| //===--- 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 "SemaInherit.h" |
| #include "clang/Basic/Diagnostic.h" |
| #include "clang/Lex/Preprocessor.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/AST/Expr.h" |
| #include "clang/AST/TypeOrdering.h" |
| #include "llvm/ADT/SmallPtrSet.h" |
| #include "llvm/Support/Compiler.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_Qualification_Adjustment, |
| ICC_Promotion, |
| ICC_Promotion, |
| 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_Promotion, |
| ICR_Promotion, |
| ICR_Conversion, |
| ICR_Conversion, |
| ICR_Conversion, |
| ICR_Conversion, |
| ICR_Conversion, |
| ICR_Conversion, |
| ICR_Conversion |
| }; |
| return Rank[(int)Kind]; |
| } |
| |
| /// GetImplicitConversionName - Return the name of this kind of |
| /// implicit conversion. |
| const char* GetImplicitConversionName(ImplicitConversionKind Kind) { |
| static const char* Name[(int)ICK_Num_Conversion_Kinds] = { |
| "No conversion", |
| "Lvalue-to-rvalue", |
| "Array-to-pointer", |
| "Function-to-pointer", |
| "Qualification", |
| "Integral promotion", |
| "Floating point promotion", |
| "Integral conversion", |
| "Floating conversion", |
| "Floating-integral conversion", |
| "Pointer conversion", |
| "Pointer-to-member conversion", |
| "Boolean conversion", |
| "Derived-to-base 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; |
| Deprecated = false; |
| ReferenceBinding = false; |
| DirectBinding = 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 |
| { |
| QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); |
| QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); |
| |
| // 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 (ToType->isBooleanType() && |
| (FromType->isPointerType() || |
| 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 = QualType::getFromOpaquePtr(FromTypePtr); |
| QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); |
| |
| // 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) |
| if (const PointerType* ToPtrType = ToType->getAsPointerType()) |
| return ToPtrType->getPointeeType()->isVoidType(); |
| |
| return false; |
| } |
| |
| /// DebugPrint - Print this standard conversion sequence to standard |
| /// error. Useful for debugging overloading issues. |
| void StandardConversionSequence::DebugPrint() const { |
| bool PrintedSomething = false; |
| if (First != ICK_Identity) { |
| fprintf(stderr, "%s", GetImplicitConversionName(First)); |
| PrintedSomething = true; |
| } |
| |
| if (Second != ICK_Identity) { |
| if (PrintedSomething) { |
| fprintf(stderr, " -> "); |
| } |
| fprintf(stderr, "%s", GetImplicitConversionName(Second)); |
| |
| if (CopyConstructor) { |
| fprintf(stderr, " (by copy constructor)"); |
| } else if (DirectBinding) { |
| fprintf(stderr, " (direct reference binding)"); |
| } else if (ReferenceBinding) { |
| fprintf(stderr, " (reference binding)"); |
| } |
| PrintedSomething = true; |
| } |
| |
| if (Third != ICK_Identity) { |
| if (PrintedSomething) { |
| fprintf(stderr, " -> "); |
| } |
| fprintf(stderr, "%s", GetImplicitConversionName(Third)); |
| PrintedSomething = true; |
| } |
| |
| if (!PrintedSomething) { |
| fprintf(stderr, "No conversions required"); |
| } |
| } |
| |
| /// DebugPrint - Print this user-defined conversion sequence to standard |
| /// error. Useful for debugging overloading issues. |
| void UserDefinedConversionSequence::DebugPrint() const { |
| if (Before.First || Before.Second || Before.Third) { |
| Before.DebugPrint(); |
| fprintf(stderr, " -> "); |
| } |
| fprintf(stderr, "'%s'", ConversionFunction->getName().c_str()); |
| if (After.First || After.Second || After.Third) { |
| fprintf(stderr, " -> "); |
| After.DebugPrint(); |
| } |
| } |
| |
| /// DebugPrint - Print this implicit conversion sequence to standard |
| /// error. Useful for debugging overloading issues. |
| void ImplicitConversionSequence::DebugPrint() const { |
| switch (ConversionKind) { |
| case StandardConversion: |
| fprintf(stderr, "Standard conversion: "); |
| Standard.DebugPrint(); |
| break; |
| case UserDefinedConversion: |
| fprintf(stderr, "User-defined conversion: "); |
| UserDefined.DebugPrint(); |
| break; |
| case EllipsisConversion: |
| fprintf(stderr, "Ellipsis conversion"); |
| break; |
| case BadConversion: |
| fprintf(stderr, "Bad conversion"); |
| break; |
| } |
| |
| fprintf(stderr, "\n"); |
| } |
| |
| // IsOverload - Determine whether the given New declaration is an |
| // overload of the Old declaration. This routine returns false if New |
| // and Old cannot be overloaded, e.g., if they are functions with the |
| // same signature (C++ 1.3.10) or if the Old declaration isn't a |
| // function (or overload set). When it does return false and Old is an |
| // OverloadedFunctionDecl, MatchedDecl will be set to point to the |
| // FunctionDecl that New cannot be overloaded with. |
| // |
| // 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 is a 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 OverloadedFunctionDecl 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. |
| bool |
| Sema::IsOverload(FunctionDecl *New, Decl* OldD, |
| OverloadedFunctionDecl::function_iterator& MatchedDecl) |
| { |
| if (OverloadedFunctionDecl* Ovl = dyn_cast<OverloadedFunctionDecl>(OldD)) { |
| // Is this new function an overload of every function in the |
| // overload set? |
| OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), |
| FuncEnd = Ovl->function_end(); |
| for (; Func != FuncEnd; ++Func) { |
| if (!IsOverload(New, *Func, MatchedDecl)) { |
| MatchedDecl = Func; |
| return false; |
| } |
| } |
| |
| // This function overloads every function in the overload set. |
| return true; |
| } else if (FunctionDecl* Old = dyn_cast<FunctionDecl>(OldD)) { |
| // 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<FunctionTypeNoProto>(OldQType.getTypePtr()) || |
| isa<FunctionTypeNoProto>(NewQType.getTypePtr())) |
| return false; |
| |
| FunctionTypeProto* OldType = cast<FunctionTypeProto>(OldQType.getTypePtr()); |
| FunctionTypeProto* NewType = cast<FunctionTypeProto>(NewQType.getTypePtr()); |
| |
| // 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() || |
