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Diffstat (limited to 'contrib/llvm/tools/clang/lib/Sema/SemaOverload.cpp')
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diff --git a/contrib/llvm/tools/clang/lib/Sema/SemaOverload.cpp b/contrib/llvm/tools/clang/lib/Sema/SemaOverload.cpp new file mode 100644 index 0000000..2754d44 --- /dev/null +++ b/contrib/llvm/tools/clang/lib/Sema/SemaOverload.cpp @@ -0,0 +1,7437 @@ +//===--- 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 "Sema.h" +#include "Lookup.h" +#include "SemaInit.h" +#include "clang/Basic/Diagnostic.h" +#include "clang/Lex/Preprocessor.h" +#include "clang/AST/ASTContext.h" +#include "clang/AST/CXXInheritance.h" +#include "clang/AST/Expr.h" +#include "clang/AST/ExprCXX.h" +#include "clang/AST/TypeOrdering.h" +#include "clang/Basic/PartialDiagnostic.h" +#include "llvm/ADT/SmallPtrSet.h" +#include "llvm/ADT/STLExtras.h" +#include <algorithm> + +namespace clang { + +/// 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 + }; + 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 + }; + 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" + }; + 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; + ReferenceBinding = false; + DirectBinding = false; + RRefBinding = 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()->isBlockPointerType() || + 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->isPointerType()) + if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) + return ToPtrType->getPointeeType()->isVoidType(); + + return false; +} + +/// DebugPrint - Print this standard conversion sequence to standard +/// error. Useful for debugging overloading issues. +void StandardConversionSequence::DebugPrint() const { + llvm::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 { + llvm::raw_ostream &OS = llvm::errs(); + if (Before.First || Before.Second || Before.Third) { + Before.DebugPrint(); + OS << " -> "; + } + OS << '\'' << ConversionFunction << '\''; + 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 { + llvm::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, + Sema::TemplateDeductionInfo &Info) { + OverloadCandidate::DeductionFailureInfo Result; + Result.Result = static_cast<unsigned>(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_InconsistentQuals: { + // 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<Sema::TemplateDeductionResult>(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_InconsistentQuals: + // 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<Sema::TemplateDeductionResult>(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_InconsistentQuals: + return static_cast<DFIParamWithArguments*>(Data)->Param; + + // Unhandled + case Sema::TDK_NonDeducedMismatch: + case Sema::TDK_FailedOverloadResolution: + break; + } + + return TemplateParameter(); +} + +TemplateArgumentList * +OverloadCandidate::DeductionFailureInfo::getTemplateArgumentList() { + switch (static_cast<Sema::TemplateDeductionResult>(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_InconsistentQuals: + return 0; + + case Sema::TDK_SubstitutionFailure: + return static_cast<TemplateArgumentList*>(Data); + + // Unhandled + case Sema::TDK_NonDeducedMismatch: + case Sema::TDK_FailedOverloadResolution: + break; + } + + return 0; +} + +const TemplateArgument *OverloadCandidate::DeductionFailureInfo::getFirstArg() { + switch (static_cast<Sema::TemplateDeductionResult>(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_InconsistentQuals: + return &static_cast<DFIParamWithArguments*>(Data)->FirstArg; + + // Unhandled + case Sema::TDK_NonDeducedMismatch: + case Sema::TDK_FailedOverloadResolution: + break; + } + + return 0; +} + +const TemplateArgument * +OverloadCandidate::DeductionFailureInfo::getSecondArg() { + switch (static_cast<Sema::TemplateDeductionResult>(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_InconsistentQuals: + return &static_cast<DFIParamWithArguments*>(Data)->SecondArg; + + // Unhandled + case Sema::TDK_NonDeducedMismatch: + case Sema::TDK_FailedOverloadResolution: + break; + } + + return 0; +} + +void OverloadCandidateSet::clear() { + inherited::clear(); + Functions.clear(); +} + +// 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. +Sema::OverloadKind +Sema::CheckOverload(FunctionDecl *New, const LookupResult &Old, + NamedDecl *&Match) { + for (LookupResult::iterator I = Old.begin(), E = Old.end(); + I != E; ++I) { + NamedDecl *OldD = (*I)->getUnderlyingDecl(); + if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { + if (!IsOverload(New, OldT->getTemplatedDecl())) { + Match = *I; + return Ovl_Match; + } + } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { + if (!IsOverload(New, OldF)) { + Match = *I; + return Ovl_Match; + } + } else if (isa<UsingDecl>(OldD) || isa<TagDecl>(OldD)) { + // We can overload with these, which can show up when doing + // redeclaration checks for UsingDecls. + assert(Old.getLookupKind() == LookupUsingDeclName); + } else if (isa<UnresolvedUsingValueDecl>(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) { + 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<FunctionNoProtoType>(OldQType.getTypePtr()) || + isa<FunctionNoProtoType>(NewQType.getTypePtr())) + return false; + + FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); + FunctionProtoType* NewType = cast<FunctionProtoType>(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. + if (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) 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<CXXMethodDecl>(Old); + CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); + if (OldMethod && NewMethod && + !OldMethod->isStatic() && !NewMethod->isStatic() && + OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) + return true; + + // The signatures match; this is not an overload. + return false; +} + +/// 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. +ImplicitConversionSequence +Sema::TryImplicitConversion(Expr* From, QualType ToType, + bool SuppressUserConversions, + bool AllowExplicit, + bool InOverloadResolution) { + ImplicitConversionSequence ICS; + if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) { + ICS.setStandard(); + return ICS; + } + + if (!getLangOptions().CPlusPlus) { + ICS.setBad(BadConversionSequence::no_conversion, From, ToType); + return ICS; + } + + if (SuppressUserConversions) { + // 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<RecordType>() || !FromType->getAs<RecordType>() || + !(Context.hasSameUnqualifiedType(FromType, ToType) || + IsDerivedFrom(FromType, ToType))) { + // 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; + } + + 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 (!Context.hasSameUnqualifiedType(FromType, ToType)) + ICS.Standard.Second = ICK_Derived_To_Base; + + return ICS; + } + + // Attempt user-defined conversion. + OverloadCandidateSet Conversions(From->getExprLoc()); + OverloadingResult UserDefResult + = IsUserDefinedConversion(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<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { + QualType FromCanon + = Context.getCanonicalType(From->getType().getUnqualifiedType()); + QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); + if (Constructor->isCopyConstructor() && + (FromCanon == ToCanon || 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; +} + +/// PerformImplicitConversion - Perform an implicit conversion of the +/// expression From to the type ToType. Returns true if there was an +/// error, false otherwise. The expression From is replaced with 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. +bool +Sema::PerformImplicitConversion(Expr *&From, QualType ToType, + AssignmentAction Action, bool AllowExplicit) { + ImplicitConversionSequence ICS; + return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS); +} + +bool +Sema::PerformImplicitConversion(Expr *&From, QualType ToType, + AssignmentAction Action, bool AllowExplicit, + ImplicitConversionSequence& ICS) { + ICS = TryImplicitConversion(From, ToType, + /*SuppressUserConversions=*/false, + AllowExplicit, + /*InOverloadResolution=*/false); + 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. +static bool IsNoReturnConversion(ASTContext &Context, QualType FromType, + QualType ToType, QualType &ResultTy) { + if (Context.hasSameUnqualifiedType(FromType, ToType)) + return false; + + // Strip the noreturn off the type we're converting from; noreturn can + // safely be removed. + FromType = Context.getNoReturnType(FromType, false); + if (!Context.hasSameUnqualifiedType(FromType, ToType)) + return false; + + ResultTy = FromType; + 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->isVectorType() && FromType->isArithmeticType()) { + ICK = ICK_Vector_Splat; + return true; + } + } + + // If lax vector conversions are permitted and the vector types are of the + // same size, we can perform the conversion. + if (Context.getLangOptions().LaxVectorConversions && + FromType->isVectorType() && ToType->isVectorType() && + Context.getTypeSize(FromType) == Context.getTypeSize(ToType)) { + ICK = ICK_Vector_Conversion; + return true; + } + + return false; +} + +/// 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. +bool +Sema::IsStandardConversion(Expr* From, QualType ToType, + bool InOverloadResolution, + StandardConversionSequence &SCS) { + 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 (getLangOptions().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 == Context.OverloadTy) { + DeclAccessPair AccessPair; + if (FunctionDecl *Fn + = 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(); + if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { + if (!Method->isStatic()) { + Type *ClassType + = Context.getTypeDeclType(Method->getParent()).getTypePtr(); + FromType = Context.getMemberPointerType(FromType, ClassType); + } + } + + // If the "from" expression takes the address of the overloaded + // function, update the type of the resulting expression accordingly. + if (FromType->getAs<FunctionType>()) + if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(From->IgnoreParens())) + if (UnOp->getOpcode() == UnaryOperator::AddrOf) + FromType = Context.getPointerType(FromType); + + // Check that we've computed the proper type after overload resolution. + assert(Context.hasSameType(FromType, + FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())); + } else { + return false; + } + } + // Lvalue-to-rvalue conversion (C++ 4.1): + // An lvalue (3.10) of a non-function, non-array type T can be + // converted to an rvalue. + Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); + if (argIsLvalue == Expr::LV_Valid && + !FromType->isFunctionType() && !FromType->isArrayType() && + Context.getCanonicalType(FromType) != Context.OverloadTy) { + SCS.First = ICK_Lvalue_To_Rvalue; + + // 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 = Context.getArrayDecayedType(FromType); + + if (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.setAllToTypes(FromType); + return true; + } + } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { + // 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 = 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 (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 (IsIntegralPromotion(From, FromType, ToType)) { + // Integral promotion (C++ 4.5). + SCS.Second = ICK_Integral_Promotion; + FromType = ToType.getUnqualifiedType(); + } else if (IsFloatingPointPromotion(FromType, ToType)) { + // Floating point promotion (C++ 4.6). + SCS.Second = ICK_Floating_Promotion; + FromType = ToType.getUnqualifiedType(); + } else if (IsComplexPromotion(FromType, ToType)) { + // Complex promotion (Clang extension) + SCS.Second = ICK_Complex_Promotion; + FromType = ToType.getUnqualifiedType(); + } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && + (ToType->isIntegralType() && !ToType->isEnumeralType())) { + // Integral conversions (C++ 4.7). + SCS.Second = ICK_Integral_Conversion; + FromType = ToType.getUnqualifiedType(); + } else if (FromType->isComplexType() && ToType->isComplexType()) { + // Complex conversions (C99 6.3.1.6) + SCS.Second = ICK_Complex_Conversion; + FromType = ToType.getUnqualifiedType(); + } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || + (ToType->isComplexType() && FromType->isArithmeticType())) { + // Complex-real conversions (C99 6.3.1.7) + SCS.Second = ICK_Complex_Real; + FromType = ToType.getUnqualifiedType(); + } else if (FromType->isFloatingType() && ToType->isFloatingType()) { + // Floating point conversions (C++ 4.8). + SCS.Second = ICK_Floating_Conversion; + FromType = ToType.getUnqualifiedType(); + } else if ((FromType->isFloatingType() && + ToType->isIntegralType() && (!ToType->isBooleanType() && + !ToType->isEnumeralType())) || + ((FromType->isIntegralType() || FromType->isEnumeralType()) && + ToType->isFloatingType())) { + // Floating-integral conversions (C++ 4.9). + SCS.Second = ICK_Floating_Integral; + FromType = ToType.getUnqualifiedType(); + } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, + FromType, IncompatibleObjC)) { + // Pointer conversions (C++ 4.10). + SCS.Second = ICK_Pointer_Conversion; + SCS.IncompatibleObjC = IncompatibleObjC; + } else if (IsMemberPointerConversion(From, FromType, ToType, + InOverloadResolution, FromType)) { + // Pointer to member conversions (4.11). + SCS.Second = ICK_Pointer_Member; + } else if (ToType->isBooleanType() && + (FromType->isArithmeticType() || + FromType->isEnumeralType() || + FromType->isAnyPointerType() || + FromType->isBlockPointerType() || + FromType->isMemberPointerType() || + FromType->isNullPtrType())) { + // Boolean conversions (C++ 4.12). + SCS.Second = ICK_Boolean_Conversion; + FromType = Context.BoolTy; + } else if (IsVectorConversion(Context, FromType, ToType, SecondICK)) { + SCS.Second = SecondICK; + FromType = ToType.getUnqualifiedType(); + } else if (!getLangOptions().CPlusPlus && + Context.typesAreCompatible(ToType, FromType)) { + // Compatible conversions (Clang extension for C function overloading) + SCS.Second = ICK_Compatible_Conversion; + FromType = ToType.getUnqualifiedType(); + } else if (IsNoReturnConversion(Context, FromType, ToType, FromType)) { + // Treat a conversion that strips "noreturn" as an identity conversion. + SCS.Second = ICK_NoReturn_Adjustment; + } 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). + if (IsQualificationConversion(FromType, ToType)) { + SCS.Third = ICK_Qualification; + FromType = ToType; + CanonFrom = Context.getCanonicalType(FromType); + CanonTo = 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 = Context.getCanonicalType(FromType); + CanonTo = Context.getCanonicalType(ToType); + if (CanonFrom.getLocalUnqualifiedType() + == CanonTo.getLocalUnqualifiedType() && + (CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers() + || CanonFrom.getObjCGCAttr() != CanonTo.getObjCGCAttr())) { + 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; +} + +/// 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<BuiltinType>(); + // 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; + } + + // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) + // can be converted to an rvalue of the first of the following types + // that can represent all the values of its underlying type: int, + // unsigned int, long, or unsigned long (C++ 4.5p2). + + // We pre-calculate the promotion type for enum types. + if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) + if (ToType->isIntegerType()) + return Context.hasSameUnqualifiedType(ToType, + FromEnumType->getDecl()->getPromotionType()); + + if (FromType->isWideCharType() && ToType->isIntegerType()) { + // Determine whether the type we're converting from is signed or + // unsigned. + bool FromIsSigned; + uint64_t FromSize = Context.getTypeSize(FromType); + + // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. + FromIsSigned = true; + + // 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() && !FromType->isEnumeralType() && + 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) { + /// An rvalue of type float can be converted to an rvalue of type + /// double. (C++ 4.6p1). + if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) + if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { + 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 (!getLangOptions().CPlusPlus && + (FromBuiltin->getKind() == BuiltinType::Float || + FromBuiltin->getKind() == BuiltinType::Double) && + (ToBuiltin->getKind() == BuiltinType::LongDouble)) + 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<ComplexType>(); + if (!FromComplex) + return false; + + const ComplexType *ToComplex = ToType->getAs<ComplexType>(); + 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 PointerType *FromPtr, + QualType ToPointee, QualType ToType, + ASTContext &Context) { + QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); + QualType CanonToPointee = Context.getCanonicalType(ToPointee); + Qualifiers Quals = CanonFromPointee.getQualifiers(); + + // 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. + return Context.getPointerType(ToPointee); + } + + // Just build a canonical type that has the right qualifiers. + return Context.getPointerType( + Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), + Quals)); +} + +/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from +/// the FromType, which is an objective-c pointer, to ToType, which may or may +/// not have the right set of qualifiers. +static QualType +BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType, + QualType ToType, + ASTContext &Context) { + QualType CanonFromType = Context.getCanonicalType(FromType); + QualType CanonToType = Context.getCanonicalType(ToType); + Qualifiers Quals = CanonFromType.getQualifiers(); + + // Exact qualifier match -> return the pointer type we're converting to. + if (CanonToType.getLocalQualifiers() == Quals) + return ToType; + + // Just build a canonical type that has the right qualifiers. + return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals); +} + +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()->isIntegralType()) + 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<protocols...