
4944 TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
4945 bool SuppressUserConversions,
4946 bool InOverloadResolution,
4947 bool AllowObjCWritebackConversion,
4948 bool AllowExplicit) {
4949 if (InitListExpr *FromInitList = dyn_cast<InitListExpr>(From))
4950 return TryListConversion(S, FromInitList, ToType, SuppressUserConversions,
4951 InOverloadResolution,AllowObjCWritebackConversion);
4953 if (ToType->isReferenceType())
4954 return TryReferenceInit(S, From, ToType,
4955 /*FIXME:*/From->getLocStart(),
4956 SuppressUserConversions,
4959 return TryImplicitConversion(S, From, ToType,
4960 SuppressUserConversions,
4961 /*AllowExplicit=*/false,
4962 InOverloadResolution,
4964 AllowObjCWritebackConversion,
4965 /*AllowObjCConversionOnExplicit=*/false);
4968 static bool TryCopyInitialization(const CanQualType FromQTy,
4969 const CanQualType ToQTy,
4972 ExprValueKind FromVK) {
4973 OpaqueValueExpr TmpExpr(Loc, FromQTy, FromVK);
4974 ImplicitConversionSequence ICS =
4975 TryCopyInitialization(S, &TmpExpr, ToQTy, true, true, false);
4977 return !ICS.isBad();
4980 /// TryObjectArgumentInitialization - Try to initialize the object
4981 /// parameter of the given member function (@c Method) from the
4982 /// expression @p From.
4983 static ImplicitConversionSequence
4984 TryObjectArgumentInitialization(Sema &S, SourceLocation Loc, QualType FromType,
4985 Expr::Classification FromClassification,
4986 CXXMethodDecl *Method,
4987 CXXRecordDecl *ActingContext) {
4988 QualType ClassType = S.Context.getTypeDeclType(ActingContext);
4989 // [class.dtor]p2: A destructor can be invoked for a const, volatile or
4990 // const volatile object.
4991 unsigned Quals = isa<CXXDestructorDecl>(Method) ?
4992 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers();
4993 QualType ImplicitParamType = S.Context.getCVRQualifiedType(ClassType, Quals);
4995 // Set up the conversion sequence as a "bad" conversion, to allow us
4997 ImplicitConversionSequence ICS;
4999 // We need to have an object of class type.
5000 if (const PointerType *PT = FromType->getAs<PointerType>()) {
5001 FromType = PT->getPointeeType();
5003 // When we had a pointer, it's implicitly dereferenced, so we
5004 // better have an lvalue.
5005 assert(FromClassification.isLValue());
5008 assert(FromType->isRecordType());
5010 // C++0x [over.match.funcs]p4:
5011 // For non-static member functions, the type of the implicit object
5014 // - "lvalue reference to cv X" for functions declared without a
5015 // ref-qualifier or with the & ref-qualifier
5016 // - "rvalue reference to cv X" for functions declared with the &&
5019 // where X is the class of which the function is a member and cv is the
5020 // cv-qualification on the member function declaration.
5022 // However, when finding an implicit conversion sequence for the argument, we
5023 // are not allowed to perform user-defined conversions
5024 // (C++ [over.match.funcs]p5). We perform a simplified version of
5025 // reference binding here, that allows class rvalues to bind to
5026 // non-constant references.
5028 // First check the qualifiers.
5029 QualType FromTypeCanon = S.Context.getCanonicalType(FromType);
5030 if (ImplicitParamType.getCVRQualifiers()
5031 != FromTypeCanon.getLocalCVRQualifiers() &&
5032 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) {
5033 ICS.setBad(BadConversionSequence::bad_qualifiers,
5034 FromType, ImplicitParamType);
5038 // Check that we have either the same type or a derived type. It
5039 // affects the conversion rank.
5040 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType);
5041 ImplicitConversionKind SecondKind;
5042 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) {
5043 SecondKind = ICK_Identity;
5044 } else if (S.IsDerivedFrom(Loc, FromType, ClassType))
5045 SecondKind = ICK_Derived_To_Base;
5047 ICS.setBad(BadConversionSequence::unrelated_class,
5048 FromType, ImplicitParamType);
5052 // Check the ref-qualifier.
5053 switch (Method->getRefQualifier()) {
5055 // Do nothing; we don't care about lvalueness or rvalueness.
5059 if (!FromClassification.isLValue() && Quals != Qualifiers::Const) {
5060 // non-const lvalue reference cannot bind to an rvalue
5061 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType,
5068 if (!FromClassification.isRValue()) {
5069 // rvalue reference cannot bind to an lvalue
5070 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType,
5077 // Success. Mark this as a reference binding.
5079 ICS.Standard.setAsIdentityConversion();
5080 ICS.Standard.Second = SecondKind;
5081 ICS.Standard.setFromType(FromType);
5082 ICS.Standard.setAllToTypes(ImplicitParamType);
5083 ICS.Standard.ReferenceBinding = true;
5084 ICS.Standard.DirectBinding = true;
5085 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue;
5086 ICS.Standard.BindsToFunctionLvalue = false;
5087 ICS.Standard.BindsToRvalue = FromClassification.isRValue();
5088 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier
5089 = (Method->getRefQualifier() == RQ_None);
5093 /// PerformObjectArgumentInitialization - Perform initialization of
5094 /// the implicit object parameter for the given Method with the given
5097 Sema::PerformObjectArgumentInitialization(Expr *From,
5098 NestedNameSpecifier *Qualifier,
5099 NamedDecl *FoundDecl,
5100 CXXMethodDecl *Method) {
5101 QualType FromRecordType, DestType;
5102 QualType ImplicitParamRecordType =
5103 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType();
5105 Expr::Classification FromClassification;
5106 if (const PointerType *PT = From->getType()->getAs<PointerType>()) {
5107 FromRecordType = PT->getPointeeType();
5108 DestType = Method->getThisType(Context);
5109 FromClassification = Expr::Classification::makeSimpleLValue();
5111 FromRecordType = From->getType();
5112 DestType = ImplicitParamRecordType;
5113 FromClassification = From->Classify(Context);
5116 // Note that we always use the true parent context when performing
5117 // the actual argument initialization.
5118 ImplicitConversionSequence ICS = TryObjectArgumentInitialization(
5119 *this, From->getLocStart(), From->getType(), FromClassification, Method,
5120 Method->getParent());
5122 if (ICS.Bad.Kind == BadConversionSequence::bad_qualifiers) {
5123 Qualifiers FromQs = FromRecordType.getQualifiers();
5124 Qualifiers ToQs = DestType.getQualifiers();
5125 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers();
5127 Diag(From->getLocStart(),
5128 diag::err_member_function_call_bad_cvr)
5129 << Method->getDeclName() << FromRecordType << (CVR - 1)
5130 << From->getSourceRange();
5131 Diag(Method->getLocation(), diag::note_previous_decl)
5132 << Method->getDeclName();
5137 return Diag(From->getLocStart(),
5138 diag::err_implicit_object_parameter_init)
5139 << ImplicitParamRecordType << FromRecordType << From->getSourceRange();
5142 if (ICS.Standard.Second == ICK_Derived_To_Base) {
5143 ExprResult FromRes =
5144 PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method);
5145 if (FromRes.isInvalid())
5147 From = FromRes.get();
5150 if (!Context.hasSameType(From->getType(), DestType))
5151 From = ImpCastExprToType(From, DestType, CK_NoOp,
5152 From->getValueKind()).get();
5156 /// TryContextuallyConvertToBool - Attempt to contextually convert the
5157 /// expression From to bool (C++0x [conv]p3).
5158 static ImplicitConversionSequence
5159 TryContextuallyConvertToBool(Sema &S, Expr *From) {
5160 return TryImplicitConversion(S, From, S.Context.BoolTy,
5161 /*SuppressUserConversions=*/false,
5162 /*AllowExplicit=*/true,
5163 /*InOverloadResolution=*/false,
5165 /*AllowObjCWritebackConversion=*/false,
5166 /*AllowObjCConversionOnExplicit=*/false);
5169 /// PerformContextuallyConvertToBool - Perform a contextual conversion
5170 /// of the expression From to bool (C++0x [conv]p3).
5171 ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) {
5172 if (checkPlaceholderForOverload(*this, From))
5175 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From);
5177 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting);
5179 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy))
5180 return Diag(From->getLocStart(),
5181 diag::err_typecheck_bool_condition)
5182 << From->getType() << From->getSourceRange();
5186 /// Check that the specified conversion is permitted in a converted constant
5187 /// expression, according to C++11 [expr.const]p3. Return true if the conversion
5189 static bool CheckConvertedConstantConversions(Sema &S,
5190 StandardConversionSequence &SCS) {
5191 // Since we know that the target type is an integral or unscoped enumeration
5192 // type, most conversion kinds are impossible. All possible First and Third
5193 // conversions are fine.
5194 switch (SCS.Second) {
5196 case ICK_Function_Conversion:
5197 case ICK_Integral_Promotion:
5198 case ICK_Integral_Conversion: // Narrowing conversions are checked elsewhere.
5199 case ICK_Zero_Queue_Conversion:
5202 case ICK_Boolean_Conversion:
5203 // Conversion from an integral or unscoped enumeration type to bool is
5204 // classified as ICK_Boolean_Conversion, but it's also arguably an integral
5205 // conversion, so we allow it in a converted constant expression.
5207 // FIXME: Per core issue 1407, we should not allow this, but that breaks
5208 // a lot of popular code. We should at least add a warning for this
5209 // (non-conforming) extension.
5210 return SCS.getFromType()->isIntegralOrUnscopedEnumerationType() &&
5211 SCS.getToType(2)->isBooleanType();
5213 case ICK_Pointer_Conversion:
5214 case ICK_Pointer_Member:
5215 // C++1z: null pointer conversions and null member pointer conversions are
5216 // only permitted if the source type is std::nullptr_t.
5217 return SCS.getFromType()->isNullPtrType();
5219 case ICK_Floating_Promotion:
5220 case ICK_Complex_Promotion:
5221 case ICK_Floating_Conversion:
5222 case ICK_Complex_Conversion:
5223 case ICK_Floating_Integral:
5224 case ICK_Compatible_Conversion:
5225 case ICK_Derived_To_Base:
5226 case ICK_Vector_Conversion:
5227 case ICK_Vector_Splat:
5228 case ICK_Complex_Real:
5229 case ICK_Block_Pointer_Conversion:
5230 case ICK_TransparentUnionConversion:
5231 case ICK_Writeback_Conversion:
5232 case ICK_Zero_Event_Conversion:
5233 case ICK_C_Only_Conversion:
5234 case ICK_Incompatible_Pointer_Conversion:
5237 case ICK_Lvalue_To_Rvalue:
5238 case ICK_Array_To_Pointer:
5239 case ICK_Function_To_Pointer:
5240 llvm_unreachable("found a first conversion kind in Second");
5242 case ICK_Qualification:
5243 llvm_unreachable("found a third conversion kind in Second");
5245 case ICK_Num_Conversion_Kinds:
5249 llvm_unreachable("unknown conversion kind");
5252 /// CheckConvertedConstantExpression - Check that the expression From is a
5253 /// converted constant expression of type T, perform the conversion and produce
5254 /// the converted expression, per C++11 [expr.const]p3.
5255 static ExprResult CheckConvertedConstantExpression(Sema &S, Expr *From,
5256 QualType T, APValue &Value,
5259 assert(S.getLangOpts().CPlusPlus11 &&
5260 "converted constant expression outside C++11");
5262 if (checkPlaceholderForOverload(S, From))
5265 // C++1z [expr.const]p3:
5266 // A converted constant expression of type T is an expression,
5267 // implicitly converted to type T, where the converted
5268 // expression is a constant expression and the implicit conversion
5269 // sequence contains only [... list of conversions ...].
5270 // C++1z [stmt.if]p2:
5271 // If the if statement is of the form if constexpr, the value of the
5272 // condition shall be a contextually converted constant expression of type
5274 ImplicitConversionSequence ICS =
5275 CCE == Sema::CCEK_ConstexprIf
5276 ? TryContextuallyConvertToBool(S, From)
5277 : TryCopyInitialization(S, From, T,
5278 /*SuppressUserConversions=*/false,
5279 /*InOverloadResolution=*/false,
5280 /*AllowObjcWritebackConversion=*/false,
5281 /*AllowExplicit=*/false);
5282 StandardConversionSequence *SCS = nullptr;
5283 switch (ICS.getKind()) {
5284 case ImplicitConversionSequence::StandardConversion:
5285 SCS = &ICS.Standard;
5287 case ImplicitConversionSequence::UserDefinedConversion:
5288 // We are converting to a non-class type, so the Before sequence
5290 SCS = &ICS.UserDefined.After;
5292 case ImplicitConversionSequence::AmbiguousConversion:
5293 case ImplicitConversionSequence::BadConversion:
5294 if (!S.DiagnoseMultipleUserDefinedConversion(From, T))
5295 return S.Diag(From->getLocStart(),
5296 diag::err_typecheck_converted_constant_expression)
5297 << From->getType() << From->getSourceRange() << T;
5300 case ImplicitConversionSequence::EllipsisConversion:
5301 llvm_unreachable("ellipsis conversion in converted constant expression");
5304 // Check that we would only use permitted conversions.
5305 if (!CheckConvertedConstantConversions(S, *SCS)) {
5306 return S.Diag(From->getLocStart(),
5307 diag::err_typecheck_converted_constant_expression_disallowed)
5308 << From->getType() << From->getSourceRange() << T;
5310 // [...] and where the reference binding (if any) binds directly.
5311 if (SCS->ReferenceBinding && !SCS->DirectBinding) {
5312 return S.Diag(From->getLocStart(),
5313 diag::err_typecheck_converted_constant_expression_indirect)
5314 << From->getType() << From->getSourceRange() << T;
5318 S.PerformImplicitConversion(From, T, ICS, Sema::AA_Converting);
5319 if (Result.isInvalid())
5322 // Check for a narrowing implicit conversion.
5323 APValue PreNarrowingValue;
5324 QualType PreNarrowingType;
5325 switch (SCS->getNarrowingKind(S.Context, Result.get(), PreNarrowingValue,
5326 PreNarrowingType)) {
5327 case NK_Dependent_Narrowing:
5328 // Implicit conversion to a narrower type, but the expression is
5329 // value-dependent so we can't tell whether it's actually narrowing.
5330 case NK_Variable_Narrowing:
5331 // Implicit conversion to a narrower type, and the value is not a constant
5332 // expression. We'll diagnose this in a moment.
5333 case NK_Not_Narrowing:
5336 case NK_Constant_Narrowing:
5337 S.Diag(From->getLocStart(), diag::ext_cce_narrowing)
5338 << CCE << /*Constant*/1
5339 << PreNarrowingValue.getAsString(S.Context, PreNarrowingType) << T;
5342 case NK_Type_Narrowing:
5343 S.Diag(From->getLocStart(), diag::ext_cce_narrowing)
5344 << CCE << /*Constant*/0 << From->getType() << T;
5348 if (Result.get()->isValueDependent()) {
5353 // Check the expression is a constant expression.
5354 SmallVector<PartialDiagnosticAt, 8> Notes;
5355 Expr::EvalResult Eval;
5358 if ((T->isReferenceType()
5359 ? !Result.get()->EvaluateAsLValue(Eval, S.Context)
5360 : !Result.get()->EvaluateAsRValue(Eval, S.Context)) ||
5361 (RequireInt && !Eval.Val.isInt())) {
5362 // The expression can't be folded, so we can't keep it at this position in
5364 Result = ExprError();
5368 if (Notes.empty()) {
5369 // It's a constant expression.
5374 // It's not a constant expression. Produce an appropriate diagnostic.
5375 if (Notes.size() == 1 &&
5376 Notes[0].second.getDiagID() == diag::note_invalid_subexpr_in_const_expr)
5377 S.Diag(Notes[0].first, diag::err_expr_not_cce) << CCE;
5379 S.Diag(From->getLocStart(), diag::err_expr_not_cce)
5380 << CCE << From->getSourceRange();
5381 for (unsigned I = 0; I < Notes.size(); ++I)
5382 S.Diag(Notes[I].first, Notes[I].second);
5387 ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5388 APValue &Value, CCEKind CCE) {
5389 return ::CheckConvertedConstantExpression(*this, From, T, Value, CCE, false);
5392 ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5393 llvm::APSInt &Value,
5395 assert(T->isIntegralOrEnumerationType() && "unexpected converted const type");
5398 auto R = ::CheckConvertedConstantExpression(*this, From, T, V, CCE, true);
5399 if (!R.isInvalid() && !R.get()->isValueDependent())
5405 /// dropPointerConversions - If the given standard conversion sequence
5406 /// involves any pointer conversions, remove them. This may change
5407 /// the result type of the conversion sequence.
5408 static void dropPointerConversion(StandardConversionSequence &SCS) {
5409 if (SCS.Second == ICK_Pointer_Conversion) {
5410 SCS.Second = ICK_Identity;
5411 SCS.Third = ICK_Identity;
5412 SCS.ToTypePtrs[2] = SCS.ToTypePtrs[1] = SCS.ToTypePtrs[0];
5416 /// TryContextuallyConvertToObjCPointer - Attempt to contextually
5417 /// convert the expression From to an Objective-C pointer type.
5418 static ImplicitConversionSequence
5419 TryContextuallyConvertToObjCPointer(Sema &S, Expr *From) {
5420 // Do an implicit conversion to 'id'.
5421 QualType Ty = S.Context.getObjCIdType();
5422 ImplicitConversionSequence ICS
5423 = TryImplicitConversion(S, From, Ty,
5424 // FIXME: Are these flags correct?
5425 /*SuppressUserConversions=*/false,
5426 /*AllowExplicit=*/true,
5427 /*InOverloadResolution=*/false,
5429 /*AllowObjCWritebackConversion=*/false,
5430 /*AllowObjCConversionOnExplicit=*/true);
5432 // Strip off any final conversions to 'id'.
5433 switch (ICS.getKind()) {
5434 case ImplicitConversionSequence::BadConversion:
5435 case ImplicitConversionSequence::AmbiguousConversion:
5436 case ImplicitConversionSequence::EllipsisConversion:
5439 case ImplicitConversionSequence::UserDefinedConversion:
5440 dropPointerConversion(ICS.UserDefined.After);
5443 case ImplicitConversionSequence::StandardConversion:
5444 dropPointerConversion(ICS.Standard);
5451 /// PerformContextuallyConvertToObjCPointer - Perform a contextual
5452 /// conversion of the expression From to an Objective-C pointer type.
5453 /// Returns a valid but null ExprResult if no conversion sequence exists.
5454 ExprResult Sema::PerformContextuallyConvertToObjCPointer(Expr *From) {
5455 if (checkPlaceholderForOverload(*this, From))
5458 QualType Ty = Context.getObjCIdType();
5459 ImplicitConversionSequence ICS =
5460 TryContextuallyConvertToObjCPointer(*this, From);
5462 return PerformImplicitConversion(From, Ty, ICS, AA_Converting);
5463 return ExprResult();
5466 /// Determine whether the provided type is an integral type, or an enumeration
5467 /// type of a permitted flavor.
5468 bool Sema::ICEConvertDiagnoser::match(QualType T) {
5469 return AllowScopedEnumerations ? T->isIntegralOrEnumerationType()
5470 : T->isIntegralOrUnscopedEnumerationType();
5474 diagnoseAmbiguousConversion(Sema &SemaRef, SourceLocation Loc, Expr *From,
5475 Sema::ContextualImplicitConverter &Converter,
5476 QualType T, UnresolvedSetImpl &ViableConversions) {
5478 if (Converter.Suppress)
5481 Converter.diagnoseAmbiguous(SemaRef, Loc, T) << From->getSourceRange();
5482 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5483 CXXConversionDecl *Conv =
5484 cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl());
5485 QualType ConvTy = Conv->getConversionType().getNonReferenceType();
5486 Converter.noteAmbiguous(SemaRef, Conv, ConvTy);
5492 diagnoseNoViableConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5493 Sema::ContextualImplicitConverter &Converter,
5494 QualType T, bool HadMultipleCandidates,
5495 UnresolvedSetImpl &ExplicitConversions) {
5496 if (ExplicitConversions.size() == 1 && !Converter.Suppress) {
5497 DeclAccessPair Found = ExplicitConversions[0];
5498 CXXConversionDecl *Conversion =
5499 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5501 // The user probably meant to invoke the given explicit
5502 // conversion; use it.
5503 QualType ConvTy = Conversion->getConversionType().getNonReferenceType();
5504 std::string TypeStr;
5505 ConvTy.getAsStringInternal(TypeStr, SemaRef.getPrintingPolicy());
5507 Converter.diagnoseExplicitConv(SemaRef, Loc, T, ConvTy)
5508 << FixItHint::CreateInsertion(From->getLocStart(),
5509 "static_cast<" + TypeStr + ">(")
5510 << FixItHint::CreateInsertion(
5511 SemaRef.getLocForEndOfToken(From->getLocEnd()), ")");
5512 Converter.noteExplicitConv(SemaRef, Conversion, ConvTy);
5514 // If we aren't in a SFINAE context, build a call to the
5515 // explicit conversion function.
5516 if (SemaRef.isSFINAEContext())
5519 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5520 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5521 HadMultipleCandidates);
5522 if (Result.isInvalid())
5524 // Record usage of conversion in an implicit cast.
5525 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5526 CK_UserDefinedConversion, Result.get(),
5527 nullptr, Result.get()->getValueKind());
5532 static bool recordConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5533 Sema::ContextualImplicitConverter &Converter,
5534 QualType T, bool HadMultipleCandidates,
5535 DeclAccessPair &Found) {
5536 CXXConversionDecl *Conversion =
5537 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5538 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5540 QualType ToType = Conversion->getConversionType().getNonReferenceType();
5541 if (!Converter.SuppressConversion) {
5542 if (SemaRef.isSFINAEContext())
5545 Converter.diagnoseConversion(SemaRef, Loc, T, ToType)
5546 << From->getSourceRange();
5549 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5550 HadMultipleCandidates);
5551 if (Result.isInvalid())
5553 // Record usage of conversion in an implicit cast.
5554 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5555 CK_UserDefinedConversion, Result.get(),
5556 nullptr, Result.get()->getValueKind());
5560 static ExprResult finishContextualImplicitConversion(
5561 Sema &SemaRef, SourceLocation Loc, Expr *From,
5562 Sema::ContextualImplicitConverter &Converter) {
5563 if (!Converter.match(From->getType()) && !Converter.Suppress)
5564 Converter.diagnoseNoMatch(SemaRef, Loc, From->getType())
5565 << From->getSourceRange();
5567 return SemaRef.DefaultLvalueConversion(From);
5571 collectViableConversionCandidates(Sema &SemaRef, Expr *From, QualType ToType,
5572 UnresolvedSetImpl &ViableConversions,
5573 OverloadCandidateSet &CandidateSet) {
5574 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5575 DeclAccessPair FoundDecl = ViableConversions[I];
5576 NamedDecl *D = FoundDecl.getDecl();
5577 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
5578 if (isa<UsingShadowDecl>(D))
5579 D = cast<UsingShadowDecl>(D)->getTargetDecl();
5581 CXXConversionDecl *Conv;
5582 FunctionTemplateDecl *ConvTemplate;
5583 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
5584 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5586 Conv = cast<CXXConversionDecl>(D);
5589 SemaRef.AddTemplateConversionCandidate(
5590 ConvTemplate, FoundDecl, ActingContext, From, ToType, CandidateSet,
5591 /*AllowObjCConversionOnExplicit=*/false);
5593 SemaRef.AddConversionCandidate(Conv, FoundDecl, ActingContext, From,
5594 ToType, CandidateSet,
5595 /*AllowObjCConversionOnExplicit=*/false);
5599 /// \brief Attempt to convert the given expression to a type which is accepted
5600 /// by the given converter.
5602 /// This routine will attempt to convert an expression of class type to a
5603 /// type accepted by the specified converter. In C++11 and before, the class
5604 /// must have a single non-explicit conversion function converting to a matching
5605 /// type. In C++1y, there can be multiple such conversion functions, but only
5606 /// one target type.
5608 /// \param Loc The source location of the construct that requires the
5611 /// \param From The expression we're converting from.
5613 /// \param Converter Used to control and diagnose the conversion process.
5615 /// \returns The expression, converted to an integral or enumeration type if
5617 ExprResult Sema::PerformContextualImplicitConversion(
5618 SourceLocation Loc, Expr *From, ContextualImplicitConverter &Converter) {
5619 // We can't perform any more checking for type-dependent expressions.
5620 if (From->isTypeDependent())
5623 // Process placeholders immediately.
5624 if (From->hasPlaceholderType()) {
5625 ExprResult result = CheckPlaceholderExpr(From);
5626 if (result.isInvalid())
5628 From = result.get();
5631 // If the expression already has a matching type, we're golden.
5632 QualType T = From->getType();
5633 if (Converter.match(T))
5634 return DefaultLvalueConversion(From);
5636 // FIXME: Check for missing '()' if T is a function type?
5638 // We can only perform contextual implicit conversions on objects of class
5640 const RecordType *RecordTy = T->getAs<RecordType>();
5641 if (!RecordTy || !getLangOpts().CPlusPlus) {
5642 if (!Converter.Suppress)
5643 Converter.diagnoseNoMatch(*this, Loc, T) << From->getSourceRange();
5647 // We must have a complete class type.
5648 struct TypeDiagnoserPartialDiag : TypeDiagnoser {
5649 ContextualImplicitConverter &Converter;
5652 TypeDiagnoserPartialDiag(ContextualImplicitConverter &Converter, Expr *From)
5653 : Converter(Converter), From(From) {}
5655 void diagnose(Sema &S, SourceLocation Loc, QualType T) override {
5656 Converter.diagnoseIncomplete(S, Loc, T) << From->getSourceRange();
5658 } IncompleteDiagnoser(Converter, From);
5660 if (Converter.Suppress ? !isCompleteType(Loc, T)
5661 : RequireCompleteType(Loc, T, IncompleteDiagnoser))
5664 // Look for a conversion to an integral or enumeration type.
5666 ViableConversions; // These are *potentially* viable in C++1y.
5667 UnresolvedSet<4> ExplicitConversions;
5668 const auto &Conversions =
5669 cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions();
5671 bool HadMultipleCandidates =
5672 (std::distance(Conversions.begin(), Conversions.end()) > 1);
5674 // To check that there is only one target type, in C++1y:
5676 bool HasUniqueTargetType = true;
5678 // Collect explicit or viable (potentially in C++1y) conversions.
5679 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
5680 NamedDecl *D = (*I)->getUnderlyingDecl();
5681 CXXConversionDecl *Conversion;
5682 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
5684 if (getLangOpts().CPlusPlus14)
5685 Conversion = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5687 continue; // C++11 does not consider conversion operator templates(?).
5689 Conversion = cast<CXXConversionDecl>(D);
5691 assert((!ConvTemplate || getLangOpts().CPlusPlus14) &&
5692 "Conversion operator templates are considered potentially "
5695 QualType CurToType = Conversion->getConversionType().getNonReferenceType();
5696 if (Converter.match(CurToType) || ConvTemplate) {
5698 if (Conversion->isExplicit()) {
5699 // FIXME: For C++1y, do we need this restriction?
5700 // cf. diagnoseNoViableConversion()
5702 ExplicitConversions.addDecl(I.getDecl(), I.getAccess());
5704 if (!ConvTemplate && getLangOpts().CPlusPlus14) {
5705 if (ToType.isNull())
5706 ToType = CurToType.getUnqualifiedType();
5707 else if (HasUniqueTargetType &&
5708 (CurToType.getUnqualifiedType() != ToType))
5709 HasUniqueTargetType = false;
5711 ViableConversions.addDecl(I.getDecl(), I.getAccess());
5716 if (getLangOpts().CPlusPlus14) {
5718 // ... An expression e of class type E appearing in such a context
5719 // is said to be contextually implicitly converted to a specified
5720 // type T and is well-formed if and only if e can be implicitly
5721 // converted to a type T that is determined as follows: E is searched
5722 // for conversion functions whose return type is cv T or reference to
5723 // cv T such that T is allowed by the context. There shall be
5724 // exactly one such T.
5726 // If no unique T is found:
5727 if (ToType.isNull()) {
5728 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5729 HadMultipleCandidates,
5730 ExplicitConversions))
5732 return finishContextualImplicitConversion(*this, Loc, From, Converter);
5735 // If more than one unique Ts are found:
5736 if (!HasUniqueTargetType)
5737 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5740 // If one unique T is found:
5741 // First, build a candidate set from the previously recorded
5742 // potentially viable conversions.
5743 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Normal);
5744 collectViableConversionCandidates(*this, From, ToType, ViableConversions,
5747 // Then, perform overload resolution over the candidate set.
5748 OverloadCandidateSet::iterator Best;
5749 switch (CandidateSet.BestViableFunction(*this, Loc, Best)) {
5751 // Apply this conversion.
5752 DeclAccessPair Found =
5753 DeclAccessPair::make(Best->Function, Best->FoundDecl.getAccess());
5754 if (recordConversion(*this, Loc, From, Converter, T,
5755 HadMultipleCandidates, Found))
5760 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5762 case OR_No_Viable_Function:
5763 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5764 HadMultipleCandidates,
5765 ExplicitConversions))
5767 // fall through 'OR_Deleted' case.
5769 // We'll complain below about a non-integral condition type.
5773 switch (ViableConversions.size()) {
5775 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5776 HadMultipleCandidates,
5777 ExplicitConversions))
5780 // We'll complain below about a non-integral condition type.
5784 // Apply this conversion.
5785 DeclAccessPair Found = ViableConversions[0];
5786 if (recordConversion(*this, Loc, From, Converter, T,
5787 HadMultipleCandidates, Found))
5792 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5797 return finishContextualImplicitConversion(*this, Loc, From, Converter);
5800 /// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is
5801 /// an acceptable non-member overloaded operator for a call whose
5802 /// arguments have types T1 (and, if non-empty, T2). This routine
5803 /// implements the check in C++ [over.match.oper]p3b2 concerning
5804 /// enumeration types.
5805 static bool IsAcceptableNonMemberOperatorCandidate(ASTContext &Context,
5807 ArrayRef<Expr *> Args) {
5808 QualType T1 = Args[0]->getType();
5809 QualType T2 = Args.size() > 1 ? Args[1]->getType() : QualType();
5811 if (T1->isDependentType() || (!T2.isNull() && T2->isDependentType()))
5814 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType()))
5817 const FunctionProtoType *Proto = Fn->getType()->getAs<FunctionProtoType>();
5818 if (Proto->getNumParams() < 1)
5821 if (T1->isEnumeralType()) {
5822 QualType ArgType = Proto->getParamType(0).getNonReferenceType();
5823 if (Context.hasSameUnqualifiedType(T1, ArgType))
5827 if (Proto->getNumParams() < 2)
5830 if (!T2.isNull() && T2->isEnumeralType()) {
5831 QualType ArgType = Proto->getParamType(1).getNonReferenceType();
5832 if (Context.hasSameUnqualifiedType(T2, ArgType))
5839 /// AddOverloadCandidate - Adds the given function to the set of
5840 /// candidate functions, using the given function call arguments. If
5841 /// @p SuppressUserConversions, then don't allow user-defined
5842 /// conversions via constructors or conversion operators.
5844 /// \param PartialOverloading true if we are performing "partial" overloading
5845 /// based on an incomplete set of function arguments. This feature is used by
5846 /// code completion.
5848 Sema::AddOverloadCandidate(FunctionDecl *Function,
5849 DeclAccessPair FoundDecl,
5850 ArrayRef<Expr *> Args,
5851 OverloadCandidateSet &CandidateSet,
5852 bool SuppressUserConversions,
5853 bool PartialOverloading,
5855 ConversionSequenceList EarlyConversions) {
5856 const FunctionProtoType *Proto
5857 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>());
5858 assert(Proto && "Functions without a prototype cannot be overloaded");
5859 assert(!Function->getDescribedFunctionTemplate() &&
5860 "Use AddTemplateOverloadCandidate for function templates");
5862 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) {
5863 if (!isa<CXXConstructorDecl>(Method)) {
5864 // If we get here, it's because we're calling a member function
5865 // that is named without a member access expression (e.g.,
5866 // "this->f") that was either written explicitly or created
5867 // implicitly. This can happen with a qualified call to a member
5868 // function, e.g., X::f(). We use an empty type for the implied
5869 // object argument (C++ [over.call.func]p3), and the acting context
5871 AddMethodCandidate(Method, FoundDecl, Method->getParent(), QualType(),
5872 Expr::Classification::makeSimpleLValue(), Args,
5873 CandidateSet, SuppressUserConversions,
5874 PartialOverloading, EarlyConversions);
5877 // We treat a constructor like a non-member function, since its object
5878 // argument doesn't participate in overload resolution.
5881 if (!CandidateSet.isNewCandidate(Function))
5884 // C++ [over.match.oper]p3:
5885 // if no operand has a class type, only those non-member functions in the
5886 // lookup set that have a first parameter of type T1 or "reference to
5887 // (possibly cv-qualified) T1", when T1 is an enumeration type, or (if there
5888 // is a right operand) a second parameter of type T2 or "reference to
5889 // (possibly cv-qualified) T2", when T2 is an enumeration type, are
5890 // candidate functions.
5891 if (CandidateSet.getKind() == OverloadCandidateSet::CSK_Operator &&
5892 !IsAcceptableNonMemberOperatorCandidate(Context, Function, Args))
5895 // C++11 [class.copy]p11: [DR1402]
5896 // A defaulted move constructor that is defined as deleted is ignored by
5897 // overload resolution.
5898 CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function);
5899 if (Constructor && Constructor->isDefaulted() && Constructor->isDeleted() &&
5900 Constructor->isMoveConstructor())
5903 // Overload resolution is always an unevaluated context.
5904 EnterExpressionEvaluationContext Unevaluated(
5905 *this, Sema::ExpressionEvaluationContext::Unevaluated);
5907 // Add this candidate
5908 OverloadCandidate &Candidate =
5909 CandidateSet.addCandidate(Args.size(), EarlyConversions);
5910 Candidate.FoundDecl = FoundDecl;
5911 Candidate.Function = Function;
5912 Candidate.Viable = true;
5913 Candidate.IsSurrogate = false;
5914 Candidate.IgnoreObjectArgument = false;
5915 Candidate.ExplicitCallArguments = Args.size();
5918 // C++ [class.copy]p3:
5919 // A member function template is never instantiated to perform the copy
5920 // of a class object to an object of its class type.
5921 QualType ClassType = Context.getTypeDeclType(Constructor->getParent());
5922 if (Args.size() == 1 && Constructor->isSpecializationCopyingObject() &&
5923 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) ||
5924 IsDerivedFrom(Args[0]->getLocStart(), Args[0]->getType(),
5926 Candidate.Viable = false;
5927 Candidate.FailureKind = ovl_fail_illegal_constructor;
5931 // C++ [over.match.funcs]p8: (proposed DR resolution)
5932 // A constructor inherited from class type C that has a first parameter
5933 // of type "reference to P" (including such a constructor instantiated
5934 // from a template) is excluded from the set of candidate functions when
5935 // constructing an object of type cv D if the argument list has exactly
5936 // one argument and D is reference-related to P and P is reference-related
5938 auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(FoundDecl.getDecl());
5939 if (Shadow && Args.size() == 1 && Constructor->getNumParams() >= 1 &&
5940 Constructor->getParamDecl(0)->getType()->isReferenceType()) {
5941 QualType P = Constructor->getParamDecl(0)->getType()->getPointeeType();
5942 QualType C = Context.getRecordType(Constructor->getParent());
5943 QualType D = Context.getRecordType(Shadow->getParent());
5944 SourceLocation Loc = Args.front()->getExprLoc();
5945 if ((Context.hasSameUnqualifiedType(P, C) || IsDerivedFrom(Loc, P, C)) &&
5946 (Context.hasSameUnqualifiedType(D, P) || IsDerivedFrom(Loc, D, P))) {
5947 Candidate.Viable = false;
5948 Candidate.FailureKind = ovl_fail_inhctor_slice;
5954 unsigned NumParams = Proto->getNumParams();
5956 // (C++ 13.3.2p2): A candidate function having fewer than m
5957 // parameters is viable only if it has an ellipsis in its parameter
5959 if (TooManyArguments(NumParams, Args.size(), PartialOverloading) &&
5960 !Proto->isVariadic()) {
5961 Candidate.Viable = false;
5962 Candidate.FailureKind = ovl_fail_too_many_arguments;
5966 // (C++ 13.3.2p2): A candidate function having more than m parameters
5967 // is viable only if the (m+1)st parameter has a default argument
5968 // (8.3.6). For the purposes of overload resolution, the
5969 // parameter list is truncated on the right, so that there are
5970 // exactly m parameters.
5971 unsigned MinRequiredArgs = Function->getMinRequiredArguments();
5972 if (Args.size() < MinRequiredArgs && !PartialOverloading) {
5973 // Not enough arguments.
5974 Candidate.Viable = false;
5975 Candidate.FailureKind = ovl_fail_too_few_arguments;
5979 // (CUDA B.1): Check for invalid calls between targets.
5980 if (getLangOpts().CUDA)
5981 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext))
5982 // Skip the check for callers that are implicit members, because in this
5983 // case we may not yet know what the member's target is; the target is
5984 // inferred for the member automatically, based on the bases and fields of
5986 if (!Caller->isImplicit() && !IsAllowedCUDACall(Caller, Function)) {
5987 Candidate.Viable = false;
5988 Candidate.FailureKind = ovl_fail_bad_target;
5992 // Determine the implicit conversion sequences for each of the
5994 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) {
5995 if (Candidate.Conversions[ArgIdx].isInitialized()) {
5996 // We already formed a conversion sequence for this parameter during
5997 // template argument deduction.
5998 } else if (ArgIdx < NumParams) {
5999 // (C++ 13.3.2p3): for F to be a viable function, there shall
6000 // exist for each argument an implicit conversion sequence
6001 // (13.3.3.1) that converts that argument to the corresponding
6003 QualType ParamType = Proto->getParamType(ArgIdx);
6004 Candidate.Conversions[ArgIdx]
6005 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
6006 SuppressUserConversions,
6007 /*InOverloadResolution=*/true,
6008 /*AllowObjCWritebackConversion=*/
6009 getLangOpts().ObjCAutoRefCount,
6011 if (Candidate.Conversions[ArgIdx].isBad()) {
6012 Candidate.Viable = false;
6013 Candidate.FailureKind = ovl_fail_bad_conversion;
6017 // (C++ 13.3.2p2): For the purposes of overload resolution, any
6018 // argument for which there is no corresponding parameter is
6019 // considered to ""match the ellipsis" (C+ 13.3.3.1.3).
6020 Candidate.Conversions[ArgIdx].setEllipsis();
6024 if (EnableIfAttr *FailedAttr = CheckEnableIf(Function, Args)) {
6025 Candidate.Viable = false;
6026 Candidate.FailureKind = ovl_fail_enable_if;
6027 Candidate.DeductionFailure.Data = FailedAttr;
6031 if (LangOpts.OpenCL && isOpenCLDisabledDecl(Function)) {
6032 Candidate.Viable = false;
6033 Candidate.FailureKind = ovl_fail_ext_disabled;
6039 Sema::SelectBestMethod(Selector Sel, MultiExprArg Args, bool IsInstance,
6040 SmallVectorImpl<ObjCMethodDecl *> &Methods) {
6041 if (Methods.size() <= 1)
6044 for (unsigned b = 0, e = Methods.size(); b < e; b++) {
6046 ObjCMethodDecl *Method = Methods[b];
6047 unsigned NumNamedArgs = Sel.getNumArgs();
6048 // Method might have more arguments than selector indicates. This is due
6049 // to addition of c-style arguments in method.
