| //===--- Overload.h - 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 defines the data structures and types used in C++ |
| // overload resolution. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_CLANG_SEMA_OVERLOAD_H |
| #define LLVM_CLANG_SEMA_OVERLOAD_H |
| |
| #include "clang/AST/Decl.h" |
| #include "clang/AST/DeclTemplate.h" |
| #include "clang/AST/Expr.h" |
| #include "clang/AST/TemplateBase.h" |
| #include "clang/AST/Type.h" |
| #include "clang/AST/UnresolvedSet.h" |
| #include "clang/Sema/SemaFixItUtils.h" |
| #include "clang/Sema/TemplateDeduction.h" |
| #include "llvm/ADT/SmallPtrSet.h" |
| #include "llvm/ADT/SmallVector.h" |
| #include "llvm/Support/AlignOf.h" |
| #include "llvm/Support/Allocator.h" |
| |
| namespace clang { |
| class ASTContext; |
| class CXXConstructorDecl; |
| class CXXConversionDecl; |
| class FunctionDecl; |
| class Sema; |
| |
| /// OverloadingResult - Capture the result of performing overload |
| /// resolution. |
| enum OverloadingResult { |
| OR_Success, ///< Overload resolution succeeded. |
| OR_No_Viable_Function, ///< No viable function found. |
| OR_Ambiguous, ///< Ambiguous candidates found. |
| OR_Deleted ///< Succeeded, but refers to a deleted function. |
| }; |
| |
| enum OverloadCandidateDisplayKind { |
| /// Requests that all candidates be shown. Viable candidates will |
| /// be printed first. |
| OCD_AllCandidates, |
| |
| /// Requests that only viable candidates be shown. |
| OCD_ViableCandidates |
| }; |
| |
| /// ImplicitConversionKind - The kind of implicit conversion used to |
| /// convert an argument to a parameter's type. The enumerator values |
| /// match with Table 9 of (C++ 13.3.3.1.1) and are listed such that |
| /// better conversion kinds have smaller values. |
| enum ImplicitConversionKind { |
| ICK_Identity = 0, ///< Identity conversion (no conversion) |
| ICK_Lvalue_To_Rvalue, ///< Lvalue-to-rvalue conversion (C++ 4.1) |
| ICK_Array_To_Pointer, ///< Array-to-pointer conversion (C++ 4.2) |
| ICK_Function_To_Pointer, ///< Function-to-pointer (C++ 4.3) |
| ICK_Function_Conversion, ///< Function pointer conversion (C++17 4.13) |
| ICK_Qualification, ///< Qualification conversions (C++ 4.4) |
| ICK_Integral_Promotion, ///< Integral promotions (C++ 4.5) |
| ICK_Floating_Promotion, ///< Floating point promotions (C++ 4.6) |
| ICK_Complex_Promotion, ///< Complex promotions (Clang extension) |
| ICK_Integral_Conversion, ///< Integral conversions (C++ 4.7) |
| ICK_Floating_Conversion, ///< Floating point conversions (C++ 4.8) |
| ICK_Complex_Conversion, ///< Complex conversions (C99 6.3.1.6) |
| ICK_Floating_Integral, ///< Floating-integral conversions (C++ 4.9) |
| ICK_Pointer_Conversion, ///< Pointer conversions (C++ 4.10) |
| ICK_Pointer_Member, ///< Pointer-to-member conversions (C++ 4.11) |
| ICK_Boolean_Conversion, ///< Boolean conversions (C++ 4.12) |
| ICK_Compatible_Conversion, ///< Conversions between compatible types in C99 |
| ICK_Derived_To_Base, ///< Derived-to-base (C++ [over.best.ics]) |
| ICK_Vector_Conversion, ///< Vector conversions |
| ICK_Vector_Splat, ///< A vector splat from an arithmetic type |
| ICK_Complex_Real, ///< Complex-real conversions (C99 6.3.1.7) |
| ICK_Block_Pointer_Conversion, ///< Block Pointer conversions |
| ICK_TransparentUnionConversion, ///< Transparent Union Conversions |
| ICK_Writeback_Conversion, ///< Objective-C ARC writeback conversion |
| ICK_Zero_Event_Conversion, ///< Zero constant to event (OpenCL1.2 6.12.10) |
| ICK_Zero_Queue_Conversion, ///< Zero constant to queue |
| ICK_C_Only_Conversion, ///< Conversions allowed in C, but not C++ |
| ICK_Incompatible_Pointer_Conversion, ///< C-only conversion between pointers |
| /// with incompatible types |
| ICK_Num_Conversion_Kinds, ///< The number of conversion kinds |
| }; |
| |
| /// ImplicitConversionRank - The rank of an implicit conversion |
| /// kind. The enumerator values match with Table 9 of (C++ |
| /// 13.3.3.1.1) and are listed such that better conversion ranks |
| /// have smaller values. |
| enum ImplicitConversionRank { |