>', 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<PointerType>()->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<PointerType>(); + 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()) { + ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType, + ToType, Context); + return true; + + } + const PointerType *FromTypePtr = FromType->getAs<PointerType>(); + if (!FromTypePtr) + return false; + + QualType FromPointeeType = FromTypePtr->getPointeeType(); + + // 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->isObjectType() && 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 (!getLangOptions().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 (getLangOptions().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; + } + + return false; +} + +/// 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 (!getLangOptions().ObjC1) + return false; + + // First, we handle all conversions on ObjC object pointer types. + const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); + const ObjCObjectPointerType *FromObjCPtr = + FromType->getAs<ObjCObjectPointerType>(); + + if (ToObjCPtr && FromObjCPtr) { + // 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 = ToType; + return true; + } + // Conversions with Objective-C's id<...>. + if ((FromObjCPtr->isObjCQualifiedIdType() || + ToObjCPtr->isObjCQualifiedIdType()) && + Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, + /*compare=*/false)) { + ConvertedType = ToType; + 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 (getLangOptions().CPlusPlus && LHS && RHS && + !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( + FromObjCPtr->getPointeeType())) + return false; + ConvertedType = ToType; + 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 = FromType; + return true; + } + } + // Beyond this point, both types need to be C pointers or block pointers. + QualType ToPointeeType; + if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) + ToPointeeType = ToCPtr->getPointeeType(); + else if (const BlockPointerType *ToBlockPtr = + ToType->getAs<BlockPointerType>()) { + // Objective C++: We're able to convert from a pointer to any object + // to a block pointer type. + if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { + ConvertedType = ToType; + return true; + } + ToPointeeType = ToBlockPtr->getPointeeType(); + } + else if (FromType->getAs<BlockPointerType>() && + ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { + // Objective C++: We're able to convert from a block pointer type to a + // pointer to any object. + ConvertedType = ToType; + return true; + } + else + return false; + + QualType FromPointeeType; + if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) + FromPointeeType = FromCPtr->getPointeeType(); + else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) + 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 = ToType; + return true; + } + // Allow conversion of pointee being objective-c pointer to another one; + // as in I* to id. + if (FromPointeeType->getAs<ObjCObjectPointerType>() && + ToPointeeType->getAs<ObjCObjectPointerType>() && + isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, + IncompatibleObjC)) { + ConvertedType = ToType; + 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<FunctionProtoType>(); + const FunctionProtoType *ToFunctionType + = ToPointeeType->getAs<FunctionProtoType>(); + 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 = ToType; + IncompatibleObjC = true; + return true; + } + } + + return false; +} + +/// FunctionArgTypesAreEqual - This routine checks two function proto types +/// for equlity 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. +bool Sema::FunctionArgTypesAreEqual(FunctionProtoType* OldType, + FunctionProtoType* NewType){ + if (!getLangOptions().ObjC1) + return std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), + NewType->arg_type_begin()); + + 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 (ToType != FromType) { + if (const PointerType *PTTo = ToType->getAs<PointerType>()) { + if (const PointerType *PTFr = FromType->getAs<PointerType>()) + if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && + PTFr->getPointeeType()->isObjCQualifiedIdType()) || + (PTTo->getPointeeType()->isObjCQualifiedClassType() && + PTFr->getPointeeType()->isObjCQualifiedClassType())) + continue; + } + else if (const ObjCObjectPointerType *PTTo = + ToType->getAs<ObjCObjectPointerType>()) { + if (const ObjCObjectPointerType *PTFr = + FromType->getAs<ObjCObjectPointerType>()) + if (PTTo->getInterfaceDecl() == PTFr->getInterfaceDecl()) + continue; + } + 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, + CastExpr::CastKind &Kind, + CXXBaseSpecifierArray& BasePath, + bool IgnoreBaseAccess) { + QualType FromType = From->getType(); + + if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) + if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { + 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 = CastExpr::CK_DerivedToBase; + } + } + if (const ObjCObjectPointerType *FromPtrType = + FromType->getAs<ObjCObjectPointerType>()) + if (const ObjCObjectPointerType *ToPtrType = + ToType->getAs<ObjCObjectPointerType>()) { + // 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; + + } + 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<MemberPointerType>(); + 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<MemberPointerType>(); + 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); + // FIXME: What happens when these are dependent? Is this function even called? + + if (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, + CastExpr::CastKind &Kind, + CXXBaseSpecifierArray &BasePath, + bool IgnoreBaseAccess) { + QualType FromType = From->getType(); + const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); + 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 = CastExpr::CK_NullToMemberPointer; + return false; + } + + const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); + 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 = CastExpr::CK_BaseToDerivedMemberPointer; + return false; +} + +/// IsQualificationConversion - Determines whether the conversion from +/// an rvalue of type FromType to ToType is a qualification conversion +/// (C++ 4.4). +bool +Sema::IsQualificationConversion(QualType FromType, QualType ToType) { + FromType = Context.getCanonicalType(FromType); + ToType = Context.getCanonicalType(ToType); + + // 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 (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; + + // -- for every j > 0, if const is in cv 1,j then const is in cv + // 2,j, and similarly for volatile. + if (!ToType.isAtLeastAsQualifiedAs(FromType)) + return false; + + // -- if the cv 1,j and cv 2,j are different, then const is in + // every cv for 0 < k < j. + if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() + && !PreviousToQualsIncludeConst) + return false; + + // Keep track of whether all prior cv-qualifiers in the "to" type + // include const. + PreviousToQualsIncludeConst + = PreviousToQualsIncludeConst && ToType.isConstQualified(); + } + + // 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); +} + +/// 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). +OverloadingResult Sema::IsUserDefinedConversion(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<RecordType>()) { + // 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 (Context.hasSameUnqualifiedType(ToType, From->getType()) || + (From->getType()->getAs<RecordType>() && + IsDerivedFrom(From->getType(), ToType))) + ConstructorsOnly = true; + + if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { + // We're not going to find any constructors. + } else if (CXXRecordDecl *ToRecordDecl + = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { + DeclarationName ConstructorName + = Context.DeclarationNames.getCXXConstructorName( + Context.getCanonicalType(ToType).getUnqualifiedType()); + DeclContext::lookup_iterator Con, ConEnd; + for (llvm::tie(Con, ConEnd) + = ToRecordDecl->lookup(ConstructorName); + 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<FunctionTemplateDecl>(D); + if (ConstructorTmpl) + Constructor + = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); + else + Constructor = cast<CXXConstructorDecl>(D); + + if (!Constructor->isInvalidDecl() && + Constructor->isConvertingConstructor(AllowExplicit)) { + if (ConstructorTmpl) + AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, + /*ExplicitArgs*/ 0, + &From, 1, CandidateSet, + /*SuppressUserConversions=*/!ConstructorsOnly); + else + // Allow one user-defined conversion when user specifies a + // From->ToType conversion via an static cast (c-style, etc). + AddOverloadCandidate(Constructor, FoundDecl, + &From, 1, CandidateSet, + /*SuppressUserConversions=*/!ConstructorsOnly); + } + } + } + } + + // Enumerate conversion functions, if we're allowed to. + if (ConstructorsOnly) { + } else if (RequireCompleteType(From->getLocStart(), From->getType(), + PDiag(0) << From->getSourceRange())) { + // No conversion functions from incomplete types. + } else if (const RecordType *FromRecordType + = From->getType()->getAs<RecordType>()) { + if (CXXRecordDecl *FromRecordDecl + = dyn_cast<CXXRecordDecl>(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<CXXRecordDecl>(D->getDeclContext()); + if (isa<UsingShadowDecl>(D)) + D = cast<UsingShadowDecl>(D)->getTargetDecl(); + + CXXConversionDecl *Conv; + FunctionTemplateDecl *ConvTemplate; + if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) + Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); + else + Conv = cast<CXXConversionDecl>(D); + + if (AllowExplicit || !Conv->isExplicit()) { + if (ConvTemplate) + AddTemplateConversionCandidate(ConvTemplate, FoundDecl, + ActingContext, From, ToType, + CandidateSet); + else + AddConversionCandidate(Conv, FoundDecl, ActingContext, + From, ToType, CandidateSet); + } + } + } + } + + OverloadCandidateSet::iterator Best; + switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { + case OR_Success: + // Record the standard conversion we used and the conversion function. + if (CXXConstructorDecl *Constructor + = dyn_cast<CXXConstructorDecl>(Best->Function)) { + // 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(Context); + if (Best->Conversions[0].isEllipsis()) + User.EllipsisConversion = true; + else { + User.Before = Best->Conversions[0].Standard; + User.EllipsisConversion = false; + } + User.ConversionFunction = Constructor; + User.After.setAsIdentityConversion(); + User.After.setFromType( + ThisType->getAs<PointerType>()->getPointeeType()); + User.After.setAllToTypes(ToType); + return OR_Success; + } else if (CXXConversionDecl *Conversion + = dyn_cast<CXXConversionDecl>(Best->Function)) { + // 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.ConversionFunction = Conversion; + 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; + } else { + assert(false && "Not a constructor or conversion function?"); + return OR_No_Viable_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; + } + + return OR_No_Viable_Function; +} + +bool +Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { + ImplicitConversionSequence ICS; + OverloadCandidateSet CandidateSet(From->getExprLoc()); + OverloadingResult OvResult = + IsUserDefinedConversion(From, ToType, ICS.UserDefined, + CandidateSet, false); + if (OvResult == OR_Ambiguous) + Diag(From->getSourceRange().getBegin(), + diag::err_typecheck_ambiguous_condition) + << From->getType() << ToType << From->getSourceRange(); + else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) + Diag(From->getSourceRange().getBegin(), + diag::err_typecheck_nonviable_condition) + << From->getType() << ToType << From->getSourceRange(); + else + return false; + PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1); + return true; +} + +/// 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). +ImplicitConversionSequence::CompareKind +Sema::CompareImplicitConversionSequences(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; + else 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; + + // 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()) + return CompareStandardConversionSequences(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) + return CompareStandardConversionSequences(ICS1.UserDefined.After, + ICS2.UserDefined.After); + } + + return ImplicitConversionSequence::Indistinguishable; +} + +// 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.ReferenceBinding == SCS2.ReferenceBinding) { + 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 (!Context.hasSameType(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; +} + +/// 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). +ImplicitConversionSequence::CompareKind +Sema::CompareStandardConversionSequences(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(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(Context); + bool SCS2ConvertsToVoid + = SCS2.isPointerConversionToVoidPointer(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(SCS1, SCS2)) + return DerivedCK; + } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { + // 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 = Context.getArrayDecayedType(FromType1); + if (SCS2.First == ICK_Array_To_Pointer) + FromType2 = Context.getArrayDecayedType(FromType2); + + QualType FromPointee1 + = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); + QualType FromPointee2 + = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); + + if (IsDerivedFrom(FromPointee2, FromPointee1)) + return ImplicitConversionSequence::Better; + else if (IsDerivedFrom(FromPointee1, FromPointee2)) + return ImplicitConversionSequence::Worse; + + // Objective-C++: If one interface is more specific than the + // other, it is the better one. + const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); + const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); + if (FromIface1 && FromIface1) { + if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) + return ImplicitConversionSequence::Better; + else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) + return ImplicitConversionSequence::Worse; + } + } + + // Compare based on qualification conversions (C++ 13.3.3.2p3, + // bullet 3). + if (ImplicitConversionSequence::CompareKind QualCK + = CompareQualificationConversions(SCS1, SCS2)) + return QualCK; + + if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { + // 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 S1 binds an rvalue reference to an + // rvalue and S2 binds an lvalue reference. + // FIXME: We don't know if we're dealing with the implicit object parameter, + // or if the member function in this case has a ref qualifier. + // (Of course, we don't have ref qualifiers yet.) + if (SCS1.RRefBinding != SCS2.RRefBinding) + return SCS1.RRefBinding ? ImplicitConversionSequence::Better + : 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 = Context.getCanonicalType(T1); + T2 = Context.getCanonicalType(T2); + Qualifiers T1Quals, T2Quals; + QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); + QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); + if (UnqualT1 == UnqualT2) { + // If the type is an array type, promote the element qualifiers to the type + // for comparison. + if (isa<ArrayType>(T1) && T1Quals) + T1 = Context.getQualifiedType(UnqualT1, T1Quals); + if (isa<ArrayType>(T2) && T2Quals) + T2 = Context.getQualifiedType(UnqualT2, T2Quals); + if (T2.isMoreQualifiedThan(T1)) + return ImplicitConversionSequence::Better; + else if (T1.isMoreQualifiedThan(T2)) + return ImplicitConversionSequence::Worse; + } + } + + 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 +Sema::CompareQualificationConversions(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 = Context.getCanonicalType(T1); + T2 = Context.getCanonicalType(T2); + Qualifiers T1Quals, T2Quals; + QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); + QualType UnqualT2 = 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<ArrayType>(T1) && T1Quals) + T1 = Context.getQualifiedType(UnqualT1, T1Quals); + if (isa<ArrayType>(T2) && T2Quals) + T2 = Context.getQualifiedType(UnqualT2, T2Quals); + + ImplicitConversionSequence::CompareKind Result + = ImplicitConversionSequence::Indistinguishable; + while (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 (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 +Sema::CompareDerivedToBaseConversions(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 = Context.getArrayDecayedType(FromType1); + if (SCS2.First == ICK_Array_To_Pointer) + FromType2 = Context.getArrayDecayedType(FromType2); + + // Canonicalize all of the types. + FromType1 = Context.getCanonicalType(FromType1); + ToType1 = Context.getCanonicalType(ToType1); + FromType2 = Context.getCanonicalType(FromType2); + ToType2 = 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, + // + // For Objective-C, we let A, B, and C also be Objective-C + // interfaces. + + // 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<PointerType>()->getPointeeType().getUnqualifiedType(); + QualType ToPointee1 + = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); + QualType FromPointee2 + = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); + QualType ToPointee2 + = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); + + const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); + const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); + const ObjCObjectType* ToIface1 = ToPointee1->getAs<ObjCObjectType>(); + const ObjCObjectType* ToIface2 = ToPointee2->getAs<ObjCObjectType>(); + + // -- conversion of C* to B* is better than conversion of C* to A*, + if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { + if (IsDerivedFrom(ToPointee1, ToPointee2)) + return ImplicitConversionSequence::Better; + else if (IsDerivedFrom(ToPointee2, ToPointee1)) + return ImplicitConversionSequence::Worse; + + if (ToIface1 && ToIface2) { + if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) + return ImplicitConversionSequence::Better; + else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) + return ImplicitConversionSequence::Worse; + } + } + + // -- conversion of B* to A* is better than conversion of C* to A*, + if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { + if (IsDerivedFrom(FromPointee2, FromPointee1)) + return ImplicitConversionSequence::Better; + else if (IsDerivedFrom(FromPointee1, FromPointee2)) + return ImplicitConversionSequence::Worse; + + if (FromIface1 && FromIface2) { + if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) + return ImplicitConversionSequence::Better; + else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) + return 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<MemberPointerType>(); + const MemberPointerType * ToMemPointer1 = + ToType1->getAs<MemberPointerType>(); + const MemberPointerType * FromMemPointer2 = + FromType2->getAs<MemberPointerType>(); + const MemberPointerType * ToMemPointer2 = + ToType2->getAs<MemberPointerType>(); + 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 (IsDerivedFrom(ToPointee1, ToPointee2)) + return ImplicitConversionSequence::Worse; + else if (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 (IsDerivedFrom(FromPointee1, FromPointee2)) + return ImplicitConversionSequence::Better; + else if (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 (Context.hasSameUnqualifiedType(FromType1, FromType2) && + !Context.hasSameUnqualifiedType(ToType1, ToType2)) { + if (IsDerivedFrom(ToType1, ToType2)) + return ImplicitConversionSequence::Better; + else if (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 (!Context.hasSameUnqualifiedType(FromType1, FromType2) && + Context.hasSameUnqualifiedType(ToType1, ToType2)) { + if (IsDerivedFrom(FromType2, FromType1)) + return ImplicitConversionSequence::Better; + else if (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) { + 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. + if (UnqualT1 == UnqualT2) + DerivedToBase = false; + else if (!RequireCompleteType(Loc, OrigT2, PDiag()) && + IsDerivedFrom(UnqualT2, UnqualT1)) + DerivedToBase = 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<ArrayType>(T1) && T1Quals) + T1 = Context.getQualifiedType(UnqualT1, T1Quals); + if (isa<ArrayType>(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). + if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers()) + return Ref_Compatible; + else if (T1.isMoreQualifiedThan(T2)) + return Ref_Compatible_With_Added_Qualification; + else + return Ref_Related; +} + +/// \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<ReferenceType>()->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; + Expr::isLvalueResult InitLvalue = Init->isLvalue(S.Context); + Sema::ReferenceCompareResult RefRelationship + = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase); + + + // C++ [over.ics.ref]p3: + // Except for an implicit object parameter, for which see 13.3.1, + // a standard conversion sequence cannot be formed if it requires + // binding an lvalue reference to non-const to an rvalue or + // binding an rvalue reference to an lvalue. + // + // FIXME: DPG doesn't trust this code. It seems far too early to + // abort because of a binding of an rvalue reference to an lvalue. + if (isRValRef && InitLvalue == Expr::LV_Valid) + return ICS; + + // C++0x [dcl.init.ref]p16: + // A reference to type "cv1 T1" is initialized by an expression + // of type "cv2 T2" as follows: + + // -- If the initializer expression + // -- 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 (InitLvalue == Expr::LV_Valid && + 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 : 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.RRefBinding = false; + 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 (!isRValRef && !SuppressUserConversions && T2->isRecordType() && + !S.RequireCompleteType(DeclLoc, T2, 0) && + RefRelationship == Sema::Ref_Incompatible) { + CXXRecordDecl *T2RecordDecl + = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->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<CXXRecordDecl>(D->getDeclContext()); + if (isa<UsingShadowDecl>(D)) + D = cast<UsingShadowDecl>(D)->getTargetDecl(); + + FunctionTemplateDecl *ConvTemplate + = dyn_cast<FunctionTemplateDecl>(D); + CXXConversionDecl *Conv; + if (ConvTemplate) + Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); + else + Conv = cast<CXXConversionDecl>(D); + + // If the conversion function doesn't return a reference type, + // it can't be considered for this conversion. + if (Conv->getConversionType()->isLValueReferenceType() && + (AllowExplicit || !Conv->isExplicit())) { + if (ConvTemplate) + S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, + Init, DeclType, CandidateSet); + else + S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, + DeclType, CandidateSet); + } + } + + OverloadCandidateSet::iterator Best; + switch (S.BestViableFunction(CandidateSet, DeclLoc, Best)) { + 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) + break; + + ICS.setUserDefined(); + ICS.UserDefined.Before = Best->Conversions[0].Standard; + ICS.UserDefined.After = Best->FinalConversion; + ICS.UserDefined.ConversionFunction = Best->Function; + ICS.UserDefined.EllipsisConversion = false; + assert(ICS.UserDefined.After.ReferenceBinding && + ICS.UserDefined.After.DirectBinding && + "Expected a direct reference binding!"); + return ICS; + + case OR_Ambiguous: + ICS.setAmbiguous(); + for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); + Cand != CandidateSet.end(); ++Cand) + if (Cand->Viable) + ICS.Ambiguous.addConversion(Cand->Function); + return ICS; + + case OR_No_Viable_Function: + case OR_Deleted: + // There was no suitable conversion, or we found a deleted + // conversion; continue with other checks. + break; + } + } + + // -- Otherwise, the reference shall be to a non-volatile const + // type (i.e., cv1 shall be const), or the reference shall be an + // rvalue reference and the initializer expression shall be an rvalue. + // + // 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. + if (!isRValRef && !T1.isConstQualified()) + return ICS; + + // -- if T2 is a class type and + // -- the initializer expression is an rvalue and "cv1 T1" + // is reference-compatible with "cv2 T2," or + // + // -- T1 is not reference-related to T2 and the initializer + // expression can be implicitly converted to an rvalue + // of type "cv3 T3" (this conversion is selected by + // enumerating the applicable conversion functions + // (13.3.1.6) and choosing the best one through overload + // resolution (13.3)), + // + // then the reference is bound to the initializer + // expression rvalue in the first case and to the object + // that is the result of the conversion in the second case + // (or, in either case, to the appropriate base class + // subobject of the object). + // + // We're only checking the first case here, which is a direct + // binding in C++0x but not in C++03. + if (InitLvalue != Expr::LV_Valid && T2->isRecordType() && + RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { + ICS.setStandard(); + ICS.Standard.First = ICK_Identity; + ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : 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 = S.getLangOptions().CPlusPlus0x; + ICS.Standard.RRefBinding = isRValRef; + ICS.Standard.CopyConstructor = 0; + 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. + 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; + + // 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 = S.TryImplicitConversion(Init, T1, SuppressUserConversions, + /*AllowExplicit=*/false, + /*InOverloadResolution=*/false); + + // Of course, that's still a reference binding. + if (ICS.isStandard()) { + ICS.Standard.ReferenceBinding = true; + ICS.Standard.RRefBinding = isRValRef; + } else if (ICS.isUserDefined()) { + ICS.UserDefined.After.ReferenceBinding = true; + ICS.UserDefined.After.RRefBinding = isRValRef; + } + return ICS; +} + +/// 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) { + if (ToType->isReferenceType()) + return TryReferenceInit(S, From, ToType, + /*FIXME:*/From->getLocStart(), + SuppressUserConversions, + /*AllowExplicit=*/false); + + return S.TryImplicitConversion(From, ToType, + SuppressUserConversions, + /*AllowExplicit=*/false, + InOverloadResolution); +} + +/// TryObjectArgumentInitialization - Try to initialize the object +/// parameter of the given member function (@c Method) from the +/// expression @p From. +ImplicitConversionSequence +Sema::TryObjectArgumentInitialization(QualType OrigFromType, + CXXMethodDecl *Method, + CXXRecordDecl *ActingContext) { + QualType ClassType = Context.getTypeDeclType(ActingContext); + // [class.dtor]p2: A destructor can be invoked for a const, volatile or + // const volatile object. + unsigned Quals = isa<CXXDestructorDecl>(Method) ? + Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); + QualType ImplicitParamType = 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<PointerType>()) + FromType = PT->getPointeeType(); + + assert(FromType->isRecordType()); + + // The implicit object parameter is has the type "reference to cv X", + // where X is the class of which the function is a member + // (C++ [over.match.funcs]p4). 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. We don't care about lvalue-vs-rvalue + // with the implicit object parameter (C++ [over.match.funcs]p5). + QualType FromTypeCanon = 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 = Context.getCanonicalType(ClassType); + ImplicitConversionKind SecondKind; + if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { + SecondKind = ICK_Identity; + } else if (IsDerivedFrom(FromType, ClassType)) + SecondKind = ICK_Derived_To_Base; + else { + ICS.setBad(BadConversionSequence::unrelated_class, + FromType, ImplicitParamType); + return ICS; + } + + // 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.RRefBinding = false; + return ICS; +} + +/// PerformObjectArgumentInitialization - Perform initialization of +/// the implicit object parameter for the given Method with the given +/// expression. +bool +Sema::PerformObjectArgumentInitialization(Expr *&From, + NestedNameSpecifier *Qualifier, + NamedDecl *FoundDecl, + CXXMethodDecl *Method) { + QualType FromRecordType, DestType; + QualType ImplicitParamRecordType = + Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); + + if (const PointerType *PT = From->getType()->getAs<PointerType>()) { + FromRecordType = PT->getPointeeType(); + DestType = Method->getThisType(Context); + } else { + FromRecordType = From->getType(); + DestType = ImplicitParamRecordType; + } + + // Note that we always use the true parent context when performing + // the actual argument initialization. + ImplicitConversionSequence ICS + = TryObjectArgumentInitialization(From->getType(), Method, + Method->getParent()); + if (ICS.isBad()) + return Diag(From->getSourceRange().getBegin(), + diag::err_implicit_object_parameter_init) + << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); + + if (ICS.Standard.Second == ICK_Derived_To_Base) + return PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); + + if (!Context.hasSameType(From->getType(), DestType)) + ImpCastExprToType(From, DestType, CastExpr::CK_NoOp, + /*isLvalue=*/!From->getType()->isPointerType()); + return false; +} + +/// TryContextuallyConvertToBool - Attempt to contextually convert the +/// expression From to bool (C++0x [conv]p3). +ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { + // FIXME: This is pretty broken. + return TryImplicitConversion(From, Context.BoolTy, + // FIXME: Are these flags correct? + /*SuppressUserConversions=*/false, + /*AllowExplicit=*/true, + /*InOverloadResolution=*/false); +} + +/// PerformContextuallyConvertToBool - Perform a contextual conversion +/// of the expression From to bool (C++0x [conv]p3). +bool Sema::PerformContextuallyConvertToBool(Expr *&From) { + ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); + if (!ICS.isBad()) + return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); + + if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) + return Diag(From->getSourceRange().getBegin(), + diag::err_typecheck_bool_condition) + << From->getType() << From->getSourceRange(); + return true; +} + +/// TryContextuallyConvertToObjCId - Attempt to contextually convert the +/// expression From to 'id'. +ImplicitConversionSequence Sema::TryContextuallyConvertToObjCId(Expr *From) { + QualType Ty = Context.getObjCIdType(); + return TryImplicitConversion(From, Ty, + // FIXME: Are these flags correct? + /*SuppressUserConversions=*/false, + /*AllowExplicit=*/true, + /*InOverloadResolution=*/false); +} + +/// PerformContextuallyConvertToObjCId - Perform a contextual conversion +/// of the expression From to 'id'. +bool Sema::PerformContextuallyConvertToObjCId(Expr *&From) { + QualType Ty = Context.getObjCIdType(); + ImplicitConversionSequence ICS = TryContextuallyConvertToObjCId(From); + if (!ICS.isBad()) + return PerformImplicitConversion(From, Ty, ICS, AA_Converting); + return true; +} + +/// 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, + Expr **Args, unsigned NumArgs, + OverloadCandidateSet& CandidateSet, + bool SuppressUserConversions, + bool PartialOverloading) { + const FunctionProtoType* Proto + = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); + assert(Proto && "Functions without a prototype cannot be overloaded"); + assert(!Function->getDescribedFunctionTemplate() && + "Use AddTemplateOverloadCandidate for function templates"); + + if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { + if (!isa<CXXConstructorDecl>(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(), Args, NumArgs, 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, Action::Unevaluated); + + if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(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 (NumArgs == 1 && + Constructor->isCopyConstructorLikeSpecialization() && + (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || + IsDerivedFrom(Args[0]->getType(), ClassType))) + return; + } + + // Add this candidate + CandidateSet.push_back(OverloadCandidate()); + OverloadCandidate& Candidate = CandidateSet.back(); + Candidate.FoundDecl = FoundDecl; + Candidate.Function = Function; + Candidate.Viable = true; + Candidate.IsSurrogate = false; + Candidate.IgnoreObjectArgument = false; + + 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 ((NumArgs + (PartialOverloading && NumArgs)) > 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 (NumArgs < MinRequiredArgs && !PartialOverloading) { + // Not enough arguments. + Candidate.Viable = false; + Candidate.FailureKind = ovl_fail_too_few_arguments; + return; + } + + // Determine the implicit conversion sequences for each of the + // arguments. + Candidate.Conversions.resize(NumArgs); + for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++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); + 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, + Expr **Args, unsigned NumArgs, + OverloadCandidateSet& CandidateSet, + bool SuppressUserConversions) { + for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { + NamedDecl *D = F.getDecl()->getUnderlyingDecl(); + if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { + if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) + AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), + cast<CXXMethodDecl>(FD)->getParent(), + Args[0]->getType(), Args + 1, NumArgs - 1, + CandidateSet, SuppressUserConversions); + else + AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, + SuppressUserConversions); + } else { + FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); + if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && + !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) + AddMethodTemplateCandidate(FunTmpl, F.getPair(), + cast<CXXRecordDecl>(FunTmpl->getDeclContext()), + /*FIXME: explicit args */ 0, + Args[0]->getType(), Args + 1, NumArgs - 1, + CandidateSet, + SuppressUserConversions); + else + AddTemplateOverloadCandidate(FunTmpl, F.getPair(), + /*FIXME: explicit args */ 0, + Args, NumArgs, 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 **Args, unsigned NumArgs, + OverloadCandidateSet& CandidateSet, + bool SuppressUserConversions) { + NamedDecl *Decl = FoundDecl.getDecl(); + CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); + + if (isa<UsingShadowDecl>(Decl)) + Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); + + if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { + assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && + "Expected a member function template"); + AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, + /*ExplicitArgs*/ 0, + ObjectType, Args, NumArgs, + CandidateSet, + SuppressUserConversions); + } else { + AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, + ObjectType, 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 **Args, unsigned NumArgs, + OverloadCandidateSet& CandidateSet, + bool SuppressUserConversions) { + const FunctionProtoType* Proto + = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); + assert(Proto && "Methods without a prototype cannot be overloaded"); + assert(!isa<CXXConstructorDecl>(Method) && + "Use AddOverloadCandidate for constructors"); + + if (!CandidateSet.isNewCandidate(Method)) + return; + + // Overload resolution is always an unevaluated context. + EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); + + // Add this candidate + CandidateSet.push_back(OverloadCandidate()); + OverloadCandidate& Candidate = CandidateSet.back(); + Candidate.FoundDecl = FoundDecl; + Candidate.Function = Method; + Candidate.IsSurrogate = false; + Candidate.IgnoreObjectArgument = false; + + 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 (NumArgs > 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 (NumArgs < MinRequiredArgs) { + // Not enough arguments. + Candidate.Viable = false; + Candidate.FailureKind = ovl_fail_too_few_arguments; + return; + } + + Candidate.Viable = true; + Candidate.Conversions.resize(NumArgs + 1); + + 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(ObjectType, 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 < NumArgs; ++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); + 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, + const TemplateArgumentListInfo *ExplicitTemplateArgs, + QualType ObjectType, + Expr **Args, unsigned NumArgs, + 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, NumArgs, Specialization, Info)) { + CandidateSet.push_back(OverloadCandidate()); + OverloadCandidate &Candidate = CandidateSet.back(); + Candidate.FoundDecl = FoundDecl; + Candidate.Function = MethodTmpl->getTemplatedDecl(); + Candidate.Viable = false; + Candidate.FailureKind = ovl_fail_bad_deduction; + Candidate.IsSurrogate = false; + Candidate.IgnoreObjectArgument = false; + 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<CXXMethodDecl>(Specialization) && + "Specialization is not a member function?"); + AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, + ActingContext, ObjectType, Args, NumArgs, + 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, + const TemplateArgumentListInfo *ExplicitTemplateArgs, + Expr **Args, unsigned NumArgs, + 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, NumArgs, Specialization, Info)) { + CandidateSet.push_back(OverloadCandidate()); + OverloadCandidate &Candidate = CandidateSet.back(); + Candidate.FoundDecl = FoundDecl; + Candidate.Function = FunctionTemplate->getTemplatedDecl(); + Candidate.Viable = false; + Candidate.FailureKind = ovl_fail_bad_deduction; + Candidate.IsSurrogate = false; + Candidate.IgnoreObjectArgument = false; + 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, NumArgs, 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, Action::Unevaluated); + + // Add this candidate + CandidateSet.push_back(OverloadCandidate()); + OverloadCandidate& Candidate = CandidateSet.back(); + Candidate.FoundDecl = FoundDecl; + Candidate.Function = Conversion; + Candidate.IsSurrogate = false; + Candidate.IgnoreObjectArgument = false; + Candidate.FinalConversion.setAsIdentityConversion(); + Candidate.FinalConversion.setFromType(ConvType); + Candidate.FinalConversion.setAllToTypes(ToType); + + // Determine the implicit conversion sequence for the implicit + // object parameter. + Candidate.Viable = true; + Candidate.Conversions.resize(1); + Candidate.Conversions[0] + = TryObjectArgumentInitialization(From->getType(), Conversion, + ActingContext); + // Conversion functions to a different type in the base class is visible in + // the derived class. So, a derived to base conversion should not participate + // in overload resolution. + if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) + Candidate.Conversions[0].Standard.Second = ICK_Identity; + 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, Conversion->getType(), + From->getLocStart()); + ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), + CastExpr::CK_FunctionToPointerDecay, + &ConversionRef, CXXBaseSpecifierArray(), false); + + // 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). + CallExpr Call(Context, &ConversionFn, 0, 0, + Conversion->getConversionType().getNonReferenceType(), + From->getLocStart()); + ImplicitConversionSequence ICS = + TryCopyInitialization(*this, &Call, ToType, + /*SuppressUserConversions=*/true, + /*InOverloadResolution=*/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; + } + + break; + + case ImplicitConversionSequence::BadConversion: + Candidate.Viable = false; + Candidate.FailureKind = ovl_fail_bad_final_conversion; + break; + + default: + assert(false && + "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<CXXConversionDecl>(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)) { + CandidateSet.push_back(OverloadCandidate()); + OverloadCandidate &Candidate = CandidateSet.back(); + Candidate.FoundDecl = FoundDecl; + Candidate.Function = FunctionTemplate->getTemplatedDecl(); + Candidate.Viable = false; + Candidate.FailureKind = ovl_fail_bad_deduction; + Candidate.IsSurrogate = false; + Candidate.IgnoreObjectArgument = false; + 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, + QualType ObjectType, + Expr **Args, unsigned NumArgs, + OverloadCandidateSet& CandidateSet) { + if (!CandidateSet.isNewCandidate(Conversion)) + return; + + // Overload resolution is always an unevaluated context. + EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); + + CandidateSet.push_back(OverloadCandidate()); + OverloadCandidate& Candidate = CandidateSet.back(); + Candidate.FoundDecl = FoundDecl; + Candidate.Function = 0; + Candidate.Surrogate = Conversion; + Candidate.Viable = true; + Candidate.IsSurrogate = true; + Candidate.IgnoreObjectArgument = false; + Candidate.Conversions.resize(NumArgs + 1); + + // Determine the implicit conversion sequence for the implicit + // object parameter. + ImplicitConversionSequence ObjectInit + = TryObjectArgumentInitialization(ObjectType, 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.ConversionFunction = Conversion; + 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 (NumArgs > 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 (NumArgs < 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 < NumArgs; ++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); + 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(); + QualType T2; + if (NumArgs > 1) + T2 = Args[1]->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<RecordType>()) { + // 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 + 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, Action::Unevaluated); + + // Add this candidate + CandidateSet.push_back(OverloadCandidate()); + OverloadCandidate& Candidate = CandidateSet.back(); + 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.Conversions.resize(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(Args[ArgIdx]); + } else { + Candidate.Conversions[ArgIdx] + = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], + ArgIdx == 0 && IsAssignmentOperator, + /*InOverloadResolution=*/false); + } + 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<QualType, 8> 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; + + /// 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) + : 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(); } +}; + +/// 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; + + const PointerType *PointerTy = Ty->getAs<PointerType>(); + assert(PointerTy && "type was not a 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; + 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); + PointerTypes.insert(Context.getPointerType(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<MemberPointerType>(); + 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<ReferenceType>()) + Ty = RefTy->getPointeeType(); + + // We don't care about qualifiers on the type. + Ty = Ty.getLocalUnqualifiedType(); + + // If we're dealing with an array type, decay to the pointer. + if (Ty->isArrayType()) + Ty = SemaRef.Context.getArrayDecayedType(Ty); + + if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { + QualType PointeeTy = PointerTy->getPointeeType(); + + // 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()) { + EnumerationTypes.insert(Ty); + } else if (Ty->isVectorType()) { + VectorTypes.insert(Ty); + } else if (AllowUserConversions) { + if (const RecordType *TyRec = Ty->getAs<RecordType>()) { + if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { + // No conversion functions in incomplete types. + return; + } + + CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(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<UsingShadowDecl>(D)) + D = cast<UsingShadowDecl>(D)->getTargetDecl(); + + // Skip conversion function templates; they don't tell us anything + // about which builtin types we can convert to. + if (isa<FunctionTemplateDecl>(D)) + continue; + + CXXConversionDecl *Conv = cast<CXXConversionDecl>(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<MemberPointerType>()) + TyRec = RHSMPType->getClass()->getAs<RecordType>(); + else + TyRec = ArgExpr->getType()->getAs<RecordType>(); + if (!TyRec) { + // Just to be safe, assume the worst case. + VRQuals.addVolatile(); + VRQuals.addRestrict(); + return VRQuals; + } + + CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(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<UsingShadowDecl>(D)) + D = cast<UsingShadowDecl>(D)->getTargetDecl(); + if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { + QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); + if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) + 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<PointerType>()) + CanTy = ResTypePtr->getPointeeType(); + else if (const MemberPointerType *ResTypeMPtr = + CanTy->getAs<MemberPointerType>()) + 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; +} + +/// 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) { + // The set of "promoted arithmetic types", which are the arithmetic + // types are that preserved by promotion (C++ [over.built]p2). Note + // that the first few of these types are the promoted integral + // types; these types need to be first. + // FIXME: What about complex? + const unsigned FirstIntegralType = 0; + const unsigned LastIntegralType = 13; + const unsigned FirstPromotedIntegralType = 7, + LastPromotedIntegralType = 13; + const unsigned FirstPromotedArithmeticType = 7, + LastPromotedArithmeticType = 16; + const unsigned NumArithmeticTypes = 16; + QualType ArithmeticTypes[NumArithmeticTypes] = { + Context.BoolTy, Context.CharTy, Context.WCharTy, +// FIXME: Context.Char16Ty, Context.Char32Ty, + Context.SignedCharTy, Context.ShortTy, + Context.UnsignedCharTy, Context.UnsignedShortTy, + Context.IntTy, Context.LongTy, Context.LongLongTy, + Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, + Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy + }; + assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && + "Invalid first promoted integral type"); + assert(ArithmeticTypes[LastPromotedIntegralType - 1] + == Context.UnsignedLongLongTy && + "Invalid last promoted integral type"); + assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && + "Invalid first promoted arithmetic type"); + assert(ArithmeticTypes[LastPromotedArithmeticType - 1] + == Context.LongDoubleTy && + "Invalid last promoted arithmetic type"); + + // 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. + Qualifiers VisibleTypeConversionsQuals; + VisibleTypeConversionsQuals.addConst(); + for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) + VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); + + BuiltinCandidateTypeSet CandidateTypes(*this); + for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) + CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), + OpLoc, + true, + (Op == OO_Exclaim || + Op == OO_AmpAmp || + Op == OO_PipePipe), + VisibleTypeConversionsQuals); + + bool isComparison = false; + switch (Op) { + case OO_None: + case NUM_OVERLOADED_OPERATORS: + assert(false && "Expected an overloaded operator"); + break; + + case OO_Star: // '*' is either unary or binary + if (NumArgs == 1) + goto UnaryStar; + else + goto BinaryStar; + break; + + case OO_Plus: // '+' is either unary or binary + if (NumArgs == 1) + goto UnaryPlus; + else + goto BinaryPlus; + break; + + case OO_Minus: // '-' is either unary or binary + if (NumArgs == 1) + goto UnaryMinus; + else + goto BinaryMinus; + break; + + case OO_Amp: // '&' is either unary or binary + if (NumArgs == 1) + goto UnaryAmp; + else + goto BinaryAmp; + + case OO_PlusPlus: + case OO_MinusMinus: + // 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); + for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); + Arith < NumArithmeticTypes; ++Arith) { + QualType ArithTy = ArithmeticTypes[Arith]; + QualType ParamTypes[2] + = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; + + // Non-volatile version. + if (NumArgs == 1) + AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); + else + AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); + // heuristic to reduce number of builtin candidates in the set. + // Add volatile version only if there are conversions to a volatile type. + if (VisibleTypeConversionsQuals.hasVolatile()) { + // Volatile version + ParamTypes[0] + = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); + if (NumArgs == 1) + AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); + else + AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); + } + } + + // 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); + for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); + Ptr != CandidateTypes.pointer_end(); ++Ptr) { + // Skip pointer types that aren't pointers to object types. + if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) + continue; + + QualType ParamTypes[2] = { + Context.getLValueReferenceType(*Ptr), Context.IntTy + }; + + // Without volatile + if (NumArgs == 1) + AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); + else + AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); + + if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && + VisibleTypeConversionsQuals.hasVolatile()) { + // With volatile + ParamTypes[0] + = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); + if (NumArgs == 1) + AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); + else + AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); + } + } + break; + + UnaryStar: + // 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, there exist candidate operator + // functions of the form + // T& operator*(T*); + for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); + Ptr != CandidateTypes.pointer_end(); ++Ptr) { + QualType ParamTy = *Ptr; + QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); + AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), + &ParamTy, Args, 1, CandidateSet); + } + break; + + UnaryPlus: + // C++ [over.built]p8: + // For every type T, there exist candidate operator functions of + // the form + // + // T* operator+(T*); + for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); + Ptr != CandidateTypes.pointer_end(); ++Ptr) { + QualType ParamTy = *Ptr; + AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); + } + + // Fall through + + UnaryMinus: + // C++ [over.built]p9: + // For every promoted arithmetic type T, there exist candidate + // operator functions of the form + // + // T operator+(T); + // T operator-(T); + for (unsigned Arith = FirstPromotedArithmeticType; + Arith < LastPromotedArithmeticType; ++Arith) { + QualType ArithTy = ArithmeticTypes[Arith]; + AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); + } + + // Extension: We also add these operators for vector types. + for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), + VecEnd = CandidateTypes.vector_end(); + Vec != VecEnd; ++Vec) { + QualType VecTy = *Vec; + AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); + } + break; + + case OO_Tilde: + // C++ [over.built]p10: + // For every promoted integral type T, there exist candidate + // operator functions of the form + // + // T operator~(T); + for (unsigned Int = FirstPromotedIntegralType; + Int < LastPromotedIntegralType; ++Int) { + QualType IntTy = ArithmeticTypes[Int]; + AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); + } + + // Extension: We also add this operator for vector types. + for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), + VecEnd = CandidateTypes.vector_end(); + Vec != VecEnd; ++Vec) { + QualType VecTy = *Vec; + AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); + } + break; + + case OO_New: + case OO_Delete: + case OO_Array_New: + case OO_Array_Delete: + case OO_Call: + assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); + break; + + case OO_Comma: + UnaryAmp: + 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_EqualEqual: + case OO_ExclaimEqual: + // 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); + for (BuiltinCandidateTypeSet::iterator + MemPtr = CandidateTypes.member_pointer_begin(), + MemPtrEnd = CandidateTypes.member_pointer_end(); + MemPtr != MemPtrEnd; + ++MemPtr) { + QualType ParamTypes[2] = { *MemPtr, *MemPtr }; + AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); + } + + // Fall through + + case OO_Less: + case OO_Greater: + case OO_LessEqual: + case OO_GreaterEqual: + // C++ [over.built]p15: + // + // For every pointer or enumeration type 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); + for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); + Ptr != CandidateTypes.pointer_end(); ++Ptr) { + QualType ParamTypes[2] = { *Ptr, *Ptr }; + AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); + } + for (BuiltinCandidateTypeSet::iterator Enum + = CandidateTypes.enumeration_begin(); + Enum != CandidateTypes.enumeration_end(); ++Enum) { + QualType ParamTypes[2] = { *Enum, *Enum }; + AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); + } + + // Fall through. + isComparison = true; + + BinaryPlus: + BinaryMinus: + if (!isComparison) { + // We didn't fall through, so we must have OO_Plus or OO_Minus. + + // 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); + for (BuiltinCandidateTypeSet::iterator Ptr + = CandidateTypes.pointer_begin(); + Ptr != CandidateTypes.pointer_end(); ++Ptr) { + QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; + + // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) + AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); + + if (Op == OO_Plus) { + // T* operator+(ptrdiff_t, T*); + ParamTypes[0] = ParamTypes[1]; + ParamTypes[1] = *Ptr; + AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); + } else { + // ptrdiff_t operator-(T, T); + ParamTypes[1] = *Ptr; + AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, + Args, 2, CandidateSet); + } + } + } + // Fall through + + case OO_Slash: + BinaryStar: + Conditional: + // 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. + for (unsigned Left = FirstPromotedArithmeticType; + Left < LastPromotedArithmeticType; ++Left) { + for (unsigned Right = FirstPromotedArithmeticType; + Right < LastPromotedArithmeticType; ++Right) { + QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; + QualType Result + = isComparison + ? Context.BoolTy + : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); + AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); + } + } + + // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the + // conditional operator for vector types. + for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), + Vec1End = CandidateTypes.vector_end(); + Vec1 != Vec1End; ++Vec1) + for (BuiltinCandidateTypeSet::iterator + Vec2 = CandidateTypes.vector_begin(), + Vec2End = CandidateTypes.vector_end(); + Vec2 != Vec2End; ++Vec2) { + QualType LandR[2] = { *Vec1, *Vec2 }; + QualType Result; + if (isComparison) + Result = Context.BoolTy; + else { + if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) + Result = *Vec1; + else + Result = *Vec2; + } + + AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); + } + + break; + + case OO_Percent: + BinaryAmp: + case OO_Caret: + case OO_Pipe: + case OO_LessLess: + case OO_GreaterGreater: + // 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. + for (unsigned Left = FirstPromotedIntegralType; + Left < LastPromotedIntegralType; ++Left) { + for (unsigned Right = FirstPromotedIntegralType; + Right < LastPromotedIntegralType; ++Right) { + QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; + QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) + ? LandR[0] + : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); + AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); + } + } + break; + + case OO_Equal: + // 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); + for (BuiltinCandidateTypeSet::iterator + Enum = CandidateTypes.enumeration_begin(), + EnumEnd = CandidateTypes.enumeration_end(); + Enum != EnumEnd; ++Enum) + AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, + CandidateSet); + for (BuiltinCandidateTypeSet::iterator + MemPtr = CandidateTypes.member_pointer_begin(), + MemPtrEnd = CandidateTypes.member_pointer_end(); + MemPtr != MemPtrEnd; ++MemPtr) + AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, + CandidateSet); + + // Fall through. + + case OO_PlusEqual: + case OO_MinusEqual: + // 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); + for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); + Ptr != CandidateTypes.pointer_end(); ++Ptr) { + QualType ParamTypes[2]; + ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); + + // non-volatile version + ParamTypes[0] = Context.getLValueReferenceType(*Ptr); + AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, + /*IsAssigmentOperator=*/Op == OO_Equal); + + if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && + VisibleTypeConversionsQuals.hasVolatile()) { + // volatile version + ParamTypes[0] + = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); + AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, + /*IsAssigmentOperator=*/Op == OO_Equal); + } + } + // Fall through. + + case OO_StarEqual: + case OO_SlashEqual: + // 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); + for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { + for (unsigned Right = FirstPromotedArithmeticType; + Right < LastPromotedArithmeticType; ++Right) { + QualType ParamTypes[2]; + ParamTypes[1] = ArithmeticTypes[Right]; + + // Add this built-in operator as a candidate (VQ is empty). + ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); + AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, + /*IsAssigmentOperator=*/Op == OO_Equal); + + // Add this built-in operator as a candidate (VQ is 'volatile'). + if (VisibleTypeConversionsQuals.hasVolatile()) { + ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); + ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); + AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, + /*IsAssigmentOperator=*/Op == OO_Equal); + } + } + } + + // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. + for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), + Vec1End = CandidateTypes.vector_end(); + Vec1 != Vec1End; ++Vec1) + for (BuiltinCandidateTypeSet::iterator + Vec2 = CandidateTypes.vector_begin(), + Vec2End = CandidateTypes.vector_end(); + Vec2 != Vec2End; ++Vec2) { + QualType ParamTypes[2]; + ParamTypes[1] = *Vec2; + // Add this built-in operator as a candidate (VQ is empty). + ParamTypes[0] = Context.getLValueReferenceType(*Vec1); + AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, + /*IsAssigmentOperator=*/Op == OO_Equal); + + // Add this built-in operator as a candidate (VQ is 'volatile'). + if (VisibleTypeConversionsQuals.hasVolatile()) { + ParamTypes[0] = Context.getVolatileType(*Vec1); + ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); + AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, + /*IsAssigmentOperator=*/Op == OO_Equal); + } + } + break; + + case OO_PercentEqual: + case OO_LessLessEqual: + case OO_GreaterGreaterEqual: + case OO_AmpEqual: + case OO_CaretEqual: + case OO_PipeEqual: + // 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); + for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { + for (unsigned Right = FirstPromotedIntegralType; + Right < LastPromotedIntegralType; ++Right) { + QualType ParamTypes[2]; + ParamTypes[1] = ArithmeticTypes[Right]; + + // Add this built-in operator as a candidate (VQ is empty). + ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); + AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); + if (VisibleTypeConversionsQuals.hasVolatile()) { + // Add this built-in operator as a candidate (VQ is 'volatile'). + ParamTypes[0] = ArithmeticTypes[Left]; + ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); + ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); + AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); + } + } + } + break; + + case OO_Exclaim: { + // C++ [over.operator]p23: + // + // There also exist candidate operator functions of the form + // + // bool operator!(bool); + // bool operator&&(bool, bool); [BELOW] + // bool operator||(bool, bool); [BELOW] + QualType ParamTy = Context.BoolTy; + AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, + /*IsAssignmentOperator=*/false, + /*NumContextualBoolArguments=*/1); + break; + } + + case OO_AmpAmp: + case OO_PipePipe: { + // C++ [over.operator]p23: + // + // There also exist candidate operator functions of the form + // + // bool operator!(bool); [ABOVE] + // bool operator&&(bool, bool); + // bool operator||(bool, bool); + QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; + AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, + /*IsAssignmentOperator=*/false, + /*NumContextualBoolArguments=*/2); + break; + } + + case OO_Subscript: + // 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*); + for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); + Ptr != CandidateTypes.pointer_end(); ++Ptr) { + QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; + QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); + QualType ResultTy = Context.getLValueReferenceType(PointeeType); + + // T& operator[](T*, ptrdiff_t) + AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); + + // T& operator[](ptrdiff_t, T*); + ParamTypes[0] = ParamTypes[1]; + ParamTypes[1] = *Ptr; + AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); + } + break; + + case OO_ArrowStar: + // 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. + { + for (BuiltinCandidateTypeSet::iterator Ptr = + CandidateTypes.pointer_begin(); + Ptr != CandidateTypes.pointer_end(); ++Ptr) { + QualType C1Ty = (*Ptr); + QualType C1; + QualifierCollector Q1; + if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { + C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); + if (!isa<RecordType>(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.member_pointer_begin(), + MemPtrEnd = CandidateTypes.member_pointer_end(); + MemPtr != MemPtrEnd; ++MemPtr) { + const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); + QualType C2 = QualType(mptr->getClass(), 0); + C2 = C2.getUnqualifiedType(); + if (C1 != C2 && !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(T); + QualType ResultTy = Context.getLValueReferenceType(T); + AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); + } + } + } + break; + + case OO_Conditional: + // 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]p24: + // For every type T, where T is a pointer or pointer-to-member type, + // there exist candidate operator functions of the form + // + // T operator?(bool, T, T); + // + for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), + E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { + QualType ParamTypes[2] = { *Ptr, *Ptr }; + AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); + } + for (BuiltinCandidateTypeSet::iterator Ptr = + CandidateTypes.member_pointer_begin(), + E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { + QualType ParamTypes[2] = { *Ptr, *Ptr }; + AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); + } + goto Conditional; + } +} + +/// \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, + Expr **Args, unsigned NumArgs, + const TemplateArgumentListInfo *ExplicitTemplateArgs, + OverloadCandidateSet& CandidateSet, + bool PartialOverloading) { + 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, Args, NumArgs, Fns); + + // 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<FunctionDecl>(*I)) { + if (ExplicitTemplateArgs) + continue; + + AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, + false, PartialOverloading); + } else + AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), + FoundDecl, ExplicitTemplateArgs, + Args, NumArgs, CandidateSet); + } +} + +/// isBetterOverloadCandidate - Determines whether the first overload +/// candidate is a better candidate than the second (C++ 13.3.3p1). +bool +Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, + const OverloadCandidate& Cand2, + SourceLocation Loc) { + // 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.Conversions.size(); + assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); + bool HasBetterConversion = false; + for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { + switch (CompareImplicitConversionSequences(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 + = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), + Cand2.Function->getPrimaryTemplate(), + Loc, + isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion + : TPOC_Call)) + 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 (Cand1.Function && Cand2.Function && + isa<CXXConversionDecl>(Cand1.Function) && + isa<CXXConversionDecl>(Cand2.Function)) { + switch (CompareStandardConversionSequences(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 Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, + SourceLocation Loc, + OverloadCandidateSet::iterator& Best) { + // Find the best viable function. + Best = CandidateSet.end(); + for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); + Cand != CandidateSet.end(); ++Cand) { + if (Cand->Viable) { + if (Best == CandidateSet.end() || + isBetterOverloadCandidate(*Cand, *Best, Loc)) + Best = Cand; + } + } + + // If we didn't find any viable functions, abort. + if (Best == CandidateSet.