6050 if (Method->param_size() > NumNamedArgs)
6051 NumNamedArgs = Method->param_size();
6052 if (Args.size() < NumNamedArgs)
6055 for (unsigned i = 0; i < NumNamedArgs; i++) {
6056 // We can't do any type-checking on a type-dependent argument.
6057 if (Args[i]->isTypeDependent()) {
6062 ParmVarDecl *param = Method->parameters()[i];
6063 Expr *argExpr = Args[i];
6064 assert(argExpr && "SelectBestMethod(): missing expression");
6066 // Strip the unbridged-cast placeholder expression off unless it's
6067 // a consumed argument.
6068 if (argExpr->hasPlaceholderType(BuiltinType::ARCUnbridgedCast) &&
6069 !param->hasAttr<CFConsumedAttr>())
6070 argExpr = stripARCUnbridgedCast(argExpr);
6072 // If the parameter is __unknown_anytype, move on to the next method.
6073 if (param->getType() == Context.UnknownAnyTy) {
6078 ImplicitConversionSequence ConversionState
6079 = TryCopyInitialization(*this, argExpr, param->getType(),
6080 /*SuppressUserConversions*/false,
6081 /*InOverloadResolution=*/true,
6082 /*AllowObjCWritebackConversion=*/
6083 getLangOpts().ObjCAutoRefCount,
6084 /*AllowExplicit*/false);
6085 // This function looks for a reasonably-exact match, so we consider
6086 // incompatible pointer conversions to be a failure here.
6087 if (ConversionState.isBad() ||
6088 (ConversionState.isStandard() &&
6089 ConversionState.Standard.Second ==
6090 ICK_Incompatible_Pointer_Conversion)) {
6095 // Promote additional arguments to variadic methods.
6096 if (Match && Method->isVariadic()) {
6097 for (unsigned i = NumNamedArgs, e = Args.size(); i < e; ++i) {
6098 if (Args[i]->isTypeDependent()) {
6102 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod,
6104 if (Arg.isInvalid()) {
6110 // Check for extra arguments to non-variadic methods.
6111 if (Args.size() != NumNamedArgs)
6113 else if (Match && NumNamedArgs == 0 && Methods.size() > 1) {
6114 // Special case when selectors have no argument. In this case, select
6115 // one with the most general result type of 'id'.
6116 for (unsigned b = 0, e = Methods.size(); b < e; b++) {
6117 QualType ReturnT = Methods[b]->getReturnType();
6118 if (ReturnT->isObjCIdType())
6130 // specific_attr_iterator iterates over enable_if attributes in reverse, and
6131 // enable_if is order-sensitive. As a result, we need to reverse things
6132 // sometimes. Size of 4 elements is arbitrary.
6133 static SmallVector<EnableIfAttr *, 4>
6134 getOrderedEnableIfAttrs(const FunctionDecl *Function) {
6135 SmallVector<EnableIfAttr *, 4> Result;
6136 if (!Function->hasAttrs())
6139 const auto &FuncAttrs = Function->getAttrs();
6140 for (Attr *Attr : FuncAttrs)
6141 if (auto *EnableIf = dyn_cast<EnableIfAttr>(Attr))
6142 Result.push_back(EnableIf);
6144 std::reverse(Result.begin(), Result.end());
6149 convertArgsForAvailabilityChecks(Sema &S, FunctionDecl *Function, Expr *ThisArg,
6150 ArrayRef<Expr *> Args, Sema::SFINAETrap &Trap,
6151 bool MissingImplicitThis, Expr *&ConvertedThis,
6152 SmallVectorImpl<Expr *> &ConvertedArgs) {
6154 CXXMethodDecl *Method = cast<CXXMethodDecl>(Function);
6155 assert(!isa<CXXConstructorDecl>(Method) &&
6156 "Shouldn't have `this` for ctors!");
6157 assert(!Method->isStatic() && "Shouldn't have `this` for static methods!");
6158 ExprResult R = S.PerformObjectArgumentInitialization(
6159 ThisArg, /*Qualifier=*/nullptr, Method, Method);
6162 ConvertedThis = R.get();
6164 if (auto *MD = dyn_cast<CXXMethodDecl>(Function)) {
6166 assert((MissingImplicitThis || MD->isStatic() ||
6167 isa<CXXConstructorDecl>(MD)) &&
6168 "Expected `this` for non-ctor instance methods");
6170 ConvertedThis = nullptr;
6173 // Ignore any variadic arguments. Converting them is pointless, since the
6174 // user can't refer to them in the function condition.
6175 unsigned ArgSizeNoVarargs = std::min(Function->param_size(), Args.size());
6177 // Convert the arguments.
6178 for (unsigned I = 0; I != ArgSizeNoVarargs; ++I) {
6180 R = S.PerformCopyInitialization(InitializedEntity::InitializeParameter(
6181 S.Context, Function->getParamDecl(I)),
6182 SourceLocation(), Args[I]);
6187 ConvertedArgs.push_back(R.get());
6190 if (Trap.hasErrorOccurred())
6193 // Push default arguments if needed.
6194 if (!Function->isVariadic() && Args.size() < Function->getNumParams()) {
6195 for (unsigned i = Args.size(), e = Function->getNumParams(); i != e; ++i) {
6196 ParmVarDecl *P = Function->getParamDecl(i);
6197 ExprResult R = S.PerformCopyInitialization(
6198 InitializedEntity::InitializeParameter(S.Context,
6199 Function->getParamDecl(i)),
6201 P->hasUninstantiatedDefaultArg() ? P->getUninstantiatedDefaultArg()
6202 : P->getDefaultArg());
6205 ConvertedArgs.push_back(R.get());
6208 if (Trap.hasErrorOccurred())
6214 EnableIfAttr *Sema::CheckEnableIf(FunctionDecl *Function, ArrayRef<Expr *> Args,
6215 bool MissingImplicitThis) {
6216 SmallVector<EnableIfAttr *, 4> EnableIfAttrs =
6217 getOrderedEnableIfAttrs(Function);
6218 if (EnableIfAttrs.empty())
6221 SFINAETrap Trap(*this);
6222 SmallVector<Expr *, 16> ConvertedArgs;
6223 // FIXME: We should look into making enable_if late-parsed.
6224 Expr *DiscardedThis;
6225 if (!convertArgsForAvailabilityChecks(
6226 *this, Function, /*ThisArg=*/nullptr, Args, Trap,
6227 /*MissingImplicitThis=*/true, DiscardedThis, ConvertedArgs))
6228 return EnableIfAttrs[0];
6230 for (auto *EIA : EnableIfAttrs) {
6232 // FIXME: This doesn't consider value-dependent cases, because doing so is
6233 // very difficult. Ideally, we should handle them more gracefully.
6234 if (!EIA->getCond()->EvaluateWithSubstitution(
6235 Result, Context, Function, llvm::makeArrayRef(ConvertedArgs)))
6238 if (!Result.isInt() || !Result.getInt().getBoolValue())
6244 template <typename CheckFn>
6245 static bool diagnoseDiagnoseIfAttrsWith(Sema &S, const FunctionDecl *FD,
6246 bool ArgDependent, SourceLocation Loc,
6247 CheckFn &&IsSuccessful) {
6248 SmallVector<const DiagnoseIfAttr *, 8> Attrs;
6249 for (const auto *DIA : FD->specific_attrs<DiagnoseIfAttr>()) {
6250 if (ArgDependent == DIA->getArgDependent())
6251 Attrs.push_back(DIA);
6254 // Common case: No diagnose_if attributes, so we can quit early.
6258 auto WarningBegin = std::stable_partition(
6259 Attrs.begin(), Attrs.end(),
6260 [](const DiagnoseIfAttr *DIA) { return DIA->isError(); });
6262 // Note that diagnose_if attributes are late-parsed, so they appear in the
6263 // correct order (unlike enable_if attributes).
6264 auto ErrAttr = llvm::find_if(llvm::make_range(Attrs.begin(), WarningBegin),
6266 if (ErrAttr != WarningBegin) {
6267 const DiagnoseIfAttr *DIA = *ErrAttr;
6268 S.Diag(Loc, diag::err_diagnose_if_succeeded) << DIA->getMessage();
6269 S.Diag(DIA->getLocation(), diag::note_from_diagnose_if)
6270 << DIA->getParent() << DIA->getCond()->getSourceRange();
6274 for (const auto *DIA : llvm::make_range(WarningBegin, Attrs.end()))
6275 if (IsSuccessful(DIA)) {
6276 S.Diag(Loc, diag::warn_diagnose_if_succeeded) << DIA->getMessage();
6277 S.Diag(DIA->getLocation(), diag::note_from_diagnose_if)
6278 << DIA->getParent() << DIA->getCond()->getSourceRange();
6284 bool Sema::diagnoseArgDependentDiagnoseIfAttrs(const FunctionDecl *Function,
6285 const Expr *ThisArg,
6286 ArrayRef<const Expr *> Args,
6287 SourceLocation Loc) {
6288 return diagnoseDiagnoseIfAttrsWith(
6289 *this, Function, /*ArgDependent=*/true, Loc,
6290 [&](const DiagnoseIfAttr *DIA) {
6292 // It's sane to use the same Args for any redecl of this function, since
6293 // EvaluateWithSubstitution only cares about the position of each
6294 // argument in the arg list, not the ParmVarDecl* it maps to.
6295 if (!DIA->getCond()->EvaluateWithSubstitution(
6296 Result, Context, DIA->getParent(), Args, ThisArg))
6298 return Result.isInt() && Result.getInt().getBoolValue();
6302 bool Sema::diagnoseArgIndependentDiagnoseIfAttrs(const FunctionDecl *Function,
6303 SourceLocation Loc) {
6304 return diagnoseDiagnoseIfAttrsWith(
6305 *this, Function, /*ArgDependent=*/false, Loc,
6306 [&](const DiagnoseIfAttr *DIA) {
6308 return DIA->getCond()->EvaluateAsBooleanCondition(Result, Context) &&
6313 /// \brief Add all of the function declarations in the given function set to
6314 /// the overload candidate set.
6315 void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns,
6316 ArrayRef<Expr *> Args,
6317 OverloadCandidateSet& CandidateSet,
6318 TemplateArgumentListInfo *ExplicitTemplateArgs,
6319 bool SuppressUserConversions,
6320 bool PartialOverloading) {
6321 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) {
6322 NamedDecl *D = F.getDecl()->getUnderlyingDecl();
6323 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
6324 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) {
6325 QualType ObjectType;
6326 Expr::Classification ObjectClassification;
6327 if (Expr *E = Args[0]) {
6328 // Use the explit base to restrict the lookup:
6329 ObjectType = E->getType();
6330 ObjectClassification = E->Classify(Context);
6331 } // .. else there is an implit base.
6332 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(),
6333 cast<CXXMethodDecl>(FD)->getParent(), ObjectType,
6334 ObjectClassification, Args.slice(1), CandidateSet,
6335 SuppressUserConversions, PartialOverloading);
6337 AddOverloadCandidate(FD, F.getPair(), Args, CandidateSet,
6338 SuppressUserConversions, PartialOverloading);
6341 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D);
6342 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) &&
6343 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) {
6344 QualType ObjectType;
6345 Expr::Classification ObjectClassification;
6346 if (Expr *E = Args[0]) {
6347 // Use the explit base to restrict the lookup:
6348 ObjectType = E->getType();
6349 ObjectClassification = E->Classify(Context);
6350 } // .. else there is an implit base.
6351 AddMethodTemplateCandidate(
6352 FunTmpl, F.getPair(),
6353 cast<CXXRecordDecl>(FunTmpl->getDeclContext()),
6354 ExplicitTemplateArgs, ObjectType, ObjectClassification,
6355 Args.slice(1), CandidateSet, SuppressUserConversions,
6356 PartialOverloading);
6358 AddTemplateOverloadCandidate(FunTmpl, F.getPair(),
6359 ExplicitTemplateArgs, Args,
6360 CandidateSet, SuppressUserConversions,
6361 PartialOverloading);
6367 /// AddMethodCandidate - Adds a named decl (which is some kind of
6368 /// method) as a method candidate to the given overload set.
6369 void Sema::AddMethodCandidate(DeclAccessPair FoundDecl,
6370 QualType ObjectType,
6371 Expr::Classification ObjectClassification,
6372 ArrayRef<Expr *> Args,
6373 OverloadCandidateSet& CandidateSet,
6374 bool SuppressUserConversions) {
6375 NamedDecl *Decl = FoundDecl.getDecl();
6376 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext());
6378 if (isa<UsingShadowDecl>(Decl))
6379 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl();
6381 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) {
6382 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) &&
6383 "Expected a member function template");
6384 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext,
6385 /*ExplicitArgs*/ nullptr, ObjectType,
6386 ObjectClassification, Args, CandidateSet,
6387 SuppressUserConversions);
6389 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext,
6390 ObjectType, ObjectClassification, Args, CandidateSet,
6391 SuppressUserConversions);
6395 /// AddMethodCandidate - Adds the given C++ member function to the set
6396 /// of candidate functions, using the given function call arguments
6397 /// and the object argument (@c Object). For example, in a call
6398 /// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain
6399 /// both @c a1 and @c a2. If @p SuppressUserConversions, then don't
6400 /// allow user-defined conversions via constructors or conversion
6403 Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl,
6404 CXXRecordDecl *ActingContext, QualType ObjectType,
6405 Expr::Classification ObjectClassification,
6406 ArrayRef<Expr *> Args,
6407 OverloadCandidateSet &CandidateSet,
6408 bool SuppressUserConversions,
6409 bool PartialOverloading,
6410 ConversionSequenceList EarlyConversions) {
6411 const FunctionProtoType *Proto
6412 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>());
6413 assert(Proto && "Methods without a prototype cannot be overloaded");
6414 assert(!isa<CXXConstructorDecl>(Method) &&
6415 "Use AddOverloadCandidate for constructors");
6417 if (!CandidateSet.isNewCandidate(Method))
6420 // C++11 [class.copy]p23: [DR1402]
6421 // A defaulted move assignment operator that is defined as deleted is
6422 // ignored by overload resolution.
6423 if (Method->isDefaulted() && Method->isDeleted() &&
6424 Method->isMoveAssignmentOperator())
6427 // Overload resolution is always an unevaluated context.
6428 EnterExpressionEvaluationContext Unevaluated(
6429 *this, Sema::ExpressionEvaluationContext::Unevaluated);
6431 // Add this candidate
6432 OverloadCandidate &Candidate =
6433 CandidateSet.addCandidate(Args.size() + 1, EarlyConversions);
6434 Candidate.FoundDecl = FoundDecl;
6435 Candidate.Function = Method;
6436 Candidate.IsSurrogate = false;
6437 Candidate.IgnoreObjectArgument = false;
6438 Candidate.ExplicitCallArguments = Args.size();
6440 unsigned NumParams = Proto->getNumParams();
6442 // (C++ 13.3.2p2): A candidate function having fewer than m
6443 // parameters is viable only if it has an ellipsis in its parameter
6445 if (TooManyArguments(NumParams, Args.size(), PartialOverloading) &&
6446 !Proto->isVariadic()) {
6447 Candidate.Viable = false;
6448 Candidate.FailureKind = ovl_fail_too_many_arguments;
6452 // (C++ 13.3.2p2): A candidate function having more than m parameters
6453 // is viable only if the (m+1)st parameter has a default argument
6454 // (8.3.6). For the purposes of overload resolution, the
6455 // parameter list is truncated on the right, so that there are
6456 // exactly m parameters.
6457 unsigned MinRequiredArgs = Method->getMinRequiredArguments();
6458 if (Args.size() < MinRequiredArgs && !PartialOverloading) {
6459 // Not enough arguments.
6460 Candidate.Viable = false;
6461 Candidate.FailureKind = ovl_fail_too_few_arguments;
6465 Candidate.Viable = true;
6467 if (Method->isStatic() || ObjectType.isNull())
6468 // The implicit object argument is ignored.
6469 Candidate.IgnoreObjectArgument = true;
6471 // Determine the implicit conversion sequence for the object
6473 Candidate.Conversions[0] = TryObjectArgumentInitialization(
6474 *this, CandidateSet.getLocation(), ObjectType, ObjectClassification,
6475 Method, ActingContext);
6476 if (Candidate.Conversions[0].isBad()) {
6477 Candidate.Viable = false;
6478 Candidate.FailureKind = ovl_fail_bad_conversion;
6483 // (CUDA B.1): Check for invalid calls between targets.
6484 if (getLangOpts().CUDA)
6485 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext))
6486 if (!IsAllowedCUDACall(Caller, Method)) {
6487 Candidate.Viable = false;
6488 Candidate.FailureKind = ovl_fail_bad_target;
6492 // Determine the implicit conversion sequences for each of the
6494 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) {
6495 if (Candidate.Conversions[ArgIdx + 1].isInitialized()) {
6496 // We already formed a conversion sequence for this parameter during
6497 // template argument deduction.
6498 } else if (ArgIdx < NumParams) {
6499 // (C++ 13.3.2p3): for F to be a viable function, there shall
6500 // exist for each argument an implicit conversion sequence
6501 // (13.3.3.1) that converts that argument to the corresponding
6503 QualType ParamType = Proto->getParamType(ArgIdx);
6504 Candidate.Conversions[ArgIdx + 1]
6505 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
6506 SuppressUserConversions,
6507 /*InOverloadResolution=*/true,
6508 /*AllowObjCWritebackConversion=*/
6509 getLangOpts().ObjCAutoRefCount);
6510 if (Candidate.Conversions[ArgIdx + 1].isBad()) {
6511 Candidate.Viable = false;
6512 Candidate.FailureKind = ovl_fail_bad_conversion;
6516 // (C++ 13.3.2p2): For the purposes of overload resolution, any
6517 // argument for which there is no corresponding parameter is
6518 // considered to "match the ellipsis" (C+ 13.3.3.1.3).
6519 Candidate.Conversions[ArgIdx + 1].setEllipsis();
6523 if (EnableIfAttr *FailedAttr = CheckEnableIf(Method, Args, true)) {
6524 Candidate.Viable = false;
6525 Candidate.FailureKind = ovl_fail_enable_if;
6526 Candidate.DeductionFailure.Data = FailedAttr;
6531 /// \brief Add a C++ member function template as a candidate to the candidate
6532 /// set, using template argument deduction to produce an appropriate member
6533 /// function template specialization.
6535 Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl,
6536 DeclAccessPair FoundDecl,
6537 CXXRecordDecl *ActingContext,
6538 TemplateArgumentListInfo *ExplicitTemplateArgs,
6539 QualType ObjectType,
6540 Expr::Classification ObjectClassification,
6541 ArrayRef<Expr *> Args,
6542 OverloadCandidateSet& CandidateSet,
6543 bool SuppressUserConversions,
6544 bool PartialOverloading) {
6545 if (!CandidateSet.isNewCandidate(MethodTmpl))
6548 // C++ [over.match.funcs]p7:
6549 // In each case where a candidate is a function template, candidate
6550 // function template specializations are generated using template argument
6551 // deduction (14.8.3, 14.8.2). Those candidates are then handled as
6552 // candidate functions in the usual way.113) A given name can refer to one
6553 // or more function templates and also to a set of overloaded non-template
6554 // functions. In such a case, the candidate functions generated from each
6555 // function template are combined with the set of non-template candidate
6557 TemplateDeductionInfo Info(CandidateSet.getLocation());
6558 FunctionDecl *Specialization = nullptr;
6559 ConversionSequenceList Conversions;
6560 if (TemplateDeductionResult Result = DeduceTemplateArguments(
6561 MethodTmpl, ExplicitTemplateArgs, Args, Specialization, Info,
6562 PartialOverloading, [&](ArrayRef<QualType> ParamTypes) {
6563 return CheckNonDependentConversions(
6564 MethodTmpl, ParamTypes, Args, CandidateSet, Conversions,
6565 SuppressUserConversions, ActingContext, ObjectType,
6566 ObjectClassification);
6568 OverloadCandidate &Candidate =
6569 CandidateSet.addCandidate(Conversions.size(), Conversions);
6570 Candidate.FoundDecl = FoundDecl;
6571 Candidate.Function = MethodTmpl->getTemplatedDecl();
6572 Candidate.Viable = false;
6573 Candidate.IsSurrogate = false;
6574 Candidate.IgnoreObjectArgument =
6575 cast<CXXMethodDecl>(Candidate.Function)->isStatic() ||
6576 ObjectType.isNull();
6577 Candidate.ExplicitCallArguments = Args.size();
6578 if (Result == TDK_NonDependentConversionFailure)
6579 Candidate.FailureKind = ovl_fail_bad_conversion;
6581 Candidate.FailureKind = ovl_fail_bad_deduction;
6582 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
6588 // Add the function template specialization produced by template argument
6589 // deduction as a candidate.
6590 assert(Specialization && "Missing member function template specialization?");
6591 assert(isa<CXXMethodDecl>(Specialization) &&
6592 "Specialization is not a member function?");
6593 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl,
6594 ActingContext, ObjectType, ObjectClassification, Args,
6595 CandidateSet, SuppressUserConversions, PartialOverloading,
6599 /// \brief Add a C++ function template specialization as a candidate
6600 /// in the candidate set, using template argument deduction to produce
6601 /// an appropriate function template specialization.
6603 Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate,
6604 DeclAccessPair FoundDecl,
6605 TemplateArgumentListInfo *ExplicitTemplateArgs,
6606 ArrayRef<Expr *> Args,
6607 OverloadCandidateSet& CandidateSet,
6608 bool SuppressUserConversions,
6609 bool PartialOverloading) {
6610 if (!CandidateSet.isNewCandidate(FunctionTemplate))
6613 // C++ [over.match.funcs]p7:
6614 // In each case where a candidate is a function template, candidate
6615 // function template specializations are generated using template argument
6616 // deduction (14.8.3, 14.8.2). Those candidates are then handled as
6617 // candidate functions in the usual way.113) A given name can refer to one
6618 // or more function templates and also to a set of overloaded non-template
6619 // functions. In such a case, the candidate functions generated from each
6620 // function template are combined with the set of non-template candidate
6622 TemplateDeductionInfo Info(CandidateSet.getLocation());
6623 FunctionDecl *Specialization = nullptr;
6624 ConversionSequenceList Conversions;
6625 if (TemplateDeductionResult Result = DeduceTemplateArguments(
6626 FunctionTemplate, ExplicitTemplateArgs, Args, Specialization, Info,
6627 PartialOverloading, [&](ArrayRef<QualType> ParamTypes) {
6628 return CheckNonDependentConversions(FunctionTemplate, ParamTypes,
6629 Args, CandidateSet, Conversions,
6630 SuppressUserConversions);
6632 OverloadCandidate &Candidate =
6633 CandidateSet.addCandidate(Conversions.size(), Conversions);
6634 Candidate.FoundDecl = FoundDecl;
6635 Candidate.Function = FunctionTemplate->getTemplatedDecl();
6636 Candidate.Viable = false;
6637 Candidate.IsSurrogate = false;
6638 // Ignore the object argument if there is one, since we don't have an object
6640 Candidate.IgnoreObjectArgument =
6641 isa<CXXMethodDecl>(Candidate.Function) &&
6642 !isa<CXXConstructorDecl>(Candidate.Function);
6643 Candidate.ExplicitCallArguments = Args.size();
6644 if (Result == TDK_NonDependentConversionFailure)
6645 Candidate.FailureKind = ovl_fail_bad_conversion;
6647 Candidate.FailureKind = ovl_fail_bad_deduction;
6648 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
6654 // Add the function template specialization produced by template argument
6655 // deduction as a candidate.
6656 assert(Specialization && "Missing function template specialization?");
6657 AddOverloadCandidate(Specialization, FoundDecl, Args, CandidateSet,
6658 SuppressUserConversions, PartialOverloading,
6659 /*AllowExplicit*/false, Conversions);
6662 /// Check that implicit conversion sequences can be formed for each argument
6663 /// whose corresponding parameter has a non-dependent type, per DR1391's
6664 /// [temp.deduct.call]p10.
6665 bool Sema::CheckNonDependentConversions(
6666 FunctionTemplateDecl *FunctionTemplate, ArrayRef<QualType> ParamTypes,
6667 ArrayRef<Expr *> Args, OverloadCandidateSet &CandidateSet,
6668 ConversionSequenceList &Conversions, bool SuppressUserConversions,
6669 CXXRecordDecl *ActingContext, QualType ObjectType,
6670 Expr::Classification ObjectClassification) {
6671 // FIXME: The cases in which we allow explicit conversions for constructor
6672 // arguments never consider calling a constructor template. It's not clear
6674 const bool AllowExplicit = false;
6676 auto *FD = FunctionTemplate->getTemplatedDecl();
6677 auto *Method = dyn_cast<CXXMethodDecl>(FD);
6678 bool HasThisConversion = Method && !isa<CXXConstructorDecl>(Method);
6679 unsigned ThisConversions = HasThisConversion ? 1 : 0;
6682 CandidateSet.allocateConversionSequences(ThisConversions + Args.size());
6684 // Overload resolution is always an unevaluated context.
6685 EnterExpressionEvaluationContext Unevaluated(
6686 *this, Sema::ExpressionEvaluationContext::Unevaluated);
6688 // For a method call, check the 'this' conversion here too. DR1391 doesn't
6689 // require that, but this check should never result in a hard error, and
6690 // overload resolution is permitted to sidestep instantiations.
6691 if (HasThisConversion && !cast<CXXMethodDecl>(FD)->isStatic() &&
6692 !ObjectType.isNull()) {
6693 Conversions[0] = TryObjectArgumentInitialization(
6694 *this, CandidateSet.getLocation(), ObjectType, ObjectClassification,
6695 Method, ActingContext);
6696 if (Conversions[0].isBad())
6700 for (unsigned I = 0, N = std::min(ParamTypes.size(), Args.size()); I != N;
6702 QualType ParamType = ParamTypes[I];
6703 if (!ParamType->isDependentType()) {
6704 Conversions[ThisConversions + I]
6705 = TryCopyInitialization(*this, Args[I], ParamType,
6706 SuppressUserConversions,
6707 /*InOverloadResolution=*/true,
6708 /*AllowObjCWritebackConversion=*/
6709 getLangOpts().ObjCAutoRefCount,
6711 if (Conversions[ThisConversions + I].isBad())
6719 /// Determine whether this is an allowable conversion from the result
6720 /// of an explicit conversion operator to the expected type, per C++
6721 /// [over.match.conv]p1 and [over.match.ref]p1.
6723 /// \param ConvType The return type of the conversion function.
6725 /// \param ToType The type we are converting to.
6727 /// \param AllowObjCPointerConversion Allow a conversion from one
6728 /// Objective-C pointer to another.
6730 /// \returns true if the conversion is allowable, false otherwise.
6731 static bool isAllowableExplicitConversion(Sema &S,
6732 QualType ConvType, QualType ToType,
6733 bool AllowObjCPointerConversion) {
6734 QualType ToNonRefType = ToType.getNonReferenceType();
6736 // Easy case: the types are the same.
6737 if (S.Context.hasSameUnqualifiedType(ConvType, ToNonRefType))
6740 // Allow qualification conversions.
6741 bool ObjCLifetimeConversion;
6742 if (S.IsQualificationConversion(ConvType, ToNonRefType, /*CStyle*/false,
6743 ObjCLifetimeConversion))
6746 // If we're not allowed to consider Objective-C pointer conversions,
6748 if (!AllowObjCPointerConversion)
6751 // Is this an Objective-C pointer conversion?
6752 bool IncompatibleObjC = false;
6753 QualType ConvertedType;
6754 return S.isObjCPointerConversion(ConvType, ToNonRefType, ConvertedType,
6758 /// AddConversionCandidate - Add a C++ conversion function as a
6759 /// candidate in the candidate set (C++ [over.match.conv],
6760 /// C++ [over.match.copy]). From is the expression we're converting from,
6761 /// and ToType is the type that we're eventually trying to convert to
6762 /// (which may or may not be the same type as the type that the
6763 /// conversion function produces).
6765 Sema::AddConversionCandidate(CXXConversionDecl *Conversion,
6766 DeclAccessPair FoundDecl,
6767 CXXRecordDecl *ActingContext,
6768 Expr *From, QualType ToType,
6769 OverloadCandidateSet& CandidateSet,
6770 bool AllowObjCConversionOnExplicit) {
6771 assert(!Conversion->getDescribedFunctionTemplate() &&
6772 "Conversion function templates use AddTemplateConversionCandidate");
6773 QualType ConvType = Conversion->getConversionType().getNonReferenceType();
6774 if (!CandidateSet.isNewCandidate(Conversion))
6777 // If the conversion function has an undeduced return type, trigger its
6779 if (getLangOpts().CPlusPlus14 && ConvType->isUndeducedType()) {
6780 if (DeduceReturnType(Conversion, From->getExprLoc()))
6782 ConvType = Conversion->getConversionType().getNonReferenceType();
6785 // Per C++ [over.match.conv]p1, [over.match.ref]p1, an explicit conversion
6786 // operator is only a candidate if its return type is the target type or
6787 // can be converted to the target type with a qualification conversion.
6788 if (Conversion->isExplicit() &&
6789 !isAllowableExplicitConversion(*this, ConvType, ToType,
6790 AllowObjCConversionOnExplicit))
6793 // Overload resolution is always an unevaluated context.
6794 EnterExpressionEvaluationContext Unevaluated(
6795 *this, Sema::ExpressionEvaluationContext::Unevaluated);
6797 // Add this candidate
6798 OverloadCandidate &Candidate = CandidateSet.addCandidate(1);
6799 Candidate.FoundDecl = FoundDecl;
6800 Candidate.Function = Conversion;
6801 Candidate.IsSurrogate = false;
6802 Candidate.IgnoreObjectArgument = false;
6803 Candidate.FinalConversion.setAsIdentityConversion();
6804 Candidate.FinalConversion.setFromType(ConvType);
6805 Candidate.FinalConversion.setAllToTypes(ToType);
6806 Candidate.Viable = true;
6807 Candidate.ExplicitCallArguments = 1;
6809 // C++ [over.match.funcs]p4:
6810 // For conversion functions, the function is considered to be a member of
6811 // the class of the implicit implied object argument for the purpose of
6812 // defining the type of the implicit object parameter.
6814 // Determine the implicit conversion sequence for the implicit
6815 // object parameter.
6816 QualType ImplicitParamType = From->getType();
6817 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>())
6818 ImplicitParamType = FromPtrType->getPointeeType();
6819 CXXRecordDecl *ConversionContext
6820 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl());
6822 Candidate.Conversions[0] = TryObjectArgumentInitialization(
6823 *this, CandidateSet.getLocation(), From->getType(),
6824 From->Classify(Context), Conversion, ConversionContext);
6826 if (Candidate.Conversions[0].isBad()) {
6827 Candidate.Viable = false;
6828 Candidate.FailureKind = ovl_fail_bad_conversion;
6832 // We won't go through a user-defined type conversion function to convert a
6833 // derived to base as such conversions are given Conversion Rank. They only
6834 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user]
6836 = Context.getCanonicalType(From->getType().getUnqualifiedType());
6837 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType();
6838 if (FromCanon == ToCanon ||
6839 IsDerivedFrom(CandidateSet.getLocation(), FromCanon, ToCanon)) {
6840 Candidate.Viable = false;
6841 Candidate.FailureKind = ovl_fail_trivial_conversion;
6845 // To determine what the conversion from the result of calling the
6846 // conversion function to the type we're eventually trying to
6847 // convert to (ToType), we need to synthesize a call to the
6848 // conversion function and attempt copy initialization from it. This
6849 // makes sure that we get the right semantics with respect to
6850 // lvalues/rvalues and the type. Fortunately, we can allocate this
6851 // call on the stack and we don't need its arguments to be
6853 DeclRefExpr ConversionRef(Conversion, false, Conversion->getType(),
6854 VK_LValue, From->getLocStart());
6855 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack,
6856 Context.getPointerType(Conversion->getType()),
6857 CK_FunctionToPointerDecay,
6858 &ConversionRef, VK_RValue);
6860 QualType ConversionType = Conversion->getConversionType();
6861 if (!isCompleteType(From->getLocStart(), ConversionType)) {
6862 Candidate.Viable = false;
6863 Candidate.FailureKind = ovl_fail_bad_final_conversion;
6867 ExprValueKind VK = Expr::getValueKindForType(ConversionType);
6869 // Note that it is safe to allocate CallExpr on the stack here because
6870 // there are 0 arguments (i.e., nothing is allocated using ASTContext's
6872 QualType CallResultType = ConversionType.getNonLValueExprType(Context);
6873 CallExpr Call(Context, &ConversionFn, None, CallResultType, VK,
6874 From->getLocStart());
6875 ImplicitConversionSequence ICS =
6876 TryCopyInitialization(*this, &Call, ToType,
6877 /*SuppressUserConversions=*/true,
6878 /*InOverloadResolution=*/false,
6879 /*AllowObjCWritebackConversion=*/false);
6881 switch (ICS.getKind()) {
6882 case ImplicitConversionSequence::StandardConversion:
6883 Candidate.FinalConversion = ICS.Standard;
6885 // C++ [over.ics.user]p3:
6886 // If the user-defined conversion is specified by a specialization of a
6887 // conversion function template, the second standard conversion sequence
6888 // shall have exact match rank.
6889 if (Conversion->getPrimaryTemplate() &&
6890 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) {
6891 Candidate.Viable = false;
6892 Candidate.FailureKind = ovl_fail_final_conversion_not_exact;
6896 // C++0x [dcl.init.ref]p5:
6897 // In the second case, if the reference is an rvalue reference and
6898 // the second standard conversion sequence of the user-defined
6899 // conversion sequence includes an lvalue-to-rvalue conversion, the
6900 // program is ill-formed.
6901 if (ToType->isRValueReferenceType() &&
6902 ICS.Standard.First == ICK_Lvalue_To_Rvalue) {
6903 Candidate.Viable = false;
6904 Candidate.FailureKind = ovl_fail_bad_final_conversion;
6909 case ImplicitConversionSequence::BadConversion:
6910 Candidate.Viable = false;
6911 Candidate.FailureKind = ovl_fail_bad_final_conversion;
6916 "Can only end up with a standard conversion sequence or failure");
6919 if (EnableIfAttr *FailedAttr = CheckEnableIf(Conversion, None)) {
6920 Candidate.Viable = false;
6921 Candidate.FailureKind = ovl_fail_enable_if;
6922 Candidate.DeductionFailure.Data = FailedAttr;
6927 /// \brief Adds a conversion function template specialization
6928 /// candidate to the overload set, using template argument deduction
6929 /// to deduce the template arguments of the conversion function
6930 /// template from the type that we are converting to (C++
6931 /// [temp.deduct.conv]).
6933 Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate,
6934 DeclAccessPair FoundDecl,
6935 CXXRecordDecl *ActingDC,
6936 Expr *From, QualType ToType,
6937 OverloadCandidateSet &CandidateSet,
6938 bool AllowObjCConversionOnExplicit) {
6939 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) &&
6940 "Only conversion function templates permitted here");
6942 if (!CandidateSet.isNewCandidate(FunctionTemplate))
6945 TemplateDeductionInfo Info(CandidateSet.getLocation());
6946 CXXConversionDecl *Specialization = nullptr;
6947 if (TemplateDeductionResult Result
6948 = DeduceTemplateArguments(FunctionTemplate, ToType,
6949 Specialization, Info)) {
6950 OverloadCandidate &Candidate = CandidateSet.addCandidate();
6951 Candidate.FoundDecl = FoundDecl;
6952 Candidate.Function = FunctionTemplate->getTemplatedDecl();
6953 Candidate.Viable = false;
6954 Candidate.FailureKind = ovl_fail_bad_deduction;
6955 Candidate.IsSurrogate = false;
6956 Candidate.IgnoreObjectArgument = false;
6957 Candidate.ExplicitCallArguments = 1;
6958 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
6963 // Add the conversion function template specialization produced by
6964 // template argument deduction as a candidate.
6965 assert(Specialization && "Missing function template specialization?");
6966 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType,
6967 CandidateSet, AllowObjCConversionOnExplicit);
6970 /// AddSurrogateCandidate - Adds a "surrogate" candidate function that
6971 /// converts the given @c Object to a function pointer via the
6972 /// conversion function @c Conversion, and then attempts to call it
6973 /// with the given arguments (C++ [over.call.object]p2-4). Proto is
6974 /// the type of function that we'll eventually be calling.
6975 void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion,
6976 DeclAccessPair FoundDecl,
6977 CXXRecordDecl *ActingContext,
6978 const FunctionProtoType *Proto,
6980 ArrayRef<Expr *> Args,
6981 OverloadCandidateSet& CandidateSet) {
6982 if (!CandidateSet.isNewCandidate(Conversion))
6985 // Overload resolution is always an unevaluated context.
6986 EnterExpressionEvaluationContext Unevaluated(
6987 *this, Sema::ExpressionEvaluationContext::Unevaluated);
6989 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1);
6990 Candidate.FoundDecl = FoundDecl;
6991 Candidate.Function = nullptr;
6992 Candidate.Surrogate = Conversion;
6993 Candidate.Viable = true;
6994 Candidate.IsSurrogate = true;
6995 Candidate.IgnoreObjectArgument = false;
6996 Candidate.ExplicitCallArguments = Args.size();
6998 // Determine the implicit conversion sequence for the implicit
6999 // object parameter.
7000 ImplicitConversionSequence ObjectInit = TryObjectArgumentInitialization(
7001 *this, CandidateSet.getLocation(), Object->getType(),
7002 Object->Classify(Context), Conversion, ActingContext);
7003 if (ObjectInit.isBad()) {
7004 Candidate.Viable = false;
7005 Candidate.FailureKind = ovl_fail_bad_conversion;
7006 Candidate.Conversions[0] = ObjectInit;
7010 // The first conversion is actually a user-defined conversion whose
7011 // first conversion is ObjectInit's standard conversion (which is
7012 // effectively a reference binding). Record it as such.
7013 Candidate.Conversions[0].setUserDefined();
7014 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard;
7015 Candidate.Conversions[0].UserDefined.EllipsisConversion = false;
7016 Candidate.Conversions[0].UserDefined.HadMultipleCandidates = false;
7017 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion;
7018 Candidate.Conversions[0].UserDefined.FoundConversionFunction = FoundDecl;
7019 Candidate.Conversions[0].UserDefined.After
7020 = Candidate.Conversions[0].UserDefined.Before;
7021 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion();
7024 unsigned NumParams = Proto->getNumParams();
7026 // (C++ 13.3.2p2): A candidate function having fewer than m
7027 // parameters is viable only if it has an ellipsis in its parameter
7029 if (Args.size() > NumParams && !Proto->isVariadic()) {
7030 Candidate.Viable = false;
7031 Candidate.FailureKind = ovl_fail_too_many_arguments;
7035 // Function types don't have any default arguments, so just check if
7036 // we have enough arguments.
7037 if (Args.size() < NumParams) {
7038 // Not enough arguments.
