llvm-project/clang/lib/Sema/SemaOverload.cpp

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//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file provides Sema routines for C++ overloading.
//
//===----------------------------------------------------------------------===//
#include "Sema.h"
#include "Lookup.h"
#include "SemaInit.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/CXXInheritance.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/TypeOrdering.h"
#include "clang/Basic/PartialDiagnostic.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/STLExtras.h"
#include <algorithm>
namespace clang {
/// GetConversionCategory - Retrieve the implicit conversion
/// category corresponding to the given implicit conversion kind.
ImplicitConversionCategory
GetConversionCategory(ImplicitConversionKind Kind) {
static const ImplicitConversionCategory
Category[(int)ICK_Num_Conversion_Kinds] = {
ICC_Identity,
ICC_Lvalue_Transformation,
ICC_Lvalue_Transformation,
ICC_Lvalue_Transformation,
ICC_Identity,
ICC_Qualification_Adjustment,
ICC_Promotion,
ICC_Promotion,
ICC_Promotion,
ICC_Conversion,
ICC_Conversion,
ICC_Conversion,
ICC_Conversion,
ICC_Conversion,
ICC_Conversion,
ICC_Conversion,
ICC_Conversion,
Initial implementation of function overloading in C. This commit adds a new attribute, "overloadable", that enables C++ function overloading in C. The attribute can only be added to function declarations, e.g., int *f(int) __attribute__((overloadable)); If the "overloadable" attribute exists on a function with a given name, *all* functions with that name (and in that scope) must have the "overloadable" attribute. Sets of overloaded functions with the "overloadable" attribute then follow the normal C++ rules for overloaded functions, e.g., overloads must have different parameter-type-lists from each other. When calling an overloaded function in C, we follow the same overloading rules as C++, with three extensions to the set of standard conversions: - A value of a given struct or union type T can be converted to the type T. This is just the identity conversion. (In C++, this would go through a copy constructor). - A value of pointer type T* can be converted to a value of type U* if T and U are compatible types. This conversion has Conversion rank (it's considered a pointer conversion in C). - A value of type T can be converted to a value of type U if T and U are compatible (and are not both pointer types). This conversion has Conversion rank (it's considered to be a new kind of conversion unique to C, a "compatible" conversion). Known defects (and, therefore, next steps): 1) The standard-conversion handling does not understand conversions involving _Complex or vector extensions, so it is likely to get these wrong. We need to add these conversions. 2) All overloadable functions with the same name will have the same linkage name, which means we'll get a collision in the linker (if not sooner). We'll need to mangle the names of these functions. llvm-svn: 64336
2009-02-12 07:02:49 +08:00
ICC_Conversion,
ICC_Conversion
};
return Category[(int)Kind];
}
/// GetConversionRank - Retrieve the implicit conversion rank
/// corresponding to the given implicit conversion kind.
ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) {
static const ImplicitConversionRank
Rank[(int)ICK_Num_Conversion_Kinds] = {
ICR_Exact_Match,
ICR_Exact_Match,
ICR_Exact_Match,
ICR_Exact_Match,
ICR_Exact_Match,
ICR_Exact_Match,
ICR_Promotion,
ICR_Promotion,
ICR_Promotion,
ICR_Conversion,
ICR_Conversion,
ICR_Conversion,
ICR_Conversion,
ICR_Conversion,
ICR_Conversion,
ICR_Conversion,
ICR_Conversion,
Initial implementation of function overloading in C. This commit adds a new attribute, "overloadable", that enables C++ function overloading in C. The attribute can only be added to function declarations, e.g., int *f(int) __attribute__((overloadable)); If the "overloadable" attribute exists on a function with a given name, *all* functions with that name (and in that scope) must have the "overloadable" attribute. Sets of overloaded functions with the "overloadable" attribute then follow the normal C++ rules for overloaded functions, e.g., overloads must have different parameter-type-lists from each other. When calling an overloaded function in C, we follow the same overloading rules as C++, with three extensions to the set of standard conversions: - A value of a given struct or union type T can be converted to the type T. This is just the identity conversion. (In C++, this would go through a copy constructor). - A value of pointer type T* can be converted to a value of type U* if T and U are compatible types. This conversion has Conversion rank (it's considered a pointer conversion in C). - A value of type T can be converted to a value of type U if T and U are compatible (and are not both pointer types). This conversion has Conversion rank (it's considered to be a new kind of conversion unique to C, a "compatible" conversion). Known defects (and, therefore, next steps): 1) The standard-conversion handling does not understand conversions involving _Complex or vector extensions, so it is likely to get these wrong. We need to add these conversions. 2) All overloadable functions with the same name will have the same linkage name, which means we'll get a collision in the linker (if not sooner). We'll need to mangle the names of these functions. llvm-svn: 64336
2009-02-12 07:02:49 +08:00
ICR_Conversion,
ICR_Complex_Real_Conversion
};
return Rank[(int)Kind];
}
/// GetImplicitConversionName - Return the name of this kind of
/// implicit conversion.
const char* GetImplicitConversionName(ImplicitConversionKind Kind) {
static const char* const Name[(int)ICK_Num_Conversion_Kinds] = {
"No conversion",
"Lvalue-to-rvalue",
"Array-to-pointer",
"Function-to-pointer",
"Noreturn adjustment",
"Qualification",
"Integral promotion",
"Floating point promotion",
"Complex promotion",
"Integral conversion",
"Floating conversion",
"Complex conversion",
"Floating-integral conversion",
"Complex-real conversion",
"Pointer conversion",
"Pointer-to-member conversion",
"Boolean conversion",
Initial implementation of function overloading in C. This commit adds a new attribute, "overloadable", that enables C++ function overloading in C. The attribute can only be added to function declarations, e.g., int *f(int) __attribute__((overloadable)); If the "overloadable" attribute exists on a function with a given name, *all* functions with that name (and in that scope) must have the "overloadable" attribute. Sets of overloaded functions with the "overloadable" attribute then follow the normal C++ rules for overloaded functions, e.g., overloads must have different parameter-type-lists from each other. When calling an overloaded function in C, we follow the same overloading rules as C++, with three extensions to the set of standard conversions: - A value of a given struct or union type T can be converted to the type T. This is just the identity conversion. (In C++, this would go through a copy constructor). - A value of pointer type T* can be converted to a value of type U* if T and U are compatible types. This conversion has Conversion rank (it's considered a pointer conversion in C). - A value of type T can be converted to a value of type U if T and U are compatible (and are not both pointer types). This conversion has Conversion rank (it's considered to be a new kind of conversion unique to C, a "compatible" conversion). Known defects (and, therefore, next steps): 1) The standard-conversion handling does not understand conversions involving _Complex or vector extensions, so it is likely to get these wrong. We need to add these conversions. 2) All overloadable functions with the same name will have the same linkage name, which means we'll get a collision in the linker (if not sooner). We'll need to mangle the names of these functions. llvm-svn: 64336
2009-02-12 07:02:49 +08:00
"Compatible-types 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;
DeprecatedStringLiteralToCharPtr = false;
ReferenceBinding = false;
DirectBinding = false;
RRefBinding = false;
CopyConstructor = 0;
}
/// getRank - Retrieve the rank of this standard conversion sequence
/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the
/// implicit conversions.
ImplicitConversionRank StandardConversionSequence::getRank() const {
ImplicitConversionRank Rank = ICR_Exact_Match;
if (GetConversionRank(First) > Rank)
Rank = GetConversionRank(First);
if (GetConversionRank(Second) > Rank)
Rank = GetConversionRank(Second);
if (GetConversionRank(Third) > Rank)
Rank = GetConversionRank(Third);
return Rank;
}
/// isPointerConversionToBool - Determines whether this conversion is
/// a conversion of a pointer or pointer-to-member to bool. This is
/// used as part of the ranking of standard conversion sequences
/// (C++ 13.3.3.2p4).
bool StandardConversionSequence::isPointerConversionToBool() const {
// Note that FromType has not necessarily been transformed by the
// array-to-pointer or function-to-pointer implicit conversions, so
// check for their presence as well as checking whether FromType is
// a pointer.
if (getToType(1)->isBooleanType() &&
(getFromType()->isPointerType() || getFromType()->isBlockPointerType() ||
First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer))
return true;
return false;
}
/// isPointerConversionToVoidPointer - Determines whether this
/// conversion is a conversion of a pointer to a void pointer. This is
/// used as part of the ranking of standard conversion sequences (C++
/// 13.3.3.2p4).
bool
StandardConversionSequence::
isPointerConversionToVoidPointer(ASTContext& Context) const {
QualType FromType = getFromType();
QualType ToType = getToType(1);
// Note that FromType has not necessarily been transformed by the
// array-to-pointer implicit conversion, so check for its presence
// and redo the conversion to get a pointer.
if (First == ICK_Array_To_Pointer)
FromType = Context.getArrayDecayedType(FromType);
if (Second == ICK_Pointer_Conversion && FromType->isPointerType())
if (const PointerType* ToPtrType = ToType->getAs<PointerType>())
return ToPtrType->getPointeeType()->isVoidType();
return false;
}
/// DebugPrint - Print this standard conversion sequence to standard
/// error. Useful for debugging overloading issues.
void StandardConversionSequence::DebugPrint() const {
llvm::raw_ostream &OS = llvm::errs();
bool PrintedSomething = false;
if (First != ICK_Identity) {
OS << GetImplicitConversionName(First);
PrintedSomething = true;
}
if (Second != ICK_Identity) {
if (PrintedSomething) {
OS << " -> ";
}
OS << GetImplicitConversionName(Second);
if (CopyConstructor) {
OS << " (by copy constructor)";
} else if (DirectBinding) {
OS << " (direct reference binding)";
} else if (ReferenceBinding) {
OS << " (reference binding)";
}
PrintedSomething = true;
}
if (Third != ICK_Identity) {
if (PrintedSomething) {
OS << " -> ";
}
OS << GetImplicitConversionName(Third);
PrintedSomething = true;
}
if (!PrintedSomething) {
OS << "No conversions required";
}
}
/// DebugPrint - Print this user-defined conversion sequence to standard
/// error. Useful for debugging overloading issues.
void UserDefinedConversionSequence::DebugPrint() const {
llvm::raw_ostream &OS = llvm::errs();
if (Before.First || Before.Second || Before.Third) {
Before.DebugPrint();
OS << " -> ";
}
OS << '\'' << ConversionFunction << '\'';
if (After.First || After.Second || After.Third) {
OS << " -> ";
After.DebugPrint();
}
}
/// DebugPrint - Print this implicit conversion sequence to standard
/// error. Useful for debugging overloading issues.
void ImplicitConversionSequence::DebugPrint() const {
llvm::raw_ostream &OS = llvm::errs();
switch (ConversionKind) {
case StandardConversion:
OS << "Standard conversion: ";
Standard.DebugPrint();
break;
case UserDefinedConversion:
OS << "User-defined conversion: ";
UserDefined.DebugPrint();
break;
case EllipsisConversion:
OS << "Ellipsis conversion";
break;
case AmbiguousConversion:
OS << "Ambiguous conversion";
break;
case BadConversion:
OS << "Bad conversion";
break;
}
OS << "\n";
}
void AmbiguousConversionSequence::construct() {
new (&conversions()) ConversionSet();
}
void AmbiguousConversionSequence::destruct() {
conversions().~ConversionSet();
}
void
AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) {
FromTypePtr = O.FromTypePtr;
ToTypePtr = O.ToTypePtr;
new (&conversions()) ConversionSet(O.conversions());
}
namespace {
// Structure used by OverloadCandidate::DeductionFailureInfo to store
// template parameter and template argument information.
struct DFIParamWithArguments {
TemplateParameter Param;
TemplateArgument FirstArg;
TemplateArgument SecondArg;
};
}
/// \brief Convert from Sema's representation of template deduction information
/// to the form used in overload-candidate information.
OverloadCandidate::DeductionFailureInfo
static MakeDeductionFailureInfo(ASTContext &Context,
Sema::TemplateDeductionResult TDK,
Sema::TemplateDeductionInfo &Info) {
OverloadCandidate::DeductionFailureInfo Result;
Result.Result = static_cast<unsigned>(TDK);
Result.Data = 0;
switch (TDK) {
case Sema::TDK_Success:
case Sema::TDK_InstantiationDepth:
case Sema::TDK_TooManyArguments:
case Sema::TDK_TooFewArguments:
break;
case Sema::TDK_Incomplete:
case Sema::TDK_InvalidExplicitArguments:
Result.Data = Info.Param.getOpaqueValue();
break;
case Sema::TDK_Inconsistent:
case Sema::TDK_InconsistentQuals: {
// FIXME: Should allocate from normal heap so that we can free this later.
DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments;
Saved->Param = Info.Param;
Saved->FirstArg = Info.FirstArg;
Saved->SecondArg = Info.SecondArg;
Result.Data = Saved;
break;
}
case Sema::TDK_SubstitutionFailure:
Result.Data = Info.take();
break;
case Sema::TDK_NonDeducedMismatch:
case Sema::TDK_FailedOverloadResolution:
break;
}
return Result;
}
void OverloadCandidate::DeductionFailureInfo::Destroy() {
switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
case Sema::TDK_Success:
case Sema::TDK_InstantiationDepth:
case Sema::TDK_Incomplete:
case Sema::TDK_TooManyArguments:
case Sema::TDK_TooFewArguments:
case Sema::TDK_InvalidExplicitArguments:
break;
case Sema::TDK_Inconsistent:
case Sema::TDK_InconsistentQuals:
// FIXME: Destroy the data?
Data = 0;
break;
case Sema::TDK_SubstitutionFailure:
// FIXME: Destroy the template arugment list?
Data = 0;
break;
// Unhandled
case Sema::TDK_NonDeducedMismatch:
case Sema::TDK_FailedOverloadResolution:
break;
}
}
TemplateParameter
OverloadCandidate::DeductionFailureInfo::getTemplateParameter() {
switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
case Sema::TDK_Success:
case Sema::TDK_InstantiationDepth:
case Sema::TDK_TooManyArguments:
case Sema::TDK_TooFewArguments:
case Sema::TDK_SubstitutionFailure:
return TemplateParameter();
case Sema::TDK_Incomplete:
case Sema::TDK_InvalidExplicitArguments:
return TemplateParameter::getFromOpaqueValue(Data);
case Sema::TDK_Inconsistent:
case Sema::TDK_InconsistentQuals:
return static_cast<DFIParamWithArguments*>(Data)->Param;
// Unhandled
case Sema::TDK_NonDeducedMismatch:
case Sema::TDK_FailedOverloadResolution:
break;
}
return TemplateParameter();
}
TemplateArgumentList *
OverloadCandidate::DeductionFailureInfo::getTemplateArgumentList() {
switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
case Sema::TDK_Success:
case Sema::TDK_InstantiationDepth:
case Sema::TDK_TooManyArguments:
case Sema::TDK_TooFewArguments:
case Sema::TDK_Incomplete:
case Sema::TDK_InvalidExplicitArguments:
case Sema::TDK_Inconsistent:
case Sema::TDK_InconsistentQuals:
return 0;
case Sema::TDK_SubstitutionFailure:
return static_cast<TemplateArgumentList*>(Data);
// Unhandled
case Sema::TDK_NonDeducedMismatch:
case Sema::TDK_FailedOverloadResolution:
break;
}
return 0;
}
const TemplateArgument *OverloadCandidate::DeductionFailureInfo::getFirstArg() {
switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
case Sema::TDK_Success:
case Sema::TDK_InstantiationDepth:
case Sema::TDK_Incomplete:
case Sema::TDK_TooManyArguments:
case Sema::TDK_TooFewArguments:
case Sema::TDK_InvalidExplicitArguments:
case Sema::TDK_SubstitutionFailure:
return 0;
case Sema::TDK_Inconsistent:
case Sema::TDK_InconsistentQuals:
return &static_cast<DFIParamWithArguments*>(Data)->FirstArg;
// Unhandled
case Sema::TDK_NonDeducedMismatch:
case Sema::TDK_FailedOverloadResolution:
break;
}
return 0;
}
const TemplateArgument *
OverloadCandidate::DeductionFailureInfo::getSecondArg() {
switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
case Sema::TDK_Success:
case Sema::TDK_InstantiationDepth:
case Sema::TDK_Incomplete:
case Sema::TDK_TooManyArguments:
case Sema::TDK_TooFewArguments:
case Sema::TDK_InvalidExplicitArguments:
case Sema::TDK_SubstitutionFailure:
return 0;
case Sema::TDK_Inconsistent:
case Sema::TDK_InconsistentQuals:
return &static_cast<DFIParamWithArguments*>(Data)->SecondArg;
// Unhandled
case Sema::TDK_NonDeducedMismatch:
case Sema::TDK_FailedOverloadResolution:
break;
}
return 0;
}
void OverloadCandidateSet::clear() {
inherited::clear();
Functions.clear();
}
// IsOverload - Determine whether the given New declaration is an
// overload of the declarations in Old. This routine returns false if
// New and Old cannot be overloaded, e.g., if New has the same
// signature as some function in Old (C++ 1.3.10) or if the Old
// declarations aren't functions (or function templates) at all. When
// it does return false, MatchedDecl will point to the decl that New
// cannot be overloaded with. This decl may be a UsingShadowDecl on
// top of the underlying declaration.
//
// Example: Given the following input:
//
// void f(int, float); // #1
// void f(int, int); // #2
// int f(int, int); // #3
//
// When we process #1, there is no previous declaration of "f",
// so IsOverload will not be used.
//
// When we process #2, Old contains only the FunctionDecl for #1. By
// comparing the parameter types, we see that #1 and #2 are overloaded
// (since they have different signatures), so this routine returns
// false; MatchedDecl is unchanged.
//
// When we process #3, Old is an overload set containing #1 and #2. We
// compare the signatures of #3 to #1 (they're overloaded, so we do
// nothing) and then #3 to #2. Since the signatures of #3 and #2 are
// identical (return types of functions are not part of the
// signature), IsOverload returns false and MatchedDecl will be set to
// point to the FunctionDecl for #2.
Sema::OverloadKind
Sema::CheckOverload(FunctionDecl *New, const LookupResult &Old,
NamedDecl *&Match) {
for (LookupResult::iterator I = Old.begin(), E = Old.end();
I != E; ++I) {
NamedDecl *OldD = (*I)->getUnderlyingDecl();
if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) {
if (!IsOverload(New, OldT->getTemplatedDecl())) {
Match = *I;
return Ovl_Match;
}
} else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) {
if (!IsOverload(New, OldF)) {
Match = *I;
return Ovl_Match;
}
} else if (isa<UsingDecl>(OldD) || isa<TagDecl>(OldD)) {
// We can overload with these, which can show up when doing
// redeclaration checks for UsingDecls.
assert(Old.getLookupKind() == LookupUsingDeclName);
} else if (isa<UnresolvedUsingValueDecl>(OldD)) {
// Optimistically assume that an unresolved using decl will
// overload; if it doesn't, we'll have to diagnose during
// template instantiation.
} else {
// (C++ 13p1):
// Only function declarations can be overloaded; object and type
// declarations cannot be overloaded.
Match = *I;
return Ovl_NonFunction;
}
}
return Ovl_Overload;
}
bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old) {
FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate();
FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate();
// C++ [temp.fct]p2:
// A function template can be overloaded with other function templates
// and with normal (non-template) functions.
if ((OldTemplate == 0) != (NewTemplate == 0))
return true;
// Is the function New an overload of the function Old?
QualType OldQType = Context.getCanonicalType(Old->getType());
QualType NewQType = Context.getCanonicalType(New->getType());
// Compare the signatures (C++ 1.3.10) of the two functions to
// determine whether they are overloads. If we find any mismatch
// in the signature, they are overloads.
// If either of these functions is a K&R-style function (no
// prototype), then we consider them to have matching signatures.
if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) ||
isa<FunctionNoProtoType>(NewQType.getTypePtr()))
return false;
FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType);
FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType);
// The signature of a function includes the types of its
// parameters (C++ 1.3.10), which includes the presence or absence
// of the ellipsis; see C++ DR 357).
if (OldQType != NewQType &&
(OldType->getNumArgs() != NewType->getNumArgs() ||
OldType->isVariadic() != NewType->isVariadic() ||
!FunctionArgTypesAreEqual(OldType, NewType)))
return true;
// C++ [temp.over.link]p4:
// The signature of a function template consists of its function
// signature, its return type and its template parameter list. The names
// of the template parameters are significant only for establishing the
// relationship between the template parameters and the rest of the
// signature.
//
// We check the return type and template parameter lists for function
// templates first; the remaining checks follow.
if (NewTemplate &&
(!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(),
OldTemplate->getTemplateParameters(),
false, TPL_TemplateMatch) ||
OldType->getResultType() != NewType->getResultType()))
return true;
// If the function is a class member, its signature includes the
// cv-qualifiers (if any) on the function itself.
//
// As part of this, also check whether one of the member functions
// is static, in which case they are not overloads (C++
// 13.1p2). While not part of the definition of the signature,
// this check is important to determine whether these functions
// can be overloaded.
CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old);
CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New);
if (OldMethod && NewMethod &&
!OldMethod->isStatic() && !NewMethod->isStatic() &&
OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers())
return true;
// The signatures match; this is not an overload.
return false;
}
/// TryImplicitConversion - Attempt to perform an implicit conversion
/// from the given expression (Expr) to the given type (ToType). This
/// function returns an implicit conversion sequence that can be used
/// to perform the initialization. Given
///
/// void f(float f);
/// void g(int i) { f(i); }
///
/// this routine would produce an implicit conversion sequence to
/// describe the initialization of f from i, which will be a standard
/// conversion sequence containing an lvalue-to-rvalue conversion (C++
/// 4.1) followed by a floating-integral conversion (C++ 4.9).
//
/// Note that this routine only determines how the conversion can be
/// performed; it does not actually perform the conversion. As such,
/// it will not produce any diagnostics if no conversion is available,
/// but will instead return an implicit conversion sequence of kind
/// "BadConversion".
///
/// If @p SuppressUserConversions, then user-defined conversions are
/// not permitted.
/// If @p AllowExplicit, then explicit user-defined conversions are
/// permitted.
ImplicitConversionSequence
Sema::TryImplicitConversion(Expr* From, QualType ToType,
bool SuppressUserConversions,
bool AllowExplicit,
bool InOverloadResolution) {
ImplicitConversionSequence ICS;
if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) {
ICS.setStandard();
return ICS;
}
if (!getLangOptions().CPlusPlus) {
ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
return ICS;
}
if (SuppressUserConversions) {
// C++ [over.ics.user]p4:
// A conversion of an expression of class type to the same class
// type is given Exact Match rank, and a conversion of an
// expression of class type to a base class of that type is
// given Conversion rank, in spite of the fact that a copy/move
// constructor (i.e., a user-defined conversion function) is
// called for those cases.
QualType FromType = From->getType();
if (!ToType->getAs<RecordType>() || !FromType->getAs<RecordType>() ||
!(Context.hasSameUnqualifiedType(FromType, ToType) ||
IsDerivedFrom(FromType, ToType))) {
// We're not in the case above, so there is no conversion that
// we can perform.
ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
return ICS;
}
ICS.setStandard();
ICS.Standard.setAsIdentityConversion();
ICS.Standard.setFromType(FromType);
ICS.Standard.setAllToTypes(ToType);
// We don't actually check at this point whether there is a valid
// copy/move constructor, since overloading just assumes that it
// exists. When we actually perform initialization, we'll find the
// appropriate constructor to copy the returned object, if needed.