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 (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); + Cand != CandidateSet.end(); ++Cand) { + if (Cand->Viable && + Cand != Best && + !isBetterOverloadCandidate(*Best, *Cand, Loc)) { + Best = CandidateSet.end(); + return OR_Ambiguous; + } + } + + // Best is the best viable function. + if (Best->Function && + (Best->Function->isDeleted() || + Best->Function->getAttr<UnavailableAttr>())) + return OR_Deleted; + + // C++ [basic.def.odr]p2: + // An overloaded function is used if it is selected by overload resolution + // when referred to from a potentially-evaluated expression. [Note: this + // covers calls to named functions (5.2.2), operator overloading + // (clause 13), user-defined conversions (12.3.2), allocation function for + // placement new (5.3.4), as well as non-default initialization (8.5). + if (Best->Function) + MarkDeclarationReferenced(Loc, Best->Function); + 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_copy_assignment +}; + +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<CXXConstructorDecl>(Fn)) { + if (!Ctor->isImplicit()) + return isTemplate ? oc_constructor_template : oc_constructor; + + return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor + : oc_implicit_default_constructor; + } + + if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(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; + + assert(Meth->isCopyAssignment() + && "implicit method is not copy assignment operator?"); + return oc_implicit_copy_assignment; + } + + return isTemplate ? oc_function_template : oc_function; +} + +} // end anonymous namespace + +// Notes the location of an overload candidate. +void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { + std::string FnDesc; + OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); + Diag(Fn->getLocation(), diag::note_ovl_candidate) + << (unsigned) K << FnDesc; +} + +/// 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 Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, + SourceLocation CaretLoc, + const PartialDiagnostic &PDiag) { + Diag(CaretLoc, PDiag) + << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); + for (AmbiguousConversionSequence::const_iterator + I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { + 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<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(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<UnaryOperator>(E)) + E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); + DeclarationName Name = cast<OverloadExpr>(E)->getName(); + + S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) + << (unsigned) FnKind << FnDesc + << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) + << ToTy << Name << I+1; + 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<ReferenceType> RT = CToTy->getAs<ReferenceType>()) + CToTy = RT->getPointeeType(); + else { + // TODO: detect and diagnose the full richness of const mismatches. + if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) + if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) + CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); + } + + if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && + !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { + // It is dumb that we have to do this here. + while (isa<ArrayType>(CFromTy)) + CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); + while (isa<ArrayType>(CToTy)) + CToTy = CFromTy->getAs<ArrayType>()->getElementType(); + + 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; + 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; + } + 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<PointerType>()) + 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; + return; + } + + // TODO: specialize more based on the kind of mismatch + S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) + << (unsigned) FnKind << FnDesc + << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) + << FromTy << ToTy << (unsigned) isObjectArgument << I+1; +} + +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<FunctionProtoType>(); + + unsigned MinParams = Fn->getMinRequiredArguments(); + + // at least / at most / exactly + // FIXME: variadic templates "at most" should account for parameter packs + 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()) + 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; +} + +/// Diagnose a failed template-argument deduction. +void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, + Expr **Args, unsigned NumArgs) { + FunctionDecl *Fn = Cand->Function; // pattern + + TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); + NamedDecl *ParamD; + (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || + (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || + (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); + 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(); + return; + } + + case Sema::TDK_Inconsistent: + case Sema::TDK_InconsistentQuals: { + assert(ParamD && "no parameter found for inconsistent deduction result"); + int which = 0; + if (isa<TemplateTypeParmDecl>(ParamD)) + which = 0; + else if (isa<NonTypeTemplateParmDecl>(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(); + 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<TemplateTypeParmDecl>(ParamD)) + index = TTP->getIndex(); + else if (NonTypeTemplateParmDecl *NTTP + = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) + index = NTTP->getIndex(); + else + index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); + S.Diag(Fn->getLocation(), + diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) + << (index + 1); + } + 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); + 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; + 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); + return; + } +} + +/// 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, + Expr **Args, unsigned NumArgs) { + FunctionDecl *Fn = Cand->Function; + + // Note deleted candidates, but only if they're viable. + if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { + std::string FnDesc; + OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); + + S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) + << FnKind << FnDesc << Fn->isDeleted(); + 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, Args, 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->Conversions.size(); 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); + } + } +} + +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<LValueReferenceType>()) { + FnType = FnTypeRef->getPointeeType(); + isLValueReference = true; + } else if (const RValueReferenceType *FnTypeRef = + FnType->getAs<RValueReferenceType>()) { + FnType = FnTypeRef->getPointeeType(); + isRValueReference = true; + } + if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { + FnType = FnTypePtr->getPointeeType(); + isPointer = true; + } + // Desugar down to a function type. + FnType = QualType(FnType->getAs<FunctionType>(), 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; +} + +void NoteBuiltinOperatorCandidate(Sema &S, + const char *Opc, + SourceLocation OpLoc, + OverloadCandidate *Cand) { + assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); + std::string TypeStr("operator"); + TypeStr += Opc; + TypeStr += "("; + TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); + if (Cand->Conversions.size() == 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->Conversions.size(); + 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; + + S.DiagnoseAmbiguousConversion(ICS, 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(); +} + +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 (S.isBetterOverloadCandidate(*L, *R, SourceLocation())) return true; + if (S.isBetterOverloadCandidate(*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; + + // If there's any ordering between the defined conversions... + // FIXME: this might not be transitive. + assert(L->Conversions.size() == R->Conversions.size()); + + int leftBetter = 0; + unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); + for (unsigned E = L->Conversions.size(); I != E; ++I) { + switch (S.CompareImplicitConversionSequences(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; + + // 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 +void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, + Expr **Args, unsigned NumArgs) { + assert(!Cand->Viable); + + // Don't do anything on failures other than bad conversion. + if (Cand->FailureKind != ovl_fail_bad_conversion) return; + + // Skip forward to the first bad conversion. + unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); + unsigned ConvCount = Cand->Conversions.size(); + while (true) { + assert(ConvIdx != ConvCount && "no bad conversion in candidate"); + ConvIdx++; + if (Cand->Conversions[ConvIdx - 1].isBad()) + 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<PointerType>()) + ConvType = ConvPtrType->getPointeeType(); + Proto = ConvType->getAs<FunctionProtoType>(); + ArgIdx--; + } else if (Cand->Function) { + Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); + if (isa<CXXMethodDecl>(Cand->Function) && + !isa<CXXConstructorDecl>(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); + 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); + else + Cand->Conversions[ConvIdx].setEllipsis(); + } +} + +} // end anonymous namespace + +/// PrintOverloadCandidates - When overload resolution fails, prints +/// diagnostic messages containing the candidates in the candidate +/// set. +void +Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, + OverloadCandidateDisplayKind OCD, + Expr **Args, unsigned NumArgs, + 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. + llvm::SmallVector<OverloadCandidate*, 32> Cands; + if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); + for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), + LastCand = CandidateSet.end(); + Cand != LastCand; ++Cand) { + if (Cand->Viable) + Cands.push_back(Cand); + else if (OCD == OCD_AllCandidates) { + CompleteNonViableCandidate(*this, Cand, Args, NumArgs); + Cands.push_back(Cand); + } + } + + std::sort(Cands.begin(), Cands.end(), + CompareOverloadCandidatesForDisplay(*this)); + + bool ReportedAmbiguousConversions = false; + + llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; + for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { + OverloadCandidate *Cand = *I; + + if (Cand->Function) + NoteFunctionCandidate(*this, Cand, Args, NumArgs); + else if (Cand->IsSurrogate) + NoteSurrogateCandidate(*this, Cand); + + // This a builtin candidate. We do not, in general, want to list + // every possible builtin candidate. + else if (Cand->Viable) { + // 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(*this, OpLoc, Cand); + ReportedAmbiguousConversions = true; + } + + // If this is a viable builtin, print it. + NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); + } + } +} + +static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) { + if (isa<UnresolvedLookupExpr>(E)) + return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D); + + return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D); +} + +/// 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 *From, QualType ToType, + bool Complain, + DeclAccessPair &FoundResult) { + QualType FunctionType = ToType; + bool IsMember = false; + if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) + FunctionType = ToTypePtr->getPointeeType(); + else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) + FunctionType = ToTypeRef->getPointeeType(); + else if (const MemberPointerType *MemTypePtr = + ToType->getAs<MemberPointerType>()) { + FunctionType = MemTypePtr->getPointeeType(); + IsMember = true; + } + + // 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. + OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); + TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; + if (OvlExpr->hasExplicitTemplateArgs()) { + OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); + ExplicitTemplateArgs = &ETABuffer; + } + + // We expect a pointer or reference to function, or a function pointer. + FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); + if (!FunctionType->isFunctionType()) { + if (Complain) + Diag(From->getLocStart(), diag::err_addr_ovl_not_func_ptrref) + << OvlExpr->getName() << ToType; + + return 0; + } + + assert(From->getType() == Context.OverloadTy); + + // Look through all of the overloaded functions, searching for one + // whose type matches exactly. + llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; + llvm::SmallVector<FunctionDecl *, 4> NonMatches; + + bool FoundNonTemplateFunction = 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<FunctionTemplateDecl>(Fn)) { + if (CXXMethodDecl *Method + = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { + // Skip non-static function templates when converting to pointer, and + // static when converting to member pointer. + if (Method->isStatic() == IsMember) + continue; + } else if (IsMember) + continue; + + // 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. + // FIXME: We don't really want to build the specialization here, do we? + FunctionDecl *Specialization = 0; + TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); + if (TemplateDeductionResult Result + = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, + FunctionType, Specialization, Info)) { + // FIXME: make a note of the failed deduction for diagnostics. + (void)Result; + } else { + // FIXME: If the match isn't exact, shouldn't we just drop this as + // a candidate? Find a testcase before changing the code. + assert(FunctionType + == Context.getCanonicalType(Specialization->getType())); + Matches.push_back(std::make_pair(I.getPair(), + cast<FunctionDecl>(Specialization->getCanonicalDecl()))); + } + + continue; + } + + if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { + // Skip non-static functions when converting to pointer, and static + // when converting to member pointer. + if (Method->isStatic() == IsMember) + continue; + + // If we have explicit template arguments, skip non-templates. + if (OvlExpr->hasExplicitTemplateArgs()) + continue; + } else if (IsMember) + continue; + + if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { + QualType ResultTy; + if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || + IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, + ResultTy)) { + Matches.push_back(std::make_pair(I.getPair(), + cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); + FoundNonTemplateFunction = true; + } + } + } + + // If there were 0 or 1 matches, we're done. + if (Matches.empty()) { + if (Complain) { + Diag(From->getLocStart(), diag::err_addr_ovl_no_viable) + << OvlExpr->getName() << FunctionType; + for (UnresolvedSetIterator I = OvlExpr->decls_begin(), + E = OvlExpr->decls_end(); + I != E; ++I) + if (FunctionDecl *F = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl())) + NoteOverloadCandidate(F); + } + + return 0; + } else if (Matches.size() == 1) { + FunctionDecl *Result = Matches[0].second; + FoundResult = Matches[0].first; + MarkDeclarationReferenced(From->getLocStart(), Result); + if (Complain) + CheckAddressOfMemberAccess(OvlExpr, Matches[0].first); + return Result; + } + + // C++ [over.over]p4: + // If more than one function is selected, [...] + if (!FoundNonTemplateFunction) { + // [...] 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 = + getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), + TPOC_Other, From->getLocStart(), + PDiag(), + PDiag(diag::err_addr_ovl_ambiguous) + << Matches[0].second->getDeclName(), + PDiag(diag::note_ovl_candidate) + << (unsigned) oc_function_template); + assert(Result != MatchesCopy.end() && "no most-specialized template"); + MarkDeclarationReferenced(From->getLocStart(), *Result); + FoundResult = Matches[Result - MatchesCopy.begin()].first; + if (Complain) { + CheckUnresolvedAccess(*this, OvlExpr, FoundResult); + DiagnoseUseOfDecl(FoundResult, OvlExpr->getNameLoc()); + } + return cast<FunctionDecl>(*Result); + } + + // [...] 