7039 Candidate.Viable = false;
7040 Candidate.FailureKind = ovl_fail_too_few_arguments;
7044 // Determine the implicit conversion sequences for each of the
7046 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7047 if (ArgIdx < NumParams) {
7048 // (C++ 13.3.2p3): for F to be a viable function, there shall
7049 // exist for each argument an implicit conversion sequence
7050 // (13.3.3.1) that converts that argument to the corresponding
7052 QualType ParamType = Proto->getParamType(ArgIdx);
7053 Candidate.Conversions[ArgIdx + 1]
7054 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
7055 /*SuppressUserConversions=*/false,
7056 /*InOverloadResolution=*/false,
7057 /*AllowObjCWritebackConversion=*/
7058 getLangOpts().ObjCAutoRefCount);
7059 if (Candidate.Conversions[ArgIdx + 1].isBad()) {
7060 Candidate.Viable = false;
7061 Candidate.FailureKind = ovl_fail_bad_conversion;
7065 // (C++ 13.3.2p2): For the purposes of overload resolution, any
7066 // argument for which there is no corresponding parameter is
7067 // considered to ""match the ellipsis" (C+ 13.3.3.1.3).
7068 Candidate.Conversions[ArgIdx + 1].setEllipsis();
7072 if (EnableIfAttr *FailedAttr = CheckEnableIf(Conversion, None)) {
7073 Candidate.Viable = false;
7074 Candidate.FailureKind = ovl_fail_enable_if;
7075 Candidate.DeductionFailure.Data = FailedAttr;
7080 /// \brief Add overload candidates for overloaded operators that are
7081 /// member functions.
7083 /// Add the overloaded operator candidates that are member functions
7084 /// for the operator Op that was used in an operator expression such
7085 /// as "x Op y". , Args/NumArgs provides the operator arguments, and
7086 /// CandidateSet will store the added overload candidates. (C++
7087 /// [over.match.oper]).
7088 void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op,
7089 SourceLocation OpLoc,
7090 ArrayRef<Expr *> Args,
7091 OverloadCandidateSet& CandidateSet,
7092 SourceRange OpRange) {
7093 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
7095 // C++ [over.match.oper]p3:
7096 // For a unary operator @ with an operand of a type whose
7097 // cv-unqualified version is T1, and for a binary operator @ with
7098 // a left operand of a type whose cv-unqualified version is T1 and
7099 // a right operand of a type whose cv-unqualified version is T2,
7100 // three sets of candidate functions, designated member
7101 // candidates, non-member candidates and built-in candidates, are
7102 // constructed as follows:
7103 QualType T1 = Args[0]->getType();
7105 // -- If T1 is a complete class type or a class currently being
7106 // defined, the set of member candidates is the result of the
7107 // qualified lookup of T1::operator@ (13.3.1.1.1); otherwise,
7108 // the set of member candidates is empty.
7109 if (const RecordType *T1Rec = T1->getAs<RecordType>()) {
7110 // Complete the type if it can be completed.
7111 if (!isCompleteType(OpLoc, T1) && !T1Rec->isBeingDefined())
7113 // If the type is neither complete nor being defined, bail out now.
7114 if (!T1Rec->getDecl()->getDefinition())
7117 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName);
7118 LookupQualifiedName(Operators, T1Rec->getDecl());
7119 Operators.suppressDiagnostics();
7121 for (LookupResult::iterator Oper = Operators.begin(),
7122 OperEnd = Operators.end();
7125 AddMethodCandidate(Oper.getPair(), Args[0]->getType(),
7126 Args[0]->Classify(Context), Args.slice(1),
7127 CandidateSet, /*SuppressUserConversions=*/false);
7131 /// AddBuiltinCandidate - Add a candidate for a built-in
7132 /// operator. ResultTy and ParamTys are the result and parameter types
7133 /// of the built-in candidate, respectively. Args and NumArgs are the
7134 /// arguments being passed to the candidate. IsAssignmentOperator
7135 /// should be true when this built-in candidate is an assignment
7136 /// operator. NumContextualBoolArguments is the number of arguments
7137 /// (at the beginning of the argument list) that will be contextually
7138 /// converted to bool.
7139 void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys,
7140 ArrayRef<Expr *> Args,
7141 OverloadCandidateSet& CandidateSet,
7142 bool IsAssignmentOperator,
7143 unsigned NumContextualBoolArguments) {
7144 // Overload resolution is always an unevaluated context.
7145 EnterExpressionEvaluationContext Unevaluated(
7146 *this, Sema::ExpressionEvaluationContext::Unevaluated);
7148 // Add this candidate
7149 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size());
7150 Candidate.FoundDecl = DeclAccessPair::make(nullptr, AS_none);
7151 Candidate.Function = nullptr;
7152 Candidate.IsSurrogate = false;
7153 Candidate.IgnoreObjectArgument = false;
7154 Candidate.BuiltinTypes.ResultTy = ResultTy;
7155 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx)
7156 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx];
7158 // Determine the implicit conversion sequences for each of the
7160 Candidate.Viable = true;
7161 Candidate.ExplicitCallArguments = Args.size();
7162 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7163 // C++ [over.match.oper]p4:
7164 // For the built-in assignment operators, conversions of the
7165 // left operand are restricted as follows:
7166 // -- no temporaries are introduced to hold the left operand, and
7167 // -- no user-defined conversions are applied to the left
7168 // operand to achieve a type match with the left-most
7169 // parameter of a built-in candidate.
7171 // We block these conversions by turning off user-defined
7172 // conversions, since that is the only way that initialization of
7173 // a reference to a non-class type can occur from something that
7174 // is not of the same type.
7175 if (ArgIdx < NumContextualBoolArguments) {
7176 assert(ParamTys[ArgIdx] == Context.BoolTy &&
7177 "Contextual conversion to bool requires bool type");
7178 Candidate.Conversions[ArgIdx]
7179 = TryContextuallyConvertToBool(*this, Args[ArgIdx]);
7181 Candidate.Conversions[ArgIdx]
7182 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx],
7183 ArgIdx == 0 && IsAssignmentOperator,
7184 /*InOverloadResolution=*/false,
7185 /*AllowObjCWritebackConversion=*/
7186 getLangOpts().ObjCAutoRefCount);
7188 if (Candidate.Conversions[ArgIdx].isBad()) {
7189 Candidate.Viable = false;
7190 Candidate.FailureKind = ovl_fail_bad_conversion;
7198 /// BuiltinCandidateTypeSet - A set of types that will be used for the
7199 /// candidate operator functions for built-in operators (C++
7200 /// [over.built]). The types are separated into pointer types and
7201 /// enumeration types.
7202 class BuiltinCandidateTypeSet {
7203 /// TypeSet - A set of types.
7204 typedef llvm::SetVector<QualType, SmallVector<QualType, 8>,
7205 llvm::SmallPtrSet<QualType, 8>> TypeSet;
7207 /// PointerTypes - The set of pointer types that will be used in the
7208 /// built-in candidates.
7209 TypeSet PointerTypes;
7211 /// MemberPointerTypes - The set of member pointer types that will be
7212 /// used in the built-in candidates.
7213 TypeSet MemberPointerTypes;
7215 /// EnumerationTypes - The set of enumeration types that will be
7216 /// used in the built-in candidates.
7217 TypeSet EnumerationTypes;
7219 /// \brief The set of vector types that will be used in the built-in
7221 TypeSet VectorTypes;
7223 /// \brief A flag indicating non-record types are viable candidates
7224 bool HasNonRecordTypes;
7226 /// \brief A flag indicating whether either arithmetic or enumeration types
7227 /// were present in the candidate set.
7228 bool HasArithmeticOrEnumeralTypes;
7230 /// \brief A flag indicating whether the nullptr type was present in the
7232 bool HasNullPtrType;
7234 /// Sema - The semantic analysis instance where we are building the
7235 /// candidate type set.
7238 /// Context - The AST context in which we will build the type sets.
7239 ASTContext &Context;
7241 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
7242 const Qualifiers &VisibleQuals);
7243 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty);
7246 /// iterator - Iterates through the types that are part of the set.
7247 typedef TypeSet::iterator iterator;
7249 BuiltinCandidateTypeSet(Sema &SemaRef)
7250 : HasNonRecordTypes(false),
7251 HasArithmeticOrEnumeralTypes(false),
7252 HasNullPtrType(false),
7254 Context(SemaRef.Context) { }
7256 void AddTypesConvertedFrom(QualType Ty,
7258 bool AllowUserConversions,
7259 bool AllowExplicitConversions,
7260 const Qualifiers &VisibleTypeConversionsQuals);
7262 /// pointer_begin - First pointer type found;
7263 iterator pointer_begin() { return PointerTypes.begin(); }
7265 /// pointer_end - Past the last pointer type found;
7266 iterator pointer_end() { return PointerTypes.end(); }
7268 /// member_pointer_begin - First member pointer type found;
7269 iterator member_pointer_begin() { return MemberPointerTypes.begin(); }
7271 /// member_pointer_end - Past the last member pointer type found;
7272 iterator member_pointer_end() { return MemberPointerTypes.end(); }
7274 /// enumeration_begin - First enumeration type found;
7275 iterator enumeration_begin() { return EnumerationTypes.begin(); }
7277 /// enumeration_end - Past the last enumeration type found;
7278 iterator enumeration_end() { return EnumerationTypes.end(); }
7280 iterator vector_begin() { return VectorTypes.begin(); }
7281 iterator vector_end() { return VectorTypes.end(); }
7283 bool hasNonRecordTypes() { return HasNonRecordTypes; }
7284 bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; }
7285 bool hasNullPtrType() const { return HasNullPtrType; }
7288 } // end anonymous namespace
7290 /// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to
7291 /// the set of pointer types along with any more-qualified variants of
7292 /// that type. For example, if @p Ty is "int const *", this routine
7293 /// will add "int const *", "int const volatile *", "int const
7294 /// restrict *", and "int const volatile restrict *" to the set of
7295 /// pointer types. Returns true if the add of @p Ty itself succeeded,
7296 /// false otherwise.
7298 /// FIXME: what to do about extended qualifiers?
7300 BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
7301 const Qualifiers &VisibleQuals) {
7303 // Insert this type.
7304 if (!PointerTypes.insert(Ty))
7308 const PointerType *PointerTy = Ty->getAs<PointerType>();
7309 bool buildObjCPtr = false;
7311 const ObjCObjectPointerType *PTy = Ty->castAs<ObjCObjectPointerType>();
7312 PointeeTy = PTy->getPointeeType();
7313 buildObjCPtr = true;
7315 PointeeTy = PointerTy->getPointeeType();
7318 // Don't add qualified variants of arrays. For one, they're not allowed
7319 // (the qualifier would sink to the element type), and for another, the
7320 // only overload situation where it matters is subscript or pointer +- int,
7321 // and those shouldn't have qualifier variants anyway.
7322 if (PointeeTy->isArrayType())
7325 unsigned BaseCVR = PointeeTy.getCVRQualifiers();
7326 bool hasVolatile = VisibleQuals.hasVolatile();
7327 bool hasRestrict = VisibleQuals.hasRestrict();
7329 // Iterate through all strict supersets of BaseCVR.
7330 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) {
7331 if ((CVR | BaseCVR) != CVR) continue;
7332 // Skip over volatile if no volatile found anywhere in the types.
7333 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue;
7335 // Skip over restrict if no restrict found anywhere in the types, or if
7336 // the type cannot be restrict-qualified.
7337 if ((CVR & Qualifiers::Restrict) &&
7339 (!(PointeeTy->isAnyPointerType() || PointeeTy->isReferenceType()))))
7342 // Build qualified pointee type.
7343 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR);
7345 // Build qualified pointer type.
7346 QualType QPointerTy;
7348 QPointerTy = Context.getPointerType(QPointeeTy);
7350 QPointerTy = Context.getObjCObjectPointerType(QPointeeTy);
7352 // Insert qualified pointer type.
7353 PointerTypes.insert(QPointerTy);
7359 /// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty
7360 /// to the set of pointer types along with any more-qualified variants of
7361 /// that type. For example, if @p Ty is "int const *", this routine
7362 /// will add "int const *", "int const volatile *", "int const
7363 /// restrict *", and "int const volatile restrict *" to the set of
7364 /// pointer types. Returns true if the add of @p Ty itself succeeded,
7365 /// false otherwise.
7367 /// FIXME: what to do about extended qualifiers?
7369 BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants(
7371 // Insert this type.
7372 if (!MemberPointerTypes.insert(Ty))
7375 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>();
7376 assert(PointerTy && "type was not a member pointer type!");
7378 QualType PointeeTy = PointerTy->getPointeeType();
7379 // Don't add qualified variants of arrays. For one, they're not allowed
7380 // (the qualifier would sink to the element type), and for another, the
7381 // only overload situation where it matters is subscript or pointer +- int,
7382 // and those shouldn't have qualifier variants anyway.
7383 if (PointeeTy->isArrayType())
7385 const Type *ClassTy = PointerTy->getClass();
7387 // Iterate through all strict supersets of the pointee type's CVR
7389 unsigned BaseCVR = PointeeTy.getCVRQualifiers();
7390 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) {
7391 if ((CVR | BaseCVR) != CVR) continue;
7393 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR);
7394 MemberPointerTypes.insert(
7395 Context.getMemberPointerType(QPointeeTy, ClassTy));
7401 /// AddTypesConvertedFrom - Add each of the types to which the type @p
7402 /// Ty can be implicit converted to the given set of @p Types. We're
7403 /// primarily interested in pointer types and enumeration types. We also
7404 /// take member pointer types, for the conditional operator.
7405 /// AllowUserConversions is true if we should look at the conversion
7406 /// functions of a class type, and AllowExplicitConversions if we
7407 /// should also include the explicit conversion functions of a class
7410 BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty,
7412 bool AllowUserConversions,
7413 bool AllowExplicitConversions,
7414 const Qualifiers &VisibleQuals) {
7415 // Only deal with canonical types.
7416 Ty = Context.getCanonicalType(Ty);
7418 // Look through reference types; they aren't part of the type of an
7419 // expression for the purposes of conversions.
7420 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>())
7421 Ty = RefTy->getPointeeType();
7423 // If we're dealing with an array type, decay to the pointer.
7424 if (Ty->isArrayType())
7425 Ty = SemaRef.Context.getArrayDecayedType(Ty);
7427 // Otherwise, we don't care about qualifiers on the type.
7428 Ty = Ty.getLocalUnqualifiedType();
7430 // Flag if we ever add a non-record type.
7431 const RecordType *TyRec = Ty->getAs<RecordType>();
7432 HasNonRecordTypes = HasNonRecordTypes || !TyRec;
7434 // Flag if we encounter an arithmetic type.
7435 HasArithmeticOrEnumeralTypes =
7436 HasArithmeticOrEnumeralTypes || Ty->isArithmeticType();
7438 if (Ty->isObjCIdType() || Ty->isObjCClassType())
7439 PointerTypes.insert(Ty);
7440 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) {
7441 // Insert our type, and its more-qualified variants, into the set
7443 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals))
7445 } else if (Ty->isMemberPointerType()) {
7446 // Member pointers are far easier, since the pointee can't be converted.
7447 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty))
7449 } else if (Ty->isEnumeralType()) {
7450 HasArithmeticOrEnumeralTypes = true;
7451 EnumerationTypes.insert(Ty);
7452 } else if (Ty->isVectorType()) {
7453 // We treat vector types as arithmetic types in many contexts as an
7455 HasArithmeticOrEnumeralTypes = true;
7456 VectorTypes.insert(Ty);
7457 } else if (Ty->isNullPtrType()) {
7458 HasNullPtrType = true;
7459 } else if (AllowUserConversions && TyRec) {
7460 // No conversion functions in incomplete types.
7461 if (!SemaRef.isCompleteType(Loc, Ty))
7464 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl());
7465 for (NamedDecl *D : ClassDecl->getVisibleConversionFunctions()) {
7466 if (isa<UsingShadowDecl>(D))
7467 D = cast<UsingShadowDecl>(D)->getTargetDecl();
7469 // Skip conversion function templates; they don't tell us anything
7470 // about which builtin types we can convert to.
7471 if (isa<FunctionTemplateDecl>(D))
7474 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D);
7475 if (AllowExplicitConversions || !Conv->isExplicit()) {
7476 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false,
7483 /// \brief Helper function for AddBuiltinOperatorCandidates() that adds
7484 /// the volatile- and non-volatile-qualified assignment operators for the
7485 /// given type to the candidate set.
7486 static void AddBuiltinAssignmentOperatorCandidates(Sema &S,
7488 ArrayRef<Expr *> Args,
7489 OverloadCandidateSet &CandidateSet) {
7490 QualType ParamTypes[2];
7492 // T& operator=(T&, T)
7493 ParamTypes[0] = S.Context.getLValueReferenceType(T);
7495 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7496 /*IsAssignmentOperator=*/true);
7498 if (!S.Context.getCanonicalType(T).isVolatileQualified()) {
7499 // volatile T& operator=(volatile T&, T)
7501 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T));
7503 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7504 /*IsAssignmentOperator=*/true);
7508 /// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers,
7509 /// if any, found in visible type conversion functions found in ArgExpr's type.
7510 static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) {
7512 const RecordType *TyRec;
7513 if (const MemberPointerType *RHSMPType =
7514 ArgExpr->getType()->getAs<MemberPointerType>())
7515 TyRec = RHSMPType->getClass()->getAs<RecordType>();
7517 TyRec = ArgExpr->getType()->getAs<RecordType>();
7519 // Just to be safe, assume the worst case.
7520 VRQuals.addVolatile();
7521 VRQuals.addRestrict();
7525 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl());
7526 if (!ClassDecl->hasDefinition())
7529 for (NamedDecl *D : ClassDecl->getVisibleConversionFunctions()) {
7530 if (isa<UsingShadowDecl>(D))
7531 D = cast<UsingShadowDecl>(D)->getTargetDecl();
7532 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) {
7533 QualType CanTy = Context.getCanonicalType(Conv->getConversionType());
7534 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>())
7535 CanTy = ResTypeRef->getPointeeType();
7536 // Need to go down the pointer/mempointer chain and add qualifiers
7540 if (CanTy.isRestrictQualified())
7541 VRQuals.addRestrict();
7542 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>())
7543 CanTy = ResTypePtr->getPointeeType();
7544 else if (const MemberPointerType *ResTypeMPtr =
7545 CanTy->getAs<MemberPointerType>())
7546 CanTy = ResTypeMPtr->getPointeeType();
7549 if (CanTy.isVolatileQualified())
7550 VRQuals.addVolatile();
7551 if (VRQuals.hasRestrict() && VRQuals.hasVolatile())
7561 /// \brief Helper class to manage the addition of builtin operator overload
7562 /// candidates. It provides shared state and utility methods used throughout
7563 /// the process, as well as a helper method to add each group of builtin
7564 /// operator overloads from the standard to a candidate set.
7565 class BuiltinOperatorOverloadBuilder {
7566 // Common instance state available to all overload candidate addition methods.
7568 ArrayRef<Expr *> Args;
7569 Qualifiers VisibleTypeConversionsQuals;
7570 bool HasArithmeticOrEnumeralCandidateType;
7571 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes;
7572 OverloadCandidateSet &CandidateSet;
7574 // Define some constants used to index and iterate over the arithemetic types
7575 // provided via the getArithmeticType() method below.
7576 // The "promoted arithmetic types" are the arithmetic
7577 // types are that preserved by promotion (C++ [over.built]p2).
7578 static const unsigned FirstIntegralType = 4;
7579 static const unsigned LastIntegralType = 21;
7580 static const unsigned FirstPromotedIntegralType = 4,
7581 LastPromotedIntegralType = 12;
7582 static const unsigned FirstPromotedArithmeticType = 0,
7583 LastPromotedArithmeticType = 12;
7584 static const unsigned NumArithmeticTypes = 21;
7586 /// \brief Get the canonical type for a given arithmetic type index.
7587 CanQualType getArithmeticType(unsigned index) {
7588 assert(index < NumArithmeticTypes);
7589 static CanQualType ASTContext::* const
7590 ArithmeticTypes[NumArithmeticTypes] = {
7591 // Start of promoted types.
7592 &ASTContext::FloatTy,
7593 &ASTContext::DoubleTy,
7594 &ASTContext::LongDoubleTy,
7595 &ASTContext::Float128Ty,
7597 // Start of integral types.
7599 &ASTContext::LongTy,
7600 &ASTContext::LongLongTy,
7601 &ASTContext::Int128Ty,
7602 &ASTContext::UnsignedIntTy,
7603 &ASTContext::UnsignedLongTy,
7604 &ASTContext::UnsignedLongLongTy,
7605 &ASTContext::UnsignedInt128Ty,
7606 // End of promoted types.
7608 &ASTContext::BoolTy,
7609 &ASTContext::CharTy,
7610 &ASTContext::WCharTy,
7611 &ASTContext::Char16Ty,
7612 &ASTContext::Char32Ty,
7613 &ASTContext::SignedCharTy,
7614 &ASTContext::ShortTy,
7615 &ASTContext::UnsignedCharTy,
7616 &ASTContext::UnsignedShortTy,
7617 // End of integral types.
7618 // FIXME: What about complex? What about half?
7620 return S.Context.*ArithmeticTypes[index];
7623 /// \brief Gets the canonical type resulting from the usual arithemetic
7624 /// converions for the given arithmetic types.
7625 CanQualType getUsualArithmeticConversions(unsigned L, unsigned R) {
7626 // Accelerator table for performing the usual arithmetic conversions.
7627 // The rules are basically:
7628 // - if either is floating-point, use the wider floating-point
7629 // - if same signedness, use the higher rank
7630 // - if same size, use unsigned of the higher rank
7631 // - use the larger type
7632 // These rules, together with the axiom that higher ranks are
7633 // never smaller, are sufficient to precompute all of these results
7634 // *except* when dealing with signed types of higher rank.
7635 // (we could precompute SLL x UI for all known platforms, but it's
7636 // better not to make any assumptions).
7637 // We assume that int128 has a higher rank than long long on all platforms.
7638 enum PromotedType : int8_t {
7640 Flt, Dbl, LDbl, SI, SL, SLL, S128, UI, UL, ULL, U128
7642 static const PromotedType ConversionsTable[LastPromotedArithmeticType]
7643 [LastPromotedArithmeticType] = {
7644 /* Flt*/ { Flt, Dbl, LDbl, Flt, Flt, Flt, Flt, Flt, Flt, Flt, Flt },
7645 /* Dbl*/ { Dbl, Dbl, LDbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl },
7646 /*LDbl*/ { LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl },
7647 /* SI*/ { Flt, Dbl, LDbl, SI, SL, SLL, S128, UI, UL, ULL, U128 },
7648 /* SL*/ { Flt, Dbl, LDbl, SL, SL, SLL, S128, Dep, UL, ULL, U128 },
7649 /* SLL*/ { Flt, Dbl, LDbl, SLL, SLL, SLL, S128, Dep, Dep, ULL, U128 },
7650 /*S128*/ { Flt, Dbl, LDbl, S128, S128, S128, S128, S128, S128, S128, U128 },
7651 /* UI*/ { Flt, Dbl, LDbl, UI, Dep, Dep, S128, UI, UL, ULL, U128 },
7652 /* UL*/ { Flt, Dbl, LDbl, UL, UL, Dep, S128, UL, UL, ULL, U128 },
7653 /* ULL*/ { Flt, Dbl, LDbl, ULL, ULL, ULL, S128, ULL, ULL, ULL, U128 },
7654 /*U128*/ { Flt, Dbl, LDbl, U128, U128, U128, U128, U128, U128, U128, U128 },
7657 assert(L < LastPromotedArithmeticType);
7658 assert(R < LastPromotedArithmeticType);
7659 int Idx = ConversionsTable[L][R];
7661 // Fast path: the table gives us a concrete answer.
7662 if (Idx != Dep) return getArithmeticType(Idx);
7664 // Slow path: we need to compare widths.
7665 // An invariant is that the signed type has higher rank.
7666 CanQualType LT = getArithmeticType(L),
7667 RT = getArithmeticType(R);
7668 unsigned LW = S.Context.getIntWidth(LT),
7669 RW = S.Context.getIntWidth(RT);
7671 // If they're different widths, use the signed type.
7672 if (LW > RW) return LT;
7673 else if (LW < RW) return RT;
7675 // Otherwise, use the unsigned type of the signed type's rank.
7676 if (L == SL || R == SL) return S.Context.UnsignedLongTy;
7677 assert(L == SLL || R == SLL);
7678 return S.Context.UnsignedLongLongTy;
7681 /// \brief Helper method to factor out the common pattern of adding overloads
7682 /// for '++' and '--' builtin operators.
7683 void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy,
7686 QualType ParamTypes[2] = {
7687 S.Context.getLValueReferenceType(CandidateTy),
7691 // Non-volatile version.
7692 if (Args.size() == 1)
7693 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
7695 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet);
7697 // Use a heuristic to reduce number of builtin candidates in the set:
7698 // add volatile version only if there are conversions to a volatile type.
7701 S.Context.getLValueReferenceType(
7702 S.Context.getVolatileType(CandidateTy));
7703 if (Args.size() == 1)
7704 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
7706 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet);
7709 // Add restrict version only if there are conversions to a restrict type
7710 // and our candidate type is a non-restrict-qualified pointer.
7711 if (HasRestrict && CandidateTy->isAnyPointerType() &&
7712 !CandidateTy.isRestrictQualified()) {
7714 = S.Context.getLValueReferenceType(
7715 S.Context.getCVRQualifiedType(CandidateTy, Qualifiers::Restrict));
7716 if (Args.size() == 1)
7717 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
7719 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet);
7723 = S.Context.getLValueReferenceType(
7724 S.Context.getCVRQualifiedType(CandidateTy,
7725 (Qualifiers::Volatile |
7726 Qualifiers::Restrict)));
7727 if (Args.size() == 1)
7728 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
7730 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet);
7737 BuiltinOperatorOverloadBuilder(
7738 Sema &S, ArrayRef<Expr *> Args,
7739 Qualifiers VisibleTypeConversionsQuals,
7740 bool HasArithmeticOrEnumeralCandidateType,
7741 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes,
7742 OverloadCandidateSet &CandidateSet)
7744 VisibleTypeConversionsQuals(VisibleTypeConversionsQuals),
7745 HasArithmeticOrEnumeralCandidateType(
7746 HasArithmeticOrEnumeralCandidateType),
7747 CandidateTypes(CandidateTypes),
7748 CandidateSet(CandidateSet) {
7749 // Validate some of our static helper constants in debug builds.
7750 assert(getArithmeticType(FirstPromotedIntegralType) == S.Context.IntTy &&
7751 "Invalid first promoted integral type");
7752 assert(getArithmeticType(LastPromotedIntegralType - 1)
7753 == S.Context.UnsignedInt128Ty &&
7754 "Invalid last promoted integral type");
7755 assert(getArithmeticType(FirstPromotedArithmeticType)
7756 == S.Context.FloatTy &&
7757 "Invalid first promoted arithmetic type");
7758 assert(getArithmeticType(LastPromotedArithmeticType - 1)
7759 == S.Context.UnsignedInt128Ty &&
7760 "Invalid last promoted arithmetic type");
7763 // C++ [over.built]p3:
7765 // For every pair (T, VQ), where T is an arithmetic type, and VQ
7766 // is either volatile or empty, there exist candidate operator
7767 // functions of the form
7769 // VQ T& operator++(VQ T&);
7770 // T operator++(VQ T&, int);
7772 // C++ [over.built]p4:
7774 // For every pair (T, VQ), where T is an arithmetic type other
7775 // than bool, and VQ is either volatile or empty, there exist
7776 // candidate operator functions of the form
7778 // VQ T& operator--(VQ T&);
7779 // T operator--(VQ T&, int);
7780 void addPlusPlusMinusMinusArithmeticOverloads(OverloadedOperatorKind Op) {
7781 if (!HasArithmeticOrEnumeralCandidateType)
7784 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1);
7785 Arith < NumArithmeticTypes; ++Arith) {
7786 addPlusPlusMinusMinusStyleOverloads(
7787 getArithmeticType(Arith),
7788 VisibleTypeConversionsQuals.hasVolatile(),
7789 VisibleTypeConversionsQuals.hasRestrict());
7793 // C++ [over.built]p5:
7795 // For every pair (T, VQ), where T is a cv-qualified or
7796 // cv-unqualified object type, and VQ is either volatile or
7797 // empty, there exist candidate operator functions of the form
7799 // T*VQ& operator++(T*VQ&);
7800 // T*VQ& operator--(T*VQ&);
7801 // T* operator++(T*VQ&, int);
7802 // T* operator--(T*VQ&, int);
7803 void addPlusPlusMinusMinusPointerOverloads() {
7804 for (BuiltinCandidateTypeSet::iterator
7805 Ptr = CandidateTypes[0].pointer_begin(),
7806 PtrEnd = CandidateTypes[0].pointer_end();
7807 Ptr != PtrEnd; ++Ptr) {
7808 // Skip pointer types that aren't pointers to object types.
7809 if (!(*Ptr)->getPointeeType()->isObjectType())
7812 addPlusPlusMinusMinusStyleOverloads(*Ptr,
7813 (!(*Ptr).isVolatileQualified() &&
7814 VisibleTypeConversionsQuals.hasVolatile()),
7815 (!(*Ptr).isRestrictQualified() &&
7816 VisibleTypeConversionsQuals.hasRestrict()));
7820 // C++ [over.built]p6:
7821 // For every cv-qualified or cv-unqualified object type T, there
7822 // exist candidate operator functions of the form
7824 // T& operator*(T*);
7826 // C++ [over.built]p7:
7827 // For every function type T that does not have cv-qualifiers or a
7828 // ref-qualifier, there exist candidate operator functions of the form
7829 // T& operator*(T*);
7830 void addUnaryStarPointerOverloads() {
7831 for (BuiltinCandidateTypeSet::iterator
7832 Ptr = CandidateTypes[0].pointer_begin(),
7833 PtrEnd = CandidateTypes[0].pointer_end();
7834 Ptr != PtrEnd; ++Ptr) {
7835 QualType ParamTy = *Ptr;
7836 QualType PointeeTy = ParamTy->getPointeeType();
7837 if (!PointeeTy->isObjectType() && !PointeeTy->isFunctionType())
7840 if (const FunctionProtoType *Proto =PointeeTy->getAs<FunctionProtoType>())
7841 if (Proto->getTypeQuals() || Proto->getRefQualifier())
7844 S.AddBuiltinCandidate(S.Context.getLValueReferenceType(PointeeTy),
7845 &ParamTy, Args, CandidateSet);
7849 // C++ [over.built]p9:
7850 // For every promoted arithmetic type T, there exist candidate
7851 // operator functions of the form
7855 void addUnaryPlusOrMinusArithmeticOverloads() {
7856 if (!HasArithmeticOrEnumeralCandidateType)
7859 for (unsigned Arith = FirstPromotedArithmeticType;
7860 Arith < LastPromotedArithmeticType; ++Arith) {
7861 QualType ArithTy = getArithmeticType(Arith);
7862 S.AddBuiltinCandidate(ArithTy, &ArithTy, Args, CandidateSet);
7865 // Extension: We also add these operators for vector types.
7866 for (BuiltinCandidateTypeSet::iterator
7867 Vec = CandidateTypes[0].vector_begin(),
7868 VecEnd = CandidateTypes[0].vector_end();
7869 Vec != VecEnd; ++Vec) {
7870 QualType VecTy = *Vec;
7871 S.AddBuiltinCandidate(VecTy, &VecTy, Args, CandidateSet);
7875 // C++ [over.built]p8:
7876 // For every type T, there exist candidate operator functions of
7879 // T* operator+(T*);
7880 void addUnaryPlusPointerOverloads() {
7881 for (BuiltinCandidateTypeSet::iterator
7882 Ptr = CandidateTypes[0].pointer_begin(),
7883 PtrEnd = CandidateTypes[0].pointer_end();
7884 Ptr != PtrEnd; ++Ptr) {
7885 QualType ParamTy = *Ptr;
7886 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, CandidateSet);
7890 // C++ [over.built]p10:
7891 // For every promoted integral type T, there exist candidate
7892 // operator functions of the form
7895 void addUnaryTildePromotedIntegralOverloads() {
7896 if (!HasArithmeticOrEnumeralCandidateType)
7899 for (unsigned Int = FirstPromotedIntegralType;
7900 Int < LastPromotedIntegralType; ++Int) {
7901 QualType IntTy = getArithmeticType(Int);
7902 S.AddBuiltinCandidate(IntTy, &IntTy, Args, CandidateSet);
7905 // Extension: We also add this operator for vector types.
7906 for (BuiltinCandidateTypeSet::iterator
7907 Vec = CandidateTypes[0].vector_begin(),
7908 VecEnd = CandidateTypes[0].vector_end();
7909 Vec != VecEnd; ++Vec) {
7910 QualType VecTy = *Vec;
7911 S.AddBuiltinCandidate(VecTy, &VecTy, Args, CandidateSet);
7915 // C++ [over.match.oper]p16:
7916 // For every pointer to member type T or type std::nullptr_t, there
7917 // exist candidate operator functions of the form
7919 // bool operator==(T,T);
7920 // bool operator!=(T,T);
7921 void addEqualEqualOrNotEqualMemberPointerOrNullptrOverloads() {
7922 /// Set of (canonical) types that we've already handled.
7923 llvm::SmallPtrSet<QualType, 8> AddedTypes;
7925 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7926 for (BuiltinCandidateTypeSet::iterator
7927 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(),
7928 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end();
7929 MemPtr != MemPtrEnd;
7931 // Don't add the same builtin candidate twice.
7932 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr)).second)
7935 QualType ParamTypes[2] = { *MemPtr, *MemPtr };
7936 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet);
7939 if (CandidateTypes[ArgIdx].hasNullPtrType()) {
7940 CanQualType NullPtrTy = S.Context.getCanonicalType(S.Context.NullPtrTy);
7941 if (AddedTypes.insert(NullPtrTy).second) {
7942 QualType ParamTypes[2] = { NullPtrTy, NullPtrTy };
7943 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args,
7950 // C++ [over.built]p15:
7952 // For every T, where T is an enumeration type or a pointer type,
7953 // there exist candidate operator functions of the form
7955 // bool operator<(T, T);
7956 // bool operator>(T, T);
7957 // bool operator<=(T, T);
7958 // bool operator>=(T, T);
7959 // bool operator==(T, T);
7960 // bool operator!=(T, T);
7961 void addRelationalPointerOrEnumeralOverloads() {
7962 // C++ [over.match.oper]p3:
7963 // [...]the built-in candidates include all of the candidate operator
7964 // functions defined in 13.6 that, compared to the given operator, [...]
7965 // do not have the same parameter-type-list as any non-template non-member
7968 // Note that in practice, this only affects enumeration types because there
7969 // aren't any built-in candidates of record type, and a user-defined operator
7970 // must have an operand of record or enumeration type. Also, the only other
7971 // overloaded operator with enumeration arguments, operator=,
7972 // cannot be overloaded for enumeration types, so this is the only place
7973 // where we must suppress candidates like this.
7974 llvm::DenseSet<std::pair<CanQualType, CanQualType> >
7975 UserDefinedBinaryOperators;
7977 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7978 if (CandidateTypes[ArgIdx].enumeration_begin() !=
7979 CandidateTypes[ArgIdx].enumeration_end()) {
7980 for (OverloadCandidateSet::iterator C = CandidateSet.begin(),
7981 CEnd = CandidateSet.end();
7983 if (!C->Viable || !C->Function || C->Function->getNumParams() != 2)
7986 if (C->Function->isFunctionTemplateSpecialization())
7989 QualType FirstParamType =
7990 C->Function->getParamDecl(0)->getType().getUnqualifiedType();
7991 QualType SecondParamType =
7992 C->Function->getParamDecl(1)->getType().getUnqualifiedType();
7994 // Skip if either parameter isn't of enumeral type.
7995 if (!FirstParamType->isEnumeralType() ||
7996 !SecondParamType->isEnumeralType())
7999 // Add this operator to the set of known user-defined operators.
8000 UserDefinedBinaryOperators.insert(
8001 std::make_pair(S.Context.getCanonicalType(FirstParamType),
8002 S.Context.getCanonicalType(SecondParamType)));
8007 /// Set of (canonical) types that we've already handled.
8008 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8010 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
8011 for (BuiltinCandidateTypeSet::iterator
8012 Ptr = CandidateTypes[ArgIdx].pointer_begin(),
8013 PtrEnd = CandidateTypes[ArgIdx].pointer_end();
8014 Ptr != PtrEnd; ++Ptr) {
8015 // Don't add the same builtin candidate twice.
8016 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
8019 QualType ParamTypes[2] = { *Ptr, *Ptr };
8020 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet);
8022 for (BuiltinCandidateTypeSet::iterator
8023 Enum = CandidateTypes[ArgIdx].enumeration_begin(),
8024 EnumEnd = CandidateTypes[ArgIdx].enumeration_end();
8025 Enum != EnumEnd; ++Enum) {
8026 CanQualType CanonType = S.Context.getCanonicalType(*Enum);
8028 // Don't add the same builtin candidate twice, or if a user defined
8029 // candidate exists.
8030 if (!AddedTypes.insert(CanonType).second ||
8031 UserDefinedBinaryOperators.count(std::make_pair(CanonType,
8035 QualType ParamTypes[2] = { *Enum, *Enum };
8036 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet);
8041 // C++ [over.built]p13:
8043 // For every cv-qualified or cv-unqualified object type T
8044 // there exist candidate operator functions of the form
8046 // T* operator+(T*, ptrdiff_t);
8047 // T& operator[](T*, ptrdiff_t); [BELOW]
8048 // T* operator-(T*, ptrdiff_t);
8049 // T* operator+(ptrdiff_t, T*);
8050 // T& operator[](ptrdiff_t, T*); [BELOW]
8052 // C++ [over.built]p14:
8054 // For every T, where T is a pointer to object type, there
8055 // exist candidate operator functions of the form
8057 // ptrdiff_t operator-(T, T);
8058 void addBinaryPlusOrMinusPointerOverloads(OverloadedOperatorKind Op) {
8059 /// Set of (canonical) types that we've already handled.
8060 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8062 for (int Arg = 0; Arg < 2; ++Arg) {
8063 QualType AsymmetricParamTypes[2] = {
8064 S.Context.getPointerDiffType(),
8065 S.Context.getPointerDiffType(),
8067 for (BuiltinCandidateTypeSet::iterator
8068 Ptr = CandidateTypes[Arg].pointer_begin(),
8069 PtrEnd = CandidateTypes[Arg].pointer_end();
8070 Ptr != PtrEnd; ++Ptr) {
8071 QualType PointeeTy = (*Ptr)->getPointeeType();
8072 if (!PointeeTy->isObjectType())
8075 AsymmetricParamTypes[Arg] = *Ptr;
8076 if (Arg == 0 || Op == OO_Plus) {
8077 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t)
8078 // T* operator+(ptrdiff_t, T*);
8079 S.AddBuiltinCandidate(*Ptr, AsymmetricParamTypes, Args, CandidateSet);
8081 if (Op == OO_Minus) {
8082 // ptrdiff_t operator-(T, T);
8083 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
8086 QualType ParamTypes[2] = { *Ptr, *Ptr };
8087 S.AddBuiltinCandidate(S.Context.getPointerDiffType(), ParamTypes,
8088 Args, CandidateSet);
8094 // C++ [over.built]p12:
8096 // For every pair of promoted arithmetic types L and R, there
8097 // exist candidate operator functions of the form
8099 // LR operator*(L, R);
8100 // LR operator/(L, R);
8101 // LR operator+(L, R);
8102 // LR operator-(L, R);
8103 // bool operator<(L, R);
8104 // bool operator>(L, R);
8105 // bool operator<=(L, R);
8106 // bool operator>=(L, R);
8107 // bool operator==(L, R);
8108 // bool operator!=(L, R);
8110 // where LR is the result of the usual arithmetic conversions
8111 // between types L and R.
