//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file provides Sema routines for C++ overloading. // //===----------------------------------------------------------------------===// #include "clang/Sema/SemaInternal.h" #include "clang/Sema/Lookup.h" #include "clang/Sema/Initialization.h" #include "clang/Sema/Template.h" #include "clang/Sema/TemplateDeduction.h" #include "clang/Basic/Diagnostic.h" #include "clang/Lex/Preprocessor.h" #include "clang/AST/ASTContext.h" #include "clang/AST/CXXInheritance.h" #include "clang/AST/DeclObjC.h" #include "clang/AST/Expr.h" #include "clang/AST/ExprCXX.h" #include "clang/AST/ExprObjC.h" #include "clang/AST/TypeOrdering.h" #include "clang/Basic/PartialDiagnostic.h" #include "llvm/ADT/DenseSet.h" #include "llvm/ADT/SmallPtrSet.h" #include "llvm/ADT/STLExtras.h" #include namespace clang { using namespace sema; /// A convenience routine for creating a decayed reference to a /// function. static ExprResult CreateFunctionRefExpr(Sema &S, FunctionDecl *Fn, bool HadMultipleCandidates, SourceLocation Loc = SourceLocation(), const DeclarationNameLoc &LocInfo = DeclarationNameLoc()){ DeclRefExpr *DRE = new (S.Context) DeclRefExpr(Fn, false, Fn->getType(), VK_LValue, Loc, LocInfo); if (HadMultipleCandidates) DRE->setHadMultipleCandidates(true); ExprResult E = S.Owned(DRE); E = S.DefaultFunctionArrayConversion(E.take()); if (E.isInvalid()) return ExprError(); return move(E); } static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, bool InOverloadResolution, StandardConversionSequence &SCS, bool CStyle, bool AllowObjCWritebackConversion); static bool IsTransparentUnionStandardConversion(Sema &S, Expr* From, QualType &ToType, bool InOverloadResolution, StandardConversionSequence &SCS, bool CStyle); static OverloadingResult IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, UserDefinedConversionSequence& User, OverloadCandidateSet& Conversions, bool AllowExplicit); static ImplicitConversionSequence::CompareKind CompareStandardConversionSequences(Sema &S, const StandardConversionSequence& SCS1, const StandardConversionSequence& SCS2); static ImplicitConversionSequence::CompareKind CompareQualificationConversions(Sema &S, const StandardConversionSequence& SCS1, const StandardConversionSequence& SCS2); static ImplicitConversionSequence::CompareKind CompareDerivedToBaseConversions(Sema &S, const StandardConversionSequence& SCS1, const StandardConversionSequence& SCS2); /// GetConversionCategory - Retrieve the implicit conversion /// category corresponding to the given implicit conversion kind. ImplicitConversionCategory GetConversionCategory(ImplicitConversionKind Kind) { static const ImplicitConversionCategory Category[(int)ICK_Num_Conversion_Kinds] = { ICC_Identity, ICC_Lvalue_Transformation, ICC_Lvalue_Transformation, ICC_Lvalue_Transformation, ICC_Identity, ICC_Qualification_Adjustment, ICC_Promotion, ICC_Promotion, ICC_Promotion, ICC_Conversion, ICC_Conversion, ICC_Conversion, ICC_Conversion, ICC_Conversion, ICC_Conversion, ICC_Conversion, ICC_Conversion, ICC_Conversion, ICC_Conversion, ICC_Conversion, ICC_Conversion, ICC_Conversion }; return Category[(int)Kind]; } /// GetConversionRank - Retrieve the implicit conversion rank /// corresponding to the given implicit conversion kind. ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { static const ImplicitConversionRank Rank[(int)ICK_Num_Conversion_Kinds] = { ICR_Exact_Match, ICR_Exact_Match, ICR_Exact_Match, ICR_Exact_Match, ICR_Exact_Match, ICR_Exact_Match, ICR_Promotion, ICR_Promotion, ICR_Promotion, ICR_Conversion, ICR_Conversion, ICR_Conversion, ICR_Conversion, ICR_Conversion, ICR_Conversion, ICR_Conversion, ICR_Conversion, ICR_Conversion, ICR_Conversion, ICR_Conversion, ICR_Complex_Real_Conversion, ICR_Conversion, ICR_Conversion, ICR_Writeback_Conversion }; return Rank[(int)Kind]; } /// GetImplicitConversionName - Return the name of this kind of /// implicit conversion. const char* GetImplicitConversionName(ImplicitConversionKind Kind) { static const char* const Name[(int)ICK_Num_Conversion_Kinds] = { "No conversion", "Lvalue-to-rvalue", "Array-to-pointer", "Function-to-pointer", "Noreturn adjustment", "Qualification", "Integral promotion", "Floating point promotion", "Complex promotion", "Integral conversion", "Floating conversion", "Complex conversion", "Floating-integral conversion", "Pointer conversion", "Pointer-to-member conversion", "Boolean conversion", "Compatible-types conversion", "Derived-to-base conversion", "Vector conversion", "Vector splat", "Complex-real conversion", "Block Pointer conversion", "Transparent Union Conversion" "Writeback conversion" }; return Name[Kind]; } /// StandardConversionSequence - Set the standard conversion /// sequence to the identity conversion. void StandardConversionSequence::setAsIdentityConversion() { First = ICK_Identity; Second = ICK_Identity; Third = ICK_Identity; DeprecatedStringLiteralToCharPtr = false; QualificationIncludesObjCLifetime = false; ReferenceBinding = false; DirectBinding = false; IsLvalueReference = true; BindsToFunctionLvalue = false; BindsToRvalue = false; BindsImplicitObjectArgumentWithoutRefQualifier = false; ObjCLifetimeConversionBinding = false; CopyConstructor = 0; } /// getRank - Retrieve the rank of this standard conversion sequence /// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the /// implicit conversions. ImplicitConversionRank StandardConversionSequence::getRank() const { ImplicitConversionRank Rank = ICR_Exact_Match; if (GetConversionRank(First) > Rank) Rank = GetConversionRank(First); if (GetConversionRank(Second) > Rank) Rank = GetConversionRank(Second); if (GetConversionRank(Third) > Rank) Rank = GetConversionRank(Third); return Rank; } /// isPointerConversionToBool - Determines whether this conversion is /// a conversion of a pointer or pointer-to-member to bool. This is /// used as part of the ranking of standard conversion sequences /// (C++ 13.3.3.2p4). bool StandardConversionSequence::isPointerConversionToBool() const { // Note that FromType has not necessarily been transformed by the // array-to-pointer or function-to-pointer implicit conversions, so // check for their presence as well as checking whether FromType is // a pointer. if (getToType(1)->isBooleanType() && (getFromType()->isPointerType() || getFromType()->isObjCObjectPointerType() || getFromType()->isBlockPointerType() || getFromType()->isNullPtrType() || First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) return true; return false; } /// isPointerConversionToVoidPointer - Determines whether this /// conversion is a conversion of a pointer to a void pointer. This is /// used as part of the ranking of standard conversion sequences (C++ /// 13.3.3.2p4). bool StandardConversionSequence:: isPointerConversionToVoidPointer(ASTContext& Context) const { QualType FromType = getFromType(); QualType ToType = getToType(1); // Note that FromType has not necessarily been transformed by the // array-to-pointer implicit conversion, so check for its presence // and redo the conversion to get a pointer. if (First == ICK_Array_To_Pointer) FromType = Context.getArrayDecayedType(FromType); if (Second == ICK_Pointer_Conversion && FromType->isAnyPointerType()) if (const PointerType* ToPtrType = ToType->getAs()) return ToPtrType->getPointeeType()->isVoidType(); return false; } /// Skip any implicit casts which could be either part of a narrowing conversion /// or after one in an implicit conversion. static const Expr *IgnoreNarrowingConversion(const Expr *Converted) { while (const ImplicitCastExpr *ICE = dyn_cast(Converted)) { switch (ICE->getCastKind()) { case CK_NoOp: case CK_IntegralCast: case CK_IntegralToBoolean: case CK_IntegralToFloating: case CK_FloatingToIntegral: case CK_FloatingToBoolean: case CK_FloatingCast: Converted = ICE->getSubExpr(); continue; default: return Converted; } } return Converted; } /// Check if this standard conversion sequence represents a narrowing /// conversion, according to C++11 [dcl.init.list]p7. /// /// \param Ctx The AST context. /// \param Converted The result of applying this standard conversion sequence. /// \param ConstantValue If this is an NK_Constant_Narrowing conversion, the /// value of the expression prior to the narrowing conversion. /// \param ConstantType If this is an NK_Constant_Narrowing conversion, the /// type of the expression prior to the narrowing conversion. NarrowingKind StandardConversionSequence::getNarrowingKind(ASTContext &Ctx, const Expr *Converted, APValue &ConstantValue, QualType &ConstantType) const { assert(Ctx.getLangOpts().CPlusPlus && "narrowing check outside C++"); // C++11 [dcl.init.list]p7: // A narrowing conversion is an implicit conversion ... QualType FromType = getToType(0); QualType ToType = getToType(1); switch (Second) { // -- from a floating-point type to an integer type, or // // -- from an integer type or unscoped enumeration type to a floating-point // type, except where the source is a constant expression and the actual // value after conversion will fit into the target type and will produce // the original value when converted back to the original type, or case ICK_Floating_Integral: if (FromType->isRealFloatingType() && ToType->isIntegralType(Ctx)) { return NK_Type_Narrowing; } else if (FromType->isIntegralType(Ctx) && ToType->isRealFloatingType()) { llvm::APSInt IntConstantValue; const Expr *Initializer = IgnoreNarrowingConversion(Converted); if (Initializer && Initializer->isIntegerConstantExpr(IntConstantValue, Ctx)) { // Convert the integer to the floating type. llvm::APFloat Result(Ctx.getFloatTypeSemantics(ToType)); Result.convertFromAPInt(IntConstantValue, IntConstantValue.isSigned(), llvm::APFloat::rmNearestTiesToEven); // And back. llvm::APSInt ConvertedValue = IntConstantValue; bool ignored; Result.convertToInteger(ConvertedValue, llvm::APFloat::rmTowardZero, &ignored); // If the resulting value is different, this was a narrowing conversion. if (IntConstantValue != ConvertedValue) { ConstantValue = APValue(IntConstantValue); ConstantType = Initializer->getType(); return NK_Constant_Narrowing; } } else { // Variables are always narrowings. return NK_Variable_Narrowing; } } return NK_Not_Narrowing; // -- from long double to double or float, or from double to float, except // where the source is a constant expression and the actual value after // conversion is within the range of values that can be represented (even // if it cannot be represented exactly), or case ICK_Floating_Conversion: if (FromType->isRealFloatingType() && ToType->isRealFloatingType() && Ctx.getFloatingTypeOrder(FromType, ToType) == 1) { // FromType is larger than ToType. const Expr *Initializer = IgnoreNarrowingConversion(Converted); if (Initializer->isCXX11ConstantExpr(Ctx, &ConstantValue)) { // Constant! assert(ConstantValue.isFloat()); llvm::APFloat FloatVal = ConstantValue.getFloat(); // Convert the source value into the target type. bool ignored; llvm::APFloat::opStatus ConvertStatus = FloatVal.convert( Ctx.getFloatTypeSemantics(ToType), llvm::APFloat::rmNearestTiesToEven, &ignored); // If there was no overflow, the source value is within the range of // values that can be represented. if (ConvertStatus & llvm::APFloat::opOverflow) { ConstantType = Initializer->getType(); return NK_Constant_Narrowing; } } else { return NK_Variable_Narrowing; } } return NK_Not_Narrowing; // -- from an integer type or unscoped enumeration type to an integer type // that cannot represent all the values of the original type, except where // the source is a constant expression and the actual value after // conversion will fit into the target type and will produce the original // value when converted back to the original type. case ICK_Boolean_Conversion: // Bools are integers too. if (!FromType->isIntegralOrUnscopedEnumerationType()) { // Boolean conversions can be from pointers and pointers to members // [conv.bool], and those aren't considered narrowing conversions. return NK_Not_Narrowing; } // Otherwise, fall through to the integral case. case ICK_Integral_Conversion: { assert(FromType->isIntegralOrUnscopedEnumerationType()); assert(ToType->isIntegralOrUnscopedEnumerationType()); const bool FromSigned = FromType->isSignedIntegerOrEnumerationType(); const unsigned FromWidth = Ctx.getIntWidth(FromType); const bool ToSigned = ToType->isSignedIntegerOrEnumerationType(); const unsigned ToWidth = Ctx.getIntWidth(ToType); if (FromWidth > ToWidth || (FromWidth == ToWidth && FromSigned != ToSigned)) { // Not all values of FromType can be represented in ToType. llvm::APSInt InitializerValue; const Expr *Initializer = IgnoreNarrowingConversion(Converted); if (Initializer->isIntegerConstantExpr(InitializerValue, Ctx)) { ConstantValue = APValue(InitializerValue); // Add a bit to the InitializerValue so we don't have to worry about // signed vs. unsigned comparisons. InitializerValue = InitializerValue.extend( InitializerValue.getBitWidth() + 1); // Convert the initializer to and from the target width and signed-ness. llvm::APSInt ConvertedValue = InitializerValue; ConvertedValue = ConvertedValue.trunc(ToWidth); ConvertedValue.setIsSigned(ToSigned); ConvertedValue = ConvertedValue.extend(InitializerValue.getBitWidth()); ConvertedValue.setIsSigned(InitializerValue.isSigned()); // If the result is different, this was a narrowing conversion. if (ConvertedValue != InitializerValue) { ConstantType = Initializer->getType(); return NK_Constant_Narrowing; } } else { // Variables are always narrowings. return NK_Variable_Narrowing; } } return NK_Not_Narrowing; } default: // Other kinds of conversions are not narrowings. return NK_Not_Narrowing; } } /// DebugPrint - Print this standard conversion sequence to standard /// error. Useful for debugging overloading issues. void StandardConversionSequence::DebugPrint() const { raw_ostream &OS = llvm::errs(); bool PrintedSomething = false; if (First != ICK_Identity) { OS << GetImplicitConversionName(First); PrintedSomething = true; } if (Second != ICK_Identity) { if (PrintedSomething) { OS << " -> "; } OS << GetImplicitConversionName(Second); if (CopyConstructor) { OS << " (by copy constructor)"; } else if (DirectBinding) { OS << " (direct reference binding)"; } else if (ReferenceBinding) { OS << " (reference binding)"; } PrintedSomething = true; } if (Third != ICK_Identity) { if (PrintedSomething) { OS << " -> "; } OS << GetImplicitConversionName(Third); PrintedSomething = true; } if (!PrintedSomething) { OS << "No conversions required"; } } /// DebugPrint - Print this user-defined conversion sequence to standard /// error. Useful for debugging overloading issues. void UserDefinedConversionSequence::DebugPrint() const { raw_ostream &OS = llvm::errs(); if (Before.First || Before.Second || Before.Third) { Before.DebugPrint(); OS << " -> "; } if (ConversionFunction) OS << '\'' << *ConversionFunction << '\''; else OS << "aggregate initialization"; if (After.First || After.Second || After.Third) { OS << " -> "; After.DebugPrint(); } } /// DebugPrint - Print this implicit conversion sequence to standard /// error. Useful for debugging overloading issues. void ImplicitConversionSequence::DebugPrint() const { raw_ostream &OS = llvm::errs(); switch (ConversionKind) { case StandardConversion: OS << "Standard conversion: "; Standard.DebugPrint(); break; case UserDefinedConversion: OS << "User-defined conversion: "; UserDefined.DebugPrint(); break; case EllipsisConversion: OS << "Ellipsis conversion"; break; case AmbiguousConversion: OS << "Ambiguous conversion"; break; case BadConversion: OS << "Bad conversion"; break; } OS << "\n"; } void AmbiguousConversionSequence::construct() { new (&conversions()) ConversionSet(); } void AmbiguousConversionSequence::destruct() { conversions().~ConversionSet(); } void AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { FromTypePtr = O.FromTypePtr; ToTypePtr = O.ToTypePtr; new (&conversions()) ConversionSet(O.conversions()); } namespace { // Structure used by OverloadCandidate::DeductionFailureInfo to store // template parameter and template argument information. struct DFIParamWithArguments { TemplateParameter Param; TemplateArgument FirstArg; TemplateArgument SecondArg; }; } /// \brief Convert from Sema's representation of template deduction information /// to the form used in overload-candidate information. OverloadCandidate::DeductionFailureInfo static MakeDeductionFailureInfo(ASTContext &Context, Sema::TemplateDeductionResult TDK, TemplateDeductionInfo &Info) { OverloadCandidate::DeductionFailureInfo Result; Result.Result = static_cast(TDK); Result.Data = 0; switch (TDK) { case Sema::TDK_Success: case Sema::TDK_InstantiationDepth: case Sema::TDK_TooManyArguments: case Sema::TDK_TooFewArguments: break; case Sema::TDK_Incomplete: case Sema::TDK_InvalidExplicitArguments: Result.Data = Info.Param.getOpaqueValue(); break; case Sema::TDK_Inconsistent: case Sema::TDK_Underqualified: { // FIXME: Should allocate from normal heap so that we can free this later. DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments; Saved->Param = Info.Param; Saved->FirstArg = Info.FirstArg; Saved->SecondArg = Info.SecondArg; Result.Data = Saved; break; } case Sema::TDK_SubstitutionFailure: Result.Data = Info.take(); break; case Sema::TDK_NonDeducedMismatch: case Sema::TDK_FailedOverloadResolution: break; } return Result; } void OverloadCandidate::DeductionFailureInfo::Destroy() { switch (static_cast(Result)) { case Sema::TDK_Success: case Sema::TDK_InstantiationDepth: case Sema::TDK_Incomplete: case Sema::TDK_TooManyArguments: case Sema::TDK_TooFewArguments: case Sema::TDK_InvalidExplicitArguments: break; case Sema::TDK_Inconsistent: case Sema::TDK_Underqualified: // FIXME: Destroy the data? Data = 0; break; case Sema::TDK_SubstitutionFailure: // FIXME: Destroy the template arugment list? Data = 0; break; // Unhandled case Sema::TDK_NonDeducedMismatch: case Sema::TDK_FailedOverloadResolution: break; } } TemplateParameter OverloadCandidate::DeductionFailureInfo::getTemplateParameter() { switch (static_cast(Result)) { case Sema::TDK_Success: case Sema::TDK_InstantiationDepth: case Sema::TDK_TooManyArguments: case Sema::TDK_TooFewArguments: case Sema::TDK_SubstitutionFailure: return TemplateParameter(); case Sema::TDK_Incomplete: case Sema::TDK_InvalidExplicitArguments: return TemplateParameter::getFromOpaqueValue(Data); case Sema::TDK_Inconsistent: case Sema::TDK_Underqualified: return static_cast(Data)->Param; // Unhandled case Sema::TDK_NonDeducedMismatch: case Sema::TDK_FailedOverloadResolution: break; } return TemplateParameter(); } TemplateArgumentList * OverloadCandidate::DeductionFailureInfo::getTemplateArgumentList() { switch (static_cast(Result)) { case Sema::TDK_Success: case Sema::TDK_InstantiationDepth: case Sema::TDK_TooManyArguments: case Sema::TDK_TooFewArguments: case Sema::TDK_Incomplete: case Sema::TDK_InvalidExplicitArguments: case Sema::TDK_Inconsistent: case Sema::TDK_Underqualified: return 0; case Sema::TDK_SubstitutionFailure: return static_cast(Data); // Unhandled case Sema::TDK_NonDeducedMismatch: case Sema::TDK_FailedOverloadResolution: break; } return 0; } const TemplateArgument *OverloadCandidate::DeductionFailureInfo::getFirstArg() { switch (static_cast(Result)) { case Sema::TDK_Success: case Sema::TDK_InstantiationDepth: case Sema::TDK_Incomplete: case Sema::TDK_TooManyArguments: case Sema::TDK_TooFewArguments: case Sema::TDK_InvalidExplicitArguments: case Sema::TDK_SubstitutionFailure: return 0; case Sema::TDK_Inconsistent: case Sema::TDK_Underqualified: return &static_cast(Data)->FirstArg; // Unhandled case Sema::TDK_NonDeducedMismatch: case Sema::TDK_FailedOverloadResolution: break; } return 0; } const TemplateArgument * OverloadCandidate::DeductionFailureInfo::getSecondArg() { switch (static_cast(Result)) { case Sema::TDK_Success: case Sema::TDK_InstantiationDepth: case Sema::TDK_Incomplete: case Sema::TDK_TooManyArguments: case Sema::TDK_TooFewArguments: case Sema::TDK_InvalidExplicitArguments: case Sema::TDK_SubstitutionFailure: return 0; case Sema::TDK_Inconsistent: case Sema::TDK_Underqualified: return &static_cast(Data)->SecondArg; // Unhandled case Sema::TDK_NonDeducedMismatch: case Sema::TDK_FailedOverloadResolution: break; } return 0; } void OverloadCandidateSet::clear() { for (iterator i = begin(), e = end(); i != e; ++i) for (unsigned ii = 0, ie = i->NumConversions; ii != ie; ++ii) i->Conversions[ii].~ImplicitConversionSequence(); NumInlineSequences = 0; Candidates.clear(); Functions.clear(); } namespace { class UnbridgedCastsSet { struct Entry { Expr **Addr; Expr *Saved; }; SmallVector Entries; public: void save(Sema &S, Expr *&E) { assert(E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast)); Entry entry = { &E, E }; Entries.push_back(entry); E = S.stripARCUnbridgedCast(E); } void restore() { for (SmallVectorImpl::iterator i = Entries.begin(), e = Entries.end(); i != e; ++i) *i->Addr = i->Saved; } }; } /// checkPlaceholderForOverload - Do any interesting placeholder-like /// preprocessing on the given expression. /// /// \param unbridgedCasts a collection to which to add unbridged casts; /// without this, they will be immediately diagnosed as errors /// /// Return true on unrecoverable error. static bool checkPlaceholderForOverload(Sema &S, Expr *&E, UnbridgedCastsSet *unbridgedCasts = 0) { if (const BuiltinType *placeholder = E->getType()->getAsPlaceholderType()) { // We can't handle overloaded expressions here because overload // resolution might reasonably tweak them. if (placeholder->getKind() == BuiltinType::Overload) return false; // If the context potentially accepts unbridged ARC casts, strip // the unbridged cast and add it to the collection for later restoration. if (placeholder->getKind() == BuiltinType::ARCUnbridgedCast && unbridgedCasts) { unbridgedCasts->save(S, E); return false; } // Go ahead and check everything else. ExprResult result = S.CheckPlaceholderExpr(E); if (result.isInvalid()) return true; E = result.take(); return false; } // Nothing to do. return false; } /// checkArgPlaceholdersForOverload - Check a set of call operands for /// placeholders. static bool checkArgPlaceholdersForOverload(Sema &S, Expr **args, unsigned numArgs, UnbridgedCastsSet &unbridged) { for (unsigned i = 0; i != numArgs; ++i) if (checkPlaceholderForOverload(S, args[i], &unbridged)) return true; return false; } // IsOverload - Determine whether the given New declaration is an // overload of the declarations in Old. This routine returns false if // New and Old cannot be overloaded, e.g., if New has the same // signature as some function in Old (C++ 1.3.10) or if the Old // declarations aren't functions (or function templates) at all. When // it does return false, MatchedDecl will point to the decl that New // cannot be overloaded with. This decl may be a UsingShadowDecl on // top of the underlying declaration. // // Example: Given the following input: // // void f(int, float); // #1 // void f(int, int); // #2 // int f(int, int); // #3 // // When we process #1, there is no previous declaration of "f", // so IsOverload will not be used. // // When we process #2, Old contains only the FunctionDecl for #1. By // comparing the parameter types, we see that #1 and #2 are overloaded // (since they have different signatures), so this routine returns // false; MatchedDecl is unchanged. // // When we process #3, Old is an overload set containing #1 and #2. We // compare the signatures of #3 to #1 (they're overloaded, so we do // nothing) and then #3 to #2. Since the signatures of #3 and #2 are // identical (return types of functions are not part of the // signature), IsOverload returns false and MatchedDecl will be set to // point to the FunctionDecl for #2. // // 'NewIsUsingShadowDecl' indicates that 'New' is being introduced // into a class by a using declaration. The rules for whether to hide // shadow declarations ignore some properties which otherwise figure // into a function template's signature. Sema::OverloadKind Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old, NamedDecl *&Match, bool NewIsUsingDecl) { for (LookupResult::iterator I = Old.begin(), E = Old.end(); I != E; ++I) { NamedDecl *OldD = *I; bool OldIsUsingDecl = false; if (isa(OldD)) { OldIsUsingDecl = true; // We can always introduce two using declarations into the same // context, even if they have identical signatures. if (NewIsUsingDecl) continue; OldD = cast(OldD)->getTargetDecl(); } // If either declaration was introduced by a using declaration, // we'll need to use slightly different rules for matching. // Essentially, these rules are the normal rules, except that // function templates hide function templates with different // return types or template parameter lists. bool UseMemberUsingDeclRules = (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord(); if (FunctionTemplateDecl *OldT = dyn_cast(OldD)) { if (!IsOverload(New, OldT->getTemplatedDecl(), UseMemberUsingDeclRules)) { if (UseMemberUsingDeclRules && OldIsUsingDecl) { HideUsingShadowDecl(S, cast(*I)); continue; } Match = *I; return Ovl_Match; } } else if (FunctionDecl *OldF = dyn_cast(OldD)) { if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) { if (UseMemberUsingDeclRules && OldIsUsingDecl) { HideUsingShadowDecl(S, cast(*I)); continue; } Match = *I; return Ovl_Match; } } else if (isa(OldD)) { // We can overload with these, which can show up when doing // redeclaration checks for UsingDecls. assert(Old.getLookupKind() == LookupUsingDeclName); } else if (isa(OldD)) { // We can always overload with tags by hiding them. } else if (isa(OldD)) { // Optimistically assume that an unresolved using decl will // overload; if it doesn't, we'll have to diagnose during // template instantiation. } else { // (C++ 13p1): // Only function declarations can be overloaded; object and type // declarations cannot be overloaded. Match = *I; return Ovl_NonFunction; } } return Ovl_Overload; } bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old, bool UseUsingDeclRules) { // If both of the functions are extern "C", then they are not // overloads. if (Old->isExternC() && New->isExternC()) return false; FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); // C++ [temp.fct]p2: // A function template can be overloaded with other function templates // and with normal (non-template) functions. if ((OldTemplate == 0) != (NewTemplate == 0)) return true; // Is the function New an overload of the function Old? QualType OldQType = Context.getCanonicalType(Old->getType()); QualType NewQType = Context.getCanonicalType(New->getType()); // Compare the signatures (C++ 1.3.10) of the two functions to // determine whether they are overloads. If we find any mismatch // in the signature, they are overloads. // If either of these functions is a K&R-style function (no // prototype), then we consider them to have matching signatures. if (isa(OldQType.getTypePtr()) || isa(NewQType.getTypePtr())) return false; const FunctionProtoType* OldType = cast(OldQType); const FunctionProtoType* NewType = cast(NewQType); // The signature of a function includes the types of its // parameters (C++ 1.3.10), which includes the presence or absence // of the ellipsis; see C++ DR 357). if (OldQType != NewQType && (OldType->getNumArgs() != NewType->getNumArgs() || OldType->isVariadic() != NewType->isVariadic() || !FunctionArgTypesAreEqual(OldType, NewType))) return true; // C++ [temp.over.link]p4: // The signature of a function template consists of its function // signature, its return type and its template parameter list. The names // of the template parameters are significant only for establishing the // relationship between the template parameters and the rest of the // signature. // // We check the return type and template parameter lists for function // templates first; the remaining checks follow. // // However, we don't consider either of these when deciding whether // a member introduced by a shadow declaration is hidden. if (!UseUsingDeclRules && NewTemplate && (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), OldTemplate->getTemplateParameters(), false, TPL_TemplateMatch) || OldType->getResultType() != NewType->getResultType())) return true; // If the function is a class member, its signature includes the // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself. // // As part of this, also check whether one of the member functions // is static, in which case they are not overloads (C++ // 13.1p2). While not part of the definition of the signature, // this check is important to determine whether these functions // can be overloaded. CXXMethodDecl* OldMethod = dyn_cast(Old); CXXMethodDecl* NewMethod = dyn_cast(New); if (OldMethod && NewMethod && !OldMethod->isStatic() && !NewMethod->isStatic() && (OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers() || OldMethod->getRefQualifier() != NewMethod->getRefQualifier())) { if (!UseUsingDeclRules && OldMethod->getRefQualifier() != NewMethod->getRefQualifier() && (OldMethod->getRefQualifier() == RQ_None || NewMethod->getRefQualifier() == RQ_None)) { // C++0x [over.load]p2: // - Member function declarations with the same name and the same // parameter-type-list as well as member function template // declarations with the same name, the same parameter-type-list, and // the same template parameter lists cannot be overloaded if any of // them, but not all, have a ref-qualifier (8.3.5). Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload) << NewMethod->getRefQualifier() << OldMethod->getRefQualifier(); Diag(OldMethod->getLocation(), diag::note_previous_declaration); } return true; } // The signatures match; this is not an overload. return false; } /// \brief Checks availability of the function depending on the current /// function context. Inside an unavailable function, unavailability is ignored. /// /// \returns true if \arg FD is unavailable and current context is inside /// an available function, false otherwise. bool Sema::isFunctionConsideredUnavailable(FunctionDecl *FD) { return FD->isUnavailable() && !cast(CurContext)->isUnavailable(); } /// \brief Tries a user-defined conversion from From to ToType. /// /// Produces an implicit conversion sequence for when a standard conversion /// is not an option. See TryImplicitConversion for more information. static ImplicitConversionSequence TryUserDefinedConversion(Sema &S, Expr *From, QualType ToType, bool SuppressUserConversions, bool AllowExplicit, bool InOverloadResolution, bool CStyle, bool AllowObjCWritebackConversion) { ImplicitConversionSequence ICS; if (SuppressUserConversions) { // We're not in the case above, so there is no conversion that // we can perform. ICS.setBad(BadConversionSequence::no_conversion, From, ToType); return ICS; } // Attempt user-defined conversion. OverloadCandidateSet Conversions(From->getExprLoc()); OverloadingResult UserDefResult = IsUserDefinedConversion(S, From, ToType, ICS.UserDefined, Conversions, AllowExplicit); if (UserDefResult == OR_Success) { ICS.setUserDefined(); // C++ [over.ics.user]p4: // A conversion of an expression of class type to the same class // type is given Exact Match rank, and a conversion of an // expression of class type to a base class of that type is // given Conversion rank, in spite of the fact that a copy // constructor (i.e., a user-defined conversion function) is // called for those cases. if (CXXConstructorDecl *Constructor = dyn_cast(ICS.UserDefined.ConversionFunction)) { QualType FromCanon = S.Context.getCanonicalType(From->getType().getUnqualifiedType()); QualType ToCanon = S.Context.getCanonicalType(ToType).getUnqualifiedType(); if (Constructor->isCopyConstructor() && (FromCanon == ToCanon || S.IsDerivedFrom(FromCanon, ToCanon))) { // Turn this into a "standard" conversion sequence, so that it // gets ranked with standard conversion sequences. ICS.setStandard(); ICS.Standard.setAsIdentityConversion(); ICS.Standard.setFromType(From->getType()); ICS.Standard.setAllToTypes(ToType); ICS.Standard.CopyConstructor = Constructor; if (ToCanon != FromCanon) ICS.Standard.Second = ICK_Derived_To_Base; } } // C++ [over.best.ics]p4: // However, when considering the argument of a user-defined // conversion function that is a candidate by 13.3.1.3 when // invoked for the copying of the temporary in the second step // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or // 13.3.1.6 in all cases, only standard conversion sequences and // ellipsis conversion sequences are allowed. if (SuppressUserConversions && ICS.isUserDefined()) { ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); } } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { ICS.setAmbiguous(); ICS.Ambiguous.setFromType(From->getType()); ICS.Ambiguous.setToType(ToType); for (OverloadCandidateSet::iterator Cand = Conversions.begin(); Cand != Conversions.end(); ++Cand) if (Cand->Viable) ICS.Ambiguous.addConversion(Cand->Function); } else { ICS.setBad(BadConversionSequence::no_conversion, From, ToType); } return ICS; } /// TryImplicitConversion - Attempt to perform an implicit conversion /// from the given expression (Expr) to the given type (ToType). This /// function returns an implicit conversion sequence that can be used /// to perform the initialization. Given /// /// void f(float f); /// void g(int i) { f(i); } /// /// this routine would produce an implicit conversion sequence to /// describe the initialization of f from i, which will be a standard /// conversion sequence containing an lvalue-to-rvalue conversion (C++ /// 4.1) followed by a floating-integral conversion (C++ 4.9). // /// Note that this routine only determines how the conversion can be /// performed; it does not actually perform the conversion. As such, /// it will not produce any diagnostics if no conversion is available, /// but will instead return an implicit conversion sequence of kind /// "BadConversion". /// /// If @p SuppressUserConversions, then user-defined conversions are /// not permitted. /// If @p AllowExplicit, then explicit user-defined conversions are /// permitted. /// /// \param AllowObjCWritebackConversion Whether we allow the Objective-C /// writeback conversion, which allows __autoreleasing id* parameters to /// be initialized with __strong id* or __weak id* arguments. static ImplicitConversionSequence TryImplicitConversion(Sema &S, Expr *From, QualType ToType, bool SuppressUserConversions, bool AllowExplicit, bool InOverloadResolution, bool CStyle, bool AllowObjCWritebackConversion) { ImplicitConversionSequence ICS; if (IsStandardConversion(S, From, ToType, InOverloadResolution, ICS.Standard, CStyle, AllowObjCWritebackConversion)){ ICS.setStandard(); return ICS; } if (!S.getLangOpts().CPlusPlus) { ICS.setBad(BadConversionSequence::no_conversion, From, ToType); return ICS; } // C++ [over.ics.user]p4: // A conversion of an expression of class type to the same class // type is given Exact Match rank, and a conversion of an // expression of class type to a base class of that type is // given Conversion rank, in spite of the fact that a copy/move // constructor (i.e., a user-defined conversion function) is // called for those cases. QualType FromType = From->getType(); if (ToType->getAs() && FromType->getAs() && (S.Context.hasSameUnqualifiedType(FromType, ToType) || S.IsDerivedFrom(FromType, ToType))) { ICS.setStandard(); ICS.Standard.setAsIdentityConversion(); ICS.Standard.setFromType(FromType); ICS.Standard.setAllToTypes(ToType); // We don't actually check at this point whether there is a valid // copy/move constructor, since overloading just assumes that it // exists. When we actually perform initialization, we'll find the // appropriate constructor to copy the returned object, if needed. ICS.Standard.CopyConstructor = 0; // Determine whether this is considered a derived-to-base conversion. if (!S.Context.hasSameUnqualifiedType(FromType, ToType)) ICS.Standard.Second = ICK_Derived_To_Base; return ICS; } return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions, AllowExplicit, InOverloadResolution, CStyle, AllowObjCWritebackConversion); } ImplicitConversionSequence Sema::TryImplicitConversion(Expr *From, QualType ToType, bool SuppressUserConversions, bool AllowExplicit, bool InOverloadResolution, bool CStyle, bool AllowObjCWritebackConversion) { return clang::TryImplicitConversion(*this, From, ToType, SuppressUserConversions, AllowExplicit, InOverloadResolution, CStyle, AllowObjCWritebackConversion); } /// PerformImplicitConversion - Perform an implicit conversion of the /// expression From to the type ToType. Returns the /// converted expression. Flavor is the kind of conversion we're /// performing, used in the error message. If @p AllowExplicit, /// explicit user-defined conversions are permitted. ExprResult Sema::PerformImplicitConversion(Expr *From, QualType ToType, AssignmentAction Action, bool AllowExplicit) { ImplicitConversionSequence ICS; return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS); } ExprResult Sema::PerformImplicitConversion(Expr *From, QualType ToType, AssignmentAction Action, bool AllowExplicit, ImplicitConversionSequence& ICS) { if (checkPlaceholderForOverload(*this, From)) return ExprError(); // Objective-C ARC: Determine whether we will allow the writeback conversion. bool AllowObjCWritebackConversion = getLangOpts().ObjCAutoRefCount && (Action == AA_Passing || Action == AA_Sending); ICS = clang::TryImplicitConversion(*this, From, ToType, /*SuppressUserConversions=*/false, AllowExplicit, /*InOverloadResolution=*/false, /*CStyle=*/false, AllowObjCWritebackConversion); return PerformImplicitConversion(From, ToType, ICS, Action); } /// \brief Determine whether the conversion from FromType to ToType is a valid /// conversion that strips "noreturn" off the nested function type. bool Sema::IsNoReturnConversion(QualType FromType, QualType ToType, QualType &ResultTy) { if (Context.hasSameUnqualifiedType(FromType, ToType)) return false; // Permit the conversion F(t __attribute__((noreturn))) -> F(t) // where F adds one of the following at most once: // - a pointer // - a member pointer // - a block pointer CanQualType CanTo = Context.getCanonicalType(ToType); CanQualType CanFrom = Context.getCanonicalType(FromType); Type::TypeClass TyClass = CanTo->getTypeClass(); if (TyClass != CanFrom->getTypeClass()) return false; if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) { if (TyClass == Type::Pointer) { CanTo = CanTo.getAs()->getPointeeType(); CanFrom = CanFrom.getAs()->getPointeeType(); } else if (TyClass == Type::BlockPointer) { CanTo = CanTo.getAs()->getPointeeType(); CanFrom = CanFrom.getAs()->getPointeeType(); } else if (TyClass == Type::MemberPointer) { CanTo = CanTo.getAs()->getPointeeType(); CanFrom = CanFrom.getAs()->getPointeeType(); } else { return false; } TyClass = CanTo->getTypeClass(); if (TyClass != CanFrom->getTypeClass()) return false; if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) return false; } const FunctionType *FromFn = cast(CanFrom); FunctionType::ExtInfo EInfo = FromFn->getExtInfo(); if (!EInfo.getNoReturn()) return false; FromFn = Context.adjustFunctionType(FromFn, EInfo.withNoReturn(false)); assert(QualType(FromFn, 0).isCanonical()); if (QualType(FromFn, 0) != CanTo) return false; ResultTy = ToType; return true; } /// \brief Determine whether the conversion from FromType to ToType is a valid /// vector conversion. /// /// \param ICK Will be set to the vector conversion kind, if this is a vector /// conversion. static bool IsVectorConversion(ASTContext &Context, QualType FromType, QualType ToType, ImplicitConversionKind &ICK) { // We need at least one of these types to be a vector type to have a vector // conversion. if (!ToType->isVectorType() && !FromType->isVectorType()) return false; // Identical types require no conversions. if (Context.hasSameUnqualifiedType(FromType, ToType)) return false; // There are no conversions between extended vector types, only identity. if (ToType->isExtVectorType()) { // There are no conversions between extended vector types other than the // identity conversion. if (FromType->isExtVectorType()) return false; // Vector splat from any arithmetic type to a vector. if (FromType->isArithmeticType()) { ICK = ICK_Vector_Splat; return true; } } // We can perform the conversion between vector types in the following cases: // 1)vector types are equivalent AltiVec and GCC vector types // 2)lax vector conversions are permitted and the vector types are of the // same size if (ToType->isVectorType() && FromType->isVectorType()) { if (Context.areCompatibleVectorTypes(FromType, ToType) || (Context.getLangOpts().LaxVectorConversions && (Context.getTypeSize(FromType) == Context.getTypeSize(ToType)))) { ICK = ICK_Vector_Conversion; return true; } } return false; } static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType, bool InOverloadResolution, StandardConversionSequence &SCS, bool CStyle); /// IsStandardConversion - Determines whether there is a standard /// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the /// expression From to the type ToType. Standard conversion sequences /// only consider non-class types; for conversions that involve class /// types, use TryImplicitConversion. If a conversion exists, SCS will /// contain the standard conversion sequence required to perform this /// conversion and this routine will return true. Otherwise, this /// routine will return false and the value of SCS is unspecified. static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, bool InOverloadResolution, StandardConversionSequence &SCS, bool CStyle, bool AllowObjCWritebackConversion) { QualType FromType = From->getType(); // Standard conversions (C++ [conv]) SCS.setAsIdentityConversion(); SCS.DeprecatedStringLiteralToCharPtr = false; SCS.IncompatibleObjC = false; SCS.setFromType(FromType); SCS.CopyConstructor = 0; // There are no standard conversions for class types in C++, so // abort early. When overloading in C, however, we do permit if (FromType->isRecordType() || ToType->isRecordType()) { if (S.getLangOpts().CPlusPlus) return false; // When we're overloading in C, we allow, as standard conversions, } // The first conversion can be an lvalue-to-rvalue conversion, // array-to-pointer conversion, or function-to-pointer conversion // (C++ 4p1). if (FromType == S.Context.OverloadTy) { DeclAccessPair AccessPair; if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(From, ToType, false, AccessPair)) { // We were able to resolve the address of the overloaded function, // so we can convert to the type of that function. FromType = Fn->getType(); // we can sometimes resolve &foo regardless of ToType, so check // if the type matches (identity) or we are converting to bool if (!S.Context.hasSameUnqualifiedType( S.ExtractUnqualifiedFunctionType(ToType), FromType)) { QualType resultTy; // if the function type matches except for [[noreturn]], it's ok if (!S.IsNoReturnConversion(FromType, S.ExtractUnqualifiedFunctionType(ToType), resultTy)) // otherwise, only a boolean conversion is standard if (!ToType->isBooleanType()) return false; } // Check if the "from" expression is taking the address of an overloaded // function and recompute the FromType accordingly. Take advantage of the // fact that non-static member functions *must* have such an address-of // expression. CXXMethodDecl *Method = dyn_cast(Fn); if (Method && !Method->isStatic()) { assert(isa(From->IgnoreParens()) && "Non-unary operator on non-static member address"); assert(cast(From->IgnoreParens())->getOpcode() == UO_AddrOf && "Non-address-of operator on non-static member address"); const Type *ClassType = S.Context.getTypeDeclType(Method->getParent()).getTypePtr(); FromType = S.Context.getMemberPointerType(FromType, ClassType); } else if (isa(From->IgnoreParens())) { assert(cast(From->IgnoreParens())->getOpcode() == UO_AddrOf && "Non-address-of operator for overloaded function expression"); FromType = S.Context.getPointerType(FromType); } // Check that we've computed the proper type after overload resolution. assert(S.Context.hasSameType( FromType, S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())); } else { return false; } } // Lvalue-to-rvalue conversion (C++11 4.1): // A glvalue (3.10) of a non-function, non-array type T can // be converted to a prvalue. bool argIsLValue = From->isGLValue(); if (argIsLValue && !FromType->isFunctionType() && !FromType->isArrayType() && S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) { SCS.First = ICK_Lvalue_To_Rvalue; // C11 6.3.2.1p2: // ... if the lvalue has atomic type, the value has the non-atomic version // of the type of the lvalue ... if (const AtomicType *Atomic = FromType->getAs()) FromType = Atomic->getValueType(); // If T is a non-class type, the type of the rvalue is the // cv-unqualified version of T. Otherwise, the type of the rvalue // is T (C++ 4.1p1). C++ can't get here with class types; in C, we // just strip the qualifiers because they don't matter. FromType = FromType.getUnqualifiedType(); } else if (FromType->isArrayType()) { // Array-to-pointer conversion (C++ 4.2) SCS.First = ICK_Array_To_Pointer; // An lvalue or rvalue of type "array of N T" or "array of unknown // bound of T" can be converted to an rvalue of type "pointer to // T" (C++ 4.2p1). FromType = S.Context.getArrayDecayedType(FromType); if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) { // This conversion is deprecated. (C++ D.4). SCS.DeprecatedStringLiteralToCharPtr = true; // For the purpose of ranking in overload resolution // (13.3.3.1.1), this conversion is considered an // array-to-pointer conversion followed by a qualification // conversion (4.4). (C++ 4.2p2) SCS.Second = ICK_Identity; SCS.Third = ICK_Qualification; SCS.QualificationIncludesObjCLifetime = false; SCS.setAllToTypes(FromType); return true; } } else if (FromType->isFunctionType() && argIsLValue) { // Function-to-pointer conversion (C++ 4.3). SCS.First = ICK_Function_To_Pointer; // An lvalue of function type T can be converted