1 //===--- SemaOverload.cpp - C++ Overloading -------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file provides Sema routines for C++ overloading.
12 //===----------------------------------------------------------------------===//
14 #include "clang/Sema/Overload.h"
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/CXXInheritance.h"
17 #include "clang/AST/DeclObjC.h"
18 #include "clang/AST/Expr.h"
19 #include "clang/AST/ExprCXX.h"
20 #include "clang/AST/ExprObjC.h"
21 #include "clang/AST/TypeOrdering.h"
22 #include "clang/Basic/Diagnostic.h"
23 #include "clang/Basic/DiagnosticOptions.h"
24 #include "clang/Basic/PartialDiagnostic.h"
25 #include "clang/Basic/TargetInfo.h"
26 #include "clang/Sema/Initialization.h"
27 #include "clang/Sema/Lookup.h"
28 #include "clang/Sema/SemaInternal.h"
29 #include "clang/Sema/Template.h"
30 #include "clang/Sema/TemplateDeduction.h"
31 #include "llvm/ADT/DenseSet.h"
32 #include "llvm/ADT/STLExtras.h"
33 #include "llvm/ADT/SmallPtrSet.h"
34 #include "llvm/ADT/SmallString.h"
38 using namespace clang;
41 static bool functionHasPassObjectSizeParams(const FunctionDecl *FD) {
42 return std::any_of(FD->param_begin(), FD->param_end(),
43 std::mem_fn(&ParmVarDecl::hasAttr<PassObjectSizeAttr>));
46 /// A convenience routine for creating a decayed reference to a function.
48 CreateFunctionRefExpr(Sema &S, FunctionDecl *Fn, NamedDecl *FoundDecl,
49 bool HadMultipleCandidates,
50 SourceLocation Loc = SourceLocation(),
51 const DeclarationNameLoc &LocInfo = DeclarationNameLoc()){
52 if (S.DiagnoseUseOfDecl(FoundDecl, Loc))
54 // If FoundDecl is different from Fn (such as if one is a template
55 // and the other a specialization), make sure DiagnoseUseOfDecl is
57 // FIXME: This would be more comprehensively addressed by modifying
58 // DiagnoseUseOfDecl to accept both the FoundDecl and the decl
60 if (FoundDecl != Fn && S.DiagnoseUseOfDecl(Fn, Loc))
62 DeclRefExpr *DRE = new (S.Context) DeclRefExpr(Fn, false, Fn->getType(),
63 VK_LValue, Loc, LocInfo);
64 if (HadMultipleCandidates)
65 DRE->setHadMultipleCandidates(true);
67 S.MarkDeclRefReferenced(DRE);
68 return S.ImpCastExprToType(DRE, S.Context.getPointerType(DRE->getType()),
69 CK_FunctionToPointerDecay);
72 static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
73 bool InOverloadResolution,
74 StandardConversionSequence &SCS,
76 bool AllowObjCWritebackConversion);
78 static bool IsTransparentUnionStandardConversion(Sema &S, Expr* From,
80 bool InOverloadResolution,
81 StandardConversionSequence &SCS,
83 static OverloadingResult
84 IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
85 UserDefinedConversionSequence& User,
86 OverloadCandidateSet& Conversions,
88 bool AllowObjCConversionOnExplicit);
91 static ImplicitConversionSequence::CompareKind
92 CompareStandardConversionSequences(Sema &S, SourceLocation Loc,
93 const StandardConversionSequence& SCS1,
94 const StandardConversionSequence& SCS2);
96 static ImplicitConversionSequence::CompareKind
97 CompareQualificationConversions(Sema &S,
98 const StandardConversionSequence& SCS1,
99 const StandardConversionSequence& SCS2);
101 static ImplicitConversionSequence::CompareKind
102 CompareDerivedToBaseConversions(Sema &S, SourceLocation Loc,
103 const StandardConversionSequence& SCS1,
104 const StandardConversionSequence& SCS2);
106 /// GetConversionRank - Retrieve the implicit conversion rank
107 /// corresponding to the given implicit conversion kind.
108 ImplicitConversionRank clang::GetConversionRank(ImplicitConversionKind Kind) {
109 static const ImplicitConversionRank
110 Rank[(int)ICK_Num_Conversion_Kinds] = {
131 ICR_Complex_Real_Conversion,
134 ICR_Writeback_Conversion,
135 ICR_Exact_Match, // NOTE(gbiv): This may not be completely right --
136 // it was omitted by the patch that added
137 // ICK_Zero_Event_Conversion
140 return Rank[(int)Kind];
143 /// GetImplicitConversionName - Return the name of this kind of
144 /// implicit conversion.
145 static const char* GetImplicitConversionName(ImplicitConversionKind Kind) {
146 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = {
150 "Function-to-pointer",
151 "Noreturn adjustment",
153 "Integral promotion",
154 "Floating point promotion",
156 "Integral conversion",
157 "Floating conversion",
158 "Complex conversion",
159 "Floating-integral conversion",
160 "Pointer conversion",
161 "Pointer-to-member conversion",
162 "Boolean conversion",
163 "Compatible-types conversion",
164 "Derived-to-base conversion",
167 "Complex-real conversion",
168 "Block Pointer conversion",
169 "Transparent Union Conversion",
170 "Writeback conversion",
171 "OpenCL Zero Event Conversion",
172 "C specific type conversion"
177 /// StandardConversionSequence - Set the standard conversion
178 /// sequence to the identity conversion.
179 void StandardConversionSequence::setAsIdentityConversion() {
180 First = ICK_Identity;
181 Second = ICK_Identity;
182 Third = ICK_Identity;
183 DeprecatedStringLiteralToCharPtr = false;
184 QualificationIncludesObjCLifetime = false;
185 ReferenceBinding = false;
186 DirectBinding = false;
187 IsLvalueReference = true;
188 BindsToFunctionLvalue = false;
189 BindsToRvalue = false;
190 BindsImplicitObjectArgumentWithoutRefQualifier = false;
191 ObjCLifetimeConversionBinding = false;
192 CopyConstructor = nullptr;
195 /// getRank - Retrieve the rank of this standard conversion sequence
196 /// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the
197 /// implicit conversions.
198 ImplicitConversionRank StandardConversionSequence::getRank() const {
199 ImplicitConversionRank Rank = ICR_Exact_Match;
200 if (GetConversionRank(First) > Rank)
201 Rank = GetConversionRank(First);
202 if (GetConversionRank(Second) > Rank)
203 Rank = GetConversionRank(Second);
204 if (GetConversionRank(Third) > Rank)
205 Rank = GetConversionRank(Third);
209 /// isPointerConversionToBool - Determines whether this conversion is
210 /// a conversion of a pointer or pointer-to-member to bool. This is
211 /// used as part of the ranking of standard conversion sequences
212 /// (C++ 13.3.3.2p4).
213 bool StandardConversionSequence::isPointerConversionToBool() const {
214 // Note that FromType has not necessarily been transformed by the
215 // array-to-pointer or function-to-pointer implicit conversions, so
216 // check for their presence as well as checking whether FromType is
218 if (getToType(1)->isBooleanType() &&
219 (getFromType()->isPointerType() ||
220 getFromType()->isObjCObjectPointerType() ||
221 getFromType()->isBlockPointerType() ||
222 getFromType()->isNullPtrType() ||
223 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer))
229 /// isPointerConversionToVoidPointer - Determines whether this
230 /// conversion is a conversion of a pointer to a void pointer. This is
231 /// used as part of the ranking of standard conversion sequences (C++
234 StandardConversionSequence::
235 isPointerConversionToVoidPointer(ASTContext& Context) const {
236 QualType FromType = getFromType();
237 QualType ToType = getToType(1);
239 // Note that FromType has not necessarily been transformed by the
240 // array-to-pointer implicit conversion, so check for its presence
241 // and redo the conversion to get a pointer.
242 if (First == ICK_Array_To_Pointer)
243 FromType = Context.getArrayDecayedType(FromType);
245 if (Second == ICK_Pointer_Conversion && FromType->isAnyPointerType())
246 if (const PointerType* ToPtrType = ToType->getAs<PointerType>())
247 return ToPtrType->getPointeeType()->isVoidType();
252 /// Skip any implicit casts which could be either part of a narrowing conversion
253 /// or after one in an implicit conversion.
254 static const Expr *IgnoreNarrowingConversion(const Expr *Converted) {
255 while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Converted)) {
256 switch (ICE->getCastKind()) {
258 case CK_IntegralCast:
259 case CK_IntegralToBoolean:
260 case CK_IntegralToFloating:
261 case CK_BooleanToSignedIntegral:
262 case CK_FloatingToIntegral:
263 case CK_FloatingToBoolean:
264 case CK_FloatingCast:
265 Converted = ICE->getSubExpr();
276 /// Check if this standard conversion sequence represents a narrowing
277 /// conversion, according to C++11 [dcl.init.list]p7.
279 /// \param Ctx The AST context.
280 /// \param Converted The result of applying this standard conversion sequence.
281 /// \param ConstantValue If this is an NK_Constant_Narrowing conversion, the
282 /// value of the expression prior to the narrowing conversion.
283 /// \param ConstantType If this is an NK_Constant_Narrowing conversion, the
284 /// type of the expression prior to the narrowing conversion.
286 StandardConversionSequence::getNarrowingKind(ASTContext &Ctx,
287 const Expr *Converted,
288 APValue &ConstantValue,
289 QualType &ConstantType) const {
290 assert(Ctx.getLangOpts().CPlusPlus && "narrowing check outside C++");
292 // C++11 [dcl.init.list]p7:
293 // A narrowing conversion is an implicit conversion ...
294 QualType FromType = getToType(0);
295 QualType ToType = getToType(1);
297 // 'bool' is an integral type; dispatch to the right place to handle it.
298 case ICK_Boolean_Conversion:
299 if (FromType->isRealFloatingType())
300 goto FloatingIntegralConversion;
301 if (FromType->isIntegralOrUnscopedEnumerationType())
302 goto IntegralConversion;
303 // Boolean conversions can be from pointers and pointers to members
304 // [conv.bool], and those aren't considered narrowing conversions.
305 return NK_Not_Narrowing;
307 // -- from a floating-point type to an integer type, or
309 // -- from an integer type or unscoped enumeration type to a floating-point
310 // type, except where the source is a constant expression and the actual
311 // value after conversion will fit into the target type and will produce
312 // the original value when converted back to the original type, or
313 case ICK_Floating_Integral:
314 FloatingIntegralConversion:
315 if (FromType->isRealFloatingType() && ToType->isIntegralType(Ctx)) {
316 return NK_Type_Narrowing;
317 } else if (FromType->isIntegralType(Ctx) && ToType->isRealFloatingType()) {
318 llvm::APSInt IntConstantValue;
319 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
321 Initializer->isIntegerConstantExpr(IntConstantValue, Ctx)) {
322 // Convert the integer to the floating type.
323 llvm::APFloat Result(Ctx.getFloatTypeSemantics(ToType));
324 Result.convertFromAPInt(IntConstantValue, IntConstantValue.isSigned(),
325 llvm::APFloat::rmNearestTiesToEven);
327 llvm::APSInt ConvertedValue = IntConstantValue;
329 Result.convertToInteger(ConvertedValue,
330 llvm::APFloat::rmTowardZero, &ignored);
331 // If the resulting value is different, this was a narrowing conversion.
332 if (IntConstantValue != ConvertedValue) {
333 ConstantValue = APValue(IntConstantValue);
334 ConstantType = Initializer->getType();
335 return NK_Constant_Narrowing;
338 // Variables are always narrowings.
339 return NK_Variable_Narrowing;
342 return NK_Not_Narrowing;
344 // -- from long double to double or float, or from double to float, except
345 // where the source is a constant expression and the actual value after
346 // conversion is within the range of values that can be represented (even
347 // if it cannot be represented exactly), or
348 case ICK_Floating_Conversion:
349 if (FromType->isRealFloatingType() && ToType->isRealFloatingType() &&
350 Ctx.getFloatingTypeOrder(FromType, ToType) == 1) {
351 // FromType is larger than ToType.
352 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
353 if (Initializer->isCXX11ConstantExpr(Ctx, &ConstantValue)) {
355 assert(ConstantValue.isFloat());
356 llvm::APFloat FloatVal = ConstantValue.getFloat();
357 // Convert the source value into the target type.
359 llvm::APFloat::opStatus ConvertStatus = FloatVal.convert(
360 Ctx.getFloatTypeSemantics(ToType),
361 llvm::APFloat::rmNearestTiesToEven, &ignored);
362 // If there was no overflow, the source value is within the range of
363 // values that can be represented.
364 if (ConvertStatus & llvm::APFloat::opOverflow) {
365 ConstantType = Initializer->getType();
366 return NK_Constant_Narrowing;
369 return NK_Variable_Narrowing;
372 return NK_Not_Narrowing;
374 // -- from an integer type or unscoped enumeration type to an integer type
375 // that cannot represent all the values of the original type, except where
376 // the source is a constant expression and the actual value after
377 // conversion will fit into the target type and will produce the original
378 // value when converted back to the original type.
379 case ICK_Integral_Conversion:
380 IntegralConversion: {
381 assert(FromType->isIntegralOrUnscopedEnumerationType());
382 assert(ToType->isIntegralOrUnscopedEnumerationType());
383 const bool FromSigned = FromType->isSignedIntegerOrEnumerationType();
384 const unsigned FromWidth = Ctx.getIntWidth(FromType);
385 const bool ToSigned = ToType->isSignedIntegerOrEnumerationType();
386 const unsigned ToWidth = Ctx.getIntWidth(ToType);
388 if (FromWidth > ToWidth ||
389 (FromWidth == ToWidth && FromSigned != ToSigned) ||
390 (FromSigned && !ToSigned)) {
391 // Not all values of FromType can be represented in ToType.
392 llvm::APSInt InitializerValue;
393 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
394 if (!Initializer->isIntegerConstantExpr(InitializerValue, Ctx)) {
395 // Such conversions on variables are always narrowing.
396 return NK_Variable_Narrowing;
398 bool Narrowing = false;
399 if (FromWidth < ToWidth) {
400 // Negative -> unsigned is narrowing. Otherwise, more bits is never
402 if (InitializerValue.isSigned() && InitializerValue.isNegative())
405 // Add a bit to the InitializerValue so we don't have to worry about
406 // signed vs. unsigned comparisons.
407 InitializerValue = InitializerValue.extend(
408 InitializerValue.getBitWidth() + 1);
409 // Convert the initializer to and from the target width and signed-ness.
410 llvm::APSInt ConvertedValue = InitializerValue;
411 ConvertedValue = ConvertedValue.trunc(ToWidth);
412 ConvertedValue.setIsSigned(ToSigned);
413 ConvertedValue = ConvertedValue.extend(InitializerValue.getBitWidth());
414 ConvertedValue.setIsSigned(InitializerValue.isSigned());
415 // If the result is different, this was a narrowing conversion.
416 if (ConvertedValue != InitializerValue)
420 ConstantType = Initializer->getType();
421 ConstantValue = APValue(InitializerValue);
422 return NK_Constant_Narrowing;
425 return NK_Not_Narrowing;
429 // Other kinds of conversions are not narrowings.
430 return NK_Not_Narrowing;
434 /// dump - Print this standard conversion sequence to standard
435 /// error. Useful for debugging overloading issues.
436 void StandardConversionSequence::dump() const {
437 raw_ostream &OS = llvm::errs();
438 bool PrintedSomething = false;
439 if (First != ICK_Identity) {
440 OS << GetImplicitConversionName(First);
441 PrintedSomething = true;
444 if (Second != ICK_Identity) {
445 if (PrintedSomething) {
448 OS << GetImplicitConversionName(Second);
450 if (CopyConstructor) {
451 OS << " (by copy constructor)";
452 } else if (DirectBinding) {
453 OS << " (direct reference binding)";
454 } else if (ReferenceBinding) {
455 OS << " (reference binding)";
457 PrintedSomething = true;
460 if (Third != ICK_Identity) {
461 if (PrintedSomething) {
464 OS << GetImplicitConversionName(Third);
465 PrintedSomething = true;
468 if (!PrintedSomething) {
469 OS << "No conversions required";
473 /// dump - Print this user-defined conversion sequence to standard
474 /// error. Useful for debugging overloading issues.
475 void UserDefinedConversionSequence::dump() const {
476 raw_ostream &OS = llvm::errs();
477 if (Before.First || Before.Second || Before.Third) {
481 if (ConversionFunction)
482 OS << '\'' << *ConversionFunction << '\'';
484 OS << "aggregate initialization";
485 if (After.First || After.Second || After.Third) {
491 /// dump - Print this implicit conversion sequence to standard
492 /// error. Useful for debugging overloading issues.
493 void ImplicitConversionSequence::dump() const {
494 raw_ostream &OS = llvm::errs();
495 if (isStdInitializerListElement())
496 OS << "Worst std::initializer_list element conversion: ";
497 switch (ConversionKind) {
498 case StandardConversion:
499 OS << "Standard conversion: ";
502 case UserDefinedConversion:
503 OS << "User-defined conversion: ";
506 case EllipsisConversion:
507 OS << "Ellipsis conversion";
509 case AmbiguousConversion:
510 OS << "Ambiguous conversion";
513 OS << "Bad conversion";
520 void AmbiguousConversionSequence::construct() {
521 new (&conversions()) ConversionSet();
524 void AmbiguousConversionSequence::destruct() {
525 conversions().~ConversionSet();
529 AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) {
530 FromTypePtr = O.FromTypePtr;
531 ToTypePtr = O.ToTypePtr;
532 new (&conversions()) ConversionSet(O.conversions());
536 // Structure used by DeductionFailureInfo to store
537 // template argument information.
538 struct DFIArguments {
539 TemplateArgument FirstArg;
540 TemplateArgument SecondArg;
542 // Structure used by DeductionFailureInfo to store
543 // template parameter and template argument information.
544 struct DFIParamWithArguments : DFIArguments {
545 TemplateParameter Param;
547 // Structure used by DeductionFailureInfo to store template argument
548 // information and the index of the problematic call argument.
549 struct DFIDeducedMismatchArgs : DFIArguments {
550 TemplateArgumentList *TemplateArgs;
551 unsigned CallArgIndex;
555 /// \brief Convert from Sema's representation of template deduction information
556 /// to the form used in overload-candidate information.
558 clang::MakeDeductionFailureInfo(ASTContext &Context,
559 Sema::TemplateDeductionResult TDK,
560 TemplateDeductionInfo &Info) {
561 DeductionFailureInfo Result;
562 Result.Result = static_cast<unsigned>(TDK);
563 Result.HasDiagnostic = false;
565 case Sema::TDK_Success:
566 case Sema::TDK_Invalid:
567 case Sema::TDK_InstantiationDepth:
568 case Sema::TDK_TooManyArguments:
569 case Sema::TDK_TooFewArguments:
570 case Sema::TDK_MiscellaneousDeductionFailure:
571 Result.Data = nullptr;
574 case Sema::TDK_Incomplete:
575 case Sema::TDK_InvalidExplicitArguments:
576 Result.Data = Info.Param.getOpaqueValue();
579 case Sema::TDK_DeducedMismatch: {
580 // FIXME: Should allocate from normal heap so that we can free this later.
581 auto *Saved = new (Context) DFIDeducedMismatchArgs;
582 Saved->FirstArg = Info.FirstArg;
583 Saved->SecondArg = Info.SecondArg;
584 Saved->TemplateArgs = Info.take();
585 Saved->CallArgIndex = Info.CallArgIndex;
590 case Sema::TDK_NonDeducedMismatch: {
591 // FIXME: Should allocate from normal heap so that we can free this later.
592 DFIArguments *Saved = new (Context) DFIArguments;
593 Saved->FirstArg = Info.FirstArg;
594 Saved->SecondArg = Info.SecondArg;
599 case Sema::TDK_Inconsistent:
600 case Sema::TDK_Underqualified: {
601 // FIXME: Should allocate from normal heap so that we can free this later.
602 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments;
603 Saved->Param = Info.Param;
604 Saved->FirstArg = Info.FirstArg;
605 Saved->SecondArg = Info.SecondArg;
610 case Sema::TDK_SubstitutionFailure:
611 Result.Data = Info.take();
612 if (Info.hasSFINAEDiagnostic()) {
613 PartialDiagnosticAt *Diag = new (Result.Diagnostic) PartialDiagnosticAt(
614 SourceLocation(), PartialDiagnostic::NullDiagnostic());
615 Info.takeSFINAEDiagnostic(*Diag);
616 Result.HasDiagnostic = true;
620 case Sema::TDK_FailedOverloadResolution:
621 Result.Data = Info.Expression;
628 void DeductionFailureInfo::Destroy() {
629 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
630 case Sema::TDK_Success:
631 case Sema::TDK_Invalid:
632 case Sema::TDK_InstantiationDepth:
633 case Sema::TDK_Incomplete:
634 case Sema::TDK_TooManyArguments:
635 case Sema::TDK_TooFewArguments:
636 case Sema::TDK_InvalidExplicitArguments:
637 case Sema::TDK_FailedOverloadResolution:
640 case Sema::TDK_Inconsistent:
641 case Sema::TDK_Underqualified:
642 case Sema::TDK_DeducedMismatch:
643 case Sema::TDK_NonDeducedMismatch:
644 // FIXME: Destroy the data?
648 case Sema::TDK_SubstitutionFailure:
649 // FIXME: Destroy the template argument list?
651 if (PartialDiagnosticAt *Diag = getSFINAEDiagnostic()) {
652 Diag->~PartialDiagnosticAt();
653 HasDiagnostic = false;
658 case Sema::TDK_MiscellaneousDeductionFailure:
663 PartialDiagnosticAt *DeductionFailureInfo::getSFINAEDiagnostic() {
665 return static_cast<PartialDiagnosticAt*>(static_cast<void*>(Diagnostic));
669 TemplateParameter DeductionFailureInfo::getTemplateParameter() {
670 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
671 case Sema::TDK_Success:
672 case Sema::TDK_Invalid:
673 case Sema::TDK_InstantiationDepth:
674 case Sema::TDK_TooManyArguments:
675 case Sema::TDK_TooFewArguments:
676 case Sema::TDK_SubstitutionFailure:
677 case Sema::TDK_DeducedMismatch:
678 case Sema::TDK_NonDeducedMismatch:
679 case Sema::TDK_FailedOverloadResolution:
680 return TemplateParameter();
682 case Sema::TDK_Incomplete:
683 case Sema::TDK_InvalidExplicitArguments:
684 return TemplateParameter::getFromOpaqueValue(Data);
686 case Sema::TDK_Inconsistent:
687 case Sema::TDK_Underqualified:
688 return static_cast<DFIParamWithArguments*>(Data)->Param;
691 case Sema::TDK_MiscellaneousDeductionFailure:
695 return TemplateParameter();
698 TemplateArgumentList *DeductionFailureInfo::getTemplateArgumentList() {
699 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
700 case Sema::TDK_Success:
701 case Sema::TDK_Invalid:
702 case Sema::TDK_InstantiationDepth:
703 case Sema::TDK_TooManyArguments:
704 case Sema::TDK_TooFewArguments:
705 case Sema::TDK_Incomplete:
706 case Sema::TDK_InvalidExplicitArguments:
707 case Sema::TDK_Inconsistent:
708 case Sema::TDK_Underqualified:
709 case Sema::TDK_NonDeducedMismatch:
710 case Sema::TDK_FailedOverloadResolution:
713 case Sema::TDK_DeducedMismatch:
714 return static_cast<DFIDeducedMismatchArgs*>(Data)->TemplateArgs;
716 case Sema::TDK_SubstitutionFailure:
717 return static_cast<TemplateArgumentList*>(Data);
720 case Sema::TDK_MiscellaneousDeductionFailure:
727 const TemplateArgument *DeductionFailureInfo::getFirstArg() {
728 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
729 case Sema::TDK_Success:
730 case Sema::TDK_Invalid:
731 case Sema::TDK_InstantiationDepth:
732 case Sema::TDK_Incomplete:
733 case Sema::TDK_TooManyArguments:
734 case Sema::TDK_TooFewArguments:
735 case Sema::TDK_InvalidExplicitArguments:
736 case Sema::TDK_SubstitutionFailure:
737 case Sema::TDK_FailedOverloadResolution:
740 case Sema::TDK_Inconsistent:
741 case Sema::TDK_Underqualified:
742 case Sema::TDK_DeducedMismatch:
743 case Sema::TDK_NonDeducedMismatch:
744 return &static_cast<DFIArguments*>(Data)->FirstArg;
747 case Sema::TDK_MiscellaneousDeductionFailure:
754 const TemplateArgument *DeductionFailureInfo::getSecondArg() {
755 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
756 case Sema::TDK_Success:
757 case Sema::TDK_Invalid:
758 case Sema::TDK_InstantiationDepth:
759 case Sema::TDK_Incomplete:
760 case Sema::TDK_TooManyArguments:
761 case Sema::TDK_TooFewArguments:
762 case Sema::TDK_InvalidExplicitArguments:
763 case Sema::TDK_SubstitutionFailure:
764 case Sema::TDK_FailedOverloadResolution:
767 case Sema::TDK_Inconsistent:
768 case Sema::TDK_Underqualified:
769 case Sema::TDK_DeducedMismatch:
770 case Sema::TDK_NonDeducedMismatch:
771 return &static_cast<DFIArguments*>(Data)->SecondArg;
774 case Sema::TDK_MiscellaneousDeductionFailure:
781 Expr *DeductionFailureInfo::getExpr() {
782 if (static_cast<Sema::TemplateDeductionResult>(Result) ==
783 Sema::TDK_FailedOverloadResolution)
784 return static_cast<Expr*>(Data);
789 llvm::Optional<unsigned> DeductionFailureInfo::getCallArgIndex() {
790 if (static_cast<Sema::TemplateDeductionResult>(Result) ==
791 Sema::TDK_DeducedMismatch)
792 return static_cast<DFIDeducedMismatchArgs*>(Data)->CallArgIndex;
797 void OverloadCandidateSet::destroyCandidates() {
798 for (iterator i = begin(), e = end(); i != e; ++i) {
799 for (unsigned ii = 0, ie = i->NumConversions; ii != ie; ++ii)
800 i->Conversions[ii].~ImplicitConversionSequence();
801 if (!i->Viable && i->FailureKind == ovl_fail_bad_deduction)
802 i->DeductionFailure.Destroy();
806 void OverloadCandidateSet::clear() {
808 NumInlineSequences = 0;
814 class UnbridgedCastsSet {
819 SmallVector<Entry, 2> Entries;
822 void save(Sema &S, Expr *&E) {
823 assert(E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast));
824 Entry entry = { &E, E };
825 Entries.push_back(entry);
826 E = S.stripARCUnbridgedCast(E);
830 for (SmallVectorImpl<Entry>::iterator
831 i = Entries.begin(), e = Entries.end(); i != e; ++i)
837 /// checkPlaceholderForOverload - Do any interesting placeholder-like
838 /// preprocessing on the given expression.
840 /// \param unbridgedCasts a collection to which to add unbridged casts;
841 /// without this, they will be immediately diagnosed as errors
843 /// Return true on unrecoverable error.
845 checkPlaceholderForOverload(Sema &S, Expr *&E,
846 UnbridgedCastsSet *unbridgedCasts = nullptr) {
847 if (const BuiltinType *placeholder = E->getType()->getAsPlaceholderType()) {
848 // We can't handle overloaded expressions here because overload
849 // resolution might reasonably tweak them.
850 if (placeholder->getKind() == BuiltinType::Overload) return false;
852 // If the context potentially accepts unbridged ARC casts, strip
853 // the unbridged cast and add it to the collection for later restoration.
854 if (placeholder->getKind() == BuiltinType::ARCUnbridgedCast &&
856 unbridgedCasts->save(S, E);
860 // Go ahead and check everything else.
861 ExprResult result = S.CheckPlaceholderExpr(E);
862 if (result.isInvalid())
873 /// checkArgPlaceholdersForOverload - Check a set of call operands for
875 static bool checkArgPlaceholdersForOverload(Sema &S,
877 UnbridgedCastsSet &unbridged) {
878 for (unsigned i = 0, e = Args.size(); i != e; ++i)
879 if (checkPlaceholderForOverload(S, Args[i], &unbridged))
885 // IsOverload - Determine whether the given New declaration is an
886 // overload of the declarations in Old. This routine returns false if
887 // New and Old cannot be overloaded, e.g., if New has the same
888 // signature as some function in Old (C++ 1.3.10) or if the Old
889 // declarations aren't functions (or function templates) at all. When
890 // it does return false, MatchedDecl will point to the decl that New
891 // cannot be overloaded with. This decl may be a UsingShadowDecl on
892 // top of the underlying declaration.
894 // Example: Given the following input:
896 // void f(int, float); // #1
897 // void f(int, int); // #2
898 // int f(int, int); // #3
900 // When we process #1, there is no previous declaration of "f",
901 // so IsOverload will not be used.
903 // When we process #2, Old contains only the FunctionDecl for #1. By
904 // comparing the parameter types, we see that #1 and #2 are overloaded
905 // (since they have different signatures), so this routine returns
906 // false; MatchedDecl is unchanged.
908 // When we process #3, Old is an overload set containing #1 and #2. We
909 // compare the signatures of #3 to #1 (they're overloaded, so we do
910 // nothing) and then #3 to #2. Since the signatures of #3 and #2 are
911 // identical (return types of functions are not part of the
912 // signature), IsOverload returns false and MatchedDecl will be set to
913 // point to the FunctionDecl for #2.
915 // 'NewIsUsingShadowDecl' indicates that 'New' is being introduced
916 // into a class by a using declaration. The rules for whether to hide
917 // shadow declarations ignore some properties which otherwise figure
918 // into a function template's signature.
920 Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old,
921 NamedDecl *&Match, bool NewIsUsingDecl) {
922 for (LookupResult::iterator I = Old.begin(), E = Old.end();
924 NamedDecl *OldD = *I;
926 bool OldIsUsingDecl = false;
927 if (isa<UsingShadowDecl>(OldD)) {
928 OldIsUsingDecl = true;
930 // We can always introduce two using declarations into the same
931 // context, even if they have identical signatures.
932 if (NewIsUsingDecl) continue;
934 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl();
937 // A using-declaration does not conflict with another declaration
938 // if one of them is hidden.
939 if ((OldIsUsingDecl || NewIsUsingDecl) && !isVisible(*I))
942 // If either declaration was introduced by a using declaration,
943 // we'll need to use slightly different rules for matching.
944 // Essentially, these rules are the normal rules, except that
945 // function templates hide function templates with different
946 // return types or template parameter lists.
947 bool UseMemberUsingDeclRules =
948 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord() &&
949 !New->getFriendObjectKind();
951 if (FunctionDecl *OldF = OldD->getAsFunction()) {
952 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) {
953 if (UseMemberUsingDeclRules && OldIsUsingDecl) {
954 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I));
958 if (!isa<FunctionTemplateDecl>(OldD) &&
959 !shouldLinkPossiblyHiddenDecl(*I, New))
965 } else if (isa<UsingDecl>(OldD)) {
966 // We can overload with these, which can show up when doing
967 // redeclaration checks for UsingDecls.
968 assert(Old.getLookupKind() == LookupUsingDeclName);
969 } else if (isa<TagDecl>(OldD)) {
970 // We can always overload with tags by hiding them.
971 } else if (isa<UnresolvedUsingValueDecl>(OldD)) {
972 // Optimistically assume that an unresolved using decl will
973 // overload; if it doesn't, we'll have to diagnose during
974 // template instantiation.
977 // Only function declarations can be overloaded; object and type
978 // declarations cannot be overloaded.
980 return Ovl_NonFunction;
987 bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old,
988 bool UseUsingDeclRules) {
989 // C++ [basic.start.main]p2: This function shall not be overloaded.
993 // MSVCRT user defined entry points cannot be overloaded.
994 if (New->isMSVCRTEntryPoint())
997 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate();
998 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate();
1000 // C++ [temp.fct]p2:
1001 // A function template can be overloaded with other function templates
1002 // and with normal (non-template) functions.
1003 if ((OldTemplate == nullptr) != (NewTemplate == nullptr))
1006 // Is the function New an overload of the function Old?
1007 QualType OldQType = Context.getCanonicalType(Old->getType());
1008 QualType NewQType = Context.getCanonicalType(New->getType());
1010 // Compare the signatures (C++ 1.3.10) of the two functions to
1011 // determine whether they are overloads. If we find any mismatch
1012 // in the signature, they are overloads.
1014 // If either of these functions is a K&R-style function (no
1015 // prototype), then we consider them to have matching signatures.
1016 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) ||
1017 isa<FunctionNoProtoType>(NewQType.getTypePtr()))
1020 const FunctionProtoType *OldType = cast<FunctionProtoType>(OldQType);
1021 const FunctionProtoType *NewType = cast<FunctionProtoType>(NewQType);
1023 // The signature of a function includes the types of its
1024 // parameters (C++ 1.3.10), which includes the presence or absence
1025 // of the ellipsis; see C++ DR 357).
1026 if (OldQType != NewQType &&
1027 (OldType->getNumParams() != NewType->getNumParams() ||
1028 OldType->isVariadic() != NewType->isVariadic() ||
1029 !FunctionParamTypesAreEqual(OldType, NewType)))
1032 // C++ [temp.over.link]p4:
1033 // The signature of a function template consists of its function
1034 // signature, its return type and its template parameter list. The names
1035 // of the template parameters are significant only for establishing the
1036 // relationship between the template parameters and the rest of the
1039 // We check the return type and template parameter lists for function
1040 // templates first; the remaining checks follow.
1042 // However, we don't consider either of these when deciding whether
1043 // a member introduced by a shadow declaration is hidden.
1044 if (!UseUsingDeclRules && NewTemplate &&
1045 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(),
1046 OldTemplate->getTemplateParameters(),
1047 false, TPL_TemplateMatch) ||
1048 OldType->getReturnType() != NewType->getReturnType()))
1051 // If the function is a class member, its signature includes the
1052 // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself.
1054 // As part of this, also check whether one of the member functions
1055 // is static, in which case they are not overloads (C++
1056 // 13.1p2). While not part of the definition of the signature,
1057 // this check is important to determine whether these functions
1058 // can be overloaded.
1059 CXXMethodDecl *OldMethod = dyn_cast<CXXMethodDecl>(Old);
1060 CXXMethodDecl *NewMethod = dyn_cast<CXXMethodDecl>(New);
1061 if (OldMethod && NewMethod &&
1062 !OldMethod->isStatic() && !NewMethod->isStatic()) {
1063 if (OldMethod->getRefQualifier() != NewMethod->getRefQualifier()) {
1064 if (!UseUsingDeclRules &&
1065 (OldMethod->getRefQualifier() == RQ_None ||
1066 NewMethod->getRefQualifier() == RQ_None)) {
1067 // C++0x [over.load]p2:
1068 // - Member function declarations with the same name and the same
1069 // parameter-type-list as well as member function template
1070 // declarations with the same name, the same parameter-type-list, and
1071 // the same template parameter lists cannot be overloaded if any of
1072 // them, but not all, have a ref-qualifier (8.3.5).
1073 Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload)
1074 << NewMethod->getRefQualifier() << OldMethod->getRefQualifier();
1075 Diag(OldMethod->getLocation(), diag::note_previous_declaration);
1080 // We may not have applied the implicit const for a constexpr member
1081 // function yet (because we haven't yet resolved whether this is a static
1082 // or non-static member function). Add it now, on the assumption that this
1083 // is a redeclaration of OldMethod.
1084 unsigned OldQuals = OldMethod->getTypeQualifiers();
1085 unsigned NewQuals = NewMethod->getTypeQualifiers();
1086 if (!getLangOpts().CPlusPlus14 && NewMethod->isConstexpr() &&
1087 !isa<CXXConstructorDecl>(NewMethod))
1088 NewQuals |= Qualifiers::Const;
1090 // We do not allow overloading based off of '__restrict'.
1091 OldQuals &= ~Qualifiers::Restrict;
1092 NewQuals &= ~Qualifiers::Restrict;
1093 if (OldQuals != NewQuals)
1097 // Though pass_object_size is placed on parameters and takes an argument, we
1098 // consider it to be a function-level modifier for the sake of function
1099 // identity. Either the function has one or more parameters with
1100 // pass_object_size or it doesn't.
1101 if (functionHasPassObjectSizeParams(New) !=
1102 functionHasPassObjectSizeParams(Old))
1105 // enable_if attributes are an order-sensitive part of the signature.
1106 for (specific_attr_iterator<EnableIfAttr>
1107 NewI = New->specific_attr_begin<EnableIfAttr>(),
1108 NewE = New->specific_attr_end<EnableIfAttr>(),
1109 OldI = Old->specific_attr_begin<EnableIfAttr>(),
1110 OldE = Old->specific_attr_end<EnableIfAttr>();
1111 NewI != NewE || OldI != OldE; ++NewI, ++OldI) {
1112 if (NewI == NewE || OldI == OldE)
1114 llvm::FoldingSetNodeID NewID, OldID;
1115 NewI->getCond()->Profile(NewID, Context, true);
1116 OldI->getCond()->Profile(OldID, Context, true);
1121 if (getLangOpts().CUDA && getLangOpts().CUDATargetOverloads) {
1122 CUDAFunctionTarget NewTarget = IdentifyCUDATarget(New),
1123 OldTarget = IdentifyCUDATarget(Old);
1124 if (NewTarget == CFT_InvalidTarget || NewTarget == CFT_Global)
1127 assert((OldTarget != CFT_InvalidTarget) && "Unexpected invalid target.");
1129 // Don't allow mixing of HD with other kinds. This guarantees that
1130 // we have only one viable function with this signature on any
1131 // side of CUDA compilation .
1132 if ((NewTarget == CFT_HostDevice) || (OldTarget == CFT_HostDevice))
1135 // Allow overloading of functions with same signature, but
1136 // different CUDA target attributes.
1137 return NewTarget != OldTarget;
1140 // The signatures match; this is not an overload.
1144 /// \brief Checks availability of the function depending on the current
1145 /// function context. Inside an unavailable function, unavailability is ignored.
1147 /// \returns true if \arg FD is unavailable and current context is inside
1148 /// an available function, false otherwise.
1149 bool Sema::isFunctionConsideredUnavailable(FunctionDecl *FD) {
1150 return FD->isUnavailable() && !cast<Decl>(CurContext)->isUnavailable();
1153 /// \brief Tries a user-defined conversion from From to ToType.
1155 /// Produces an implicit conversion sequence for when a standard conversion
1156 /// is not an option. See TryImplicitConversion for more information.
1157 static ImplicitConversionSequence
1158 TryUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
1159 bool SuppressUserConversions,
1161 bool InOverloadResolution,
1163 bool AllowObjCWritebackConversion,
1164 bool AllowObjCConversionOnExplicit) {
1165 ImplicitConversionSequence ICS;
1167 if (SuppressUserConversions) {
1168 // We're not in the case above, so there is no conversion that
1170 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1174 // Attempt user-defined conversion.
1175 OverloadCandidateSet Conversions(From->getExprLoc(),
1176 OverloadCandidateSet::CSK_Normal);
1177 switch (IsUserDefinedConversion(S, From, ToType, ICS.UserDefined,
1178 Conversions, AllowExplicit,
1179 AllowObjCConversionOnExplicit)) {
1182 ICS.setUserDefined();
1183 ICS.UserDefined.Before.setAsIdentityConversion();
1184 // C++ [over.ics.user]p4:
1185 // A conversion of an expression of class type to the same class
1186 // type is given Exact Match rank, and a conversion of an
1187 // expression of class type to a base class of that type is
1188 // given Conversion rank, in spite of the fact that a copy
1189 // constructor (i.e., a user-defined conversion function) is
1190 // called for those cases.
1191 if (CXXConstructorDecl *Constructor
1192 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) {
1194 = S.Context.getCanonicalType(From->getType().getUnqualifiedType());
1196 = S.Context.getCanonicalType(ToType).getUnqualifiedType();
1197 if (Constructor->isCopyConstructor() &&
1198 (FromCanon == ToCanon ||
1199 S.IsDerivedFrom(From->getLocStart(), FromCanon, ToCanon))) {
1200 // Turn this into a "standard" conversion sequence, so that it
1201 // gets ranked with standard conversion sequences.
1203 ICS.Standard.setAsIdentityConversion();
1204 ICS.Standard.setFromType(From->getType());
1205 ICS.Standard.setAllToTypes(ToType);
1206 ICS.Standard.CopyConstructor = Constructor;
1207 if (ToCanon != FromCanon)
1208 ICS.Standard.Second = ICK_Derived_To_Base;
1215 ICS.Ambiguous.setFromType(From->getType());
1216 ICS.Ambiguous.setToType(ToType);
1217 for (OverloadCandidateSet::iterator Cand = Conversions.begin();
1218 Cand != Conversions.end(); ++Cand)
1220 ICS.Ambiguous.addConversion(Cand->Function);
1224 case OR_No_Viable_Function:
1225 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1232 /// TryImplicitConversion - Attempt to perform an implicit conversion
1233 /// from the given expression (Expr) to the given type (ToType). This
1234 /// function returns an implicit conversion sequence that can be used
1235 /// to perform the initialization. Given
1237 /// void f(float f);
1238 /// void g(int i) { f(i); }
1240 /// this routine would produce an implicit conversion sequence to
1241 /// describe the initialization of f from i, which will be a standard
1242 /// conversion sequence containing an lvalue-to-rvalue conversion (C++
1243 /// 4.1) followed by a floating-integral conversion (C++ 4.9).
1245 /// Note that this routine only determines how the conversion can be
1246 /// performed; it does not actually perform the conversion. As such,
1247 /// it will not produce any diagnostics if no conversion is available,
1248 /// but will instead return an implicit conversion sequence of kind
1249 /// "BadConversion".
1251 /// If @p SuppressUserConversions, then user-defined conversions are
1253 /// If @p AllowExplicit, then explicit user-defined conversions are
1256 /// \param AllowObjCWritebackConversion Whether we allow the Objective-C
1257 /// writeback conversion, which allows __autoreleasing id* parameters to
1258 /// be initialized with __strong id* or __weak id* arguments.
1259 static ImplicitConversionSequence
1260 TryImplicitConversion(Sema &S, Expr *From, QualType ToType,
1261 bool SuppressUserConversions,
1263 bool InOverloadResolution,
1265 bool AllowObjCWritebackConversion,
1266 bool AllowObjCConversionOnExplicit) {
1267 ImplicitConversionSequence ICS;
1268 if (IsStandardConversion(S, From, ToType, InOverloadResolution,
1269 ICS.Standard, CStyle, AllowObjCWritebackConversion)){
1274 if (!S.getLangOpts().CPlusPlus) {
1275 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1279 // C++ [over.ics.user]p4:
1280 // A conversion of an expression of class type to the same class
1281 // type is given Exact Match rank, and a conversion of an
1282 // expression of class type to a base class of that type is
1283 // given Conversion rank, in spite of the fact that a copy/move
1284 // constructor (i.e., a user-defined conversion function) is
1285 // called for those cases.
1286 QualType FromType = From->getType();
1287 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() &&
1288 (S.Context.hasSameUnqualifiedType(FromType, ToType) ||
1289 S.IsDerivedFrom(From->getLocStart(), FromType, ToType))) {
1291 ICS.Standard.setAsIdentityConversion();
1292 ICS.Standard.setFromType(FromType);
1293 ICS.Standard.setAllToTypes(ToType);
1295 // We don't actually check at this point whether there is a valid
1296 // copy/move constructor, since overloading just assumes that it
1297 // exists. When we actually perform initialization, we'll find the
1298 // appropriate constructor to copy the returned object, if needed.
1299 ICS.Standard.CopyConstructor = nullptr;
1301 // Determine whether this is considered a derived-to-base conversion.
1302 if (!S.Context.hasSameUnqualifiedType(FromType, ToType))
1303 ICS.Standard.Second = ICK_Derived_To_Base;
1308 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
1309 AllowExplicit, InOverloadResolution, CStyle,
1310 AllowObjCWritebackConversion,
1311 AllowObjCConversionOnExplicit);
1314 ImplicitConversionSequence
1315 Sema::TryImplicitConversion(Expr *From, QualType ToType,
1316 bool SuppressUserConversions,
1318 bool InOverloadResolution,
1320 bool AllowObjCWritebackConversion) {
1321 return ::TryImplicitConversion(*this, From, ToType,
1322 SuppressUserConversions, AllowExplicit,
1323 InOverloadResolution, CStyle,
1324 AllowObjCWritebackConversion,
1325 /*AllowObjCConversionOnExplicit=*/false);
1328 /// PerformImplicitConversion - Perform an implicit conversion of the
1329 /// expression From to the type ToType. Returns the
1330 /// converted expression. Flavor is the kind of conversion we're
1331 /// performing, used in the error message. If @p AllowExplicit,
1332 /// explicit user-defined conversions are permitted.
1334 Sema::PerformImplicitConversion(Expr *From, QualType ToType,
1335 AssignmentAction Action, bool AllowExplicit) {
1336 ImplicitConversionSequence ICS;
1337 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS);
1341 Sema::PerformImplicitConversion(Expr *From, QualType ToType,
1342 AssignmentAction Action, bool AllowExplicit,
1343 ImplicitConversionSequence& ICS) {
1344 if (checkPlaceholderForOverload(*this, From))
1347 // Objective-C ARC: Determine whether we will allow the writeback conversion.
1348 bool AllowObjCWritebackConversion
1349 = getLangOpts().ObjCAutoRefCount &&
1350 (Action == AA_Passing || Action == AA_Sending);
1351 if (getLangOpts().ObjC1)
1352 CheckObjCBridgeRelatedConversions(From->getLocStart(),
1353 ToType, From->getType(), From);
1354 ICS = ::TryImplicitConversion(*this, From, ToType,
1355 /*SuppressUserConversions=*/false,
1357 /*InOverloadResolution=*/false,
1359 AllowObjCWritebackConversion,
1360 /*AllowObjCConversionOnExplicit=*/false);
1361 return PerformImplicitConversion(From, ToType, ICS, Action);
1364 /// \brief Determine whether the conversion from FromType to ToType is a valid
1365 /// conversion that strips "noreturn" off the nested function type.
1366 bool Sema::IsNoReturnConversion(QualType FromType, QualType ToType,
1367 QualType &ResultTy) {
1368 if (Context.hasSameUnqualifiedType(FromType, ToType))
1371 // Permit the conversion F(t __attribute__((noreturn))) -> F(t)
1372 // where F adds one of the following at most once:
1374 // - a member pointer
1375 // - a block pointer
1376 CanQualType CanTo = Context.getCanonicalType(ToType);
1377 CanQualType CanFrom = Context.getCanonicalType(FromType);
1378 Type::TypeClass TyClass = CanTo->getTypeClass();
1379 if (TyClass != CanFrom->getTypeClass()) return false;
1380 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) {
1381 if (TyClass == Type::Pointer) {
1382 CanTo = CanTo.getAs<PointerType>()->getPointeeType();
1383 CanFrom = CanFrom.getAs<PointerType>()->getPointeeType();
1384 } else if (TyClass == Type::BlockPointer) {
1385 CanTo = CanTo.getAs<BlockPointerType>()->getPointeeType();
1386 CanFrom = CanFrom.getAs<BlockPointerType>()->getPointeeType();
1387 } else if (TyClass == Type::MemberPointer) {
1388 CanTo = CanTo.getAs<MemberPointerType>()->getPointeeType();
1389 CanFrom = CanFrom.getAs<MemberPointerType>()->getPointeeType();
1394 TyClass = CanTo->getTypeClass();
1395 if (TyClass != CanFrom->getTypeClass()) return false;
1396 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto)
1400 const FunctionType *FromFn = cast<FunctionType>(CanFrom);
1401 FunctionType::ExtInfo EInfo = FromFn->getExtInfo();
1402 if (!EInfo.getNoReturn()) return false;
1404 FromFn = Context.adjustFunctionType(FromFn, EInfo.withNoReturn(false));
1405 assert(QualType(FromFn, 0).isCanonical());
1406 if (QualType(FromFn, 0) != CanTo) return false;
1412 /// \brief Determine whether the conversion from FromType to ToType is a valid
1413 /// vector conversion.
1415 /// \param ICK Will be set to the vector conversion kind, if this is a vector
1417 static bool IsVectorConversion(Sema &S, QualType FromType,
1418 QualType ToType, ImplicitConversionKind &ICK) {
1419 // We need at least one of these types to be a vector type to have a vector
1421 if (!ToType->isVectorType() && !FromType->isVectorType())
1424 // Identical types require no conversions.
1425 if (S.Context.hasSameUnqualifiedType(FromType, ToType))
1428 // There are no conversions between extended vector types, only identity.
1429 if (ToType->isExtVectorType()) {
1430 // There are no conversions between extended vector types other than the
1431 // identity conversion.
1432 if (FromType->isExtVectorType())
1435 // Vector splat from any arithmetic type to a vector.
1436 if (FromType->isArithmeticType()) {
1437 ICK = ICK_Vector_Splat;
1442 // We can perform the conversion between vector types in the following cases:
1443 // 1)vector types are equivalent AltiVec and GCC vector types
1444 // 2)lax vector conversions are permitted and the vector types are of the
1446 if (ToType->isVectorType() && FromType->isVectorType()) {
1447 if (S.Context.areCompatibleVectorTypes(FromType, ToType) ||
1448 S.isLaxVectorConversion(FromType, ToType)) {
1449 ICK = ICK_Vector_Conversion;
1457 static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
1458 bool InOverloadResolution,
1459 StandardConversionSequence &SCS,
1462 /// IsStandardConversion - Determines whether there is a standard
1463 /// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the
1464 /// expression From to the type ToType. Standard conversion sequences
1465 /// only consider non-class types; for conversions that involve class
1466 /// types, use TryImplicitConversion. If a conversion exists, SCS will
1467 /// contain the standard conversion sequence required to perform this
1468 /// conversion and this routine will return true. Otherwise, this
1469 /// routine will return false and the value of SCS is unspecified.
1470 static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
1471 bool InOverloadResolution,
1472 StandardConversionSequence &SCS,
1474 bool AllowObjCWritebackConversion) {
1475 QualType FromType = From->getType();
1477 // Standard conversions (C++ [conv])
1478 SCS.setAsIdentityConversion();
1479 SCS.IncompatibleObjC = false;
1480 SCS.setFromType(FromType);
1481 SCS.CopyConstructor = nullptr;
1483 // There are no standard conversions for class types in C++, so
1484 // abort early. When overloading in C, however, we do permit them.
1485 if (S.getLangOpts().CPlusPlus &&
1486 (FromType->isRecordType() || ToType->isRecordType()))
1489 // The first conversion can be an lvalue-to-rvalue conversion,
1490 // array-to-pointer conversion, or function-to-pointer conversion
1493 if (FromType == S.Context.OverloadTy) {
1494 DeclAccessPair AccessPair;
1495 if (FunctionDecl *Fn
1496 = S.ResolveAddressOfOverloadedFunction(From, ToType, false,
1498 // We were able to resolve the address of the overloaded function,
1499 // so we can convert to the type of that function.
1500 FromType = Fn->getType();
1501 SCS.setFromType(FromType);
1503 // we can sometimes resolve &foo<int> regardless of ToType, so check
1504 // if the type matches (identity) or we are converting to bool
1505 if (!S.Context.hasSameUnqualifiedType(
1506 S.ExtractUnqualifiedFunctionType(ToType), FromType)) {
1508 // if the function type matches except for [[noreturn]], it's ok
1509 if (!S.IsNoReturnConversion(FromType,
1510 S.ExtractUnqualifiedFunctionType(ToType), resultTy))
1511 // otherwise, only a boolean conversion is standard
1512 if (!ToType->isBooleanType())
1516 // Check if the "from" expression is taking the address of an overloaded
1517 // function and recompute the FromType accordingly. Take advantage of the
1518 // fact that non-static member functions *must* have such an address-of
1520 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn);
1521 if (Method && !Method->isStatic()) {
1522 assert(isa<UnaryOperator>(From->IgnoreParens()) &&
1523 "Non-unary operator on non-static member address");
1524 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode()
1526 "Non-address-of operator on non-static member address");
1527 const Type *ClassType
1528 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr();
1529 FromType = S.Context.getMemberPointerType(FromType, ClassType);
1530 } else if (isa<UnaryOperator>(From->IgnoreParens())) {
1531 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() ==
1533 "Non-address-of operator for overloaded function expression");
1534 FromType = S.Context.getPointerType(FromType);
1537 // Check that we've computed the proper type after overload resolution.
1538 assert(S.Context.hasSameType(
1540 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType()));
1545 // Lvalue-to-rvalue conversion (C++11 4.1):
1546 // A glvalue (3.10) of a non-function, non-array type T can
1547 // be converted to a prvalue.
1548 bool argIsLValue = From->isGLValue();
1550 !FromType->isFunctionType() && !FromType->isArrayType() &&
1551 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) {
1552 SCS.First = ICK_Lvalue_To_Rvalue;
1555 // ... if the lvalue has atomic type, the value has the non-atomic version
1556 // of the type of the lvalue ...
1557 if (const AtomicType *Atomic = FromType->getAs<AtomicType>())
1558 FromType = Atomic->getValueType();
1560 // If T is a non-class type, the type of the rvalue is the
1561 // cv-unqualified version of T. Otherwise, the type of the rvalue
1562 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we
1563 // just strip the qualifiers because they don't matter.
1564 FromType = FromType.getUnqualifiedType();
1565 } else if (FromType->isArrayType()) {
1566 // Array-to-pointer conversion (C++ 4.2)
1567 SCS.First = ICK_Array_To_Pointer;
1569 // An lvalue or rvalue of type "array of N T" or "array of unknown
1570 // bound of T" can be converted to an rvalue of type "pointer to
1572 FromType = S.Context.getArrayDecayedType(FromType);
1574 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) {
1575 // This conversion is deprecated in C++03 (D.4)
1576 SCS.DeprecatedStringLiteralToCharPtr = true;
1578 // For the purpose of ranking in overload resolution
1579 // (13.3.3.1.1), this conversion is considered an
1580 // array-to-pointer conversion followed by a qualification
1581 // conversion (4.4). (C++ 4.2p2)
1582 SCS.Second = ICK_Identity;
1583 SCS.Third = ICK_Qualification;
1584 SCS.QualificationIncludesObjCLifetime = false;
1585 SCS.setAllToTypes(FromType);
1588 } else if (FromType->isFunctionType() && argIsLValue) {
1589 // Function-to-pointer conversion (C++ 4.3).
1590 SCS.First = ICK_Function_To_Pointer;
1592 if (auto *DRE = dyn_cast<DeclRefExpr>(From->IgnoreParenCasts()))
1593 if (auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl()))
1594 if (!S.checkAddressOfFunctionIsAvailable(FD))
1597 // An lvalue of function type T can be converted to an rvalue of
1598 // type "pointer to T." The result is a pointer to the
1599 // function. (C++ 4.3p1).
1600 FromType = S.Context.getPointerType(FromType);
1602 // We don't require any conversions for the first step.
1603 SCS.First = ICK_Identity;
1605 SCS.setToType(0, FromType);
1607 // The second conversion can be an integral promotion, floating
1608 // point promotion, integral conversion, floating point conversion,
1609 // floating-integral conversion, pointer conversion,
1610 // pointer-to-member conversion, or boolean conversion (C++ 4p1).
1611 // For overloading in C, this can also be a "compatible-type"
1613 bool IncompatibleObjC = false;
1614 ImplicitConversionKind SecondICK = ICK_Identity;
1615 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) {
1616 // The unqualified versions of the types are the same: there's no
1617 // conversion to do.
1618 SCS.Second = ICK_Identity;
1619 } else if (S.IsIntegralPromotion(From, FromType, ToType)) {
1620 // Integral promotion (C++ 4.5).
1621 SCS.Second = ICK_Integral_Promotion;
1622 FromType = ToType.getUnqualifiedType();
1623 } else if (S.IsFloatingPointPromotion(FromType, ToType)) {
1624 // Floating point promotion (C++ 4.6).
1625 SCS.Second = ICK_Floating_Promotion;
1626 FromType = ToType.getUnqualifiedType();
1627 } else if (S.IsComplexPromotion(FromType, ToType)) {
1628 // Complex promotion (Clang extension)
1629 SCS.Second = ICK_Complex_Promotion;
1630 FromType = ToType.getUnqualifiedType();
1631 } else if (ToType->isBooleanType() &&
1632 (FromType->isArithmeticType() ||
1633 FromType->isAnyPointerType() ||
1634 FromType->isBlockPointerType() ||
1635 FromType->isMemberPointerType() ||
1636 FromType->isNullPtrType())) {
1637 // Boolean conversions (C++ 4.12).
1638 SCS.Second = ICK_Boolean_Conversion;
1639 FromType = S.Context.BoolTy;
1640 } else if (FromType->isIntegralOrUnscopedEnumerationType() &&
1641 ToType->isIntegralType(S.Context)) {
1642 // Integral conversions (C++ 4.7).
1643 SCS.Second = ICK_Integral_Conversion;
1644 FromType = ToType.getUnqualifiedType();
1645 } else if (FromType->isAnyComplexType() && ToType->isAnyComplexType()) {
1646 // Complex conversions (C99 6.3.1.6)
1647 SCS.Second = ICK_Complex_Conversion;
1648 FromType = ToType.getUnqualifiedType();
1649 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) ||
1650 (ToType->isAnyComplexType() && FromType->isArithmeticType())) {
1651 // Complex-real conversions (C99 6.3.1.7)
1652 SCS.Second = ICK_Complex_Real;
1653 FromType = ToType.getUnqualifiedType();
1654 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) {
1655 // Floating point conversions (C++ 4.8).
1656 SCS.Second = ICK_Floating_Conversion;
1657 FromType = ToType.getUnqualifiedType();
1658 } else if ((FromType->isRealFloatingType() &&
1659 ToType->isIntegralType(S.Context)) ||
1660 (FromType->isIntegralOrUnscopedEnumerationType() &&
1661 ToType->isRealFloatingType())) {
1662 // Floating-integral conversions (C++ 4.9).