| ICR_Exact_Match = 0, ///< Exact Match |
| ICR_Promotion, ///< Promotion |
| ICR_Conversion, ///< Conversion |
| ICR_OCL_Scalar_Widening, ///< OpenCL Scalar Widening |
| ICR_Complex_Real_Conversion, ///< Complex <-> Real conversion |
| ICR_Writeback_Conversion, ///< ObjC ARC writeback conversion |
| ICR_C_Conversion, ///< Conversion only allowed in the C standard. |
| /// (e.g. void* to char*) |
| ICR_C_Conversion_Extension ///< Conversion not allowed by the C standard, |
| /// but that we accept as an extension anyway. |
| }; |
| |
| ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind); |
| |
| /// NarrowingKind - The kind of narrowing conversion being performed by a |
| /// standard conversion sequence according to C++11 [dcl.init.list]p7. |
| enum NarrowingKind { |
| /// Not a narrowing conversion. |
| NK_Not_Narrowing, |
| |
| /// A narrowing conversion by virtue of the source and destination types. |
| NK_Type_Narrowing, |
| |
| /// A narrowing conversion, because a constant expression got narrowed. |
| NK_Constant_Narrowing, |
| |
| /// A narrowing conversion, because a non-constant-expression variable might |
| /// have got narrowed. |
| NK_Variable_Narrowing, |
| |
| /// Cannot tell whether this is a narrowing conversion because the |
| /// expression is value-dependent. |
| NK_Dependent_Narrowing, |
| }; |
| |
| /// StandardConversionSequence - represents a standard conversion |
| /// sequence (C++ 13.3.3.1.1). A standard conversion sequence |
| /// contains between zero and three conversions. If a particular |
| /// conversion is not needed, it will be set to the identity conversion |
| /// (ICK_Identity). Note that the three conversions are |
| /// specified as separate members (rather than in an array) so that |
| /// we can keep the size of a standard conversion sequence to a |
| /// single word. |
| class StandardConversionSequence { |
| public: |
| /// First -- The first conversion can be an lvalue-to-rvalue |
| /// conversion, array-to-pointer conversion, or |
| /// function-to-pointer conversion. |
| ImplicitConversionKind First : 8; |
| |
| /// Second - 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. |
| ImplicitConversionKind Second : 8; |
| |
| /// Third - The third conversion can be a qualification conversion |
| /// or a function conversion. |
| ImplicitConversionKind Third : 8; |
| |
| /// \brief Whether this is the deprecated conversion of a |
| /// string literal to a pointer to non-const character data |
| /// (C++ 4.2p2). |
| unsigned DeprecatedStringLiteralToCharPtr : 1; |
| |
| /// \brief Whether the qualification conversion involves a change in the |
| /// Objective-C lifetime (for automatic reference counting). |
| unsigned QualificationIncludesObjCLifetime : 1; |
| |
| /// IncompatibleObjC - Whether this is an Objective-C conversion |
| /// that we should warn about (if we actually use it). |
| unsigned IncompatibleObjC : 1; |
| |
| /// ReferenceBinding - True when this is a reference binding |
| /// (C++ [over.ics.ref]). |
| unsigned ReferenceBinding : 1; |
| |
| /// DirectBinding - True when this is a reference binding that is a |
| /// direct binding (C++ [dcl.init.ref]). |
| unsigned DirectBinding : 1; |
| |
| /// \brief Whether this is an lvalue reference binding (otherwise, it's |
| /// an rvalue reference binding). |
| unsigned IsLvalueReference : 1; |
| |
| /// \brief Whether we're binding to a function lvalue. |
| unsigned BindsToFunctionLvalue : 1; |
| |
| /// \brief Whether we're binding to an rvalue. |
| unsigned BindsToRvalue : 1; |
| |
| /// \brief Whether this binds an implicit object argument to a |
| /// non-static member function without a ref-qualifier. |
| unsigned BindsImplicitObjectArgumentWithoutRefQualifier : 1; |
| |
| /// \brief Whether this binds a reference to an object with a different |
| /// Objective-C lifetime qualifier. |
| unsigned ObjCLifetimeConversionBinding : 1; |
| |
| /// FromType - The type that this conversion is converting |
| /// from. This is an opaque pointer that can be translated into a |
| /// QualType. |
| void *FromTypePtr; |