| !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), |
| NewType->arg_type_begin()))) |
| 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() && |
| OldQType.getCVRQualifiers() != NewQType.getCVRQualifiers()) |
| return true; |
| |
| // The signatures match; this is not an overload. |
| return false; |
| } else { |
| // (C++ 13p1): |
| // Only function declarations can be overloaded; object and type |
| // declarations cannot be overloaded. |
| 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. |
| ImplicitConversionSequence |
| Sema::TryImplicitConversion(Expr* From, QualType ToType, |
| bool SuppressUserConversions) |
| { |
| ImplicitConversionSequence ICS; |
| if (IsStandardConversion(From, ToType, ICS.Standard)) |
| ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; |
| else if (!SuppressUserConversions && |
| IsUserDefinedConversion(From, ToType, ICS.UserDefined)) { |
| ICS.ConversionKind = ImplicitConversionSequence::UserDefinedConversion; |
| // 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)) { |
| if (Constructor->isCopyConstructor(Context)) { |
| // Turn this into a "standard" conversion sequence, so that it |
| // gets ranked with standard conversion sequences. |
| ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; |
| ICS.Standard.setAsIdentityConversion(); |
| ICS.Standard.FromTypePtr = From->getType().getAsOpaquePtr(); |
| ICS.Standard.ToTypePtr = ToType.getAsOpaquePtr(); |
| ICS.Standard.CopyConstructor = Constructor; |
| if (IsDerivedFrom(From->getType().getUnqualifiedType(), |
| ToType.getUnqualifiedType())) |
| ICS.Standard.Second = ICK_Derived_To_Base; |
| } |
| } |
| } else |
| ICS.ConversionKind = ImplicitConversionSequence::BadConversion; |
| |
| return ICS; |
| } |
| |
| /// 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, |
| StandardConversionSequence &SCS) |
| { |
| QualType FromType = From->getType(); |
| |
| // There are no standard conversions for class types, so abort early. |
| if (FromType->isRecordType() || ToType->isRecordType()) |
| return false; |
| |
| // Standard conversions (C++ [conv]) |
| SCS.setAsIdentityConversion(); |
| SCS.Deprecated = false; |
| SCS.FromTypePtr = FromType.getAsOpaquePtr(); |
| SCS.CopyConstructor = 0; |
| |
| // The first conversion can be an lvalue-to-rvalue conversion, |
| // array-to-pointer conversion, or function-to-pointer conversion |
| // (C++ 4p1). |
| |
| // 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() && |
| !FromType->isOverloadType()) { |
| 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). |
| FromType = FromType.getUnqualifiedType(); |
| } |
| // Array-to-pointer conversion (C++ 4.2) |
| else if (FromType->isArrayType()) { |
| 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.Deprecated = 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.ToTypePtr = ToType.getAsOpaquePtr(); |
| return true; |
| } |
| } |
| // Function-to-pointer conversion (C++ 4.3). |
| else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { |
| 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); |
| } |
| // Address of overloaded function (C++ [over.over]). |
| else if (FunctionDecl *Fn |
| = ResolveAddressOfOverloadedFunction(From, ToType, false)) { |
| SCS.First = ICK_Function_To_Pointer; |
| |
| // 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 (ToType->isReferenceType()) |
| FromType = Context.getReferenceType(FromType); |
| else |
| FromType = Context.getPointerType(FromType); |
| } |
| // We don't require any conversions for the first step. |
| else { |
| SCS.First = ICK_Identity; |
| } |
| |
| // 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). |
| if (Context.getCanonicalType(FromType).getUnqualifiedType() == |
| Context.getCanonicalType(ToType).getUnqualifiedType()) { |
| // The unqualified versions of the types are the same: there's no |
| // conversion to do. |
| SCS.Second = ICK_Identity; |
| } |
| // Integral promotion (C++ 4.5). |
| else if (IsIntegralPromotion(From, FromType, ToType)) { |
| SCS.Second = ICK_Integral_Promotion; |
| FromType = ToType.getUnqualifiedType(); |
| } |
| // Floating point promotion (C++ 4.6). |
| else if (IsFloatingPointPromotion(FromType, ToType)) { |
| SCS.Second = ICK_Floating_Promotion; |
| FromType = ToType.getUnqualifiedType(); |
| } |
| // Integral conversions (C++ 4.7). |
| // FIXME: isIntegralType shouldn't be true for enums in C++. |
| else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && |
| (ToType->isIntegralType() && !ToType->isEnumeralType())) { |
| SCS.Second = ICK_Integral_Conversion; |
| FromType = ToType.getUnqualifiedType(); |
| } |
| // Floating point conversions (C++ 4.8). |
| else if (FromType->isFloatingType() && ToType->isFloatingType()) { |
| SCS.Second = ICK_Floating_Conversion; |
| FromType = ToType.getUnqualifiedType(); |
| } |
| // Floating-integral conversions (C++ 4.9). |
| // FIXME: isIntegralType shouldn't be true for enums in C++. |
| else if ((FromType->isFloatingType() && |
| ToType->isIntegralType() && !ToType->isBooleanType() && |
| !ToType->isEnumeralType()) || |
| ((FromType->isIntegralType() || FromType->isEnumeralType()) && |
| ToType->isFloatingType())) { |
| SCS.Second = ICK_Floating_Integral; |
| FromType = ToType.getUnqualifiedType(); |
| } |
| // Pointer conversions (C++ 4.10). |
| else if (IsPointerConversion(From, FromType, ToType, FromType)) { |
| SCS.Second = ICK_Pointer_Conversion; |
| } |
| // FIXME: Pointer to member conversions (4.11). |
| // Boolean conversions (C++ 4.12). |
| // FIXME: pointer-to-member type |
| else if (ToType->isBooleanType() && |
| (FromType->isArithmeticType() || |
| FromType->isEnumeralType() || |
| FromType->isPointerType())) { |
| SCS.Second = ICK_Boolean_Conversion; |
| FromType = Context.BoolTy; |
| } else { |
| // No second conversion required. |
| SCS.Second = ICK_Identity; |
| } |
| |
| 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.getUnqualifiedType() == CanonTo.getUnqualifiedType() && |
| CanonFrom.getCVRQualifiers() != CanonTo.getCVRQualifiers()) { |
| FromType = ToType; |
| CanonFrom = CanonTo; |
| } |
| } |
| |
| // If we have not converted the argument type to the parameter type, |