1663 SCS.Second = ICK_Floating_Integral;
1664 FromType = ToType.getUnqualifiedType();
1665 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) {
1666 SCS.Second = ICK_Block_Pointer_Conversion;
1667 } else if (AllowObjCWritebackConversion &&
1668 S.isObjCWritebackConversion(FromType, ToType, FromType)) {
1669 SCS.Second = ICK_Writeback_Conversion;
1670 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution,
1671 FromType, IncompatibleObjC)) {
1672 // Pointer conversions (C++ 4.10).
1673 SCS.Second = ICK_Pointer_Conversion;
1674 SCS.IncompatibleObjC = IncompatibleObjC;
1675 FromType = FromType.getUnqualifiedType();
1676 } else if (S.IsMemberPointerConversion(From, FromType, ToType,
1677 InOverloadResolution, FromType)) {
1678 // Pointer to member conversions (4.11).
1679 SCS.Second = ICK_Pointer_Member;
1680 } else if (IsVectorConversion(S, FromType, ToType, SecondICK)) {
1681 SCS.Second = SecondICK;
1682 FromType = ToType.getUnqualifiedType();
1683 } else if (!S.getLangOpts().CPlusPlus &&
1684 S.Context.typesAreCompatible(ToType, FromType)) {
1685 // Compatible conversions (Clang extension for C function overloading)
1686 SCS.Second = ICK_Compatible_Conversion;
1687 FromType = ToType.getUnqualifiedType();
1688 } else if (S.IsNoReturnConversion(FromType, ToType, FromType)) {
1689 // Treat a conversion that strips "noreturn" as an identity conversion.
1690 SCS.Second = ICK_NoReturn_Adjustment;
1691 } else if (IsTransparentUnionStandardConversion(S, From, ToType,
1692 InOverloadResolution,
1694 SCS.Second = ICK_TransparentUnionConversion;
1696 } else if (tryAtomicConversion(S, From, ToType, InOverloadResolution, SCS,
1698 // tryAtomicConversion has updated the standard conversion sequence
1701 } else if (ToType->isEventT() &&
1702 From->isIntegerConstantExpr(S.getASTContext()) &&
1703 From->EvaluateKnownConstInt(S.getASTContext()) == 0) {
1704 SCS.Second = ICK_Zero_Event_Conversion;
1707 // No second conversion required.
1708 SCS.Second = ICK_Identity;
1710 SCS.setToType(1, FromType);
1714 // The third conversion can be a qualification conversion (C++ 4p1).
1715 bool ObjCLifetimeConversion;
1716 if (S.IsQualificationConversion(FromType, ToType, CStyle,
1717 ObjCLifetimeConversion)) {
1718 SCS.Third = ICK_Qualification;
1719 SCS.QualificationIncludesObjCLifetime = ObjCLifetimeConversion;
1721 CanonFrom = S.Context.getCanonicalType(FromType);
1722 CanonTo = S.Context.getCanonicalType(ToType);
1724 // No conversion required
1725 SCS.Third = ICK_Identity;
1727 // C++ [over.best.ics]p6:
1728 // [...] Any difference in top-level cv-qualification is
1729 // subsumed by the initialization itself and does not constitute
1730 // a conversion. [...]
1731 CanonFrom = S.Context.getCanonicalType(FromType);
1732 CanonTo = S.Context.getCanonicalType(ToType);
1733 if (CanonFrom.getLocalUnqualifiedType()
1734 == CanonTo.getLocalUnqualifiedType() &&
1735 CanonFrom.getLocalQualifiers() != CanonTo.getLocalQualifiers()) {
1737 CanonFrom = CanonTo;
1740 SCS.setToType(2, FromType);
1742 if (CanonFrom == CanonTo)
1745 // If we have not converted the argument type to the parameter type,
1746 // this is a bad conversion sequence, unless we're resolving an overload in C.
1747 if (S.getLangOpts().CPlusPlus || !InOverloadResolution)
1750 ExprResult ER = ExprResult{From};
1751 auto Conv = S.CheckSingleAssignmentConstraints(ToType, ER,
1753 /*DiagnoseCFAudited=*/false,
1754 /*ConvertRHS=*/false);
1755 if (Conv != Sema::Compatible)
1758 SCS.setAllToTypes(ToType);
1759 // We need to set all three because we want this conversion to rank terribly,
1760 // and we don't know what conversions it may overlap with.
1761 SCS.First = ICK_C_Only_Conversion;
1762 SCS.Second = ICK_C_Only_Conversion;
1763 SCS.Third = ICK_C_Only_Conversion;
1768 IsTransparentUnionStandardConversion(Sema &S, Expr* From,
1770 bool InOverloadResolution,
1771 StandardConversionSequence &SCS,
1774 const RecordType *UT = ToType->getAsUnionType();
1775 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>())
1777 // The field to initialize within the transparent union.
1778 RecordDecl *UD = UT->getDecl();
1779 // It's compatible if the expression matches any of the fields.
1780 for (const auto *it : UD->fields()) {
1781 if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS,
1782 CStyle, /*ObjCWritebackConversion=*/false)) {
1783 ToType = it->getType();
1790 /// IsIntegralPromotion - Determines whether the conversion from the
1791 /// expression From (whose potentially-adjusted type is FromType) to
1792 /// ToType is an integral promotion (C++ 4.5). If so, returns true and
1793 /// sets PromotedType to the promoted type.
1794 bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) {
1795 const BuiltinType *To = ToType->getAs<BuiltinType>();
1796 // All integers are built-in.
1801 // An rvalue of type char, signed char, unsigned char, short int, or
1802 // unsigned short int can be converted to an rvalue of type int if
1803 // int can represent all the values of the source type; otherwise,
1804 // the source rvalue can be converted to an rvalue of type unsigned
1806 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() &&
1807 !FromType->isEnumeralType()) {
1808 if (// We can promote any signed, promotable integer type to an int
1809 (FromType->isSignedIntegerType() ||
1810 // We can promote any unsigned integer type whose size is
1811 // less than int to an int.
1812 (!FromType->isSignedIntegerType() &&
1813 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) {
1814 return To->getKind() == BuiltinType::Int;
1817 return To->getKind() == BuiltinType::UInt;
1820 // C++11 [conv.prom]p3:
1821 // A prvalue of an unscoped enumeration type whose underlying type is not
1822 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the
1823 // following types that can represent all the values of the enumeration
1824 // (i.e., the values in the range bmin to bmax as described in 7.2): int,
1825 // unsigned int, long int, unsigned long int, long long int, or unsigned
1826 // long long int. If none of the types in that list can represent all the
1827 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration
1828 // type can be converted to an rvalue a prvalue of the extended integer type
1829 // with lowest integer conversion rank (4.13) greater than the rank of long
1830 // long in which all the values of the enumeration can be represented. If
1831 // there are two such extended types, the signed one is chosen.
1832 // C++11 [conv.prom]p4:
1833 // A prvalue of an unscoped enumeration type whose underlying type is fixed
1834 // can be converted to a prvalue of its underlying type. Moreover, if
1835 // integral promotion can be applied to its underlying type, a prvalue of an
1836 // unscoped enumeration type whose underlying type is fixed can also be
1837 // converted to a prvalue of the promoted underlying type.
1838 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) {
1839 // C++0x 7.2p9: Note that this implicit enum to int conversion is not
1840 // provided for a scoped enumeration.
1841 if (FromEnumType->getDecl()->isScoped())
1844 // We can perform an integral promotion to the underlying type of the enum,
1845 // even if that's not the promoted type. Note that the check for promoting
1846 // the underlying type is based on the type alone, and does not consider
1847 // the bitfield-ness of the actual source expression.
1848 if (FromEnumType->getDecl()->isFixed()) {
1849 QualType Underlying = FromEnumType->getDecl()->getIntegerType();
1850 return Context.hasSameUnqualifiedType(Underlying, ToType) ||
1851 IsIntegralPromotion(nullptr, Underlying, ToType);
1854 // We have already pre-calculated the promotion type, so this is trivial.
1855 if (ToType->isIntegerType() &&
1856 isCompleteType(From->getLocStart(), FromType))
1857 return Context.hasSameUnqualifiedType(
1858 ToType, FromEnumType->getDecl()->getPromotionType());
1861 // C++0x [conv.prom]p2:
1862 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted
1863 // to an rvalue a prvalue of the first of the following types that can
1864 // represent all the values of its underlying type: int, unsigned int,
1865 // long int, unsigned long int, long long int, or unsigned long long int.
1866 // If none of the types in that list can represent all the values of its
1867 // underlying type, an rvalue a prvalue of type char16_t, char32_t,
1868 // or wchar_t can be converted to an rvalue a prvalue of its underlying
1870 if (FromType->isAnyCharacterType() && !FromType->isCharType() &&
1871 ToType->isIntegerType()) {
1872 // Determine whether the type we're converting from is signed or
1874 bool FromIsSigned = FromType->isSignedIntegerType();
1875 uint64_t FromSize = Context.getTypeSize(FromType);
1877 // The types we'll try to promote to, in the appropriate
1878 // order. Try each of these types.
1879 QualType PromoteTypes[6] = {
1880 Context.IntTy, Context.UnsignedIntTy,
1881 Context.LongTy, Context.UnsignedLongTy ,
1882 Context.LongLongTy, Context.UnsignedLongLongTy
1884 for (int Idx = 0; Idx < 6; ++Idx) {
1885 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]);
1886 if (FromSize < ToSize ||
1887 (FromSize == ToSize &&
1888 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) {
1889 // We found the type that we can promote to. If this is the
1890 // type we wanted, we have a promotion. Otherwise, no
1892 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]);
1897 // An rvalue for an integral bit-field (9.6) can be converted to an
1898 // rvalue of type int if int can represent all the values of the
1899 // bit-field; otherwise, it can be converted to unsigned int if
1900 // unsigned int can represent all the values of the bit-field. If
1901 // the bit-field is larger yet, no integral promotion applies to
1902 // it. If the bit-field has an enumerated type, it is treated as any
1903 // other value of that type for promotion purposes (C++ 4.5p3).
1904 // FIXME: We should delay checking of bit-fields until we actually perform the
1907 if (FieldDecl *MemberDecl = From->getSourceBitField()) {
1908 llvm::APSInt BitWidth;
1909 if (FromType->isIntegralType(Context) &&
1910 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) {
1911 llvm::APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned());
1912 ToSize = Context.getTypeSize(ToType);
1914 // Are we promoting to an int from a bitfield that fits in an int?
1915 if (BitWidth < ToSize ||
1916 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) {
1917 return To->getKind() == BuiltinType::Int;
1920 // Are we promoting to an unsigned int from an unsigned bitfield
1921 // that fits into an unsigned int?
1922 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) {
1923 return To->getKind() == BuiltinType::UInt;
1931 // An rvalue of type bool can be converted to an rvalue of type int,
1932 // with false becoming zero and true becoming one (C++ 4.5p4).
1933 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) {
1940 /// IsFloatingPointPromotion - Determines whether the conversion from
1941 /// FromType to ToType is a floating point promotion (C++ 4.6). If so,
1942 /// returns true and sets PromotedType to the promoted type.
1943 bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) {
1944 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>())
1945 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) {
1946 /// An rvalue of type float can be converted to an rvalue of type
1947 /// double. (C++ 4.6p1).
1948 if (FromBuiltin->getKind() == BuiltinType::Float &&
1949 ToBuiltin->getKind() == BuiltinType::Double)
1953 // When a float is promoted to double or long double, or a
1954 // double is promoted to long double [...].
1955 if (!getLangOpts().CPlusPlus &&
1956 (FromBuiltin->getKind() == BuiltinType::Float ||
1957 FromBuiltin->getKind() == BuiltinType::Double) &&
1958 (ToBuiltin->getKind() == BuiltinType::LongDouble))
1961 // Half can be promoted to float.
1962 if (!getLangOpts().NativeHalfType &&
1963 FromBuiltin->getKind() == BuiltinType::Half &&
1964 ToBuiltin->getKind() == BuiltinType::Float)
1971 /// \brief Determine if a conversion is a complex promotion.
1973 /// A complex promotion is defined as a complex -> complex conversion
1974 /// where the conversion between the underlying real types is a
1975 /// floating-point or integral promotion.
1976 bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) {
1977 const ComplexType *FromComplex = FromType->getAs<ComplexType>();
1981 const ComplexType *ToComplex = ToType->getAs<ComplexType>();
1985 return IsFloatingPointPromotion(FromComplex->getElementType(),
1986 ToComplex->getElementType()) ||
1987 IsIntegralPromotion(nullptr, FromComplex->getElementType(),
1988 ToComplex->getElementType());
1991 /// BuildSimilarlyQualifiedPointerType - In a pointer conversion from
1992 /// the pointer type FromPtr to a pointer to type ToPointee, with the
1993 /// same type qualifiers as FromPtr has on its pointee type. ToType,
1994 /// if non-empty, will be a pointer to ToType that may or may not have
1995 /// the right set of qualifiers on its pointee.
1998 BuildSimilarlyQualifiedPointerType(const Type *FromPtr,
1999 QualType ToPointee, QualType ToType,
2000 ASTContext &Context,
2001 bool StripObjCLifetime = false) {
2002 assert((FromPtr->getTypeClass() == Type::Pointer ||
2003 FromPtr->getTypeClass() == Type::ObjCObjectPointer) &&
2004 "Invalid similarly-qualified pointer type");
2006 /// Conversions to 'id' subsume cv-qualifier conversions.
2007 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType())
2008 return ToType.getUnqualifiedType();
2010 QualType CanonFromPointee
2011 = Context.getCanonicalType(FromPtr->getPointeeType());
2012 QualType CanonToPointee = Context.getCanonicalType(ToPointee);
2013 Qualifiers Quals = CanonFromPointee.getQualifiers();
2015 if (StripObjCLifetime)
2016 Quals.removeObjCLifetime();
2018 // Exact qualifier match -> return the pointer type we're converting to.
2019 if (CanonToPointee.getLocalQualifiers() == Quals) {
2020 // ToType is exactly what we need. Return it.
2021 if (!ToType.isNull())
2022 return ToType.getUnqualifiedType();
2024 // Build a pointer to ToPointee. It has the right qualifiers
2026 if (isa<ObjCObjectPointerType>(ToType))
2027 return Context.getObjCObjectPointerType(ToPointee);
2028 return Context.getPointerType(ToPointee);
2031 // Just build a canonical type that has the right qualifiers.
2032 QualType QualifiedCanonToPointee
2033 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals);
2035 if (isa<ObjCObjectPointerType>(ToType))
2036 return Context.getObjCObjectPointerType(QualifiedCanonToPointee);
2037 return Context.getPointerType(QualifiedCanonToPointee);
2040 static bool isNullPointerConstantForConversion(Expr *Expr,
2041 bool InOverloadResolution,
2042 ASTContext &Context) {
2043 // Handle value-dependent integral null pointer constants correctly.
2044 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903
2045 if (Expr->isValueDependent() && !Expr->isTypeDependent() &&
2046 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType())
2047 return !InOverloadResolution;
2049 return Expr->isNullPointerConstant(Context,
2050 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
2051 : Expr::NPC_ValueDependentIsNull);
2054 /// IsPointerConversion - Determines whether the conversion of the
2055 /// expression From, which has the (possibly adjusted) type FromType,
2056 /// can be converted to the type ToType via a pointer conversion (C++
2057 /// 4.10). If so, returns true and places the converted type (that
2058 /// might differ from ToType in its cv-qualifiers at some level) into
2061 /// This routine also supports conversions to and from block pointers
2062 /// and conversions with Objective-C's 'id', 'id<protocols...>', and
2063 /// pointers to interfaces. FIXME: Once we've determined the
2064 /// appropriate overloading rules for Objective-C, we may want to
2065 /// split the Objective-C checks into a different routine; however,
2066 /// GCC seems to consider all of these conversions to be pointer
2067 /// conversions, so for now they live here. IncompatibleObjC will be
2068 /// set if the conversion is an allowed Objective-C conversion that
2069 /// should result in a warning.
2070 bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType,
2071 bool InOverloadResolution,
2072 QualType& ConvertedType,
2073 bool &IncompatibleObjC) {
2074 IncompatibleObjC = false;
2075 if (isObjCPointerConversion(FromType, ToType, ConvertedType,
2079 // Conversion from a null pointer constant to any Objective-C pointer type.
2080 if (ToType->isObjCObjectPointerType() &&
2081 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2082 ConvertedType = ToType;
2086 // Blocks: Block pointers can be converted to void*.
2087 if (FromType->isBlockPointerType() && ToType->isPointerType() &&
2088 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) {
2089 ConvertedType = ToType;
2092 // Blocks: A null pointer constant can be converted to a block
2094 if (ToType->isBlockPointerType() &&
2095 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2096 ConvertedType = ToType;
2100 // If the left-hand-side is nullptr_t, the right side can be a null
2101 // pointer constant.
2102 if (ToType->isNullPtrType() &&
2103 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2104 ConvertedType = ToType;
2108 const PointerType* ToTypePtr = ToType->getAs<PointerType>();
2112 // A null pointer constant can be converted to a pointer type (C++ 4.10p1).
2113 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2114 ConvertedType = ToType;
2118 // Beyond this point, both types need to be pointers
2119 // , including objective-c pointers.
2120 QualType ToPointeeType = ToTypePtr->getPointeeType();
2121 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType() &&
2122 !getLangOpts().ObjCAutoRefCount) {
2123 ConvertedType = BuildSimilarlyQualifiedPointerType(
2124 FromType->getAs<ObjCObjectPointerType>(),
2129 const PointerType *FromTypePtr = FromType->getAs<PointerType>();
2133 QualType FromPointeeType = FromTypePtr->getPointeeType();
2135 // If the unqualified pointee types are the same, this can't be a
2136 // pointer conversion, so don't do all of the work below.
2137 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType))
2140 // An rvalue of type "pointer to cv T," where T is an object type,
2141 // can be converted to an rvalue of type "pointer to cv void" (C++
2143 if (FromPointeeType->isIncompleteOrObjectType() &&
2144 ToPointeeType->isVoidType()) {
2145 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2148 /*StripObjCLifetime=*/true);
2152 // MSVC allows implicit function to void* type conversion.
2153 if (getLangOpts().MSVCCompat && FromPointeeType->isFunctionType() &&
2154 ToPointeeType->isVoidType()) {
2155 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2161 // When we're overloading in C, we allow a special kind of pointer
2162 // conversion for compatible-but-not-identical pointee types.
2163 if (!getLangOpts().CPlusPlus &&
2164 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) {
2165 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2171 // C++ [conv.ptr]p3:
2173 // An rvalue of type "pointer to cv D," where D is a class type,
2174 // can be converted to an rvalue of type "pointer to cv B," where
2175 // B is a base class (clause 10) of D. If B is an inaccessible
2176 // (clause 11) or ambiguous (10.2) base class of D, a program that
2177 // necessitates this conversion is ill-formed. The result of the
2178 // conversion is a pointer to the base class sub-object of the
2179 // derived class object. The null pointer value is converted to
2180 // the null pointer value of the destination type.
2182 // Note that we do not check for ambiguity or inaccessibility
2183 // here. That is handled by CheckPointerConversion.
2184 if (getLangOpts().CPlusPlus &&
2185 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() &&
2186 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) &&
2187 IsDerivedFrom(From->getLocStart(), FromPointeeType, ToPointeeType)) {
2188 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2194 if (FromPointeeType->isVectorType() && ToPointeeType->isVectorType() &&
2195 Context.areCompatibleVectorTypes(FromPointeeType, ToPointeeType)) {
2196 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2205 /// \brief Adopt the given qualifiers for the given type.
2206 static QualType AdoptQualifiers(ASTContext &Context, QualType T, Qualifiers Qs){
2207 Qualifiers TQs = T.getQualifiers();
2209 // Check whether qualifiers already match.
2213 if (Qs.compatiblyIncludes(TQs))
2214 return Context.getQualifiedType(T, Qs);
2216 return Context.getQualifiedType(T.getUnqualifiedType(), Qs);
2219 /// isObjCPointerConversion - Determines whether this is an
2220 /// Objective-C pointer conversion. Subroutine of IsPointerConversion,
2221 /// with the same arguments and return values.
2222 bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType,
2223 QualType& ConvertedType,
2224 bool &IncompatibleObjC) {
2225 if (!getLangOpts().ObjC1)
2228 // The set of qualifiers on the type we're converting from.
2229 Qualifiers FromQualifiers = FromType.getQualifiers();
2231 // First, we handle all conversions on ObjC object pointer types.
2232 const ObjCObjectPointerType* ToObjCPtr =
2233 ToType->getAs<ObjCObjectPointerType>();
2234 const ObjCObjectPointerType *FromObjCPtr =
2235 FromType->getAs<ObjCObjectPointerType>();
2237 if (ToObjCPtr && FromObjCPtr) {
2238 // If the pointee types are the same (ignoring qualifications),
2239 // then this is not a pointer conversion.
2240 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(),
2241 FromObjCPtr->getPointeeType()))
2244 // Conversion between Objective-C pointers.
2245 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) {
2246 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType();
2247 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType();
2248 if (getLangOpts().CPlusPlus && LHS && RHS &&
2249 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs(
2250 FromObjCPtr->getPointeeType()))
2252 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2253 ToObjCPtr->getPointeeType(),
2255 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2259 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) {
2260 // Okay: this is some kind of implicit downcast of Objective-C
2261 // interfaces, which is permitted. However, we're going to
2262 // complain about it.
2263 IncompatibleObjC = true;
2264 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2265 ToObjCPtr->getPointeeType(),
2267 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2271 // Beyond this point, both types need to be C pointers or block pointers.
2272 QualType ToPointeeType;
2273 if (const PointerType *ToCPtr = ToType->getAs<PointerType>())
2274 ToPointeeType = ToCPtr->getPointeeType();
2275 else if (const BlockPointerType *ToBlockPtr =
2276 ToType->getAs<BlockPointerType>()) {
2277 // Objective C++: We're able to convert from a pointer to any object
2278 // to a block pointer type.
2279 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) {
2280 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2283 ToPointeeType = ToBlockPtr->getPointeeType();
2285 else if (FromType->getAs<BlockPointerType>() &&
2286 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) {
2287 // Objective C++: We're able to convert from a block pointer type to a
2288 // pointer to any object.
2289 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2295 QualType FromPointeeType;
2296 if (const PointerType *FromCPtr = FromType->getAs<PointerType>())
2297 FromPointeeType = FromCPtr->getPointeeType();
2298 else if (const BlockPointerType *FromBlockPtr =
2299 FromType->getAs<BlockPointerType>())
2300 FromPointeeType = FromBlockPtr->getPointeeType();
2304 // If we have pointers to pointers, recursively check whether this
2305 // is an Objective-C conversion.
2306 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() &&
2307 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2308 IncompatibleObjC)) {
2309 // We always complain about this conversion.
2310 IncompatibleObjC = true;
2311 ConvertedType = Context.getPointerType(ConvertedType);
2312 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2315 // Allow conversion of pointee being objective-c pointer to another one;
2317 if (FromPointeeType->getAs<ObjCObjectPointerType>() &&
2318 ToPointeeType->getAs<ObjCObjectPointerType>() &&
2319 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2320 IncompatibleObjC)) {
2322 ConvertedType = Context.getPointerType(ConvertedType);
2323 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2327 // If we have pointers to functions or blocks, check whether the only
2328 // differences in the argument and result types are in Objective-C
2329 // pointer conversions. If so, we permit the conversion (but
2330 // complain about it).
2331 const FunctionProtoType *FromFunctionType
2332 = FromPointeeType->getAs<FunctionProtoType>();
2333 const FunctionProtoType *ToFunctionType
2334 = ToPointeeType->getAs<FunctionProtoType>();
2335 if (FromFunctionType && ToFunctionType) {
2336 // If the function types are exactly the same, this isn't an
2337 // Objective-C pointer conversion.
2338 if (Context.getCanonicalType(FromPointeeType)
2339 == Context.getCanonicalType(ToPointeeType))
2342 // Perform the quick checks that will tell us whether these
2343 // function types are obviously different.
2344 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2345 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() ||
2346 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals())
2349 bool HasObjCConversion = false;
2350 if (Context.getCanonicalType(FromFunctionType->getReturnType()) ==
2351 Context.getCanonicalType(ToFunctionType->getReturnType())) {
2352 // Okay, the types match exactly. Nothing to do.
2353 } else if (isObjCPointerConversion(FromFunctionType->getReturnType(),
2354 ToFunctionType->getReturnType(),
2355 ConvertedType, IncompatibleObjC)) {
2356 // Okay, we have an Objective-C pointer conversion.
2357 HasObjCConversion = true;
2359 // Function types are too different. Abort.
2363 // Check argument types.
2364 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2365 ArgIdx != NumArgs; ++ArgIdx) {
2366 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2367 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2368 if (Context.getCanonicalType(FromArgType)
2369 == Context.getCanonicalType(ToArgType)) {
2370 // Okay, the types match exactly. Nothing to do.
2371 } else if (isObjCPointerConversion(FromArgType, ToArgType,
2372 ConvertedType, IncompatibleObjC)) {
2373 // Okay, we have an Objective-C pointer conversion.
2374 HasObjCConversion = true;
2376 // Argument types are too different. Abort.
2381 if (HasObjCConversion) {
2382 // We had an Objective-C conversion. Allow this pointer
2383 // conversion, but complain about it.
2384 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2385 IncompatibleObjC = true;
2393 /// \brief Determine whether this is an Objective-C writeback conversion,
2394 /// used for parameter passing when performing automatic reference counting.
2396 /// \param FromType The type we're converting form.
2398 /// \param ToType The type we're converting to.
2400 /// \param ConvertedType The type that will be produced after applying
2401 /// this conversion.
2402 bool Sema::isObjCWritebackConversion(QualType FromType, QualType ToType,
2403 QualType &ConvertedType) {
2404 if (!getLangOpts().ObjCAutoRefCount ||
2405 Context.hasSameUnqualifiedType(FromType, ToType))
2408 // Parameter must be a pointer to __autoreleasing (with no other qualifiers).
2410 if (const PointerType *ToPointer = ToType->getAs<PointerType>())
2411 ToPointee = ToPointer->getPointeeType();
2415 Qualifiers ToQuals = ToPointee.getQualifiers();
2416 if (!ToPointee->isObjCLifetimeType() ||
2417 ToQuals.getObjCLifetime() != Qualifiers::OCL_Autoreleasing ||
2418 !ToQuals.withoutObjCLifetime().empty())
2421 // Argument must be a pointer to __strong to __weak.
2422 QualType FromPointee;
2423 if (const PointerType *FromPointer = FromType->getAs<PointerType>())
2424 FromPointee = FromPointer->getPointeeType();
2428 Qualifiers FromQuals = FromPointee.getQualifiers();
2429 if (!FromPointee->isObjCLifetimeType() ||
2430 (FromQuals.getObjCLifetime() != Qualifiers::OCL_Strong &&
2431 FromQuals.getObjCLifetime() != Qualifiers::OCL_Weak))
2434 // Make sure that we have compatible qualifiers.
2435 FromQuals.setObjCLifetime(Qualifiers::OCL_Autoreleasing);
2436 if (!ToQuals.compatiblyIncludes(FromQuals))
2439 // Remove qualifiers from the pointee type we're converting from; they
2440 // aren't used in the compatibility check belong, and we'll be adding back
2441 // qualifiers (with __autoreleasing) if the compatibility check succeeds.
2442 FromPointee = FromPointee.getUnqualifiedType();
2444 // The unqualified form of the pointee types must be compatible.
2445 ToPointee = ToPointee.getUnqualifiedType();
2446 bool IncompatibleObjC;
2447 if (Context.typesAreCompatible(FromPointee, ToPointee))
2448 FromPointee = ToPointee;
2449 else if (!isObjCPointerConversion(FromPointee, ToPointee, FromPointee,
2453 /// \brief Construct the type we're converting to, which is a pointer to
2454 /// __autoreleasing pointee.
2455 FromPointee = Context.getQualifiedType(FromPointee, FromQuals);
2456 ConvertedType = Context.getPointerType(FromPointee);
2460 bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType,
2461 QualType& ConvertedType) {
2462 QualType ToPointeeType;
2463 if (const BlockPointerType *ToBlockPtr =
2464 ToType->getAs<BlockPointerType>())
2465 ToPointeeType = ToBlockPtr->getPointeeType();
2469 QualType FromPointeeType;
2470 if (const BlockPointerType *FromBlockPtr =
2471 FromType->getAs<BlockPointerType>())
2472 FromPointeeType = FromBlockPtr->getPointeeType();
2475 // We have pointer to blocks, check whether the only
2476 // differences in the argument and result types are in Objective-C
2477 // pointer conversions. If so, we permit the conversion.
2479 const FunctionProtoType *FromFunctionType
2480 = FromPointeeType->getAs<FunctionProtoType>();
2481 const FunctionProtoType *ToFunctionType
2482 = ToPointeeType->getAs<FunctionProtoType>();
2484 if (!FromFunctionType || !ToFunctionType)
2487 if (Context.hasSameType(FromPointeeType, ToPointeeType))
2490 // Perform the quick checks that will tell us whether these
2491 // function types are obviously different.
2492 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2493 FromFunctionType->isVariadic() != ToFunctionType->isVariadic())
2496 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo();
2497 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo();
2498 if (FromEInfo != ToEInfo)
2501 bool IncompatibleObjC = false;
2502 if (Context.hasSameType(FromFunctionType->getReturnType(),
2503 ToFunctionType->getReturnType())) {
2504 // Okay, the types match exactly. Nothing to do.
2506 QualType RHS = FromFunctionType->getReturnType();
2507 QualType LHS = ToFunctionType->getReturnType();
2508 if ((!getLangOpts().CPlusPlus || !RHS->isRecordType()) &&
2509 !RHS.hasQualifiers() && LHS.hasQualifiers())
2510 LHS = LHS.getUnqualifiedType();
2512 if (Context.hasSameType(RHS,LHS)) {
2514 } else if (isObjCPointerConversion(RHS, LHS,
2515 ConvertedType, IncompatibleObjC)) {
2516 if (IncompatibleObjC)
2518 // Okay, we have an Objective-C pointer conversion.
2524 // Check argument types.
2525 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2526 ArgIdx != NumArgs; ++ArgIdx) {
2527 IncompatibleObjC = false;
2528 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2529 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2530 if (Context.hasSameType(FromArgType, ToArgType)) {
2531 // Okay, the types match exactly. Nothing to do.
2532 } else if (isObjCPointerConversion(ToArgType, FromArgType,
2533 ConvertedType, IncompatibleObjC)) {
2534 if (IncompatibleObjC)
2536 // Okay, we have an Objective-C pointer conversion.
2538 // Argument types are too different. Abort.
2541 if (LangOpts.ObjCAutoRefCount &&
2542 !Context.FunctionTypesMatchOnNSConsumedAttrs(FromFunctionType,
2546 ConvertedType = ToType;
2554 ft_parameter_mismatch,
2556 ft_qualifer_mismatch
2559 /// Attempts to get the FunctionProtoType from a Type. Handles
2560 /// MemberFunctionPointers properly.
2561 static const FunctionProtoType *tryGetFunctionProtoType(QualType FromType) {
2562 if (auto *FPT = FromType->getAs<FunctionProtoType>())
2565 if (auto *MPT = FromType->getAs<MemberPointerType>())
2566 return MPT->getPointeeType()->getAs<FunctionProtoType>();
2571 /// HandleFunctionTypeMismatch - Gives diagnostic information for differeing
2572 /// function types. Catches different number of parameter, mismatch in
2573 /// parameter types, and different return types.
2574 void Sema::HandleFunctionTypeMismatch(PartialDiagnostic &PDiag,
2575 QualType FromType, QualType ToType) {
2576 // If either type is not valid, include no extra info.
2577 if (FromType.isNull() || ToType.isNull()) {
2578 PDiag << ft_default;
2582 // Get the function type from the pointers.
2583 if (FromType->isMemberPointerType() && ToType->isMemberPointerType()) {
2584 const MemberPointerType *FromMember = FromType->getAs<MemberPointerType>(),
2585 *ToMember = ToType->getAs<MemberPointerType>();
2586 if (!Context.hasSameType(FromMember->getClass(), ToMember->getClass())) {
2587 PDiag << ft_different_class << QualType(ToMember->getClass(), 0)
2588 << QualType(FromMember->getClass(), 0);
2591 FromType = FromMember->getPointeeType();
2592 ToType = ToMember->getPointeeType();
2595 if (FromType->isPointerType())
2596 FromType = FromType->getPointeeType();
2597 if (ToType->isPointerType())
2598 ToType = ToType->getPointeeType();
2600 // Remove references.
2601 FromType = FromType.getNonReferenceType();
2602 ToType = ToType.getNonReferenceType();
2604 // Don't print extra info for non-specialized template functions.
2605 if (FromType->isInstantiationDependentType() &&
2606 !FromType->getAs<TemplateSpecializationType>()) {
2607 PDiag << ft_default;
2611 // No extra info for same types.
2612 if (Context.hasSameType(FromType, ToType)) {
2613 PDiag << ft_default;
2617 const FunctionProtoType *FromFunction = tryGetFunctionProtoType(FromType),
2618 *ToFunction = tryGetFunctionProtoType(ToType);
2620 // Both types need to be function types.
2621 if (!FromFunction || !ToFunction) {
2622 PDiag << ft_default;
2626 if (FromFunction->getNumParams() != ToFunction->getNumParams()) {
2627 PDiag << ft_parameter_arity << ToFunction->getNumParams()
2628 << FromFunction->getNumParams();
2632 // Handle different parameter types.
2634 if (!FunctionParamTypesAreEqual(FromFunction, ToFunction, &ArgPos)) {
2635 PDiag << ft_parameter_mismatch << ArgPos + 1
2636 << ToFunction->getParamType(ArgPos)
2637 << FromFunction->getParamType(ArgPos);
2641 // Handle different return type.
2642 if (!Context.hasSameType(FromFunction->getReturnType(),
2643 ToFunction->getReturnType())) {
2644 PDiag << ft_return_type << ToFunction->getReturnType()
2645 << FromFunction->getReturnType();
2649 unsigned FromQuals = FromFunction->getTypeQuals(),
2650 ToQuals = ToFunction->getTypeQuals();
2651 if (FromQuals != ToQuals) {
2652 PDiag << ft_qualifer_mismatch << ToQuals << FromQuals;
2656 // Unable to find a difference, so add no extra info.
2657 PDiag << ft_default;
2660 /// FunctionParamTypesAreEqual - This routine checks two function proto types
2661 /// for equality of their argument types. Caller has already checked that
2662 /// they have same number of arguments. If the parameters are different,
2663 /// ArgPos will have the parameter index of the first different parameter.
2664 bool Sema::FunctionParamTypesAreEqual(const FunctionProtoType *OldType,
2665 const FunctionProtoType *NewType,
2667 for (FunctionProtoType::param_type_iterator O = OldType->param_type_begin(),
2668 N = NewType->param_type_begin(),
2669 E = OldType->param_type_end();
2670 O && (O != E); ++O, ++N) {
2671 if (!Context.hasSameType(O->getUnqualifiedType(),
2672 N->getUnqualifiedType())) {
2674 *ArgPos = O - OldType->param_type_begin();
2681 /// CheckPointerConversion - Check the pointer conversion from the
2682 /// expression From to the type ToType. This routine checks for
2683 /// ambiguous or inaccessible derived-to-base pointer
2684 /// conversions for which IsPointerConversion has already returned
2685 /// true. It returns true and produces a diagnostic if there was an
2686 /// error, or returns false otherwise.
2687 bool Sema::CheckPointerConversion(Expr *From, QualType ToType,
2689 CXXCastPath& BasePath,
2690 bool IgnoreBaseAccess,
2692 QualType FromType = From->getType();
2693 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess;
2697 if (Diagnose && !IsCStyleOrFunctionalCast && !FromType->isAnyPointerType() &&
2698 From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) ==
2699 Expr::NPCK_ZeroExpression) {
2700 if (Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy))
2701 DiagRuntimeBehavior(From->getExprLoc(), From,
2702 PDiag(diag::warn_impcast_bool_to_null_pointer)
2703 << ToType << From->getSourceRange());
2704 else if (!isUnevaluatedContext())
2705 Diag(From->getExprLoc(), diag::warn_non_literal_null_pointer)
2706 << ToType << From->getSourceRange();
2708 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) {
2709 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) {
2710 QualType FromPointeeType = FromPtrType->getPointeeType(),
2711 ToPointeeType = ToPtrType->getPointeeType();
2713 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() &&
2714 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) {
2715 // We must have a derived-to-base conversion. Check an
2716 // ambiguous or inaccessible conversion.
2717 unsigned InaccessibleID = 0;
2718 unsigned AmbigiousID = 0;
2720 InaccessibleID = diag::err_upcast_to_inaccessible_base;
2721 AmbigiousID = diag::err_ambiguous_derived_to_base_conv;
2723 if (CheckDerivedToBaseConversion(
2724 FromPointeeType, ToPointeeType, InaccessibleID, AmbigiousID,
2725 From->getExprLoc(), From->getSourceRange(), DeclarationName(),
2726 &BasePath, IgnoreBaseAccess))
2729 // The conversion was successful.
2730 Kind = CK_DerivedToBase;
2733 if (Diagnose && !IsCStyleOrFunctionalCast &&
2734 FromPointeeType->isFunctionType() && ToPointeeType->isVoidType()) {
2735 assert(getLangOpts().MSVCCompat &&
2736 "this should only be possible with MSVCCompat!");
2737 Diag(From->getExprLoc(), diag::ext_ms_impcast_fn_obj)
2738 << From->getSourceRange();
2741 } else if (const ObjCObjectPointerType *ToPtrType =
2742 ToType->getAs<ObjCObjectPointerType>()) {
2743 if (const ObjCObjectPointerType *FromPtrType =
2744 FromType->getAs<ObjCObjectPointerType>()) {
2745 // Objective-C++ conversions are always okay.
2746 // FIXME: We should have a different class of conversions for the
2747 // Objective-C++ implicit conversions.
2748 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType())
2750 } else if (FromType->isBlockPointerType()) {
2751 Kind = CK_BlockPointerToObjCPointerCast;
2753 Kind = CK_CPointerToObjCPointerCast;
2755 } else if (ToType->isBlockPointerType()) {
2756 if (!FromType->isBlockPointerType())
2757 Kind = CK_AnyPointerToBlockPointerCast;
2760 // We shouldn't fall into this case unless it's valid for other
2762 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull))
2763 Kind = CK_NullToPointer;
2768 /// IsMemberPointerConversion - Determines whether the conversion of the
2769 /// expression From, which has the (possibly adjusted) type FromType, can be
2770 /// converted to the type ToType via a member pointer conversion (C++ 4.11).
2771 /// If so, returns true and places the converted type (that might differ from
2772 /// ToType in its cv-qualifiers at some level) into ConvertedType.
2773 bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType,
2775 bool InOverloadResolution,
2776 QualType &ConvertedType) {
2777 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>();
2781 // A null pointer constant can be converted to a member pointer (C++ 4.11p1)
2782 if (From->isNullPointerConstant(Context,
2783 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
2784 : Expr::NPC_ValueDependentIsNull)) {
2785 ConvertedType = ToType;
2789 // Otherwise, both types have to be member pointers.
2790 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>();
2794 // A pointer to member of B can be converted to a pointer to member of D,
2795 // where D is derived from B (C++ 4.11p2).
2796 QualType FromClass(FromTypePtr->getClass(), 0);
2797 QualType ToClass(ToTypePtr->getClass(), 0);
2799 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) &&
2800 IsDerivedFrom(From->getLocStart(), ToClass, FromClass)) {
2801 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(),
2802 ToClass.getTypePtr());
2809 /// CheckMemberPointerConversion - Check the member pointer conversion from the
2810 /// expression From to the type ToType. This routine checks for ambiguous or
2811 /// virtual or inaccessible base-to-derived member pointer conversions
2812 /// for which IsMemberPointerConversion has already returned true. It returns
2813 /// true and produces a diagnostic if there was an error, or returns false
2815 bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType,
2817 CXXCastPath &BasePath,
2818 bool IgnoreBaseAccess) {
2819 QualType FromType = From->getType();
2820 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>();
2822 // This must be a null pointer to member pointer conversion
2823 assert(From->isNullPointerConstant(Context,
2824 Expr::NPC_ValueDependentIsNull) &&
2825 "Expr must be null pointer constant!");
2826 Kind = CK_NullToMemberPointer;
2830 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>();
2831 assert(ToPtrType && "No member pointer cast has a target type "
2832 "that is not a member pointer.");
2834 QualType FromClass = QualType(FromPtrType->getClass(), 0);
2835 QualType ToClass = QualType(ToPtrType->getClass(), 0);
2837 // FIXME: What about dependent types?
2838 assert(FromClass->isRecordType() && "Pointer into non-class.");
2839 assert(ToClass->isRecordType() && "Pointer into non-class.");
2841 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2842 /*DetectVirtual=*/true);
2843 bool DerivationOkay =
2844 IsDerivedFrom(From->getLocStart(), ToClass, FromClass, Paths);
2845 assert(DerivationOkay &&
2846 "Should not have been called if derivation isn't OK.");
2847 (void)DerivationOkay;
2849 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass).
2850 getUnqualifiedType())) {
2851 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
2852 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv)
2853 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange();
2857 if (const RecordType *VBase = Paths.getDetectedVirtual()) {
2858 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual)
2859 << FromClass << ToClass << QualType(VBase, 0)
2860 << From->getSourceRange();
2864 if (!IgnoreBaseAccess)
2865 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass,
2867 diag::err_downcast_from_inaccessible_base);
2869 // Must be a base to derived member conversion.
2870 BuildBasePathArray(Paths, BasePath);
2871 Kind = CK_BaseToDerivedMemberPointer;
2875 /// Determine whether the lifetime conversion between the two given
2876 /// qualifiers sets is nontrivial.
2877 static bool isNonTrivialObjCLifetimeConversion(Qualifiers FromQuals,
2878 Qualifiers ToQuals) {
2879 // Converting anything to const __unsafe_unretained is trivial.
2880 if (ToQuals.hasConst() &&
2881 ToQuals.getObjCLifetime() == Qualifiers::OCL_ExplicitNone)
2887 /// IsQualificationConversion - Determines whether the conversion from
2888 /// an rvalue of type FromType to ToType is a qualification conversion
2891 /// \param ObjCLifetimeConversion Output parameter that will be set to indicate
2892 /// when the qualification conversion involves a change in the Objective-C
2893 /// object lifetime.
2895 Sema::IsQualificationConversion(QualType FromType, QualType ToType,
2896 bool CStyle, bool &ObjCLifetimeConversion) {
2897 FromType = Context.getCanonicalType(FromType);
2898 ToType = Context.getCanonicalType(ToType);
2899 ObjCLifetimeConversion = false;
2901 // If FromType and ToType are the same type, this is not a
2902 // qualification conversion.
2903 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType())
2907 // A conversion can add cv-qualifiers at levels other than the first
2908 // in multi-level pointers, subject to the following rules: [...]
2909 bool PreviousToQualsIncludeConst = true;
2910 bool UnwrappedAnyPointer = false;
2911 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) {
2912 // Within each iteration of the loop, we check the qualifiers to
2913 // determine if this still looks like a qualification
2914 // conversion. Then, if all is well, we unwrap one more level of
2915 // pointers or pointers-to-members and do it all again
2916 // until there are no more pointers or pointers-to-members left to
2918 UnwrappedAnyPointer = true;
2920 Qualifiers FromQuals = FromType.getQualifiers();
2921 Qualifiers ToQuals = ToType.getQualifiers();
2924 // Check Objective-C lifetime conversions.
2925 if (FromQuals.getObjCLifetime() != ToQuals.getObjCLifetime() &&
2926 UnwrappedAnyPointer) {
2927 if (ToQuals.compatiblyIncludesObjCLifetime(FromQuals)) {
2928 if (isNonTrivialObjCLifetimeConversion(FromQuals, ToQuals))
2929 ObjCLifetimeConversion = true;
2930 FromQuals.removeObjCLifetime();
2931 ToQuals.removeObjCLifetime();
2933 // Qualification conversions cannot cast between different
2934 // Objective-C lifetime qualifiers.
2939 // Allow addition/removal of GC attributes but not changing GC attributes.
2940 if (FromQuals.getObjCGCAttr() != ToQuals.getObjCGCAttr() &&
2941 (!FromQuals.hasObjCGCAttr() || !ToQuals.hasObjCGCAttr())) {
2942 FromQuals.removeObjCGCAttr();
2943 ToQuals.removeObjCGCAttr();
2946 // -- for every j > 0, if const is in cv 1,j then const is in cv
2947 // 2,j, and similarly for volatile.
2948 if (!CStyle && !ToQuals.compatiblyIncludes(FromQuals))
2951 // -- if the cv 1,j and cv 2,j are different, then const is in
2952 // every cv for 0 < k < j.
2953 if (!CStyle && FromQuals.getCVRQualifiers() != ToQuals.getCVRQualifiers()
2954 && !PreviousToQualsIncludeConst)
2957 // Keep track of whether all prior cv-qualifiers in the "to" type
2959 PreviousToQualsIncludeConst
2960 = PreviousToQualsIncludeConst && ToQuals.hasConst();
2963 // We are left with FromType and ToType being the pointee types
2964 // after unwrapping the original FromType and ToType the same number
2965 // of types. If we unwrapped any pointers, and if FromType and
2966 // ToType have the same unqualified type (since we checked
2967 // qualifiers above), then this is a qualification conversion.
2968 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType);
2971 /// \brief - Determine whether this is a conversion from a scalar type to an
2974 /// If successful, updates \c SCS's second and third steps in the conversion
2975 /// sequence to finish the conversion.
2976 static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
2977 bool InOverloadResolution,
2978 StandardConversionSequence &SCS,
2980 const AtomicType *ToAtomic = ToType->getAs<AtomicType>();
2984 StandardConversionSequence InnerSCS;
2985 if (!IsStandardConversion(S, From, ToAtomic->getValueType(),
2986 InOverloadResolution, InnerSCS,
2987 CStyle, /*AllowObjCWritebackConversion=*/false))
2990 SCS.Second = InnerSCS.Second;
2991 SCS.setToType(1, InnerSCS.getToType(1));
2992 SCS.Third = InnerSCS.Third;
2993 SCS.QualificationIncludesObjCLifetime
2994 = InnerSCS.QualificationIncludesObjCLifetime;
2995 SCS.setToType(2, InnerSCS.getToType(2));
2999 static bool isFirstArgumentCompatibleWithType(ASTContext &Context,
3000 CXXConstructorDecl *Constructor,
3002 const FunctionProtoType *CtorType =
3003 Constructor->getType()->getAs<FunctionProtoType>();
3004 if (CtorType->getNumParams() > 0) {
3005 QualType FirstArg = CtorType->getParamType(0);
3006 if (Context.hasSameUnqualifiedType(Type, FirstArg.getNonReferenceType()))
3012 static OverloadingResult
3013 IsInitializerListConstructorConversion(Sema &S, Expr *From, QualType ToType,
3015 UserDefinedConversionSequence &User,
3016 OverloadCandidateSet &CandidateSet,
3017 bool AllowExplicit) {
3018 DeclContext::lookup_result R = S.LookupConstructors(To);
3019 for (DeclContext::lookup_iterator Con = R.begin(), ConEnd = R.end();
3020 Con != ConEnd; ++Con) {
3021 NamedDecl *D = *Con;
3022 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess());
3024 // Find the constructor (which may be a template).
3025 CXXConstructorDecl *Constructor = nullptr;
3026 FunctionTemplateDecl *ConstructorTmpl
3027 = dyn_cast<FunctionTemplateDecl>(D);
3028 if (ConstructorTmpl)
3030 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl());
3032 Constructor = cast<CXXConstructorDecl>(D);
3034 bool Usable = !Constructor->isInvalidDecl() &&
3035 S.isInitListConstructor(Constructor) &&
3036 (AllowExplicit || !Constructor->isExplicit());
3038 // If the first argument is (a reference to) the target type,
3039 // suppress conversions.
3040 bool SuppressUserConversions =
3041 isFirstArgumentCompatibleWithType(S.Context, Constructor, ToType);
3042 if (ConstructorTmpl)
3043 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl,
3044 /*ExplicitArgs*/ nullptr,
3046 SuppressUserConversions);
3048 S.AddOverloadCandidate(Constructor, FoundDecl,
3050 SuppressUserConversions);
3054 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3056 OverloadCandidateSet::iterator Best;
3057 switch (auto Result =
3058 CandidateSet.BestViableFunction(S, From->getLocStart(),
3062 // Record the standard conversion we used and the conversion function.
3063 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function);
3064 QualType ThisType = Constructor->getThisType(S.Context);
3065 // Initializer lists don't have conversions as such.
3066 User.Before.setAsIdentityConversion();
3067 User.HadMultipleCandidates = HadMultipleCandidates;
3068 User.ConversionFunction = Constructor;
3069 User.FoundConversionFunction = Best->FoundDecl;
3070 User.After.setAsIdentityConversion();
3071 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType());
3072 User.After.setAllToTypes(ToType);
3076 case OR_No_Viable_Function:
3077 return OR_No_Viable_Function;
3079 return OR_Ambiguous;
3082 llvm_unreachable("Invalid OverloadResult!");
3085 /// Determines whether there is a user-defined conversion sequence
3086 /// (C++ [over.ics.user]) that converts expression From to the type
3087 /// ToType. If such a conversion exists, User will contain the
3088 /// user-defined conversion sequence that performs such a conversion
3089 /// and this routine will return true. Otherwise, this routine returns
3090 /// false and User is unspecified.
3092 /// \param AllowExplicit true if the conversion should consider C++0x
3093 /// "explicit" conversion functions as well as non-explicit conversion
3094 /// functions (C++0x [class.conv.fct]p2).
3096 /// \param AllowObjCConversionOnExplicit true if the conversion should
3097 /// allow an extra Objective-C pointer conversion on uses of explicit
3098 /// constructors. Requires \c AllowExplicit to also be set.
3099 static OverloadingResult
3100 IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
3101 UserDefinedConversionSequence &User,
3102 OverloadCandidateSet &CandidateSet,
3104 bool AllowObjCConversionOnExplicit) {
3105 assert(AllowExplicit || !AllowObjCConversionOnExplicit);
3107 // Whether we will only visit constructors.
3108 bool ConstructorsOnly = false;
3110 // If the type we are conversion to is a class type, enumerate its
3112 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) {
3113 // C++ [over.match.ctor]p1:
3114 // When objects of class type are direct-initialized (8.5), or
3115 // copy-initialized from an expression of the same or a
3116 // derived class type (8.5), overload resolution selects the
3117 // constructor. [...] For copy-initialization, the candidate
3118 // functions are all the converting constructors (12.3.1) of
3119 // that class. The argument list is the expression-list within
3120 // the parentheses of the initializer.
3121 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) ||
3122 (From->getType()->getAs<RecordType>() &&
3123 S.IsDerivedFrom(From->getLocStart(), From->getType(), ToType)))
3124 ConstructorsOnly = true;
3126 if (!S.isCompleteType(From->getExprLoc(), ToType)) {
3127 // We're not going to find any constructors.
3128 } else if (CXXRecordDecl *ToRecordDecl
3129 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) {
3131 Expr **Args = &From;
3132 unsigned NumArgs = 1;
3133 bool ListInitializing = false;
3134 if (InitListExpr *InitList = dyn_cast<InitListExpr>(From)) {
3135 // But first, see if there is an init-list-constructor that will work.
3136 OverloadingResult Result = IsInitializerListConstructorConversion(
3137 S, From, ToType, ToRecordDecl, User, CandidateSet, AllowExplicit);
3138 if (Result != OR_No_Viable_Function)
3141 CandidateSet.clear();
3143 // If we're list-initializing, we pass the individual elements as
3144 // arguments, not the entire list.
3145 Args = InitList->getInits();
3146 NumArgs = InitList->getNumInits();
3147 ListInitializing = true;
3150 DeclContext::lookup_result R = S.LookupConstructors(ToRecordDecl);
3151 for (DeclContext::lookup_iterator Con = R.begin(), ConEnd = R.end();
3152 Con != ConEnd; ++Con) {
3153 NamedDecl *D = *Con;
3154 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess());
3156 // Find the constructor (which may be a template).
3157 CXXConstructorDecl *Constructor = nullptr;
3158 FunctionTemplateDecl *ConstructorTmpl
3159 = dyn_cast<FunctionTemplateDecl>(D);
3160 if (ConstructorTmpl)
3162 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl());
3164 Constructor = cast<CXXConstructorDecl>(D);
3166 bool Usable = !Constructor->isInvalidDecl();
3167 if (ListInitializing)
3168 Usable = Usable && (AllowExplicit || !Constructor->isExplicit());
3170 Usable = Usable &&Constructor->isConvertingConstructor(AllowExplicit);
3172 bool SuppressUserConversions = !ConstructorsOnly;
3173 if (SuppressUserConversions && ListInitializing) {
3174 SuppressUserConversions = false;
3176 // If the first argument is (a reference to) the target type,
3177 // suppress conversions.
3178 SuppressUserConversions = isFirstArgumentCompatibleWithType(
3179 S.Context, Constructor, ToType);
3182 if (ConstructorTmpl)
3183 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl,
3184 /*ExplicitArgs*/ nullptr,
3185 llvm::makeArrayRef(Args, NumArgs),
3186 CandidateSet, SuppressUserConversions);
3188 // Allow one user-defined conversion when user specifies a
3189 // From->ToType conversion via an static cast (c-style, etc).
3190 S.AddOverloadCandidate(Constructor, FoundDecl,
3191 llvm::makeArrayRef(Args, NumArgs),
3192 CandidateSet, SuppressUserConversions);
3198 // Enumerate conversion functions, if we're allowed to.
3199 if (ConstructorsOnly || isa<InitListExpr>(From)) {
3200 } else if (!S.isCompleteType(From->getLocStart(), From->getType())) {
3201 // No conversion functions from incomplete types.
3202 } else if (const RecordType *FromRecordType
3203 = From->getType()->getAs<RecordType>()) {
3204 if (CXXRecordDecl *FromRecordDecl
3205 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) {
3206 // Add all of the conversion functions as candidates.
3207 const auto &Conversions = FromRecordDecl->getVisibleConversionFunctions();
3208 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
3209 DeclAccessPair FoundDecl = I.getPair();
3210 NamedDecl *D = FoundDecl.getDecl();
3211 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
3212 if (isa<UsingShadowDecl>(D))
3213 D = cast<UsingShadowDecl>(D)->getTargetDecl();
3215 CXXConversionDecl *Conv;
3216 FunctionTemplateDecl *ConvTemplate;
3217 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
3218 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
3220 Conv = cast<CXXConversionDecl>(D);
3222 if (AllowExplicit || !Conv->isExplicit()) {
3224 S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl,
3225 ActingContext, From, ToType,
3227 AllowObjCConversionOnExplicit);
3229 S.AddConversionCandidate(Conv, FoundDecl, ActingContext,
3230 From, ToType, CandidateSet,
3231 AllowObjCConversionOnExplicit);
3237 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3239 OverloadCandidateSet::iterator Best;
3240 switch (auto Result = CandidateSet.BestViableFunction(S, From->getLocStart(),
3244 // Record the standard conversion we used and the conversion function.
3245 if (CXXConstructorDecl *Constructor
3246 = dyn_cast<CXXConstructorDecl>(Best->Function)) {
3247 // C++ [over.ics.user]p1:
3248 // If the user-defined conversion is specified by a
3249 // constructor (12.3.1), the initial standard conversion
3250 // sequence converts the source type to the type required by
3251 // the argument of the constructor.
3253 QualType ThisType = Constructor->getThisType(S.Context);
3254 if (isa<InitListExpr>(From)) {
3255 // Initializer lists don't have conversions as such.
3256 User.Before.setAsIdentityConversion();
3258 if (Best->Conversions[0].isEllipsis())
3259 User.EllipsisConversion = true;
3261 User.Before = Best->Conversions[0].Standard;
3262 User.EllipsisConversion = false;
3265 User.HadMultipleCandidates = HadMultipleCandidates;
3266 User.ConversionFunction = Constructor;
3267 User.FoundConversionFunction = Best->FoundDecl;
3268 User.After.setAsIdentityConversion();
3269 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType());
3270 User.After.setAllToTypes(ToType);
3273 if (CXXConversionDecl *Conversion
3274 = dyn_cast<CXXConversionDecl>(Best->Function)) {
3275 // C++ [over.ics.user]p1:
3277 // [...] If the user-defined conversion is specified by a
3278 // conversion function (12.3.2), the initial standard
3279 // conversion sequence converts the source type to the
3280 // implicit object parameter of the conversion function.
3281 User.Before = Best->Conversions[0].Standard;
3282 User.HadMultipleCandidates = HadMultipleCandidates;
3283 User.ConversionFunction = Conversion;
3284 User.FoundConversionFunction = Best->FoundDecl;
3285 User.EllipsisConversion = false;
3287 // C++ [over.ics.user]p2:
3288 // The second standard conversion sequence converts the
3289 // result of the user-defined conversion to the target type
3290 // for the sequence. Since an implicit conversion sequence
3291 // is an initialization, the special rules for
3292 // initialization by user-defined conversion apply when
3293 // selecting the best user-defined conversion for a
3294 // user-defined conversion sequence (see 13.3.3 and
3296 User.After = Best->FinalConversion;
3299 llvm_unreachable("Not a constructor or conversion function?");
3301 case OR_No_Viable_Function:
3302 return OR_No_Viable_Function;
3305 return OR_Ambiguous;
3308 llvm_unreachable("Invalid OverloadResult!");
3312 Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) {
3313 ImplicitConversionSequence ICS;
3314 OverloadCandidateSet CandidateSet(From->getExprLoc(),
3315 OverloadCandidateSet::CSK_Normal);
3316 OverloadingResult OvResult =
3317 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined,
3318 CandidateSet, false, false);
3319 if (OvResult == OR_Ambiguous)
3320 Diag(From->getLocStart(), diag::err_typecheck_ambiguous_condition)
3321 << From->getType() << ToType << From->getSourceRange();
3322 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) {
3323 if (!RequireCompleteType(From->getLocStart(), ToType,
3324 diag::err_typecheck_nonviable_condition_incomplete,
3325 From->getType(), From->getSourceRange()))
3326 Diag(From->getLocStart(), diag::err_typecheck_nonviable_condition)
3327 << false << From->getType() << From->getSourceRange() << ToType;
3330 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, From);
3334 /// \brief Compare the user-defined conversion functions or constructors
3335 /// of two user-defined conversion sequences to determine whether any ordering
3337 static ImplicitConversionSequence::CompareKind
3338 compareConversionFunctions(Sema &S, FunctionDecl *Function1,
3339 FunctionDecl *Function2) {
3340 if (!S.getLangOpts().ObjC1 || !S.getLangOpts().CPlusPlus11)
3341 return ImplicitConversionSequence::Indistinguishable;
3344 // If both conversion functions are implicitly-declared conversions from
3345 // a lambda closure type to a function pointer and a block pointer,
3346 // respectively, always prefer the conversion to a function pointer,
3347 // because the function pointer is more lightweight and is more likely
3348 // to keep code working.