| |
| /// ToType - The types that this conversion is converting to in |
| /// each step. This is an opaque pointer that can be translated |
| /// into a QualType. |
| void *ToTypePtrs[3]; |
| |
| /// CopyConstructor - The copy constructor that is used to perform |
| /// this conversion, when the conversion is actually just the |
| /// initialization of an object via copy constructor. Such |
| /// conversions are either identity conversions or derived-to-base |
| /// conversions. |
| CXXConstructorDecl *CopyConstructor; |
| DeclAccessPair FoundCopyConstructor; |
| |
| void setFromType(QualType T) { FromTypePtr = T.getAsOpaquePtr(); } |
| void setToType(unsigned Idx, QualType T) { |
| assert(Idx < 3 && "To type index is out of range"); |
| ToTypePtrs[Idx] = T.getAsOpaquePtr(); |
| } |
| void setAllToTypes(QualType T) { |
| ToTypePtrs[0] = T.getAsOpaquePtr(); |
| ToTypePtrs[1] = ToTypePtrs[0]; |
| ToTypePtrs[2] = ToTypePtrs[0]; |
| } |
| |
| QualType getFromType() const { |
| return QualType::getFromOpaquePtr(FromTypePtr); |
| } |
| QualType getToType(unsigned Idx) const { |
| assert(Idx < 3 && "To type index is out of range"); |
| return QualType::getFromOpaquePtr(ToTypePtrs[Idx]); |
| } |
| |
| void setAsIdentityConversion(); |
| |
| bool isIdentityConversion() const { |
| return Second == ICK_Identity && Third == ICK_Identity; |
| } |
| |
| ImplicitConversionRank getRank() const; |
| NarrowingKind getNarrowingKind(ASTContext &Context, const Expr *Converted, |
| APValue &ConstantValue, |
| QualType &ConstantType) const; |
| bool isPointerConversionToBool() const; |
| bool isPointerConversionToVoidPointer(ASTContext& Context) const; |
| void dump() const; |
| }; |
| |
| /// UserDefinedConversionSequence - Represents a user-defined |
| /// conversion sequence (C++ 13.3.3.1.2). |
| struct UserDefinedConversionSequence { |
| /// \brief Represents the standard conversion that occurs before |
| /// the actual user-defined conversion. |
| /// |
| /// C++11 13.3.3.1.2p1: |
| /// 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. 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. |
| StandardConversionSequence Before; |
| |
| /// EllipsisConversion - When this is true, it means user-defined |
| /// conversion sequence starts with a ... (ellipsis) conversion, instead of |
| /// a standard conversion. In this case, 'Before' field must be ignored. |
| // FIXME. I much rather put this as the first field. But there seems to be |
| // a gcc code gen. bug which causes a crash in a test. Putting it here seems |
| // to work around the crash. |
| bool EllipsisConversion : 1; |
| |
| /// HadMultipleCandidates - When this is true, it means that the |
| /// conversion function was resolved from an overloaded set having |
| /// size greater than 1. |
| bool HadMultipleCandidates : 1; |
| |
| /// After - Represents the standard conversion that occurs after |
| /// the actual user-defined conversion. |
| StandardConversionSequence After; |
| |
| /// ConversionFunction - The function that will perform the |
| /// user-defined conversion. Null if the conversion is an |
| /// aggregate initialization from an initializer list. |
| FunctionDecl* ConversionFunction; |
| |
| /// \brief The declaration that we found via name lookup, which might be |
| /// the same as \c ConversionFunction or it might be a using declaration |
| /// that refers to \c ConversionFunction. |
| DeclAccessPair FoundConversionFunction; |
| |
| void dump() const; |
| }; |
| |
| /// Represents an ambiguous user-defined conversion sequence. |
| struct AmbiguousConversionSequence { |
| typedef SmallVector<std::pair<NamedDecl*, FunctionDecl*>, 4> ConversionSet; |
| |
| void *FromTypePtr; |
| void *ToTypePtr; |
| char Buffer[sizeof(ConversionSet)]; |
| |
| QualType getFromType() const { |
| return QualType::getFromOpaquePtr(FromTypePtr); |
| } |
| QualType getToType() const { |
| return QualType::getFromOpaquePtr(ToTypePtr); |
| } |
| void setFromType(QualType T) { FromTypePtr = T.getAsOpaquePtr(); } |
| void setToType(QualType T) { ToTypePtr = T.getAsOpaquePtr(); } |