| // this is a bad conversion sequence. |
| if (CanonFrom != CanonTo) |
| return false; |
| |
| SCS.ToTypePtr = FromType.getAsOpaquePtr(); |
| 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->getAsBuiltinType(); |
| // 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()) { |
| 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). |
| if ((FromType->isEnumeralType() || FromType->isWideCharType()) |
| && ToType->isIntegerType()) { |
| // Determine whether the type we're converting from is signed or |
| // unsigned. |
| bool FromIsSigned; |
| uint64_t FromSize = Context.getTypeSize(FromType); |
| if (const EnumType *FromEnumType = FromType->getAsEnumType()) { |
| QualType UnderlyingType = FromEnumType->getDecl()->getIntegerType(); |
| FromIsSigned = UnderlyingType->isSignedIntegerType(); |
| } else { |
| // 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[4] = { |
| Context.IntTy, Context.UnsignedIntTy, |
| Context.LongTy, Context.UnsignedLongTy |
| }; |
| for (int Idx = 0; Idx < 0; ++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.getCanonicalType(ToType).getUnqualifiedType() |
| == Context.getCanonicalType(PromoteTypes[Idx]).getUnqualifiedType(); |
| } |
| } |
| } |
| |
| // 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). |
| if (MemberExpr *MemRef = dyn_cast<MemberExpr>(From)) { |
| using llvm::APSInt; |
| FieldDecl *MemberDecl = MemRef->getMemberDecl(); |
| APSInt BitWidth; |
| if (MemberDecl->isBitField() && |
| FromType->isIntegralType() && !FromType->isEnumeralType() && |
| From->isIntegerConstantExpr(BitWidth, Context)) { |
| APSInt 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->getAsBuiltinType()) |
| if (const BuiltinType *ToBuiltin = ToType->getAsBuiltinType()) |
| if (FromBuiltin->getKind() == BuiltinType::Float && |
| ToBuiltin->getKind() == BuiltinType::Double) |
| return true; |
| |
| return false; |
| } |
| |
| /// 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. |
| bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, |
| QualType& ConvertedType) |
| { |
| const PointerType* ToTypePtr = ToType->getAsPointerType(); |
| if (!ToTypePtr) |
| return false; |
| |
| // A null pointer constant can be converted to a pointer type (C++ 4.10p1). |
| if (From->isNullPointerConstant(Context)) { |
| ConvertedType = ToType; |
| return true; |
| } |
| |
| // 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 (FromType->isPointerType() && |
| FromType->getAsPointerType()->getPointeeType()->isObjectType() && |
| ToTypePtr->getPointeeType()->isVoidType()) { |
| // We need to produce a pointer to cv void, where cv is the same |
| // set of cv-qualifiers as we had on the incoming pointee type. |
| QualType toPointee = ToTypePtr->getPointeeType(); |
| unsigned Quals = Context.getCanonicalType(FromType)->getAsPointerType() |
| ->getPointeeType().getCVRQualifiers(); |
| |
| if (Context.getCanonicalType(ToTypePtr->getPointeeType()).getCVRQualifiers() |
| == Quals) { |
| // ToType is exactly the type we want. Use it. |
| ConvertedType = ToType; |
| } else { |
| // Build a new type with the right qualifiers. |
| ConvertedType |
| = Context.getPointerType(Context.VoidTy.getQualifiedType(Quals)); |
| } |
| 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 (const PointerType *FromPtrType = FromType->getAsPointerType()) |
| if (const PointerType *ToPtrType = ToType->getAsPointerType()) { |
| if (FromPtrType->getPointeeType()->isRecordType() && |
| ToPtrType->getPointeeType()->isRecordType() && |
| IsDerivedFrom(FromPtrType->getPointeeType(), |
| ToPtrType->getPointeeType())) { |
| // The conversion is okay. Now, we need to produce the type |
| // that results from this conversion, which will have the same |
| // qualifiers as the incoming type. |
| QualType CanonFromPointee |
| = Context.getCanonicalType(FromPtrType->getPointeeType()); |
| QualType ToPointee = ToPtrType->getPointeeType(); |
| QualType CanonToPointee = Context.getCanonicalType(ToPointee); |
| unsigned Quals = CanonFromPointee.getCVRQualifiers(); |
| |
| if (CanonToPointee.getCVRQualifiers() == Quals) { |
| // ToType is exactly the type we want. Use it. |
| ConvertedType = ToType; |
| } else { |
| // Build a new type with the right qualifiers. |
| ConvertedType |
| = Context.getPointerType(CanonToPointee.getQualifiedType(Quals)); |
| } |
| return true; |
| } |
| } |
| |
| return false; |
| } |
| |
| /// CheckPointerConversion - Check the pointer conversion from the |
| /// expression From to the type ToType. This routine checks for |
| /// ambiguous (FIXME: 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) { |
| QualType FromType = From->getType(); |
| |
| if (const PointerType *FromPtrType = FromType->getAsPointerType()) |
| if (const PointerType *ToPtrType = ToType->getAsPointerType()) { |
| BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, |
| /*DetectVirtual=*/false); |
| QualType FromPointeeType = FromPtrType->getPointeeType(), |
| ToPointeeType = ToPtrType->getPointeeType(); |
| if (FromPointeeType->isRecordType() && |
| ToPointeeType->isRecordType()) { |
| // We must have a derived-to-base conversion. Check an |
| // ambiguous or inaccessible conversion. |
| return CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, |
| From->getExprLoc(), |
| From->getSourceRange()); |
| } |
| } |
| |
| 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 == ToType) |
| 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 && |
| FromType.getUnqualifiedType() == ToType.getUnqualifiedType(); |
| } |
| |
| /// IsUserDefinedConversion - 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. |
| bool Sema::IsUserDefinedConversion(Expr *From, QualType ToType, |
| UserDefinedConversionSequence& User) |
| { |
| OverloadCandidateSet CandidateSet; |
| if (const CXXRecordType *ToRecordType |
| = dyn_cast_or_null<CXXRecordType>(ToType->getAsRecordType())) { |
| // 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. |
| CXXRecordDecl *ToRecordDecl = ToRecordType->getDecl(); |
| const OverloadedFunctionDecl *Constructors = ToRecordDecl->getConstructors(); |
| for (OverloadedFunctionDecl::function_const_iterator func |
| = Constructors->function_begin(); |
| func != Constructors->function_end(); ++func) { |
| CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*func); |
| if (Constructor->isConvertingConstructor()) |
| AddOverloadCandidate(Constructor, &From, 1, CandidateSet, |
| /*SuppressUserConversions=*/true); |
| } |
| } |
| |
| if (const CXXRecordType *FromRecordType |
| = dyn_cast_or_null<CXXRecordType>(From->getType()->getAsRecordType())) { |
| // Add all of the conversion functions as candidates. |
| // FIXME: Look for conversions in base classes! |
| CXXRecordDecl *FromRecordDecl = FromRecordType->getDecl(); |
| OverloadedFunctionDecl *Conversions |
| = FromRecordDecl->getConversionFunctions(); |
| for (OverloadedFunctionDecl::function_iterator Func |
| = Conversions->function_begin(); |
| Func != Conversions->function_end(); ++Func) { |
| CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); |
| AddConversionCandidate(Conv, From, ToType, CandidateSet); |
| } |
| } |
| |
| OverloadCandidateSet::iterator Best; |
| switch (BestViableFunction(CandidateSet, 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. |
| // |
| // FIXME: What about ellipsis conversions? |
| QualType ThisType = Constructor->getThisType(Context); |
| User.Before = Best->Conversions[0].Standard; |
| User.ConversionFunction = Constructor; |
| User.After.setAsIdentityConversion(); |
| User.After.FromTypePtr |
| = ThisType->getAsPointerType()->getPointeeType().getAsOpaquePtr(); |
| User.After.ToTypePtr = ToType.getAsOpaquePtr(); |
| return true; |
| } 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; |
| |
| // 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 true; |
| } else { |
| assert(false && "Not a constructor or conversion function?"); |
| return false; |
| } |
| |
| case OR_No_Viable_Function: |
| // No conversion here! We're done. |
| return false; |
| |
| case OR_Ambiguous: |
| // FIXME: See C++ [over.best.ics]p10 for the handling of |
| // ambiguous conversion sequences. |
| return false; |
| } |
| |
| return false; |
| } |
| |
| /// 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). |
| // |
| if (ICS1.ConversionKind < ICS2.ConversionKind) |
| return ImplicitConversionSequence::Better; |
| else if (ICS2.ConversionKind < ICS1.ConversionKind) |
| return ImplicitConversionSequence::Worse; |
| |
| // 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.ConversionKind == ImplicitConversionSequence::StandardConversion) |
| return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); |
| else if (ICS1.ConversionKind == |
| ImplicitConversionSequence::UserDefinedConversion) { |
| // 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; |
| } |
| |
| /// 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 (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) |
| // Neither is a proper subsequence of the other. Do nothing. |
| ; |
| else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || |
| (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || |
| (SCS1.Second == ICK_Identity && |
| SCS1.Third == ICK_Identity)) |
| // SCS1 is a proper subsequence of SCS2. |
| return ImplicitConversionSequence::Better; |
| else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || |
| (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || |
| (SCS2.Second == ICK_Identity && |
| SCS2.Third == ICK_Identity)) |
| // SCS2 is a proper subsequence of SCS1. |
| return ImplicitConversionSequence::Worse; |
| |
| // -- 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 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); |
| QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); |
| |
| // 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->getAsPointerType()->getPointeeType().getUnqualifiedType(); |
| QualType FromPointee2 |
| = FromType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); |
| |
| if (IsDerivedFrom(FromPointee2, FromPointee1)) |
| return ImplicitConversionSequence::Better; |
| else if (IsDerivedFrom(FromPointee1, FromPointee2)) |
| return ImplicitConversionSequence::Worse; |
| } |
| |
| // Compare based on qualification conversions (C++ 13.3.3.2p3, |
| // bullet 3). |
| if (ImplicitConversionSequence::CompareKind QualCK |
| = CompareQualificationConversions(SCS1, SCS2)) |
| return QualCK; |
| |
| // 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. |
| if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { |
| QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); |
| QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); |
| T1 = Context.getCanonicalType(T1); |
| T2 = Context.getCanonicalType(T2); |
| if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) { |
| 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 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); |
| QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); |
| T1 = Context.getCanonicalType(T1); |
| T2 = Context.getCanonicalType(T2); |
| |
| // If the types are the same, we won't learn anything by unwrapped |
| // them. |
| if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) |
| return ImplicitConversionSequence::Indistinguishable; |
| |
| 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 (T1.getUnqualifiedType() == T2.getUnqualifiedType()) |
| 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.Deprecated) |
| Result = ImplicitConversionSequence::Indistinguishable; |
| break; |
| |
| case ImplicitConversionSequence::Indistinguishable: |
| break; |
| |
| case ImplicitConversionSequence::Worse: |
| if (SCS2.Deprecated) |
| 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). |
| ImplicitConversionSequence::CompareKind |
| Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, |
| const StandardConversionSequence& SCS2) { |
| QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); |
| QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); |
| QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); |
| QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); |
| |
| // 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, |
| |
| // Compare based on pointer conversions. |
| if (SCS1.Second == ICK_Pointer_Conversion && |
| SCS2.Second == ICK_Pointer_Conversion) { |
| QualType FromPointee1 |
| = FromType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); |