3349 CXXConversionDecl *Conv1 = dyn_cast_or_null<CXXConversionDecl>(Function1);
3351 return ImplicitConversionSequence::Indistinguishable;
3353 CXXConversionDecl *Conv2 = dyn_cast<CXXConversionDecl>(Function2);
3355 return ImplicitConversionSequence::Indistinguishable;
3357 if (Conv1->getParent()->isLambda() && Conv2->getParent()->isLambda()) {
3358 bool Block1 = Conv1->getConversionType()->isBlockPointerType();
3359 bool Block2 = Conv2->getConversionType()->isBlockPointerType();
3360 if (Block1 != Block2)
3361 return Block1 ? ImplicitConversionSequence::Worse
3362 : ImplicitConversionSequence::Better;
3365 return ImplicitConversionSequence::Indistinguishable;
3368 static bool hasDeprecatedStringLiteralToCharPtrConversion(
3369 const ImplicitConversionSequence &ICS) {
3370 return (ICS.isStandard() && ICS.Standard.DeprecatedStringLiteralToCharPtr) ||
3371 (ICS.isUserDefined() &&
3372 ICS.UserDefined.Before.DeprecatedStringLiteralToCharPtr);
3375 /// CompareImplicitConversionSequences - Compare two implicit
3376 /// conversion sequences to determine whether one is better than the
3377 /// other or if they are indistinguishable (C++ 13.3.3.2).
3378 static ImplicitConversionSequence::CompareKind
3379 CompareImplicitConversionSequences(Sema &S, SourceLocation Loc,
3380 const ImplicitConversionSequence& ICS1,
3381 const ImplicitConversionSequence& ICS2)
3383 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit
3384 // conversion sequences (as defined in 13.3.3.1)
3385 // -- a standard conversion sequence (13.3.3.1.1) is a better
3386 // conversion sequence than a user-defined conversion sequence or
3387 // an ellipsis conversion sequence, and
3388 // -- a user-defined conversion sequence (13.3.3.1.2) is a better
3389 // conversion sequence than an ellipsis conversion sequence
3392 // C++0x [over.best.ics]p10:
3393 // For the purpose of ranking implicit conversion sequences as
3394 // described in 13.3.3.2, the ambiguous conversion sequence is
3395 // treated as a user-defined sequence that is indistinguishable
3396 // from any other user-defined conversion sequence.
3398 // String literal to 'char *' conversion has been deprecated in C++03. It has
3399 // been removed from C++11. We still accept this conversion, if it happens at
3400 // the best viable function. Otherwise, this conversion is considered worse
3401 // than ellipsis conversion. Consider this as an extension; this is not in the
3402 // standard. For example:
3404 // int &f(...); // #1
3405 // void f(char*); // #2
3406 // void g() { int &r = f("foo"); }
3408 // In C++03, we pick #2 as the best viable function.
3409 // In C++11, we pick #1 as the best viable function, because ellipsis
3410 // conversion is better than string-literal to char* conversion (since there
3411 // is no such conversion in C++11). If there was no #1 at all or #1 couldn't
3412 // convert arguments, #2 would be the best viable function in C++11.
3413 // If the best viable function has this conversion, a warning will be issued
3414 // in C++03, or an ExtWarn (+SFINAE failure) will be issued in C++11.
3416 if (S.getLangOpts().CPlusPlus11 && !S.getLangOpts().WritableStrings &&
3417 hasDeprecatedStringLiteralToCharPtrConversion(ICS1) !=
3418 hasDeprecatedStringLiteralToCharPtrConversion(ICS2))
3419 return hasDeprecatedStringLiteralToCharPtrConversion(ICS1)
3420 ? ImplicitConversionSequence::Worse
3421 : ImplicitConversionSequence::Better;
3423 if (ICS1.getKindRank() < ICS2.getKindRank())
3424 return ImplicitConversionSequence::Better;
3425 if (ICS2.getKindRank() < ICS1.getKindRank())
3426 return ImplicitConversionSequence::Worse;
3428 // The following checks require both conversion sequences to be of
3430 if (ICS1.getKind() != ICS2.getKind())
3431 return ImplicitConversionSequence::Indistinguishable;
3433 ImplicitConversionSequence::CompareKind Result =
3434 ImplicitConversionSequence::Indistinguishable;
3436 // Two implicit conversion sequences of the same form are
3437 // indistinguishable conversion sequences unless one of the
3438 // following rules apply: (C++ 13.3.3.2p3):
3440 // List-initialization sequence L1 is a better conversion sequence than
3441 // list-initialization sequence L2 if:
3442 // - L1 converts to std::initializer_list<X> for some X and L2 does not, or,
3444 // - L1 converts to type "array of N1 T", L2 converts to type "array of N2 T",
3445 // and N1 is smaller than N2.,
3446 // even if one of the other rules in this paragraph would otherwise apply.
3447 if (!ICS1.isBad()) {
3448 if (ICS1.isStdInitializerListElement() &&
3449 !ICS2.isStdInitializerListElement())
3450 return ImplicitConversionSequence::Better;
3451 if (!ICS1.isStdInitializerListElement() &&
3452 ICS2.isStdInitializerListElement())
3453 return ImplicitConversionSequence::Worse;
3456 if (ICS1.isStandard())
3457 // Standard conversion sequence S1 is a better conversion sequence than
3458 // standard conversion sequence S2 if [...]
3459 Result = CompareStandardConversionSequences(S, Loc,
3460 ICS1.Standard, ICS2.Standard);
3461 else if (ICS1.isUserDefined()) {
3462 // User-defined conversion sequence U1 is a better conversion
3463 // sequence than another user-defined conversion sequence U2 if
3464 // they contain the same user-defined conversion function or
3465 // constructor and if the second standard conversion sequence of
3466 // U1 is better than the second standard conversion sequence of
3467 // U2 (C++ 13.3.3.2p3).
3468 if (ICS1.UserDefined.ConversionFunction ==
3469 ICS2.UserDefined.ConversionFunction)
3470 Result = CompareStandardConversionSequences(S, Loc,
3471 ICS1.UserDefined.After,
3472 ICS2.UserDefined.After);
3474 Result = compareConversionFunctions(S,
3475 ICS1.UserDefined.ConversionFunction,
3476 ICS2.UserDefined.ConversionFunction);
3482 static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) {
3483 while (Context.UnwrapSimilarPointerTypes(T1, T2)) {
3485 T1 = Context.getUnqualifiedArrayType(T1, Quals);
3486 T2 = Context.getUnqualifiedArrayType(T2, Quals);
3489 return Context.hasSameUnqualifiedType(T1, T2);
3492 // Per 13.3.3.2p3, compare the given standard conversion sequences to
3493 // determine if one is a proper subset of the other.
3494 static ImplicitConversionSequence::CompareKind
3495 compareStandardConversionSubsets(ASTContext &Context,
3496 const StandardConversionSequence& SCS1,
3497 const StandardConversionSequence& SCS2) {
3498 ImplicitConversionSequence::CompareKind Result
3499 = ImplicitConversionSequence::Indistinguishable;
3501 // the identity conversion sequence is considered to be a subsequence of
3502 // any non-identity conversion sequence
3503 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion())
3504 return ImplicitConversionSequence::Better;
3505 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion())
3506 return ImplicitConversionSequence::Worse;
3508 if (SCS1.Second != SCS2.Second) {
3509 if (SCS1.Second == ICK_Identity)
3510 Result = ImplicitConversionSequence::Better;
3511 else if (SCS2.Second == ICK_Identity)
3512 Result = ImplicitConversionSequence::Worse;
3514 return ImplicitConversionSequence::Indistinguishable;
3515 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1)))
3516 return ImplicitConversionSequence::Indistinguishable;
3518 if (SCS1.Third == SCS2.Third) {
3519 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result
3520 : ImplicitConversionSequence::Indistinguishable;
3523 if (SCS1.Third == ICK_Identity)
3524 return Result == ImplicitConversionSequence::Worse
3525 ? ImplicitConversionSequence::Indistinguishable
3526 : ImplicitConversionSequence::Better;
3528 if (SCS2.Third == ICK_Identity)
3529 return Result == ImplicitConversionSequence::Better
3530 ? ImplicitConversionSequence::Indistinguishable
3531 : ImplicitConversionSequence::Worse;
3533 return ImplicitConversionSequence::Indistinguishable;
3536 /// \brief Determine whether one of the given reference bindings is better
3537 /// than the other based on what kind of bindings they are.
3539 isBetterReferenceBindingKind(const StandardConversionSequence &SCS1,
3540 const StandardConversionSequence &SCS2) {
3541 // C++0x [over.ics.rank]p3b4:
3542 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an
3543 // implicit object parameter of a non-static member function declared
3544 // without a ref-qualifier, and *either* S1 binds an rvalue reference
3545 // to an rvalue and S2 binds an lvalue reference *or S1 binds an
3546 // lvalue reference to a function lvalue and S2 binds an rvalue
3549 // FIXME: Rvalue references. We're going rogue with the above edits,
3550 // because the semantics in the current C++0x working paper (N3225 at the
3551 // time of this writing) break the standard definition of std::forward
3552 // and std::reference_wrapper when dealing with references to functions.
3553 // Proposed wording changes submitted to CWG for consideration.
3554 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier ||
3555 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier)
3558 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue &&
3559 SCS2.IsLvalueReference) ||
3560 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue &&
3561 !SCS2.IsLvalueReference && SCS2.BindsToFunctionLvalue);
3564 /// CompareStandardConversionSequences - Compare two standard
3565 /// conversion sequences to determine whether one is better than the
3566 /// other or if they are indistinguishable (C++ 13.3.3.2p3).
3567 static ImplicitConversionSequence::CompareKind
3568 CompareStandardConversionSequences(Sema &S, SourceLocation Loc,
3569 const StandardConversionSequence& SCS1,
3570 const StandardConversionSequence& SCS2)
3572 // Standard conversion sequence S1 is a better conversion sequence
3573 // than standard conversion sequence S2 if (C++ 13.3.3.2p3):
3575 // -- S1 is a proper subsequence of S2 (comparing the conversion
3576 // sequences in the canonical form defined by 13.3.3.1.1,
3577 // excluding any Lvalue Transformation; the identity conversion
3578 // sequence is considered to be a subsequence of any
3579 // non-identity conversion sequence) or, if not that,
3580 if (ImplicitConversionSequence::CompareKind CK
3581 = compareStandardConversionSubsets(S.Context, SCS1, SCS2))
3584 // -- the rank of S1 is better than the rank of S2 (by the rules
3585 // defined below), or, if not that,
3586 ImplicitConversionRank Rank1 = SCS1.getRank();
3587 ImplicitConversionRank Rank2 = SCS2.getRank();
3589 return ImplicitConversionSequence::Better;
3590 else if (Rank2 < Rank1)
3591 return ImplicitConversionSequence::Worse;
3593 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank
3594 // are indistinguishable unless one of the following rules
3597 // A conversion that is not a conversion of a pointer, or
3598 // pointer to member, to bool is better than another conversion
3599 // that is such a conversion.
3600 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool())
3601 return SCS2.isPointerConversionToBool()
3602 ? ImplicitConversionSequence::Better
3603 : ImplicitConversionSequence::Worse;
3605 // C++ [over.ics.rank]p4b2:
3607 // If class B is derived directly or indirectly from class A,
3608 // conversion of B* to A* is better than conversion of B* to
3609 // void*, and conversion of A* to void* is better than conversion
3611 bool SCS1ConvertsToVoid
3612 = SCS1.isPointerConversionToVoidPointer(S.Context);
3613 bool SCS2ConvertsToVoid
3614 = SCS2.isPointerConversionToVoidPointer(S.Context);
3615 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) {
3616 // Exactly one of the conversion sequences is a conversion to
3617 // a void pointer; it's the worse conversion.
3618 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better
3619 : ImplicitConversionSequence::Worse;
3620 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) {
3621 // Neither conversion sequence converts to a void pointer; compare
3622 // their derived-to-base conversions.
3623 if (ImplicitConversionSequence::CompareKind DerivedCK
3624 = CompareDerivedToBaseConversions(S, Loc, SCS1, SCS2))
3626 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid &&
3627 !S.Context.hasSameType(SCS1.getFromType(), SCS2.getFromType())) {
3628 // Both conversion sequences are conversions to void
3629 // pointers. Compare the source types to determine if there's an
3630 // inheritance relationship in their sources.
3631 QualType FromType1 = SCS1.getFromType();
3632 QualType FromType2 = SCS2.getFromType();
3634 // Adjust the types we're converting from via the array-to-pointer
3635 // conversion, if we need to.
3636 if (SCS1.First == ICK_Array_To_Pointer)
3637 FromType1 = S.Context.getArrayDecayedType(FromType1);
3638 if (SCS2.First == ICK_Array_To_Pointer)
3639 FromType2 = S.Context.getArrayDecayedType(FromType2);
3641 QualType FromPointee1 = FromType1->getPointeeType().getUnqualifiedType();
3642 QualType FromPointee2 = FromType2->getPointeeType().getUnqualifiedType();
3644 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
3645 return ImplicitConversionSequence::Better;
3646 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
3647 return ImplicitConversionSequence::Worse;
3649 // Objective-C++: If one interface is more specific than the
3650 // other, it is the better one.
3651 const ObjCObjectPointerType* FromObjCPtr1
3652 = FromType1->getAs<ObjCObjectPointerType>();
3653 const ObjCObjectPointerType* FromObjCPtr2
3654 = FromType2->getAs<ObjCObjectPointerType>();
3655 if (FromObjCPtr1 && FromObjCPtr2) {
3656 bool AssignLeft = S.Context.canAssignObjCInterfaces(FromObjCPtr1,
3658 bool AssignRight = S.Context.canAssignObjCInterfaces(FromObjCPtr2,
3660 if (AssignLeft != AssignRight) {
3661 return AssignLeft? ImplicitConversionSequence::Better
3662 : ImplicitConversionSequence::Worse;
3667 // Compare based on qualification conversions (C++ 13.3.3.2p3,
3669 if (ImplicitConversionSequence::CompareKind QualCK
3670 = CompareQualificationConversions(S, SCS1, SCS2))
3673 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) {
3674 // Check for a better reference binding based on the kind of bindings.
3675 if (isBetterReferenceBindingKind(SCS1, SCS2))
3676 return ImplicitConversionSequence::Better;
3677 else if (isBetterReferenceBindingKind(SCS2, SCS1))
3678 return ImplicitConversionSequence::Worse;
3680 // C++ [over.ics.rank]p3b4:
3681 // -- S1 and S2 are reference bindings (8.5.3), and the types to
3682 // which the references refer are the same type except for
3683 // top-level cv-qualifiers, and the type to which the reference
3684 // initialized by S2 refers is more cv-qualified than the type
3685 // to which the reference initialized by S1 refers.
3686 QualType T1 = SCS1.getToType(2);
3687 QualType T2 = SCS2.getToType(2);
3688 T1 = S.Context.getCanonicalType(T1);
3689 T2 = S.Context.getCanonicalType(T2);
3690 Qualifiers T1Quals, T2Quals;
3691 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
3692 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
3693 if (UnqualT1 == UnqualT2) {
3694 // Objective-C++ ARC: If the references refer to objects with different
3695 // lifetimes, prefer bindings that don't change lifetime.
3696 if (SCS1.ObjCLifetimeConversionBinding !=
3697 SCS2.ObjCLifetimeConversionBinding) {
3698 return SCS1.ObjCLifetimeConversionBinding
3699 ? ImplicitConversionSequence::Worse
3700 : ImplicitConversionSequence::Better;
3703 // If the type is an array type, promote the element qualifiers to the
3704 // type for comparison.
3705 if (isa<ArrayType>(T1) && T1Quals)
3706 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals);
3707 if (isa<ArrayType>(T2) && T2Quals)
3708 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals);
3709 if (T2.isMoreQualifiedThan(T1))
3710 return ImplicitConversionSequence::Better;
3711 else if (T1.isMoreQualifiedThan(T2))
3712 return ImplicitConversionSequence::Worse;
3716 // In Microsoft mode, prefer an integral conversion to a
3717 // floating-to-integral conversion if the integral conversion
3718 // is between types of the same size.
3726 // Here, MSVC will call f(int) instead of generating a compile error
3727 // as clang will do in standard mode.
3728 if (S.getLangOpts().MSVCCompat && SCS1.Second == ICK_Integral_Conversion &&
3729 SCS2.Second == ICK_Floating_Integral &&
3730 S.Context.getTypeSize(SCS1.getFromType()) ==
3731 S.Context.getTypeSize(SCS1.getToType(2)))
3732 return ImplicitConversionSequence::Better;
3734 return ImplicitConversionSequence::Indistinguishable;
3737 /// CompareQualificationConversions - Compares two standard conversion
3738 /// sequences to determine whether they can be ranked based on their
3739 /// qualification conversions (C++ 13.3.3.2p3 bullet 3).
3740 static ImplicitConversionSequence::CompareKind
3741 CompareQualificationConversions(Sema &S,
3742 const StandardConversionSequence& SCS1,
3743 const StandardConversionSequence& SCS2) {
3745 // -- S1 and S2 differ only in their qualification conversion and
3746 // yield similar types T1 and T2 (C++ 4.4), respectively, and the
3747 // cv-qualification signature of type T1 is a proper subset of
3748 // the cv-qualification signature of type T2, and S1 is not the
3749 // deprecated string literal array-to-pointer conversion (4.2).
3750 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second ||
3751 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification)
3752 return ImplicitConversionSequence::Indistinguishable;
3754 // FIXME: the example in the standard doesn't use a qualification
3756 QualType T1 = SCS1.getToType(2);
3757 QualType T2 = SCS2.getToType(2);
3758 T1 = S.Context.getCanonicalType(T1);
3759 T2 = S.Context.getCanonicalType(T2);
3760 Qualifiers T1Quals, T2Quals;
3761 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
3762 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
3764 // If the types are the same, we won't learn anything by unwrapped
3766 if (UnqualT1 == UnqualT2)
3767 return ImplicitConversionSequence::Indistinguishable;
3769 // If the type is an array type, promote the element qualifiers to the type
3771 if (isa<ArrayType>(T1) && T1Quals)
3772 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals);
3773 if (isa<ArrayType>(T2) && T2Quals)
3774 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals);
3776 ImplicitConversionSequence::CompareKind Result
3777 = ImplicitConversionSequence::Indistinguishable;
3779 // Objective-C++ ARC:
3780 // Prefer qualification conversions not involving a change in lifetime
3781 // to qualification conversions that do not change lifetime.
3782 if (SCS1.QualificationIncludesObjCLifetime !=
3783 SCS2.QualificationIncludesObjCLifetime) {
3784 Result = SCS1.QualificationIncludesObjCLifetime
3785 ? ImplicitConversionSequence::Worse
3786 : ImplicitConversionSequence::Better;
3789 while (S.Context.UnwrapSimilarPointerTypes(T1, T2)) {
3790 // Within each iteration of the loop, we check the qualifiers to
3791 // determine if this still looks like a qualification
3792 // conversion. Then, if all is well, we unwrap one more level of
3793 // pointers or pointers-to-members and do it all again
3794 // until there are no more pointers or pointers-to-members left
3795 // to unwrap. This essentially mimics what
3796 // IsQualificationConversion does, but here we're checking for a
3797 // strict subset of qualifiers.
3798 if (T1.getCVRQualifiers() == T2.getCVRQualifiers())
3799 // The qualifiers are the same, so this doesn't tell us anything
3800 // about how the sequences rank.
3802 else if (T2.isMoreQualifiedThan(T1)) {
3803 // T1 has fewer qualifiers, so it could be the better sequence.
3804 if (Result == ImplicitConversionSequence::Worse)
3805 // Neither has qualifiers that are a subset of the other's
3807 return ImplicitConversionSequence::Indistinguishable;
3809 Result = ImplicitConversionSequence::Better;
3810 } else if (T1.isMoreQualifiedThan(T2)) {
3811 // T2 has fewer qualifiers, so it could be the better sequence.
3812 if (Result == ImplicitConversionSequence::Better)
3813 // Neither has qualifiers that are a subset of the other's
3815 return ImplicitConversionSequence::Indistinguishable;
3817 Result = ImplicitConversionSequence::Worse;
3819 // Qualifiers are disjoint.
3820 return ImplicitConversionSequence::Indistinguishable;
3823 // If the types after this point are equivalent, we're done.
3824 if (S.Context.hasSameUnqualifiedType(T1, T2))
3828 // Check that the winning standard conversion sequence isn't using
3829 // the deprecated string literal array to pointer conversion.
3831 case ImplicitConversionSequence::Better:
3832 if (SCS1.DeprecatedStringLiteralToCharPtr)
3833 Result = ImplicitConversionSequence::Indistinguishable;
3836 case ImplicitConversionSequence::Indistinguishable:
3839 case ImplicitConversionSequence::Worse:
3840 if (SCS2.DeprecatedStringLiteralToCharPtr)
3841 Result = ImplicitConversionSequence::Indistinguishable;
3848 /// CompareDerivedToBaseConversions - Compares two standard conversion
3849 /// sequences to determine whether they can be ranked based on their
3850 /// various kinds of derived-to-base conversions (C++
3851 /// [over.ics.rank]p4b3). As part of these checks, we also look at
3852 /// conversions between Objective-C interface types.
3853 static ImplicitConversionSequence::CompareKind
3854 CompareDerivedToBaseConversions(Sema &S, SourceLocation Loc,
3855 const StandardConversionSequence& SCS1,
3856 const StandardConversionSequence& SCS2) {
3857 QualType FromType1 = SCS1.getFromType();
3858 QualType ToType1 = SCS1.getToType(1);
3859 QualType FromType2 = SCS2.getFromType();
3860 QualType ToType2 = SCS2.getToType(1);
3862 // Adjust the types we're converting from via the array-to-pointer
3863 // conversion, if we need to.
3864 if (SCS1.First == ICK_Array_To_Pointer)
3865 FromType1 = S.Context.getArrayDecayedType(FromType1);
3866 if (SCS2.First == ICK_Array_To_Pointer)
3867 FromType2 = S.Context.getArrayDecayedType(FromType2);
3869 // Canonicalize all of the types.
3870 FromType1 = S.Context.getCanonicalType(FromType1);
3871 ToType1 = S.Context.getCanonicalType(ToType1);
3872 FromType2 = S.Context.getCanonicalType(FromType2);
3873 ToType2 = S.Context.getCanonicalType(ToType2);
3875 // C++ [over.ics.rank]p4b3:
3877 // If class B is derived directly or indirectly from class A and
3878 // class C is derived directly or indirectly from B,
3880 // Compare based on pointer conversions.
3881 if (SCS1.Second == ICK_Pointer_Conversion &&
3882 SCS2.Second == ICK_Pointer_Conversion &&
3883 /*FIXME: Remove if Objective-C id conversions get their own rank*/
3884 FromType1->isPointerType() && FromType2->isPointerType() &&
3885 ToType1->isPointerType() && ToType2->isPointerType()) {
3886 QualType FromPointee1
3887 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
3889 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
3890 QualType FromPointee2
3891 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
3893 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
3895 // -- conversion of C* to B* is better than conversion of C* to A*,
3896 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
3897 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
3898 return ImplicitConversionSequence::Better;
3899 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
3900 return ImplicitConversionSequence::Worse;
3903 // -- conversion of B* to A* is better than conversion of C* to A*,
3904 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) {
3905 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
3906 return ImplicitConversionSequence::Better;
3907 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
3908 return ImplicitConversionSequence::Worse;
3910 } else if (SCS1.Second == ICK_Pointer_Conversion &&
3911 SCS2.Second == ICK_Pointer_Conversion) {
3912 const ObjCObjectPointerType *FromPtr1
3913 = FromType1->getAs<ObjCObjectPointerType>();
3914 const ObjCObjectPointerType *FromPtr2
3915 = FromType2->getAs<ObjCObjectPointerType>();
3916 const ObjCObjectPointerType *ToPtr1
3917 = ToType1->getAs<ObjCObjectPointerType>();
3918 const ObjCObjectPointerType *ToPtr2
3919 = ToType2->getAs<ObjCObjectPointerType>();
3921 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) {
3922 // Apply the same conversion ranking rules for Objective-C pointer types
3923 // that we do for C++ pointers to class types. However, we employ the
3924 // Objective-C pseudo-subtyping relationship used for assignment of
3925 // Objective-C pointer types.
3927 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2);
3928 bool FromAssignRight
3929 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1);
3931 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2);
3933 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1);
3935 // A conversion to an a non-id object pointer type or qualified 'id'
3936 // type is better than a conversion to 'id'.
3937 if (ToPtr1->isObjCIdType() &&
3938 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl()))
3939 return ImplicitConversionSequence::Worse;
3940 if (ToPtr2->isObjCIdType() &&
3941 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl()))
3942 return ImplicitConversionSequence::Better;
3944 // A conversion to a non-id object pointer type is better than a
3945 // conversion to a qualified 'id' type
3946 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl())
3947 return ImplicitConversionSequence::Worse;
3948 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl())
3949 return ImplicitConversionSequence::Better;
3951 // A conversion to an a non-Class object pointer type or qualified 'Class'
3952 // type is better than a conversion to 'Class'.
3953 if (ToPtr1->isObjCClassType() &&
3954 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl()))
3955 return ImplicitConversionSequence::Worse;
3956 if (ToPtr2->isObjCClassType() &&
3957 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl()))
3958 return ImplicitConversionSequence::Better;
3960 // A conversion to a non-Class object pointer type is better than a
3961 // conversion to a qualified 'Class' type.
3962 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl())
3963 return ImplicitConversionSequence::Worse;
3964 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl())
3965 return ImplicitConversionSequence::Better;
3967 // -- "conversion of C* to B* is better than conversion of C* to A*,"
3968 if (S.Context.hasSameType(FromType1, FromType2) &&
3969 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() &&
3970 (ToAssignLeft != ToAssignRight))
3971 return ToAssignLeft? ImplicitConversionSequence::Worse
3972 : ImplicitConversionSequence::Better;
3974 // -- "conversion of B* to A* is better than conversion of C* to A*,"
3975 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) &&
3976 (FromAssignLeft != FromAssignRight))
3977 return FromAssignLeft? ImplicitConversionSequence::Better
3978 : ImplicitConversionSequence::Worse;
3982 // Ranking of member-pointer types.
3983 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member &&
3984 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() &&
3985 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) {
3986 const MemberPointerType * FromMemPointer1 =
3987 FromType1->getAs<MemberPointerType>();
3988 const MemberPointerType * ToMemPointer1 =
3989 ToType1->getAs<MemberPointerType>();
3990 const MemberPointerType * FromMemPointer2 =
3991 FromType2->getAs<MemberPointerType>();
3992 const MemberPointerType * ToMemPointer2 =
3993 ToType2->getAs<MemberPointerType>();
3994 const Type *FromPointeeType1 = FromMemPointer1->getClass();
3995 const Type *ToPointeeType1 = ToMemPointer1->getClass();
3996 const Type *FromPointeeType2 = FromMemPointer2->getClass();
3997 const Type *ToPointeeType2 = ToMemPointer2->getClass();
3998 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType();
3999 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType();
4000 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType();
4001 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType();
4002 // conversion of A::* to B::* is better than conversion of A::* to C::*,
4003 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
4004 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
4005 return ImplicitConversionSequence::Worse;
4006 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
4007 return ImplicitConversionSequence::Better;
4009 // conversion of B::* to C::* is better than conversion of A::* to C::*
4010 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) {
4011 if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
4012 return ImplicitConversionSequence::Better;
4013 else if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
4014 return ImplicitConversionSequence::Worse;
4018 if (SCS1.Second == ICK_Derived_To_Base) {
4019 // -- conversion of C to B is better than conversion of C to A,
4020 // -- binding of an expression of type C to a reference of type
4021 // B& is better than binding an expression of type C to a
4022 // reference of type A&,
4023 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4024 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4025 if (S.IsDerivedFrom(Loc, ToType1, ToType2))
4026 return ImplicitConversionSequence::Better;
4027 else if (S.IsDerivedFrom(Loc, ToType2, ToType1))
4028 return ImplicitConversionSequence::Worse;
4031 // -- conversion of B to A is better than conversion of C to A.
4032 // -- binding of an expression of type B to a reference of type
4033 // A& is better than binding an expression of type C to a
4034 // reference of type A&,
4035 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4036 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4037 if (S.IsDerivedFrom(Loc, FromType2, FromType1))
4038 return ImplicitConversionSequence::Better;
4039 else if (S.IsDerivedFrom(Loc, FromType1, FromType2))
4040 return ImplicitConversionSequence::Worse;
4044 return ImplicitConversionSequence::Indistinguishable;
4047 /// \brief Determine whether the given type is valid, e.g., it is not an invalid
4049 static bool isTypeValid(QualType T) {
4050 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl())
4051 return !Record->isInvalidDecl();
4056 /// CompareReferenceRelationship - Compare the two types T1 and T2 to
4057 /// determine whether they are reference-related,
4058 /// reference-compatible, reference-compatible with added
4059 /// qualification, or incompatible, for use in C++ initialization by
4060 /// reference (C++ [dcl.ref.init]p4). Neither type can be a reference
4061 /// type, and the first type (T1) is the pointee type of the reference
4062 /// type being initialized.
4063 Sema::ReferenceCompareResult
4064 Sema::CompareReferenceRelationship(SourceLocation Loc,
4065 QualType OrigT1, QualType OrigT2,
4066 bool &DerivedToBase,
4067 bool &ObjCConversion,
4068 bool &ObjCLifetimeConversion) {
4069 assert(!OrigT1->isReferenceType() &&
4070 "T1 must be the pointee type of the reference type");
4071 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type");
4073 QualType T1 = Context.getCanonicalType(OrigT1);
4074 QualType T2 = Context.getCanonicalType(OrigT2);
4075 Qualifiers T1Quals, T2Quals;
4076 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals);
4077 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals);
4079 // C++ [dcl.init.ref]p4:
4080 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is
4081 // reference-related to "cv2 T2" if T1 is the same type as T2, or
4082 // T1 is a base class of T2.
4083 DerivedToBase = false;
4084 ObjCConversion = false;
4085 ObjCLifetimeConversion = false;
4086 if (UnqualT1 == UnqualT2) {
4088 } else if (isCompleteType(Loc, OrigT2) &&
4089 isTypeValid(UnqualT1) && isTypeValid(UnqualT2) &&
4090 IsDerivedFrom(Loc, UnqualT2, UnqualT1))
4091 DerivedToBase = true;
4092 else if (UnqualT1->isObjCObjectOrInterfaceType() &&
4093 UnqualT2->isObjCObjectOrInterfaceType() &&
4094 Context.canBindObjCObjectType(UnqualT1, UnqualT2))
4095 ObjCConversion = true;
4097 return Ref_Incompatible;
4099 // At this point, we know that T1 and T2 are reference-related (at
4102 // If the type is an array type, promote the element qualifiers to the type
4104 if (isa<ArrayType>(T1) && T1Quals)
4105 T1 = Context.getQualifiedType(UnqualT1, T1Quals);
4106 if (isa<ArrayType>(T2) && T2Quals)
4107 T2 = Context.getQualifiedType(UnqualT2, T2Quals);
4109 // C++ [dcl.init.ref]p4:
4110 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is
4111 // reference-related to T2 and cv1 is the same cv-qualification
4112 // as, or greater cv-qualification than, cv2. For purposes of
4113 // overload resolution, cases for which cv1 is greater
4114 // cv-qualification than cv2 are identified as
4115 // reference-compatible with added qualification (see 13.3.3.2).
4117 // Note that we also require equivalence of Objective-C GC and address-space
4118 // qualifiers when performing these computations, so that e.g., an int in
4119 // address space 1 is not reference-compatible with an int in address
4121 if (T1Quals.getObjCLifetime() != T2Quals.getObjCLifetime() &&
4122 T1Quals.compatiblyIncludesObjCLifetime(T2Quals)) {
4123 if (isNonTrivialObjCLifetimeConversion(T2Quals, T1Quals))
4124 ObjCLifetimeConversion = true;
4126 T1Quals.removeObjCLifetime();
4127 T2Quals.removeObjCLifetime();
4130 if (T1Quals == T2Quals)
4131 return Ref_Compatible;
4132 else if (T1Quals.compatiblyIncludes(T2Quals))
4133 return Ref_Compatible_With_Added_Qualification;
4138 /// \brief Look for a user-defined conversion to an value reference-compatible
4139 /// with DeclType. Return true if something definite is found.
4141 FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS,
4142 QualType DeclType, SourceLocation DeclLoc,
4143 Expr *Init, QualType T2, bool AllowRvalues,
4144 bool AllowExplicit) {
4145 assert(T2->isRecordType() && "Can only find conversions of record types.");
4146 CXXRecordDecl *T2RecordDecl
4147 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl());
4149 OverloadCandidateSet CandidateSet(DeclLoc, OverloadCandidateSet::CSK_Normal);
4150 const auto &Conversions = T2RecordDecl->getVisibleConversionFunctions();
4151 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
4153 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
4154 if (isa<UsingShadowDecl>(D))
4155 D = cast<UsingShadowDecl>(D)->getTargetDecl();
4157 FunctionTemplateDecl *ConvTemplate
4158 = dyn_cast<FunctionTemplateDecl>(D);
4159 CXXConversionDecl *Conv;
4161 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
4163 Conv = cast<CXXConversionDecl>(D);
4165 // If this is an explicit conversion, and we're not allowed to consider
4166 // explicit conversions, skip it.
4167 if (!AllowExplicit && Conv->isExplicit())
4171 bool DerivedToBase = false;
4172 bool ObjCConversion = false;
4173 bool ObjCLifetimeConversion = false;
4175 // If we are initializing an rvalue reference, don't permit conversion
4176 // functions that return lvalues.
4177 if (!ConvTemplate && DeclType->isRValueReferenceType()) {
4178 const ReferenceType *RefType
4179 = Conv->getConversionType()->getAs<LValueReferenceType>();
4180 if (RefType && !RefType->getPointeeType()->isFunctionType())
4184 if (!ConvTemplate &&
4185 S.CompareReferenceRelationship(
4187 Conv->getConversionType().getNonReferenceType()
4188 .getUnqualifiedType(),
4189 DeclType.getNonReferenceType().getUnqualifiedType(),
4190 DerivedToBase, ObjCConversion, ObjCLifetimeConversion) ==
4191 Sema::Ref_Incompatible)
4194 // If the conversion function doesn't return a reference type,
4195 // it can't be considered for this conversion. An rvalue reference
4196 // is only acceptable if its referencee is a function type.
4198 const ReferenceType *RefType =
4199 Conv->getConversionType()->getAs<ReferenceType>();
4201 (!RefType->isLValueReferenceType() &&
4202 !RefType->getPointeeType()->isFunctionType()))
4207 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC,
4208 Init, DeclType, CandidateSet,
4209 /*AllowObjCConversionOnExplicit=*/false);
4211 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init,
4212 DeclType, CandidateSet,
4213 /*AllowObjCConversionOnExplicit=*/false);
4216 bool HadMultipleCandidates = (CandidateSet.size() > 1);
4218 OverloadCandidateSet::iterator Best;
4219 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) {
4221 // C++ [over.ics.ref]p1:
4223 // [...] If the parameter binds directly to the result of
4224 // applying a conversion function to the argument
4225 // expression, the implicit conversion sequence is a
4226 // user-defined conversion sequence (13.3.3.1.2), with the
4227 // second standard conversion sequence either an identity
4228 // conversion or, if the conversion function returns an
4229 // entity of a type that is a derived class of the parameter
4230 // type, a derived-to-base Conversion.
4231 if (!Best->FinalConversion.DirectBinding)
4234 ICS.setUserDefined();
4235 ICS.UserDefined.Before = Best->Conversions[0].Standard;
4236 ICS.UserDefined.After = Best->FinalConversion;
4237 ICS.UserDefined.HadMultipleCandidates = HadMultipleCandidates;
4238 ICS.UserDefined.ConversionFunction = Best->Function;
4239 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl;
4240 ICS.UserDefined.EllipsisConversion = false;
4241 assert(ICS.UserDefined.After.ReferenceBinding &&
4242 ICS.UserDefined.After.DirectBinding &&
4243 "Expected a direct reference binding!");
4248 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin();
4249 Cand != CandidateSet.end(); ++Cand)
4251 ICS.Ambiguous.addConversion(Cand->Function);
4254 case OR_No_Viable_Function:
4256 // There was no suitable conversion, or we found a deleted
4257 // conversion; continue with other checks.
4261 llvm_unreachable("Invalid OverloadResult!");
4264 /// \brief Compute an implicit conversion sequence for reference
4266 static ImplicitConversionSequence
4267 TryReferenceInit(Sema &S, Expr *Init, QualType DeclType,
4268 SourceLocation DeclLoc,
4269 bool SuppressUserConversions,
4270 bool AllowExplicit) {
4271 assert(DeclType->isReferenceType() && "Reference init needs a reference");
4273 // Most paths end in a failed conversion.
4274 ImplicitConversionSequence ICS;
4275 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4277 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType();
4278 QualType T2 = Init->getType();
4280 // If the initializer is the address of an overloaded function, try
4281 // to resolve the overloaded function. If all goes well, T2 is the
4282 // type of the resulting function.
4283 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
4284 DeclAccessPair Found;
4285 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType,
4290 // Compute some basic properties of the types and the initializer.
4291 bool isRValRef = DeclType->isRValueReferenceType();
4292 bool DerivedToBase = false;
4293 bool ObjCConversion = false;
4294 bool ObjCLifetimeConversion = false;
4295 Expr::Classification InitCategory = Init->Classify(S.Context);
4296 Sema::ReferenceCompareResult RefRelationship
4297 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase,
4298 ObjCConversion, ObjCLifetimeConversion);
4301 // C++0x [dcl.init.ref]p5:
4302 // A reference to type "cv1 T1" is initialized by an expression
4303 // of type "cv2 T2" as follows:
4305 // -- If reference is an lvalue reference and the initializer expression
4307 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is
4308 // reference-compatible with "cv2 T2," or
4310 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here.
4311 if (InitCategory.isLValue() &&
4312 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) {
4313 // C++ [over.ics.ref]p1:
4314 // When a parameter of reference type binds directly (8.5.3)
4315 // to an argument expression, the implicit conversion sequence
4316 // is the identity conversion, unless the argument expression
4317 // has a type that is a derived class of the parameter type,
4318 // in which case the implicit conversion sequence is a
4319 // derived-to-base Conversion (13.3.3.1).
4321 ICS.Standard.First = ICK_Identity;
4322 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base
4323 : ObjCConversion? ICK_Compatible_Conversion
4325 ICS.Standard.Third = ICK_Identity;
4326 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
4327 ICS.Standard.setToType(0, T2);
4328 ICS.Standard.setToType(1, T1);
4329 ICS.Standard.setToType(2, T1);
4330 ICS.Standard.ReferenceBinding = true;
4331 ICS.Standard.DirectBinding = true;
4332 ICS.Standard.IsLvalueReference = !isRValRef;
4333 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType();
4334 ICS.Standard.BindsToRvalue = false;
4335 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4336 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion;
4337 ICS.Standard.CopyConstructor = nullptr;
4338 ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
4340 // Nothing more to do: the inaccessibility/ambiguity check for
4341 // derived-to-base conversions is suppressed when we're
4342 // computing the implicit conversion sequence (C++
4343 // [over.best.ics]p2).
4347 // -- has a class type (i.e., T2 is a class type), where T1 is
4348 // not reference-related to T2, and can be implicitly
4349 // converted to an lvalue of type "cv3 T3," where "cv1 T1"
4350 // is reference-compatible with "cv3 T3" 92) (this
4351 // conversion is selected by enumerating the applicable
4352 // conversion functions (13.3.1.6) and choosing the best
4353 // one through overload resolution (13.3)),
4354 if (!SuppressUserConversions && T2->isRecordType() &&
4355 S.isCompleteType(DeclLoc, T2) &&
4356 RefRelationship == Sema::Ref_Incompatible) {
4357 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4358 Init, T2, /*AllowRvalues=*/false,
4364 // -- Otherwise, the reference shall be an lvalue reference to a
4365 // non-volatile const type (i.e., cv1 shall be const), or the reference
4366 // shall be an rvalue reference.
4367 if (!isRValRef && (!T1.isConstQualified() || T1.isVolatileQualified()))
4370 // -- If the initializer expression
4372 // -- is an xvalue, class prvalue, array prvalue or function
4373 // lvalue and "cv1 T1" is reference-compatible with "cv2 T2", or
4374 if (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification &&
4375 (InitCategory.isXValue() ||
4376 (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) ||
4377 (InitCategory.isLValue() && T2->isFunctionType()))) {
4379 ICS.Standard.First = ICK_Identity;
4380 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base
4381 : ObjCConversion? ICK_Compatible_Conversion
4383 ICS.Standard.Third = ICK_Identity;
4384 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
4385 ICS.Standard.setToType(0, T2);
4386 ICS.Standard.setToType(1, T1);
4387 ICS.Standard.setToType(2, T1);
4388 ICS.Standard.ReferenceBinding = true;
4389 // In C++0x, this is always a direct binding. In C++98/03, it's a direct
4390 // binding unless we're binding to a class prvalue.
4391 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we
4392 // allow the use of rvalue references in C++98/03 for the benefit of
4393 // standard library implementors; therefore, we need the xvalue check here.
4394 ICS.Standard.DirectBinding =
4395 S.getLangOpts().CPlusPlus11 ||
4396 !(InitCategory.isPRValue() || T2->isRecordType());
4397 ICS.Standard.IsLvalueReference = !isRValRef;
4398 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType();
4399 ICS.Standard.BindsToRvalue = InitCategory.isRValue();
4400 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4401 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion;
4402 ICS.Standard.CopyConstructor = nullptr;
4403 ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
4407 // -- has a class type (i.e., T2 is a class type), where T1 is not
4408 // reference-related to T2, and can be implicitly converted to
4409 // an xvalue, class prvalue, or function lvalue of type
4410 // "cv3 T3", where "cv1 T1" is reference-compatible with
4413 // then the reference is bound to the value of the initializer
4414 // expression in the first case and to the result of the conversion
4415 // in the second case (or, in either case, to an appropriate base
4416 // class subobject).
4417 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4418 T2->isRecordType() && S.isCompleteType(DeclLoc, T2) &&
4419 FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4420 Init, T2, /*AllowRvalues=*/true,
4422 // In the second case, if the reference is an rvalue reference
4423 // and the second standard conversion sequence of the
4424 // user-defined conversion sequence includes an lvalue-to-rvalue
4425 // conversion, the program is ill-formed.
4426 if (ICS.isUserDefined() && isRValRef &&
4427 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue)
4428 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4433 // A temporary of function type cannot be created; don't even try.
4434 if (T1->isFunctionType())
4437 // -- Otherwise, a temporary of type "cv1 T1" is created and
4438 // initialized from the initializer expression using the
4439 // rules for a non-reference copy initialization (8.5). The
4440 // reference is then bound to the temporary. If T1 is
4441 // reference-related to T2, cv1 must be the same
4442 // cv-qualification as, or greater cv-qualification than,
4443 // cv2; otherwise, the program is ill-formed.
4444 if (RefRelationship == Sema::Ref_Related) {
4445 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then
4446 // we would be reference-compatible or reference-compatible with
4447 // added qualification. But that wasn't the case, so the reference
4448 // initialization fails.
4450 // Note that we only want to check address spaces and cvr-qualifiers here.
4451 // ObjC GC and lifetime qualifiers aren't important.
4452 Qualifiers T1Quals = T1.getQualifiers();
4453 Qualifiers T2Quals = T2.getQualifiers();
4454 T1Quals.removeObjCGCAttr();
4455 T1Quals.removeObjCLifetime();
4456 T2Quals.removeObjCGCAttr();
4457 T2Quals.removeObjCLifetime();
4458 if (!T1Quals.compatiblyIncludes(T2Quals))
4462 // If at least one of the types is a class type, the types are not
4463 // related, and we aren't allowed any user conversions, the
4464 // reference binding fails. This case is important for breaking
4465 // recursion, since TryImplicitConversion below will attempt to
4466 // create a temporary through the use of a copy constructor.
4467 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4468 (T1->isRecordType() || T2->isRecordType()))
4471 // If T1 is reference-related to T2 and the reference is an rvalue
4472 // reference, the initializer expression shall not be an lvalue.
4473 if (RefRelationship >= Sema::Ref_Related &&
4474 isRValRef && Init->Classify(S.Context).isLValue())
4477 // C++ [over.ics.ref]p2:
4478 // When a parameter of reference type is not bound directly to
4479 // an argument expression, the conversion sequence is the one
4480 // required to convert the argument expression to the
4481 // underlying type of the reference according to
4482 // 13.3.3.1. Conceptually, this conversion sequence corresponds
4483 // to copy-initializing a temporary of the underlying type with
4484 // the argument expression. Any difference in top-level
4485 // cv-qualification is subsumed by the initialization itself
4486 // and does not constitute a conversion.
4487 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions,
4488 /*AllowExplicit=*/false,
4489 /*InOverloadResolution=*/false,
4491 /*AllowObjCWritebackConversion=*/false,
4492 /*AllowObjCConversionOnExplicit=*/false);
4494 // Of course, that's still a reference binding.
4495 if (ICS.isStandard()) {
4496 ICS.Standard.ReferenceBinding = true;
4497 ICS.Standard.IsLvalueReference = !isRValRef;
4498 ICS.Standard.BindsToFunctionLvalue = false;
4499 ICS.Standard.BindsToRvalue = true;
4500 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4501 ICS.Standard.ObjCLifetimeConversionBinding = false;
4502 } else if (ICS.isUserDefined()) {
4503 const ReferenceType *LValRefType =
4504 ICS.UserDefined.ConversionFunction->getReturnType()
4505 ->getAs<LValueReferenceType>();
4507 // C++ [over.ics.ref]p3:
4508 // Except for an implicit object parameter, for which see 13.3.1, a
4509 // standard conversion sequence cannot be formed if it requires [...]
4510 // binding an rvalue reference to an lvalue other than a function
4512 // Note that the function case is not possible here.
4513 if (DeclType->isRValueReferenceType() && LValRefType) {
4514 // FIXME: This is the wrong BadConversionSequence. The problem is binding
4515 // an rvalue reference to a (non-function) lvalue, not binding an lvalue
4516 // reference to an rvalue!
4517 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, Init, DeclType);
4521 ICS.UserDefined.Before.setAsIdentityConversion();
4522 ICS.UserDefined.After.ReferenceBinding = true;
4523 ICS.UserDefined.After.IsLvalueReference = !isRValRef;
4524 ICS.UserDefined.After.BindsToFunctionLvalue = false;
4525 ICS.UserDefined.After.BindsToRvalue = !LValRefType;
4526 ICS.UserDefined.After.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4527 ICS.UserDefined.After.ObjCLifetimeConversionBinding = false;
4533 static ImplicitConversionSequence
4534 TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
4535 bool SuppressUserConversions,
4536 bool InOverloadResolution,
4537 bool AllowObjCWritebackConversion,
4538 bool AllowExplicit = false);
4540 /// TryListConversion - Try to copy-initialize a value of type ToType from the
4541 /// initializer list From.
4542 static ImplicitConversionSequence
4543 TryListConversion(Sema &S, InitListExpr *From, QualType ToType,
4544 bool SuppressUserConversions,
4545 bool InOverloadResolution,
4546 bool AllowObjCWritebackConversion) {
4547 // C++11 [over.ics.list]p1:
4548 // When an argument is an initializer list, it is not an expression and
4549 // special rules apply for converting it to a parameter type.
4551 ImplicitConversionSequence Result;
4552 Result.setBad(BadConversionSequence::no_conversion, From, ToType);
4554 // We need a complete type for what follows. Incomplete types can never be
4555 // initialized from init lists.
4556 if (!S.isCompleteType(From->getLocStart(), ToType))
4560 // If the parameter type is a class X and the initializer list has a single
4561 // element of type cv U, where U is X or a class derived from X, the
4562 // implicit conversion sequence is the one required to convert the element
4563 // to the parameter type.
4565 // Otherwise, if the parameter type is a character array [... ]
4566 // and the initializer list has a single element that is an
4567 // appropriately-typed string literal (8.5.2 [dcl.init.string]), the
4568 // implicit conversion sequence is the identity conversion.
4569 if (From->getNumInits() == 1) {
4570 if (ToType->isRecordType()) {
4571 QualType InitType = From->getInit(0)->getType();
4572 if (S.Context.hasSameUnqualifiedType(InitType, ToType) ||
4573 S.IsDerivedFrom(From->getLocStart(), InitType, ToType))
4574 return TryCopyInitialization(S, From->getInit(0), ToType,
4575 SuppressUserConversions,
4576 InOverloadResolution,
4577 AllowObjCWritebackConversion);
4579 // FIXME: Check the other conditions here: array of character type,
4580 // initializer is a string literal.
4581 if (ToType->isArrayType()) {
4582 InitializedEntity Entity =
4583 InitializedEntity::InitializeParameter(S.Context, ToType,
4584 /*Consumed=*/false);
4585 if (S.CanPerformCopyInitialization(Entity, From)) {
4586 Result.setStandard();
4587 Result.Standard.setAsIdentityConversion();
4588 Result.Standard.setFromType(ToType);
4589 Result.Standard.setAllToTypes(ToType);
4595 // C++14 [over.ics.list]p2: Otherwise, if the parameter type [...] (below).
4596 // C++11 [over.ics.list]p2:
4597 // If the parameter type is std::initializer_list<X> or "array of X" and
4598 // all the elements can be implicitly converted to X, the implicit
4599 // conversion sequence is the worst conversion necessary to convert an
4600 // element of the list to X.
4602 // C++14 [over.ics.list]p3:
4603 // Otherwise, if the parameter type is "array of N X", if the initializer
4604 // list has exactly N elements or if it has fewer than N elements and X is
4605 // default-constructible, and if all the elements of the initializer list
4606 // can be implicitly converted to X, the implicit conversion sequence is
4607 // the worst conversion necessary to convert an element of the list to X.
4609 // FIXME: We're missing a lot of these checks.
4610 bool toStdInitializerList = false;
4612 if (ToType->isArrayType())
4613 X = S.Context.getAsArrayType(ToType)->getElementType();
4615 toStdInitializerList = S.isStdInitializerList(ToType, &X);
4617 for (unsigned i = 0, e = From->getNumInits(); i < e; ++i) {
4618 Expr *Init = From->getInit(i);
4619 ImplicitConversionSequence ICS =
4620 TryCopyInitialization(S, Init, X, SuppressUserConversions,
4621 InOverloadResolution,
4622 AllowObjCWritebackConversion);
4623 // If a single element isn't convertible, fail.
4628 // Otherwise, look for the worst conversion.
4629 if (Result.isBad() ||
4630 CompareImplicitConversionSequences(S, From->getLocStart(), ICS,
4632 ImplicitConversionSequence::Worse)
4636 // For an empty list, we won't have computed any conversion sequence.
4637 // Introduce the identity conversion sequence.
4638 if (From->getNumInits() == 0) {
4639 Result.setStandard();
4640 Result.Standard.setAsIdentityConversion();
4641 Result.Standard.setFromType(ToType);
4642 Result.Standard.setAllToTypes(ToType);
4645 Result.setStdInitializerListElement(toStdInitializerList);
4649 // C++14 [over.ics.list]p4:
4650 // C++11 [over.ics.list]p3:
4651 // Otherwise, if the parameter is a non-aggregate class X and overload
4652 // resolution chooses a single best constructor [...] the implicit
4653 // conversion sequence is a user-defined conversion sequence. If multiple
4654 // constructors are viable but none is better than the others, the
4655 // implicit conversion sequence is a user-defined conversion sequence.
4656 if (ToType->isRecordType() && !ToType->isAggregateType()) {
4657 // This function can deal with initializer lists.
4658 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
4659 /*AllowExplicit=*/false,
4660 InOverloadResolution, /*CStyle=*/false,
4661 AllowObjCWritebackConversion,
4662 /*AllowObjCConversionOnExplicit=*/false);
4665 // C++14 [over.ics.list]p5:
4666 // C++11 [over.ics.list]p4:
4667 // Otherwise, if the parameter has an aggregate type which can be
4668 // initialized from the initializer list [...] the implicit conversion
4669 // sequence is a user-defined conversion sequence.
4670 if (ToType->isAggregateType()) {
4671 // Type is an aggregate, argument is an init list. At this point it comes
4672 // down to checking whether the initialization works.
4673 // FIXME: Find out whether this parameter is consumed or not.
4674 InitializedEntity Entity =
4675 InitializedEntity::InitializeParameter(S.Context, ToType,
4676 /*Consumed=*/false);
4677 if (S.CanPerformCopyInitialization(Entity, From)) {
4678 Result.setUserDefined();
4679 Result.UserDefined.Before.setAsIdentityConversion();
4680 // Initializer lists don't have a type.
4681 Result.UserDefined.Before.setFromType(QualType());
4682 Result.UserDefined.Before.setAllToTypes(QualType());
4684 Result.UserDefined.After.setAsIdentityConversion();
4685 Result.UserDefined.After.setFromType(ToType);
4686 Result.UserDefined.After.setAllToTypes(ToType);
4687 Result.UserDefined.ConversionFunction = nullptr;
4692 // C++14 [over.ics.list]p6:
4693 // C++11 [over.ics.list]p5:
4694 // Otherwise, if the parameter is a reference, see 13.3.3.1.4.
4695 if (ToType->isReferenceType()) {
4696 // The standard is notoriously unclear here, since 13.3.3.1.4 doesn't
4697 // mention initializer lists in any way. So we go by what list-
4698 // initialization would do and try to extrapolate from that.
4700 QualType T1 = ToType->getAs<ReferenceType>()->getPointeeType();
4702 // If the initializer list has a single element that is reference-related
4703 // to the parameter type, we initialize the reference from that.
4704 if (From->getNumInits() == 1) {
4705 Expr *Init = From->getInit(0);
4707 QualType T2 = Init->getType();
4709 // If the initializer is the address of an overloaded function, try
4710 // to resolve the overloaded function. If all goes well, T2 is the
4711 // type of the resulting function.
4712 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
4713 DeclAccessPair Found;
4714 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(
4715 Init, ToType, false, Found))
4719 // Compute some basic properties of the types and the initializer.
4720 bool dummy1 = false;
4721 bool dummy2 = false;
4722 bool dummy3 = false;
4723 Sema::ReferenceCompareResult RefRelationship
4724 = S.CompareReferenceRelationship(From->getLocStart(), T1, T2, dummy1,
4727 if (RefRelationship >= Sema::Ref_Related) {
4728 return TryReferenceInit(S, Init, ToType, /*FIXME*/From->getLocStart(),
4729 SuppressUserConversions,
4730 /*AllowExplicit=*/false);
4734 // Otherwise, we bind the reference to a temporary created from the
4735 // initializer list.
4736 Result = TryListConversion(S, From, T1, SuppressUserConversions,
4737 InOverloadResolution,
4738 AllowObjCWritebackConversion);
4739 if (Result.isFailure())
4741 assert(!Result.isEllipsis() &&
4742 "Sub-initialization cannot result in ellipsis conversion.");
4744 // Can we even bind to a temporary?
4745 if (ToType->isRValueReferenceType() ||
4746 (T1.isConstQualified() && !T1.isVolatileQualified())) {
4747 StandardConversionSequence &SCS = Result.isStandard() ? Result.Standard :
4748 Result.UserDefined.After;
4749 SCS.ReferenceBinding = true;
4750 SCS.IsLvalueReference = ToType->isLValueReferenceType();
4751 SCS.BindsToRvalue = true;
4752 SCS.BindsToFunctionLvalue = false;
4753 SCS.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4754 SCS.ObjCLifetimeConversionBinding = false;
4756 Result.setBad(BadConversionSequence::lvalue_ref_to_rvalue,
4761 // C++14 [over.ics.list]p7:
4762 // C++11 [over.ics.list]p6:
4763 // Otherwise, if the parameter type is not a class:
4764 if (!ToType->isRecordType()) {
4765 // - if the initializer list has one element that is not itself an
4766 // initializer list, the implicit conversion sequence is the one
4767 // required to convert the element to the parameter type.
4768 unsigned NumInits = From->getNumInits();
4769 if (NumInits == 1 && !isa<InitListExpr>(From->getInit(0)))
4770 Result = TryCopyInitialization(S, From->getInit(0), ToType,
4771 SuppressUserConversions,
4772 InOverloadResolution,
4773 AllowObjCWritebackConversion);
4774 // - if the initializer list has no elements, the implicit conversion
4775 // sequence is the identity conversion.
4776 else if (NumInits == 0) {
4777 Result.setStandard();
4778 Result.Standard.setAsIdentityConversion();
4779 Result.Standard.setFromType(ToType);
4780 Result.Standard.setAllToTypes(ToType);
4785 // C++14 [over.ics.list]p8:
4786 // C++11 [over.ics.list]p7:
4787 // In all cases other than those enumerated above, no conversion is possible
4791 /// TryCopyInitialization - Try to copy-initialize a value of type
4792 /// ToType from the expression From. Return the implicit conversion
4793 /// sequence required to pass this argument, which may be a bad
4794 /// conversion sequence (meaning that the argument cannot be passed to
4795 /// a parameter of this type). If @p SuppressUserConversions, then we
4796 /// do not permit any user-defined conversion sequences.