ICS.Standard.CopyConstructor = 0;
// Determine whether this is considered a derived-to-base conversion.
if (!Context.hasSameUnqualifiedType(FromType, ToType))
ICS.Standard.Second = ICK_Derived_To_Base;
return ICS;
}
// Attempt user-defined conversion.
OverloadCandidateSet Conversions(From->getExprLoc());
OverloadingResult UserDefResult
= IsUserDefinedConversion(From, ToType, ICS.UserDefined, Conversions,
AllowExplicit);
if (UserDefResult == OR_Success) {
ICS.setUserDefined();
// C++ [over.ics.user]p4:
// A conversion of an expression of class type to the same class
// type is given Exact Match rank, and a conversion of an
// expression of class type to a base class of that type is
// given Conversion rank, in spite of the fact that a copy
// constructor (i.e., a user-defined conversion function) is
// called for those cases.
if (CXXConstructorDecl *Constructor
= dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) {
QualType FromCanon
= Context.getCanonicalType(From->getType().getUnqualifiedType());
QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType();
if (Constructor->isCopyConstructor() &&
(FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon))) {
// Turn this into a "standard" conversion sequence, so that it
// gets ranked with standard conversion sequences.
ICS.setStandard();
ICS.Standard.setAsIdentityConversion();
ICS.Standard.setFromType(From->getType());
ICS.Standard.setAllToTypes(ToType);
ICS.Standard.CopyConstructor = Constructor;
if (ToCanon != FromCanon)
ICS.Standard.Second = ICK_Derived_To_Base;
}
}
// C++ [over.best.ics]p4:
// However, when considering the argument of a user-defined
// conversion function that is a candidate by 13.3.1.3 when
// invoked for the copying of the temporary in the second step
// of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or
// 13.3.1.6 in all cases, only standard conversion sequences and
// ellipsis conversion sequences are allowed.
if (SuppressUserConversions && ICS.isUserDefined()) {
ICS.setBad(BadConversionSequence::suppressed_user, From, ToType);
}
} else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) {
ICS.setAmbiguous();
ICS.Ambiguous.setFromType(From->getType());
ICS.Ambiguous.setToType(ToType);
for (OverloadCandidateSet::iterator Cand = Conversions.begin();
Cand != Conversions.end(); ++Cand)
if (Cand->Viable)
ICS.Ambiguous.addConversion(Cand->Function);
} else {
ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
}
return ICS;
}
/// PerformImplicitConversion - Perform an implicit conversion of the
/// expression From to the type ToType. Returns true if there was an
/// error, false otherwise. The expression From is replaced with the
/// converted expression. Flavor is the kind of conversion we're
/// performing, used in the error message. If @p AllowExplicit,
/// explicit user-defined conversions are permitted.
bool
Sema::PerformImplicitConversion(Expr *&From, QualType ToType,
AssignmentAction Action, bool AllowExplicit) {
ImplicitConversionSequence ICS;
return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS);
}
bool
Sema::PerformImplicitConversion(Expr *&From, QualType ToType,
AssignmentAction Action, bool AllowExplicit,
ImplicitConversionSequence& ICS) {
ICS = TryImplicitConversion(From, ToType,
/*SuppressUserConversions=*/false,
AllowExplicit,
/*InOverloadResolution=*/false);
return PerformImplicitConversion(From, ToType, ICS, Action);
}
/// \brief Determine whether the conversion from FromType to ToType is a valid
/// conversion that strips "noreturn" off the nested function type.
static bool IsNoReturnConversion(ASTContext &Context, QualType FromType,
QualType ToType, QualType &ResultTy) {
if (Context.hasSameUnqualifiedType(FromType, ToType))
return false;
// Strip the noreturn off the type we're converting from; noreturn can
// safely be removed.
FromType = Context.getNoReturnType(FromType, false);
if (!Context.hasSameUnqualifiedType(FromType, ToType))
return false;
ResultTy = FromType;
return true;
}
/// IsStandardConversion - Determines whether there is a standard
/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the
/// expression From to the type ToType. Standard conversion sequences
/// only consider non-class types; for conversions that involve class
/// types, use TryImplicitConversion. If a conversion exists, SCS will
/// contain the standard conversion sequence required to perform this
/// conversion and this routine will return true. Otherwise, this
/// routine will return false and the value of SCS is unspecified.
bool
Sema::IsStandardConversion(Expr* From, QualType ToType,
bool InOverloadResolution,
StandardConversionSequence &SCS) {
QualType FromType = From->getType();
// Standard conversions (C++ [conv])
SCS.setAsIdentityConversion();
SCS.DeprecatedStringLiteralToCharPtr = false;
SCS.IncompatibleObjC = false;
SCS.setFromType(FromType);
SCS.CopyConstructor = 0;
Initial implementation of function overloading in C. This commit adds a new attribute, "overloadable", that enables C++ function overloading in C. The attribute can only be added to function declarations, e.g., int *f(int) __attribute__((overloadable)); If the "overloadable" attribute exists on a function with a given name, *all* functions with that name (and in that scope) must have the "overloadable" attribute. Sets of overloaded functions with the "overloadable" attribute then follow the normal C++ rules for overloaded functions, e.g., overloads must have different parameter-type-lists from each other. When calling an overloaded function in C, we follow the same overloading rules as C++, with three extensions to the set of standard conversions: - A value of a given struct or union type T can be converted to the type T. This is just the identity conversion. (In C++, this would go through a copy constructor). - A value of pointer type T* can be converted to a value of type U* if T and U are compatible types. This conversion has Conversion rank (it's considered a pointer conversion in C). - A value of type T can be converted to a value of type U if T and U are compatible (and are not both pointer types). This conversion has Conversion rank (it's considered to be a new kind of conversion unique to C, a "compatible" conversion). Known defects (and, therefore, next steps): 1) The standard-conversion handling does not understand conversions involving _Complex or vector extensions, so it is likely to get these wrong. We need to add these conversions. 2) All overloadable functions with the same name will have the same linkage name, which means we'll get a collision in the linker (if not sooner). We'll need to mangle the names of these functions. llvm-svn: 64336
2009-02-12 07:02:49 +08:00
// There are no standard conversions for class types in C++, so
// abort early. When overloading in C, however, we do permit
Initial implementation of function overloading in C. This commit adds a new attribute, "overloadable", that enables C++ function overloading in C. The attribute can only be added to function declarations, e.g., int *f(int) __attribute__((overloadable)); If the "overloadable" attribute exists on a function with a given name, *all* functions with that name (and in that scope) must have the "overloadable" attribute. Sets of overloaded functions with the "overloadable" attribute then follow the normal C++ rules for overloaded functions, e.g., overloads must have different parameter-type-lists from each other. When calling an overloaded function in C, we follow the same overloading rules as C++, with three extensions to the set of standard conversions: - A value of a given struct or union type T can be converted to the type T. This is just the identity conversion. (In C++, this would go through a copy constructor). - A value of pointer type T* can be converted to a value of type U* if T and U are compatible types. This conversion has Conversion rank (it's considered a pointer conversion in C). - A value of type T can be converted to a value of type U if T and U are compatible (and are not both pointer types). This conversion has Conversion rank (it's considered to be a new kind of conversion unique to C, a "compatible" conversion). Known defects (and, therefore, next steps): 1) The standard-conversion handling does not understand conversions involving _Complex or vector extensions, so it is likely to get these wrong. We need to add these conversions. 2) All overloadable functions with the same name will have the same linkage name, which means we'll get a collision in the linker (if not sooner). We'll need to mangle the names of these functions. llvm-svn: 64336
2009-02-12 07:02:49 +08:00
if (FromType->isRecordType() || ToType->isRecordType()) {
if (getLangOptions().CPlusPlus)
return false;
// When we're overloading in C, we allow, as standard conversions,
Initial implementation of function overloading in C. This commit adds a new attribute, "overloadable", that enables C++ function overloading in C. The attribute can only be added to function declarations, e.g., int *f(int) __attribute__((overloadable)); If the "overloadable" attribute exists on a function with a given name, *all* functions with that name (and in that scope) must have the "overloadable" attribute. Sets of overloaded functions with the "overloadable" attribute then follow the normal C++ rules for overloaded functions, e.g., overloads must have different parameter-type-lists from each other. When calling an overloaded function in C, we follow the same overloading rules as C++, with three extensions to the set of standard conversions: - A value of a given struct or union type T can be converted to the type T. This is just the identity conversion. (In C++, this would go through a copy constructor). - A value of pointer type T* can be converted to a value of type U* if T and U are compatible types. This conversion has Conversion rank (it's considered a pointer conversion in C). - A value of type T can be converted to a value of type U if T and U are compatible (and are not both pointer types). This conversion has Conversion rank (it's considered to be a new kind of conversion unique to C, a "compatible" conversion). Known defects (and, therefore, next steps): 1) The standard-conversion handling does not understand conversions involving _Complex or vector extensions, so it is likely to get these wrong. We need to add these conversions. 2) All overloadable functions with the same name will have the same linkage name, which means we'll get a collision in the linker (if not sooner). We'll need to mangle the names of these functions. llvm-svn: 64336
2009-02-12 07:02:49 +08:00
}
// The first conversion can be an lvalue-to-rvalue conversion,
// array-to-pointer conversion, or function-to-pointer conversion
// (C++ 4p1).
if (FromType == Context.OverloadTy) {
DeclAccessPair AccessPair;
if (FunctionDecl *Fn
= ResolveAddressOfOverloadedFunction(From, ToType, false,
AccessPair)) {
// We were able to resolve the address of the overloaded function,
// so we can convert to the type of that function.
FromType = Fn->getType();
if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) {
if (!Method->isStatic()) {
Type *ClassType
= Context.getTypeDeclType(Method->getParent()).getTypePtr();
FromType = Context.getMemberPointerType(FromType, ClassType);
}
}
// If the "from" expression takes the address of the overloaded
// function, update the type of the resulting expression accordingly.
if (FromType->getAs<FunctionType>())
if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(From->IgnoreParens()))
if (UnOp->getOpcode() == UnaryOperator::AddrOf)
FromType = Context.getPointerType(FromType);
// Check that we've computed the proper type after overload resolution.
assert(Context.hasSameType(FromType,
FixOverloadedFunctionReference(From, AccessPair, Fn)->getType()));
} else {
return false;
}
}
// Lvalue-to-rvalue conversion (C++ 4.1):
// An lvalue (3.10) of a non-function, non-array type T can be
// converted to an rvalue.
Expr::isLvalueResult argIsLvalue = From->isLvalue(Context);
if (argIsLvalue == Expr::LV_Valid &&
!FromType->isFunctionType() && !FromType->isArrayType() &&
Context.getCanonicalType(FromType) != Context.OverloadTy) {
SCS.First = ICK_Lvalue_To_Rvalue;
// If T is a non-class type, the type of the rvalue is the
// cv-unqualified version of T. Otherwise, the type of the rvalue
Initial implementation of function overloading in C. This commit adds a new attribute, "overloadable", that enables C++ function overloading in C. The attribute can only be added to function declarations, e.g., int *f(int) __attribute__((overloadable)); If the "overloadable" attribute exists on a function with a given name, *all* functions with that name (and in that scope) must have the "overloadable" attribute. Sets of overloaded functions with the "overloadable" attribute then follow the normal C++ rules for overloaded functions, e.g., overloads must have different parameter-type-lists from each other. When calling an overloaded function in C, we follow the same overloading rules as C++, with three extensions to the set of standard conversions: - A value of a given struct or union type T can be converted to the type T. This is just the identity conversion. (In C++, this would go through a copy constructor). - A value of pointer type T* can be converted to a value of type U* if T and U are compatible types. This conversion has Conversion rank (it's considered a pointer conversion in C). - A value of type T can be converted to a value of type U if T and U are compatible (and are not both pointer types). This conversion has Conversion rank (it's considered to be a new kind of conversion unique to C, a "compatible" conversion). Known defects (and, therefore, next steps): 1) The standard-conversion handling does not understand conversions involving _Complex or vector extensions, so it is likely to get these wrong. We need to add these conversions. 2) All overloadable functions with the same name will have the same linkage name, which means we'll get a collision in the linker (if not sooner). We'll need to mangle the names of these functions. llvm-svn: 64336
2009-02-12 07:02:49 +08:00
// is T (C++ 4.1p1). C++ can't get here with class types; in C, we
// just strip the qualifiers because they don't matter.
FromType = FromType.getUnqualifiedType();
2009-08-05 05:02:39 +08:00
} else if (FromType->isArrayType()) {
// Array-to-pointer conversion (C++ 4.2)
SCS.First = ICK_Array_To_Pointer;
// An lvalue or rvalue of type "array of N T" or "array of unknown
// bound of T" can be converted to an rvalue of type "pointer to
// T" (C++ 4.2p1).
FromType = Context.getArrayDecayedType(FromType);
if (IsStringLiteralToNonConstPointerConversion(From, ToType)) {
// This conversion is deprecated. (C++ D.4).
SCS.DeprecatedStringLiteralToCharPtr = true;
// For the purpose of ranking in overload resolution
// (13.3.3.1.1), this conversion is considered an
// array-to-pointer conversion followed by a qualification
// conversion (4.4). (C++ 4.2p2)
SCS.Second = ICK_Identity;
SCS.Third = ICK_Qualification;
SCS.setAllToTypes(FromType);
return true;
}
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} else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) {
// Function-to-pointer conversion (C++ 4.3).
SCS.First = ICK_Function_To_Pointer;
// An lvalue of function type T can be converted to an rvalue of
// type "pointer to T." The result is a pointer to the
// function. (C++ 4.3p1).
FromType = Context.getPointerType(FromType);
2009-08-05 05:02:39 +08:00
} else {
// We don't require any conversions for the first step.
SCS.First = ICK_Identity;
}
SCS.setToType(0, FromType);
// The second conversion can be an integral promotion, floating
// point promotion, integral conversion, floating point conversion,
// floating-integral conversion, pointer conversion,
// pointer-to-member conversion, or boolean conversion (C++ 4p1).
Initial implementation of function overloading in C. This commit adds a new attribute, "overloadable", that enables C++ function overloading in C. The attribute can only be added to function declarations, e.g., int *f(int) __attribute__((overloadable)); If the "overloadable" attribute exists on a function with a given name, *all* functions with that name (and in that scope) must have the "overloadable" attribute. Sets of overloaded functions with the "overloadable" attribute then follow the normal C++ rules for overloaded functions, e.g., overloads must have different parameter-type-lists from each other. When calling an overloaded function in C, we follow the same overloading rules as C++, with three extensions to the set of standard conversions: - A value of a given struct or union type T can be converted to the type T. This is just the identity conversion. (In C++, this would go through a copy constructor). - A value of pointer type T* can be converted to a value of type U* if T and U are compatible types. This conversion has Conversion rank (it's considered a pointer conversion in C). - A value of type T can be converted to a value of type U if T and U are compatible (and are not both pointer types). This conversion has Conversion rank (it's considered to be a new kind of conversion unique to C, a "compatible" conversion). Known defects (and, therefore, next steps): 1) The standard-conversion handling does not understand conversions involving _Complex or vector extensions, so it is likely to get these wrong. We need to add these conversions. 2) All overloadable functions with the same name will have the same linkage name, which means we'll get a collision in the linker (if not sooner). We'll need to mangle the names of these functions. llvm-svn: 64336
2009-02-12 07:02:49 +08:00
// For overloading in C, this can also be a "compatible-type"
// conversion.
bool IncompatibleObjC = false;
Initial implementation of function overloading in C. This commit adds a new attribute, "overloadable", that enables C++ function overloading in C. The attribute can only be added to function declarations, e.g., int *f(int) __attribute__((overloadable)); If the "overloadable" attribute exists on a function with a given name, *all* functions with that name (and in that scope) must have the "overloadable" attribute. Sets of overloaded functions with the "overloadable" attribute then follow the normal C++ rules for overloaded functions, e.g., overloads must have different parameter-type-lists from each other. When calling an overloaded function in C, we follow the same overloading rules as C++, with three extensions to the set of standard conversions: - A value of a given struct or union type T can be converted to the type T. This is just the identity conversion. (In C++, this would go through a copy constructor). - A value of pointer type T* can be converted to a value of type U* if T and U are compatible types. This conversion has Conversion rank (it's considered a pointer conversion in C). - A value of type T can be converted to a value of type U if T and U are compatible (and are not both pointer types). This conversion has Conversion rank (it's considered to be a new kind of conversion unique to C, a "compatible" conversion). Known defects (and, therefore, next steps): 1) The standard-conversion handling does not understand conversions involving _Complex or vector extensions, so it is likely to get these wrong. We need to add these conversions. 2) All overloadable functions with the same name will have the same linkage name, which means we'll get a collision in the linker (if not sooner). We'll need to mangle the names of these functions. llvm-svn: 64336
2009-02-12 07:02:49 +08:00
if (Context.hasSameUnqualifiedType(FromType, ToType)) {
// The unqualified versions of the types are the same: there's no
// conversion to do.
SCS.Second = ICK_Identity;
2009-08-05 05:02:39 +08:00
} else if (IsIntegralPromotion(From, FromType, ToType)) {
// Integral promotion (C++ 4.5).
SCS.Second = ICK_Integral_Promotion;
FromType = ToType.getUnqualifiedType();
2009-08-05 05:02:39 +08:00
} else if (IsFloatingPointPromotion(FromType, ToType)) {
// Floating point promotion (C++ 4.6).
SCS.Second = ICK_Floating_Promotion;
FromType = ToType.getUnqualifiedType();
2009-08-05 05:02:39 +08:00
} else if (IsComplexPromotion(FromType, ToType)) {
// Complex promotion (Clang extension)
SCS.Second = ICK_Complex_Promotion;
FromType = ToType.getUnqualifiedType();
2009-08-05 05:02:39 +08:00
} else if ((FromType->isIntegralType() || FromType->isEnumeralType()) &&
(ToType->isIntegralType() && !ToType->isEnumeralType())) {
2009-08-05 05:02:39 +08:00
// Integral conversions (C++ 4.7).
SCS.Second = ICK_Integral_Conversion;
FromType = ToType.getUnqualifiedType();
2009-08-05 05:02:39 +08:00
} else if (FromType->isComplexType() && ToType->isComplexType()) {
// Complex conversions (C99 6.3.1.6)
SCS.Second = ICK_Complex_Conversion;
FromType = ToType.getUnqualifiedType();
} else if ((FromType->isComplexType() && ToType->isArithmeticType()) ||
(ToType->isComplexType() && FromType->isArithmeticType())) {
// Complex-real conversions (C99 6.3.1.7)
SCS.Second = ICK_Complex_Real;
FromType = ToType.getUnqualifiedType();
} else if (FromType->isFloatingType() && ToType->isFloatingType()) {
// Floating point conversions (C++ 4.8).
SCS.Second = ICK_Floating_Conversion;
FromType = ToType.getUnqualifiedType();
2009-08-05 05:02:39 +08:00
} else if ((FromType->isFloatingType() &&
ToType->isIntegralType() && (!ToType->isBooleanType() &&
!ToType->isEnumeralType())) ||
((FromType->isIntegralType() || FromType->isEnumeralType()) &&
2009-08-05 05:02:39 +08:00
ToType->isFloatingType())) {
// Floating-integral conversions (C++ 4.9).
SCS.Second = ICK_Floating_Integral;
FromType = ToType.getUnqualifiedType();
} else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution,
FromType, IncompatibleObjC)) {
2009-08-05 05:02:39 +08:00
// Pointer conversions (C++ 4.10).
SCS.Second = ICK_Pointer_Conversion;
SCS.IncompatibleObjC = IncompatibleObjC;
} else if (IsMemberPointerConversion(From, FromType, ToType,
InOverloadResolution, FromType)) {
2009-08-05 05:02:39 +08:00
// Pointer to member conversions (4.11).
SCS.Second = ICK_Pointer_Member;
2009-08-05 05:02:39 +08:00
} else if (ToType->isBooleanType() &&
(FromType->isArithmeticType() ||
FromType->isEnumeralType() ||
FromType->isAnyPointerType() ||
2009-08-05 05:02:39 +08:00
FromType->isBlockPointerType() ||
FromType->isMemberPointerType() ||
FromType->isNullPtrType())) {
// Boolean conversions (C++ 4.12).
SCS.Second = ICK_Boolean_Conversion;
FromType = Context.BoolTy;
} else if (!getLangOptions().CPlusPlus &&
2009-08-05 05:02:39 +08:00
Context.typesAreCompatible(ToType, FromType)) {
// Compatible conversions (Clang extension for C function overloading)
Initial implementation of function overloading in C. This commit adds a new attribute, "overloadable", that enables C++ function overloading in C. The attribute can only be added to function declarations, e.g., int *f(int) __attribute__((overloadable)); If the "overloadable" attribute exists on a function with a given name, *all* functions with that name (and in that scope) must have the "overloadable" attribute. Sets of overloaded functions with the "overloadable" attribute then follow the normal C++ rules for overloaded functions, e.g., overloads must have different parameter-type-lists from each other. When calling an overloaded function in C, we follow the same overloading rules as C++, with three extensions to the set of standard conversions: - A value of a given struct or union type T can be converted to the type T. This is just the identity conversion. (In C++, this would go through a copy constructor). - A value of pointer type T* can be converted to a value of type U* if T and U are compatible types. This conversion has Conversion rank (it's considered a pointer conversion in C). - A value of type T can be converted to a value of type U if T and U are compatible (and are not both pointer types). This conversion has Conversion rank (it's considered to be a new kind of conversion unique to C, a "compatible" conversion). Known defects (and, therefore, next steps): 1) The standard-conversion handling does not understand conversions involving _Complex or vector extensions, so it is likely to get these wrong. We need to add these conversions. 2) All overloadable functions with the same name will have the same linkage name, which means we'll get a collision in the linker (if not sooner). We'll need to mangle the names of these functions. llvm-svn: 64336
2009-02-12 07:02:49 +08:00
SCS.Second = ICK_Compatible_Conversion;
} else if (IsNoReturnConversion(Context, FromType, ToType, FromType)) {
// Treat a conversion that strips "noreturn" as an identity conversion.
SCS.Second = ICK_NoReturn_Adjustment;
} else {
// No second conversion required.
SCS.Second = ICK_Identity;
}
SCS.setToType(1, FromType);
QualType CanonFrom;
QualType CanonTo;
// The third conversion can be a qualification conversion (C++ 4p1).
if (IsQualificationConversion(FromType, ToType)) {
SCS.Third = ICK_Qualification;
FromType = ToType;
CanonFrom = Context.getCanonicalType(FromType);
CanonTo = Context.getCanonicalType(ToType);
} else {
// No conversion required
SCS.Third = ICK_Identity;
// C++ [over.best.ics]p6:
// [...] Any difference in top-level cv-qualification is
// subsumed by the initialization itself and does not constitute
// a conversion. [...]
CanonFrom = Context.getCanonicalType(FromType);
CanonTo = Context.getCanonicalType(ToType);
if (CanonFrom.getLocalUnqualifiedType()
== CanonTo.getLocalUnqualifiedType() &&
CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers()) {
FromType = ToType;
CanonFrom = CanonTo;
}
}
SCS.setToType(2, FromType);
// If we have not converted the argument type to the parameter type,
// this is a bad conversion sequence.
if (CanonFrom != CanonTo)
return false;
return true;
}
/// IsIntegralPromotion - Determines whether the conversion from the
/// expression From (whose potentially-adjusted type is FromType) to
/// ToType is an integral promotion (C++ 4.5). If so, returns true and
/// sets PromotedType to the promoted type.
bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) {
const BuiltinType *To = ToType->getAs<BuiltinType>();
// All integers are built-in.
if (!To) {
return false;
}
// An rvalue of type char, signed char, unsigned char, short int, or
// unsigned short int can be converted to an rvalue of type int if
// int can represent all the values of the source type; otherwise,
// the source rvalue can be converted to an rvalue of type unsigned
// int (C++ 4.5p1).
if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() &&
!FromType->isEnumeralType()) {
if (// We can promote any signed, promotable integer type to an int
(FromType->isSignedIntegerType() ||
// We can promote any unsigned integer type whose size is
// less than int to an int.