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); + } + } + + // [...] After such eliminations, if any, there shall remain exactly one + // selected function. + if (Matches.size() == 1) { + MarkDeclarationReferenced(From->getLocStart(), Matches[0].second); + FoundResult = Matches[0].first; + if (Complain) { + CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first); + DiagnoseUseOfDecl(Matches[0].first, OvlExpr->getNameLoc()); + } + return cast<FunctionDecl>(Matches[0].second); + } + + // FIXME: We should probably return the same thing that BestViableFunction + // returns (even if we issue the diagnostics here). + Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) + << Matches[0].second->getDeclName(); + for (unsigned I = 0, E = Matches.size(); I != E; ++I) + NoteOverloadCandidate(Matches[I].second); + return 0; +} + +/// \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(Expr *From) { + // 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 (From->getType() != Context.OverloadTy) + return 0; + + OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); + + // If we didn't actually find any template-ids, we're done. + if (!OvlExpr->hasExplicitTemplateArgs()) + return 0; + + TemplateArgumentListInfo ExplicitTemplateArgs; + OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); + + // Look through all of the overloaded functions, searching for one + // whose type matches exactly. + FunctionDecl *Matched = 0; + for (UnresolvedSetIterator I = OvlExpr->decls_begin(), + E = OvlExpr->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<FunctionTemplateDecl>(*I); + + // 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 (TemplateDeductionResult Result + = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, + Specialization, Info)) { + // FIXME: make a note of the failed deduction for diagnostics. + (void)Result; + continue; + } + + // Multiple matches; we can't resolve to a single declaration. + if (Matched) + return 0; + + Matched = Specialization; + } + + return Matched; +} + +/// \brief Add a single candidate to the overload set. +static void AddOverloadedCallCandidate(Sema &S, + DeclAccessPair FoundDecl, + const TemplateArgumentListInfo *ExplicitTemplateArgs, + Expr **Args, unsigned NumArgs, + OverloadCandidateSet &CandidateSet, + bool PartialOverloading) { + NamedDecl *Callee = FoundDecl.getDecl(); + if (isa<UsingShadowDecl>(Callee)) + Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); + + if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { + assert(!ExplicitTemplateArgs && "Explicit template arguments?"); + S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, + false, PartialOverloading); + return; + } + + if (FunctionTemplateDecl *FuncTemplate + = dyn_cast<FunctionTemplateDecl>(Callee)) { + S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, + ExplicitTemplateArgs, + Args, NumArgs, CandidateSet); + return; + } + + assert(false && "unhandled case in overloaded call candidate"); + + // do nothing? +} + +/// \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, + Expr **Args, unsigned NumArgs, + 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<UsingShadowDecl>(*I) || + !(*I)->getDeclContext()->isFunctionOrMethod()); + assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); + } + } +#endif + + // It would be nice to avoid this copy. + TemplateArgumentListInfo TABuffer; + const 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, NumArgs, CandidateSet, + PartialOverloading); + + if (ULE->requiresADL()) + AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, + Args, NumArgs, + ExplicitTemplateArgs, + CandidateSet, + PartialOverloading); +} + +static Sema::OwningExprResult Destroy(Sema &SemaRef, Expr *Fn, + Expr **Args, unsigned NumArgs) { + Fn->Destroy(SemaRef.Context); + for (unsigned Arg = 0; Arg < NumArgs; ++Arg) + Args[Arg]->Destroy(SemaRef.Context); + return SemaRef.ExprError(); +} + +/// Attempts to recover from a call where no functions were found. +/// +/// Returns true if new candidates were found. +static Sema::OwningExprResult +BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, + UnresolvedLookupExpr *ULE, + SourceLocation LParenLoc, + Expr **Args, unsigned NumArgs, + SourceLocation *CommaLocs, + SourceLocation RParenLoc) { + + CXXScopeSpec SS; + if (ULE->getQualifier()) { + SS.setScopeRep(ULE->getQualifier()); + SS.setRange(ULE->getQualifierRange()); + } + + TemplateArgumentListInfo TABuffer; + const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; + if (ULE->hasExplicitTemplateArgs()) { + ULE->copyTemplateArgumentsInto(TABuffer); + ExplicitTemplateArgs = &TABuffer; + } + + LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), + Sema::LookupOrdinaryName); + if (SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression)) + return Destroy(SemaRef, Fn, Args, NumArgs); + + 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. + Sema::OwningExprResult NewFn = SemaRef.ExprError(); + if ((*R.begin())->isCXXClassMember()) + NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); + else if (ExplicitTemplateArgs) + NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); + else + NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); + + if (NewFn.isInvalid()) + return Destroy(SemaRef, Fn, Args, NumArgs); + + Fn->Destroy(SemaRef.Context); + + // This shouldn't cause an infinite loop because we're giving it + // an expression with non-empty lookup results, which should never + // end up here. + return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc, + Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs), + CommaLocs, 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. +Sema::OwningExprResult +Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, + SourceLocation LParenLoc, + Expr **Args, unsigned NumArgs, + SourceLocation *CommaLocs, + SourceLocation RParenLoc) { +#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<FunctionDecl>(*ULE->decls_begin())) && + F->getBuiltinID() && F->isImplicit()) + assert(0 && "performing ADL for builtin"); + + // We don't perform ADL in C. + assert(getLangOptions().CPlusPlus && "ADL enabled in C"); + } +#endif + + 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, Args, NumArgs, CandidateSet); + + // If we found nothing, try to recover. + // AddRecoveryCallCandidates diagnoses the error itself, so we just + // bailout out if it fails. + if (CandidateSet.empty()) + return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, + CommaLocs, RParenLoc); + + OverloadCandidateSet::iterator Best; + switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { + case OR_Success: { + FunctionDecl *FDecl = Best->Function; + CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); + DiagnoseUseOfDecl(Best->FoundDecl, ULE->getNameLoc()); + Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); + return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); + } + + case OR_No_Viable_Function: + Diag(Fn->getSourceRange().getBegin(), + diag::err_ovl_no_viable_function_in_call) + << ULE->getName() << Fn->getSourceRange(); + PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); + break; + + case OR_Ambiguous: + Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) + << ULE->getName() << Fn->getSourceRange(); + PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); + break; + + case OR_Deleted: + Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) + << Best->Function->isDeleted() + << ULE->getName() + << Fn->getSourceRange(); + PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); + break; + } + + // Overload resolution failed. Destroy all of the subexpressions and + // return NULL. + Fn->Destroy(Context); + for (unsigned Arg = 0; Arg < NumArgs; ++Arg) + Args[Arg]->Destroy(Context); + return ExprError(); +} + +static bool IsOverloaded(const UnresolvedSetImpl &Functions) { + return Functions.size() > 1 || + (Functions.size() == 1 && isa<FunctionTemplateDecl>(*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. +Sema::OwningExprResult +Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, + const UnresolvedSetImpl &Fns, + ExprArg input) { + UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); + Expr *Input = (Expr *)input.get(); + + OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); + assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); + DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); + + 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 == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { + llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); + Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, + SourceLocation()); + NumArgs = 2; + } + + if (Input->isTypeDependent()) { + CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators + UnresolvedLookupExpr *Fn + = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, + 0, SourceRange(), OpName, OpLoc, + /*ADL*/ true, IsOverloaded(Fns), + Fns.begin(), Fns.end()); + input.release(); + return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, + &Args[0], NumArgs, + Context.DependentTy, + OpLoc)); + } + + // Build an empty overload set. + OverloadCandidateSet CandidateSet(OpLoc); + + // Add the candidates from the given function set. + AddFunctionCandidates(Fns, &Args[0], 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, + Args, NumArgs, + /*ExplicitTemplateArgs*/ 0, + CandidateSet); + + // Add builtin operator candidates. + AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); + + // Perform overload resolution. + OverloadCandidateSet::iterator Best; + switch (BestViableFunction(CandidateSet, 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. + + // Convert the arguments. + if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { + CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); + + if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, + Best->FoundDecl, Method)) + return ExprError(); + } else { + // Convert the arguments. + OwningExprResult InputInit + = PerformCopyInitialization(InitializedEntity::InitializeParameter( + FnDecl->getParamDecl(0)), + SourceLocation(), + move(input)); + if (InputInit.isInvalid()) + return ExprError(); + + input = move(InputInit); + Input = (Expr *)input.get(); + } + + DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); + + // Determine the result type + QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); + + // Build the actual expression node. + Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), + SourceLocation()); + UsualUnaryConversions(FnExpr); + + input.release(); + Args[0] = Input; + ExprOwningPtr<CallExpr> TheCall(this, + new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, + Args, NumArgs, ResultTy, OpLoc)); + + if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), + FnDecl)) + return ExprError(); + + return MaybeBindToTemporary(TheCall.release()); + } else { + // We matched a built-in operator. Convert the arguments, then + // break out so that we will build the appropriate built-in + // operator node. + if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], + Best->Conversions[0], AA_Passing)) + return ExprError(); + + break; + } + } + + case OR_No_Viable_Function: + // 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) + << UnaryOperator::getOpcodeStr(Opc) + << Input->getSourceRange(); + PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, + UnaryOperator::getOpcodeStr(Opc), OpLoc); + return ExprError(); + + case OR_Deleted: + Diag(OpLoc, diag::err_ovl_deleted_oper) + << Best->Function->isDeleted() + << UnaryOperator::getOpcodeStr(Opc) + << Input->getSourceRange(); + PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); + 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. + input.release(); + return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(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. +Sema::OwningExprResult +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<BinaryOperator::Opcode>(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 <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) + return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, + Context.DependentTy, OpLoc)); + + return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, + Context.DependentTy, + Context.DependentTy, + Context.DependentTy, + OpLoc)); + } + + // FIXME: save results of ADL from here? + CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators + UnresolvedLookupExpr *Fn + = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, + 0, SourceRange(), OpName, OpLoc, + /*ADL*/ true, IsOverloaded(Fns), + Fns.begin(), Fns.end()); + return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, + Args, 2, + Context.DependentTy, + OpLoc)); + } + + // If this is the .* operator, which is not overloadable, just + // create a built-in binary operator. + if (Opc == BinaryOperator::PtrMemD) + return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); + + // 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==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) + 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, 2, CandidateSet, false); + + // Add operator candidates that are member functions. + AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); + + // Add candidates from ADL. + AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, + Args, 2, + /*ExplicitTemplateArgs*/ 0, + CandidateSet); + + // Add builtin operator candidates. + AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); + + // Perform overload resolution. + OverloadCandidateSet::iterator Best; + switch (BestViableFunction(CandidateSet, 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. + + // Convert the arguments. + if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { + // Best->Access is only meaningful for class members. + CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); + + OwningExprResult Arg1 + = PerformCopyInitialization( + InitializedEntity::InitializeParameter( + FnDecl->getParamDecl(0)), + SourceLocation(), + Owned(Args[1])); + if (Arg1.isInvalid()) + return ExprError(); + + if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, + Best->FoundDecl, Method)) + return ExprError(); + + Args[1] = RHS = Arg1.takeAs<Expr>(); + } else { + // Convert the arguments. + OwningExprResult Arg0 + = PerformCopyInitialization( + InitializedEntity::InitializeParameter( + FnDecl->getParamDecl(0)), + SourceLocation(), + Owned(Args[0])); + if (Arg0.isInvalid()) + return ExprError(); + + OwningExprResult Arg1 + = PerformCopyInitialization( + InitializedEntity::InitializeParameter( + FnDecl->getParamDecl(1)), + SourceLocation(), + Owned(Args[1])); + if (Arg1.isInvalid()) + return ExprError(); + Args[0] = LHS = Arg0.takeAs<Expr>(); + Args[1] = RHS = Arg1.takeAs<Expr>(); + } + + DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); + + // Determine the result type + QualType ResultTy + = FnDecl->getType()->getAs<FunctionType>()->getResultType(); + ResultTy = ResultTy.getNonReferenceType(); + + // Build the actual expression node. + Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), + OpLoc); + UsualUnaryConversions(FnExpr); + + ExprOwningPtr<CXXOperatorCallExpr> + TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, + Args, 2, ResultTy, + OpLoc)); + + if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), + FnDecl)) + return ExprError(); + + return MaybeBindToTemporary(TheCall.release()); + } else { + // We matched a built-in operator. Convert the arguments, then + // break out so that we will build the appropriate built-in + // operator node. + if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], + Best->Conversions[0], AA_Passing) || + PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], + Best->Conversions[1], AA_Passing)) + return ExprError(); + + 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 == BinaryOperator::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 + OwningExprResult Result = ExprError(); + if (Args[0]->getType()->isRecordType() && + Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { + Diag(OpLoc, diag::err_ovl_no_viable_oper) + << BinaryOperator::getOpcodeStr(Opc) + << Args[0]->getSourceRange() << Args[1]->getSourceRange(); + } else { + // 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()) + PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, + BinaryOperator::getOpcodeStr(Opc), OpLoc); + return move(Result); + } + + case OR_Ambiguous: + Diag(OpLoc, diag::err_ovl_ambiguous_oper) + << BinaryOperator::getOpcodeStr(Opc) + << Args[0]->getSourceRange() << Args[1]->getSourceRange(); + PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, + BinaryOperator::getOpcodeStr(Opc), OpLoc); + return ExprError(); + + case OR_Deleted: + Diag(OpLoc, diag::err_ovl_deleted_oper) + << Best->Function->isDeleted() + << BinaryOperator::getOpcodeStr(Opc) + << Args[0]->getSourceRange() << Args[1]->getSourceRange(); + PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); + return ExprError(); + } + + // We matched a built-in operator; build it. + return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); +} + +Action::OwningExprResult +Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, + SourceLocation RLoc, + ExprArg Base, ExprArg Idx) { + Expr *Args[2] = { static_cast<Expr*>(Base.get()), + static_cast<Expr*>(Idx.get()) }; + 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 + UnresolvedLookupExpr *Fn + = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, + 0, SourceRange(), OpName, LLoc, + /*ADL*/ true, /*Overloaded*/ false, + UnresolvedSetIterator(), + UnresolvedSetIterator()); + // Can't add any actual overloads yet + + Base.release(); + Idx.release(); + return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, + Args, 2, + Context.DependentTy, + RLoc)); + } + + // 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); + + // Perform