| QualType ToPointee1 |
| = ToType1->getAsPointerType()->getPointeeType().getUnqualifiedType(); |
| QualType FromPointee2 |
| = FromType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); |
| QualType ToPointee2 |
| = ToType2->getAsPointerType()->getPointeeType().getUnqualifiedType(); |
| // -- 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; |
| } |
| |
| // -- 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; |
| } |
| } |
| |
| // Compare based on reference bindings. |
| if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && |
| SCS1.Second == ICK_Derived_To_Base) { |
| // -- 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 (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && |
| ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { |
| if (IsDerivedFrom(ToType1, ToType2)) |
| return ImplicitConversionSequence::Better; |
| else if (IsDerivedFrom(ToType2, ToType1)) |
| return ImplicitConversionSequence::Worse; |
| } |
| |
| // -- 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 (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && |
| ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { |
| if (IsDerivedFrom(FromType2, FromType1)) |
| return ImplicitConversionSequence::Better; |
| else if (IsDerivedFrom(FromType1, FromType2)) |
| return ImplicitConversionSequence::Worse; |
| } |
| } |
| |
| |
| // FIXME: conversion of A::* to B::* is better than conversion of |
| // A::* to C::*, |
| |
| // FIXME: conversion of B::* to C::* is better than conversion of |
| // A::* to C::*, and |
| |
| if (SCS1.CopyConstructor && SCS2.CopyConstructor && |
| SCS1.Second == ICK_Derived_To_Base) { |
| // -- conversion of C to B is better than conversion of C to A, |
| if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && |
| ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { |
| 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. |
| if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && |
| ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { |
| if (IsDerivedFrom(FromType2, FromType1)) |
| return ImplicitConversionSequence::Better; |
| else if (IsDerivedFrom(FromType1, FromType2)) |
| return ImplicitConversionSequence::Worse; |
| } |
| } |
| |
| return ImplicitConversionSequence::Indistinguishable; |
| } |
| |
| /// 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. |
| ImplicitConversionSequence |
| Sema::TryCopyInitialization(Expr *From, QualType ToType, |
| bool SuppressUserConversions) { |
| if (!getLangOptions().CPlusPlus) { |
| // In C, copy initialization is the same as performing an assignment. |
| AssignConvertType ConvTy = |
| CheckSingleAssignmentConstraints(ToType, From); |
| ImplicitConversionSequence ICS; |
| if (getLangOptions().NoExtensions? ConvTy != Compatible |
| : ConvTy == Incompatible) |
| ICS.ConversionKind = ImplicitConversionSequence::BadConversion; |
| else |
| ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; |
| return ICS; |
| } else if (ToType->isReferenceType()) { |
| ImplicitConversionSequence ICS; |
| CheckReferenceInit(From, ToType, &ICS, SuppressUserConversions); |
| return ICS; |
| } else { |
| return TryImplicitConversion(From, ToType, SuppressUserConversions); |
| } |
| } |
| |
| /// PerformArgumentPassing - Pass the argument Arg into a parameter of |
| /// type ToType. Returns true (and emits a diagnostic) if there was |
| /// an error, returns false if the initialization succeeded. |
| bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, |
| const char* Flavor) { |
| if (!getLangOptions().CPlusPlus) { |
| // In C, argument passing is the same as performing an assignment. |
| QualType FromType = From->getType(); |
| AssignConvertType ConvTy = |
| CheckSingleAssignmentConstraints(ToType, From); |
| |
| return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, |
| FromType, From, Flavor); |
| } else if (ToType->isReferenceType()) { |
| return CheckReferenceInit(From, ToType); |
| } else { |
| if (PerformImplicitConversion(From, ToType)) |
| return Diag(From->getSourceRange().getBegin(), |
| diag::err_typecheck_convert_incompatible, |
| ToType.getAsString(), From->getType().getAsString(), |
| Flavor, |
| From->getSourceRange()); |
| else |
| return false; |
| } |
| } |
| |
| /// 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. |
| void |
| Sema::AddOverloadCandidate(FunctionDecl *Function, |
| Expr **Args, unsigned NumArgs, |
| OverloadCandidateSet& CandidateSet, |
| bool SuppressUserConversions) |
| { |
| const FunctionTypeProto* Proto |
| = dyn_cast<FunctionTypeProto>(Function->getType()->getAsFunctionType()); |
| assert(Proto && "Functions without a prototype cannot be overloaded"); |
| assert(!isa<CXXConversionDecl>(Function) && |
| "Use AddConversionCandidate for conversion functions"); |
| |
| // Add this candidate |
| CandidateSet.push_back(OverloadCandidate()); |
| OverloadCandidate& Candidate = CandidateSet.back(); |
| Candidate.Function = Function; |
| |
| 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; |
| 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) { |
| // Not enough arguments. |
| Candidate.Viable = false; |
| return; |
| } |
| |
| // Determine the implicit conversion sequences for each of the |
| // arguments. |
| Candidate.Viable = true; |
| 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(Args[ArgIdx], ParamType, |
| SuppressUserConversions); |
| if (Candidate.Conversions[ArgIdx].ConversionKind |
| == ImplicitConversionSequence::BadConversion) |
| Candidate.Viable = false; |
| } 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].ConversionKind |
| = ImplicitConversionSequence::EllipsisConversion; |
| } |
| } |
| } |
| |
| /// 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, |
| Expr *From, QualType ToType, |
| OverloadCandidateSet& CandidateSet) { |
| // Add this candidate |
| CandidateSet.push_back(OverloadCandidate()); |
| OverloadCandidate& Candidate = CandidateSet.back(); |
| Candidate.Function = Conversion; |
| Candidate.FinalConversion.setAsIdentityConversion(); |
| Candidate.FinalConversion.FromTypePtr |
| = Conversion->getConversionType().getAsOpaquePtr(); |
| Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); |