4797 static ImplicitConversionSequence
4798 TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
4799 bool SuppressUserConversions,
4800 bool InOverloadResolution,
4801 bool AllowObjCWritebackConversion,
4802 bool AllowExplicit) {
4803 if (InitListExpr *FromInitList = dyn_cast<InitListExpr>(From))
4804 return TryListConversion(S, FromInitList, ToType, SuppressUserConversions,
4805 InOverloadResolution,AllowObjCWritebackConversion);
4807 if (ToType->isReferenceType())
4808 return TryReferenceInit(S, From, ToType,
4809 /*FIXME:*/From->getLocStart(),
4810 SuppressUserConversions,
4813 return TryImplicitConversion(S, From, ToType,
4814 SuppressUserConversions,
4815 /*AllowExplicit=*/false,
4816 InOverloadResolution,
4818 AllowObjCWritebackConversion,
4819 /*AllowObjCConversionOnExplicit=*/false);
4822 static bool TryCopyInitialization(const CanQualType FromQTy,
4823 const CanQualType ToQTy,
4826 ExprValueKind FromVK) {
4827 OpaqueValueExpr TmpExpr(Loc, FromQTy, FromVK);
4828 ImplicitConversionSequence ICS =
4829 TryCopyInitialization(S, &TmpExpr, ToQTy, true, true, false);
4831 return !ICS.isBad();
4834 /// TryObjectArgumentInitialization - Try to initialize the object
4835 /// parameter of the given member function (@c Method) from the
4836 /// expression @p From.
4837 static ImplicitConversionSequence
4838 TryObjectArgumentInitialization(Sema &S, SourceLocation Loc, QualType FromType,
4839 Expr::Classification FromClassification,
4840 CXXMethodDecl *Method,
4841 CXXRecordDecl *ActingContext) {
4842 QualType ClassType = S.Context.getTypeDeclType(ActingContext);
4843 // [class.dtor]p2: A destructor can be invoked for a const, volatile or
4844 // const volatile object.
4845 unsigned Quals = isa<CXXDestructorDecl>(Method) ?
4846 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers();
4847 QualType ImplicitParamType = S.Context.getCVRQualifiedType(ClassType, Quals);
4849 // Set up the conversion sequence as a "bad" conversion, to allow us
4851 ImplicitConversionSequence ICS;
4853 // We need to have an object of class type.
4854 if (const PointerType *PT = FromType->getAs<PointerType>()) {
4855 FromType = PT->getPointeeType();
4857 // When we had a pointer, it's implicitly dereferenced, so we
4858 // better have an lvalue.
4859 assert(FromClassification.isLValue());
4862 assert(FromType->isRecordType());
4864 // C++0x [over.match.funcs]p4:
4865 // For non-static member functions, the type of the implicit object
4868 // - "lvalue reference to cv X" for functions declared without a
4869 // ref-qualifier or with the & ref-qualifier
4870 // - "rvalue reference to cv X" for functions declared with the &&
4873 // where X is the class of which the function is a member and cv is the
4874 // cv-qualification on the member function declaration.
4876 // However, when finding an implicit conversion sequence for the argument, we
4877 // are not allowed to create temporaries or perform user-defined conversions
4878 // (C++ [over.match.funcs]p5). We perform a simplified version of
4879 // reference binding here, that allows class rvalues to bind to
4880 // non-constant references.
4882 // First check the qualifiers.
4883 QualType FromTypeCanon = S.Context.getCanonicalType(FromType);
4884 if (ImplicitParamType.getCVRQualifiers()
4885 != FromTypeCanon.getLocalCVRQualifiers() &&
4886 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) {
4887 ICS.setBad(BadConversionSequence::bad_qualifiers,
4888 FromType, ImplicitParamType);
4892 // Check that we have either the same type or a derived type. It
4893 // affects the conversion rank.
4894 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType);
4895 ImplicitConversionKind SecondKind;
4896 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) {
4897 SecondKind = ICK_Identity;
4898 } else if (S.IsDerivedFrom(Loc, FromType, ClassType))
4899 SecondKind = ICK_Derived_To_Base;
4901 ICS.setBad(BadConversionSequence::unrelated_class,
4902 FromType, ImplicitParamType);
4906 // Check the ref-qualifier.
4907 switch (Method->getRefQualifier()) {
4909 // Do nothing; we don't care about lvalueness or rvalueness.
4913 if (!FromClassification.isLValue() && Quals != Qualifiers::Const) {
4914 // non-const lvalue reference cannot bind to an rvalue
4915 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType,
4922 if (!FromClassification.isRValue()) {
4923 // rvalue reference cannot bind to an lvalue
4924 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType,
4931 // Success. Mark this as a reference binding.
4933 ICS.Standard.setAsIdentityConversion();
4934 ICS.Standard.Second = SecondKind;
4935 ICS.Standard.setFromType(FromType);
4936 ICS.Standard.setAllToTypes(ImplicitParamType);
4937 ICS.Standard.ReferenceBinding = true;
4938 ICS.Standard.DirectBinding = true;
4939 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue;
4940 ICS.Standard.BindsToFunctionLvalue = false;
4941 ICS.Standard.BindsToRvalue = FromClassification.isRValue();
4942 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier
4943 = (Method->getRefQualifier() == RQ_None);
4947 /// PerformObjectArgumentInitialization - Perform initialization of
4948 /// the implicit object parameter for the given Method with the given
4951 Sema::PerformObjectArgumentInitialization(Expr *From,
4952 NestedNameSpecifier *Qualifier,
4953 NamedDecl *FoundDecl,
4954 CXXMethodDecl *Method) {
4955 QualType FromRecordType, DestType;
4956 QualType ImplicitParamRecordType =
4957 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType();
4959 Expr::Classification FromClassification;
4960 if (const PointerType *PT = From->getType()->getAs<PointerType>()) {
4961 FromRecordType = PT->getPointeeType();
4962 DestType = Method->getThisType(Context);
4963 FromClassification = Expr::Classification::makeSimpleLValue();
4965 FromRecordType = From->getType();
4966 DestType = ImplicitParamRecordType;
4967 FromClassification = From->Classify(Context);
4970 // Note that we always use the true parent context when performing
4971 // the actual argument initialization.
4972 ImplicitConversionSequence ICS = TryObjectArgumentInitialization(
4973 *this, From->getLocStart(), From->getType(), FromClassification, Method,
4974 Method->getParent());
4976 if (ICS.Bad.Kind == BadConversionSequence::bad_qualifiers) {
4977 Qualifiers FromQs = FromRecordType.getQualifiers();
4978 Qualifiers ToQs = DestType.getQualifiers();
4979 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers();
4981 Diag(From->getLocStart(),
4982 diag::err_member_function_call_bad_cvr)
4983 << Method->getDeclName() << FromRecordType << (CVR - 1)
4984 << From->getSourceRange();
4985 Diag(Method->getLocation(), diag::note_previous_decl)
4986 << Method->getDeclName();
4991 return Diag(From->getLocStart(),
4992 diag::err_implicit_object_parameter_init)
4993 << ImplicitParamRecordType << FromRecordType << From->getSourceRange();
4996 if (ICS.Standard.Second == ICK_Derived_To_Base) {
4997 ExprResult FromRes =
4998 PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method);
4999 if (FromRes.isInvalid())
5001 From = FromRes.get();
5004 if (!Context.hasSameType(From->getType(), DestType))
5005 From = ImpCastExprToType(From, DestType, CK_NoOp,
5006 From->getValueKind()).get();
5010 /// TryContextuallyConvertToBool - Attempt to contextually convert the
5011 /// expression From to bool (C++0x [conv]p3).
5012 static ImplicitConversionSequence
5013 TryContextuallyConvertToBool(Sema &S, Expr *From) {
5014 return TryImplicitConversion(S, From, S.Context.BoolTy,
5015 /*SuppressUserConversions=*/false,
5016 /*AllowExplicit=*/true,
5017 /*InOverloadResolution=*/false,
5019 /*AllowObjCWritebackConversion=*/false,
5020 /*AllowObjCConversionOnExplicit=*/false);
5023 /// PerformContextuallyConvertToBool - Perform a contextual conversion
5024 /// of the expression From to bool (C++0x [conv]p3).
5025 ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) {
5026 if (checkPlaceholderForOverload(*this, From))
5029 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From);
5031 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting);
5033 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy))
5034 return Diag(From->getLocStart(),
5035 diag::err_typecheck_bool_condition)
5036 << From->getType() << From->getSourceRange();
5040 /// Check that the specified conversion is permitted in a converted constant
5041 /// expression, according to C++11 [expr.const]p3. Return true if the conversion
5043 static bool CheckConvertedConstantConversions(Sema &S,
5044 StandardConversionSequence &SCS) {
5045 // Since we know that the target type is an integral or unscoped enumeration
5046 // type, most conversion kinds are impossible. All possible First and Third
5047 // conversions are fine.
5048 switch (SCS.Second) {
5050 case ICK_NoReturn_Adjustment:
5051 case ICK_Integral_Promotion:
5052 case ICK_Integral_Conversion: // Narrowing conversions are checked elsewhere.
5055 case ICK_Boolean_Conversion:
5056 // Conversion from an integral or unscoped enumeration type to bool is
5057 // classified as ICK_Boolean_Conversion, but it's also arguably an integral
5058 // conversion, so we allow it in a converted constant expression.
5060 // FIXME: Per core issue 1407, we should not allow this, but that breaks
5061 // a lot of popular code. We should at least add a warning for this
5062 // (non-conforming) extension.
5063 return SCS.getFromType()->isIntegralOrUnscopedEnumerationType() &&
5064 SCS.getToType(2)->isBooleanType();
5066 case ICK_Pointer_Conversion:
5067 case ICK_Pointer_Member:
5068 // C++1z: null pointer conversions and null member pointer conversions are
5069 // only permitted if the source type is std::nullptr_t.
5070 return SCS.getFromType()->isNullPtrType();
5072 case ICK_Floating_Promotion:
5073 case ICK_Complex_Promotion:
5074 case ICK_Floating_Conversion:
5075 case ICK_Complex_Conversion:
5076 case ICK_Floating_Integral:
5077 case ICK_Compatible_Conversion:
5078 case ICK_Derived_To_Base:
5079 case ICK_Vector_Conversion:
5080 case ICK_Vector_Splat:
5081 case ICK_Complex_Real:
5082 case ICK_Block_Pointer_Conversion:
5083 case ICK_TransparentUnionConversion:
5084 case ICK_Writeback_Conversion:
5085 case ICK_Zero_Event_Conversion:
5086 case ICK_C_Only_Conversion:
5089 case ICK_Lvalue_To_Rvalue:
5090 case ICK_Array_To_Pointer:
5091 case ICK_Function_To_Pointer:
5092 llvm_unreachable("found a first conversion kind in Second");
5094 case ICK_Qualification:
5095 llvm_unreachable("found a third conversion kind in Second");
5097 case ICK_Num_Conversion_Kinds:
5101 llvm_unreachable("unknown conversion kind");
5104 /// CheckConvertedConstantExpression - Check that the expression From is a
5105 /// converted constant expression of type T, perform the conversion and produce
5106 /// the converted expression, per C++11 [expr.const]p3.
5107 static ExprResult CheckConvertedConstantExpression(Sema &S, Expr *From,
5108 QualType T, APValue &Value,
5111 assert(S.getLangOpts().CPlusPlus11 &&
5112 "converted constant expression outside C++11");
5114 if (checkPlaceholderForOverload(S, From))
5117 // C++1z [expr.const]p3:
5118 // A converted constant expression of type T is an expression,
5119 // implicitly converted to type T, where the converted
5120 // expression is a constant expression and the implicit conversion
5121 // sequence contains only [... list of conversions ...].
5122 ImplicitConversionSequence ICS =
5123 TryCopyInitialization(S, From, T,
5124 /*SuppressUserConversions=*/false,
5125 /*InOverloadResolution=*/false,
5126 /*AllowObjcWritebackConversion=*/false,
5127 /*AllowExplicit=*/false);
5128 StandardConversionSequence *SCS = nullptr;
5129 switch (ICS.getKind()) {
5130 case ImplicitConversionSequence::StandardConversion:
5131 SCS = &ICS.Standard;
5133 case ImplicitConversionSequence::UserDefinedConversion:
5134 // We are converting to a non-class type, so the Before sequence
5136 SCS = &ICS.UserDefined.After;
5138 case ImplicitConversionSequence::AmbiguousConversion:
5139 case ImplicitConversionSequence::BadConversion:
5140 if (!S.DiagnoseMultipleUserDefinedConversion(From, T))
5141 return S.Diag(From->getLocStart(),
5142 diag::err_typecheck_converted_constant_expression)
5143 << From->getType() << From->getSourceRange() << T;
5146 case ImplicitConversionSequence::EllipsisConversion:
5147 llvm_unreachable("ellipsis conversion in converted constant expression");
5150 // Check that we would only use permitted conversions.
5151 if (!CheckConvertedConstantConversions(S, *SCS)) {
5152 return S.Diag(From->getLocStart(),
5153 diag::err_typecheck_converted_constant_expression_disallowed)
5154 << From->getType() << From->getSourceRange() << T;
5156 // [...] and where the reference binding (if any) binds directly.
5157 if (SCS->ReferenceBinding && !SCS->DirectBinding) {
5158 return S.Diag(From->getLocStart(),
5159 diag::err_typecheck_converted_constant_expression_indirect)
5160 << From->getType() << From->getSourceRange() << T;
5164 S.PerformImplicitConversion(From, T, ICS, Sema::AA_Converting);
5165 if (Result.isInvalid())
5168 // Check for a narrowing implicit conversion.
5169 APValue PreNarrowingValue;
5170 QualType PreNarrowingType;
5171 switch (SCS->getNarrowingKind(S.Context, Result.get(), PreNarrowingValue,
5172 PreNarrowingType)) {
5173 case NK_Variable_Narrowing:
5174 // Implicit conversion to a narrower type, and the value is not a constant
5175 // expression. We'll diagnose this in a moment.
5176 case NK_Not_Narrowing:
5179 case NK_Constant_Narrowing:
5180 S.Diag(From->getLocStart(), diag::ext_cce_narrowing)
5181 << CCE << /*Constant*/1
5182 << PreNarrowingValue.getAsString(S.Context, PreNarrowingType) << T;
5185 case NK_Type_Narrowing:
5186 S.Diag(From->getLocStart(), diag::ext_cce_narrowing)
5187 << CCE << /*Constant*/0 << From->getType() << T;
5191 // Check the expression is a constant expression.
5192 SmallVector<PartialDiagnosticAt, 8> Notes;
5193 Expr::EvalResult Eval;
5196 if ((T->isReferenceType()
5197 ? !Result.get()->EvaluateAsLValue(Eval, S.Context)
5198 : !Result.get()->EvaluateAsRValue(Eval, S.Context)) ||
5199 (RequireInt && !Eval.Val.isInt())) {
5200 // The expression can't be folded, so we can't keep it at this position in
5202 Result = ExprError();
5206 if (Notes.empty()) {
5207 // It's a constant expression.
5212 // It's not a constant expression. Produce an appropriate diagnostic.
5213 if (Notes.size() == 1 &&
5214 Notes[0].second.getDiagID() == diag::note_invalid_subexpr_in_const_expr)
5215 S.Diag(Notes[0].first, diag::err_expr_not_cce) << CCE;
5217 S.Diag(From->getLocStart(), diag::err_expr_not_cce)
5218 << CCE << From->getSourceRange();
5219 for (unsigned I = 0; I < Notes.size(); ++I)
5220 S.Diag(Notes[I].first, Notes[I].second);
5225 ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5226 APValue &Value, CCEKind CCE) {
5227 return ::CheckConvertedConstantExpression(*this, From, T, Value, CCE, false);
5230 ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5231 llvm::APSInt &Value,
5233 assert(T->isIntegralOrEnumerationType() && "unexpected converted const type");
5236 auto R = ::CheckConvertedConstantExpression(*this, From, T, V, CCE, true);
5243 /// dropPointerConversions - If the given standard conversion sequence
5244 /// involves any pointer conversions, remove them. This may change
5245 /// the result type of the conversion sequence.
5246 static void dropPointerConversion(StandardConversionSequence &SCS) {
5247 if (SCS.Second == ICK_Pointer_Conversion) {
5248 SCS.Second = ICK_Identity;
5249 SCS.Third = ICK_Identity;
5250 SCS.ToTypePtrs[2] = SCS.ToTypePtrs[1] = SCS.ToTypePtrs[0];
5254 /// TryContextuallyConvertToObjCPointer - Attempt to contextually
5255 /// convert the expression From to an Objective-C pointer type.
5256 static ImplicitConversionSequence
5257 TryContextuallyConvertToObjCPointer(Sema &S, Expr *From) {
5258 // Do an implicit conversion to 'id'.
5259 QualType Ty = S.Context.getObjCIdType();
5260 ImplicitConversionSequence ICS
5261 = TryImplicitConversion(S, From, Ty,
5262 // FIXME: Are these flags correct?
5263 /*SuppressUserConversions=*/false,
5264 /*AllowExplicit=*/true,
5265 /*InOverloadResolution=*/false,
5267 /*AllowObjCWritebackConversion=*/false,
5268 /*AllowObjCConversionOnExplicit=*/true);
5270 // Strip off any final conversions to 'id'.
5271 switch (ICS.getKind()) {
5272 case ImplicitConversionSequence::BadConversion:
5273 case ImplicitConversionSequence::AmbiguousConversion:
5274 case ImplicitConversionSequence::EllipsisConversion:
5277 case ImplicitConversionSequence::UserDefinedConversion:
5278 dropPointerConversion(ICS.UserDefined.After);
5281 case ImplicitConversionSequence::StandardConversion:
5282 dropPointerConversion(ICS.Standard);
5289 /// PerformContextuallyConvertToObjCPointer - Perform a contextual
5290 /// conversion of the expression From to an Objective-C pointer type.
5291 ExprResult Sema::PerformContextuallyConvertToObjCPointer(Expr *From) {
5292 if (checkPlaceholderForOverload(*this, From))
5295 QualType Ty = Context.getObjCIdType();
5296 ImplicitConversionSequence ICS =
5297 TryContextuallyConvertToObjCPointer(*this, From);
5299 return PerformImplicitConversion(From, Ty, ICS, AA_Converting);
5303 /// Determine whether the provided type is an integral type, or an enumeration
5304 /// type of a permitted flavor.
5305 bool Sema::ICEConvertDiagnoser::match(QualType T) {
5306 return AllowScopedEnumerations ? T->isIntegralOrEnumerationType()
5307 : T->isIntegralOrUnscopedEnumerationType();
5311 diagnoseAmbiguousConversion(Sema &SemaRef, SourceLocation Loc, Expr *From,
5312 Sema::ContextualImplicitConverter &Converter,
5313 QualType T, UnresolvedSetImpl &ViableConversions) {
5315 if (Converter.Suppress)
5318 Converter.diagnoseAmbiguous(SemaRef, Loc, T) << From->getSourceRange();
5319 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5320 CXXConversionDecl *Conv =
5321 cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl());
5322 QualType ConvTy = Conv->getConversionType().getNonReferenceType();
5323 Converter.noteAmbiguous(SemaRef, Conv, ConvTy);
5329 diagnoseNoViableConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5330 Sema::ContextualImplicitConverter &Converter,
5331 QualType T, bool HadMultipleCandidates,
5332 UnresolvedSetImpl &ExplicitConversions) {
5333 if (ExplicitConversions.size() == 1 && !Converter.Suppress) {
5334 DeclAccessPair Found = ExplicitConversions[0];
5335 CXXConversionDecl *Conversion =
5336 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5338 // The user probably meant to invoke the given explicit
5339 // conversion; use it.
5340 QualType ConvTy = Conversion->getConversionType().getNonReferenceType();
5341 std::string TypeStr;
5342 ConvTy.getAsStringInternal(TypeStr, SemaRef.getPrintingPolicy());
5344 Converter.diagnoseExplicitConv(SemaRef, Loc, T, ConvTy)
5345 << FixItHint::CreateInsertion(From->getLocStart(),
5346 "static_cast<" + TypeStr + ">(")
5347 << FixItHint::CreateInsertion(
5348 SemaRef.getLocForEndOfToken(From->getLocEnd()), ")");
5349 Converter.noteExplicitConv(SemaRef, Conversion, ConvTy);
5351 // If we aren't in a SFINAE context, build a call to the
5352 // explicit conversion function.
5353 if (SemaRef.isSFINAEContext())
5356 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5357 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5358 HadMultipleCandidates);
5359 if (Result.isInvalid())
5361 // Record usage of conversion in an implicit cast.
5362 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5363 CK_UserDefinedConversion, Result.get(),
5364 nullptr, Result.get()->getValueKind());
5369 static bool recordConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5370 Sema::ContextualImplicitConverter &Converter,
5371 QualType T, bool HadMultipleCandidates,
5372 DeclAccessPair &Found) {
5373 CXXConversionDecl *Conversion =
5374 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5375 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5377 QualType ToType = Conversion->getConversionType().getNonReferenceType();
5378 if (!Converter.SuppressConversion) {
5379 if (SemaRef.isSFINAEContext())
5382 Converter.diagnoseConversion(SemaRef, Loc, T, ToType)
5383 << From->getSourceRange();
5386 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5387 HadMultipleCandidates);
5388 if (Result.isInvalid())
5390 // Record usage of conversion in an implicit cast.
5391 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5392 CK_UserDefinedConversion, Result.get(),
5393 nullptr, Result.get()->getValueKind());
5397 static ExprResult finishContextualImplicitConversion(
5398 Sema &SemaRef, SourceLocation Loc, Expr *From,
5399 Sema::ContextualImplicitConverter &Converter) {
5400 if (!Converter.match(From->getType()) && !Converter.Suppress)
5401 Converter.diagnoseNoMatch(SemaRef, Loc, From->getType())
5402 << From->getSourceRange();
5404 return SemaRef.DefaultLvalueConversion(From);
5408 collectViableConversionCandidates(Sema &SemaRef, Expr *From, QualType ToType,
5409 UnresolvedSetImpl &ViableConversions,
5410 OverloadCandidateSet &CandidateSet) {
5411 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5412 DeclAccessPair FoundDecl = ViableConversions[I];
5413 NamedDecl *D = FoundDecl.getDecl();
5414 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
5415 if (isa<UsingShadowDecl>(D))
5416 D = cast<UsingShadowDecl>(D)->getTargetDecl();
5418 CXXConversionDecl *Conv;
5419 FunctionTemplateDecl *ConvTemplate;
5420 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
5421 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5423 Conv = cast<CXXConversionDecl>(D);
5426 SemaRef.AddTemplateConversionCandidate(
5427 ConvTemplate, FoundDecl, ActingContext, From, ToType, CandidateSet,
5428 /*AllowObjCConversionOnExplicit=*/false);
5430 SemaRef.AddConversionCandidate(Conv, FoundDecl, ActingContext, From,
5431 ToType, CandidateSet,
5432 /*AllowObjCConversionOnExplicit=*/false);
5436 /// \brief Attempt to convert the given expression to a type which is accepted
5437 /// by the given converter.
5439 /// This routine will attempt to convert an expression of class type to a
5440 /// type accepted by the specified converter. In C++11 and before, the class
5441 /// must have a single non-explicit conversion function converting to a matching
5442 /// type. In C++1y, there can be multiple such conversion functions, but only
5443 /// one target type.
5445 /// \param Loc The source location of the construct that requires the
5448 /// \param From The expression we're converting from.
5450 /// \param Converter Used to control and diagnose the conversion process.
5452 /// \returns The expression, converted to an integral or enumeration type if
5454 ExprResult Sema::PerformContextualImplicitConversion(
5455 SourceLocation Loc, Expr *From, ContextualImplicitConverter &Converter) {
5456 // We can't perform any more checking for type-dependent expressions.
5457 if (From->isTypeDependent())
5460 // Process placeholders immediately.
5461 if (From->hasPlaceholderType()) {
5462 ExprResult result = CheckPlaceholderExpr(From);
5463 if (result.isInvalid())
5465 From = result.get();
5468 // If the expression already has a matching type, we're golden.
5469 QualType T = From->getType();
5470 if (Converter.match(T))
5471 return DefaultLvalueConversion(From);
5473 // FIXME: Check for missing '()' if T is a function type?
5475 // We can only perform contextual implicit conversions on objects of class
5477 const RecordType *RecordTy = T->getAs<RecordType>();
5478 if (!RecordTy || !getLangOpts().CPlusPlus) {
5479 if (!Converter.Suppress)
5480 Converter.diagnoseNoMatch(*this, Loc, T) << From->getSourceRange();
5484 // We must have a complete class type.
5485 struct TypeDiagnoserPartialDiag : TypeDiagnoser {
5486 ContextualImplicitConverter &Converter;
5489 TypeDiagnoserPartialDiag(ContextualImplicitConverter &Converter, Expr *From)
5490 : Converter(Converter), From(From) {}
5492 void diagnose(Sema &S, SourceLocation Loc, QualType T) override {
5493 Converter.diagnoseIncomplete(S, Loc, T) << From->getSourceRange();
5495 } IncompleteDiagnoser(Converter, From);
5497 if (Converter.Suppress ? !isCompleteType(Loc, T)
5498 : RequireCompleteType(Loc, T, IncompleteDiagnoser))
5501 // Look for a conversion to an integral or enumeration type.
5503 ViableConversions; // These are *potentially* viable in C++1y.
5504 UnresolvedSet<4> ExplicitConversions;
5505 const auto &Conversions =
5506 cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions();
5508 bool HadMultipleCandidates =
5509 (std::distance(Conversions.begin(), Conversions.end()) > 1);
5511 // To check that there is only one target type, in C++1y:
5513 bool HasUniqueTargetType = true;
5515 // Collect explicit or viable (potentially in C++1y) conversions.
5516 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
5517 NamedDecl *D = (*I)->getUnderlyingDecl();
5518 CXXConversionDecl *Conversion;
5519 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
5521 if (getLangOpts().CPlusPlus14)
5522 Conversion = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5524 continue; // C++11 does not consider conversion operator templates(?).
5526 Conversion = cast<CXXConversionDecl>(D);
5528 assert((!ConvTemplate || getLangOpts().CPlusPlus14) &&
5529 "Conversion operator templates are considered potentially "
5532 QualType CurToType = Conversion->getConversionType().getNonReferenceType();
5533 if (Converter.match(CurToType) || ConvTemplate) {
5535 if (Conversion->isExplicit()) {
5536 // FIXME: For C++1y, do we need this restriction?
5537 // cf. diagnoseNoViableConversion()
5539 ExplicitConversions.addDecl(I.getDecl(), I.getAccess());
5541 if (!ConvTemplate && getLangOpts().CPlusPlus14) {
5542 if (ToType.isNull())
5543 ToType = CurToType.getUnqualifiedType();
5544 else if (HasUniqueTargetType &&
5545 (CurToType.getUnqualifiedType() != ToType))
5546 HasUniqueTargetType = false;
5548 ViableConversions.addDecl(I.getDecl(), I.getAccess());
5553 if (getLangOpts().CPlusPlus14) {
5555 // ... An expression e of class type E appearing in such a context
5556 // is said to be contextually implicitly converted to a specified
5557 // type T and is well-formed if and only if e can be implicitly
5558 // converted to a type T that is determined as follows: E is searched
5559 // for conversion functions whose return type is cv T or reference to
5560 // cv T such that T is allowed by the context. There shall be
5561 // exactly one such T.
5563 // If no unique T is found:
5564 if (ToType.isNull()) {
5565 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5566 HadMultipleCandidates,
5567 ExplicitConversions))
5569 return finishContextualImplicitConversion(*this, Loc, From, Converter);
5572 // If more than one unique Ts are found:
5573 if (!HasUniqueTargetType)
5574 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5577 // If one unique T is found:
5578 // First, build a candidate set from the previously recorded
5579 // potentially viable conversions.
5580 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Normal);
5581 collectViableConversionCandidates(*this, From, ToType, ViableConversions,
5584 // Then, perform overload resolution over the candidate set.
5585 OverloadCandidateSet::iterator Best;
5586 switch (CandidateSet.BestViableFunction(*this, Loc, Best)) {
5588 // Apply this conversion.
5589 DeclAccessPair Found =
5590 DeclAccessPair::make(Best->Function, Best->FoundDecl.getAccess());
5591 if (recordConversion(*this, Loc, From, Converter, T,
5592 HadMultipleCandidates, Found))
5597 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5599 case OR_No_Viable_Function:
5600 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5601 HadMultipleCandidates,
5602 ExplicitConversions))
5604 // fall through 'OR_Deleted' case.
5606 // We'll complain below about a non-integral condition type.
5610 switch (ViableConversions.size()) {
5612 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5613 HadMultipleCandidates,
5614 ExplicitConversions))
5617 // We'll complain below about a non-integral condition type.
5621 // Apply this conversion.
5622 DeclAccessPair Found = ViableConversions[0];
5623 if (recordConversion(*this, Loc, From, Converter, T,
5624 HadMultipleCandidates, Found))
5629 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5634 return finishContextualImplicitConversion(*this, Loc, From, Converter);
5637 /// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is
5638 /// an acceptable non-member overloaded operator for a call whose
5639 /// arguments have types T1 (and, if non-empty, T2). This routine
5640 /// implements the check in C++ [over.match.oper]p3b2 concerning
5641 /// enumeration types.
5642 static bool IsAcceptableNonMemberOperatorCandidate(ASTContext &Context,
5644 ArrayRef<Expr *> Args) {
5645 QualType T1 = Args[0]->getType();
5646 QualType T2 = Args.size() > 1 ? Args[1]->getType() : QualType();
5648 if (T1->isDependentType() || (!T2.isNull() && T2->isDependentType()))
5651 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType()))
5654 const FunctionProtoType *Proto = Fn->getType()->getAs<FunctionProtoType>();
5655 if (Proto->getNumParams() < 1)
5658 if (T1->isEnumeralType()) {
5659 QualType ArgType = Proto->getParamType(0).getNonReferenceType();
5660 if (Context.hasSameUnqualifiedType(T1, ArgType))
5664 if (Proto->getNumParams() < 2)
5667 if (!T2.isNull() && T2->isEnumeralType()) {
5668 QualType ArgType = Proto->getParamType(1).getNonReferenceType();
5669 if (Context.hasSameUnqualifiedType(T2, ArgType))
5676 /// AddOverloadCandidate - Adds the given function to the set of
5677 /// candidate functions, using the given function call arguments. If
5678 /// @p SuppressUserConversions, then don't allow user-defined
5679 /// conversions via constructors or conversion operators.
5681 /// \param PartialOverloading true if we are performing "partial" overloading
5682 /// based on an incomplete set of function arguments. This feature is used by
5683 /// code completion.
5685 Sema::AddOverloadCandidate(FunctionDecl *Function,
5686 DeclAccessPair FoundDecl,
5687 ArrayRef<Expr *> Args,
5688 OverloadCandidateSet &CandidateSet,
5689 bool SuppressUserConversions,
5690 bool PartialOverloading,
5691 bool AllowExplicit) {
5692 const FunctionProtoType *Proto
5693 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>());
5694 assert(Proto && "Functions without a prototype cannot be overloaded");
5695 assert(!Function->getDescribedFunctionTemplate() &&
5696 "Use AddTemplateOverloadCandidate for function templates");
5698 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) {
5699 if (!isa<CXXConstructorDecl>(Method)) {
5700 // If we get here, it's because we're calling a member function
5701 // that is named without a member access expression (e.g.,
5702 // "this->f") that was either written explicitly or created
5703 // implicitly. This can happen with a qualified call to a member
5704 // function, e.g., X::f(). We use an empty type for the implied
5705 // object argument (C++ [over.call.func]p3), and the acting context
5707 AddMethodCandidate(Method, FoundDecl, Method->getParent(),
5708 QualType(), Expr::Classification::makeSimpleLValue(),
5709 Args, CandidateSet, SuppressUserConversions,
5710 PartialOverloading);
5713 // We treat a constructor like a non-member function, since its object
5714 // argument doesn't participate in overload resolution.
5717 if (!CandidateSet.isNewCandidate(Function))
5720 // C++ [over.match.oper]p3:
5721 // if no operand has a class type, only those non-member functions in the
5722 // lookup set that have a first parameter of type T1 or "reference to
5723 // (possibly cv-qualified) T1", when T1 is an enumeration type, or (if there
5724 // is a right operand) a second parameter of type T2 or "reference to
5725 // (possibly cv-qualified) T2", when T2 is an enumeration type, are
5726 // candidate functions.
5727 if (CandidateSet.getKind() == OverloadCandidateSet::CSK_Operator &&
5728 !IsAcceptableNonMemberOperatorCandidate(Context, Function, Args))
5731 // C++11 [class.copy]p11: [DR1402]
5732 // A defaulted move constructor that is defined as deleted is ignored by
5733 // overload resolution.
5734 CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function);
5735 if (Constructor && Constructor->isDefaulted() && Constructor->isDeleted() &&
5736 Constructor->isMoveConstructor())
5739 // Overload resolution is always an unevaluated context.
5740 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated);
5742 // Add this candidate
5743 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size());
5744 Candidate.FoundDecl = FoundDecl;
5745 Candidate.Function = Function;
5746 Candidate.Viable = true;
5747 Candidate.IsSurrogate = false;
5748 Candidate.IgnoreObjectArgument = false;
5749 Candidate.ExplicitCallArguments = Args.size();
5752 // C++ [class.copy]p3:
5753 // A member function template is never instantiated to perform the copy
5754 // of a class object to an object of its class type.
5755 QualType ClassType = Context.getTypeDeclType(Constructor->getParent());
5756 if (Args.size() == 1 && Constructor->isSpecializationCopyingObject() &&
5757 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) ||
5758 IsDerivedFrom(Args[0]->getLocStart(), Args[0]->getType(),
5760 Candidate.Viable = false;
5761 Candidate.FailureKind = ovl_fail_illegal_constructor;
5766 unsigned NumParams = Proto->getNumParams();
5768 // (C++ 13.3.2p2): A candidate function having fewer than m
5769 // parameters is viable only if it has an ellipsis in its parameter
5771 if (TooManyArguments(NumParams, Args.size(), PartialOverloading) &&
5772 !Proto->isVariadic()) {
5773 Candidate.Viable = false;
5774 Candidate.FailureKind = ovl_fail_too_many_arguments;
5778 // (C++ 13.3.2p2): A candidate function having more than m parameters
5779 // is viable only if the (m+1)st parameter has a default argument
5780 // (8.3.6). For the purposes of overload resolution, the
5781 // parameter list is truncated on the right, so that there are
5782 // exactly m parameters.
5783 unsigned MinRequiredArgs = Function->getMinRequiredArguments();
5784 if (Args.size() < MinRequiredArgs && !PartialOverloading) {
5785 // Not enough arguments.
5786 Candidate.Viable = false;
5787 Candidate.FailureKind = ovl_fail_too_few_arguments;
5791 // (CUDA B.1): Check for invalid calls between targets.
5792 if (getLangOpts().CUDA)
5793 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext))
5794 // Skip the check for callers that are implicit members, because in this
5795 // case we may not yet know what the member's target is; the target is
5796 // inferred for the member automatically, based on the bases and fields of
5798 if (!Caller->isImplicit() && CheckCUDATarget(Caller, Function)) {
5799 Candidate.Viable = false;
5800 Candidate.FailureKind = ovl_fail_bad_target;
5804 // Determine the implicit conversion sequences for each of the
5806 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) {
5807 if (ArgIdx < NumParams) {
5808 // (C++ 13.3.2p3): for F to be a viable function, there shall
5809 // exist for each argument an implicit conversion sequence
5810 // (13.3.3.1) that converts that argument to the corresponding
5812 QualType ParamType = Proto->getParamType(ArgIdx);
5813 Candidate.Conversions[ArgIdx]
5814 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
5815 SuppressUserConversions,
5816 /*InOverloadResolution=*/true,
5817 /*AllowObjCWritebackConversion=*/
5818 getLangOpts().ObjCAutoRefCount,
5820 if (Candidate.Conversions[ArgIdx].isBad()) {
5821 Candidate.Viable = false;
5822 Candidate.FailureKind = ovl_fail_bad_conversion;
5826 // (C++ 13.3.2p2): For the purposes of overload resolution, any
5827 // argument for which there is no corresponding parameter is
5828 // considered to ""match the ellipsis" (C+ 13.3.3.1.3).
5829 Candidate.Conversions[ArgIdx].setEllipsis();
5833 if (EnableIfAttr *FailedAttr = CheckEnableIf(Function, Args)) {
5834 Candidate.Viable = false;
5835 Candidate.FailureKind = ovl_fail_enable_if;
5836 Candidate.DeductionFailure.Data = FailedAttr;
5841 ObjCMethodDecl *Sema::SelectBestMethod(Selector Sel, MultiExprArg Args,
5843 SmallVector<ObjCMethodDecl*, 4> Methods;
5844 if (!CollectMultipleMethodsInGlobalPool(Sel, Methods, IsInstance))
5847 for (unsigned b = 0, e = Methods.size(); b < e; b++) {
5849 ObjCMethodDecl *Method = Methods[b];
5850 unsigned NumNamedArgs = Sel.getNumArgs();
5851 // Method might have more arguments than selector indicates. This is due
5852 // to addition of c-style arguments in method.
5853 if (Method->param_size() > NumNamedArgs)
5854 NumNamedArgs = Method->param_size();
5855 if (Args.size() < NumNamedArgs)
5858 for (unsigned i = 0; i < NumNamedArgs; i++) {
5859 // We can't do any type-checking on a type-dependent argument.
5860 if (Args[i]->isTypeDependent()) {
5865 ParmVarDecl *param = Method->parameters()[i];
5866 Expr *argExpr = Args[i];
5867 assert(argExpr && "SelectBestMethod(): missing expression");
5869 // Strip the unbridged-cast placeholder expression off unless it's
5870 // a consumed argument.
5871 if (argExpr->hasPlaceholderType(BuiltinType::ARCUnbridgedCast) &&
5872 !param->hasAttr<CFConsumedAttr>())
5873 argExpr = stripARCUnbridgedCast(argExpr);
5875 // If the parameter is __unknown_anytype, move on to the next method.
5876 if (param->getType() == Context.UnknownAnyTy) {
5881 ImplicitConversionSequence ConversionState
5882 = TryCopyInitialization(*this, argExpr, param->getType(),
5883 /*SuppressUserConversions*/false,
5884 /*InOverloadResolution=*/true,
5885 /*AllowObjCWritebackConversion=*/
5886 getLangOpts().ObjCAutoRefCount,
5887 /*AllowExplicit*/false);
5888 if (ConversionState.isBad()) {
5893 // Promote additional arguments to variadic methods.
5894 if (Match && Method->isVariadic()) {
5895 for (unsigned i = NumNamedArgs, e = Args.size(); i < e; ++i) {
5896 if (Args[i]->isTypeDependent()) {
5900 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod,
5902 if (Arg.isInvalid()) {
5908 // Check for extra arguments to non-variadic methods.
5909 if (Args.size() != NumNamedArgs)
5911 else if (Match && NumNamedArgs == 0 && Methods.size() > 1) {
5912 // Special case when selectors have no argument. In this case, select
5913 // one with the most general result type of 'id'.
5914 for (unsigned b = 0, e = Methods.size(); b < e; b++) {
5915 QualType ReturnT = Methods[b]->getReturnType();
5916 if (ReturnT->isObjCIdType())
5928 // specific_attr_iterator iterates over enable_if attributes in reverse, and
5929 // enable_if is order-sensitive. As a result, we need to reverse things
5930 // sometimes. Size of 4 elements is arbitrary.
5931 static SmallVector<EnableIfAttr *, 4>
5932 getOrderedEnableIfAttrs(const FunctionDecl *Function) {
5933 SmallVector<EnableIfAttr *, 4> Result;
5934 if (!Function->hasAttrs())
5937 const auto &FuncAttrs = Function->getAttrs();
5938 for (Attr *Attr : FuncAttrs)
5939 if (auto *EnableIf = dyn_cast<EnableIfAttr>(Attr))
5940 Result.push_back(EnableIf);
5942 std::reverse(Result.begin(), Result.end());
5946 EnableIfAttr *Sema::CheckEnableIf(FunctionDecl *Function, ArrayRef<Expr *> Args,
5947 bool MissingImplicitThis) {
5948 auto EnableIfAttrs = getOrderedEnableIfAttrs(Function);
5949 if (EnableIfAttrs.empty())
5952 SFINAETrap Trap(*this);
5953 SmallVector<Expr *, 16> ConvertedArgs;
5954 bool InitializationFailed = false;
5955 bool ContainsValueDependentExpr = false;
5957 // Convert the arguments.
5958 for (unsigned i = 0, e = Args.size(); i != e; ++i) {
5959 if (i == 0 && !MissingImplicitThis && isa<CXXMethodDecl>(Function) &&
5960 !cast<CXXMethodDecl>(Function)->isStatic() &&
5961 !isa<CXXConstructorDecl>(Function)) {
5962 CXXMethodDecl *Method = cast<CXXMethodDecl>(Function);
5964 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/nullptr,
5966 if (R.isInvalid()) {
5967 InitializationFailed = true;
5970 ContainsValueDependentExpr |= R.get()->isValueDependent();
5971 ConvertedArgs.push_back(R.get());
5974 PerformCopyInitialization(InitializedEntity::InitializeParameter(
5976 Function->getParamDecl(i)),
5979 if (R.isInvalid()) {
5980 InitializationFailed = true;
5983 ContainsValueDependentExpr |= R.get()->isValueDependent();
5984 ConvertedArgs.push_back(R.get());
5988 if (InitializationFailed || Trap.hasErrorOccurred())
5989 return EnableIfAttrs[0];
5991 // Push default arguments if needed.
5992 if (!Function->isVariadic() && Args.size() < Function->getNumParams()) {
5993 for (unsigned i = Args.size(), e = Function->getNumParams(); i != e; ++i) {
5994 ParmVarDecl *P = Function->getParamDecl(i);
5995 ExprResult R = PerformCopyInitialization(
5996 InitializedEntity::InitializeParameter(Context,
5997 Function->getParamDecl(i)),
5999 P->hasUninstantiatedDefaultArg() ? P->getUninstantiatedDefaultArg()
6000 : P->getDefaultArg());
6001 if (R.isInvalid()) {
6002 InitializationFailed = true;
6005 ContainsValueDependentExpr |= R.get()->isValueDependent();
6006 ConvertedArgs.push_back(R.get());
6009 if (InitializationFailed || Trap.hasErrorOccurred())
6010 return EnableIfAttrs[0];
6013 for (auto *EIA : EnableIfAttrs) {
6015 if (EIA->getCond()->isValueDependent()) {
6016 // Don't even try now, we'll examine it after instantiation.
6020 if (!EIA->getCond()->EvaluateWithSubstitution(
6021 Result, Context, Function, llvm::makeArrayRef(ConvertedArgs))) {
6022 if (!ContainsValueDependentExpr)
6024 } else if (!Result.isInt() || !Result.getInt().getBoolValue()) {
6031 /// \brief Add all of the function declarations in the given function set to
6032 /// the overload candidate set.
6033 void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns,
6034 ArrayRef<Expr *> Args,
6035 OverloadCandidateSet& CandidateSet,
6036 TemplateArgumentListInfo *ExplicitTemplateArgs,
6037 bool SuppressUserConversions,
6038 bool PartialOverloading) {
6039 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) {
6040 NamedDecl *D = F.getDecl()->getUnderlyingDecl();
6041 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
6042 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic())
6043 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(),
6044 cast<CXXMethodDecl>(FD)->getParent(),
6045 Args[0]->getType(), Args[0]->Classify(Context),
6046 Args.slice(1), CandidateSet,
6047 SuppressUserConversions, PartialOverloading);
6049 AddOverloadCandidate(FD, F.getPair(), Args, CandidateSet,
6050 SuppressUserConversions, PartialOverloading);
6052 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D);
6053 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) &&
6054 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic())
6055 AddMethodTemplateCandidate(FunTmpl, F.getPair(),
6056 cast<CXXRecordDecl>(FunTmpl->getDeclContext()),
6057 ExplicitTemplateArgs,
6059 Args[0]->Classify(Context), Args.slice(1),
6060 CandidateSet, SuppressUserConversions,
6061 PartialOverloading);
6063 AddTemplateOverloadCandidate(FunTmpl, F.getPair(),
6064 ExplicitTemplateArgs, Args,
6065 CandidateSet, SuppressUserConversions,
6066 PartialOverloading);
6071 /// AddMethodCandidate - Adds a named decl (which is some kind of
6072 /// method) as a method candidate to the given overload set.
6073 void Sema::AddMethodCandidate(DeclAccessPair FoundDecl,
6074 QualType ObjectType,
6075 Expr::Classification ObjectClassification,
6076 ArrayRef<Expr *> Args,
6077 OverloadCandidateSet& CandidateSet,
6078 bool SuppressUserConversions) {
6079 NamedDecl *Decl = FoundDecl.getDecl();
6080 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext());
6082 if (isa<UsingShadowDecl>(Decl))
6083 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl();
6085 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) {
6086 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) &&
6087 "Expected a member function template");
6088 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext,
6089 /*ExplicitArgs*/ nullptr,
6090 ObjectType, ObjectClassification,
6092 SuppressUserConversions);
6094 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext,
6095 ObjectType, ObjectClassification,
6097 CandidateSet, SuppressUserConversions);
6101 /// AddMethodCandidate - Adds the given C++ member function to the set
6102 /// of candidate functions, using the given function call arguments
6103 /// and the object argument (@c Object). For example, in a call
6104 /// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain
6105 /// both @c a1 and @c a2. If @p SuppressUserConversions, then don't
6106 /// allow user-defined conversions via constructors or conversion
6109 Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl,
6110 CXXRecordDecl *ActingContext, QualType ObjectType,
6111 Expr::Classification ObjectClassification,
6112 ArrayRef<Expr *> Args,
6113 OverloadCandidateSet &CandidateSet,
6114 bool SuppressUserConversions,
6115 bool PartialOverloading) {
6116 const FunctionProtoType *Proto
6117 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>());
6118 assert(Proto && "Methods without a prototype cannot be overloaded");
6119 assert(!isa<CXXConstructorDecl>(Method) &&
6120 "Use AddOverloadCandidate for constructors");
6122 if (!CandidateSet.isNewCandidate(Method))
6125 // C++11 [class.copy]p23: [DR1402]
6126 // A defaulted move assignment operator that is defined as deleted is
6127 // ignored by overload resolution.
6128 if (Method->isDefaulted() && Method->isDeleted() &&
6129 Method->isMoveAssignmentOperator())
6132 // Overload resolution is always an unevaluated context.
6133 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated);
6135 // Add this candidate
6136 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1);
6137 Candidate.FoundDecl = FoundDecl;
6138 Candidate.Function = Method;
6139 Candidate.IsSurrogate = false;
6140 Candidate.IgnoreObjectArgument = false;
6141 Candidate.ExplicitCallArguments = Args.size();
6143 unsigned NumParams = Proto->getNumParams();
6145 // (C++ 13.3.2p2): A candidate function having fewer than m
6146 // parameters is viable only if it has an ellipsis in its parameter
6148 if (TooManyArguments(NumParams, Args.size(), PartialOverloading) &&
6149 !Proto->isVariadic()) {
6150 Candidate.Viable = false;
6151 Candidate.FailureKind = ovl_fail_too_many_arguments;
6155 // (C++ 13.3.2p2): A candidate function having more than m parameters
6156 // is viable only if the (m+1)st parameter has a default argument
6157 // (8.3.6). For the purposes of overload resolution, the
6158 // parameter list is truncated on the right, so that there are
6159 // exactly m parameters.
6160 unsigned MinRequiredArgs = Method->getMinRequiredArguments();
6161 if (Args.size() < MinRequiredArgs && !PartialOverloading) {
6162 // Not enough arguments.
6163 Candidate.Viable = false;
6164 Candidate.FailureKind = ovl_fail_too_few_arguments;
6168 Candidate.Viable = true;
6170 if (Method->isStatic() || ObjectType.isNull())
6171 // The implicit object argument is ignored.
6172 Candidate.IgnoreObjectArgument = true;
6174 // Determine the implicit conversion sequence for the object
6176 Candidate.Conversions[0] = TryObjectArgumentInitialization(
6177 *this, CandidateSet.getLocation(), ObjectType, ObjectClassification,
6178 Method, ActingContext);
6179 if (Candidate.Conversions[0].isBad()) {
6180 Candidate.Viable = false;
6181 Candidate.FailureKind = ovl_fail_bad_conversion;
6186 // (CUDA B.1): Check for invalid calls between targets.
6187 if (getLangOpts().CUDA)
6188 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext))
6189 if (CheckCUDATarget(Caller, Method)) {
6190 Candidate.Viable = false;
6191 Candidate.FailureKind = ovl_fail_bad_target;
6195 // Determine the implicit conversion sequences for each of the
6197 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) {
6198 if (ArgIdx < NumParams) {
6199 // (C++ 13.3.2p3): for F to be a viable function, there shall
6200 // exist for each argument an implicit conversion sequence
6201 // (13.3.3.1) that converts that argument to the corresponding
6203 QualType ParamType = Proto->getParamType(ArgIdx);
6204 Candidate.Conversions[ArgIdx + 1]
6205 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
6206 SuppressUserConversions,
6207 /*InOverloadResolution=*/true,
6208 /*AllowObjCWritebackConversion=*/
6209 getLangOpts().ObjCAutoRefCount);
6210 if (Candidate.Conversions[ArgIdx + 1].isBad()) {
6211 Candidate.Viable = false;
6212 Candidate.FailureKind = ovl_fail_bad_conversion;
6216 // (C++ 13.3.2p2): For the purposes of overload resolution, any
6217 // argument for which there is no corresponding parameter is
6218 // considered to "match the ellipsis" (C+ 13.3.3.1.3).
6219 Candidate.Conversions[ArgIdx + 1].setEllipsis();
6223 if (EnableIfAttr *FailedAttr = CheckEnableIf(Method, Args, true)) {
6224 Candidate.Viable = false;
6225 Candidate.FailureKind = ovl_fail_enable_if;
6226 Candidate.DeductionFailure.Data = FailedAttr;
6231 /// \brief Add a C++ member function template as a candidate to the candidate
6232 /// set, using template argument deduction to produce an appropriate member
6233 /// function template specialization.
6235 Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl,
6236 DeclAccessPair FoundDecl,
6237 CXXRecordDecl *ActingContext,
6238 TemplateArgumentListInfo *ExplicitTemplateArgs,
6239 QualType ObjectType,
6240 Expr::Classification ObjectClassification,
6241 ArrayRef<Expr *> Args,
6242 OverloadCandidateSet& CandidateSet,
6243 bool SuppressUserConversions,
6244 bool PartialOverloading) {
6245 if (!CandidateSet.isNewCandidate(MethodTmpl))
6248 // C++ [over.match.funcs]p7:
6249 // In each case where a candidate is a function template, candidate
6250 // function template specializations are generated using template argument
6251 // deduction (14.8.3, 14.8.2). Those candidates are then handled as
6252 // candidate functions in the usual way.113) A given name can refer to one
6253 // or more function templates and also to a set of overloaded non-template
6254 // functions. In such a case, the candidate functions generated from each
6255 // function template are combined with the set of non-template candidate
6257 TemplateDeductionInfo Info(CandidateSet.getLocation());
6258 FunctionDecl *Specialization = nullptr;
6259 if (TemplateDeductionResult Result
6260 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, Args,
6261 Specialization, Info, PartialOverloading)) {
6262 OverloadCandidate &Candidate = CandidateSet.addCandidate();
6263 Candidate.FoundDecl = FoundDecl;
6264 Candidate.Function = MethodTmpl->getTemplatedDecl();
6265 Candidate.Viable = false;
6266 Candidate.FailureKind = ovl_fail_bad_deduction;
6267 Candidate.IsSurrogate = false;
6268 Candidate.IgnoreObjectArgument = false;
6269 Candidate.ExplicitCallArguments = Args.size();
6270 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
6275 // Add the function template specialization produced by template argument
6276 // deduction as a candidate.
6277 assert(Specialization && "Missing member function template specialization?");
6278 assert(isa<CXXMethodDecl>(Specialization) &&
6279 "Specialization is not a member function?");
6280 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl,
6281 ActingContext, ObjectType, ObjectClassification, Args,
6282 CandidateSet, SuppressUserConversions, PartialOverloading);
6285 /// \brief Add a C++ function template specialization as a candidate
6286 /// in the candidate set, using template argument deduction to produce
6287 /// an appropriate function template specialization.
6289 Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate,
6290 DeclAccessPair FoundDecl,
6291 TemplateArgumentListInfo *ExplicitTemplateArgs,
6292 ArrayRef<Expr *> Args,
6293 OverloadCandidateSet& CandidateSet,
6294 bool SuppressUserConversions,
6295 bool PartialOverloading) {
6296 if (!CandidateSet.isNewCandidate(FunctionTemplate))
6299 // C++ [over.match.funcs]p7:
6300 // In each case where a candidate is a function template, candidate
6301 // function template specializations are generated using template argument
6302 // deduction (14.8.3, 14.8.2). Those candidates are then handled as
6303 // candidate functions in the usual way.113) A given name can refer to one
6304 // or more function templates and also to a set of overloaded non-template
6305 // functions. In such a case, the candidate functions generated from each
6306 // function template are combined with the set of non-template candidate
6308 TemplateDeductionInfo Info(CandidateSet.getLocation());
6309 FunctionDecl *Specialization = nullptr;
6310 if (TemplateDeductionResult Result
6311 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, Args,
6312 Specialization, Info, PartialOverloading)) {
6313 OverloadCandidate &Candidate = CandidateSet.addCandidate();
6314 Candidate.FoundDecl = FoundDecl;
6315 Candidate.Function = FunctionTemplate->getTemplatedDecl();
6316 Candidate.Viable = false;
6317 Candidate.FailureKind = ovl_fail_bad_deduction;
6318 Candidate.IsSurrogate = false;
6319 Candidate.IgnoreObjectArgument = false;
6320 Candidate.ExplicitCallArguments = Args.size();
6321 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
6326 // Add the function template specialization produced by template argument
6327 // deduction as a candidate.
6328 assert(Specialization && "Missing function template specialization?");
6329 AddOverloadCandidate(Specialization, FoundDecl, Args, CandidateSet,
6330 SuppressUserConversions, PartialOverloading);
6333 /// Determine whether this is an allowable conversion from the result
6334 /// of an explicit conversion operator to the expected type, per C++
6335 /// [over.match.conv]p1 and [over.match.ref]p1.
6337 /// \param ConvType The return type of the conversion function.
6339 /// \param ToType The type we are converting to.
6341 /// \param AllowObjCPointerConversion Allow a conversion from one
6342 /// Objective-C pointer to another.
6344 /// \returns true if the conversion is allowable, false otherwise.
6345 static bool isAllowableExplicitConversion(Sema &S,
6346 QualType ConvType, QualType ToType,
6347 bool AllowObjCPointerConversion) {
6348 QualType ToNonRefType = ToType.getNonReferenceType();
6350 // Easy case: the types are the same.
6351 if (S.Context.hasSameUnqualifiedType(ConvType, ToNonRefType))
6354 // Allow qualification conversions.
6355 bool ObjCLifetimeConversion;
6356 if (S.IsQualificationConversion(ConvType, ToNonRefType, /*CStyle*/false,
6357 ObjCLifetimeConversion))
6360 // If we're not allowed to consider Objective-C pointer conversions,
6362 if (!AllowObjCPointerConversion)
6365 // Is this an Objective-C pointer conversion?
6366 bool IncompatibleObjC = false;
6367 QualType ConvertedType;
6368 return S.isObjCPointerConversion(ConvType, ToNonRefType, ConvertedType,
6372 /// AddConversionCandidate - Add a C++ conversion function as a
6373 /// candidate in the candidate set (C++ [over.match.conv],
6374 /// C++ [over.match.copy]). From is the expression we're converting from,
6375 /// and ToType is the type that we're eventually trying to convert to
6376 /// (which may or may not be the same type as the type that the
6377 /// conversion function produces).
6379 Sema::AddConversionCandidate(CXXConversionDecl *Conversion,
6380 DeclAccessPair FoundDecl,
6381 CXXRecordDecl *ActingContext,
6382 Expr *From, QualType ToType,
6383 OverloadCandidateSet& CandidateSet,
6384 bool AllowObjCConversionOnExplicit) {
6385 assert(!Conversion->getDescribedFunctionTemplate() &&
6386 "Conversion function templates use AddTemplateConversionCandidate");
6387 QualType ConvType = Conversion->getConversionType().getNonReferenceType();
6388 if (!CandidateSet.isNewCandidate(Conversion))
6391 // If the conversion function has an undeduced return type, trigger its
6393 if (getLangOpts().CPlusPlus14 && ConvType->isUndeducedType()) {
6394 if (DeduceReturnType(Conversion, From->getExprLoc()))
6396 ConvType = Conversion->getConversionType().getNonReferenceType();
6399 // Per C++ [over.match.conv]p1, [over.match.ref]p1, an explicit conversion
6400 // operator is only a candidate if its return type is the target type or
6401 // can be converted to the target type with a qualification conversion.
6402 if (Conversion->isExplicit() &&
6403 !isAllowableExplicitConversion(*this, ConvType, ToType,
6404 AllowObjCConversionOnExplicit))
6407 // Overload resolution is always an unevaluated context.
6408 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated);
6410 // Add this candidate
6411 OverloadCandidate &Candidate = CandidateSet.addCandidate(1);
6412 Candidate.FoundDecl = FoundDecl;
6413 Candidate.Function = Conversion;
6414 Candidate.IsSurrogate = false;
6415 Candidate.IgnoreObjectArgument = false;
6416 Candidate.FinalConversion.setAsIdentityConversion();
6417 Candidate.FinalConversion.setFromType(ConvType);
6418 Candidate.FinalConversion.setAllToTypes(ToType);
6419 Candidate.Viable = true;
6420 Candidate.ExplicitCallArguments = 1;
6422 // C++ [over.match.funcs]p4:
6423 // For conversion functions, the function is considered to be a member of
6424 // the class of the implicit implied object argument for the purpose of
6425 // defining the type of the implicit object parameter.
6427 // Determine the implicit conversion sequence for the implicit
6428 // object parameter.