to an rvalue of // type "pointer to T." The result is a pointer to the // function. (C++ 4.3p1). FromType = S.Context.getPointerType(FromType); } else { // We don't require any conversions for the first step. SCS.First = ICK_Identity; } SCS.setToType(0, FromType); // The second conversion can be an integral promotion, floating // point promotion, integral conversion, floating point conversion, // floating-integral conversion, pointer conversion, // pointer-to-member conversion, or boolean conversion (C++ 4p1). // For overloading in C, this can also be a "compatible-type" // conversion. bool IncompatibleObjC = false; ImplicitConversionKind SecondICK = ICK_Identity; if (S.Context.hasSameUnqualifiedType(FromType, ToType)) { // The unqualified versions of the types are the same: there's no // conversion to do. SCS.Second = ICK_Identity; } else if (S.IsIntegralPromotion(From, FromType, ToType)) { // Integral promotion (C++ 4.5). SCS.Second = ICK_Integral_Promotion; FromType = ToType.getUnqualifiedType(); } else if (S.IsFloatingPointPromotion(FromType, ToType)) { // Floating point promotion (C++ 4.6). SCS.Second = ICK_Floating_Promotion; FromType = ToType.getUnqualifiedType(); } else if (S.IsComplexPromotion(FromType, ToType)) { // Complex promotion (Clang extension) SCS.Second = ICK_Complex_Promotion; FromType = ToType.getUnqualifiedType(); } else if (ToType->isBooleanType() && (FromType->isArithmeticType() || FromType->isAnyPointerType() || FromType->isBlockPointerType() || FromType->isMemberPointerType() || FromType->isNullPtrType())) { // Boolean conversions (C++ 4.12). SCS.Second = ICK_Boolean_Conversion; FromType = S.Context.BoolTy; } else if (FromType->isIntegralOrUnscopedEnumerationType() && ToType->isIntegralType(S.Context)) { // Integral conversions (C++ 4.7). SCS.Second = ICK_Integral_Conversion; FromType = ToType.getUnqualifiedType(); } else if (FromType->isAnyComplexType() && ToType->isComplexType()) { // Complex conversions (C99 6.3.1.6) SCS.Second = ICK_Complex_Conversion; FromType = ToType.getUnqualifiedType(); } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) || (ToType->isAnyComplexType() && FromType->isArithmeticType())) { // Complex-real conversions (C99 6.3.1.7) SCS.Second = ICK_Complex_Real; FromType = ToType.getUnqualifiedType(); } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) { // Floating point conversions (C++ 4.8). SCS.Second = ICK_Floating_Conversion; FromType = ToType.getUnqualifiedType(); } else if ((FromType->isRealFloatingType() && ToType->isIntegralType(S.Context)) || (FromType->isIntegralOrUnscopedEnumerationType() && ToType->isRealFloatingType())) { // Floating-integral conversions (C++ 4.9). SCS.Second = ICK_Floating_Integral; FromType = ToType.getUnqualifiedType(); } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) { SCS.Second = ICK_Block_Pointer_Conversion; } else if (AllowObjCWritebackConversion && S.isObjCWritebackConversion(FromType, ToType, FromType)) { SCS.Second = ICK_Writeback_Conversion; } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution, FromType, IncompatibleObjC)) { // Pointer conversions (C++ 4.10). SCS.Second = ICK_Pointer_Conversion; SCS.IncompatibleObjC = IncompatibleObjC; FromType = FromType.getUnqualifiedType(); } else if (S.IsMemberPointerConversion(From, FromType, ToType, InOverloadResolution, FromType)) { // Pointer to member conversions (4.11). SCS.Second = ICK_Pointer_Member; } else if (IsVectorConversion(S.Context, FromType, ToType, SecondICK)) { SCS.Second = SecondICK; FromType = ToType.getUnqualifiedType(); } else if (!S.getLangOpts().CPlusPlus && S.Context.typesAreCompatible(ToType, FromType)) { // Compatible conversions (Clang extension for C function overloading) SCS.Second = ICK_Compatible_Conversion; FromType = ToType.getUnqualifiedType(); } else if (S.IsNoReturnConversion(FromType, ToType, FromType)) { // Treat a conversion that strips "noreturn" as an identity conversion. SCS.Second = ICK_NoReturn_Adjustment; } else if (IsTransparentUnionStandardConversion(S, From, ToType, InOverloadResolution, SCS, CStyle)) { SCS.Second = ICK_TransparentUnionConversion; FromType = ToType; } else if (tryAtomicConversion(S, From, ToType, InOverloadResolution, SCS, CStyle)) { // tryAtomicConversion has updated the standard conversion sequence // appropriately. return true; } else { // No second conversion required. SCS.Second = ICK_Identity; } SCS.setToType(1, FromType); QualType CanonFrom; QualType CanonTo; // The third conversion can be a qualification conversion (C++ 4p1). bool ObjCLifetimeConversion; if (S.IsQualificationConversion(FromType, ToType, CStyle, ObjCLifetimeConversion)) { SCS.Third = ICK_Qualification; SCS.QualificationIncludesObjCLifetime = ObjCLifetimeConversion; FromType = ToType; CanonFrom = S.Context.getCanonicalType(FromType); CanonTo = S.Context.getCanonicalType(ToType); } else { // No conversion required SCS.Third = ICK_Identity; // C++ [over.best.ics]p6: // [...] Any difference in top-level cv-qualification is // subsumed by the initialization itself and does not constitute // a conversion. [...] CanonFrom = S.Context.getCanonicalType(FromType); CanonTo = S.Context.getCanonicalType(ToType); if (CanonFrom.getLocalUnqualifiedType() == CanonTo.getLocalUnqualifiedType() && (CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers() || CanonFrom.getObjCGCAttr() != CanonTo.getObjCGCAttr() || CanonFrom.getObjCLifetime() != CanonTo.getObjCLifetime())) { FromType = ToType; CanonFrom = CanonTo; } } SCS.setToType(2, FromType); // If we have not converted the argument type to the parameter type, // this is a bad conversion sequence. if (CanonFrom != CanonTo) return false; return true; } static bool IsTransparentUnionStandardConversion(Sema &S, Expr* From, QualType &ToType, bool InOverloadResolution, StandardConversionSequence &SCS, bool CStyle) { const RecordType *UT = ToType->getAsUnionType(); if (!UT || !UT->getDecl()->hasAttr()) return false; // The field to initialize within the transparent union. RecordDecl *UD = UT->getDecl(); // It's compatible if the expression matches any of the fields. for (RecordDecl::field_iterator it = UD->field_begin(), itend = UD->field_end(); it != itend; ++it) { if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS, CStyle, /*ObjCWritebackConversion=*/false)) { ToType = it->getType(); return true; } } return false; } /// IsIntegralPromotion - Determines whether the conversion from the /// expression From (whose potentially-adjusted type is FromType) to /// ToType is an integral promotion (C++ 4.5). If so, returns true and /// sets PromotedType to the promoted type. bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { const BuiltinType *To = ToType->getAs(); // All integers are built-in. if (!To) { return false; } // An rvalue of type char, signed char, unsigned char, short int, or // unsigned short int can be converted to an rvalue of type int if // int can represent all the values of the source type; otherwise, // the source rvalue can be converted to an rvalue of type unsigned // int (C++ 4.5p1). if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && !FromType->isEnumeralType()) { if (// We can promote any signed, promotable integer type to an int (FromType->isSignedIntegerType() || // We can promote any unsigned integer type whose size is // less than int to an int. (!FromType->isSignedIntegerType() && Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { return To->getKind() == BuiltinType::Int; } return To->getKind() == BuiltinType::UInt; } // C++0x [conv.prom]p3: // A prvalue of an unscoped enumeration type whose underlying type is not // fixed (7.2) can be converted to an rvalue a prvalue of the first of the // following types that can represent all the values of the enumeration // (i.e., the values in the range bmin to bmax as described in 7.2): int, // unsigned int, long int, unsigned long int, long long int, or unsigned // long long int. If none of the types in that list can represent all the // values of the enumeration, an rvalue a prvalue of an unscoped enumeration // type can be converted to an rvalue a prvalue of the extended integer type // with lowest integer conversion rank (4.13) greater than the rank of long // long in which all the values of the enumeration can be represented. If // there are two such extended types, the signed one is chosen. if (const EnumType *FromEnumType = FromType->getAs()) { // C++0x 7.2p9: Note that this implicit enum to int conversion is not // provided for a scoped enumeration. if (FromEnumType->getDecl()->isScoped()) return false; // We have already pre-calculated the promotion type, so this is trivial. if (ToType->isIntegerType() && !RequireCompleteType(From->getLocStart(), FromType, PDiag())) return Context.hasSameUnqualifiedType(ToType, FromEnumType->getDecl()->getPromotionType()); } // C++0x [conv.prom]p2: // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted // to an rvalue a prvalue of the first of the following types that can // represent all the values of its underlying type: int, unsigned int, // long int, unsigned long int, long long int, or unsigned long long int. // If none of the types in that list can represent all the values of its // underlying type, an rvalue a prvalue of type char16_t, char32_t, // or wchar_t can be converted to an rvalue a prvalue of its underlying // type. if (FromType->isAnyCharacterType() && !FromType->isCharType() && ToType->isIntegerType()) { // Determine whether the type we're converting from is signed or // unsigned. bool FromIsSigned = FromType->isSignedIntegerType(); uint64_t FromSize = Context.getTypeSize(FromType); // The types we'll try to promote to, in the appropriate // order. Try each of these types. QualType PromoteTypes[6] = { Context.IntTy, Context.UnsignedIntTy, Context.LongTy, Context.UnsignedLongTy , Context.LongLongTy, Context.UnsignedLongLongTy }; for (int Idx = 0; Idx < 6; ++Idx) { uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); if (FromSize < ToSize || (FromSize == ToSize && FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { // We found the type that we can promote to. If this is the // type we wanted, we have a promotion. Otherwise, no // promotion. return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); } } } // An rvalue for an integral bit-field (9.6) can be converted to an // rvalue of type int if int can represent all the values of the // bit-field; otherwise, it can be converted to unsigned int if // unsigned int can represent all the values of the bit-field. If // the bit-field is larger yet, no integral promotion applies to // it. If the bit-field has an enumerated type, it is treated as any // other value of that type for promotion purposes (C++ 4.5p3). // FIXME: We should delay checking of bit-fields until we actually perform the // conversion. using llvm::APSInt; if (From) if (FieldDecl *MemberDecl = From->getBitField()) { APSInt BitWidth; if (FromType->isIntegralType(Context) && MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); ToSize = Context.getTypeSize(ToType); // Are we promoting to an int from a bitfield that fits in an int? if (BitWidth < ToSize || (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { return To->getKind() == BuiltinType::Int; } // Are we promoting to an unsigned int from an unsigned bitfield // that fits into an unsigned int? if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { return To->getKind() == BuiltinType::UInt; } return false; } } // An rvalue of type bool can be converted to an rvalue of type int, // with false becoming zero and true becoming one (C++ 4.5p4). if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { return true; } return false; } /// IsFloatingPointPromotion - Determines whether the conversion from /// FromType to ToType is a floating point promotion (C++ 4.6). If so, /// returns true and sets PromotedType to the promoted type. bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { if (const BuiltinType *FromBuiltin = FromType->getAs()) if (const BuiltinType *ToBuiltin = ToType->getAs()) { /// An rvalue of type float can be converted to an rvalue of type /// double. (C++ 4.6p1). if (FromBuiltin->getKind() == BuiltinType::Float && ToBuiltin->getKind() == BuiltinType::Double) return true; // C99 6.3.1.5p1: // When a float is promoted to double or long double, or a // double is promoted to long double [...]. if (!getLangOpts().CPlusPlus && (FromBuiltin->getKind() == BuiltinType::Float || FromBuiltin->getKind() == BuiltinType::Double) && (ToBuiltin->getKind() == BuiltinType::LongDouble)) return true; // Half can be promoted to float. if (FromBuiltin->getKind() == BuiltinType::Half && ToBuiltin->getKind() == BuiltinType::Float) return true; } return false; } /// \brief Determine if a conversion is a complex promotion. /// /// A complex promotion is defined as a complex -> complex conversion /// where the conversion between the underlying real types is a /// floating-point or integral promotion. bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { const ComplexType *FromComplex = FromType->getAs(); if (!FromComplex) return false; const ComplexType *ToComplex = ToType->getAs(); if (!ToComplex) return false; return IsFloatingPointPromotion(FromComplex->getElementType(), ToComplex->getElementType()) || IsIntegralPromotion(0, FromComplex->getElementType(), ToComplex->getElementType()); } /// BuildSimilarlyQualifiedPointerType - In a pointer conversion from /// the pointer type FromPtr to a pointer to type ToPointee, with the /// same type qualifiers as FromPtr has on its pointee type. ToType, /// if non-empty, will be a pointer to ToType that may or may not have /// the right set of qualifiers on its pointee. /// static QualType BuildSimilarlyQualifiedPointerType(const Type *FromPtr, QualType ToPointee, QualType ToType, ASTContext &Context, bool StripObjCLifetime = false) { assert((FromPtr->getTypeClass() == Type::Pointer || FromPtr->getTypeClass() == Type::ObjCObjectPointer) && "Invalid similarly-qualified pointer type"); /// Conversions to 'id' subsume cv-qualifier conversions. if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType()) return ToType.getUnqualifiedType(); QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); QualType CanonToPointee = Context.getCanonicalType(ToPointee); Qualifiers Quals = CanonFromPointee.getQualifiers(); if (StripObjCLifetime) Quals.removeObjCLifetime(); // Exact qualifier match -> return the pointer type we're converting to. if (CanonToPointee.getLocalQualifiers() == Quals) { // ToType is exactly what we need. Return it. if (!ToType.isNull()) return ToType.getUnqualifiedType(); // Build a pointer to ToPointee. It has the right qualifiers // already. if (isa(ToType)) return Context.getObjCObjectPointerType(ToPointee); return Context.getPointerType(ToPointee); } // Just build a canonical type that has the right qualifiers. QualType QualifiedCanonToPointee = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals); if (isa(ToType)) return Context.getObjCObjectPointerType(QualifiedCanonToPointee); return Context.getPointerType(QualifiedCanonToPointee); } static bool isNullPointerConstantForConversion(Expr *Expr, bool InOverloadResolution, ASTContext &Context) { // Handle value-dependent integral null pointer constants correctly. // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 if (Expr->isValueDependent() && !Expr->isTypeDependent() && Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType()) return !InOverloadResolution; return Expr->isNullPointerConstant(Context, InOverloadResolution? Expr::NPC_ValueDependentIsNotNull : Expr::NPC_ValueDependentIsNull); } /// IsPointerConversion - Determines whether the conversion of the /// expression From, which has the (possibly adjusted) type FromType, /// can be converted to the type ToType via a pointer conversion (C++ /// 4.10). If so, returns true and places the converted type (that /// might differ from ToType in its cv-qualifiers at some level) into /// ConvertedType. /// /// This routine also supports conversions to and from block pointers /// and conversions with Objective-C's 'id', 'id', and /// pointers to interfaces. FIXME: Once we've determined the /// appropriate overloading rules for Objective-C, we may want to /// split the Objective-C checks into a different routine; however, /// GCC seems to consider all of these conversions to be pointer /// conversions, so for now they live here. IncompatibleObjC will be /// set if the conversion is an allowed Objective-C conversion that /// should result in a warning. bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, bool InOverloadResolution, QualType& ConvertedType, bool &IncompatibleObjC) { IncompatibleObjC = false; if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) return true; // Conversion from a null pointer constant to any Objective-C pointer type. if (ToType->isObjCObjectPointerType() && isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { ConvertedType = ToType; return true; } // Blocks: Block pointers can be converted to void*. if (FromType->isBlockPointerType() && ToType->isPointerType() && ToType->getAs()->getPointeeType()->isVoidType()) { ConvertedType = ToType; return true; } // Blocks: A null pointer constant can be converted to a block // pointer type. if (ToType->isBlockPointerType() && isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { ConvertedType = ToType; return true; } // If the left-hand-side is nullptr_t, the right side can be a null // pointer constant. if (ToType->isNullPtrType() && isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { ConvertedType = ToType; return true; } const PointerType* ToTypePtr = ToType->getAs(); if (!ToTypePtr) return false; // A null pointer constant can be converted to a pointer type (C++ 4.10p1). if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { ConvertedType = ToType; return true; } // Beyond this point, both types need to be pointers // , including objective-c pointers. QualType ToPointeeType = ToTypePtr->getPointeeType(); if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType() && !getLangOpts().ObjCAutoRefCount) { ConvertedType = BuildSimilarlyQualifiedPointerType( FromType->getAs(), ToPointeeType, ToType, Context); return true; } const PointerType *FromTypePtr = FromType->getAs(); if (!FromTypePtr) return false; QualType FromPointeeType = FromTypePtr->getPointeeType(); // If the unqualified pointee types are the same, this can't be a // pointer conversion, so don't do all of the work below. if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) return false; // An rvalue of type "pointer to cv T," where T is an object type, // can be converted to an rvalue of type "pointer to cv void" (C++ // 4.10p2). if (FromPointeeType->isIncompleteOrObjectType() && ToPointeeType->isVoidType()) { ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, ToPointeeType, ToType, Context, /*StripObjCLifetime=*/true); return true; } // MSVC allows implicit function to void* type conversion. if (getLangOpts().MicrosoftExt && FromPointeeType->isFunctionType() && ToPointeeType->isVoidType()) { ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, ToPointeeType, ToType, Context); return true; } // When we're overloading in C, we allow a special kind of pointer // conversion for compatible-but-not-identical pointee types. if (!getLangOpts().CPlusPlus && Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, ToPointeeType, ToType, Context); return true; } // C++ [conv.ptr]p3: // // An rvalue of type "pointer to cv D," where D is a class type, // can be converted to an rvalue of type "pointer to cv B," where // B is a base class (clause 10) of D. If B is an inaccessible // (clause 11) or ambiguous (10.2) base class of D, a program that // necessitates this conversion is ill-formed. The result of the // conversion is a pointer to the base class sub-object of the // derived class object. The null pointer value is converted to // the null pointer value of the destination type. // // Note that we do not check for ambiguity or inaccessibility // here. That is handled by CheckPointerConversion. if (getLangOpts().CPlusPlus && FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && IsDerivedFrom(FromPointeeType, ToPointeeType)) { ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, ToPointeeType, ToType, Context); return true; } if (FromPointeeType->isVectorType() && ToPointeeType->isVectorType() && Context.areCompatibleVectorTypes(FromPointeeType, ToPointeeType)) { ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, ToPointeeType, ToType, Context); return true; } return false; } /// \brief Adopt the given qualifiers for the given type. static QualType AdoptQualifiers(ASTContext &Context, QualType T, Qualifiers Qs){ Qualifiers TQs = T.getQualifiers(); // Check whether qualifiers already match. if (TQs == Qs) return T; if (Qs.compatiblyIncludes(TQs)) return Context.getQualifiedType(T, Qs); return Context.getQualifiedType(T.getUnqualifiedType(), Qs); } /// isObjCPointerConversion - Determines whether this is an /// Objective-C pointer conversion. Subroutine of IsPointerConversion, /// with the same arguments and return values. bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, QualType& ConvertedType, bool &IncompatibleObjC) { if (!getLangOpts().ObjC1) return false; // The set of qualifiers on the type we're converting from. Qualifiers FromQualifiers = FromType.getQualifiers(); // First, we handle all conversions on ObjC object pointer types. const ObjCObjectPointerType* ToObjCPtr = ToType->getAs(); const ObjCObjectPointerType *FromObjCPtr = FromType->getAs(); if (ToObjCPtr && FromObjCPtr) { // If the pointee types are the same (ignoring qualifications), // then this is not a pointer conversion. if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(), FromObjCPtr->getPointeeType())) return false; // Check for compatible // Objective C++: We're able to convert between "id" or "Class" and a // pointer to any interface (in both directions). if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); return true; } // Conversions with Objective-C's id<...>. if ((FromObjCPtr->isObjCQualifiedIdType() || ToObjCPtr->isObjCQualifiedIdType()) && Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, /*compare=*/false)) { ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); return true; } // Objective C++: We're able to convert from a pointer to an // interface to a pointer to a different interface. if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); if (getLangOpts().CPlusPlus && LHS && RHS && !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( FromObjCPtr->getPointeeType())) return false; ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, ToObjCPtr->getPointeeType(), ToType, Context); ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); return true; } if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { // Okay: this is some kind of implicit downcast of Objective-C // interfaces, which is permitted. However, we're going to // complain about it. IncompatibleObjC = true; ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, ToObjCPtr->getPointeeType(), ToType, Context); ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); return true; } } // Beyond this point, both types need to be C pointers or block pointers. QualType ToPointeeType; if (const PointerType *ToCPtr = ToType->getAs()) ToPointeeType = ToCPtr->getPointeeType(); else if (const BlockPointerType *ToBlockPtr = ToType->getAs()) { // Objective C++: We're able to convert from a pointer to any object // to a block pointer type. if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); return true; } ToPointeeType = ToBlockPtr->getPointeeType(); } else if (FromType->getAs() && ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { // Objective C++: We're able to convert from a block pointer type to a // pointer to any object. ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); return true; } else return false; QualType FromPointeeType; if (const PointerType *FromCPtr = FromType->getAs()) FromPointeeType = FromCPtr->getPointeeType(); else if (const BlockPointerType *FromBlockPtr = FromType->getAs()) FromPointeeType = FromBlockPtr->getPointeeType(); else return false; // If we have pointers to pointers, recursively check whether this // is an Objective-C conversion. if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, IncompatibleObjC)) { // We always complain about this conversion. IncompatibleObjC = true; ConvertedType = Context.getPointerType(ConvertedType); ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); return true; } // Allow conversion of pointee being objective-c pointer to another one; // as in I* to id. if (FromPointeeType->getAs() && ToPointeeType->getAs() && isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, IncompatibleObjC)) { ConvertedType = Context.getPointerType(ConvertedType); ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); return true; } // If we have pointers to functions or blocks, check whether the only // differences in the argument and result types are in Objective-C // pointer conversions. If so, we permit the conversion (but // complain about it). const FunctionProtoType *FromFunctionType = FromPointeeType->getAs(); const FunctionProtoType *ToFunctionType = ToPointeeType->getAs(); if (FromFunctionType && ToFunctionType) { // If the function types are exactly the same, this isn't an // Objective-C pointer conversion. if (Context.getCanonicalType(FromPointeeType) == Context.getCanonicalType(ToPointeeType)) return false; // Perform the quick checks that will tell us whether these // function types are obviously different. if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) return false; bool HasObjCConversion = false; if (Context.getCanonicalType(FromFunctionType->getResultType()) == Context.getCanonicalType(ToFunctionType->getResultType())) { // Okay, the types match exactly. Nothing to do. } else if (isObjCPointerConversion(FromFunctionType->getResultType(), ToFunctionType->getResultType(), ConvertedType, IncompatibleObjC)) { // Okay, we have an Objective-C pointer conversion. HasObjCConversion = true; } else { // Function types are too different. Abort. return false; } // Check argument types. for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); ArgIdx != NumArgs; ++ArgIdx) { QualType FromArgType = FromFunctionType->getArgType(ArgIdx); QualType ToArgType = ToFunctionType->getArgType(ArgIdx); if (Context.getCanonicalType(FromArgType) == Context.getCanonicalType(ToArgType)) { // Okay, the types match exactly. Nothing to do. } else if (isObjCPointerConversion(FromArgType, ToArgType, ConvertedType, IncompatibleObjC)) { // Okay, we have an Objective-C pointer conversion. HasObjCConversion = true; } else { // Argument types are too different. Abort. return false; } } if (HasObjCConversion) { // We had an Objective-C conversion. Allow this pointer // conversion, but complain about it. ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); IncompatibleObjC = true; return true; } } return false; } /// \brief Determine whether this is an Objective-C writeback conversion, /// used for parameter passing when performing automatic reference counting. /// /// \param FromType The type we're converting form. /// /// \param ToType The type we're converting to. /// /// \param ConvertedType The type that will be produced after applying /// this conversion. bool Sema::isObjCWritebackConversion(QualType FromType, QualType ToType, QualType &ConvertedType) { if (!getLangOpts().ObjCAutoRefCount || Context.hasSameUnqualifiedType(FromType, ToType)) return false; // Parameter must be a pointer to __autoreleasing (with no other qualifiers). QualType ToPointee; if (const PointerType *ToPointer = ToType->getAs()) ToPointee = ToPointer->getPointeeType(); else return false; Qualifiers ToQuals = ToPointee.getQualifiers(); if (!ToPointee->isObjCLifetimeType() || ToQuals.getObjCLifetime() != Qualifiers::OCL_Autoreleasing || !ToQuals.withoutObjCLifetime().empty()) return false; // Argument must be a pointer to __strong to __weak. QualType FromPointee; if (const PointerType *FromPointer = FromType->getAs()) FromPointee = FromPointer->getPointeeType(); else return false; Qualifiers FromQuals = FromPointee.getQualifiers(); if (!FromPointee->isObjCLifetimeType() || (FromQuals.getObjCLifetime() != Qualifiers::OCL_Strong && FromQuals.getObjCLifetime() != Qualifiers::OCL_Weak)) return false; // Make sure that we have compatible qualifiers. FromQuals.setObjCLifetime(Qualifiers::OCL_Autoreleasing); if (!ToQuals.compatiblyIncludes(FromQuals)) return false; // Remove qualifiers from the pointee type we're converting from; they // aren't used in the compatibility check belong, and we'll be adding back // qualifiers (with __autoreleasing) if the compatibility check succeeds. FromPointee = FromPointee.getUnqualifiedType(); // The unqualified form of the pointee types must be compatible. ToPointee = ToPointee.getUnqualifiedType(); bool IncompatibleObjC; if (Context.typesAreCompatible(FromPointee, ToPointee)) FromPointee = ToPointee; else if (!isObjCPointerConversion(FromPointee, ToPointee, FromPointee, IncompatibleObjC)) return false; /// \brief Construct the type we're converting to, which is a pointer to /// __autoreleasing pointee. FromPointee = Context.getQualifiedType(FromPointee, FromQuals); ConvertedType = Context.getPointerType(FromPointee); return true; } bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType, QualType& ConvertedType) { QualType ToPointeeType; if (const BlockPointerType *ToBlockPtr = ToType->getAs()) ToPointeeType = ToBlockPtr->getPointeeType(); else return false; QualType FromPointeeType; if (const BlockPointerType *FromBlockPtr = FromType->getAs()) FromPointeeType = FromBlockPtr->getPointeeType(); else return false; // We have pointer to blocks, check whether the only // differences in the argument and result types are in Objective-C // pointer conversions. If so, we permit the conversion. const FunctionProtoType *FromFunctionType = FromPointeeType->getAs(); const FunctionProtoType *ToFunctionType = ToPointeeType->getAs(); if (!FromFunctionType || !ToFunctionType) return false; if (Context.hasSameType(FromPointeeType, ToPointeeType)) return true; // Perform the quick checks that will tell us whether these // function types are obviously different. if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || FromFunctionType->isVariadic() != ToFunctionType->isVariadic()) return false; FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo(); FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo(); if (FromEInfo != ToEInfo) return false; bool IncompatibleObjC = false; if (Context.hasSameType(FromFunctionType->getResultType(), ToFunctionType->getResultType())) { // Okay, the types match exactly. Nothing to do. } else { QualType RHS = FromFunctionType->getResultType(); QualType LHS = ToFunctionType->getResultType(); if ((!getLangOpts().CPlusPlus || !RHS->isRecordType()) && !RHS.hasQualifiers() && LHS.hasQualifiers()) LHS = LHS.getUnqualifiedType(); if (Context.hasSameType(RHS,LHS)) { // OK exact match. } else if (isObjCPointerConversion(RHS, LHS, ConvertedType, IncompatibleObjC)) { if (IncompatibleObjC) return false; // Okay, we have an Objective-C pointer conversion. } else return false; } // Check argument types. for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); ArgIdx != NumArgs; ++ArgIdx) { IncompatibleObjC = false; QualType FromArgType = FromFunctionType->getArgType(ArgIdx); QualType ToArgType = ToFunctionType->getArgType(ArgIdx); if (Context.hasSameType(FromArgType, ToArgType)) { // Okay, the types match exactly. Nothing to do. } else if (isObjCPointerConversion(ToArgType, FromArgType, ConvertedType, IncompatibleObjC)) { if (IncompatibleObjC) return false; // Okay, we have an Objective-C pointer conversion. } else // Argument types are too different. Abort. return false; } if (LangOpts.ObjCAutoRefCount && !Context.FunctionTypesMatchOnNSConsumedAttrs(FromFunctionType, ToFunctionType)) return false; ConvertedType = ToType; return true; } enum { ft_default, ft_different_class, ft_parameter_arity, ft_parameter_mismatch, ft_return_type, ft_qualifer_mismatch }; /// HandleFunctionTypeMismatch - Gives diagnostic information for differeing /// function types. Catches different number of parameter, mismatch in /// parameter types, and different return types. void Sema::HandleFunctionTypeMismatch(PartialDiagnostic &PDiag, QualType FromType, QualType ToType) { // If either type is not valid, include no extra info. if (FromType.isNull() || ToType.isNull()) { PDiag << ft_default; return; } // Get the function type from the pointers. if (FromType->isMemberPointerType() && ToType->isMemberPointerType()) { const MemberPointerType *FromMember = FromType->getAs(), *ToMember = ToType->getAs(); if (FromMember->getClass() != ToMember->getClass()) { PDiag << ft_different_class << QualType(ToMember->getClass(), 0) << QualType(FromMember->getClass(), 0); return; } FromType = FromMember->getPointeeType(); ToType = ToMember->getPointeeType(); } if (FromType->isPointerType()) FromType = FromType->getPointeeType(); if (ToType->isPointerType()) ToType = ToType->getPointeeType(); // Remove references. FromType = FromType.getNonReferenceType(); ToType = ToType.getNonReferenceType(); // Don't print extra info for non-specialized template functions. if (FromType->isInstantiationDependentType() && !FromType->getAs()) { PDiag << ft_default; return; } // No extra info for same types. if (Context.hasSameType(FromType, ToType)) { PDiag << ft_default; return; } const FunctionProtoType *FromFunction = FromType->getAs(), *ToFunction = ToType->getAs(); // Both types need to be function types. if (!FromFunction || !ToFunction) { PDiag << ft_default; return; } if (FromFunction->getNumArgs() != ToFunction->getNumArgs()) { PDiag << ft_parameter_arity << ToFunction->getNumArgs() << FromFunction->getNumArgs(); return; } // Handle different parameter types. unsigned ArgPos; if (!FunctionArgTypesAreEqual(FromFunction, ToFunction, &ArgPos)) { PDiag << ft_parameter_mismatch << ArgPos + 1 << ToFunction->getArgType(ArgPos) << FromFunction->getArgType(ArgPos); return; } // Handle different return type. if (!Context.hasSameType(FromFunction->getResultType(), ToFunction->getResultType())) { PDiag << ft_return_type << ToFunction->getResultType() << FromFunction->getResultType(); return; } unsigned FromQuals = FromFunction->getTypeQuals(), ToQuals = ToFunction->getTypeQuals(); if (FromQuals != ToQuals) { PDiag << ft_qualifer_mismatch << ToQuals << FromQuals; return; } // Unable to find a difference, so add no extra info. PDiag << ft_default; } /// FunctionArgTypesAreEqual - This routine checks two function proto types /// for equality of their argument types. Caller has already checked that /// they have same number of arguments. This routine assumes that Objective-C /// pointer types which only differ in their protocol qualifiers are equal. /// If the parameters are different, ArgPos will have the the parameter index /// of the first different parameter. bool Sema::FunctionArgTypesAreEqual(const FunctionProtoType *OldType, const FunctionProtoType *NewType, unsigned *ArgPos) { if (!getLangOpts().ObjC1) { for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), N = NewType->arg_type_begin(), E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { if (!Context.hasSameType(*O, *N)) { if (ArgPos) *ArgPos = O - OldType->arg_type_begin(); return false; } } return true; } for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), N = NewType->arg_type_begin(), E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { QualType ToType = (*O); QualType FromType = (*N); if (!Context.hasSameType(ToType, FromType)) { if (const PointerType *PTTo = ToType->getAs()) { if (const PointerType *PTFr = FromType->getAs()) if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && PTFr->getPointeeType()->isObjCQualifiedIdType()) || (PTTo->getPointeeType()->isObjCQualifiedClassType() && PTFr->getPointeeType()->isObjCQualifiedClassType())) continue; } else if (const ObjCObjectPointerType *PTTo = ToType->getAs()) { if (const ObjCObjectPointerType *PTFr = FromType->getAs()) if (Context.hasSameUnqualifiedType( PTTo->getObjectType()->getBaseType(), PTFr->getObjectType()->getBaseType())) continue; } if (ArgPos) *ArgPos = O - OldType->arg_type_begin(); return false; } } return true; } /// CheckPointerConversion - Check the pointer conversion from the /// expression From to the type ToType. This routine checks for /// ambiguous or inaccessible derived-to-base pointer /// conversions for which IsPointerConversion has already returned /// true. It returns true and produces a diagnostic if there was an /// error, or returns false otherwise. bool Sema::CheckPointerConversion(Expr *From, QualType ToType, CastKind &Kind, CXXCastPath& BasePath, bool IgnoreBaseAccess) { QualType FromType = From->getType(); bool IsCStyleOrFunctionalCast = IgnoreBaseAccess; Kind = CK_BitCast; if (!IsCStyleOrFunctionalCast && Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy) && From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) DiagRuntimeBehavior(From->getExprLoc(), From, PDiag(diag::warn_impcast_bool_to_null_pointer) << ToType << From->getSourceRange()); if (const PointerType *ToPtrType = ToType->getAs()) { if (const PointerType *FromPtrType = FromType->getAs()) { QualType FromPointeeType = FromPtrType->getPointeeType(), ToPointeeType = ToPtrType->getPointeeType(); if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { // We must have a derived-to-base conversion. Check an // ambiguous or inaccessible conversion. if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, From->getExprLoc(), From->getSourceRange(), &BasePath, IgnoreBaseAccess)) return true; // The conversion was successful. Kind = CK_DerivedToBase; } } } else if (const ObjCObjectPointerType *ToPtrType = ToType->getAs()) { if (const ObjCObjectPointerType *FromPtrType = FromType->getAs()) { // Objective-C++ conversions are always okay. // FIXME: We should have a different class of conversions for the // Objective-C++ implicit conversions. if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) return false; } else if (FromType->isBlockPointerType()) { Kind = CK_BlockPointerToObjCPointerCast; } else { Kind = CK_CPointerToObjCPointerCast; } } else if (ToType->isBlockPointerType()) { if (!FromType->isBlockPointerType()) Kind = CK_AnyPointerToBlockPointerCast; } // We shouldn't fall into this case unless it's valid for other // reasons. if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) Kind = CK_NullToPointer; return false; } /// IsMemberPointerConversion - Determines whether the conversion of the /// expression From, which has the (possibly adjusted) type FromType, can be /// converted to the type ToType via a member pointer conversion (C++ 4.11). /// If so, returns true and places the converted type (that might differ from /// ToType in its cv-qualifiers at some level) into ConvertedType. bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, QualType ToType, bool InOverloadResolution, QualType &ConvertedType) { const MemberPointerType *ToTypePtr = ToType->getAs(); if (!ToTypePtr) return false; // A null pointer constant can be converted to a member pointer (C++ 4.11p1) if (From->isNullPointerConstant(Context, InOverloadResolution? Expr::NPC_ValueDependentIsNotNull : Expr::NPC_ValueDependentIsNull)) { ConvertedType = ToType; return true; } // Otherwise, both types have to be member pointers. const MemberPointerType *FromTypePtr = FromType->getAs(); if (!FromTypePtr) return false; // A pointer to member of B can be converted to a pointer to member of D, // where D is derived from B (C++ 4.11p2). QualType FromClass(FromTypePtr->getClass(), 0); QualType ToClass(ToTypePtr->getClass(), 0); if (!Context.hasSameUnqualifiedType(FromClass, ToClass) && !RequireCompleteType(From->getLocStart(), ToClass, PDiag()) && IsDerivedFrom(ToClass, FromClass)) { ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), ToClass.getTypePtr()); return true; } return false; } /// CheckMemberPointerConversion - Check the member pointer conversion from the /// expression From to the type ToType. This routine checks for ambiguous or /// virtual or inaccessible base-to-derived member pointer conversions /// for which IsMemberPointerConversion has already returned true. It returns /// true and produces a diagnostic if there was an error, or returns false /// otherwise. bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, CastKind &Kind, CXXCastPath &BasePath, bool IgnoreBaseAccess) { QualType FromType = From->getType(); const MemberPointerType *FromPtrType = FromType->getAs(); if (!FromPtrType) { // This must be a null pointer to member pointer conversion assert(From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull) && "Expr must be null pointer constant!"); Kind = CK_NullToMemberPointer; return false; } const MemberPointerType *ToPtrType = ToType->getAs(); assert(ToPtrType && "No member pointer cast has a target type " "that is not a member pointer."); QualType FromClass = QualType(FromPtrType->getClass(), 0); QualType ToClass = QualType(ToPtrType->getClass(), 0); // FIXME: What about dependent types? assert(FromClass->isRecordType() && "Pointer into non-class."); assert(ToClass->isRecordType() && "Pointer into non-class."); CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, /*DetectVirtual=*/true); bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); assert(DerivationOkay && "Should not have been called if derivation isn't OK."); (void)DerivationOkay; if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). getUnqualifiedType())) { std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); return true; } if (const RecordType *VBase = Paths.getDetectedVirtual()) { Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) << FromClass << ToClass << QualType(VBase, 0) << From->getSourceRange(); return true; } if (!IgnoreBaseAccess) CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, Paths.front(), diag::err_downcast_from_inaccessible_base); // Must be a base to derived member conversion. BuildBasePathArray(Paths, BasePath); Kind = CK_BaseToDerivedMemberPointer; return false; } /// IsQualificationConversion - Determines whether the conversion from /// an rvalue of type FromType to ToType is a qualification conversion /// (C++ 4.4). /// /// \param ObjCLifetimeConversion Output parameter that will be set to indicate /// when the qualification conversion involves a change in the Objective-C /// object lifetime. bool Sema::IsQualificationConversion(QualType FromType, QualType ToType, bool CStyle, bool &ObjCLifetimeConversion) { FromType = Context.getCanonicalType(FromType); ToType = Context.getCanonicalType(ToType); ObjCLifetimeConversion = false; // If FromType and ToType are the same type, this is not a // qualification conversion. if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) return false; // (C++ 4.4p4): // A conversion can add cv-qualifiers at levels other than the first // in multi-level pointers, subject to the following rules: [...] bool PreviousToQualsIncludeConst = true; bool UnwrappedAnyPointer = false; while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) { // Within each iteration of the loop, we check the qualifiers to // determine if this still looks like a qualification // conversion. Then, if all is well, we unwrap one more level of // pointers or pointers-to-members and do it all again // until there are no more pointers or pointers-to-members left to // unwrap. UnwrappedAnyPointer = true; Qualifiers FromQuals = FromType.getQualifiers(); Qualifiers ToQuals = ToType.getQualifiers(); // Objective-C ARC: // Check Objective-C lifetime conversions. if (FromQuals.getObjCLifetime() != ToQuals.getObjCLifetime() && UnwrappedAnyPointer) { if (ToQuals.compatiblyIncludesObjCLifetime(FromQuals)) { ObjCLifetimeConversion = true; FromQuals.removeObjCLifetime(); ToQuals.removeObjCLifetime(); } else { // Qualification conversions cannot cast between different // Objective-C lifetime qualifiers. return false; } } // Allow addition/removal of GC attributes but not changing GC attributes. if (FromQuals.getObjCGCAttr() != ToQuals.getObjCGCAttr() && (!FromQuals.hasObjCGCAttr() || !ToQuals.hasObjCGCAttr())) { FromQuals.removeObjCGCAttr(); ToQuals.removeObjCGCAttr(); } // -- for every j > 0, if const is in cv 1,j then const is in cv // 2,j, and similarly for volatile. if (!CStyle && !ToQuals.compatiblyIncludes(FromQuals)) return false; // -- if the cv 1,j and cv 2,j are different, then const is in // every cv for 0 < k < j. if (!CStyle && FromQuals.getCVRQualifiers() != ToQuals.getCVRQualifiers() && !PreviousToQualsIncludeConst) return false; // Keep track of whether all prior cv-qualifiers in the "to" type // include const. PreviousToQualsIncludeConst = PreviousToQualsIncludeConst && ToQuals.hasConst(); } // We are left with FromType and ToType being the pointee types // after unwrapping the original FromType and ToType the same number // of types. If we unwrapped any pointers, and if FromType and // ToType have the same unqualified type (since we checked // qualifiers above), then this is a qualification conversion. return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); } /// \brief - Determine whether this is a conversion from a scalar type to an /// atomic type. /// /// If successful, updates \c SCS's second and third steps in the conversion /// sequence to finish the conversion. static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType, bool InOverloadResolution, StandardConversionSequence &SCS, bool CStyle) { const AtomicType *ToAtomic = ToType->getAs(); if (!ToAtomic) return false; StandardConversionSequence InnerSCS; if (!IsStandardConversion(S, From, ToAtomic->getValueType(), InOverloadResolution, InnerSCS, CStyle, /*AllowObjCWritebackConversion=*/false)) return false; SCS.Second = InnerSCS.Second; SCS.setToType(1, InnerSCS.getToType(1)); SCS.Third = InnerSCS.Third; SCS.QualificationIncludesObjCLifetime = InnerSCS.QualificationIncludesObjCLifetime; SCS.setToType(2, InnerSCS.getToType(2)); return true; } static bool isFirstArgumentCompatibleWithType(ASTContext &Context, CXXConstructorDecl *Constructor, QualType Type) { const FunctionProtoType *CtorType = Constructor->getType()->getAs(); if (CtorType->getNumArgs() > 0) { QualType FirstArg = CtorType->getArgType(0); if (Context.hasSameUnqualifiedType(Type, FirstArg.getNonReferenceType())) return true; } return false; } static OverloadingResult IsInitializerListConstructorConversion(Sema &S, Expr *From, QualType ToType, CXXRecordDecl *To, UserDefinedConversionSequence &User, OverloadCandidateSet &CandidateSet, bool AllowExplicit) { DeclContext::lookup_iterator Con, ConEnd; for (llvm::tie(Con, ConEnd) = S.LookupConstructors(To); Con != ConEnd; ++Con) { NamedDecl *D = *Con; DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); // Find the constructor (which may be a template). CXXConstructorDecl *Constructor = 0; FunctionTemplateDecl *ConstructorTmpl = dyn_cast(D); if (ConstructorTmpl) Constructor = cast(ConstructorTmpl->getTemplatedDecl()); else Constructor = cast(D); bool Usable = !Constructor->isInvalidDecl() && S.isInitListConstructor(Constructor) && (AllowExplicit || !Constructor->isExplicit()); if (Usable) { // If the first argument is (a reference to) the target type, // suppress conversions. bool SuppressUserConversions = isFirstArgumentCompatibleWithType(S.Context, Constructor, ToType); if (ConstructorTmpl) S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, /*ExplicitArgs*/ 0, From, CandidateSet, SuppressUserConversions); else S.AddOverloadCandidate(Constructor, FoundDecl, From, CandidateSet, SuppressUserConversions); } } bool HadMultipleCandidates = (CandidateSet.size() > 1); OverloadCandidateSet::iterator Best; switch (CandidateSet.BestViableFunction(S, From->getLocStart(), Best, true)) { case OR_Success: { // Record the standard conversion we used and the conversion function. CXXConstructorDecl *Constructor = cast(Best->Function); S.MarkFunctionReferenced(From->getLocStart(), Constructor); QualType ThisType = Constructor->getThisType(S.Context); // Initializer lists don't have conversions as such. User.Before.setAsIdentityConversion(); User.HadMultipleCandidates = HadMultipleCandidates; User.ConversionFunction = Constructor; User.FoundConversionFunction = Best->FoundDecl; User.After.setAsIdentityConversion(); User.After.setFromType(ThisType->getAs()->getPointeeType()); User.After.setAllToTypes(ToType); return OR_Success; } case OR_No_Viable_Function: return OR_No_Viable_Function; case OR_Deleted: return OR_Deleted; case OR_Ambiguous: return OR_Ambiguous; } llvm_unreachable("Invalid OverloadResult!"); } /// Determines whether there is a user-defined conversion sequence /// (C++ [over.ics.user]) that converts expression From to the type /// ToType. If such a conversion exists, User will contain the /// user-defined conversion sequence that performs such a conversion /// and this routine will return true. Otherwise, this routine returns /// false and User is unspecified. /// /// \param AllowExplicit true if the conversion should consider C++0x /// "explicit" conversion functions as well as non-explicit conversion /// functions (C++0x [class.conv.fct]p2). static OverloadingResult IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, UserDefinedConversionSequence &User, OverloadCandidateSet &CandidateSet, bool AllowExplicit) { // Whether we will only visit constructors. bool ConstructorsOnly = false; // If the type we are conversion to is a class type, enumerate its // constructors. if (const RecordType *ToRecordType = ToType->getAs()) { // C++ [over.match.ctor]p1: // When objects of class type are direct-initialized (8.5), or // copy-initialized from an expression of the same or a // derived class type (8.5), overload resolution selects the // constructor. [...] For copy-initialization, the candidate // functions are all the converting constructors (12.3.1) of // that class. The argument list is the expression-list within // the parentheses of the initializer. if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) || (From->getType()->getAs() && S.IsDerivedFrom(From->getType(), ToType))) ConstructorsOnly = true; S.RequireCompleteType(From->getLocStart(), ToType, S.PDiag()); // RequireCompleteType may have returned true due to some invalid decl // during template instantiation, but ToType may be complete enough now // to try to recover. if (ToType->isIncompleteType()) { // We're not going to find any constructors. } else if (CXXRecordDecl *ToRecordDecl = dyn_cast(ToRecordType->getDecl())) { Expr **Args = &From; unsigned NumArgs = 1; bool ListInitializing = false; if (InitListExpr *InitList = dyn_cast(From)) { // But first, see if there is an init-list-contructor that will work. OverloadingResult Result = IsInitializerListConstructorConversion( S, From, ToType, ToRecordDecl, User, CandidateSet, AllowExplicit); if (Result != OR_No_Viable_Function) return Result; // Never mind. CandidateSet.clear(); // If we're list-initializing, we pass the individual elements as // arguments, not the entire list. Args = InitList->getInits(); NumArgs = InitList->getNumInits(); ListInitializing = true; } DeclContext::lookup_iterator Con, ConEnd; for (llvm::tie(Con, ConEnd) = S.LookupConstructors(ToRecordDecl); Con != ConEnd; ++Con) { NamedDecl *D = *Con; DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); // Find the constructor (which may be a template). CXXConstructorDecl *Constructor = 0; FunctionTemplateDecl *ConstructorTmpl = dyn_cast(D); if (ConstructorTmpl) Constructor = cast(ConstructorTmpl->getTemplatedDecl()); else Constructor = cast(D); bool Usable = !Constructor->isInvalidDecl(); if (ListInitializing) Usable = Usable && (AllowExplicit || !Constructor->isExplicit()); else Usable = Usable &&Constructor->isConvertingConstructor(AllowExplicit); if (Usable) { bool SuppressUserConversions = !ConstructorsOnly; if (SuppressUserConversions && ListInitializing) { SuppressUserConversions = false; if (NumArgs == 1) { // If the first argument is (a reference to) the target type, // suppress conversions. SuppressUserConversions = isFirstArgumentCompatibleWithType( S.Context, Constructor, ToType); } } if (ConstructorTmpl) S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, /*ExplicitArgs*/ 0, llvm::makeArrayRef(Args, NumArgs), CandidateSet, SuppressUserConversions); else // Allow one user-defined conversion when user specifies a // From->ToType conversion via an static cast (c-style, etc). S.AddOverloadCandidate(Constructor, FoundDecl, llvm::makeArrayRef(Args, NumArgs), CandidateSet, SuppressUserConversions); } } } } // Enumerate conversion functions, if we're allowed to. if (ConstructorsOnly || isa(From)) { } else if (S.RequireCompleteType(From->getLocStart(), From->getType(), S.PDiag(0) << From->getSourceRange())) { // No conversion functions from incomplete types. } else if (const RecordType *FromRecordType = From->getType()->getAs()) { if (CXXRecordDecl *FromRecordDecl = dyn_cast(FromRecordType->getDecl())) { // Add all of the conversion functions as candidates. const UnresolvedSetImpl *Conversions = FromRecordDecl->getVisibleConversionFunctions(); for (UnresolvedSetImpl::iterator I = Conversions->begin(), E = Conversions->end(); I != E; ++I) { DeclAccessPair FoundDecl = I.getPair(); NamedDecl *D = FoundDecl.getDecl(); CXXRecordDecl *ActingContext = cast(D->getDeclContext()); if (isa(D)) D = cast(D)->getTargetDecl(); CXXConversionDecl *Conv; FunctionTemplateDecl *ConvTemplate; if ((ConvTemplate = dyn_cast(D))) Conv = cast(ConvTemplate->getTemplatedDecl()); else Conv = cast(D); if (AllowExplicit || !Conv->isExplicit()) { if (ConvTemplate) S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl, ActingContext, From, ToType, CandidateSet); else S.AddConversionCandidate(Conv, FoundDecl, ActingContext, From, ToType, CandidateSet); } } } } bool HadMultipleCandidates = (CandidateSet.size() > 1); OverloadCandidateSet::iterator Best; switch (CandidateSet.BestViableFunction(S, From->getLocStart(), Best, true)) { case OR_Success: // Record the standard conversion we used and the conversion function. if (CXXConstructorDecl *Constructor = dyn_cast(Best->Function)) { S.MarkFunctionReferenced(From->getLocStart(), Constructor); // C++ [over.ics.user]p1: // If the user-defined conversion is specified by a // constructor (12.3.1), the initial standard conversion // sequence converts the source type to the type required by // the argument of the constructor. // QualType ThisType = Constructor->getThisType(S.Context); if (isa(From)) { // Initializer lists don't have conversions as such. User.Before.setAsIdentityConversion(); } else { if (Best->Conversions[0].isEllipsis()) User.EllipsisConversion = true; else { User.Before = Best->Conversions[0].Standard; User.EllipsisConversion = false; } } User.HadMultipleCandidates = HadMultipleCandidates; User.ConversionFunction = Constructor; User.FoundConversionFunction = Best->FoundDecl; User.After.setAsIdentityConversion(); User.After.setFromType(ThisType->getAs()->getPointeeType()); User.After.setAllToTypes(ToType); return OR_Success; } if (CXXConversionDecl *Conversion = dyn_cast(Best->Function)) { S.MarkFunctionReferenced(From->getLocStart(), Conversion); // C++ [over.ics.user]p1: // // [...] If the user-defined conversion is specified by a // conversion function (12.3.2), the initial standard // conversion sequence converts the source type to the // implicit object parameter of the conversion function. User.Before = Best->Conversions[0].Standard; User.HadMultipleCandidates = HadMultipleCandidates; User.ConversionFunction = Conversion; User.FoundConversionFunction = Best->FoundDecl; User.EllipsisConversion = false; // C++ [over.ics.user]p2: // The second standard conversion sequence converts the // result of the user-defined conversion to the target type // for the sequence. Since an implicit conversion sequence // is an initialization, the special rules for // initialization by user-defined conversion apply when // selecting the best user-defined conversion for a // user-defined conversion sequence (see 13.3.3 and // 13.3.3.1). User.After = Best->FinalConversion; return OR_Success; } llvm_unreachable("Not a constructor or conversion function?"); case OR_No_Viable_Function: return OR_No_Viable_Function; case OR_Deleted: // No conversion here! We're done. return OR_Deleted; case OR_Ambiguous: return OR_Ambiguous; } llvm_unreachable("Invalid OverloadResult!"); } bool Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { ImplicitConversionSequence ICS; OverloadCandidateSet CandidateSet(From->getExprLoc()); OverloadingResult OvResult = IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined, CandidateSet, false); if (OvResult == OR_Ambiguous) Diag(From->getLocStart(), diag::err_typecheck_ambiguous_condition) << From->getType() << ToType << From->getSourceRange(); else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) Diag(From->getLocStart(), diag::err_typecheck_nonviable_condition) << From->getType() << ToType << From->getSourceRange(); else return false; CandidateSet.NoteCandidates(*this, OCD_AllCandidates, From); return true; } /// \brief Compare the user-defined conversion functions or constructors /// of two user-defined conversion sequences to determine whether any ordering /// is possible. static ImplicitConversionSequence::CompareKind compareConversionFunctions(Sema &S, FunctionDecl *Function1, FunctionDecl *Function2) { if (!S.getLangOpts().ObjC1 || !S.getLangOpts().CPlusPlus0x) return ImplicitConversionSequence::Indistinguishable; // Objective-C++: // If both conversion functions are implicitly-declared conversions from // a lambda closure type to a function pointer and a block pointer, // respectively, always prefer the conversion to a function pointer, // because the function pointer is more lightweight and is more likely // to keep code working. CXXConversionDecl *Conv1 = dyn_cast(Function1); if (!Conv1) return ImplicitConversionSequence::Indistinguishable; CXXConversionDecl *Conv2 = dyn_cast(Function2); if (!Conv2) return ImplicitConversionSequence::Indistinguishable; if (Conv1->getParent()->isLambda() && Conv2->getParent()->isLambda()) { bool Block1 = Conv1->getConversionType()->isBlockPointerType(); bool Block2 = Conv2->getConversionType()->isBlockPointerType(); if (Block1 != Block2) return Block1? ImplicitConversionSequence::Worse : ImplicitConversionSequence::Better; } return ImplicitConversionSequence::Indistinguishable; } /// CompareImplicitConversionSequences - Compare two implicit /// conversion sequences to determine whether one is better than the /// other or if they are indistinguishable (C++ 13.3.3.2). static ImplicitConversionSequence::CompareKind CompareImplicitConversionSequences(Sema &S, const ImplicitConversionSequence& ICS1, const ImplicitConversionSequence& ICS2) { // (C++ 13.3.3.2p2): When comparing the basic forms of implicit // conversion sequences (as defined in 13.3.3.1) // -- a standard conversion sequence (13.3.3.1.1) is a better // conversion sequence than a user-defined conversion sequence or // an ellipsis conversion sequence, and // -- a user-defined conversion sequence (13.3.3.1.2) is a better // conversion sequence than an ellipsis conversion sequence // (13.3.3.1.3). // // C++0x [over.best.ics]p10: // For the purpose of ranking implicit conversion sequences as // described in 13.3.3.2, the ambiguous conversion sequence is // treated as a user-defined sequence that is indistinguishable // from any other user-defined conversion sequence. if (ICS1.getKindRank() < ICS2.getKindRank()) return ImplicitConversionSequence::Better; if (ICS2.getKindRank() < ICS1.getKindRank()) return ImplicitConversionSequence::Worse; // The following checks require both conversion sequences to be of // the same kind. if (ICS1.getKind() != ICS2.getKind()) return ImplicitConversionSequence::Indistinguishable; ImplicitConversionSequence::CompareKind Result = ImplicitConversionSequence::Indistinguishable; // Two implicit conversion sequences of the same form are // indistinguishable conversion sequences unless one of the // following rules apply: (C++ 13.3.3.2p3): if (ICS1.isStandard()) Result = CompareStandardConversionSequences(S, ICS1.Standard, ICS2.Standard); else if (ICS1.isUserDefined()) { // User-defined conversion sequence U1 is a better conversion // sequence than another user-defined conversion sequence U2 if // they contain the same user-defined conversion function or // constructor and if the second standard conversion sequence of // U1 is better than the second standard conversion sequence of // U2 (C++ 13.3.3.2p3). if (ICS1.UserDefined.ConversionFunction == ICS2.UserDefined.ConversionFunction) Result = CompareStandardConversionSequences(S, ICS1.UserDefined.After, ICS2.UserDefined.After); else Result = compareConversionFunctions(S, ICS1.UserDefined.ConversionFunction, ICS2.UserDefined.ConversionFunction); } // List-initialization sequence L1 is a better conversion sequence than // list-initialization sequence L2 if L1 converts to std::initializer_list // for some X and L2 does not. if (Result == ImplicitConversionSequence::Indistinguishable && !ICS1.isBad() && ICS1.isListInitializationSequence() && ICS2.isListInitializationSequence()) { if (ICS1.isStdInitializerListElement() && !ICS2.isStdInitializerListElement()) return ImplicitConversionSequence::Better; if (!ICS1.isStdInitializerListElement() && ICS2.isStdInitializerListElement()) return ImplicitConversionSequence::Worse; } return Result; } static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { while (Context.UnwrapSimilarPointerTypes(T1, T2)) { Qualifiers Quals; T1 = Context.getUnqualifiedArrayType(T1, Quals); T2 = Context.getUnqualifiedArrayType(T2, Quals); } return Context.hasSameUnqualifiedType(T1, T2); } // Per 13.3.3.2p3, compare the given standard conversion sequences to // determine if one is a proper subset of the other. static ImplicitConversionSequence::CompareKind compareStandardConversionSubsets(ASTContext &Context, const StandardConversionSequence& SCS1, const StandardConversionSequence& SCS2) { ImplicitConversionSequence::CompareKind Result = ImplicitConversionSequence::Indistinguishable; // the identity conversion sequence is considered to be a subsequence of // any non-identity conversion sequence if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) return ImplicitConversionSequence::Better; else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) return ImplicitConversionSequence::Worse; if (SCS1.Second != SCS2.Second) { if (SCS1.Second == ICK_Identity) Result = ImplicitConversionSequence::Better; else if (SCS2.Second == ICK_Identity) Result = ImplicitConversionSequence::Worse; else return ImplicitConversionSequence::Indistinguishable; } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) return ImplicitConversionSequence::Indistinguishable; if (SCS1.Third == SCS2.Third) { return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result : ImplicitConversionSequence::Indistinguishable; } if (SCS1.Third == ICK_Identity) return Result == ImplicitConversionSequence::Worse ? ImplicitConversionSequence::Indistinguishable : ImplicitConversionSequence::Better; if (SCS2.Third == ICK_Identity) return Result == ImplicitConversionSequence::Better ? ImplicitConversionSequence::Indistinguishable : ImplicitConversionSequence::Worse; return ImplicitConversionSequence::Indistinguishable; } /// \brief Determine whether one of the given reference bindings is better /// than the other based on what kind of bindings they are. static bool isBetterReferenceBindingKind(const StandardConversionSequence &SCS1, const StandardConversionSequence &SCS2) { // C++0x [over.ics.rank]p3b4: // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an // implicit object parameter of a non-static member function declared // without a ref-qualifier, and *either* S1 binds an rvalue reference // to an rvalue and S2 binds an lvalue reference *or S1 binds an // lvalue reference to a function lvalue and S2 binds an rvalue // reference*. // // FIXME: Rvalue references. We're going rogue with the above edits, // because the semantics in the current C++0x working paper (N3225 at the // time of this writing) break the standard definition of std::forward // and std::reference_wrapper when dealing with references to functions. // Proposed wording changes submitted to CWG for consideration. if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier || SCS2.BindsImplicitObjectArgumentWithoutRefQualifier) return false; return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue && SCS2.IsLvalueReference) || (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue && !SCS2.IsLvalueReference); } /// CompareStandardConversionSequences - Compare two standard /// conversion sequences to determine whether one is better than the /// other or if they are indistinguishable (C++ 13.3.3.2p3). static ImplicitConversionSequence::CompareKind CompareStandardConversionSequences(Sema &S, const StandardConversionSequence& SCS1, const StandardConversionSequence& SCS2) { // Standard conversion sequence S1 is a better conversion sequence // than standard conversion sequence S2 if (C++ 13.3.3.2p3): // -- S1 is a proper subsequence of S2 (comparing the conversion // sequences in the canonical form defined by 13.3.3.1.1, // excluding any Lvalue Transformation; the identity conversion // sequence is considered to be a subsequence of any // non-identity conversion sequence) or, if not that, if (ImplicitConversionSequence::CompareKind CK = compareStandardConversionSubsets(S.Context, SCS1, SCS2)) return CK; // -- the rank of S1 is better than the rank of S2 (by the rules // defined below), or, if not that, ImplicitConversionRank Rank1 = SCS1.getRank(); ImplicitConversionRank Rank2 = SCS2.getRank(); if (Rank1 < Rank2) return ImplicitConversionSequence::Better; else if (Rank2 < Rank1) return ImplicitConversionSequence::Worse; // (C++ 13.3.3.2p4): Two conversion sequences with the same rank // are indistinguishable unless one of the following rules // applies: // A conversion that is not a conversion of a pointer, or // pointer to member, to bool is better than another conversion // that is such a conversion. if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) return SCS2.isPointerConversionToBool() ? ImplicitConversionSequence::Better : ImplicitConversionSequence::Worse; // C++ [over.ics.rank]p4b2: // // If class B is derived directly or indirectly from class A, // conversion of B* to A* is better than conversion of B* to // void*, and conversion of A* to void* is better than conversion // of B* to void*. bool SCS1ConvertsToVoid = SCS1.isPointerConversionToVoidPointer(S.Context); bool SCS2ConvertsToVoid = SCS2.isPointerConversionToVoidPointer(S.Context); if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { // Exactly one of the conversion sequences is a conversion to // a void pointer; it's the worse conversion. return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better : ImplicitConversionSequence::Worse; } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { // Neither conversion sequence converts to a void pointer; compare // their derived-to-base conversions. if (ImplicitConversionSequence::CompareKind DerivedCK = CompareDerivedToBaseConversions(S, SCS1, SCS2)) return DerivedCK; } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid && !S.Context.hasSameType(SCS1.getFromType(), SCS2.getFromType())) { // Both conversion sequences are conversions to void // pointers. Compare the source types to determine if there's an // inheritance relationship in their sources. QualType FromType1 = SCS1.getFromType(); QualType FromType2 = SCS2.getFromType(); // Adjust the types we're converting from via the array-to-pointer // conversion, if we need to. if (SCS1.First == ICK_Array_To_Pointer) FromType1 = S.Context.getArrayDecayedType(FromType1); if (SCS2.First == ICK_Array_To_Pointer) FromType2 = S.Context.getArrayDecayedType(FromType2); QualType FromPointee1 = FromType1->getPointeeType().getUnqualifiedType(); QualType FromPointee2 = FromType2->getPointeeType().getUnqualifiedType(); if (S.IsDerivedFrom(FromPointee2, FromPointee1)) return ImplicitConversionSequence::Better; else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) return ImplicitConversionSequence::Worse; // Objective-C++: If one interface is more specific than the // other, it is the better one. const ObjCObjectPointerType* FromObjCPtr1 = FromType1->getAs(); const ObjCObjectPointerType* FromObjCPtr2 = FromType2->getAs(); if (FromObjCPtr1 && FromObjCPtr2) { bool AssignLeft = S.Context.canAssignObjCInterfaces(FromObjCPtr1, FromObjCPtr2); bool AssignRight = S.Context.canAssignObjCInterfaces(FromObjCPtr2, FromObjCPtr1); if (AssignLeft != AssignRight) { return AssignLeft? ImplicitConversionSequence::Better : ImplicitConversionSequence::Worse; } } } // Compare based on qualification conversions (C++ 13.3.3.2p3, // bullet 3). if (ImplicitConversionSequence::CompareKind QualCK = CompareQualificationConversions(S, SCS1, SCS2)) return QualCK; if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { // Check for a better reference binding based on the kind of bindings. if (isBetterReferenceBindingKind(SCS1, SCS2)) return ImplicitConversionSequence::Better; else if (isBetterReferenceBindingKind(SCS2, SCS1)) return ImplicitConversionSequence::Worse; // C++ [over.ics.rank]p3b4: // -- S1 and S2 are reference bindings (8.5.3), and the types to // which the references refer are the same type except for // top-level cv-qualifiers, and the type to which the reference // initialized by S2 refers is more cv-qualified than the type // to which the reference initialized by S1 refers. QualType T1 = SCS1.getToType(2); QualType T2 = SCS2.getToType(2); T1 = S.Context.getCanonicalType(T1); T2 = S.Context.getCanonicalType(T2); Qualifiers T1Quals, T2Quals; QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); if (UnqualT1 == UnqualT2) { // Objective-C++ ARC: If the references refer to objects with different // lifetimes, prefer bindings that don't change lifetime. if (SCS1.ObjCLifetimeConversionBinding != SCS2.ObjCLifetimeConversionBinding) { return SCS1.ObjCLifetimeConversionBinding ? ImplicitConversionSequence::Worse : ImplicitConversionSequence::Better; } // If the type is an array type, promote the element qualifiers to the // type for comparison. if (isa(T1) && T1Quals) T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); if (isa(T2) && T2Quals) T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); if (T2.isMoreQualifiedThan(T1)) return ImplicitConversionSequence::Better; else if (T1.isMoreQualifiedThan(T2)) return ImplicitConversionSequence::Worse; } } // In Microsoft mode, prefer an integral conversion to a // floating-to-integral conversion if the integral conversion // is between types of the same size. // For example: // void f(float); // void f(int); // int main { // long a; // f(a); // } // Here, MSVC will call f(int) instead of generating a compile error // as clang will do in standard mode. if (S.getLangOpts().MicrosoftMode && SCS1.Second == ICK_Integral_Conversion && SCS2.Second == ICK_Floating_Integral && S.Context.getTypeSize(SCS1.getFromType()) == S.Context.getTypeSize(SCS1.getToType(2))) return ImplicitConversionSequence::Better; return ImplicitConversionSequence::Indistinguishable; } /// CompareQualificationConversions - Compares two standard conversion /// sequences to determine whether they can be ranked based on their /// qualification conversions (C++ 13.3.3.2p3 bullet 3). ImplicitConversionSequence::CompareKind CompareQualificationConversions(Sema &S, const StandardConversionSequence& SCS1, const StandardConversionSequence& SCS2) { // C++ 13.3.3.2p3: // -- S1 and S2 differ only in their qualification conversion and // yield similar types T1 and T2 (C++ 4.4), respectively, and the // cv-qualification signature of type T1 is a proper subset of // the cv-qualification signature of type T2, and S1 is not the // deprecated string literal array-to-pointer conversion (4.2). if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) return ImplicitConversionSequence::Indistinguishable; // FIXME: the example in the standard doesn't use a qualification // conversion (!) QualType T1 = SCS1.getToType(2); QualType T2 = SCS2.getToType(2); T1 = S.Context.getCanonicalType(T1); T2 = S.Context.getCanonicalType(T2); Qualifiers T1Quals, T2Quals; QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); // If the types are the same, we won't learn anything by unwrapped // them. if (UnqualT1 == UnqualT2) return ImplicitConversionSequence::Indistinguishable; // If the type is an array type, promote the element qualifiers to the type // for comparison. if (isa(T1) && T1Quals) T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); if (isa(T2) && T2Quals) T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); ImplicitConversionSequence::CompareKind Result = ImplicitConversionSequence::Indistinguishable; // Objective-C++ ARC: // Prefer qualification conversions not involving a change in lifetime // to qualification conversions that do not change lifetime. if (SCS1.QualificationIncludesObjCLifetime != SCS2.QualificationIncludesObjCLifetime) { Result = SCS1.QualificationIncludesObjCLifetime ? ImplicitConversionSequence::Worse : ImplicitConversionSequence::Better; } while (S.Context.UnwrapSimilarPointerTypes(T1, T2)) { // Within each iteration of the loop, we check the qualifiers to // determine if this still looks like a qualification // conversion. Then, if all is well, we unwrap one more level of // pointers or pointers-to-members and do it all again // until there are no more pointers or pointers-to-members left // to unwrap. This essentially mimics what // IsQualificationConversion does, but here we're checking for a // strict subset of qualifiers. if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) // The qualifiers are the same, so this doesn't tell us anything // about how the sequences rank. ; else if (T2.isMoreQualifiedThan(T1)) { // T1 has fewer qualifiers, so it could be the better sequence. if (Result == ImplicitConversionSequence::Worse) // Neither has qualifiers that are a subset of the other's // qualifiers. return ImplicitConversionSequence::Indistinguishable; Result = ImplicitConversionSequence::Better; } else if (T1.isMoreQualifiedThan(T2)) { // T2 has fewer qualifiers, so it could be the better sequence. if (Result == ImplicitConversionSequence::Better) // Neither has qualifiers that are a subset of the other's // qualifiers. return ImplicitConversionSequence::Indistinguishable; Result = ImplicitConversionSequence::Worse; } else { // Qualifiers are disjoint. return ImplicitConversionSequence::Indistinguishable; } // If the types after this point are equivalent, we're done. if (S.Context.hasSameUnqualifiedType(T1, T2)) break; } // Check that the winning standard conversion sequence isn't using // the deprecated string literal array to pointer conversion. switch (Result) { case ImplicitConversionSequence::Better: if (SCS1.DeprecatedStringLiteralToCharPtr) Result = ImplicitConversionSequence::Indistinguishable; break; case ImplicitConversionSequence::Indistinguishable: break; case ImplicitConversionSequence::Worse: if (SCS2.DeprecatedStringLiteralToCharPtr) Result = ImplicitConversionSequence::Indistinguishable; break; } return Result; } /// CompareDerivedToBaseConversions - Compares two standard conversion /// sequences to determine whether they can be ranked based on their /// various kinds of derived-to-base conversions (C++ /// [over.ics.rank]p4b3). As part of these checks, we also look at /// conversions between Objective-C interface types. ImplicitConversionSequence::CompareKind CompareDerivedToBaseConversions(Sema &S, const StandardConversionSequence& SCS1, const StandardConversionSequence& SCS2) { QualType FromType1 = SCS1.getFromType(); QualType ToType1 = SCS1.getToType(1); QualType FromType2 = SCS2.getFromType(); QualType ToType2 = SCS2.getToType(1); // Adjust the types we're converting from via the array-to-pointer // conversion, if we need to. if (SCS1.First == ICK_Array_To_Pointer) FromType1 = S.Context.getArrayDecayedType(FromType1); if (SCS2.First == ICK_Array_To_Pointer) FromType2 = S.Context.getArrayDecayedType(FromType2); // Canonicalize all of the types. FromType1 = S.Context.getCanonicalType(FromType1); ToType1 = S.Context.getCanonicalType(ToType1); FromType2 = S.Context.getCanonicalType(FromType2); ToType2 = S.Context.getCanonicalType(ToType2); // C++ [over.ics.rank]p4b3: // // If class B is derived directly or indirectly from class A and // class C is derived directly or indirectly from B, // // Compare based on pointer conversions. if (SCS1.Second == ICK_Pointer_Conversion && SCS2.Second == ICK_Pointer_Conversion && /*FIXME: Remove if Objective-C id conversions get their own rank*/ FromType1->isPointerType() && FromType2->isPointerType() && ToType1->isPointerType() && ToType2->isPointerType()) { QualType FromPointee1 = FromType1->getAs()->getPointeeType().getUnqualifiedType(); QualType ToPointee1 = ToType1->getAs()->getPointeeType().getUnqualifiedType(); QualType FromPointee2 = FromType2->getAs()->getPointeeType().getUnqualifiedType(); QualType ToPointee2 = ToType2->getAs()->getPointeeType().getUnqualifiedType(); // -- conversion of C* to B* is better than conversion of C* to A*, if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { if (S.IsDerivedFrom(ToPointee1, ToPointee2)) return ImplicitConversionSequence::Better; else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) return ImplicitConversionSequence::Worse; } // -- conversion of B* to A* is better than conversion of C* to A*, if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { if (S.IsDerivedFrom(FromPointee2, FromPointee1)) return ImplicitConversionSequence::Better; else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) return ImplicitConversionSequence::Worse; } } else if (SCS1.Second == ICK_Pointer_Conversion && SCS2.Second == ICK_Pointer_Conversion) { const ObjCObjectPointerType *FromPtr1 = FromType1->getAs(); const ObjCObjectPointerType *FromPtr2 = FromType2->getAs(); const ObjCObjectPointerType *ToPtr1 = ToType1->getAs(); const ObjCObjectPointerType *ToPtr2 = ToType2->getAs(); if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) { // Apply the same conversion ranking rules for Objective-C pointer types // that we do for C++ pointers to class types. However, we employ the // Objective-C pseudo-subtyping relationship used for assignment of // Objective-C pointer types. bool FromAssignLeft = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2); bool FromAssignRight = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1); bool ToAssignLeft = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2); bool ToAssignRight = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1); // A conversion to an a non-id object pointer type or qualified 'id' // type is better than a conversion to 'id'. if (ToPtr1->isObjCIdType() && (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl())) return ImplicitConversionSequence::Worse; if (ToPtr2->isObjCIdType() && (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl())) return ImplicitConversionSequence::Better; // A conversion to a non-id object pointer type is better than a // conversion to a qualified 'id' type if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl()) return ImplicitConversionSequence::Worse; if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl()) return ImplicitConversionSequence::Better; // A conversion to an a non-Class object pointer type or qualified 'Class' // type is better than a conversion to 'Class'. if (ToPtr1->isObjCClassType() && (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl())) return ImplicitConversionSequence::Worse; if (ToPtr2->isObjCClassType() && (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl())) return ImplicitConversionSequence::Better; // A conversion to a non-Class object pointer type is better than a // conversion to a qualified 'Class' type. if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl()) return ImplicitConversionSequence::Worse; if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl()) return ImplicitConversionSequence::Better; // -- "conversion of C* to B* is better than conversion of C* to A*," if (S.Context.hasSameType(FromType1, FromType2) && !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() && (ToAssignLeft != ToAssignRight)) return ToAssignLeft? ImplicitConversionSequence::Worse : ImplicitConversionSequence::Better; // -- "conversion of B* to A* is better than conversion of C* to A*," if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) && (FromAssignLeft != FromAssignRight)) return FromAssignLeft? ImplicitConversionSequence::Better : ImplicitConversionSequence::Worse; } } // Ranking of member-pointer types. if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { const MemberPointerType * FromMemPointer1 = FromType1->getAs(); const MemberPointerType * ToMemPointer1 = ToType1->getAs(); const MemberPointerType * FromMemPointer2 = FromType2->getAs(); const MemberPointerType * ToMemPointer2 = ToType2->getAs(); const Type *FromPointeeType1 = FromMemPointer1->getClass(); const Type *ToPointeeType1 = ToMemPointer1->getClass(); const Type *FromPointeeType2 = FromMemPointer2->getClass(); const Type *ToPointeeType2 = ToMemPointer2->getClass(); QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); // conversion of A::* to B::* is better than conversion of A::* to C::*, if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { if (S.IsDerivedFrom(ToPointee1, ToPointee2)) return ImplicitConversionSequence::Worse; else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) return ImplicitConversionSequence::Better; } // conversion of B::* to C::* is better than conversion of A::* to C::* if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { if (S.IsDerivedFrom(FromPointee1, FromPointee2)) return ImplicitConversionSequence::Better; else if (S.IsDerivedFrom(FromPointee2, FromPointee1)) return ImplicitConversionSequence::Worse; } } if (SCS1.Second == ICK_Derived_To_Base) { // -- conversion of C to B is better than conversion of C to A, // -- binding of an expression of type C to a reference of type // B& is better than binding an expression of type C to a // reference of type A&, if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) && !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { if (S.IsDerivedFrom(ToType1, ToType2)) return ImplicitConversionSequence::Better; else if (S.IsDerivedFrom(ToType2, ToType1)) return ImplicitConversionSequence::Worse; } // -- conversion of B to A is better than conversion of C to A. // -- binding of an expression of type B to a reference of type // A& is better than binding an expression of type C to a // reference of type A&, if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) && S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { if (S.IsDerivedFrom(FromType2, FromType1)) return ImplicitConversionSequence::Better; else if (S.IsDerivedFrom(FromType1, FromType2)) return ImplicitConversionSequence::Worse; } } return ImplicitConversionSequence::Indistinguishable; } /// CompareReferenceRelationship - Compare the two types T1 and T2 to /// determine whether they are reference-related, /// reference-compatible, reference-compatible with added /// qualification, or incompatible, for use in C++ initialization by /// reference (C++ [dcl.ref.init]p4). Neither type can be a reference /// type, and the first type (T1) is the pointee type of the reference /// type being initialized. Sema::ReferenceCompareResult Sema::CompareReferenceRelationship(SourceLocation Loc, QualType OrigT1, QualType OrigT2, bool &DerivedToBase, bool &ObjCConversion, bool &ObjCLifetimeConversion) { assert(!OrigT1->isReferenceType() && "T1 must be the pointee type of the reference type"); assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); QualType T1 = Context.getCanonicalType(OrigT1); QualType T2 = Context.getCanonicalType(OrigT2); Qualifiers T1Quals, T2Quals; QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); // C++ [dcl.init.ref]p4: // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is // reference-related to "cv2 T2" if T1 is the same type as T2, or // T1 is a base class of T2. DerivedToBase = false; ObjCConversion = false; ObjCLifetimeConversion = false; if (UnqualT1 == UnqualT2) { // Nothing to do. } else if (!RequireCompleteType(Loc, OrigT2, PDiag()) && IsDerivedFrom(UnqualT2, UnqualT1)) DerivedToBase = true; else if (UnqualT1->isObjCObjectOrInterfaceType() && UnqualT2->isObjCObjectOrInterfaceType() && Context.canBindObjCObjectType(UnqualT1, UnqualT2)) ObjCConversion = true; else return Ref_Incompatible; // At this point, we know that T1 and T2 are reference-related (at // least). // If the type is an array type, promote the element qualifiers to the type // for comparison. if (isa(T1) && T1Quals) T1 = Context.getQualifiedType(UnqualT1, T1Quals); if (isa(T2) && T2Quals) T2 = Context.getQualifiedType(UnqualT2, T2Quals); // C++ [dcl.init.ref]p4: // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is // reference-related to T2 and cv1 is the same cv-qualification // as, or greater cv-qualification than, cv2. For purposes of // overload resolution, cases for which cv1 is greater // cv-qualification than cv2 are identified as // reference-compatible with added qualification (see 13.3.3.2). // // Note that we also require equivalence of Objective-C GC and address-space // qualifiers when performing these computations, so that e.g., an int in // address space 1 is not reference-compatible with an int in address // space 2. if (T1Quals.getObjCLifetime() != T2Quals.getObjCLifetime() && T1Quals.compatiblyIncludesObjCLifetime(T2Quals)) { T1Quals.removeObjCLifetime(); T2Quals.removeObjCLifetime(); ObjCLifetimeConversion = true; } if (T1Quals == T2Quals) return Ref_Compatible; else if (T1Quals.compatiblyIncludes(T2Quals)) return Ref_Compatible_With_Added_Qualification; else return Ref_Related; } /// \brief Look for a user-defined conversion to an value reference-compatible /// with DeclType. Return true if something definite is found. static bool FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS, QualType DeclType, SourceLocation DeclLoc, Expr *Init, QualType T2, bool AllowRvalues, bool AllowExplicit) { assert(T2->isRecordType() && "Can only find conversions of record types."); CXXRecordDecl *T2RecordDecl = dyn_cast(T2->getAs()->getDecl()); OverloadCandidateSet CandidateSet(DeclLoc); const UnresolvedSetImpl *Conversions = T2RecordDecl->getVisibleConversionFunctions(); for (UnresolvedSetImpl::iterator I = Conversions->begin(), E = Conversions->end(); I != E; ++I) { NamedDecl *D = *I; CXXRecordDecl *ActingDC = cast(D->getDeclContext()); if (isa(D)) D = cast(D)->getTargetDecl(); FunctionTemplateDecl *ConvTemplate = dyn_cast(D); CXXConversionDecl *Conv; if (ConvTemplate) Conv = cast(ConvTemplate->getTemplatedDecl()); else Conv = cast(D); // If this is an explicit conversion, and we're not allowed to consider // explicit conversions, skip it. if (!AllowExplicit && Conv->isExplicit()) continue; if (AllowRvalues) { bool DerivedToBase = false; bool ObjCConversion = false; bool ObjCLifetimeConversion = false; // If we are initializing an rvalue reference, don't permit conversion // functions that return lvalues. if (!ConvTemplate && DeclType->isRValueReferenceType()) { const ReferenceType *RefType = Conv->getConversionType()->getAs(); if (RefType && !RefType->getPointeeType()->isFunctionType()) continue; } if (!ConvTemplate && S.CompareReferenceRelationship( DeclLoc, Conv->getConversionType().getNonReferenceType() .getUnqualifiedType(), DeclType.getNonReferenceType().getUnqualifiedType(), DerivedToBase, ObjCConversion, ObjCLifetimeConversion) == Sema::Ref_Incompatible) continue; } else { // If the conversion function doesn't return a reference type, // it can't be considered for this conversion. An rvalue reference // is only acceptable if its referencee is a function type. const ReferenceType *RefType = Conv->getConversionType()->getAs(); if (!RefType || (!RefType->isLValueReferenceType() && !RefType->getPointeeType()->isFunctionType())) continue; } if (ConvTemplate) S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, Init, DeclType, CandidateSet); else S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, DeclType, CandidateSet); } bool HadMultipleCandidates = (CandidateSet.size() > 1); OverloadCandidateSet::iterator Best; switch (CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) { case OR_Success: // C++ [over.ics.ref]p1: // // [...] If the parameter binds directly to the result of // applying a conversion function to the argument // expression, the implicit conversion sequence is a // user-defined conversion sequence (13.3.3.1.2), with the // second standard conversion sequence either an identity // conversion or, if the conversion function returns an // entity of a type that is a derived class of the parameter // type, a derived-to-base Conversion. if (!Best->FinalConversion.DirectBinding) return false; if (Best->Function) S.MarkFunctionReferenced(DeclLoc, Best->Function); ICS.setUserDefined(); ICS.UserDefined.Before = Best->Conversions[0].Standard; ICS.UserDefined.After = Best->FinalConversion; ICS.UserDefined.HadMultipleCandidates = HadMultipleCandidates; ICS.UserDefined.ConversionFunction = Best->Function; ICS.UserDefined.FoundConversionFunction = Best->FoundDecl; ICS.UserDefined.EllipsisConversion = false; assert(ICS.UserDefined.After.ReferenceBinding && ICS.UserDefined.After.DirectBinding && "Expected a direct reference binding!"); return true; case OR_Ambiguous: ICS.setAmbiguous(); for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); Cand != CandidateSet.end(); ++Cand) if (Cand->Viable) ICS.Ambiguous.addConversion(Cand->Function); return true; case OR_No_Viable_Function: case OR_Deleted: // There was no suitable conversion, or we found a deleted // conversion; continue with other checks. return false; } llvm_unreachable("Invalid OverloadResult!"); } /// \brief Compute an implicit conversion sequence for reference /// initialization. static ImplicitConversionSequence TryReferenceInit(Sema &S, Expr *Init, QualType DeclType, SourceLocation DeclLoc, bool SuppressUserConversions, bool AllowExplicit) { assert(DeclType->isReferenceType() && "Reference init needs a reference"); // Most paths end in a failed conversion. ImplicitConversionSequence ICS; ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); QualType T1 = DeclType->getAs()->getPointeeType(); QualType T2 = Init->getType(); // If the initializer is the address of an overloaded function, try // to resolve the overloaded function. If all goes well, T2 is the // type of the resulting function. if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { DeclAccessPair Found; if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, false, Found)) T2 = Fn->getType(); } // Compute some basic properties of the types and the initializer. bool isRValRef = DeclType->isRValueReferenceType(); bool DerivedToBase = false; bool ObjCConversion = false; bool ObjCLifetimeConversion = false; Expr::Classification InitCategory = Init->Classify(S.Context); Sema::ReferenceCompareResult RefRelationship = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase, ObjCConversion, ObjCLifetimeConversion); // C++0x [dcl.init.ref]p5: // A reference to type "cv1 T1" is initialized by an expression // of type "cv2 T2" as follows: // -- If reference is an lvalue reference and the initializer expression if (!isRValRef) { // -- is an lvalue (but is not a bit-field), and "cv1 T1" is // reference-compatible with "cv2 T2," or // // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. if (InitCategory.isLValue() && RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { // C++ [over.ics.ref]p1: // When a parameter of reference type binds directly (8.5.3) // to an argument expression, the implicit conversion sequence // is the identity conversion, unless the argument expression // has a type that is a derived class of the parameter type, // in which case the implicit conversion sequence is a // derived-to-base Conversion (13.3.3.1). ICS.setStandard(); ICS.Standard.First = ICK_Identity; ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ObjCConversion? ICK_Compatible_Conversion : ICK_Identity; ICS.Standard.Third = ICK_Identity; ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); ICS.Standard.setToType(0, T2); ICS.Standard.setToType(1, T1); ICS.Standard.setToType(2, T1); ICS.Standard.ReferenceBinding = true; ICS.Standard.DirectBinding = true; ICS.Standard.IsLvalueReference = !isRValRef; ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); ICS.Standard.BindsToRvalue = false; ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion; ICS.Standard.CopyConstructor = 0; // Nothing more to do: the inaccessibility/ambiguity check for // derived-to-base conversions is suppressed when we're // computing the implicit conversion sequence (C++ // [over.best.ics]p2). return ICS; } // -- has a class type (i.e., T2 is a class type), where T1 is // not reference-related to T2, and can be implicitly // converted to an lvalue of type "cv3 T3," where "cv1 T1" // is reference-compatible with "cv3 T3" 92) (this // conversion is selected by enumerating the applicable // conversion functions (13.3.1.6) and choosing the best // one through overload resolution (13.3)), if (!SuppressUserConversions && T2->isRecordType() && !S.RequireCompleteType(DeclLoc, T2, 0) && RefRelationship == Sema::Ref_Incompatible) { if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc, Init, T2, /*AllowRvalues=*/false, AllowExplicit)) return ICS; } } // -- Otherwise, the reference shall be an lvalue reference to a // non-volatile const type (i.e., cv1 shall be const), or the reference // shall be an rvalue reference. // // We actually handle one oddity of C++ [over.ics.ref] at this // point, which is that, due to p2 (which short-circuits reference // binding by only attempting a simple conversion for non-direct // bindings) and p3's strange wording, we allow a const volatile // reference to bind to an rvalue. Hence the check for the presence // of "const" rather than checking for "const" being the only // qualifier. // This is also the point where rvalue references and lvalue inits no longer // go together. if (!isRValRef && !T1.isConstQualified()) return ICS; // -- If the initializer expression // // -- is an xvalue, class prvalue, array prvalue or function // lvalue and "cv1 T1" is reference-compatible with "cv2 T2", or if (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification && (InitCategory.isXValue() || (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) || (InitCategory.isLValue() && T2->isFunctionType()))) { ICS.setStandard(); ICS.Standard.First = ICK_Identity; ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ObjCConversion? ICK_Compatible_Conversion : ICK_Identity; ICS.Standard.Third = ICK_Identity; ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); ICS.Standard.setToType(0, T2); ICS.Standard.setToType(1, T1); ICS.Standard.setToType(2, T1); ICS.Standard.ReferenceBinding = true; // In C++0x, this is always a direct binding. In C++98/03, it's a direct // binding unless we're binding to a class prvalue. // Note: Although xvalues wouldn't normally show up in C++98/03 code, we // allow the use of rvalue references in C++98/03 for the benefit of // standard library implementors; therefore, we need the xvalue check here. ICS.Standard.DirectBinding = S.getLangOpts().CPlusPlus0x || (InitCategory.isPRValue() && !T2->isRecordType()); ICS.Standard.IsLvalueReference = !isRValRef; ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); ICS.Standard.BindsToRvalue = InitCategory.isRValue(); ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion; ICS.Standard.CopyConstructor = 0; return ICS; } // -- has a class type (i.e., T2 is a class type), where T1 is not // reference-related to T2, and can be implicitly converted to // an xvalue, class prvalue, or function lvalue of type // "cv3 T3", where "cv1 T1" is reference-compatible with // "cv3 T3", // // then the reference is bound to the value of the initializer // expression in the first case and to the result of the conversion // in the second case (or, in either case, to an appropriate base // class subobject). if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && T2->isRecordType() && !S.RequireCompleteType(DeclLoc, T2, 0) && FindConversionForRefInit(S, ICS, DeclType, DeclLoc, Init, T2, /*AllowRvalues=*/true, AllowExplicit)) { // In the second case, if the reference is an rvalue reference // and the second standard conversion sequence of the // user-defined conversion sequence includes an lvalue-to-rvalue // conversion, the program is ill-formed. if (ICS.isUserDefined() && isRValRef && ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue) ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); return ICS; } // -- Otherwise, a temporary of type "cv1 T1" is created and // initialized from the initializer expression using the // rules for a non-reference copy initialization (8.5). The // reference is then bound to the temporary. If T1 is // reference-related to T2, cv1 must be the same // cv-qualification as, or greater cv-qualification than, // cv2; otherwise, the program is ill-formed. if (RefRelationship == Sema::Ref_Related) { // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then // we would be reference-compatible or reference-compatible with // added qualification. But that wasn't the case, so the reference // initialization fails. // // Note that we only want to check address spaces and cvr-qualifiers here. // ObjC GC and lifetime qualifiers aren't important. Qualifiers T1Quals = T1.getQualifiers(); Qualifiers T2Quals = T2.getQualifiers(); T1Quals.removeObjCGCAttr(); T1Quals.removeObjCLifetime(); T2Quals.removeObjCGCAttr(); T2Quals.removeObjCLifetime(); if (!T1Quals.compatiblyIncludes(T2Quals)) return ICS; } // If at least one of the types is a class type, the types are not // related, and we aren't allowed any user conversions, the // reference binding fails. This case is important for breaking // recursion, since TryImplicitConversion below will attempt to // create a temporary through the use of a copy constructor. if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && (T1->isRecordType() || T2->isRecordType())) return ICS; // If T1 is reference-related to T2 and the reference is an rvalue // reference, the initializer expression shall not be an lvalue. if (RefRelationship >= Sema::Ref_Related && isRValRef && Init->Classify(S.Context).isLValue()) return ICS; // C++ [over.ics.ref]p2: // When a parameter of reference type is not bound directly to // an argument expression, the conversion sequence is the one // required to convert the argument expression to the // underlying type of the reference according to // 13.3.3.1. Conceptually, this conversion sequence corresponds // to copy-initializing a temporary of the underlying type with // the argument expression. Any difference in top-level // cv-qualification is subsumed by the initialization itself // and does not constitute a conversion. ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions, /*AllowExplicit=*/false, /*InOverloadResolution=*/false, /*CStyle=*/false, /*AllowObjCWritebackConversion=*/false); // Of course, that's still a reference binding. if (ICS.isStandard()) { ICS.Standard.ReferenceBinding = true; ICS.Standard.IsLvalueReference = !isRValRef; ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); ICS.Standard.BindsToRvalue = true; ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; ICS.Standard.ObjCLifetimeConversionBinding = false; } else if (ICS.isUserDefined()) { // Don't allow rvalue references to bind to lvalues. if (DeclType->isRValueReferenceType()) { if (const ReferenceType *RefType = ICS.UserDefined.ConversionFunction->getResultType() ->getAs()) { if (!RefType->getPointeeType()->isFunctionType()) { ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, Init, DeclType); return ICS; } } } ICS.UserDefined.After.ReferenceBinding = true; ICS.UserDefined.After.IsLvalueReference = !isRValRef; ICS.UserDefined.After.BindsToFunctionLvalue = T2->isFunctionType(); ICS.UserDefined.After.BindsToRvalue = true; ICS.UserDefined.After.BindsImplicitObjectArgumentWithoutRefQualifier = false; ICS.UserDefined.After.ObjCLifetimeConversionBinding = false; } return ICS; } static ImplicitConversionSequence TryCopyInitialization(Sema &S, Expr *From, QualType ToType, bool SuppressUserConversions, bool InOverloadResolution, bool AllowObjCWritebackConversion, bool AllowExplicit = false); /// TryListConversion - Try to copy-initialize a value of type ToType from the /// initializer list From. static ImplicitConversionSequence TryListConversion(Sema &S, InitListExpr *From, QualType ToType, bool SuppressUserConversions, bool InOverloadResolution, bool AllowObjCWritebackConversion) { // C++11 [over.ics.list]p1: // When an argument is an initializer list, it is not an expression and // special rules apply for converting it to a parameter type. ImplicitConversionSequence Result; Result.setBad(BadConversionSequence::no_conversion, From, ToType); Result.setListInitializationSequence(); // We need a complete type for what follows. Incomplete types can never be // initialized from init lists. if (S.RequireCompleteType(From->getLocStart(), ToType, S.PDiag())) return Result; // C++11 [over.ics.list]p2: // If the parameter type is std::initializer_list or "array of X" and // all the elements can be implicitly converted to X, the implicit // conversion sequence is the worst conversion necessary to convert an // element of the list to X. bool toStdInitializerList = false; QualType X; if (ToType->isArrayType()) X = S.Context.getBaseElementType(ToType); else toStdInitializerList = S.isStdInitializerList(ToType, &X); if (!X.isNull()) { for (unsigned i = 0, e = From->getNumInits(); i < e; ++i) { Expr *Init = From->getInit(i); ImplicitConversionSequence ICS = TryCopyInitialization(S, Init, X, SuppressUserConversions, InOverloadResolution, AllowObjCWritebackConversion); // If a single element isn't convertible, fail. if (ICS.isBad()) { Result = ICS; break; } // Otherwise, look for the worst conversion. if (Result.isBad() || CompareImplicitConversionSequences(S, ICS, Result) == ImplicitConversionSequence::Worse) Result = ICS; } // For an empty list, we won't have computed any conversion sequence. // Introduce the identity conversion sequence. if (From->getNumInits() == 0) { Result.setStandard(); Result.Standard.setAsIdentityConversion(); Result.Standard.setFromType(ToType); Result.Standard.setAllToTypes(ToType); } Result.setListInitializationSequence(); Result.setStdInitializerListElement(toStdInitializerList); return Result; } // C++11 [over.ics.list]p3: // Otherwise, if the parameter is a non-aggregate class X and overload // resolution chooses a single best constructor [...] the implicit // conversion sequence is a user-defined conversion sequence. If multiple // constructors are viable but none is better than the others, the // implicit conversion sequence is a user-defined conversion sequence. if (ToType->isRecordType() && !ToType->isAggregateType()) { // This function can deal with initializer lists. Result = TryUserDefinedConversion(S, From, ToType, SuppressUserConversions, /*AllowExplicit=*/false, InOverloadResolution, /*CStyle=*/false, AllowObjCWritebackConversion); Result.setListInitializationSequence(); return Result; } // C++11 [over.ics.list]p4: // Otherwise, if the parameter has an aggregate type which can be // initialized from the initializer list [...] the implicit conversion // sequence is a user-defined conversion sequence. if (ToType->isAggregateType()) { // Type is an aggregate, argument is an init list. At this point it comes // down to checking whether the initialization works. // FIXME: Find out whether this parameter is consumed or not. InitializedEntity Entity = InitializedEntity::InitializeParameter(S.Context, ToType, /*Consumed=*/false); if (S.CanPerformCopyInitialization(Entity, S.Owned(From))) { Result.setUserDefined(); Result.UserDefined.Before.setAsIdentityConversion(); // Initializer lists don't have a type. Result.UserDefined.Before.setFromType(QualType()); Result.UserDefined.Before.setAllToTypes(QualType()); Result.UserDefined.After.setAsIdentityConversion(); Result.UserDefined.After.setFromType(ToType); Result.UserDefined.After.setAllToTypes(ToType); Result.UserDefined.ConversionFunction = 0; } return Result; } // C++11 [over.ics.list]p5: // Otherwise, if the parameter is a reference, see 13.3.3.1.4. if (ToType->isReferenceType()) { // The standard is notoriously unclear here, since 13.3.3.1.4 doesn't // mention initializer lists in any way. So we go by what list- // initialization would do and try to extrapolate from that. QualType T1 = ToType->getAs()->getPointeeType(); // If the initializer list has a single element that is reference-related // to the parameter type, we initialize the reference from that. if (From->getNumInits() == 1) { Expr *Init = From->getInit(0); QualType T2 = Init->getType(); // If the initializer is the address of an overloaded function, try // to resolve the overloaded function. If all goes well, T2 is the // type of the resulting function. if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { DeclAccessPair Found; if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction( Init, ToType, false, Found)) T2 = Fn->getType(); } // Compute some basic properties of the types and the initializer. bool dummy1 = false; bool dummy2 = false; bool dummy3 = false; Sema::ReferenceCompareResult RefRelationship = S.CompareReferenceRelationship(From->getLocStart(), T1, T2, dummy1, dummy2, dummy3); if (RefRelationship >= Sema::Ref_Related) return TryReferenceInit(S, Init, ToType, /*FIXME:*/From->getLocStart(), SuppressUserConversions, /*AllowExplicit=*/false); } // Otherwise, we bind the reference to a temporary created from the // initializer list. Result = TryListConversion(S, From, T1, SuppressUserConversions, InOverloadResolution, AllowObjCWritebackConversion); if (Result.isFailure()) return Result; assert(!Result.isEllipsis() && "Sub-initialization cannot result in ellipsis conversion."); // Can we even bind to a temporary? if (ToType->isRValueReferenceType() || (T1.isConstQualified() && !T1.isVolatileQualified())) { StandardConversionSequence &SCS = Result.isStandard() ? Result.Standard : Result.UserDefined.After; SCS.ReferenceBinding = true; SCS.IsLvalueReference = ToType->isLValueReferenceType(); SCS.BindsToRvalue = true; SCS.BindsToFunctionLvalue = false; SCS.BindsImplicitObjectArgumentWithoutRefQualifier = false; SCS.ObjCLifetimeConversionBinding = false; } else Result.setBad(BadConversionSequence::lvalue_ref_to_rvalue, From, ToType); return Result; } // C++11 [over.ics.list]p6: // Otherwise, if the parameter type is not a class: if (!ToType->isRecordType()) { // - if the initializer list has one element, the implicit conversion // sequence is the one required to convert the element to the // parameter type. unsigned NumInits = From->getNumInits(); if (NumInits == 1) Result = TryCopyInitialization(S, From->getInit(0), ToType, SuppressUserConversions, InOverloadResolution, AllowObjCWritebackConversion); // - if the initializer list has no elements, the implicit conversion // sequence is the identity conversion. else if (NumInits == 0) { Result.setStandard(); Result.Standard.setAsIdentityConversion(); Result.Standard.setFromType(ToType); Result.Standard.setAllToTypes(ToType); } Result.setListInitializationSequence(); return Result; } // C++11 [over.ics.list]p7: // In all cases other than those enumerated above, no conversion is possible return Result; } /// TryCopyInitialization - Try to copy-initialize a value of type /// ToType from the expression From. Return the implicit conversion /// sequence required to pass this argument, which may be a bad /// conversion sequence (meaning that the argument cannot be passed to /// a parameter of this type). If @p SuppressUserConversions, then we /// do not permit any user-defined conversion sequences. static ImplicitConversionSequence TryCopyInitialization(Sema &S, Expr *From, QualType ToType, bool SuppressUserConversions, bool InOverloadResolution, bool AllowObjCWritebackConversion, bool AllowExplicit) { if (InitListExpr *FromInitList = dyn_cast(From)) return TryListConversion(S, FromInitList, ToType, SuppressUserConversions, InOverloadResolution,AllowObjCWritebackConversion); if (ToType->isReferenceType()) return TryReferenceInit(S, From, ToType, /*FIXME:*/From->getLocStart(), SuppressUserConversions, AllowExplicit); return TryImplicitConversion(S, From, ToType, SuppressUserConversions, /*AllowExplicit=*/false, InOverloadResolution, /*CStyle=*/false, AllowObjCWritebackConversion); } static bool TryCopyInitialization(const CanQualType FromQTy, const CanQualType ToQTy, Sema &S, SourceLocation Loc, ExprValueKind FromVK) { OpaqueValueExpr TmpExpr(Loc, FromQTy, FromVK); ImplicitConversionSequence ICS = TryCopyInitialization(S, &TmpExpr, ToQTy, true, true, false); return !ICS.isBad(); } /// TryObjectArgumentInitialization - Try to initialize the object /// parameter of the given member function (@c Method) from the /// expression @p From. static ImplicitConversionSequence TryObjectArgumentInitialization(Sema &S, QualType OrigFromType, Expr::Classification FromClassification, CXXMethodDecl *Method, CXXRecordDecl *ActingContext) { QualType ClassType = S.Context.getTypeDeclType(ActingContext); // [class.dtor]p2: A destructor can be invoked for a const, volatile or // const volatile object. unsigned Quals = isa(Method) ? Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); QualType ImplicitParamType = S.Context.getCVRQualifiedType(ClassType, Quals); // Set up the conversion sequence as a "bad" conversion, to allow us // to exit early. ImplicitConversionSequence ICS; // We need to have an object of class type. QualType FromType = OrigFromType; if (const PointerType *PT = FromType->getAs()) { FromType = PT->getPointeeType(); // When we had a pointer, it's implicitly dereferenced, so we // better have an lvalue. assert(FromClassification.isLValue()); } assert(FromType->isRecordType()); // C++0x [over.match.funcs]p4: // For non-static member functions, the type of the implicit object // parameter is // // - "lvalue reference to cv X" for functions declared without a // ref-qualifier or with the & ref-qualifier // - "rvalue reference to cv X" for functions declared with the && // ref-qualifier // // where X is the class of which the function is a member and cv is the // cv-qualification on the member function declaration. // // However, when finding an implicit conversion sequence for the argument, we // are not allowed to create temporaries or perform user-defined conversions // (C++ [over.match.funcs]p5). We perform a simplified version of // reference binding here, that allows class rvalues to bind to // non-constant references. // First check the qualifiers. QualType FromTypeCanon = S.Context.getCanonicalType(FromType); if (ImplicitParamType.getCVRQualifiers() != FromTypeCanon.getLocalCVRQualifiers() && !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { ICS.setBad(BadConversionSequence::bad_qualifiers, OrigFromType, ImplicitParamType); return ICS; } // Check that we have either the same type or a derived type. It // affects the conversion rank. QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType); ImplicitConversionKind SecondKind; if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { SecondKind = ICK_Identity; } else if (S.IsDerivedFrom(FromType, ClassType)) SecondKind = ICK_Derived_To_Base; else { ICS.setBad(BadConversionSequence::unrelated_class, FromType, ImplicitParamType); return ICS; } // Check the ref-qualifier. switch (Method->getRefQualifier()) { case RQ_None: // Do nothing; we don't care about lvalueness or rvalueness. break; case RQ_LValue: if (!FromClassification.isLValue() && Quals != Qualifiers::Const) { // non-const lvalue reference cannot bind to an rvalue ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType, ImplicitParamType); return ICS; } break; case RQ_RValue: if (!FromClassification.isRValue()) { // rvalue reference cannot bind to an lvalue ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType, ImplicitParamType); return ICS; } break; } // Success. Mark this as a reference binding. ICS.setStandard(); ICS.Standard.setAsIdentityConversion(); ICS.Standard.Second = SecondKind; ICS.Standard.setFromType(FromType); ICS.Standard.setAllToTypes(ImplicitParamType); ICS.Standard.ReferenceBinding = true; ICS.Standard.DirectBinding = true; ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue; ICS.Standard.BindsToFunctionLvalue = false; ICS.Standard.BindsToRvalue = FromClassification.isRValue(); ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = (Method->getRefQualifier() == RQ_None); return ICS; } /// PerformObjectArgumentInitialization - Perform initialization of /// the implicit object parameter for the given Method with the given /// expression. ExprResult Sema::PerformObjectArgumentInitialization(Expr *From, NestedNameSpecifier *Qualifier, NamedDecl *FoundDecl, CXXMethodDecl *Method) { QualType FromRecordType, DestType; QualType ImplicitParamRecordType = Method->getThisType(Context)->getAs()->getPointeeType(); Expr::Classification FromClassification; if (const PointerType *PT = From->getType()->getAs()) { FromRecordType = PT->getPointeeType(); DestType = Method->getThisType(Context); FromClassification = Expr::Classification::makeSimpleLValue(); } else { FromRecordType = From->getType(); DestType = ImplicitParamRecordType; FromClassification = From->Classify(Context); } // Note that we always use the true parent context when performing // the actual argument initialization. ImplicitConversionSequence ICS = TryObjectArgumentInitialization(*this, From->getType(), FromClassification, Method, Method->getParent()); if (ICS.isBad()) { if (ICS.Bad.Kind == BadConversionSequence::bad_qualifiers) { Qualifiers FromQs = FromRecordType.getQualifiers(); Qualifiers ToQs = DestType.getQualifiers(); unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); if (CVR) { Diag(From->getLocStart(), diag::err_member_function_call_bad_cvr) << Method->getDeclName() << FromRecordType << (CVR - 1) << From->getSourceRange(); Diag(Method->getLocation(), diag::note_previous_decl) << Method->getDeclName(); return ExprError(); } } return Diag(From->getLocStart(), diag::err_implicit_object_parameter_init) << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); } if (ICS.Standard.Second == ICK_Derived_To_Base) { ExprResult FromRes = PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); if (FromRes.isInvalid()) return ExprError(); From = FromRes.take(); } if (!Context.hasSameType(From->getType(), DestType)) From = ImpCastExprToType(From, DestType, CK_NoOp, From->getValueKind()).take(); return Owned(From); } /// TryContextuallyConvertToBool - Attempt to contextually convert the /// expression From to bool (C++0x [conv]p3). static ImplicitConversionSequence TryContextuallyConvertToBool(Sema &S, Expr *From) { // FIXME: This is pretty broken. return TryImplicitConversion(S, From, S.Context.BoolTy, // FIXME: Are these flags correct? /*SuppressUserConversions=*/false, /*AllowExplicit=*/true, /*InOverloadResolution=*/false, /*CStyle=*/false, /*AllowObjCWritebackConversion=*/false); } /// PerformContextuallyConvertToBool - Perform a contextual conversion /// of the expression From to bool (C++0x [conv]p3). ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) { if (checkPlaceholderForOverload(*this, From)) return ExprError(); ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From); if (!ICS.isBad()) return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) return Diag(From->getLocStart(), diag::err_typecheck_bool_condition) << From->getType() << From->getSourceRange(); return ExprError(); } /// Check that the specified conversion is permitted in a converted constant /// expression, according to C++11 [expr.const]p3. Return true if the conversion /// is acceptable. static bool CheckConvertedConstantConversions(Sema &S, StandardConversionSequence &SCS) { // Since we know that the target type is an integral or unscoped enumeration // type, most conversion kinds are impossible. All possible First and Third // conversions are fine. switch (SCS.Second) { case ICK_Identity: case ICK_Integral_Promotion: case ICK_Integral_Conversion: return true; case ICK_Boolean_Conversion: // Conversion from an integral or unscoped enumeration type to bool is // classified as ICK_Boolean_Conversion, but it's also an integral // conversion, so it's permitted in a converted constant expression. return SCS.getFromType()->isIntegralOrUnscopedEnumerationType() && SCS.getToType(2)->isBooleanType(); case ICK_Floating_Integral: case ICK_Complex_Real: return false; case ICK_Lvalue_To_Rvalue: case ICK_Array_To_Pointer: case ICK_Function_To_Pointer: case ICK_NoReturn_Adjustment: case ICK_Qualification: case ICK_Compatible_Conversion: case ICK_Vector_Conversion: case ICK_Vector_Splat: case ICK_Derived_To_Base: case ICK_Pointer_Conversion: case ICK_Pointer_Member: case ICK_Block_Pointer_Conversion: case ICK_Writeback_Conversion: case ICK_Floating_Promotion: case ICK_Complex_Promotion: case ICK_Complex_Conversion: case ICK_Floating_Conversion: case ICK_TransparentUnionConversion: llvm_unreachable("unexpected second conversion kind"); case ICK_Num_Conversion_Kinds: break; } llvm_unreachable("unknown conversion kind"); } /// CheckConvertedConstantExpression - Check that the expression From is a /// converted constant expression of type T, perform the conversion and produce /// the converted expression, per C++11 [expr.const]p3. ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T, llvm::APSInt &Value, CCEKind CCE) { assert(LangOpts.CPlusPlus0x && "converted constant expression outside C++11"); assert(T->isIntegralOrEnumerationType() && "unexpected converted const type"); if (checkPlaceholderForOverload(*this, From)) return ExprError(); // C++11 [expr.const]p3 with proposed wording fixes: // A converted constant expression of type T is a core constant expression, // implicitly converted to a prvalue of type T, where the converted // expression is a literal constant expression and the implicit conversion // sequence contains only user-defined conversions, lvalue-to-rvalue // conversions, integral promotions, and integral conversions other than // narrowing conversions. ImplicitConversionSequence ICS = TryImplicitConversion(From, T, /*SuppressUserConversions=*/false, /*AllowExplicit=*/false, /*InOverloadResolution=*/false, /*CStyle=*/false, /*AllowObjcWritebackConversion=*/false); StandardConversionSequence *SCS = 0; switch (ICS.getKind()) { case ImplicitConversionSequence::StandardConversion: if (!CheckConvertedConstantConversions(*this, ICS.Standard)) return Diag(From->getLocStart(), diag::err_typecheck_converted_constant_expression_disallowed) << From->getType() << From->getSourceRange() << T; SCS = &ICS.Standard; break; case ImplicitConversionSequence::UserDefinedConversion: // We are converting from class type to an integral or enumeration type, so // the Before sequence must be trivial. if (!CheckConvertedConstantConversions(*this, ICS.UserDefined.After)) return Diag(From->getLocStart(), diag::err_typecheck_converted_constant_expression_disallowed) << From->getType() << From->getSourceRange() << T; SCS = &ICS.UserDefined.After; break; case ImplicitConversionSequence::AmbiguousConversion: case ImplicitConversionSequence::BadConversion: if (!DiagnoseMultipleUserDefinedConversion(From, T)) return Diag(From->getLocStart(), diag::err_typecheck_converted_constant_expression) << From->getType() << From->getSourceRange() << T; return ExprError(); case ImplicitConversionSequence::EllipsisConversion: llvm_unreachable("ellipsis conversion in converted constant expression"); } ExprResult Result = PerformImplicitConversion(From, T, ICS, AA_Converting); if (Result.isInvalid()) return Result; // Check for a narrowing implicit conversion. APValue PreNarrowingValue; QualType PreNarrowingType; switch (SCS->getNarrowingKind(Context, Result.get(), PreNarrowingValue, PreNarrowingType)) { case NK_Variable_Narrowing: // Implicit conversion to a narrower type, and the value is not a constant // expression. We'll diagnose this in a moment. case NK_Not_Narrowing: break; case NK_Constant_Narrowing: Diag(From->getLocStart(), isSFINAEContext() ? diag::err_cce_narrowing_sfinae : diag::err_cce_narrowing) << CCE << /*Constant*/1 << PreNarrowingValue.getAsString(Context, PreNarrowingType) << T; break; case NK_Type_Narrowing: Diag(From->getLocStart(), isSFINAEContext() ? diag::err_cce_narrowing_sfinae : diag::err_cce_narrowing) << CCE << /*Constant*/0 << From->getType() << T; break; } // Check the expression is a constant expression. llvm::SmallVector Notes; Expr::EvalResult Eval; Eval.Diag = &Notes; if (!Result.get()->EvaluateAsRValue(Eval, Context)) { // The expression can't be folded, so we can't keep it at this position in // the AST. Result = ExprError(); } else { Value = Eval.Val.getInt(); if (Notes.empty()) { // It's a constant expression. return Result; } } // It's not a constant expression. Produce an appropriate diagnostic. if (Notes.size() == 1 && Notes[0].second.getDiagID() == diag::note_invalid_subexpr_in_const_expr) Diag(Notes[0].first, diag::err_expr_not_cce) << CCE; else { Diag(From->getLocStart(), diag::err_expr_not_cce) << CCE << From->getSourceRange(); for (unsigned I = 0; I < Notes.size(); ++I) Diag(Notes[I].first, Notes[I].second); } return Result; } /// dropPointerConversions - If the given standard conversion sequence /// involves any pointer conversions, remove them. This may change /// the result type of the conversion sequence. static void dropPointerConversion(StandardConversionSequence &SCS) { if (SCS.Second == ICK_Pointer_Conversion) { SCS.Second = ICK_Identity; SCS.Third = ICK_Identity; SCS.ToTypePtrs[2] = SCS.ToTypePtrs[1] = SCS.ToTypePtrs[0]; } } /// TryContextuallyConvertToObjCPointer - Attempt to contextually /// convert the expression From to an Objective-C pointer type. static ImplicitConversionSequence TryContextuallyConvertToObjCPointer(Sema &S, Expr *From) { // Do an implicit conversion to 'id'. QualType Ty = S.Context.getObjCIdType(); ImplicitConversionSequence ICS = TryImplicitConversion(S, From, Ty, // FIXME: Are these flags correct? /*SuppressUserConversions=*/false, /*AllowExplicit=*/true, /*InOverloadResolution=*/false, /*CStyle=*/false, /*AllowObjCWritebackConversion=*/false); // Strip off any final conversions to 'id'. switch (ICS.getKind()) { case ImplicitConversionSequence::BadConversion: case ImplicitConversionSequence::AmbiguousConversion: case ImplicitConversionSequence::EllipsisConversion: break; case ImplicitConversionSequence::UserDefinedConversion: dropPointerConversion(ICS.UserDefined.After); break; case ImplicitConversionSequence::StandardConversion: dropPointerConversion(ICS.Standard); break; } return ICS; } /// PerformContextuallyConvertToObjCPointer - Perform a contextual /// conversion of the expression From to an Objective-C pointer type. ExprResult Sema::PerformContextuallyConvertToObjCPointer(Expr *From) { if (checkPlaceholderForOverload(*this, From)) return ExprError(); QualType Ty = Context.getObjCIdType(); ImplicitConversionSequence ICS = TryContextuallyConvertToObjCPointer(*this, From); if (!ICS.isBad()) return PerformImplicitConversion(From, Ty, ICS, AA_Converting); return ExprError(); } /// Determine whether the provided type is an integral type, or an enumeration /// type of a permitted flavor. static bool isIntegralOrEnumerationType(QualType T, bool AllowScopedEnum) { return AllowScopedEnum ? T->isIntegralOrEnumerationType() : T->isIntegralOrUnscopedEnumerationType(); } /// \brief Attempt to convert the given expression to an integral or /// enumeration type. /// /// This routine will attempt to convert an expression of class type to an /// integral or enumeration type, if that class type only has a single /// conversion to an integral or enumeration type. /// /// \param Loc The source location of the construct that requires the /// conversion. /// /// \param FromE The expression we're converting from. /// /// \param NotIntDiag The diagnostic to be emitted if the expression does not /// have integral or enumeration type. /// /// \param IncompleteDiag The diagnostic to be emitted if the expression has /// incomplete class type. /// /// \param ExplicitConvDiag The diagnostic to be emitted if we're calling an /// explicit conversion function (because no implicit conversion functions /// were available). This is a recovery mode. /// /// \param ExplicitConvNote The note to be emitted with \p ExplicitConvDiag, /// showing which conversion was picked. /// /// \param AmbigDiag The diagnostic to be emitted if there is more than one /// conversion function that could convert to integral or enumeration type. /// /// \param AmbigNote The note to be emitted with \p AmbigDiag for each /// usable conversion function. /// /// \param ConvDiag The diagnostic to be emitted if we are calling a conversion /// function, which may be an extension in this case. /// /// \param AllowScopedEnumerations Specifies whether conversions to scoped /// enumerations should be considered. /// /// \returns The expression, converted to an integral or enumeration type if /// successful. ExprResult Sema::ConvertToIntegralOrEnumerationType(SourceLocation Loc, Expr *From, const PartialDiagnostic &NotIntDiag, const PartialDiagnostic &IncompleteDiag, const PartialDiagnostic &ExplicitConvDiag, const PartialDiagnostic &ExplicitConvNote, const PartialDiagnostic &AmbigDiag, const PartialDiagnostic &AmbigNote, const PartialDiagnostic &ConvDiag, bool AllowScopedEnumerations) { // We can't perform any more checking for type-dependent expressions. if (From->isTypeDependent()) return Owned(From); // Process placeholders immediately. if (From->hasPlaceholderType()) { ExprResult result = CheckPlaceholderExpr(From); if (result.isInvalid()) return result; From = result.take(); } // If the expression already has integral or enumeration type, we're golden. QualType T = From->getType(); if (isIntegralOrEnumerationType(T, AllowScopedEnumerations)) return DefaultLvalueConversion(From); // FIXME: Check for missing '()' if T is a function type? // If we don't have a class type in C++, there's no way we can get an // expression of integral or enumeration type. const RecordType *RecordTy = T->getAs(); if (!RecordTy || !getLangOpts().CPlusPlus) { if (NotIntDiag.getDiagID()) Diag(Loc, NotIntDiag) << T << From->getSourceRange(); return Owned(From); } // We must have a complete class type. if (RequireCompleteType(Loc, T, IncompleteDiag)) return Owned(From); // Look for a conversion to an integral or enumeration type. UnresolvedSet<4> ViableConversions; UnresolvedSet<4> ExplicitConversions; const UnresolvedSetImpl *Conversions = cast(RecordTy->getDecl())->getVisibleConversionFunctions(); bool HadMultipleCandidates = (Conversions->size() > 1); for (UnresolvedSetImpl::iterator I = Conversions->begin(), E = Conversions->end(); I != E; ++I) { if (CXXConversionDecl *Conversion = dyn_cast((*I)->getUnderlyingDecl())) { if (isIntegralOrEnumerationType( Conversion->getConversionType().getNonReferenceType(), AllowScopedEnumerations)) { if (Conversion->isExplicit()) ExplicitConversions.addDecl(I.getDecl(), I.getAccess()); else ViableConversions.addDecl(I.getDecl(), I.getAccess()); } } } switch (ViableConversions.size()) { case 0: if (ExplicitConversions.size() == 1 && ExplicitConvDiag.getDiagID()) { DeclAccessPair Found = ExplicitConversions[0]; CXXConversionDecl *Conversion = cast(Found->getUnderlyingDecl()); // The user probably meant to invoke the given explicit // conversion; use it. QualType ConvTy = Conversion->getConversionType().getNonReferenceType(); std::string TypeStr; ConvTy.getAsStringInternal(TypeStr, getPrintingPolicy()); Diag(Loc, ExplicitConvDiag) << T << ConvTy << FixItHint::CreateInsertion(From->getLocStart(), "static_cast<" + TypeStr + ">(") << FixItHint::CreateInsertion(PP.getLocForEndOfToken(From->getLocEnd()), ")"); Diag(Conversion->getLocation(), ExplicitConvNote) << ConvTy->isEnumeralType() << ConvTy; // If we aren't in a SFINAE context, build a call to the // explicit conversion function. if (isSFINAEContext()) return ExprError(); CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); ExprResult Result = BuildCXXMemberCallExpr(From, Found, Conversion, HadMultipleCandidates); if (Result.isInvalid()) return ExprError(); // Record usage of conversion in an implicit cast. From = ImplicitCastExpr::Create(Context, Result.get()->getType(), CK_UserDefinedConversion, Result.get(), 0, Result.get()->getValueKind()); } // We'll complain below about a non-integral condition type. break; case 1: { // Apply this conversion. DeclAccessPair Found = ViableConversions[0]; CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); CXXConversionDecl *Conversion = cast(Found->getUnderlyingDecl()); QualType ConvTy = Conversion->getConversionType().getNonReferenceType(); if (ConvDiag.getDiagID()) { if (isSFINAEContext()) return ExprError(); Diag(Loc, ConvDiag) << T << ConvTy->isEnumeralType() << ConvTy << From->getSourceRange(); } ExprResult Result = BuildCXXMemberCallExpr(From, Found, Conversion, HadMultipleCandidates); if (Result.isInvalid()) return ExprError(); // Record usage of conversion in an implicit cast. From = ImplicitCastExpr::Create(Context, Result.get()->getType(), CK_UserDefinedConversion, Result.get(), 0, Result.get()->getValueKind()); break; } default: if (!AmbigDiag.getDiagID()) return Owned(From); Diag(Loc, AmbigDiag) << T << From->getSourceRange(); for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { CXXConversionDecl *Conv = cast(ViableConversions[I]->getUnderlyingDecl()); QualType ConvTy = Conv->getConversionType().getNonReferenceType(); Diag(Conv->getLocation(), AmbigNote) << ConvTy->isEnumeralType() << ConvTy; } return Owned(From); } if (!isIntegralOrEnumerationType(From->getType(), AllowScopedEnumerations) && NotIntDiag.getDiagID()) Diag(Loc, NotIntDiag) << From->getType() << From->getSourceRange(); return DefaultLvalueConversion(From); } /// AddOverloadCandidate - Adds the given function to the set of /// candidate functions, using the given function call arguments. If /// @p SuppressUserConversions, then don't allow user-defined /// conversions via constructors or conversion operators. /// /// \para PartialOverloading true if we are performing "partial" overloading /// based on an incomplete set of function arguments. This feature is used by /// code completion. void Sema::AddOverloadCandidate(FunctionDecl *Function, DeclAccessPair FoundDecl, llvm::ArrayRef Args, OverloadCandidateSet& CandidateSet, bool SuppressUserConversions, bool PartialOverloading, bool AllowExplicit) { const FunctionProtoType* Proto = dyn_cast(Function->getType()->getAs()); assert(Proto && "Functions without a prototype cannot be overloaded"); assert(!Function->getDescribedFunctionTemplate() && "Use AddTemplateOverloadCandidate for function templates"); if (CXXMethodDecl *Method = dyn_cast(Function)) { if (!isa(Method)) { // If we get here, it's because we're calling a member function // that is named without a member access expression (e.g., // "this->f") that was either written explicitly or created // implicitly. This can happen with a qualified call to a member // function, e.g., X::f(). We use an empty type for the implied // object argument (C++ [over.call.func]p3), and the acting context // is irrelevant. AddMethodCandidate(Method, FoundDecl, Method->getParent(), QualType(), Expr::Classification::makeSimpleLValue(), Args, CandidateSet, SuppressUserConversions); return; } // We treat a constructor like a non-member function, since its object // argument doesn't participate in overload resolution. } if (!CandidateSet.isNewCandidate(Function)) return; // Overload resolution is always an unevaluated context. EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); if (CXXConstructorDecl *Constructor = dyn_cast(Function)){ // C++ [class.copy]p3: // A member function template is never instantiated to perform the copy // of a class object to an object of its class type. QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); if (Args.size() == 1 && Constructor->isSpecializationCopyingObject() && (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || IsDerivedFrom(Args[0]->getType(), ClassType))) return; } // Add this candidate OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size()); Candidate.FoundDecl = FoundDecl; Candidate.Function = Function; Candidate.Viable = true; Candidate.IsSurrogate = false; Candidate.IgnoreObjectArgument = false; Candidate.ExplicitCallArguments = Args.size(); unsigned NumArgsInProto = Proto->getNumArgs(); // (C++ 13.3.2p2): A candidate function having fewer than m // parameters is viable only if it has an ellipsis in its parameter // list (8.3.5). if ((Args.size() + (PartialOverloading && Args.size())) > NumArgsInProto && !Proto->isVariadic()) { Candidate.Viable = false; Candidate.FailureKind = ovl_fail_too_many_arguments; return; } // (C++ 13.3.2p2): A candidate function having more than m parameters // is viable only if the (m+1)st parameter has a default argument // (8.3.6). For the purposes of overload resolution, the // parameter list is truncated on the right, so that there are // exactly m parameters. unsigned MinRequiredArgs = Function->getMinRequiredArguments(); if (Args.size() < MinRequiredArgs && !PartialOverloading) { // Not enough arguments. Candidate.Viable = false; Candidate.FailureKind = ovl_fail_too_few_arguments; return; } // (CUDA B.1): Check for invalid calls between targets. if (getLangOpts().CUDA) if (const FunctionDecl *Caller = dyn_cast(CurContext)) if (CheckCUDATarget(Caller, Function)) { Candidate.Viable = false; Candidate.FailureKind = ovl_fail_bad_target; return; } // Determine the implicit conversion sequences for each of the // arguments. for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) { if (ArgIdx < NumArgsInProto) { // (C++ 13.3.2p3): for F to be a viable function, there shall // exist for each argument an implicit conversion sequence // (13.3.3.1) that converts that argument to the corresponding // parameter of F. QualType ParamType = Proto->getArgType(ArgIdx); Candidate.Conversions[ArgIdx] = TryCopyInitialization(*this, Args[ArgIdx], ParamType, SuppressUserConversions, /*InOverloadResolution=*/true, /*AllowObjCWritebackConversion=*/ getLangOpts().ObjCAutoRefCount, AllowExplicit); if (Candidate.Conversions[ArgIdx].isBad()) { Candidate.Viable = false; Candidate.FailureKind = ovl_fail_bad_conversion; break; } } else { // (C++ 13.3.2p2): For the purposes of overload resolution, any // argument for which there is no corresponding parameter is // considered to ""match the ellipsis" (C+ 13.3.3.1.3). Candidate.Conversions[ArgIdx].setEllipsis(); } } } /// \brief Add all of the function declarations in the given function set to /// the overload canddiate set. void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, llvm::ArrayRef Args, OverloadCandidateSet& CandidateSet, bool SuppressUserConversions, TemplateArgumentListInfo *ExplicitTemplateArgs) { for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { NamedDecl *D = F.getDecl()->getUnderlyingDecl(); if (FunctionDecl *FD = dyn_cast(D)) { if (isa(FD) && !cast(FD)->isStatic()) AddMethodCandidate(cast(FD), F.getPair(), cast(FD)->getParent(), Args[0]->getType(), Args[0]->Classify(Context), Args.slice(1), CandidateSet, SuppressUserConversions); else AddOverloadCandidate(FD, F.getPair(), Args, CandidateSet, SuppressUserConversions); } else { FunctionTemplateDecl *FunTmpl = cast(D); if (isa(FunTmpl->getTemplatedDecl()) && !cast(FunTmpl->getTemplatedDecl())->isStatic()) AddMethodTemplateCandidate(FunTmpl, F.getPair(), cast(FunTmpl->getDeclContext()), ExplicitTemplateArgs, Args[0]->getType(), Args[0]->Classify(Context), Args.slice(1), CandidateSet, SuppressUserConversions); else AddTemplateOverloadCandidate(FunTmpl, F.getPair(), ExplicitTemplateArgs, Args, CandidateSet, SuppressUserConversions); } } } /// AddMethodCandidate - Adds a named decl (which is some kind of /// method) as a method candidate to the given overload set. void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, QualType ObjectType, Expr::Classification ObjectClassification, Expr **Args, unsigned NumArgs, OverloadCandidateSet& CandidateSet, bool SuppressUserConversions) { NamedDecl *Decl = FoundDecl.getDecl(); CXXRecordDecl *ActingContext = cast(Decl->getDeclContext()); if (isa(Decl)) Decl = cast(Decl)->getTargetDecl(); if (FunctionTemplateDecl *TD = dyn_cast(Decl)) { assert(isa(TD->getTemplatedDecl()) && "Expected a member function template"); AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, /*ExplicitArgs*/ 0, ObjectType, ObjectClassification, llvm::makeArrayRef(Args, NumArgs), CandidateSet, SuppressUserConversions); } else { AddMethodCandidate(cast(Decl), FoundDecl, ActingContext, ObjectType, ObjectClassification, llvm::makeArrayRef(Args, NumArgs), CandidateSet, SuppressUserConversions); } } /// AddMethodCandidate - Adds the given C++ member function to the set /// of candidate functions, using the given function call arguments /// and the object argument (@c Object). For example, in a call /// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain /// both @c a1 and @c a2. If @p SuppressUserConversions, then don't /// allow user-defined conversions via