| |
| // Determine the implicit conversion sequences for each of the |
| // arguments. |
| Candidate.Viable = true; |
| Candidate.Conversions.resize(1); |
| |
| // FIXME: We need to follow the rules for the implicit object |
| // parameter. |
| QualType ImplicitObjectType |
| = Context.getTypeDeclType(Conversion->getParent()); |
| ImplicitObjectType |
| = ImplicitObjectType.getQualifiedType(Conversion->getTypeQualifiers()); |
| ImplicitObjectType = Context.getReferenceType(ImplicitObjectType); |
| Candidate.Conversions[0] = TryCopyInitialization(From, ImplicitObjectType, |
| true); |
| if (Candidate.Conversions[0].ConversionKind |
| == ImplicitConversionSequence::BadConversion) { |
| Candidate.Viable = false; |
| 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(), |
| SourceLocation()); |
| ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), |
| &ConversionRef, false); |
| CallExpr Call(&ConversionFn, 0, 0, |
| Conversion->getConversionType().getNonReferenceType(), |
| SourceLocation()); |
| ImplicitConversionSequence ICS = TryCopyInitialization(&Call, ToType, true); |
| switch (ICS.ConversionKind) { |
| case ImplicitConversionSequence::StandardConversion: |
| Candidate.FinalConversion = ICS.Standard; |
| break; |
| |
| case ImplicitConversionSequence::BadConversion: |
| Candidate.Viable = false; |
| break; |
| |
| default: |
| assert(false && |
| "Can only end up with a standard conversion sequence or failure"); |
| } |
| } |
| |
| /// 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. |
| void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, |
| Expr **Args, unsigned NumArgs, |
| OverloadCandidateSet& CandidateSet) { |
| // Add this candidate |
| CandidateSet.push_back(OverloadCandidate()); |
| OverloadCandidate& Candidate = CandidateSet.back(); |
| Candidate.Function = 0; |
| 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) { |
| Candidate.Conversions[ArgIdx] |
| = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], false); |
| if (Candidate.Conversions[ArgIdx].ConversionKind |
| == ImplicitConversionSequence::BadConversion) |
| Candidate.Viable = false; |
| } |
| } |
| |
| /// 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<void*, 8> TypeSet; |
| |
| /// PointerTypes - The set of pointer types that will be used in the |
| /// built-in candidates. |
| TypeSet PointerTypes; |
| |
| /// EnumerationTypes - The set of enumeration types that will be |
| /// used in the built-in candidates. |
| TypeSet EnumerationTypes; |
| |
| /// Context - The AST context in which we will build the type sets. |
| ASTContext &Context; |
| |
| bool AddWithMoreQualifiedTypeVariants(QualType Ty); |
| |
| public: |
| /// iterator - Iterates through the types that are part of the set. |
| class iterator { |
| TypeSet::iterator Base; |
| |
| public: |
| typedef QualType value_type; |
| typedef QualType reference; |
| typedef QualType pointer; |
| typedef std::ptrdiff_t difference_type; |
| typedef std::input_iterator_tag iterator_category; |
| |
| iterator(TypeSet::iterator B) : Base(B) { } |
| |
| iterator& operator++() { |
| ++Base; |
| return *this; |
| } |
| |
| iterator operator++(int) { |
| iterator tmp(*this); |
| ++(*this); |
| return tmp; |
| } |
| |
| reference operator*() const { |
| return QualType::getFromOpaquePtr(*Base); |
| } |
| |
| pointer operator->() const { |
| return **this; |
| } |
| |
| friend bool operator==(iterator LHS, iterator RHS) { |
| return LHS.Base == RHS.Base; |
| } |
| |
| friend bool operator!=(iterator LHS, iterator RHS) { |
| return LHS.Base != RHS.Base; |
| } |
| }; |
| |
| BuiltinCandidateTypeSet(ASTContext &Context) : Context(Context) { } |
| |
| void AddTypesConvertedFrom(QualType Ty, bool AllowUserConversions = true); |
| |
| /// pointer_begin - First pointer type found; |
| iterator pointer_begin() { return PointerTypes.begin(); } |
| |
| /// pointer_end - Last pointer type found; |
| iterator pointer_end() { return PointerTypes.end(); } |
| |
| /// enumeration_begin - First enumeration type found; |
| iterator enumeration_begin() { return EnumerationTypes.begin(); } |
| |
| /// enumeration_end - Last enumeration type found; |
| iterator enumeration_end() { return EnumerationTypes.end(); } |
| }; |
| |
| /// AddWithMoreQualifiedTypeVariants - 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. |
| bool BuiltinCandidateTypeSet::AddWithMoreQualifiedTypeVariants(QualType Ty) { |
| // Insert this type. |
| if (!PointerTypes.insert(Ty.getAsOpaquePtr())) |
| return false; |
| |
| if (const PointerType *PointerTy = Ty->getAsPointerType()) { |
| QualType PointeeTy = PointerTy->getPointeeType(); |
| // FIXME: Optimize this so that we don't keep trying to add the same types. |
| |
| // FIXME: Do we have to add CVR qualifiers at *all* levels to deal |
| // with all pointer conversions that don't cast away constness? |
| if (!PointeeTy.isConstQualified()) |
| AddWithMoreQualifiedTypeVariants |
| (Context.getPointerType(PointeeTy.withConst())); |
| if (!PointeeTy.isVolatileQualified()) |
| AddWithMoreQualifiedTypeVariants |
| (Context.getPointerType(PointeeTy.withVolatile())); |
| if (!PointeeTy.isRestrictQualified()) |
| AddWithMoreQualifiedTypeVariants |
| (Context.getPointerType(PointeeTy.withRestrict())); |
| } |
| |
| 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, enumeration types, |
| void BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, |
| bool AllowUserConversions) { |
| // 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->getAsReferenceType()) |
| Ty = RefTy->getPointeeType(); |
| |
| // We don't care about qualifiers on the type. |
| Ty = Ty.getUnqualifiedType(); |
| |
| if (const PointerType *PointerTy = Ty->getAsPointerType()) { |
| QualType PointeeTy = PointerTy->getPointeeType(); |
| |
| // Insert our type, and its more-qualified variants, into the set |
| // of types. |
| if (!AddWithMoreQualifiedTypeVariants(Ty)) |
| return; |
| |
| // Add 'cv void*' to our set of types. |
| if (!Ty->isVoidType()) { |
| QualType QualVoid |
| = Context.VoidTy.getQualifiedType(PointeeTy.getCVRQualifiers()); |
| AddWithMoreQualifiedTypeVariants(Context.getPointerType(QualVoid)); |
| } |