6429 QualType ImplicitParamType = From->getType();
6430 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>())
6431 ImplicitParamType = FromPtrType->getPointeeType();
6432 CXXRecordDecl *ConversionContext
6433 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl());
6435 Candidate.Conversions[0] = TryObjectArgumentInitialization(
6436 *this, CandidateSet.getLocation(), From->getType(),
6437 From->Classify(Context), Conversion, ConversionContext);
6439 if (Candidate.Conversions[0].isBad()) {
6440 Candidate.Viable = false;
6441 Candidate.FailureKind = ovl_fail_bad_conversion;
6445 // We won't go through a user-defined type conversion function to convert a
6446 // derived to base as such conversions are given Conversion Rank. They only
6447 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user]
6449 = Context.getCanonicalType(From->getType().getUnqualifiedType());
6450 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType();
6451 if (FromCanon == ToCanon ||
6452 IsDerivedFrom(CandidateSet.getLocation(), FromCanon, ToCanon)) {
6453 Candidate.Viable = false;
6454 Candidate.FailureKind = ovl_fail_trivial_conversion;
6458 // To determine what the conversion from the result of calling the
6459 // conversion function to the type we're eventually trying to
6460 // convert to (ToType), we need to synthesize a call to the
6461 // conversion function and attempt copy initialization from it. This
6462 // makes sure that we get the right semantics with respect to
6463 // lvalues/rvalues and the type. Fortunately, we can allocate this
6464 // call on the stack and we don't need its arguments to be
6466 DeclRefExpr ConversionRef(Conversion, false, Conversion->getType(),
6467 VK_LValue, From->getLocStart());
6468 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack,
6469 Context.getPointerType(Conversion->getType()),
6470 CK_FunctionToPointerDecay,
6471 &ConversionRef, VK_RValue);
6473 QualType ConversionType = Conversion->getConversionType();
6474 if (!isCompleteType(From->getLocStart(), ConversionType)) {
6475 Candidate.Viable = false;
6476 Candidate.FailureKind = ovl_fail_bad_final_conversion;
6480 ExprValueKind VK = Expr::getValueKindForType(ConversionType);
6482 // Note that it is safe to allocate CallExpr on the stack here because
6483 // there are 0 arguments (i.e., nothing is allocated using ASTContext's
6485 QualType CallResultType = ConversionType.getNonLValueExprType(Context);
6486 CallExpr Call(Context, &ConversionFn, None, CallResultType, VK,
6487 From->getLocStart());
6488 ImplicitConversionSequence ICS =
6489 TryCopyInitialization(*this, &Call, ToType,
6490 /*SuppressUserConversions=*/true,
6491 /*InOverloadResolution=*/false,
6492 /*AllowObjCWritebackConversion=*/false);
6494 switch (ICS.getKind()) {
6495 case ImplicitConversionSequence::StandardConversion:
6496 Candidate.FinalConversion = ICS.Standard;
6498 // C++ [over.ics.user]p3:
6499 // If the user-defined conversion is specified by a specialization of a
6500 // conversion function template, the second standard conversion sequence
6501 // shall have exact match rank.
6502 if (Conversion->getPrimaryTemplate() &&
6503 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) {
6504 Candidate.Viable = false;
6505 Candidate.FailureKind = ovl_fail_final_conversion_not_exact;
6509 // C++0x [dcl.init.ref]p5:
6510 // In the second case, if the reference is an rvalue reference and
6511 // the second standard conversion sequence of the user-defined
6512 // conversion sequence includes an lvalue-to-rvalue conversion, the
6513 // program is ill-formed.
6514 if (ToType->isRValueReferenceType() &&
6515 ICS.Standard.First == ICK_Lvalue_To_Rvalue) {
6516 Candidate.Viable = false;
6517 Candidate.FailureKind = ovl_fail_bad_final_conversion;
6522 case ImplicitConversionSequence::BadConversion:
6523 Candidate.Viable = false;
6524 Candidate.FailureKind = ovl_fail_bad_final_conversion;
6529 "Can only end up with a standard conversion sequence or failure");
6532 if (EnableIfAttr *FailedAttr = CheckEnableIf(Conversion, None)) {
6533 Candidate.Viable = false;
6534 Candidate.FailureKind = ovl_fail_enable_if;
6535 Candidate.DeductionFailure.Data = FailedAttr;
6540 /// \brief Adds a conversion function template specialization
6541 /// candidate to the overload set, using template argument deduction
6542 /// to deduce the template arguments of the conversion function
6543 /// template from the type that we are converting to (C++
6544 /// [temp.deduct.conv]).
6546 Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate,
6547 DeclAccessPair FoundDecl,
6548 CXXRecordDecl *ActingDC,
6549 Expr *From, QualType ToType,
6550 OverloadCandidateSet &CandidateSet,
6551 bool AllowObjCConversionOnExplicit) {
6552 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) &&
6553 "Only conversion function templates permitted here");
6555 if (!CandidateSet.isNewCandidate(FunctionTemplate))
6558 TemplateDeductionInfo Info(CandidateSet.getLocation());
6559 CXXConversionDecl *Specialization = nullptr;
6560 if (TemplateDeductionResult Result
6561 = DeduceTemplateArguments(FunctionTemplate, ToType,
6562 Specialization, Info)) {
6563 OverloadCandidate &Candidate = CandidateSet.addCandidate();
6564 Candidate.FoundDecl = FoundDecl;
6565 Candidate.Function = FunctionTemplate->getTemplatedDecl();
6566 Candidate.Viable = false;
6567 Candidate.FailureKind = ovl_fail_bad_deduction;
6568 Candidate.IsSurrogate = false;
6569 Candidate.IgnoreObjectArgument = false;
6570 Candidate.ExplicitCallArguments = 1;
6571 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
6576 // Add the conversion function template specialization produced by
6577 // template argument deduction as a candidate.
6578 assert(Specialization && "Missing function template specialization?");
6579 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType,
6580 CandidateSet, AllowObjCConversionOnExplicit);
6583 /// AddSurrogateCandidate - Adds a "surrogate" candidate function that
6584 /// converts the given @c Object to a function pointer via the
6585 /// conversion function @c Conversion, and then attempts to call it
6586 /// with the given arguments (C++ [over.call.object]p2-4). Proto is
6587 /// the type of function that we'll eventually be calling.
6588 void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion,
6589 DeclAccessPair FoundDecl,
6590 CXXRecordDecl *ActingContext,
6591 const FunctionProtoType *Proto,
6593 ArrayRef<Expr *> Args,
6594 OverloadCandidateSet& CandidateSet) {
6595 if (!CandidateSet.isNewCandidate(Conversion))
6598 // Overload resolution is always an unevaluated context.
6599 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated);
6601 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1);
6602 Candidate.FoundDecl = FoundDecl;
6603 Candidate.Function = nullptr;
6604 Candidate.Surrogate = Conversion;
6605 Candidate.Viable = true;
6606 Candidate.IsSurrogate = true;
6607 Candidate.IgnoreObjectArgument = false;
6608 Candidate.ExplicitCallArguments = Args.size();
6610 // Determine the implicit conversion sequence for the implicit
6611 // object parameter.
6612 ImplicitConversionSequence ObjectInit = TryObjectArgumentInitialization(
6613 *this, CandidateSet.getLocation(), Object->getType(),
6614 Object->Classify(Context), Conversion, ActingContext);
6615 if (ObjectInit.isBad()) {
6616 Candidate.Viable = false;
6617 Candidate.FailureKind = ovl_fail_bad_conversion;
6618 Candidate.Conversions[0] = ObjectInit;
6622 // The first conversion is actually a user-defined conversion whose
6623 // first conversion is ObjectInit's standard conversion (which is
6624 // effectively a reference binding). Record it as such.
6625 Candidate.Conversions[0].setUserDefined();
6626 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard;
6627 Candidate.Conversions[0].UserDefined.EllipsisConversion = false;
6628 Candidate.Conversions[0].UserDefined.HadMultipleCandidates = false;
6629 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion;
6630 Candidate.Conversions[0].UserDefined.FoundConversionFunction = FoundDecl;
6631 Candidate.Conversions[0].UserDefined.After
6632 = Candidate.Conversions[0].UserDefined.Before;
6633 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion();
6636 unsigned NumParams = Proto->getNumParams();
6638 // (C++ 13.3.2p2): A candidate function having fewer than m
6639 // parameters is viable only if it has an ellipsis in its parameter
6641 if (Args.size() > NumParams && !Proto->isVariadic()) {
6642 Candidate.Viable = false;
6643 Candidate.FailureKind = ovl_fail_too_many_arguments;
6647 // Function types don't have any default arguments, so just check if
6648 // we have enough arguments.
6649 if (Args.size() < NumParams) {
6650 // Not enough arguments.
6651 Candidate.Viable = false;
6652 Candidate.FailureKind = ovl_fail_too_few_arguments;
6656 // Determine the implicit conversion sequences for each of the
6658 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
6659 if (ArgIdx < NumParams) {
6660 // (C++ 13.3.2p3): for F to be a viable function, there shall
6661 // exist for each argument an implicit conversion sequence
6662 // (13.3.3.1) that converts that argument to the corresponding
6664 QualType ParamType = Proto->getParamType(ArgIdx);
6665 Candidate.Conversions[ArgIdx + 1]
6666 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
6667 /*SuppressUserConversions=*/false,
6668 /*InOverloadResolution=*/false,
6669 /*AllowObjCWritebackConversion=*/
6670 getLangOpts().ObjCAutoRefCount);
6671 if (Candidate.Conversions[ArgIdx + 1].isBad()) {
6672 Candidate.Viable = false;
6673 Candidate.FailureKind = ovl_fail_bad_conversion;
6677 // (C++ 13.3.2p2): For the purposes of overload resolution, any
6678 // argument for which there is no corresponding parameter is
6679 // considered to ""match the ellipsis" (C+ 13.3.3.1.3).
6680 Candidate.Conversions[ArgIdx + 1].setEllipsis();
6684 if (EnableIfAttr *FailedAttr = CheckEnableIf(Conversion, None)) {
6685 Candidate.Viable = false;
6686 Candidate.FailureKind = ovl_fail_enable_if;
6687 Candidate.DeductionFailure.Data = FailedAttr;
6692 /// \brief Add overload candidates for overloaded operators that are
6693 /// member functions.
6695 /// Add the overloaded operator candidates that are member functions
6696 /// for the operator Op that was used in an operator expression such
6697 /// as "x Op y". , Args/NumArgs provides the operator arguments, and
6698 /// CandidateSet will store the added overload candidates. (C++
6699 /// [over.match.oper]).
6700 void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op,
6701 SourceLocation OpLoc,
6702 ArrayRef<Expr *> Args,
6703 OverloadCandidateSet& CandidateSet,
6704 SourceRange OpRange) {
6705 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
6707 // C++ [over.match.oper]p3:
6708 // For a unary operator @ with an operand of a type whose
6709 // cv-unqualified version is T1, and for a binary operator @ with
6710 // a left operand of a type whose cv-unqualified version is T1 and
6711 // a right operand of a type whose cv-unqualified version is T2,
6712 // three sets of candidate functions, designated member
6713 // candidates, non-member candidates and built-in candidates, are
6714 // constructed as follows:
6715 QualType T1 = Args[0]->getType();
6717 // -- If T1 is a complete class type or a class currently being
6718 // defined, the set of member candidates is the result of the
6719 // qualified lookup of T1::operator@ (13.3.1.1.1); otherwise,
6720 // the set of member candidates is empty.
6721 if (const RecordType *T1Rec = T1->getAs<RecordType>()) {
6722 // Complete the type if it can be completed.
6723 if (!isCompleteType(OpLoc, T1) && !T1Rec->isBeingDefined())
6725 // If the type is neither complete nor being defined, bail out now.
6726 if (!T1Rec->getDecl()->getDefinition())
6729 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName);
6730 LookupQualifiedName(Operators, T1Rec->getDecl());
6731 Operators.suppressDiagnostics();
6733 for (LookupResult::iterator Oper = Operators.begin(),
6734 OperEnd = Operators.end();
6737 AddMethodCandidate(Oper.getPair(), Args[0]->getType(),
6738 Args[0]->Classify(Context),
6741 /* SuppressUserConversions = */ false);
6745 /// AddBuiltinCandidate - Add a candidate for a built-in
6746 /// operator. ResultTy and ParamTys are the result and parameter types
6747 /// of the built-in candidate, respectively. Args and NumArgs are the
6748 /// arguments being passed to the candidate. IsAssignmentOperator
6749 /// should be true when this built-in candidate is an assignment
6750 /// operator. NumContextualBoolArguments is the number of arguments
6751 /// (at the beginning of the argument list) that will be contextually
6752 /// converted to bool.
6753 void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys,
6754 ArrayRef<Expr *> Args,
6755 OverloadCandidateSet& CandidateSet,
6756 bool IsAssignmentOperator,
6757 unsigned NumContextualBoolArguments) {
6758 // Overload resolution is always an unevaluated context.
6759 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated);
6761 // Add this candidate
6762 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size());
6763 Candidate.FoundDecl = DeclAccessPair::make(nullptr, AS_none);
6764 Candidate.Function = nullptr;
6765 Candidate.IsSurrogate = false;
6766 Candidate.IgnoreObjectArgument = false;
6767 Candidate.BuiltinTypes.ResultTy = ResultTy;
6768 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx)
6769 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx];
6771 // Determine the implicit conversion sequences for each of the
6773 Candidate.Viable = true;
6774 Candidate.ExplicitCallArguments = Args.size();
6775 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
6776 // C++ [over.match.oper]p4:
6777 // For the built-in assignment operators, conversions of the
6778 // left operand are restricted as follows:
6779 // -- no temporaries are introduced to hold the left operand, and
6780 // -- no user-defined conversions are applied to the left
6781 // operand to achieve a type match with the left-most
6782 // parameter of a built-in candidate.
6784 // We block these conversions by turning off user-defined
6785 // conversions, since that is the only way that initialization of
6786 // a reference to a non-class type can occur from something that
6787 // is not of the same type.
6788 if (ArgIdx < NumContextualBoolArguments) {
6789 assert(ParamTys[ArgIdx] == Context.BoolTy &&
6790 "Contextual conversion to bool requires bool type");
6791 Candidate.Conversions[ArgIdx]
6792 = TryContextuallyConvertToBool(*this, Args[ArgIdx]);
6794 Candidate.Conversions[ArgIdx]
6795 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx],
6796 ArgIdx == 0 && IsAssignmentOperator,
6797 /*InOverloadResolution=*/false,
6798 /*AllowObjCWritebackConversion=*/
6799 getLangOpts().ObjCAutoRefCount);
6801 if (Candidate.Conversions[ArgIdx].isBad()) {
6802 Candidate.Viable = false;
6803 Candidate.FailureKind = ovl_fail_bad_conversion;
6811 /// BuiltinCandidateTypeSet - A set of types that will be used for the
6812 /// candidate operator functions for built-in operators (C++
6813 /// [over.built]). The types are separated into pointer types and
6814 /// enumeration types.
6815 class BuiltinCandidateTypeSet {
6816 /// TypeSet - A set of types.
6817 typedef llvm::SmallPtrSet<QualType, 8> TypeSet;
6819 /// PointerTypes - The set of pointer types that will be used in the
6820 /// built-in candidates.
6821 TypeSet PointerTypes;
6823 /// MemberPointerTypes - The set of member pointer types that will be
6824 /// used in the built-in candidates.
6825 TypeSet MemberPointerTypes;
6827 /// EnumerationTypes - The set of enumeration types that will be
6828 /// used in the built-in candidates.
6829 TypeSet EnumerationTypes;
6831 /// \brief The set of vector types that will be used in the built-in
6833 TypeSet VectorTypes;
6835 /// \brief A flag indicating non-record types are viable candidates
6836 bool HasNonRecordTypes;
6838 /// \brief A flag indicating whether either arithmetic or enumeration types
6839 /// were present in the candidate set.
6840 bool HasArithmeticOrEnumeralTypes;
6842 /// \brief A flag indicating whether the nullptr type was present in the
6844 bool HasNullPtrType;
6846 /// Sema - The semantic analysis instance where we are building the
6847 /// candidate type set.
6850 /// Context - The AST context in which we will build the type sets.
6851 ASTContext &Context;
6853 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
6854 const Qualifiers &VisibleQuals);
6855 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty);
6858 /// iterator - Iterates through the types that are part of the set.
6859 typedef TypeSet::iterator iterator;
6861 BuiltinCandidateTypeSet(Sema &SemaRef)
6862 : HasNonRecordTypes(false),
6863 HasArithmeticOrEnumeralTypes(false),
6864 HasNullPtrType(false),
6866 Context(SemaRef.Context) { }
6868 void AddTypesConvertedFrom(QualType Ty,
6870 bool AllowUserConversions,
6871 bool AllowExplicitConversions,
6872 const Qualifiers &VisibleTypeConversionsQuals);
6874 /// pointer_begin - First pointer type found;
6875 iterator pointer_begin() { return PointerTypes.begin(); }
6877 /// pointer_end - Past the last pointer type found;
6878 iterator pointer_end() { return PointerTypes.end(); }
6880 /// member_pointer_begin - First member pointer type found;
6881 iterator member_pointer_begin() { return MemberPointerTypes.begin(); }
6883 /// member_pointer_end - Past the last member pointer type found;
6884 iterator member_pointer_end() { return MemberPointerTypes.end(); }
6886 /// enumeration_begin - First enumeration type found;
6887 iterator enumeration_begin() { return EnumerationTypes.begin(); }
6889 /// enumeration_end - Past the last enumeration type found;
6890 iterator enumeration_end() { return EnumerationTypes.end(); }
6892 iterator vector_begin() { return VectorTypes.begin(); }
6893 iterator vector_end() { return VectorTypes.end(); }
6895 bool hasNonRecordTypes() { return HasNonRecordTypes; }
6896 bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; }
6897 bool hasNullPtrType() const { return HasNullPtrType; }
6900 } // end anonymous namespace
6902 /// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to
6903 /// the set of pointer types along with any more-qualified variants of
6904 /// that type. For example, if @p Ty is "int const *", this routine
6905 /// will add "int const *", "int const volatile *", "int const
6906 /// restrict *", and "int const volatile restrict *" to the set of
6907 /// pointer types. Returns true if the add of @p Ty itself succeeded,
6908 /// false otherwise.
6910 /// FIXME: what to do about extended qualifiers?
6912 BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
6913 const Qualifiers &VisibleQuals) {
6915 // Insert this type.
6916 if (!PointerTypes.insert(Ty).second)
6920 const PointerType *PointerTy = Ty->getAs<PointerType>();
6921 bool buildObjCPtr = false;
6923 const ObjCObjectPointerType *PTy = Ty->castAs<ObjCObjectPointerType>();
6924 PointeeTy = PTy->getPointeeType();
6925 buildObjCPtr = true;
6927 PointeeTy = PointerTy->getPointeeType();
6930 // Don't add qualified variants of arrays. For one, they're not allowed
6931 // (the qualifier would sink to the element type), and for another, the
6932 // only overload situation where it matters is subscript or pointer +- int,
6933 // and those shouldn't have qualifier variants anyway.
6934 if (PointeeTy->isArrayType())
6937 unsigned BaseCVR = PointeeTy.getCVRQualifiers();
6938 bool hasVolatile = VisibleQuals.hasVolatile();
6939 bool hasRestrict = VisibleQuals.hasRestrict();
6941 // Iterate through all strict supersets of BaseCVR.
6942 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) {
6943 if ((CVR | BaseCVR) != CVR) continue;
6944 // Skip over volatile if no volatile found anywhere in the types.
6945 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue;
6947 // Skip over restrict if no restrict found anywhere in the types, or if
6948 // the type cannot be restrict-qualified.
6949 if ((CVR & Qualifiers::Restrict) &&
6951 (!(PointeeTy->isAnyPointerType() || PointeeTy->isReferenceType()))))
6954 // Build qualified pointee type.
6955 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR);
6957 // Build qualified pointer type.
6958 QualType QPointerTy;
6960 QPointerTy = Context.getPointerType(QPointeeTy);
6962 QPointerTy = Context.getObjCObjectPointerType(QPointeeTy);
6964 // Insert qualified pointer type.
6965 PointerTypes.insert(QPointerTy);
6971 /// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty
6972 /// to the set of pointer types along with any more-qualified variants of
6973 /// that type. For example, if @p Ty is "int const *", this routine
6974 /// will add "int const *", "int const volatile *", "int const
6975 /// restrict *", and "int const volatile restrict *" to the set of
6976 /// pointer types. Returns true if the add of @p Ty itself succeeded,
6977 /// false otherwise.
6979 /// FIXME: what to do about extended qualifiers?
6981 BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants(
6983 // Insert this type.
6984 if (!MemberPointerTypes.insert(Ty).second)
6987 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>();
6988 assert(PointerTy && "type was not a member pointer type!");
6990 QualType PointeeTy = PointerTy->getPointeeType();
6991 // Don't add qualified variants of arrays. For one, they're not allowed
6992 // (the qualifier would sink to the element type), and for another, the
6993 // only overload situation where it matters is subscript or pointer +- int,
6994 // and those shouldn't have qualifier variants anyway.
6995 if (PointeeTy->isArrayType())
6997 const Type *ClassTy = PointerTy->getClass();
6999 // Iterate through all strict supersets of the pointee type's CVR
7001 unsigned BaseCVR = PointeeTy.getCVRQualifiers();
7002 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) {
7003 if ((CVR | BaseCVR) != CVR) continue;
7005 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR);
7006 MemberPointerTypes.insert(
7007 Context.getMemberPointerType(QPointeeTy, ClassTy));
7013 /// AddTypesConvertedFrom - Add each of the types to which the type @p
7014 /// Ty can be implicit converted to the given set of @p Types. We're
7015 /// primarily interested in pointer types and enumeration types. We also
7016 /// take member pointer types, for the conditional operator.
7017 /// AllowUserConversions is true if we should look at the conversion
7018 /// functions of a class type, and AllowExplicitConversions if we
7019 /// should also include the explicit conversion functions of a class
7022 BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty,
7024 bool AllowUserConversions,
7025 bool AllowExplicitConversions,
7026 const Qualifiers &VisibleQuals) {
7027 // Only deal with canonical types.
7028 Ty = Context.getCanonicalType(Ty);
7030 // Look through reference types; they aren't part of the type of an
7031 // expression for the purposes of conversions.
7032 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>())
7033 Ty = RefTy->getPointeeType();
7035 // If we're dealing with an array type, decay to the pointer.
7036 if (Ty->isArrayType())
7037 Ty = SemaRef.Context.getArrayDecayedType(Ty);
7039 // Otherwise, we don't care about qualifiers on the type.
7040 Ty = Ty.getLocalUnqualifiedType();
7042 // Flag if we ever add a non-record type.
7043 const RecordType *TyRec = Ty->getAs<RecordType>();
7044 HasNonRecordTypes = HasNonRecordTypes || !TyRec;
7046 // Flag if we encounter an arithmetic type.
7047 HasArithmeticOrEnumeralTypes =
7048 HasArithmeticOrEnumeralTypes || Ty->isArithmeticType();
7050 if (Ty->isObjCIdType() || Ty->isObjCClassType())
7051 PointerTypes.insert(Ty);
7052 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) {
7053 // Insert our type, and its more-qualified variants, into the set
7055 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals))
7057 } else if (Ty->isMemberPointerType()) {
7058 // Member pointers are far easier, since the pointee can't be converted.
7059 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty))
7061 } else if (Ty->isEnumeralType()) {
7062 HasArithmeticOrEnumeralTypes = true;
7063 EnumerationTypes.insert(Ty);
7064 } else if (Ty->isVectorType()) {
7065 // We treat vector types as arithmetic types in many contexts as an
7067 HasArithmeticOrEnumeralTypes = true;
7068 VectorTypes.insert(Ty);
7069 } else if (Ty->isNullPtrType()) {
7070 HasNullPtrType = true;
7071 } else if (AllowUserConversions && TyRec) {
7072 // No conversion functions in incomplete types.
7073 if (!SemaRef.isCompleteType(Loc, Ty))
7076 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl());
7077 for (NamedDecl *D : ClassDecl->getVisibleConversionFunctions()) {
7078 if (isa<UsingShadowDecl>(D))
7079 D = cast<UsingShadowDecl>(D)->getTargetDecl();
7081 // Skip conversion function templates; they don't tell us anything
7082 // about which builtin types we can convert to.
7083 if (isa<FunctionTemplateDecl>(D))
7086 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D);
7087 if (AllowExplicitConversions || !Conv->isExplicit()) {
7088 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false,
7095 /// \brief Helper function for AddBuiltinOperatorCandidates() that adds
7096 /// the volatile- and non-volatile-qualified assignment operators for the
7097 /// given type to the candidate set.
7098 static void AddBuiltinAssignmentOperatorCandidates(Sema &S,
7100 ArrayRef<Expr *> Args,
7101 OverloadCandidateSet &CandidateSet) {
7102 QualType ParamTypes[2];
7104 // T& operator=(T&, T)
7105 ParamTypes[0] = S.Context.getLValueReferenceType(T);
7107 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7108 /*IsAssignmentOperator=*/true);
7110 if (!S.Context.getCanonicalType(T).isVolatileQualified()) {
7111 // volatile T& operator=(volatile T&, T)
7113 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T));
7115 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7116 /*IsAssignmentOperator=*/true);
7120 /// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers,
7121 /// if any, found in visible type conversion functions found in ArgExpr's type.
7122 static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) {
7124 const RecordType *TyRec;
7125 if (const MemberPointerType *RHSMPType =
7126 ArgExpr->getType()->getAs<MemberPointerType>())
7127 TyRec = RHSMPType->getClass()->getAs<RecordType>();
7129 TyRec = ArgExpr->getType()->getAs<RecordType>();
7131 // Just to be safe, assume the worst case.
7132 VRQuals.addVolatile();
7133 VRQuals.addRestrict();
7137 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl());
7138 if (!ClassDecl->hasDefinition())
7141 for (NamedDecl *D : ClassDecl->getVisibleConversionFunctions()) {
7142 if (isa<UsingShadowDecl>(D))
7143 D = cast<UsingShadowDecl>(D)->getTargetDecl();
7144 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) {
7145 QualType CanTy = Context.getCanonicalType(Conv->getConversionType());
7146 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>())
7147 CanTy = ResTypeRef->getPointeeType();
7148 // Need to go down the pointer/mempointer chain and add qualifiers
7152 if (CanTy.isRestrictQualified())
7153 VRQuals.addRestrict();
7154 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>())
7155 CanTy = ResTypePtr->getPointeeType();
7156 else if (const MemberPointerType *ResTypeMPtr =
7157 CanTy->getAs<MemberPointerType>())
7158 CanTy = ResTypeMPtr->getPointeeType();
7161 if (CanTy.isVolatileQualified())
7162 VRQuals.addVolatile();
7163 if (VRQuals.hasRestrict() && VRQuals.hasVolatile())
7173 /// \brief Helper class to manage the addition of builtin operator overload
7174 /// candidates. It provides shared state and utility methods used throughout
7175 /// the process, as well as a helper method to add each group of builtin
7176 /// operator overloads from the standard to a candidate set.
7177 class BuiltinOperatorOverloadBuilder {
7178 // Common instance state available to all overload candidate addition methods.
7180 ArrayRef<Expr *> Args;
7181 Qualifiers VisibleTypeConversionsQuals;
7182 bool HasArithmeticOrEnumeralCandidateType;
7183 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes;
7184 OverloadCandidateSet &CandidateSet;
7186 // Define some constants used to index and iterate over the arithemetic types
7187 // provided via the getArithmeticType() method below.
7188 // The "promoted arithmetic types" are the arithmetic
7189 // types are that preserved by promotion (C++ [over.built]p2).
7190 static const unsigned FirstIntegralType = 3;
7191 static const unsigned LastIntegralType = 20;
7192 static const unsigned FirstPromotedIntegralType = 3,
7193 LastPromotedIntegralType = 11;
7194 static const unsigned FirstPromotedArithmeticType = 0,
7195 LastPromotedArithmeticType = 11;
7196 static const unsigned NumArithmeticTypes = 20;
7198 /// \brief Get the canonical type for a given arithmetic type index.
7199 CanQualType getArithmeticType(unsigned index) {
7200 assert(index < NumArithmeticTypes);
7201 static CanQualType ASTContext::* const
7202 ArithmeticTypes[NumArithmeticTypes] = {
7203 // Start of promoted types.
7204 &ASTContext::FloatTy,
7205 &ASTContext::DoubleTy,
7206 &ASTContext::LongDoubleTy,
7208 // Start of integral types.
7210 &ASTContext::LongTy,
7211 &ASTContext::LongLongTy,
7212 &ASTContext::Int128Ty,
7213 &ASTContext::UnsignedIntTy,
7214 &ASTContext::UnsignedLongTy,
7215 &ASTContext::UnsignedLongLongTy,
7216 &ASTContext::UnsignedInt128Ty,
7217 // End of promoted types.
7219 &ASTContext::BoolTy,
7220 &ASTContext::CharTy,
7221 &ASTContext::WCharTy,
7222 &ASTContext::Char16Ty,
7223 &ASTContext::Char32Ty,
7224 &ASTContext::SignedCharTy,
7225 &ASTContext::ShortTy,
7226 &ASTContext::UnsignedCharTy,
7227 &ASTContext::UnsignedShortTy,
7228 // End of integral types.
7229 // FIXME: What about complex? What about half?
7231 return S.Context.*ArithmeticTypes[index];
7234 /// \brief Gets the canonical type resulting from the usual arithemetic
7235 /// converions for the given arithmetic types.
7236 CanQualType getUsualArithmeticConversions(unsigned L, unsigned R) {
7237 // Accelerator table for performing the usual arithmetic conversions.
7238 // The rules are basically:
7239 // - if either is floating-point, use the wider floating-point
7240 // - if same signedness, use the higher rank
7241 // - if same size, use unsigned of the higher rank
7242 // - use the larger type
7243 // These rules, together with the axiom that higher ranks are
7244 // never smaller, are sufficient to precompute all of these results
7245 // *except* when dealing with signed types of higher rank.
7246 // (we could precompute SLL x UI for all known platforms, but it's
7247 // better not to make any assumptions).
7248 // We assume that int128 has a higher rank than long long on all platforms.
7251 Flt, Dbl, LDbl, SI, SL, SLL, S128, UI, UL, ULL, U128
7253 static const PromotedType ConversionsTable[LastPromotedArithmeticType]
7254 [LastPromotedArithmeticType] = {
7255 /* Flt*/ { Flt, Dbl, LDbl, Flt, Flt, Flt, Flt, Flt, Flt, Flt, Flt },
7256 /* Dbl*/ { Dbl, Dbl, LDbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl },
7257 /*LDbl*/ { LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl },
7258 /* SI*/ { Flt, Dbl, LDbl, SI, SL, SLL, S128, UI, UL, ULL, U128 },
7259 /* SL*/ { Flt, Dbl, LDbl, SL, SL, SLL, S128, Dep, UL, ULL, U128 },
7260 /* SLL*/ { Flt, Dbl, LDbl, SLL, SLL, SLL, S128, Dep, Dep, ULL, U128 },
7261 /*S128*/ { Flt, Dbl, LDbl, S128, S128, S128, S128, S128, S128, S128, U128 },
7262 /* UI*/ { Flt, Dbl, LDbl, UI, Dep, Dep, S128, UI, UL, ULL, U128 },
7263 /* UL*/ { Flt, Dbl, LDbl, UL, UL, Dep, S128, UL, UL, ULL, U128 },
7264 /* ULL*/ { Flt, Dbl, LDbl, ULL, ULL, ULL, S128, ULL, ULL, ULL, U128 },
7265 /*U128*/ { Flt, Dbl, LDbl, U128, U128, U128, U128, U128, U128, U128, U128 },
7268 assert(L < LastPromotedArithmeticType);
7269 assert(R < LastPromotedArithmeticType);
7270 int Idx = ConversionsTable[L][R];
7272 // Fast path: the table gives us a concrete answer.
7273 if (Idx != Dep) return getArithmeticType(Idx);
7275 // Slow path: we need to compare widths.
7276 // An invariant is that the signed type has higher rank.
7277 CanQualType LT = getArithmeticType(L),
7278 RT = getArithmeticType(R);
7279 unsigned LW = S.Context.getIntWidth(LT),
7280 RW = S.Context.getIntWidth(RT);
7282 // If they're different widths, use the signed type.
7283 if (LW > RW) return LT;
7284 else if (LW < RW) return RT;
7286 // Otherwise, use the unsigned type of the signed type's rank.
7287 if (L == SL || R == SL) return S.Context.UnsignedLongTy;
7288 assert(L == SLL || R == SLL);
7289 return S.Context.UnsignedLongLongTy;
7292 /// \brief Helper method to factor out the common pattern of adding overloads
7293 /// for '++' and '--' builtin operators.
7294 void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy,
7297 QualType ParamTypes[2] = {
7298 S.Context.getLValueReferenceType(CandidateTy),
7302 // Non-volatile version.
7303 if (Args.size() == 1)
7304 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
7306 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet);
7308 // Use a heuristic to reduce number of builtin candidates in the set:
7309 // add volatile version only if there are conversions to a volatile type.
7312 S.Context.getLValueReferenceType(
7313 S.Context.getVolatileType(CandidateTy));
7314 if (Args.size() == 1)
7315 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
7317 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet);
7320 // Add restrict version only if there are conversions to a restrict type
7321 // and our candidate type is a non-restrict-qualified pointer.
7322 if (HasRestrict && CandidateTy->isAnyPointerType() &&
7323 !CandidateTy.isRestrictQualified()) {
7325 = S.Context.getLValueReferenceType(
7326 S.Context.getCVRQualifiedType(CandidateTy, Qualifiers::Restrict));
7327 if (Args.size() == 1)
7328 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
7330 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet);
7334 = S.Context.getLValueReferenceType(
7335 S.Context.getCVRQualifiedType(CandidateTy,
7336 (Qualifiers::Volatile |
7337 Qualifiers::Restrict)));
7338 if (Args.size() == 1)
7339 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
7341 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet);
7348 BuiltinOperatorOverloadBuilder(
7349 Sema &S, ArrayRef<Expr *> Args,
7350 Qualifiers VisibleTypeConversionsQuals,
7351 bool HasArithmeticOrEnumeralCandidateType,
7352 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes,
7353 OverloadCandidateSet &CandidateSet)
7355 VisibleTypeConversionsQuals(VisibleTypeConversionsQuals),
7356 HasArithmeticOrEnumeralCandidateType(
7357 HasArithmeticOrEnumeralCandidateType),
7358 CandidateTypes(CandidateTypes),
7359 CandidateSet(CandidateSet) {
7360 // Validate some of our static helper constants in debug builds.
7361 assert(getArithmeticType(FirstPromotedIntegralType) == S.Context.IntTy &&
7362 "Invalid first promoted integral type");
7363 assert(getArithmeticType(LastPromotedIntegralType - 1)
7364 == S.Context.UnsignedInt128Ty &&
7365 "Invalid last promoted integral type");
7366 assert(getArithmeticType(FirstPromotedArithmeticType)
7367 == S.Context.FloatTy &&
7368 "Invalid first promoted arithmetic type");
7369 assert(getArithmeticType(LastPromotedArithmeticType - 1)
7370 == S.Context.UnsignedInt128Ty &&
7371 "Invalid last promoted arithmetic type");
7374 // C++ [over.built]p3:
7376 // For every pair (T, VQ), where T is an arithmetic type, and VQ
7377 // is either volatile or empty, there exist candidate operator
7378 // functions of the form
7380 // VQ T& operator++(VQ T&);
7381 // T operator++(VQ T&, int);
7383 // C++ [over.built]p4:
7385 // For every pair (T, VQ), where T is an arithmetic type other
7386 // than bool, and VQ is either volatile or empty, there exist
7387 // candidate operator functions of the form
7389 // VQ T& operator--(VQ T&);
7390 // T operator--(VQ T&, int);
7391 void addPlusPlusMinusMinusArithmeticOverloads(OverloadedOperatorKind Op) {
7392 if (!HasArithmeticOrEnumeralCandidateType)
7395 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1);
7396 Arith < NumArithmeticTypes; ++Arith) {
7397 addPlusPlusMinusMinusStyleOverloads(
7398 getArithmeticType(Arith),
7399 VisibleTypeConversionsQuals.hasVolatile(),
7400 VisibleTypeConversionsQuals.hasRestrict());
7404 // C++ [over.built]p5:
7406 // For every pair (T, VQ), where T is a cv-qualified or
7407 // cv-unqualified object type, and VQ is either volatile or
7408 // empty, there exist candidate operator functions of the form
7410 // T*VQ& operator++(T*VQ&);
7411 // T*VQ& operator--(T*VQ&);
7412 // T* operator++(T*VQ&, int);
7413 // T* operator--(T*VQ&, int);
7414 void addPlusPlusMinusMinusPointerOverloads() {
7415 for (BuiltinCandidateTypeSet::iterator
7416 Ptr = CandidateTypes[0].pointer_begin(),
7417 PtrEnd = CandidateTypes[0].pointer_end();
7418 Ptr != PtrEnd; ++Ptr) {
7419 // Skip pointer types that aren't pointers to object types.
7420 if (!(*Ptr)->getPointeeType()->isObjectType())
7423 addPlusPlusMinusMinusStyleOverloads(*Ptr,
7424 (!(*Ptr).isVolatileQualified() &&
7425 VisibleTypeConversionsQuals.hasVolatile()),
7426 (!(*Ptr).isRestrictQualified() &&
7427 VisibleTypeConversionsQuals.hasRestrict()));
7431 // C++ [over.built]p6:
7432 // For every cv-qualified or cv-unqualified object type T, there
7433 // exist candidate operator functions of the form
7435 // T& operator*(T*);
7437 // C++ [over.built]p7:
7438 // For every function type T that does not have cv-qualifiers or a
7439 // ref-qualifier, there exist candidate operator functions of the form
7440 // T& operator*(T*);
7441 void addUnaryStarPointerOverloads() {
7442 for (BuiltinCandidateTypeSet::iterator
7443 Ptr = CandidateTypes[0].pointer_begin(),
7444 PtrEnd = CandidateTypes[0].pointer_end();
7445 Ptr != PtrEnd; ++Ptr) {
7446 QualType ParamTy = *Ptr;
7447 QualType PointeeTy = ParamTy->getPointeeType();
7448 if (!PointeeTy->isObjectType() && !PointeeTy->isFunctionType())
7451 if (const FunctionProtoType *Proto =PointeeTy->getAs<FunctionProtoType>())
7452 if (Proto->getTypeQuals() || Proto->getRefQualifier())
7455 S.AddBuiltinCandidate(S.Context.getLValueReferenceType(PointeeTy),
7456 &ParamTy, Args, CandidateSet);
7460 // C++ [over.built]p9:
7461 // For every promoted arithmetic type T, there exist candidate
7462 // operator functions of the form
7466 void addUnaryPlusOrMinusArithmeticOverloads() {
7467 if (!HasArithmeticOrEnumeralCandidateType)
7470 for (unsigned Arith = FirstPromotedArithmeticType;
7471 Arith < LastPromotedArithmeticType; ++Arith) {
7472 QualType ArithTy = getArithmeticType(Arith);
7473 S.AddBuiltinCandidate(ArithTy, &ArithTy, Args, CandidateSet);
7476 // Extension: We also add these operators for vector types.
7477 for (BuiltinCandidateTypeSet::iterator
7478 Vec = CandidateTypes[0].vector_begin(),
7479 VecEnd = CandidateTypes[0].vector_end();
7480 Vec != VecEnd; ++Vec) {
7481 QualType VecTy = *Vec;
7482 S.AddBuiltinCandidate(VecTy, &VecTy, Args, CandidateSet);
7486 // C++ [over.built]p8:
7487 // For every type T, there exist candidate operator functions of
7490 // T* operator+(T*);
7491 void addUnaryPlusPointerOverloads() {
7492 for (BuiltinCandidateTypeSet::iterator
7493 Ptr = CandidateTypes[0].pointer_begin(),
7494 PtrEnd = CandidateTypes[0].pointer_end();
7495 Ptr != PtrEnd; ++Ptr) {
7496 QualType ParamTy = *Ptr;
7497 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, CandidateSet);
7501 // C++ [over.built]p10:
7502 // For every promoted integral type T, there exist candidate
7503 // operator functions of the form
7506 void addUnaryTildePromotedIntegralOverloads() {
7507 if (!HasArithmeticOrEnumeralCandidateType)
7510 for (unsigned Int = FirstPromotedIntegralType;
7511 Int < LastPromotedIntegralType; ++Int) {
7512 QualType IntTy = getArithmeticType(Int);
7513 S.AddBuiltinCandidate(IntTy, &IntTy, Args, CandidateSet);
7516 // Extension: We also add this operator for vector types.
7517 for (BuiltinCandidateTypeSet::iterator
7518 Vec = CandidateTypes[0].vector_begin(),
7519 VecEnd = CandidateTypes[0].vector_end();
7520 Vec != VecEnd; ++Vec) {
7521 QualType VecTy = *Vec;
7522 S.AddBuiltinCandidate(VecTy, &VecTy, Args, CandidateSet);
7526 // C++ [over.match.oper]p16:
7527 // For every pointer to member type T, there exist candidate operator
7528 // functions of the form
7530 // bool operator==(T,T);
7531 // bool operator!=(T,T);
7532 void addEqualEqualOrNotEqualMemberPointerOverloads() {
7533 /// Set of (canonical) types that we've already handled.
7534 llvm::SmallPtrSet<QualType, 8> AddedTypes;
7536 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7537 for (BuiltinCandidateTypeSet::iterator
7538 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(),
7539 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end();
7540 MemPtr != MemPtrEnd;
7542 // Don't add the same builtin candidate twice.
7543 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr)).second)
7546 QualType ParamTypes[2] = { *MemPtr, *MemPtr };
7547 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet);
7552 // C++ [over.built]p15:
7554 // For every T, where T is an enumeration type, a pointer type, or
7555 // std::nullptr_t, there exist candidate operator functions of the form
7557 // bool operator<(T, T);
7558 // bool operator>(T, T);
7559 // bool operator<=(T, T);
7560 // bool operator>=(T, T);
7561 // bool operator==(T, T);
7562 // bool operator!=(T, T);
7563 void addRelationalPointerOrEnumeralOverloads() {
7564 // C++ [over.match.oper]p3:
7565 // [...]the built-in candidates include all of the candidate operator
7566 // functions defined in 13.6 that, compared to the given operator, [...]
7567 // do not have the same parameter-type-list as any non-template non-member
7570 // Note that in practice, this only affects enumeration types because there
7571 // aren't any built-in candidates of record type, and a user-defined operator
7572 // must have an operand of record or enumeration type. Also, the only other
7573 // overloaded operator with enumeration arguments, operator=,
7574 // cannot be overloaded for enumeration types, so this is the only place
7575 // where we must suppress candidates like this.
7576 llvm::DenseSet<std::pair<CanQualType, CanQualType> >
7577 UserDefinedBinaryOperators;
7579 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7580 if (CandidateTypes[ArgIdx].enumeration_begin() !=
7581 CandidateTypes[ArgIdx].enumeration_end()) {
7582 for (OverloadCandidateSet::iterator C = CandidateSet.begin(),
7583 CEnd = CandidateSet.end();
7585 if (!C->Viable || !C->Function || C->Function->getNumParams() != 2)
7588 if (C->Function->isFunctionTemplateSpecialization())
7591 QualType FirstParamType =
7592 C->Function->getParamDecl(0)->getType().getUnqualifiedType();
7593 QualType SecondParamType =
7594 C->Function->getParamDecl(1)->getType().getUnqualifiedType();
7596 // Skip if either parameter isn't of enumeral type.
7597 if (!FirstParamType->isEnumeralType() ||
7598 !SecondParamType->isEnumeralType())
7601 // Add this operator to the set of known user-defined operators.
7602 UserDefinedBinaryOperators.insert(
7603 std::make_pair(S.Context.getCanonicalType(FirstParamType),
7604 S.Context.getCanonicalType(SecondParamType)));
7609 /// Set of (canonical) types that we've already handled.
7610 llvm::SmallPtrSet<QualType, 8> AddedTypes;
7612 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7613 for (BuiltinCandidateTypeSet::iterator
7614 Ptr = CandidateTypes[ArgIdx].pointer_begin(),
7615 PtrEnd = CandidateTypes[ArgIdx].pointer_end();
7616 Ptr != PtrEnd; ++Ptr) {
7617 // Don't add the same builtin candidate twice.
7618 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
7621 QualType ParamTypes[2] = { *Ptr, *Ptr };
7622 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet);
7624 for (BuiltinCandidateTypeSet::iterator
7625 Enum = CandidateTypes[ArgIdx].enumeration_begin(),
7626 EnumEnd = CandidateTypes[ArgIdx].enumeration_end();
7627 Enum != EnumEnd; ++Enum) {
7628 CanQualType CanonType = S.Context.getCanonicalType(*Enum);
7630 // Don't add the same builtin candidate twice, or if a user defined
7631 // candidate exists.
7632 if (!AddedTypes.insert(CanonType).second ||
7633 UserDefinedBinaryOperators.count(std::make_pair(CanonType,
7637 QualType ParamTypes[2] = { *Enum, *Enum };
7638 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet);
7641 if (CandidateTypes[ArgIdx].hasNullPtrType()) {
7642 CanQualType NullPtrTy = S.Context.getCanonicalType(S.Context.NullPtrTy);
7643 if (AddedTypes.insert(NullPtrTy).second &&
7644 !UserDefinedBinaryOperators.count(std::make_pair(NullPtrTy,
7646 QualType ParamTypes[2] = { NullPtrTy, NullPtrTy };
7647 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args,
7654 // C++ [over.built]p13:
7656 // For every cv-qualified or cv-unqualified object type T
7657 // there exist candidate operator functions of the form
7659 // T* operator+(T*, ptrdiff_t);
7660 // T& operator[](T*, ptrdiff_t); [BELOW]
7661 // T* operator-(T*, ptrdiff_t);
7662 // T* operator+(ptrdiff_t, T*);
7663 // T& operator[](ptrdiff_t, T*); [BELOW]
7665 // C++ [over.built]p14:
7667 // For every T, where T is a pointer to object type, there
7668 // exist candidate operator functions of the form
7670 // ptrdiff_t operator-(T, T);
7671 void addBinaryPlusOrMinusPointerOverloads(OverloadedOperatorKind Op) {
7672 /// Set of (canonical) types that we've already handled.
7673 llvm::SmallPtrSet<QualType, 8> AddedTypes;
7675 for (int Arg = 0; Arg < 2; ++Arg) {
7676 QualType AsymmetricParamTypes[2] = {
7677 S.Context.getPointerDiffType(),
7678 S.Context.getPointerDiffType(),
7680 for (BuiltinCandidateTypeSet::iterator
7681 Ptr = CandidateTypes[Arg].pointer_begin(),
7682 PtrEnd = CandidateTypes[Arg].pointer_end();
7683 Ptr != PtrEnd; ++Ptr) {
7684 QualType PointeeTy = (*Ptr)->getPointeeType();
7685 if (!PointeeTy->isObjectType())
7688 AsymmetricParamTypes[Arg] = *Ptr;
7689 if (Arg == 0 || Op == OO_Plus) {
7690 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t)
7691 // T* operator+(ptrdiff_t, T*);
7692 S.AddBuiltinCandidate(*Ptr, AsymmetricParamTypes, Args, CandidateSet);
7694 if (Op == OO_Minus) {
7695 // ptrdiff_t operator-(T, T);
7696 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
7699 QualType ParamTypes[2] = { *Ptr, *Ptr };
7700 S.AddBuiltinCandidate(S.Context.getPointerDiffType(), ParamTypes,
7701 Args, CandidateSet);
7707 // C++ [over.built]p12:
7709 // For every pair of promoted arithmetic types L and R, there
7710 // exist candidate operator functions of the form
7712 // LR operator*(L, R);
7713 // LR operator/(L, R);
7714 // LR operator+(L, R);
7715 // LR operator-(L, R);
7716 // bool operator<(L, R);
7717 // bool operator>(L, R);
7718 // bool operator<=(L, R);
7719 // bool operator>=(L, R);
7720 // bool operator==(L, R);
7721 // bool operator!=(L, R);
7723 // where LR is the result of the usual arithmetic conversions
7724 // between types L and R.
7726 // C++ [over.built]p24:
7728 // For every pair of promoted arithmetic types L and R, there exist
7729 // candidate operator functions of the form
7731 // LR operator?(bool, L, R);
7733 // where LR is the result of the usual arithmetic conversions
7734 // between types L and R.
7735 // Our candidates ignore the first parameter.
7736 void addGenericBinaryArithmeticOverloads(bool isComparison) {
7737 if (!HasArithmeticOrEnumeralCandidateType)
7740 for (unsigned Left = FirstPromotedArithmeticType;
7741 Left < LastPromotedArithmeticType; ++Left) {
7742 for (unsigned Right = FirstPromotedArithmeticType;
7743 Right < LastPromotedArithmeticType; ++Right) {
7744 QualType LandR[2] = { getArithmeticType(Left),
7745 getArithmeticType(Right) };
7747 isComparison ? S.Context.BoolTy
7748 : getUsualArithmeticConversions(Left, Right);
7749 S.AddBuiltinCandidate(Result, LandR, Args, CandidateSet);
7753 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the
7754 // conditional operator for vector types.
7755 for (BuiltinCandidateTypeSet::iterator
7756 Vec1 = CandidateTypes[0].vector_begin(),
7757 Vec1End = CandidateTypes[0].vector_end();
7758 Vec1 != Vec1End; ++Vec1) {
7759 for (BuiltinCandidateTypeSet::iterator
7760 Vec2 = CandidateTypes[1].vector_begin(),
7761 Vec2End = CandidateTypes[1].vector_end();
7762 Vec2 != Vec2End; ++Vec2) {
7763 QualType LandR[2] = { *Vec1, *Vec2 };
7764 QualType Result = S.Context.BoolTy;
7765 if (!isComparison) {
7766 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType())
7772 S.AddBuiltinCandidate(Result, LandR, Args, CandidateSet);
7777 // C++ [over.built]p17:
7779 // For every pair of promoted integral types L and R, there
7780 // exist candidate operator functions of the form
7782 // LR operator%(L, R);
7783 // LR operator&(L, R);
7784 // LR operator^(L, R);
7785 // LR operator|(L, R);
7786 // L operator<<(L, R);
7787 // L operator>>(L, R);
7789 // where LR is the result of the usual arithmetic conversions
7790 // between types L and R.
7791 void addBinaryBitwiseArithmeticOverloads(OverloadedOperatorKind Op) {
7792 if (!HasArithmeticOrEnumeralCandidateType)
7795 for (unsigned Left = FirstPromotedIntegralType;
7796 Left < LastPromotedIntegralType; ++Left) {
7797 for (unsigned Right = FirstPromotedIntegralType;
7798 Right < LastPromotedIntegralType; ++Right) {
7799 QualType LandR[2] = { getArithmeticType(Left),
7800 getArithmeticType(Right) };
7801 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater)
7803 : getUsualArithmeticConversions(Left, Right);
7804 S.AddBuiltinCandidate(Result, LandR, Args, CandidateSet);
7809 // C++ [over.built]p20:
7811 // For every pair (T, VQ), where T is an enumeration or
7812 // pointer to member type and VQ is either volatile or
7813 // empty, there exist candidate operator functions of the form
7815 // VQ T& operator=(VQ T&, T);
7816 void addAssignmentMemberPointerOrEnumeralOverloads() {
7817 /// Set of (canonical) types that we've already handled.
7818 llvm::SmallPtrSet<QualType, 8> AddedTypes;
7820 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) {
7821 for (BuiltinCandidateTypeSet::iterator
7822 Enum = CandidateTypes[ArgIdx].enumeration_begin(),
7823 EnumEnd = CandidateTypes[ArgIdx].enumeration_end();
7824 Enum != EnumEnd; ++Enum) {
7825 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum)).second)
7828 AddBuiltinAssignmentOperatorCandidates(S, *Enum, Args, CandidateSet);
7831 for (BuiltinCandidateTypeSet::iterator
7832 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(),
7833 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end();
7834 MemPtr != MemPtrEnd; ++MemPtr) {
7835 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr)).second)
7838 AddBuiltinAssignmentOperatorCandidates(S, *MemPtr, Args, CandidateSet);
7843 // C++ [over.built]p19:
7845 // For every pair (T, VQ), where T is any type and VQ is either
7846 // volatile or empty, there exist candidate operator functions
7849 // T*VQ& operator=(T*VQ&, T*);
7851 // C++ [over.built]p21:
7853 // For every pair (T, VQ), where T is a cv-qualified or
7854 // cv-unqualified object type and VQ is either volatile or
7855 // empty, there exist candidate operator functions of the form
7857 // T*VQ& operator+=(T*VQ&, ptrdiff_t);
7858 // T*VQ& operator-=(T*VQ&, ptrdiff_t);
7859 void addAssignmentPointerOverloads(bool isEqualOp) {
7860 /// Set of (canonical) types that we've already handled.
7861 llvm::SmallPtrSet<QualType, 8> AddedTypes;
7863 for (BuiltinCandidateTypeSet::iterator
7864 Ptr = CandidateTypes[0].pointer_begin(),
7865 PtrEnd = CandidateTypes[0].pointer_end();
7866 Ptr != PtrEnd; ++Ptr) {
7867 // If this is operator=, keep track of the builtin candidates we added.
7869 AddedTypes.insert(S.Context.getCanonicalType(*Ptr));
7870 else if (!(*Ptr)->getPointeeType()->isObjectType())
7873 // non-volatile version
7874 QualType ParamTypes[2] = {
7875 S.Context.getLValueReferenceType(*Ptr),
7876 isEqualOp ? *Ptr : S.Context.getPointerDiffType(),
7878 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7879 /*IsAssigmentOperator=*/ isEqualOp);
7881 bool NeedVolatile = !(*Ptr).isVolatileQualified() &&
7882 VisibleTypeConversionsQuals.hasVolatile();
7886 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr));
7887 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7888 /*IsAssigmentOperator=*/isEqualOp);
7891 if (!(*Ptr).isRestrictQualified() &&
7892 VisibleTypeConversionsQuals.hasRestrict()) {
7895 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr));
7896 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7897 /*IsAssigmentOperator=*/isEqualOp);
7900 // volatile restrict version
7902 = S.Context.getLValueReferenceType(
7903 S.Context.getCVRQualifiedType(*Ptr,
7904 (Qualifiers::Volatile |
7905 Qualifiers::Restrict)));
7906 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7907 /*IsAssigmentOperator=*/isEqualOp);
7913 for (BuiltinCandidateTypeSet::iterator
7914 Ptr = CandidateTypes[1].pointer_begin(),
7915 PtrEnd = CandidateTypes[1].pointer_end();
7916 Ptr != PtrEnd; ++Ptr) {
7917 // Make sure we don't add the same candidate twice.
7918 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
7921 QualType ParamTypes[2] = {
7922 S.Context.getLValueReferenceType(*Ptr),
7926 // non-volatile version
7927 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7928 /*IsAssigmentOperator=*/true);
7930 bool NeedVolatile = !(*Ptr).isVolatileQualified() &&
7931 VisibleTypeConversionsQuals.hasVolatile();
7935 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr));
7936 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7937 /*IsAssigmentOperator=*/true);
7940 if (!(*Ptr).isRestrictQualified() &&
7941 VisibleTypeConversionsQuals.hasRestrict()) {
7944 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr));
7945 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7946 /*IsAssigmentOperator=*/true);
7949 // volatile restrict version
7951 = S.Context.getLValueReferenceType(
7952 S.Context.getCVRQualifiedType(*Ptr,
7953 (Qualifiers::Volatile |
7954 Qualifiers::Restrict)));
7955 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7956 /*IsAssigmentOperator=*/true);
7963 // C++ [over.built]p18:
7965 // For every triple (L, VQ, R), where L is an arithmetic type,
7966 // VQ is either volatile or empty, and R is a promoted
7967 // arithmetic type, there exist candidate operator functions of
7970 // VQ L& operator=(VQ L&, R);
7971 // VQ L& operator*=(VQ L&, R);
7972 // VQ L& operator/=(VQ L&, R);
7973 // VQ L& operator+=(VQ L&, R);
7974 // VQ L& operator-=(VQ L&, R);
7975 void addAssignmentArithmeticOverloads(bool isEqualOp) {
7976 if (!HasArithmeticOrEnumeralCandidateType)
7979 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) {
7980 for (unsigned Right = FirstPromotedArithmeticType;
7981 Right < LastPromotedArithmeticType; ++Right) {
7982 QualType ParamTypes[2];
7983 ParamTypes[1] = getArithmeticType(Right);
7985 // Add this built-in operator as a candidate (VQ is empty).
7987 S.Context.getLValueReferenceType(getArithmeticType(Left));
7988 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7989 /*IsAssigmentOperator=*/isEqualOp);
7991 // Add this built-in operator as a candidate (VQ is 'volatile').
7992 if (VisibleTypeConversionsQuals.hasVolatile()) {
7994 S.Context.getVolatileType(getArithmeticType(Left));
7995 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
7996 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7997 /*IsAssigmentOperator=*/isEqualOp);
8002 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types.
8003 for (BuiltinCandidateTypeSet::iterator
8004 Vec1 = CandidateTypes[0].vector_begin(),
8005 Vec1End = CandidateTypes[0].vector_end();
8006 Vec1 != Vec1End; ++Vec1) {
8007 for (BuiltinCandidateTypeSet::iterator
8008 Vec2 = CandidateTypes[1].vector_begin(),
8009 Vec2End = CandidateTypes[1].vector_end();
8010 Vec2 != Vec2End; ++Vec2) {
8011 QualType ParamTypes[2];
8012 ParamTypes[1] = *Vec2;
8013 // Add this built-in operator as a candidate (VQ is empty).
8014 ParamTypes[0] = S.Context.getLValueReferenceType(*Vec1);
8015 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8016 /*IsAssigmentOperator=*/isEqualOp);
8018 // Add this built-in operator as a candidate (VQ is 'volatile').