| |
| ConversionSet &conversions() { |
| return *reinterpret_cast<ConversionSet*>(Buffer); |
| } |
| |
| const ConversionSet &conversions() const { |
| return *reinterpret_cast<const ConversionSet*>(Buffer); |
| } |
| |
| void addConversion(NamedDecl *Found, FunctionDecl *D) { |
| conversions().push_back(std::make_pair(Found, D)); |
| } |
| |
| typedef ConversionSet::iterator iterator; |
| iterator begin() { return conversions().begin(); } |
| iterator end() { return conversions().end(); } |
| |
| typedef ConversionSet::const_iterator const_iterator; |
| const_iterator begin() const { return conversions().begin(); } |
| const_iterator end() const { return conversions().end(); } |
| |
| void construct(); |
| void destruct(); |
| void copyFrom(const AmbiguousConversionSequence &); |
| }; |
| |
| /// BadConversionSequence - Records information about an invalid |
| /// conversion sequence. |
| struct BadConversionSequence { |
| enum FailureKind { |
| no_conversion, |
| unrelated_class, |
| bad_qualifiers, |
| lvalue_ref_to_rvalue, |
| rvalue_ref_to_lvalue |
| }; |
| |
| // This can be null, e.g. for implicit object arguments. |
| Expr *FromExpr; |
| |
| FailureKind Kind; |
| |
| private: |
| // The type we're converting from (an opaque QualType). |
| void *FromTy; |
| |
| // The type we're converting to (an opaque QualType). |
| void *ToTy; |
| |
| public: |
| void init(FailureKind K, Expr *From, QualType To) { |
| init(K, From->getType(), To); |
| FromExpr = From; |
| } |
| void init(FailureKind K, QualType From, QualType To) { |
| Kind = K; |
| FromExpr = nullptr; |
| setFromType(From); |
| setToType(To); |
| } |
| |
| QualType getFromType() const { return QualType::getFromOpaquePtr(FromTy); } |
| QualType getToType() const { return QualType::getFromOpaquePtr(ToTy); } |
| |
| void setFromExpr(Expr *E) { |
| FromExpr = E; |
| setFromType(E->getType()); |
| } |
| void setFromType(QualType T) { FromTy = T.getAsOpaquePtr(); } |
| void setToType(QualType T) { ToTy = T.getAsOpaquePtr(); } |
| }; |
| |
| /// ImplicitConversionSequence - Represents an implicit conversion |
| /// sequence, which may be a standard conversion sequence |
| /// (C++ 13.3.3.1.1), user-defined conversion sequence (C++ 13.3.3.1.2), |
| /// or an ellipsis conversion sequence (C++ 13.3.3.1.3). |
| class ImplicitConversionSequence { |
| public: |
| /// Kind - The kind of implicit conversion sequence. BadConversion |
| /// specifies that there is no conversion from the source type to |
| /// the target type. AmbiguousConversion represents the unique |
| /// ambiguous conversion (C++0x [over.best.ics]p10). |
| enum Kind { |
| StandardConversion = 0, |
| UserDefinedConversion, |
| AmbiguousConversion, |
| EllipsisConversion, |
| BadConversion |
| }; |
| |
| private: |
| enum { |
| Uninitialized = BadConversion + 1 |
| }; |
| |
| /// ConversionKind - The kind of implicit conversion sequence. |
| unsigned ConversionKind : 30; |
| |
| /// \brief Whether the target is really a std::initializer_list, and the |
| /// sequence only represents the worst element conversion. |
| unsigned StdInitializerListElement : 1; |
| |
| void setKind(Kind K) { |
| destruct(); |
| ConversionKind = K; |
| } |
| |
| void destruct() { |
| if (ConversionKind == AmbiguousConversion) Ambiguous.destruct(); |
| } |
| |
| public: |
| union { |
| /// When ConversionKind == StandardConversion, provides the |
| /// details of the standard conversion sequence. |
| StandardConversionSequence Standard; |
| |
| /// When ConversionKind == UserDefinedConversion, provides the |
| /// details of the user-defined conversion sequence. |
| UserDefinedConversionSequence UserDefined; |
| |
| /// When ConversionKind == AmbiguousConversion, provides the |
| /// details of the ambiguous conversion. |
| AmbiguousConversionSequence Ambiguous; |
| |
| /// When ConversionKind == BadConversion, provides the details |
| /// of the bad conversion. |
| BadConversionSequence Bad; |
| }; |
| |
| ImplicitConversionSequence() |
| : ConversionKind(Uninitialized), StdInitializerListElement(false) { |