constructors or conversion /// operators. void Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, CXXRecordDecl *ActingContext, QualType ObjectType, Expr::Classification ObjectClassification, llvm::ArrayRef Args, OverloadCandidateSet& CandidateSet, bool SuppressUserConversions) { const FunctionProtoType* Proto = dyn_cast(Method->getType()->getAs()); assert(Proto && "Methods without a prototype cannot be overloaded"); assert(!isa(Method) && "Use AddOverloadCandidate for constructors"); if (!CandidateSet.isNewCandidate(Method)) return; // Overload resolution is always an unevaluated context. EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); // Add this candidate OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1); Candidate.FoundDecl = FoundDecl; Candidate.Function = Method; Candidate.IsSurrogate = false; Candidate.IgnoreObjectArgument = false; Candidate.ExplicitCallArguments = Args.size(); unsigned NumArgsInProto = Proto->getNumArgs(); // (C++ 13.3.2p2): A candidate function having fewer than m // parameters is viable only if it has an ellipsis in its parameter // list (8.3.5). if (Args.size() > NumArgsInProto && !Proto->isVariadic()) { Candidate.Viable = false; Candidate.FailureKind = ovl_fail_too_many_arguments; return; } // (C++ 13.3.2p2): A candidate function having more than m parameters // is viable only if the (m+1)st parameter has a default argument // (8.3.6). For the purposes of overload resolution, the // parameter list is truncated on the right, so that there are // exactly m parameters. unsigned MinRequiredArgs = Method->getMinRequiredArguments(); if (Args.size() < MinRequiredArgs) { // Not enough arguments. Candidate.Viable = false; Candidate.FailureKind = ovl_fail_too_few_arguments; return; } Candidate.Viable = true; if (Method->isStatic() || ObjectType.isNull()) // The implicit object argument is ignored. Candidate.IgnoreObjectArgument = true; else { // Determine the implicit conversion sequence for the object // parameter. Candidate.Conversions[0] = TryObjectArgumentInitialization(*this, ObjectType, ObjectClassification, Method, ActingContext); if (Candidate.Conversions[0].isBad()) { Candidate.Viable = false; Candidate.FailureKind = ovl_fail_bad_conversion; return; } } // Determine the implicit conversion sequences for each of the // arguments. for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) { if (ArgIdx < NumArgsInProto) { // (C++ 13.3.2p3): for F to be a viable function, there shall // exist for each argument an implicit conversion sequence // (13.3.3.1) that converts that argument to the corresponding // parameter of F. QualType ParamType = Proto->getArgType(ArgIdx); Candidate.Conversions[ArgIdx + 1] = TryCopyInitialization(*this, Args[ArgIdx], ParamType, SuppressUserConversions, /*InOverloadResolution=*/true, /*AllowObjCWritebackConversion=*/ getLangOpts().ObjCAutoRefCount); if (Candidate.Conversions[ArgIdx + 1].isBad()) { Candidate.Viable = false; Candidate.FailureKind = ovl_fail_bad_conversion; break; } } else { // (C++ 13.3.2p2): For the purposes of overload resolution, any // argument for which there is no corresponding parameter is // considered to ""match the ellipsis" (C+ 13.3.3.1.3). Candidate.Conversions[ArgIdx + 1].setEllipsis(); } } } /// \brief Add a C++ member function template as a candidate to the candidate /// set, using template argument deduction to produce an appropriate member /// function template specialization. void Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, DeclAccessPair FoundDecl, CXXRecordDecl *ActingContext, TemplateArgumentListInfo *ExplicitTemplateArgs, QualType ObjectType, Expr::Classification ObjectClassification, llvm::ArrayRef Args, OverloadCandidateSet& CandidateSet, bool SuppressUserConversions) { if (!CandidateSet.isNewCandidate(MethodTmpl)) return; // C++ [over.match.funcs]p7: // In each case where a candidate is a function template, candidate // function template specializations are generated using template argument // deduction (14.8.3, 14.8.2). Those candidates are then handled as // candidate functions in the usual way.113) A given name can refer to one // or more function templates and also to a set of overloaded non-template // functions. In such a case, the candidate functions generated from each // function template are combined with the set of non-template candidate // functions. TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); FunctionDecl *Specialization = 0; if (TemplateDeductionResult Result = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, Args, Specialization, Info)) { OverloadCandidate &Candidate = CandidateSet.addCandidate(); Candidate.FoundDecl = FoundDecl; Candidate.Function = MethodTmpl->getTemplatedDecl(); Candidate.Viable = false; Candidate.FailureKind = ovl_fail_bad_deduction; Candidate.IsSurrogate = false; Candidate.IgnoreObjectArgument = false; Candidate.ExplicitCallArguments = Args.size(); Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, Info); return; } // Add the function template specialization produced by template argument // deduction as a candidate. assert(Specialization && "Missing member function template specialization?"); assert(isa(Specialization) && "Specialization is not a member function?"); AddMethodCandidate(cast(Specialization), FoundDecl, ActingContext, ObjectType, ObjectClassification, Args, CandidateSet, SuppressUserConversions); } /// \brief Add a C++ function template specialization as a candidate /// in the candidate set, using template argument deduction to produce /// an appropriate function template specialization. void Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, DeclAccessPair FoundDecl, TemplateArgumentListInfo *ExplicitTemplateArgs, llvm::ArrayRef Args, OverloadCandidateSet& CandidateSet, bool SuppressUserConversions) { if (!CandidateSet.isNewCandidate(FunctionTemplate)) return; // C++ [over.match.funcs]p7: // In each case where a candidate is a function template, candidate // function template specializations are generated using template argument // deduction (14.8.3, 14.8.2). Those candidates are then handled as // candidate functions in the usual way.113) A given name can refer to one // or more function templates and also to a set of overloaded non-template // functions. In such a case, the candidate functions generated from each // function template are combined with the set of non-template candidate // functions. TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); FunctionDecl *Specialization = 0; if (TemplateDeductionResult Result = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, Args, Specialization, Info)) { OverloadCandidate &Candidate = CandidateSet.addCandidate(); Candidate.FoundDecl = FoundDecl; Candidate.Function = FunctionTemplate->getTemplatedDecl(); Candidate.Viable = false; Candidate.FailureKind = ovl_fail_bad_deduction; Candidate.IsSurrogate = false; Candidate.IgnoreObjectArgument = false; Candidate.ExplicitCallArguments = Args.size(); Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, Info); return; } // Add the function template specialization produced by template argument // deduction as a candidate. assert(Specialization && "Missing function template specialization?"); AddOverloadCandidate(Specialization, FoundDecl, Args, CandidateSet, SuppressUserConversions); } /// AddConversionCandidate - Add a C++ conversion function as a /// candidate in the candidate set (C++ [over.match.conv], /// C++ [over.match.copy]). From is the expression we're converting from, /// and ToType is the type that we're eventually trying to convert to /// (which may or may not be the same type as the type that the /// conversion function produces). void Sema::AddConversionCandidate(CXXConversionDecl *Conversion, DeclAccessPair FoundDecl, CXXRecordDecl *ActingContext, Expr *From, QualType ToType, OverloadCandidateSet& CandidateSet) { assert(!Conversion->getDescribedFunctionTemplate() && "Conversion function templates use AddTemplateConversionCandidate"); QualType ConvType = Conversion->getConversionType().getNonReferenceType(); if (!CandidateSet.isNewCandidate(Conversion)) return; // Overload resolution is always an unevaluated context. EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); // Add this candidate OverloadCandidate &Candidate = CandidateSet.addCandidate(1); Candidate.FoundDecl = FoundDecl; Candidate.Function = Conversion; Candidate.IsSurrogate = false; Candidate.IgnoreObjectArgument = false; Candidate.FinalConversion.setAsIdentityConversion(); Candidate.FinalConversion.setFromType(ConvType); Candidate.FinalConversion.setAllToTypes(ToType); Candidate.Viable = true; Candidate.ExplicitCallArguments = 1; // C++ [over.match.funcs]p4: // For conversion functions, the function is considered to be a member of // the class of the implicit implied object argument for the purpose of // defining the type of the implicit object parameter. // // Determine the implicit conversion sequence for the implicit // object parameter. QualType ImplicitParamType = From->getType(); if (const PointerType *FromPtrType = ImplicitParamType->getAs()) ImplicitParamType = FromPtrType->getPointeeType(); CXXRecordDecl *ConversionContext = cast(ImplicitParamType->getAs()->getDecl()); Candidate.Conversions[0] = TryObjectArgumentInitialization(*this, From->getType(), From->Classify(Context), Conversion, ConversionContext); if (Candidate.Conversions[0].isBad()) { Candidate.Viable = false; Candidate.FailureKind = ovl_fail_bad_conversion; return; } // We won't go through a user-define type conversion function to convert a // derived to base as such conversions are given Conversion Rank. They only // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] QualType FromCanon = Context.getCanonicalType(From->getType().getUnqualifiedType()); QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { Candidate.Viable = false; Candidate.FailureKind = ovl_fail_trivial_conversion; return; } // To determine what the conversion from the result of calling the // conversion function to the type we're eventually trying to // convert to (ToType), we need to synthesize a call to the // conversion function and attempt copy initialization from it. This // makes sure that we get the right semantics with respect to // lvalues/rvalues and the type. Fortunately, we can allocate this // call on the stack and we don't need its arguments to be // well-formed. DeclRefExpr ConversionRef(Conversion, false, Conversion->getType(), VK_LValue, From->getLocStart()); ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack, Context.getPointerType(Conversion->getType()), CK_FunctionToPointerDecay, &ConversionRef, VK_RValue); QualType ConversionType = Conversion->getConversionType(); if (RequireCompleteType(From->getLocStart(), ConversionType, 0)) { Candidate.Viable = false; Candidate.FailureKind = ovl_fail_bad_final_conversion; return; } ExprValueKind VK = Expr::getValueKindForType(ConversionType); // Note that it is safe to allocate CallExpr on the stack here because // there are 0 arguments (i.e., nothing is allocated using ASTContext's // allocator). QualType CallResultType = ConversionType.getNonLValueExprType(Context); CallExpr Call(Context, &ConversionFn, 0, 0, CallResultType, VK, From->getLocStart()); ImplicitConversionSequence ICS = TryCopyInitialization(*this, &Call, ToType, /*SuppressUserConversions=*/true, /*InOverloadResolution=*/false, /*AllowObjCWritebackConversion=*/false); switch (ICS.getKind()) { case ImplicitConversionSequence::StandardConversion: Candidate.FinalConversion = ICS.Standard; // C++ [over.ics.user]p3: // If the user-defined conversion is specified by a specialization of a // conversion function template, the second standard conversion sequence // shall have exact match rank. if (Conversion->getPrimaryTemplate() && GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { Candidate.Viable = false; Candidate.FailureKind = ovl_fail_final_conversion_not_exact; } // C++0x [dcl.init.ref]p5: // In the second case, if the reference is an rvalue reference and // the second standard conversion sequence of the user-defined // conversion sequence includes an lvalue-to-rvalue conversion, the // program is ill-formed. if (ToType->isRValueReferenceType() && ICS.Standard.First == ICK_Lvalue_To_Rvalue) { Candidate.Viable = false; Candidate.FailureKind = ovl_fail_bad_final_conversion; } break; case ImplicitConversionSequence::BadConversion: Candidate.Viable = false; Candidate.FailureKind = ovl_fail_bad_final_conversion; break; default: llvm_unreachable( "Can only end up with a standard conversion sequence or failure"); } } /// \brief Adds a conversion function template specialization /// candidate to the overload set, using template argument deduction /// to deduce the template arguments of the conversion function /// template from the type that we are converting to (C++ /// [temp.deduct.conv]). void Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, DeclAccessPair FoundDecl, CXXRecordDecl *ActingDC, Expr *From, QualType ToType, OverloadCandidateSet &CandidateSet) { assert(isa(FunctionTemplate->getTemplatedDecl()) && "Only conversion function templates permitted here"); if (!CandidateSet.isNewCandidate(FunctionTemplate)) return; TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); CXXConversionDecl *Specialization = 0; if (TemplateDeductionResult Result = DeduceTemplateArguments(FunctionTemplate, ToType, Specialization, Info)) { OverloadCandidate &Candidate = CandidateSet.addCandidate(); Candidate.FoundDecl = FoundDecl; Candidate.Function = FunctionTemplate->getTemplatedDecl(); Candidate.Viable = false; Candidate.FailureKind = ovl_fail_bad_deduction; Candidate.IsSurrogate = false; Candidate.IgnoreObjectArgument = false; Candidate.ExplicitCallArguments = 1; Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, Info); return; } // Add the conversion function template specialization produced by // template argument deduction as a candidate. assert(Specialization && "Missing function template specialization?"); AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, CandidateSet); } /// AddSurrogateCandidate - Adds a "surrogate" candidate function that /// converts the given @c Object to a function pointer via the /// conversion function @c Conversion, and then attempts to call it /// with the given arguments (C++ [over.call.object]p2-4). Proto is /// the type of function that we'll eventually be calling. void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, DeclAccessPair FoundDecl, CXXRecordDecl *ActingContext, const FunctionProtoType *Proto, Expr *Object, llvm::ArrayRef Args, OverloadCandidateSet& CandidateSet) { if (!CandidateSet.isNewCandidate(Conversion)) return; // Overload resolution is always an unevaluated context. EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1); Candidate.FoundDecl = FoundDecl; Candidate.Function = 0; Candidate.Surrogate = Conversion; Candidate.Viable = true; Candidate.IsSurrogate = true; Candidate.IgnoreObjectArgument = false; Candidate.ExplicitCallArguments = Args.size(); // Determine the implicit conversion sequence for the implicit // object parameter. ImplicitConversionSequence ObjectInit = TryObjectArgumentInitialization(*this, Object->getType(), Object->Classify(Context), Conversion, ActingContext); if (ObjectInit.isBad()) { Candidate.Viable = false; Candidate.FailureKind = ovl_fail_bad_conversion; Candidate.Conversions[0] = ObjectInit; return; } // The first conversion is actually a user-defined conversion whose // first conversion is ObjectInit's standard conversion (which is // effectively a reference binding). Record it as such. Candidate.Conversions[0].setUserDefined(); Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; Candidate.Conversions[0].UserDefined.EllipsisConversion = false; Candidate.Conversions[0].UserDefined.HadMultipleCandidates = false; Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; Candidate.Conversions[0].UserDefined.FoundConversionFunction = FoundDecl; Candidate.Conversions[0].UserDefined.After = Candidate.Conversions[0].UserDefined.Before; Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); // Find the unsigned NumArgsInProto = Proto->getNumArgs(); // (C++ 13.3.2p2): A candidate function having fewer than m // parameters is viable only if it has an ellipsis in its parameter // list (8.3.5). if (Args.size() > NumArgsInProto && !Proto->isVariadic()) { Candidate.Viable = false; Candidate.FailureKind = ovl_fail_too_many_arguments; return; } // Function types don't have any default arguments, so just check if // we have enough arguments. if (Args.size() < NumArgsInProto) { // Not enough arguments. Candidate.Viable = false; Candidate.FailureKind = ovl_fail_too_few_arguments; return; } // Determine the implicit conversion sequences for each of the // arguments. for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) { if (ArgIdx < NumArgsInProto) { // (C++ 13.3.2p3): for F to be a viable function, there shall // exist for each argument an implicit conversion sequence // (13.3.3.1) that converts that argument to the corresponding // parameter of F. QualType ParamType = Proto->getArgType(ArgIdx); Candidate.Conversions[ArgIdx + 1] = TryCopyInitialization(*this, Args[ArgIdx], ParamType, /*SuppressUserConversions=*/false, /*InOverloadResolution=*/false, /*AllowObjCWritebackConversion=*/ getLangOpts().ObjCAutoRefCount); if (Candidate.Conversions[ArgIdx + 1].isBad()) { Candidate.Viable = false; Candidate.FailureKind = ovl_fail_bad_conversion; break; } } else { // (C++ 13.3.2p2): For the purposes of overload resolution, any // argument for which there is no corresponding parameter is // considered to ""match the ellipsis" (C+ 13.3.3.1.3). Candidate.Conversions[ArgIdx + 1].setEllipsis(); } } } /// \brief Add overload candidates for overloaded operators that are /// member functions. /// /// Add the overloaded operator candidates that are member functions /// for the operator Op that was used in an operator expression such /// as "x Op y". , Args/NumArgs provides the operator arguments, and /// CandidateSet will store the added overload candidates. (C++ /// [over.match.oper]). void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, SourceLocation OpLoc, Expr **Args, unsigned NumArgs, OverloadCandidateSet& CandidateSet, SourceRange OpRange) { DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); // C++ [over.match.oper]p3: // For a unary operator @ with an operand of a type whose // cv-unqualified version is T1, and for a binary operator @ with // a left operand of a type whose cv-unqualified version is T1 and // a right operand of a type whose cv-unqualified version is T2, // three sets of candidate functions, designated member // candidates, non-member candidates and built-in candidates, are // constructed as follows: QualType T1 = Args[0]->getType(); // -- If T1 is a class type, the set of member candidates is the // result of the qualified lookup of T1::operator@ // (13.3.1.1.1); otherwise, the set of member candidates is // empty. if (const RecordType *T1Rec = T1->getAs()) { // Complete the type if it can be completed. Otherwise, we're done. if (RequireCompleteType(OpLoc, T1, PDiag())) return; LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); LookupQualifiedName(Operators, T1Rec->getDecl()); Operators.suppressDiagnostics(); for (LookupResult::iterator Oper = Operators.begin(), OperEnd = Operators.end(); Oper != OperEnd; ++Oper) AddMethodCandidate(Oper.getPair(), Args[0]->getType(), Args[0]->Classify(Context), Args + 1, NumArgs - 1, CandidateSet, /* SuppressUserConversions = */ false); } } /// AddBuiltinCandidate - Add a candidate for a built-in /// operator. ResultTy and ParamTys are the result and parameter types /// of the built-in candidate, respectively. Args and NumArgs are the /// arguments being passed to the candidate. IsAssignmentOperator /// should be true when this built-in candidate is an assignment /// operator. NumContextualBoolArguments is the number of arguments /// (at the beginning of the argument list) that will be contextually /// converted to bool. void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, Expr **Args, unsigned NumArgs, OverloadCandidateSet& CandidateSet, bool IsAssignmentOperator, unsigned NumContextualBoolArguments) { // Overload resolution is always an unevaluated context. EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); // Add this candidate OverloadCandidate &Candidate = CandidateSet.addCandidate(NumArgs); Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); Candidate.Function = 0; Candidate.IsSurrogate = false; Candidate.IgnoreObjectArgument = false; Candidate.BuiltinTypes.ResultTy = ResultTy; for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; // Determine the implicit conversion sequences for each of the // arguments. Candidate.Viable = true; Candidate.ExplicitCallArguments = NumArgs; for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { // C++ [over.match.oper]p4: // For the built-in assignment operators, conversions of the // left operand are restricted as follows: // -- no temporaries are introduced to hold the left operand, and // -- no user-defined conversions are applied to the left // operand to achieve a type match with the left-most // parameter of a built-in candidate. // // We block these conversions by turning off user-defined // conversions, since that is the only way that initialization of // a reference to a non-class type can occur from something that // is not of the same type. if (ArgIdx < NumContextualBoolArguments) { assert(ParamTys[ArgIdx] == Context.BoolTy && "Contextual conversion to bool requires bool type"); Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(*this, Args[ArgIdx]); } else { Candidate.Conversions[ArgIdx] = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], ArgIdx == 0 && IsAssignmentOperator, /*InOverloadResolution=*/false, /*AllowObjCWritebackConversion=*/ getLangOpts().ObjCAutoRefCount); } if (Candidate.Conversions[ArgIdx].isBad()) { Candidate.Viable = false; Candidate.FailureKind = ovl_fail_bad_conversion; break; } } } /// BuiltinCandidateTypeSet - A set of types that will be used for the /// candidate operator functions for built-in operators (C++ /// [over.built]). The types are separated into pointer types and /// enumeration types. class BuiltinCandidateTypeSet { /// TypeSet - A set of types. typedef llvm::SmallPtrSet TypeSet; /// PointerTypes - The set of pointer types that will be used in the /// built-in candidates. TypeSet PointerTypes; /// MemberPointerTypes - The set of member pointer types that will be /// used in the built-in candidates. TypeSet MemberPointerTypes; /// EnumerationTypes - The set of enumeration types that will be /// used in the built-in candidates. TypeSet EnumerationTypes; /// \brief The set of vector types that will be used in the built-in /// candidates. TypeSet VectorTypes; /// \brief A flag indicating non-record types are viable candidates bool HasNonRecordTypes; /// \brief A flag indicating whether either arithmetic or enumeration types /// were present in the candidate set. bool HasArithmeticOrEnumeralTypes; /// \brief A flag indicating whether the nullptr type was present in the /// candidate set. bool HasNullPtrType; /// Sema - The semantic analysis instance where we are building the /// candidate type set. Sema &SemaRef; /// Context - The AST context in which we will build the type sets. ASTContext &Context; bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, const Qualifiers &VisibleQuals); bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); public: /// iterator - Iterates through the types that are part of the set. typedef TypeSet::iterator iterator; BuiltinCandidateTypeSet(Sema &SemaRef) : HasNonRecordTypes(false), HasArithmeticOrEnumeralTypes(false), HasNullPtrType(false), SemaRef(SemaRef), Context(SemaRef.Context) { } void AddTypesConvertedFrom(QualType Ty, SourceLocation Loc, bool AllowUserConversions, bool AllowExplicitConversions, const Qualifiers &VisibleTypeConversionsQuals); /// pointer_begin - First pointer type found; iterator pointer_begin() { return PointerTypes.begin(); } /// pointer_end - Past the last pointer type found; iterator pointer_end() { return PointerTypes.end(); } /// member_pointer_begin - First member pointer type found; iterator member_pointer_begin() { return MemberPointerTypes.begin(); } /// member_pointer_end - Past the last member pointer type found; iterator member_pointer_end() { return MemberPointerTypes.end(); } /// enumeration_begin - First enumeration type found; iterator enumeration_begin() { return EnumerationTypes.begin(); } /// enumeration_end - Past the last enumeration type found; iterator enumeration_end() { return EnumerationTypes.end(); } iterator vector_begin() { return VectorTypes.begin(); } iterator vector_end() { return VectorTypes.end(); } bool hasNonRecordTypes() { return HasNonRecordTypes; } bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; } bool hasNullPtrType() const { return HasNullPtrType; } }; /// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to /// the set of pointer types along with any more-qualified variants of /// that type. For example, if @p Ty is "int const *", this routine /// will add "int const *", "int const volatile *", "int const /// restrict *", and "int const volatile restrict *" to the set of /// pointer types. Returns true if the add of @p Ty itself succeeded, /// false otherwise. /// /// FIXME: what to do about extended qualifiers? bool BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, const Qualifiers &VisibleQuals) { // Insert this type. if (!PointerTypes.insert(Ty)) return false; QualType PointeeTy; const PointerType *PointerTy = Ty->getAs(); bool buildObjCPtr = false; if (!PointerTy) { if (const ObjCObjectPointerType *PTy = Ty->getAs()) { PointeeTy = PTy->getPointeeType(); buildObjCPtr = true; } else llvm_unreachable("type was not a pointer type!"); } else PointeeTy = PointerTy->getPointeeType(); // Don't add qualified variants of arrays. For one, they're not allowed // (the qualifier would sink to the element type), and for another, the // only overload situation where it matters is subscript or pointer +- int, // and those shouldn't have qualifier variants anyway. if (PointeeTy->isArrayType()) return true; unsigned BaseCVR = PointeeTy.getCVRQualifiers(); if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) BaseCVR = Array->getElementType().getCVRQualifiers(); bool hasVolatile = VisibleQuals.hasVolatile(); bool hasRestrict = VisibleQuals.hasRestrict(); // Iterate through all strict supersets of BaseCVR. for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { if ((CVR | BaseCVR) != CVR) continue; // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere // in the types. if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); if (!buildObjCPtr) PointerTypes.insert(Context.getPointerType(QPointeeTy)); else PointerTypes.insert(Context.getObjCObjectPointerType(QPointeeTy)); } return true; } /// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty /// to the set of pointer types along with any more-qualified variants of /// that type. For example, if @p Ty is "int const *", this routine /// will add "int const *", "int const volatile *", "int const /// restrict *", and "int const volatile restrict *" to the set of /// pointer types. Returns true if the add of @p Ty itself succeeded, /// false otherwise. /// /// FIXME: what to do about extended qualifiers? bool BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( QualType Ty) { // Insert this type. if (!MemberPointerTypes.insert(Ty)) return false; const MemberPointerType *PointerTy = Ty->getAs(); assert(PointerTy && "type was not a member pointer type!"); QualType PointeeTy = PointerTy->getPointeeType(); // Don't add qualified variants of arrays. For one, they're not allowed // (the qualifier would sink to the element type), and for another, the // only overload situation where it matters is subscript or pointer +- int, // and those shouldn't have qualifier variants anyway. if (PointeeTy->isArrayType()) return true; const Type *ClassTy = PointerTy->getClass(); // Iterate through all strict supersets of the pointee type's CVR // qualifiers. unsigned BaseCVR = PointeeTy.getCVRQualifiers(); for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { if ((CVR | BaseCVR) != CVR) continue; QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); MemberPointerTypes.insert( Context.getMemberPointerType(QPointeeTy, ClassTy)); } return true; } /// AddTypesConvertedFrom - Add each of the types to which the type @p /// Ty can be implicit converted to the given set of @p Types. We're /// primarily interested in pointer types and enumeration types. We also /// take member pointer types, for the conditional operator. /// AllowUserConversions is true if we should look at the conversion /// functions of a class type, and AllowExplicitConversions if we /// should also include the explicit conversion functions of a class /// type. void BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, SourceLocation Loc, bool AllowUserConversions, bool AllowExplicitConversions, const Qualifiers &VisibleQuals) { // Only deal with canonical types. Ty = Context.getCanonicalType(Ty); // Look through reference types; they aren't part of the type of an // expression for the purposes of conversions. if (const ReferenceType *RefTy = Ty->getAs()) Ty = RefTy->getPointeeType(); // If we're dealing with an array type, decay to the pointer. if (Ty->isArrayType()) Ty = SemaRef.Context.getArrayDecayedType(Ty); // Otherwise, we don't care about qualifiers on the type. Ty = Ty.getLocalUnqualifiedType(); // Flag if we ever add a non-record type. const RecordType *TyRec = Ty->getAs(); HasNonRecordTypes = HasNonRecordTypes || !TyRec; // Flag if we encounter an arithmetic type. HasArithmeticOrEnumeralTypes = HasArithmeticOrEnumeralTypes || Ty->isArithmeticType(); if (Ty->isObjCIdType() || Ty->isObjCClassType()) PointerTypes.insert(Ty); else if (Ty->getAs() || Ty->getAs()) { // Insert our type, and its more-qualified variants, into the set // of types. if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) return; } else if (Ty->isMemberPointerType()) { // Member pointers are far easier, since the pointee can't be converted. if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) return; } else if (Ty->isEnumeralType()) { HasArithmeticOrEnumeralTypes = true; EnumerationTypes.insert(Ty); } else if (Ty->isVectorType()) { // We treat vector types as arithmetic types in many contexts as an // extension. HasArithmeticOrEnumeralTypes = true; VectorTypes.insert(Ty); } else if (Ty->isNullPtrType()) { HasNullPtrType = true; } else if (AllowUserConversions && TyRec) { // No conversion functions in incomplete types. if (SemaRef.RequireCompleteType(Loc, Ty, 0)) return; CXXRecordDecl *ClassDecl = cast(TyRec->getDecl()); const UnresolvedSetImpl *Conversions = ClassDecl->getVisibleConversionFunctions(); for (UnresolvedSetImpl::iterator I = Conversions->begin(), E = Conversions->end(); I != E; ++I) { NamedDecl *D = I.getDecl(); if (isa(D)) D = cast(D)->getTargetDecl(); // Skip conversion function templates; they don't tell us anything // about which builtin types we can convert to. if (isa(D)) continue; CXXConversionDecl *Conv = cast(D); if (AllowExplicitConversions || !Conv->isExplicit()) { AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, VisibleQuals); } } } } /// \brief Helper function for AddBuiltinOperatorCandidates() that adds /// the volatile- and non-volatile-qualified assignment operators for the /// given type to the candidate set. static void AddBuiltinAssignmentOperatorCandidates(Sema &S, QualType T, Expr **Args, unsigned NumArgs, OverloadCandidateSet &CandidateSet) { QualType ParamTypes[2]; // T& operator=(T&, T) ParamTypes[0] = S.Context.getLValueReferenceType(T); ParamTypes[1] = T; S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, /*IsAssignmentOperator=*/true); if (!S.Context.getCanonicalType(T).isVolatileQualified()) { // volatile T& operator=(volatile T&, T) ParamTypes[0] = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); ParamTypes[1] = T; S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, /*IsAssignmentOperator=*/true); } } /// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, /// if any, found in visible type conversion functions found in ArgExpr's type. static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { Qualifiers VRQuals; const RecordType *TyRec; if (const MemberPointerType *RHSMPType = ArgExpr->getType()->getAs()) TyRec = RHSMPType->getClass()->getAs(); else TyRec = ArgExpr->getType()->getAs(); if (!TyRec) { // Just to be safe, assume the worst case. VRQuals.addVolatile(); VRQuals.addRestrict(); return VRQuals; } CXXRecordDecl *ClassDecl = cast(TyRec->getDecl()); if (!ClassDecl->hasDefinition()) return VRQuals; const UnresolvedSetImpl *Conversions = ClassDecl->getVisibleConversionFunctions(); for (UnresolvedSetImpl::iterator I = Conversions->begin(), E = Conversions->end(); I != E; ++I) { NamedDecl *D = I.getDecl(); if (isa(D)) D = cast(D)->getTargetDecl(); if (CXXConversionDecl *Conv = dyn_cast(D)) { QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); if (const ReferenceType *ResTypeRef = CanTy->getAs()) CanTy = ResTypeRef->getPointeeType(); // Need to go down the pointer/mempointer chain and add qualifiers // as see them. bool done = false; while (!done) { if (const PointerType *ResTypePtr = CanTy->getAs()) CanTy = ResTypePtr->getPointeeType(); else if (const MemberPointerType *ResTypeMPtr = CanTy->getAs()) CanTy = ResTypeMPtr->getPointeeType(); else done = true; if (CanTy.isVolatileQualified()) VRQuals.addVolatile(); if (CanTy.isRestrictQualified()) VRQuals.addRestrict(); if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) return VRQuals; } } } return VRQuals; } namespace { /// \brief Helper class to manage the addition of builtin operator overload /// candidates. It provides shared state and utility methods used throughout /// the process, as well as a helper method to add each group of builtin /// operator overloads from the standard to a candidate set. class BuiltinOperatorOverloadBuilder { // Common instance state available to all overload candidate addition methods. Sema &S; Expr **Args; unsigned NumArgs; Qualifiers VisibleTypeConversionsQuals; bool HasArithmeticOrEnumeralCandidateType; SmallVectorImpl &CandidateTypes; OverloadCandidateSet &CandidateSet; // Define some constants used to index and iterate over the arithemetic types // provided via the getArithmeticType() method below. // The "promoted arithmetic types" are the arithmetic // types are that preserved by promotion (C++ [over.built]p2). static const unsigned FirstIntegralType = 3; static const unsigned LastIntegralType = 18; static const unsigned FirstPromotedIntegralType = 3, LastPromotedIntegralType = 9; static const unsigned FirstPromotedArithmeticType = 0, LastPromotedArithmeticType = 9; static const unsigned NumArithmeticTypes = 18; /// \brief Get the canonical type for a given arithmetic type index. CanQualType getArithmeticType(unsigned index) { assert(index < NumArithmeticTypes); static CanQualType ASTContext::* const ArithmeticTypes[NumArithmeticTypes] = { // Start of promoted types. &ASTContext::FloatTy, &ASTContext::DoubleTy, &ASTContext::LongDoubleTy, // Start of integral types. &ASTContext::IntTy, &ASTContext::LongTy, &ASTContext::LongLongTy, &ASTContext::UnsignedIntTy, &ASTContext::UnsignedLongTy, &ASTContext::UnsignedLongLongTy, // End of promoted types. &ASTContext::BoolTy, &ASTContext::CharTy, &ASTContext::WCharTy, &ASTContext::Char16Ty, &ASTContext::Char32Ty, &ASTContext::SignedCharTy, &ASTContext::ShortTy, &ASTContext::UnsignedCharTy, &ASTContext::UnsignedShortTy, // End of integral types. // FIXME: What about complex? }; return S.Context.*ArithmeticTypes[index]; } /// \brief Gets the canonical type resulting from the usual arithemetic /// converions for the given arithmetic types. CanQualType getUsualArithmeticConversions(unsigned L, unsigned R) { // Accelerator table for performing the usual arithmetic conversions. // The rules are basically: // - if either is floating-point, use the wider floating-point // - if same signedness, use the higher rank // - if same size, use unsigned of the higher rank // - use the larger type // These rules, together with the axiom that higher ranks are // never smaller, are sufficient to precompute all of these results // *except* when dealing with signed types of higher rank. // (we could precompute SLL x UI for all known platforms, but it's // better not to make any assumptions). enum PromotedType { Flt, Dbl, LDbl, SI, SL, SLL, UI, UL, ULL, Dep=-1 }; static PromotedType ConversionsTable[LastPromotedArithmeticType] [LastPromotedArithmeticType] = { /* Flt*/ { Flt, Dbl, LDbl, Flt, Flt, Flt, Flt, Flt, Flt }, /* Dbl*/ { Dbl, Dbl, LDbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl }, /*LDbl*/ { LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl }, /* SI*/ { Flt, Dbl, LDbl, SI, SL, SLL, UI, UL, ULL }, /* SL*/ { Flt, Dbl, LDbl, SL, SL, SLL, Dep, UL, ULL }, /* SLL*/ { Flt, Dbl, LDbl, SLL, SLL, SLL, Dep, Dep, ULL }, /* UI*/ { Flt, Dbl, LDbl, UI, Dep, Dep, UI, UL, ULL }, /* UL*/ { Flt, Dbl, LDbl, UL, UL, Dep, UL, UL, ULL }, /* ULL*/ { Flt, Dbl, LDbl, ULL, ULL, ULL, ULL, ULL, ULL }, }; assert(L < LastPromotedArithmeticType); assert(R < LastPromotedArithmeticType); int Idx = ConversionsTable[L][R]; // Fast path: the table gives us a concrete answer. if (Idx != Dep) return getArithmeticType(Idx); // Slow path: we need to compare widths. // An invariant is that the signed type has higher rank. CanQualType LT = getArithmeticType(L), RT = getArithmeticType(R); unsigned LW = S.Context.getIntWidth(LT), RW = S.Context.getIntWidth(RT); // If they're different widths, use the signed type. if (LW > RW) return LT; else if (LW < RW) return RT; // Otherwise, use the unsigned type of the signed type's rank. if (L == SL || R == SL) return S.Context.UnsignedLongTy; assert(L == SLL || R == SLL); return S.Context.UnsignedLongLongTy; } /// \brief Helper method to factor out the common pattern of adding overloads /// for '++' and '--' builtin operators. void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy, bool HasVolatile) { QualType ParamTypes[2] = { S.Context.getLValueReferenceType(CandidateTy), S.Context.IntTy }; // Non-volatile version. if (NumArgs == 1) S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); else S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); // Use a heuristic to reduce number of builtin candidates in the set: // add volatile version only if there are conversions to a volatile type. if (HasVolatile) { ParamTypes[0] = S.Context.getLValueReferenceType( S.Context.getVolatileType(CandidateTy)); if (NumArgs == 1) S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); else S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); } } public: BuiltinOperatorOverloadBuilder( Sema &S, Expr **Args, unsigned NumArgs, Qualifiers VisibleTypeConversionsQuals, bool HasArithmeticOrEnumeralCandidateType, SmallVectorImpl &CandidateTypes, OverloadCandidateSet &CandidateSet) : S(S), Args(Args), NumArgs(NumArgs), VisibleTypeConversionsQuals(VisibleTypeConversionsQuals), HasArithmeticOrEnumeralCandidateType( HasArithmeticOrEnumeralCandidateType), CandidateTypes(CandidateTypes), CandidateSet(CandidateSet) { // Validate some of our static helper constants in debug builds. assert(getArithmeticType(FirstPromotedIntegralType) == S.Context.IntTy && "Invalid first promoted integral type"); assert(getArithmeticType(LastPromotedIntegralType - 1) == S.Context.UnsignedLongLongTy && "Invalid last promoted integral type"); assert(getArithmeticType(FirstPromotedArithmeticType) == S.Context.FloatTy && "Invalid first promoted arithmetic type"); assert(getArithmeticType(LastPromotedArithmeticType - 1) == S.Context.UnsignedLongLongTy && "Invalid last promoted arithmetic type"); } // C++ [over.built]p3: // // For every pair (T, VQ), where T is an arithmetic type, and VQ // is either volatile or empty, there exist candidate operator // functions of the form // // VQ T& operator++(VQ T&); // T operator++(VQ T&, int); // // C++ [over.built]p4: // // For every pair (T, VQ), where T is an arithmetic type other // than bool, and VQ is either volatile or empty, there exist // candidate operator functions of the form // // VQ T& operator--(VQ T&); // T operator--(VQ T&, int); void addPlusPlusMinusMinusArithmeticOverloads(OverloadedOperatorKind Op) { if (!HasArithmeticOrEnumeralCandidateType) return; for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); Arith < NumArithmeticTypes; ++Arith) { addPlusPlusMinusMinusStyleOverloads( getArithmeticType(Arith), VisibleTypeConversionsQuals.hasVolatile()); } } // C++ [over.built]p5: // // For every pair (T, VQ), where T is a cv-qualified or // cv-unqualified object type, and VQ is either volatile or // empty, there exist candidate operator functions of the form // // T*VQ& operator++(T*VQ&); // T*VQ& operator--(T*VQ&); // T* operator++(T*VQ&, int); // T* operator--(T*VQ&, int); void addPlusPlusMinusMinusPointerOverloads() { for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes[0].pointer_begin(), PtrEnd = CandidateTypes[0].pointer_end(); Ptr != PtrEnd; ++Ptr) { // Skip pointer types that aren't pointers to object types. if (!(*Ptr)->getPointeeType()->isObjectType()) continue; addPlusPlusMinusMinusStyleOverloads(*Ptr, (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && VisibleTypeConversionsQuals.hasVolatile())); } } // C++ [over.built]p6: // For every cv-qualified or cv-unqualified object type T, there // exist candidate operator functions of the form // // T& operator*(T*); // // C++ [over.built]p7: // For every function type T that does not have cv-qualifiers or a // ref-qualifier, there exist candidate operator functions of the form // T& operator*(T*); void addUnaryStarPointerOverloads() { for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes[0].pointer_begin(), PtrEnd = CandidateTypes[0].pointer_end(); Ptr != PtrEnd; ++Ptr) { QualType ParamTy = *Ptr; QualType PointeeTy = ParamTy->getPointeeType(); if (!PointeeTy->isObjectType() && !PointeeTy->isFunctionType()) continue; if (const FunctionProtoType *Proto =PointeeTy->getAs()) if (Proto->getTypeQuals() || Proto->getRefQualifier()) continue; S.AddBuiltinCandidate(S.Context.getLValueReferenceType(PointeeTy), &ParamTy, Args, 1, CandidateSet); } } // C++ [over.built]p9: // For every promoted arithmetic type T, there exist candidate // operator functions of the form // // T operator+(T); // T operator-(T); void addUnaryPlusOrMinusArithmeticOverloads() { if (!HasArithmeticOrEnumeralCandidateType) return; for (unsigned Arith = FirstPromotedArithmeticType; Arith < LastPromotedArithmeticType; ++Arith) { QualType ArithTy = getArithmeticType(Arith); S.AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); } // Extension: We also add these operators for vector types. for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes[0].vector_begin(), VecEnd = CandidateTypes[0].vector_end(); Vec != VecEnd; ++Vec) { QualType VecTy = *Vec; S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); } } // C++ [over.built]p8: // For every type T, there exist candidate operator functions of // the form // // T* operator+(T*); void addUnaryPlusPointerOverloads() { for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes[0].pointer_begin(), PtrEnd = CandidateTypes[0].pointer_end(); Ptr != PtrEnd; ++Ptr) { QualType ParamTy = *Ptr; S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); } } // C++ [over.built]p10: // For every promoted integral type T, there exist candidate // operator functions of the form // // T operator~(T); void addUnaryTildePromotedIntegralOverloads() { if (!HasArithmeticOrEnumeralCandidateType) return; for (unsigned Int = FirstPromotedIntegralType; Int < LastPromotedIntegralType; ++Int) { QualType IntTy = getArithmeticType(Int); S.AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); } // Extension: We also add this operator for vector types. for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes[0].vector_begin(), VecEnd = CandidateTypes[0].vector_end(); Vec != VecEnd; ++Vec) { QualType VecTy = *Vec; S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); } } // C++ [over.match.oper]p16: // For every pointer to member type T, there exist candidate operator // functions of the form // // bool operator==(T,T); // bool operator!=(T,T); void addEqualEqualOrNotEqualMemberPointerOverloads() { /// Set of (canonical) types that we've already handled. llvm::SmallPtrSet AddedTypes; for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { for (BuiltinCandidateTypeSet::iterator MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); MemPtr != MemPtrEnd; ++MemPtr) { // Don't add the same builtin candidate twice. if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) continue; QualType ParamTypes[2] = { *MemPtr, *MemPtr }; S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, CandidateSet); } } } // C++ [over.built]p15: // // For every T, where T is an enumeration type, a pointer type, or // std::nullptr_t, there exist candidate operator functions of the form // // bool operator<(T, T); // bool operator>(T, T); // bool operator<=(T, T); // bool operator>=(T, T); // bool operator==(T, T); // bool operator!