8019 if (VisibleTypeConversionsQuals.hasVolatile()) {
8020 ParamTypes[0] = S.Context.getVolatileType(*Vec1);
8021 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
8022 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
8023 /*IsAssigmentOperator=*/isEqualOp);
8029 // C++ [over.built]p22:
8031 // For every triple (L, VQ, R), where L is an integral type, VQ
8032 // is either volatile or empty, and R is a promoted integral
8033 // type, there exist candidate operator functions of the form
8035 // VQ L& operator%=(VQ L&, R);
8036 // VQ L& operator<<=(VQ L&, R);
8037 // VQ L& operator>>=(VQ L&, R);
8038 // VQ L& operator&=(VQ L&, R);
8039 // VQ L& operator^=(VQ L&, R);
8040 // VQ L& operator|=(VQ L&, R);
8041 void addAssignmentIntegralOverloads() {
8042 if (!HasArithmeticOrEnumeralCandidateType)
8045 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) {
8046 for (unsigned Right = FirstPromotedIntegralType;
8047 Right < LastPromotedIntegralType; ++Right) {
8048 QualType ParamTypes[2];
8049 ParamTypes[1] = getArithmeticType(Right);
8051 // Add this built-in operator as a candidate (VQ is empty).
8053 S.Context.getLValueReferenceType(getArithmeticType(Left));
8054 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
8055 if (VisibleTypeConversionsQuals.hasVolatile()) {
8056 // Add this built-in operator as a candidate (VQ is 'volatile').
8057 ParamTypes[0] = getArithmeticType(Left);
8058 ParamTypes[0] = S.Context.getVolatileType(ParamTypes[0]);
8059 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]);
8060 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
8066 // C++ [over.operator]p23:
8068 // There also exist candidate operator functions of the form
8070 // bool operator!(bool);
8071 // bool operator&&(bool, bool);
8072 // bool operator||(bool, bool);
8073 void addExclaimOverload() {
8074 QualType ParamTy = S.Context.BoolTy;
8075 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, CandidateSet,
8076 /*IsAssignmentOperator=*/false,
8077 /*NumContextualBoolArguments=*/1);
8079 void addAmpAmpOrPipePipeOverload() {
8080 QualType ParamTypes[2] = { S.Context.BoolTy, S.Context.BoolTy };
8081 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet,
8082 /*IsAssignmentOperator=*/false,
8083 /*NumContextualBoolArguments=*/2);
8086 // C++ [over.built]p13:
8088 // For every cv-qualified or cv-unqualified object type T there
8089 // exist candidate operator functions of the form
8091 // T* operator+(T*, ptrdiff_t); [ABOVE]
8092 // T& operator[](T*, ptrdiff_t);
8093 // T* operator-(T*, ptrdiff_t); [ABOVE]
8094 // T* operator+(ptrdiff_t, T*); [ABOVE]
8095 // T& operator[](ptrdiff_t, T*);
8096 void addSubscriptOverloads() {
8097 for (BuiltinCandidateTypeSet::iterator
8098 Ptr = CandidateTypes[0].pointer_begin(),
8099 PtrEnd = CandidateTypes[0].pointer_end();
8100 Ptr != PtrEnd; ++Ptr) {
8101 QualType ParamTypes[2] = { *Ptr, S.Context.getPointerDiffType() };
8102 QualType PointeeType = (*Ptr)->getPointeeType();
8103 if (!PointeeType->isObjectType())
8106 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType);
8108 // T& operator[](T*, ptrdiff_t)
8109 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, CandidateSet);
8112 for (BuiltinCandidateTypeSet::iterator
8113 Ptr = CandidateTypes[1].pointer_begin(),
8114 PtrEnd = CandidateTypes[1].pointer_end();
8115 Ptr != PtrEnd; ++Ptr) {
8116 QualType ParamTypes[2] = { S.Context.getPointerDiffType(), *Ptr };
8117 QualType PointeeType = (*Ptr)->getPointeeType();
8118 if (!PointeeType->isObjectType())
8121 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType);
8123 // T& operator[](ptrdiff_t, T*)
8124 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, CandidateSet);
8128 // C++ [over.built]p11:
8129 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type,
8130 // C1 is the same type as C2 or is a derived class of C2, T is an object
8131 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
8132 // there exist candidate operator functions of the form
8134 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
8136 // where CV12 is the union of CV1 and CV2.
8137 void addArrowStarOverloads() {
8138 for (BuiltinCandidateTypeSet::iterator
8139 Ptr = CandidateTypes[0].pointer_begin(),
8140 PtrEnd = CandidateTypes[0].pointer_end();
8141 Ptr != PtrEnd; ++Ptr) {
8142 QualType C1Ty = (*Ptr);
8144 QualifierCollector Q1;
8145 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0);
8146 if (!isa<RecordType>(C1))
8148 // heuristic to reduce number of builtin candidates in the set.
8149 // Add volatile/restrict version only if there are conversions to a
8150 // volatile/restrict type.
8151 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile())
8153 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict())
8155 for (BuiltinCandidateTypeSet::iterator
8156 MemPtr = CandidateTypes[1].member_pointer_begin(),
8157 MemPtrEnd = CandidateTypes[1].member_pointer_end();
8158 MemPtr != MemPtrEnd; ++MemPtr) {
8159 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr);
8160 QualType C2 = QualType(mptr->getClass(), 0);
8161 C2 = C2.getUnqualifiedType();
8162 if (C1 != C2 && !S.IsDerivedFrom(CandidateSet.getLocation(), C1, C2))
8164 QualType ParamTypes[2] = { *Ptr, *MemPtr };
8166 QualType T = mptr->getPointeeType();
8167 if (!VisibleTypeConversionsQuals.hasVolatile() &&
8168 T.isVolatileQualified())
8170 if (!VisibleTypeConversionsQuals.hasRestrict() &&
8171 T.isRestrictQualified())
8173 T = Q1.apply(S.Context, T);
8174 QualType ResultTy = S.Context.getLValueReferenceType(T);
8175 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, CandidateSet);
8180 // Note that we don't consider the first argument, since it has been
8181 // contextually converted to bool long ago. The candidates below are
8182 // therefore added as binary.
8184 // C++ [over.built]p25:
8185 // For every type T, where T is a pointer, pointer-to-member, or scoped
8186 // enumeration type, there exist candidate operator functions of the form
8188 // T operator?(bool, T, T);
8190 void addConditionalOperatorOverloads() {
8191 /// Set of (canonical) types that we've already handled.
8192 llvm::SmallPtrSet<QualType, 8> AddedTypes;
8194 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) {
8195 for (BuiltinCandidateTypeSet::iterator
8196 Ptr = CandidateTypes[ArgIdx].pointer_begin(),
8197 PtrEnd = CandidateTypes[ArgIdx].pointer_end();
8198 Ptr != PtrEnd; ++Ptr) {
8199 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr)).second)
8202 QualType ParamTypes[2] = { *Ptr, *Ptr };
8203 S.AddBuiltinCandidate(*Ptr, ParamTypes, Args, CandidateSet);
8206 for (BuiltinCandidateTypeSet::iterator
8207 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(),
8208 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end();
8209 MemPtr != MemPtrEnd; ++MemPtr) {
8210 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr)).second)
8213 QualType ParamTypes[2] = { *MemPtr, *MemPtr };
8214 S.AddBuiltinCandidate(*MemPtr, ParamTypes, Args, CandidateSet);
8217 if (S.getLangOpts().CPlusPlus11) {
8218 for (BuiltinCandidateTypeSet::iterator
8219 Enum = CandidateTypes[ArgIdx].enumeration_begin(),
8220 EnumEnd = CandidateTypes[ArgIdx].enumeration_end();
8221 Enum != EnumEnd; ++Enum) {
8222 if (!(*Enum)->getAs<EnumType>()->getDecl()->isScoped())
8225 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum)).second)
8228 QualType ParamTypes[2] = { *Enum, *Enum };
8229 S.AddBuiltinCandidate(*Enum, ParamTypes, Args, CandidateSet);
8236 } // end anonymous namespace
8238 /// AddBuiltinOperatorCandidates - Add the appropriate built-in
8239 /// operator overloads to the candidate set (C++ [over.built]), based
8240 /// on the operator @p Op and the arguments given. For example, if the
8241 /// operator is a binary '+', this routine might add "int
8242 /// operator+(int, int)" to cover integer addition.
8243 void Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op,
8244 SourceLocation OpLoc,
8245 ArrayRef<Expr *> Args,
8246 OverloadCandidateSet &CandidateSet) {
8247 // Find all of the types that the arguments can convert to, but only
8248 // if the operator we're looking at has built-in operator candidates
8249 // that make use of these types. Also record whether we encounter non-record
8250 // candidate types or either arithmetic or enumeral candidate types.
8251 Qualifiers VisibleTypeConversionsQuals;
8252 VisibleTypeConversionsQuals.addConst();
8253 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx)
8254 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]);
8256 bool HasNonRecordCandidateType = false;
8257 bool HasArithmeticOrEnumeralCandidateType = false;
8258 SmallVector<BuiltinCandidateTypeSet, 2> CandidateTypes;
8259 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
8260 CandidateTypes.emplace_back(*this);
8261 CandidateTypes[ArgIdx].AddTypesConvertedFrom(Args[ArgIdx]->getType(),
8264 (Op == OO_Exclaim ||
8267 VisibleTypeConversionsQuals);
8268 HasNonRecordCandidateType = HasNonRecordCandidateType ||
8269 CandidateTypes[ArgIdx].hasNonRecordTypes();
8270 HasArithmeticOrEnumeralCandidateType =
8271 HasArithmeticOrEnumeralCandidateType ||
8272 CandidateTypes[ArgIdx].hasArithmeticOrEnumeralTypes();
8275 // Exit early when no non-record types have been added to the candidate set
8276 // for any of the arguments to the operator.
8278 // We can't exit early for !, ||, or &&, since there we have always have
8279 // 'bool' overloads.
8280 if (!HasNonRecordCandidateType &&
8281 !(Op == OO_Exclaim || Op == OO_AmpAmp || Op == OO_PipePipe))
8284 // Setup an object to manage the common state for building overloads.
8285 BuiltinOperatorOverloadBuilder OpBuilder(*this, Args,
8286 VisibleTypeConversionsQuals,
8287 HasArithmeticOrEnumeralCandidateType,
8288 CandidateTypes, CandidateSet);
8290 // Dispatch over the operation to add in only those overloads which apply.
8293 case NUM_OVERLOADED_OPERATORS:
8294 llvm_unreachable("Expected an overloaded operator");
8299 case OO_Array_Delete:
8302 "Special operators don't use AddBuiltinOperatorCandidates");
8307 // C++ [over.match.oper]p3:
8308 // -- For the operator ',', the unary operator '&', the
8309 // operator '->', or the operator 'co_await', the
8310 // built-in candidates set is empty.
8313 case OO_Plus: // '+' is either unary or binary
8314 if (Args.size() == 1)
8315 OpBuilder.addUnaryPlusPointerOverloads();
8318 case OO_Minus: // '-' is either unary or binary
8319 if (Args.size() == 1) {
8320 OpBuilder.addUnaryPlusOrMinusArithmeticOverloads();
8322 OpBuilder.addBinaryPlusOrMinusPointerOverloads(Op);
8323 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false);
8327 case OO_Star: // '*' is either unary or binary
8328 if (Args.size() == 1)
8329 OpBuilder.addUnaryStarPointerOverloads();
8331 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false);
8335 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false);
8340 OpBuilder.addPlusPlusMinusMinusArithmeticOverloads(Op);
8341 OpBuilder.addPlusPlusMinusMinusPointerOverloads();
8345 case OO_ExclaimEqual:
8346 OpBuilder.addEqualEqualOrNotEqualMemberPointerOverloads();
8352 case OO_GreaterEqual:
8353 OpBuilder.addRelationalPointerOrEnumeralOverloads();
8354 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/true);
8361 case OO_GreaterGreater:
8362 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op);
8365 case OO_Amp: // '&' is either unary or binary
8366 if (Args.size() == 1)
8367 // C++ [over.match.oper]p3:
8368 // -- For the operator ',', the unary operator '&', or the
8369 // operator '->', the built-in candidates set is empty.
8372 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op);
8376 OpBuilder.addUnaryTildePromotedIntegralOverloads();
8380 OpBuilder.addAssignmentMemberPointerOrEnumeralOverloads();
8385 OpBuilder.addAssignmentPointerOverloads(Op == OO_Equal);
8390 OpBuilder.addAssignmentArithmeticOverloads(Op == OO_Equal);
8393 case OO_PercentEqual:
8394 case OO_LessLessEqual:
8395 case OO_GreaterGreaterEqual:
8399 OpBuilder.addAssignmentIntegralOverloads();
8403 OpBuilder.addExclaimOverload();
8408 OpBuilder.addAmpAmpOrPipePipeOverload();
8412 OpBuilder.addSubscriptOverloads();
8416 OpBuilder.addArrowStarOverloads();
8419 case OO_Conditional:
8420 OpBuilder.addConditionalOperatorOverloads();
8421 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false);
8426 /// \brief Add function candidates found via argument-dependent lookup
8427 /// to the set of overloading candidates.
8429 /// This routine performs argument-dependent name lookup based on the
8430 /// given function name (which may also be an operator name) and adds
8431 /// all of the overload candidates found by ADL to the overload
8432 /// candidate set (C++ [basic.lookup.argdep]).
8434 Sema::AddArgumentDependentLookupCandidates(DeclarationName Name,
8436 ArrayRef<Expr *> Args,
8437 TemplateArgumentListInfo *ExplicitTemplateArgs,
8438 OverloadCandidateSet& CandidateSet,
8439 bool PartialOverloading) {
8442 // FIXME: This approach for uniquing ADL results (and removing
8443 // redundant candidates from the set) relies on pointer-equality,
8444 // which means we need to key off the canonical decl. However,
8445 // always going back to the canonical decl might not get us the
8446 // right set of default arguments. What default arguments are
8447 // we supposed to consider on ADL candidates, anyway?
8449 // FIXME: Pass in the explicit template arguments?
8450 ArgumentDependentLookup(Name, Loc, Args, Fns);
8452 // Erase all of the candidates we already knew about.
8453 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(),
8454 CandEnd = CandidateSet.end();
8455 Cand != CandEnd; ++Cand)
8456 if (Cand->Function) {
8457 Fns.erase(Cand->Function);
8458 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate())
8462 // For each of the ADL candidates we found, add it to the overload
8464 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) {
8465 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none);
8466 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) {
8467 if (ExplicitTemplateArgs)
8470 AddOverloadCandidate(FD, FoundDecl, Args, CandidateSet, false,
8471 PartialOverloading);
8473 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I),
8474 FoundDecl, ExplicitTemplateArgs,
8475 Args, CandidateSet, PartialOverloading);
8479 // Determines whether Cand1 is "better" in terms of its enable_if attrs than
8480 // Cand2 for overloading. This function assumes that all of the enable_if attrs
8481 // on Cand1 and Cand2 have conditions that evaluate to true.
8483 // Cand1's set of enable_if attributes are said to be "better" than Cand2's iff
8484 // Cand1's first N enable_if attributes have precisely the same conditions as
8485 // Cand2's first N enable_if attributes (where N = the number of enable_if
8486 // attributes on Cand2), and Cand1 has more than N enable_if attributes.
8487 static bool hasBetterEnableIfAttrs(Sema &S, const FunctionDecl *Cand1,
8488 const FunctionDecl *Cand2) {
8490 // FIXME: The next several lines are just
8491 // specific_attr_iterator<EnableIfAttr> but going in declaration order,
8492 // instead of reverse order which is how they're stored in the AST.
8493 auto Cand1Attrs = getOrderedEnableIfAttrs(Cand1);
8494 auto Cand2Attrs = getOrderedEnableIfAttrs(Cand2);
8496 // Candidate 1 is better if it has strictly more attributes and
8497 // the common sequence is identical.
8498 if (Cand1Attrs.size() <= Cand2Attrs.size())
8501 auto Cand1I = Cand1Attrs.begin();
8502 llvm::FoldingSetNodeID Cand1ID, Cand2ID;
8503 for (auto &Cand2A : Cand2Attrs) {
8507 auto &Cand1A = *Cand1I++;
8508 Cand1A->getCond()->Profile(Cand1ID, S.getASTContext(), true);
8509 Cand2A->getCond()->Profile(Cand2ID, S.getASTContext(), true);
8510 if (Cand1ID != Cand2ID)
8517 /// isBetterOverloadCandidate - Determines whether the first overload
8518 /// candidate is a better candidate than the second (C++ 13.3.3p1).
8519 bool clang::isBetterOverloadCandidate(Sema &S, const OverloadCandidate &Cand1,
8520 const OverloadCandidate &Cand2,
8522 bool UserDefinedConversion) {
8523 // Define viable functions to be better candidates than non-viable
8526 return Cand1.Viable;
8527 else if (!Cand1.Viable)
8530 // C++ [over.match.best]p1:
8532 // -- if F is a static member function, ICS1(F) is defined such
8533 // that ICS1(F) is neither better nor worse than ICS1(G) for
8534 // any function G, and, symmetrically, ICS1(G) is neither
8535 // better nor worse than ICS1(F).
8536 unsigned StartArg = 0;
8537 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument)
8540 // C++ [over.match.best]p1:
8541 // A viable function F1 is defined to be a better function than another
8542 // viable function F2 if for all arguments i, ICSi(F1) is not a worse
8543 // conversion sequence than ICSi(F2), and then...
8544 unsigned NumArgs = Cand1.NumConversions;
8545 assert(Cand2.NumConversions == NumArgs && "Overload candidate mismatch");
8546 bool HasBetterConversion = false;
8547 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) {
8548 switch (CompareImplicitConversionSequences(S, Loc,
8549 Cand1.Conversions[ArgIdx],
8550 Cand2.Conversions[ArgIdx])) {
8551 case ImplicitConversionSequence::Better:
8552 // Cand1 has a better conversion sequence.
8553 HasBetterConversion = true;
8556 case ImplicitConversionSequence::Worse:
8557 // Cand1 can't be better than Cand2.
8560 case ImplicitConversionSequence::Indistinguishable:
8566 // -- for some argument j, ICSj(F1) is a better conversion sequence than
8567 // ICSj(F2), or, if not that,
8568 if (HasBetterConversion)
8571 // -- the context is an initialization by user-defined conversion
8572 // (see 8.5, 13.3.1.5) and the standard conversion sequence
8573 // from the return type of F1 to the destination type (i.e.,
8574 // the type of the entity being initialized) is a better
8575 // conversion sequence than the standard conversion sequence
8576 // from the return type of F2 to the destination type.
8577 if (UserDefinedConversion && Cand1.Function && Cand2.Function &&
8578 isa<CXXConversionDecl>(Cand1.Function) &&
8579 isa<CXXConversionDecl>(Cand2.Function)) {
8580 // First check whether we prefer one of the conversion functions over the
8581 // other. This only distinguishes the results in non-standard, extension
8582 // cases such as the conversion from a lambda closure type to a function
8583 // pointer or block.
8584 ImplicitConversionSequence::CompareKind Result =
8585 compareConversionFunctions(S, Cand1.Function, Cand2.Function);
8586 if (Result == ImplicitConversionSequence::Indistinguishable)
8587 Result = CompareStandardConversionSequences(S, Loc,
8588 Cand1.FinalConversion,
8589 Cand2.FinalConversion);
8591 if (Result != ImplicitConversionSequence::Indistinguishable)
8592 return Result == ImplicitConversionSequence::Better;
8594 // FIXME: Compare kind of reference binding if conversion functions
8595 // convert to a reference type used in direct reference binding, per
8596 // C++14 [over.match.best]p1 section 2 bullet 3.
8599 // -- F1 is a non-template function and F2 is a function template
8600 // specialization, or, if not that,
8601 bool Cand1IsSpecialization = Cand1.Function &&
8602 Cand1.Function->getPrimaryTemplate();
8603 bool Cand2IsSpecialization = Cand2.Function &&
8604 Cand2.Function->getPrimaryTemplate();
8605 if (Cand1IsSpecialization != Cand2IsSpecialization)
8606 return Cand2IsSpecialization;
8608 // -- F1 and F2 are function template specializations, and the function
8609 // template for F1 is more specialized than the template for F2
8610 // according to the partial ordering rules described in 14.5.5.2, or,
8612 if (Cand1IsSpecialization && Cand2IsSpecialization) {
8613 if (FunctionTemplateDecl *BetterTemplate
8614 = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(),
8615 Cand2.Function->getPrimaryTemplate(),
8617 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion
8619 Cand1.ExplicitCallArguments,
8620 Cand2.ExplicitCallArguments))
8621 return BetterTemplate == Cand1.Function->getPrimaryTemplate();
8624 // Check for enable_if value-based overload resolution.
8625 if (Cand1.Function && Cand2.Function &&
8626 (Cand1.Function->hasAttr<EnableIfAttr>() ||
8627 Cand2.Function->hasAttr<EnableIfAttr>()))
8628 return hasBetterEnableIfAttrs(S, Cand1.Function, Cand2.Function);
8630 if (S.getLangOpts().CUDA && S.getLangOpts().CUDATargetOverloads &&
8631 Cand1.Function && Cand2.Function) {
8632 FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext);
8633 return S.IdentifyCUDAPreference(Caller, Cand1.Function) >
8634 S.IdentifyCUDAPreference(Caller, Cand2.Function);
8637 bool HasPS1 = Cand1.Function != nullptr &&
8638 functionHasPassObjectSizeParams(Cand1.Function);
8639 bool HasPS2 = Cand2.Function != nullptr &&
8640 functionHasPassObjectSizeParams(Cand2.Function);
8641 return HasPS1 != HasPS2 && HasPS1;
8644 /// Determine whether two declarations are "equivalent" for the purposes of
8645 /// name lookup and overload resolution. This applies when the same internal/no
8646 /// linkage entity is defined by two modules (probably by textually including
8647 /// the same header). In such a case, we don't consider the declarations to
8648 /// declare the same entity, but we also don't want lookups with both
8649 /// declarations visible to be ambiguous in some cases (this happens when using
8650 /// a modularized libstdc++).
8651 bool Sema::isEquivalentInternalLinkageDeclaration(const NamedDecl *A,
8652 const NamedDecl *B) {
8653 auto *VA = dyn_cast_or_null<ValueDecl>(A);
8654 auto *VB = dyn_cast_or_null<ValueDecl>(B);
8658 // The declarations must be declaring the same name as an internal linkage
8659 // entity in different modules.
8660 if (!VA->getDeclContext()->getRedeclContext()->Equals(
8661 VB->getDeclContext()->getRedeclContext()) ||
8662 getOwningModule(const_cast<ValueDecl *>(VA)) ==
8663 getOwningModule(const_cast<ValueDecl *>(VB)) ||
8664 VA->isExternallyVisible() || VB->isExternallyVisible())
8667 // Check that the declarations appear to be equivalent.
8669 // FIXME: Checking the type isn't really enough to resolve the ambiguity.
8670 // For constants and functions, we should check the initializer or body is
8671 // the same. For non-constant variables, we shouldn't allow it at all.
8672 if (Context.hasSameType(VA->getType(), VB->getType()))
8675 // Enum constants within unnamed enumerations will have different types, but
8676 // may still be similar enough to be interchangeable for our purposes.
8677 if (auto *EA = dyn_cast<EnumConstantDecl>(VA)) {
8678 if (auto *EB = dyn_cast<EnumConstantDecl>(VB)) {
8679 // Only handle anonymous enums. If the enumerations were named and
8680 // equivalent, they would have been merged to the same type.
8681 auto *EnumA = cast<EnumDecl>(EA->getDeclContext());
8682 auto *EnumB = cast<EnumDecl>(EB->getDeclContext());
8683 if (EnumA->hasNameForLinkage() || EnumB->hasNameForLinkage() ||
8684 !Context.hasSameType(EnumA->getIntegerType(),
8685 EnumB->getIntegerType()))
8687 // Allow this only if the value is the same for both enumerators.
8688 return llvm::APSInt::isSameValue(EA->getInitVal(), EB->getInitVal());
8692 // Nothing else is sufficiently similar.
8696 void Sema::diagnoseEquivalentInternalLinkageDeclarations(
8697 SourceLocation Loc, const NamedDecl *D, ArrayRef<const NamedDecl *> Equiv) {
8698 Diag(Loc, diag::ext_equivalent_internal_linkage_decl_in_modules) << D;
8700 Module *M = getOwningModule(const_cast<NamedDecl*>(D));
8701 Diag(D->getLocation(), diag::note_equivalent_internal_linkage_decl)
8702 << !M << (M ? M->getFullModuleName() : "");
8704 for (auto *E : Equiv) {
8705 Module *M = getOwningModule(const_cast<NamedDecl*>(E));
8706 Diag(E->getLocation(), diag::note_equivalent_internal_linkage_decl)
8707 << !M << (M ? M->getFullModuleName() : "");
8711 /// \brief Computes the best viable function (C++ 13.3.3)
8712 /// within an overload candidate set.
8714 /// \param Loc The location of the function name (or operator symbol) for
8715 /// which overload resolution occurs.
8717 /// \param Best If overload resolution was successful or found a deleted
8718 /// function, \p Best points to the candidate function found.
8720 /// \returns The result of overload resolution.
8722 OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc,
8724 bool UserDefinedConversion) {
8725 // Find the best viable function.
8727 for (iterator Cand = begin(); Cand != end(); ++Cand) {
8729 if (Best == end() || isBetterOverloadCandidate(S, *Cand, *Best, Loc,
8730 UserDefinedConversion))
8734 // If we didn't find any viable functions, abort.
8736 return OR_No_Viable_Function;
8738 llvm::SmallVector<const NamedDecl *, 4> EquivalentCands;
8740 // Make sure that this function is better than every other viable
8741 // function. If not, we have an ambiguity.
8742 for (iterator Cand = begin(); Cand != end(); ++Cand) {
8745 !isBetterOverloadCandidate(S, *Best, *Cand, Loc,
8746 UserDefinedConversion)) {
8747 if (S.isEquivalentInternalLinkageDeclaration(Best->Function,
8749 EquivalentCands.push_back(Cand->Function);
8754 return OR_Ambiguous;
8758 // Best is the best viable function.
8759 if (Best->Function &&
8760 (Best->Function->isDeleted() ||
8761 S.isFunctionConsideredUnavailable(Best->Function)))
8764 if (!EquivalentCands.empty())
8765 S.diagnoseEquivalentInternalLinkageDeclarations(Loc, Best->Function,
8773 enum OverloadCandidateKind {
8777 oc_function_template,
8779 oc_constructor_template,
8780 oc_implicit_default_constructor,
8781 oc_implicit_copy_constructor,
8782 oc_implicit_move_constructor,
8783 oc_implicit_copy_assignment,
8784 oc_implicit_move_assignment,
8785 oc_implicit_inherited_constructor
8788 OverloadCandidateKind ClassifyOverloadCandidate(Sema &S,
8790 std::string &Description) {
8791 bool isTemplate = false;
8793 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) {
8795 Description = S.getTemplateArgumentBindingsText(
8796 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs());
8799 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) {
8800 if (!Ctor->isImplicit())
8801 return isTemplate ? oc_constructor_template : oc_constructor;
8803 if (Ctor->getInheritedConstructor())
8804 return oc_implicit_inherited_constructor;
8806 if (Ctor->isDefaultConstructor())
8807 return oc_implicit_default_constructor;
8809 if (Ctor->isMoveConstructor())
8810 return oc_implicit_move_constructor;
8812 assert(Ctor->isCopyConstructor() &&
8813 "unexpected sort of implicit constructor");
8814 return oc_implicit_copy_constructor;
8817 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) {
8818 // This actually gets spelled 'candidate function' for now, but
8819 // it doesn't hurt to split it out.
8820 if (!Meth->isImplicit())
8821 return isTemplate ? oc_method_template : oc_method;
8823 if (Meth->isMoveAssignmentOperator())
8824 return oc_implicit_move_assignment;
8826 if (Meth->isCopyAssignmentOperator())
8827 return oc_implicit_copy_assignment;
8829 assert(isa<CXXConversionDecl>(Meth) && "expected conversion");
8833 return isTemplate ? oc_function_template : oc_function;
8836 void MaybeEmitInheritedConstructorNote(Sema &S, Decl *Fn) {
8837 const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn);
8840 Ctor = Ctor->getInheritedConstructor();
8843 S.Diag(Ctor->getLocation(), diag::note_ovl_candidate_inherited_constructor);
8846 } // end anonymous namespace
8848 static bool isFunctionAlwaysEnabled(const ASTContext &Ctx,
8849 const FunctionDecl *FD) {
8850 for (auto *EnableIf : FD->specific_attrs<EnableIfAttr>()) {
8852 if (!EnableIf->getCond()->EvaluateAsBooleanCondition(AlwaysTrue, Ctx))
8860 /// \brief Returns true if we can take the address of the function.
8862 /// \param Complain - If true, we'll emit a diagnostic
8863 /// \param InOverloadResolution - For the purposes of emitting a diagnostic, are
8864 /// we in overload resolution?
8865 /// \param Loc - The location of the statement we're complaining about. Ignored
8866 /// if we're not complaining, or if we're in overload resolution.
8867 static bool checkAddressOfFunctionIsAvailable(Sema &S, const FunctionDecl *FD,
8869 bool InOverloadResolution,
8870 SourceLocation Loc) {
8871 if (!isFunctionAlwaysEnabled(S.Context, FD)) {
8873 if (InOverloadResolution)
8874 S.Diag(FD->getLocStart(),
8875 diag::note_addrof_ovl_candidate_disabled_by_enable_if_attr);
8877 S.Diag(Loc, diag::err_addrof_function_disabled_by_enable_if_attr) << FD;
8882 auto I = std::find_if(FD->param_begin(), FD->param_end(),
8883 std::mem_fn(&ParmVarDecl::hasAttr<PassObjectSizeAttr>));
8884 if (I == FD->param_end())
8888 // Add one to ParamNo because it's user-facing
8889 unsigned ParamNo = std::distance(FD->param_begin(), I) + 1;
8890 if (InOverloadResolution)
8891 S.Diag(FD->getLocation(),
8892 diag::note_ovl_candidate_has_pass_object_size_params)
8895 S.Diag(Loc, diag::err_address_of_function_with_pass_object_size_params)
8901 static bool checkAddressOfCandidateIsAvailable(Sema &S,
8902 const FunctionDecl *FD) {
8903 return checkAddressOfFunctionIsAvailable(S, FD, /*Complain=*/true,
8904 /*InOverloadResolution=*/true,
8905 /*Loc=*/SourceLocation());
8908 bool Sema::checkAddressOfFunctionIsAvailable(const FunctionDecl *Function,
8910 SourceLocation Loc) {
8911 return ::checkAddressOfFunctionIsAvailable(*this, Function, Complain,
8912 /*InOverloadResolution=*/false,
8916 // Notes the location of an overload candidate.
8917 void Sema::NoteOverloadCandidate(FunctionDecl *Fn, QualType DestType,
8918 bool TakingAddress) {
8919 if (TakingAddress && !checkAddressOfCandidateIsAvailable(*this, Fn))
8923 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc);
8924 PartialDiagnostic PD = PDiag(diag::note_ovl_candidate)
8925 << (unsigned) K << FnDesc;
8927 HandleFunctionTypeMismatch(PD, Fn->getType(), DestType);
8928 Diag(Fn->getLocation(), PD);
8929 MaybeEmitInheritedConstructorNote(*this, Fn);
8932 // Notes the location of all overload candidates designated through
8934 void Sema::NoteAllOverloadCandidates(Expr *OverloadedExpr, QualType DestType,
8935 bool TakingAddress) {
8936 assert(OverloadedExpr->getType() == Context.OverloadTy);
8938 OverloadExpr::FindResult Ovl = OverloadExpr::find(OverloadedExpr);
8939 OverloadExpr *OvlExpr = Ovl.Expression;
8941 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
8942 IEnd = OvlExpr->decls_end();
8944 if (FunctionTemplateDecl *FunTmpl =
8945 dyn_cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()) ) {
8946 NoteOverloadCandidate(FunTmpl->getTemplatedDecl(), DestType,
8948 } else if (FunctionDecl *Fun
8949 = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()) ) {
8950 NoteOverloadCandidate(Fun, DestType, TakingAddress);
8955 /// Diagnoses an ambiguous conversion. The partial diagnostic is the
8956 /// "lead" diagnostic; it will be given two arguments, the source and
8957 /// target types of the conversion.
8958 void ImplicitConversionSequence::DiagnoseAmbiguousConversion(
8960 SourceLocation CaretLoc,
8961 const PartialDiagnostic &PDiag) const {
8962 S.Diag(CaretLoc, PDiag)
8963 << Ambiguous.getFromType() << Ambiguous.getToType();
8964 // FIXME: The note limiting machinery is borrowed from
8965 // OverloadCandidateSet::NoteCandidates; there's an opportunity for
8966 // refactoring here.
8967 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
8968 unsigned CandsShown = 0;
8969 AmbiguousConversionSequence::const_iterator I, E;
8970 for (I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) {
8971 if (CandsShown >= 4 && ShowOverloads == Ovl_Best)
8974 S.NoteOverloadCandidate(*I);
8977 S.Diag(SourceLocation(), diag::note_ovl_too_many_candidates) << int(E - I);
8980 static void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand,
8981 unsigned I, bool TakingCandidateAddress) {
8982 const ImplicitConversionSequence &Conv = Cand->Conversions[I];
8983 assert(Conv.isBad());
8984 assert(Cand->Function && "for now, candidate must be a function");
8985 FunctionDecl *Fn = Cand->Function;
8987 // There's a conversion slot for the object argument if this is a
8988 // non-constructor method. Note that 'I' corresponds the
8989 // conversion-slot index.
8990 bool isObjectArgument = false;
8991 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) {
8993 isObjectArgument = true;
8999 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc);
9001 Expr *FromExpr = Conv.Bad.FromExpr;
9002 QualType FromTy = Conv.Bad.getFromType();
9003 QualType ToTy = Conv.Bad.getToType();
9005 if (FromTy == S.Context.OverloadTy) {
9006 assert(FromExpr && "overload set argument came from implicit argument?");
9007 Expr *E = FromExpr->IgnoreParens();
9008 if (isa<UnaryOperator>(E))
9009 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens();
9010 DeclarationName Name = cast<OverloadExpr>(E)->getName();
9012 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload)
9013 << (unsigned) FnKind << FnDesc
9014 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9015 << ToTy << Name << I+1;
9016 MaybeEmitInheritedConstructorNote(S, Fn);
9020 // Do some hand-waving analysis to see if the non-viability is due
9021 // to a qualifier mismatch.
9022 CanQualType CFromTy = S.Context.getCanonicalType(FromTy);
9023 CanQualType CToTy = S.Context.getCanonicalType(ToTy);
9024 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>())
9025 CToTy = RT->getPointeeType();
9027 // TODO: detect and diagnose the full richness of const mismatches.
9028 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>())
9029 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>())
9030 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType();
9033 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() &&
9034 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) {
9035 Qualifiers FromQs = CFromTy.getQualifiers();
9036 Qualifiers ToQs = CToTy.getQualifiers();
9038 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) {
9039 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace)
9040 << (unsigned) FnKind << FnDesc
9041 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9043 << FromQs.getAddressSpace() << ToQs.getAddressSpace()
9044 << (unsigned) isObjectArgument << I+1;
9045 MaybeEmitInheritedConstructorNote(S, Fn);
9049 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) {
9050 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_ownership)
9051 << (unsigned) FnKind << FnDesc
9052 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9054 << FromQs.getObjCLifetime() << ToQs.getObjCLifetime()
9055 << (unsigned) isObjectArgument << I+1;
9056 MaybeEmitInheritedConstructorNote(S, Fn);
9060 if (FromQs.getObjCGCAttr() != ToQs.getObjCGCAttr()) {
9061 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_gc)
9062 << (unsigned) FnKind << FnDesc
9063 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9065 << FromQs.getObjCGCAttr() << ToQs.getObjCGCAttr()
9066 << (unsigned) isObjectArgument << I+1;
9067 MaybeEmitInheritedConstructorNote(S, Fn);
9071 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers();
9072 assert(CVR && "unexpected qualifiers mismatch");
9074 if (isObjectArgument) {
9075 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this)
9076 << (unsigned) FnKind << FnDesc
9077 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9078 << FromTy << (CVR - 1);
9080 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr)
9081 << (unsigned) FnKind << FnDesc
9082 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9083 << FromTy << (CVR - 1) << I+1;
9085 MaybeEmitInheritedConstructorNote(S, Fn);
9089 // Special diagnostic for failure to convert an initializer list, since
9090 // telling the user that it has type void is not useful.
9091 if (FromExpr && isa<InitListExpr>(FromExpr)) {
9092 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_list_argument)
9093 << (unsigned) FnKind << FnDesc
9094 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9095 << FromTy << ToTy << (unsigned) isObjectArgument << I+1;
9096 MaybeEmitInheritedConstructorNote(S, Fn);
9100 // Diagnose references or pointers to incomplete types differently,
9101 // since it's far from impossible that the incompleteness triggered
9103 QualType TempFromTy = FromTy.getNonReferenceType();
9104 if (const PointerType *PTy = TempFromTy->getAs<PointerType>())
9105 TempFromTy = PTy->getPointeeType();
9106 if (TempFromTy->isIncompleteType()) {
9107 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete)
9108 << (unsigned) FnKind << FnDesc
9109 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9110 << FromTy << ToTy << (unsigned) isObjectArgument << I+1;
9111 MaybeEmitInheritedConstructorNote(S, Fn);
9115 // Diagnose base -> derived pointer conversions.
9116 unsigned BaseToDerivedConversion = 0;
9117 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) {
9118 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) {
9119 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs(
9120 FromPtrTy->getPointeeType()) &&
9121 !FromPtrTy->getPointeeType()->isIncompleteType() &&
9122 !ToPtrTy->getPointeeType()->isIncompleteType() &&
9123 S.IsDerivedFrom(SourceLocation(), ToPtrTy->getPointeeType(),
9124 FromPtrTy->getPointeeType()))
9125 BaseToDerivedConversion = 1;
9127 } else if (const ObjCObjectPointerType *FromPtrTy
9128 = FromTy->getAs<ObjCObjectPointerType>()) {
9129 if (const ObjCObjectPointerType *ToPtrTy
9130 = ToTy->getAs<ObjCObjectPointerType>())
9131 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl())
9132 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl())
9133 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs(
9134 FromPtrTy->getPointeeType()) &&
9135 FromIface->isSuperClassOf(ToIface))
9136 BaseToDerivedConversion = 2;
9137 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) {
9138 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) &&
9139 !FromTy->isIncompleteType() &&
9140 !ToRefTy->getPointeeType()->isIncompleteType() &&
9141 S.IsDerivedFrom(SourceLocation(), ToRefTy->getPointeeType(), FromTy)) {
9142 BaseToDerivedConversion = 3;
9143 } else if (ToTy->isLValueReferenceType() && !FromExpr->isLValue() &&
9144 ToTy.getNonReferenceType().getCanonicalType() ==
9145 FromTy.getNonReferenceType().getCanonicalType()) {
9146 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_lvalue)
9147 << (unsigned) FnKind << FnDesc
9148 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9149 << (unsigned) isObjectArgument << I + 1;
9150 MaybeEmitInheritedConstructorNote(S, Fn);
9155 if (BaseToDerivedConversion) {
9156 S.Diag(Fn->getLocation(),
9157 diag::note_ovl_candidate_bad_base_to_derived_conv)
9158 << (unsigned) FnKind << FnDesc
9159 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9160 << (BaseToDerivedConversion - 1)
9161 << FromTy << ToTy << I+1;
9162 MaybeEmitInheritedConstructorNote(S, Fn);
9166 if (isa<ObjCObjectPointerType>(CFromTy) &&
9167 isa<PointerType>(CToTy)) {
9168 Qualifiers FromQs = CFromTy.getQualifiers();
9169 Qualifiers ToQs = CToTy.getQualifiers();
9170 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) {
9171 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_arc_conv)
9172 << (unsigned) FnKind << FnDesc
9173 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9174 << FromTy << ToTy << (unsigned) isObjectArgument << I+1;
9175 MaybeEmitInheritedConstructorNote(S, Fn);
9180 if (TakingCandidateAddress &&
9181 !checkAddressOfCandidateIsAvailable(S, Cand->Function))
9184 // Emit the generic diagnostic and, optionally, add the hints to it.
9185 PartialDiagnostic FDiag = S.PDiag(diag::note_ovl_candidate_bad_conv);
9186 FDiag << (unsigned) FnKind << FnDesc
9187 << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
9188 << FromTy << ToTy << (unsigned) isObjectArgument << I + 1
9189 << (unsigned) (Cand->Fix.Kind);
9191 // If we can fix the conversion, suggest the FixIts.
9192 for (std::vector<FixItHint>::iterator HI = Cand->Fix.Hints.begin(),
9193 HE = Cand->Fix.Hints.end(); HI != HE; ++HI)
9195 S.Diag(Fn->getLocation(), FDiag);
9197 MaybeEmitInheritedConstructorNote(S, Fn);
9200 /// Additional arity mismatch diagnosis specific to a function overload
9201 /// candidates. This is not covered by the more general DiagnoseArityMismatch()
9202 /// over a candidate in any candidate set.
9203 static bool CheckArityMismatch(Sema &S, OverloadCandidate *Cand,
9205 FunctionDecl *Fn = Cand->Function;
9206 unsigned MinParams = Fn->getMinRequiredArguments();
9208 // With invalid overloaded operators, it's possible that we think we
9209 // have an arity mismatch when in fact it looks like we have the
9210 // right number of arguments, because only overloaded operators have
9211 // the weird behavior of overloading member and non-member functions.
9212 // Just don't report anything.
9213 if (Fn->isInvalidDecl() &&
9214 Fn->getDeclName().getNameKind() == DeclarationName::CXXOperatorName)
9217 if (NumArgs < MinParams) {
9218 assert((Cand->FailureKind == ovl_fail_too_few_arguments) ||
9219 (Cand->FailureKind == ovl_fail_bad_deduction &&
9220 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments));
9222 assert((Cand->FailureKind == ovl_fail_too_many_arguments) ||
9223 (Cand->FailureKind == ovl_fail_bad_deduction &&
9224 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments));
9230 /// General arity mismatch diagnosis over a candidate in a candidate set.
9231 static void DiagnoseArityMismatch(Sema &S, Decl *D, unsigned NumFormalArgs) {
9232 assert(isa<FunctionDecl>(D) &&
9233 "The templated declaration should at least be a function"
9234 " when diagnosing bad template argument deduction due to too many"
9235 " or too few arguments");
9237 FunctionDecl *Fn = cast<FunctionDecl>(D);
9239 // TODO: treat calls to a missing default constructor as a special case
9240 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>();
9241 unsigned MinParams = Fn->getMinRequiredArguments();
9243 // at least / at most / exactly
9244 unsigned mode, modeCount;
9245 if (NumFormalArgs < MinParams) {
9246 if (MinParams != FnTy->getNumParams() || FnTy->isVariadic() ||
9247 FnTy->isTemplateVariadic())
9248 mode = 0; // "at least"
9250 mode = 2; // "exactly"
9251 modeCount = MinParams;
9253 if (MinParams != FnTy->getNumParams())
9254 mode = 1; // "at most"
9256 mode = 2; // "exactly"
9257 modeCount = FnTy->getNumParams();
9260 std::string Description;
9261 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description);
9263 if (modeCount == 1 && Fn->getParamDecl(0)->getDeclName())
9264 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity_one)
9265 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != nullptr)
9266 << mode << Fn->getParamDecl(0) << NumFormalArgs;
9268 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity)
9269 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != nullptr)
9270 << mode << modeCount << NumFormalArgs;
9271 MaybeEmitInheritedConstructorNote(S, Fn);
9274 /// Arity mismatch diagnosis specific to a function overload candidate.
9275 static void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand,
9276 unsigned NumFormalArgs) {
9277 if (!CheckArityMismatch(S, Cand, NumFormalArgs))
9278 DiagnoseArityMismatch(S, Cand->Function, NumFormalArgs);
9281 static TemplateDecl *getDescribedTemplate(Decl *Templated) {
9282 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Templated))
9283 return FD->getDescribedFunctionTemplate();
9284 else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Templated))
9285 return RD->getDescribedClassTemplate();
9287 llvm_unreachable("Unsupported: Getting the described template declaration"
9288 " for bad deduction diagnosis");
9291 /// Diagnose a failed template-argument deduction.
9292 static void DiagnoseBadDeduction(Sema &S, Decl *Templated,
9293 DeductionFailureInfo &DeductionFailure,
9295 bool TakingCandidateAddress) {
9296 TemplateParameter Param = DeductionFailure.getTemplateParameter();
9298 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) ||
9299 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) ||
9300 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>());
9301 switch (DeductionFailure.Result) {
9302 case Sema::TDK_Success:
9303 llvm_unreachable("TDK_success while diagnosing bad deduction");
9305 case Sema::TDK_Incomplete: {
9306 assert(ParamD && "no parameter found for incomplete deduction result");
9307 S.Diag(Templated->getLocation(),
9308 diag::note_ovl_candidate_incomplete_deduction)
9309 << ParamD->getDeclName();
9310 MaybeEmitInheritedConstructorNote(S, Templated);
9314 case Sema::TDK_Underqualified: {
9315 assert(ParamD && "no parameter found for bad qualifiers deduction result");
9316 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD);
9318 QualType Param = DeductionFailure.getFirstArg()->getAsType();
9320 // Param will have been canonicalized, but it should just be a
9321 // qualified version of ParamD, so move the qualifiers to that.
9322 QualifierCollector Qs;
9324 QualType NonCanonParam = Qs.apply(S.Context, TParam->getTypeForDecl());
9325 assert(S.Context.hasSameType(Param, NonCanonParam));
9327 // Arg has also been canonicalized, but there's nothing we can do
9328 // about that. It also doesn't matter as much, because it won't
9329 // have any template parameters in it (because deduction isn't
9330 // done on dependent types).
9331 QualType Arg = DeductionFailure.getSecondArg()->getAsType();
9333 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_underqualified)
9334 << ParamD->getDeclName() << Arg << NonCanonParam;
9335 MaybeEmitInheritedConstructorNote(S, Templated);
9339 case Sema::TDK_Inconsistent: {
9340 assert(ParamD && "no parameter found for inconsistent deduction result");
9342 if (isa<TemplateTypeParmDecl>(ParamD))
9344 else if (isa<NonTypeTemplateParmDecl>(ParamD))
9350 S.Diag(Templated->getLocation(),
9351 diag::note_ovl_candidate_inconsistent_deduction)
9352 << which << ParamD->getDeclName() << *DeductionFailure.getFirstArg()
9353 << *DeductionFailure.getSecondArg();
9354 MaybeEmitInheritedConstructorNote(S, Templated);
9358 case Sema::TDK_InvalidExplicitArguments:
9359 assert(ParamD && "no parameter found for invalid explicit arguments");
9360 if (ParamD->getDeclName())
9361 S.Diag(Templated->getLocation(),
9362 diag::note_ovl_candidate_explicit_arg_mismatch_named)
9363 << ParamD->getDeclName();
9366 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD))
9367 index = TTP->getIndex();
9368 else if (NonTypeTemplateParmDecl *NTTP
9369 = dyn_cast<NonTypeTemplateParmDecl>(ParamD))
9370 index = NTTP->getIndex();
9372 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex();
9373 S.Diag(Templated->getLocation(),
9374 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed)
9377 MaybeEmitInheritedConstructorNote(S, Templated);
9380 case Sema::TDK_TooManyArguments:
9381 case Sema::TDK_TooFewArguments:
9382 DiagnoseArityMismatch(S, Templated, NumArgs);
9385 case Sema::TDK_InstantiationDepth:
9386 S.Diag(Templated->getLocation(),
9387 diag::note_ovl_candidate_instantiation_depth);
9388 MaybeEmitInheritedConstructorNote(S, Templated);
9391 case Sema::TDK_SubstitutionFailure: {
9392 // Format the template argument list into the argument string.
9393 SmallString<128> TemplateArgString;
9394 if (TemplateArgumentList *Args =
9395 DeductionFailure.getTemplateArgumentList()) {
9396 TemplateArgString = " ";
9397 TemplateArgString += S.getTemplateArgumentBindingsText(
9398 getDescribedTemplate(Templated)->getTemplateParameters(), *Args);
9401 // If this candidate was disabled by enable_if, say so.
9402 PartialDiagnosticAt *PDiag = DeductionFailure.getSFINAEDiagnostic();
9403 if (PDiag && PDiag->second.getDiagID() ==
9404 diag::err_typename_nested_not_found_enable_if) {
9405 // FIXME: Use the source range of the condition, and the fully-qualified
9406 // name of the enable_if template. These are both present in PDiag.
9407 S.Diag(PDiag->first, diag::note_ovl_candidate_disabled_by_enable_if)
9408 << "'enable_if'" << TemplateArgString;
9412 // Format the SFINAE diagnostic into the argument string.
9413 // FIXME: Add a general mechanism to include a PartialDiagnostic *'s
9414 // formatted message in another diagnostic.
9415 SmallString<128> SFINAEArgString;
9418 SFINAEArgString = ": ";
9419 R = SourceRange(PDiag->first, PDiag->first);
9420 PDiag->second.EmitToString(S.getDiagnostics(), SFINAEArgString);
9423 S.Diag(Templated->getLocation(),
9424 diag::note_ovl_candidate_substitution_failure)
9425 << TemplateArgString << SFINAEArgString << R;
9426 MaybeEmitInheritedConstructorNote(S, Templated);
9430 case Sema::TDK_FailedOverloadResolution: {
9431 OverloadExpr::FindResult R = OverloadExpr::find(DeductionFailure.getExpr());
9432 S.Diag(Templated->getLocation(),
9433 diag::note_ovl_candidate_failed_overload_resolution)
9434 << R.Expression->getName();
9438 case Sema::TDK_DeducedMismatch: {
9439 // Format the template argument list into the argument string.
9440 SmallString<128> TemplateArgString;
9441 if (TemplateArgumentList *Args =
9442 DeductionFailure.getTemplateArgumentList()) {
9443 TemplateArgString = " ";
9444 TemplateArgString += S.getTemplateArgumentBindingsText(
9445 getDescribedTemplate(Templated)->getTemplateParameters(), *Args);
9448 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_deduced_mismatch)
9449 << (*DeductionFailure.getCallArgIndex() + 1)
9450 << *DeductionFailure.getFirstArg() << *DeductionFailure.getSecondArg()
9451 << TemplateArgString;
9455 case Sema::TDK_NonDeducedMismatch: {
9456 // FIXME: Provide a source location to indicate what we couldn't match.
9457 TemplateArgument FirstTA = *DeductionFailure.getFirstArg();
9458 TemplateArgument SecondTA = *DeductionFailure.getSecondArg();
9459 if (FirstTA.getKind() == TemplateArgument::Template &&
9460 SecondTA.getKind() == TemplateArgument::Template) {
9461 TemplateName FirstTN = FirstTA.getAsTemplate();
9462 TemplateName SecondTN = SecondTA.getAsTemplate();
9463 if (FirstTN.getKind() == TemplateName::Template &&
9464 SecondTN.getKind() == TemplateName::Template) {
9465 if (FirstTN.getAsTemplateDecl()->getName() ==
9466 SecondTN.getAsTemplateDecl()->getName()) {
9467 // FIXME: This fixes a bad diagnostic where both templates are named
9468 // the same. This particular case is a bit difficult since:
9469 // 1) It is passed as a string to the diagnostic printer.
9470 // 2) The diagnostic printer only attempts to find a better
9471 // name for types, not decls.
9472 // Ideally, this should folded into the diagnostic printer.
9473 S.Diag(Templated->getLocation(),
9474 diag::note_ovl_candidate_non_deduced_mismatch_qualified)
9475 << FirstTN.getAsTemplateDecl() << SecondTN.getAsTemplateDecl();
9481 if (TakingCandidateAddress && isa<FunctionDecl>(Templated) &&
9482 !checkAddressOfCandidateIsAvailable(S, cast<FunctionDecl>(Templated)))
9485 // FIXME: For generic lambda parameters, check if the function is a lambda
9486 // call operator, and if so, emit a prettier and more informative
9487 // diagnostic that mentions 'auto' and lambda in addition to
9488 // (or instead of?) the canonical template type parameters.
9489 S.Diag(Templated->getLocation(),
9490 diag::note_ovl_candidate_non_deduced_mismatch)
9491 << FirstTA << SecondTA;
9494 // TODO: diagnose these individually, then kill off
9495 // note_ovl_candidate_bad_deduction, which is uselessly vague.
9496 case Sema::TDK_MiscellaneousDeductionFailure:
9497 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_bad_deduction);
9498 MaybeEmitInheritedConstructorNote(S, Templated);
9503 /// Diagnose a failed template-argument deduction, for function calls.
9504 static void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand,
9506 bool TakingCandidateAddress) {
9507 unsigned TDK = Cand->DeductionFailure.Result;
9508 if (TDK == Sema::TDK_TooFewArguments || TDK == Sema::TDK_TooManyArguments) {
9509 if (CheckArityMismatch(S, Cand, NumArgs))
9512 DiagnoseBadDeduction(S, Cand->Function, // pattern
9513 Cand->DeductionFailure, NumArgs, TakingCandidateAddress);
9516 /// CUDA: diagnose an invalid call across targets.
9517 static void DiagnoseBadTarget(Sema &S, OverloadCandidate *Cand) {
9518 FunctionDecl *Caller = cast<FunctionDecl>(S.CurContext);
9519 FunctionDecl *Callee = Cand->Function;
9521 Sema::CUDAFunctionTarget CallerTarget = S.IdentifyCUDATarget(Caller),
9522 CalleeTarget = S.IdentifyCUDATarget(Callee);
9525 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Callee, FnDesc);
9527 S.Diag(Callee->getLocation(), diag::note_ovl_candidate_bad_target)
9528 << (unsigned)FnKind << CalleeTarget << CallerTarget;
9530 // This could be an implicit constructor for which we could not infer the
9531 // target due to a collsion. Diagnose that case.
9532 CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Callee);
9533 if (Meth != nullptr && Meth->isImplicit()) {
9534 CXXRecordDecl *ParentClass = Meth->getParent();
9535 Sema::CXXSpecialMember CSM;
9540 case oc_implicit_default_constructor:
9541 CSM = Sema::CXXDefaultConstructor;
9543 case oc_implicit_copy_constructor:
9544 CSM = Sema::CXXCopyConstructor;
9546 case oc_implicit_move_constructor:
9547 CSM = Sema::CXXMoveConstructor;
9549 case oc_implicit_copy_assignment:
9550 CSM = Sema::CXXCopyAssignment;
9552 case oc_implicit_move_assignment:
9553 CSM = Sema::CXXMoveAssignment;
9557 bool ConstRHS = false;
9558 if (Meth->getNumParams()) {
9559 if (const ReferenceType *RT =
9560 Meth->getParamDecl(0)->getType()->getAs<ReferenceType>()) {
9561 ConstRHS = RT->getPointeeType().isConstQualified();
9565 S.inferCUDATargetForImplicitSpecialMember(ParentClass, CSM, Meth,
9566 /* ConstRHS */ ConstRHS,
9567 /* Diagnose */ true);
9571 static void DiagnoseFailedEnableIfAttr(Sema &S, OverloadCandidate *Cand) {
9572 FunctionDecl *Callee = Cand->Function;
9573 EnableIfAttr *Attr = static_cast<EnableIfAttr*>(Cand->DeductionFailure.Data);
9575 S.Diag(Callee->getLocation(),
9576 diag::note_ovl_candidate_disabled_by_enable_if_attr)
9577 << Attr->getCond()->getSourceRange() << Attr->getMessage();
9580 /// Generates a 'note' diagnostic for an overload candidate. We've
9581 /// already generated a primary error at the call site.
9583 /// It really does need to be a single diagnostic with its caret
9584 /// pointed at the candidate declaration. Yes, this creates some
9585 /// major challenges of technical writing. Yes, this makes pointing
9586 /// out problems with specific arguments quite awkward. It's still
9587 /// better than generating twenty screens of text for every failed
9590 /// It would be great to be able to express per-candidate problems
9591 /// more richly for those diagnostic clients that cared, but we'd
9592 /// still have to be just as careful with the default diagnostics.
9593 static void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand,
9595 bool TakingCandidateAddress) {
9596 FunctionDecl *Fn = Cand->Function;
9598 // Note deleted candidates, but only if they're viable.
9599 if (Cand->Viable && (Fn->isDeleted() ||
9600 S.isFunctionConsideredUnavailable(Fn))) {
9602 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc);
9604 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted)
9606 << (Fn->isDeleted() ? (Fn->isDeletedAsWritten() ? 1 : 2) : 0);
9607 MaybeEmitInheritedConstructorNote(S, Fn);
9611 // We don't really have anything else to say about viable candidates.
9613 S.NoteOverloadCandidate(Fn);
9617 switch (Cand->FailureKind) {
9618 case ovl_fail_too_many_arguments:
9619 case ovl_fail_too_few_arguments:
9620 return DiagnoseArityMismatch(S, Cand, NumArgs);
9622 case ovl_fail_bad_deduction:
9623 return DiagnoseBadDeduction(S, Cand, NumArgs, TakingCandidateAddress);
9625 case ovl_fail_illegal_constructor: {
9626 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_illegal_constructor)
9627 << (Fn->getPrimaryTemplate() ? 1 : 0);
9628 MaybeEmitInheritedConstructorNote(S, Fn);
9632 case ovl_fail_trivial_conversion:
9633 case ovl_fail_bad_final_conversion:
9634 case ovl_fail_final_conversion_not_exact:
9635 return S.NoteOverloadCandidate(Fn);
9637 case ovl_fail_bad_conversion: {
9638 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0);
9639 for (unsigned N = Cand->NumConversions; I != N; ++I)
9640 if (Cand->Conversions[I].isBad())
9641 return DiagnoseBadConversion(S, Cand, I, TakingCandidateAddress);
9643 // FIXME: this currently happens when we're called from SemaInit
9644 // when user-conversion overload fails. Figure out how to handle
9645 // those conditions and diagnose them well.