| Standard.setAsIdentityConversion(); |
| } |
| ~ImplicitConversionSequence() { |
| destruct(); |
| } |
| ImplicitConversionSequence(const ImplicitConversionSequence &Other) |
| : ConversionKind(Other.ConversionKind), |
| StdInitializerListElement(Other.StdInitializerListElement) |
| { |
| switch (ConversionKind) { |
| case Uninitialized: break; |
| case StandardConversion: Standard = Other.Standard; break; |
| case UserDefinedConversion: UserDefined = Other.UserDefined; break; |
| case AmbiguousConversion: Ambiguous.copyFrom(Other.Ambiguous); break; |
| case EllipsisConversion: break; |
| case BadConversion: Bad = Other.Bad; break; |
| } |
| } |
| |
| ImplicitConversionSequence & |
| operator=(const ImplicitConversionSequence &Other) { |
| destruct(); |
| new (this) ImplicitConversionSequence(Other); |
| return *this; |
| } |
| |
| Kind getKind() const { |
| assert(isInitialized() && "querying uninitialized conversion"); |
| return Kind(ConversionKind); |
| } |
| |
| /// \brief Return a ranking of the implicit conversion sequence |
| /// kind, where smaller ranks represent better conversion |
| /// sequences. |
| /// |
| /// In particular, this routine gives user-defined conversion |
| /// sequences and ambiguous conversion sequences the same rank, |
| /// per C++ [over.best.ics]p10. |
| unsigned getKindRank() const { |
| switch (getKind()) { |
| case StandardConversion: |
| return 0; |
| |
| case UserDefinedConversion: |
| case AmbiguousConversion: |
| return 1; |
| |
| case EllipsisConversion: |
| return 2; |
| |
| case BadConversion: |
| return 3; |
| } |
| |
| llvm_unreachable("Invalid ImplicitConversionSequence::Kind!"); |
| } |
| |
| bool isBad() const { return getKind() == BadConversion; } |
| bool isStandard() const { return getKind() == StandardConversion; } |
| bool isEllipsis() const { return getKind() == EllipsisConversion; } |
| bool isAmbiguous() const { return getKind() == AmbiguousConversion; } |
| bool isUserDefined() const { return getKind() == UserDefinedConversion; } |
| bool isFailure() const { return isBad() || isAmbiguous(); } |
| |
| /// Determines whether this conversion sequence has been |
| /// initialized. Most operations should never need to query |
| /// uninitialized conversions and should assert as above. |
| bool isInitialized() const { return ConversionKind != Uninitialized; } |
| |
| /// Sets this sequence as a bad conversion for an explicit argument. |
| void setBad(BadConversionSequence::FailureKind Failure, |
| Expr *FromExpr, QualType ToType) { |
| setKind(BadConversion); |
| Bad.init(Failure, FromExpr, ToType); |
| } |
| |
| /// Sets this sequence as a bad conversion for an implicit argument. |
| void setBad(BadConversionSequence::FailureKind Failure, |
| QualType FromType, QualType ToType) { |
| setKind(BadConversion); |
| Bad.init(Failure, FromType, ToType); |
| } |
| |
| void setStandard() { setKind(StandardConversion); } |
| void setEllipsis() { setKind(EllipsisConversion); } |
| void setUserDefined() { setKind(UserDefinedConversion); } |
| void setAmbiguous() { |
| if (ConversionKind == AmbiguousConversion) return; |
| ConversionKind = AmbiguousConversion; |
| Ambiguous.construct(); |
| } |
| |
| void setAsIdentityConversion(QualType T) { |
| setStandard(); |
| Standard.setAsIdentityConversion(); |
| Standard.setFromType(T); |
| Standard.setAllToTypes(T); |
| } |
| |
| /// \brief Whether the target is really a std::initializer_list, and the |
| /// sequence only represents the worst element conversion. |
| bool isStdInitializerListElement() const { |
| return StdInitializerListElement; |
| } |
| |
| void setStdInitializerListElement(bool V = true) { |
| StdInitializerListElement = V; |
| } |
| |
| // The result of a comparison between implicit conversion |
| // sequences. Use Sema::CompareImplicitConversionSequences to |
| // actually perform the comparison. |
| enum CompareKind { |
| Better = -1, |
| Indistinguishable = 0, |
| Worse = 1 |
| }; |
| |
| void DiagnoseAmbiguousConversion(Sema &S, |
| SourceLocation CaretLoc, |
| const PartialDiagnostic &PDiag) const; |