8113 // C++ [over.built]p24:
8115 // For every pair of promoted arithmetic types L and R, there exist
8116 // candidate operator functions of the form
8118 // LR operator?(bool, L, R);
8120 // where LR is the result of the usual arithmetic conversions
8121 // between types L and R.
8122 // Our candidates ignore the first parameter.
8123 void addGenericBinaryArithmeticOverloads(bool isComparison) {
8124 if (!HasArithmeticOrEnumeralCandidateType)
8127 for (unsigned Left = FirstPromotedArithmeticType;
8128 Left < LastPromotedArithmeticType; ++Left) {
8129 for (unsigned Right = FirstPromotedArithmeticType;
8130 Right < LastPromotedArithmeticType; ++Right) {
8131 QualType LandR[2] = { getArithmeticType(Left),
8132 getArithmeticType(Right) };
8134 isComparison ? S.Context.BoolTy
8135 : getUsualArithmeticConversions(Left, Right);
8136 S.AddBuiltinCandidate(Result, LandR, Args, CandidateSet);
8140 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the
8141 // conditional operator for vector types.
8142 for (BuiltinCandidateTypeSet::iterator
8143 Vec1 = CandidateTypes[0].vector_begin(),
8144 Vec1End = CandidateTypes[0].vector_end();
8145 Vec1 != Vec1End; ++Vec1) {
8146 for (BuiltinCandidateTypeSet::iterator
8147 Vec2 = CandidateTypes[1].vector_begin(),
8148 Vec2End = CandidateTypes[1].vector_end();
8149 Vec2 != Vec2End; ++Vec2) {
8150 QualType LandR[2] = { *Vec1, *Vec2 };
8151 QualType Result = S.Context.BoolTy;
8152 if (!isComparison) {
8153 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType())
8159 S.AddBuiltinCandidate(Result, LandR, Args, CandidateSet);
8164 // C++ [over.built]p17:
8166 // For every pair of promoted integral types L and R, there
8167 // exist candidate operator functions of the form
8169 // LR operator%(L, R);
8170 // LR operator&(L, R);
8171 // LR operator^(L, R);
8172 // LR operator|(L, R);
8173 // L operator<<(L, R);
8174 // L operator>>(L, R);
8176 // where LR is the result of the usual arithmetic conversions
8177 // between types L and R.
8178 void addBinaryBitwiseArithmeticOverloads(OverloadedOperatorKind Op) {
8179 if (!HasArithmeticOrEnumeralCandidateType)
8182 for (unsigned Left = FirstPromotedIntegralType;
8183 Left < LastPromotedIntegralType; ++Left) {
8184 for (unsigned Right = FirstPromotedIntegralType;
8185 Right < LastPromotedIntegralType; ++Right) {
8186 QualType LandR[2] = { getArithmeticType(Left),
8187 getArithmeticType(Right) };
8188 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater)
8190 : getUsualArithmeticConversions(Left, Right);
8191 S.AddBuiltinCandidate(Result, LandR, Args, CandidateSet);
8196 // C++ [over.built]p20:
8198 // For every pair (T, VQ), where T is an enumeration or
8199 // pointer to member type and VQ is either volatile or
8200 // empty, there exist candidate operator functions of the form
8202 // VQ T& operator=(VQ T&, T);
8203 void addAssignmentMemberPointerOrEnumeralOverloads() {
8204 /// Set of (canonical) types that we've already handled.
8205 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8207 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) {
8208 for (BuiltinCandidateTypeSet::iterator
8209 Enum = CandidateTypes[ArgIdx].enumeration_begin(),
8210 EnumEnd = CandidateTypes[ArgIdx].enumeration_end();
8211 Enum != EnumEnd; ++Enum) {
8212 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum)).second)
8215 AddBuiltinAssignmentOperatorCandidates(S, *Enum, Args, CandidateSet);
8218 for (BuiltinCandidateTypeSet::iterator
8219 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(),
8220 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end();
8221 MemPtr != MemPtrEnd; ++MemPtr) {
8222 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr)).second)
8225 AddBuiltinAssignmentOperatorCandidates(S, *MemPtr, Args, CandidateSet);
8230 // C++ [over.built]p19:
8232 // For every pair (T, VQ), where T is any type and VQ is either
8233 // volatile or empty, there exist candidate operator functions
8236 // T*VQ& operator=(T*VQ&, T*);
8238 // C++ [over.built]p21:
8240 // For every pair (T, VQ), where T is a cv-qualified or
8241 // cv-unqualified object type and VQ is either volatile or
8242 // empty, there exist candidate operator functions of the form
8244 // T*VQ& operator+=(T*VQ&, ptrdiff_t);
8245 // T*VQ& operator-=(T*VQ&, ptrdiff_t);
8246 void addAssignmentPointerOverloads(bool isEqualOp) {
8247 /// Set of (canonical) types that we've already handled.
8248 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8250 for (BuiltinCandidateTypeSet::iterator
8251 Ptr = CandidateTypes[0].pointer_begin(),
8252 PtrEnd = CandidateTypes[0].pointer_end();
8253 Ptr != PtrEnd; ++Ptr) {
8254 // If this is operator=, keep track of the builtin candidates we added.
8256 AddedTypes.insert(S.Context.getCanonicalType(*Ptr));
8257 else if (!(*Ptr)->getPointeeType()->isObjectType())
8260 // non-volatile version
8261 QualType ParamTypes[2] = {
8262 S.Context.getLValueReferenceType(*Ptr),
8263 isEqualOp ? *Ptr : S.Context.getPointerDiffType(),
8265 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8266 /*IsAssigmentOperator=*/ isEqualOp);
8268 bool NeedVolatile = !(*Ptr).isVolatileQualified() &&
8269 VisibleTypeConversionsQuals.hasVolatile();
8273 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr));
8274 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8275 /*IsAssigmentOperator=*/isEqualOp);
8278 if (!(*Ptr).isRestrictQualified() &&
8279 VisibleTypeConversionsQuals.hasRestrict()) {
8282 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr));
8283 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8284 /*IsAssigmentOperator=*/isEqualOp);
8287 // volatile restrict version
8289 = S.Context.getLValueReferenceType(
8290 S.Context.getCVRQualifiedType(*Ptr,
8291 (Qualifiers::Volatile |
8292 Qualifiers::Restrict)));
8293 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8294 /*IsAssigmentOperator=*/isEqualOp);
8300 for (BuiltinCandidateTypeSet::iterator
8301 Ptr = CandidateTypes[1].pointer_begin(),
8302 PtrEnd = CandidateTypes[1].pointer_end();
8303 Ptr != PtrEnd; ++Ptr) {
8304 // Make sure we don't add the same candidate twice.
8305 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
8308 QualType ParamTypes[2] = {
8309 S.Context.getLValueReferenceType(*Ptr),
8313 // non-volatile version
8314 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8315 /*IsAssigmentOperator=*/true);
8317 bool NeedVolatile = !(*Ptr).isVolatileQualified() &&
8318 VisibleTypeConversionsQuals.hasVolatile();
8322 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr));
8323 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8324 /*IsAssigmentOperator=*/true);
8327 if (!(*Ptr).isRestrictQualified() &&
8328 VisibleTypeConversionsQuals.hasRestrict()) {
8331 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr));
8332 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8333 /*IsAssigmentOperator=*/true);
8336 // volatile restrict version
8338 = S.Context.getLValueReferenceType(
8339 S.Context.getCVRQualifiedType(*Ptr,
8340 (Qualifiers::Volatile |
8341 Qualifiers::Restrict)));
8342 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8343 /*IsAssigmentOperator=*/true);
8350 // C++ [over.built]p18:
8352 // For every triple (L, VQ, R), where L is an arithmetic type,
8353 // VQ is either volatile or empty, and R is a promoted
8354 // arithmetic type, there exist candidate operator functions of
8357 // VQ L& operator=(VQ L&, R);
8358 // VQ L& operator*=(VQ L&, R);
8359 // VQ L& operator/=(VQ L&, R);
8360 // VQ L& operator+=(VQ L&, R);
8361 // VQ L& operator-=(VQ L&, R);
8362 void addAssignmentArithmeticOverloads(bool isEqualOp) {
8363 if (!HasArithmeticOrEnumeralCandidateType)
8366 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) {
8367 for (unsigned Right = FirstPromotedArithmeticType;
8368 Right < LastPromotedArithmeticType; ++Right) {
8369 QualType ParamTypes[2];
8370 ParamTypes[1] = getArithmeticType(Right);
8372 // Add this built-in operator as a candidate (VQ is empty).
8374 S.Context.getLValueReferenceType(getArithmeticType(Left));
8375 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8376 /*IsAssigmentOperator=*/isEqualOp);
8378 // Add this built-in operator as a candidate (VQ is 'volatile').
8379 if (VisibleTypeConversionsQuals.hasVolatile()) {
8381 S.Context.getVolatileType(getArithmeticType(Left));
8382 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
8383 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8384 /*IsAssigmentOperator=*/isEqualOp);
8389 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types.
8390 for (BuiltinCandidateTypeSet::iterator
8391 Vec1 = CandidateTypes[0].vector_begin(),
8392 Vec1End = CandidateTypes[0].vector_end();
8393 Vec1 != Vec1End; ++Vec1) {
8394 for (BuiltinCandidateTypeSet::iterator
8395 Vec2 = CandidateTypes[1].vector_begin(),
8396 Vec2End = CandidateTypes[1].vector_end();
8397 Vec2 != Vec2End; ++Vec2) {
8398 QualType ParamTypes[2];
8399 ParamTypes[1] = *Vec2;
8400 // Add this built-in operator as a candidate (VQ is empty).
8401 ParamTypes[0] = S.Context.getLValueReferenceType(*Vec1);
8402 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8403 /*IsAssigmentOperator=*/isEqualOp);
8405 // Add this built-in operator as a candidate (VQ is 'volatile').
8406 if (VisibleTypeConversionsQuals.hasVolatile()) {
8407 ParamTypes[0] = S.Context.getVolatileType(*Vec1);
8408 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
8409 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8410 /*IsAssigmentOperator=*/isEqualOp);
8416 // C++ [over.built]p22:
8418 // For every triple (L, VQ, R), where L is an integral type, VQ
8419 // is either volatile or empty, and R is a promoted integral
8420 // type, there exist candidate operator functions of the form
8422 // VQ L& operator%=(VQ L&, R);
8423 // VQ L& operator<<=(VQ L&, R);
8424 // VQ L& operator>>=(VQ L&, R);
8425 // VQ L& operator&=(VQ L&, R);
8426 // VQ L& operator^=(VQ L&, R);
8427 // VQ L& operator|=(VQ L&, R);
8428 void addAssignmentIntegralOverloads() {
8429 if (!HasArithmeticOrEnumeralCandidateType)
8432 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) {
8433 for (unsigned Right = FirstPromotedIntegralType;
8434 Right < LastPromotedIntegralType; ++Right) {
8435 QualType ParamTypes[2];
8436 ParamTypes[1] = getArithmeticType(Right);
8438 // Add this built-in operator as a candidate (VQ is empty).
8440 S.Context.getLValueReferenceType(getArithmeticType(Left));
8441 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
8442 if (VisibleTypeConversionsQuals.hasVolatile()) {
8443 // Add this built-in operator as a candidate (VQ is 'volatile').
8444 ParamTypes[0] = getArithmeticType(Left);
8445 ParamTypes[0] = S.Context.getVolatileType(ParamTypes[0]);
8446 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
8447 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
8453 // C++ [over.operator]p23:
8455 // There also exist candidate operator functions of the form
8457 // bool operator!(bool);
8458 // bool operator&&(bool, bool);
8459 // bool operator||(bool, bool);
8460 void addExclaimOverload() {
8461 QualType ParamTy = S.Context.BoolTy;
8462 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, CandidateSet,
8463 /*IsAssignmentOperator=*/false,
8464 /*NumContextualBoolArguments=*/1);
8466 void addAmpAmpOrPipePipeOverload() {
8467 QualType ParamTypes[2] = { S.Context.BoolTy, S.Context.BoolTy };
8468 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet,
8469 /*IsAssignmentOperator=*/false,
8470 /*NumContextualBoolArguments=*/2);
8473 // C++ [over.built]p13:
8475 // For every cv-qualified or cv-unqualified object type T there
8476 // exist candidate operator functions of the form
8478 // T* operator+(T*, ptrdiff_t); [ABOVE]
8479 // T& operator[](T*, ptrdiff_t);
8480 // T* operator-(T*, ptrdiff_t); [ABOVE]
8481 // T* operator+(ptrdiff_t, T*); [ABOVE]
8482 // T& operator[](ptrdiff_t, T*);
8483 void addSubscriptOverloads() {
8484 for (BuiltinCandidateTypeSet::iterator
8485 Ptr = CandidateTypes[0].pointer_begin(),
8486 PtrEnd = CandidateTypes[0].pointer_end();
8487 Ptr != PtrEnd; ++Ptr) {
8488 QualType ParamTypes[2] = { *Ptr, S.Context.getPointerDiffType() };
8489 QualType PointeeType = (*Ptr)->getPointeeType();
8490 if (!PointeeType->isObjectType())
8493 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType);
8495 // T& operator[](T*, ptrdiff_t)
8496 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, CandidateSet);
8499 for (BuiltinCandidateTypeSet::iterator
8500 Ptr = CandidateTypes[1].pointer_begin(),
8501 PtrEnd = CandidateTypes[1].pointer_end();
8502 Ptr != PtrEnd; ++Ptr) {
8503 QualType ParamTypes[2] = { S.Context.getPointerDiffType(), *Ptr };
8504 QualType PointeeType = (*Ptr)->getPointeeType();
8505 if (!PointeeType->isObjectType())
8508 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType);
8510 // T& operator[](ptrdiff_t, T*)
8511 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, CandidateSet);
8515 // C++ [over.built]p11:
8516 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type,
8517 // C1 is the same type as C2 or is a derived class of C2, T is an object
8518 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
8519 // there exist candidate operator functions of the form
8521 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
8523 // where CV12 is the union of CV1 and CV2.
8524 void addArrowStarOverloads() {
8525 for (BuiltinCandidateTypeSet::iterator
8526 Ptr = CandidateTypes[0].pointer_begin(),
8527 PtrEnd = CandidateTypes[0].pointer_end();
8528 Ptr != PtrEnd; ++Ptr) {
8529 QualType C1Ty = (*Ptr);
8531 QualifierCollector Q1;
8532 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0);
8533 if (!isa<RecordType>(C1))
8535 // heuristic to reduce number of builtin candidates in the set.
8536 // Add volatile/restrict version only if there are conversions to a
8537 // volatile/restrict type.
8538 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile())
8540 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict())
8542 for (BuiltinCandidateTypeSet::iterator
8543 MemPtr = CandidateTypes[1].member_pointer_begin(),
8544 MemPtrEnd = CandidateTypes[1].member_pointer_end();
8545 MemPtr != MemPtrEnd; ++MemPtr) {
8546 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr);
8547 QualType C2 = QualType(mptr->getClass(), 0);
8548 C2 = C2.getUnqualifiedType();
8549 if (C1 != C2 && !S.IsDerivedFrom(CandidateSet.getLocation(), C1, C2))
8551 QualType ParamTypes[2] = { *Ptr, *MemPtr };
8553 QualType T = mptr->getPointeeType();
8554 if (!VisibleTypeConversionsQuals.hasVolatile() &&
8555 T.isVolatileQualified())
8557 if (!VisibleTypeConversionsQuals.hasRestrict() &&
8558 T.isRestrictQualified())
8560 T = Q1.apply(S.Context, T);
8561 QualType ResultTy = S.Context.getLValueReferenceType(T);
8562 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, CandidateSet);
8567 // Note that we don't consider the first argument, since it has been
8568 // contextually converted to bool long ago. The candidates below are
8569 // therefore added as binary.
8571 // C++ [over.built]p25:
8572 // For every type T, where T is a pointer, pointer-to-member, or scoped
8573 // enumeration type, there exist candidate operator functions of the form
8575 // T operator?(bool, T, T);
8577 void addConditionalOperatorOverloads() {
8578 /// Set of (canonical) types that we've already handled.
8579 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8581 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) {
8582 for (BuiltinCandidateTypeSet::iterator
8583 Ptr = CandidateTypes[ArgIdx].pointer_begin(),
8584 PtrEnd = CandidateTypes[ArgIdx].pointer_end();
8585 Ptr != PtrEnd; ++Ptr) {
8586 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
8589 QualType ParamTypes[2] = { *Ptr, *Ptr };
8590 S.AddBuiltinCandidate(*Ptr, ParamTypes, Args, CandidateSet);
8593 for (BuiltinCandidateTypeSet::iterator
8594 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(),
8595 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end();
8596 MemPtr != MemPtrEnd; ++MemPtr) {
8597 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr)).second)
8600 QualType ParamTypes[2] = { *MemPtr, *MemPtr };
8601 S.AddBuiltinCandidate(*MemPtr, ParamTypes, Args, CandidateSet);
8604 if (S.getLangOpts().CPlusPlus11) {
8605 for (BuiltinCandidateTypeSet::iterator
8606 Enum = CandidateTypes[ArgIdx].enumeration_begin(),
8607 EnumEnd = CandidateTypes[ArgIdx].enumeration_end();
8608 Enum != EnumEnd; ++Enum) {
8609 if (!(*Enum)->getAs<EnumType>()->getDecl()->isScoped())
8612 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum)).second)
8615 QualType ParamTypes[2] = { *Enum, *Enum };
8616 S.AddBuiltinCandidate(*Enum, ParamTypes, Args, CandidateSet);
8623 } // end anonymous namespace
8625 /// AddBuiltinOperatorCandidates - Add the appropriate built-in
8626 /// operator overloads to the candidate set (C++ [over.built]), based
8627 /// on the operator @p Op and the arguments given. For example, if the
8628 /// operator is a binary '+', this routine might add "int
8629 /// operator+(int, int)" to cover integer addition.
8630 void Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op,
8631 SourceLocation OpLoc,
8632 ArrayRef<Expr *> Args,
8633 OverloadCandidateSet &CandidateSet) {
8634 // Find all of the types that the arguments can convert to, but only
8635 // if the operator we're looking at has built-in operator candidates
8636 // that make use of these types. Also record whether we encounter non-record
8637 // candidate types or either arithmetic or enumeral candidate types.
8638 Qualifiers VisibleTypeConversionsQuals;
8639 VisibleTypeConversionsQuals.addConst();
8640 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx)
8641 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]);
8643 bool HasNonRecordCandidateType = false;
8644 bool HasArithmeticOrEnumeralCandidateType = false;
8645 SmallVector<BuiltinCandidateTypeSet, 2> CandidateTypes;
8646 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
8647 CandidateTypes.emplace_back(*this);
8648 CandidateTypes[ArgIdx].AddTypesConvertedFrom(Args[ArgIdx]->getType(),
8651 (Op == OO_Exclaim ||
8654 VisibleTypeConversionsQuals);
8655 HasNonRecordCandidateType = HasNonRecordCandidateType ||
8656 CandidateTypes[ArgIdx].hasNonRecordTypes();
8657 HasArithmeticOrEnumeralCandidateType =
8658 HasArithmeticOrEnumeralCandidateType ||
8659 CandidateTypes[ArgIdx].hasArithmeticOrEnumeralTypes();
8662 // Exit early when no non-record types have been added to the candidate set
8663 // for any of the arguments to the operator.
8665 // We can't exit early for !, ||, or &&, since there we have always have
8666 // 'bool' overloads.
8667 if (!HasNonRecordCandidateType &&
8668 !(Op == OO_Exclaim || Op == OO_AmpAmp || Op == OO_PipePipe))
8671 // Setup an object to manage the common state for building overloads.
8672 BuiltinOperatorOverloadBuilder OpBuilder(*this, Args,
8673 VisibleTypeConversionsQuals,
8674 HasArithmeticOrEnumeralCandidateType,
8675 CandidateTypes, CandidateSet);
8677 // Dispatch over the operation to add in only those overloads which apply.
8680 case NUM_OVERLOADED_OPERATORS:
8681 llvm_unreachable("Expected an overloaded operator");
8686 case OO_Array_Delete:
8689 "Special operators don't use AddBuiltinOperatorCandidates");
8694 // C++ [over.match.oper]p3:
8695 // -- For the operator ',', the unary operator '&', the
8696 // operator '->', or the operator 'co_await', the
8697 // built-in candidates set is empty.
8700 case OO_Plus: // '+' is either unary or binary
8701 if (Args.size() == 1)
8702 OpBuilder.addUnaryPlusPointerOverloads();
8705 case OO_Minus: // '-' is either unary or binary
8706 if (Args.size() == 1) {
8707 OpBuilder.addUnaryPlusOrMinusArithmeticOverloads();
8709 OpBuilder.addBinaryPlusOrMinusPointerOverloads(Op);
8710 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false);
8714 case OO_Star: // '*' is either unary or binary
8715 if (Args.size() == 1)
8716 OpBuilder.addUnaryStarPointerOverloads();
8718 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false);
8722 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false);
8727 OpBuilder.addPlusPlusMinusMinusArithmeticOverloads(Op);
8728 OpBuilder.addPlusPlusMinusMinusPointerOverloads();
8732 case OO_ExclaimEqual:
8733 OpBuilder.addEqualEqualOrNotEqualMemberPointerOrNullptrOverloads();
8739 case OO_GreaterEqual:
8740 OpBuilder.addRelationalPointerOrEnumeralOverloads();
8741 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/true);
8748 case OO_GreaterGreater:
8749 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op);
8752 case OO_Amp: // '&' is either unary or binary
8753 if (Args.size() == 1)
8754 // C++ [over.match.oper]p3:
8755 // -- For the operator ',', the unary operator '&', or the
8756 // operator '->', the built-in candidates set is empty.
8759 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op);
8763 OpBuilder.addUnaryTildePromotedIntegralOverloads();
8767 OpBuilder.addAssignmentMemberPointerOrEnumeralOverloads();
8772 OpBuilder.addAssignmentPointerOverloads(Op == OO_Equal);
8777 OpBuilder.addAssignmentArithmeticOverloads(Op == OO_Equal);
8780 case OO_PercentEqual:
8781 case OO_LessLessEqual:
8782 case OO_GreaterGreaterEqual:
8786 OpBuilder.addAssignmentIntegralOverloads();
8790 OpBuilder.addExclaimOverload();
8795 OpBuilder.addAmpAmpOrPipePipeOverload();
8799 OpBuilder.addSubscriptOverloads();
8803 OpBuilder.addArrowStarOverloads();
8806 case OO_Conditional:
8807 OpBuilder.addConditionalOperatorOverloads();
8808 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false);
8813 /// \brief Add function candidates found via argument-dependent lookup
8814 /// to the set of overloading candidates.
8816 /// This routine performs argument-dependent name lookup based on the
8817 /// given function name (which may also be an operator name) and adds
8818 /// all of the overload candidates found by ADL to the overload
8819 /// candidate set (C++ [basic.lookup.argdep]).
8821 Sema::AddArgumentDependentLookupCandidates(DeclarationName Name,
8823 ArrayRef<Expr *> Args,
8824 TemplateArgumentListInfo *ExplicitTemplateArgs,
8825 OverloadCandidateSet& CandidateSet,
8826 bool PartialOverloading) {
8829 // FIXME: This approach for uniquing ADL results (and removing
8830 // redundant candidates from the set) relies on pointer-equality,
8831 // which means we need to key off the canonical decl. However,
8832 // always going back to the canonical decl might not get us the
8833 // right set of default arguments. What default arguments are
8834 // we supposed to consider on ADL candidates, anyway?
8836 // FIXME: Pass in the explicit template arguments?
8837 ArgumentDependentLookup(Name, Loc, Args, Fns);
8839 // Erase all of the candidates we already knew about.
8840 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(),
8841 CandEnd = CandidateSet.end();
8842 Cand != CandEnd; ++Cand)
8843 if (Cand->Function) {
8844 Fns.erase(Cand->Function);
8845 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate())
8849 // For each of the ADL candidates we found, add it to the overload
8851 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) {
8852 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none);
8853 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) {
8854 if (ExplicitTemplateArgs)
8857 AddOverloadCandidate(FD, FoundDecl, Args, CandidateSet, false,
8858 PartialOverloading);
8860 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I),
8861 FoundDecl, ExplicitTemplateArgs,
8862 Args, CandidateSet, PartialOverloading);
8867 enum class Comparison { Equal, Better, Worse };
8870 /// Compares the enable_if attributes of two FunctionDecls, for the purposes of
8871 /// overload resolution.
8873 /// Cand1's set of enable_if attributes are said to be "better" than Cand2's iff
8874 /// Cand1's first N enable_if attributes have precisely the same conditions as
8875 /// Cand2's first N enable_if attributes (where N = the number of enable_if
8876 /// attributes on Cand2), and Cand1 has more than N enable_if attributes.
8878 /// Note that you can have a pair of candidates such that Cand1's enable_if
8879 /// attributes are worse than Cand2's, and Cand2's enable_if attributes are
8880 /// worse than Cand1's.
8881 static Comparison compareEnableIfAttrs(const Sema &S, const FunctionDecl *Cand1,
8882 const FunctionDecl *Cand2) {
8883 // Common case: One (or both) decls don't have enable_if attrs.
8884 bool Cand1Attr = Cand1->hasAttr<EnableIfAttr>();
8885 bool Cand2Attr = Cand2->hasAttr<EnableIfAttr>();
8886 if (!Cand1Attr || !Cand2Attr) {
8887 if (Cand1Attr == Cand2Attr)
8888 return Comparison::Equal;
8889 return Cand1Attr ? Comparison::Better : Comparison::Worse;
8892 // FIXME: The next several lines are just
8893 // specific_attr_iterator<EnableIfAttr> but going in declaration order,
8894 // instead of reverse order which is how they're stored in the AST.
8895 auto Cand1Attrs = getOrderedEnableIfAttrs(Cand1);
8896 auto Cand2Attrs = getOrderedEnableIfAttrs(Cand2);
8898 // It's impossible for Cand1 to be better than (or equal to) Cand2 if Cand1
8899 // has fewer enable_if attributes than Cand2.
8900 if (Cand1Attrs.size() < Cand2Attrs.size())
8901 return Comparison::Worse;
8903 auto Cand1I = Cand1Attrs.begin();
8904 llvm::FoldingSetNodeID Cand1ID, Cand2ID;
8905 for (auto &Cand2A : Cand2Attrs) {
8909 auto &Cand1A = *Cand1I++;
8910 Cand1A->getCond()->Profile(Cand1ID, S.getASTContext(), true);
8911 Cand2A->getCond()->Profile(Cand2ID, S.getASTContext(), true);
8912 if (Cand1ID != Cand2ID)
8913 return Comparison::Worse;
8916 return Cand1I == Cand1Attrs.end() ? Comparison::Equal : Comparison::Better;
8919 /// isBetterOverloadCandidate - Determines whether the first overload
8920 /// candidate is a better candidate than the second (C++ 13.3.3p1).
8921 bool clang::isBetterOverloadCandidate(Sema &S, const OverloadCandidate &Cand1,
8922 const OverloadCandidate &Cand2,
8924 bool UserDefinedConversion) {
8925 // Define viable functions to be better candidates than non-viable
8928 return Cand1.Viable;
8929 else if (!Cand1.Viable)
8932 // C++ [over.match.best]p1:
8934 // -- if F is a static member function, ICS1(F) is defined such
8935 // that ICS1(F) is neither better nor worse than ICS1(G) for
8936 // any function G, and, symmetrically, ICS1(G) is neither
8937 // better nor worse than ICS1(F).
8938 unsigned StartArg = 0;
8939 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument)
8942 auto IsIllFormedConversion = [&](const ImplicitConversionSequence &ICS) {
8943 // We don't allow incompatible pointer conversions in C++.
8944 if (!S.getLangOpts().CPlusPlus)
8945 return ICS.isStandard() &&
8946 ICS.Standard.Second == ICK_Incompatible_Pointer_Conversion;
8948 // The only ill-formed conversion we allow in C++ is the string literal to
8949 // char* conversion, which is only considered ill-formed after C++11.
8950 return S.getLangOpts().CPlusPlus11 && !S.getLangOpts().WritableStrings &&
8951 hasDeprecatedStringLiteralToCharPtrConversion(ICS);
8954 // Define functions that don't require ill-formed conversions for a given
8955 // argument to be better candidates than functions that do.
8956 unsigned NumArgs = Cand1.Conversions.size();
8957 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch");
8958 bool HasBetterConversion = false;
8959 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) {
8960 bool Cand1Bad = IsIllFormedConversion(Cand1.Conversions[ArgIdx]);
8961 bool Cand2Bad = IsIllFormedConversion(Cand2.Conversions[ArgIdx]);
8962 if (Cand1Bad != Cand2Bad) {
8965 HasBetterConversion = true;
8969 if (HasBetterConversion)
8972 // C++ [over.match.best]p1:
8973 // A viable function F1 is defined to be a better function than another
8974 // viable function F2 if for all arguments i, ICSi(F1) is not a worse
8975 // conversion sequence than ICSi(F2), and then...
8976 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) {
8977 switch (CompareImplicitConversionSequences(S, Loc,
8978 Cand1.Conversions[ArgIdx],
8979 Cand2.Conversions[ArgIdx])) {
8980 case ImplicitConversionSequence::Better:
8981 // Cand1 has a better conversion sequence.
8982 HasBetterConversion = true;
8985 case ImplicitConversionSequence::Worse:
8986 // Cand1 can't be better than Cand2.
8989 case ImplicitConversionSequence::Indistinguishable:
8995 // -- for some argument j, ICSj(F1) is a better conversion sequence than
8996 // ICSj(F2), or, if not that,
8997 if (HasBetterConversion)
9000 // -- the context is an initialization by user-defined conversion
9001 // (see 8.5, 13.3.1.5) and the standard conversion sequence
9002 // from the return type of F1 to the destination type (i.e.,
9003 // the type of the entity being initialized) is a better
9004 // conversion sequence than the standard conversion sequence
9005 // from the return type of F2 to the destination type.
9006 if (UserDefinedConversion && Cand1.Function && Cand2.Function &&
9007 isa<CXXConversionDecl>(Cand1.Function) &&
9008 isa<CXXConversionDecl>(Cand2.Function)) {
9009 // First check whether we prefer one of the conversion functions over the
9010 // other. This only distinguishes the results in non-standard, extension
9011 // cases such as the conversion from a lambda closure type to a function
9012 // pointer or block.
9013 ImplicitConversionSequence::CompareKind Result =
9014 compareConversionFunctions(S, Cand1.Function, Cand2.Function);
9015 if (Result == ImplicitConversionSequence::Indistinguishable)
9016 Result = CompareStandardConversionSequences(S, Loc,
9017 Cand1.FinalConversion,
9018 Cand2.FinalConversion);
9020 if (Result != ImplicitConversionSequence::Indistinguishable)
9021 return Result == ImplicitConversionSequence::Better;
9023 // FIXME: Compare kind of reference binding if conversion functions
9024 // convert to a reference type used in direct reference binding, per
9025 // C++14 [over.match.best]p1 section 2 bullet 3.
9028 // -- F1 is generated from a deduction-guide and F2 is not
9029 auto *Guide1 = dyn_cast_or_null<CXXDeductionGuideDecl>(Cand1.Function);
9030 auto *Guide2 = dyn_cast_or_null<CXXDeductionGuideDecl>(Cand2.Function);
9031 if (Guide1 && Guide2 && Guide1->isImplicit() != Guide2->isImplicit())
9032 return Guide2->isImplicit();
9034 // -- F1 is a non-template function and F2 is a function template
9035 // specialization, or, if not that,
9036 bool Cand1IsSpecialization = Cand1.Function &&
9037 Cand1.Function->getPrimaryTemplate();
9038 bool Cand2IsSpecialization = Cand2.Function &&
9039 Cand2.Function->getPrimaryTemplate();
9040 if (Cand1IsSpecialization != Cand2IsSpecialization)
9041 return Cand2IsSpecialization;
9043 // -- F1 and F2 are function template specializations, and the function
9044 // template for F1 is more specialized than the template for F2
9045 // according to the partial ordering rules described in 14.5.5.2, or,
9047 if (Cand1IsSpecialization && Cand2IsSpecialization) {
9048 if (FunctionTemplateDecl *BetterTemplate
9049 = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(),
9050 Cand2.Function->getPrimaryTemplate(),
9052 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion
9054 Cand1.ExplicitCallArguments,
9055 Cand2.ExplicitCallArguments))
9056 return BetterTemplate == Cand1.Function->getPrimaryTemplate();
9059 // FIXME: Work around a defect in the C++17 inheriting constructor wording.
9060 // A derived-class constructor beats an (inherited) base class constructor.
9061 bool Cand1IsInherited =
9062 dyn_cast_or_null<ConstructorUsingShadowDecl>(Cand1.FoundDecl.getDecl());
9063 bool Cand2IsInherited =
9064 dyn_cast_or_null<ConstructorUsingShadowDecl>(Cand2.FoundDecl.getDecl());
9065 if (Cand1IsInherited != Cand2IsInherited)
9066 return Cand2IsInherited;
9067 else if (Cand1IsInherited) {
9068 assert(Cand2IsInherited);
9069 auto *Cand1Class = cast<CXXRecordDecl>(Cand1.Function->getDeclContext());
9070 auto *Cand2Class = cast<CXXRecordDecl>(Cand2.Function->getDeclContext());
9071 if (Cand1Class->isDerivedFrom(Cand2Class))
9073 if (Cand2Class->isDerivedFrom(Cand1Class))
9075 // Inherited from sibling base classes: still ambiguous.
9078 // Check for enable_if value-based overload resolution.
9079 if (Cand1.Function && Cand2.Function) {
9080 Comparison Cmp = compareEnableIfAttrs(S, Cand1.Function, Cand2.Function);
9081 if (Cmp != Comparison::Equal)
9082 return Cmp == Comparison::Better;
9085 if (S.getLangOpts().CUDA && Cand1.Function && Cand2.Function) {
9086 FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext);
9087 return S.IdentifyCUDAPreference(Caller, Cand1.Function) >
9088 S.IdentifyCUDAPreference(Caller, Cand2.Function);
9091 bool HasPS1 = Cand1.Function != nullptr &&
9092 functionHasPassObjectSizeParams(Cand1.Function);
9093 bool HasPS2 = Cand2.Function != nullptr &&
9094 functionHasPassObjectSizeParams(Cand2.Function);
9095 return HasPS1 != HasPS2 && HasPS1;
9098 /// Determine whether two declarations are "equivalent" for the purposes of
9099 /// name lookup and overload resolution. This applies when the same internal/no
9100 /// linkage entity is defined by two modules (probably by textually including
9101 /// the same header). In such a case, we don't consider the declarations to
9102 /// declare the same entity, but we also don't want lookups with both
9103 /// declarations visible to be ambiguous in some cases (this happens when using
9104 /// a modularized libstdc++).
9105 bool Sema::isEquivalentInternalLinkageDeclaration(const NamedDecl *A,
9106 const NamedDecl *B) {
9107 auto *VA = dyn_cast_or_null<ValueDecl>(A);
9108 auto *VB = dyn_cast_or_null<ValueDecl>(B);
9112 // The declarations must be declaring the same name as an internal linkage
9113 // entity in different modules.
9114 if (!VA->getDeclContext()->getRedeclContext()->Equals(
9115 VB->getDeclContext()->getRedeclContext()) ||
9116 getOwningModule(const_cast<ValueDecl *>(VA)) ==
9117 getOwningModule(const_cast<ValueDecl *>(VB)) ||
9118 VA->isExternallyVisible() || VB->isExternallyVisible())
9121 // Check that the declarations appear to be equivalent.
9123 // FIXME: Checking the type isn't really enough to resolve the ambiguity.
9124 // For constants and functions, we should check the initializer or body is
9125 // the same. For non-constant variables, we shouldn't allow it at all.
9126 if (Context.hasSameType(VA->getType(), VB->getType()))
9129 // Enum constants within unnamed enumerations will have different types, but
9130 // may still be similar enough to be interchangeable for our purposes.
9131 if (auto *EA = dyn_cast<EnumConstantDecl>(VA)) {
9132 if (auto *EB = dyn_cast<EnumConstantDecl>(VB)) {
9133 // Only handle anonymous enums. If the enumerations were named and
9134 // equivalent, they would have been merged to the same type.
9135 auto *EnumA = cast<EnumDecl>(EA->getDeclContext());
9136 auto *EnumB = cast<EnumDecl>(EB->getDeclContext());
9137 if (EnumA->hasNameForLinkage() || EnumB->hasNameForLinkage() ||
9138 !Context.hasSameType(EnumA->getIntegerType(),
9139 EnumB->getIntegerType()))
9141 // Allow this only if the value is the same for both enumerators.
9142 return llvm::APSInt::isSameValue(EA->getInitVal(), EB->getInitVal());
9146 // Nothing else is sufficiently similar.
9150 void Sema::diagnoseEquivalentInternalLinkageDeclarations(
9151 SourceLocation Loc, const NamedDecl *D, ArrayRef<const NamedDecl *> Equiv) {
9152 Diag(Loc, diag::ext_equivalent_internal_linkage_decl_in_modules) << D;
9154 Module *M = getOwningModule(const_cast<NamedDecl*>(D));
9155 Diag(D->getLocation(), diag::note_equivalent_internal_linkage_decl)
9156 << !M << (M ? M->getFullModuleName() : "");
9158 for (auto *E : Equiv) {
9159 Module *M = getOwningModule(const_cast<NamedDecl*>(E));
9160 Diag(E->getLocation(), diag::note_equivalent_internal_linkage_decl)
9161 << !M << (M ? M->getFullModuleName() : "");
9165 /// \brief Computes the best viable function (C++ 13.3.3)
9166 /// within an overload candidate set.
9168 /// \param Loc The location of the function name (or operator symbol) for
9169 /// which overload resolution occurs.
9171 /// \param Best If overload resolution was successful or found a deleted
9172 /// function, \p Best points to the candidate function found.
9174 /// \returns The result of overload resolution.
9176 OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc,
9178 bool UserDefinedConversion) {
9179 llvm::SmallVector<OverloadCandidate *, 16> Candidates;
9180 std::transform(begin(), end(), std::back_inserter(Candidates),
9181 [](OverloadCandidate &Cand) { return &Cand; });
9183 // [CUDA] HD->H or HD->D calls are technically not allowed by CUDA but
9184 // are accepted by both clang and NVCC. However, during a particular
9185 // compilation mode only one call variant is viable. We need to
9186 // exclude non-viable overload candidates from consideration based
9187 // only on their host/device attributes. Specifically, if one
9188 // candidate call is WrongSide and the other is SameSide, we ignore
9189 // the WrongSide candidate.
9190 if (S.getLangOpts().CUDA) {
9191 const FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext);
9192 bool ContainsSameSideCandidate =
9193 llvm::any_of(Candidates, [&](OverloadCandidate *Cand) {
9194 return Cand->Function &&
9195 S.IdentifyCUDAPreference(Caller, Cand->Function) ==
9198 if (ContainsSameSideCandidate) {
9199 auto IsWrongSideCandidate = [&](OverloadCandidate *Cand) {
9200 return Cand->Function &&
9201 S.IdentifyCUDAPreference(Caller, Cand->Function) ==
9202 Sema::CFP_WrongSide;
9204 llvm::erase_if(Candidates, IsWrongSideCandidate);
9208 // Find the best viable function.
9210 for (auto *Cand : Candidates)
9212 if (Best == end() || isBetterOverloadCandidate(S, *Cand, *Best, Loc,
9213 UserDefinedConversion))
9216 // If we didn't find any viable functions, abort.