(!FromType->isSignedIntegerType() &&
Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) {
return To->getKind() == BuiltinType::Int;
}
return To->getKind() == BuiltinType::UInt;
}
// An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2)
// can be converted to an rvalue of the first of the following types
// that can represent all the values of its underlying type: int,
// unsigned int, long, or unsigned long (C++ 4.5p2).
// We pre-calculate the promotion type for enum types.
if (const EnumType *FromEnumType = FromType->getAs<EnumType>())
if (ToType->isIntegerType())
return Context.hasSameUnqualifiedType(ToType,
FromEnumType->getDecl()->getPromotionType());
if (FromType->isWideCharType() && ToType->isIntegerType()) {
// Determine whether the type we're converting from is signed or
// unsigned.
bool FromIsSigned;
uint64_t FromSize = Context.getTypeSize(FromType);
// FIXME: Is wchar_t signed or unsigned? We assume it's signed for now.
FromIsSigned = true;
// The types we'll try to promote to, in the appropriate
// order. Try each of these types.
QualType PromoteTypes[6] = {
Context.IntTy, Context.UnsignedIntTy,
Context.LongTy, Context.UnsignedLongTy ,
Context.LongLongTy, Context.UnsignedLongLongTy
};
for (int Idx = 0; Idx < 6; ++Idx) {
uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]);
if (FromSize < ToSize ||
(FromSize == ToSize &&
FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) {
// We found the type that we can promote to. If this is the
// type we wanted, we have a promotion. Otherwise, no
// promotion.
return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]);
}
}
}
// An rvalue for an integral bit-field (9.6) can be converted to an
// rvalue of type int if int can represent all the values of the
// bit-field; otherwise, it can be converted to unsigned int if
// unsigned int can represent all the values of the bit-field. If
// the bit-field is larger yet, no integral promotion applies to
// it. If the bit-field has an enumerated type, it is treated as any
// other value of that type for promotion purposes (C++ 4.5p3).
2009-05-16 15:39:55 +08:00
// FIXME: We should delay checking of bit-fields until we actually perform the
// conversion.
using llvm::APSInt;
if (From)
if (FieldDecl *MemberDecl = From->getBitField()) {
APSInt BitWidth;
if (FromType->isIntegralType() && !FromType->isEnumeralType() &&
MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) {
APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned());
ToSize = Context.getTypeSize(ToType);
// Are we promoting to an int from a bitfield that fits in an int?
if (BitWidth < ToSize ||
(FromType->isSignedIntegerType() && BitWidth <= ToSize)) {
return To->getKind() == BuiltinType::Int;
}
// Are we promoting to an unsigned int from an unsigned bitfield
// that fits into an unsigned int?
if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) {
return To->getKind() == BuiltinType::UInt;
}
return false;
}
}
// An rvalue of type bool can be converted to an rvalue of type int,
// with false becoming zero and true becoming one (C++ 4.5p4).
if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) {
return true;
}
return false;
}
/// IsFloatingPointPromotion - Determines whether the conversion from
/// FromType to ToType is a floating point promotion (C++ 4.6). If so,
/// returns true and sets PromotedType to the promoted type.
bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) {
/// An rvalue of type float can be converted to an rvalue of type
/// double. (C++ 4.6p1).
if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>())
if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) {
if (FromBuiltin->getKind() == BuiltinType::Float &&
ToBuiltin->getKind() == BuiltinType::Double)
return true;
// C99 6.3.1.5p1:
// When a float is promoted to double or long double, or a
// double is promoted to long double [...].
if (!getLangOptions().CPlusPlus &&
(FromBuiltin->getKind() == BuiltinType::Float ||
FromBuiltin->getKind() == BuiltinType::Double) &&
(ToBuiltin->getKind() == BuiltinType::LongDouble))
return true;
}
return false;
}
/// \brief Determine if a conversion is a complex promotion.
///
/// A complex promotion is defined as a complex -> complex conversion
/// where the conversion between the underlying real types is a
/// floating-point or integral promotion.
bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) {
const ComplexType *FromComplex = FromType->getAs<ComplexType>();
if (!FromComplex)
return false;
const ComplexType *ToComplex = ToType->getAs<ComplexType>();
if (!ToComplex)
return false;
return IsFloatingPointPromotion(FromComplex->getElementType(),
ToComplex->getElementType()) ||
IsIntegralPromotion(0, FromComplex->getElementType(),
ToComplex->getElementType());
}
/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from
/// the pointer type FromPtr to a pointer to type ToPointee, with the
/// same type qualifiers as FromPtr has on its pointee type. ToType,
/// if non-empty, will be a pointer to ToType that may or may not have
/// the right set of qualifiers on its pointee.
static QualType
BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr,
QualType ToPointee, QualType ToType,
ASTContext &Context) {
QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType());
QualType CanonToPointee = Context.getCanonicalType(ToPointee);
Qualifiers Quals = CanonFromPointee.getQualifiers();
// Exact qualifier match -> return the pointer type we're converting to.
if (CanonToPointee.getLocalQualifiers() == Quals) {
// ToType is exactly what we need. Return it.
if (!ToType.isNull())
return ToType;
// Build a pointer to ToPointee. It has the right qualifiers
// already.
return Context.getPointerType(ToPointee);
}
// Just build a canonical type that has the right qualifiers.
return Context.getPointerType(
Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(),
Quals));
}
/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from
/// the FromType, which is an objective-c pointer, to ToType, which may or may
/// not have the right set of qualifiers.
static QualType
BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType,
QualType ToType,
ASTContext &Context) {
QualType CanonFromType = Context.getCanonicalType(FromType);
QualType CanonToType = Context.getCanonicalType(ToType);
Qualifiers Quals = CanonFromType.getQualifiers();
// Exact qualifier match -> return the pointer type we're converting to.
if (CanonToType.getLocalQualifiers() == Quals)
return ToType;
// Just build a canonical type that has the right qualifiers.
return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals);
}
static bool isNullPointerConstantForConversion(Expr *Expr,
bool InOverloadResolution,
ASTContext &Context) {
// Handle value-dependent integral null pointer constants correctly.
// http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903
if (Expr->isValueDependent() && !Expr->isTypeDependent() &&
Expr->getType()->isIntegralType())
return !InOverloadResolution;
return Expr->isNullPointerConstant(Context,
InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
: Expr::NPC_ValueDependentIsNull);
}
/// IsPointerConversion - Determines whether the conversion of the
/// expression From, which has the (possibly adjusted) type FromType,
/// can be converted to the type ToType via a pointer conversion (C++
/// 4.10). If so, returns true and places the converted type (that
/// might differ from ToType in its cv-qualifiers at some level) into
/// ConvertedType.
///
/// This routine also supports conversions to and from block pointers
/// and conversions with Objective-C's 'id', 'id<protocols...>', and
/// pointers to interfaces. FIXME: Once we've determined the
/// appropriate overloading rules for Objective-C, we may want to
/// split the Objective-C checks into a different routine; however,
/// GCC seems to consider all of these conversions to be pointer
/// conversions, so for now they live here. IncompatibleObjC will be
/// set if the conversion is an allowed Objective-C conversion that
/// should result in a warning.
bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType,
bool InOverloadResolution,
QualType& ConvertedType,
bool &IncompatibleObjC) {
IncompatibleObjC = false;
if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC))
return true;
// Conversion from a null pointer constant to any Objective-C pointer type.
if (ToType->isObjCObjectPointerType() &&
isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
ConvertedType = ToType;
return true;
}
// Blocks: Block pointers can be converted to void*.
if (FromType->isBlockPointerType() && ToType->isPointerType() &&
ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) {
ConvertedType = ToType;
return true;
}
// Blocks: A null pointer constant can be converted to a block
// pointer type.
if (ToType->isBlockPointerType() &&
isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
ConvertedType = ToType;
return true;
}
// If the left-hand-side is nullptr_t, the right side can be a null
// pointer constant.
if (ToType->isNullPtrType() &&
isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
ConvertedType = ToType;
return true;
}
const PointerType* ToTypePtr = ToType->getAs<PointerType>();
if (!ToTypePtr)
return false;
// A null pointer constant can be converted to a pointer type (C++ 4.10p1).
if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
ConvertedType = ToType;
return true;
}
// Beyond this point, both types need to be pointers
// , including objective-c pointers.
QualType ToPointeeType = ToTypePtr->getPointeeType();
if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) {
ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType,
ToType, Context);
return true;
}
const PointerType *FromTypePtr = FromType->getAs<PointerType>();
if (!FromTypePtr)
return false;
QualType FromPointeeType = FromTypePtr->getPointeeType();
// An rvalue of type "pointer to cv T," where T is an object type,
// can be converted to an rvalue of type "pointer to cv void" (C++
// 4.10p2).
if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) {
ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2008-11-27 08:52:49 +08:00
ToPointeeType,
ToType, Context);
return true;
}
Initial implementation of function overloading in C. This commit adds a new attribute, "overloadable", that enables C++ function overloading in C. The attribute can only be added to function declarations, e.g., int *f(int) __attribute__((overloadable)); If the "overloadable" attribute exists on a function with a given name, *all* functions with that name (and in that scope) must have the "overloadable" attribute. Sets of overloaded functions with the "overloadable" attribute then follow the normal C++ rules for overloaded functions, e.g., overloads must have different parameter-type-lists from each other. When calling an overloaded function in C, we follow the same overloading rules as C++, with three extensions to the set of standard conversions: - A value of a given struct or union type T can be converted to the type T. This is just the identity conversion. (In C++, this would go through a copy constructor). - A value of pointer type T* can be converted to a value of type U* if T and U are compatible types. This conversion has Conversion rank (it's considered a pointer conversion in C). - A value of type T can be converted to a value of type U if T and U are compatible (and are not both pointer types). This conversion has Conversion rank (it's considered to be a new kind of conversion unique to C, a "compatible" conversion). Known defects (and, therefore, next steps): 1) The standard-conversion handling does not understand conversions involving _Complex or vector extensions, so it is likely to get these wrong. We need to add these conversions. 2) All overloadable functions with the same name will have the same linkage name, which means we'll get a collision in the linker (if not sooner). We'll need to mangle the names of these functions. llvm-svn: 64336
2009-02-12 07:02:49 +08:00
// When we're overloading in C, we allow a special kind of pointer
// conversion for compatible-but-not-identical pointee types.
if (!getLangOptions().CPlusPlus &&
Initial implementation of function overloading in C. This commit adds a new attribute, "overloadable", that enables C++ function overloading in C. The attribute can only be added to function declarations, e.g., int *f(int) __attribute__((overloadable)); If the "overloadable" attribute exists on a function with a given name, *all* functions with that name (and in that scope) must have the "overloadable" attribute. Sets of overloaded functions with the "overloadable" attribute then follow the normal C++ rules for overloaded functions, e.g., overloads must have different parameter-type-lists from each other. When calling an overloaded function in C, we follow the same overloading rules as C++, with three extensions to the set of standard conversions: - A value of a given struct or union type T can be converted to the type T. This is just the identity conversion. (In C++, this would go through a copy constructor). - A value of pointer type T* can be converted to a value of type U* if T and U are compatible types. This conversion has Conversion rank (it's considered a pointer conversion in C). - A value of type T can be converted to a value of type U if T and U are compatible (and are not both pointer types). This conversion has Conversion rank (it's considered to be a new kind of conversion unique to C, a "compatible" conversion). Known defects (and, therefore, next steps): 1) The standard-conversion handling does not understand conversions involving _Complex or vector extensions, so it is likely to get these wrong. We need to add these conversions. 2) All overloadable functions with the same name will have the same linkage name, which means we'll get a collision in the linker (if not sooner). We'll need to mangle the names of these functions. llvm-svn: 64336
2009-02-12 07:02:49 +08:00
Context.typesAreCompatible(FromPointeeType, ToPointeeType)) {
ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
Initial implementation of function overloading in C. This commit adds a new attribute, "overloadable", that enables C++ function overloading in C. The attribute can only be added to function declarations, e.g., int *f(int) __attribute__((overloadable)); If the "overloadable" attribute exists on a function with a given name, *all* functions with that name (and in that scope) must have the "overloadable" attribute. Sets of overloaded functions with the "overloadable" attribute then follow the normal C++ rules for overloaded functions, e.g., overloads must have different parameter-type-lists from each other. When calling an overloaded function in C, we follow the same overloading rules as C++, with three extensions to the set of standard conversions: - A value of a given struct or union type T can be converted to the type T. This is just the identity conversion. (In C++, this would go through a copy constructor). - A value of pointer type T* can be converted to a value of type U* if T and U are compatible types. This conversion has Conversion rank (it's considered a pointer conversion in C). - A value of type T can be converted to a value of type U if T and U are compatible (and are not both pointer types). This conversion has Conversion rank (it's considered to be a new kind of conversion unique to C, a "compatible" conversion). Known defects (and, therefore, next steps): 1) The standard-conversion handling does not understand conversions involving _Complex or vector extensions, so it is likely to get these wrong. We need to add these conversions. 2) All overloadable functions with the same name will have the same linkage name, which means we'll get a collision in the linker (if not sooner). We'll need to mangle the names of these functions. llvm-svn: 64336
2009-02-12 07:02:49 +08:00
ToPointeeType,
ToType, Context);
Initial implementation of function overloading in C. This commit adds a new attribute, "overloadable", that enables C++ function overloading in C. The attribute can only be added to function declarations, e.g., int *f(int) __attribute__((overloadable)); If the "overloadable" attribute exists on a function with a given name, *all* functions with that name (and in that scope) must have the "overloadable" attribute. Sets of overloaded functions with the "overloadable" attribute then follow the normal C++ rules for overloaded functions, e.g., overloads must have different parameter-type-lists from each other. When calling an overloaded function in C, we follow the same overloading rules as C++, with three extensions to the set of standard conversions: - A value of a given struct or union type T can be converted to the type T. This is just the identity conversion. (In C++, this would go through a copy constructor). - A value of pointer type T* can be converted to a value of type U* if T and U are compatible types. This conversion has Conversion rank (it's considered a pointer conversion in C). - A value of type T can be converted to a value of type U if T and U are compatible (and are not both pointer types). This conversion has Conversion rank (it's considered to be a new kind of conversion unique to C, a "compatible" conversion). Known defects (and, therefore, next steps): 1) The standard-conversion handling does not understand conversions involving _Complex or vector extensions, so it is likely to get these wrong. We need to add these conversions. 2) All overloadable functions with the same name will have the same linkage name, which means we'll get a collision in the linker (if not sooner). We'll need to mangle the names of these functions. llvm-svn: 64336
2009-02-12 07:02:49 +08:00
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.
Initial implementation of function overloading in C. This commit adds a new attribute, "overloadable", that enables C++ function overloading in C. The attribute can only be added to function declarations, e.g., int *f(int) __attribute__((overloadable)); If the "overloadable" attribute exists on a function with a given name, *all* functions with that name (and in that scope) must have the "overloadable" attribute. Sets of overloaded functions with the "overloadable" attribute then follow the normal C++ rules for overloaded functions, e.g., overloads must have different parameter-type-lists from each other. When calling an overloaded function in C, we follow the same overloading rules as C++, with three extensions to the set of standard conversions: - A value of a given struct or union type T can be converted to the type T. This is just the identity conversion. (In C++, this would go through a copy constructor). - A value of pointer type T* can be converted to a value of type U* if T and U are compatible types. This conversion has Conversion rank (it's considered a pointer conversion in C). - A value of type T can be converted to a value of type U if T and U are compatible (and are not both pointer types). This conversion has Conversion rank (it's considered to be a new kind of conversion unique to C, a "compatible" conversion). Known defects (and, therefore, next steps): 1) The standard-conversion handling does not understand conversions involving _Complex or vector extensions, so it is likely to get these wrong. We need to add these conversions. 2) All overloadable functions with the same name will have the same linkage name, which means we'll get a collision in the linker (if not sooner). We'll need to mangle the names of these functions. llvm-svn: 64336
2009-02-12 07:02:49 +08:00
if (getLangOptions().CPlusPlus &&
FromPointeeType->isRecordType() && ToPointeeType->isRecordType() &&
!Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) &&
!RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) &&
IsDerivedFrom(FromPointeeType, ToPointeeType)) {
ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2008-11-27 08:52:49 +08:00
ToPointeeType,
ToType, Context);
return true;
}
return false;
}
/// isObjCPointerConversion - Determines whether this is an
/// Objective-C pointer conversion. Subroutine of IsPointerConversion,
/// with the same arguments and return values.
bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType,
QualType& ConvertedType,
bool &IncompatibleObjC) {
if (!getLangOptions().ObjC1)
return false;
// First, we handle all conversions on ObjC object pointer types.
const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>();
const ObjCObjectPointerType *FromObjCPtr =
FromType->getAs<ObjCObjectPointerType>();
if (ToObjCPtr && FromObjCPtr) {
// Objective C++: We're able to convert between "id" or "Class" and a
// pointer to any interface (in both directions).
if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) {
ConvertedType = ToType;
return true;
}
// Conversions with Objective-C's id<...>.
if ((FromObjCPtr->isObjCQualifiedIdType() ||
ToObjCPtr->isObjCQualifiedIdType()) &&
Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType,
/*compare=*/false)) {
ConvertedType = ToType;
return true;
}
// Objective C++: We're able to convert from a pointer to an
// interface to a pointer to a different interface.
if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) {
const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType();
const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType();
if (getLangOptions().CPlusPlus && LHS && RHS &&
!ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs(
FromObjCPtr->getPointeeType()))
return false;
ConvertedType = ToType;
return true;
}
if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) {
// Okay: this is some kind of implicit downcast of Objective-C
// interfaces, which is permitted. However, we're going to
// complain about it.
IncompatibleObjC = true;
ConvertedType = FromType;
return true;
}
}
// Beyond this point, both types need to be C pointers or block pointers.
QualType ToPointeeType;
if (const PointerType *ToCPtr = ToType->getAs<PointerType>())
ToPointeeType = ToCPtr->getPointeeType();
else if (const BlockPointerType *ToBlockPtr =
ToType->getAs<BlockPointerType>()) {
2010-01-21 08:08:17 +08:00
// Objective C++: We're able to convert from a pointer to any object
// to a block pointer type.
if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) {
ConvertedType = ToType;
return true;
}
ToPointeeType = ToBlockPtr->getPointeeType();
}
else if (FromType->getAs<BlockPointerType>() &&
ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) {
// Objective C++: We're able to convert from a block pointer type to a
2010-01-21 08:08:17 +08:00
// pointer to any object.
ConvertedType = ToType;
return true;
}
else
return false;
QualType FromPointeeType;
if (const PointerType *FromCPtr = FromType->getAs<PointerType>())
FromPointeeType = FromCPtr->getPointeeType();
else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>())
FromPointeeType = FromBlockPtr->getPointeeType();
else
return false;
// If we have pointers to pointers, recursively check whether this
// is an Objective-C conversion.
if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() &&
isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
IncompatibleObjC)) {
// We always complain about this conversion.
IncompatibleObjC = true;
ConvertedType = ToType;
return true;
}
// Allow conversion of pointee being objective-c pointer to another one;
// as in I* to id.
if (FromPointeeType->getAs<ObjCObjectPointerType>() &&
ToPointeeType->getAs<ObjCObjectPointerType>() &&
isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
IncompatibleObjC)) {
ConvertedType = ToType;
return true;
}
// If we have pointers to functions or blocks, check whether the only
// differences in the argument and result types are in Objective-C
// pointer conversions. If so, we permit the conversion (but
// complain about it).
const FunctionProtoType *FromFunctionType
= FromPointeeType->getAs<FunctionProtoType>();
const FunctionProtoType *ToFunctionType
= ToPointeeType->getAs<FunctionProtoType>();
if (FromFunctionType && ToFunctionType) {
// If the function types are exactly the same, this isn't an
// Objective-C pointer conversion.
if (Context.getCanonicalType(FromPointeeType)
== Context.getCanonicalType(ToPointeeType))
return false;
// Perform the quick checks that will tell us whether these
// function types are obviously different.
if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() ||
FromFunctionType->isVariadic() != ToFunctionType->isVariadic() ||
FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals())
return false;
bool HasObjCConversion = false;
if (Context.getCanonicalType(FromFunctionType->getResultType())
== Context.getCanonicalType(ToFunctionType->getResultType())) {
// Okay, the types match exactly. Nothing to do.
} else if (isObjCPointerConversion(FromFunctionType->getResultType(),
ToFunctionType->getResultType(),
ConvertedType, IncompatibleObjC)) {
// Okay, we have an Objective-C pointer conversion.
HasObjCConversion = true;
} else {
// Function types are too different. Abort.
return false;
}
// Check argument types.
for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs();
ArgIdx != NumArgs; ++ArgIdx) {
QualType FromArgType = FromFunctionType->getArgType(ArgIdx);
QualType ToArgType = ToFunctionType->getArgType(ArgIdx);
if (Context.getCanonicalType(FromArgType)
== Context.getCanonicalType(ToArgType)) {
// Okay, the types match exactly. Nothing to do.
} else if (isObjCPointerConversion(FromArgType, ToArgType,
ConvertedType, IncompatibleObjC)) {
// Okay, we have an Objective-C pointer conversion.
HasObjCConversion = true;
} else {
// Argument types are too different. Abort.
return false;
}
}
if (HasObjCConversion) {
// We had an Objective-C conversion. Allow this pointer
// conversion, but complain about it.
ConvertedType = ToType;
IncompatibleObjC = true;
return true;
}
}
return false;
}
/// FunctionArgTypesAreEqual - This routine checks two function proto types
/// for equlity of their argument types. Caller has already checked that
/// they have same number of arguments. This routine assumes that Objective-C
/// pointer types which only differ in their protocol qualifiers are equal.
bool Sema::FunctionArgTypesAreEqual(FunctionProtoType* OldType,
FunctionProtoType* NewType){
if (!getLangOptions().ObjC1)
return std::equal(OldType->arg_type_begin(), OldType->arg_type_end(),
NewType->arg_type_begin());
for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(),
N = NewType->arg_type_begin(),
E = OldType->arg_type_end(); O && (O != E); ++O, ++N) {
QualType ToType = (*O);
QualType FromType = (*N);
if (ToType != FromType) {
if (const PointerType *PTTo = ToType->getAs<PointerType>()) {
if (const PointerType *PTFr = FromType->getAs<PointerType>())
if ((PTTo->getPointeeType()->isObjCQualifiedIdType() &&
PTFr->getPointeeType()->isObjCQualifiedIdType()) ||
(PTTo->getPointeeType()->isObjCQualifiedClassType() &&
PTFr->getPointeeType()->isObjCQualifiedClassType()))
continue;
}
else if (const ObjCObjectPointerType *PTTo =
ToType->getAs<ObjCObjectPointerType>()) {
if (const ObjCObjectPointerType *PTFr =
FromType->getAs<ObjCObjectPointerType>())
if (PTTo->getInterfaceDecl() == PTFr->getInterfaceDecl())
continue;
}
return false;
}
}
return true;
}
/// CheckPointerConversion - Check the pointer conversion from the
/// expression From to the type ToType. This routine checks for
/// ambiguous or inaccessible derived-to-base pointer
/// conversions for which IsPointerConversion has already returned
/// true. It returns true and produces a diagnostic if there was an
/// error, or returns false otherwise.
bool Sema::CheckPointerConversion(Expr *From, QualType ToType,
CastExpr::CastKind &Kind,
CXXBaseSpecifierArray& BasePath,
bool IgnoreBaseAccess) {
QualType FromType = From->getType();
if (const PointerType *FromPtrType = FromType->getAs<PointerType>())
if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) {
QualType FromPointeeType = FromPtrType->getPointeeType(),
ToPointeeType = ToPtrType->getPointeeType();
if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() &&
!Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) {
// We must have a derived-to-base conversion. Check an
// ambiguous or inaccessible conversion.
if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType,
From->getExprLoc(),
From->getSourceRange(), &BasePath,
IgnoreBaseAccess))
return true;
// The conversion was successful.