| |
| void dump() const; |
| }; |
| |
| enum OverloadFailureKind { |
| ovl_fail_too_many_arguments, |
| ovl_fail_too_few_arguments, |
| ovl_fail_bad_conversion, |
| ovl_fail_bad_deduction, |
| |
| /// This conversion candidate was not considered because it |
| /// duplicates the work of a trivial or derived-to-base |
| /// conversion. |
| ovl_fail_trivial_conversion, |
| |
| /// This conversion candidate was not considered because it is |
| /// an illegal instantiation of a constructor temploid: it is |
| /// callable with one argument, we only have one argument, and |
| /// its first parameter type is exactly the type of the class. |
| /// |
| /// Defining such a constructor directly is illegal, and |
| /// template-argument deduction is supposed to ignore such |
| /// instantiations, but we can still get one with the right |
| /// kind of implicit instantiation. |
| ovl_fail_illegal_constructor, |
| |
| /// This conversion candidate is not viable because its result |
| /// type is not implicitly convertible to the desired type. |
| ovl_fail_bad_final_conversion, |
| |
| /// This conversion function template specialization candidate is not |
| /// viable because the final conversion was not an exact match. |
| ovl_fail_final_conversion_not_exact, |
| |
| /// (CUDA) This candidate was not viable because the callee |
| /// was not accessible from the caller's target (i.e. host->device, |
| /// global->host, device->host). |
| ovl_fail_bad_target, |
| |
| /// This candidate function was not viable because an enable_if |
| /// attribute disabled it. |
| ovl_fail_enable_if, |
| |
| /// This candidate was not viable because its address could not be taken. |
| ovl_fail_addr_not_available, |
| |
| /// This candidate was not viable because its OpenCL extension is disabled. |
| ovl_fail_ext_disabled, |
| |
| /// This inherited constructor is not viable because it would slice the |
| /// argument. |
| ovl_fail_inhctor_slice, |
| }; |
| |
| /// A list of implicit conversion sequences for the arguments of an |
| /// OverloadCandidate. |
| typedef llvm::MutableArrayRef<ImplicitConversionSequence> |
| ConversionSequenceList; |
| |
| /// OverloadCandidate - A single candidate in an overload set (C++ 13.3). |
| struct OverloadCandidate { |
| /// Function - The actual function that this candidate |
| /// represents. When NULL, this is a built-in candidate |
| /// (C++ [over.oper]) or a surrogate for a conversion to a |
| /// function pointer or reference (C++ [over.call.object]). |
| FunctionDecl *Function; |
| |
| /// FoundDecl - The original declaration that was looked up / |
| /// invented / otherwise found, together with its access. |
| /// Might be a UsingShadowDecl or a FunctionTemplateDecl. |
| DeclAccessPair FoundDecl; |
| |
| /// BuiltinParamTypes - Provides the parameter types of a built-in overload |
| /// candidate. Only valid when Function is NULL. |
| QualType BuiltinParamTypes[3]; |
| |
| /// Surrogate - The conversion function for which this candidate |
| /// is a surrogate, but only if IsSurrogate is true. |
| CXXConversionDecl *Surrogate; |
| |
| /// The conversion sequences used to convert the function arguments |
| /// to the function parameters. |
| ConversionSequenceList Conversions; |
| |
| /// The FixIt hints which can be used to fix the Bad candidate. |
| ConversionFixItGenerator Fix; |
| |
| /// Viable - True to indicate that this overload candidate is viable. |
| bool Viable; |
| |
| /// IsSurrogate - True to indicate that this candidate is a |
| /// surrogate for a conversion to a function pointer or reference |
| /// (C++ [over.call.object]). |
| bool IsSurrogate; |
| |
| /// IgnoreObjectArgument - True to indicate that the first |
| /// argument's conversion, which for this function represents the |
| /// implicit object argument, should be ignored. This will be true |
| /// when the candidate is a static member function (where the |
| /// implicit object argument is just a placeholder) or a |
| /// non-static member function when the call doesn't have an |
| /// object argument. |