9218 return OR_No_Viable_Function;
9220 llvm::SmallVector<const NamedDecl *, 4> EquivalentCands;
9222 // Make sure that this function is better than every other viable
9223 // function. If not, we have an ambiguity.
9224 for (auto *Cand : Candidates) {
9227 !isBetterOverloadCandidate(S, *Best, *Cand, Loc,
9228 UserDefinedConversion)) {
9229 if (S.isEquivalentInternalLinkageDeclaration(Best->Function,
9231 EquivalentCands.push_back(Cand->Function);
9236 return OR_Ambiguous;
9240 // Best is the best viable function.
9241 if (Best->Function &&
9242 (Best->Function->isDeleted() ||
9243 S.isFunctionConsideredUnavailable(Best->Function)))
9246 if (!EquivalentCands.empty())
9247 S.diagnoseEquivalentInternalLinkageDeclarations(Loc, Best->Function,
9255 enum OverloadCandidateKind {
9259 oc_function_template,
9261 oc_constructor_template,
9262 oc_implicit_default_constructor,
9263 oc_implicit_copy_constructor,
9264 oc_implicit_move_constructor,
9265 oc_implicit_copy_assignment,
9266 oc_implicit_move_assignment,
9267 oc_inherited_constructor,
9268 oc_inherited_constructor_template
9271 static OverloadCandidateKind
9272 ClassifyOverloadCandidate(Sema &S, NamedDecl *Found, FunctionDecl *Fn,
9273 std::string &Description) {
9274 bool isTemplate = false;
9276 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) {
9278 Description = S.getTemplateArgumentBindingsText(
9279 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs());
9282 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) {
9283 if (!Ctor->isImplicit()) {
9284 if (isa<ConstructorUsingShadowDecl>(Found))
9285 return isTemplate ? oc_inherited_constructor_template
9286 : oc_inherited_constructor;
9288 return isTemplate ? oc_constructor_template : oc_constructor;
9291 if (Ctor->isDefaultConstructor())
9292 return oc_implicit_default_constructor;
9294 if (Ctor->isMoveConstructor())
9295 return oc_implicit_move_constructor;
9297 assert(Ctor->isCopyConstructor() &&
9298 "unexpected sort of implicit constructor");
9299 return oc_implicit_copy_constructor;
9302 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) {
9303 // This actually gets spelled 'candidate function' for now, but
9304 // it doesn't hurt to split it out.
9305 if (!Meth->isImplicit())
9306 return isTemplate ? oc_method_template : oc_method;
9308 if (Meth->isMoveAssignmentOperator())
9309 return oc_implicit_move_assignment;
9311 if (Meth->isCopyAssignmentOperator())
9312 return oc_implicit_copy_assignment;
9314 assert(isa<CXXConversionDecl>(Meth) && "expected conversion");
9318 return isTemplate ? oc_function_template : oc_function;
9321 void MaybeEmitInheritedConstructorNote(Sema &S, Decl *FoundDecl) {
9322 // FIXME: It'd be nice to only emit a note once per using-decl per overload
9324 if (auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(FoundDecl))
9325 S.Diag(FoundDecl->getLocation(),
9326 diag::note_ovl_candidate_inherited_constructor)
9327 << Shadow->getNominatedBaseClass();
9330 } // end anonymous namespace
9332 static bool isFunctionAlwaysEnabled(const ASTContext &Ctx,
9333 const FunctionDecl *FD) {
9334 for (auto *EnableIf : FD->specific_attrs<EnableIfAttr>()) {
9336 if (!EnableIf->getCond()->EvaluateAsBooleanCondition(AlwaysTrue, Ctx))
9344 /// \brief Returns true if we can take the address of the function.
9346 /// \param Complain - If true, we'll emit a diagnostic
9347 /// \param InOverloadResolution - For the purposes of emitting a diagnostic, are
9348 /// we in overload resolution?
9349 /// \param Loc - The location of the statement we're complaining about. Ignored
9350 /// if we're not complaining, or if we're in overload resolution.
9351 static bool checkAddressOfFunctionIsAvailable(Sema &S, const FunctionDecl *FD,
9353 bool InOverloadResolution,
9354 SourceLocation Loc) {
9355 if (!isFunctionAlwaysEnabled(S.Context, FD)) {
9357 if (InOverloadResolution)
9358 S.Diag(FD->getLocStart(),
9359 diag::note_addrof_ovl_candidate_disabled_by_enable_if_attr);
9361 S.Diag(Loc, diag::err_addrof_function_disabled_by_enable_if_attr) << FD;
9366 auto I = llvm::find_if(FD->parameters(), [](const ParmVarDecl *P) {
9367 return P->hasAttr<PassObjectSizeAttr>();
9369 if (I == FD->param_end())
9373 // Add one to ParamNo because it's user-facing
9374 unsigned ParamNo = std::distance(FD->param_begin(), I) + 1;
9375 if (InOverloadResolution)
9376 S.Diag(FD->getLocation(),
9377 diag::note_ovl_candidate_has_pass_object_size_params)
9380 S.Diag(Loc, diag::err_address_of_function_with_pass_object_size_params)
9386 static bool checkAddressOfCandidateIsAvailable(Sema &S,
9387 const FunctionDecl *FD) {
9388 return checkAddressOfFunctionIsAvailable(S, FD, /*Complain=*/true,
9389 /*InOverloadResolution=*/true,
9390 /*Loc=*/SourceLocation());
9393 bool Sema::checkAddressOfFunctionIsAvailable(const FunctionDecl *Function,
9395 SourceLocation Loc) {
9396 return ::checkAddressOfFunctionIsAvailable(*this, Function, Complain,
9397 /*InOverloadResolution=*/false,
9401 // Notes the location of an overload candidate.
9402 void Sema::NoteOverloadCandidate(NamedDecl *Found, FunctionDecl *Fn,
9403 QualType DestType, bool TakingAddress) {
9404 if (TakingAddress && !checkAddressOfCandidateIsAvailable(*this, Fn))
9408 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Found, Fn, FnDesc);
9409 PartialDiagnostic PD = PDiag(diag::note_ovl_candidate)
9410 << (unsigned) K << Fn << FnDesc;
9412 HandleFunctionTypeMismatch(PD, Fn->getType(), DestType);
9413 Diag(Fn->getLocation(), PD);
9414 MaybeEmitInheritedConstructorNote(*this, Found);
9417 // Notes the location of all overload candidates designated through
9419 void Sema::NoteAllOverloadCandidates(Expr *OverloadedExpr, QualType DestType,
9420 bool TakingAddress) {
9421 assert(OverloadedExpr->getType() == Context.OverloadTy);
9423 OverloadExpr::FindResult Ovl = OverloadExpr::find(OverloadedExpr);
9424 OverloadExpr *OvlExpr = Ovl.Expression;
9426 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
9427 IEnd = OvlExpr->decls_end();
9429 if (FunctionTemplateDecl *FunTmpl =
9430 dyn_cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()) ) {
9431 NoteOverloadCandidate(*I, FunTmpl->getTemplatedDecl(), DestType,
9433 } else if (FunctionDecl *Fun
9434 = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()) ) {
9435 NoteOverloadCandidate(*I, Fun, DestType, TakingAddress);
9440 /// Diagnoses an ambiguous conversion. The partial diagnostic is the
9441 /// "lead" diagnostic; it will be given two arguments, the source and
9442 /// target types of the conversion.
9443 void ImplicitConversionSequence::DiagnoseAmbiguousConversion(
9445 SourceLocation CaretLoc,
9446 const PartialDiagnostic &PDiag) const {
9447 S.Diag(CaretLoc, PDiag)
9448 << Ambiguous.getFromType() << Ambiguous.getToType();
9449 // FIXME: The note limiting machinery is borrowed from
9450 // OverloadCandidateSet::NoteCandidates; there's an opportunity for
9451 // refactoring here.
9452 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
9453 unsigned CandsShown = 0;
9454 AmbiguousConversionSequence::const_iterator I, E;
9455 for (I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) {
9456 if (CandsShown >= 4 && ShowOverloads == Ovl_Best)
9459 S.NoteOverloadCandidate(I->first, I->second);
9462 S.Diag(SourceLocation(), diag::note_ovl_too_many_candidates) << int(E - I);
9465 static void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand,
9466 unsigned I, bool TakingCandidateAddress) {
9467 const ImplicitConversionSequence &Conv = Cand->Conversions[I];
9468 assert(Conv.isBad());
9469 assert(Cand->Function && "for now, candidate must be a function");
9470 FunctionDecl *Fn = Cand->Function;
9472 // There's a conversion slot for the object argument if this is a
9473 // non-constructor method. Note that 'I' corresponds the
9474 // conversion-slot index.
9475 bool isObjectArgument = false;
9476 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) {
9478 isObjectArgument = true;
9484 OverloadCandidateKind FnKind =
9485 ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn, FnDesc);
9487 Expr *FromExpr = Conv.Bad.FromExpr;
9488 QualType FromTy = Conv.Bad.getFromType();
9489 QualType ToTy = Conv.Bad.getToType();
9491 if (FromTy == S.Context.OverloadTy) {
9492 assert(FromExpr && "overload set argument came from implicit argument?");
9493 Expr *E = FromExpr->IgnoreParens();
9494 if (isa<UnaryOperator>(E))
9495 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens();
9496 DeclarationName Name = cast<OverloadExpr>(E)->getName();
9498 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload)
9499 << (unsigned) FnKind << FnDesc
9500 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9501 << ToTy << Name << I+1;
9502 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9506 // Do some hand-waving analysis to see if the non-viability is due
9507 // to a qualifier mismatch.
9508 CanQualType CFromTy = S.Context.getCanonicalType(FromTy);
9509 CanQualType CToTy = S.Context.getCanonicalType(ToTy);
9510 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>())
9511 CToTy = RT->getPointeeType();
9513 // TODO: detect and diagnose the full richness of const mismatches.
9514 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>())
9515 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) {
9516 CFromTy = FromPT->getPointeeType();
9517 CToTy = ToPT->getPointeeType();
9521 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() &&
9522 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) {
9523 Qualifiers FromQs = CFromTy.getQualifiers();
9524 Qualifiers ToQs = CToTy.getQualifiers();
9526 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) {
9527 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace)
9528 << (unsigned) FnKind << FnDesc
9529 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9531 << FromQs.getAddressSpaceAttributePrintValue()
9532 << ToQs.getAddressSpaceAttributePrintValue()
9533 << (unsigned) isObjectArgument << I+1;
9534 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9538 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) {
9539 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_ownership)
9540 << (unsigned) FnKind << FnDesc
9541 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9543 << FromQs.getObjCLifetime() << ToQs.getObjCLifetime()
9544 << (unsigned) isObjectArgument << I+1;
9545 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9549 if (FromQs.getObjCGCAttr() != ToQs.getObjCGCAttr()) {
9550 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_gc)
9551 << (unsigned) FnKind << FnDesc
9552 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9554 << FromQs.getObjCGCAttr() << ToQs.getObjCGCAttr()
9555 << (unsigned) isObjectArgument << I+1;
9556 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9560 if (FromQs.hasUnaligned() != ToQs.hasUnaligned()) {
9561 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_unaligned)
9562 << (unsigned) FnKind << FnDesc
9563 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9564 << FromTy << FromQs.hasUnaligned() << I+1;
9565 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9569 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers();
9570 assert(CVR && "unexpected qualifiers mismatch");
9572 if (isObjectArgument) {
9573 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this)
9574 << (unsigned) FnKind << FnDesc
9575 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9576 << FromTy << (CVR - 1);
9578 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr)
9579 << (unsigned) FnKind << FnDesc
9580 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9581 << FromTy << (CVR - 1) << I+1;
9583 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9587 // Special diagnostic for failure to convert an initializer list, since
9588 // telling the user that it has type void is not useful.
9589 if (FromExpr && isa<InitListExpr>(FromExpr)) {
9590 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_list_argument)
9591 << (unsigned) FnKind << FnDesc
9592 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9593 << FromTy << ToTy << (unsigned) isObjectArgument << I+1;
9594 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9598 // Diagnose references or pointers to incomplete types differently,
9599 // since it's far from impossible that the incompleteness triggered
9601 QualType TempFromTy = FromTy.getNonReferenceType();
9602 if (const PointerType *PTy = TempFromTy->getAs<PointerType>())
9603 TempFromTy = PTy->getPointeeType();
9604 if (TempFromTy->isIncompleteType()) {
9605 // Emit the generic diagnostic and, optionally, add the hints to it.
9606 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete)
9607 << (unsigned) FnKind << FnDesc
9608 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9609 << FromTy << ToTy << (unsigned) isObjectArgument << I+1
9610 << (unsigned) (Cand->Fix.Kind);
9612 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9616 // Diagnose base -> derived pointer conversions.
9617 unsigned BaseToDerivedConversion = 0;
9618 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) {
9619 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) {
9620 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs(
9621 FromPtrTy->getPointeeType()) &&
9622 !FromPtrTy->getPointeeType()->isIncompleteType() &&
9623 !ToPtrTy->getPointeeType()->isIncompleteType() &&
9624 S.IsDerivedFrom(SourceLocation(), ToPtrTy->getPointeeType(),
9625 FromPtrTy->getPointeeType()))
9626 BaseToDerivedConversion = 1;
9628 } else if (const ObjCObjectPointerType *FromPtrTy
9629 = FromTy->getAs<ObjCObjectPointerType>()) {
9630 if (const ObjCObjectPointerType *ToPtrTy
9631 = ToTy->getAs<ObjCObjectPointerType>())
9632 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl())
9633 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl())
9634 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs(
9635 FromPtrTy->getPointeeType()) &&
9636 FromIface->isSuperClassOf(ToIface))
9637 BaseToDerivedConversion = 2;
9638 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) {
9639 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) &&
9640 !FromTy->isIncompleteType() &&
9641 !ToRefTy->getPointeeType()->isIncompleteType() &&
9642 S.IsDerivedFrom(SourceLocation(), ToRefTy->getPointeeType(), FromTy)) {
9643 BaseToDerivedConversion = 3;
9644 } else if (ToTy->isLValueReferenceType() && !FromExpr->isLValue() &&
9645 ToTy.getNonReferenceType().getCanonicalType() ==
9646 FromTy.getNonReferenceType().getCanonicalType()) {
9647 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_lvalue)
9648 << (unsigned) FnKind << FnDesc
9649 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9650 << (unsigned) isObjectArgument << I + 1;
9651 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9656 if (BaseToDerivedConversion) {
9657 S.Diag(Fn->getLocation(),
9658 diag::note_ovl_candidate_bad_base_to_derived_conv)
9659 << (unsigned) FnKind << FnDesc
9660 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9661 << (BaseToDerivedConversion - 1)
9662 << FromTy << ToTy << I+1;
9663 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9667 if (isa<ObjCObjectPointerType>(CFromTy) &&
9668 isa<PointerType>(CToTy)) {
9669 Qualifiers FromQs = CFromTy.getQualifiers();
9670 Qualifiers ToQs = CToTy.getQualifiers();
9671 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) {
9672 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_arc_conv)
9673 << (unsigned) FnKind << FnDesc
9674 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9675 << FromTy << ToTy << (unsigned) isObjectArgument << I+1;
9676 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9681 if (TakingCandidateAddress &&
9682 !checkAddressOfCandidateIsAvailable(S, Cand->Function))
9685 // Emit the generic diagnostic and, optionally, add the hints to it.
9686 PartialDiagnostic FDiag = S.PDiag(diag::note_ovl_candidate_bad_conv);
9687 FDiag << (unsigned) FnKind << FnDesc
9688 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9689 << FromTy << ToTy << (unsigned) isObjectArgument << I + 1
9690 << (unsigned) (Cand->Fix.Kind);
9692 // If we can fix the conversion, suggest the FixIts.
9693 for (std::vector<FixItHint>::iterator HI = Cand->Fix.Hints.begin(),
9694 HE = Cand->Fix.Hints.end(); HI != HE; ++HI)
9696 S.Diag(Fn->getLocation(), FDiag);
9698 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
9701 /// Additional arity mismatch diagnosis specific to a function overload
9702 /// candidates. This is not covered by the more general DiagnoseArityMismatch()
9703 /// over a candidate in any candidate set.
9704 static bool CheckArityMismatch(Sema &S, OverloadCandidate *Cand,
9706 FunctionDecl *Fn = Cand->Function;
9707 unsigned MinParams = Fn->getMinRequiredArguments();
9709 // With invalid overloaded operators, it's possible that we think we
9710 // have an arity mismatch when in fact it looks like we have the
9711 // right number of arguments, because only overloaded operators have
9712 // the weird behavior of overloading member and non-member functions.
9713 // Just don't report anything.
9714 if (Fn->isInvalidDecl() &&
9715 Fn->getDeclName().getNameKind() == DeclarationName::CXXOperatorName)
9718 if (NumArgs < MinParams) {
9719 assert((Cand->FailureKind == ovl_fail_too_few_arguments) ||
9720 (Cand->FailureKind == ovl_fail_bad_deduction &&
9721 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments));
9723 assert((Cand->FailureKind == ovl_fail_too_many_arguments) ||
9724 (Cand->FailureKind == ovl_fail_bad_deduction &&
9725 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments));
9731 /// General arity mismatch diagnosis over a candidate in a candidate set.
9732 static void DiagnoseArityMismatch(Sema &S, NamedDecl *Found, Decl *D,
9733 unsigned NumFormalArgs) {
9734 assert(isa<FunctionDecl>(D) &&
9735 "The templated declaration should at least be a function"
9736 " when diagnosing bad template argument deduction due to too many"
9737 " or too few arguments");
9739 FunctionDecl *Fn = cast<FunctionDecl>(D);
9741 // TODO: treat calls to a missing default constructor as a special case
9742 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>();
9743 unsigned MinParams = Fn->getMinRequiredArguments();
9745 // at least / at most / exactly
9746 unsigned mode, modeCount;
9747 if (NumFormalArgs < MinParams) {
9748 if (MinParams != FnTy->getNumParams() || FnTy->isVariadic() ||
9749 FnTy->isTemplateVariadic())
9750 mode = 0; // "at least"
9752 mode = 2; // "exactly"
9753 modeCount = MinParams;
9755 if (MinParams != FnTy->getNumParams())
9756 mode = 1; // "at most"
9758 mode = 2; // "exactly"
9759 modeCount = FnTy->getNumParams();
9762 std::string Description;
9763 OverloadCandidateKind FnKind =
9764 ClassifyOverloadCandidate(S, Found, Fn, Description);
9766 if (modeCount == 1 && Fn->getParamDecl(0)->getDeclName())
9767 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity_one)
9768 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != nullptr)
9769 << mode << Fn->getParamDecl(0) << NumFormalArgs;
9771 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity)
9772 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != nullptr)
9773 << mode << modeCount << NumFormalArgs;
9774 MaybeEmitInheritedConstructorNote(S, Found);
9777 /// Arity mismatch diagnosis specific to a function overload candidate.
9778 static void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand,
9779 unsigned NumFormalArgs) {
9780 if (!CheckArityMismatch(S, Cand, NumFormalArgs))
9781 DiagnoseArityMismatch(S, Cand->FoundDecl, Cand->Function, NumFormalArgs);
9784 static TemplateDecl *getDescribedTemplate(Decl *Templated) {
9785 if (TemplateDecl *TD = Templated->getDescribedTemplate())
9787 llvm_unreachable("Unsupported: Getting the described template declaration"
9788 " for bad deduction diagnosis");
9791 /// Diagnose a failed template-argument deduction.
9792 static void DiagnoseBadDeduction(Sema &S, NamedDecl *Found, Decl *Templated,
9793 DeductionFailureInfo &DeductionFailure,
9795 bool TakingCandidateAddress) {
9796 TemplateParameter Param = DeductionFailure.getTemplateParameter();
9798 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) ||
9799 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) ||
9800 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>());
9801 switch (DeductionFailure.Result) {
9802 case Sema::TDK_Success:
9803 llvm_unreachable("TDK_success while diagnosing bad deduction");
9805 case Sema::TDK_Incomplete: {
9806 assert(ParamD && "no parameter found for incomplete deduction result");
9807 S.Diag(Templated->getLocation(),
9808 diag::note_ovl_candidate_incomplete_deduction)
9809 << ParamD->getDeclName();
9810 MaybeEmitInheritedConstructorNote(S, Found);
9814 case Sema::TDK_Underqualified: {
9815 assert(ParamD && "no parameter found for bad qualifiers deduction result");
9816 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD);
9818 QualType Param = DeductionFailure.getFirstArg()->getAsType();
9820 // Param will have been canonicalized, but it should just be a
9821 // qualified version of ParamD, so move the qualifiers to that.
9822 QualifierCollector Qs;
9824 QualType NonCanonParam = Qs.apply(S.Context, TParam->getTypeForDecl());
9825 assert(S.Context.hasSameType(Param, NonCanonParam));
9827 // Arg has also been canonicalized, but there's nothing we can do
9828 // about that. It also doesn't matter as much, because it won't
9829 // have any template parameters in it (because deduction isn't
9830 // done on dependent types).
9831 QualType Arg = DeductionFailure.getSecondArg()->getAsType();
9833 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_underqualified)
9834 << ParamD->getDeclName() << Arg << NonCanonParam;
9835 MaybeEmitInheritedConstructorNote(S, Found);
9839 case Sema::TDK_Inconsistent: {
9840 assert(ParamD && "no parameter found for inconsistent deduction result");
9842 if (isa<TemplateTypeParmDecl>(ParamD))
9844 else if (isa<NonTypeTemplateParmDecl>(ParamD)) {
9845 // Deduction might have failed because we deduced arguments of two
9846 // different types for a non-type template parameter.
9847 // FIXME: Use a different TDK value for this.
9849 DeductionFailure.getFirstArg()->getNonTypeTemplateArgumentType();
9851 DeductionFailure.getSecondArg()->getNonTypeTemplateArgumentType();
9852 if (!S.Context.hasSameType(T1, T2)) {
9853 S.Diag(Templated->getLocation(),
9854 diag::note_ovl_candidate_inconsistent_deduction_types)
9855 << ParamD->getDeclName() << *DeductionFailure.getFirstArg() << T1
9856 << *DeductionFailure.getSecondArg() << T2;
9857 MaybeEmitInheritedConstructorNote(S, Found);
9866 S.Diag(Templated->getLocation(),
9867 diag::note_ovl_candidate_inconsistent_deduction)
9868 << which << ParamD->getDeclName() << *DeductionFailure.getFirstArg()
9869 << *DeductionFailure.getSecondArg();
9870 MaybeEmitInheritedConstructorNote(S, Found);
9874 case Sema::TDK_InvalidExplicitArguments:
9875 assert(ParamD && "no parameter found for invalid explicit arguments");
9876 if (ParamD->getDeclName())
9877 S.Diag(Templated->getLocation(),
9878 diag::note_ovl_candidate_explicit_arg_mismatch_named)
9879 << ParamD->getDeclName();
9882 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD))
9883 index = TTP->getIndex();
9884 else if (NonTypeTemplateParmDecl *NTTP
9885 = dyn_cast<NonTypeTemplateParmDecl>(ParamD))
9886 index = NTTP->getIndex();
9888 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex();
9889 S.Diag(Templated->getLocation(),
9890 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed)
9893 MaybeEmitInheritedConstructorNote(S, Found);
9896 case Sema::TDK_TooManyArguments:
9897 case Sema::TDK_TooFewArguments:
9898 DiagnoseArityMismatch(S, Found, Templated, NumArgs);
9901 case Sema::TDK_InstantiationDepth:
9902 S.Diag(Templated->getLocation(),
9903 diag::note_ovl_candidate_instantiation_depth);
9904 MaybeEmitInheritedConstructorNote(S, Found);
9907 case Sema::TDK_SubstitutionFailure: {
9908 // Format the template argument list into the argument string.
9909 SmallString<128> TemplateArgString;
9910 if (TemplateArgumentList *Args =
9911 DeductionFailure.getTemplateArgumentList()) {
9912 TemplateArgString = " ";
9913 TemplateArgString += S.getTemplateArgumentBindingsText(
9914 getDescribedTemplate(Templated)->getTemplateParameters(), *Args);
9917 // If this candidate was disabled by enable_if, say so.
9918 PartialDiagnosticAt *PDiag = DeductionFailure.getSFINAEDiagnostic();
9919 if (PDiag && PDiag->second.getDiagID() ==
9920 diag::err_typename_nested_not_found_enable_if) {
9921 // FIXME: Use the source range of the condition, and the fully-qualified
9922 // name of the enable_if template. These are both present in PDiag.
9923 S.Diag(PDiag->first, diag::note_ovl_candidate_disabled_by_enable_if)
9924 << "'enable_if'" << TemplateArgString;
9928 // Format the SFINAE diagnostic into the argument string.
9929 // FIXME: Add a general mechanism to include a PartialDiagnostic *'s
9930 // formatted message in another diagnostic.
9931 SmallString<128> SFINAEArgString;
9934 SFINAEArgString = ": ";
9935 R = SourceRange(PDiag->first, PDiag->first);
9936 PDiag->second.EmitToString(S.getDiagnostics(), SFINAEArgString);
9939 S.Diag(Templated->getLocation(),
9940 diag::note_ovl_candidate_substitution_failure)
9941 << TemplateArgString << SFINAEArgString << R;
9942 MaybeEmitInheritedConstructorNote(S, Found);
9946 case Sema::TDK_DeducedMismatch:
9947 case Sema::TDK_DeducedMismatchNested: {
9948 // Format the template argument list into the argument string.
9949 SmallString<128> TemplateArgString;
9950 if (TemplateArgumentList *Args =
9951 DeductionFailure.getTemplateArgumentList()) {
9952 TemplateArgString = " ";
9953 TemplateArgString += S.getTemplateArgumentBindingsText(
9954 getDescribedTemplate(Templated)->getTemplateParameters(), *Args);
9957 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_deduced_mismatch)
9958 << (*DeductionFailure.getCallArgIndex() + 1)
9959 << *DeductionFailure.getFirstArg() << *DeductionFailure.getSecondArg()
9960 << TemplateArgString
9961 << (DeductionFailure.Result == Sema::TDK_DeducedMismatchNested);
9965 case Sema::TDK_NonDeducedMismatch: {
9966 // FIXME: Provide a source location to indicate what we couldn't match.
9967 TemplateArgument FirstTA = *DeductionFailure.getFirstArg();
9968 TemplateArgument SecondTA = *DeductionFailure.getSecondArg();
9969 if (FirstTA.getKind() == TemplateArgument::Template &&
9970 SecondTA.getKind() == TemplateArgument::Template) {
9971 TemplateName FirstTN = FirstTA.getAsTemplate();
9972 TemplateName SecondTN = SecondTA.getAsTemplate();
9973 if (FirstTN.getKind() == TemplateName::Template &&
9974 SecondTN.getKind() == TemplateName::Template) {
9975 if (FirstTN.getAsTemplateDecl()->getName() ==
9976 SecondTN.getAsTemplateDecl()->getName()) {
9977 // FIXME: This fixes a bad diagnostic where both templates are named
9978 // the same. This particular case is a bit difficult since:
9979 // 1) It is passed as a string to the diagnostic printer.
9980 // 2) The diagnostic printer only attempts to find a better
9981 // name for types, not decls.
9982 // Ideally, this should folded into the diagnostic printer.
9983 S.Diag(Templated->getLocation(),
9984 diag::note_ovl_candidate_non_deduced_mismatch_qualified)
9985 << FirstTN.getAsTemplateDecl() << SecondTN.getAsTemplateDecl();
9991 if (TakingCandidateAddress && isa<FunctionDecl>(Templated) &&
9992 !checkAddressOfCandidateIsAvailable(S, cast<FunctionDecl>(Templated)))
9995 // FIXME: For generic lambda parameters, check if the function is a lambda
9996 // call operator, and if so, emit a prettier and more informative
9997 // diagnostic that mentions 'auto' and lambda in addition to
9998 // (or instead of?) the canonical template type parameters.
9999 S.Diag(Templated->getLocation(),
10000 diag::note_ovl_candidate_non_deduced_mismatch)
10001 << FirstTA << SecondTA;
10004 // TODO: diagnose these individually, then kill off
10005 // note_ovl_candidate_bad_deduction, which is uselessly vague.
10006 case Sema::TDK_MiscellaneousDeductionFailure:
10007 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_bad_deduction);
10008 MaybeEmitInheritedConstructorNote(S, Found);
10010 case Sema::TDK_CUDATargetMismatch:
10011 S.Diag(Templated->getLocation(),
10012 diag::note_cuda_ovl_candidate_target_mismatch);
10017 /// Diagnose a failed template-argument deduction, for function calls.
10018 static void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand,
10020 bool TakingCandidateAddress) {
10021 unsigned TDK = Cand->DeductionFailure.Result;
10022 if (TDK == Sema::TDK_TooFewArguments || TDK == Sema::TDK_TooManyArguments) {
10023 if (CheckArityMismatch(S, Cand, NumArgs))
10026 DiagnoseBadDeduction(S, Cand->FoundDecl, Cand->Function, // pattern
10027 Cand->DeductionFailure, NumArgs, TakingCandidateAddress);
10030 /// CUDA: diagnose an invalid call across targets.
10031 static void DiagnoseBadTarget(Sema &S, OverloadCandidate *Cand) {
10032 FunctionDecl *Caller = cast<FunctionDecl>(S.CurContext);
10033 FunctionDecl *Callee = Cand->Function;
10035 Sema::CUDAFunctionTarget CallerTarget = S.IdentifyCUDATarget(Caller),
10036 CalleeTarget = S.IdentifyCUDATarget(Callee);
10038 std::string FnDesc;
10039 OverloadCandidateKind FnKind =
10040 ClassifyOverloadCandidate(S, Cand->FoundDecl, Callee, FnDesc);
10042 S.Diag(Callee->getLocation(), diag::note_ovl_candidate_bad_target)
10043 << (unsigned)FnKind << CalleeTarget << CallerTarget;
10045 // This could be an implicit constructor for which we could not infer the
10046 // target due to a collsion. Diagnose that case.
10047 CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Callee);
10048 if (Meth != nullptr && Meth->isImplicit()) {
10049 CXXRecordDecl *ParentClass = Meth->getParent();
10050 Sema::CXXSpecialMember CSM;
10055 case oc_implicit_default_constructor:
10056 CSM = Sema::CXXDefaultConstructor;
10058 case oc_implicit_copy_constructor:
10059 CSM = Sema::CXXCopyConstructor;
10061 case oc_implicit_move_constructor:
10062 CSM = Sema::CXXMoveConstructor;
10064 case oc_implicit_copy_assignment:
10065 CSM = Sema::CXXCopyAssignment;
10067 case oc_implicit_move_assignment:
10068 CSM = Sema::CXXMoveAssignment;
10072 bool ConstRHS = false;
10073 if (Meth->getNumParams()) {
10074 if (const ReferenceType *RT =
10075 Meth->getParamDecl(0)->getType()->getAs<ReferenceType>()) {
10076 ConstRHS = RT->getPointeeType().isConstQualified();
10080 S.inferCUDATargetForImplicitSpecialMember(ParentClass, CSM, Meth,
10081 /* ConstRHS */ ConstRHS,
10082 /* Diagnose */ true);
10086 static void DiagnoseFailedEnableIfAttr(Sema &S, OverloadCandidate *Cand) {
10087 FunctionDecl *Callee = Cand->Function;
10088 EnableIfAttr *Attr = static_cast<EnableIfAttr*>(Cand->DeductionFailure.Data);
10090 S.Diag(Callee->getLocation(),
10091 diag::note_ovl_candidate_disabled_by_function_cond_attr)
10092 << Attr->getCond()->getSourceRange() << Attr->getMessage();
10095 static void DiagnoseOpenCLExtensionDisabled(Sema &S, OverloadCandidate *Cand) {
10096 FunctionDecl *Callee = Cand->Function;
10098 S.Diag(Callee->getLocation(),
10099 diag::note_ovl_candidate_disabled_by_extension);
10102 /// Generates a 'note' diagnostic for an overload candidate. We've
10103 /// already generated a primary error at the call site.
10105 /// It really does need to be a single diagnostic with its caret
10106 /// pointed at the candidate declaration. Yes, this creates some
10107 /// major challenges of technical writing. Yes, this makes pointing
10108 /// out problems with specific arguments quite awkward. It's still
10109 /// better than generating twenty screens of text for every failed
10112 /// It would be great to be able to express per-candidate problems
10113 /// more richly for those diagnostic clients that cared, but we'd
10114 /// still have to be just as careful with the default diagnostics.
10115 static void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand,
10117 bool TakingCandidateAddress) {
10118 FunctionDecl *Fn = Cand->Function;
10120 // Note deleted candidates, but only if they're viable.
10121 if (Cand->Viable) {
10122 if (Fn->isDeleted() || S.isFunctionConsideredUnavailable(Fn)) {
10123 std::string FnDesc;
10124 OverloadCandidateKind FnKind =
10125 ClassifyOverloadCandidate(S, Cand->FoundDecl, Fn, FnDesc);
10127 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted)
10128 << FnKind << FnDesc
10129 << (Fn->isDeleted() ? (Fn->isDeletedAsWritten() ? 1 : 2) : 0);
10130 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10134 // We don't really have anything else to say about viable candidates.
10135 S.NoteOverloadCandidate(Cand->FoundDecl, Fn);
10139 switch (Cand->FailureKind) {
10140 case ovl_fail_too_many_arguments:
10141 case ovl_fail_too_few_arguments:
10142 return DiagnoseArityMismatch(S, Cand, NumArgs);
10144 case ovl_fail_bad_deduction:
10145 return DiagnoseBadDeduction(S, Cand, NumArgs,
10146 TakingCandidateAddress);
10148 case ovl_fail_illegal_constructor: {
10149 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_illegal_constructor)
10150 << (Fn->getPrimaryTemplate() ? 1 : 0);
10151 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10155 case ovl_fail_trivial_conversion:
10156 case ovl_fail_bad_final_conversion:
10157 case ovl_fail_final_conversion_not_exact:
10158 return S.NoteOverloadCandidate(Cand->FoundDecl, Fn);
10160 case ovl_fail_bad_conversion: {
10161 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0);
10162 for (unsigned N = Cand->Conversions.size(); I != N; ++I)
10163 if (Cand->Conversions[I].isBad())
10164 return DiagnoseBadConversion(S, Cand, I, TakingCandidateAddress);
10166 // FIXME: this currently happens when we're called from SemaInit
10167 // when user-conversion overload fails. Figure out how to handle
10168 // those conditions and diagnose them well.
10169 return S.NoteOverloadCandidate(Cand->FoundDecl, Fn);
10172 case ovl_fail_bad_target:
10173 return DiagnoseBadTarget(S, Cand);
10175 case ovl_fail_enable_if:
10176 return DiagnoseFailedEnableIfAttr(S, Cand);
10178 case ovl_fail_ext_disabled:
10179 return DiagnoseOpenCLExtensionDisabled(S, Cand);
10181 case ovl_fail_inhctor_slice:
10182 // It's generally not interesting to note copy/move constructors here.
10183 if (cast<CXXConstructorDecl>(Fn)->isCopyOrMoveConstructor())
10185 S.Diag(Fn->getLocation(),
10186 diag::note_ovl_candidate_inherited_constructor_slice)
10187 << (Fn->getPrimaryTemplate() ? 1 : 0)
10188 << Fn->getParamDecl(0)->getType()->isRValueReferenceType();
10189 MaybeEmitInheritedConstructorNote(S, Cand->FoundDecl);
10192 case ovl_fail_addr_not_available: {
10193 bool Available = checkAddressOfCandidateIsAvailable(S, Cand->Function);
10195 assert(!Available);
10201 static void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) {
10202 // Desugar the type of the surrogate down to a function type,
10203 // retaining as many typedefs as possible while still showing
10204 // the function type (and, therefore, its parameter types).
10205 QualType FnType = Cand->Surrogate->getConversionType();
10206 bool isLValueReference = false;
10207 bool isRValueReference = false;
10208 bool isPointer = false;
10209 if (const LValueReferenceType *FnTypeRef =
10210 FnType->getAs<LValueReferenceType>()) {
10211 FnType = FnTypeRef->getPointeeType();
10212 isLValueReference = true;
10213 } else if (const RValueReferenceType *FnTypeRef =
10214 FnType->getAs<RValueReferenceType>()) {
10215 FnType = FnTypeRef->getPointeeType();
10216 isRValueReference = true;
10218 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) {
10219 FnType = FnTypePtr->getPointeeType();
10222 // Desugar down to a function type.
10223 FnType = QualType(FnType->getAs<FunctionType>(), 0);
10224 // Reconstruct the pointer/reference as appropriate.
10225 if (isPointer) FnType = S.Context.getPointerType(FnType);
10226 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType);
10227 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType);
10229 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand)
10233 static void NoteBuiltinOperatorCandidate(Sema &S, StringRef Opc,
10234 SourceLocation OpLoc,
10235 OverloadCandidate *Cand) {
10236 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary");
10237 std::string TypeStr("operator");
10240 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString();
10241 if (Cand->Conversions.size() == 1) {
10243 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr;
10246 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString();
10248 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr;
10252 static void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc,
10253 OverloadCandidate *Cand) {
10254 for (const ImplicitConversionSequence &ICS : Cand->Conversions) {
10255 if (ICS.isBad()) break; // all meaningless after first invalid
10256 if (!ICS.isAmbiguous()) continue;
10258 ICS.DiagnoseAmbiguousConversion(
10259 S, OpLoc, S.PDiag(diag::note_ambiguous_type_conversion));
10263 static SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) {
10264 if (Cand->Function)
10265 return Cand->Function->getLocation();
10266 if (Cand->IsSurrogate)
10267 return Cand->Surrogate->getLocation();
10268 return SourceLocation();
10271 static unsigned RankDeductionFailure(const DeductionFailureInfo &DFI) {
10272 switch ((Sema::TemplateDeductionResult)DFI.Result) {
10273 case Sema::TDK_Success:
10274 case Sema::TDK_NonDependentConversionFailure:
10275 llvm_unreachable("non-deduction failure while diagnosing bad deduction");
10277 case Sema::TDK_Invalid:
10278 case Sema::TDK_Incomplete:
10281 case Sema::TDK_Underqualified:
10282 case Sema::TDK_Inconsistent:
10285 case Sema::TDK_SubstitutionFailure:
10286 case Sema::TDK_DeducedMismatch:
10287 case Sema::TDK_DeducedMismatchNested:
10288 case Sema::TDK_NonDeducedMismatch:
10289 case Sema::TDK_MiscellaneousDeductionFailure:
10290 case Sema::TDK_CUDATargetMismatch:
10293 case Sema::TDK_InstantiationDepth:
10296 case Sema::TDK_InvalidExplicitArguments:
10299 case Sema::TDK_TooManyArguments:
10300 case Sema::TDK_TooFewArguments:
10303 llvm_unreachable("Unhandled deduction result");
10307 struct CompareOverloadCandidatesForDisplay {
10309 SourceLocation Loc;
10312 CompareOverloadCandidatesForDisplay(Sema &S, SourceLocation Loc, size_t nArgs)
10313 : S(S), NumArgs(nArgs) {}
10315 bool operator()(const OverloadCandidate *L,
10316 const OverloadCandidate *R) {
10317 // Fast-path this check.
10318 if (L == R) return false;
10320 // Order first by viability.
10322 if (!R->Viable) return true;
10324 // TODO: introduce a tri-valued comparison for overload
10325 // candidates. Would be more worthwhile if we had a sort
10326 // that could exploit it.