Kind = CastExpr::CK_DerivedToBase;
}
}
if (const ObjCObjectPointerType *FromPtrType =
FromType->getAs<ObjCObjectPointerType>())
if (const ObjCObjectPointerType *ToPtrType =
ToType->getAs<ObjCObjectPointerType>()) {
// Objective-C++ conversions are always okay.
// FIXME: We should have a different class of conversions for the
// Objective-C++ implicit conversions.
if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType())
return false;
}
return false;
}
/// IsMemberPointerConversion - Determines whether the conversion of the
/// expression From, which has the (possibly adjusted) type FromType, can be
/// converted to the type ToType via a member pointer conversion (C++ 4.11).
/// If so, returns true and places the converted type (that might differ from
/// ToType in its cv-qualifiers at some level) into ConvertedType.
bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType,
QualType ToType,
bool InOverloadResolution,
QualType &ConvertedType) {
const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>();
if (!ToTypePtr)
return false;
// A null pointer constant can be converted to a member pointer (C++ 4.11p1)
if (From->isNullPointerConstant(Context,
InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
: Expr::NPC_ValueDependentIsNull)) {
ConvertedType = ToType;
return true;
}
// Otherwise, both types have to be member pointers.
const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>();
if (!FromTypePtr)
return false;
// A pointer to member of B can be converted to a pointer to member of D,
// where D is derived from B (C++ 4.11p2).
QualType FromClass(FromTypePtr->getClass(), 0);
QualType ToClass(ToTypePtr->getClass(), 0);
// FIXME: What happens when these are dependent? Is this function even called?
if (IsDerivedFrom(ToClass, FromClass)) {
ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(),
ToClass.getTypePtr());
return true;
}
return false;
}
/// CheckMemberPointerConversion - Check the member pointer conversion from the
/// expression From to the type ToType. This routine checks for ambiguous or
/// virtual or inaccessible base-to-derived member pointer conversions
/// for which IsMemberPointerConversion has already returned true. It returns
/// true and produces a diagnostic if there was an error, or returns false
/// otherwise.
bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType,
CastExpr::CastKind &Kind,
CXXBaseSpecifierArray &BasePath,
bool IgnoreBaseAccess) {
QualType FromType = From->getType();
const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>();
if (!FromPtrType) {
// This must be a null pointer to member pointer conversion
assert(From->isNullPointerConstant(Context,
Expr::NPC_ValueDependentIsNull) &&
"Expr must be null pointer constant!");
Kind = CastExpr::CK_NullToMemberPointer;
return false;
}
const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>();
assert(ToPtrType && "No member pointer cast has a target type "
"that is not a member pointer.");
QualType FromClass = QualType(FromPtrType->getClass(), 0);
QualType ToClass = QualType(ToPtrType->getClass(), 0);
// FIXME: What about dependent types?
assert(FromClass->isRecordType() && "Pointer into non-class.");
assert(ToClass->isRecordType() && "Pointer into non-class.");
CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
/*DetectVirtual=*/true);
bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths);
assert(DerivationOkay &&
"Should not have been called if derivation isn't OK.");
(void)DerivationOkay;
if (Paths.isAmbiguous(Context.getCanonicalType(FromClass).
getUnqualifiedType())) {
std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv)
<< 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange();
return true;
}
if (const RecordType *VBase = Paths.getDetectedVirtual()) {
Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual)
<< FromClass << ToClass << QualType(VBase, 0)
<< From->getSourceRange();
return true;
}
if (!IgnoreBaseAccess)
CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass,
Paths.front(),
diag::err_downcast_from_inaccessible_base);
// Must be a base to derived member conversion.
BuildBasePathArray(Paths, BasePath);
Kind = CastExpr::CK_BaseToDerivedMemberPointer;
return false;
}
/// IsQualificationConversion - Determines whether the conversion from
/// an rvalue of type FromType to ToType is a qualification conversion
/// (C++ 4.4).
bool
Sema::IsQualificationConversion(QualType FromType, QualType ToType) {
FromType = Context.getCanonicalType(FromType);
ToType = Context.getCanonicalType(ToType);
// If FromType and ToType are the same type, this is not a
// qualification conversion.
if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType())
return false;
// (C++ 4.4p4):
// A conversion can add cv-qualifiers at levels other than the first
// in multi-level pointers, subject to the following rules: [...]
bool PreviousToQualsIncludeConst = true;
bool UnwrappedAnyPointer = false;
while (UnwrapSimilarPointerTypes(FromType, ToType)) {
// Within each iteration of the loop, we check the qualifiers to
// determine if this still looks like a qualification
// conversion. Then, if all is well, we unwrap one more level of
// pointers or pointers-to-members and do it all again
// until there are no more pointers or pointers-to-members left to
// unwrap.
UnwrappedAnyPointer = true;
// -- for every j > 0, if const is in cv 1,j then const is in cv
// 2,j, and similarly for volatile.
if (!ToType.isAtLeastAsQualifiedAs(FromType))
return false;
// -- if the cv 1,j and cv 2,j are different, then const is in
// every cv for 0 < k < j.
if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers()
&& !PreviousToQualsIncludeConst)
return false;
// Keep track of whether all prior cv-qualifiers in the "to" type
// include const.
PreviousToQualsIncludeConst
= PreviousToQualsIncludeConst && ToType.isConstQualified();
}
// We are left with FromType and ToType being the pointee types
// after unwrapping the original FromType and ToType the same number
// of types. If we unwrapped any pointers, and if FromType and
// ToType have the same unqualified type (since we checked
// qualifiers above), then this is a qualification conversion.
return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType);
}
/// Determines whether there is a user-defined conversion sequence
/// (C++ [over.ics.user]) that converts expression From to the type
/// ToType. If such a conversion exists, User will contain the
/// user-defined conversion sequence that performs such a conversion
/// and this routine will return true. Otherwise, this routine returns
/// false and User is unspecified.
///
/// \param AllowExplicit true if the conversion should consider C++0x
/// "explicit" conversion functions as well as non-explicit conversion
/// functions (C++0x [class.conv.fct]p2).
Reimplement reference initialization (C++ [dcl.init.ref]) using the new notion of an "initialization sequence", which encapsulates the computation of the initialization sequence along with diagnostic information and the capability to turn the computed sequence into an expression. At present, I've only switched one CheckReferenceInit callers over to this new mechanism; more will follow. Aside from (hopefully) being much more true to the standard, the diagnostics provided by this reference-initialization code are a bit better than before. Some examples: p5-var.cpp:54:12: error: non-const lvalue reference to type 'struct Derived' cannot bind to a value of unrelated type 'struct Base' Derived &dr2 = b; // expected-error{{non-const lvalue reference to ... ^ ~ p5-var.cpp:55:9: error: binding of reference to type 'struct Base' to a value of type 'struct Base const' drops qualifiers Base &br3 = bc; // expected-error{{drops qualifiers}} ^ ~~ p5-var.cpp:57:15: error: ambiguous conversion from derived class 'struct Diamond' to base class 'struct Base': struct Diamond -> struct Derived -> struct Base struct Diamond -> struct Derived2 -> struct Base Base &br5 = diamond; // expected-error{{ambiguous conversion from ... ^~~~~~~ p5-var.cpp:59:9: error: non-const lvalue reference to type 'long' cannot bind to a value of unrelated type 'int' long &lr = i; // expected-error{{non-const lvalue reference to type ... ^ ~ p5-var.cpp:74:9: error: non-const lvalue reference to type 'struct Base' cannot bind to a temporary of type 'struct Base' Base &br1 = Base(); // expected-error{{non-const lvalue reference to ... ^ ~~~~~~ p5-var.cpp:102:9: error: non-const reference cannot bind to bit-field 'i' int & ir1 = (ib.i); // expected-error{{non-const reference cannot ... ^ ~~~~~~ p5-var.cpp:98:7: note: bit-field is declared here int i : 17; // expected-note{{bit-field is declared here}} ^ llvm-svn: 90992
2009-12-10 07:02:17 +08:00
OverloadingResult Sema::IsUserDefinedConversion(Expr *From, QualType ToType,
UserDefinedConversionSequence& User,
OverloadCandidateSet& CandidateSet,
bool AllowExplicit) {
// Whether we will only visit constructors.
bool ConstructorsOnly = false;
// If the type we are conversion to is a class type, enumerate its
// constructors.
if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) {
// C++ [over.match.ctor]p1:
// When objects of class type are direct-initialized (8.5), or
// copy-initialized from an expression of the same or a
// derived class type (8.5), overload resolution selects the
// constructor. [...] For copy-initialization, the candidate
// functions are all the converting constructors (12.3.1) of
// that class. The argument list is the expression-list within
// the parentheses of the initializer.
if (Context.hasSameUnqualifiedType(ToType, From->getType()) ||
(From->getType()->getAs<RecordType>() &&
IsDerivedFrom(From->getType(), ToType)))
ConstructorsOnly = true;
if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) {
// We're not going to find any constructors.
} else if (CXXRecordDecl *ToRecordDecl
= dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) {
DeclarationName ConstructorName
= Context.DeclarationNames.getCXXConstructorName(
Context.getCanonicalType(ToType).getUnqualifiedType());
DeclContext::lookup_iterator Con, ConEnd;
for (llvm::tie(Con, ConEnd)
= ToRecordDecl->lookup(ConstructorName);
Con != ConEnd; ++Con) {
NamedDecl *D = *Con;
DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess());
// Find the constructor (which may be a template).
CXXConstructorDecl *Constructor = 0;
FunctionTemplateDecl *ConstructorTmpl
= dyn_cast<FunctionTemplateDecl>(D);
if (ConstructorTmpl)
Constructor
= cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl());
else
Constructor = cast<CXXConstructorDecl>(D);
if (!Constructor->isInvalidDecl() &&
2009-08-29 00:57:08 +08:00
Constructor->isConvertingConstructor(AllowExplicit)) {
if (ConstructorTmpl)
AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl,
/*ExplicitArgs*/ 0,
&From, 1, CandidateSet,
/*SuppressUserConversions=*/!ConstructorsOnly);
else
// Allow one user-defined conversion when user specifies a
// From->ToType conversion via an static cast (c-style, etc).
AddOverloadCandidate(Constructor, FoundDecl,
&From, 1, CandidateSet,
/*SuppressUserConversions=*/!ConstructorsOnly);
}
}
}
}
// Enumerate conversion functions, if we're allowed to.
if (ConstructorsOnly) {
} else if (RequireCompleteType(From->getLocStart(), From->getType(),
PDiag(0) << From->getSourceRange())) {
// No conversion functions from incomplete types.
} else if (const RecordType *FromRecordType
= From->getType()->getAs<RecordType>()) {
if (CXXRecordDecl *FromRecordDecl
= dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) {
// Add all of the conversion functions as candidates.
const UnresolvedSetImpl *Conversions
= FromRecordDecl->getVisibleConversionFunctions();
for (UnresolvedSetImpl::iterator I = Conversions->begin(),
E = Conversions->end(); I != E; ++I) {
DeclAccessPair FoundDecl = I.getPair();
NamedDecl *D = FoundDecl.getDecl();
CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
if (isa<UsingShadowDecl>(D))
D = cast<UsingShadowDecl>(D)->getTargetDecl();
CXXConversionDecl *Conv;
FunctionTemplateDecl *ConvTemplate;
if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
else
Conv = cast<CXXConversionDecl>(D);
if (AllowExplicit || !Conv->isExplicit()) {
if (ConvTemplate)
AddTemplateConversionCandidate(ConvTemplate, FoundDecl,
ActingContext, From, ToType,
CandidateSet);
else
AddConversionCandidate(Conv, FoundDecl, ActingContext,
From, ToType, CandidateSet);
}
}
}
}
OverloadCandidateSet::iterator Best;
switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) {
case OR_Success:
// Record the standard conversion we used and the conversion function.
if (CXXConstructorDecl *Constructor
= dyn_cast<CXXConstructorDecl>(Best->Function)) {
// C++ [over.ics.user]p1:
// If the user-defined conversion is specified by a
// constructor (12.3.1), the initial standard conversion
// sequence converts the source type to the type required by
// the argument of the constructor.
//
QualType ThisType = Constructor->getThisType(Context);
if (Best->Conversions[0].isEllipsis())
User.EllipsisConversion = true;
else {
User.Before = Best->Conversions[0].Standard;
User.EllipsisConversion = false;
}
User.ConversionFunction = Constructor;
User.After.setAsIdentityConversion();
User.After.setFromType(
ThisType->getAs<PointerType>()->getPointeeType());
User.After.setAllToTypes(ToType);
return OR_Success;
} else if (CXXConversionDecl *Conversion
= dyn_cast<CXXConversionDecl>(Best->Function)) {
// C++ [over.ics.user]p1:
//
// [...] If the user-defined conversion is specified by a
// conversion function (12.3.2), the initial standard
// conversion sequence converts the source type to the
// implicit object parameter of the conversion function.
User.Before = Best->Conversions[0].Standard;
User.ConversionFunction = Conversion;
User.EllipsisConversion = false;
// C++ [over.ics.user]p2:
// The second standard conversion sequence converts the
// result of the user-defined conversion to the target type
// for the sequence. Since an implicit conversion sequence
// is an initialization, the special rules for
// initialization by user-defined conversion apply when
// selecting the best user-defined conversion for a
// user-defined conversion sequence (see 13.3.3 and
// 13.3.3.1).
User.After = Best->FinalConversion;
return OR_Success;
} else {
assert(false && "Not a constructor or conversion function?");
return OR_No_Viable_Function;
}
case OR_No_Viable_Function:
return OR_No_Viable_Function;
case OR_Deleted:
// No conversion here! We're done.
return OR_Deleted;
case OR_Ambiguous:
return OR_Ambiguous;
}
return OR_No_Viable_Function;
}
bool
Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) {
ImplicitConversionSequence ICS;
OverloadCandidateSet CandidateSet(From->getExprLoc());
OverloadingResult OvResult =
IsUserDefinedConversion(From, ToType, ICS.UserDefined,
CandidateSet, false);
if (OvResult == OR_Ambiguous)
Diag(From->getSourceRange().getBegin(),
diag::err_typecheck_ambiguous_condition)
<< From->getType() << ToType << From->getSourceRange();
else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty())
Diag(From->getSourceRange().getBegin(),
diag::err_typecheck_nonviable_condition)
<< From->getType() << ToType << From->getSourceRange();
else
return false;
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1);
return true;
}
/// CompareImplicitConversionSequences - Compare two implicit
/// conversion sequences to determine whether one is better than the
/// other or if they are indistinguishable (C++ 13.3.3.2).
ImplicitConversionSequence::CompareKind
Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1,
const ImplicitConversionSequence& ICS2)
{
// (C++ 13.3.3.2p2): When comparing the basic forms of implicit
// conversion sequences (as defined in 13.3.3.1)
// -- a standard conversion sequence (13.3.3.1.1) is a better
// conversion sequence than a user-defined conversion sequence or
// an ellipsis conversion sequence, and
// -- a user-defined conversion sequence (13.3.3.1.2) is a better
// conversion sequence than an ellipsis conversion sequence
// (13.3.3.1.3).
//
// C++0x [over.best.ics]p10:
// For the purpose of ranking implicit conversion sequences as
// described in 13.3.3.2, the ambiguous conversion sequence is
// treated as a user-defined sequence that is indistinguishable
// from any other user-defined conversion sequence.
if (ICS1.getKindRank() < ICS2.getKindRank())
return ImplicitConversionSequence::Better;
else if (ICS2.getKindRank() < ICS1.getKindRank())
return ImplicitConversionSequence::Worse;
// The following checks require both conversion sequences to be of
// the same kind.
if (ICS1.getKind() != ICS2.getKind())
return ImplicitConversionSequence::Indistinguishable;
// Two implicit conversion sequences of the same form are
// indistinguishable conversion sequences unless one of the
// following rules apply: (C++ 13.3.3.2p3):
if (ICS1.isStandard())
return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard);
else if (ICS1.isUserDefined()) {
// User-defined conversion sequence U1 is a better conversion
// sequence than another user-defined conversion sequence U2 if
// they contain the same user-defined conversion function or
// constructor and if the second standard conversion sequence of
// U1 is better than the second standard conversion sequence of
// U2 (C++ 13.3.3.2p3).
if (ICS1.UserDefined.ConversionFunction ==
ICS2.UserDefined.ConversionFunction)
return CompareStandardConversionSequences(ICS1.UserDefined.After,
ICS2.UserDefined.After);
}
return ImplicitConversionSequence::Indistinguishable;
}
// Per 13.3.3.2p3, compare the given standard conversion sequences to
// determine if one is a proper subset of the other.
static ImplicitConversionSequence::CompareKind
compareStandardConversionSubsets(ASTContext &Context,
const StandardConversionSequence& SCS1,
const StandardConversionSequence& SCS2) {
ImplicitConversionSequence::CompareKind Result
= ImplicitConversionSequence::Indistinguishable;
if (SCS1.Second != SCS2.Second) {
if (SCS1.Second == ICK_Identity)
Result = ImplicitConversionSequence::Better;
else if (SCS2.Second == ICK_Identity)
Result = ImplicitConversionSequence::Worse;
else
return ImplicitConversionSequence::Indistinguishable;
} else if (!Context.hasSameType(SCS1.getToType(1), SCS2.getToType(1)))
return ImplicitConversionSequence::Indistinguishable;
if (SCS1.Third == SCS2.Third) {
return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result
: ImplicitConversionSequence::Indistinguishable;
}
if (SCS1.Third == ICK_Identity)
return Result == ImplicitConversionSequence::Worse
? ImplicitConversionSequence::Indistinguishable
: ImplicitConversionSequence::Better;
if (SCS2.Third == ICK_Identity)
return Result == ImplicitConversionSequence::Better
? ImplicitConversionSequence::Indistinguishable
: ImplicitConversionSequence::Worse;
return ImplicitConversionSequence::Indistinguishable;
}
/// CompareStandardConversionSequences - Compare two standard
/// conversion sequences to determine whether one is better than the
/// other or if they are indistinguishable (C++ 13.3.3.2p3).
ImplicitConversionSequence::CompareKind
Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1,
const StandardConversionSequence& SCS2)
{
// Standard conversion sequence S1 is a better conversion sequence
// than standard conversion sequence S2 if (C++ 13.3.3.2p3):
// -- S1 is a proper subsequence of S2 (comparing the conversion
// sequences in the canonical form defined by 13.3.3.1.1,
// excluding any Lvalue Transformation; the identity conversion
// sequence is considered to be a subsequence of any
// non-identity conversion sequence) or, if not that,
if (ImplicitConversionSequence::CompareKind CK
= compareStandardConversionSubsets(Context, SCS1, SCS2))
return CK;
// -- the rank of S1 is better than the rank of S2 (by the rules
// defined below), or, if not that,
ImplicitConversionRank Rank1 = SCS1.getRank();
ImplicitConversionRank Rank2 = SCS2.getRank();
if (Rank1 < Rank2)
return ImplicitConversionSequence::Better;
else if (Rank2 < Rank1)
return ImplicitConversionSequence::Worse;
// (C++ 13.3.3.2p4): Two conversion sequences with the same rank
// are indistinguishable unless one of the following rules
// applies:
// A conversion that is not a conversion of a pointer, or
// pointer to member, to bool is better than another conversion
// that is such a conversion.
if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool())
return SCS2.isPointerConversionToBool()
? ImplicitConversionSequence::Better
: ImplicitConversionSequence::Worse;
// C++ [over.ics.rank]p4b2:
//
// If class B is derived directly or indirectly from class A,
// conversion of B* to A* is better than conversion of B* to
// void*, and conversion of A* to void* is better than conversion
// of B* to void*.
bool SCS1ConvertsToVoid
= SCS1.isPointerConversionToVoidPointer(Context);
bool SCS2ConvertsToVoid
= SCS2.isPointerConversionToVoidPointer(Context);
if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) {
// Exactly one of the conversion sequences is a conversion to
// a void pointer; it's the worse conversion.
return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better
: ImplicitConversionSequence::Worse;
} else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) {
// Neither conversion sequence converts to a void pointer; compare
// their derived-to-base conversions.
if (ImplicitConversionSequence::CompareKind DerivedCK
= CompareDerivedToBaseConversions(SCS1, SCS2))
return DerivedCK;
} else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) {
// Both conversion sequences are conversions to void
// pointers. Compare the source types to determine if there's an
// inheritance relationship in their sources.
QualType FromType1 = SCS1.getFromType();
QualType FromType2 = SCS2.getFromType();
// Adjust the types we're converting from via the array-to-pointer
// conversion, if we need to.
if (SCS1.First == ICK_Array_To_Pointer)
FromType1 = Context.getArrayDecayedType(FromType1);
if (SCS2.First == ICK_Array_To_Pointer)
FromType2 = Context.getArrayDecayedType(FromType2);
QualType FromPointee1
= FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
QualType FromPointee2
= FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
if (IsDerivedFrom(FromPointee2, FromPointee1))
return ImplicitConversionSequence::Better;
else if (IsDerivedFrom(FromPointee1, FromPointee2))
return ImplicitConversionSequence::Worse;
// Objective-C++: If one interface is more specific than the
// other, it is the better one.
const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>();
const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>();
if (FromIface1 && FromIface1) {
if (Context.canAssignObjCInterfaces(FromIface2, FromIface1))
return ImplicitConversionSequence::Better;
else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2))
return ImplicitConversionSequence::Worse;
}
}
// Compare based on qualification conversions (C++ 13.3.3.2p3,
// bullet 3).
if (ImplicitConversionSequence::CompareKind QualCK
= CompareQualificationConversions(SCS1, SCS2))
return QualCK;
if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) {
// C++0x [over.ics.rank]p3b4:
// -- S1 and S2 are reference bindings (8.5.3) and neither refers to an
// implicit object parameter of a non-static member function declared
// without a ref-qualifier, and S1 binds an rvalue reference to an
// rvalue and S2 binds an lvalue reference.
// FIXME: We don't know if we're dealing with the implicit object parameter,
// or if the member function in this case has a ref qualifier.
// (Of course, we don't have ref qualifiers yet.)
if (SCS1.RRefBinding != SCS2.RRefBinding)
return SCS1.RRefBinding ? ImplicitConversionSequence::Better
: ImplicitConversionSequence::Worse;
// C++ [over.ics.rank]p3b4:
// -- S1 and S2 are reference bindings (8.5.3), and the types to
// which the references refer are the same type except for
// top-level cv-qualifiers, and the type to which the reference
// initialized by S2 refers is more cv-qualified than the type
// to which the reference initialized by S1 refers.