9646 return S.NoteOverloadCandidate(Fn);
9649 case ovl_fail_bad_target:
9650 return DiagnoseBadTarget(S, Cand);
9652 case ovl_fail_enable_if:
9653 return DiagnoseFailedEnableIfAttr(S, Cand);
9655 case ovl_fail_addr_not_available: {
9656 bool Available = checkAddressOfCandidateIsAvailable(S, Cand->Function);
9664 static void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) {
9665 // Desugar the type of the surrogate down to a function type,
9666 // retaining as many typedefs as possible while still showing
9667 // the function type (and, therefore, its parameter types).
9668 QualType FnType = Cand->Surrogate->getConversionType();
9669 bool isLValueReference = false;
9670 bool isRValueReference = false;
9671 bool isPointer = false;
9672 if (const LValueReferenceType *FnTypeRef =
9673 FnType->getAs<LValueReferenceType>()) {
9674 FnType = FnTypeRef->getPointeeType();
9675 isLValueReference = true;
9676 } else if (const RValueReferenceType *FnTypeRef =
9677 FnType->getAs<RValueReferenceType>()) {
9678 FnType = FnTypeRef->getPointeeType();
9679 isRValueReference = true;
9681 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) {
9682 FnType = FnTypePtr->getPointeeType();
9685 // Desugar down to a function type.
9686 FnType = QualType(FnType->getAs<FunctionType>(), 0);
9687 // Reconstruct the pointer/reference as appropriate.
9688 if (isPointer) FnType = S.Context.getPointerType(FnType);
9689 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType);
9690 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType);
9692 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand)
9694 MaybeEmitInheritedConstructorNote(S, Cand->Surrogate);
9697 static void NoteBuiltinOperatorCandidate(Sema &S, StringRef Opc,
9698 SourceLocation OpLoc,
9699 OverloadCandidate *Cand) {
9700 assert(Cand->NumConversions <= 2 && "builtin operator is not binary");
9701 std::string TypeStr("operator");
9704 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString();
9705 if (Cand->NumConversions == 1) {
9707 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr;
9710 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString();
9712 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr;
9716 static void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc,
9717 OverloadCandidate *Cand) {
9718 unsigned NoOperands = Cand->NumConversions;
9719 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) {
9720 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx];
9721 if (ICS.isBad()) break; // all meaningless after first invalid
9722 if (!ICS.isAmbiguous()) continue;
9724 ICS.DiagnoseAmbiguousConversion(S, OpLoc,
9725 S.PDiag(diag::note_ambiguous_type_conversion));
9729 static SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) {
9731 return Cand->Function->getLocation();
9732 if (Cand->IsSurrogate)
9733 return Cand->Surrogate->getLocation();
9734 return SourceLocation();
9737 static unsigned RankDeductionFailure(const DeductionFailureInfo &DFI) {
9738 switch ((Sema::TemplateDeductionResult)DFI.Result) {
9739 case Sema::TDK_Success:
9740 llvm_unreachable("TDK_success while diagnosing bad deduction");
9742 case Sema::TDK_Invalid:
9743 case Sema::TDK_Incomplete:
9746 case Sema::TDK_Underqualified:
9747 case Sema::TDK_Inconsistent:
9750 case Sema::TDK_SubstitutionFailure:
9751 case Sema::TDK_DeducedMismatch:
9752 case Sema::TDK_NonDeducedMismatch:
9753 case Sema::TDK_MiscellaneousDeductionFailure:
9756 case Sema::TDK_InstantiationDepth:
9757 case Sema::TDK_FailedOverloadResolution:
9760 case Sema::TDK_InvalidExplicitArguments:
9763 case Sema::TDK_TooManyArguments:
9764 case Sema::TDK_TooFewArguments:
9767 llvm_unreachable("Unhandled deduction result");
9771 struct CompareOverloadCandidatesForDisplay {
9776 CompareOverloadCandidatesForDisplay(Sema &S, SourceLocation Loc, size_t nArgs)
9777 : S(S), NumArgs(nArgs) {}
9779 bool operator()(const OverloadCandidate *L,
9780 const OverloadCandidate *R) {
9781 // Fast-path this check.
9782 if (L == R) return false;
9784 // Order first by viability.
9786 if (!R->Viable) return true;
9788 // TODO: introduce a tri-valued comparison for overload
9789 // candidates. Would be more worthwhile if we had a sort
9790 // that could exploit it.
9791 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation())) return true;
9792 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation())) return false;
9793 } else if (R->Viable)
9796 assert(L->Viable == R->Viable);
9798 // Criteria by which we can sort non-viable candidates:
9800 // 1. Arity mismatches come after other candidates.
9801 if (L->FailureKind == ovl_fail_too_many_arguments ||
9802 L->FailureKind == ovl_fail_too_few_arguments) {
9803 if (R->FailureKind == ovl_fail_too_many_arguments ||
9804 R->FailureKind == ovl_fail_too_few_arguments) {
9805 int LDist = std::abs((int)L->getNumParams() - (int)NumArgs);
9806 int RDist = std::abs((int)R->getNumParams() - (int)NumArgs);
9807 if (LDist == RDist) {
9808 if (L->FailureKind == R->FailureKind)
9809 // Sort non-surrogates before surrogates.
9810 return !L->IsSurrogate && R->IsSurrogate;
9811 // Sort candidates requiring fewer parameters than there were
9812 // arguments given after candidates requiring more parameters
9813 // than there were arguments given.
9814 return L->FailureKind == ovl_fail_too_many_arguments;
9816 return LDist < RDist;
9820 if (R->FailureKind == ovl_fail_too_many_arguments ||
9821 R->FailureKind == ovl_fail_too_few_arguments)
9824 // 2. Bad conversions come first and are ordered by the number
9825 // of bad conversions and quality of good conversions.
9826 if (L->FailureKind == ovl_fail_bad_conversion) {
9827 if (R->FailureKind != ovl_fail_bad_conversion)
9830 // The conversion that can be fixed with a smaller number of changes,
9832 unsigned numLFixes = L->Fix.NumConversionsFixed;
9833 unsigned numRFixes = R->Fix.NumConversionsFixed;
9834 numLFixes = (numLFixes == 0) ? UINT_MAX : numLFixes;
9835 numRFixes = (numRFixes == 0) ? UINT_MAX : numRFixes;
9836 if (numLFixes != numRFixes) {
9837 return numLFixes < numRFixes;
9840 // If there's any ordering between the defined conversions...
9841 // FIXME: this might not be transitive.
9842 assert(L->NumConversions == R->NumConversions);
9845 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument);
9846 for (unsigned E = L->NumConversions; I != E; ++I) {
9847 switch (CompareImplicitConversionSequences(S, Loc,
9849 R->Conversions[I])) {
9850 case ImplicitConversionSequence::Better:
9854 case ImplicitConversionSequence::Worse:
9858 case ImplicitConversionSequence::Indistinguishable:
9862 if (leftBetter > 0) return true;
9863 if (leftBetter < 0) return false;
9865 } else if (R->FailureKind == ovl_fail_bad_conversion)
9868 if (L->FailureKind == ovl_fail_bad_deduction) {
9869 if (R->FailureKind != ovl_fail_bad_deduction)
9872 if (L->DeductionFailure.Result != R->DeductionFailure.Result)
9873 return RankDeductionFailure(L->DeductionFailure)
9874 < RankDeductionFailure(R->DeductionFailure);
9875 } else if (R->FailureKind == ovl_fail_bad_deduction)
9881 // Sort everything else by location.
9882 SourceLocation LLoc = GetLocationForCandidate(L);
9883 SourceLocation RLoc = GetLocationForCandidate(R);
9885 // Put candidates without locations (e.g. builtins) at the end.
9886 if (LLoc.isInvalid()) return false;
9887 if (RLoc.isInvalid()) return true;
9889 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc);
9894 /// CompleteNonViableCandidate - Normally, overload resolution only
9895 /// computes up to the first. Produces the FixIt set if possible.
9896 static void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand,
9897 ArrayRef<Expr *> Args) {
9898 assert(!Cand->Viable);
9900 // Don't do anything on failures other than bad conversion.
9901 if (Cand->FailureKind != ovl_fail_bad_conversion) return;
9903 // We only want the FixIts if all the arguments can be corrected.
9904 bool Unfixable = false;
9905 // Use a implicit copy initialization to check conversion fixes.
9906 Cand->Fix.setConversionChecker(TryCopyInitialization);
9908 // Skip forward to the first bad conversion.
9909 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0);
9910 unsigned ConvCount = Cand->NumConversions;
9912 assert(ConvIdx != ConvCount && "no bad conversion in candidate");
9914 if (Cand->Conversions[ConvIdx - 1].isBad()) {
9915 Unfixable = !Cand->TryToFixBadConversion(ConvIdx - 1, S);
9920 if (ConvIdx == ConvCount)
9923 assert(!Cand->Conversions[ConvIdx].isInitialized() &&
9924 "remaining conversion is initialized?");
9926 // FIXME: this should probably be preserved from the overload
9927 // operation somehow.
9928 bool SuppressUserConversions = false;
9930 const FunctionProtoType* Proto;
9931 unsigned ArgIdx = ConvIdx;
9933 if (Cand->IsSurrogate) {
9935 = Cand->Surrogate->getConversionType().getNonReferenceType();
9936 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
9937 ConvType = ConvPtrType->getPointeeType();
9938 Proto = ConvType->getAs<FunctionProtoType>();
9940 } else if (Cand->Function) {
9941 Proto = Cand->Function->getType()->getAs<FunctionProtoType>();
9942 if (isa<CXXMethodDecl>(Cand->Function) &&
9943 !isa<CXXConstructorDecl>(Cand->Function))
9946 // Builtin binary operator with a bad first conversion.
9947 assert(ConvCount <= 3);
9948 for (; ConvIdx != ConvCount; ++ConvIdx)
9949 Cand->Conversions[ConvIdx]
9950 = TryCopyInitialization(S, Args[ConvIdx],
9951 Cand->BuiltinTypes.ParamTypes[ConvIdx],
9952 SuppressUserConversions,
9953 /*InOverloadResolution*/ true,
9954 /*AllowObjCWritebackConversion=*/
9955 S.getLangOpts().ObjCAutoRefCount);
9959 // Fill in the rest of the conversions.
9960 unsigned NumParams = Proto->getNumParams();
9961 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) {
9962 if (ArgIdx < NumParams) {
9963 Cand->Conversions[ConvIdx] = TryCopyInitialization(
9964 S, Args[ArgIdx], Proto->getParamType(ArgIdx), SuppressUserConversions,
9965 /*InOverloadResolution=*/true,
9966 /*AllowObjCWritebackConversion=*/
9967 S.getLangOpts().ObjCAutoRefCount);
9968 // Store the FixIt in the candidate if it exists.
9969 if (!Unfixable && Cand->Conversions[ConvIdx].isBad())
9970 Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S);
9973 Cand->Conversions[ConvIdx].setEllipsis();
9977 /// PrintOverloadCandidates - When overload resolution fails, prints
9978 /// diagnostic messages containing the candidates in the candidate
9980 void OverloadCandidateSet::NoteCandidates(Sema &S,
9981 OverloadCandidateDisplayKind OCD,
9982 ArrayRef<Expr *> Args,
9984 SourceLocation OpLoc) {
9985 // Sort the candidates by viability and position. Sorting directly would
9986 // be prohibitive, so we make a set of pointers and sort those.
9987 SmallVector<OverloadCandidate*, 32> Cands;
9988 if (OCD == OCD_AllCandidates) Cands.reserve(size());
9989 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) {
9991 Cands.push_back(Cand);
9992 else if (OCD == OCD_AllCandidates) {
9993 CompleteNonViableCandidate(S, Cand, Args);
9994 if (Cand->Function || Cand->IsSurrogate)
9995 Cands.push_back(Cand);
9996 // Otherwise, this a non-viable builtin candidate. We do not, in general,
9997 // want to list every possible builtin candidate.
10001 std::sort(Cands.begin(), Cands.end(),
10002 CompareOverloadCandidatesForDisplay(S, OpLoc, Args.size()));
10004 bool ReportedAmbiguousConversions = false;
10006 SmallVectorImpl<OverloadCandidate*>::iterator I, E;
10007 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
10008 unsigned CandsShown = 0;
10009 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) {
10010 OverloadCandidate *Cand = *I;
10012 // Set an arbitrary limit on the number of candidate functions we'll spam
10013 // the user with. FIXME: This limit should depend on details of the
10015 if (CandsShown >= 4 && ShowOverloads == Ovl_Best) {
10020 if (Cand->Function)
10021 NoteFunctionCandidate(S, Cand, Args.size(),
10022 /*TakingCandidateAddress=*/false);
10023 else if (Cand->IsSurrogate)
10024 NoteSurrogateCandidate(S, Cand);
10026 assert(Cand->Viable &&
10027 "Non-viable built-in candidates are not added to Cands.");
10028 // Generally we only see ambiguities including viable builtin
10029 // operators if overload resolution got screwed up by an
10030 // ambiguous user-defined conversion.
10032 // FIXME: It's quite possible for different conversions to see
10033 // different ambiguities, though.
10034 if (!ReportedAmbiguousConversions) {
10035 NoteAmbiguousUserConversions(S, OpLoc, Cand);
10036 ReportedAmbiguousConversions = true;
10039 // If this is a viable builtin, print it.
10040 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand);
10045 S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I);
10048 static SourceLocation
10049 GetLocationForCandidate(const TemplateSpecCandidate *Cand) {
10050 return Cand->Specialization ? Cand->Specialization->getLocation()
10051 : SourceLocation();
10055 struct CompareTemplateSpecCandidatesForDisplay {
10057 CompareTemplateSpecCandidatesForDisplay(Sema &S) : S(S) {}
10059 bool operator()(const TemplateSpecCandidate *L,
10060 const TemplateSpecCandidate *R) {
10061 // Fast-path this check.
10065 // Assuming that both candidates are not matches...
10067 // Sort by the ranking of deduction failures.
10068 if (L->DeductionFailure.Result != R->DeductionFailure.Result)
10069 return RankDeductionFailure(L->DeductionFailure) <
10070 RankDeductionFailure(R->DeductionFailure);
10072 // Sort everything else by location.
10073 SourceLocation LLoc = GetLocationForCandidate(L);
10074 SourceLocation RLoc = GetLocationForCandidate(R);
10076 // Put candidates without locations (e.g. builtins) at the end.
10077 if (LLoc.isInvalid())
10079 if (RLoc.isInvalid())
10082 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc);
10087 /// Diagnose a template argument deduction failure.
10088 /// We are treating these failures as overload failures due to bad
10090 void TemplateSpecCandidate::NoteDeductionFailure(Sema &S,
10091 bool ForTakingAddress) {
10092 DiagnoseBadDeduction(S, Specialization, // pattern
10093 DeductionFailure, /*NumArgs=*/0, ForTakingAddress);
10096 void TemplateSpecCandidateSet::destroyCandidates() {
10097 for (iterator i = begin(), e = end(); i != e; ++i) {
10098 i->DeductionFailure.Destroy();
10102 void TemplateSpecCandidateSet::clear() {
10103 destroyCandidates();
10104 Candidates.clear();
10107 /// NoteCandidates - When no template specialization match is found, prints
10108 /// diagnostic messages containing the non-matching specializations that form
10109 /// the candidate set.
10110 /// This is analoguous to OverloadCandidateSet::NoteCandidates() with
10111 /// OCD == OCD_AllCandidates and Cand->Viable == false.
10112 void TemplateSpecCandidateSet::NoteCandidates(Sema &S, SourceLocation Loc) {
10113 // Sort the candidates by position (assuming no candidate is a match).
10114 // Sorting directly would be prohibitive, so we make a set of pointers
10116 SmallVector<TemplateSpecCandidate *, 32> Cands;
10117 Cands.reserve(size());
10118 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) {
10119 if (Cand->Specialization)
10120 Cands.push_back(Cand);
10121 // Otherwise, this is a non-matching builtin candidate. We do not,
10122 // in general, want to list every possible builtin candidate.
10125 std::sort(Cands.begin(), Cands.end(),
10126 CompareTemplateSpecCandidatesForDisplay(S));
10128 // FIXME: Perhaps rename OverloadsShown and getShowOverloads()
10129 // for generalization purposes (?).
10130 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads();
10132 SmallVectorImpl<TemplateSpecCandidate *>::iterator I, E;
10133 unsigned CandsShown = 0;
10134 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) {
10135 TemplateSpecCandidate *Cand = *I;
10137 // Set an arbitrary limit on the number of candidates we'll spam
10138 // the user with. FIXME: This limit should depend on details of the
10140 if (CandsShown >= 4 && ShowOverloads == Ovl_Best)
10144 assert(Cand->Specialization &&
10145 "Non-matching built-in candidates are not added to Cands.");
10146 Cand->NoteDeductionFailure(S, ForTakingAddress);
10150 S.Diag(Loc, diag::note_ovl_too_many_candidates) << int(E - I);
10153 // [PossiblyAFunctionType] --> [Return]
10154 // NonFunctionType --> NonFunctionType
10156 // R (*)(A) --> R (A)
10157 // R (&)(A) --> R (A)
10158 // R (S::*)(A) --> R (A)
10159 QualType Sema::ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType) {
10160 QualType Ret = PossiblyAFunctionType;
10161 if (const PointerType *ToTypePtr =
10162 PossiblyAFunctionType->getAs<PointerType>())
10163 Ret = ToTypePtr->getPointeeType();
10164 else if (const ReferenceType *ToTypeRef =
10165 PossiblyAFunctionType->getAs<ReferenceType>())
10166 Ret = ToTypeRef->getPointeeType();
10167 else if (const MemberPointerType *MemTypePtr =
10168 PossiblyAFunctionType->getAs<MemberPointerType>())
10169 Ret = MemTypePtr->getPointeeType();
10171 Context.getCanonicalType(Ret).getUnqualifiedType();
10176 // A helper class to help with address of function resolution
10177 // - allows us to avoid passing around all those ugly parameters
10178 class AddressOfFunctionResolver {
10181 const QualType& TargetType;
10182 QualType TargetFunctionType; // Extracted function type from target type
10185 //DeclAccessPair& ResultFunctionAccessPair;
10186 ASTContext& Context;
10188 bool TargetTypeIsNonStaticMemberFunction;
10189 bool FoundNonTemplateFunction;
10190 bool StaticMemberFunctionFromBoundPointer;
10191 bool HasComplained;
10193 OverloadExpr::FindResult OvlExprInfo;
10194 OverloadExpr *OvlExpr;
10195 TemplateArgumentListInfo OvlExplicitTemplateArgs;
10196 SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches;
10197 TemplateSpecCandidateSet FailedCandidates;
10200 AddressOfFunctionResolver(Sema &S, Expr *SourceExpr,
10201 const QualType &TargetType, bool Complain)
10202 : S(S), SourceExpr(SourceExpr), TargetType(TargetType),
10203 Complain(Complain), Context(S.getASTContext()),
10204 TargetTypeIsNonStaticMemberFunction(
10205 !!TargetType->getAs<MemberPointerType>()),
10206 FoundNonTemplateFunction(false),
10207 StaticMemberFunctionFromBoundPointer(false),
10208 HasComplained(false),
10209 OvlExprInfo(OverloadExpr::find(SourceExpr)),
10210 OvlExpr(OvlExprInfo.Expression),
10211 FailedCandidates(OvlExpr->getNameLoc(), /*ForTakingAddress=*/true) {
10212 ExtractUnqualifiedFunctionTypeFromTargetType();
10214 if (TargetFunctionType->isFunctionType()) {
10215 if (UnresolvedMemberExpr *UME = dyn_cast<UnresolvedMemberExpr>(OvlExpr))
10216 if (!UME->isImplicitAccess() &&
10217 !S.ResolveSingleFunctionTemplateSpecialization(UME))
10218 StaticMemberFunctionFromBoundPointer = true;
10219 } else if (OvlExpr->hasExplicitTemplateArgs()) {
10220 DeclAccessPair dap;
10221 if (FunctionDecl *Fn = S.ResolveSingleFunctionTemplateSpecialization(
10222 OvlExpr, false, &dap)) {
10223 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn))
10224 if (!Method->isStatic()) {
10225 // If the target type is a non-function type and the function found
10226 // is a non-static member function, pretend as if that was the
10227 // target, it's the only possible type to end up with.
10228 TargetTypeIsNonStaticMemberFunction = true;
10230 // And skip adding the function if its not in the proper form.
10231 // We'll diagnose this due to an empty set of functions.
10232 if (!OvlExprInfo.HasFormOfMemberPointer)
10236 Matches.push_back(std::make_pair(dap, Fn));
10241 if (OvlExpr->hasExplicitTemplateArgs())
10242 OvlExpr->copyTemplateArgumentsInto(OvlExplicitTemplateArgs);
10244 if (FindAllFunctionsThatMatchTargetTypeExactly()) {
10245 // C++ [over.over]p4:
10246 // If more than one function is selected, [...]
10247 if (Matches.size() > 1 && !eliminiateSuboptimalOverloadCandidates()) {
10248 if (FoundNonTemplateFunction)
10249 EliminateAllTemplateMatches();
10251 EliminateAllExceptMostSpecializedTemplate();
10255 if (S.getLangOpts().CUDA && S.getLangOpts().CUDATargetOverloads &&
10256 Matches.size() > 1)
10257 EliminateSuboptimalCudaMatches();
10260 bool hasComplained() const { return HasComplained; }
10263 // Is A considered a better overload candidate for the desired type than B?
10264 bool isBetterCandidate(const FunctionDecl *A, const FunctionDecl *B) {
10265 return hasBetterEnableIfAttrs(S, A, B);
10268 // Returns true if we've eliminated any (read: all but one) candidates, false
10270 bool eliminiateSuboptimalOverloadCandidates() {
10271 // Same algorithm as overload resolution -- one pass to pick the "best",
10272 // another pass to be sure that nothing is better than the best.
10273 auto Best = Matches.begin();
10274 for (auto I = Matches.begin()+1, E = Matches.end(); I != E; ++I)
10275 if (isBetterCandidate(I->second, Best->second))
10278 const FunctionDecl *BestFn = Best->second;
10279 auto IsBestOrInferiorToBest = [this, BestFn](
10280 const std::pair<DeclAccessPair, FunctionDecl *> &Pair) {
10281 return BestFn == Pair.second || isBetterCandidate(BestFn, Pair.second);
10284 // Note: We explicitly leave Matches unmodified if there isn't a clear best
10285 // option, so we can potentially give the user a better error
10286 if (!std::all_of(Matches.begin(), Matches.end(), IsBestOrInferiorToBest))
10288 Matches[0] = *Best;
10293 bool isTargetTypeAFunction() const {
10294 return TargetFunctionType->isFunctionType();
10297 // [ToType] [Return]
10299 // R (*)(A) --> R (A), IsNonStaticMemberFunction = false
10300 // R (&)(A) --> R (A), IsNonStaticMemberFunction = false
10301 // R (S::*)(A) --> R (A), IsNonStaticMemberFunction = true
10302 void inline ExtractUnqualifiedFunctionTypeFromTargetType() {
10303 TargetFunctionType = S.ExtractUnqualifiedFunctionType(TargetType);
10306 // return true if any matching specializations were found
10307 bool AddMatchingTemplateFunction(FunctionTemplateDecl* FunctionTemplate,
10308 const DeclAccessPair& CurAccessFunPair) {
10309 if (CXXMethodDecl *Method
10310 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) {
10311 // Skip non-static function templates when converting to pointer, and
10312 // static when converting to member pointer.
10313 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction)
10316 else if (TargetTypeIsNonStaticMemberFunction)
10319 // C++ [over.over]p2:
10320 // If the name is a function template, template argument deduction is
10321 // done (14.8.2.2), and if the argument deduction succeeds, the
10322 // resulting template argument list is used to generate a single
10323 // function template specialization, which is added to the set of
10324 // overloaded functions considered.
10325 FunctionDecl *Specialization = nullptr;
10326 TemplateDeductionInfo Info(FailedCandidates.getLocation());
10327 if (Sema::TemplateDeductionResult Result
10328 = S.DeduceTemplateArguments(FunctionTemplate,
10329 &OvlExplicitTemplateArgs,
10330 TargetFunctionType, Specialization,
10331 Info, /*InOverloadResolution=*/true)) {
10332 // Make a note of the failed deduction for diagnostics.
10333 FailedCandidates.addCandidate()
10334 .set(FunctionTemplate->getTemplatedDecl(),
10335 MakeDeductionFailureInfo(Context, Result, Info));
10339 // Template argument deduction ensures that we have an exact match or
10340 // compatible pointer-to-function arguments that would be adjusted by ICS.
10341 // This function template specicalization works.
10342 Specialization = cast<FunctionDecl>(Specialization->getCanonicalDecl());
10343 assert(S.isSameOrCompatibleFunctionType(
10344 Context.getCanonicalType(Specialization->getType()),
10345 Context.getCanonicalType(TargetFunctionType)));
10347 if (!S.checkAddressOfFunctionIsAvailable(Specialization))
10350 Matches.push_back(std::make_pair(CurAccessFunPair, Specialization));
10354 bool AddMatchingNonTemplateFunction(NamedDecl* Fn,
10355 const DeclAccessPair& CurAccessFunPair) {
10356 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) {
10357 // Skip non-static functions when converting to pointer, and static
10358 // when converting to member pointer.
10359 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction)
10362 else if (TargetTypeIsNonStaticMemberFunction)
10365 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) {
10366 if (S.getLangOpts().CUDA)
10367 if (FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext))
10368 if (!Caller->isImplicit() && S.CheckCUDATarget(Caller, FunDecl))
10371 // If any candidate has a placeholder return type, trigger its deduction
10373 if (S.getLangOpts().CPlusPlus14 &&
10374 FunDecl->getReturnType()->isUndeducedType() &&
10375 S.DeduceReturnType(FunDecl, SourceExpr->getLocStart(), Complain)) {
10376 HasComplained |= Complain;
10380 if (!S.checkAddressOfFunctionIsAvailable(FunDecl))
10384 if (Context.hasSameUnqualifiedType(TargetFunctionType,
10385 FunDecl->getType()) ||
10386 S.IsNoReturnConversion(FunDecl->getType(), TargetFunctionType,
10388 (!S.getLangOpts().CPlusPlus && TargetType->isVoidPointerType())) {
10389 Matches.push_back(std::make_pair(
10390 CurAccessFunPair, cast<FunctionDecl>(FunDecl->getCanonicalDecl())));
10391 FoundNonTemplateFunction = true;
10399 bool FindAllFunctionsThatMatchTargetTypeExactly() {
10402 // If the overload expression doesn't have the form of a pointer to
10403 // member, don't try to convert it to a pointer-to-member type.
10404 if (IsInvalidFormOfPointerToMemberFunction())
10407 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
10408 E = OvlExpr->decls_end();
10410 // Look through any using declarations to find the underlying function.
10411 NamedDecl *Fn = (*I)->getUnderlyingDecl();
10413 // C++ [over.over]p3:
10414 // Non-member functions and static member functions match
10415 // targets of type "pointer-to-function" or "reference-to-function."
10416 // Nonstatic member functions match targets of
10417 // type "pointer-to-member-function."
10418 // Note that according to DR 247, the containing class does not matter.
10419 if (FunctionTemplateDecl *FunctionTemplate
10420 = dyn_cast<FunctionTemplateDecl>(Fn)) {
10421 if (AddMatchingTemplateFunction(FunctionTemplate, I.getPair()))
10424 // If we have explicit template arguments supplied, skip non-templates.
10425 else if (!OvlExpr->hasExplicitTemplateArgs() &&
10426 AddMatchingNonTemplateFunction(Fn, I.getPair()))
10429 assert(Ret || Matches.empty());
10433 void EliminateAllExceptMostSpecializedTemplate() {
10434 // [...] and any given function template specialization F1 is
10435 // eliminated if the set contains a second function template
10436 // specialization whose function template is more specialized
10437 // than the function template of F1 according to the partial
10438 // ordering rules of 14.5.5.2.
10440 // The algorithm specified above is quadratic. We instead use a
10441 // two-pass algorithm (similar to the one used to identify the
10442 // best viable function in an overload set) that identifies the
10443 // best function template (if it exists).
10445 UnresolvedSet<4> MatchesCopy; // TODO: avoid!
10446 for (unsigned I = 0, E = Matches.size(); I != E; ++I)
10447 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess());
10449 // TODO: It looks like FailedCandidates does not serve much purpose
10450 // here, since the no_viable diagnostic has index 0.
10451 UnresolvedSetIterator Result = S.getMostSpecialized(
10452 MatchesCopy.begin(), MatchesCopy.end(), FailedCandidates,
10453 SourceExpr->getLocStart(), S.PDiag(),
10454 S.PDiag(diag::err_addr_ovl_ambiguous) << Matches[0]
10455 .second->getDeclName(),
10456 S.PDiag(diag::note_ovl_candidate) << (unsigned)oc_function_template,
10457 Complain, TargetFunctionType);
10459 if (Result != MatchesCopy.end()) {
10460 // Make it the first and only element
10461 Matches[0].first = Matches[Result - MatchesCopy.begin()].first;
10462 Matches[0].second = cast<FunctionDecl>(*Result);
10465 HasComplained |= Complain;
10468 void EliminateAllTemplateMatches() {
10469 // [...] any function template specializations in the set are
10470 // eliminated if the set also contains a non-template function, [...]
10471 for (unsigned I = 0, N = Matches.size(); I != N; ) {
10472 if (Matches[I].second->getPrimaryTemplate() == nullptr)
10475 Matches[I] = Matches[--N];
10481 void EliminateSuboptimalCudaMatches() {
10482 S.EraseUnwantedCUDAMatches(dyn_cast<FunctionDecl>(S.CurContext), Matches);
10486 void ComplainNoMatchesFound() const {
10487 assert(Matches.empty());
10488 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_no_viable)
10489 << OvlExpr->getName() << TargetFunctionType
10490 << OvlExpr->getSourceRange();
10491 if (FailedCandidates.empty())
10492 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType,
10493 /*TakingAddress=*/true);
10495 // We have some deduction failure messages. Use them to diagnose
10496 // the function templates, and diagnose the non-template candidates
10498 for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
10499 IEnd = OvlExpr->decls_end();
10501 if (FunctionDecl *Fun =
10502 dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()))
10503 if (!functionHasPassObjectSizeParams(Fun))
10504 S.NoteOverloadCandidate(Fun, TargetFunctionType,
10505 /*TakingAddress=*/true);
10506 FailedCandidates.NoteCandidates(S, OvlExpr->getLocStart());
10510 bool IsInvalidFormOfPointerToMemberFunction() const {
10511 return TargetTypeIsNonStaticMemberFunction &&
10512 !OvlExprInfo.HasFormOfMemberPointer;
10515 void ComplainIsInvalidFormOfPointerToMemberFunction() const {
10516 // TODO: Should we condition this on whether any functions might
10517 // have matched, or is it more appropriate to do that in callers?
10518 // TODO: a fixit wouldn't hurt.
10519 S.Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier)
10520 << TargetType << OvlExpr->getSourceRange();
10523 bool IsStaticMemberFunctionFromBoundPointer() const {
10524 return StaticMemberFunctionFromBoundPointer;
10527 void ComplainIsStaticMemberFunctionFromBoundPointer() const {
10528 S.Diag(OvlExpr->getLocStart(),
10529 diag::err_invalid_form_pointer_member_function)
10530 << OvlExpr->getSourceRange();
10533 void ComplainOfInvalidConversion() const {
10534 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_not_func_ptrref)
10535 << OvlExpr->getName() << TargetType;
10538 void ComplainMultipleMatchesFound() const {
10539 assert(Matches.size() > 1);
10540 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_ambiguous)
10541 << OvlExpr->getName()
10542 << OvlExpr->getSourceRange();
10543 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType,
10544 /*TakingAddress=*/true);
10547 bool hadMultipleCandidates() const { return (OvlExpr->getNumDecls() > 1); }
10549 int getNumMatches() const { return Matches.size(); }
10551 FunctionDecl* getMatchingFunctionDecl() const {
10552 if (Matches.size() != 1) return nullptr;
10553 return Matches[0].second;
10556 const DeclAccessPair* getMatchingFunctionAccessPair() const {
10557 if (Matches.size() != 1) return nullptr;
10558 return &Matches[0].first;
10563 /// ResolveAddressOfOverloadedFunction - Try to resolve the address of
10564 /// an overloaded function (C++ [over.over]), where @p From is an
10565 /// expression with overloaded function type and @p ToType is the type
10566 /// we're trying to resolve to. For example:
10572 /// int (*pfd)(double) = f; // selects f(double)
10575 /// This routine returns the resulting FunctionDecl if it could be
10576 /// resolved, and NULL otherwise. When @p Complain is true, this
10577 /// routine will emit diagnostics if there is an error.
10579 Sema::ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr,
10580 QualType TargetType,
10582 DeclAccessPair &FoundResult,
10583 bool *pHadMultipleCandidates) {
10584 assert(AddressOfExpr->getType() == Context.OverloadTy);
10586 AddressOfFunctionResolver Resolver(*this, AddressOfExpr, TargetType,
10588 int NumMatches = Resolver.getNumMatches();
10589 FunctionDecl *Fn = nullptr;
10590 bool ShouldComplain = Complain && !Resolver.hasComplained();
10591 if (NumMatches == 0 && ShouldComplain) {
10592 if (Resolver.IsInvalidFormOfPointerToMemberFunction())
10593 Resolver.ComplainIsInvalidFormOfPointerToMemberFunction();
10595 Resolver.ComplainNoMatchesFound();
10597 else if (NumMatches > 1 && ShouldComplain)
10598 Resolver.ComplainMultipleMatchesFound();
10599 else if (NumMatches == 1) {
10600 Fn = Resolver.getMatchingFunctionDecl();
10602 FoundResult = *Resolver.getMatchingFunctionAccessPair();
10604 if (Resolver.IsStaticMemberFunctionFromBoundPointer())
10605 Resolver.ComplainIsStaticMemberFunctionFromBoundPointer();
10607 CheckAddressOfMemberAccess(AddressOfExpr, FoundResult);
10611 if (pHadMultipleCandidates)
10612 *pHadMultipleCandidates = Resolver.hadMultipleCandidates();
10616 /// \brief Given an expression that refers to an overloaded function, try to
10617 /// resolve that overloaded function expression down to a single function.
10619 /// This routine can only resolve template-ids that refer to a single function
10620 /// template, where that template-id refers to a single template whose template
10621 /// arguments are either provided by the template-id or have defaults,
10622 /// as described in C++0x [temp.arg.explicit]p3.
10624 /// If no template-ids are found, no diagnostics are emitted and NULL is
10627 Sema::ResolveSingleFunctionTemplateSpecialization(OverloadExpr *ovl,
10629 DeclAccessPair *FoundResult) {
10630 // C++ [over.over]p1:
10631 // [...] [Note: any redundant set of parentheses surrounding the
10632 // overloaded function name is ignored (5.1). ]
10633 // C++ [over.over]p1:
10634 // [...] The overloaded function name can be preceded by the &
10637 // If we didn't actually find any template-ids, we're done.
10638 if (!ovl->hasExplicitTemplateArgs())
10641 TemplateArgumentListInfo ExplicitTemplateArgs;
10642 ovl->copyTemplateArgumentsInto(ExplicitTemplateArgs);
10643 TemplateSpecCandidateSet FailedCandidates(ovl->getNameLoc());
10645 // Look through all of the overloaded functions, searching for one
10646 // whose type matches exactly.
10647 FunctionDecl *Matched = nullptr;
10648 for (UnresolvedSetIterator I = ovl->decls_begin(),
10649 E = ovl->decls_end(); I != E; ++I) {
10650 // C++0x [temp.arg.explicit]p3:
10651 // [...] In contexts where deduction is done and fails, or in contexts
10652 // where deduction is not done, if a template argument list is
10653 // specified and it, along with any default template arguments,
10654 // identifies a single function template specialization, then the
10655 // template-id is an lvalue for the function template specialization.
10656 FunctionTemplateDecl *FunctionTemplate
10657 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl());
10659 // C++ [over.over]p2:
10660 // If the name is a function template, template argument deduction is
10661 // done (14.8.2.2), and if the argument deduction succeeds, the
10662 // resulting template argument list is used to generate a single
10663 // function template specialization, which is added to the set of
10664 // overloaded functions considered.
10665 FunctionDecl *Specialization = nullptr;
10666 TemplateDeductionInfo Info(FailedCandidates.getLocation());
10667 if (TemplateDeductionResult Result
10668 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs,
10669 Specialization, Info,
10670 /*InOverloadResolution=*/true)) {
10671 // Make a note of the failed deduction for diagnostics.
10672 // TODO: Actually use the failed-deduction info?
10673 FailedCandidates.addCandidate()
10674 .set(FunctionTemplate->getTemplatedDecl(),
10675 MakeDeductionFailureInfo(Context, Result, Info));
10679 assert(Specialization && "no specialization and no error?");
10681 // Multiple matches; we can't resolve to a single declaration.
10684 Diag(ovl->getExprLoc(), diag::err_addr_ovl_ambiguous)
10686 NoteAllOverloadCandidates(ovl);
10691 Matched = Specialization;
10692 if (FoundResult) *FoundResult = I.getPair();
10695 if (Matched && getLangOpts().CPlusPlus14 &&
10696 Matched->getReturnType()->isUndeducedType() &&
10697 DeduceReturnType(Matched, ovl->getExprLoc(), Complain))
10706 // Resolve and fix an overloaded expression that can be resolved
10707 // because it identifies a single function template specialization.
10709 // Last three arguments should only be supplied if Complain = true
10711 // Return true if it was logically possible to so resolve the
10712 // expression, regardless of whether or not it succeeded. Always
10713 // returns true if 'complain' is set.
10714 bool Sema::ResolveAndFixSingleFunctionTemplateSpecialization(
10715 ExprResult &SrcExpr, bool doFunctionPointerConverion,
10716 bool complain, SourceRange OpRangeForComplaining,
10717 QualType DestTypeForComplaining,
10718 unsigned DiagIDForComplaining) {
10719 assert(SrcExpr.get()->getType() == Context.OverloadTy);
10721 OverloadExpr::FindResult ovl = OverloadExpr::find(SrcExpr.get());
10723 DeclAccessPair found;
10724 ExprResult SingleFunctionExpression;
10725 if (FunctionDecl *fn = ResolveSingleFunctionTemplateSpecialization(
10726 ovl.Expression, /*complain*/ false, &found)) {
10727 if (DiagnoseUseOfDecl(fn, SrcExpr.get()->getLocStart())) {
10728 SrcExpr = ExprError();
10732 // It is only correct to resolve to an instance method if we're
10733 // resolving a form that's permitted to be a pointer to member.
10734 // Otherwise we'll end up making a bound member expression, which
10735 // is illegal in all the contexts we resolve like this.
10736 if (!ovl.HasFormOfMemberPointer &&
10737 isa<CXXMethodDecl>(fn) &&
10738 cast<CXXMethodDecl>(fn)->isInstance()) {
10739 if (!complain) return false;
10741 Diag(ovl.Expression->getExprLoc(),
10742 diag::err_bound_member_function)
10743 << 0 << ovl.Expression->getSourceRange();
10745 // TODO: I believe we only end up here if there's a mix of
10746 // static and non-static candidates (otherwise the expression
10747 // would have 'bound member' type, not 'overload' type).
10748 // Ideally we would note which candidate was chosen and why
10749 // the static candidates were rejected.
10750 SrcExpr = ExprError();
10754 // Fix the expression to refer to 'fn'.
10755 SingleFunctionExpression =
10756 FixOverloadedFunctionReference(SrcExpr.get(), found, fn);
10758 // If desired, do function-to-pointer decay.
10759 if (doFunctionPointerConverion) {
10760 SingleFunctionExpression =
10761 DefaultFunctionArrayLvalueConversion(SingleFunctionExpression.get());
10762 if (SingleFunctionExpression.isInvalid()) {
10763 SrcExpr = ExprError();
10769 if (!SingleFunctionExpression.isUsable()) {
10771 Diag(OpRangeForComplaining.getBegin(), DiagIDForComplaining)
10772 << ovl.Expression->getName()
10773 << DestTypeForComplaining
10774 << OpRangeForComplaining
10775 << ovl.Expression->getQualifierLoc().getSourceRange();
10776 NoteAllOverloadCandidates(SrcExpr.get());
10778 SrcExpr = ExprError();
10785 SrcExpr = SingleFunctionExpression;
10789 /// \brief Add a single candidate to the overload set.
10790 static void AddOverloadedCallCandidate(Sema &S,
10791 DeclAccessPair FoundDecl,
10792 TemplateArgumentListInfo *ExplicitTemplateArgs,
10793 ArrayRef<Expr *> Args,
10794 OverloadCandidateSet &CandidateSet,
10795 bool PartialOverloading,
10797 NamedDecl *Callee = FoundDecl.getDecl();
10798 if (isa<UsingShadowDecl>(Callee))
10799 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl();
10801 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) {
10802 if (ExplicitTemplateArgs) {
10803 assert(!KnownValid && "Explicit template arguments?");
10806 S.AddOverloadCandidate(Func, FoundDecl, Args, CandidateSet,
10807 /*SuppressUsedConversions=*/false,
10808 PartialOverloading);
10812 if (FunctionTemplateDecl *FuncTemplate
10813 = dyn_cast<FunctionTemplateDecl>(Callee)) {
10814 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl,
10815 ExplicitTemplateArgs, Args, CandidateSet,
10816 /*SuppressUsedConversions=*/false,
10817 PartialOverloading);
10821 assert(!KnownValid && "unhandled case in overloaded call candidate");
10824 /// \brief Add the overload candidates named by callee and/or found by argument
10825 /// dependent lookup to the given overload set.
10826 void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE,
10827 ArrayRef<Expr *> Args,
10828 OverloadCandidateSet &CandidateSet,
10829 bool PartialOverloading) {
10832 // Verify that ArgumentDependentLookup is consistent with the rules
10833 // in C++0x [basic.lookup.argdep]p3:
10835 // Let X be the lookup set produced by unqualified lookup (3.4.1)
10836 // and let Y be the lookup set produced by argument dependent
10837 // lookup (defined as follows). If X contains
10839 // -- a declaration of a class member, or
10841 // -- a block-scope function declaration that is not a
10842 // using-declaration, or
10844 // -- a declaration that is neither a function or a function
10847 // then Y is empty.
10849 if (ULE->requiresADL()) {
10850 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(),
10851 E = ULE->decls_end(); I != E; ++I) {
10852 assert(!(*I)->getDeclContext()->isRecord());
10853 assert(isa<UsingShadowDecl>(*I) ||
10854 !(*I)->getDeclContext()->isFunctionOrMethod());
10855 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate());
10860 // It would be nice to avoid this copy.
10861 TemplateArgumentListInfo TABuffer;
10862 TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr;
10863 if (ULE->hasExplicitTemplateArgs()) {
10864 ULE->copyTemplateArgumentsInto(TABuffer);
10865 ExplicitTemplateArgs = &TABuffer;
10868 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(),
10869 E = ULE->decls_end(); I != E; ++I)
10870 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, Args,
10871 CandidateSet, PartialOverloading,
10872 /*KnownValid*/ true);
10874 if (ULE->requiresADL())
10875 AddArgumentDependentLookupCandidates(ULE->getName(), ULE->getExprLoc(),
10876 Args, ExplicitTemplateArgs,
10877 CandidateSet, PartialOverloading);
10880 /// Determine whether a declaration with the specified name could be moved into
10881 /// a different namespace.
10882 static bool canBeDeclaredInNamespace(const DeclarationName &Name) {
10883 switch (Name.getCXXOverloadedOperator()) {
10884 case OO_New: case OO_Array_New:
10885 case OO_Delete: case OO_Array_Delete:
10893 /// Attempt to recover from an ill-formed use of a non-dependent name in a
10894 /// template, where the non-dependent name was declared after the template
10895 /// was defined. This is common in code written for a compilers which do not
10896 /// correctly implement two-stage name lookup.
10898 /// Returns true if a viable candidate was found and a diagnostic was issued.
10900 DiagnoseTwoPhaseLookup(Sema &SemaRef, SourceLocation FnLoc,
10901 const CXXScopeSpec &SS, LookupResult &R,
10902 OverloadCandidateSet::CandidateSetKind CSK,
10903 TemplateArgumentListInfo *ExplicitTemplateArgs,
10904 ArrayRef<Expr *> Args,
10905 bool *DoDiagnoseEmptyLookup = nullptr) {
10906 if (SemaRef.ActiveTemplateInstantiations.empty() || !SS.isEmpty())
10909 for (DeclContext *DC = SemaRef.CurContext; DC; DC = DC->getParent()) {
10910 if (DC->isTransparentContext())
10913 SemaRef.LookupQualifiedName(R, DC);
10916 R.suppressDiagnostics();
10918 if (isa<CXXRecordDecl>(DC)) {
10919 // Don't diagnose names we find in classes; we get much better
10920 // diagnostics for these from DiagnoseEmptyLookup.
10922 if (DoDiagnoseEmptyLookup)
10923 *DoDiagnoseEmptyLookup = true;
10927 OverloadCandidateSet Candidates(FnLoc, CSK);
10928 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
10929 AddOverloadedCallCandidate(SemaRef, I.getPair(),
10930 ExplicitTemplateArgs, Args,
10931 Candidates, false, /*KnownValid*/ false);
10933 OverloadCandidateSet::iterator Best;
10934 if (Candidates.BestViableFunction(SemaRef, FnLoc, Best) != OR_Success) {
10935 // No viable functions. Don't bother the user with notes for functions
10936 // which don't work and shouldn't be found anyway.
10941 // Find the namespaces where ADL would have looked, and suggest
10942 // declaring the function there instead.
10943 Sema::AssociatedNamespaceSet AssociatedNamespaces;
10944 Sema::AssociatedClassSet AssociatedClasses;
10945 SemaRef.FindAssociatedClassesAndNamespaces(FnLoc, Args,
10946 AssociatedNamespaces,
10947 AssociatedClasses);
10948 Sema::AssociatedNamespaceSet SuggestedNamespaces;
10949 if (canBeDeclaredInNamespace(R.getLookupName())) {
10950 DeclContext *Std = SemaRef.getStdNamespace();
10951 for (Sema::AssociatedNamespaceSet::iterator
10952 it = AssociatedNamespaces.begin(),
10953 end = AssociatedNamespaces.end(); it != end; ++it) {
10954 // Never suggest declaring a function within namespace 'std'.
10955 if (Std && Std->Encloses(*it))
10958 // Never suggest declaring a function within a namespace with a
10959 // reserved name, like __gnu_cxx.
10960 NamespaceDecl *NS = dyn_cast<NamespaceDecl>(*it);
10962 NS->getQualifiedNameAsString().find("__") != std::string::npos)
10965 SuggestedNamespaces.insert(*it);
10969 SemaRef.Diag(R.getNameLoc(), diag::err_not_found_by_two_phase_lookup)
10970 << R.getLookupName();
10971 if (SuggestedNamespaces.empty()) {
10972 SemaRef.Diag(Best->Function->getLocation(),
10973 diag::note_not_found_by_two_phase_lookup)
10974 << R.getLookupName() << 0;
10975 } else if (SuggestedNamespaces.size() == 1) {
10976 SemaRef.Diag(Best->Function->getLocation(),
10977 diag::note_not_found_by_two_phase_lookup)
10978 << R.getLookupName() << 1 << *SuggestedNamespaces.begin();
10980 // FIXME: It would be useful to list the associated namespaces here,
10981 // but the diagnostics infrastructure doesn't provide a way to produce
10982 // a localized representation of a list of items.
10983 SemaRef.Diag(Best->Function->getLocation(),
10984 diag::note_not_found_by_two_phase_lookup)
10985 << R.getLookupName() << 2;
10988 // Try to recover by calling this function.
10998 /// Attempt to recover from ill-formed use of a non-dependent operator in a
10999 /// template, where the non-dependent operator was declared after the template
11002 /// Returns true if a viable candidate was found and a diagnostic was issued.
11004 DiagnoseTwoPhaseOperatorLookup(Sema &SemaRef, OverloadedOperatorKind Op,
11005 SourceLocation OpLoc,
11006 ArrayRef<Expr *> Args) {
11007 DeclarationName OpName =
11008 SemaRef.Context.DeclarationNames.getCXXOperatorName(Op);
11009 LookupResult R(SemaRef, OpName, OpLoc, Sema::LookupOperatorName);
11010 return DiagnoseTwoPhaseLookup(SemaRef, OpLoc, CXXScopeSpec(), R,
11011 OverloadCandidateSet::CSK_Operator,
11012 /*ExplicitTemplateArgs=*/nullptr, Args);
11016 class BuildRecoveryCallExprRAII {
11019 BuildRecoveryCallExprRAII(Sema &S) : SemaRef(S) {
11020 assert(SemaRef.IsBuildingRecoveryCallExpr == false);
11021 SemaRef.IsBuildingRecoveryCallExpr = true;
11024 ~BuildRecoveryCallExprRAII() {
11025 SemaRef.IsBuildingRecoveryCallExpr = false;
11031 static std::unique_ptr<CorrectionCandidateCallback>
11032 MakeValidator(Sema &SemaRef, MemberExpr *ME, size_t NumArgs,
11033 bool HasTemplateArgs, bool AllowTypoCorrection) {
11034 if (!AllowTypoCorrection)
11035 return llvm::make_unique<NoTypoCorrectionCCC>();
11036 return llvm::make_unique<FunctionCallFilterCCC>(SemaRef, NumArgs,
11037 HasTemplateArgs, ME);
11040 /// Attempts to recover from a call where no functions were found.
11042 /// Returns true if new candidates were found.
11044 BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn,
11045 UnresolvedLookupExpr *ULE,
11046 SourceLocation LParenLoc,
11047 MutableArrayRef<Expr *> Args,
11048 SourceLocation RParenLoc,
11049 bool EmptyLookup, bool AllowTypoCorrection) {
11050 // Do not try to recover if it is already building a recovery call.
11051 // This stops infinite loops for template instantiations like
11053 // template <typename T> auto foo(T t) -> decltype(foo(t)) {}
11054 // template <typename T> auto foo(T t) -> decltype(foo(&t)) {}
11056 if (SemaRef.IsBuildingRecoveryCallExpr)
11057 return ExprError();
11058 BuildRecoveryCallExprRAII RCE(SemaRef);
11061 SS.Adopt(ULE->getQualifierLoc());
11062 SourceLocation TemplateKWLoc = ULE->getTemplateKeywordLoc();
11064 TemplateArgumentListInfo TABuffer;
11065 TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr;
11066 if (ULE->hasExplicitTemplateArgs()) {
11067 ULE->copyTemplateArgumentsInto(TABuffer);
11068 ExplicitTemplateArgs = &TABuffer;
11071 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(),
11072 Sema::LookupOrdinaryName);
11073 bool DoDiagnoseEmptyLookup = EmptyLookup;
11074 if (!DiagnoseTwoPhaseLookup(SemaRef, Fn->getExprLoc(), SS, R,
11075 OverloadCandidateSet::CSK_Normal,
11076 ExplicitTemplateArgs, Args,
11077 &DoDiagnoseEmptyLookup) &&
11078 (!DoDiagnoseEmptyLookup || SemaRef.DiagnoseEmptyLookup(
11080 MakeValidator(SemaRef, dyn_cast<MemberExpr>(Fn), Args.size(),
11081 ExplicitTemplateArgs != nullptr, AllowTypoCorrection),
11082 ExplicitTemplateArgs, Args)))
11083 return ExprError();
11085 assert(!R.empty() && "lookup results empty despite recovery");
11087 // Build an implicit member call if appropriate. Just drop the
11088 // casts and such from the call, we don't really care.
11089 ExprResult NewFn = ExprError();
11090 if ((*R.begin())->isCXXClassMember())
11091 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, TemplateKWLoc, R,
11092 ExplicitTemplateArgs, S);
11093 else if (ExplicitTemplateArgs || TemplateKWLoc.isValid())
11094 NewFn = SemaRef.BuildTemplateIdExpr(SS, TemplateKWLoc, R, false,
11095 ExplicitTemplateArgs);
11097 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false);
11099 if (NewFn.isInvalid())
11100 return ExprError();
11102 // This shouldn't cause an infinite loop because we're giving it
11103 // an expression with viable lookup results, which should never
11105 return SemaRef.ActOnCallExpr(/*Scope*/ nullptr, NewFn.get(), LParenLoc,
11106 MultiExprArg(Args.data(), Args.size()),
11110 /// \brief Constructs and populates an OverloadedCandidateSet from
11111 /// the given function.
11112 /// \returns true when an the ExprResult output parameter has been set.
11113 bool Sema::buildOverloadedCallSet(Scope *S, Expr *Fn,
11114 UnresolvedLookupExpr *ULE,
11116 SourceLocation RParenLoc,
11117 OverloadCandidateSet *CandidateSet,
11118 ExprResult *Result) {
11120 if (ULE->requiresADL()) {
11121 // To do ADL, we must have found an unqualified name.
11122 assert(!ULE->getQualifier() && "qualified name with ADL");
11124 // We don't perform ADL for implicit declarations of builtins.
11125 // Verify that this was correctly set up.
11127 if (ULE->decls_begin() + 1 == ULE->decls_end() &&
11128 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) &&
11129 F->getBuiltinID() && F->isImplicit())
11130 llvm_unreachable("performing ADL for builtin");
11132 // We don't perform ADL in C.
11133 assert(getLangOpts().CPlusPlus && "ADL enabled in C");
11137 UnbridgedCastsSet UnbridgedCasts;
11138 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts)) {
11139 *Result = ExprError();
11143 // Add the functions denoted by the callee to the set of candidate
11144 // functions, including those from argument-dependent lookup.
11145 AddOverloadedCallCandidates(ULE, Args, *CandidateSet);
11147 if (getLangOpts().MSVCCompat &&
11148 CurContext->isDependentContext() && !isSFINAEContext() &&
11149 (isa<FunctionDecl>(CurContext) || isa<CXXRecordDecl>(CurContext))) {
11151 OverloadCandidateSet::iterator Best;
11152 if (CandidateSet->empty() ||
11153 CandidateSet->BestViableFunction(*this, Fn->getLocStart(), Best) ==
11154 OR_No_Viable_Function) {
11155 // In Microsoft mode, if we are inside a template class member function then
11156 // create a type dependent CallExpr. The goal is to postpone name lookup
11157 // to instantiation time to be able to search into type dependent base
11159 CallExpr *CE = new (Context) CallExpr(
11160 Context, Fn, Args, Context.DependentTy, VK_RValue, RParenLoc);
11161 CE->setTypeDependent(true);
11162 CE->setValueDependent(true);
11163 CE->setInstantiationDependent(true);
11169 if (CandidateSet->empty())
11172 UnbridgedCasts.restore();
11176 /// FinishOverloadedCallExpr - given an OverloadCandidateSet, builds and returns
11177 /// the completed call expression. If overload resolution fails, emits
11178 /// diagnostics and returns ExprError()
11179 static ExprResult FinishOverloadedCallExpr(Sema &SemaRef, Scope *S, Expr *Fn,
11180 UnresolvedLookupExpr *ULE,
11181 SourceLocation LParenLoc,
11183 SourceLocation RParenLoc,
11185 OverloadCandidateSet *CandidateSet,
11186 OverloadCandidateSet::iterator *Best,
11187 OverloadingResult OverloadResult,
11188 bool AllowTypoCorrection) {
11189 if (CandidateSet->empty())
11190 return BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc, Args,
11191 RParenLoc, /*EmptyLookup=*/true,
11192 AllowTypoCorrection);
11194 switch (OverloadResult) {
11196 FunctionDecl *FDecl = (*Best)->Function;
11197 SemaRef.CheckUnresolvedLookupAccess(ULE, (*Best)->FoundDecl);
11198 if (SemaRef.DiagnoseUseOfDecl(FDecl, ULE->getNameLoc()))
11199 return ExprError();
11200 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl);
11201 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, RParenLoc,
11205 case OR_No_Viable_Function: {
11206 // Try to recover by looking for viable functions which the user might
11207 // have meant to call.
11208 ExprResult Recovery = BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc,
11210 /*EmptyLookup=*/false,
11211 AllowTypoCorrection);
11212 if (!Recovery.isInvalid())
11215 // If the user passes in a function that we can't take the address of, we
11216 // generally end up emitting really bad error messages. Here, we attempt to
11217 // emit better ones.
11218 for (const Expr *Arg : Args) {
11219 if (!Arg->getType()->isFunctionType())
11221 if (auto *DRE = dyn_cast<DeclRefExpr>(Arg->IgnoreParenImpCasts())) {
11222 auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl());
11224 !SemaRef.checkAddressOfFunctionIsAvailable(FD, /*Complain=*/true,
11225 Arg->getExprLoc()))
11226 return ExprError();
11230 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_no_viable_function_in_call)
11231 << ULE->getName() << Fn->getSourceRange();
11232 CandidateSet->NoteCandidates(SemaRef, OCD_AllCandidates, Args);
11237 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_ambiguous_call)
11238 << ULE->getName() << Fn->getSourceRange();
11239 CandidateSet->NoteCandidates(SemaRef, OCD_ViableCandidates, Args);
11243 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_deleted_call)
11244 << (*Best)->Function->isDeleted()
11246 << SemaRef.getDeletedOrUnavailableSuffix((*Best)->Function)
11247 << Fn->getSourceRange();
11248 CandidateSet->NoteCandidates(SemaRef, OCD_AllCandidates, Args);
11250 // We emitted an error for the unvailable/deleted function call but keep
11251 // the call in the AST.
11252 FunctionDecl *FDecl = (*Best)->Function;
11253 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl);
11254 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, RParenLoc,
11259 // Overload resolution failed.
11260 return ExprError();
11263 static void markUnaddressableCandidatesUnviable(Sema &S,
11264 OverloadCandidateSet &CS) {
11265 for (auto I = CS.begin(), E = CS.end(); I != E; ++I) {
11267 !S.checkAddressOfFunctionIsAvailable(I->Function, /*Complain=*/false)) {
11269 I->FailureKind = ovl_fail_addr_not_available;
11274 /// BuildOverloadedCallExpr - Given the call expression that calls Fn
11275 /// (which eventually refers to the declaration Func) and the call
11276 /// arguments Args/NumArgs, attempt to resolve the function call down
11277 /// to a specific function. If overload resolution succeeds, returns
11278 /// the call expression produced by overload resolution.