=(T, T); void addRelationalPointerOrEnumeralOverloads() { // C++ [over.built]p1: // If there is a user-written candidate with the same name and parameter // types as a built-in candidate operator function, the built-in operator // function is hidden and is not included in the set of candidate // functions. // // The text is actually in a note, but if we don't implement it then we end // up with ambiguities when the user provides an overloaded operator for // an enumeration type. Note that only enumeration types have this problem, // so we track which enumeration types we've seen operators for. Also, the // only other overloaded operator with enumeration argumenst, operator=, // cannot be overloaded for enumeration types, so this is the only place // where we must suppress candidates like this. llvm::DenseSet > UserDefinedBinaryOperators; for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { if (CandidateTypes[ArgIdx].enumeration_begin() != CandidateTypes[ArgIdx].enumeration_end()) { for (OverloadCandidateSet::iterator C = CandidateSet.begin(), CEnd = CandidateSet.end(); C != CEnd; ++C) { if (!C->Viable || !C->Function || C->Function->getNumParams() != 2) continue; QualType FirstParamType = C->Function->getParamDecl(0)->getType().getUnqualifiedType(); QualType SecondParamType = C->Function->getParamDecl(1)->getType().getUnqualifiedType(); // Skip if either parameter isn't of enumeral type. if (!FirstParamType->isEnumeralType() || !SecondParamType->isEnumeralType()) continue; // Add this operator to the set of known user-defined operators. UserDefinedBinaryOperators.insert( std::make_pair(S.Context.getCanonicalType(FirstParamType), S.Context.getCanonicalType(SecondParamType))); } } } /// Set of (canonical) types that we've already handled. llvm::SmallPtrSet AddedTypes; for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes[ArgIdx].pointer_begin(), PtrEnd = CandidateTypes[ArgIdx].pointer_end(); Ptr != PtrEnd; ++Ptr) { // Don't add the same builtin candidate twice. if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) continue; QualType ParamTypes[2] = { *Ptr, *Ptr }; S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, CandidateSet); } for (BuiltinCandidateTypeSet::iterator Enum = CandidateTypes[ArgIdx].enumeration_begin(), EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); Enum != EnumEnd; ++Enum) { CanQualType CanonType = S.Context.getCanonicalType(*Enum); // Don't add the same builtin candidate twice, or if a user defined // candidate exists. if (!AddedTypes.insert(CanonType) || UserDefinedBinaryOperators.count(std::make_pair(CanonType, CanonType))) continue; QualType ParamTypes[2] = { *Enum, *Enum }; S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, CandidateSet); } if (CandidateTypes[ArgIdx].hasNullPtrType()) { CanQualType NullPtrTy = S.Context.getCanonicalType(S.Context.NullPtrTy); if (AddedTypes.insert(NullPtrTy) && !UserDefinedBinaryOperators.count(std::make_pair(NullPtrTy, NullPtrTy))) { QualType ParamTypes[2] = { NullPtrTy, NullPtrTy }; S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, CandidateSet); } } } } // C++ [over.built]p13: // // For every cv-qualified or cv-unqualified object type T // there exist candidate operator functions of the form // // T* operator+(T*, ptrdiff_t); // T& operator[](T*, ptrdiff_t); [BELOW] // T* operator-(T*, ptrdiff_t); // T* operator+(ptrdiff_t, T*); // T& operator[](ptrdiff_t, T*); [BELOW] // // C++ [over.built]p14: // // For every T, where T is a pointer to object type, there // exist candidate operator functions of the form // // ptrdiff_t operator-(T, T); void addBinaryPlusOrMinusPointerOverloads(OverloadedOperatorKind Op) { /// Set of (canonical) types that we've already handled. llvm::SmallPtrSet AddedTypes; for (int Arg = 0; Arg < 2; ++Arg) { QualType AsymetricParamTypes[2] = { S.Context.getPointerDiffType(), S.Context.getPointerDiffType(), }; for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes[Arg].pointer_begin(), PtrEnd = CandidateTypes[Arg].pointer_end(); Ptr != PtrEnd; ++Ptr) { QualType PointeeTy = (*Ptr)->getPointeeType(); if (!PointeeTy->isObjectType()) continue; AsymetricParamTypes[Arg] = *Ptr; if (Arg == 0 || Op == OO_Plus) { // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) // T* operator+(ptrdiff_t, T*); S.AddBuiltinCandidate(*Ptr, AsymetricParamTypes, Args, 2, CandidateSet); } if (Op == OO_Minus) { // ptrdiff_t operator-(T, T); if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) continue; QualType ParamTypes[2] = { *Ptr, *Ptr }; S.AddBuiltinCandidate(S.Context.getPointerDiffType(), ParamTypes, Args, 2, CandidateSet); } } } } // C++ [over.built]p12: // // For every pair of promoted arithmetic types L and R, there // exist candidate operator functions of the form // // LR operator*(L, R); // LR operator/(L, R); // LR operator+(L, R); // LR operator-(L, R); // bool operator<(L, R); // bool operator>(L, R); // bool operator<=(L, R); // bool operator>=(L, R); // bool operator==(L, R); // bool operator!=(L, R); // // where LR is the result of the usual arithmetic conversions // between types L and R. // // C++ [over.built]p24: // // For every pair of promoted arithmetic types L and R, there exist // candidate operator functions of the form // // LR operator?(bool, L, R); // // where LR is the result of the usual arithmetic conversions // between types L and R. // Our candidates ignore the first parameter. void addGenericBinaryArithmeticOverloads(bool isComparison) { if (!HasArithmeticOrEnumeralCandidateType) return; for (unsigned Left = FirstPromotedArithmeticType; Left < LastPromotedArithmeticType; ++Left) { for (unsigned Right = FirstPromotedArithmeticType; Right < LastPromotedArithmeticType; ++Right) { QualType LandR[2] = { getArithmeticType(Left), getArithmeticType(Right) }; QualType Result = isComparison ? S.Context.BoolTy : getUsualArithmeticConversions(Left, Right); S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); } } // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the // conditional operator for vector types. for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes[0].vector_begin(), Vec1End = CandidateTypes[0].vector_end(); Vec1 != Vec1End; ++Vec1) { for (BuiltinCandidateTypeSet::iterator Vec2 = CandidateTypes[1].vector_begin(), Vec2End = CandidateTypes[1].vector_end(); Vec2 != Vec2End; ++Vec2) { QualType LandR[2] = { *Vec1, *Vec2 }; QualType Result = S.Context.BoolTy; if (!isComparison) { if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) Result = *Vec1; else Result = *Vec2; } S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); } } } // C++ [over.built]p17: // // For every pair of promoted integral types L and R, there // exist candidate operator functions of the form // // LR operator%(L, R); // LR operator&(L, R); // LR operator^(L, R); // LR operator|(L, R); // L operator<<(L, R); // L operator>>(L, R); // // where LR is the result of the usual arithmetic conversions // between types L and R. void addBinaryBitwiseArithmeticOverloads(OverloadedOperatorKind Op) { if (!HasArithmeticOrEnumeralCandidateType) return; for (unsigned Left = FirstPromotedIntegralType; Left < LastPromotedIntegralType; ++Left) { for (unsigned Right = FirstPromotedIntegralType; Right < LastPromotedIntegralType; ++Right) { QualType LandR[2] = { getArithmeticType(Left), getArithmeticType(Right) }; QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) ? LandR[0] : getUsualArithmeticConversions(Left, Right); S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); } } } // C++ [over.built]p20: // // For every pair (T, VQ), where T is an enumeration or // pointer to member type and VQ is either volatile or // empty, there exist candidate operator functions of the form // // VQ T& operator=(VQ T&, T); void addAssignmentMemberPointerOrEnumeralOverloads() { /// Set of (canonical) types that we've already handled. llvm::SmallPtrSet AddedTypes; for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { for (BuiltinCandidateTypeSet::iterator Enum = CandidateTypes[ArgIdx].enumeration_begin(), EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); Enum != EnumEnd; ++Enum) { if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) continue; AddBuiltinAssignmentOperatorCandidates(S, *Enum, Args, 2, CandidateSet); } for (BuiltinCandidateTypeSet::iterator MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); MemPtr != MemPtrEnd; ++MemPtr) { if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) continue; AddBuiltinAssignmentOperatorCandidates(S, *MemPtr, Args, 2, CandidateSet); } } } // C++ [over.built]p19: // // For every pair (T, VQ), where T is any type and VQ is either // volatile or empty, there exist candidate operator functions // of the form // // T*VQ& operator=(T*VQ&, T*); // // C++ [over.built]p21: // // For every pair (T, VQ), where T is a cv-qualified or // cv-unqualified object type and VQ is either volatile or // empty, there exist candidate operator functions of the form // // T*VQ& operator+=(T*VQ&, ptrdiff_t); // T*VQ& operator-=(T*VQ&, ptrdiff_t); void addAssignmentPointerOverloads(bool isEqualOp) { /// Set of (canonical) types that we've already handled. llvm::SmallPtrSet AddedTypes; for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes[0].pointer_begin(), PtrEnd = CandidateTypes[0].pointer_end(); Ptr != PtrEnd; ++Ptr) { // If this is operator=, keep track of the builtin candidates we added. if (isEqualOp) AddedTypes.insert(S.Context.getCanonicalType(*Ptr)); else if (!(*Ptr)->getPointeeType()->isObjectType()) continue; // non-volatile version QualType ParamTypes[2] = { S.Context.getLValueReferenceType(*Ptr), isEqualOp ? *Ptr : S.Context.getPointerDiffType(), }; S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, /*IsAssigmentOperator=*/ isEqualOp); if (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && VisibleTypeConversionsQuals.hasVolatile()) { // volatile version ParamTypes[0] = S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, /*IsAssigmentOperator=*/isEqualOp); } } if (isEqualOp) { for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes[1].pointer_begin(), PtrEnd = CandidateTypes[1].pointer_end(); Ptr != PtrEnd; ++Ptr) { // Make sure we don't add the same candidate twice. if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) continue; QualType ParamTypes[2] = { S.Context.getLValueReferenceType(*Ptr), *Ptr, }; // non-volatile version S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, /*IsAssigmentOperator=*/true); if (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && VisibleTypeConversionsQuals.hasVolatile()) { // volatile version ParamTypes[0] = S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, /*IsAssigmentOperator=*/true); } } } } // C++ [over.built]p18: // // For every triple (L, VQ, R), where L is an arithmetic type, // VQ is either volatile or empty, and R is a promoted // arithmetic type, there exist candidate operator functions of // the form // // VQ L& operator=(VQ L&, R); // VQ L& operator*=(VQ L&, R); // VQ L& operator/=(VQ L&, R); // VQ L& operator+=(VQ L&, R); // VQ L& operator-=(VQ L&, R); void addAssignmentArithmeticOverloads(bool isEqualOp) { if (!HasArithmeticOrEnumeralCandidateType) return; for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { for (unsigned Right = FirstPromotedArithmeticType; Right < LastPromotedArithmeticType; ++Right) { QualType ParamTypes[2]; ParamTypes[1] = getArithmeticType(Right); // Add this built-in operator as a candidate (VQ is empty). ParamTypes[0] = S.Context.getLValueReferenceType(getArithmeticType(Left)); S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, /*IsAssigmentOperator=*/isEqualOp); // Add this built-in operator as a candidate (VQ is 'volatile'). if (VisibleTypeConversionsQuals.hasVolatile()) { ParamTypes[0] = S.Context.getVolatileType(getArithmeticType(Left)); ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, /*IsAssigmentOperator=*/isEqualOp); } } } // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes[0].vector_begin(), Vec1End = CandidateTypes[0].vector_end(); Vec1 != Vec1End; ++Vec1) { for (BuiltinCandidateTypeSet::iterator Vec2 = CandidateTypes[1].vector_begin(), Vec2End = CandidateTypes[1].vector_end(); Vec2 != Vec2End; ++Vec2) { QualType ParamTypes[2]; ParamTypes[1] = *Vec2; // Add this built-in operator as a candidate (VQ is empty). ParamTypes[0] = S.Context.getLValueReferenceType(*Vec1); S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, /*IsAssigmentOperator=*/isEqualOp); // Add this built-in operator as a candidate (VQ is 'volatile'). if (VisibleTypeConversionsQuals.hasVolatile()) { ParamTypes[0] = S.Context.getVolatileType(*Vec1); ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, /*IsAssigmentOperator=*/isEqualOp); } } } } // C++ [over.built]p22: // // For every triple (L, VQ, R), where L is an integral type, VQ // is either volatile or empty, and R is a promoted integral // type, there exist candidate operator functions of the form // // VQ L& operator%=(VQ L&, R); // VQ L& operator<<=(VQ L&, R); // VQ L& operator>>=(VQ L&, R); // VQ L& operator&=(VQ L&, R); // VQ L& operator^=(VQ L&, R); // VQ L& operator|=(VQ L&, R); void addAssignmentIntegralOverloads() { if (!HasArithmeticOrEnumeralCandidateType) return; for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { for (unsigned Right = FirstPromotedIntegralType; Right < LastPromotedIntegralType; ++Right) { QualType ParamTypes[2]; ParamTypes[1] = getArithmeticType(Right); // Add this built-in operator as a candidate (VQ is empty). ParamTypes[0] = S.Context.getLValueReferenceType(getArithmeticType(Left)); S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); if (VisibleTypeConversionsQuals.hasVolatile()) { // Add this built-in operator as a candidate (VQ is 'volatile'). ParamTypes[0] = getArithmeticType(Left); ParamTypes[0] = S.Context.getVolatileType(ParamTypes[0]); ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); } } } } // C++ [over.operator]p23: // // There also exist candidate operator functions of the form // // bool operator!(bool); // bool operator&&(bool, bool); // bool operator||(bool, bool); void addExclaimOverload() { QualType ParamTy = S.Context.BoolTy; S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, /*IsAssignmentOperator=*/false, /*NumContextualBoolArguments=*/1); } void addAmpAmpOrPipePipeOverload() { QualType ParamTypes[2] = { S.Context.BoolTy, S.Context.BoolTy }; S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, CandidateSet, /*IsAssignmentOperator=*/false, /*NumContextualBoolArguments=*/2); } // C++ [over.built]p13: // // For every cv-qualified or cv-unqualified object type T there // exist candidate operator functions of the form // // T* operator+(T*, ptrdiff_t); [ABOVE] // T& operator[](T*, ptrdiff_t); // T* operator-(T*, ptrdiff_t); [ABOVE] // T* operator+(ptrdiff_t, T*); [ABOVE] // T& operator[](ptrdiff_t, T*); void addSubscriptOverloads() { for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes[0].pointer_begin(), PtrEnd = CandidateTypes[0].pointer_end(); Ptr != PtrEnd; ++Ptr) { QualType ParamTypes[2] = { *Ptr, S.Context.getPointerDiffType() }; QualType PointeeType = (*Ptr)->getPointeeType(); if (!PointeeType->isObjectType()) continue; QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); // T& operator[](T*, ptrdiff_t) S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); } for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes[1].pointer_begin(), PtrEnd = CandidateTypes[1].pointer_end(); Ptr != PtrEnd; ++Ptr) { QualType ParamTypes[2] = { S.Context.getPointerDiffType(), *Ptr }; QualType PointeeType = (*Ptr)->getPointeeType(); if (!PointeeType->isObjectType()) continue; QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); // T& operator[](ptrdiff_t, T*) S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); } } // C++ [over.built]p11: // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, // C1 is the same type as C2 or is a derived class of C2, T is an object // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, // there exist candidate operator functions of the form // // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); // // where CV12 is the union of CV1 and CV2. void addArrowStarOverloads() { for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes[0].pointer_begin(), PtrEnd = CandidateTypes[0].pointer_end(); Ptr != PtrEnd; ++Ptr) { QualType C1Ty = (*Ptr); QualType C1; QualifierCollector Q1; C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0); if (!isa(C1)) continue; // heuristic to reduce number of builtin candidates in the set. // Add volatile/restrict version only if there are conversions to a // volatile/restrict type. if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) continue; if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) continue; for (BuiltinCandidateTypeSet::iterator MemPtr = CandidateTypes[1].member_pointer_begin(), MemPtrEnd = CandidateTypes[1].member_pointer_end(); MemPtr != MemPtrEnd; ++MemPtr) { const MemberPointerType *mptr = cast(*MemPtr); QualType C2 = QualType(mptr->getClass(), 0); C2 = C2.getUnqualifiedType(); if (C1 != C2 && !S.IsDerivedFrom(C1, C2)) break; QualType ParamTypes[2] = { *Ptr, *MemPtr }; // build CV12 T& QualType T = mptr->getPointeeType(); if (!VisibleTypeConversionsQuals.hasVolatile() && T.isVolatileQualified()) continue; if (!VisibleTypeConversionsQuals.hasRestrict() && T.isRestrictQualified()) continue; T = Q1.apply(S.Context, T); QualType ResultTy = S.Context.getLValueReferenceType(T); S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); } } } // Note that we don't consider the first argument, since it has been // contextually converted to bool long ago. The candidates below are // therefore added as binary. // // C++ [over.built]p25: // For every type T, where T is a pointer, pointer-to-member, or scoped // enumeration type, there exist candidate operator functions of the form // // T operator?(bool, T, T); // void addConditionalOperatorOverloads() { /// Set of (canonical) types that we've already handled. llvm::SmallPtrSet AddedTypes; for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes[ArgIdx].pointer_begin(), PtrEnd = CandidateTypes[ArgIdx].pointer_end(); Ptr != PtrEnd; ++Ptr) { if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) continue; QualType ParamTypes[2] = { *Ptr, *Ptr }; S.AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); } for (BuiltinCandidateTypeSet::iterator MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); MemPtr != MemPtrEnd; ++MemPtr) { if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) continue; QualType ParamTypes[2] = { *MemPtr, *MemPtr }; S.AddBuiltinCandidate(*MemPtr, ParamTypes, Args, 2, CandidateSet); } if (S.getLangOpts().CPlusPlus0x) { for (BuiltinCandidateTypeSet::iterator Enum = CandidateTypes[ArgIdx].enumeration_begin(), EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); Enum != EnumEnd; ++Enum) { if (!(*Enum)->getAs()->getDecl()->isScoped()) continue; if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) continue; QualType ParamTypes[2] = { *Enum, *Enum }; S.AddBuiltinCandidate(*Enum, ParamTypes, Args, 2, CandidateSet); } } } } }; } // end anonymous namespace /// AddBuiltinOperatorCandidates - Add the appropriate built-in /// operator overloads to the candidate set (C++ [over.built]), based /// on the operator @p Op and the arguments given. For example, if the /// operator is a binary '+', this routine might add "int /// operator+(int, int)" to cover integer addition. void Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, SourceLocation OpLoc, Expr **Args, unsigned NumArgs, OverloadCandidateSet& CandidateSet) { // Find all of the types that the arguments can convert to, but only // if the operator we're looking at has built-in operator candidates // that make use of these types. Also record whether we encounter non-record // candidate types or either arithmetic or enumeral candidate types. Qualifiers VisibleTypeConversionsQuals; VisibleTypeConversionsQuals.addConst(); for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); bool HasNonRecordCandidateType = false; bool HasArithmeticOrEnumeralCandidateType = false; SmallVector CandidateTypes; for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { CandidateTypes.push_back(BuiltinCandidateTypeSet(*this)); CandidateTypes[ArgIdx].AddTypesConvertedFrom(Args[ArgIdx]->getType(), OpLoc, true, (Op == OO_Exclaim || Op == OO_AmpAmp || Op == OO_PipePipe), VisibleTypeConversionsQuals); HasNonRecordCandidateType = HasNonRecordCandidateType || CandidateTypes[ArgIdx].hasNonRecordTypes(); HasArithmeticOrEnumeralCandidateType = HasArithmeticOrEnumeralCandidateType || CandidateTypes[ArgIdx].hasArithmeticOrEnumeralTypes(); } // Exit early when no non-record types have been added to the candidate set // for any of the arguments to the operator. // // We can't exit early for !, ||, or &&, since there we have always have // 'bool' overloads. if (!HasNonRecordCandidateType && !(Op == OO_Exclaim || Op == OO_AmpAmp || Op == OO_PipePipe)) return; // Setup an object to manage the common state for building overloads. BuiltinOperatorOverloadBuilder OpBuilder(*this, Args, NumArgs, VisibleTypeConversionsQuals, HasArithmeticOrEnumeralCandidateType, CandidateTypes, CandidateSet); // Dispatch over the operation to add in only those overloads which apply. switch (Op) { case OO_None: case NUM_OVERLOADED_OPERATORS: llvm_unreachable("Expected an overloaded operator"); case OO_New: case OO_Delete: case OO_Array_New: case OO_Array_Delete: case OO_Call: llvm_unreachable( "Special operators don't use AddBuiltinOperatorCandidates"); case OO_Comma: case OO_Arrow: // C++ [over.match.oper]p3: // -- For the operator ',', the unary operator '&', or the // operator '->', the built-in candidates set is empty. break; case OO_Plus: // '+' is either unary or binary if (NumArgs == 1) OpBuilder.addUnaryPlusPointerOverloads(); // Fall through. case OO_Minus: // '-' is either unary or binary if (NumArgs == 1) { OpBuilder.addUnaryPlusOrMinusArithmeticOverloads(); } else { OpBuilder.addBinaryPlusOrMinusPointerOverloads(Op); OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); } break; case OO_Star: // '*' is either unary or binary if (NumArgs == 1) OpBuilder.addUnaryStarPointerOverloads(); else OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); break; case OO_Slash: OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); break; case OO_PlusPlus: case OO_MinusMinus: OpBuilder.addPlusPlusMinusMinusArithmeticOverloads(Op); OpBuilder.addPlusPlusMinusMinusPointerOverloads(); break; case OO_EqualEqual: case OO_ExclaimEqual: OpBuilder.addEqualEqualOrNotEqualMemberPointerOverloads(); // Fall through. case OO_Less: case OO_Greater: case OO_LessEqual: case OO_GreaterEqual: OpBuilder.addRelationalPointerOrEnumeralOverloads(); OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/true); break; case OO_Percent: case OO_Caret: case OO_Pipe: case OO_LessLess: case OO_GreaterGreater: OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); break; case OO_Amp: // '&' is either unary or binary if (NumArgs == 1) // C++ [over.match.oper]p3: // -- For the operator ',', the unary operator '&', or the // operator '->', the built-in candidates set is empty. break; OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); break; case OO_Tilde: OpBuilder.addUnaryTildePromotedIntegralOverloads(); break; case OO_Equal: OpBuilder.addAssignmentMemberPointerOrEnumeralOverloads(); // Fall through. case OO_PlusEqual: case OO_MinusEqual: OpBuilder.addAssignmentPointerOverloads(Op == OO_Equal); // Fall through. case OO_StarEqual: case OO_SlashEqual: OpBuilder.addAssignmentArithmeticOverloads(Op == OO_Equal); break; case OO_PercentEqual: case OO_LessLessEqual: case OO_GreaterGreaterEqual: case OO_AmpEqual: case OO_CaretEqual: case OO_PipeEqual: OpBuilder.addAssignmentIntegralOverloads(); break; case OO_Exclaim: OpBuilder.addExclaimOverload(); break; case OO_AmpAmp: case OO_PipePipe: OpBuilder.addAmpAmpOrPipePipeOverload(); break; case OO_Subscript: OpBuilder.addSubscriptOverloads(); break; case OO_ArrowStar: OpBuilder.addArrowStarOverloads(); break; case OO_Conditional: OpBuilder.addConditionalOperatorOverloads(); OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); break; } } /// \brief Add function candidates found via argument-dependent lookup /// to the set of overloading candidates. /// /// This routine performs argument-dependent name lookup based on the /// given function name (which may also be an operator name) and adds /// all of the overload candidates found by ADL to the overload /// candidate set (C++ [basic.lookup.argdep]). void Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, bool Operator, SourceLocation Loc, llvm::ArrayRef Args, TemplateArgumentListInfo *ExplicitTemplateArgs, OverloadCandidateSet& CandidateSet, bool PartialOverloading, bool StdNamespaceIsAssociated) { ADLResult Fns; // FIXME: This approach for uniquing ADL results (and removing // redundant candidates from the set) relies on pointer-equality, // which means we need to key off the canonical decl. However, // always going back to the canonical decl might not get us the // right set of default arguments. What default arguments are // we supposed to consider on ADL candidates, anyway? // FIXME: Pass in the explicit template arguments? ArgumentDependentLookup(Name, Operator, Loc, Args, Fns, StdNamespaceIsAssociated); // Erase all of the candidates we already knew about. for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), CandEnd = CandidateSet.end(); Cand != CandEnd; ++Cand) if (Cand->Function) { Fns.erase(Cand->Function); if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) Fns.erase(FunTmpl); } // For each of the ADL candidates we found, add it to the overload // set. for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); if (FunctionDecl *FD = dyn_cast(*I)) { if (ExplicitTemplateArgs) continue; AddOverloadCandidate(FD, FoundDecl, Args, CandidateSet, false, PartialOverloading); } else AddTemplateOverloadCandidate(cast(*I), FoundDecl, ExplicitTemplateArgs, Args, CandidateSet); } } /// isBetterOverloadCandidate - Determines whether the first overload /// candidate is a better candidate than the second (C++ 13.3.3p1). bool isBetterOverloadCandidate(Sema &S, const OverloadCandidate &Cand1, const OverloadCandidate &Cand2, SourceLocation Loc, bool UserDefinedConversion) { // Define viable functions to be better candidates than non-viable // functions. if (!Cand2.Viable) return Cand1.Viable; else if (!Cand1.Viable) return false; // C++ [over.match.best]p1: // // -- if F is a static member function, ICS1(F) is defined such // that ICS1(F) is neither better nor worse than ICS1(G) for // any function G, and, symmetrically, ICS1(G) is neither // better nor worse than ICS1(F). unsigned StartArg = 0; if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) StartArg = 1; // C++ [over.match.best]p1: // A viable function F1 is defined to be a better function than another // viable function F2 if for all arguments i, ICSi(F1) is not a worse // conversion sequence than ICSi(F2), and then... unsigned NumArgs = Cand1.NumConversions; assert(Cand2.NumConversions == NumArgs && "Overload candidate mismatch"); bool HasBetterConversion = false; for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { switch (CompareImplicitConversionSequences(S, Cand1.Conversions[ArgIdx], Cand2.Conversions[ArgIdx])) { case ImplicitConversionSequence::Better: // Cand1 has a better conversion sequence. HasBetterConversion = true; break; case ImplicitConversionSequence::Worse: // Cand1 can't be better than Cand2. return false; case ImplicitConversionSequence::Indistinguishable: // Do nothing. break; } } // -- for some argument j, ICSj(F1) is a better conversion sequence than // ICSj(F2), or, if not that, if (HasBetterConversion) return true; // - F1 is a non-template function and F2 is a function template // specialization, or, if not that, if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && Cand2.Function && Cand2.Function->getPrimaryTemplate()) return true; // -- F1 and F2 are function template specializations, and the function // template for F1 is more specialized than the template for F2 // according to the partial ordering rules described in 14.5.5.2, or, // if not that, if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && Cand2.Function && Cand2.Function->getPrimaryTemplate()) { if (FunctionTemplateDecl *BetterTemplate = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), Cand2.Function->getPrimaryTemplate(), Loc, isa(Cand1.Function)? TPOC_Conversion : TPOC_Call, Cand1.ExplicitCallArguments)) return BetterTemplate == Cand1.Function->getPrimaryTemplate(); } // -- the context is an initialization by user-defined conversion // (see 8.5, 13.3.1.5) and the standard conversion sequence // from the return type of F1 to the destination type (i.e., // the type of the entity being initialized) is a better // conversion sequence than the standard conversion sequence // from the return type of F2 to the destination type. if (UserDefinedConversion && Cand1.Function && Cand2.Function && isa(Cand1.Function) && isa(Cand2.Function)) { // First check whether we prefer one of the conversion functions over the // other. This only distinguishes the results in non-standard, extension // cases such as the conversion from a lambda closure type to a function // pointer or block. ImplicitConversionSequence::CompareKind FuncResult = compareConversionFunctions(S, Cand1.Function, Cand2.Function); if (FuncResult != ImplicitConversionSequence::Indistinguishable) return FuncResult; switch (CompareStandardConversionSequences(S, Cand1.FinalConversion, Cand2.FinalConversion)) { case ImplicitConversionSequence::Better: // Cand1 has a better conversion sequence. return true; case ImplicitConversionSequence::Worse: // Cand1 can't be better than Cand2. return false; case ImplicitConversionSequence::Indistinguishable: // Do nothing break; } } return false; } /// \brief Computes the best viable function (C++ 13.3.3) /// within an overload candidate set. /// /// \param CandidateSet the set of candidate functions. /// /// \param Loc the location of the function name (or operator symbol) for /// which overload resolution occurs. /// /// \param Best f overload resolution was successful or found a deleted /// function, Best points to the candidate function found. /// /// \returns The result of overload resolution. OverloadingResult OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc, iterator &Best, bool UserDefinedConversion) { // Find the best viable function. Best = end(); for (iterator Cand = begin(); Cand != end(); ++Cand) { if (Cand->Viable) if (Best == end() || isBetterOverloadCandidate(S, *Cand, *Best, Loc, UserDefinedConversion)) Best = Cand; } // If we didn't find any viable functions, abort. if (Best == end()) return OR_No_Viable_Function; // Make sure that this function is better than every other viable // function. If not, we have an ambiguity. for (iterator Cand = begin(); Cand != end(); ++Cand) { if (Cand->Viable && Cand != Best && !isBetterOverloadCandidate(S, *Best, *Cand, Loc, UserDefinedConversion)) { Best = end(); return OR_Ambiguous; } } // Best is the best viable function. if (Best->Function && (Best->Function->isDeleted() || S.isFunctionConsideredUnavailable(Best->Function))) return OR_Deleted; return OR_Success; } namespace { enum OverloadCandidateKind { oc_function, oc_method, oc_constructor, oc_function_template, oc_method_template, oc_constructor_template, oc_implicit_default_constructor, oc_implicit_copy_constructor, oc_implicit_move_constructor, oc_implicit_copy_assignment, oc_implicit_move_assignment, oc_implicit_inherited_constructor }; OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, FunctionDecl *Fn, std::string &Description) { bool isTemplate = false; if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { isTemplate = true; Description = S.getTemplateArgumentBindingsText( FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); } if (CXXConstructorDecl *Ctor = dyn_cast(Fn)) { if (!Ctor->isImplicit()) return isTemplate ? oc_constructor_template : oc_constructor; if (Ctor->getInheritedConstructor()) return oc_implicit_inherited_constructor; if (Ctor->isDefaultConstructor()) return oc_implicit_default_constructor; if (Ctor->isMoveConstructor()) return oc_implicit_move_constructor; assert(Ctor->isCopyConstructor() && "unexpected sort of implicit constructor"); return oc_implicit_copy_constructor; } if (CXXMethodDecl *Meth = dyn_cast(Fn)) { // This actually gets spelled 'candidate function' for now, but // it doesn't hurt to split it out. if (!Meth->isImplicit()) return isTemplate ? oc_method_template : oc_method; if (Meth->isMoveAssignmentOperator()) return oc_implicit_move_assignment; if (Meth->isCopyAssignmentOperator()) return oc_implicit_copy_assignment; assert(isa(Meth) && "expected conversion"); return oc_method; } return isTemplate ? oc_function_template : oc_function; } void MaybeEmitInheritedConstructorNote(Sema &S, FunctionDecl *Fn) { const CXXConstructorDecl *Ctor = dyn_cast(Fn); if (!Ctor) return; Ctor = Ctor->getInheritedConstructor(); if (!Ctor) return; S.Diag(Ctor->getLocation(), diag::note_ovl_candidate_inherited_constructor); } } // end anonymous namespace // Notes the location of an overload candidate. void Sema::NoteOverloadCandidate(FunctionDecl *Fn, QualType DestType) { std::string FnDesc; OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); PartialDiagnostic PD = PDiag(diag::note_ovl_candidate) << (unsigned) K << FnDesc; HandleFunctionTypeMismatch(PD, Fn->getType(), DestType); Diag(Fn->getLocation(), PD); MaybeEmitInheritedConstructorNote(*this, Fn); } //Notes the location of all overload candidates designated through // OverloadedExpr void Sema::NoteAllOverloadCandidates(Expr* OverloadedExpr, QualType DestType) { assert(OverloadedExpr->getType() == Context.OverloadTy); OverloadExpr::FindResult Ovl = OverloadExpr::find(OverloadedExpr); OverloadExpr *OvlExpr = Ovl.Expression; for (UnresolvedSetIterator I = OvlExpr->decls_begin(), IEnd = OvlExpr->decls_end(); I != IEnd; ++I) { if (FunctionTemplateDecl *FunTmpl = dyn_cast((*I)->getUnderlyingDecl()) ) { NoteOverloadCandidate(FunTmpl->getTemplatedDecl(), DestType); } else if (FunctionDecl *Fun = dyn_cast((*I)->getUnderlyingDecl()) ) { NoteOverloadCandidate(Fun, DestType); } } } /// Diagnoses an ambiguous conversion. The partial diagnostic is the /// "lead" diagnostic; it will be given two arguments, the source and /// target types of the conversion. void ImplicitConversionSequence::DiagnoseAmbiguousConversion( Sema &S, SourceLocation CaretLoc, const PartialDiagnostic &PDiag) const { S.Diag(CaretLoc, PDiag) << Ambiguous.getFromType() << Ambiguous.getToType(); for (AmbiguousConversionSequence::const_iterator I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) { S.NoteOverloadCandidate(*I); } } namespace { void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { const ImplicitConversionSequence &Conv = Cand->Conversions[I]; assert(Conv.isBad()); assert(Cand->Function && "for now, candidate must be a function"); FunctionDecl *Fn = Cand->Function; // There's a conversion slot for the object argument if this is a // non-constructor method. Note that 'I' corresponds the // conversion-slot index. bool isObjectArgument = false; if (isa(Fn) && !isa(Fn)) { if (I == 0) isObjectArgument = true; else I--; } std::string FnDesc; OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); Expr *FromExpr = Conv.Bad.FromExpr; QualType FromTy = Conv.Bad.getFromType(); QualType ToTy = Conv.Bad.getToType(); if (FromTy == S.Context.OverloadTy) { assert(FromExpr && "overload set argument came from implicit argument?"); Expr *E = FromExpr->IgnoreParens(); if (isa(E)) E = cast(E)->getSubExpr()->IgnoreParens(); DeclarationName Name = cast(E)->getName(); S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) << (unsigned) FnKind << FnDesc << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << ToTy << Name << I+1; MaybeEmitInheritedConstructorNote(S, Fn); return; } // Do some hand-waving analysis to see if the non-viability is due // to a qualifier mismatch. CanQualType CFromTy = S.Context.getCanonicalType(FromTy); CanQualType CToTy = S.Context.getCanonicalType(ToTy); if (CanQual RT = CToTy->getAs()) CToTy = RT->getPointeeType(); else { // TODO: detect and diagnose the full richness of const mismatches. if (CanQual FromPT = CFromTy->getAs()) if (CanQual ToPT = CToTy->getAs()) CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); } if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { Qualifiers FromQs = CFromTy.getQualifiers(); Qualifiers ToQs = CToTy.getQualifiers(); if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) << (unsigned) FnKind << FnDesc << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy << FromQs.getAddressSpace() << ToQs.getAddressSpace() << (unsigned) isObjectArgument << I+1; MaybeEmitInheritedConstructorNote(S, Fn); return; } if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) { S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_ownership) << (unsigned) FnKind << FnDesc << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy << FromQs.getObjCLifetime() << ToQs.getObjCLifetime() << (unsigned) isObjectArgument << I+1; MaybeEmitInheritedConstructorNote(S, Fn); return; } if (FromQs.getObjCGCAttr() != ToQs.getObjCGCAttr()) { S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_gc) << (unsigned) FnKind << FnDesc << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy << FromQs.getObjCGCAttr() << ToQs.getObjCGCAttr() << (unsigned) isObjectArgument << I+1; MaybeEmitInheritedConstructorNote(S, Fn); return; } unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); assert(CVR && "unexpected qualifiers mismatch"); if (isObjectArgument) { S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) << (unsigned) FnKind << FnDesc << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy << (CVR - 1); } else { S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) << (unsigned) FnKind << FnDesc << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy << (CVR - 1) << I+1; } MaybeEmitInheritedConstructorNote(S, Fn); return; } // Special diagnostic for failure to convert an initializer list, since // telling the user that it has type void is not useful. if (FromExpr && isa(FromExpr)) { S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_list_argument) << (unsigned) FnKind << FnDesc << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy << ToTy << (unsigned) isObjectArgument << I+1; MaybeEmitInheritedConstructorNote(S, Fn); return; } // Diagnose references or pointers to incomplete types differently, // since it's far from impossible that the incompleteness triggered // the failure. QualType TempFromTy = FromTy.getNonReferenceType(); if (const PointerType *PTy = TempFromTy->getAs()) TempFromTy = PTy->getPointeeType(); if (TempFromTy->isIncompleteType()) { S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) << (unsigned) FnKind << FnDesc << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy << ToTy << (unsigned) isObjectArgument << I+1; MaybeEmitInheritedConstructorNote(S, Fn); return; } // Diagnose base -> derived pointer conversions. unsigned BaseToDerivedConversion = 0; if (const PointerType *FromPtrTy = FromTy->getAs()) { if (const PointerType *ToPtrTy = ToTy->getAs()) { if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( FromPtrTy->getPointeeType()) && !FromPtrTy->getPointeeType()->isIncompleteType() && !ToPtrTy->getPointeeType()->isIncompleteType() && S.IsDerivedFrom(ToPtrTy->getPointeeType(), FromPtrTy->getPointeeType())) BaseToDerivedConversion = 1; } } else if (const ObjCObjectPointerType *FromPtrTy = FromTy->getAs()) { if (const ObjCObjectPointerType *ToPtrTy = ToTy->getAs()) if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl()) if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl()) if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( FromPtrTy->getPointeeType()) && FromIface->isSuperClassOf(ToIface)) BaseToDerivedConversion = 2; } else if (const ReferenceType *ToRefTy = ToTy->getAs()) { if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) && !FromTy->isIncompleteType() && !ToRefTy->getPointeeType()->isIncompleteType() && S.IsDerivedFrom(ToRefTy->getPointeeType(), FromTy)) BaseToDerivedConversion = 3; } if (BaseToDerivedConversion) { S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_base_to_derived_conv) << (unsigned) FnKind << FnDesc << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << (BaseToDerivedConversion - 1) << FromTy << ToTy << I+1; MaybeEmitInheritedConstructorNote(S, Fn); return; } if (isa(CFromTy) && isa(CToTy)) { Qualifiers FromQs = CFromTy.getQualifiers(); Qualifiers ToQs = CToTy.getQualifiers(); if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) { S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_arc_conv) << (unsigned) FnKind << FnDesc << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy << ToTy << (unsigned) isObjectArgument << I+1; MaybeEmitInheritedConstructorNote(S, Fn); return; } } // Emit the generic diagnostic and, optionally, add the hints to it. PartialDiagnostic FDiag = S.PDiag(diag::note_ovl_candidate_bad_conv); FDiag << (unsigned) FnKind << FnDesc << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) << FromTy << ToTy << (unsigned) isObjectArgument << I + 1 << (unsigned) (Cand->Fix.Kind); // If we can fix the conversion, suggest the FixIts. for (std::vector::iterator HI = Cand->Fix.Hints.begin(), HE = Cand->Fix.Hints.end(); HI != HE; ++HI) FDiag << *HI; S.Diag(Fn->getLocation(), FDiag); MaybeEmitInheritedConstructorNote(S, Fn); } void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, unsigned NumFormalArgs) { // TODO: treat calls to a missing default constructor as a special case FunctionDecl *Fn = Cand->Function; const FunctionProtoType *FnTy = Fn->getType()->getAs(); unsigned MinParams = Fn->getMinRequiredArguments(); // With invalid overloaded operators, it's possible that we think we // have an arity mismatch when it fact it looks like we have the // right number of arguments, because only overloaded operators have // the weird behavior of overloading member and non-member functions. // Just don't report anything. if (Fn->isInvalidDecl() && Fn->getDeclName().getNameKind() == DeclarationName::CXXOperatorName) return; // at least / at most / exactly unsigned mode, modeCount; if (NumFormalArgs < MinParams) { assert((Cand->FailureKind == ovl_fail_too_few_arguments) || (Cand->FailureKind == ovl_fail_bad_deduction && Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic() || FnTy->isTemplateVariadic()) mode = 0; // "at least" else mode = 2; // "exactly" modeCount = MinParams; } else { assert((Cand->FailureKind == ovl_fail_too_many_arguments) || (Cand->FailureKind == ovl_fail_bad_deduction && Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); if (MinParams != FnTy->getNumArgs()) mode = 1; // "at most" else mode = 2; // "exactly" modeCount = FnTy->getNumArgs(); } std::string Description; OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode << modeCount << NumFormalArgs; MaybeEmitInheritedConstructorNote(S, Fn); } /// Diagnose a failed template-argument deduction. void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, unsigned NumArgs) { FunctionDecl *Fn = Cand->Function; // pattern TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); NamedDecl *ParamD; (ParamD = Param.dyn_cast()) || (ParamD = Param.dyn_cast()) || (ParamD = Param.dyn_cast()); switch (Cand->DeductionFailure.Result) { case Sema::TDK_Success: llvm_unreachable("TDK_success while diagnosing bad deduction"); case Sema::TDK_Incomplete: { assert(ParamD && "no parameter found for incomplete deduction result"); S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) << ParamD->getDeclName(); MaybeEmitInheritedConstructorNote(S, Fn); return; } case Sema::TDK_Underqualified: { assert(ParamD && "no parameter found for bad qualifiers deduction result"); TemplateTypeParmDecl *TParam = cast(ParamD); QualType Param = Cand->DeductionFailure.getFirstArg()->getAsType(); // Param will have been canonicalized, but it should just be a // qualified version of ParamD, so move the qualifiers to that. QualifierCollector Qs; Qs.strip(Param); QualType NonCanonParam = Qs.apply(S.Context, TParam->getTypeForDecl()); assert(S.Context.hasSameType(Param, NonCanonParam)); // Arg has also been canonicalized, but there's nothing we can do // about that. It also doesn't matter as much, because it won't // have any template parameters in it (because deduction isn't // done on dependent types). QualType Arg = Cand->DeductionFailure.getSecondArg()->getAsType(); S.Diag(Fn->getLocation(), diag::note_ovl_candidate_underqualified) << ParamD->getDeclName() << Arg << NonCanonParam; MaybeEmitInheritedConstructorNote(S, Fn); return; } case Sema::TDK_Inconsistent: { assert(ParamD && "no parameter found for inconsistent deduction result"); int which = 0; if (isa(ParamD)) which = 0; else if (isa(ParamD)) which = 1; else { which = 2; } S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) << which << ParamD->getDeclName() << *Cand->DeductionFailure.getFirstArg() << *Cand->DeductionFailure.getSecondArg(); MaybeEmitInheritedConstructorNote(S, Fn); return; } case Sema::TDK_InvalidExplicitArguments: assert(ParamD && "no parameter found for invalid explicit arguments"); if (ParamD->getDeclName()) S.Diag(Fn->getLocation(), diag::note_ovl_candidate_explicit_arg_mismatch_named) << ParamD->getDeclName(); else { int index = 0; if (TemplateTypeParmDecl *TTP = dyn_cast(ParamD)) index = TTP->getIndex(); else if (NonTypeTemplateParmDecl *NTTP = dyn_cast(ParamD)) index = NTTP->getIndex(); else index = cast(ParamD)->getIndex(); S.Diag(Fn->getLocation(), diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) << (index + 1); } MaybeEmitInheritedConstructorNote(S, Fn); return; case Sema::TDK_TooManyArguments: case Sema::TDK_TooFewArguments: DiagnoseArityMismatch(S, Cand, NumArgs); return; case Sema::TDK_InstantiationDepth: S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); MaybeEmitInheritedConstructorNote(S, Fn); return; case Sema::TDK_SubstitutionFailure: { std::string ArgString; if (TemplateArgumentList *Args = Cand->DeductionFailure.getTemplateArgumentList()) ArgString = S.getTemplateArgumentBindingsText( Fn->getDescribedFunctionTemplate()->getTemplateParameters(), *Args); S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) << ArgString; MaybeEmitInheritedConstructorNote(S, Fn); return; } // TODO: diagnose these individually, then kill off // note_ovl_candidate_bad_deduction, which is uselessly vague. case Sema::TDK_NonDeducedMismatch: case Sema::TDK_FailedOverloadResolution: S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); MaybeEmitInheritedConstructorNote(S, Fn); return; } } /// CUDA: diagnose an invalid call across targets. void DiagnoseBadTarget(Sema &S, OverloadCandidate *Cand) { FunctionDecl *Caller = cast(S.CurContext); FunctionDecl *Callee = Cand->Function; Sema::CUDAFunctionTarget CallerTarget = S.IdentifyCUDATarget(Caller), CalleeTarget = S.IdentifyCUDATarget(Callee); std::string FnDesc; OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Callee, FnDesc); S.Diag(Callee->getLocation(), diag::note_ovl_candidate_bad_target) << (unsigned) FnKind << CalleeTarget << CallerTarget; } /// Generates a 'note' diagnostic for an overload candidate. We've /// already generated a primary error at the call site. /// /// It really does need to be a single diagnostic with its caret /// pointed at the candidate declaration. Yes, this creates some /// major challenges of technical writing. Yes, this makes pointing /// out problems with specific arguments quite awkward. It's still /// better than generating twenty screens of text for every failed /// overload. /// /// It would be great to be able to express per-candidate problems /// more richly for those diagnostic clients that cared, but we'd /// still have to be just as careful with the default diagnostics. void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, unsigned NumArgs) { FunctionDecl *Fn = Cand->Function; // Note deleted candidates, but only if they're viable. if (Cand->Viable && (Fn->isDeleted() || S.isFunctionConsideredUnavailable(Fn))) { std::string FnDesc; OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) << FnKind << FnDesc << (Fn->isDeleted() ? (Fn->isDeletedAsWritten() ? 