overload resolution. + OverloadCandidateSet::iterator Best; + switch (BestViableFunction(CandidateSet, 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. + + CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); + DiagnoseUseOfDecl(Best->FoundDecl, LLoc); + + // Convert the arguments. + CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); + if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, + Best->FoundDecl, Method)) + return ExprError(); + + // Convert the arguments. + OwningExprResult InputInit + = PerformCopyInitialization(InitializedEntity::InitializeParameter( + FnDecl->getParamDecl(0)), + SourceLocation(), + Owned(Args[1])); + if (InputInit.isInvalid()) + return ExprError(); + + Args[1] = InputInit.takeAs<Expr>(); + + // Determine the result type + QualType ResultTy + = FnDecl->getType()->getAs<FunctionType>()->getResultType(); + ResultTy = ResultTy.getNonReferenceType(); + + // Build the actual expression node. + Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), + LLoc); + UsualUnaryConversions(FnExpr); + + Base.release(); + Idx.release(); + ExprOwningPtr<CXXOperatorCallExpr> + TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, + FnExpr, Args, 2, + ResultTy, RLoc)); + + if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), + FnDecl)) + return ExprError(); + + return MaybeBindToTemporary(TheCall.release()); + } else { + // We matched a built-in operator. Convert the arguments, then + // break out so that we will build the appropriate built-in + // operator node. + if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], + Best->Conversions[0], AA_Passing) || + PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], + Best->Conversions[1], AA_Passing)) + return ExprError(); + + 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(); + PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, + "[]", LLoc); + return ExprError(); + } + + case OR_Ambiguous: + Diag(LLoc, diag::err_ovl_ambiguous_oper) + << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); + PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, + "[]", LLoc); + return ExprError(); + + case OR_Deleted: + Diag(LLoc, diag::err_ovl_deleted_oper) + << Best->Function->isDeleted() << "[]" + << Args[0]->getSourceRange() << Args[1]->getSourceRange(); + PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, + "[]", LLoc); + return ExprError(); + } + + // We matched a built-in operator; build it. + Base.release(); + Idx.release(); + return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, + Owned(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 member function or an overloaded member +/// function. +Sema::OwningExprResult +Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, + SourceLocation LParenLoc, Expr **Args, + unsigned NumArgs, SourceLocation *CommaLocs, + SourceLocation RParenLoc) { + // Dig out the member expression. This holds both the object + // argument and the member function we're referring to. + Expr *NakedMemExpr = MemExprE->IgnoreParens(); + + MemberExpr *MemExpr; + CXXMethodDecl *Method = 0; + DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); + NestedNameSpecifier *Qualifier = 0; + if (isa<MemberExpr>(NakedMemExpr)) { + MemExpr = cast<MemberExpr>(NakedMemExpr); + Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); + FoundDecl = MemExpr->getFoundDecl(); + Qualifier = MemExpr->getQualifier(); + } else { + UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); + Qualifier = UnresExpr->getQualifier(); + + QualType ObjectType = UnresExpr->getBaseType(); + + // 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<CXXRecordDecl>(Func->getDeclContext()); + if (isa<UsingShadowDecl>(Func)) + Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); + + if ((Method = dyn_cast<CXXMethodDecl>(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, + Args, NumArgs, + CandidateSet, /*SuppressUserConversions=*/false); + } else { + AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), + I.getPair(), ActingDC, TemplateArgs, + ObjectType, Args, NumArgs, + CandidateSet, + /*SuppressUsedConversions=*/false); + } + } + + DeclarationName DeclName = UnresExpr->getMemberName(); + + OverloadCandidateSet::iterator Best; + switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) { + case OR_Success: + Method = cast<CXXMethodDecl>(Best->Function); + 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(); + PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); + // FIXME: Leaking incoming expressions! + return ExprError(); + + case OR_Ambiguous: + Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) + << DeclName << MemExprE->getSourceRange(); + PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); + // FIXME: Leaking incoming expressions! + return ExprError(); + + case OR_Deleted: + Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) + << Best->Function->isDeleted() + << DeclName << MemExprE->getSourceRange(); + PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, 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<MemberExpr>(MemExprE->IgnoreParens()); + } + + assert(Method && "Member call to something that isn't a method?"); + ExprOwningPtr<CXXMemberCallExpr> + TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args, + NumArgs, + Method->getResultType().getNonReferenceType(), + RParenLoc)); + + // Check for a valid return type. + if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), + TheCall.get(), 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. + Expr *ObjectArg = MemExpr->getBase(); + if (!Method->isStatic() && + PerformObjectArgumentInitialization(ObjectArg, Qualifier, + FoundDecl, Method)) + return ExprError(); + MemExpr->setBase(ObjectArg); + + // Convert the rest of the arguments + const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); + if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, + RParenLoc)) + return ExprError(); + + if (CheckFunctionCall(Method, TheCall.get())) + return ExprError(); + + return MaybeBindToTemporary(TheCall.release()); +} + +/// 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. +Sema::ExprResult +Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, + SourceLocation LParenLoc, + Expr **Args, unsigned NumArgs, + SourceLocation *CommaLocs, + SourceLocation RParenLoc) { + assert(Object->getType()->isRecordType() && "Requires object type argument"); + const RecordType *Record = Object->getType()->getAs<RecordType>(); + + // 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->getType(), + PDiag(diag::err_incomplete_object_call) + << Object->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->getType(), + Args, NumArgs, CandidateSet, + /*SuppressUserConversions=*/ false); + } + + // C++ [over.call.object]p2: + // In addition, for each 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<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); + for (UnresolvedSetImpl::iterator I = Conversions->begin(), + E = Conversions->end(); I != E; ++I) { + NamedDecl *D = *I; + CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); + if (isa<UsingShadowDecl>(D)) + D = cast<UsingShadowDecl>(D)->getTargetDecl(); + + // Skip over templated conversion functions; they aren't + // surrogates. + if (isa<FunctionTemplateDecl>(D)) + continue; + + CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); + + // 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<PointerType>()) + ConvType = ConvPtrType->getPointeeType(); + + if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) + AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, + Object->getType(), Args, NumArgs, + CandidateSet); + } + + // Perform overload resolution. + OverloadCandidateSet::iterator Best; + switch (BestViableFunction(CandidateSet, Object->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->getSourceRange().getBegin(), diag::err_ovl_no_oper) + << Object->getType() << /*call*/ 1 + << Object->getSourceRange(); + else + Diag(Object->getSourceRange().getBegin(), + diag::err_ovl_no_viable_object_call) + << Object->getType() << Object->getSourceRange(); + PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); + break; + + case OR_Ambiguous: + Diag(Object->getSourceRange().getBegin(), + diag::err_ovl_ambiguous_object_call) + << Object->getType() << Object->getSourceRange(); + PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); + break; + + case OR_Deleted: + Diag(Object->getSourceRange().getBegin(), + diag::err_ovl_deleted_object_call) + << Best->Function->isDeleted() + << Object->getType() << Object->getSourceRange(); + PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); + break; + } + + if (Best == CandidateSet.end()) { + // We had an error; delete all of the subexpressions and return + // the error. + Object->Destroy(Context); + for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) + Args[ArgIdx]->Destroy(Context); + return true; + } + + 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<CXXConversionDecl>( + Best->Conversions[0].UserDefined.ConversionFunction); + + CheckMemberOperatorAccess(LParenLoc, Object, 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. + CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Best->FoundDecl, + Conv); + + return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, + MultiExprArg(*this, (ExprTy**)Args, NumArgs), + CommaLocs, RParenLoc).result(); + } + + CheckMemberOperatorAccess(LParenLoc, Object, 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<CXXMethodDecl>(Best->Function); + const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); + + 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; + for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) + MethodArgs[ArgIdx + 1] = Args[ArgIdx]; + + Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), + SourceLocation()); + UsualUnaryConversions(NewFn); + + // Once we've built TheCall, all of the expressions are properly + // owned. + QualType ResultTy = Method->getResultType().getNonReferenceType(); + ExprOwningPtr<CXXOperatorCallExpr> + TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, + MethodArgs, NumArgs + 1, + ResultTy, RParenLoc)); + delete [] MethodArgs; + + if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), + 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. + IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, + Best->FoundDecl, Method); + TheCall->setArg(0, Object); + + + // Check the argument types. + for (unsigned i = 0; i != NumArgsToCheck; i++) { + Expr *Arg; + if (i < NumArgs) { + Arg = Args[i]; + + // Pass the argument. + + OwningExprResult InputInit + = PerformCopyInitialization(InitializedEntity::InitializeParameter( + Method->getParamDecl(i)), + SourceLocation(), Owned(Arg)); + + IsError |= InputInit.isInvalid(); + Arg = InputInit.takeAs<Expr>(); + } else { + OwningExprResult DefArg + = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); + if (DefArg.isInvalid()) { + IsError = true; + break; + } + + Arg = DefArg.takeAs<Expr>(); + } + + 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++) { + Expr *Arg = Args[i]; + IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod, 0); + TheCall->setArg(i + 1, Arg); + } + } + + if (IsError) return true; + + if (CheckFunctionCall(Method, TheCall.get())) + return true; + + return MaybeBindToTemporary(TheCall.release()).result(); +} + +/// 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. +Sema::OwningExprResult +Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { + Expr *Base = static_cast<Expr *>(BaseIn.get()); + assert(Base->getType()->isRecordType() && "left-hand side must have class type"); + + 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<RecordType>(); + + 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(), 0, 0, CandidateSet, + /*SuppressUserConversions=*/false); + } + + // Perform overload resolution. + OverloadCandidateSet::iterator Best; + switch (BestViableFunction(CandidateSet, 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(); + PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); + return ExprError(); + + case OR_Ambiguous: + Diag(OpLoc, diag::err_ovl_ambiguous_oper) + << "->" << Base->getSourceRange(); + PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); + return ExprError(); + + case OR_Deleted: + Diag(OpLoc, diag::err_ovl_deleted_oper) + << Best->Function->isDeleted() + << "->" << Base->getSourceRange(); + PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); + return ExprError(); + } + + CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); + DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); + + // Convert the object parameter. + CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); + if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, + Best->FoundDecl, Method)) + return ExprError(); + + // No concerns about early exits now. + BaseIn.release(); + + // Build the operator call. + Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), + SourceLocation()); + UsualUnaryConversions(FnExpr); + + QualType ResultTy = Method->getResultType().getNonReferenceType(); + ExprOwningPtr<CXXOperatorCallExpr> + TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, + &Base, 1, ResultTy, OpLoc)); + + if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), + Method)) + return ExprError(); + return move(TheCall); +} + +/// 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<ParenExpr>(E)) { + Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), + Found, Fn); + if (SubExpr == PE->getSubExpr()) + return PE->Retain(); + + return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); + } + + if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { + Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), + Found, Fn); + assert(Context.hasSameType(ICE->getSubExpr()->getType(), + SubExpr->getType()) && + "Implicit cast type cannot be determined from overload"); + if (SubExpr == ICE->getSubExpr()) + return ICE->Retain(); + + return new (Context) ImplicitCastExpr(ICE->getType(), + ICE->getCastKind(), + SubExpr, CXXBaseSpecifierArray(), + ICE->isLvalueCast()); + } + + if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { + assert(UnOp->getOpcode() == UnaryOperator::AddrOf && + "Can only take the address of an overloaded function"); + if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(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->Retain(); + + assert(isa<DeclRefExpr>(SubExpr) + && "fixed to something other than a decl ref"); + assert(cast<DeclRefExpr>(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<RecordDecl>(Method->getDeclContext())); + QualType MemPtrType + = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); + + return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, + MemPtrType, UnOp->getOperatorLoc()); + } + } + Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), + Found, Fn); + if (SubExpr == UnOp->getSubExpr()) + return UnOp->Retain(); + + return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, + Context.getPointerType(SubExpr->getType()), + UnOp->getOperatorLoc()); + } + + if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { + // FIXME: avoid copy. + TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; + if (ULE->hasExplicitTemplateArgs()) { + ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); + TemplateArgs = &TemplateArgsBuffer; + } + + return DeclRefExpr::Create(Context, + ULE->getQualifier(), + ULE->getQualifierRange(), + Fn, + ULE->getNameLoc(), + Fn->getType(), + TemplateArgs); + } + + if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { + // FIXME: avoid copy. + TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; + if (MemExpr->hasExplicitTemplateArgs()) { + MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); + TemplateArgs = &TemplateArgsBuffer; + } + + Expr *Base; + + // If we're filling in + if (MemExpr->isImplicitAccess()) { + if (cast<CXXMethodDecl>(Fn)->isStatic()) { + return DeclRefExpr::Create(Context, + MemExpr->getQualifier(), + MemExpr->getQualifierRange(), + Fn, + MemExpr->getMemberLoc(), + Fn->getType(), + TemplateArgs); + } else { + SourceLocation Loc = MemExpr->getMemberLoc(); + if (MemExpr->getQualifier()) + Loc = MemExpr->getQualifierRange().getBegin(); + Base = new (Context) CXXThisExpr(Loc, + MemExpr->getBaseType(), + /*isImplicit=*/true); + } + } else + Base = MemExpr->getBase()->Retain(); + + return MemberExpr::Create(Context, Base, + MemExpr->isArrow(), + MemExpr->getQualifier(), + MemExpr->getQualifierRange(), + Fn, + Found, + MemExpr->getMemberLoc(), + TemplateArgs, + Fn->getType()); + } + + assert(false && "Invalid reference to overloaded function"); + return E->Retain(); +} + +Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, + DeclAccessPair Found, + FunctionDecl *Fn) { + return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); +} + +} // end namespace clang |