11279 /// Otherwise, emits diagnostics and returns ExprError.
11280 ExprResult Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn,
11281 UnresolvedLookupExpr *ULE,
11282 SourceLocation LParenLoc,
11284 SourceLocation RParenLoc,
11286 bool AllowTypoCorrection,
11287 bool CalleesAddressIsTaken) {
11288 OverloadCandidateSet CandidateSet(Fn->getExprLoc(),
11289 OverloadCandidateSet::CSK_Normal);
11292 if (buildOverloadedCallSet(S, Fn, ULE, Args, LParenLoc, &CandidateSet,
11296 // If the user handed us something like `(&Foo)(Bar)`, we need to ensure that
11297 // functions that aren't addressible are considered unviable.
11298 if (CalleesAddressIsTaken)
11299 markUnaddressableCandidatesUnviable(*this, CandidateSet);
11301 OverloadCandidateSet::iterator Best;
11302 OverloadingResult OverloadResult =
11303 CandidateSet.BestViableFunction(*this, Fn->getLocStart(), Best);
11305 return FinishOverloadedCallExpr(*this, S, Fn, ULE, LParenLoc, Args,
11306 RParenLoc, ExecConfig, &CandidateSet,
11307 &Best, OverloadResult,
11308 AllowTypoCorrection);
11311 static bool IsOverloaded(const UnresolvedSetImpl &Functions) {
11312 return Functions.size() > 1 ||
11313 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin()));
11316 /// \brief Create a unary operation that may resolve to an overloaded
11319 /// \param OpLoc The location of the operator itself (e.g., '*').
11321 /// \param Opc The UnaryOperatorKind that describes this operator.
11323 /// \param Fns The set of non-member functions that will be
11324 /// considered by overload resolution. The caller needs to build this
11325 /// set based on the context using, e.g.,
11326 /// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This
11327 /// set should not contain any member functions; those will be added
11328 /// by CreateOverloadedUnaryOp().
11330 /// \param Input The input argument.
11332 Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, UnaryOperatorKind Opc,
11333 const UnresolvedSetImpl &Fns,
11335 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc);
11336 assert(Op != OO_None && "Invalid opcode for overloaded unary operator");
11337 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
11338 // TODO: provide better source location info.
11339 DeclarationNameInfo OpNameInfo(OpName, OpLoc);
11341 if (checkPlaceholderForOverload(*this, Input))
11342 return ExprError();
11344 Expr *Args[2] = { Input, nullptr };
11345 unsigned NumArgs = 1;
11347 // For post-increment and post-decrement, add the implicit '0' as
11348 // the second argument, so that we know this is a post-increment or
11350 if (Opc == UO_PostInc || Opc == UO_PostDec) {
11351 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false);
11352 Args[1] = IntegerLiteral::Create(Context, Zero, Context.IntTy,
11357 ArrayRef<Expr *> ArgsArray(Args, NumArgs);
11359 if (Input->isTypeDependent()) {
11361 return new (Context) UnaryOperator(Input, Opc, Context.DependentTy,
11362 VK_RValue, OK_Ordinary, OpLoc);
11364 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
11365 UnresolvedLookupExpr *Fn
11366 = UnresolvedLookupExpr::Create(Context, NamingClass,
11367 NestedNameSpecifierLoc(), OpNameInfo,
11368 /*ADL*/ true, IsOverloaded(Fns),
11369 Fns.begin(), Fns.end());
11370 return new (Context)
11371 CXXOperatorCallExpr(Context, Op, Fn, ArgsArray, Context.DependentTy,
11372 VK_RValue, OpLoc, false);
11375 // Build an empty overload set.
11376 OverloadCandidateSet CandidateSet(OpLoc, OverloadCandidateSet::CSK_Operator);
11378 // Add the candidates from the given function set.
11379 AddFunctionCandidates(Fns, ArgsArray, CandidateSet);
11381 // Add operator candidates that are member functions.
11382 AddMemberOperatorCandidates(Op, OpLoc, ArgsArray, CandidateSet);
11384 // Add candidates from ADL.
11385 AddArgumentDependentLookupCandidates(OpName, OpLoc, ArgsArray,
11386 /*ExplicitTemplateArgs*/nullptr,
11389 // Add builtin operator candidates.
11390 AddBuiltinOperatorCandidates(Op, OpLoc, ArgsArray, CandidateSet);
11392 bool HadMultipleCandidates = (CandidateSet.size() > 1);
11394 // Perform overload resolution.
11395 OverloadCandidateSet::iterator Best;
11396 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
11398 // We found a built-in operator or an overloaded operator.
11399 FunctionDecl *FnDecl = Best->Function;
11402 // We matched an overloaded operator. Build a call to that
11405 // Convert the arguments.
11406 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) {
11407 CheckMemberOperatorAccess(OpLoc, Args[0], nullptr, Best->FoundDecl);
11409 ExprResult InputRes =
11410 PerformObjectArgumentInitialization(Input, /*Qualifier=*/nullptr,
11411 Best->FoundDecl, Method);
11412 if (InputRes.isInvalid())
11413 return ExprError();
11414 Input = InputRes.get();
11416 // Convert the arguments.
11417 ExprResult InputInit
11418 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
11420 FnDecl->getParamDecl(0)),
11423 if (InputInit.isInvalid())
11424 return ExprError();
11425 Input = InputInit.get();
11428 // Build the actual expression node.
11429 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, Best->FoundDecl,
11430 HadMultipleCandidates, OpLoc);
11431 if (FnExpr.isInvalid())
11432 return ExprError();
11434 // Determine the result type.
11435 QualType ResultTy = FnDecl->getReturnType();
11436 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
11437 ResultTy = ResultTy.getNonLValueExprType(Context);
11440 CallExpr *TheCall =
11441 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.get(), ArgsArray,
11442 ResultTy, VK, OpLoc, false);
11444 if (CheckCallReturnType(FnDecl->getReturnType(), OpLoc, TheCall, FnDecl))
11445 return ExprError();
11447 return MaybeBindToTemporary(TheCall);
11449 // We matched a built-in operator. Convert the arguments, then
11450 // break out so that we will build the appropriate built-in
11452 ExprResult InputRes =
11453 PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0],
11454 Best->Conversions[0], AA_Passing);
11455 if (InputRes.isInvalid())
11456 return ExprError();
11457 Input = InputRes.get();
11462 case OR_No_Viable_Function:
11463 // This is an erroneous use of an operator which can be overloaded by
11464 // a non-member function. Check for non-member operators which were
11465 // defined too late to be candidates.
11466 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, ArgsArray))
11467 // FIXME: Recover by calling the found function.
11468 return ExprError();
11470 // No viable function; fall through to handling this as a
11471 // built-in operator, which will produce an error message for us.
11475 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary)
11476 << UnaryOperator::getOpcodeStr(Opc)
11477 << Input->getType()
11478 << Input->getSourceRange();
11479 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, ArgsArray,
11480 UnaryOperator::getOpcodeStr(Opc), OpLoc);
11481 return ExprError();
11484 Diag(OpLoc, diag::err_ovl_deleted_oper)
11485 << Best->Function->isDeleted()
11486 << UnaryOperator::getOpcodeStr(Opc)
11487 << getDeletedOrUnavailableSuffix(Best->Function)
11488 << Input->getSourceRange();
11489 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, ArgsArray,
11490 UnaryOperator::getOpcodeStr(Opc), OpLoc);
11491 return ExprError();
11494 // Either we found no viable overloaded operator or we matched a
11495 // built-in operator. In either case, fall through to trying to
11496 // build a built-in operation.
11497 return CreateBuiltinUnaryOp(OpLoc, Opc, Input);
11500 /// \brief Create a binary operation that may resolve to an overloaded
11503 /// \param OpLoc The location of the operator itself (e.g., '+').
11505 /// \param Opc The BinaryOperatorKind that describes this operator.
11507 /// \param Fns The set of non-member functions that will be
11508 /// considered by overload resolution. The caller needs to build this
11509 /// set based on the context using, e.g.,
11510 /// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This
11511 /// set should not contain any member functions; those will be added
11512 /// by CreateOverloadedBinOp().
11514 /// \param LHS Left-hand argument.
11515 /// \param RHS Right-hand argument.
11517 Sema::CreateOverloadedBinOp(SourceLocation OpLoc,
11518 BinaryOperatorKind Opc,
11519 const UnresolvedSetImpl &Fns,
11520 Expr *LHS, Expr *RHS) {
11521 Expr *Args[2] = { LHS, RHS };
11522 LHS=RHS=nullptr; // Please use only Args instead of LHS/RHS couple
11524 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc);
11525 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
11527 // If either side is type-dependent, create an appropriate dependent
11529 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) {
11531 // If there are no functions to store, just build a dependent
11532 // BinaryOperator or CompoundAssignment.
11533 if (Opc <= BO_Assign || Opc > BO_OrAssign)
11534 return new (Context) BinaryOperator(
11535 Args[0], Args[1], Opc, Context.DependentTy, VK_RValue, OK_Ordinary,
11536 OpLoc, FPFeatures.fp_contract);
11538 return new (Context) CompoundAssignOperator(
11539 Args[0], Args[1], Opc, Context.DependentTy, VK_LValue, OK_Ordinary,
11540 Context.DependentTy, Context.DependentTy, OpLoc,
11541 FPFeatures.fp_contract);
11544 // FIXME: save results of ADL from here?
11545 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
11546 // TODO: provide better source location info in DNLoc component.
11547 DeclarationNameInfo OpNameInfo(OpName, OpLoc);
11548 UnresolvedLookupExpr *Fn
11549 = UnresolvedLookupExpr::Create(Context, NamingClass,
11550 NestedNameSpecifierLoc(), OpNameInfo,
11551 /*ADL*/ true, IsOverloaded(Fns),
11552 Fns.begin(), Fns.end());
11553 return new (Context)
11554 CXXOperatorCallExpr(Context, Op, Fn, Args, Context.DependentTy,
11555 VK_RValue, OpLoc, FPFeatures.fp_contract);
11558 // Always do placeholder-like conversions on the RHS.
11559 if (checkPlaceholderForOverload(*this, Args[1]))
11560 return ExprError();
11562 // Do placeholder-like conversion on the LHS; note that we should
11563 // not get here with a PseudoObject LHS.
11564 assert(Args[0]->getObjectKind() != OK_ObjCProperty);
11565 if (checkPlaceholderForOverload(*this, Args[0]))
11566 return ExprError();
11568 // If this is the assignment operator, we only perform overload resolution
11569 // if the left-hand side is a class or enumeration type. This is actually
11570 // a hack. The standard requires that we do overload resolution between the
11571 // various built-in candidates, but as DR507 points out, this can lead to
11572 // problems. So we do it this way, which pretty much follows what GCC does.
11573 // Note that we go the traditional code path for compound assignment forms.
11574 if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType())
11575 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
11577 // If this is the .* operator, which is not overloadable, just
11578 // create a built-in binary operator.
11579 if (Opc == BO_PtrMemD)
11580 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
11582 // Build an empty overload set.
11583 OverloadCandidateSet CandidateSet(OpLoc, OverloadCandidateSet::CSK_Operator);
11585 // Add the candidates from the given function set.
11586 AddFunctionCandidates(Fns, Args, CandidateSet);
11588 // Add operator candidates that are member functions.
11589 AddMemberOperatorCandidates(Op, OpLoc, Args, CandidateSet);
11591 // Add candidates from ADL. Per [over.match.oper]p2, this lookup is not
11592 // performed for an assignment operator (nor for operator[] nor operator->,
11593 // which don't get here).
11594 if (Opc != BO_Assign)
11595 AddArgumentDependentLookupCandidates(OpName, OpLoc, Args,
11596 /*ExplicitTemplateArgs*/ nullptr,
11599 // Add builtin operator candidates.
11600 AddBuiltinOperatorCandidates(Op, OpLoc, Args, CandidateSet);
11602 bool HadMultipleCandidates = (CandidateSet.size() > 1);
11604 // Perform overload resolution.
11605 OverloadCandidateSet::iterator Best;
11606 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
11608 // We found a built-in operator or an overloaded operator.
11609 FunctionDecl *FnDecl = Best->Function;
11612 // We matched an overloaded operator. Build a call to that
11615 // Convert the arguments.
11616 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) {
11617 // Best->Access is only meaningful for class members.
11618 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl);
11621 PerformCopyInitialization(
11622 InitializedEntity::InitializeParameter(Context,
11623 FnDecl->getParamDecl(0)),
11624 SourceLocation(), Args[1]);
11625 if (Arg1.isInvalid())
11626 return ExprError();
11629 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/nullptr,
11630 Best->FoundDecl, Method);
11631 if (Arg0.isInvalid())
11632 return ExprError();
11633 Args[0] = Arg0.getAs<Expr>();
11634 Args[1] = RHS = Arg1.getAs<Expr>();
11636 // Convert the arguments.
11637 ExprResult Arg0 = PerformCopyInitialization(
11638 InitializedEntity::InitializeParameter(Context,
11639 FnDecl->getParamDecl(0)),
11640 SourceLocation(), Args[0]);
11641 if (Arg0.isInvalid())
11642 return ExprError();
11645 PerformCopyInitialization(
11646 InitializedEntity::InitializeParameter(Context,
11647 FnDecl->getParamDecl(1)),
11648 SourceLocation(), Args[1]);
11649 if (Arg1.isInvalid())
11650 return ExprError();
11651 Args[0] = LHS = Arg0.getAs<Expr>();
11652 Args[1] = RHS = Arg1.getAs<Expr>();
11655 // Build the actual expression node.
11656 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl,
11658 HadMultipleCandidates, OpLoc);
11659 if (FnExpr.isInvalid())
11660 return ExprError();
11662 // Determine the result type.
11663 QualType ResultTy = FnDecl->getReturnType();
11664 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
11665 ResultTy = ResultTy.getNonLValueExprType(Context);
11667 CXXOperatorCallExpr *TheCall =
11668 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.get(),
11669 Args, ResultTy, VK, OpLoc,
11670 FPFeatures.fp_contract);
11672 if (CheckCallReturnType(FnDecl->getReturnType(), OpLoc, TheCall,
11674 return ExprError();
11676 ArrayRef<const Expr *> ArgsArray(Args, 2);
11677 // Cut off the implicit 'this'.
11678 if (isa<CXXMethodDecl>(FnDecl))
11679 ArgsArray = ArgsArray.slice(1);
11681 // Check for a self move.
11682 if (Op == OO_Equal)
11683 DiagnoseSelfMove(Args[0], Args[1], OpLoc);
11685 checkCall(FnDecl, nullptr, ArgsArray, isa<CXXMethodDecl>(FnDecl), OpLoc,
11686 TheCall->getSourceRange(), VariadicDoesNotApply);
11688 return MaybeBindToTemporary(TheCall);
11690 // We matched a built-in operator. Convert the arguments, then
11691 // break out so that we will build the appropriate built-in
11693 ExprResult ArgsRes0 =
11694 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0],
11695 Best->Conversions[0], AA_Passing);
11696 if (ArgsRes0.isInvalid())
11697 return ExprError();
11698 Args[0] = ArgsRes0.get();
11700 ExprResult ArgsRes1 =
11701 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1],
11702 Best->Conversions[1], AA_Passing);
11703 if (ArgsRes1.isInvalid())
11704 return ExprError();
11705 Args[1] = ArgsRes1.get();
11710 case OR_No_Viable_Function: {
11711 // C++ [over.match.oper]p9:
11712 // If the operator is the operator , [...] and there are no
11713 // viable functions, then the operator is assumed to be the
11714 // built-in operator and interpreted according to clause 5.
11715 if (Opc == BO_Comma)
11718 // For class as left operand for assignment or compound assigment
11719 // operator do not fall through to handling in built-in, but report that
11720 // no overloaded assignment operator found
11721 ExprResult Result = ExprError();
11722 if (Args[0]->getType()->isRecordType() &&
11723 Opc >= BO_Assign && Opc <= BO_OrAssign) {
11724 Diag(OpLoc, diag::err_ovl_no_viable_oper)
11725 << BinaryOperator::getOpcodeStr(Opc)
11726 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
11727 if (Args[0]->getType()->isIncompleteType()) {
11728 Diag(OpLoc, diag::note_assign_lhs_incomplete)
11729 << Args[0]->getType()
11730 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
11733 // This is an erroneous use of an operator which can be overloaded by
11734 // a non-member function. Check for non-member operators which were
11735 // defined too late to be candidates.
11736 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, Args))
11737 // FIXME: Recover by calling the found function.
11738 return ExprError();
11740 // No viable function; try to create a built-in operation, which will
11741 // produce an error. Then, show the non-viable candidates.
11742 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
11744 assert(Result.isInvalid() &&
11745 "C++ binary operator overloading is missing candidates!");
11746 if (Result.isInvalid())
11747 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args,
11748 BinaryOperator::getOpcodeStr(Opc), OpLoc);
11753 Diag(OpLoc, diag::err_ovl_ambiguous_oper_binary)
11754 << BinaryOperator::getOpcodeStr(Opc)
11755 << Args[0]->getType() << Args[1]->getType()
11756 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
11757 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args,
11758 BinaryOperator::getOpcodeStr(Opc), OpLoc);
11759 return ExprError();
11762 if (isImplicitlyDeleted(Best->Function)) {
11763 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
11764 Diag(OpLoc, diag::err_ovl_deleted_special_oper)
11765 << Context.getRecordType(Method->getParent())
11766 << getSpecialMember(Method);
11768 // The user probably meant to call this special member. Just
11769 // explain why it's deleted.
11770 NoteDeletedFunction(Method);
11771 return ExprError();
11773 Diag(OpLoc, diag::err_ovl_deleted_oper)
11774 << Best->Function->isDeleted()
11775 << BinaryOperator::getOpcodeStr(Opc)
11776 << getDeletedOrUnavailableSuffix(Best->Function)
11777 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
11779 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args,
11780 BinaryOperator::getOpcodeStr(Opc), OpLoc);
11781 return ExprError();
11784 // We matched a built-in operator; build it.
11785 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
11789 Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc,
11790 SourceLocation RLoc,
11791 Expr *Base, Expr *Idx) {
11792 Expr *Args[2] = { Base, Idx };
11793 DeclarationName OpName =
11794 Context.DeclarationNames.getCXXOperatorName(OO_Subscript);
11796 // If either side is type-dependent, create an appropriate dependent
11798 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) {
11800 CXXRecordDecl *NamingClass = nullptr; // lookup ignores member operators
11801 // CHECKME: no 'operator' keyword?
11802 DeclarationNameInfo OpNameInfo(OpName, LLoc);
11803 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc));
11804 UnresolvedLookupExpr *Fn
11805 = UnresolvedLookupExpr::Create(Context, NamingClass,
11806 NestedNameSpecifierLoc(), OpNameInfo,
11807 /*ADL*/ true, /*Overloaded*/ false,
11808 UnresolvedSetIterator(),
11809 UnresolvedSetIterator());
11810 // Can't add any actual overloads yet
11812 return new (Context)
11813 CXXOperatorCallExpr(Context, OO_Subscript, Fn, Args,
11814 Context.DependentTy, VK_RValue, RLoc, false);
11817 // Handle placeholders on both operands.
11818 if (checkPlaceholderForOverload(*this, Args[0]))
11819 return ExprError();
11820 if (checkPlaceholderForOverload(*this, Args[1]))
11821 return ExprError();
11823 // Build an empty overload set.
11824 OverloadCandidateSet CandidateSet(LLoc, OverloadCandidateSet::CSK_Operator);
11826 // Subscript can only be overloaded as a member function.
11828 // Add operator candidates that are member functions.
11829 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, CandidateSet);
11831 // Add builtin operator candidates.
11832 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, CandidateSet);
11834 bool HadMultipleCandidates = (CandidateSet.size() > 1);
11836 // Perform overload resolution.
11837 OverloadCandidateSet::iterator Best;
11838 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) {
11840 // We found a built-in operator or an overloaded operator.
11841 FunctionDecl *FnDecl = Best->Function;
11844 // We matched an overloaded operator. Build a call to that
11847 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl);
11849 // Convert the arguments.
11850 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl);
11852 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/nullptr,
11853 Best->FoundDecl, Method);
11854 if (Arg0.isInvalid())
11855 return ExprError();
11856 Args[0] = Arg0.get();
11858 // Convert the arguments.
11859 ExprResult InputInit
11860 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
11862 FnDecl->getParamDecl(0)),
11865 if (InputInit.isInvalid())
11866 return ExprError();
11868 Args[1] = InputInit.getAs<Expr>();
11870 // Build the actual expression node.
11871 DeclarationNameInfo OpLocInfo(OpName, LLoc);
11872 OpLocInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc));
11873 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl,
11875 HadMultipleCandidates,
11876 OpLocInfo.getLoc(),
11877 OpLocInfo.getInfo());
11878 if (FnExpr.isInvalid())
11879 return ExprError();
11881 // Determine the result type
11882 QualType ResultTy = FnDecl->getReturnType();
11883 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
11884 ResultTy = ResultTy.getNonLValueExprType(Context);
11886 CXXOperatorCallExpr *TheCall =
11887 new (Context) CXXOperatorCallExpr(Context, OO_Subscript,
11888 FnExpr.get(), Args,
11889 ResultTy, VK, RLoc,
11892 if (CheckCallReturnType(FnDecl->getReturnType(), LLoc, TheCall, FnDecl))
11893 return ExprError();
11895 return MaybeBindToTemporary(TheCall);
11897 // We matched a built-in operator. Convert the arguments, then
11898 // break out so that we will build the appropriate built-in
11900 ExprResult ArgsRes0 =
11901 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0],
11902 Best->Conversions[0], AA_Passing);
11903 if (ArgsRes0.isInvalid())
11904 return ExprError();
11905 Args[0] = ArgsRes0.get();
11907 ExprResult ArgsRes1 =
11908 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1],
11909 Best->Conversions[1], AA_Passing);
11910 if (ArgsRes1.isInvalid())
11911 return ExprError();
11912 Args[1] = ArgsRes1.get();
11918 case OR_No_Viable_Function: {
11919 if (CandidateSet.empty())
11920 Diag(LLoc, diag::err_ovl_no_oper)
11921 << Args[0]->getType() << /*subscript*/ 0
11922 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
11924 Diag(LLoc, diag::err_ovl_no_viable_subscript)
11925 << Args[0]->getType()
11926 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
11927 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args,
11929 return ExprError();
11933 Diag(LLoc, diag::err_ovl_ambiguous_oper_binary)
11935 << Args[0]->getType() << Args[1]->getType()
11936 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
11937 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args,
11939 return ExprError();
11942 Diag(LLoc, diag::err_ovl_deleted_oper)
11943 << Best->Function->isDeleted() << "[]"
11944 << getDeletedOrUnavailableSuffix(Best->Function)
11945 << Args[0]->getSourceRange() << Args[1]->getSourceRange();
11946 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args,
11948 return ExprError();
11951 // We matched a built-in operator; build it.
11952 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc);
11955 /// BuildCallToMemberFunction - Build a call to a member
11956 /// function. MemExpr is the expression that refers to the member
11957 /// function (and includes the object parameter), Args/NumArgs are the
11958 /// arguments to the function call (not including the object
11959 /// parameter). The caller needs to validate that the member
11960 /// expression refers to a non-static member function or an overloaded
11961 /// member function.
11963 Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE,
11964 SourceLocation LParenLoc,
11966 SourceLocation RParenLoc) {
11967 assert(MemExprE->getType() == Context.BoundMemberTy ||
11968 MemExprE->getType() == Context.OverloadTy);
11970 // Dig out the member expression. This holds both the object
11971 // argument and the member function we're referring to.
11972 Expr *NakedMemExpr = MemExprE->IgnoreParens();
11974 // Determine whether this is a call to a pointer-to-member function.
11975 if (BinaryOperator *op = dyn_cast<BinaryOperator>(NakedMemExpr)) {
11976 assert(op->getType() == Context.BoundMemberTy);
11977 assert(op->getOpcode() == BO_PtrMemD || op->getOpcode() == BO_PtrMemI);
11980 op->getRHS()->getType()->castAs<MemberPointerType>()->getPointeeType();
11982 const FunctionProtoType *proto = fnType->castAs<FunctionProtoType>();
11983 QualType resultType = proto->getCallResultType(Context);
11984 ExprValueKind valueKind = Expr::getValueKindForType(proto->getReturnType());
11986 // Check that the object type isn't more qualified than the
11987 // member function we're calling.
11988 Qualifiers funcQuals = Qualifiers::fromCVRMask(proto->getTypeQuals());
11990 QualType objectType = op->getLHS()->getType();
11991 if (op->getOpcode() == BO_PtrMemI)
11992 objectType = objectType->castAs<PointerType>()->getPointeeType();
11993 Qualifiers objectQuals = objectType.getQualifiers();
11995 Qualifiers difference = objectQuals - funcQuals;
11996 difference.removeObjCGCAttr();
11997 difference.removeAddressSpace();
11999 std::string qualsString = difference.getAsString();
12000 Diag(LParenLoc, diag::err_pointer_to_member_call_drops_quals)
12001 << fnType.getUnqualifiedType()
12003 << (qualsString.find(' ') == std::string::npos ? 1 : 2);
12006 CXXMemberCallExpr *call
12007 = new (Context) CXXMemberCallExpr(Context, MemExprE, Args,
12008 resultType, valueKind, RParenLoc);
12010 if (CheckCallReturnType(proto->getReturnType(), op->getRHS()->getLocStart(),
12012 return ExprError();
12014 if (ConvertArgumentsForCall(call, op, nullptr, proto, Args, RParenLoc))
12015 return ExprError();
12017 if (CheckOtherCall(call, proto))
12018 return ExprError();
12020 return MaybeBindToTemporary(call);
12023 if (isa<CXXPseudoDestructorExpr>(NakedMemExpr))
12024 return new (Context)
12025 CallExpr(Context, MemExprE, Args, Context.VoidTy, VK_RValue, RParenLoc);
12027 UnbridgedCastsSet UnbridgedCasts;
12028 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts))
12029 return ExprError();
12031 MemberExpr *MemExpr;
12032 CXXMethodDecl *Method = nullptr;
12033 DeclAccessPair FoundDecl = DeclAccessPair::make(nullptr, AS_public);
12034 NestedNameSpecifier *Qualifier = nullptr;
12035 if (isa<MemberExpr>(NakedMemExpr)) {
12036 MemExpr = cast<MemberExpr>(NakedMemExpr);
12037 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl());
12038 FoundDecl = MemExpr->getFoundDecl();
12039 Qualifier = MemExpr->getQualifier();
12040 UnbridgedCasts.restore();
12042 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr);
12043 Qualifier = UnresExpr->getQualifier();
12045 QualType ObjectType = UnresExpr->getBaseType();
12046 Expr::Classification ObjectClassification
12047 = UnresExpr->isArrow()? Expr::Classification::makeSimpleLValue()
12048 : UnresExpr->getBase()->Classify(Context);
12050 // Add overload candidates
12051 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc(),
12052 OverloadCandidateSet::CSK_Normal);
12054 // FIXME: avoid copy.
12055 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
12056 if (UnresExpr->hasExplicitTemplateArgs()) {
12057 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer);
12058 TemplateArgs = &TemplateArgsBuffer;
12061 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(),
12062 E = UnresExpr->decls_end(); I != E; ++I) {
12064 NamedDecl *Func = *I;
12065 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext());
12066 if (isa<UsingShadowDecl>(Func))
12067 Func = cast<UsingShadowDecl>(Func)->getTargetDecl();
12070 // Microsoft supports direct constructor calls.
12071 if (getLangOpts().MicrosoftExt && isa<CXXConstructorDecl>(Func)) {
12072 AddOverloadCandidate(cast<CXXConstructorDecl>(Func), I.getPair(),
12073 Args, CandidateSet);
12074 } else if ((Method = dyn_cast<CXXMethodDecl>(Func))) {
12075 // If explicit template arguments were provided, we can't call a
12076 // non-template member function.
12080 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType,
12081 ObjectClassification, Args, CandidateSet,
12082 /*SuppressUserConversions=*/false);
12084 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func),
12085 I.getPair(), ActingDC, TemplateArgs,
12086 ObjectType, ObjectClassification,
12087 Args, CandidateSet,
12088 /*SuppressUsedConversions=*/false);
12092 DeclarationName DeclName = UnresExpr->getMemberName();
12094 UnbridgedCasts.restore();
12096 OverloadCandidateSet::iterator Best;
12097 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getLocStart(),
12100 Method = cast<CXXMethodDecl>(Best->Function);
12101 FoundDecl = Best->FoundDecl;
12102 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl);
12103 if (DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()))
12104 return ExprError();
12105 // If FoundDecl is different from Method (such as if one is a template
12106 // and the other a specialization), make sure DiagnoseUseOfDecl is
12108 // FIXME: This would be more comprehensively addressed by modifying
12109 // DiagnoseUseOfDecl to accept both the FoundDecl and the decl
12111 if (Method != FoundDecl.getDecl() &&
12112 DiagnoseUseOfDecl(Method, UnresExpr->getNameLoc()))
12113 return ExprError();
12116 case OR_No_Viable_Function:
12117 Diag(UnresExpr->getMemberLoc(),
12118 diag::err_ovl_no_viable_member_function_in_call)
12119 << DeclName << MemExprE->getSourceRange();
12120 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
12121 // FIXME: Leaking incoming expressions!
12122 return ExprError();
12125 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call)
12126 << DeclName << MemExprE->getSourceRange();
12127 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
12128 // FIXME: Leaking incoming expressions!
12129 return ExprError();
12132 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call)
12133 << Best->Function->isDeleted()
12135 << getDeletedOrUnavailableSuffix(Best->Function)
12136 << MemExprE->getSourceRange();
12137 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
12138 // FIXME: Leaking incoming expressions!
12139 return ExprError();
12142 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method);
12144 // If overload resolution picked a static member, build a
12145 // non-member call based on that function.
12146 if (Method->isStatic()) {
12147 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, Args,
12151 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens());
12154 QualType ResultType = Method->getReturnType();
12155 ExprValueKind VK = Expr::getValueKindForType(ResultType);
12156 ResultType = ResultType.getNonLValueExprType(Context);
12158 assert(Method && "Member call to something that isn't a method?");
12159 CXXMemberCallExpr *TheCall =
12160 new (Context) CXXMemberCallExpr(Context, MemExprE, Args,
12161 ResultType, VK, RParenLoc);
12163 // (CUDA B.1): Check for invalid calls between targets.
12164 if (getLangOpts().CUDA) {
12165 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext)) {
12166 if (CheckCUDATarget(Caller, Method)) {
12167 Diag(MemExpr->getMemberLoc(), diag::err_ref_bad_target)
12168 << IdentifyCUDATarget(Method) << Method->getIdentifier()
12169 << IdentifyCUDATarget(Caller);
12170 return ExprError();
12175 // Check for a valid return type.
12176 if (CheckCallReturnType(Method->getReturnType(), MemExpr->getMemberLoc(),
12178 return ExprError();
12180 // Convert the object argument (for a non-static member function call).
12181 // We only need to do this if there was actually an overload; otherwise
12182 // it was done at lookup.
12183 if (!Method->isStatic()) {
12184 ExprResult ObjectArg =
12185 PerformObjectArgumentInitialization(MemExpr->getBase(), Qualifier,
12186 FoundDecl, Method);
12187 if (ObjectArg.isInvalid())
12188 return ExprError();
12189 MemExpr->setBase(ObjectArg.get());
12192 // Convert the rest of the arguments
12193 const FunctionProtoType *Proto =
12194 Method->getType()->getAs<FunctionProtoType>();
12195 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args,
12197 return ExprError();
12199 DiagnoseSentinelCalls(Method, LParenLoc, Args);
12201 if (CheckFunctionCall(Method, TheCall, Proto))
12202 return ExprError();
12204 // In the case the method to call was not selected by the overloading
12205 // resolution process, we still need to handle the enable_if attribute. Do
12206 // that here, so it will not hide previous -- and more relevant -- errors
12207 if (isa<MemberExpr>(NakedMemExpr)) {
12208 if (const EnableIfAttr *Attr = CheckEnableIf(Method, Args, true)) {
12209 Diag(MemExprE->getLocStart(),
12210 diag::err_ovl_no_viable_member_function_in_call)
12211 << Method << Method->getSourceRange();
12212 Diag(Method->getLocation(),
12213 diag::note_ovl_candidate_disabled_by_enable_if_attr)
12214 << Attr->getCond()->getSourceRange() << Attr->getMessage();
12215 return ExprError();
12219 if ((isa<CXXConstructorDecl>(CurContext) ||
12220 isa<CXXDestructorDecl>(CurContext)) &&
12221 TheCall->getMethodDecl()->isPure()) {
12222 const CXXMethodDecl *MD = TheCall->getMethodDecl();
12224 if (isa<CXXThisExpr>(MemExpr->getBase()->IgnoreParenCasts()) &&
12225 MemExpr->performsVirtualDispatch(getLangOpts())) {
12226 Diag(MemExpr->getLocStart(),
12227 diag::warn_call_to_pure_virtual_member_function_from_ctor_dtor)
12228 << MD->getDeclName() << isa<CXXDestructorDecl>(CurContext)
12229 << MD->getParent()->getDeclName();
12231 Diag(MD->getLocStart(), diag::note_previous_decl) << MD->getDeclName();
12232 if (getLangOpts().AppleKext)
12233 Diag(MemExpr->getLocStart(),
12234 diag::note_pure_qualified_call_kext)
12235 << MD->getParent()->getDeclName()
12236 << MD->getDeclName();
12239 return MaybeBindToTemporary(TheCall);
12242 /// BuildCallToObjectOfClassType - Build a call to an object of class
12243 /// type (C++ [over.call.object]), which can end up invoking an
12244 /// overloaded function call operator (@c operator()) or performing a
12245 /// user-defined conversion on the object argument.
12247 Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj,
12248 SourceLocation LParenLoc,
12250 SourceLocation RParenLoc) {
12251 if (checkPlaceholderForOverload(*this, Obj))
12252 return ExprError();
12253 ExprResult Object = Obj;
12255 UnbridgedCastsSet UnbridgedCasts;
12256 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts))
12257 return ExprError();
12259 assert(Object.get()->getType()->isRecordType() &&
12260 "Requires object type argument");
12261 const RecordType *Record = Object.get()->getType()->getAs<RecordType>();
12263 // C++ [over.call.object]p1:
12264 // If the primary-expression E in the function call syntax
12265 // evaluates to a class object of type "cv T", then the set of
12266 // candidate functions includes at least the function call
12267 // operators of T. The function call operators of T are obtained by
12268 // ordinary lookup of the name operator() in the context of
12270 OverloadCandidateSet CandidateSet(LParenLoc,
12271 OverloadCandidateSet::CSK_Operator);
12272 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call);
12274 if (RequireCompleteType(LParenLoc, Object.get()->getType(),
12275 diag::err_incomplete_object_call, Object.get()))
12278 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName);
12279 LookupQualifiedName(R, Record->getDecl());
12280 R.suppressDiagnostics();
12282 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end();
12283 Oper != OperEnd; ++Oper) {
12284 AddMethodCandidate(Oper.getPair(), Object.get()->getType(),
12285 Object.get()->Classify(Context),
12286 Args, CandidateSet,
12287 /*SuppressUserConversions=*/ false);
12290 // C++ [over.call.object]p2:
12291 // In addition, for each (non-explicit in C++0x) conversion function
12292 // declared in T of the form
12294 // operator conversion-type-id () cv-qualifier;
12296 // where cv-qualifier is the same cv-qualification as, or a
12297 // greater cv-qualification than, cv, and where conversion-type-id
12298 // denotes the type "pointer to function of (P1,...,Pn) returning
12299 // R", or the type "reference to pointer to function of
12300 // (P1,...,Pn) returning R", or the type "reference to function
12301 // of (P1,...,Pn) returning R", a surrogate call function [...]
12302 // is also considered as a candidate function. Similarly,
12303 // surrogate call functions are added to the set of candidate
12304 // functions for each conversion function declared in an
12305 // accessible base class provided the function is not hidden
12306 // within T by another intervening declaration.
12307 const auto &Conversions =
12308 cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions();
12309 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
12311 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
12312 if (isa<UsingShadowDecl>(D))
12313 D = cast<UsingShadowDecl>(D)->getTargetDecl();
12315 // Skip over templated conversion functions; they aren't
12317 if (isa<FunctionTemplateDecl>(D))
12320 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D);
12321 if (!Conv->isExplicit()) {
12322 // Strip the reference type (if any) and then the pointer type (if
12323 // any) to get down to what might be a function type.
12324 QualType ConvType = Conv->getConversionType().getNonReferenceType();
12325 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
12326 ConvType = ConvPtrType->getPointeeType();
12328 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>())
12330 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto,
12331 Object.get(), Args, CandidateSet);
12336 bool HadMultipleCandidates = (CandidateSet.size() > 1);
12338 // Perform overload resolution.
12339 OverloadCandidateSet::iterator Best;
12340 switch (CandidateSet.BestViableFunction(*this, Object.get()->getLocStart(),
12343 // Overload resolution succeeded; we'll build the appropriate call
12347 case OR_No_Viable_Function:
12348 if (CandidateSet.empty())
12349 Diag(Object.get()->getLocStart(), diag::err_ovl_no_oper)
12350 << Object.get()->getType() << /*call*/ 1
12351 << Object.get()->getSourceRange();
12353 Diag(Object.get()->getLocStart(),
12354 diag::err_ovl_no_viable_object_call)
12355 << Object.get()->getType() << Object.get()->getSourceRange();
12356 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
12360 Diag(Object.get()->getLocStart(),
12361 diag::err_ovl_ambiguous_object_call)
12362 << Object.get()->getType() << Object.get()->getSourceRange();
12363 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args);
12367 Diag(Object.get()->getLocStart(),
12368 diag::err_ovl_deleted_object_call)
12369 << Best->Function->isDeleted()
12370 << Object.get()->getType()
12371 << getDeletedOrUnavailableSuffix(Best->Function)
12372 << Object.get()->getSourceRange();
12373 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
12377 if (Best == CandidateSet.end())
12380 UnbridgedCasts.restore();
12382 if (Best->Function == nullptr) {
12383 // Since there is no function declaration, this is one of the
12384 // surrogate candidates. Dig out the conversion function.
12385 CXXConversionDecl *Conv
12386 = cast<CXXConversionDecl>(
12387 Best->Conversions[0].UserDefined.ConversionFunction);
12389 CheckMemberOperatorAccess(LParenLoc, Object.get(), nullptr,
12391 if (DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc))
12392 return ExprError();
12393 assert(Conv == Best->FoundDecl.getDecl() &&
12394 "Found Decl & conversion-to-functionptr should be same, right?!");
12395 // We selected one of the surrogate functions that converts the
12396 // object parameter to a function pointer. Perform the conversion
12397 // on the object argument, then let ActOnCallExpr finish the job.
12399 // Create an implicit member expr to refer to the conversion operator.
12400 // and then call it.
12401 ExprResult Call = BuildCXXMemberCallExpr(Object.get(), Best->FoundDecl,
12402 Conv, HadMultipleCandidates);
12403 if (Call.isInvalid())
12404 return ExprError();
12405 // Record usage of conversion in an implicit cast.
12406 Call = ImplicitCastExpr::Create(Context, Call.get()->getType(),
12407 CK_UserDefinedConversion, Call.get(),
12408 nullptr, VK_RValue);
12410 return ActOnCallExpr(S, Call.get(), LParenLoc, Args, RParenLoc);
12413 CheckMemberOperatorAccess(LParenLoc, Object.get(), nullptr, Best->FoundDecl);
12415 // We found an overloaded operator(). Build a CXXOperatorCallExpr
12416 // that calls this method, using Object for the implicit object
12417 // parameter and passing along the remaining arguments.
12418 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
12420 // An error diagnostic has already been printed when parsing the declaration.
12421 if (Method->isInvalidDecl())
12422 return ExprError();
12424 const FunctionProtoType *Proto =
12425 Method->getType()->getAs<FunctionProtoType>();
12427 unsigned NumParams = Proto->getNumParams();
12429 DeclarationNameInfo OpLocInfo(
12430 Context.DeclarationNames.getCXXOperatorName(OO_Call), LParenLoc);
12431 OpLocInfo.setCXXOperatorNameRange(SourceRange(LParenLoc, RParenLoc));
12432 ExprResult NewFn = CreateFunctionRefExpr(*this, Method, Best->FoundDecl,
12433 HadMultipleCandidates,
12434 OpLocInfo.getLoc(),
12435 OpLocInfo.getInfo());
12436 if (NewFn.isInvalid())
12439 // Build the full argument list for the method call (the implicit object
12440 // parameter is placed at the beginning of the list).
12441 std::unique_ptr<Expr * []> MethodArgs(new Expr *[Args.size() + 1]);
12442 MethodArgs[0] = Object.get();
12443 std::copy(Args.begin(), Args.end(), &MethodArgs[1]);
12445 // Once we've built TheCall, all of the expressions are properly
12447 QualType ResultTy = Method->getReturnType();
12448 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
12449 ResultTy = ResultTy.getNonLValueExprType(Context);
12451 CXXOperatorCallExpr *TheCall = new (Context)
12452 CXXOperatorCallExpr(Context, OO_Call, NewFn.get(),
12453 llvm::makeArrayRef(MethodArgs.get(), Args.size() + 1),
12454 ResultTy, VK, RParenLoc, false);
12455 MethodArgs.reset();
12457 if (CheckCallReturnType(Method->getReturnType(), LParenLoc, TheCall, Method))
12460 // We may have default arguments. If so, we need to allocate more
12461 // slots in the call for them.
12462 if (Args.size() < NumParams)
12463 TheCall->setNumArgs(Context, NumParams + 1);
12465 bool IsError = false;
12467 // Initialize the implicit object parameter.
12468 ExprResult ObjRes =
12469 PerformObjectArgumentInitialization(Object.get(), /*Qualifier=*/nullptr,
12470 Best->FoundDecl, Method);
12471 if (ObjRes.isInvalid())
12475 TheCall->setArg(0, Object.get());
12477 // Check the argument types.
12478 for (unsigned i = 0; i != NumParams; i++) {
12480 if (i < Args.size()) {
12483 // Pass the argument.
12485 ExprResult InputInit
12486 = PerformCopyInitialization(InitializedEntity::InitializeParameter(
12488 Method->getParamDecl(i)),
12489 SourceLocation(), Arg);
12491 IsError |= InputInit.isInvalid();
12492 Arg = InputInit.getAs<Expr>();
12495 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i));
12496 if (DefArg.isInvalid()) {
12501 Arg = DefArg.getAs<Expr>();
12504 TheCall->setArg(i + 1, Arg);
12507 // If this is a variadic call, handle args passed through "...".
12508 if (Proto->isVariadic()) {
12509 // Promote the arguments (C99 6.5.2.2p7).
12510 for (unsigned i = NumParams, e = Args.size(); i < e; i++) {
12511 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod,
12513 IsError |= Arg.isInvalid();
12514 TheCall->setArg(i + 1, Arg.get());
12518 if (IsError) return true;
12520 DiagnoseSentinelCalls(Method, LParenLoc, Args);
12522 if (CheckFunctionCall(Method, TheCall, Proto))
12525 return MaybeBindToTemporary(TheCall);
12528 /// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator->
12529 /// (if one exists), where @c Base is an expression of class type and
12530 /// @c Member is the name of the member we're trying to find.
12532 Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc,
12533 bool *NoArrowOperatorFound) {
12534 assert(Base->getType()->isRecordType() &&
12535 "left-hand side must have class type");
12537 if (checkPlaceholderForOverload(*this, Base))
12538 return ExprError();
12540 SourceLocation Loc = Base->getExprLoc();
12542 // C++ [over.ref]p1:
12544 // [...] An expression x->m is interpreted as (x.operator->())->m
12545 // for a class object x of type T if T::operator->() exists and if
12546 // the operator is selected as the best match function by the
12547 // overload resolution mechanism (13.3).
12548 DeclarationName OpName =
12549 Context.DeclarationNames.getCXXOperatorName(OO_Arrow);
12550 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Operator);
12551 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>();
12553 if (RequireCompleteType(Loc, Base->getType(),
12554 diag::err_typecheck_incomplete_tag, Base))
12555 return ExprError();
12557 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName);
12558 LookupQualifiedName(R, BaseRecord->getDecl());
12559 R.suppressDiagnostics();
12561 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end();
12562 Oper != OperEnd; ++Oper) {
12563 AddMethodCandidate(Oper.getPair(), Base->getType(), Base->Classify(Context),
12564 None, CandidateSet, /*SuppressUserConversions=*/false);
12567 bool HadMultipleCandidates = (CandidateSet.size() > 1);
12569 // Perform overload resolution.
12570 OverloadCandidateSet::iterator Best;
12571 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) {
12573 // Overload resolution succeeded; we'll build the call below.
12576 case OR_No_Viable_Function:
12577 if (CandidateSet.empty()) {
12578 QualType BaseType = Base->getType();
12579 if (NoArrowOperatorFound) {
12580 // Report this specific error to the caller instead of emitting a
12581 // diagnostic, as requested.
12582 *NoArrowOperatorFound = true;
12583 return ExprError();
12585 Diag(OpLoc, diag::err_typecheck_member_reference_arrow)
12586 << BaseType << Base->getSourceRange();
12587 if (BaseType->isRecordType() && !BaseType->isPointerType()) {
12588 Diag(OpLoc, diag::note_typecheck_member_reference_suggestion)
12589 << FixItHint::CreateReplacement(OpLoc, ".");
12592 Diag(OpLoc, diag::err_ovl_no_viable_oper)
12593 << "operator->" << Base->getSourceRange();
12594 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Base);
12595 return ExprError();
12598 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary)
12599 << "->" << Base->getType() << Base->getSourceRange();
12600 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Base);
12601 return ExprError();
12604 Diag(OpLoc, diag::err_ovl_deleted_oper)
12605 << Best->Function->isDeleted()
12607 << getDeletedOrUnavailableSuffix(Best->Function)
12608 << Base->getSourceRange();
12609 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Base);
12610 return ExprError();
12613 CheckMemberOperatorAccess(OpLoc, Base, nullptr, Best->FoundDecl);
12615 // Convert the object parameter.
12616 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
12617 ExprResult BaseResult =
12618 PerformObjectArgumentInitialization(Base, /*Qualifier=*/nullptr,
12619 Best->FoundDecl, Method);
12620 if (BaseResult.isInvalid())
12621 return ExprError();
12622 Base = BaseResult.get();
12624 // Build the operator call.
12625 ExprResult FnExpr = CreateFunctionRefExpr(*this, Method, Best->FoundDecl,
12626 HadMultipleCandidates, OpLoc);
12627 if (FnExpr.isInvalid())
12628 return ExprError();
12630 QualType ResultTy = Method->getReturnType();
12631 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
12632 ResultTy = ResultTy.getNonLValueExprType(Context);
12633 CXXOperatorCallExpr *TheCall =
12634 new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr.get(),
12635 Base, ResultTy, VK, OpLoc, false);
12637 if (CheckCallReturnType(Method->getReturnType(), OpLoc, TheCall, Method))
12638 return ExprError();
12640 return MaybeBindToTemporary(TheCall);
12643 /// BuildLiteralOperatorCall - Build a UserDefinedLiteral by creating a call to
12644 /// a literal operator described by the provided lookup results.
12645 ExprResult Sema::BuildLiteralOperatorCall(LookupResult &R,
12646 DeclarationNameInfo &SuffixInfo,
12647 ArrayRef<Expr*> Args,
12648 SourceLocation LitEndLoc,
12649 TemplateArgumentListInfo *TemplateArgs) {
12650 SourceLocation UDSuffixLoc = SuffixInfo.getCXXLiteralOperatorNameLoc();
12652 OverloadCandidateSet CandidateSet(UDSuffixLoc,
12653 OverloadCandidateSet::CSK_Normal);
12654 AddFunctionCandidates(R.asUnresolvedSet(), Args, CandidateSet, TemplateArgs,
12655 /*SuppressUserConversions=*/true);
12657 bool HadMultipleCandidates = (CandidateSet.size() > 1);
12659 // Perform overload resolution. This will usually be trivial, but might need
12660 // to perform substitutions for a literal operator template.
12661 OverloadCandidateSet::iterator Best;
12662 switch (CandidateSet.BestViableFunction(*this, UDSuffixLoc, Best)) {
12667 case OR_No_Viable_Function:
12668 Diag(UDSuffixLoc, diag::err_ovl_no_viable_function_in_call)
12669 << R.getLookupName();
12670 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args);
12671 return ExprError();
12674 Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName();
12675 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args);
12676 return ExprError();
12679 FunctionDecl *FD = Best->Function;
12680 ExprResult Fn = CreateFunctionRefExpr(*this, FD, Best->FoundDecl,
12681 HadMultipleCandidates,
12682 SuffixInfo.getLoc(),
12683 SuffixInfo.getInfo());
12684 if (Fn.isInvalid())
12687 // Check the argument types. This should almost always be a no-op, except
12688 // that array-to-pointer decay is applied to string literals.
12690 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
12691 ExprResult InputInit = PerformCopyInitialization(
12692 InitializedEntity::InitializeParameter(Context, FD->getParamDecl(ArgIdx)),
12693 SourceLocation(), Args[ArgIdx]);
12694 if (InputInit.isInvalid())
12696 ConvArgs[ArgIdx] = InputInit.get();
12699 QualType ResultTy = FD->getReturnType();
12700 ExprValueKind VK = Expr::getValueKindForType(ResultTy);
12701 ResultTy = ResultTy.getNonLValueExprType(Context);
12703 UserDefinedLiteral *UDL =
12704 new (Context) UserDefinedLiteral(Context, Fn.get(),
12705 llvm::makeArrayRef(ConvArgs, Args.size()),
12706 ResultTy, VK, LitEndLoc, UDSuffixLoc);
12708 if (CheckCallReturnType(FD->getReturnType(), UDSuffixLoc, UDL, FD))
12709 return ExprError();
12711 if (CheckFunctionCall(FD, UDL, nullptr))
12712 return ExprError();
12714 return MaybeBindToTemporary(UDL);
12717 /// Build a call to 'begin' or 'end' for a C++11 for-range statement. If the
12718 /// given LookupResult is non-empty, it is assumed to describe a member which
12719 /// will be invoked. Otherwise, the function will be found via argument
12720 /// dependent lookup.
12721 /// CallExpr is set to a valid expression and FRS_Success returned on success,
12722 /// otherwise CallExpr is set to ExprError() and some non-success value
12724 Sema::ForRangeStatus
12725 Sema::BuildForRangeBeginEndCall(SourceLocation Loc,
12726 SourceLocation RangeLoc,
12727 const DeclarationNameInfo &NameInfo,
12728 LookupResult &MemberLookup,
12729 OverloadCandidateSet *CandidateSet,
12730 Expr *Range, ExprResult *CallExpr) {
12731 Scope *S = nullptr;
12733 CandidateSet->clear();
12734 if (!MemberLookup.empty()) {
12735 ExprResult MemberRef =
12736 BuildMemberReferenceExpr(Range, Range->getType(), Loc,
12737 /*IsPtr=*/false, CXXScopeSpec(),
12738 /*TemplateKWLoc=*/SourceLocation(),
12739 /*FirstQualifierInScope=*/nullptr,
12741 /*TemplateArgs=*/nullptr, S);
12742 if (MemberRef.isInvalid()) {
12743 *CallExpr = ExprError();
12744 return FRS_DiagnosticIssued;
12746 *CallExpr = ActOnCallExpr(S, MemberRef.get(), Loc, None, Loc, nullptr);
12747 if (CallExpr->isInvalid()) {
12748 *CallExpr = ExprError();
12749 return FRS_DiagnosticIssued;
12752 UnresolvedSet<0> FoundNames;
12753 UnresolvedLookupExpr *Fn =
12754 UnresolvedLookupExpr::Create(Context, /*NamingClass=*/nullptr,
12755 NestedNameSpecifierLoc(), NameInfo,
12756 /*NeedsADL=*/true, /*Overloaded=*/false,
12757 FoundNames.begin(), FoundNames.end());
12759 bool CandidateSetError = buildOverloadedCallSet(S, Fn, Fn, Range, Loc,
12760 CandidateSet, CallExpr);
12761 if (CandidateSet->empty() || CandidateSetError) {
12762 *CallExpr = ExprError();
12763 return FRS_NoViableFunction;
12765 OverloadCandidateSet::iterator Best;
12766 OverloadingResult OverloadResult =
12767 CandidateSet->BestViableFunction(*this, Fn->getLocStart(), Best);
12769 if (OverloadResult == OR_No_Viable_Function) {
12770 *CallExpr = ExprError();
12771 return FRS_NoViableFunction;
12773 *CallExpr = FinishOverloadedCallExpr(*this, S, Fn, Fn, Loc, Range,
12774 Loc, nullptr, CandidateSet, &Best,
12776 /*AllowTypoCorrection=*/false);
12777 if (CallExpr->isInvalid() || OverloadResult != OR_Success) {
12778 *CallExpr = ExprError();
12779 return FRS_DiagnosticIssued;
12782 return FRS_Success;
12786 /// FixOverloadedFunctionReference - E is an expression that refers to
12787 /// a C++ overloaded function (possibly with some parentheses and
12788 /// perhaps a '&' around it). We have resolved the overloaded function
12789 /// to the function declaration Fn, so patch up the expression E to
12790 /// refer (possibly indirectly) to Fn. Returns the new expr.
12791 Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found,
12792 FunctionDecl *Fn) {
12793 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
12794 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(),
12796 if (SubExpr == PE->getSubExpr())
12799 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr);
12802 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
12803 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(),
12805 assert(Context.hasSameType(ICE->getSubExpr()->getType(),
12806 SubExpr->getType()) &&
12807 "Implicit cast type cannot be determined from overload");
12808 assert(ICE->path_empty() && "fixing up hierarchy conversion?");
12809 if (SubExpr == ICE->getSubExpr())
12812 return ImplicitCastExpr::Create(Context, ICE->getType(),
12813 ICE->getCastKind(),
12815 ICE->getValueKind());
12818 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) {
12819 assert(UnOp->getOpcode() == UO_AddrOf &&
12820 "Can only take the address of an overloaded function");
12821 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) {
12822 if (Method->isStatic()) {
12823 // Do nothing: static member functions aren't any different
12824 // from non-member functions.
12826 // Fix the subexpression, which really has to be an
12827 // UnresolvedLookupExpr holding an overloaded member function
12829 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(),
12831 if (SubExpr == UnOp->getSubExpr())
12834 assert(isa<DeclRefExpr>(SubExpr)
12835 && "fixed to something other than a decl ref");
12836 assert(cast<DeclRefExpr>(SubExpr)->getQualifier()
12837 && "fixed to a member ref with no nested name qualifier");
12839 // We have taken the address of a pointer to member
12840 // function. Perform the computation here so that we get the
12841 // appropriate pointer to member type.
12843 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext()));
12844 QualType MemPtrType
12845 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr());
12847 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, MemPtrType,
12848 VK_RValue, OK_Ordinary,
12849 UnOp->getOperatorLoc());
12852 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(),
12854 if (SubExpr == UnOp->getSubExpr())
12857 return new (Context) UnaryOperator(SubExpr, UO_AddrOf,
12858 Context.getPointerType(SubExpr->getType()),
12859 VK_RValue, OK_Ordinary,
12860 UnOp->getOperatorLoc());
12863 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) {
12864 // FIXME: avoid copy.
12865 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
12866 if (ULE->hasExplicitTemplateArgs()) {
12867 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer);
12868 TemplateArgs = &TemplateArgsBuffer;
12871 DeclRefExpr *DRE = DeclRefExpr::Create(Context,
12872 ULE->getQualifierLoc(),
12873 ULE->getTemplateKeywordLoc(),
12875 /*enclosing*/ false, // FIXME?
12881 MarkDeclRefReferenced(DRE);
12882 DRE->setHadMultipleCandidates(ULE->getNumDecls() > 1);
12886 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) {
12887 // FIXME: avoid copy.
12888 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = nullptr;
12889 if (MemExpr->hasExplicitTemplateArgs()) {
12890 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer);
12891 TemplateArgs = &TemplateArgsBuffer;
12896 // If we're filling in a static method where we used to have an
12897 // implicit member access, rewrite to a simple decl ref.
12898 if (MemExpr->isImplicitAccess()) {
12899 if (cast<CXXMethodDecl>(Fn)->isStatic()) {
12900 DeclRefExpr *DRE = DeclRefExpr::Create(Context,
12901 MemExpr->getQualifierLoc(),
12902 MemExpr->getTemplateKeywordLoc(),
12904 /*enclosing*/ false,
12905 MemExpr->getMemberLoc(),
12910 MarkDeclRefReferenced(DRE);
12911 DRE->setHadMultipleCandidates(MemExpr->getNumDecls() > 1);
12914 SourceLocation Loc = MemExpr->getMemberLoc();
12915 if (MemExpr->getQualifier())
12916 Loc = MemExpr->getQualifierLoc().getBeginLoc();
12917 CheckCXXThisCapture(Loc);
12918 Base = new (Context) CXXThisExpr(Loc,
12919 MemExpr->getBaseType(),
12920 /*isImplicit=*/true);
12923 Base = MemExpr->getBase();
12925 ExprValueKind valueKind;
12927 if (cast<CXXMethodDecl>(Fn)->isStatic()) {
12928 valueKind = VK_LValue;
12929 type = Fn->getType();
12931 valueKind = VK_RValue;
12932 type = Context.BoundMemberTy;
12935 MemberExpr *ME = MemberExpr::Create(
12936 Context, Base, MemExpr->isArrow(), MemExpr->getOperatorLoc(),
12937 MemExpr->getQualifierLoc(), MemExpr->getTemplateKeywordLoc(), Fn, Found,
12938 MemExpr->getMemberNameInfo(), TemplateArgs, type, valueKind,
12940 ME->setHadMultipleCandidates(true);
12941 MarkMemberReferenced(ME);
12945 llvm_unreachable("Invalid reference to overloaded function");
12948 ExprResult Sema::FixOverloadedFunctionReference(ExprResult E,
12949 DeclAccessPair Found,
12950 FunctionDecl *Fn) {
12951 return FixOverloadedFunctionReference(E.get(), Found, Fn);