1 : 2) : 0); MaybeEmitInheritedConstructorNote(S, Fn); return; } // We don't really have anything else to say about viable candidates. if (Cand->Viable) { S.NoteOverloadCandidate(Fn); return; } switch (Cand->FailureKind) { case ovl_fail_too_many_arguments: case ovl_fail_too_few_arguments: return DiagnoseArityMismatch(S, Cand, NumArgs); case ovl_fail_bad_deduction: return DiagnoseBadDeduction(S, Cand, NumArgs); case ovl_fail_trivial_conversion: case ovl_fail_bad_final_conversion: case ovl_fail_final_conversion_not_exact: return S.NoteOverloadCandidate(Fn); case ovl_fail_bad_conversion: { unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); for (unsigned N = Cand->NumConversions; I != N; ++I) if (Cand->Conversions[I].isBad()) return DiagnoseBadConversion(S, Cand, I); // FIXME: this currently happens when we're called from SemaInit // when user-conversion overload fails. Figure out how to handle // those conditions and diagnose them well. return S.NoteOverloadCandidate(Fn); } case ovl_fail_bad_target: return DiagnoseBadTarget(S, Cand); } } void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { // Desugar the type of the surrogate down to a function type, // retaining as many typedefs as possible while still showing // the function type (and, therefore, its parameter types). QualType FnType = Cand->Surrogate->getConversionType(); bool isLValueReference = false; bool isRValueReference = false; bool isPointer = false; if (const LValueReferenceType *FnTypeRef = FnType->getAs()) { FnType = FnTypeRef->getPointeeType(); isLValueReference = true; } else if (const RValueReferenceType *FnTypeRef = FnType->getAs()) { FnType = FnTypeRef->getPointeeType(); isRValueReference = true; } if (const PointerType *FnTypePtr = FnType->getAs()) { FnType = FnTypePtr->getPointeeType(); isPointer = true; } // Desugar down to a function type. FnType = QualType(FnType->getAs(), 0); // Reconstruct the pointer/reference as appropriate. if (isPointer) FnType = S.Context.getPointerType(FnType); if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) << FnType; MaybeEmitInheritedConstructorNote(S, Cand->Surrogate); } void NoteBuiltinOperatorCandidate(Sema &S, const char *Opc, SourceLocation OpLoc, OverloadCandidate *Cand) { assert(Cand->NumConversions <= 2 && "builtin operator is not binary"); std::string TypeStr("operator"); TypeStr += Opc; TypeStr += "("; TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); if (Cand->NumConversions == 1) { TypeStr += ")"; S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; } else { TypeStr += ", "; TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); TypeStr += ")"; S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; } } void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, OverloadCandidate *Cand) { unsigned NoOperands = Cand->NumConversions; for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; if (ICS.isBad()) break; // all meaningless after first invalid if (!ICS.isAmbiguous()) continue; ICS.DiagnoseAmbiguousConversion(S, OpLoc, S.PDiag(diag::note_ambiguous_type_conversion)); } } SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { if (Cand->Function) return Cand->Function->getLocation(); if (Cand->IsSurrogate) return Cand->Surrogate->getLocation(); return SourceLocation(); } static unsigned RankDeductionFailure(const OverloadCandidate::DeductionFailureInfo &DFI) { switch ((Sema::TemplateDeductionResult)DFI.Result) { case Sema::TDK_Success: llvm_unreachable("TDK_success while diagnosing bad deduction"); case Sema::TDK_Incomplete: return 1; case Sema::TDK_Underqualified: case Sema::TDK_Inconsistent: return 2; case Sema::TDK_SubstitutionFailure: case Sema::TDK_NonDeducedMismatch: return 3; case Sema::TDK_InstantiationDepth: case Sema::TDK_FailedOverloadResolution: return 4; case Sema::TDK_InvalidExplicitArguments: return 5; case Sema::TDK_TooManyArguments: case Sema::TDK_TooFewArguments: return 6; } llvm_unreachable("Unhandled deduction result"); } struct CompareOverloadCandidatesForDisplay { Sema &S; CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} bool operator()(const OverloadCandidate *L, const OverloadCandidate *R) { // Fast-path this check. if (L == R) return false; // Order first by viability. if (L->Viable) { if (!R->Viable) return true; // TODO: introduce a tri-valued comparison for overload // candidates. Would be more worthwhile if we had a sort // that could exploit it. if (isBetterOverloadCandidate(S, *L, *R, SourceLocation())) return true; if (isBetterOverloadCandidate(S, *R, *L, SourceLocation())) return false; } else if (R->Viable) return false; assert(L->Viable == R->Viable); // Criteria by which we can sort non-viable candidates: if (!L->Viable) { // 1. Arity mismatches come after other candidates. if (L->FailureKind == ovl_fail_too_many_arguments || L->FailureKind == ovl_fail_too_few_arguments) return false; if (R->FailureKind == ovl_fail_too_many_arguments || R->FailureKind == ovl_fail_too_few_arguments) return true; // 2. Bad conversions come first and are ordered by the number // of bad conversions and quality of good conversions. if (L->FailureKind == ovl_fail_bad_conversion) { if (R->FailureKind != ovl_fail_bad_conversion) return true; // The conversion that can be fixed with a smaller number of changes, // comes first. unsigned numLFixes = L->Fix.NumConversionsFixed; unsigned numRFixes = R->Fix.NumConversionsFixed; numLFixes = (numLFixes == 0) ? UINT_MAX : numLFixes; numRFixes = (numRFixes == 0) ? UINT_MAX : numRFixes; if (numLFixes != numRFixes) { if (numLFixes < numRFixes) return true; else return false; } // If there's any ordering between the defined conversions... // FIXME: this might not be transitive. assert(L->NumConversions == R->NumConversions); int leftBetter = 0; unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); for (unsigned E = L->NumConversions; I != E; ++I) { switch (CompareImplicitConversionSequences(S, L->Conversions[I], R->Conversions[I])) { case ImplicitConversionSequence::Better: leftBetter++; break; case ImplicitConversionSequence::Worse: leftBetter--; break; case ImplicitConversionSequence::Indistinguishable: break; } } if (leftBetter > 0) return true; if (leftBetter < 0) return false; } else if (R->FailureKind == ovl_fail_bad_conversion) return false; if (L->FailureKind == ovl_fail_bad_deduction) { if (R->FailureKind != ovl_fail_bad_deduction) return true; if (L->DeductionFailure.Result != R->DeductionFailure.Result) return RankDeductionFailure(L->DeductionFailure) < RankDeductionFailure(R->DeductionFailure); } else if (R->FailureKind == ovl_fail_bad_deduction) return false; // TODO: others? } // Sort everything else by location. SourceLocation LLoc = GetLocationForCandidate(L); SourceLocation RLoc = GetLocationForCandidate(R); // Put candidates without locations (e.g. builtins) at the end. if (LLoc.isInvalid()) return false; if (RLoc.isInvalid()) return true; return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); } }; /// CompleteNonViableCandidate - Normally, overload resolution only /// computes up to the first. Produces the FixIt set if possible. void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, llvm::ArrayRef Args) { assert(!Cand->Viable); // Don't do anything on failures other than bad conversion. if (Cand->FailureKind != ovl_fail_bad_conversion) return; // We only want the FixIts if all the arguments can be corrected. bool Unfixable = false; // Use a implicit copy initialization to check conversion fixes. Cand->Fix.setConversionChecker(TryCopyInitialization); // Skip forward to the first bad conversion. unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); unsigned ConvCount = Cand->NumConversions; while (true) { assert(ConvIdx != ConvCount && "no bad conversion in candidate"); ConvIdx++; if (Cand->Conversions[ConvIdx - 1].isBad()) { Unfixable = !Cand->TryToFixBadConversion(ConvIdx - 1, S); break; } } if (ConvIdx == ConvCount) return; assert(!Cand->Conversions[ConvIdx].isInitialized() && "remaining conversion is initialized?"); // FIXME: this should probably be preserved from the overload // operation somehow. bool SuppressUserConversions = false; const FunctionProtoType* Proto; unsigned ArgIdx = ConvIdx; if (Cand->IsSurrogate) { QualType ConvType = Cand->Surrogate->getConversionType().getNonReferenceType(); if (const PointerType *ConvPtrType = ConvType->getAs()) ConvType = ConvPtrType->getPointeeType(); Proto = ConvType->getAs(); ArgIdx--; } else if (Cand->Function) { Proto = Cand->Function->getType()->getAs(); if (isa(Cand->Function) && !isa(Cand->Function)) ArgIdx--; } else { // Builtin binary operator with a bad first conversion. assert(ConvCount <= 3); for (; ConvIdx != ConvCount; ++ConvIdx) Cand->Conversions[ConvIdx] = TryCopyInitialization(S, Args[ConvIdx], Cand->BuiltinTypes.ParamTypes[ConvIdx], SuppressUserConversions, /*InOverloadResolution*/ true, /*AllowObjCWritebackConversion=*/ S.getLangOpts().ObjCAutoRefCount); return; } // Fill in the rest of the conversions. unsigned NumArgsInProto = Proto->getNumArgs(); for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { if (ArgIdx < NumArgsInProto) { Cand->Conversions[ConvIdx] = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), SuppressUserConversions, /*InOverloadResolution=*/true, /*AllowObjCWritebackConversion=*/ S.getLangOpts().ObjCAutoRefCount); // Store the FixIt in the candidate if it exists. if (!Unfixable && Cand->Conversions[ConvIdx].isBad()) Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S); } else Cand->Conversions[ConvIdx].setEllipsis(); } } } // end anonymous namespace /// PrintOverloadCandidates - When overload resolution fails, prints /// diagnostic messages containing the candidates in the candidate /// set. void OverloadCandidateSet::NoteCandidates(Sema &S, OverloadCandidateDisplayKind OCD, llvm::ArrayRef Args, const char *Opc, SourceLocation OpLoc) { // Sort the candidates by viability and position. Sorting directly would // be prohibitive, so we make a set of pointers and sort those. SmallVector Cands; if (OCD == OCD_AllCandidates) Cands.reserve(size()); for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) { if (Cand->Viable) Cands.push_back(Cand); else if (OCD == OCD_AllCandidates) { CompleteNonViableCandidate(S, Cand, Args); if (Cand->Function || Cand->IsSurrogate) Cands.push_back(Cand); // Otherwise, this a non-viable builtin candidate. We do not, in general, // want to list every possible builtin candidate. } } std::sort(Cands.begin(), Cands.end(), CompareOverloadCandidatesForDisplay(S)); bool ReportedAmbiguousConversions = false; SmallVectorImpl::iterator I, E; const DiagnosticsEngine::OverloadsShown ShowOverloads = S.Diags.getShowOverloads(); unsigned CandsShown = 0; for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { OverloadCandidate *Cand = *I; // Set an arbitrary limit on the number of candidate functions we'll spam // the user with. FIXME: This limit should depend on details of the // candidate list. if (CandsShown >= 4 && ShowOverloads == DiagnosticsEngine::Ovl_Best) { break; } ++CandsShown; if (Cand->Function) NoteFunctionCandidate(S, Cand, Args.size()); else if (Cand->IsSurrogate) NoteSurrogateCandidate(S, Cand); else { assert(Cand->Viable && "Non-viable built-in candidates are not added to Cands."); // Generally we only see ambiguities including viable builtin // operators if overload resolution got screwed up by an // ambiguous user-defined conversion. // // FIXME: It's quite possible for different conversions to see // different ambiguities, though. if (!ReportedAmbiguousConversions) { NoteAmbiguousUserConversions(S, OpLoc, Cand); ReportedAmbiguousConversions = true; } // If this is a viable builtin, print it. NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand); } } if (I != E) S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); } // [PossiblyAFunctionType] --> [Return] // NonFunctionType --> NonFunctionType // R (A) --> R(A) // R (*)(A) --> R (A) // R (&)(A) --> R (A) // R (S::*)(A) --> R (A) QualType Sema::ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType) { QualType Ret = PossiblyAFunctionType; if (const PointerType *ToTypePtr = PossiblyAFunctionType->getAs()) Ret = ToTypePtr->getPointeeType(); else if (const ReferenceType *ToTypeRef = PossiblyAFunctionType->getAs()) Ret = ToTypeRef->getPointeeType(); else if (const MemberPointerType *MemTypePtr = PossiblyAFunctionType->getAs()) Ret = MemTypePtr->getPointeeType(); Ret = Context.getCanonicalType(Ret).getUnqualifiedType(); return Ret; } // A helper class to help with address of function resolution // - allows us to avoid passing around all those ugly parameters class AddressOfFunctionResolver { Sema& S; Expr* SourceExpr; const QualType& TargetType; QualType TargetFunctionType; // Extracted function type from target type bool Complain; //DeclAccessPair& ResultFunctionAccessPair; ASTContext& Context; bool TargetTypeIsNonStaticMemberFunction; bool FoundNonTemplateFunction; OverloadExpr::FindResult OvlExprInfo; OverloadExpr *OvlExpr; TemplateArgumentListInfo OvlExplicitTemplateArgs; SmallVector, 4> Matches; public: AddressOfFunctionResolver(Sema &S, Expr* SourceExpr, const QualType& TargetType, bool Complain) : S(S), SourceExpr(SourceExpr), TargetType(TargetType), Complain(Complain), Context(S.getASTContext()), TargetTypeIsNonStaticMemberFunction( !!TargetType->getAs()), FoundNonTemplateFunction(false), OvlExprInfo(OverloadExpr::find(SourceExpr)), OvlExpr(OvlExprInfo.Expression) { ExtractUnqualifiedFunctionTypeFromTargetType(); if (!TargetFunctionType->isFunctionType()) { if (OvlExpr->hasExplicitTemplateArgs()) { DeclAccessPair dap; if (FunctionDecl* Fn = S.ResolveSingleFunctionTemplateSpecialization( OvlExpr, false, &dap) ) { if (CXXMethodDecl *Method = dyn_cast(Fn)) { if (!Method->isStatic()) { // If the target type is a non-function type and the function // found is a non-static member function, pretend as if that was // the target, it's the only possible type to end up with. TargetTypeIsNonStaticMemberFunction = true; // And skip adding the function if its not in the proper form. // We'll diagnose this due to an empty set of functions. if (!OvlExprInfo.HasFormOfMemberPointer) return; } } Matches.push_back(std::make_pair(dap,Fn)); } } return; } if (OvlExpr->hasExplicitTemplateArgs()) OvlExpr->getExplicitTemplateArgs().copyInto(OvlExplicitTemplateArgs); if (FindAllFunctionsThatMatchTargetTypeExactly()) { // C++ [over.over]p4: // If more than one function is selected, [...] if (Matches.size() > 1) { if (FoundNonTemplateFunction) EliminateAllTemplateMatches(); else EliminateAllExceptMostSpecializedTemplate(); } } } private: bool isTargetTypeAFunction() const { return TargetFunctionType->isFunctionType(); } // [ToType] [Return] // R (*)(A) --> R (A), IsNonStaticMemberFunction = false // R (&)(A) --> R (A), IsNonStaticMemberFunction = false // R (S::*)(A) --> R (A), IsNonStaticMemberFunction = true void inline ExtractUnqualifiedFunctionTypeFromTargetType() { TargetFunctionType = S.ExtractUnqualifiedFunctionType(TargetType); } // return true if any matching specializations were found bool AddMatchingTemplateFunction(FunctionTemplateDecl* FunctionTemplate, const DeclAccessPair& CurAccessFunPair) { if (CXXMethodDecl *Method = dyn_cast(FunctionTemplate->getTemplatedDecl())) { // Skip non-static function templates when converting to pointer, and // static when converting to member pointer. if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) return false; } else if (TargetTypeIsNonStaticMemberFunction) return false; // C++ [over.over]p2: // If the name is a function template, template argument deduction is // done (14.8.2.2), and if the argument deduction succeeds, the // resulting template argument list is used to generate a single // function template specialization, which is added to the set of // overloaded functions considered. FunctionDecl *Specialization = 0; TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); if (Sema::TemplateDeductionResult Result = S.DeduceTemplateArguments(FunctionTemplate, &OvlExplicitTemplateArgs, TargetFunctionType, Specialization, Info)) { // FIXME: make a note of the failed deduction for diagnostics. (void)Result; return false; } // Template argument deduction ensures that we have an exact match. // This function template specicalization works. Specialization = cast(Specialization->getCanonicalDecl()); assert(TargetFunctionType == Context.getCanonicalType(Specialization->getType())); Matches.push_back(std::make_pair(CurAccessFunPair, Specialization)); return true; } bool AddMatchingNonTemplateFunction(NamedDecl* Fn, const DeclAccessPair& CurAccessFunPair) { if (CXXMethodDecl *Method = dyn_cast(Fn)) { // Skip non-static functions when converting to pointer, and static // when converting to member pointer. if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) return false; } else if (TargetTypeIsNonStaticMemberFunction) return false; if (FunctionDecl *FunDecl = dyn_cast(Fn)) { if (S.getLangOpts().CUDA) if (FunctionDecl *Caller = dyn_cast(S.CurContext)) if (S.CheckCUDATarget(Caller, FunDecl)) return false; QualType ResultTy; if (Context.hasSameUnqualifiedType(TargetFunctionType, FunDecl->getType()) || S.IsNoReturnConversion(FunDecl->getType(), TargetFunctionType, ResultTy)) { Matches.push_back(std::make_pair(CurAccessFunPair, cast(FunDecl->getCanonicalDecl()))); FoundNonTemplateFunction = true; return true; } } return false; } bool FindAllFunctionsThatMatchTargetTypeExactly() { bool Ret = false; // If the overload expression doesn't have the form of a pointer to // member, don't try to convert it to a pointer-to-member type. if (IsInvalidFormOfPointerToMemberFunction()) return false; for (UnresolvedSetIterator I = OvlExpr->decls_begin(), E = OvlExpr->decls_end(); I != E; ++I) { // Look through any using declarations to find the underlying function. NamedDecl *Fn = (*I)->getUnderlyingDecl(); // C++ [over.over]p3: // Non-member functions and static member functions match // targets of type "pointer-to-function" or "reference-to-function." // Nonstatic member functions match targets of // type "pointer-to-member-function." // Note that according to DR 247, the containing class does not matter. if (FunctionTemplateDecl *FunctionTemplate = dyn_cast(Fn)) { if (AddMatchingTemplateFunction(FunctionTemplate, I.getPair())) Ret = true; } // If we have explicit template arguments supplied, skip non-templates. else if (!OvlExpr->hasExplicitTemplateArgs() && AddMatchingNonTemplateFunction(Fn, I.getPair())) Ret = true; } assert(Ret || Matches.empty()); return Ret; } void EliminateAllExceptMostSpecializedTemplate() { // [...] and any given function template specialization F1 is // eliminated if the set contains a second function template // specialization whose function template is more specialized // than the function template of F1 according to the partial // ordering rules of 14.5.5.2. // The algorithm specified above is quadratic. We instead use a // two-pass algorithm (similar to the one used to identify the // best viable function in an overload set) that identifies the // best function template (if it exists). UnresolvedSet<4> MatchesCopy; // TODO: avoid! for (unsigned I = 0, E = Matches.size(); I != E; ++I) MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); UnresolvedSetIterator Result = S.getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), TPOC_Other, 0, SourceExpr->getLocStart(), S.PDiag(), S.PDiag(diag::err_addr_ovl_ambiguous) << Matches[0].second->getDeclName(), S.PDiag(diag::note_ovl_candidate) << (unsigned) oc_function_template, Complain, TargetFunctionType); if (Result != MatchesCopy.end()) { // Make it the first and only element Matches[0].first = Matches[Result - MatchesCopy.begin()].first; Matches[0].second = cast(*Result); Matches.resize(1); } } void EliminateAllTemplateMatches() { // [...] any function template specializations in the set are // eliminated if the set also contains a non-template function, [...] for (unsigned I = 0, N = Matches.size(); I != N; ) { if (Matches[I].second->getPrimaryTemplate() == 0) ++I; else { Matches[I] = Matches[--N]; Matches.set_size(N); } } } public: void ComplainNoMatchesFound() const { assert(Matches.empty()); S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_no_viable) << OvlExpr->getName() << TargetFunctionType << OvlExpr->getSourceRange(); S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType); } bool IsInvalidFormOfPointerToMemberFunction() const { return TargetTypeIsNonStaticMemberFunction && !OvlExprInfo.HasFormOfMemberPointer; } void ComplainIsInvalidFormOfPointerToMemberFunction() const { // TODO: Should we condition this on whether any functions might // have matched, or is it more appropriate to do that in callers? // TODO: a fixit wouldn't hurt. S.Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier) << TargetType << OvlExpr->getSourceRange(); } void ComplainOfInvalidConversion() const { S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_not_func_ptrref) << OvlExpr->getName() << TargetType; } void ComplainMultipleMatchesFound() const { assert(Matches.size() > 1); S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_ambiguous) << OvlExpr->getName() << OvlExpr->getSourceRange(); S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType); } bool hadMultipleCandidates() const { return (OvlExpr->getNumDecls() > 1); } int getNumMatches() const { return Matches.size(); } FunctionDecl* getMatchingFunctionDecl() const { if (Matches.size() != 1) return 0; return Matches[0].second; } const DeclAccessPair* getMatchingFunctionAccessPair() const { if (Matches.size() != 1) return 0; return &Matches[0].first; } }; /// ResolveAddressOfOverloadedFunction - Try to resolve the address of /// an overloaded function (C++ [over.over]), where @p From is an /// expression with overloaded function type and @p ToType is the type /// we're trying to resolve to. For example: /// /// @code /// int f(double); /// int f(int); /// /// int (*pfd)(double) = f; // selects f(double) /// @endcode /// /// This routine returns the resulting FunctionDecl if it could be /// resolved, and NULL otherwise. When @p Complain is true, this /// routine will emit diagnostics if there is an error. FunctionDecl * Sema::ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr, QualType TargetType, bool Complain, DeclAccessPair &FoundResult, bool *pHadMultipleCandidates) { assert(AddressOfExpr->getType() == Context.OverloadTy); AddressOfFunctionResolver Resolver(*this, AddressOfExpr, TargetType, Complain); int NumMatches = Resolver.getNumMatches(); FunctionDecl* Fn = 0; if (NumMatches == 0 && Complain) { if (Resolver.IsInvalidFormOfPointerToMemberFunction()) Resolver.ComplainIsInvalidFormOfPointerToMemberFunction(); else Resolver.ComplainNoMatchesFound(); } else if (NumMatches > 1 && Complain) Resolver.ComplainMultipleMatchesFound(); else if (NumMatches == 1) { Fn = Resolver.getMatchingFunctionDecl(); assert(Fn); FoundResult = *Resolver.getMatchingFunctionAccessPair(); MarkFunctionReferenced(AddressOfExpr->getLocStart(), Fn); if (Complain) CheckAddressOfMemberAccess(AddressOfExpr, FoundResult); } if (pHadMultipleCandidates) *pHadMultipleCandidates = Resolver.hadMultipleCandidates(); return Fn; } /// \brief Given an expression that refers to an overloaded function, try to /// resolve that overloaded function expression down to a single function. /// /// This routine can only resolve template-ids that refer to a single function /// template, where that template-id refers to a single template whose template /// arguments are either provided by the template-id or have defaults, /// as described in C++0x [temp.arg.explicit]p3. FunctionDecl * Sema::ResolveSingleFunctionTemplateSpecialization(OverloadExpr *ovl, bool Complain, DeclAccessPair *FoundResult) { // C++ [over.over]p1: // [...] [Note: any redundant set of parentheses surrounding the // overloaded function name is ignored (5.1). ] // C++ [over.over]p1: // [...] The overloaded function name can be preceded by the & // operator. // If we didn't actually find any template-ids, we're done. if (!ovl->hasExplicitTemplateArgs()) return 0; TemplateArgumentListInfo ExplicitTemplateArgs; ovl->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); // Look through all of the overloaded functions, searching for one // whose type matches exactly. FunctionDecl *Matched = 0; for (UnresolvedSetIterator I = ovl->decls_begin(), E = ovl->decls_end(); I != E; ++I) { // C++0x [temp.arg.explicit]p3: // [...] In contexts where deduction is done and fails, or in contexts // where deduction is not done, if a template argument list is // specified and it, along with any default template arguments, // identifies a single function template specialization, then the // template-id is an lvalue for the function template specialization. FunctionTemplateDecl *FunctionTemplate = cast((*I)->getUnderlyingDecl()); // C++ [over.over]p2: // If the name is a function template, template argument deduction is // done (14.8.2.2), and if the argument deduction succeeds, the // resulting template argument list is used to generate a single // function template specialization, which is added to the set of // overloaded functions considered. FunctionDecl *Specialization = 0; TemplateDeductionInfo Info(Context, ovl->getNameLoc()); if (TemplateDeductionResult Result = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, Specialization, Info)) { // FIXME: make a note of the failed deduction for diagnostics. (void)Result; continue; } assert(Specialization && "no specialization and no error?"); // Multiple matches; we can't resolve to a single declaration. if (Matched) { if (Complain) { Diag(ovl->getExprLoc(), diag::err_addr_ovl_ambiguous) << ovl->getName(); NoteAllOverloadCandidates(ovl); } return 0; } Matched = Specialization; if (FoundResult) *FoundResult = I.getPair(); } return Matched; } // Resolve and fix an overloaded expression that can be resolved // because it identifies a single function template specialization. // // Last three arguments should only be supplied if Complain = true // // Return true if it was logically possible to so resolve the // expression, regardless of whether or not it succeeded. Always // returns true if 'complain' is set. bool Sema::ResolveAndFixSingleFunctionTemplateSpecialization( ExprResult &SrcExpr, bool doFunctionPointerConverion, bool complain, const SourceRange& OpRangeForComplaining, QualType DestTypeForComplaining, unsigned DiagIDForComplaining) { assert(SrcExpr.get()->getType() == Context.OverloadTy); OverloadExpr::FindResult ovl = OverloadExpr::find(SrcExpr.get()); DeclAccessPair found; ExprResult SingleFunctionExpression; if (FunctionDecl *fn = ResolveSingleFunctionTemplateSpecialization( ovl.Expression, /*complain*/ false, &found)) { if (DiagnoseUseOfDecl(fn, SrcExpr.get()->getLocStart())) { SrcExpr = ExprError(); return true; } // It is only correct to resolve to an instance method if we're // resolving a form that's permitted to be a pointer to member. // Otherwise we'll end up making a bound member expression, which // is illegal in all the contexts we resolve like this. if (!ovl.HasFormOfMemberPointer && isa(fn) && cast(fn)->isInstance()) { if (!complain) return false; Diag(ovl.Expression->getExprLoc(), diag::err_bound_member_function) << 0 << ovl.Expression->getSourceRange(); // TODO: I believe we only end up here if there's a mix of // static and non-static candidates (otherwise the expression // would have 'bound member' type, not 'overload' type). // Ideally we would note which candidate was chosen and why // the static candidates were rejected. SrcExpr = ExprError(); return true; } // Fix the expresion to refer to 'fn'. SingleFunctionExpression = Owned(FixOverloadedFunctionReference(SrcExpr.take(), found, fn)); // If desired, do function-to-pointer decay. if (doFunctionPointerConverion) { SingleFunctionExpression = DefaultFunctionArrayLvalueConversion(SingleFunctionExpression.take()); if (SingleFunctionExpression.isInvalid()) { SrcExpr = ExprError(); return true; } } } if (!SingleFunctionExpression.isUsable()) { if (complain) { Diag(OpRangeForComplaining.getBegin(), DiagIDForComplaining) << ovl.Expression->getName() << DestTypeForComplaining << OpRangeForComplaining << ovl.Expression->getQualifierLoc().getSourceRange(); NoteAllOverloadCandidates(SrcExpr.get()); SrcExpr = ExprError(); return true; } return false; } SrcExpr = SingleFunctionExpression; return true; } /// \brief Add a single candidate to the overload set. static void AddOverloadedCallCandidate(Sema &S, DeclAccessPair FoundDecl, TemplateArgumentListInfo *ExplicitTemplateArgs, llvm::ArrayRef Args, OverloadCandidateSet &CandidateSet, bool PartialOverloading, bool KnownValid) { NamedDecl *Callee = FoundDecl.getDecl(); if (isa(Callee)) Callee = cast(Callee)->getTargetDecl(); if (FunctionDecl *Func = dyn_cast(Callee)) { if (ExplicitTemplateArgs) { assert(!KnownValid && "Explicit template arguments?"); return; } S.AddOverloadCandidate(Func, FoundDecl, Args, CandidateSet, false, PartialOverloading); return; } if (FunctionTemplateDecl *FuncTemplate = dyn_cast(Callee)) { S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, ExplicitTemplateArgs, Args, CandidateSet); return; } assert(!KnownValid && "unhandled case in overloaded call candidate"); } /// \brief Add the overload candidates named by callee and/or found by argument /// dependent lookup to the given overload set. void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, llvm::ArrayRef Args, OverloadCandidateSet &CandidateSet, bool PartialOverloading) { #ifndef NDEBUG // Verify that ArgumentDependentLookup is consistent with the rules // in C++0x [basic.lookup.argdep]p3: // // Let X be the lookup set produced by unqualified lookup (3.4.1) // and let Y be the lookup set produced by argument dependent // lookup (defined as follows). If X contains // // -- a declaration of a class member, or // // -- a block-scope function declaration that is not a // using-declaration, or // // -- a declaration that is neither a function or a function // template // // then Y is empty. if (ULE->requiresADL()) { for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), E = ULE->decls_end(); I != E; ++I) { assert(!(*I)->getDeclContext()->isRecord()); assert(isa(*I) || !(*I)->getDeclContext()->isFunctionOrMethod()); assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); } } #endif // It would be nice to avoid this copy. TemplateArgumentListInfo TABuffer; TemplateArgumentListInfo *ExplicitTemplateArgs = 0; if (ULE->hasExplicitTemplateArgs()) { ULE->copyTemplateArgumentsInto(TABuffer); ExplicitTemplateArgs = &TABuffer; } for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), E = ULE->decls_end(); I != E; ++I) AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, Args, CandidateSet, PartialOverloading, /*KnownValid*/ true); if (ULE->requiresADL()) AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, ULE->getExprLoc(), Args, ExplicitTemplateArgs, CandidateSet, PartialOverloading, ULE->isStdAssociatedNamespace()); } /// Attempt to recover from an ill-formed use of a non-dependent name in a /// template, where the non-dependent name was declared after the template /// was defined. This is common in code written for a compilers which do not /// correctly implement two-stage name lookup. /// /// Returns true if a viable candidate was found and a diagnostic was issued. static bool DiagnoseTwoPhaseLookup(Sema &SemaRef, SourceLocation FnLoc, const CXXScopeSpec &SS, LookupResult &R, TemplateArgumentListInfo *ExplicitTemplateArgs, llvm::ArrayRef Args) { if (SemaRef.ActiveTemplateInstantiations.empty() || !SS.isEmpty()) return false; for (DeclContext *DC = SemaRef.CurContext; DC; DC = DC->getParent()) { if (DC->isTransparentContext()) continue; SemaRef.LookupQualifiedName(R, DC); if (!R.empty()) { R.suppressDiagnostics(); if (isa(DC)) { // Don't diagnose names we find in classes; we get much better // diagnostics for these from DiagnoseEmptyLookup. R.clear(); return false; } OverloadCandidateSet Candidates(FnLoc); for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) AddOverloadedCallCandidate(SemaRef, I.getPair(), ExplicitTemplateArgs, Args, Candidates, false, /*KnownValid*/ false); OverloadCandidateSet::iterator Best; if (Candidates.BestViableFunction(SemaRef, FnLoc, Best) != OR_Success) { // No viable functions. Don't bother the user with notes for functions // which don't work and shouldn't be found anyway. R.clear(); return false; } // Find the namespaces where ADL would have looked, and suggest // declaring the function there instead. Sema::AssociatedNamespaceSet AssociatedNamespaces; Sema::AssociatedClassSet AssociatedClasses; SemaRef.FindAssociatedClassesAndNamespaces(Args, AssociatedNamespaces, AssociatedClasses); // Never suggest declaring a function within namespace 'std'. Sema::AssociatedNamespaceSet SuggestedNamespaces; if (DeclContext *Std = SemaRef.getStdNamespace()) { for (Sema::AssociatedNamespaceSet::iterator it = AssociatedNamespaces.begin(), end = AssociatedNamespaces.end(); it != end; ++it) { if (!Std->Encloses(*it)) SuggestedNamespaces.insert(*it); } } else { // Lacking the 'std::' namespace, use all of the associated namespaces. SuggestedNamespaces = AssociatedNamespaces; } SemaRef.Diag(R.getNameLoc(), diag::err_not_found_by_two_phase_lookup) << R.getLookupName(); if (SuggestedNamespaces.empty()) { SemaRef.Diag(Best->Function->getLocation(), diag::note_not_found_by_two_phase_lookup) << R.getLookupName() << 0; } else if (SuggestedNamespaces.size() == 1) { SemaRef.Diag(Best->Function->getLocation(), diag::note_not_found_by_two_phase_lookup) << R.getLookupName() << 1 << *SuggestedNamespaces.begin(); } else { // FIXME: It would be useful to list the associated namespaces here, // but the diagnostics infrastructure doesn't provide a way to produce // a localized representation of a list of items. SemaRef.Diag(Best->Function->getLocation(), diag::note_not_found_by_two_phase_lookup) << R.getLookupName() << 2; } // Try to recover by calling this function. return true; } R.clear(); } return false; } /// Attempt to recover from ill-formed use of a non-dependent operator in a /// template, where the non-dependent operator was declared after the template /// was defined. /// /// Returns true if a viable candidate was found and a diagnostic was issued. static bool DiagnoseTwoPhaseOperatorLookup(Sema &SemaRef, OverloadedOperatorKind Op, SourceLocation OpLoc, llvm::ArrayRef Args) { DeclarationName OpName = SemaRef.Context.DeclarationNames.getCXXOperatorName(Op); LookupResult R(SemaRef, OpName, OpLoc, Sema::LookupOperatorName); return DiagnoseTwoPhaseLookup(SemaRef, OpLoc, CXXScopeSpec(), R, /*ExplicitTemplateArgs=*/0, Args); } namespace { // Callback to limit the allowed keywords and to only accept typo corrections // that are keywords or whose decls refer to functions (or template functions) // that accept the given number of arguments. class RecoveryCallCCC : public CorrectionCandidateCallback { public: RecoveryCallCCC(Sema &SemaRef, unsigned NumArgs, bool HasExplicitTemplateArgs) : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs) { WantTypeSpecifiers = SemaRef.getLangOpts().CPlusPlus; WantRemainingKeywords = false; } virtual bool ValidateCandidate(const TypoCorrection &candidate) { if (!candidate.getCorrectionDecl()) return candidate.isKeyword(); for (TypoCorrection::const_decl_iterator DI = candidate.begin(), DIEnd = candidate.end(); DI != DIEnd; ++DI) { FunctionDecl *FD = 0; NamedDecl *ND = (*DI)->getUnderlyingDecl(); if (FunctionTemplateDecl *FTD = dyn_cast(ND)) FD = FTD->getTemplatedDecl(); if (!HasExplicitTemplateArgs && !FD) { if (!(FD = dyn_cast(ND)) && isa(ND)) { // If the Decl is neither a function nor a template function, // determine if it is a pointer or reference to a function. If so, // check against the number of arguments expected for the pointee. QualType ValType = cast(ND)->getType(); if (ValType->isAnyPointerType() || ValType->isReferenceType()) ValType = ValType->getPointeeType(); if (const FunctionProtoType *FPT = ValType->getAs()) if (FPT->getNumArgs() == NumArgs) return true; } } if (FD && FD->getNumParams() >= NumArgs && FD->getMinRequiredArguments() <= NumArgs) return true; } return false; } private: unsigned NumArgs; bool HasExplicitTemplateArgs; }; // Callback that effectively disabled typo correction class NoTypoCorrectionCCC : public CorrectionCandidateCallback { public: NoTypoCorrectionCCC() { WantTypeSpecifiers = false; WantExpressionKeywords = false; WantCXXNamedCasts = false; WantRemainingKeywords = false; } virtual bool ValidateCandidate(const TypoCorrection &candidate) { return false; } }; } /// Attempts to recover from a call where no functions were found. /// /// Returns true if new candidates were found. static ExprResult BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, SourceLocation LParenLoc, llvm::MutableArrayRef Args, SourceLocation RParenLoc, bool EmptyLookup, bool AllowTypoCorrection) { CXXScopeSpec SS; SS.Adopt(ULE->getQualifierLoc()); SourceLocation TemplateKWLoc = ULE->getTemplateKeywordLoc(); TemplateArgumentListInfo TABuffer; TemplateArgumentListInfo *ExplicitTemplateArgs = 0; if (ULE->hasExplicitTemplateArgs()) { ULE->copyTemplateArgumentsInto(TABuffer); ExplicitTemplateArgs = &TABuffer; } LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), Sema::LookupOrdinaryName); RecoveryCallCCC Validator(SemaRef, Args.size(), ExplicitTemplateArgs != 0); NoTypoCorrectionCCC RejectAll; CorrectionCandidateCallback *CCC = AllowTypoCorrection ? (CorrectionCandidateCallback*)&Validator : (CorrectionCandidateCallback*)&RejectAll; if (!DiagnoseTwoPhaseLookup(SemaRef, Fn->getExprLoc(), SS, R, ExplicitTemplateArgs, Args) && (!EmptyLookup || SemaRef.DiagnoseEmptyLookup(S, SS, R, *CCC, ExplicitTemplateArgs, Args))) return ExprError(); assert(!R.empty() && "lookup results empty despite recovery"); // Build an implicit member call if appropriate. Just drop the // casts and such from the call, we don't really care. ExprResult NewFn = ExprError(); if ((*R.begin())->isCXXClassMember()) NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, TemplateKWLoc, R, ExplicitTemplateArgs); else if (ExplicitTemplateArgs || TemplateKWLoc.isValid()) NewFn = SemaRef.BuildTemplateIdExpr(SS, TemplateKWLoc, R, false, ExplicitTemplateArgs); else NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); if (NewFn.isInvalid()) return ExprError(); // This shouldn't cause an infinite loop because we're giving it // an expression with viable lookup results, which should never // end up here. return SemaRef.ActOnCallExpr(/*Scope*/ 0, NewFn.take(), LParenLoc, MultiExprArg(Args.data(), Args.size()), RParenLoc); } /// ResolveOverloadedCallFn - Given the call expression that calls Fn /// (which eventually refers to the declaration Func) and the call /// arguments Args/NumArgs, attempt to resolve the function call down /// to a specific function. If overload resolution succeeds, returns /// the function declaration produced by overload /// resolution. Otherwise, emits diagnostics, deletes all of the /// arguments and Fn, and returns NULL. ExprResult Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, SourceLocation LParenLoc, Expr **Args, unsigned NumArgs, SourceLocation RParenLoc, Expr *ExecConfig, bool AllowTypoCorrection) { #ifndef NDEBUG if (ULE->requiresADL()) { // To do ADL, we must have found an unqualified name. assert(!ULE->getQualifier() && "qualified name with ADL"); // We don't perform ADL for implicit declarations of builtins. // Verify that this was correctly set up. FunctionDecl *F; if (ULE->decls_begin() + 1 == ULE->decls_end() && (F = dyn_cast(*ULE->decls_begin())) && F->getBuiltinID() && F->isImplicit()) llvm_unreachable("performing ADL for builtin"); // We don't perform ADL in C. assert(getLangOpts().CPlusPlus && "ADL enabled in C"); } else assert(!ULE->isStdAssociatedNamespace() && "std is associated namespace but not doing ADL"); #endif UnbridgedCastsSet UnbridgedCasts; if (checkArgPlaceholdersForOverload(*this, Args, NumArgs, UnbridgedCasts)) return ExprError(); OverloadCandidateSet CandidateSet(Fn->getExprLoc()); // Add the functions denoted by the callee to the set of candidate // functions, including those from argument-dependent lookup. AddOverloadedCallCandidates(ULE, llvm::makeArrayRef(Args, NumArgs), CandidateSet); // If we found nothing, try to recover. // BuildRecoveryCallExpr diagnoses the error itself, so we just bail // out if it fails. if (CandidateSet.empty()) { // In Microsoft mode, if we are inside a template class member function then // create a type dependent CallExpr. The goal is to postpone name lookup // to instantiation time to be able to search into type dependent base // classes. if (getLangOpts().MicrosoftMode && CurContext->isDependentContext() && (isa(CurContext) || isa(CurContext))) { CallExpr *CE = new (Context) CallExpr(Context, Fn, Args, NumArgs, Context.DependentTy, VK_RValue, RParenLoc); CE->setTypeDependent(true); return Owned(CE); } return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, llvm::MutableArrayRef(Args, NumArgs), RParenLoc, /*EmptyLookup=*/true, AllowTypoCorrection); } UnbridgedCasts.restore(); OverloadCandidateSet::iterator Best; switch (CandidateSet.BestViableFunction(*this, Fn->getLocStart(), Best)) { case OR_Success: { FunctionDecl *FDecl = Best->Function; MarkFunctionReferenced(Fn->getExprLoc(), FDecl); CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); DiagnoseUseOfDecl(FDecl, ULE->getNameLoc()); Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc, ExecConfig); } case OR_No_Viable_Function: { // Try to recover by looking for viable functions which the user might // have meant to call. ExprResult Recovery = BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, llvm::MutableArrayRef(Args, NumArgs), RParenLoc, /*EmptyLookup=*/false, AllowTypoCorrection); if (!Recovery.isInvalid()) return Recovery; Diag(Fn->getLocStart(), diag::err_ovl_no_viable_function_in_call) << ULE->getName() << Fn->getSourceRange(); CandidateSet.NoteCandidates(*this, OCD_AllCandidates, llvm::makeArrayRef(Args, NumArgs)); break; } case OR_Ambiguous: Diag(Fn->getLocStart(), diag::err_ovl_ambiguous_call) << ULE->getName() << Fn->getSourceRange(); CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, llvm::makeArrayRef(Args, NumArgs)); break; case OR_Deleted: { Diag(Fn->getLocStart(), diag::err_ovl_deleted_call) << Best->Function->isDeleted() << ULE->getName() << getDeletedOrUnavailableSuffix(Best->Function) << Fn->getSourceRange(); CandidateSet.NoteCandidates(*this, OCD_AllCandidates, llvm::makeArrayRef(Args, NumArgs)); // We emitted an error for the unvailable/deleted function call but keep // the call in the AST. FunctionDecl *FDecl = Best->Function; Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc, ExecConfig); } } // Overload resolution failed. return ExprError(); } static bool IsOverloaded(const UnresolvedSetImpl &Functions) { return Functions.size() > 1 || (Functions.size() == 1 && isa(*Functions.begin())); } /// \brief Create a unary operation that may resolve to an overloaded /// operator. /// /// \param OpLoc The location of the operator itself (e.g., '*'). /// /// \param OpcIn The UnaryOperator::Opcode that describes this /// operator. /// /// \param Functions The set of non-member functions that will be /// considered by overload resolution. The caller needs to build this /// set based on the context using, e.g., /// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This /// set should not contain any member functions; those will be added /// by CreateOverloadedUnaryOp(). /// /// \param input The input argument. ExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, const UnresolvedSetImpl &Fns, Expr *Input) { UnaryOperator::Opcode Opc = static_cast(OpcIn); OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); // TODO: provide better source location info. DeclarationNameInfo OpNameInfo(OpName, OpLoc); if (checkPlaceholderForOverload(*this, Input)) return ExprError(); Expr *Args[2] = { Input, 0 }; unsigned NumArgs = 1; // For post-increment and post-decrement, add the implicit '0' as // the second argument, so that we know this is a post-increment or // post-decrement. if (Opc == UO_PostInc || Opc == UO_PostDec) { llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); Args[1] = IntegerLiteral::Create(Context, Zero, Context.IntTy, SourceLocation()); NumArgs = 2; } if (Input->isTypeDependent()) { if (Fns.empty()) return Owned(new (Context) UnaryOperator(Input, Opc, Context.DependentTy, VK_RValue, OK_Ordinary, OpLoc)); CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators UnresolvedLookupExpr *Fn = UnresolvedLookupExpr::Create(Context, NamingClass, NestedNameSpecifierLoc(), OpNameInfo, /*ADL*/ true, IsOverloaded(Fns), Fns.begin(), Fns.end()); return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, &Args[0], NumArgs, Context.DependentTy, VK_RValue, OpLoc)); } // Build an empty overload set. OverloadCandidateSet CandidateSet(OpLoc); // Add the candidates from the given function set. AddFunctionCandidates(Fns, llvm::makeArrayRef(Args, NumArgs), CandidateSet, false); // Add operator candidates that are member functions. AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); // Add candidates from ADL. AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, OpLoc, llvm::makeArrayRef(Args, NumArgs), /*ExplicitTemplateArgs*/ 0, CandidateSet); // Add builtin operator candidates. AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); bool HadMultipleCandidates = (CandidateSet.size() > 1); // Perform overload resolution. OverloadCandidateSet::iterator Best; switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { case OR_Success: { // We found a built-in operator or an overloaded operator. FunctionDecl *FnDecl = Best->Function; if (FnDecl) { // We matched an overloaded operator. Build a call to that // operator. MarkFunctionReferenced(OpLoc, FnDecl); // Convert the arguments. if (CXXMethodDecl *Method = dyn_cast(FnDecl)) { CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); ExprResult InputRes = PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, Best->FoundDecl, Method); if (InputRes.isInvalid()) return ExprError(); Input = InputRes.take(); } else { // Convert the arguments. ExprResult InputInit = PerformCopyInitialization(InitializedEntity::InitializeParameter( Context, FnDecl->getParamDecl(0)), SourceLocation(), Input); if (InputInit.isInvalid()) return ExprError(); Input = InputInit.take(); } DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); // Determine the result type. QualType ResultTy = FnDecl->getResultType(); ExprValueKind VK = Expr::getValueKindForType(ResultTy); ResultTy = ResultTy.getNonLValueExprType(Context); // Build the actual expression node. ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, HadMultipleCandidates, OpLoc); if (FnExpr.isInvalid()) return ExprError(); Args[0] = Input; CallExpr *TheCall = new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.take(), Args, NumArgs, ResultTy, VK, OpLoc); if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, FnDecl)) return ExprError(); return MaybeBindToTemporary(TheCall); } else { // We matched a built-in operator. Convert the arguments, then // break out so that we will build the appropriate built-in // operator node. ExprResult InputRes = PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], Best->Conversions[0], AA_Passing); if (InputRes.isInvalid()) return ExprError(); Input = InputRes.take(); break; } } case OR_No_Viable_Function: // This is an erroneous use of an operator which can be overloaded by // a non-member function. Check for non-member operators which were // defined too late to be candidates. if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, llvm::makeArrayRef(Args, NumArgs))) // FIXME: Recover by calling the found function. return ExprError(); // No viable function; fall through to handling this as a // built-in operator, which will produce an error message for us. break; case OR_Ambiguous: Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) << UnaryOperator::getOpcodeStr(Opc) << Input->getType() << Input->getSourceRange(); CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, llvm::makeArrayRef(Args, NumArgs), UnaryOperator::getOpcodeStr(Opc), OpLoc); return ExprError(); case OR_Deleted: Diag(OpLoc, diag::err_ovl_deleted_oper) << Best->Function->isDeleted() << UnaryOperator::getOpcodeStr(Opc) << getDeletedOrUnavailableSuffix(Best->Function) << Input->getSourceRange(); CandidateSet.NoteCandidates(*this, OCD_AllCandidates, llvm::makeArrayRef(Args, NumArgs), UnaryOperator::getOpcodeStr(Opc), OpLoc); return ExprError(); } // Either we found no viable overloaded operator or we matched a // built-in operator. In either case, fall through to trying to // build a built-in operation. return CreateBuiltinUnaryOp(OpLoc, Opc, Input); } /// \brief Create a binary operation that may resolve to an overloaded /// operator. /// /// \param OpLoc The location of the operator itself (e.g., '+'). /// /// \param OpcIn The BinaryOperator::Opcode that describes this /// operator. /// /// \param Functions The set of non-member functions that will be /// considered by overload resolution. The caller needs to build this /// set based on the context using, e.g., /// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This /// set should not contain any member functions; those will be added /// by CreateOverloadedBinOp(). /// /// \param LHS Left-hand argument. /// \param RHS Right-hand argument. ExprResult Sema::CreateOverloadedBinOp(SourceLocation OpLoc, unsigned OpcIn, const UnresolvedSetImpl &Fns, Expr *LHS, Expr *RHS) { Expr *Args[2] = { LHS, RHS }; LHS=RHS=0; //Please use only Args instead of LHS/RHS couple BinaryOperator::Opcode Opc = static_cast(OpcIn); OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); // If either side is type-dependent, create an appropriate dependent // expression. if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { if (Fns.empty()) { // If there are no functions to store, just build a dependent // BinaryOperator or CompoundAssignment. if (Opc <= BO_Assign || Opc > BO_OrAssign) return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, Context.DependentTy, VK_RValue, OK_Ordinary, OpLoc)); return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, Context.DependentTy, VK_LValue, OK_Ordinary, Context.DependentTy, Context.DependentTy, OpLoc)); } // FIXME: save results of ADL from here? CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators // TODO: provide better source location info in DNLoc component. DeclarationNameInfo OpNameInfo(OpName, OpLoc); UnresolvedLookupExpr *Fn = UnresolvedLookupExpr::Create(Context, NamingClass, NestedNameSpecifierLoc(), OpNameInfo, /*ADL*/ true, IsOverloaded(Fns), Fns.begin(), Fns.end()); return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, Args, 2, Context.DependentTy, VK_RValue, OpLoc)); } // Always do placeholder-like conversions on the RHS. if (checkPlaceholderForOverload(*this, Args[1])) return ExprError(); // Do placeholder-like conversion on the LHS; note that we should // not get here with a PseudoObject LHS. assert(Args[0]->getObjectKind() != OK_ObjCProperty); if (checkPlaceholderForOverload(*this, Args[0])) return ExprError(); // If this is the assignment operator, we only perform overload resolution // if the left-hand side is a class or enumeration type. This is actually // a hack. The standard requires that we do overload resolution between the // various built-in candidates, but as DR507 points out, this can lead to // problems. So we do it this way, which pretty much follows what GCC does. // Note that we go the traditional code path for compound assignment forms. if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType()) return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); // If this is the .* operator, which is not overloadable, just // create a built-in binary operator. if (Opc == BO_PtrMemD) return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); // Build an empty overload set. OverloadCandidateSet CandidateSet(OpLoc); // Add the candidates from the given function set. AddFunctionCandidates(Fns, Args, CandidateSet, false); // Add operator candidates that are member functions. AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); // Add candidates from ADL. AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, OpLoc, Args, /*ExplicitTemplateArgs*/ 0, CandidateSet); // Add builtin operator candidates. AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); bool HadMultipleCandidates = (CandidateSet.size() > 1); // Perform overload resolution. OverloadCandidateSet::iterator Best; switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { case OR_Success: { // We found a built-in operator or an overloaded operator. FunctionDecl *FnDecl = Best->Function; if (FnDecl) { // We matched an overloaded operator. Build a call to that // operator. MarkFunctionReferenced(OpLoc, FnDecl); // Convert the arguments. if (CXXMethodDecl *Method = dyn_cast(FnDecl)) { // Best->Access is only meaningful for class members. CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); ExprResult Arg1 = PerformCopyInitialization( InitializedEntity::InitializeParameter(Context, FnDecl->getParamDecl(0)), SourceLocation(), Owned(Args[1])); if (Arg1.isInvalid()) return ExprError(); ExprResult Arg0 = PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, Best->FoundDecl, Method); if (Arg0.isInvalid()) return ExprError(); Args[0] = Arg0.takeAs(); Args[1] = RHS = Arg1.takeAs(); } else { // Convert the arguments. ExprResult Arg0 = PerformCopyInitialization( InitializedEntity::InitializeParameter(Context, FnDecl->getParamDecl(0)), SourceLocation(), Owned(Args[0])); if (Arg0.isInvalid()) return ExprError(); ExprResult Arg1 = PerformCopyInitialization( InitializedEntity::InitializeParameter(Context, FnDecl->getParamDecl(1)), SourceLocation(), Owned(Args[1])); if (Arg1.isInvalid()) return ExprError(); Args[0] = LHS = Arg0.takeAs(); Args[1] = RHS = Arg1.takeAs(); } DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); // Determine the result type. QualType ResultTy = FnDecl->getResultType(); ExprValueKind VK = Expr::getValueKindForType(ResultTy); ResultTy = ResultTy.getNonLValueExprType(Context); // Build the actual expression node. ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, HadMultipleCandidates, OpLoc); if (FnExpr.isInvalid()) return ExprError(); CXXOperatorCallExpr *TheCall = new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.take(), Args, 2, ResultTy, VK, OpLoc); if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, FnDecl)) return ExprError(); return MaybeBindToTemporary(TheCall); } else { // We matched a built-in operator. Convert the arguments, then // break out so that we will build the appropriate built-in // operator node. ExprResult ArgsRes0 = PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], Best->Conversions[0], AA_Passing); if (ArgsRes0.isInvalid()) return ExprError(); Args[0] = ArgsRes0.take(); ExprResult ArgsRes1 = PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], Best->Conversions[1], AA_Passing); if (ArgsRes1.isInvalid()) return ExprError(); Args[1] = ArgsRes1.take(); break; } } case OR_No_Viable_Function: { // C++ [over.match.oper]p9: // If the operator is the operator , [...] and there are no // viable functions, then the operator is assumed to be the // built-in operator and interpreted according to clause 5. if (Opc == BO_Comma) break; // For class as left operand for assignment or compound assigment // operator do not fall through to handling in built-in, but report that // no overloaded assignment operator found ExprResult Result = ExprError(); if (Args[0]->getType()->isRecordType() && Opc >= BO_Assign && Opc <= BO_OrAssign) { Diag(OpLoc, diag::err_ovl_no_viable_oper) << BinaryOperator::getOpcodeStr(Opc) << Args[0]->getSourceRange() << Args[1]->getSourceRange(); } else { // This is an erroneous use of an operator which can be overloaded by // a non-member function. Check for non-member operators which were // defined too late to be candidates. if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, Args)) // FIXME: Recover by calling the found function. return ExprError(); // No viable function; try to create a built-in operation, which will // produce an error. Then, show the non-viable candidates. Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); } assert(Result.isInvalid() && "C++ binary operator overloading is missing candidates!"); if (Result.isInvalid()) CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, BinaryOperator::getOpcodeStr(Opc), OpLoc); return move(Result); } case OR_Ambiguous: Diag(OpLoc, diag::err_ovl_ambiguous_oper_binary) << BinaryOperator::getOpcodeStr(Opc) << Args[0]->getType() << Args[1]->getType() << Args[0]->getSourceRange() << Args[1]->getSourceRange(); CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, BinaryOperator::getOpcodeStr(Opc), OpLoc); return ExprError(); case OR_Deleted: if (isImplicitlyDeleted(Best->Function)) { CXXMethodDecl *Method = cast(Best->Function); Diag(OpLoc, diag::err_ovl_deleted_special_oper) << getSpecialMember(Method) << BinaryOperator::getOpcodeStr(Opc) << getDeletedOrUnavailableSuffix(Best->Function); if (getSpecialMember(Method) != CXXInvalid) { // The user probably meant to call this special member. Just // explain why it's deleted. NoteDeletedFunction(Method); return ExprError(); } } else { Diag(OpLoc, diag::err_ovl_deleted_oper) << Best->Function->isDeleted() << BinaryOperator::getOpcodeStr(Opc) << getDeletedOrUnavailableSuffix(Best->Function) << Args[0]->getSourceRange() << Args[1]->getSourceRange(); } CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, BinaryOperator::getOpcodeStr(Opc), OpLoc); return ExprError(); } // We matched a built-in operator; build it. return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); } ExprResult Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, SourceLocation RLoc, Expr *Base, Expr *Idx) { Expr *Args[2] = { Base, Idx }; DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Subscript); // If either side is type-dependent, create an appropriate dependent // expression. if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators // CHECKME: no 'operator' keyword? DeclarationNameInfo OpNameInfo(OpName, LLoc); OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); UnresolvedLookupExpr *Fn = UnresolvedLookupExpr::Create(Context, NamingClass, NestedNameSpecifierLoc(), OpNameInfo, /*ADL*/ true, /*Overloaded*/ false, UnresolvedSetIterator(), UnresolvedSetIterator()); // Can't add any actual overloads yet return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, Args, 2, Context.DependentTy, VK_RValue, RLoc)); } // Handle placeholders on both operands. if (checkPlaceholderForOverload(*this, Args[0])) return ExprError(); if (checkPlaceholderForOverload(*this, Args[1])) return ExprError(); // Build an empty overload set. OverloadCandidateSet CandidateSet(LLoc); // Subscript can only be overloaded as a member function. // Add operator candidates that are member functions. AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); // Add builtin operator candidates. AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); bool HadMultipleCandidates = (CandidateSet.size() > 1); // Perform overload resolution. OverloadCandidateSet::iterator Best; switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) { case OR_Success: { // We found a built-in operator or an overloaded operator. FunctionDecl *FnDecl = Best->Function; if (FnDecl) { // We matched an overloaded operator. Build a call to that // operator. MarkFunctionReferenced(LLoc, FnDecl); CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); DiagnoseUseOfDecl(Best->FoundDecl, LLoc); // Convert the arguments. CXXMethodDecl *Method = cast(FnDecl); ExprResult Arg0 = PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, Best->FoundDecl, Method); if (Arg0.isInvalid()) return ExprError(); Args[0] = Arg0.take(); // Convert the arguments. ExprResult InputInit = PerformCopyInitialization(InitializedEntity::InitializeParameter( Context, FnDecl->getParamDecl(0)), SourceLocation(), Owned(Args[1])); if (InputInit.isInvalid()) return ExprError(); Args[1] = InputInit.takeAs(); // Determine the result type QualType ResultTy = FnDecl->getResultType(); ExprValueKind VK = Expr::getValueKindForType(ResultTy); ResultTy = ResultTy.getNonLValueExprType(Context); // Build the actual expression node. DeclarationNameInfo OpLocInfo(OpName, LLoc); OpLocInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, HadMultipleCandidates, OpLocInfo.getLoc(), OpLocInfo.getInfo()); if (FnExpr.isInvalid()) return ExprError(); CXXOperatorCallExpr *TheCall = new (Context) CXXOperatorCallExpr(Context, OO_Subscript, FnExpr.take(), Args, 2, ResultTy, VK, RLoc); if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall, FnDecl)) return ExprError(); return MaybeBindToTemporary(TheCall); } else { // We matched a built-in operator. Convert the arguments, then // break out so that we will build the appropriate built-in // operator node. ExprResult ArgsRes0 = PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], Best->Conversions[0], AA_Passing); if (ArgsRes0.isInvalid()) return ExprError(); Args[0] = ArgsRes0.take(); ExprResult ArgsRes1 = PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], Best->Conversions[1], AA_Passing); if (ArgsRes1.isInvalid()) return ExprError(); Args[1] = ArgsRes1.take(); break; } } case OR_No_Viable_Function: { if (CandidateSet.empty()) Diag(LLoc, diag::err_ovl_no_oper) << Args[0]->getType() << /*subscript*/ 0 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); else Diag(LLoc, diag::err_ovl_no_viable_subscript) << Args[0]->getType() << Args[0]->getSourceRange() << Args[1]->getSourceRange(); CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, "[]", LLoc); return ExprError(); } case OR_Ambiguous: Diag(LLoc, diag::err_ovl_ambiguous_oper_binary) << "[]" << Args[0]->getType() << Args[1]->getType() << Args[0]->getSourceRange() << Args[1]->getSourceRange(); CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, "[]", LLoc); return ExprError(); case OR_Deleted: Diag(LLoc, diag::err_ovl_deleted_oper) << Best->Function->isDeleted() << "[]" << getDeletedOrUnavailableSuffix(Best->Function) << Args[0]->getSourceRange() << Args[1]->getSourceRange(); CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, "[]", LLoc); return ExprError(); } // We matched a built-in operator; build it. return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc); } /// BuildCallToMemberFunction - Build a call to a member /// function. MemExpr is the expression that refers to the member /// function (and includes the object parameter), Args/NumArgs are the /// arguments to the function call (not including the object /// parameter). The caller needs to validate that the member /// expression refers to a non-static member function or an overloaded /// member function. ExprResult Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, SourceLocation LParenLoc, Expr **Args, unsigned NumArgs, SourceLocation RParenLoc) { assert(MemExprE->getType() == Context.BoundMemberTy || MemExprE->getType() == Context.OverloadTy); // Dig out the member expression. This holds both the object // argument and the member function we're referring to. Expr *NakedMemExpr = MemExprE->IgnoreParens(); // Determine whether this is a call to a pointer-to-member function. if (BinaryOperator *op = dyn_cast(NakedMemExpr)) { assert(op->getType() == Context.BoundMemberTy); assert(op->getOpcode() == BO_PtrMemD || op->getOpcode() == BO_PtrMemI); QualType fnType = op->getRHS()->getType()->castAs()->getPointeeType(); const FunctionProtoType *proto = fnType->castAs(); QualType resultType = proto->getCallResultType(Context); ExprValueKind valueKind = Expr::getValueKindForType(proto->getResultType()); // Check that the object type isn't more qualified than the // member function we're calling. Qualifiers funcQuals = Qualifiers::fromCVRMask(proto->getTypeQuals()); QualType objectType = op->getLHS()->getType(); if (op->getOpcode() == BO_PtrMemI) objectType = objectType->castAs()->getPointeeType(); Qualifiers objectQuals = objectType.getQualifiers(); Qualifiers difference = objectQuals - funcQuals; difference.removeObjCGCAttr(); difference.removeAddressSpace(); if (difference) { std::string qualsString = difference.getAsString(); Diag(LParenLoc, diag::err_pointer_to_member_call_drops_quals) << fnType.getUnqualifiedType() << qualsString << (qualsString.find(' ') == std::string::npos ? 1 : 2); } CXXMemberCallExpr *call = new (Context) CXXMemberCallExpr(Context, MemExprE, Args, NumArgs, resultType, valueKind, RParenLoc); if (CheckCallReturnType(proto->getResultType(), op->getRHS()->getLocStart(), call, 0)) return ExprError(); if (ConvertArgumentsForCall(call, op, 0, proto, Args, NumArgs, RParenLoc)) return ExprError(); return MaybeBindToTemporary(call); } UnbridgedCastsSet UnbridgedCasts; if (checkArgPlaceholdersForOverload(*this, Args, NumArgs, UnbridgedCasts)) return ExprError(); MemberExpr *MemExpr; CXXMethodDecl *Method = 0; DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); NestedNameSpecifier *Qualifier = 0; if (isa(NakedMemExpr)) { MemExpr = cast(NakedMemExpr); Method = cast(MemExpr->getMemberDecl()); FoundDecl = MemExpr->getFoundDecl(); Qualifier = MemExpr->getQualifier(); UnbridgedCasts.restore(); } else { UnresolvedMemberExpr *UnresExpr = cast(NakedMemExpr); Qualifier = UnresExpr->getQualifier(); QualType ObjectType = UnresExpr->getBaseType(); Expr::Classification ObjectClassification = UnresExpr->isArrow()? Expr::Classification::makeSimpleLValue() : UnresExpr->getBase()->Classify(Context); // Add overload candidates OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); // FIXME: avoid copy. TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; if (UnresExpr->hasExplicitTemplateArgs()) { UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); TemplateArgs = &TemplateArgsBuffer; } for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), E = UnresExpr->decls_end(); I != E; ++I) { NamedDecl *Func = *I; CXXRecordDecl *ActingDC = cast(Func->getDeclContext()); if (isa(Func)) Func = cast(Func)->getTargetDecl(); // Microsoft supports direct constructor calls. if (getLangOpts().MicrosoftExt && isa(Func)) { AddOverloadCandidate(cast(Func), I.getPair(), llvm::makeArrayRef(Args, NumArgs), CandidateSet); } else if ((Method = dyn_cast(Func))) { // If explicit template arguments were provided, we can't call a // non-template member function. if (TemplateArgs) continue; AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, ObjectClassification, llvm::makeArrayRef(Args, NumArgs), CandidateSet, /*SuppressUserConversions=*/false); } else { AddMethodTemplateCandidate(cast(Func), I.getPair(), ActingDC, TemplateArgs, ObjectType, ObjectClassification, llvm::makeArrayRef(Args, NumArgs), CandidateSet, /*SuppressUsedConversions=*/false); } } DeclarationName DeclName = UnresExpr->getMemberName(); UnbridgedCasts.restore(); OverloadCandidateSet::iterator Best; switch (CandidateSet.BestViableFunction(*this, UnresExpr->getLocStart(), Best)) { case OR_Success: Method = cast(Best->Function); MarkFunctionReferenced(UnresExpr->getMemberLoc(), Method); FoundDecl = Best->FoundDecl; CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()); break; case OR_No_Viable_Function: Diag(UnresExpr->getMemberLoc(), diag::err_ovl_no_viable_member_function_in_call) << DeclName << MemExprE->getSourceRange(); CandidateSet.NoteCandidates(*this, OCD_AllCandidates, llvm::makeArrayRef(Args, NumArgs)); // FIXME: Leaking incoming expressions! return ExprError(); case OR_Ambiguous: Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) << DeclName << MemExprE->getSourceRange(); CandidateSet.NoteCandidates(*this, OCD_AllCandidates, llvm::makeArrayRef(Args, NumArgs)); // FIXME: Leaking incoming expressions! return ExprError(); case OR_Deleted: Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) << Best->Function->isDeleted() << DeclName << getDeletedOrUnavailableSuffix(Best->Function) << MemExprE->getSourceRange(); CandidateSet.NoteCandidates(*this, OCD_AllCandidates, llvm::makeArrayRef(Args, NumArgs)); // FIXME: Leaking incoming expressions! return ExprError(); } MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); // If overload resolution picked a static member, build a // non-member call based on that function. if (Method->isStatic()) { return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, Args, NumArgs, RParenLoc); } MemExpr = cast(MemExprE->IgnoreParens()); } QualType ResultType = Method->getResultType(); ExprValueKind VK = Expr::getValueKindForType(ResultType); ResultType = ResultType.getNonLValueExprType(Context); assert(Method && "Member call to something that isn't a method?"); CXXMemberCallExpr *TheCall = new (Context) CXXMemberCallExpr(Context, MemExprE, Args, NumArgs, ResultType, VK, RParenLoc); // Check for a valid return type. if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), TheCall, Method)) return ExprError(); // Convert the object argument (for a non-static member function call). // We only need to do this if there was actually an overload; otherwise // it was done at lookup. if (!Method->isStatic()) { ExprResult ObjectArg = PerformObjectArgumentInitialization(MemExpr->getBase(), Qualifier, FoundDecl, Method); if (ObjectArg.isInvalid()) return ExprError(); MemExpr->setBase(ObjectArg.take()); } // Convert the rest of the arguments const FunctionProtoType *Proto = Method->getType()->getAs(); if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args, NumArgs, RParenLoc)) return ExprError(); DiagnoseSentinelCalls(Method, LParenLoc, Args, NumArgs); if (CheckFunctionCall(Method, TheCall)) return ExprError(); if ((isa(CurContext) || isa(CurContext)) && TheCall->getMethodDecl()->isPure()) { const CXXMethodDecl *MD = TheCall->getMethodDecl(); if (isa(MemExpr->getBase()->IgnoreParenCasts())) { Diag(MemExpr->getLocStart(), diag::warn_call_to_pure_virtual_member_function_from_ctor_dtor) << MD->getDeclName() << isa(CurContext) << MD->getParent()->getDeclName(); Diag(MD->getLocStart(), diag::note_previous_decl) << MD->getDeclName(); } } return MaybeBindToTemporary(TheCall); } /// BuildCallToObjectOfClassType - Build a call to an object of class /// type (C++ [over.call.object]), which can end up invoking an /// overloaded function call operator (@c operator()) or performing a /// user-defined conversion on the object argument. ExprResult Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj, SourceLocation LParenLoc, Expr **Args, unsigned NumArgs, SourceLocation RParenLoc) { if (checkPlaceholderForOverload(*this, Obj)) return ExprError(); ExprResult Object = Owned(Obj); UnbridgedCastsSet UnbridgedCasts; if (checkArgPlaceholdersForOverload(*this, Args, NumArgs, UnbridgedCasts)) return ExprError(); assert(Object.get()->getType()->isRecordType() && "Requires object type argument"); const RecordType *Record = Object.get()->getType()->getAs(); // C++ [over.call.object]p1: // If the primary-expression E in the function call syntax // evaluates to a class object of type "cv T", then the set of // candidate functions includes at least the function call // operators of T. The function call operators of T are obtained by // ordinary lookup of the name operator() in the context of // (E).operator(). OverloadCandidateSet CandidateSet(LParenLoc); DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); if (RequireCompleteType(LParenLoc, Object.get()->getType(), PDiag(diag::err_incomplete_object_call) << Object.get()->getSourceRange())) return true; LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); LookupQualifiedName(R, Record->getDecl()); R.suppressDiagnostics(); for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); Oper != OperEnd; ++Oper) { AddMethodCandidate(Oper.getPair(), Object.get()->getType(), Object.get()->Classify(Context), Args, NumArgs, CandidateSet, /*SuppressUserConversions=*/ false); } // C++ [over.call.object]p2: // In addition, for each (non-explicit in C++0x) conversion function // declared in T of the form // // operator conversion-type-id () cv-qualifier; // // where cv-qualifier is the same cv-qualification as, or a // greater cv-qualification than, cv, and where conversion-type-id // denotes the type "pointer to function of (P1,...,Pn) returning // R", or the type "reference to pointer to function of // (P1,...,Pn) returning R", or the type "reference to function // of (P1,...,Pn) returning R", a surrogate call function [...] // is also considered as a candidate function. Similarly, // surrogate call functions are added to the set of candidate // functions for each conversion function declared in an // accessible base class provided the function is not hidden // within T by another intervening declaration. const UnresolvedSetImpl *Conversions = cast(Record->getDecl())->getVisibleConversionFunctions(); for (UnresolvedSetImpl::iterator I = Conversions->begin(), E = Conversions->end(); I != E; ++I) { NamedDecl *D = *I; CXXRecordDecl *ActingContext = cast(D->getDeclContext()); if (isa(D)) D = cast(D)->getTargetDecl(); // Skip over templated conversion functions; they aren't // surrogates. if (isa(D)) continue; CXXConversionDecl *Conv = cast(D); if (!Conv->isExplicit()) { // Strip the reference type (if any) and then the pointer type (if // any) to get down to what might be a function type. QualType ConvType = Conv->getConversionType().getNonReferenceType(); if (const PointerType *ConvPtrType = ConvType->getAs()) ConvType = ConvPtrType->getPointeeType(); if (const FunctionProtoType *Proto = ConvType->getAs()) { AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, Object.get(), llvm::makeArrayRef(Args, NumArgs), CandidateSet); } } } bool HadMultipleCandidates = (CandidateSet.size() > 1); // Perform overload resolution. OverloadCandidateSet::iterator Best; switch (CandidateSet.BestViableFunction(*this, Object.get()->getLocStart(), Best)) { case OR_Success: // Overload resolution succeeded; we'll build the appropriate call // below. break; case OR_No_Viable_Function: if (CandidateSet.empty()) Diag(Object.get()->getLocStart(), diag::err_ovl_no_oper) << Object.get()->getType() << /*call*/ 1 << Object.get()->getSourceRange(); else Diag(Object.get()->getLocStart(), diag::err_ovl_no_viable_object_call) << Object.get()->getType() << Object.get()->getSourceRange(); CandidateSet.NoteCandidates(*this, OCD_AllCandidates, llvm::makeArrayRef(Args, NumArgs)); break; case OR_Ambiguous: Diag(Object.get()->getLocStart(), diag::err_ovl_ambiguous_object_call) << Object.get()->getType() << Object.get()->getSourceRange(); CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, llvm::makeArrayRef(Args, NumArgs)); break; case OR_Deleted: Diag(Object.get()->getLocStart(), diag::err_ovl_deleted_object_call) << Best->Function->isDeleted() << Object.get()->getType() << getDeletedOrUnavailableSuffix(Best->Function) << Object.get()->getSourceRange(); CandidateSet.NoteCandidates(*this, OCD_AllCandidates, llvm::makeArrayRef(Args, NumArgs)); break; } if (Best == CandidateSet.end()) return true; UnbridgedCasts.restore(); if (Best->Function == 0) { // Since there is no function declaration, this is one of the // surrogate candidates. Dig out the conversion function. CXXConversionDecl *Conv = cast( Best->Conversions[0].UserDefined.ConversionFunction); CheckMemberOperatorAccess(LParenLoc, Object.get(), 0, Best->FoundDecl); DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); // We selected one of the surrogate functions that converts the // object parameter to a function pointer. Perform the conversion // on the object argument, then let ActOnCallExpr finish the job. // Create an implicit member expr to refer to the conversion operator. // and then call it. ExprResult Call = BuildCXXMemberCallExpr(Object.get(), Best->FoundDecl, Conv, HadMultipleCandidates); if (Call.isInvalid()) return ExprError(); // Record usage of conversion in an implicit cast. Call = Owned(ImplicitCastExpr::Create(Context, Call.get()->getType(), CK_UserDefinedConversion, Call.get(), 0, VK_RValue)); return ActOnCallExpr(S, Call.get(), LParenLoc, MultiExprArg(Args, NumArgs), RParenLoc); } MarkFunctionReferenced(LParenLoc, Best->Function); CheckMemberOperatorAccess(LParenLoc, Object.get(), 0, Best->FoundDecl); DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); // We found an overloaded operator(). Build a CXXOperatorCallExpr // that calls this method, using Object for the implicit object // parameter and passing along the remaining arguments. CXXMethodDecl *Method = cast(Best->Function); const FunctionProtoType *Proto = Method->getType()->getAs(); unsigned NumArgsInProto = Proto->getNumArgs(); unsigned NumArgsToCheck = NumArgs; // Build the full argument list for the method call (the // implicit object parameter is placed at the beginning of the // list). Expr **MethodArgs; if (NumArgs < NumArgsInProto) { NumArgsToCheck = NumArgsInProto; MethodArgs = new Expr*[NumArgsInProto + 1]; } else { MethodArgs = new Expr*[NumArgs + 1]; } MethodArgs[0] = Object.get(); for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) MethodArgs[ArgIdx + 1] = Args[ArgIdx]; DeclarationNameInfo OpLocInfo( Context.DeclarationNames.getCXXOperatorName(OO_Call), LParenLoc); OpLocInfo.setCXXOperatorNameRange(SourceRange(LParenLoc, RParenLoc)); ExprResult NewFn = CreateFunctionRefExpr(*this, Method, HadMultipleCandidates, OpLocInfo.getLoc(), OpLocInfo.getInfo()); if (NewFn.isInvalid()) return true; // Once we've built TheCall, all of the expressions are properly // owned. QualType ResultTy = Method->getResultType(); ExprValueKind VK = Expr::getValueKindForType(ResultTy); ResultTy = ResultTy.getNonLValueExprType(Context); CXXOperatorCallExpr *TheCall = new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn.take(), MethodArgs, NumArgs + 1, ResultTy, VK, RParenLoc); delete [] MethodArgs; if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall, Method)) return true; // We may have default arguments. If so, we need to allocate more // slots in the call for them. if (NumArgs < NumArgsInProto) TheCall->setNumArgs(Context, NumArgsInProto + 1); else if (NumArgs > NumArgsInProto) NumArgsToCheck = NumArgsInProto; bool IsError = false; // Initialize the implicit object parameter. ExprResult ObjRes = PerformObjectArgumentInitialization(Object.get(), /*Qualifier=*/0, Best->FoundDecl, Method); if (ObjRes.isInvalid()) IsError = true; else Object = move(ObjRes); TheCall->setArg(0, Object.take()); // Check the argument types. for (unsigned i = 0; i != NumArgsToCheck; i++) { Expr *Arg; if (i < NumArgs) { Arg = Args[i]; // Pass the argument. ExprResult InputInit = PerformCopyInitialization(InitializedEntity::InitializeParameter( Context, Method->getParamDecl(i)), SourceLocation(), Arg); IsError |= InputInit.isInvalid(); Arg = InputInit.takeAs(); } else { ExprResult DefArg = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); if (DefArg.isInvalid()) { IsError = true; break; } Arg = DefArg.takeAs(); } TheCall->setArg(i + 1, Arg); } // If this is a variadic call, handle args passed through "...". if (Proto->isVariadic()) { // Promote the arguments (C99 6.5.2.2p7). for (unsigned i = NumArgsInProto; i != NumArgs; i++) { ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod, 0); IsError |= Arg.isInvalid(); TheCall->setArg(i + 1, Arg.take()); } } if (IsError) return true; DiagnoseSentinelCalls(Method, LParenLoc, Args, NumArgs); if (CheckFunctionCall(Method, TheCall)) return true; return MaybeBindToTemporary(TheCall); } /// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> /// (if one exists), where @c Base is an expression of class type and /// @c Member is the name of the member we're trying to find. ExprResult Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc) { assert(Base->getType()->isRecordType() && "left-hand side must have class type"); if (checkPlaceholderForOverload(*this, Base)) return ExprError(); SourceLocation Loc = Base->getExprLoc(); // C++ [over.ref]p1: // // [...] An expression x->m is interpreted as (x.operator->())->m // for a class object x of type T if T::operator->() exists and if // the operator is selected as the best match function by the // overload resolution mechanism (13.3). DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); OverloadCandidateSet CandidateSet(Loc); const RecordType *BaseRecord = Base->getType()->getAs(); if (RequireCompleteType(Loc, Base->getType(), PDiag(diag::err_typecheck_incomplete_tag) << Base->getSourceRange())) return ExprError(); LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); LookupQualifiedName(R, BaseRecord->getDecl()); R.suppressDiagnostics(); for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); Oper != OperEnd; ++Oper) { AddMethodCandidate(Oper.getPair(), Base->getType(), Base->Classify(Context), 0, 0, CandidateSet, /*SuppressUserConversions=*/false); } bool HadMultipleCandidates = (CandidateSet.size() > 1); // Perform overload resolution. OverloadCandidateSet::iterator Best; switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { case OR_Success: // Overload resolution succeeded; we'll build the call below. break; case OR_No_Viable_Function: if (CandidateSet.empty()) Diag(OpLoc, diag::err_typecheck_member_reference_arrow) << Base->getType() << Base->getSourceRange(); else Diag(OpLoc, diag::err_ovl_no_viable_oper) << "operator->" << Base->getSourceRange(); CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Base); return ExprError(); case OR_Ambiguous: Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) << "->" << Base->getType() << Base->getSourceRange(); CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Base); return ExprError(); case OR_Deleted: Diag(OpLoc, diag::err_ovl_deleted_oper) << Best->Function->isDeleted() << "->" << getDeletedOrUnavailableSuffix(Best->Function) << Base->getSourceRange(); CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Base); return ExprError(); } MarkFunctionReferenced(OpLoc, Best->Function); CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); // Convert the object parameter. CXXMethodDecl *Method = cast(Best->Function); ExprResult BaseResult = PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, Best->FoundDecl, Method); if (BaseResult.isInvalid()) return ExprError(); Base = BaseResult.take(); // Build the operator call. ExprResult FnExpr = CreateFunctionRefExpr(*this, Method, HadMultipleCandidates, OpLoc); if (FnExpr.isInvalid()) return ExprError(); QualType ResultTy = Method->getResultType(); ExprValueKind VK = Expr::getValueKindForType(ResultTy); ResultTy = ResultTy.getNonLValueExprType(Context); CXXOperatorCallExpr *TheCall = new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr.take(), &Base, 1, ResultTy, VK, OpLoc); if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall, Method)) return ExprError(); return MaybeBindToTemporary(TheCall); } /// BuildLiteralOperatorCall - Build a UserDefinedLiteral by creating a call to /// a literal operator described by the provided lookup results. ExprResult Sema::BuildLiteralOperatorCall(LookupResult &R, DeclarationNameInfo &SuffixInfo, ArrayRef Args, SourceLocation LitEndLoc, TemplateArgumentListInfo *TemplateArgs) { SourceLocation UDSuffixLoc = SuffixInfo.getCXXLiteralOperatorNameLoc(); OverloadCandidateSet CandidateSet(UDSuffixLoc); AddFunctionCandidates(R.asUnresolvedSet(), Args, CandidateSet, true, TemplateArgs); bool HadMultipleCandidates = (CandidateSet.size() > 1); // Perform overload resolution. This will usually be trivial, but might need // to perform substitutions for a literal operator template. OverloadCandidateSet::iterator Best; switch (CandidateSet.BestViableFunction(*this, UDSuffixLoc, Best)) { case OR_Success: case OR_Deleted: break; case OR_No_Viable_Function: Diag(UDSuffixLoc, diag::err_ovl_no_viable_function_in_call) << R.getLookupName(); CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args); return ExprError(); case OR_Ambiguous: Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName(); CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args); return ExprError(); } FunctionDecl *FD = Best->Function; MarkFunctionReferenced(UDSuffixLoc, FD); DiagnoseUseOfDecl(Best->FoundDecl, UDSuffixLoc); ExprResult Fn = CreateFunctionRefExpr(*this, FD, HadMultipleCandidates, SuffixInfo.getLoc(), SuffixInfo.getInfo()); if (Fn.isInvalid()) return true; // Check the argument types. This should almost always be a no-op, except // that array-to-pointer decay is applied to string literals. Expr *ConvArgs[2]; for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) { ExprResult InputInit = PerformCopyInitialization( InitializedEntity::InitializeParameter(Context, FD->getParamDecl(ArgIdx)), SourceLocation(), Args[ArgIdx]); if (InputInit.isInvalid()) return true; ConvArgs[ArgIdx] = InputInit.take(); } QualType ResultTy = FD->getResultType(); ExprValueKind VK = Expr::getValueKindForType(ResultTy); ResultTy = ResultTy.getNonLValueExprType(Context); UserDefinedLiteral *UDL = new (Context) UserDefinedLiteral(Context, Fn.take(), ConvArgs, Args.size(), ResultTy, VK, LitEndLoc, UDSuffixLoc); if (CheckCallReturnType(FD->getResultType(), UDSuffixLoc, UDL, FD)) return ExprError(); if (CheckFunctionCall(FD, UDL)) return ExprError(); return MaybeBindToTemporary(UDL); } /// FixOverloadedFunctionReference - E is an expression that refers to /// a C++ overloaded function (possibly with some parentheses and /// perhaps a '&' around it). We have resolved the overloaded function /// to the function declaration Fn, so patch up the expression E to /// refer (possibly indirectly) to Fn. Returns the new expr. Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, FunctionDecl *Fn) { if (ParenExpr *PE = dyn_cast(E)) { Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), Found, Fn); if (SubExpr == PE->getSubExpr()) return PE; return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); } if (ImplicitCastExpr *ICE = dyn_cast(E)) { Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), Found, Fn); assert(Context.hasSameType(ICE->getSubExpr()->getType(), SubExpr->getType()) && "Implicit cast type cannot be determined from overload"); assert(ICE->path_empty() && "fixing up hierarchy conversion?"); if (SubExpr == ICE->getSubExpr()) return ICE; return ImplicitCastExpr::Create(Context, ICE->getType(), ICE->getCastKind(), SubExpr, 0, ICE->getValueKind()); } if (UnaryOperator *UnOp = dyn_cast(E)) { assert(UnOp->getOpcode() == UO_AddrOf && "Can only take the address of an overloaded function"); if (CXXMethodDecl *Method = dyn_cast(Fn)) { if (Method->isStatic()) { // Do nothing: static member functions aren't any different // from non-member functions. } else { // Fix the sub expression, which really has to be an // UnresolvedLookupExpr holding an overloaded member function // or template. Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), Found, Fn); if (SubExpr == UnOp->getSubExpr()) return UnOp; assert(isa(SubExpr) && "fixed to something other than a decl ref"); assert(cast(SubExpr)->getQualifier() && "fixed to a member ref with no nested name qualifier"); // We have taken the address of a pointer to member // function. Perform the computation here so that we get the // appropriate pointer to member type. QualType ClassType = Context.getTypeDeclType(cast(Method->getDeclContext())); QualType MemPtrType = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); return new (Context) UnaryOperator(SubExpr, UO_AddrOf, MemPtrType, VK_RValue, OK_Ordinary, UnOp->getOperatorLoc()); } } Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), Found, Fn); if (SubExpr == UnOp->getSubExpr()) return UnOp; return new (Context) UnaryOperator(SubExpr, UO_AddrOf, Context.getPointerType(SubExpr->getType()), VK_RValue, OK_Ordinary, UnOp->getOperatorLoc()); } if (UnresolvedLookupExpr *ULE = dyn_cast(E)) { // FIXME: avoid copy. TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; if (ULE->hasExplicitTemplateArgs()) { ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); TemplateArgs = &TemplateArgsBuffer; } DeclRefExpr *DRE = DeclRefExpr::Create(Context, ULE->getQualifierLoc(), ULE->getTemplateKeywordLoc(), Fn, /*enclosing*/ false, // FIXME? ULE->getNameLoc(), Fn->getType(), VK_LValue, Found.getDecl(), TemplateArgs); MarkDeclRefReferenced(DRE); DRE->setHadMultipleCandidates(ULE->getNumDecls() > 1); return DRE; } if (UnresolvedMemberExpr *MemExpr = dyn_cast(E)) { // FIXME: avoid copy. TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; if (MemExpr->hasExplicitTemplateArgs()) { MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); TemplateArgs = &TemplateArgsBuffer; } Expr *Base; // If we're filling in a static method where we used to have an // implicit member access, rewrite to a simple decl ref. if (MemExpr->isImplicitAccess()) { if (cast(Fn)->isStatic()) { DeclRefExpr *DRE = DeclRefExpr::Create(Context, MemExpr->getQualifierLoc(), MemExpr->getTemplateKeywordLoc(), Fn, /*enclosing*/ false, MemExpr->getMemberLoc(), Fn->getType(), VK_LValue, Found.getDecl(), TemplateArgs); MarkDeclRefReferenced(DRE); DRE->setHadMultipleCandidates(MemExpr->getNumDecls() > 1); return DRE; } else { SourceLocation Loc = MemExpr->getMemberLoc(); if (MemExpr->getQualifier()) Loc = MemExpr->getQualifierLoc().getBeginLoc(); CheckCXXThisCapture(Loc); Base = new (Context) CXXThisExpr(Loc, MemExpr->getBaseType(), /*isImplicit=*/true); } } else Base = MemExpr->getBase(); ExprValueKind valueKind; QualType type; if (cast(Fn)->isStatic()) { valueKind = VK_LValue; type = Fn->getType(); } else { valueKind = VK_RValue; type = Context.BoundMemberTy; } MemberExpr *ME = MemberExpr::Create(Context, Base, MemExpr->isArrow(), MemExpr->getQualifierLoc(), MemExpr->getTemplateKeywordLoc(), Fn, Found, MemExpr->getMemberNameInfo(), TemplateArgs, type, valueKind, OK_Ordinary); ME->setHadMultipleCandidates(true); return ME; } llvm_unreachable("Invalid reference to overloaded function"); } ExprResult Sema::FixOverloadedFunctionReference(ExprResult E, DeclAccessPair Found, FunctionDecl *Fn) { return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); } } // end namespace clang