QualType T1 = SCS1.getToType(2);
QualType T2 = SCS2.getToType(2);
T1 = Context.getCanonicalType(T1);
T2 = Context.getCanonicalType(T2);
Qualifiers T1Quals, T2Quals;
QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals);
QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals);
if (UnqualT1 == UnqualT2) {
// If the type is an array type, promote the element qualifiers to the type
// for comparison.
if (isa<ArrayType>(T1) && T1Quals)
T1 = Context.getQualifiedType(UnqualT1, T1Quals);
if (isa<ArrayType>(T2) && T2Quals)
T2 = Context.getQualifiedType(UnqualT2, T2Quals);
if (T2.isMoreQualifiedThan(T1))
return ImplicitConversionSequence::Better;
else if (T1.isMoreQualifiedThan(T2))
return ImplicitConversionSequence::Worse;
}
}
return ImplicitConversionSequence::Indistinguishable;
}
/// CompareQualificationConversions - Compares two standard conversion
/// sequences to determine whether they can be ranked based on their
/// qualification conversions (C++ 13.3.3.2p3 bullet 3).
ImplicitConversionSequence::CompareKind
Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1,
const StandardConversionSequence& SCS2) {
// C++ 13.3.3.2p3:
// -- S1 and S2 differ only in their qualification conversion and
// yield similar types T1 and T2 (C++ 4.4), respectively, and the
// cv-qualification signature of type T1 is a proper subset of
// the cv-qualification signature of type T2, and S1 is not the
// deprecated string literal array-to-pointer conversion (4.2).
if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second ||
SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification)
return ImplicitConversionSequence::Indistinguishable;
// FIXME: the example in the standard doesn't use a qualification
// conversion (!)
QualType T1 = SCS1.getToType(2);
QualType T2 = SCS2.getToType(2);
T1 = Context.getCanonicalType(T1);
T2 = Context.getCanonicalType(T2);
Qualifiers T1Quals, T2Quals;
QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals);
QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals);
// If the types are the same, we won't learn anything by unwrapped
// them.
if (UnqualT1 == UnqualT2)
return ImplicitConversionSequence::Indistinguishable;
// If the type is an array type, promote the element qualifiers to the type
// for comparison.
if (isa<ArrayType>(T1) && T1Quals)
T1 = Context.getQualifiedType(UnqualT1, T1Quals);
if (isa<ArrayType>(T2) && T2Quals)
T2 = Context.getQualifiedType(UnqualT2, T2Quals);
ImplicitConversionSequence::CompareKind Result
= ImplicitConversionSequence::Indistinguishable;
while (UnwrapSimilarPointerTypes(T1, T2)) {
// Within each iteration of the loop, we check the qualifiers to
// determine if this still looks like a qualification
// conversion. Then, if all is well, we unwrap one more level of
// pointers or pointers-to-members and do it all again
// until there are no more pointers or pointers-to-members left
// to unwrap. This essentially mimics what
// IsQualificationConversion does, but here we're checking for a
// strict subset of qualifiers.
if (T1.getCVRQualifiers() == T2.getCVRQualifiers())
// The qualifiers are the same, so this doesn't tell us anything
// about how the sequences rank.
;
else if (T2.isMoreQualifiedThan(T1)) {
// T1 has fewer qualifiers, so it could be the better sequence.
if (Result == ImplicitConversionSequence::Worse)
// Neither has qualifiers that are a subset of the other's
// qualifiers.
return ImplicitConversionSequence::Indistinguishable;
Result = ImplicitConversionSequence::Better;
} else if (T1.isMoreQualifiedThan(T2)) {
// T2 has fewer qualifiers, so it could be the better sequence.
if (Result == ImplicitConversionSequence::Better)
// Neither has qualifiers that are a subset of the other's
// qualifiers.
return ImplicitConversionSequence::Indistinguishable;
Result = ImplicitConversionSequence::Worse;
} else {
// Qualifiers are disjoint.
return ImplicitConversionSequence::Indistinguishable;
}
// If the types after this point are equivalent, we're done.
if (Context.hasSameUnqualifiedType(T1, T2))
break;
}
// Check that the winning standard conversion sequence isn't using
// the deprecated string literal array to pointer conversion.
switch (Result) {
case ImplicitConversionSequence::Better:
if (SCS1.DeprecatedStringLiteralToCharPtr)
Result = ImplicitConversionSequence::Indistinguishable;
break;
case ImplicitConversionSequence::Indistinguishable:
break;
case ImplicitConversionSequence::Worse:
if (SCS2.DeprecatedStringLiteralToCharPtr)
Result = ImplicitConversionSequence::Indistinguishable;
break;
}
return Result;
}
/// CompareDerivedToBaseConversions - Compares two standard conversion
/// sequences to determine whether they can be ranked based on their
/// various kinds of derived-to-base conversions (C++
/// [over.ics.rank]p4b3). As part of these checks, we also look at
/// conversions between Objective-C interface types.
ImplicitConversionSequence::CompareKind
Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1,
const StandardConversionSequence& SCS2) {
QualType FromType1 = SCS1.getFromType();
QualType ToType1 = SCS1.getToType(1);
QualType FromType2 = SCS2.getFromType();
QualType ToType2 = SCS2.getToType(1);
// Adjust the types we're converting from via the array-to-pointer
// conversion, if we need to.
if (SCS1.First == ICK_Array_To_Pointer)
FromType1 = Context.getArrayDecayedType(FromType1);
if (SCS2.First == ICK_Array_To_Pointer)
FromType2 = Context.getArrayDecayedType(FromType2);
// Canonicalize all of the types.
FromType1 = Context.getCanonicalType(FromType1);
ToType1 = Context.getCanonicalType(ToType1);
FromType2 = Context.getCanonicalType(FromType2);
ToType2 = Context.getCanonicalType(ToType2);
// C++ [over.ics.rank]p4b3:
//
// If class B is derived directly or indirectly from class A and
// class C is derived directly or indirectly from B,
//
// For Objective-C, we let A, B, and C also be Objective-C
// interfaces.
// Compare based on pointer conversions.
if (SCS1.Second == ICK_Pointer_Conversion &&
SCS2.Second == ICK_Pointer_Conversion &&
/*FIXME: Remove if Objective-C id conversions get their own rank*/
FromType1->isPointerType() && FromType2->isPointerType() &&
ToType1->isPointerType() && ToType2->isPointerType()) {
QualType FromPointee1
= FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
QualType ToPointee1
= ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
QualType FromPointee2
= FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
QualType ToPointee2
= ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>();
const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>();
const ObjCObjectType* ToIface1 = ToPointee1->getAs<ObjCObjectType>();
const ObjCObjectType* ToIface2 = ToPointee2->getAs<ObjCObjectType>();
// -- conversion of C* to B* is better than conversion of C* to A*,
if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
if (IsDerivedFrom(ToPointee1, ToPointee2))
return ImplicitConversionSequence::Better;
else if (IsDerivedFrom(ToPointee2, ToPointee1))
return ImplicitConversionSequence::Worse;
if (ToIface1 && ToIface2) {
if (Context.canAssignObjCInterfaces(ToIface2, ToIface1))
return ImplicitConversionSequence::Better;
else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2))
return ImplicitConversionSequence::Worse;
}
}
// -- conversion of B* to A* is better than conversion of C* to A*,
if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) {
if (IsDerivedFrom(FromPointee2, FromPointee1))
return ImplicitConversionSequence::Better;
else if (IsDerivedFrom(FromPointee1, FromPointee2))
return ImplicitConversionSequence::Worse;
if (FromIface1 && FromIface2) {
if (Context.canAssignObjCInterfaces(FromIface1, FromIface2))
return ImplicitConversionSequence::Better;
else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1))
return ImplicitConversionSequence::Worse;
}
}
}
// Ranking of member-pointer types.
if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member &&
FromType1->isMemberPointerType() && FromType2->isMemberPointerType() &&
ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) {
const MemberPointerType * FromMemPointer1 =
FromType1->getAs<MemberPointerType>();
const MemberPointerType * ToMemPointer1 =
ToType1->getAs<MemberPointerType>();
const MemberPointerType * FromMemPointer2 =
FromType2->getAs<MemberPointerType>();
const MemberPointerType * ToMemPointer2 =
ToType2->getAs<MemberPointerType>();
const Type *FromPointeeType1 = FromMemPointer1->getClass();
const Type *ToPointeeType1 = ToMemPointer1->getClass();
const Type *FromPointeeType2 = FromMemPointer2->getClass();
const Type *ToPointeeType2 = ToMemPointer2->getClass();
QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType();
QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType();
QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType();
QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType();
// conversion of A::* to B::* is better than conversion of A::* to C::*,
if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
if (IsDerivedFrom(ToPointee1, ToPointee2))
return ImplicitConversionSequence::Worse;
else if (IsDerivedFrom(ToPointee2, ToPointee1))
return ImplicitConversionSequence::Better;
}
// conversion of B::* to C::* is better than conversion of A::* to C::*
if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) {
if (IsDerivedFrom(FromPointee1, FromPointee2))
return ImplicitConversionSequence::Better;
else if (IsDerivedFrom(FromPointee2, FromPointee1))
return ImplicitConversionSequence::Worse;
}
}
if (SCS1.Second == ICK_Derived_To_Base) {
// -- conversion of C to B is better than conversion of C to A,
// -- binding of an expression of type C to a reference of type
// B& is better than binding an expression of type C to a
// reference of type A&,
if (Context.hasSameUnqualifiedType(FromType1, FromType2) &&
!Context.hasSameUnqualifiedType(ToType1, ToType2)) {
if (IsDerivedFrom(ToType1, ToType2))
return ImplicitConversionSequence::Better;
else if (IsDerivedFrom(ToType2, ToType1))
return ImplicitConversionSequence::Worse;
}
// -- conversion of B to A is better than conversion of C to A.
// -- binding of an expression of type B to a reference of type
// A& is better than binding an expression of type C to a
// reference of type A&,
if (!Context.hasSameUnqualifiedType(FromType1, FromType2) &&
Context.hasSameUnqualifiedType(ToType1, ToType2)) {
if (IsDerivedFrom(FromType2, FromType1))
return ImplicitConversionSequence::Better;
else if (IsDerivedFrom(FromType1, FromType2))
return ImplicitConversionSequence::Worse;
}
}
return ImplicitConversionSequence::Indistinguishable;
}
/// CompareReferenceRelationship - Compare the two types T1 and T2 to
/// determine whether they are reference-related,
/// reference-compatible, reference-compatible with added
/// qualification, or incompatible, for use in C++ initialization by
/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference
/// type, and the first type (T1) is the pointee type of the reference
/// type being initialized.
Sema::ReferenceCompareResult
Sema::CompareReferenceRelationship(SourceLocation Loc,
QualType OrigT1, QualType OrigT2,
bool& DerivedToBase) {
assert(!OrigT1->isReferenceType() &&
"T1 must be the pointee type of the reference type");
assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type");
QualType T1 = Context.getCanonicalType(OrigT1);
QualType T2 = Context.getCanonicalType(OrigT2);
Qualifiers T1Quals, T2Quals;
QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals);
QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals);
// C++ [dcl.init.ref]p4:
// Given types "cv1 T1" and "cv2 T2," "cv1 T1" is
// reference-related to "cv2 T2" if T1 is the same type as T2, or
// T1 is a base class of T2.
if (UnqualT1 == UnqualT2)
DerivedToBase = false;
else if (!RequireCompleteType(Loc, OrigT2, PDiag()) &&
IsDerivedFrom(UnqualT2, UnqualT1))
DerivedToBase = true;
else
return Ref_Incompatible;
// At this point, we know that T1 and T2 are reference-related (at
// least).
// If the type is an array type, promote the element qualifiers to the type
// for comparison.
if (isa<ArrayType>(T1) && T1Quals)
T1 = Context.getQualifiedType(UnqualT1, T1Quals);
if (isa<ArrayType>(T2) && T2Quals)
T2 = Context.getQualifiedType(UnqualT2, T2Quals);
// C++ [dcl.init.ref]p4:
// "cv1 T1" is reference-compatible with "cv2 T2" if T1 is
// reference-related to T2 and cv1 is the same cv-qualification
// as, or greater cv-qualification than, cv2. For purposes of
// overload resolution, cases for which cv1 is greater
// cv-qualification than cv2 are identified as
// reference-compatible with added qualification (see 13.3.3.2).
if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers())
return Ref_Compatible;
else if (T1.isMoreQualifiedThan(T2))
return Ref_Compatible_With_Added_Qualification;
else
return Ref_Related;
}
/// \brief Compute an implicit conversion sequence for reference
/// initialization.
static ImplicitConversionSequence
TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType,
SourceLocation DeclLoc,
bool SuppressUserConversions,
bool AllowExplicit) {
assert(DeclType->isReferenceType() && "Reference init needs a reference");
// Most paths end in a failed conversion.
ImplicitConversionSequence ICS;
ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType();
QualType T2 = Init->getType();
// If the initializer is the address of an overloaded function, try
// to resolve the overloaded function. If all goes well, T2 is the
// type of the resulting function.
if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
DeclAccessPair Found;
if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType,
false, Found))
T2 = Fn->getType();
}
// Compute some basic properties of the types and the initializer.
bool isRValRef = DeclType->isRValueReferenceType();
bool DerivedToBase = false;
Expr::isLvalueResult InitLvalue = Init->isLvalue(S.Context);
Sema::ReferenceCompareResult RefRelationship
= S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase);
// C++ [over.ics.ref]p3:
// Except for an implicit object parameter, for which see 13.3.1,
// a standard conversion sequence cannot be formed if it requires
// binding an lvalue reference to non-const to an rvalue or
// binding an rvalue reference to an lvalue.
//
// FIXME: DPG doesn't trust this code. It seems far too early to
// abort because of a binding of an rvalue reference to an lvalue.
if (isRValRef && InitLvalue == Expr::LV_Valid)
return ICS;
// C++0x [dcl.init.ref]p16:
// A reference to type "cv1 T1" is initialized by an expression
// of type "cv2 T2" as follows:
// -- If the initializer expression
// -- is an lvalue (but is not a bit-field), and "cv1 T1" is
// reference-compatible with "cv2 T2," or
//
// Per C++ [over.ics.ref]p4, we don't check the bit-field property here.
if (InitLvalue == Expr::LV_Valid &&
RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) {
// C++ [over.ics.ref]p1:
// When a parameter of reference type binds directly (8.5.3)
// to an argument expression, the implicit conversion sequence
// is the identity conversion, unless the argument expression
// has a type that is a derived class of the parameter type,
// in which case the implicit conversion sequence is a
// derived-to-base Conversion (13.3.3.1).
ICS.setStandard();
ICS.Standard.First = ICK_Identity;
ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity;
ICS.Standard.Third = ICK_Identity;
ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
ICS.Standard.setToType(0, T2);
ICS.Standard.setToType(1, T1);
ICS.Standard.setToType(2, T1);
ICS.Standard.ReferenceBinding = true;
ICS.Standard.DirectBinding = true;
ICS.Standard.RRefBinding = false;
ICS.Standard.CopyConstructor = 0;
// Nothing more to do: the inaccessibility/ambiguity check for
// derived-to-base conversions is suppressed when we're
// computing the implicit conversion sequence (C++
// [over.best.ics]p2).
return ICS;
}
// -- has a class type (i.e., T2 is a class type), where T1 is
// not reference-related to T2, and can be implicitly
// converted to an lvalue of type "cv3 T3," where "cv1 T1"
// is reference-compatible with "cv3 T3" 92) (this
// conversion is selected by enumerating the applicable
// conversion functions (13.3.1.6) and choosing the best
// one through overload resolution (13.3)),
if (!isRValRef && !SuppressUserConversions && T2->isRecordType() &&
!S.RequireCompleteType(DeclLoc, T2, 0) &&
RefRelationship == Sema::Ref_Incompatible) {
CXXRecordDecl *T2RecordDecl
= dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl());
OverloadCandidateSet CandidateSet(DeclLoc);
const UnresolvedSetImpl *Conversions
= T2RecordDecl->getVisibleConversionFunctions();
for (UnresolvedSetImpl::iterator I = Conversions->begin(),
E = Conversions->end(); I != E; ++I) {
NamedDecl *D = *I;
CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
if (isa<UsingShadowDecl>(D))
D = cast<UsingShadowDecl>(D)->getTargetDecl();
FunctionTemplateDecl *ConvTemplate
= dyn_cast<FunctionTemplateDecl>(D);
CXXConversionDecl *Conv;
if (ConvTemplate)
Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
else
Conv = cast<CXXConversionDecl>(D);
// If the conversion function doesn't return a reference type,
// it can't be considered for this conversion.
if (Conv->getConversionType()->isLValueReferenceType() &&
(AllowExplicit || !Conv->isExplicit())) {
if (ConvTemplate)
S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC,
Init, DeclType, CandidateSet);
else
S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init,
DeclType, CandidateSet);
}
}
OverloadCandidateSet::iterator Best;
switch (S.BestViableFunction(CandidateSet, DeclLoc, Best)) {
case OR_Success:
// C++ [over.ics.ref]p1:
//
// [...] If the parameter binds directly to the result of
// applying a conversion function to the argument
// expression, the implicit conversion sequence is a
// user-defined conversion sequence (13.3.3.1.2), with the
// second standard conversion sequence either an identity
// conversion or, if the conversion function returns an
// entity of a type that is a derived class of the parameter
// type, a derived-to-base Conversion.
if (!Best->FinalConversion.DirectBinding)
break;
ICS.setUserDefined();
ICS.UserDefined.Before = Best->Conversions[0].Standard;
ICS.UserDefined.After = Best->FinalConversion;
ICS.UserDefined.ConversionFunction = Best->Function;
ICS.UserDefined.EllipsisConversion = false;
assert(ICS.UserDefined.After.ReferenceBinding &&
ICS.UserDefined.After.DirectBinding &&
"Expected a direct reference binding!");
return ICS;
case OR_Ambiguous:
ICS.setAmbiguous();
for (OverloadCandidateSet::iterator Cand = CandidateSet.begin();
Cand != CandidateSet.end(); ++Cand)
if (Cand->Viable)
ICS.Ambiguous.addConversion(Cand->Function);
return ICS;
case OR_No_Viable_Function:
case OR_Deleted:
// There was no suitable conversion, or we found a deleted
// conversion; continue with other checks.
break;
}
}
// -- Otherwise, the reference shall be to a non-volatile const
// type (i.e., cv1 shall be const), or the reference shall be an
// rvalue reference and the initializer expression shall be an rvalue.
//
// We actually handle one oddity of C++ [over.ics.ref] at this
// point, which is that, due to p2 (which short-circuits reference
// binding by only attempting a simple conversion for non-direct
// bindings) and p3's strange wording, we allow a const volatile
// reference to bind to an rvalue. Hence the check for the presence
// of "const" rather than checking for "const" being the only
// qualifier.
if (!isRValRef && !T1.isConstQualified())
return ICS;
// -- if T2 is a class type and
// -- the initializer expression is an rvalue and "cv1 T1"
// is reference-compatible with "cv2 T2," or
//
// -- T1 is not reference-related to T2 and the initializer
// expression can be implicitly converted to an rvalue
// of type "cv3 T3" (this conversion is selected by
// enumerating the applicable conversion functions
// (13.3.1.6) and choosing the best one through overload
// resolution (13.3)),
//
// then the reference is bound to the initializer
// expression rvalue in the first case and to the object
// that is the result of the conversion in the second case
// (or, in either case, to the appropriate base class
// subobject of the object).
//
// We're only checking the first case here, which is a direct
// binding in C++0x but not in C++03.
if (InitLvalue != Expr::LV_Valid && T2->isRecordType() &&
RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) {
ICS.setStandard();
ICS.Standard.First = ICK_Identity;
ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity;
ICS.Standard.Third = ICK_Identity;
ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
ICS.Standard.setToType(0, T2);
ICS.Standard.setToType(1, T1);
ICS.Standard.setToType(2, T1);
ICS.Standard.ReferenceBinding = true;
ICS.Standard.DirectBinding = S.getLangOptions().CPlusPlus0x;
ICS.Standard.RRefBinding = isRValRef;
ICS.Standard.CopyConstructor = 0;
return ICS;
}
// -- Otherwise, a temporary of type "cv1 T1" is created and
// initialized from the initializer expression using the
// rules for a non-reference copy initialization (8.5). The
// reference is then bound to the temporary. If T1 is
// reference-related to T2, cv1 must be the same
// cv-qualification as, or greater cv-qualification than,
// cv2; otherwise, the program is ill-formed.
if (RefRelationship == Sema::Ref_Related) {
// If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then
// we would be reference-compatible or reference-compatible with
// added qualification. But that wasn't the case, so the reference
// initialization fails.
return ICS;
}
// If at least one of the types is a class type, the types are not
// related, and we aren't allowed any user conversions, the
// reference binding fails. This case is important for breaking
// recursion, since TryImplicitConversion below will attempt to
// create a temporary through the use of a copy constructor.
if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
(T1->isRecordType() || T2->isRecordType()))
return ICS;
// C++ [over.ics.ref]p2:
// When a parameter of reference type is not bound directly to
// an argument expression, the conversion sequence is the one
// required to convert the argument expression to the
// underlying type of the reference according to
// 13.3.3.1. Conceptually, this conversion sequence corresponds
// to copy-initializing a temporary of the underlying type with
// the argument expression. Any difference in top-level
// cv-qualification is subsumed by the initialization itself
// and does not constitute a conversion.
ICS = S.TryImplicitConversion(Init, T1, SuppressUserConversions,
/*AllowExplicit=*/false,
/*InOverloadResolution=*/false);
// Of course, that's still a reference binding.
if (ICS.isStandard()) {
ICS.Standard.ReferenceBinding = true;
ICS.Standard.RRefBinding = isRValRef;
} else if (ICS.isUserDefined()) {
ICS.UserDefined.After.ReferenceBinding = true;
ICS.UserDefined.After.RRefBinding = isRValRef;
}
return ICS;
}
/// TryCopyInitialization - Try to copy-initialize a value of type
/// ToType from the expression From. Return the implicit conversion
/// sequence required to pass this argument, which may be a bad
/// conversion sequence (meaning that the argument cannot be passed to
/// a parameter of this type). If @p SuppressUserConversions, then we
/// do not permit any user-defined conversion sequences.
static ImplicitConversionSequence
TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
bool SuppressUserConversions,
bool InOverloadResolution) {
if (ToType->isReferenceType())
return TryReferenceInit(S, From, ToType,
/*FIXME:*/From->getLocStart(),
SuppressUserConversions,
/*AllowExplicit=*/false);
return S.TryImplicitConversion(From, ToType,
SuppressUserConversions,
/*AllowExplicit=*/false,
InOverloadResolution);
}
/// TryObjectArgumentInitialization - Try to initialize the object
/// parameter of the given member function (@c Method) from the
/// expression @p From.
ImplicitConversionSequence
Sema::TryObjectArgumentInitialization(QualType OrigFromType,
CXXMethodDecl *Method,
CXXRecordDecl *ActingContext) {
QualType ClassType = Context.getTypeDeclType(ActingContext);
// [class.dtor]p2: A destructor can be invoked for a const, volatile or
// const volatile object.
unsigned Quals = isa<CXXDestructorDecl>(Method) ?
Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers();
QualType ImplicitParamType = Context.getCVRQualifiedType(ClassType, Quals);
// Set up the conversion sequence as a "bad" conversion, to allow us
// to exit early.