| |
| // If this is a pointer to a class type, add pointers to its bases |
| // (with the same level of cv-qualification as the original |
| // derived class, of course). |
| if (const RecordType *PointeeRec = PointeeTy->getAsRecordType()) { |
| CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(PointeeRec->getDecl()); |
| for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(); |
| Base != ClassDecl->bases_end(); ++Base) { |
| QualType BaseTy = Context.getCanonicalType(Base->getType()); |
| BaseTy = BaseTy.getQualifiedType(PointeeTy.getCVRQualifiers()); |
| |
| // Add the pointer type, recursively, so that we get all of |
| // the indirect base classes, too. |
| AddTypesConvertedFrom(Context.getPointerType(BaseTy), false); |
| } |
| } |
| } else if (Ty->isEnumeralType()) { |
| EnumerationTypes.insert(Ty.getAsOpaquePtr()); |
| } else if (AllowUserConversions) { |
| if (const RecordType *TyRec = Ty->getAsRecordType()) { |
| CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); |
| // FIXME: Visit conversion functions in the base classes, too. |
| OverloadedFunctionDecl *Conversions |
| = ClassDecl->getConversionFunctions(); |
| for (OverloadedFunctionDecl::function_iterator Func |
| = Conversions->function_begin(); |
| Func != Conversions->function_end(); ++Func) { |
| CXXConversionDecl *Conv = cast<CXXConversionDecl>(*Func); |
| AddTypesConvertedFrom(Conv->getConversionType(), false); |
| } |
| } |
| } |
| } |
| |
| /// AddBuiltinCandidates - 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::AddBuiltinBinaryOperatorCandidates(OverloadedOperatorKind Op, |
| Expr **Args, |
| 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, |
| 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 |
| }; |
| |
| // 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. |
| BuiltinCandidateTypeSet CandidateTypes(Context); |
| if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || |
| Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || |
| Op == OO_Plus || Op == OO_Minus || Op == OO_Equal || |
| Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || |
| Op == OO_ArrowStar) { |
| for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) |
| CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType()); |
| } |
| |
| bool isComparison = false; |
| switch (Op) { |
| case OO_None: |
| case NUM_OVERLOADED_OPERATORS: |
| assert(false && "Expected an overloaded operator"); |
| break; |
| |
| case OO_New: |
| case OO_Delete: |
| case OO_Array_New: |
| case OO_Array_Delete: |
| case OO_Tilde: |
| case OO_Exclaim: |
| case OO_PlusPlus: |
| case OO_MinusMinus: |
| case OO_Arrow: |
| case OO_Call: |
| assert(false && "Expected a binary operator"); |
| break; |
| |
| case OO_Comma: |
| // C++ [over.match.oper]p3: |
| // -- For the operator ',', the unary operator '&', or the |
| // operator '->', the built-in candidates set is empty. |
| // We don't check '&' or '->' here, since they are unary operators. |
| break; |
| |
| case OO_Less: |
| case OO_Greater: |
| case OO_LessEqual: |
| case OO_GreaterEqual: |
| case OO_EqualEqual: |
| case OO_ExclaimEqual: |
| // 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; |
| |
| case OO_Plus: |
| case OO_Minus: |
| 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_Star: |
| case OO_Slash: |
| // 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. |
| 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 |
| : UsualArithmeticConversionsType(LandR[0], LandR[1]); |
| AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); |
| } |
| } |
| break; |
| |
| case OO_Percent: |
| case OO_Amp: |
| 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] |
| : 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 |
| // (FIXME:) 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(); |
| Enum != CandidateTypes.enumeration_end(); ++Enum) { |
| QualType ParamTypes[2]; |
| |
| // T& operator=(T&, T) |
| ParamTypes[0] = Context.getReferenceType(*Enum); |
| ParamTypes[1] = *Enum; |
| AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); |
| |
| // volatile T& operator=(volatile T&, T) |
| ParamTypes[0] = Context.getReferenceType((*Enum).withVolatile()); |
| ParamTypes[1] = *Enum; |
| AddBuiltinCandidate(ParamTypes[0], ParamTypes, 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.getReferenceType(*Ptr); |
| AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); |
| |
| // volatile version |
| ParamTypes[0] = Context.getReferenceType((*Ptr).withVolatile()); |
| AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); |
| } |
| // 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.getReferenceType(ArithmeticTypes[Left]); |
| AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); |
| |
| // Add this built-in operator as a candidate (VQ is 'volatile'). |
| ParamTypes[0] = ArithmeticTypes[Left].withVolatile(); |
| ParamTypes[0] = Context.getReferenceType(ParamTypes[0]); |
| AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); |
| } |
| } |
| 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). |
| // FIXME: We should be caching these declarations somewhere, |
| // rather than re-building them every time. |
| ParamTypes[0] = Context.getReferenceType(ArithmeticTypes[Left]); |
| AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); |
| |
| // Add this built-in operator as a candidate (VQ is 'volatile'). |
| ParamTypes[0] = ArithmeticTypes[Left]; |
| ParamTypes[0].addVolatile(); |
| ParamTypes[0] = Context.getReferenceType(ParamTypes[0]); |
| AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); |
| } |
| } |
| break; |
| |
| case OO_AmpAmp: |
| case OO_PipePipe: { |
| // C++ [over.operator]p23: |
| // |
| // There also exist candidate operator functions of the form |
| // |
| // bool operator!(bool); [In Unary version] |
| // bool operator&&(bool, bool); |
| // bool operator||(bool, bool); |
| QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; |
| AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); |
| 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)->getAsPointerType()->getPointeeType(); |
| QualType ResultTy = Context.getReferenceType(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: |