10327 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation())) return true;
10328 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation())) return false;
10329 } else if (R->Viable)
10332 assert(L->Viable == R->Viable);
10334 // Criteria by which we can sort non-viable candidates:
10336 // 1. Arity mismatches come after other candidates.
10337 if (L->FailureKind == ovl_fail_too_many_arguments ||
10338 L->FailureKind == ovl_fail_too_few_arguments) {
10339 if (R->FailureKind == ovl_fail_too_many_arguments ||
10340 R->FailureKind == ovl_fail_too_few_arguments) {
10341 int LDist = std::abs((int)L->getNumParams() - (int)NumArgs);
10342 int RDist = std::abs((int)R->getNumParams() - (int)NumArgs);
10343 if (LDist == RDist) {
10344 if (L->FailureKind == R->FailureKind)
10345 // Sort non-surrogates before surrogates.
10346 return !L->IsSurrogate && R->IsSurrogate;
10347 // Sort candidates requiring fewer parameters than there were
10348 // arguments given after candidates requiring more parameters
10349 // than there were arguments given.
10350 return L->FailureKind == ovl_fail_too_many_arguments;
10352 return LDist < RDist;
10356 if (R->FailureKind == ovl_fail_too_many_arguments ||
10357 R->FailureKind == ovl_fail_too_few_arguments)
10360 // 2. Bad conversions come first and are ordered by the number
10361 // of bad conversions and quality of good conversions.
10362 if (L->FailureKind == ovl_fail_bad_conversion) {
10363 if (R->FailureKind != ovl_fail_bad_conversion)
10366 // The conversion that can be fixed with a smaller number of changes,
10368 unsigned numLFixes = L->Fix.NumConversionsFixed;
10369 unsigned numRFixes = R->Fix.NumConversionsFixed;
10370 numLFixes = (numLFixes == 0) ? UINT_MAX : numLFixes;
10371 numRFixes = (numRFixes == 0) ? UINT_MAX : numRFixes;
10372 if (numLFixes != numRFixes) {
10373 return numLFixes < numRFixes;
10376 // If there's any ordering between the defined conversions...
10377 // FIXME: this might not be transitive.
10378 assert(L->Conversions.size() == R->Conversions.size());
10380 int leftBetter = 0;
10381 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument);
10382 for (unsigned E = L->Conversions.size(); I != E; ++I) {
10383 switch (CompareImplicitConversionSequences(S, Loc,
10385 R->Conversions[I])) {
10386 case ImplicitConversionSequence::Better:
10390 case ImplicitConversionSequence::Worse:
10394 case ImplicitConversionSequence::Indistinguishable:
10398 if (leftBetter > 0) return true;
10399 if (leftBetter < 0) return false;
10401 } else if (R->FailureKind == ovl_fail_bad_conversion)
10404 if (L->FailureKind == ovl_fail_bad_deduction) {
10405 if (R->FailureKind != ovl_fail_bad_deduction)
10408 if (L->DeductionFailure.Result != R->DeductionFailure.Result)
10409 return RankDeductionFailure(L->DeductionFailure)
10410 < RankDeductionFailure(R->DeductionFailure);
10411 } else if (R->FailureKind == ovl_fail_bad_deduction)
10417 // Sort everything else by location.
10418 SourceLocation LLoc = GetLocationForCandidate(L);
10419 SourceLocation RLoc = GetLocationForCandidate(R);
10421 // Put candidates without locations (e.g. builtins) at the end.
10422 if (LLoc.isInvalid()) return false;
10423 if (RLoc.isInvalid()) return true;
10425 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc);
10430 /// CompleteNonViableCandidate - Normally, overload resolution only
10431 /// computes up to the first bad conversion. Produces the FixIt set if
10433 static void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand,
10434 ArrayRef<Expr *> Args) {
10435 assert(!Cand->Viable);
10437 // Don't do anything on failures other than bad conversion.
10438 if (Cand->FailureKind != ovl_fail_bad_conversion) return;
10440 // We only want the FixIts if all the arguments can be corrected.
10441 bool Unfixable = false;
10442 // Use a implicit copy initialization to check conversion fixes.
10443 Cand->Fix.setConversionChecker(TryCopyInitialization);
10445 // Attempt to fix the bad conversion.
10446 unsigned ConvCount = Cand->Conversions.size();
10447 for (unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); /**/;
10449 assert(ConvIdx != ConvCount && "no bad conversion in candidate");
10450 if (Cand->Conversions[ConvIdx].isInitialized() &&
10451 Cand->Conversions[ConvIdx].isBad()) {
10452 Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S);
10457 // FIXME: this should probably be preserved from the overload
10458 // operation somehow.
10459 bool SuppressUserConversions = false;
10461 unsigned ConvIdx = 0;
10462 ArrayRef<QualType> ParamTypes;
10464 if (Cand->IsSurrogate) {
10466 = Cand->Surrogate->getConversionType().getNonReferenceType();
10467 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
10468 ConvType = ConvPtrType->getPointeeType();
10469 ParamTypes = ConvType->getAs<FunctionProtoType>()->getParamTypes();
10470 // Conversion 0 is 'this', which doesn't have a corresponding argument.
10472 } else if (Cand->Function) {
10474 Cand->Function->getType()->getAs<FunctionProtoType>()->getParamTypes();
10475 if (isa<CXXMethodDecl>(Cand->Function) &&
10476 !isa<CXXConstructorDecl>(Cand->Function)) {
10477 // Conversion 0 is 'this', which doesn't have a corresponding argument.
10481 // Builtin operator.
10482 assert(ConvCount <= 3);
10483 ParamTypes = Cand->BuiltinTypes.ParamTypes;
10486 // Fill in the rest of the conversions.
10487 for (unsigned ArgIdx = 0; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) {
10488 if (Cand->Conversions[ConvIdx].isInitialized()) {
10489 // We've already checked this conversion.
10490 } else if (ArgIdx < ParamTypes.size()) {
10491 if (ParamTypes[ArgIdx]->isDependentType())
10492 Cand->Conversions[ConvIdx].setAsIdentityConversion(
10493 Args[ArgIdx]->getType());
10495 Cand->Conversions[ConvIdx] =
10496 TryCopyInitialization(S, Args[ArgIdx], ParamTypes[ArgIdx],
10497 SuppressUserConversions,
10498 /*InOverloadResolution=*/true,
10499 /*AllowObjCWritebackConversion=*/
10500 S.getLangOpts().ObjCAutoRefCount);
10501 // Store the FixIt in the candidate if it exists.
10502 if (!Unfixable && Cand->Conversions[ConvIdx].isBad())
10503 Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S);
10506 Cand->Conversions[ConvIdx].setEllipsis();
10510 /// PrintOverloadCandidates - When overload resolution fails, prints
10511 /// diagnostic messages containing the candidates in the candidate
10513 void OverloadCandidateSet::NoteCandidates(
10514 Sema &S, OverloadCandidateDisplayKind OCD, ArrayRef<Expr *> Args,
10515 StringRef Opc, SourceLocation OpLoc,
10516 llvm::function_ref<bool(OverloadCandidate &)> Filter) {
10517 // Sort the candidates by viability and position. Sorting directly would
10518 // be prohibitive, so we make a set of pointers and sort those.
10519 SmallVector<OverloadCandidate*, 32> Cands;
10520 if (OCD == OCD_AllCandidates) Cands.reserve(size());
10521 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) {
10522 if (!Filter(*Cand))
10525 Cands.push_back(Cand);
10526 else if (OCD == OCD_AllCandidates) {
10527 CompleteNonViableCandidate(S, Cand, Args);
10528 if (Cand->Function || Cand->IsSurrogate)
10529 Cands.push_back(Cand);
10530 // Otherwise, this a non-viable builtin candidate. We do not, in general,
10531 // want to list every possible builtin candidate.
10535 std::sort(Cands.begin(), Cands.end(),
10536 CompareOverloadCandidatesForDisplay(S, OpLoc, Args.size()));
10538 bool ReportedAmbiguousConversions = false;
10540 SmallVectorImpl<OverloadCandidate*>::iterator I, E;
10541 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
10542 unsigned CandsShown = 0;
10543 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) {
10544 OverloadCandidate *Cand = *I;
10546 // Set an arbitrary limit on the number of candidate functions we'll spam
10547 // the user with. FIXME: This limit should depend on details of the
10549 if (CandsShown >= 4 && ShowOverloads == Ovl_Best) {
10554 if (Cand->Function)
10555 NoteFunctionCandidate(S, Cand, Args.size(),
10556 /*TakingCandidateAddress=*/false);
10557 else if (Cand->IsSurrogate)
10558 NoteSurrogateCandidate(S, Cand);
10560 assert(Cand->Viable &&
10561 "Non-viable built-in candidates are not added to Cands.");
10562 // Generally we only see ambiguities including viable builtin
10563 // operators if overload resolution got screwed up by an
10564 // ambiguous user-defined conversion.
10566 // FIXME: It's quite possible for different conversions to see
10567 // different ambiguities, though.
10568 if (!ReportedAmbiguousConversions) {
10569 NoteAmbiguousUserConversions(S, OpLoc, Cand);
10570 ReportedAmbiguousConversions = true;
10573 // If this is a viable builtin, print it.
10574 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand);
10579 S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I);
10582 static SourceLocation
10583 GetLocationForCandidate(const TemplateSpecCandidate *Cand) {
10584 return Cand->Specialization ? Cand->Specialization->getLocation()
10585 : SourceLocation();
10589 struct CompareTemplateSpecCandidatesForDisplay {
10591 CompareTemplateSpecCandidatesForDisplay(Sema &S) : S(S) {}
10593 bool operator()(const TemplateSpecCandidate *L,
10594 const TemplateSpecCandidate *R) {
10595 // Fast-path this check.
10599 // Assuming that both candidates are not matches...
10601 // Sort by the ranking of deduction failures.
10602 if (L->DeductionFailure.Result != R->DeductionFailure.Result)
10603 return RankDeductionFailure(L->DeductionFailure) <
10604 RankDeductionFailure(R->DeductionFailure);
10606 // Sort everything else by location.
10607 SourceLocation LLoc = GetLocationForCandidate(L);
10608 SourceLocation RLoc = GetLocationForCandidate(R);
10610 // Put candidates without locations (e.g. builtins) at the end.
10611 if (LLoc.isInvalid())
10613 if (RLoc.isInvalid())
10616 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc);
10621 /// Diagnose a template argument deduction failure.
10622 /// We are treating these failures as overload failures due to bad
10624 void TemplateSpecCandidate::NoteDeductionFailure(Sema &S,
10625 bool ForTakingAddress) {
10626 DiagnoseBadDeduction(S, FoundDecl, Specialization, // pattern
10627 DeductionFailure, /*NumArgs=*/0, ForTakingAddress);
10630 void TemplateSpecCandidateSet::destroyCandidates() {
10631 for (iterator i = begin(), e = end(); i != e; ++i) {
10632 i->DeductionFailure.Destroy();
10636 void TemplateSpecCandidateSet::clear() {
10637 destroyCandidates();
10638 Candidates.clear();
10641 /// NoteCandidates - When no template specialization match is found, prints
10642 /// diagnostic messages containing the non-matching specializations that form
10643 /// the candidate set.
10644 /// This is analoguous to OverloadCandidateSet::NoteCandidates() with
10645 /// OCD == OCD_AllCandidates and Cand->Viable == false.
10646 void TemplateSpecCandidateSet::NoteCandidates(Sema &S, SourceLocation Loc) {
10647 // Sort the candidates by position (assuming no candidate is a match).
10648 // Sorting directly would be prohibitive, so we make a set of pointers
10650 SmallVector<TemplateSpecCandidate *, 32> Cands;
10651 Cands.reserve(size());
10652 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) {
10653 if (Cand->Specialization)
10654 Cands.push_back(Cand);
10655 // Otherwise, this is a non-matching builtin candidate. We do not,
10656 // in general, want to list every possible builtin candidate.
10659 std::sort(Cands.begin(), Cands.end(),
10660 CompareTemplateSpecCandidatesForDisplay(S));
10662 // FIXME: Perhaps rename OverloadsShown and getShowOverloads()
10663 // for generalization purposes (?).
10664 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
10666 SmallVectorImpl<TemplateSpecCandidate *>::iterator I, E;
10667 unsigned CandsShown = 0;
10668 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) {
10669 TemplateSpecCandidate *Cand = *I;
10671 // Set an arbitrary limit on the number of candidates we'll spam
10672 // the user with. FIXME: This limit should depend on details of the
10674 if (CandsShown >= 4 && ShowOverloads == Ovl_Best)
10678 assert(Cand->Specialization &&
10679 "Non-matching built-in candidates are not added to Cands.");
10680 Cand->NoteDeductionFailure(S, ForTakingAddress);
10684 S.Diag(Loc, diag::note_ovl_too_many_candidates) << int(E - I);
10687 // [PossiblyAFunctionType] --> [Return]
10688 // NonFunctionType --> NonFunctionType
10690 // R (*)(A) --> R (A)
10691 // R (&)(A) --> R (A)
10692 // R (S::*)(A) --> R (A)
10693 QualType Sema::ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType) {
10694 QualType Ret = PossiblyAFunctionType;
10695 if (const PointerType *ToTypePtr =
10696 PossiblyAFunctionType->getAs<PointerType>())
10697 Ret = ToTypePtr->getPointeeType();
10698 else if (const ReferenceType *ToTypeRef =
10699 PossiblyAFunctionType->getAs<ReferenceType>())
10700 Ret = ToTypeRef->getPointeeType();
10701 else if (const MemberPointerType *MemTypePtr =
10702 PossiblyAFunctionType->getAs<MemberPointerType>())
10703 Ret = MemTypePtr->getPointeeType();
10705 Context.getCanonicalType(Ret).getUnqualifiedType();
10709 static bool completeFunctionType(Sema &S, FunctionDecl *FD, SourceLocation Loc,
10710 bool Complain = true) {
10711 if (S.getLangOpts().CPlusPlus14 && FD->getReturnType()->isUndeducedType() &&
10712 S.DeduceReturnType(FD, Loc, Complain))
10715 auto *FPT = FD->getType()->castAs<FunctionProtoType>();
10716 if (S.getLangOpts().CPlusPlus1z &&
10717 isUnresolvedExceptionSpec(FPT->getExceptionSpecType()) &&
10718 !S.ResolveExceptionSpec(Loc, FPT))
10725 // A helper class to help with address of function resolution
10726 // - allows us to avoid passing around all those ugly parameters
10727 class AddressOfFunctionResolver {
10730 const QualType& TargetType;
10731 QualType TargetFunctionType; // Extracted function type from target type
10734 //DeclAccessPair& ResultFunctionAccessPair;
10735 ASTContext& Context;
10737 bool TargetTypeIsNonStaticMemberFunction;
10738 bool FoundNonTemplateFunction;
10739 bool StaticMemberFunctionFromBoundPointer;
10740 bool HasComplained;
10742 OverloadExpr::FindResult OvlExprInfo;
10743 OverloadExpr *OvlExpr;
10744 TemplateArgumentListInfo OvlExplicitTemplateArgs;
10745 SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches;
10746 TemplateSpecCandidateSet FailedCandidates;
10749 AddressOfFunctionResolver(Sema &S, Expr *SourceExpr,
10750 const QualType &TargetType, bool Complain)
10751 : S(S), SourceExpr(SourceExpr), TargetType(TargetType),
10752 Complain(Complain), Context(S.getASTContext()),
10753 TargetTypeIsNonStaticMemberFunction(
10754 !!TargetType->getAs<MemberPointerType>()),
10755 FoundNonTemplateFunction(false),
10756 StaticMemberFunctionFromBoundPointer(false),
10757 HasComplained(false),
10758 OvlExprInfo(OverloadExpr::find(SourceExpr)),
10759 OvlExpr(OvlExprInfo.Expression),
10760 FailedCandidates(OvlExpr->getNameLoc(), /*ForTakingAddress=*/true) {
10761 ExtractUnqualifiedFunctionTypeFromTargetType();
10763 if (TargetFunctionType->isFunctionType()) {
10764 if (UnresolvedMemberExpr *UME = dyn_cast<UnresolvedMemberExpr>(OvlExpr))
10765 if (!UME->isImplicitAccess() &&
10766 !S.ResolveSingleFunctionTemplateSpecialization(UME))
10767 StaticMemberFunctionFromBoundPointer = true;
10768 } else if (OvlExpr->hasExplicitTemplateArgs()) {
10769 DeclAccessPair dap;
10770 if (FunctionDecl *Fn = S.ResolveSingleFunctionTemplateSpecialization(
10771 OvlExpr, false, &dap)) {
10772 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn))
10773 if (!Method->isStatic()) {
10774 // If the target type is a non-function type and the function found
10775 // is a non-static member function, pretend as if that was the
10776 // target, it's the only possible type to end up with.
10777 TargetTypeIsNonStaticMemberFunction = true;
10779 // And skip adding the function if its not in the proper form.
10780 // We'll diagnose this due to an empty set of functions.
10781 if (!OvlExprInfo.HasFormOfMemberPointer)
10785 Matches.push_back(std::make_pair(dap, Fn));
10790 if (OvlExpr->hasExplicitTemplateArgs())
10791 OvlExpr->copyTemplateArgumentsInto(OvlExplicitTemplateArgs);
10793 if (FindAllFunctionsThatMatchTargetTypeExactly()) {
10794 // C++ [over.over]p4:
10795 // If more than one function is selected, [...]
10796 if (Matches.size() > 1 && !eliminiateSuboptimalOverloadCandidates()) {
10797 if (FoundNonTemplateFunction)
10798 EliminateAllTemplateMatches();
10800 EliminateAllExceptMostSpecializedTemplate();
10804 if (S.getLangOpts().CUDA && Matches.size() > 1)
10805 EliminateSuboptimalCudaMatches();
10808 bool hasComplained() const { return HasComplained; }
10811 bool candidateHasExactlyCorrectType(const FunctionDecl *FD) {
10813 return Context.hasSameUnqualifiedType(TargetFunctionType, FD->getType()) ||
10814 S.IsFunctionConversion(FD->getType(), TargetFunctionType, Discard);
10817 /// \return true if A is considered a better overload candidate for the
10818 /// desired type than B.
10819 bool isBetterCandidate(const FunctionDecl *A, const FunctionDecl *B) {
10820 // If A doesn't have exactly the correct type, we don't want to classify it
10821 // as "better" than anything else. This way, the user is required to
10822 // disambiguate for us if there are multiple candidates and no exact match.
10823 return candidateHasExactlyCorrectType(A) &&
10824 (!candidateHasExactlyCorrectType(B) ||
10825 compareEnableIfAttrs(S, A, B) == Comparison::Better);
10828 /// \return true if we were able to eliminate all but one overload candidate,
10829 /// false otherwise.
10830 bool eliminiateSuboptimalOverloadCandidates() {
10831 // Same algorithm as overload resolution -- one pass to pick the "best",
10832 // another pass to be sure that nothing is better than the best.
10833 auto Best = Matches.begin();
10834 for (auto I = Matches.begin()+1, E = Matches.end(); I != E; ++I)
10835 if (isBetterCandidate(I->second, Best->second))
10838 const FunctionDecl *BestFn = Best->second;
10839 auto IsBestOrInferiorToBest = [this, BestFn](
10840 const std::pair<DeclAccessPair, FunctionDecl *> &Pair) {
10841 return BestFn == Pair.second || isBetterCandidate(BestFn, Pair.second);
10844 // Note: We explicitly leave Matches unmodified if there isn't a clear best
10845 // option, so we can potentially give the user a better error
10846 if (!std::all_of(Matches.begin(), Matches.end(), IsBestOrInferiorToBest))
10848 Matches[0] = *Best;
10853 bool isTargetTypeAFunction() const {
10854 return TargetFunctionType->isFunctionType();
10857 // [ToType] [Return]
10859 // R (*)(A) --> R (A), IsNonStaticMemberFunction = false
10860 // R (&)(A) --> R (A), IsNonStaticMemberFunction = false
10861 // R (S::*)(A) --> R (A), IsNonStaticMemberFunction = true
10862 void inline ExtractUnqualifiedFunctionTypeFromTargetType() {
10863 TargetFunctionType = S.ExtractUnqualifiedFunctionType(TargetType);
10866 // return true if any matching specializations were found
10867 bool AddMatchingTemplateFunction(FunctionTemplateDecl* FunctionTemplate,
10868 const DeclAccessPair& CurAccessFunPair) {
10869 if (CXXMethodDecl *Method
10870 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) {
10871 // Skip non-static function templates when converting to pointer, and
10872 // static when converting to member pointer.
10873 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction)
10876 else if (TargetTypeIsNonStaticMemberFunction)
10879 // C++ [over.over]p2:
10880 // If the name is a function template, template argument deduction is
10881 // done (14.8.2.2), and if the argument deduction succeeds, the
10882 // resulting template argument list is used to generate a single
10883 // function template specialization, which is added to the set of
10884 // overloaded functions considered.
10885 FunctionDecl *Specialization = nullptr;
10886 TemplateDeductionInfo Info(FailedCandidates.getLocation());
10887 if (Sema::TemplateDeductionResult Result
10888 = S.DeduceTemplateArguments(FunctionTemplate,
10889 &OvlExplicitTemplateArgs,
10890 TargetFunctionType, Specialization,
10891 Info, /*IsAddressOfFunction*/true)) {
10892 // Make a note of the failed deduction for diagnostics.
10893 FailedCandidates.addCandidate()
10894 .set(CurAccessFunPair, FunctionTemplate->getTemplatedDecl(),
10895 MakeDeductionFailureInfo(Context, Result, Info));
10899 // Template argument deduction ensures that we have an exact match or
10900 // compatible pointer-to-function arguments that would be adjusted by ICS.
10901 // This function template specicalization works.
10902 assert(S.isSameOrCompatibleFunctionType(
10903 Context.getCanonicalType(Specialization->getType()),
10904 Context.getCanonicalType(TargetFunctionType)));
10906 if (!S.checkAddressOfFunctionIsAvailable(Specialization))
10909 Matches.push_back(std::make_pair(CurAccessFunPair, Specialization));
10913 bool AddMatchingNonTemplateFunction(NamedDecl* Fn,
10914 const DeclAccessPair& CurAccessFunPair) {
10915 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) {
10916 // Skip non-static functions when converting to pointer, and static
10917 // when converting to member pointer.
10918 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction)
10921 else if (TargetTypeIsNonStaticMemberFunction)
10924 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) {
10925 if (S.getLangOpts().CUDA)
10926 if (FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext))
10927 if (!Caller->isImplicit() && !S.IsAllowedCUDACall(Caller, FunDecl))
10930 // If any candidate has a placeholder return type, trigger its deduction
10932 if (completeFunctionType(S, FunDecl, SourceExpr->getLocStart(),
10934 HasComplained |= Complain;
10938 if (!S.checkAddressOfFunctionIsAvailable(FunDecl))
10941 // If we're in C, we need to support types that aren't exactly identical.
10942 if (!S.getLangOpts().CPlusPlus ||
10943 candidateHasExactlyCorrectType(FunDecl)) {
10944 Matches.push_back(std::make_pair(
10945 CurAccessFunPair, cast<FunctionDecl>(FunDecl->getCanonicalDecl())));
10946 FoundNonTemplateFunction = true;
10954 bool FindAllFunctionsThatMatchTargetTypeExactly() {
10957 // If the overload expression doesn't have the form of a pointer to
10958 // member, don't try to convert it to a pointer-to-member type.
10959 if (IsInvalidFormOfPointerToMemberFunction())
10962 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
10963 E = OvlExpr->decls_end();
10965 // Look through any using declarations to find the underlying function.
10966 NamedDecl *Fn = (*I)->getUnderlyingDecl();
10968 // C++ [over.over]p3:
10969 // Non-member functions and static member functions match
10970 // targets of type "pointer-to-function" or "reference-to-function."
10971 // Nonstatic member functions match targets of
10972 // type "pointer-to-member-function."
10973 // Note that according to DR 247, the containing class does not matter.
10974 if (FunctionTemplateDecl *FunctionTemplate
10975 = dyn_cast<FunctionTemplateDecl>(Fn)) {
10976 if (AddMatchingTemplateFunction(FunctionTemplate, I.getPair()))
10979 // If we have explicit template arguments supplied, skip non-templates.
10980 else if (!OvlExpr->hasExplicitTemplateArgs() &&
10981 AddMatchingNonTemplateFunction(Fn, I.getPair()))
10984 assert(Ret || Matches.empty());
10988 void EliminateAllExceptMostSpecializedTemplate() {
10989 // [...] and any given function template specialization F1 is
10990 // eliminated if the set contains a second function template
10991 // specialization whose function template is more specialized
10992 // than the function template of F1 according to the partial
10993 // ordering rules of 14.5.5.2.
10995 // The algorithm specified above is quadratic. We instead use a
10996 // two-pass algorithm (similar to the one used to identify the
10997 // best viable function in an overload set) that identifies the
10998 // best function template (if it exists).
11000 UnresolvedSet<4> MatchesCopy; // TODO: avoid!
11001 for (unsigned I = 0, E = Matches.size(); I != E; ++I)
11002 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess());
11004 // TODO: It looks like FailedCandidates does not serve much purpose
11005 // here, since the no_viable diagnostic has index 0.
11006 UnresolvedSetIterator Result = S.getMostSpecialized(
11007 MatchesCopy.begin(), MatchesCopy.end(), FailedCandidates,
11008 SourceExpr->getLocStart(), S.PDiag(),
11009 S.PDiag(diag::err_addr_ovl_ambiguous)
11010 << Matches[0].second->getDeclName(),
11011 S.PDiag(diag::note_ovl_candidate)
11012 << (unsigned)oc_function_template,
11013 Complain, TargetFunctionType);
11015 if (Result != MatchesCopy.end()) {
11016 // Make it the first and only element
11017 Matches[0].first = Matches[Result - MatchesCopy.begin()].first;
11018 Matches[0].second = cast<FunctionDecl>(*Result);
11021 HasComplained |= Complain;
11024 void EliminateAllTemplateMatches() {
11025 // [...] any function template specializations in the set are
11026 // eliminated if the set also contains a non-template function, [...]
11027 for (unsigned I = 0, N = Matches.size(); I != N; ) {
11028 if (Matches[I].second->getPrimaryTemplate() == nullptr)
11031 Matches[I] = Matches[--N];
11037 void EliminateSuboptimalCudaMatches() {
11038 S.EraseUnwantedCUDAMatches(dyn_cast<FunctionDecl>(S.CurContext), Matches);
11042 void ComplainNoMatchesFound() const {
11043 assert(Matches.empty());
11044 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_no_viable)
11045 << OvlExpr->getName() << TargetFunctionType
11046 << OvlExpr->getSourceRange();
11047 if (FailedCandidates.empty())
11048 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType,
11049 /*TakingAddress=*/true);
11051 // We have some deduction failure messages. Use them to diagnose
11052 // the function templates, and diagnose the non-template candidates
11054 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
11055 IEnd = OvlExpr->decls_end();
11057 if (FunctionDecl *Fun =
11058 dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()))
11059 if (!functionHasPassObjectSizeParams(Fun))
11060 S.NoteOverloadCandidate(*I, Fun, TargetFunctionType,
11061 /*TakingAddress=*/true);
11062 FailedCandidates.NoteCandidates(S, OvlExpr->getLocStart());
11066 bool IsInvalidFormOfPointerToMemberFunction() const {
11067 return TargetTypeIsNonStaticMemberFunction &&
11068 !OvlExprInfo.HasFormOfMemberPointer;
11071 void ComplainIsInvalidFormOfPointerToMemberFunction() const {
11072 // TODO: Should we condition this on whether any functions might
11073 // have matched, or is it more appropriate to do that in callers?
11074 // TODO: a fixit wouldn't hurt.
11075 S.Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier)
11076 << TargetType << OvlExpr->getSourceRange();
11079 bool IsStaticMemberFunctionFromBoundPointer() const {
11080 return StaticMemberFunctionFromBoundPointer;
11083 void ComplainIsStaticMemberFunctionFromBoundPointer() const {
11084 S.Diag(OvlExpr->getLocStart(),
11085 diag::err_invalid_form_pointer_member_function)
11086 << OvlExpr->getSourceRange();
11089 void ComplainOfInvalidConversion() const {
11090 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_not_func_ptrref)
11091 << OvlExpr->getName() << TargetType;
11094 void ComplainMultipleMatchesFound() const {
11095 assert(Matches.size() > 1);
11096 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_ambiguous)
11097 << OvlExpr->getName()
11098 << OvlExpr->getSourceRange();
11099 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType,
11100 /*TakingAddress=*/true);
11103 bool hadMultipleCandidates() const { return (OvlExpr->getNumDecls() > 1); }
11105 int getNumMatches() const { return Matches.size(); }
11107 FunctionDecl* getMatchingFunctionDecl() const {
11108 if (Matches.size() != 1) return nullptr;
11109 return Matches[0].second;
11112 const DeclAccessPair* getMatchingFunctionAccessPair() const {
11113 if (Matches.size() != 1) return nullptr;
11114 return &Matches[0].first;
11119 /// ResolveAddressOfOverloadedFunction - Try to resolve the address of
11120 /// an overloaded function (C++ [over.over]), where @p From is an
11121 /// expression with overloaded function type and @p ToType is the type
11122 /// we're trying to resolve to. For example:
11128 /// int (*pfd)(double) = f; // selects f(double)
11131 /// This routine returns the resulting FunctionDecl if it could be
11132 /// resolved, and NULL otherwise. When @p Complain is true, this
11133 /// routine will emit diagnostics if there is an error.
11135 Sema::ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr,
11136 QualType TargetType,
11138 DeclAccessPair &FoundResult,
11139 bool *pHadMultipleCandidates) {
11140 assert(AddressOfExpr->getType() == Context.OverloadTy);
11142 AddressOfFunctionResolver Resolver(*this, AddressOfExpr, TargetType,
11144 int NumMatches = Resolver.getNumMatches();
11145 FunctionDecl *Fn = nullptr;
11146 bool ShouldComplain = Complain && !Resolver.hasComplained();
11147 if (NumMatches == 0 && ShouldComplain) {
11148 if (Resolver.IsInvalidFormOfPointerToMemberFunction())
11149 Resolver.ComplainIsInvalidFormOfPointerToMemberFunction();
11151 Resolver.ComplainNoMatchesFound();
11153 else if (NumMatches > 1 && ShouldComplain)
11154 Resolver.ComplainMultipleMatchesFound();
11155 else if (NumMatches == 1) {
11156 Fn = Resolver.getMatchingFunctionDecl();
11158 if (auto *FPT = Fn->getType()->getAs<FunctionProtoType>())
11159 ResolveExceptionSpec(AddressOfExpr->getExprLoc(), FPT);
11160 FoundResult = *Resolver.getMatchingFunctionAccessPair();
11162 if (Resolver.IsStaticMemberFunctionFromBoundPointer())
11163 Resolver.ComplainIsStaticMemberFunctionFromBoundPointer();
11165 CheckAddressOfMemberAccess(AddressOfExpr, FoundResult);
11169 if (pHadMultipleCandidates)
11170 *pHadMultipleCandidates = Resolver.hadMultipleCandidates();
11174 /// \brief Given an expression that refers to an overloaded function, try to
11175 /// resolve that function to a single function that can have its address taken.
11176 /// This will modify `Pair` iff it returns non-null.
11178 /// This routine can only realistically succeed if all but one candidates in the
11179 /// overload set for SrcExpr cannot have their addresses taken.
11181 Sema::resolveAddressOfOnlyViableOverloadCandidate(Expr *E,
11182 DeclAccessPair &Pair) {
11183 OverloadExpr::FindResult R = OverloadExpr::find(E);
11184 OverloadExpr *Ovl = R.Expression;
11185 FunctionDecl *Result = nullptr;
11186 DeclAccessPair DAP;
11187 // Don't use the AddressOfResolver because we're specifically looking for
11188 // cases where we have one overload candidate that lacks
11189 // enable_if/pass_object_size/...
11190 for (auto I = Ovl->decls_begin(), E = Ovl->decls_end(); I != E; ++I) {
11191 auto *FD = dyn_cast<FunctionDecl>(I->getUnderlyingDecl());
11195 if (!checkAddressOfFunctionIsAvailable(FD))
11198 // We have more than one result; quit.
11210 /// \brief Given an overloaded function, tries to turn it into a non-overloaded
11211 /// function reference using resolveAddressOfOnlyViableOverloadCandidate. This
11212 /// will perform access checks, diagnose the use of the resultant decl, and, if
11213 /// requested, potentially perform a function-to-pointer decay.
11215 /// Returns false if resolveAddressOfOnlyViableOverloadCandidate fails.
11216 /// Otherwise, returns true. This may emit diagnostics and return true.
11217 bool Sema::resolveAndFixAddressOfOnlyViableOverloadCandidate(
11218 ExprResult &SrcExpr, bool DoFunctionPointerConverion) {
11219 Expr *E = SrcExpr.get();
11220 assert(E->getType() == Context.OverloadTy && "SrcExpr must be an overload");
11222 DeclAccessPair DAP;
11223 FunctionDecl *Found = resolveAddressOfOnlyViableOverloadCandidate(E, DAP);
11227 // Emitting multiple diagnostics for a function that is both inaccessible and
11228 // unavailable is consistent with our behavior elsewhere. So, always check
11230 DiagnoseUseOfDecl(Found, E->getExprLoc());
11231 CheckAddressOfMemberAccess(E, DAP);
11232 Expr *Fixed = FixOverloadedFunctionReference(E, DAP, Found);
11233 if (DoFunctionPointerConverion && Fixed->getType()->isFunctionType())
11234 SrcExpr = DefaultFunctionArrayConversion(Fixed, /*Diagnose=*/false);
11240 /// \brief Given an expression that refers to an overloaded function, try to
11241 /// resolve that overloaded function expression down to a single function.
11243 /// This routine can only resolve template-ids that refer to a single function
11244 /// template, where that template-id refers to a single template whose template
11245 /// arguments are either provided by the template-id or have defaults,
11246 /// as described in C++0x [temp.arg.explicit]p3.
11248 /// If no template-ids are found, no diagnostics are emitted and NULL is
11251 Sema::ResolveSingleFunctionTemplateSpecialization(OverloadExpr *ovl,
11253 DeclAccessPair *FoundResult) {
11254 // C++ [over.over]p1:
11255 // [...] [Note: any redundant set of parentheses surrounding the
11256 // overloaded function name is ignored (5.1). ]
11257 // C++ [over.over]p1:
11258 // [...] The overloaded function name can be preceded by the &
11261 // If we didn't actually find any template-ids, we're done.
11262 if (!ovl->hasExplicitTemplateArgs())
11265 TemplateArgumentListInfo ExplicitTemplateArgs;
11266 ovl->copyTemplateArgumentsInto(ExplicitTemplateArgs);
11267 TemplateSpecCandidateSet FailedCandidates(ovl->getNameLoc());
11269 // Look through all of the overloaded functions, searching for one
11270 // whose type matches exactly.
11271 FunctionDecl *Matched = nullptr;
11272 for (UnresolvedSetIterator I = ovl->decls_begin(),
11273 E = ovl->decls_end(); I != E; ++I) {
11274 // C++0x [temp.arg.explicit]p3:
11275 // [...] In contexts where deduction is done and fails, or in contexts
11276 // where deduction is not done, if a template argument list is
11277 // specified and it, along with any default template arguments,
11278 // identifies a single function template specialization, then the
11279 // template-id is an lvalue for the function template specialization.
11280 FunctionTemplateDecl *FunctionTemplate
11281 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl());
11283 // C++ [over.over]p2:
11284 // If the name is a function template, template argument deduction is
11285 // done (14.8.2.2), and if the argument deduction succeeds, the
11286 // resulting template argument list is used to generate a single
11287 // function template specialization, which is added to the set of
11288 // overloaded functions considered.
11289 FunctionDecl *Specialization = nullptr;
11290 TemplateDeductionInfo Info(FailedCandidates.getLocation());
11291 if (TemplateDeductionResult Result
11292 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs,
11293 Specialization, Info,
11294 /*IsAddressOfFunction*/true)) {
11295 // Make a note of the failed deduction for diagnostics.
11296 // TODO: Actually use the failed-deduction info?
11297 FailedCandidates.addCandidate()
11298 .set(I.getPair(), FunctionTemplate->getTemplatedDecl(),
11299 MakeDeductionFailureInfo(Context, Result, Info));
11303 assert(Specialization && "no specialization and no error?");
11305 // Multiple matches; we can't resolve to a single declaration.
11308 Diag(ovl->getExprLoc(), diag::err_addr_ovl_ambiguous)
11310 NoteAllOverloadCandidates(ovl);
11315 Matched = Specialization;
11316 if (FoundResult) *FoundResult = I.getPair();
11320 completeFunctionType(*this, Matched, ovl->getExprLoc(), Complain))
11329 // Resolve and fix an overloaded expression that can be resolved
11330 // because it identifies a single function template specialization.
11332 // Last three arguments should only be supplied if Complain = true
11334 // Return true if it was logically possible to so resolve the
11335 // expression, regardless of whether or not it succeeded. Always
11336 // returns true if 'complain' is set.
11337 bool Sema::ResolveAndFixSingleFunctionTemplateSpecialization(
11338 ExprResult &SrcExpr, bool doFunctionPointerConverion,
11339 bool complain, SourceRange OpRangeForComplaining,
11340 QualType DestTypeForComplaining,
11341 unsigned DiagIDForComplaining) {
11342 assert(SrcExpr.get()->getType() == Context.OverloadTy);
11344 OverloadExpr::FindResult ovl = OverloadExpr::find(SrcExpr.get());
11346 DeclAccessPair found;
11347 ExprResult SingleFunctionExpression;
11348 if (FunctionDecl *fn = ResolveSingleFunctionTemplateSpecialization(
11349 ovl.Expression, /*complain*/ false, &found)) {
11350 if (DiagnoseUseOfDecl(fn, SrcExpr.get()->getLocStart())) {
11351 SrcExpr = ExprError();
11355 // It is only correct to resolve to an instance method if we're
11356 // resolving a form that's permitted to be a pointer to member.
11357 // Otherwise we'll end up making a bound member expression, which
11358 // is illegal in all the contexts we resolve like this.
11359 if (!ovl.HasFormOfMemberPointer &&
11360 isa<CXXMethodDecl>(fn) &&
11361 cast<CXXMethodDecl>(fn)->isInstance()) {
11362 if (!complain) return false;
11364 Diag(ovl.Expression->getExprLoc(),
11365 diag::err_bound_member_function)
11366 << 0 << ovl.Expression->getSourceRange();
11368 // TODO: I believe we only end up here if there's a mix of
11369 // static and non-static candidates (otherwise the expression
11370 // would have 'bound member' type, not 'overload' type).
11371 // Ideally we would note which candidate was chosen and why
11372 // the static candidates were rejected.
11373 SrcExpr = ExprError();
11377 // Fix the expression to refer to 'fn'.
11378 SingleFunctionExpression =
11379 FixOverloadedFunctionReference(SrcExpr.get(), found, fn);
11381 // If desired, do function-to-pointer decay.