ImplicitConversionSequence ICS;
// We need to have an object of class type.
QualType FromType = OrigFromType;
if (const PointerType *PT = FromType->getAs<PointerType>())
FromType = PT->getPointeeType();
assert(FromType->isRecordType());
// The implicit object parameter is has the type "reference to cv X",
// where X is the class of which the function is a member
// (C++ [over.match.funcs]p4). However, when finding an implicit
// conversion sequence for the argument, we are not allowed to
// create temporaries or perform user-defined conversions
// (C++ [over.match.funcs]p5). We perform a simplified version of
// reference binding here, that allows class rvalues to bind to
// non-constant references.
// First check the qualifiers. We don't care about lvalue-vs-rvalue
// with the implicit object parameter (C++ [over.match.funcs]p5).
QualType FromTypeCanon = Context.getCanonicalType(FromType);
if (ImplicitParamType.getCVRQualifiers()
!= FromTypeCanon.getLocalCVRQualifiers() &&
!ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) {
ICS.setBad(BadConversionSequence::bad_qualifiers,
OrigFromType, ImplicitParamType);
return ICS;
}
// Check that we have either the same type or a derived type. It
// affects the conversion rank.
QualType ClassTypeCanon = Context.getCanonicalType(ClassType);
ImplicitConversionKind SecondKind;
if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) {
SecondKind = ICK_Identity;
} else if (IsDerivedFrom(FromType, ClassType))
SecondKind = ICK_Derived_To_Base;
else {
ICS.setBad(BadConversionSequence::unrelated_class,
FromType, ImplicitParamType);
return ICS;
}
// Success. Mark this as a reference binding.
ICS.setStandard();
ICS.Standard.setAsIdentityConversion();
ICS.Standard.Second = SecondKind;
ICS.Standard.setFromType(FromType);
ICS.Standard.setAllToTypes(ImplicitParamType);
ICS.Standard.ReferenceBinding = true;
ICS.Standard.DirectBinding = true;
ICS.Standard.RRefBinding = false;
return ICS;
}
/// PerformObjectArgumentInitialization - Perform initialization of
/// the implicit object parameter for the given Method with the given
/// expression.
bool
Sema::PerformObjectArgumentInitialization(Expr *&From,
NestedNameSpecifier *Qualifier,
NamedDecl *FoundDecl,
CXXMethodDecl *Method) {
QualType FromRecordType, DestType;
QualType ImplicitParamRecordType =
Method->getThisType(Context)->getAs<PointerType>()->getPointeeType();
if (const PointerType *PT = From->getType()->getAs<PointerType>()) {
FromRecordType = PT->getPointeeType();
DestType = Method->getThisType(Context);
} else {
FromRecordType = From->getType();
DestType = ImplicitParamRecordType;
}
// Note that we always use the true parent context when performing
// the actual argument initialization.
ImplicitConversionSequence ICS
= TryObjectArgumentInitialization(From->getType(), Method,
Method->getParent());
if (ICS.isBad())
return Diag(From->getSourceRange().getBegin(),
diag::err_implicit_object_parameter_init)
<< ImplicitParamRecordType << FromRecordType << From->getSourceRange();
if (ICS.Standard.Second == ICK_Derived_To_Base)
return PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method);
if (!Context.hasSameType(From->getType(), DestType))
ImpCastExprToType(From, DestType, CastExpr::CK_NoOp,
/*isLvalue=*/!From->getType()->isPointerType());
return false;
}
/// TryContextuallyConvertToBool - Attempt to contextually convert the
/// expression From to bool (C++0x [conv]p3).
ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) {
// FIXME: This is pretty broken.
return TryImplicitConversion(From, Context.BoolTy,
// FIXME: Are these flags correct?
/*SuppressUserConversions=*/false,
/*AllowExplicit=*/true,
/*InOverloadResolution=*/false);
}
/// PerformContextuallyConvertToBool - Perform a contextual conversion
/// of the expression From to bool (C++0x [conv]p3).
bool Sema::PerformContextuallyConvertToBool(Expr *&From) {
ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From);
if (!ICS.isBad())
return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting);
if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy))
return Diag(From->getSourceRange().getBegin(),
diag::err_typecheck_bool_condition)
<< From->getType() << From->getSourceRange();
return true;
}
/// TryContextuallyConvertToObjCId - Attempt to contextually convert the
/// expression From to 'id'.
ImplicitConversionSequence Sema::TryContextuallyConvertToObjCId(Expr *From) {
QualType Ty = Context.getObjCIdType();
return TryImplicitConversion(From, Ty,
// FIXME: Are these flags correct?
/*SuppressUserConversions=*/false,
/*AllowExplicit=*/true,
/*InOverloadResolution=*/false);
}
/// PerformContextuallyConvertToObjCId - Perform a contextual conversion
/// of the expression From to 'id'.
bool Sema::PerformContextuallyConvertToObjCId(Expr *&From) {
QualType Ty = Context.getObjCIdType();
ImplicitConversionSequence ICS = TryContextuallyConvertToObjCId(From);
if (!ICS.isBad())
return PerformImplicitConversion(From, Ty, ICS, AA_Converting);
return true;
}
/// AddOverloadCandidate - Adds the given function to the set of
/// candidate functions, using the given function call arguments. If
/// @p SuppressUserConversions, then don't allow user-defined
/// conversions via constructors or conversion operators.
///
/// \para PartialOverloading true if we are performing "partial" overloading
/// based on an incomplete set of function arguments. This feature is used by
/// code completion.
void
Sema::AddOverloadCandidate(FunctionDecl *Function,
DeclAccessPair FoundDecl,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet& CandidateSet,
bool SuppressUserConversions,
bool PartialOverloading) {
const FunctionProtoType* Proto
= dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>());
assert(Proto && "Functions without a prototype cannot be overloaded");
assert(!Function->getDescribedFunctionTemplate() &&
"Use AddTemplateOverloadCandidate for function templates");
if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) {
if (!isa<CXXConstructorDecl>(Method)) {
// If we get here, it's because we're calling a member function
// that is named without a member access expression (e.g.,
// "this->f") that was either written explicitly or created
// implicitly. This can happen with a qualified call to a member
// function, e.g., X::f(). We use an empty type for the implied
// object argument (C++ [over.call.func]p3), and the acting context
// is irrelevant.
AddMethodCandidate(Method, FoundDecl, Method->getParent(),
QualType(), Args, NumArgs, CandidateSet,
SuppressUserConversions);
return;
}
// We treat a constructor like a non-member function, since its object
// argument doesn't participate in overload resolution.
}
if (!CandidateSet.isNewCandidate(Function))
return;
// Overload resolution is always an unevaluated context.
EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated);
if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){
// C++ [class.copy]p3:
// A member function template is never instantiated to perform the copy
// of a class object to an object of its class type.
QualType ClassType = Context.getTypeDeclType(Constructor->getParent());
if (NumArgs == 1 &&
Constructor->isCopyConstructorLikeSpecialization() &&
(Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) ||
IsDerivedFrom(Args[0]->getType(), ClassType)))
return;
}
// Add this candidate
CandidateSet.push_back(OverloadCandidate());
OverloadCandidate& Candidate = CandidateSet.back();
Candidate.FoundDecl = FoundDecl;
Candidate.Function = Function;
Candidate.Viable = true;
Candidate.IsSurrogate = false;
Candidate.IgnoreObjectArgument = false;
unsigned NumArgsInProto = Proto->getNumArgs();
// (C++ 13.3.2p2): A candidate function having fewer than m
// parameters is viable only if it has an ellipsis in its parameter
// list (8.3.5).
if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto &&
!Proto->isVariadic()) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_too_many_arguments;
return;
}
// (C++ 13.3.2p2): A candidate function having more than m parameters
// is viable only if the (m+1)st parameter has a default argument
// (8.3.6). For the purposes of overload resolution, the
// parameter list is truncated on the right, so that there are
// exactly m parameters.
unsigned MinRequiredArgs = Function->getMinRequiredArguments();
if (NumArgs < MinRequiredArgs && !PartialOverloading) {
// Not enough arguments.
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_too_few_arguments;
return;
}
// Determine the implicit conversion sequences for each of the
// arguments.
Candidate.Conversions.resize(NumArgs);
for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) {
if (ArgIdx < NumArgsInProto) {
// (C++ 13.3.2p3): for F to be a viable function, there shall
// exist for each argument an implicit conversion sequence
// (13.3.3.1) that converts that argument to the corresponding
// parameter of F.
QualType ParamType = Proto->getArgType(ArgIdx);
Candidate.Conversions[ArgIdx]
= TryCopyInitialization(*this, Args[ArgIdx], ParamType,
SuppressUserConversions,
/*InOverloadResolution=*/true);
if (Candidate.Conversions[ArgIdx].isBad()) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_bad_conversion;
break;
}
} else {
// (C++ 13.3.2p2): For the purposes of overload resolution, any
// argument for which there is no corresponding parameter is
// considered to ""match the ellipsis" (C+ 13.3.3.1.3).
Candidate.Conversions[ArgIdx].setEllipsis();
}
}
}
/// \brief Add all of the function declarations in the given function set to
/// the overload canddiate set.
void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet& CandidateSet,
bool SuppressUserConversions) {
for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) {
NamedDecl *D = F.getDecl()->getUnderlyingDecl();
if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic())
AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(),
cast<CXXMethodDecl>(FD)->getParent(),
Args[0]->getType(), Args + 1, NumArgs - 1,
CandidateSet, SuppressUserConversions);
else
AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet,
SuppressUserConversions);
} else {
FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D);
if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) &&
!cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic())
AddMethodTemplateCandidate(FunTmpl, F.getPair(),
cast<CXXRecordDecl>(FunTmpl->getDeclContext()),
/*FIXME: explicit args */ 0,
Args[0]->getType(), Args + 1, NumArgs - 1,
CandidateSet,
SuppressUserConversions);
else
AddTemplateOverloadCandidate(FunTmpl, F.getPair(),
/*FIXME: explicit args */ 0,
Args, NumArgs, CandidateSet,
SuppressUserConversions);
}
}
}
/// AddMethodCandidate - Adds a named decl (which is some kind of
/// method) as a method candidate to the given overload set.
void Sema::AddMethodCandidate(DeclAccessPair FoundDecl,
QualType ObjectType,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet& CandidateSet,
bool SuppressUserConversions) {
NamedDecl *Decl = FoundDecl.getDecl();
CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext());
if (isa<UsingShadowDecl>(Decl))
Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl();
if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) {
assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) &&
"Expected a member function template");
AddMethodTemplateCandidate(TD, FoundDecl, ActingContext,
/*ExplicitArgs*/ 0,
ObjectType, Args, NumArgs,
CandidateSet,
SuppressUserConversions);
} else {
AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext,
ObjectType, Args, NumArgs,
CandidateSet, SuppressUserConversions);
}
}
/// AddMethodCandidate - Adds the given C++ member function to the set
/// of candidate functions, using the given function call arguments
/// and the object argument (@c Object). For example, in a call
/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain
/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't
/// allow user-defined conversions via constructors or conversion
/// operators.
void
Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl,
CXXRecordDecl *ActingContext, QualType ObjectType,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet& CandidateSet,
bool SuppressUserConversions) {
const FunctionProtoType* Proto
= dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>());
assert(Proto && "Methods without a prototype cannot be overloaded");
assert(!isa<CXXConstructorDecl>(Method) &&
"Use AddOverloadCandidate for constructors");
if (!CandidateSet.isNewCandidate(Method))
return;
// Overload resolution is always an unevaluated context.
EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated);
// Add this candidate
CandidateSet.push_back(OverloadCandidate());
OverloadCandidate& Candidate = CandidateSet.back();
Candidate.FoundDecl = FoundDecl;
Candidate.Function = Method;
Candidate.IsSurrogate = false;
Candidate.IgnoreObjectArgument = false;
unsigned NumArgsInProto = Proto->getNumArgs();
// (C++ 13.3.2p2): A candidate function having fewer than m
// parameters is viable only if it has an ellipsis in its parameter
// list (8.3.5).
if (NumArgs > NumArgsInProto && !Proto->isVariadic()) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_too_many_arguments;
return;
}
// (C++ 13.3.2p2): A candidate function having more than m parameters
// is viable only if the (m+1)st parameter has a default argument
// (8.3.6). For the purposes of overload resolution, the
// parameter list is truncated on the right, so that there are
// exactly m parameters.
unsigned MinRequiredArgs = Method->getMinRequiredArguments();
if (NumArgs < MinRequiredArgs) {
// Not enough arguments.
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_too_few_arguments;
return;
}
Candidate.Viable = true;
Candidate.Conversions.resize(NumArgs + 1);
if (Method->isStatic() || ObjectType.isNull())
// The implicit object argument is ignored.
Candidate.IgnoreObjectArgument = true;
else {
// Determine the implicit conversion sequence for the object
// parameter.
Candidate.Conversions[0]
= TryObjectArgumentInitialization(ObjectType, Method, ActingContext);
if (Candidate.Conversions[0].isBad()) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_bad_conversion;
return;
}
}
// Determine the implicit conversion sequences for each of the
// arguments.
for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) {
if (ArgIdx < NumArgsInProto) {
// (C++ 13.3.2p3): for F to be a viable function, there shall
// exist for each argument an implicit conversion sequence
// (13.3.3.1) that converts that argument to the corresponding
// parameter of F.
QualType ParamType = Proto->getArgType(ArgIdx);
Candidate.Conversions[ArgIdx + 1]
= TryCopyInitialization(*this, Args[ArgIdx], ParamType,
SuppressUserConversions,
/*InOverloadResolution=*/true);
if (Candidate.Conversions[ArgIdx + 1].isBad()) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_bad_conversion;
break;
}
} else {
// (C++ 13.3.2p2): For the purposes of overload resolution, any
// argument for which there is no corresponding parameter is
// considered to ""match the ellipsis" (C+ 13.3.3.1.3).
Candidate.Conversions[ArgIdx + 1].setEllipsis();
}
}
}
/// \brief Add a C++ member function template as a candidate to the candidate
/// set, using template argument deduction to produce an appropriate member
/// function template specialization.
void
Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl,
DeclAccessPair FoundDecl,
CXXRecordDecl *ActingContext,
const TemplateArgumentListInfo *ExplicitTemplateArgs,
QualType ObjectType,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet& CandidateSet,
bool SuppressUserConversions) {
if (!CandidateSet.isNewCandidate(MethodTmpl))
return;
// C++ [over.match.funcs]p7:
// In each case where a candidate is a function template, candidate
// function template specializations are generated using template argument
// deduction (14.8.3, 14.8.2). Those candidates are then handled as
// candidate functions in the usual way.113) A given name can refer to one
// or more function templates and also to a set of overloaded non-template
// functions. In such a case, the candidate functions generated from each
// function template are combined with the set of non-template candidate
// functions.
TemplateDeductionInfo Info(Context, CandidateSet.getLocation());
FunctionDecl *Specialization = 0;
if (TemplateDeductionResult Result
= DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs,
Args, NumArgs, Specialization, Info)) {
CandidateSet.push_back(OverloadCandidate());
OverloadCandidate &Candidate = CandidateSet.back();
Candidate.FoundDecl = FoundDecl;
Candidate.Function = MethodTmpl->getTemplatedDecl();
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_bad_deduction;
Candidate.IsSurrogate = false;
Candidate.IgnoreObjectArgument = false;
Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
Info);
return;
}
// Add the function template specialization produced by template argument
// deduction as a candidate.
assert(Specialization && "Missing member function template specialization?");
assert(isa<CXXMethodDecl>(Specialization) &&
"Specialization is not a member function?");
AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl,
ActingContext, ObjectType, Args, NumArgs,
CandidateSet, SuppressUserConversions);
}
/// \brief Add a C++ function template specialization as a candidate
/// in the candidate set, using template argument deduction to produce
/// an appropriate function template specialization.
void
Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate,
DeclAccessPair FoundDecl,
const TemplateArgumentListInfo *ExplicitTemplateArgs,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet& CandidateSet,
bool SuppressUserConversions) {
if (!CandidateSet.isNewCandidate(FunctionTemplate))
return;
// C++ [over.match.funcs]p7:
// In each case where a candidate is a function template, candidate
// function template specializations are generated using template argument
// deduction (14.8.3, 14.8.2). Those candidates are then handled as
// candidate functions in the usual way.113) A given name can refer to one
// or more function templates and also to a set of overloaded non-template
// functions. In such a case, the candidate functions generated from each
// function template are combined with the set of non-template candidate
// functions.
TemplateDeductionInfo Info(Context, CandidateSet.getLocation());
FunctionDecl *Specialization = 0;
if (TemplateDeductionResult Result
= DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs,
Args, NumArgs, Specialization, Info)) {
CandidateSet.push_back(OverloadCandidate());
OverloadCandidate &Candidate = CandidateSet.back();
Candidate.FoundDecl = FoundDecl;
Candidate.Function = FunctionTemplate->getTemplatedDecl();
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_bad_deduction;
Candidate.IsSurrogate = false;
Candidate.IgnoreObjectArgument = false;
Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
Info);
return;
}
// Add the function template specialization produced by template argument
// deduction as a candidate.
assert(Specialization && "Missing function template specialization?");
AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet,
SuppressUserConversions);
}
/// AddConversionCandidate - Add a C++ conversion function as a
/// candidate in the candidate set (C++ [over.match.conv],
/// C++ [over.match.copy]). From is the expression we're converting from,
/// and ToType is the type that we're eventually trying to convert to
/// (which may or may not be the same type as the type that the
/// conversion function produces).
void
Sema::AddConversionCandidate(CXXConversionDecl *Conversion,
DeclAccessPair FoundDecl,
CXXRecordDecl *ActingContext,
Expr *From, QualType ToType,
OverloadCandidateSet& CandidateSet) {
assert(!Conversion->getDescribedFunctionTemplate() &&
"Conversion function templates use AddTemplateConversionCandidate");
QualType ConvType = Conversion->getConversionType().getNonReferenceType();
if (!CandidateSet.isNewCandidate(Conversion))
return;
// Overload resolution is always an unevaluated context.
EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated);
// Add this candidate
CandidateSet.push_back(OverloadCandidate());
OverloadCandidate& Candidate = CandidateSet.back();
Candidate.FoundDecl = FoundDecl;
Candidate.Function = Conversion;
Candidate.IsSurrogate = false;
Candidate.IgnoreObjectArgument = false;
Candidate.FinalConversion.setAsIdentityConversion();
Candidate.FinalConversion.setFromType(ConvType);
Candidate.FinalConversion.setAllToTypes(ToType);
// Determine the implicit conversion sequence for the implicit
// object parameter.
Candidate.Viable = true;
Candidate.Conversions.resize(1);
Candidate.Conversions[0]
= TryObjectArgumentInitialization(From->getType(), Conversion,
ActingContext);
// Conversion functions to a different type in the base class is visible in
// the derived class. So, a derived to base conversion should not participate
// in overload resolution.
if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base)
Candidate.Conversions[0].Standard.Second = ICK_Identity;
if (Candidate.Conversions[0].isBad()) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_bad_conversion;
return;
}
// We won't go through a user-define type conversion function to convert a
// derived to base as such conversions are given Conversion Rank. They only
// go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user]
QualType FromCanon
= Context.getCanonicalType(From->getType().getUnqualifiedType());
QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType();
if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_trivial_conversion;
return;
}
// To determine what the conversion from the result of calling the
// conversion function to the type we're eventually trying to
// convert to (ToType), we need to synthesize a call to the
// conversion function and attempt copy initialization from it. This
// makes sure that we get the right semantics with respect to
// lvalues/rvalues and the type. Fortunately, we can allocate this
// call on the stack and we don't need its arguments to be
// well-formed.
DeclRefExpr ConversionRef(Conversion, Conversion->getType(),
From->getLocStart());
ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()),
CastExpr::CK_FunctionToPointerDecay,
&ConversionRef, CXXBaseSpecifierArray(), false);
// Note that it is safe to allocate CallExpr on the stack here because
// there are 0 arguments (i.e., nothing is allocated using ASTContext's
// allocator).
CallExpr Call(Context, &ConversionFn, 0, 0,
Conversion->getConversionType().getNonReferenceType(),
From->getLocStart());
ImplicitConversionSequence ICS =
TryCopyInitialization(*this, &Call, ToType,
/*SuppressUserConversions=*/true,
/*InOverloadResolution=*/false);
switch (ICS.getKind()) {
case ImplicitConversionSequence::StandardConversion:
Candidate.FinalConversion = ICS.Standard;
// C++ [over.ics.user]p3:
// If the user-defined conversion is specified by a specialization of a
// conversion function template, the second standard conversion sequence
// shall have exact match rank.
if (Conversion->getPrimaryTemplate() &&
GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_final_conversion_not_exact;
}
break;
case ImplicitConversionSequence::BadConversion:
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_bad_final_conversion;
break;
default:
assert(false &&
"Can only end up with a standard conversion sequence or failure");
}
}
/// \brief Adds a conversion function template specialization
/// candidate to the overload set, using template argument deduction
/// to deduce the template arguments of the conversion function
/// template from the type that we are converting to (C++
/// [temp.deduct.conv]).
void
Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate,
DeclAccessPair FoundDecl,
CXXRecordDecl *ActingDC,
Expr *From, QualType ToType,
OverloadCandidateSet &CandidateSet) {
assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) &&
"Only conversion function templates permitted here");
if (!CandidateSet.isNewCandidate(FunctionTemplate))
return;
TemplateDeductionInfo Info(Context, CandidateSet.getLocation());
CXXConversionDecl *Specialization = 0;
if (TemplateDeductionResult Result
= DeduceTemplateArguments(FunctionTemplate, ToType,
Specialization, Info)) {
CandidateSet.push_back(OverloadCandidate());
OverloadCandidate &Candidate = CandidateSet.back();
Candidate.FoundDecl = FoundDecl;
Candidate.Function = FunctionTemplate->getTemplatedDecl();
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_bad_deduction;
Candidate.IsSurrogate = false;
Candidate.IgnoreObjectArgument = false;
Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
Info);
return;
}
// Add the conversion function template specialization produced by
// template argument deduction as a candidate.
assert(Specialization && "Missing function template specialization?");
AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType,
CandidateSet);
}
/// AddSurrogateCandidate - Adds a "surrogate" candidate function that
/// converts the given @c Object to a function pointer via the
/// conversion function @c Conversion, and then attempts to call it
/// with the given arguments (C++ [over.call.object]p2-4). Proto is
/// the type of function that we'll eventually be calling.
void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion,
DeclAccessPair FoundDecl,
CXXRecordDecl *ActingContext,
const FunctionProtoType *Proto,
QualType ObjectType,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet& CandidateSet) {
if (!CandidateSet.isNewCandidate(Conversion))
return;
// Overload resolution is always an unevaluated context.
EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated);
CandidateSet.push_back(OverloadCandidate());
OverloadCandidate& Candidate = CandidateSet.back();
Candidate.FoundDecl = FoundDecl;
Candidate.Function = 0;
Candidate.Surrogate = Conversion;
Candidate.Viable = true;
Candidate.IsSurrogate = true;
Candidate.IgnoreObjectArgument = false;
Candidate.Conversions.resize(NumArgs + 1);
// Determine the implicit conversion sequence for the implicit
// object parameter.
ImplicitConversionSequence ObjectInit
= TryObjectArgumentInitialization(ObjectType, Conversion, ActingContext);
if (ObjectInit.isBad()) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_bad_conversion;
Candidate.Conversions[0] = ObjectInit;
return;
}
// The first conversion is actually a user-defined conversion whose
// first conversion is ObjectInit's standard conversion (which is
// effectively a reference binding). Record it as such.