| bool IgnoreObjectArgument; |
| |
| /// FailureKind - The reason why this candidate is not viable. |
| /// Actually an OverloadFailureKind. |
| unsigned char FailureKind; |
| |
| /// \brief The number of call arguments that were explicitly provided, |
| /// to be used while performing partial ordering of function templates. |
| unsigned ExplicitCallArguments; |
| |
| union { |
| DeductionFailureInfo DeductionFailure; |
| |
| /// FinalConversion - For a conversion function (where Function is |
| /// a CXXConversionDecl), the standard conversion that occurs |
| /// after the call to the overload candidate to convert the result |
| /// of calling the conversion function to the required type. |
| StandardConversionSequence FinalConversion; |
| }; |
| |
| /// hasAmbiguousConversion - Returns whether this overload |
| /// candidate requires an ambiguous conversion or not. |
| bool hasAmbiguousConversion() const { |
| for (auto &C : Conversions) { |
| if (!C.isInitialized()) return false; |
| if (C.isAmbiguous()) return true; |
| } |
| return false; |
| } |
| |
| bool TryToFixBadConversion(unsigned Idx, Sema &S) { |
| bool CanFix = Fix.tryToFixConversion( |
| Conversions[Idx].Bad.FromExpr, |
| Conversions[Idx].Bad.getFromType(), |
| Conversions[Idx].Bad.getToType(), S); |
| |
| // If at least one conversion fails, the candidate cannot be fixed. |
| if (!CanFix) |
| Fix.clear(); |
| |
| return CanFix; |
| } |
| |
| unsigned getNumParams() const { |
| if (IsSurrogate) { |
| auto STy = Surrogate->getConversionType(); |
| while (STy->isPointerType() || STy->isReferenceType()) |
| STy = STy->getPointeeType(); |
| return STy->getAs<FunctionProtoType>()->getNumParams(); |
| } |
| if (Function) |
| return Function->getNumParams(); |
| return ExplicitCallArguments; |
| } |
| }; |
| |
| /// OverloadCandidateSet - A set of overload candidates, used in C++ |
| /// overload resolution (C++ 13.3). |
| class OverloadCandidateSet { |
| public: |
| enum CandidateSetKind { |
| /// Normal lookup. |
| CSK_Normal, |
| /// C++ [over.match.oper]: |
| /// Lookup of operator function candidates in a call using operator |
| /// syntax. Candidates that have no parameters of class type will be |
| /// skipped unless there is a parameter of (reference to) enum type and |
| /// the corresponding argument is of the same enum type. |
| CSK_Operator, |
| /// C++ [over.match.copy]: |
| /// Copy-initialization of an object of class type by user-defined |
| /// conversion. |
| CSK_InitByUserDefinedConversion, |
| /// C++ [over.match.ctor], [over.match.list] |
| /// Initialization of an object of class type by constructor, |
| /// using either a parenthesized or braced list of arguments. |
| CSK_InitByConstructor, |
| }; |
| |
| private: |
| SmallVector<OverloadCandidate, 16> Candidates; |
| llvm::SmallPtrSet<Decl *, 16> Functions; |
| |
| // Allocator for ConversionSequenceLists. We store the first few of these |
| // inline to avoid allocation for small sets. |
| llvm::BumpPtrAllocator SlabAllocator; |
| |
| SourceLocation Loc; |
| CandidateSetKind Kind; |
| |
| constexpr static unsigned NumInlineBytes = |
| 24 * sizeof(ImplicitConversionSequence); |
| unsigned NumInlineBytesUsed; |
| llvm::AlignedCharArray<alignof(void *), NumInlineBytes> InlineSpace; |
| |
| /// If we have space, allocates from inline storage. Otherwise, allocates |
| /// from the slab allocator. |
| /// FIXME: It would probably be nice to have a SmallBumpPtrAllocator |
| /// instead. |
| /// FIXME: Now that this only allocates ImplicitConversionSequences, do we |
| /// want to un-generalize this? |
| template <typename T> |
| T *slabAllocate(unsigned N) { |
| // It's simpler if this doesn't need to consider alignment. |
| static_assert(alignof(T) == alignof(void *), |
| "Only works for pointer-aligned types."); |
| static_assert(std::is_trivial<T>::value || |
| std::is_same<ImplicitConversionSequence, T>::value, |
| "Add destruction logic to OverloadCandidateSet::clear()."); |
| |
| unsigned NBytes = sizeof(T) * N; |
| if (NBytes > NumInlineBytes - NumInlineBytesUsed) |