11382 if (doFunctionPointerConverion) {
11383 SingleFunctionExpression =
11384 DefaultFunctionArrayLvalueConversion(SingleFunctionExpression.get());
11385 if (SingleFunctionExpression.isInvalid()) {
11386 SrcExpr = ExprError();
11392 if (!SingleFunctionExpression.isUsable()) {
11394 Diag(OpRangeForComplaining.getBegin(), DiagIDForComplaining)
11395 << ovl.Expression->getName()
11396 << DestTypeForComplaining
11397 << OpRangeForComplaining
11398 << ovl.Expression->getQualifierLoc().getSourceRange();
11399 NoteAllOverloadCandidates(SrcExpr.get());
11401 SrcExpr = ExprError();
11408 SrcExpr = SingleFunctionExpression;
11412 /// \brief Add a single candidate to the overload set.
11413 static void AddOverloadedCallCandidate(Sema &S,
11414 DeclAccessPair FoundDecl,
11415 TemplateArgumentListInfo *ExplicitTemplateArgs,
11416 ArrayRef<Expr *> Args,
11417 OverloadCandidateSet &CandidateSet,
11418 bool PartialOverloading,
11420 NamedDecl *Callee = FoundDecl.getDecl();
11421 if (isa<UsingShadowDecl>(Callee))
11422 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl();
11424 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) {
11425 if (ExplicitTemplateArgs) {
11426 assert(!KnownValid && "Explicit template arguments?");
11429 // Prevent ill-formed function decls to be added as overload candidates.
11430 if (!dyn_cast<FunctionProtoType>(Func->getType()->getAs<FunctionType>()))
11433 S.AddOverloadCandidate(Func, FoundDecl, Args, CandidateSet,
11434 /*SuppressUsedConversions=*/false,
11435 PartialOverloading);
11439 if (FunctionTemplateDecl *FuncTemplate
11440 = dyn_cast<FunctionTemplateDecl>(Callee)) {
11441 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl,
11442 ExplicitTemplateArgs, Args, CandidateSet,
11443 /*SuppressUsedConversions=*/false,
11444 PartialOverloading);
11448 assert(!KnownValid && "unhandled case in overloaded call candidate");
11451 /// \brief Add the overload candidates named by callee and/or found by argument
11452 /// dependent lookup to the given overload set.
11453 void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE,
11454 ArrayRef<Expr *> Args,
11455 OverloadCandidateSet &CandidateSet,
11456 bool PartialOverloading) {
11459 // Verify that ArgumentDependentLookup is consistent with the rules
11460 // in C++0x [basic.lookup.argdep]p3:
11462 // Let X be the lookup set produced by unqualified lookup (3.4.1)
11463 // and let Y be the lookup set produced by argument dependent
11464 // lookup (defined as follows). If X contains
11466 // -- a declaration of a class member, or
11468 // -- a block-scope function declaration that is not a
11469 // using-declaration, or
11471 // -- a declaration that is neither a function or a function
11474 // then Y is empty.
11476 if (ULE->requiresADL()) {
11477 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(),
11478 E = ULE->decls_end(); I != E; ++I) {
11479 assert(!(*I)->getDeclContext()->isRecord());
11480 assert(isa<UsingShadowDecl>(*I) ||
11481 !(*I)->getDeclContext()->isFunctionOrMethod());
11482 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate());
11487 // It would be nice to avoid this copy.
11488 TemplateArgumentListInfo TABuffer;
11489 TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr;
11490 if (ULE->hasExplicitTemplateArgs()) {
11491 ULE->copyTemplateArgumentsInto(TABuffer);
11492 ExplicitTemplateArgs = &TABuffer;
11495 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(),
11496 E = ULE->decls_end(); I != E; ++I)
11497 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, Args,
11498 CandidateSet, PartialOverloading,
11499 /*KnownValid*/ true);
11501 if (ULE->requiresADL())
11502 AddArgumentDependentLookupCandidates(ULE->getName(), ULE->getExprLoc(),
11503 Args, ExplicitTemplateArgs,
11504 CandidateSet, PartialOverloading);
11507 /// Determine whether a declaration with the specified name could be moved into
11508 /// a different namespace.
11509 static bool canBeDeclaredInNamespace(const DeclarationName &Name) {
11510 switch (Name.getCXXOverloadedOperator()) {
11511 case OO_New: case OO_Array_New:
11512 case OO_Delete: case OO_Array_Delete:
11520 /// Attempt to recover from an ill-formed use of a non-dependent name in a
11521 /// template, where the non-dependent name was declared after the template
11522 /// was defined. This is common in code written for a compilers which do not
11523 /// correctly implement two-stage name lookup.
11525 /// Returns true if a viable candidate was found and a diagnostic was issued.
11527 DiagnoseTwoPhaseLookup(Sema &SemaRef, SourceLocation FnLoc,
11528 const CXXScopeSpec &SS, LookupResult &R,
11529 OverloadCandidateSet::CandidateSetKind CSK,
11530 TemplateArgumentListInfo *ExplicitTemplateArgs,
11531 ArrayRef<Expr *> Args,
11532 bool *DoDiagnoseEmptyLookup = nullptr) {
11533 if (!SemaRef.inTemplateInstantiation() || !SS.isEmpty())
11536 for (DeclContext *DC = SemaRef.CurContext; DC; DC = DC->getParent()) {
11537 if (DC->isTransparentContext())
11540 SemaRef.LookupQualifiedName(R, DC);
11543 R.suppressDiagnostics();
11545 if (isa<CXXRecordDecl>(DC)) {
11546 // Don't diagnose names we find in classes; we get much better
11547 // diagnostics for these from DiagnoseEmptyLookup.
11549 if (DoDiagnoseEmptyLookup)
11550 *DoDiagnoseEmptyLookup = true;
11554 OverloadCandidateSet Candidates(FnLoc, CSK);
11555 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
11556 AddOverloadedCallCandidate(SemaRef, I.getPair(),
11557 ExplicitTemplateArgs, Args,
11558 Candidates, false, /*KnownValid*/ false);
11560 OverloadCandidateSet::iterator Best;
11561 if (Candidates.BestViableFunction(SemaRef, FnLoc, Best) != OR_Success) {
11562 // No viable functions. Don't bother the user with notes for functions
11563 // which don't work and shouldn't be found anyway.
11568 // Find the namespaces where ADL would have looked, and suggest
11569 // declaring the function there instead.
11570 Sema::AssociatedNamespaceSet AssociatedNamespaces;
11571 Sema::AssociatedClassSet AssociatedClasses;
11572 SemaRef.FindAssociatedClassesAndNamespaces(FnLoc, Args,
11573 AssociatedNamespaces,
11574 AssociatedClasses);
11575 Sema::AssociatedNamespaceSet SuggestedNamespaces;
11576 if (canBeDeclaredInNamespace(R.getLookupName())) {
11577 DeclContext *Std = SemaRef.getStdNamespace();
11578 for (Sema::AssociatedNamespaceSet::iterator
11579 it = AssociatedNamespaces.begin(),
11580 end = AssociatedNamespaces.end(); it != end; ++it) {
11581 // Never suggest declaring a function within namespace 'std'.
11582 if (Std && Std->Encloses(*it))
11585 // Never suggest declaring a function within a namespace with a
11586 // reserved name, like __gnu_cxx.
11587 NamespaceDecl *NS = dyn_cast<NamespaceDecl>(*it);
11589 NS->getQualifiedNameAsString().find("__") != std::string::npos)
11592 SuggestedNamespaces.insert(*it);
11596 SemaRef.Diag(R.getNameLoc(), diag::err_not_found_by_two_phase_lookup)
11597 << R.getLookupName();
11598 if (SuggestedNamespaces.empty()) {
11599 SemaRef.Diag(Best->Function->getLocation(),
11600 diag::note_not_found_by_two_phase_lookup)
11601 << R.getLookupName() << 0;
11602 } else if (SuggestedNamespaces.size() == 1) {
11603 SemaRef.Diag(Best->Function->getLocation(),
11604 diag::note_not_found_by_two_phase_lookup)
11605 << R.getLookupName() << 1 << *SuggestedNamespaces.begin();
11607 // FIXME: It would be useful to list the associated namespaces here,
11608 // but the diagnostics infrastructure doesn't provide a way to produce
11609 // a localized representation of a list of items.
11610 SemaRef.Diag(Best->Function->getLocation(),
11611 diag::note_not_found_by_two_phase_lookup)
11612 << R.getLookupName() << 2;
11615 // Try to recover by calling this function.
11625 /// Attempt to recover from ill-formed use of a non-dependent operator in a
11626 /// template, where the non-dependent operator was declared after the template
11629 /// Returns true if a viable candidate was found and a diagnostic was issued.
11631 DiagnoseTwoPhaseOperatorLookup(Sema &SemaRef, OverloadedOperatorKind Op,
11632 SourceLocation OpLoc,
11633 ArrayRef<Expr *> Args) {
11634 DeclarationName OpName =
11635 SemaRef.Context.DeclarationNames.getCXXOperatorName(Op);
11636 LookupResult R(SemaRef, OpName, OpLoc, Sema::LookupOperatorName);
11637 return DiagnoseTwoPhaseLookup(SemaRef, OpLoc, CXXScopeSpec(), R,
11638 OverloadCandidateSet::CSK_Operator,
11639 /*ExplicitTemplateArgs=*/nullptr, Args);
11643 class BuildRecoveryCallExprRAII {
11646 BuildRecoveryCallExprRAII(Sema &S) : SemaRef(S) {
11647 assert(SemaRef.IsBuildingRecoveryCallExpr == false);
11648 SemaRef.IsBuildingRecoveryCallExpr = true;
11651 ~BuildRecoveryCallExprRAII() {
11652 SemaRef.IsBuildingRecoveryCallExpr = false;
11658 static std::unique_ptr<CorrectionCandidateCallback>
11659 MakeValidator(Sema &SemaRef, MemberExpr *ME, size_t NumArgs,
11660 bool HasTemplateArgs, bool AllowTypoCorrection) {
11661 if (!AllowTypoCorrection)
11662 return llvm::make_unique<NoTypoCorrectionCCC>();
11663 return llvm::make_unique<FunctionCallFilterCCC>(SemaRef, NumArgs,
11664 HasTemplateArgs, ME);
11667 /// Attempts to recover from a call where no functions were found.
11669 /// Returns true if new candidates were found.
11671 BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn,
11672 UnresolvedLookupExpr *ULE,
11673 SourceLocation LParenLoc,
11674 MutableArrayRef<Expr *> Args,
11675 SourceLocation RParenLoc,
11676 bool EmptyLookup, bool AllowTypoCorrection) {
11677 // Do not try to recover if it is already building a recovery call.
11678 // This stops infinite loops for template instantiations like
11680 // template <typename T> auto foo(T t) -> decltype(foo(t)) {}
11681 // template <typename T> auto foo(T t) -> decltype(foo(&t)) {}
11683 if (SemaRef.IsBuildingRecoveryCallExpr)
11684 return ExprError();
11685 BuildRecoveryCallExprRAII RCE(SemaRef);
11688 SS.Adopt(ULE->getQualifierLoc());
11689 SourceLocation TemplateKWLoc = ULE->getTemplateKeywordLoc();
11691 TemplateArgumentListInfo TABuffer;
11692 TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr;
11693 if (ULE->hasExplicitTemplateArgs()) {
11694 ULE->copyTemplateArgumentsInto(TABuffer);
11695 ExplicitTemplateArgs = &TABuffer;
11698 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(),
11699 Sema::LookupOrdinaryName);
11700 bool DoDiagnoseEmptyLookup = EmptyLookup;
11701 if (!DiagnoseTwoPhaseLookup(SemaRef, Fn->getExprLoc(), SS, R,
11702 OverloadCandidateSet::CSK_Normal,
11703 ExplicitTemplateArgs, Args,
11704 &DoDiagnoseEmptyLookup) &&
11705 (!DoDiagnoseEmptyLookup || SemaRef.DiagnoseEmptyLookup(
11707 MakeValidator(SemaRef, dyn_cast<MemberExpr>(Fn), Args.size(),
11708 ExplicitTemplateArgs != nullptr, AllowTypoCorrection),
11709 ExplicitTemplateArgs, Args)))
11710 return ExprError();
11712 assert(!R.empty() && "lookup results empty despite recovery");
11714 // If recovery created an ambiguity, just bail out.
11715 if (R.isAmbiguous()) {
11716 R.suppressDiagnostics();
11717 return ExprError();
11720 // Build an implicit member call if appropriate. Just drop the
11721 // casts and such from the call, we don't really care.
11722 ExprResult NewFn = ExprError();
11723 if ((*R.begin())->isCXXClassMember())
11724 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, TemplateKWLoc, R,
11725 ExplicitTemplateArgs, S);
11726 else if (ExplicitTemplateArgs || TemplateKWLoc.isValid())
11727 NewFn = SemaRef.BuildTemplateIdExpr(SS, TemplateKWLoc, R, false,
11728 ExplicitTemplateArgs);
11730 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false);
11732 if (NewFn.isInvalid())
11733 return ExprError();
11735 // This shouldn't cause an infinite loop because we're giving it
11736 // an expression with viable lookup results, which should never
11738 return SemaRef.ActOnCallExpr(/*Scope*/ nullptr, NewFn.get(), LParenLoc,
11739 MultiExprArg(Args.data(), Args.size()),
11743 /// \brief Constructs and populates an OverloadedCandidateSet from
11744 /// the given function.
11745 /// \returns true when an the ExprResult output parameter has been set.
11746 bool Sema::buildOverloadedCallSet(Scope *S, Expr *Fn,
11747 UnresolvedLookupExpr *ULE,
11749 SourceLocation RParenLoc,
11750 OverloadCandidateSet *CandidateSet,
11751 ExprResult *Result) {
11753 if (ULE->requiresADL()) {
11754 // To do ADL, we must have found an unqualified name.
11755 assert(!ULE->getQualifier() && "qualified name with ADL");
11757 // We don't perform ADL for implicit declarations of builtins.
11758 // Verify that this was correctly set up.
11760 if (ULE->decls_begin() + 1 == ULE->decls_end() &&
11761 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) &&
11762 F->getBuiltinID() && F->isImplicit())
11763 llvm_unreachable("performing ADL for builtin");
11765 // We don't perform ADL in C.
11766 assert(getLangOpts().CPlusPlus && "ADL enabled in C");
11770 UnbridgedCastsSet UnbridgedCasts;
11771 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts)) {
11772 *Result = ExprError();
11776 // Add the functions denoted by the callee to the set of candidate
11777 // functions, including those from argument-dependent lookup.
11778 AddOverloadedCallCandidates(ULE, Args, *CandidateSet);
11780 if (getLangOpts().MSVCCompat &&
11781 CurContext->isDependentContext() && !isSFINAEContext() &&
11782 (isa<FunctionDecl>(CurContext) || isa<CXXRecordDecl>(CurContext))) {
11784 OverloadCandidateSet::iterator Best;
11785 if (CandidateSet->empty() ||
11786 CandidateSet->BestViableFunction(*this, Fn->getLocStart(), Best) ==
11787 OR_No_Viable_Function) {
11788 // In Microsoft mode, if we are inside a template class member function then
11789 // create a type dependent CallExpr. The goal is to postpone name lookup
11790 // to instantiation time to be able to search into type dependent base
11792 CallExpr *CE = new (Context) CallExpr(
11793 Context, Fn, Args, Context.DependentTy, VK_RValue, RParenLoc);
11794 CE->setTypeDependent(true);
11795 CE->setValueDependent(true);
11796 CE->setInstantiationDependent(true);
11802 if (CandidateSet->empty())
11805 UnbridgedCasts.restore();
11809 /// FinishOverloadedCallExpr - given an OverloadCandidateSet, builds and returns
11810 /// the completed call expression. If overload resolution fails, emits
11811 /// diagnostics and returns ExprError()
11812 static ExprResult FinishOverloadedCallExpr(Sema &SemaRef, Scope *S, Expr *Fn,
11813 UnresolvedLookupExpr *ULE,
11814 SourceLocation LParenLoc,
11816 SourceLocation RParenLoc,
11818 OverloadCandidateSet *CandidateSet,
11819 OverloadCandidateSet::iterator *Best,
11820 OverloadingResult OverloadResult,
11821 bool AllowTypoCorrection) {
11822 if (CandidateSet->empty())
11823 return BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc, Args,
11824 RParenLoc, /*EmptyLookup=*/true,
11825 AllowTypoCorrection);
11827 switch (OverloadResult) {
11829 FunctionDecl *FDecl = (*Best)->Function;
11830 SemaRef.CheckUnresolvedLookupAccess(ULE, (*Best)->FoundDecl);
11831 if (SemaRef.DiagnoseUseOfDecl(FDecl, ULE->getNameLoc()))
11832 return ExprError();
11833 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl);
11834 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, RParenLoc,
11838 case OR_No_Viable_Function: {
11839 // Try to recover by looking for viable functions which the user might
11840 // have meant to call.
11841 ExprResult Recovery = BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc,
11843 /*EmptyLookup=*/false,
11844 AllowTypoCorrection);
11845 if (!Recovery.isInvalid())
11848 // If the user passes in a function that we can't take the address of, we
11849 // generally end up emitting really bad error messages. Here, we attempt to
11850 // emit better ones.
11851 for (const Expr *Arg : Args) {
11852 if (!Arg->getType()->isFunctionType())
11854 if (auto *DRE = dyn_cast<DeclRefExpr>(Arg->IgnoreParenImpCasts())) {
11855 auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl());
11857 !SemaRef.checkAddressOfFunctionIsAvailable(FD, /*Complain=*/true,
11858 Arg->getExprLoc()))
11859 return ExprError();
11863 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_no_viable_function_in_call)
11864 << ULE->getName() << Fn->getSourceRange();
11865 CandidateSet->NoteCandidates(SemaRef, OCD_AllCandidates, Args);
11870 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_ambiguous_call)
11871 << ULE->getName() << Fn->getSourceRange();
11872 CandidateSet->NoteCandidates(SemaRef, OCD_ViableCandidates, Args);
11876 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_deleted_call)
11877 << (*Best)->Function->isDeleted()
11879 << SemaRef.getDeletedOrUnavailableSuffix((*Best)->Function)
11880 << Fn->getSourceRange();
11881 CandidateSet->NoteCandidates(SemaRef, OCD_AllCandidates, Args);
11883 // We emitted an error for the unvailable/deleted function call but keep
11884 // the call in the AST.
11885 FunctionDecl *FDecl = (*Best)->Function;
11886 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl);
11887 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, RParenLoc,
11892 // Overload resolution failed.
11893 return ExprError();
11896 static void markUnaddressableCandidatesUnviable(Sema &S,
11897 OverloadCandidateSet &CS) {
11898 for (auto I = CS.begin(), E = CS.end(); I != E; ++I) {
11900 !S.checkAddressOfFunctionIsAvailable(I->Function, /*Complain=*/false)) {
11902 I->FailureKind = ovl_fail_addr_not_available;
11907 /// BuildOverloadedCallExpr - Given the call expression that calls Fn
11908 /// (which eventually refers to the declaration Func) and the call
11909 /// arguments Args/NumArgs, attempt to resolve the function call down
11910 /// to a specific function. If overload resolution succeeds, returns
11911 /// the call expression produced by overload resolution.
11912 /// Otherwise, emits diagnostics and returns ExprError.
11913 ExprResult Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn,
11914 UnresolvedLookupExpr *ULE,
11915 SourceLocation LParenLoc,
11917 SourceLocation RParenLoc,
11919 bool AllowTypoCorrection,
11920 bool CalleesAddressIsTaken) {
11921 OverloadCandidateSet CandidateSet(Fn->getExprLoc(),
11922 OverloadCandidateSet::CSK_Normal);
11925 if (buildOverloadedCallSet(S, Fn, ULE, Args, LParenLoc, &CandidateSet,
11929 // If the user handed us something like `(&Foo)(Bar)`, we need to ensure that
11930 // functions that aren't addressible are considered unviable.
11931 if (CalleesAddressIsTaken)
11932 markUnaddressableCandidatesUnviable(*this, CandidateSet);
11934 OverloadCandidateSet::iterator Best;
11935 OverloadingResult OverloadResult =
11936 CandidateSet.BestViableFunction(*this, Fn->getLocStart(), Best);
11938 return FinishOverloadedCallExpr(*this, S, Fn, ULE, LParenLoc, Args,
11939 RParenLoc, ExecConfig, &CandidateSet,
11940 &Best, OverloadResult,
11941 AllowTypoCorrection);
11944 static bool IsOverloaded(const UnresolvedSetImpl &Functions) {
11945 return Functions.size() > 1 ||
11946 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin()));
11949 /// \brief Create a unary operation that may resolve to an overloaded
11952 /// \param OpLoc The location of the operator itself (e.g., '*').
11954 /// \param Opc The UnaryOperatorKind that describes this operator.
11956 /// \param Fns The set of non-member functions that will be
11957 /// considered by overload resolution. The caller needs to build this
11958 /// set based on the context using, e.g.,
11959 /// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This
11960 /// set should not contain any member functions; those will be added
11961 /// by CreateOverloadedUnaryOp().
11963 /// \param Input The input argument.
11965 Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, UnaryOperatorKind Opc,
11966 const UnresolvedSetImpl &Fns,
11968 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc);
11969 assert(Op != OO_None && "Invalid opcode for overloaded unary operator");
11970 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
11971 // TODO: provide better source location info.
11972 DeclarationNameInfo OpNameInfo(OpName, OpLoc);
11974 if (checkPlaceholderForOverload(*this, Input))
11975 return ExprError();
11977 Expr *Args[2] = { Input, nullptr };
11978 unsigned NumArgs = 1;
11980 // For post-increment and post-decrement, add the implicit '0' as
11981 // the second argument, so that we know this is a post-increment or
11983 if (Opc == UO_PostInc || Opc == UO_PostDec) {
11984 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false);
11985 Args[1] = IntegerLiteral::Create(Context, Zero, Context.IntTy,
11990 ArrayRef<Expr *> ArgsArray(Args, NumArgs);
11992 if (Input->isTypeDependent()) {
11994 return new (Context) UnaryOperator(Input, Opc, Context.DependentTy,
11995 VK_RValue, OK_Ordinary, OpLoc);
11997 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
11998 UnresolvedLookupExpr *Fn
11999 = UnresolvedLookupExpr::Create(Context, NamingClass,
12000 NestedNameSpecifierLoc(), OpNameInfo,
12001 /*ADL*/ true, IsOverloaded(Fns),
12002 Fns.begin(), Fns.end());
12003 return new (Context)
12004 CXXOperatorCallExpr(Context, Op, Fn, ArgsArray, Context.DependentTy,
12005 VK_RValue, OpLoc, FPOptions());
12008 // Build an empty overload set.
12009 OverloadCandidateSet CandidateSet(OpLoc, OverloadCandidateSet::CSK_Operator);
12011 // Add the candidates from the given function set.
12012 AddFunctionCandidates(Fns, ArgsArray, CandidateSet);
12014 // Add operator candidates that are member functions.
12015 AddMemberOperatorCandidates(Op, OpLoc, ArgsArray, CandidateSet);
12017 // Add candidates from ADL.
12018 AddArgumentDependentLookupCandidates(OpName, OpLoc, ArgsArray,
12019 /*ExplicitTemplateArgs*/nullptr,
12022 // Add builtin operator candidates.
12023 AddBuiltinOperatorCandidates(Op, OpLoc, ArgsArray, CandidateSet);
12025 bool HadMultipleCandidates = (CandidateSet.size() > 1);
12027 // Perform overload resolution.
12028 OverloadCandidateSet::iterator Best;
12029 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
12031 // We found a built-in operator or an overloaded operator.
12032 FunctionDecl *FnDecl = Best->Function;
12035 // We matched an overloaded operator. Build a call to that
12038 // Convert the arguments.
12039 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) {
12040 CheckMemberOperatorAccess(OpLoc, Args[0], nullptr, Best->FoundDecl);
12042 ExprResult InputRes =
12043 PerformObjectArgumentInitialization(Input, /*Qualifier=*/nullptr,
12044 Best->FoundDecl, Method);
12045 if (InputRes.isInvalid())
12046 return ExprError();
12047 Input = InputRes.get();
12049 // Convert the arguments.
12050 ExprResult InputInit
12051 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
12053 FnDecl->getParamDecl(0)),
12056 if (InputInit.isInvalid())
12057 return ExprError();
12058 Input = InputInit.get();
12061 // Build the actual expression node.
12062 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, Best->FoundDecl,
12063 HadMultipleCandidates, OpLoc);
12064 if (FnExpr.isInvalid())
12065 return ExprError();
12067 // Determine the result type.
12068 QualType ResultTy = FnDecl->getReturnType();
12069 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
12070 ResultTy = ResultTy.getNonLValueExprType(Context);
12073 CallExpr *TheCall =
12074 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.get(), ArgsArray,
12075 ResultTy, VK, OpLoc, FPOptions());
12077 if (CheckCallReturnType(FnDecl->getReturnType(), OpLoc, TheCall, FnDecl))
12078 return ExprError();
12080 if (CheckFunctionCall(FnDecl, TheCall,
12081 FnDecl->getType()->castAs<FunctionProtoType>()))
12082 return ExprError();
12084 return MaybeBindToTemporary(TheCall);
12086 // We matched a built-in operator. Convert the arguments, then
12087 // break out so that we will build the appropriate built-in
12089 ExprResult InputRes =
12090 PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0],
12091 Best->Conversions[0], AA_Passing);
12092 if (InputRes.isInvalid())
12093 return ExprError();
12094 Input = InputRes.get();
12099 case OR_No_Viable_Function:
12100 // This is an erroneous use of an operator which can be overloaded by
12101 // a non-member function. Check for non-member operators which were
12102 // defined too late to be candidates.
12103 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, ArgsArray))
12104 // FIXME: Recover by calling the found function.
12105 return ExprError();
12107 // No viable function; fall through to handling this as a
12108 // built-in operator, which will produce an error message for us.
12112 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary)
12113 << UnaryOperator::getOpcodeStr(Opc)
12114 << Input->getType()
12115 << Input->getSourceRange();
12116 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, ArgsArray,
12117 UnaryOperator::getOpcodeStr(Opc), OpLoc);
12118 return ExprError();
12121 Diag(OpLoc, diag::err_ovl_deleted_oper)
12122 << Best->Function->isDeleted()
12123 << UnaryOperator::getOpcodeStr(Opc)
12124 << getDeletedOrUnavailableSuffix(Best->Function)
12125 << Input->getSourceRange();
12126 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, ArgsArray,
12127 UnaryOperator::getOpcodeStr(Opc), OpLoc);
12128 return ExprError();
12131 // Either we found no viable overloaded operator or we matched a
12132 // built-in operator. In either case, fall through to trying to
12133 // build a built-in operation.
12134 return CreateBuiltinUnaryOp(OpLoc, Opc, Input);
12137 /// \brief Create a binary operation that may resolve to an overloaded
12140 /// \param OpLoc The location of the operator itself (e.g., '+').
12142 /// \param Opc The BinaryOperatorKind that describes this operator.
12144 /// \param Fns The set of non-member functions that will be
12145 /// considered by overload resolution. The caller needs to build this
12146 /// set based on the context using, e.g.,
12147 /// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This
12148 /// set should not contain any member functions; those will be added
12149 /// by CreateOverloadedBinOp().
12151 /// \param LHS Left-hand argument.
12152 /// \param RHS Right-hand argument.
12154 Sema::CreateOverloadedBinOp(SourceLocation OpLoc,
12155 BinaryOperatorKind Opc,
12156 const UnresolvedSetImpl &Fns,
12157 Expr *LHS, Expr *RHS) {
12158 Expr *Args[2] = { LHS, RHS };
12159 LHS=RHS=nullptr; // Please use only Args instead of LHS/RHS couple
12161 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc);
12162 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
12164 // If either side is type-dependent, create an appropriate dependent
12166 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) {
12168 // If there are no functions to store, just build a dependent
12169 // BinaryOperator or CompoundAssignment.
12170 if (Opc <= BO_Assign || Opc > BO_OrAssign)
12171 return new (Context) BinaryOperator(
12172 Args[0], Args[1], Opc, Context.DependentTy, VK_RValue, OK_Ordinary,
12173 OpLoc, FPFeatures);
12175 return new (Context) CompoundAssignOperator(
12176 Args[0], Args[1], Opc, Context.DependentTy, VK_LValue, OK_Ordinary,
12177 Context.DependentTy, Context.DependentTy, OpLoc,
12181 // FIXME: save results of ADL from here?
12182 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
12183 // TODO: provide better source location info in DNLoc component.
12184 DeclarationNameInfo OpNameInfo(OpName, OpLoc);
12185 UnresolvedLookupExpr *Fn
12186 = UnresolvedLookupExpr::Create(Context, NamingClass,
12187 NestedNameSpecifierLoc(), OpNameInfo,
12188 /*ADL*/ true, IsOverloaded(Fns),
12189 Fns.begin(), Fns.end());
12190 return new (Context)
12191 CXXOperatorCallExpr(Context, Op, Fn, Args, Context.DependentTy,
12192 VK_RValue, OpLoc, FPFeatures);
12195 // Always do placeholder-like conversions on the RHS.
12196 if (checkPlaceholderForOverload(*this, Args[1]))
12197 return ExprError();
12199 // Do placeholder-like conversion on the LHS; note that we should
12200 // not get here with a PseudoObject LHS.
12201 assert(Args[0]->getObjectKind() != OK_ObjCProperty);
12202 if (checkPlaceholderForOverload(*this, Args[0]))
12203 return ExprError();
12205 // If this is the assignment operator, we only perform overload resolution
12206 // if the left-hand side is a class or enumeration type. This is actually
12207 // a hack. The standard requires that we do overload resolution between the
12208 // various built-in candidates, but as DR507 points out, this can lead to
12209 // problems. So we do it this way, which pretty much follows what GCC does.
12210 // Note that we go the traditional code path for compound assignment forms.
12211 if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType())
12212 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
12214 // If this is the .* operator, which is not overloadable, just
12215 // create a built-in binary operator.
12216 if (Opc == BO_PtrMemD)
12217 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
12219 // Build an empty overload set.
12220 OverloadCandidateSet CandidateSet(OpLoc, OverloadCandidateSet::CSK_Operator);
12222 // Add the candidates from the given function set.
12223 AddFunctionCandidates(Fns, Args, CandidateSet);
12225 // Add operator candidates that are member functions.
12226 AddMemberOperatorCandidates(Op, OpLoc, Args, CandidateSet);
12228 // Add candidates from ADL. Per [over.match.oper]p2, this lookup is not
12229 // performed for an assignment operator (nor for operator[] nor operator->,
12230 // which don't get here).
12231 if (Opc != BO_Assign)
12232 AddArgumentDependentLookupCandidates(OpName, OpLoc, Args,
12233 /*ExplicitTemplateArgs*/ nullptr,
12236 // Add builtin operator candidates.
12237 AddBuiltinOperatorCandidates(Op, OpLoc, Args, CandidateSet);
12239 bool HadMultipleCandidates = (CandidateSet.size() > 1);
12241 // Perform overload resolution.
12242 OverloadCandidateSet::iterator Best;
12243 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
12245 // We found a built-in operator or an overloaded operator.
12246 FunctionDecl *FnDecl = Best->Function;
12249 // We matched an overloaded operator. Build a call to that
12252 // Convert the arguments.
12253 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) {
12254 // Best->Access is only meaningful for class members.
12255 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl);
12258 PerformCopyInitialization(
12259 InitializedEntity::InitializeParameter(Context,
12260 FnDecl->getParamDecl(0)),
12261 SourceLocation(), Args[1]);
12262 if (Arg1.isInvalid())
12263 return ExprError();
12266 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/nullptr,
12267 Best->FoundDecl, Method);
12268 if (Arg0.isInvalid())
12269 return ExprError();
12270 Args[0] = Arg0.getAs<Expr>();
12271 Args[1] = RHS = Arg1.getAs<Expr>();
12273 // Convert the arguments.
12274 ExprResult Arg0 = PerformCopyInitialization(
12275 InitializedEntity::InitializeParameter(Context,
12276 FnDecl->getParamDecl(0)),
12277 SourceLocation(), Args[0]);
12278 if (Arg0.isInvalid())
12279 return ExprError();
12282 PerformCopyInitialization(
12283 InitializedEntity::InitializeParameter(Context,
12284 FnDecl->getParamDecl(1)),
12285 SourceLocation(), Args[1]);
12286 if (Arg1.isInvalid())
12287 return ExprError();
12288 Args[0] = LHS = Arg0.getAs<Expr>();
12289 Args[1] = RHS = Arg1.getAs<Expr>();
12292 // Build the actual expression node.
12293 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl,
12295 HadMultipleCandidates, OpLoc);
12296 if (FnExpr.isInvalid())
12297 return ExprError();
12299 // Determine the result type.
12300 QualType ResultTy = FnDecl->getReturnType();
12301 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
12302 ResultTy = ResultTy.getNonLValueExprType(Context);
12304 CXXOperatorCallExpr *TheCall =
12305 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.get(),
12306 Args, ResultTy, VK, OpLoc,
12309 if (CheckCallReturnType(FnDecl->getReturnType(), OpLoc, TheCall,
12311 return ExprError();
12313 ArrayRef<const Expr *> ArgsArray(Args, 2);
12314 const Expr *ImplicitThis = nullptr;
12315 // Cut off the implicit 'this'.
12316 if (isa<CXXMethodDecl>(FnDecl)) {
12317 ImplicitThis = ArgsArray[0];
12318 ArgsArray = ArgsArray.slice(1);
12321 // Check for a self move.
12322 if (Op == OO_Equal)
12323 DiagnoseSelfMove(Args[0], Args[1], OpLoc);
12325 checkCall(FnDecl, nullptr, ImplicitThis, ArgsArray,
12326 isa<CXXMethodDecl>(FnDecl), OpLoc, TheCall->getSourceRange(),
12327 VariadicDoesNotApply);
12329 return MaybeBindToTemporary(TheCall);
12331 // We matched a built-in operator. Convert the arguments, then
12332 // break out so that we will build the appropriate built-in
12334 ExprResult ArgsRes0 =
12335 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0],
12336 Best->Conversions[0], AA_Passing);
12337 if (ArgsRes0.isInvalid())
12338 return ExprError();
12339 Args[0] = ArgsRes0.get();
12341 ExprResult ArgsRes1 =
12342 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1],
12343 Best->Conversions[1], AA_Passing);
12344 if (ArgsRes1.isInvalid())
12345 return ExprError();
12346 Args[1] = ArgsRes1.get();
12351 case OR_No_Viable_Function: {
12352 // C++ [over.match.oper]p9:
12353 // If the operator is the operator , [...] and there are no
12354 // viable functions, then the operator is assumed to be the
12355 // built-in operator and interpreted according to clause 5.
12356 if (Opc == BO_Comma)
12359 // For class as left operand for assignment or compound assigment
12360 // operator do not fall through to handling in built-in, but report that
12361 // no overloaded assignment operator found
12362 ExprResult Result = ExprError();
12363 if (Args[0]->getType()->isRecordType() &&
12364 Opc >= BO_Assign && Opc <= BO_OrAssign) {
12365 Diag(OpLoc, diag::err_ovl_no_viable_oper)
12366 << BinaryOperator::getOpcodeStr(Opc)
12367 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12368 if (Args[0]->getType()->isIncompleteType()) {
12369 Diag(OpLoc, diag::note_assign_lhs_incomplete)
12370 << Args[0]->getType()
12371 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12374 // This is an erroneous use of an operator which can be overloaded by
12375 // a non-member function. Check for non-member operators which were
12376 // defined too late to be candidates.
12377 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, Args))
12378 // FIXME: Recover by calling the found function.
12379 return ExprError();
12381 // No viable function; try to create a built-in operation, which will
12382 // produce an error. Then, show the non-viable candidates.
12383 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
12385 assert(Result.isInvalid() &&
12386 "C++ binary operator overloading is missing candidates!");
12387 if (Result.isInvalid())
12388 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args,
12389 BinaryOperator::getOpcodeStr(Opc), OpLoc);
12394 Diag(OpLoc, diag::err_ovl_ambiguous_oper_binary)
12395 << BinaryOperator::getOpcodeStr(Opc)
12396 << Args[0]->getType() << Args[1]->getType()
12397 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12398 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args,
12399 BinaryOperator::getOpcodeStr(Opc), OpLoc);
12400 return ExprError();
12403 if (isImplicitlyDeleted(Best->Function)) {
12404 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
12405 Diag(OpLoc, diag::err_ovl_deleted_special_oper)
12406 << Context.getRecordType(Method->getParent())
12407 << getSpecialMember(Method);
12409 // The user probably meant to call this special member. Just
12410 // explain why it's deleted.
12411 NoteDeletedFunction(Method);
12412 return ExprError();
12414 Diag(OpLoc, diag::err_ovl_deleted_oper)
12415 << Best->Function->isDeleted()
12416 << BinaryOperator::getOpcodeStr(Opc)
12417 << getDeletedOrUnavailableSuffix(Best->Function)
12418 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12420 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args,
12421 BinaryOperator::getOpcodeStr(Opc), OpLoc);
12422 return ExprError();
12425 // We matched a built-in operator; build it.
12426 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
12430 Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc,
12431 SourceLocation RLoc,
12432 Expr *Base, Expr *Idx) {
12433 Expr *Args[2] = { Base, Idx };
12434 DeclarationName OpName =
12435 Context.DeclarationNames.getCXXOperatorName(OO_Subscript);
12437 // If either side is type-dependent, create an appropriate dependent
12439 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) {
12441 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
12442 // CHECKME: no 'operator' keyword?
12443 DeclarationNameInfo OpNameInfo(OpName, LLoc);
12444 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc));
12445 UnresolvedLookupExpr *Fn
12446 = UnresolvedLookupExpr::Create(Context, NamingClass,
12447 NestedNameSpecifierLoc(), OpNameInfo,
12448 /*ADL*/ true, /*Overloaded*/ false,
12449 UnresolvedSetIterator(),
12450 UnresolvedSetIterator());
12451 // Can't add any actual overloads yet
12453 return new (Context)
12454 CXXOperatorCallExpr(Context, OO_Subscript, Fn, Args,
12455 Context.DependentTy, VK_RValue, RLoc, FPOptions());
12458 // Handle placeholders on both operands.
12459 if (checkPlaceholderForOverload(*this, Args[0]))
12460 return ExprError();
12461 if (checkPlaceholderForOverload(*this, Args[1]))
12462 return ExprError();
12464 // Build an empty overload set.
12465 OverloadCandidateSet CandidateSet(LLoc, OverloadCandidateSet::CSK_Operator);
12467 // Subscript can only be overloaded as a member function.
12469 // Add operator candidates that are member functions.
12470 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, CandidateSet);
12472 // Add builtin operator candidates.
12473 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, CandidateSet);
12475 bool HadMultipleCandidates = (CandidateSet.size() > 1);
12477 // Perform overload resolution.
12478 OverloadCandidateSet::iterator Best;
12479 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) {
12481 // We found a built-in operator or an overloaded operator.
12482 FunctionDecl *FnDecl = Best->Function;
12485 // We matched an overloaded operator. Build a call to that
12488 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl);
12490 // Convert the arguments.
12491 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl);
12493 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/nullptr,
12494 Best->FoundDecl, Method);
12495 if (Arg0.isInvalid())
12496 return ExprError();
12497 Args[0] = Arg0.get();
12499 // Convert the arguments.
12500 ExprResult InputInit
12501 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
12503 FnDecl->getParamDecl(0)),
12506 if (InputInit.isInvalid())
12507 return ExprError();
12509 Args[1] = InputInit.getAs<Expr>();
12511 // Build the actual expression node.