| // FIXME: No support for pointer-to-members yet. |
| break; |
| } |
| } |
| |
| /// AddOverloadCandidates - Add all of the function overloads in Ovl |
| /// to the candidate set. |
| void |
| Sema::AddOverloadCandidates(const OverloadedFunctionDecl *Ovl, |
| Expr **Args, unsigned NumArgs, |
| OverloadCandidateSet& CandidateSet, |
| bool SuppressUserConversions) |
| { |
| for (OverloadedFunctionDecl::function_const_iterator Func |
| = Ovl->function_begin(); |
| Func != Ovl->function_end(); ++Func) |
| AddOverloadCandidate(*Func, Args, NumArgs, CandidateSet, |
| SuppressUserConversions); |
| } |
| |
| /// 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) |
| { |
| // Define viable functions to be better candidates than non-viable |
| // functions. |
| if (!Cand2.Viable) |
| return Cand1.Viable; |
| else if (!Cand1.Viable) |
| return false; |
| |
| // FIXME: Deal with the implicit object parameter for static member |
| // functions. (C++ 13.3.3p1). |
| |
| // (C++ 13.3.3p1): 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 = 0; 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; |
| } |
| } |
| |
| if (HasBetterConversion) |
| return true; |
| |
| // FIXME: Several other bullets in (C++ 13.3.3p1) need to be |
| // implemented, but they require template support. |
| |
| // C++ [over.match.best]p1b4: |
| // |
| // -- 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 (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; |
| } |
| |
| /// BestViableFunction - Computes the best viable function (C++ 13.3.3) |
| /// within an overload candidate set. If overloading is successful, |
| /// the result will be OR_Success and Best will be set to point to the |
| /// best viable function within the candidate set. Otherwise, one of |
| /// several kinds of errors will be returned; see |
| /// Sema::OverloadingResult. |
| Sema::OverloadingResult |
| Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, |
| 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)) |
| 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)) |
| return OR_Ambiguous; |
| } |
| |
| // Best is the best viable function. |
| return OR_Success; |
| } |
| |
| /// PrintOverloadCandidates - When overload resolution fails, prints |
| /// diagnostic messages containing the candidates in the candidate |
| /// set. If OnlyViable is true, only viable candidates will be printed. |
| void |
| Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, |
| bool OnlyViable) |
| { |
| OverloadCandidateSet::iterator Cand = CandidateSet.begin(), |
| LastCand = CandidateSet.end(); |
| for (; Cand != LastCand; ++Cand) { |
| if (Cand->Viable || !OnlyViable) { |
| if (Cand->Function) { |
| // Normal function |
| Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); |
| } else { |
| // FIXME: We need to get the identifier in here |
| // FIXME: Do we want the error message to point at the |
| // operator? (built-ins won't have a location) |
| QualType FnType |
| = Context.getFunctionType(Cand->BuiltinTypes.ResultTy, |
| Cand->BuiltinTypes.ParamTypes, |
| Cand->Conversions.size(), |
| false, 0); |
| |
| Diag(SourceLocation(), diag::err_ovl_builtin_candidate, |
| FnType.getAsString()); |
| } |
| } |
| } |
| } |
| |
| /// 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) { |
| QualType FunctionType = ToType; |
| if (const PointerLikeType *ToTypePtr = ToType->getAsPointerLikeType()) |
| FunctionType = ToTypePtr->getPointeeType(); |
| |
| // We only look at pointers or references to functions. |
| if (!FunctionType->isFunctionType()) |
| return 0; |
| |
| // Find the actual overloaded function declaration. |
| OverloadedFunctionDecl *Ovl = 0; |
| |
| // C++ [over.over]p1: |
| // [...] [Note: any redundant set of parentheses surrounding the |
| // overloaded function name is ignored (5.1). ] |
| Expr *OvlExpr = From->IgnoreParens(); |
| |
| // C++ [over.over]p1: |
| // [...] The overloaded function name can be preceded by the & |
| // operator. |
| if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { |
| if (UnOp->getOpcode() == UnaryOperator::AddrOf) |
| OvlExpr = UnOp->getSubExpr()->IgnoreParens(); |
| } |
| |
| // Try to dig out the overloaded function. |
| if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) |
| Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); |
| |
| // If there's no overloaded function declaration, we're done. |
| if (!Ovl) |
| return 0; |
| |
| // Look through all of the overloaded functions, searching for one |
| // whose type matches exactly. |
| // FIXME: When templates or using declarations come along, we'll actually |
| // have to deal with duplicates, partial ordering, etc. For now, we |
| // can just do a simple search. |
| FunctionType = Context.getCanonicalType(FunctionType.getUnqualifiedType()); |
| for (OverloadedFunctionDecl::function_iterator Fun = Ovl->function_begin(); |
| Fun != Ovl->function_end(); ++Fun) { |
| // C++ [over.over]p3: |
| // Non-member functions and static member functions match |
| // targets of type “pointer-to-function”or |
| // “reference-to-function.” |
| if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) |
| if (!Method->isStatic()) |
| continue; |
| |
| if (FunctionType == Context.getCanonicalType((*Fun)->getType())) |
| return *Fun; |
| } |
| |
| return 0; |
| } |
| |
| /// 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. |
| void Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { |
| if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { |
| FixOverloadedFunctionReference(PE->getSubExpr(), Fn); |
| E->setType(PE->getSubExpr()->getType()); |
| } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { |
| assert(UnOp->getOpcode() == UnaryOperator::AddrOf && |
| "Can only take the address of an overloaded function"); |
| FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); |
| E->setType(Context.getPointerType(E->getType())); |
| } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { |
| assert(isa<OverloadedFunctionDecl>(DR->getDecl()) && |
| "Expected overloaded function"); |
| DR->setDecl(Fn); |
| E->setType(Fn->getType()); |
| } else { |
| assert(false && "Invalid reference to overloaded function"); |
| } |
| } |
| |
| } // end namespace clang |