Candidate.Conversions[0].setUserDefined();
Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard;
Candidate.Conversions[0].UserDefined.EllipsisConversion = false;
Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion;
Candidate.Conversions[0].UserDefined.After
= Candidate.Conversions[0].UserDefined.Before;
Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion();
// Find the
unsigned NumArgsInProto = Proto->getNumArgs();
// (C++ 13.3.2p2): A candidate function having fewer than m
// parameters is viable only if it has an ellipsis in its parameter
// list (8.3.5).
if (NumArgs > NumArgsInProto && !Proto->isVariadic()) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_too_many_arguments;
return;
}
// Function types don't have any default arguments, so just check if
// we have enough arguments.
if (NumArgs < NumArgsInProto) {
// Not enough arguments.
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_too_few_arguments;
return;
}
// Determine the implicit conversion sequences for each of the
// arguments.
for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) {
if (ArgIdx < NumArgsInProto) {
// (C++ 13.3.2p3): for F to be a viable function, there shall
// exist for each argument an implicit conversion sequence
// (13.3.3.1) that converts that argument to the corresponding
// parameter of F.
QualType ParamType = Proto->getArgType(ArgIdx);
Candidate.Conversions[ArgIdx + 1]
= TryCopyInitialization(*this, Args[ArgIdx], ParamType,
/*SuppressUserConversions=*/false,
/*InOverloadResolution=*/false);
if (Candidate.Conversions[ArgIdx + 1].isBad()) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_bad_conversion;
break;
}
} else {
// (C++ 13.3.2p2): For the purposes of overload resolution, any
// argument for which there is no corresponding parameter is
// considered to ""match the ellipsis" (C+ 13.3.3.1.3).
Candidate.Conversions[ArgIdx + 1].setEllipsis();
}
}
}
/// \brief Add overload candidates for overloaded operators that are
/// member functions.
///
/// Add the overloaded operator candidates that are member functions
/// for the operator Op that was used in an operator expression such
/// as "x Op y". , Args/NumArgs provides the operator arguments, and
/// CandidateSet will store the added overload candidates. (C++
/// [over.match.oper]).
void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op,
SourceLocation OpLoc,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet& CandidateSet,
SourceRange OpRange) {
DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
// C++ [over.match.oper]p3:
// For a unary operator @ with an operand of a type whose
// cv-unqualified version is T1, and for a binary operator @ with
// a left operand of a type whose cv-unqualified version is T1 and
// a right operand of a type whose cv-unqualified version is T2,
// three sets of candidate functions, designated member
// candidates, non-member candidates and built-in candidates, are
// constructed as follows:
QualType T1 = Args[0]->getType();
QualType T2;
if (NumArgs > 1)
T2 = Args[1]->getType();
// -- If T1 is a class type, the set of member candidates is the
// result of the qualified lookup of T1::operator@
// (13.3.1.1.1); otherwise, the set of member candidates is
// empty.
if (const RecordType *T1Rec = T1->getAs<RecordType>()) {
// Complete the type if it can be completed. Otherwise, we're done.
if (RequireCompleteType(OpLoc, T1, PDiag()))
return;
LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName);
LookupQualifiedName(Operators, T1Rec->getDecl());
Operators.suppressDiagnostics();
for (LookupResult::iterator Oper = Operators.begin(),
OperEnd = Operators.end();
Oper != OperEnd;
++Oper)
AddMethodCandidate(Oper.getPair(), Args[0]->getType(),
Args + 1, NumArgs - 1, CandidateSet,
/* SuppressUserConversions = */ false);
}
}
/// AddBuiltinCandidate - Add a candidate for a built-in
/// operator. ResultTy and ParamTys are the result and parameter types
/// of the built-in candidate, respectively. Args and NumArgs are the
/// arguments being passed to the candidate. IsAssignmentOperator
/// should be true when this built-in candidate is an assignment
/// operator. NumContextualBoolArguments is the number of arguments
/// (at the beginning of the argument list) that will be contextually
/// converted to bool.
void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet& CandidateSet,
bool IsAssignmentOperator,
unsigned NumContextualBoolArguments) {
// Overload resolution is always an unevaluated context.
EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated);
// Add this candidate
CandidateSet.push_back(OverloadCandidate());
OverloadCandidate& Candidate = CandidateSet.back();
Candidate.FoundDecl = DeclAccessPair::make(0, AS_none);
Candidate.Function = 0;
Candidate.IsSurrogate = false;
Candidate.IgnoreObjectArgument = false;
Candidate.BuiltinTypes.ResultTy = ResultTy;
for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx)
Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx];
// Determine the implicit conversion sequences for each of the
// arguments.
Candidate.Viable = true;
Candidate.Conversions.resize(NumArgs);
for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) {
// C++ [over.match.oper]p4:
// For the built-in assignment operators, conversions of the
// left operand are restricted as follows:
// -- no temporaries are introduced to hold the left operand, and
// -- no user-defined conversions are applied to the left
// operand to achieve a type match with the left-most
// parameter of a built-in candidate.
//
// We block these conversions by turning off user-defined
// conversions, since that is the only way that initialization of
// a reference to a non-class type can occur from something that
// is not of the same type.
if (ArgIdx < NumContextualBoolArguments) {
assert(ParamTys[ArgIdx] == Context.BoolTy &&
"Contextual conversion to bool requires bool type");
Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]);
} else {
Candidate.Conversions[ArgIdx]
= TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx],
ArgIdx == 0 && IsAssignmentOperator,
/*InOverloadResolution=*/false);
}
if (Candidate.Conversions[ArgIdx].isBad()) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_bad_conversion;
break;
}
}
}
/// BuiltinCandidateTypeSet - A set of types that will be used for the
/// candidate operator functions for built-in operators (C++
/// [over.built]). The types are separated into pointer types and
/// enumeration types.
class BuiltinCandidateTypeSet {
/// TypeSet - A set of types.
typedef llvm::SmallPtrSet<QualType, 8> TypeSet;
/// PointerTypes - The set of pointer types that will be used in the
/// built-in candidates.
TypeSet PointerTypes;
/// MemberPointerTypes - The set of member pointer types that will be
/// used in the built-in candidates.
TypeSet MemberPointerTypes;
/// EnumerationTypes - The set of enumeration types that will be
/// used in the built-in candidates.
TypeSet EnumerationTypes;
/// Sema - The semantic analysis instance where we are building the
/// candidate type set.
Sema &SemaRef;
/// Context - The AST context in which we will build the type sets.
ASTContext &Context;
bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
const Qualifiers &VisibleQuals);
bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty);
public:
/// iterator - Iterates through the types that are part of the set.
typedef TypeSet::iterator iterator;
BuiltinCandidateTypeSet(Sema &SemaRef)
: SemaRef(SemaRef), Context(SemaRef.Context) { }
void AddTypesConvertedFrom(QualType Ty,
SourceLocation Loc,
bool AllowUserConversions,
bool AllowExplicitConversions,
const Qualifiers &VisibleTypeConversionsQuals);
/// pointer_begin - First pointer type found;
iterator pointer_begin() { return PointerTypes.begin(); }
/// pointer_end - Past the last pointer type found;
iterator pointer_end() { return PointerTypes.end(); }
/// member_pointer_begin - First member pointer type found;
iterator member_pointer_begin() { return MemberPointerTypes.begin(); }
/// member_pointer_end - Past the last member pointer type found;
iterator member_pointer_end() { return MemberPointerTypes.end(); }
/// enumeration_begin - First enumeration type found;
iterator enumeration_begin() { return EnumerationTypes.begin(); }
/// enumeration_end - Past the last enumeration type found;
iterator enumeration_end() { return EnumerationTypes.end(); }
};
/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to
/// the set of pointer types along with any more-qualified variants of
/// that type. For example, if @p Ty is "int const *", this routine
/// will add "int const *", "int const volatile *", "int const
/// restrict *", and "int const volatile restrict *" to the set of
/// pointer types. Returns true if the add of @p Ty itself succeeded,
/// false otherwise.
///
/// FIXME: what to do about extended qualifiers?
bool
BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
const Qualifiers &VisibleQuals) {
// Insert this type.
if (!PointerTypes.insert(Ty))
return false;
const PointerType *PointerTy = Ty->getAs<PointerType>();
assert(PointerTy && "type was not a pointer type!");
QualType PointeeTy = PointerTy->getPointeeType();
// Don't add qualified variants of arrays. For one, they're not allowed
// (the qualifier would sink to the element type), and for another, the
// only overload situation where it matters is subscript or pointer +- int,
// and those shouldn't have qualifier variants anyway.
if (PointeeTy->isArrayType())
return true;
unsigned BaseCVR = PointeeTy.getCVRQualifiers();
if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy))
BaseCVR = Array->getElementType().getCVRQualifiers();
bool hasVolatile = VisibleQuals.hasVolatile();
bool hasRestrict = VisibleQuals.hasRestrict();
// Iterate through all strict supersets of BaseCVR.
for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) {
if ((CVR | BaseCVR) != CVR) continue;
// Skip over Volatile/Restrict if no Volatile/Restrict found anywhere
// in the types.
if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue;
if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue;
QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR);
PointerTypes.insert(Context.getPointerType(QPointeeTy));
}
return true;
}
/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty
/// to the set of pointer types along with any more-qualified variants of
/// that type. For example, if @p Ty is "int const *", this routine
/// will add "int const *", "int const volatile *", "int const
/// restrict *", and "int const volatile restrict *" to the set of
/// pointer types. Returns true if the add of @p Ty itself succeeded,
/// false otherwise.
///
/// FIXME: what to do about extended qualifiers?
bool
BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants(
QualType Ty) {
// Insert this type.
if (!MemberPointerTypes.insert(Ty))
return false;
const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>();
assert(PointerTy && "type was not a member pointer type!");
QualType PointeeTy = PointerTy->getPointeeType();
// Don't add qualified variants of arrays. For one, they're not allowed
// (the qualifier would sink to the element type), and for another, the
// only overload situation where it matters is subscript or pointer +- int,
// and those shouldn't have qualifier variants anyway.
if (PointeeTy->isArrayType())
return true;
const Type *ClassTy = PointerTy->getClass();
// Iterate through all strict supersets of the pointee type's CVR
// qualifiers.
unsigned BaseCVR = PointeeTy.getCVRQualifiers();
for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) {
if ((CVR | BaseCVR) != CVR) continue;
QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR);
MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy));
}
return true;
}
/// AddTypesConvertedFrom - Add each of the types to which the type @p
/// Ty can be implicit converted to the given set of @p Types. We're
/// primarily interested in pointer types and enumeration types. We also
/// take member pointer types, for the conditional operator.
/// AllowUserConversions is true if we should look at the conversion
/// functions of a class type, and AllowExplicitConversions if we
/// should also include the explicit conversion functions of a class
/// type.
void
BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty,
SourceLocation Loc,
bool AllowUserConversions,
bool AllowExplicitConversions,
const Qualifiers &VisibleQuals) {
// Only deal with canonical types.
Ty = Context.getCanonicalType(Ty);
// Look through reference types; they aren't part of the type of an
// expression for the purposes of conversions.
if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>())
Ty = RefTy->getPointeeType();
// We don't care about qualifiers on the type.
Ty = Ty.getLocalUnqualifiedType();
// If we're dealing with an array type, decay to the pointer.
if (Ty->isArrayType())
Ty = SemaRef.Context.getArrayDecayedType(Ty);
if (const PointerType *PointerTy = Ty->getAs<PointerType>()) {
QualType PointeeTy = PointerTy->getPointeeType();
// Insert our type, and its more-qualified variants, into the set
// of types.
if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals))
return;
} else if (Ty->isMemberPointerType()) {
// Member pointers are far easier, since the pointee can't be converted.
if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty))
return;
} else if (Ty->isEnumeralType()) {
EnumerationTypes.insert(Ty);
} else if (AllowUserConversions) {
if (const RecordType *TyRec = Ty->getAs<RecordType>()) {
if (SemaRef.RequireCompleteType(Loc, Ty, 0)) {
// No conversion functions in incomplete types.
return;
}
CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl());
const UnresolvedSetImpl *Conversions
= ClassDecl->getVisibleConversionFunctions();
for (UnresolvedSetImpl::iterator I = Conversions->begin(),
E = Conversions->end(); I != E; ++I) {
NamedDecl *D = I.getDecl();
if (isa<UsingShadowDecl>(D))
D = cast<UsingShadowDecl>(D)->getTargetDecl();
// Skip conversion function templates; they don't tell us anything
// about which builtin types we can convert to.
if (isa<FunctionTemplateDecl>(D))
continue;
CXXConversionDecl *Conv = cast<CXXConversionDecl>(D);
if (AllowExplicitConversions || !Conv->isExplicit()) {
AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false,
VisibleQuals);
}
}
}
}
}
/// \brief Helper function for AddBuiltinOperatorCandidates() that adds
/// the volatile- and non-volatile-qualified assignment operators for the
/// given type to the candidate set.
static void AddBuiltinAssignmentOperatorCandidates(Sema &S,
QualType T,
Expr **Args,
unsigned NumArgs,
OverloadCandidateSet &CandidateSet) {
QualType ParamTypes[2];
// T& operator=(T&, T)
ParamTypes[0] = S.Context.getLValueReferenceType(T);
ParamTypes[1] = T;
S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet,
/*IsAssignmentOperator=*/true);
if (!S.Context.getCanonicalType(T).isVolatileQualified()) {
// volatile T& operator=(volatile T&, T)
ParamTypes[0]
= S.Context.getLValueReferenceType(S.Context.getVolatileType(T));
ParamTypes[1] = T;
S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet,
/*IsAssignmentOperator=*/true);
}
}
/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers,
/// if any, found in visible type conversion functions found in ArgExpr's type.
static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) {
Qualifiers VRQuals;
const RecordType *TyRec;
if (const MemberPointerType *RHSMPType =
ArgExpr->getType()->getAs<MemberPointerType>())
TyRec = RHSMPType->getClass()->getAs<RecordType>();
else
TyRec = ArgExpr->getType()->getAs<RecordType>();
if (!TyRec) {
// Just to be safe, assume the worst case.
VRQuals.addVolatile();
VRQuals.addRestrict();
return VRQuals;
}
CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl());
if (!ClassDecl->hasDefinition())
return VRQuals;
const UnresolvedSetImpl *Conversions =
ClassDecl->getVisibleConversionFunctions();
for (UnresolvedSetImpl::iterator I = Conversions->begin(),
E = Conversions->end(); I != E; ++I) {
NamedDecl *D = I.getDecl();
if (isa<UsingShadowDecl>(D))
D = cast<UsingShadowDecl>(D)->getTargetDecl();
if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) {
QualType CanTy = Context.getCanonicalType(Conv->getConversionType());
if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>())
CanTy = ResTypeRef->getPointeeType();
// Need to go down the pointer/mempointer chain and add qualifiers
// as see them.
bool done = false;
while (!done) {
if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>())
CanTy = ResTypePtr->getPointeeType();
else if (const MemberPointerType *ResTypeMPtr =
CanTy->getAs<MemberPointerType>())
CanTy = ResTypeMPtr->getPointeeType();
else
done = true;
if (CanTy.isVolatileQualified())
VRQuals.addVolatile();
if (CanTy.isRestrictQualified())
VRQuals.addRestrict();
if (VRQuals.hasRestrict() && VRQuals.hasVolatile())
return VRQuals;
}
}
}
return VRQuals;
}
/// AddBuiltinOperatorCandidates - Add the appropriate built-in
/// operator overloads to the candidate set (C++ [over.built]), based
/// on the operator @p Op and the arguments given. For example, if the
/// operator is a binary '+', this routine might add "int
/// operator+(int, int)" to cover integer addition.
void
Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op,
SourceLocation OpLoc,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet& CandidateSet) {
// The set of "promoted arithmetic types", which are the arithmetic
// types are that preserved by promotion (C++ [over.built]p2). Note
// that the first few of these types are the promoted integral
// types; these types need to be first.
// FIXME: What about complex?
const unsigned FirstIntegralType = 0;
const unsigned LastIntegralType = 13;
const unsigned FirstPromotedIntegralType = 7,
LastPromotedIntegralType = 13;
const unsigned FirstPromotedArithmeticType = 7,
LastPromotedArithmeticType = 16;
const unsigned NumArithmeticTypes = 16;
QualType ArithmeticTypes[NumArithmeticTypes] = {
Context.BoolTy, Context.CharTy, Context.WCharTy,
// FIXME: Context.Char16Ty, Context.Char32Ty,
Context.SignedCharTy, Context.ShortTy,
Context.UnsignedCharTy, Context.UnsignedShortTy,
Context.IntTy, Context.LongTy, Context.LongLongTy,
Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy,
Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy
};
assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy &&
"Invalid first promoted integral type");
assert(ArithmeticTypes[LastPromotedIntegralType - 1]
== Context.UnsignedLongLongTy &&
"Invalid last promoted integral type");
assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy &&
"Invalid first promoted arithmetic type");
assert(ArithmeticTypes[LastPromotedArithmeticType - 1]
== Context.LongDoubleTy &&
"Invalid last promoted arithmetic type");
// Find all of the types that the arguments can convert to, but only
// if the operator we're looking at has built-in operator candidates
// that make use of these types.
Qualifiers VisibleTypeConversionsQuals;
VisibleTypeConversionsQuals.addConst();
for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx)
VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]);
BuiltinCandidateTypeSet CandidateTypes(*this);
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 && NumArgs == 2) || Op == OO_Equal ||
Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript ||
Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus ||
(Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) {
for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx)
CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(),
OpLoc,
true,
(Op == OO_Exclaim ||
Op == OO_AmpAmp ||
Op == OO_PipePipe),
VisibleTypeConversionsQuals);
}
bool isComparison = false;
switch (Op) {
case OO_None:
case NUM_OVERLOADED_OPERATORS:
assert(false && "Expected an overloaded operator");
break;
case OO_Star: // '*' is either unary or binary
if (NumArgs == 1)
goto UnaryStar;
else
goto BinaryStar;
break;
case OO_Plus: // '+' is either unary or binary
if (NumArgs == 1)
goto UnaryPlus;
else
goto BinaryPlus;
break;
case OO_Minus: // '-' is either unary or binary
if (NumArgs == 1)
goto UnaryMinus;
else
goto BinaryMinus;
break;
case OO_Amp: // '&' is either unary or binary
if (NumArgs == 1)
goto UnaryAmp;
else
goto BinaryAmp;
case OO_PlusPlus:
case OO_MinusMinus:
// C++ [over.built]p3:
//
// For every pair (T, VQ), where T is an arithmetic type, and VQ
// is either volatile or empty, there exist candidate operator
// functions of the form
//
// VQ T& operator++(VQ T&);
// T operator++(VQ T&, int);
//
// C++ [over.built]p4:
//
// For every pair (T, VQ), where T is an arithmetic type other
// than bool, and VQ is either volatile or empty, there exist
// candidate operator functions of the form
//
// VQ T& operator--(VQ T&);
// T operator--(VQ T&, int);
for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1);
Arith < NumArithmeticTypes; ++Arith) {
QualType ArithTy = ArithmeticTypes[Arith];
QualType ParamTypes[2]
= { Context.getLValueReferenceType(ArithTy), Context.IntTy };
// Non-volatile version.
if (NumArgs == 1)
AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet);
else
AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet);
// heuristic to reduce number of builtin candidates in the set.
// Add volatile version only if there are conversions to a volatile type.
if (VisibleTypeConversionsQuals.hasVolatile()) {
// Volatile version
ParamTypes[0]
= Context.getLValueReferenceType(Context.getVolatileType(ArithTy));
if (NumArgs == 1)
AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet);
else
AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet);
}
}
// C++ [over.built]p5:
//
// For every pair (T, VQ), where T is a cv-qualified or
// cv-unqualified object type, and VQ is either volatile or
// empty, there exist candidate operator functions of the form
//
// T*VQ& operator++(T*VQ&);
// T*VQ& operator--(T*VQ&);
// T* operator++(T*VQ&, int);
// T* operator--(T*VQ&, int);
for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin();
Ptr != CandidateTypes.pointer_end(); ++Ptr) {
// Skip pointer types that aren't pointers to object types.
if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType())
continue;
QualType ParamTypes[2] = {
Context.getLValueReferenceType(*Ptr), Context.IntTy
};
// Without volatile
if (NumArgs == 1)
AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet);
else
AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet);
if (!Context.getCanonicalType(*Ptr).isVolatileQualified() &&
VisibleTypeConversionsQuals.hasVolatile()) {
// With volatile
ParamTypes[0]
= Context.getLValueReferenceType(Context.getVolatileType(*Ptr));
if (NumArgs == 1)
AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet);
else
AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet);
}
}
break;
UnaryStar:
// C++ [over.built]p6:
// For every cv-qualified or cv-unqualified object type T, there
// exist candidate operator functions of the form
//
// T& operator*(T*);
//
// C++ [over.built]p7:
// For every function type T, there exist candidate operator
// functions of the form
// T& operator*(T*);
for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin();
Ptr != CandidateTypes.pointer_end(); ++Ptr) {
QualType ParamTy = *Ptr;
QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType();
AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy),
&ParamTy, Args, 1, CandidateSet);
}
break;
UnaryPlus:
// C++ [over.built]p8:
// For every type T, there exist candidate operator functions of
// the form
//
// T* operator+(T*);
for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin();
Ptr != CandidateTypes.pointer_end(); ++Ptr) {
QualType ParamTy = *Ptr;
AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet);
}
// Fall through
UnaryMinus:
// C++ [over.built]p9:
// For every promoted arithmetic type T, there exist candidate
// operator functions of the form
//
// T operator+(T);
// T operator-(T);
for (unsigned Arith = FirstPromotedArithmeticType;
Arith < LastPromotedArithmeticType; ++Arith) {
QualType ArithTy = ArithmeticTypes[Arith];
AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet);
}
break;
case OO_Tilde:
// C++ [over.built]p10:
// For every promoted integral type T, there exist candidate
// operator functions of the form
//
// T operator~(T);
for (unsigned Int = FirstPromotedIntegralType;
Int < LastPromotedIntegralType; ++Int) {
QualType IntTy = ArithmeticTypes[Int];
AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet);
}
break;
case OO_New:
case OO_Delete:
case OO_Array_New:
case OO_Array_Delete:
case OO_Call:
assert(false && "Special operators don't use AddBuiltinOperatorCandidates");
break;
case OO_Comma:
UnaryAmp:
case OO_Arrow:
// C++ [over.match.oper]p3:
// -- For the operator ',', the unary operator '&', or the
// operator '->', the built-in candidates set is empty.
break;
case OO_EqualEqual:
case OO_ExclaimEqual:
// C++ [over.match.oper]p16:
// For every pointer to member type T, there exist candidate operator
// functions of the form
//
// bool operator==(T,T);
// bool operator!=(T,T);
for (BuiltinCandidateTypeSet::iterator
MemPtr = CandidateTypes.member_pointer_begin(),
MemPtrEnd = CandidateTypes.member_pointer_end();
MemPtr != MemPtrEnd;
++MemPtr) {
QualType ParamTypes[2] = { *MemPtr, *MemPtr };
AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet);
}
// Fall through
case OO_Less:
case OO_Greater:
case OO_LessEqual:
case OO_GreaterEqual:
// C++ [over.built]p15:
//
// For every pointer or enumeration type T, there exist
// candidate operator functions of the form
//
// bool operator<(T, T);
// bool operator>(T, T);
// bool operator<=(T, T);
// bool operator>=(T, T);
// bool operator==(T, T);
// bool operator!=(T, T);
for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin();
Ptr != CandidateTypes.pointer_end(); ++Ptr) {
QualType ParamTypes[2] = { *Ptr, *Ptr };
AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet);
}
for (BuiltinCandidateTypeSet::iterator Enum
= CandidateTypes.enumeration_begin();
Enum != CandidateTypes.enumeration_end(); ++Enum) {
QualType ParamTypes[2] = { *Enum, *Enum };
AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet);
}
// Fall through.
isComparison = true;
BinaryPlus:
BinaryMinus:
if (!isComparison) {
// We didn't fall through, so we must have OO_Plus or OO_Minus.