12512 DeclarationNameInfo OpLocInfo(OpName, LLoc);
12513 OpLocInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc));
12514 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl,
12516 HadMultipleCandidates,
12517 OpLocInfo.getLoc(),
12518 OpLocInfo.getInfo());
12519 if (FnExpr.isInvalid())
12520 return ExprError();
12522 // Determine the result type
12523 QualType ResultTy = FnDecl->getReturnType();
12524 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
12525 ResultTy = ResultTy.getNonLValueExprType(Context);
12527 CXXOperatorCallExpr *TheCall =
12528 new (Context) CXXOperatorCallExpr(Context, OO_Subscript,
12529 FnExpr.get(), Args,
12530 ResultTy, VK, RLoc,
12533 if (CheckCallReturnType(FnDecl->getReturnType(), LLoc, TheCall, FnDecl))
12534 return ExprError();
12536 if (CheckFunctionCall(Method, TheCall,
12537 Method->getType()->castAs<FunctionProtoType>()))
12538 return ExprError();
12540 return MaybeBindToTemporary(TheCall);
12542 // We matched a built-in operator. Convert the arguments, then
12543 // break out so that we will build the appropriate built-in
12545 ExprResult ArgsRes0 =
12546 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0],
12547 Best->Conversions[0], AA_Passing);
12548 if (ArgsRes0.isInvalid())
12549 return ExprError();
12550 Args[0] = ArgsRes0.get();
12552 ExprResult ArgsRes1 =
12553 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1],
12554 Best->Conversions[1], AA_Passing);
12555 if (ArgsRes1.isInvalid())
12556 return ExprError();
12557 Args[1] = ArgsRes1.get();
12563 case OR_No_Viable_Function: {
12564 if (CandidateSet.empty())
12565 Diag(LLoc, diag::err_ovl_no_oper)
12566 << Args[0]->getType() << /*subscript*/ 0
12567 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12569 Diag(LLoc, diag::err_ovl_no_viable_subscript)
12570 << Args[0]->getType()
12571 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12572 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args,
12574 return ExprError();
12578 Diag(LLoc, diag::err_ovl_ambiguous_oper_binary)
12580 << Args[0]->getType() << Args[1]->getType()
12581 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12582 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args,
12584 return ExprError();
12587 Diag(LLoc, diag::err_ovl_deleted_oper)
12588 << Best->Function->isDeleted() << "[]"
12589 << getDeletedOrUnavailableSuffix(Best->Function)
12590 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
12591 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args,
12593 return ExprError();
12596 // We matched a built-in operator; build it.
12597 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc);
12600 /// BuildCallToMemberFunction - Build a call to a member
12601 /// function. MemExpr is the expression that refers to the member
12602 /// function (and includes the object parameter), Args/NumArgs are the
12603 /// arguments to the function call (not including the object
12604 /// parameter). The caller needs to validate that the member
12605 /// expression refers to a non-static member function or an overloaded
12606 /// member function.
12608 Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE,
12609 SourceLocation LParenLoc,
12611 SourceLocation RParenLoc) {
12612 assert(MemExprE->getType() == Context.BoundMemberTy ||
12613 MemExprE->getType() == Context.OverloadTy);
12615 // Dig out the member expression. This holds both the object
12616 // argument and the member function we're referring to.
12617 Expr *NakedMemExpr = MemExprE->IgnoreParens();
12619 // Determine whether this is a call to a pointer-to-member function.
12620 if (BinaryOperator *op = dyn_cast<BinaryOperator>(NakedMemExpr)) {
12621 assert(op->getType() == Context.BoundMemberTy);
12622 assert(op->getOpcode() == BO_PtrMemD || op->getOpcode() == BO_PtrMemI);
12625 op->getRHS()->getType()->castAs<MemberPointerType>()->getPointeeType();
12627 const FunctionProtoType *proto = fnType->castAs<FunctionProtoType>();
12628 QualType resultType = proto->getCallResultType(Context);
12629 ExprValueKind valueKind = Expr::getValueKindForType(proto->getReturnType());
12631 // Check that the object type isn't more qualified than the
12632 // member function we're calling.
12633 Qualifiers funcQuals = Qualifiers::fromCVRMask(proto->getTypeQuals());
12635 QualType objectType = op->getLHS()->getType();
12636 if (op->getOpcode() == BO_PtrMemI)
12637 objectType = objectType->castAs<PointerType>()->getPointeeType();
12638 Qualifiers objectQuals = objectType.getQualifiers();
12640 Qualifiers difference = objectQuals - funcQuals;
12641 difference.removeObjCGCAttr();
12642 difference.removeAddressSpace();
12644 std::string qualsString = difference.getAsString();
12645 Diag(LParenLoc, diag::err_pointer_to_member_call_drops_quals)
12646 << fnType.getUnqualifiedType()
12648 << (qualsString.find(' ') == std::string::npos ? 1 : 2);
12651 CXXMemberCallExpr *call
12652 = new (Context) CXXMemberCallExpr(Context, MemExprE, Args,
12653 resultType, valueKind, RParenLoc);
12655 if (CheckCallReturnType(proto->getReturnType(), op->getRHS()->getLocStart(),
12657 return ExprError();
12659 if (ConvertArgumentsForCall(call, op, nullptr, proto, Args, RParenLoc))
12660 return ExprError();
12662 if (CheckOtherCall(call, proto))
12663 return ExprError();
12665 return MaybeBindToTemporary(call);
12668 if (isa<CXXPseudoDestructorExpr>(NakedMemExpr))
12669 return new (Context)
12670 CallExpr(Context, MemExprE, Args, Context.VoidTy, VK_RValue, RParenLoc);
12672 UnbridgedCastsSet UnbridgedCasts;
12673 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts))
12674 return ExprError();
12676 MemberExpr *MemExpr;
12677 CXXMethodDecl *Method = nullptr;
12678 DeclAccessPair FoundDecl = DeclAccessPair::make(nullptr, AS_public);
12679 NestedNameSpecifier *Qualifier = nullptr;
12680 if (isa<MemberExpr>(NakedMemExpr)) {
12681 MemExpr = cast<MemberExpr>(NakedMemExpr);
12682 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl());
12683 FoundDecl = MemExpr->getFoundDecl();
12684 Qualifier = MemExpr->getQualifier();
12685 UnbridgedCasts.restore();
12687 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr);
12688 Qualifier = UnresExpr->getQualifier();
12690 QualType ObjectType = UnresExpr->getBaseType();
12691 Expr::Classification ObjectClassification
12692 = UnresExpr->isArrow()? Expr::Classification::makeSimpleLValue()
12693 : UnresExpr->getBase()->Classify(Context);
12695 // Add overload candidates
12696 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc(),
12697 OverloadCandidateSet::CSK_Normal);
12699 // FIXME: avoid copy.
12700 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
12701 if (UnresExpr->hasExplicitTemplateArgs()) {
12702 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer);
12703 TemplateArgs = &TemplateArgsBuffer;
12706 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(),
12707 E = UnresExpr->decls_end(); I != E; ++I) {
12709 NamedDecl *Func = *I;
12710 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext());
12711 if (isa<UsingShadowDecl>(Func))
12712 Func = cast<UsingShadowDecl>(Func)->getTargetDecl();
12715 // Microsoft supports direct constructor calls.
12716 if (getLangOpts().MicrosoftExt && isa<CXXConstructorDecl>(Func)) {
12717 AddOverloadCandidate(cast<CXXConstructorDecl>(Func), I.getPair(),
12718 Args, CandidateSet);
12719 } else if ((Method = dyn_cast<CXXMethodDecl>(Func))) {
12720 // If explicit template arguments were provided, we can't call a
12721 // non-template member function.
12725 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType,
12726 ObjectClassification, Args, CandidateSet,
12727 /*SuppressUserConversions=*/false);
12729 AddMethodTemplateCandidate(
12730 cast<FunctionTemplateDecl>(Func), I.getPair(), ActingDC,
12731 TemplateArgs, ObjectType, ObjectClassification, Args, CandidateSet,
12732 /*SuppressUsedConversions=*/false);
12736 DeclarationName DeclName = UnresExpr->getMemberName();
12738 UnbridgedCasts.restore();
12740 OverloadCandidateSet::iterator Best;
12741 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getLocStart(),
12744 Method = cast<CXXMethodDecl>(Best->Function);
12745 FoundDecl = Best->FoundDecl;
12746 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl);
12747 if (DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()))
12748 return ExprError();
12749 // If FoundDecl is different from Method (such as if one is a template
12750 // and the other a specialization), make sure DiagnoseUseOfDecl is
12752 // FIXME: This would be more comprehensively addressed by modifying
12753 // DiagnoseUseOfDecl to accept both the FoundDecl and the decl
12755 if (Method != FoundDecl.getDecl() &&
12756 DiagnoseUseOfDecl(Method, UnresExpr->getNameLoc()))
12757 return ExprError();
12760 case OR_No_Viable_Function:
12761 Diag(UnresExpr->getMemberLoc(),
12762 diag::err_ovl_no_viable_member_function_in_call)
12763 << DeclName << MemExprE->getSourceRange();
12764 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
12765 // FIXME: Leaking incoming expressions!
12766 return ExprError();
12769 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call)
12770 << DeclName << MemExprE->getSourceRange();
12771 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
12772 // FIXME: Leaking incoming expressions!
12773 return ExprError();
12776 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call)
12777 << Best->Function->isDeleted()
12779 << getDeletedOrUnavailableSuffix(Best->Function)
12780 << MemExprE->getSourceRange();
12781 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
12782 // FIXME: Leaking incoming expressions!
12783 return ExprError();
12786 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method);
12788 // If overload resolution picked a static member, build a
12789 // non-member call based on that function.
12790 if (Method->isStatic()) {
12791 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, Args,
12795 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens());
12798 QualType ResultType = Method->getReturnType();
12799 ExprValueKind VK = Expr::getValueKindForType(ResultType);
12800 ResultType = ResultType.getNonLValueExprType(Context);
12802 assert(Method && "Member call to something that isn't a method?");
12803 CXXMemberCallExpr *TheCall =
12804 new (Context) CXXMemberCallExpr(Context, MemExprE, Args,
12805 ResultType, VK, RParenLoc);
12807 // Check for a valid return type.
12808 if (CheckCallReturnType(Method->getReturnType(), MemExpr->getMemberLoc(),
12810 return ExprError();
12812 // Convert the object argument (for a non-static member function call).
12813 // We only need to do this if there was actually an overload; otherwise
12814 // it was done at lookup.
12815 if (!Method->isStatic()) {
12816 ExprResult ObjectArg =
12817 PerformObjectArgumentInitialization(MemExpr->getBase(), Qualifier,
12818 FoundDecl, Method);
12819 if (ObjectArg.isInvalid())
12820 return ExprError();
12821 MemExpr->setBase(ObjectArg.get());
12824 // Convert the rest of the arguments
12825 const FunctionProtoType *Proto =
12826 Method->getType()->getAs<FunctionProtoType>();
12827 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args,
12829 return ExprError();
12831 DiagnoseSentinelCalls(Method, LParenLoc, Args);
12833 if (CheckFunctionCall(Method, TheCall, Proto))
12834 return ExprError();
12836 // In the case the method to call was not selected by the overloading
12837 // resolution process, we still need to handle the enable_if attribute. Do
12838 // that here, so it will not hide previous -- and more relevant -- errors.
12839 if (auto *MemE = dyn_cast<MemberExpr>(NakedMemExpr)) {
12840 if (const EnableIfAttr *Attr = CheckEnableIf(Method, Args, true)) {
12841 Diag(MemE->getMemberLoc(),
12842 diag::err_ovl_no_viable_member_function_in_call)
12843 << Method << Method->getSourceRange();
12844 Diag(Method->getLocation(),
12845 diag::note_ovl_candidate_disabled_by_function_cond_attr)
12846 << Attr->getCond()->getSourceRange() << Attr->getMessage();
12847 return ExprError();
12851 if ((isa<CXXConstructorDecl>(CurContext) ||
12852 isa<CXXDestructorDecl>(CurContext)) &&
12853 TheCall->getMethodDecl()->isPure()) {
12854 const CXXMethodDecl *MD = TheCall->getMethodDecl();
12856 if (isa<CXXThisExpr>(MemExpr->getBase()->IgnoreParenCasts()) &&
12857 MemExpr->performsVirtualDispatch(getLangOpts())) {
12858 Diag(MemExpr->getLocStart(),
12859 diag::warn_call_to_pure_virtual_member_function_from_ctor_dtor)
12860 << MD->getDeclName() << isa<CXXDestructorDecl>(CurContext)
12861 << MD->getParent()->getDeclName();
12863 Diag(MD->getLocStart(), diag::note_previous_decl) << MD->getDeclName();
12864 if (getLangOpts().AppleKext)
12865 Diag(MemExpr->getLocStart(),
12866 diag::note_pure_qualified_call_kext)
12867 << MD->getParent()->getDeclName()
12868 << MD->getDeclName();
12872 if (CXXDestructorDecl *DD =
12873 dyn_cast<CXXDestructorDecl>(TheCall->getMethodDecl())) {
12874 // a->A::f() doesn't go through the vtable, except in AppleKext mode.
12875 bool CallCanBeVirtual = !MemExpr->hasQualifier() || getLangOpts().AppleKext;
12876 CheckVirtualDtorCall(DD, MemExpr->getLocStart(), /*IsDelete=*/false,
12877 CallCanBeVirtual, /*WarnOnNonAbstractTypes=*/true,
12878 MemExpr->getMemberLoc());
12881 return MaybeBindToTemporary(TheCall);
12884 /// BuildCallToObjectOfClassType - Build a call to an object of class
12885 /// type (C++ [over.call.object]), which can end up invoking an
12886 /// overloaded function call operator (@c operator()) or performing a
12887 /// user-defined conversion on the object argument.
12889 Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj,
12890 SourceLocation LParenLoc,
12892 SourceLocation RParenLoc) {
12893 if (checkPlaceholderForOverload(*this, Obj))
12894 return ExprError();
12895 ExprResult Object = Obj;
12897 UnbridgedCastsSet UnbridgedCasts;
12898 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts))
12899 return ExprError();
12901 assert(Object.get()->getType()->isRecordType() &&
12902 "Requires object type argument");
12903 const RecordType *Record = Object.get()->getType()->getAs<RecordType>();
12905 // C++ [over.call.object]p1:
12906 // If the primary-expression E in the function call syntax
12907 // evaluates to a class object of type "cv T", then the set of
12908 // candidate functions includes at least the function call
12909 // operators of T. The function call operators of T are obtained by
12910 // ordinary lookup of the name operator() in the context of
12912 OverloadCandidateSet CandidateSet(LParenLoc,
12913 OverloadCandidateSet::CSK_Operator);
12914 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call);
12916 if (RequireCompleteType(LParenLoc, Object.get()->getType(),
12917 diag::err_incomplete_object_call, Object.get()))
12920 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName);
12921 LookupQualifiedName(R, Record->getDecl());
12922 R.suppressDiagnostics();
12924 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end();
12925 Oper != OperEnd; ++Oper) {
12926 AddMethodCandidate(Oper.getPair(), Object.get()->getType(),
12927 Object.get()->Classify(Context), Args, CandidateSet,
12928 /*SuppressUserConversions=*/false);
12931 // C++ [over.call.object]p2:
12932 // In addition, for each (non-explicit in C++0x) conversion function
12933 // declared in T of the form
12935 // operator conversion-type-id () cv-qualifier;
12937 // where cv-qualifier is the same cv-qualification as, or a
12938 // greater cv-qualification than, cv, and where conversion-type-id
12939 // denotes the type "pointer to function of (P1,...,Pn) returning
12940 // R", or the type "reference to pointer to function of
12941 // (P1,...,Pn) returning R", or the type "reference to function
12942 // of (P1,...,Pn) returning R", a surrogate call function [...]
12943 // is also considered as a candidate function. Similarly,
12944 // surrogate call functions are added to the set of candidate
12945 // functions for each conversion function declared in an
12946 // accessible base class provided the function is not hidden
12947 // within T by another intervening declaration.
12948 const auto &Conversions =
12949 cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions();
12950 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
12952 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
12953 if (isa<UsingShadowDecl>(D))
12954 D = cast<UsingShadowDecl>(D)->getTargetDecl();
12956 // Skip over templated conversion functions; they aren't
12958 if (isa<FunctionTemplateDecl>(D))
12961 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D);
12962 if (!Conv->isExplicit()) {
12963 // Strip the reference type (if any) and then the pointer type (if
12964 // any) to get down to what might be a function type.
12965 QualType ConvType = Conv->getConversionType().getNonReferenceType();
12966 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
12967 ConvType = ConvPtrType->getPointeeType();
12969 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>())
12971 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto,
12972 Object.get(), Args, CandidateSet);
12977 bool HadMultipleCandidates = (CandidateSet.size() > 1);
12979 // Perform overload resolution.
12980 OverloadCandidateSet::iterator Best;
12981 switch (CandidateSet.BestViableFunction(*this, Object.get()->getLocStart(),
12984 // Overload resolution succeeded; we'll build the appropriate call
12988 case OR_No_Viable_Function:
12989 if (CandidateSet.empty())
12990 Diag(Object.get()->getLocStart(), diag::err_ovl_no_oper)
12991 << Object.get()->getType() << /*call*/ 1
12992 << Object.get()->getSourceRange();
12994 Diag(Object.get()->getLocStart(),
12995 diag::err_ovl_no_viable_object_call)
12996 << Object.get()->getType() << Object.get()->getSourceRange();
12997 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
13001 Diag(Object.get()->getLocStart(),
13002 diag::err_ovl_ambiguous_object_call)
13003 << Object.get()->getType() << Object.get()->getSourceRange();
13004 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args);
13008 Diag(Object.get()->getLocStart(),
13009 diag::err_ovl_deleted_object_call)
13010 << Best->Function->isDeleted()
13011 << Object.get()->getType()
13012 << getDeletedOrUnavailableSuffix(Best->Function)
13013 << Object.get()->getSourceRange();
13014 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
13018 if (Best == CandidateSet.end())
13021 UnbridgedCasts.restore();
13023 if (Best->Function == nullptr) {
13024 // Since there is no function declaration, this is one of the
13025 // surrogate candidates. Dig out the conversion function.
13026 CXXConversionDecl *Conv
13027 = cast<CXXConversionDecl>(
13028 Best->Conversions[0].UserDefined.ConversionFunction);
13030 CheckMemberOperatorAccess(LParenLoc, Object.get(), nullptr,
13032 if (DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc))
13033 return ExprError();
13034 assert(Conv == Best->FoundDecl.getDecl() &&
13035 "Found Decl & conversion-to-functionptr should be same, right?!");
13036 // We selected one of the surrogate functions that converts the
13037 // object parameter to a function pointer. Perform the conversion
13038 // on the object argument, then let ActOnCallExpr finish the job.
13040 // Create an implicit member expr to refer to the conversion operator.
13041 // and then call it.
13042 ExprResult Call = BuildCXXMemberCallExpr(Object.get(), Best->FoundDecl,
13043 Conv, HadMultipleCandidates);
13044 if (Call.isInvalid())
13045 return ExprError();
13046 // Record usage of conversion in an implicit cast.
13047 Call = ImplicitCastExpr::Create(Context, Call.get()->getType(),
13048 CK_UserDefinedConversion, Call.get(),
13049 nullptr, VK_RValue);
13051 return ActOnCallExpr(S, Call.get(), LParenLoc, Args, RParenLoc);
13054 CheckMemberOperatorAccess(LParenLoc, Object.get(), nullptr, Best->FoundDecl);
13056 // We found an overloaded operator(). Build a CXXOperatorCallExpr
13057 // that calls this method, using Object for the implicit object
13058 // parameter and passing along the remaining arguments.
13059 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
13061 // An error diagnostic has already been printed when parsing the declaration.
13062 if (Method->isInvalidDecl())
13063 return ExprError();
13065 const FunctionProtoType *Proto =
13066 Method->getType()->getAs<FunctionProtoType>();
13068 unsigned NumParams = Proto->getNumParams();
13070 DeclarationNameInfo OpLocInfo(
13071 Context.DeclarationNames.getCXXOperatorName(OO_Call), LParenLoc);
13072 OpLocInfo.setCXXOperatorNameRange(SourceRange(LParenLoc, RParenLoc));
13073 ExprResult NewFn = CreateFunctionRefExpr(*this, Method, Best->FoundDecl,
13074 HadMultipleCandidates,
13075 OpLocInfo.getLoc(),
13076 OpLocInfo.getInfo());
13077 if (NewFn.isInvalid())
13080 // Build the full argument list for the method call (the implicit object
13081 // parameter is placed at the beginning of the list).
13082 SmallVector<Expr *, 8> MethodArgs(Args.size() + 1);
13083 MethodArgs[0] = Object.get();
13084 std::copy(Args.begin(), Args.end(), MethodArgs.begin() + 1);
13086 // Once we've built TheCall, all of the expressions are properly
13088 QualType ResultTy = Method->getReturnType();
13089 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
13090 ResultTy = ResultTy.getNonLValueExprType(Context);
13092 CXXOperatorCallExpr *TheCall = new (Context)
13093 CXXOperatorCallExpr(Context, OO_Call, NewFn.get(), MethodArgs, ResultTy,
13094 VK, RParenLoc, FPOptions());
13096 if (CheckCallReturnType(Method->getReturnType(), LParenLoc, TheCall, Method))
13099 // We may have default arguments. If so, we need to allocate more
13100 // slots in the call for them.
13101 if (Args.size() < NumParams)
13102 TheCall->setNumArgs(Context, NumParams + 1);
13104 bool IsError = false;
13106 // Initialize the implicit object parameter.
13107 ExprResult ObjRes =
13108 PerformObjectArgumentInitialization(Object.get(), /*Qualifier=*/nullptr,
13109 Best->FoundDecl, Method);
13110 if (ObjRes.isInvalid())
13114 TheCall->setArg(0, Object.get());
13116 // Check the argument types.
13117 for (unsigned i = 0; i != NumParams; i++) {
13119 if (i < Args.size()) {
13122 // Pass the argument.
13124 ExprResult InputInit
13125 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
13127 Method->getParamDecl(i)),
13128 SourceLocation(), Arg);
13130 IsError |= InputInit.isInvalid();
13131 Arg = InputInit.getAs<Expr>();
13134 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i));
13135 if (DefArg.isInvalid()) {
13140 Arg = DefArg.getAs<Expr>();
13143 TheCall->setArg(i + 1, Arg);
13146 // If this is a variadic call, handle args passed through "...".
13147 if (Proto->isVariadic()) {
13148 // Promote the arguments (C99 6.5.2.2p7).
13149 for (unsigned i = NumParams, e = Args.size(); i < e; i++) {
13150 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod,
13152 IsError |= Arg.isInvalid();
13153 TheCall->setArg(i + 1, Arg.get());
13157 if (IsError) return true;
13159 DiagnoseSentinelCalls(Method, LParenLoc, Args);
13161 if (CheckFunctionCall(Method, TheCall, Proto))
13164 return MaybeBindToTemporary(TheCall);
13167 /// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator->
13168 /// (if one exists), where @c Base is an expression of class type and
13169 /// @c Member is the name of the member we're trying to find.
13171 Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc,
13172 bool *NoArrowOperatorFound) {
13173 assert(Base->getType()->isRecordType() &&
13174 "left-hand side must have class type");
13176 if (checkPlaceholderForOverload(*this, Base))
13177 return ExprError();
13179 SourceLocation Loc = Base->getExprLoc();
13181 // C++ [over.ref]p1:
13183 // [...] An expression x->m is interpreted as (x.operator->())->m
13184 // for a class object x of type T if T::operator->() exists and if
13185 // the operator is selected as the best match function by the
13186 // overload resolution mechanism (13.3).
13187 DeclarationName OpName =
13188 Context.DeclarationNames.getCXXOperatorName(OO_Arrow);
13189 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Operator);
13190 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>();
13192 if (RequireCompleteType(Loc, Base->getType(),
13193 diag::err_typecheck_incomplete_tag, Base))
13194 return ExprError();
13196 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName);
13197 LookupQualifiedName(R, BaseRecord->getDecl());
13198 R.suppressDiagnostics();
13200 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end();
13201 Oper != OperEnd; ++Oper) {
13202 AddMethodCandidate(Oper.getPair(), Base->getType(), Base->Classify(Context),
13203 None, CandidateSet, /*SuppressUserConversions=*/false);
13206 bool HadMultipleCandidates = (CandidateSet.size() > 1);
13208 // Perform overload resolution.
13209 OverloadCandidateSet::iterator Best;
13210 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
13212 // Overload resolution succeeded; we'll build the call below.
13215 case OR_No_Viable_Function:
13216 if (CandidateSet.empty()) {
13217 QualType BaseType = Base->getType();
13218 if (NoArrowOperatorFound) {
13219 // Report this specific error to the caller instead of emitting a
13220 // diagnostic, as requested.
13221 *NoArrowOperatorFound = true;
13222 return ExprError();
13224 Diag(OpLoc, diag::err_typecheck_member_reference_arrow)
13225 << BaseType << Base->getSourceRange();
13226 if (BaseType->isRecordType() && !BaseType->isPointerType()) {
13227 Diag(OpLoc, diag::note_typecheck_member_reference_suggestion)
13228 << FixItHint::CreateReplacement(OpLoc, ".");
13231 Diag(OpLoc, diag::err_ovl_no_viable_oper)
13232 << "operator->" << Base->getSourceRange();
13233 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Base);
13234 return ExprError();
13237 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary)
13238 << "->" << Base->getType() << Base->getSourceRange();
13239 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Base);
13240 return ExprError();
13243 Diag(OpLoc, diag::err_ovl_deleted_oper)
13244 << Best->Function->isDeleted()
13246 << getDeletedOrUnavailableSuffix(Best->Function)
13247 << Base->getSourceRange();
13248 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Base);
13249 return ExprError();
13252 CheckMemberOperatorAccess(OpLoc, Base, nullptr, Best->FoundDecl);
13254 // Convert the object parameter.
13255 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
13256 ExprResult BaseResult =
13257 PerformObjectArgumentInitialization(Base, /*Qualifier=*/nullptr,
13258 Best->FoundDecl, Method);
13259 if (BaseResult.isInvalid())
13260 return ExprError();
13261 Base = BaseResult.get();
13263 // Build the operator call.
13264 ExprResult FnExpr = CreateFunctionRefExpr(*this, Method, Best->FoundDecl,
13265 HadMultipleCandidates, OpLoc);
13266 if (FnExpr.isInvalid())
13267 return ExprError();
13269 QualType ResultTy = Method->getReturnType();
13270 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
13271 ResultTy = ResultTy.getNonLValueExprType(Context);
13272 CXXOperatorCallExpr *TheCall =
13273 new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr.get(),
13274 Base, ResultTy, VK, OpLoc, FPOptions());
13276 if (CheckCallReturnType(Method->getReturnType(), OpLoc, TheCall, Method))
13277 return ExprError();
13279 if (CheckFunctionCall(Method, TheCall,
13280 Method->getType()->castAs<FunctionProtoType>()))
13281 return ExprError();
13283 return MaybeBindToTemporary(TheCall);
13286 /// BuildLiteralOperatorCall - Build a UserDefinedLiteral by creating a call to
13287 /// a literal operator described by the provided lookup results.
13288 ExprResult Sema::BuildLiteralOperatorCall(LookupResult &R,
13289 DeclarationNameInfo &SuffixInfo,
13290 ArrayRef<Expr*> Args,
13291 SourceLocation LitEndLoc,
13292 TemplateArgumentListInfo *TemplateArgs) {
13293 SourceLocation UDSuffixLoc = SuffixInfo.getCXXLiteralOperatorNameLoc();
13295 OverloadCandidateSet CandidateSet(UDSuffixLoc,
13296 OverloadCandidateSet::CSK_Normal);
13297 AddFunctionCandidates(R.asUnresolvedSet(), Args, CandidateSet, TemplateArgs,
13298 /*SuppressUserConversions=*/true);
13300 bool HadMultipleCandidates = (CandidateSet.size() > 1);
13302 // Perform overload resolution. This will usually be trivial, but might need
13303 // to perform substitutions for a literal operator template.
13304 OverloadCandidateSet::iterator Best;
13305 switch (CandidateSet.BestViableFunction(*this, UDSuffixLoc, Best)) {
13310 case OR_No_Viable_Function:
13311 Diag(UDSuffixLoc, diag::err_ovl_no_viable_function_in_call)
13312 << R.getLookupName();
13313 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
13314 return ExprError();
13317 Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName();
13318 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args);
13319 return ExprError();
13322 FunctionDecl *FD = Best->Function;
13323 ExprResult Fn = CreateFunctionRefExpr(*this, FD, Best->FoundDecl,
13324 HadMultipleCandidates,
13325 SuffixInfo.getLoc(),
13326 SuffixInfo.getInfo());
13327 if (Fn.isInvalid())
13330 // Check the argument types. This should almost always be a no-op, except
13331 // that array-to-pointer decay is applied to string literals.
13333 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
13334 ExprResult InputInit = PerformCopyInitialization(
13335 InitializedEntity::InitializeParameter(Context, FD->getParamDecl(ArgIdx)),
13336 SourceLocation(), Args[ArgIdx]);
13337 if (InputInit.isInvalid())
13339 ConvArgs[ArgIdx] = InputInit.get();
13342 QualType ResultTy = FD->getReturnType();
13343 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
13344 ResultTy = ResultTy.getNonLValueExprType(Context);
13346 UserDefinedLiteral *UDL =
13347 new (Context) UserDefinedLiteral(Context, Fn.get(),
13348 llvm::makeArrayRef(ConvArgs, Args.size()),
13349 ResultTy, VK, LitEndLoc, UDSuffixLoc);
13351 if (CheckCallReturnType(FD->getReturnType(), UDSuffixLoc, UDL, FD))
13352 return ExprError();
13354 if (CheckFunctionCall(FD, UDL, nullptr))
13355 return ExprError();
13357 return MaybeBindToTemporary(UDL);
13360 /// Build a call to 'begin' or 'end' for a C++11 for-range statement. If the
13361 /// given LookupResult is non-empty, it is assumed to describe a member which
13362 /// will be invoked. Otherwise, the function will be found via argument
13363 /// dependent lookup.
13364 /// CallExpr is set to a valid expression and FRS_Success returned on success,
13365 /// otherwise CallExpr is set to ExprError() and some non-success value
13367 Sema::ForRangeStatus
13368 Sema::BuildForRangeBeginEndCall(SourceLocation Loc,
13369 SourceLocation RangeLoc,
13370 const DeclarationNameInfo &NameInfo,
13371 LookupResult &MemberLookup,
13372 OverloadCandidateSet *CandidateSet,
13373 Expr *Range, ExprResult *CallExpr) {
13374 Scope *S = nullptr;
13376 CandidateSet->clear();
13377 if (!MemberLookup.empty()) {
13378 ExprResult MemberRef =
13379 BuildMemberReferenceExpr(Range, Range->getType(), Loc,
13380 /*IsPtr=*/false, CXXScopeSpec(),
13381 /*TemplateKWLoc=*/SourceLocation(),
13382 /*FirstQualifierInScope=*/nullptr,
13384 /*TemplateArgs=*/nullptr, S);
13385 if (MemberRef.isInvalid()) {
13386 *CallExpr = ExprError();
13387 return FRS_DiagnosticIssued;
13389 *CallExpr = ActOnCallExpr(S, MemberRef.get(), Loc, None, Loc, nullptr);
13390 if (CallExpr->isInvalid()) {
13391 *CallExpr = ExprError();
13392 return FRS_DiagnosticIssued;
13395 UnresolvedSet<0> FoundNames;
13396 UnresolvedLookupExpr *Fn =
13397 UnresolvedLookupExpr::Create(Context, /*NamingClass=*/nullptr,
13398 NestedNameSpecifierLoc(), NameInfo,
13399 /*NeedsADL=*/true, /*Overloaded=*/false,
13400 FoundNames.begin(), FoundNames.end());
13402 bool CandidateSetError = buildOverloadedCallSet(S, Fn, Fn, Range, Loc,
13403 CandidateSet, CallExpr);
13404 if (CandidateSet->empty() || CandidateSetError) {
13405 *CallExpr = ExprError();
13406 return FRS_NoViableFunction;
13408 OverloadCandidateSet::iterator Best;
13409 OverloadingResult OverloadResult =
13410 CandidateSet->BestViableFunction(*this, Fn->getLocStart(), Best);
13412 if (OverloadResult == OR_No_Viable_Function) {
13413 *CallExpr = ExprError();
13414 return FRS_NoViableFunction;
13416 *CallExpr = FinishOverloadedCallExpr(*this, S, Fn, Fn, Loc, Range,
13417 Loc, nullptr, CandidateSet, &Best,
13419 /*AllowTypoCorrection=*/false);
13420 if (CallExpr->isInvalid() || OverloadResult != OR_Success) {
13421 *CallExpr = ExprError();
13422 return FRS_DiagnosticIssued;
13425 return FRS_Success;
13429 /// FixOverloadedFunctionReference - E is an expression that refers to
13430 /// a C++ overloaded function (possibly with some parentheses and
13431 /// perhaps a '&' around it). We have resolved the overloaded function
13432 /// to the function declaration Fn, so patch up the expression E to
13433 /// refer (possibly indirectly) to Fn. Returns the new expr.
13434 Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found,
13435 FunctionDecl *Fn) {
13436 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
13437 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(),
13439 if (SubExpr == PE->getSubExpr())
13442 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr);
13445 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
13446 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(),
13448 assert(Context.hasSameType(ICE->getSubExpr()->getType(),
13449 SubExpr->getType()) &&
13450 "Implicit cast type cannot be determined from overload");
13451 assert(ICE->path_empty() && "fixing up hierarchy conversion?");
13452 if (SubExpr == ICE->getSubExpr())
13455 return ImplicitCastExpr::Create(Context, ICE->getType(),
13456 ICE->getCastKind(),
13458 ICE->getValueKind());
13461 if (auto *GSE = dyn_cast<GenericSelectionExpr>(E)) {
13462 if (!GSE->isResultDependent()) {
13464 FixOverloadedFunctionReference(GSE->getResultExpr(), Found, Fn);
13465 if (SubExpr == GSE->getResultExpr())
13468 // Replace the resulting type information before rebuilding the generic
13469 // selection expression.
13470 ArrayRef<Expr *> A = GSE->getAssocExprs();
13471 SmallVector<Expr *, 4> AssocExprs(A.begin(), A.end());
13472 unsigned ResultIdx = GSE->getResultIndex();
13473 AssocExprs[ResultIdx] = SubExpr;
13475 return new (Context) GenericSelectionExpr(
13476 Context, GSE->getGenericLoc(), GSE->getControllingExpr(),
13477 GSE->getAssocTypeSourceInfos(), AssocExprs, GSE->getDefaultLoc(),
13478 GSE->getRParenLoc(), GSE->containsUnexpandedParameterPack(),
13481 // Rather than fall through to the unreachable, return the original generic
13482 // selection expression.
13486 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) {
13487 assert(UnOp->getOpcode() == UO_AddrOf &&
13488 "Can only take the address of an overloaded function");
13489 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) {
13490 if (Method->isStatic()) {
13491 // Do nothing: static member functions aren't any different
13492 // from non-member functions.
13494 // Fix the subexpression, which really has to be an
13495 // UnresolvedLookupExpr holding an overloaded member function
13497 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(),
13499 if (SubExpr == UnOp->getSubExpr())
13502 assert(isa<DeclRefExpr>(SubExpr)
13503 && "fixed to something other than a decl ref");
13504 assert(cast<DeclRefExpr>(SubExpr)->getQualifier()
13505 && "fixed to a member ref with no nested name qualifier");
13507 // We have taken the address of a pointer to member
13508 // function. Perform the computation here so that we get the
13509 // appropriate pointer to member type.
13511 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext()));
13512 QualType MemPtrType
13513 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr());
13514 // Under the MS ABI, lock down the inheritance model now.
13515 if (Context.getTargetInfo().getCXXABI().isMicrosoft())
13516 (void)isCompleteType(UnOp->getOperatorLoc(), MemPtrType);
13518 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, MemPtrType,
13519 VK_RValue, OK_Ordinary,
13520 UnOp->getOperatorLoc());
13523 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(),
13525 if (SubExpr == UnOp->getSubExpr())
13528 return new (Context) UnaryOperator(SubExpr, UO_AddrOf,
13529 Context.getPointerType(SubExpr->getType()),
13530 VK_RValue, OK_Ordinary,
13531 UnOp->getOperatorLoc());
13534 // C++ [except.spec]p17:
13535 // An exception-specification is considered to be needed when:
13536 // - in an expression the function is the unique lookup result or the
13537 // selected member of a set of overloaded functions
13538 if (auto *FPT = Fn->getType()->getAs<FunctionProtoType>())
13539 ResolveExceptionSpec(E->getExprLoc(), FPT);
13541 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) {
13542 // FIXME: avoid copy.
13543 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
13544 if (ULE->hasExplicitTemplateArgs()) {
13545 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer);
13546 TemplateArgs = &TemplateArgsBuffer;
13549 DeclRefExpr *DRE = DeclRefExpr::Create(Context,
13550 ULE->getQualifierLoc(),
13551 ULE->getTemplateKeywordLoc(),
13553 /*enclosing*/ false, // FIXME?
13559 MarkDeclRefReferenced(DRE);
13560 DRE->setHadMultipleCandidates(ULE->getNumDecls() > 1);
13564 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) {
13565 // FIXME: avoid copy.
13566 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
13567 if (MemExpr->hasExplicitTemplateArgs()) {
13568 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer);
13569 TemplateArgs = &TemplateArgsBuffer;
13574 // If we're filling in a static method where we used to have an
13575 // implicit member access, rewrite to a simple decl ref.
13576 if (MemExpr->isImplicitAccess()) {
13577 if (cast<CXXMethodDecl>(Fn)->isStatic()) {
13578 DeclRefExpr *DRE = DeclRefExpr::Create(Context,
13579 MemExpr->getQualifierLoc(),
13580 MemExpr->getTemplateKeywordLoc(),
13582 /*enclosing*/ false,
13583 MemExpr->getMemberLoc(),
13588 MarkDeclRefReferenced(DRE);
13589 DRE->setHadMultipleCandidates(MemExpr->getNumDecls() > 1);
13592 SourceLocation Loc = MemExpr->getMemberLoc();
13593 if (MemExpr->getQualifier())
13594 Loc = MemExpr->getQualifierLoc().getBeginLoc();
13595 CheckCXXThisCapture(Loc);
13596 Base = new (Context) CXXThisExpr(Loc,
13597 MemExpr->getBaseType(),
13598 /*isImplicit=*/true);
13601 Base = MemExpr->getBase();
13603 ExprValueKind valueKind;
13605 if (cast<CXXMethodDecl>(Fn)->isStatic()) {
13606 valueKind = VK_LValue;
13607 type = Fn->getType();
13609 valueKind = VK_RValue;
13610 type = Context.BoundMemberTy;
13613 MemberExpr *ME = MemberExpr::Create(
13614 Context, Base, MemExpr->isArrow(), MemExpr->getOperatorLoc(),
13615 MemExpr->getQualifierLoc(), MemExpr->getTemplateKeywordLoc(), Fn, Found,
13616 MemExpr->getMemberNameInfo(), TemplateArgs, type, valueKind,
13618 ME->setHadMultipleCandidates(true);
13619 MarkMemberReferenced(ME);
13623 llvm_unreachable("Invalid reference to overloaded function");
13626 ExprResult Sema::FixOverloadedFunctionReference(ExprResult E,
13627 DeclAccessPair Found,
13628 FunctionDecl *Fn) {
13629 return FixOverloadedFunctionReference(E.get(), Found, Fn);