| return SlabAllocator.Allocate<T>(N); |
| char *FreeSpaceStart = InlineSpace.buffer + NumInlineBytesUsed; |
| assert(uintptr_t(FreeSpaceStart) % alignof(void *) == 0 && |
| "Misaligned storage!"); |
| |
| NumInlineBytesUsed += NBytes; |
| return reinterpret_cast<T *>(FreeSpaceStart); |
| } |
| |
| OverloadCandidateSet(const OverloadCandidateSet &) = delete; |
| void operator=(const OverloadCandidateSet &) = delete; |
| |
| void destroyCandidates(); |
| |
| public: |
| OverloadCandidateSet(SourceLocation Loc, CandidateSetKind CSK) |
| : Loc(Loc), Kind(CSK), NumInlineBytesUsed(0) {} |
| ~OverloadCandidateSet() { destroyCandidates(); } |
| |
| SourceLocation getLocation() const { return Loc; } |
| CandidateSetKind getKind() const { return Kind; } |
| |
| /// \brief Determine when this overload candidate will be new to the |
| /// overload set. |
| bool isNewCandidate(Decl *F) { |
| return Functions.insert(F->getCanonicalDecl()).second; |
| } |
| |
| /// \brief Clear out all of the candidates. |
| void clear(CandidateSetKind CSK); |
| |
| typedef SmallVectorImpl<OverloadCandidate>::iterator iterator; |
| iterator begin() { return Candidates.begin(); } |
| iterator end() { return Candidates.end(); } |
| |
| size_t size() const { return Candidates.size(); } |
| bool empty() const { return Candidates.empty(); } |
| |
| /// \brief Allocate storage for conversion sequences for NumConversions |
| /// conversions. |
| ConversionSequenceList |
| allocateConversionSequences(unsigned NumConversions) { |
| ImplicitConversionSequence *Conversions = |
| slabAllocate<ImplicitConversionSequence>(NumConversions); |
| |
| // Construct the new objects. |
| for (unsigned I = 0; I != NumConversions; ++I) |
| new (&Conversions[I]) ImplicitConversionSequence(); |
| |
| return ConversionSequenceList(Conversions, NumConversions); |
| } |
| |
| /// \brief Add a new candidate with NumConversions conversion sequence slots |
| /// to the overload set. |
| OverloadCandidate &addCandidate(unsigned NumConversions = 0, |
| ConversionSequenceList Conversions = None) { |
| assert((Conversions.empty() || Conversions.size() == NumConversions) && |
| "preallocated conversion sequence has wrong length"); |
| |
| Candidates.push_back(OverloadCandidate()); |
| OverloadCandidate &C = Candidates.back(); |
| C.Conversions = Conversions.empty() |
| ? allocateConversionSequences(NumConversions) |
| : Conversions; |
| return C; |
| } |
| |
| /// Find the best viable function on this overload set, if it exists. |
| OverloadingResult BestViableFunction(Sema &S, SourceLocation Loc, |
| OverloadCandidateSet::iterator& Best); |
| |
| void NoteCandidates(Sema &S, |
| OverloadCandidateDisplayKind OCD, |
| ArrayRef<Expr *> Args, |
| StringRef Opc = "", |
| SourceLocation Loc = SourceLocation(), |
| llvm::function_ref<bool(OverloadCandidate&)> Filter = |
| [](OverloadCandidate&) { return true; }); |
| }; |
| |
| bool isBetterOverloadCandidate(Sema &S, |
| const OverloadCandidate &Cand1, |
| const OverloadCandidate &Cand2, |
| SourceLocation Loc, |
| OverloadCandidateSet::CandidateSetKind Kind); |
| |
| struct ConstructorInfo { |
| DeclAccessPair FoundDecl; |
| CXXConstructorDecl *Constructor; |
| FunctionTemplateDecl *ConstructorTmpl; |
| explicit operator bool() const { return Constructor; } |
| }; |
| // FIXME: Add an AddOverloadCandidate / AddTemplateOverloadCandidate overload |
| // that takes one of these. |
| inline ConstructorInfo getConstructorInfo(NamedDecl *ND) { |
| if (isa<UsingDecl>(ND)) |
| return ConstructorInfo{}; |
| |
| // For constructors, the access check is performed against the underlying |
| // declaration, not the found declaration. |
| auto *D = ND->getUnderlyingDecl(); |
| ConstructorInfo Info = {DeclAccessPair::make(ND, D->getAccess()), nullptr, |
| nullptr}; |
| Info.ConstructorTmpl = dyn_cast<FunctionTemplateDecl>(D); |
| if (Info.ConstructorTmpl) |
| D = Info.ConstructorTmpl->getTemplatedDecl(); |
| Info.Constructor = dyn_cast<CXXConstructorDecl>(D); |
| return Info; |
| } |
| } // end namespace clang |
| |
| #endif // LLVM_CLANG_SEMA_OVERLOAD_H |