// C++ [over.built]p13:
//
// For every cv-qualified or cv-unqualified object type T
// there exist candidate operator functions of the form
//
// T* operator+(T*, ptrdiff_t);
// T& operator[](T*, ptrdiff_t); [BELOW]
// T* operator-(T*, ptrdiff_t);
// T* operator+(ptrdiff_t, T*);
// T& operator[](ptrdiff_t, T*); [BELOW]
//
// C++ [over.built]p14:
//
// For every T, where T is a pointer to object type, there
// exist candidate operator functions of the form
//
// ptrdiff_t operator-(T, T);
for (BuiltinCandidateTypeSet::iterator Ptr
= CandidateTypes.pointer_begin();
Ptr != CandidateTypes.pointer_end(); ++Ptr) {
QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() };
// operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t)
AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet);
if (Op == OO_Plus) {
// T* operator+(ptrdiff_t, T*);
ParamTypes[0] = ParamTypes[1];
ParamTypes[1] = *Ptr;
AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet);
} else {
// ptrdiff_t operator-(T, T);
ParamTypes[1] = *Ptr;
AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes,
Args, 2, CandidateSet);
}
}
}
// Fall through
case OO_Slash:
BinaryStar:
Conditional:
// C++ [over.built]p12:
//
// For every pair of promoted arithmetic types L and R, there
// exist candidate operator functions of the form
//
// LR operator*(L, R);
// LR operator/(L, R);
// LR operator+(L, R);
// LR operator-(L, R);
// bool operator<(L, R);
// bool operator>(L, R);
// bool operator<=(L, R);
// bool operator>=(L, R);
// bool operator==(L, R);
// bool operator!=(L, R);
//
// where LR is the result of the usual arithmetic conversions
// between types L and R.
//
// C++ [over.built]p24:
//
// For every pair of promoted arithmetic types L and R, there exist
// candidate operator functions of the form
//
// LR operator?(bool, L, R);
//
// where LR is the result of the usual arithmetic conversions
// between types L and R.
// Our candidates ignore the first parameter.
for (unsigned Left = FirstPromotedArithmeticType;
Left < LastPromotedArithmeticType; ++Left) {
for (unsigned Right = FirstPromotedArithmeticType;
Right < LastPromotedArithmeticType; ++Right) {
QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] };
QualType Result
= isComparison
? Context.BoolTy
: Context.UsualArithmeticConversionsType(LandR[0], LandR[1]);
AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet);
}
}
break;
case OO_Percent:
BinaryAmp:
case OO_Caret:
case OO_Pipe:
case OO_LessLess:
case OO_GreaterGreater:
// C++ [over.built]p17:
//
// For every pair of promoted integral types L and R, there
// exist candidate operator functions of the form
//
// LR operator%(L, R);
// LR operator&(L, R);
// LR operator^(L, R);
// LR operator|(L, R);
// L operator<<(L, R);
// L operator>>(L, R);
//
// where LR is the result of the usual arithmetic conversions
// between types L and R.
for (unsigned Left = FirstPromotedIntegralType;
Left < LastPromotedIntegralType; ++Left) {
for (unsigned Right = FirstPromotedIntegralType;
Right < LastPromotedIntegralType; ++Right) {
QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] };
QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater)
? LandR[0]
: Context.UsualArithmeticConversionsType(LandR[0], LandR[1]);
AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet);
}
}
break;
case OO_Equal:
// C++ [over.built]p20:
//
// For every pair (T, VQ), where T is an enumeration or
// pointer to member type and VQ is either volatile or
// empty, there exist candidate operator functions of the form
//
// VQ T& operator=(VQ T&, T);
for (BuiltinCandidateTypeSet::iterator
Enum = CandidateTypes.enumeration_begin(),
EnumEnd = CandidateTypes.enumeration_end();
Enum != EnumEnd; ++Enum)
AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2,
CandidateSet);
for (BuiltinCandidateTypeSet::iterator
MemPtr = CandidateTypes.member_pointer_begin(),
MemPtrEnd = CandidateTypes.member_pointer_end();
MemPtr != MemPtrEnd; ++MemPtr)
AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2,
CandidateSet);
// Fall through.
case OO_PlusEqual:
case OO_MinusEqual:
// C++ [over.built]p19:
//
// For every pair (T, VQ), where T is any type and VQ is either
// volatile or empty, there exist candidate operator functions
// of the form
//
// T*VQ& operator=(T*VQ&, T*);
//
// C++ [over.built]p21:
//
// For every pair (T, VQ), where T is a cv-qualified or
// cv-unqualified object type and VQ is either volatile or
// empty, there exist candidate operator functions of the form
//
// T*VQ& operator+=(T*VQ&, ptrdiff_t);
// T*VQ& operator-=(T*VQ&, ptrdiff_t);
for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin();
Ptr != CandidateTypes.pointer_end(); ++Ptr) {
QualType ParamTypes[2];
ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType();
// non-volatile version
ParamTypes[0] = Context.getLValueReferenceType(*Ptr);
AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet,
/*IsAssigmentOperator=*/Op == OO_Equal);
if (!Context.getCanonicalType(*Ptr).isVolatileQualified() &&
VisibleTypeConversionsQuals.hasVolatile()) {
// volatile version
ParamTypes[0]
= Context.getLValueReferenceType(Context.getVolatileType(*Ptr));
AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet,
/*IsAssigmentOperator=*/Op == OO_Equal);
}
}
// Fall through.
case OO_StarEqual:
case OO_SlashEqual:
// C++ [over.built]p18:
//
// For every triple (L, VQ, R), where L is an arithmetic type,
// VQ is either volatile or empty, and R is a promoted
// arithmetic type, there exist candidate operator functions of
// the form
//
// VQ L& operator=(VQ L&, R);
// VQ L& operator*=(VQ L&, R);
// VQ L& operator/=(VQ L&, R);
// VQ L& operator+=(VQ L&, R);
// VQ L& operator-=(VQ L&, R);
for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) {
for (unsigned Right = FirstPromotedArithmeticType;
Right < LastPromotedArithmeticType; ++Right) {
QualType ParamTypes[2];
ParamTypes[1] = ArithmeticTypes[Right];
// Add this built-in operator as a candidate (VQ is empty).
ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]);
AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet,
/*IsAssigmentOperator=*/Op == OO_Equal);
// Add this built-in operator as a candidate (VQ is 'volatile').
if (VisibleTypeConversionsQuals.hasVolatile()) {
ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]);
ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]);
AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet,
/*IsAssigmentOperator=*/Op == OO_Equal);
}
}
}
break;
case OO_PercentEqual:
case OO_LessLessEqual:
case OO_GreaterGreaterEqual:
case OO_AmpEqual:
case OO_CaretEqual:
case OO_PipeEqual:
// C++ [over.built]p22:
//
// For every triple (L, VQ, R), where L is an integral type, VQ
// is either volatile or empty, and R is a promoted integral
// type, there exist candidate operator functions of the form
//
// VQ L& operator%=(VQ L&, R);
// VQ L& operator<<=(VQ L&, R);
// VQ L& operator>>=(VQ L&, R);
// VQ L& operator&=(VQ L&, R);
// VQ L& operator^=(VQ L&, R);
// VQ L& operator|=(VQ L&, R);
for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) {
for (unsigned Right = FirstPromotedIntegralType;
Right < LastPromotedIntegralType; ++Right) {
QualType ParamTypes[2];
ParamTypes[1] = ArithmeticTypes[Right];
// Add this built-in operator as a candidate (VQ is empty).
ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]);
AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet);
if (VisibleTypeConversionsQuals.hasVolatile()) {
// Add this built-in operator as a candidate (VQ is 'volatile').
ParamTypes[0] = ArithmeticTypes[Left];
ParamTypes[0] = Context.getVolatileType(ParamTypes[0]);
ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]);
AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet);
}
}
}
break;
case OO_Exclaim: {
// C++ [over.operator]p23:
//
// There also exist candidate operator functions of the form
//
// bool operator!(bool);
// bool operator&&(bool, bool); [BELOW]
// bool operator||(bool, bool); [BELOW]
QualType ParamTy = Context.BoolTy;
AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet,
/*IsAssignmentOperator=*/false,
/*NumContextualBoolArguments=*/1);
break;
}
case OO_AmpAmp:
case OO_PipePipe: {
// C++ [over.operator]p23:
//
// There also exist candidate operator functions of the form
//
// bool operator!(bool); [ABOVE]
// bool operator&&(bool, bool);
// bool operator||(bool, bool);
QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy };
AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet,
/*IsAssignmentOperator=*/false,
/*NumContextualBoolArguments=*/2);
break;
}
case OO_Subscript:
// C++ [over.built]p13:
//
// For every cv-qualified or cv-unqualified object type T there
// exist candidate operator functions of the form
//
// T* operator+(T*, ptrdiff_t); [ABOVE]
// T& operator[](T*, ptrdiff_t);
// T* operator-(T*, ptrdiff_t); [ABOVE]
// T* operator+(ptrdiff_t, T*); [ABOVE]
// T& operator[](ptrdiff_t, T*);
for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin();
Ptr != CandidateTypes.pointer_end(); ++Ptr) {
QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() };
QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType();
QualType ResultTy = Context.getLValueReferenceType(PointeeType);
// T& operator[](T*, ptrdiff_t)
AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet);
// T& operator[](ptrdiff_t, T*);
ParamTypes[0] = ParamTypes[1];
ParamTypes[1] = *Ptr;
AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet);
}
break;
case OO_ArrowStar:
// C++ [over.built]p11:
// For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type,
// C1 is the same type as C2 or is a derived class of C2, T is an object
// type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
// there exist candidate operator functions of the form
// CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
// where CV12 is the union of CV1 and CV2.
{
for (BuiltinCandidateTypeSet::iterator Ptr =
CandidateTypes.pointer_begin();
Ptr != CandidateTypes.pointer_end(); ++Ptr) {
QualType C1Ty = (*Ptr);
QualType C1;
QualifierCollector Q1;
if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) {
C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0);
if (!isa<RecordType>(C1))
continue;
// heuristic to reduce number of builtin candidates in the set.
// Add volatile/restrict version only if there are conversions to a
// volatile/restrict type.
if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile())
continue;
if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict())
continue;
}
for (BuiltinCandidateTypeSet::iterator
MemPtr = CandidateTypes.member_pointer_begin(),
MemPtrEnd = CandidateTypes.member_pointer_end();
MemPtr != MemPtrEnd; ++MemPtr) {
const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr);
QualType C2 = QualType(mptr->getClass(), 0);
C2 = C2.getUnqualifiedType();
if (C1 != C2 && !IsDerivedFrom(C1, C2))
break;
QualType ParamTypes[2] = { *Ptr, *MemPtr };
// build CV12 T&
QualType T = mptr->getPointeeType();
if (!VisibleTypeConversionsQuals.hasVolatile() &&
T.isVolatileQualified())
continue;
if (!VisibleTypeConversionsQuals.hasRestrict() &&
T.isRestrictQualified())
continue;
T = Q1.apply(T);
QualType ResultTy = Context.getLValueReferenceType(T);
AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet);
}
}
}
break;
case OO_Conditional:
// Note that we don't consider the first argument, since it has been
// contextually converted to bool long ago. The candidates below are
// therefore added as binary.
//
// C++ [over.built]p24:
// For every type T, where T is a pointer or pointer-to-member type,
// there exist candidate operator functions of the form
//
// T operator?(bool, T, T);
//
for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(),
E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) {
QualType ParamTypes[2] = { *Ptr, *Ptr };
AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet);
}
for (BuiltinCandidateTypeSet::iterator Ptr =
CandidateTypes.member_pointer_begin(),
E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) {
QualType ParamTypes[2] = { *Ptr, *Ptr };
AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet);
}
goto Conditional;
}
}
/// \brief Add function candidates found via argument-dependent lookup
/// to the set of overloading candidates.
///
/// This routine performs argument-dependent name lookup based on the
/// given function name (which may also be an operator name) and adds
/// all of the overload candidates found by ADL to the overload
/// candidate set (C++ [basic.lookup.argdep]).
void
Sema::AddArgumentDependentLookupCandidates(DeclarationName Name,
bool Operator,
Expr **Args, unsigned NumArgs,
const TemplateArgumentListInfo *ExplicitTemplateArgs,
OverloadCandidateSet& CandidateSet,
bool PartialOverloading) {
ADLResult Fns;
// FIXME: This approach for uniquing ADL results (and removing
// redundant candidates from the set) relies on pointer-equality,
// which means we need to key off the canonical decl. However,
// always going back to the canonical decl might not get us the
// right set of default arguments. What default arguments are
// we supposed to consider on ADL candidates, anyway?
// FIXME: Pass in the explicit template arguments?
ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns);
// Erase all of the candidates we already knew about.
for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(),
CandEnd = CandidateSet.end();
Cand != CandEnd; ++Cand)
if (Cand->Function) {
Fns.erase(Cand->Function);
if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate())
Fns.erase(FunTmpl);
}
// For each of the ADL candidates we found, add it to the overload
// set.
for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) {
DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none);
if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) {
if (ExplicitTemplateArgs)
continue;
AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet,
false, PartialOverloading);
} else
AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I),
FoundDecl, ExplicitTemplateArgs,
Args, NumArgs, CandidateSet);
}
}
/// isBetterOverloadCandidate - Determines whether the first overload
/// candidate is a better candidate than the second (C++ 13.3.3p1).
bool
Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1,
const OverloadCandidate& Cand2,
SourceLocation Loc) {
// Define viable functions to be better candidates than non-viable
// functions.
if (!Cand2.Viable)
return Cand1.Viable;
else if (!Cand1.Viable)
return false;
// C++ [over.match.best]p1:
//
// -- if F is a static member function, ICS1(F) is defined such
// that ICS1(F) is neither better nor worse than ICS1(G) for
// any function G, and, symmetrically, ICS1(G) is neither
// better nor worse than ICS1(F).
unsigned StartArg = 0;
if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument)
StartArg = 1;
// C++ [over.match.best]p1:
// A viable function F1 is defined to be a better function than another
// viable function F2 if for all arguments i, ICSi(F1) is not a worse
// conversion sequence than ICSi(F2), and then...
unsigned NumArgs = Cand1.Conversions.size();
assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch");
bool HasBetterConversion = false;
for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) {
switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx],
Cand2.Conversions[ArgIdx])) {
case ImplicitConversionSequence::Better:
// Cand1 has a better conversion sequence.
HasBetterConversion = true;
break;
case ImplicitConversionSequence::Worse:
// Cand1 can't be better than Cand2.
return false;
case ImplicitConversionSequence::Indistinguishable:
// Do nothing.
break;
}
}
// -- for some argument j, ICSj(F1) is a better conversion sequence than
// ICSj(F2), or, if not that,
if (HasBetterConversion)
return true;
// - F1 is a non-template function and F2 is a function template
// specialization, or, if not that,
if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() &&
Cand2.Function && Cand2.Function->getPrimaryTemplate())
return true;
// -- F1 and F2 are function template specializations, and the function
// template for F1 is more specialized than the template for F2
// according to the partial ordering rules described in 14.5.5.2, or,
// if not that,
if (Cand1.Function && Cand1.Function->getPrimaryTemplate() &&
Cand2.Function && Cand2.Function->getPrimaryTemplate())
if (FunctionTemplateDecl *BetterTemplate
= getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(),
Cand2.Function->getPrimaryTemplate(),
Loc,
isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion
: TPOC_Call))
return BetterTemplate == Cand1.Function->getPrimaryTemplate();
// -- the context is an initialization by user-defined conversion
// (see 8.5, 13.3.1.5) and the standard conversion sequence
// from the return type of F1 to the destination type (i.e.,
// the type of the entity being initialized) is a better
// conversion sequence than the standard conversion sequence
// from the return type of F2 to the destination type.
if (Cand1.Function && Cand2.Function &&
isa<CXXConversionDecl>(Cand1.Function) &&
isa<CXXConversionDecl>(Cand2.Function)) {
switch (CompareStandardConversionSequences(Cand1.FinalConversion,
Cand2.FinalConversion)) {
case ImplicitConversionSequence::Better:
// Cand1 has a better conversion sequence.
return true;
case ImplicitConversionSequence::Worse:
// Cand1 can't be better than Cand2.
return false;
case ImplicitConversionSequence::Indistinguishable:
// Do nothing
break;
}
}
return false;
}
/// \brief Computes the best viable function (C++ 13.3.3)
/// within an overload candidate set.
///
/// \param CandidateSet the set of candidate functions.
///
/// \param Loc the location of the function name (or operator symbol) for
/// which overload resolution occurs.
///
/// \param Best f overload resolution was successful or found a deleted
/// function, Best points to the candidate function found.
///
/// \returns The result of overload resolution.
Reimplement reference initialization (C++ [dcl.init.ref]) using the new notion of an "initialization sequence", which encapsulates the computation of the initialization sequence along with diagnostic information and the capability to turn the computed sequence into an expression. At present, I've only switched one CheckReferenceInit callers over to this new mechanism; more will follow. Aside from (hopefully) being much more true to the standard, the diagnostics provided by this reference-initialization code are a bit better than before. Some examples: p5-var.cpp:54:12: error: non-const lvalue reference to type 'struct Derived' cannot bind to a value of unrelated type 'struct Base' Derived &dr2 = b; // expected-error{{non-const lvalue reference to ... ^ ~ p5-var.cpp:55:9: error: binding of reference to type 'struct Base' to a value of type 'struct Base const' drops qualifiers Base &br3 = bc; // expected-error{{drops qualifiers}} ^ ~~ p5-var.cpp:57:15: error: ambiguous conversion from derived class 'struct Diamond' to base class 'struct Base': struct Diamond -> struct Derived -> struct Base struct Diamond -> struct Derived2 -> struct Base Base &br5 = diamond; // expected-error{{ambiguous conversion from ... ^~~~~~~ p5-var.cpp:59:9: error: non-const lvalue reference to type 'long' cannot bind to a value of unrelated type 'int' long &lr = i; // expected-error{{non-const lvalue reference to type ... ^ ~ p5-var.cpp:74:9: error: non-const lvalue reference to type 'struct Base' cannot bind to a temporary of type 'struct Base' Base &br1 = Base(); // expected-error{{non-const lvalue reference to ... ^ ~~~~~~ p5-var.cpp:102:9: error: non-const reference cannot bind to bit-field 'i' int & ir1 = (ib.i); // expected-error{{non-const reference cannot ... ^ ~~~~~~ p5-var.cpp:98:7: note: bit-field is declared here int i : 17; // expected-note{{bit-field is declared here}} ^ llvm-svn: 90992
2009-12-10 07:02:17 +08:00
OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet,
SourceLocation Loc,
OverloadCandidateSet::iterator& Best) {
// Find the best viable function.
Best = CandidateSet.end();
for (OverloadCandidateSet::iterator Cand = CandidateSet.begin();
Cand != CandidateSet.end(); ++Cand) {
if (Cand->Viable) {
if (Best == CandidateSet.end() ||
isBetterOverloadCandidate(*Cand, *Best, Loc))
Best = Cand;
}
}
// If we didn't find any viable functions, abort.
if (Best == CandidateSet.end())
return OR_No_Viable_Function;
// Make sure that this function is better than every other viable
// function. If not, we have an ambiguity.
for (OverloadCandidateSet::iterator Cand = CandidateSet.begin();
Cand != CandidateSet.end(); ++Cand) {
if (Cand->Viable &&
Cand != Best &&
!isBetterOverloadCandidate(*Best, *Cand, Loc)) {
Best = CandidateSet.end();
return OR_Ambiguous;
}
}
// Best is the best viable function.
if (Best->Function &&
(Best->Function->isDeleted() ||
Best->Function->getAttr<UnavailableAttr>()))
return OR_Deleted;
// C++ [basic.def.odr]p2:
// An overloaded function is used if it is selected by overload resolution
// when referred to from a potentially-evaluated expression. [Note: this
// covers calls to named functions (5.2.2), operator overloading
// (clause 13), user-defined conversions (12.3.2), allocation function for
// placement new (5.3.4), as well as non-default initialization (8.5).
if (Best->Function)
MarkDeclarationReferenced(Loc, Best->Function);
return OR_Success;
}
namespace {
enum OverloadCandidateKind {
oc_function,
oc_method,
oc_constructor,
oc_function_template,
oc_method_template,
oc_constructor_template,
oc_implicit_default_constructor,
oc_implicit_copy_constructor,
oc_implicit_copy_assignment
};
OverloadCandidateKind ClassifyOverloadCandidate(Sema &S,
FunctionDecl *Fn,
std::string &Description) {
bool isTemplate = false;
if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) {
isTemplate = true;
Description = S.getTemplateArgumentBindingsText(
FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs());
}
if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) {
if (!Ctor->isImplicit())
return isTemplate ? oc_constructor_template : oc_constructor;
return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor
: oc_implicit_default_constructor;
}
if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) {
// This actually gets spelled 'candidate function' for now, but
// it doesn't hurt to split it out.
if (!Meth->isImplicit())
return isTemplate ? oc_method_template : oc_method;
assert(Meth->isCopyAssignment()
&& "implicit method is not copy assignment operator?");
return oc_implicit_copy_assignment;
}
return isTemplate ? oc_function_template : oc_function;
}
} // end anonymous namespace
// Notes the location of an overload candidate.
void Sema::NoteOverloadCandidate(FunctionDecl *Fn) {
std::string FnDesc;
OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc);
Diag(Fn->getLocation(), diag::note_ovl_candidate)
<< (unsigned) K << FnDesc;
}
/// Diagnoses an ambiguous conversion. The partial diagnostic is the
/// "lead" diagnostic; it will be given two arguments, the source and
/// target types of the conversion.
void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS,
SourceLocation CaretLoc,
const PartialDiagnostic &PDiag) {
Diag(CaretLoc, PDiag)
<< ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType();
for (AmbiguousConversionSequence::const_iterator
I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) {
NoteOverloadCandidate(*I);
}
}
namespace {
void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) {
const ImplicitConversionSequence &Conv = Cand->Conversions[I];
assert(Conv.isBad());
assert(Cand->Function && "for now, candidate must be a function");
FunctionDecl *Fn = Cand->Function;
// There's a conversion slot for the object argument if this is a
// non-constructor method. Note that 'I' corresponds the
// conversion-slot index.
bool isObjectArgument = false;
if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) {
if (I == 0)
isObjectArgument = true;
else
I--;
}
std::string FnDesc;
OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc);
Expr *FromExpr = Conv.Bad.FromExpr;
QualType FromTy = Conv.Bad.getFromType();
QualType ToTy = Conv.Bad.getToType();
if (FromTy == S.Context.OverloadTy) {
assert(FromExpr && "overload set argument came from implicit argument?");
Expr *E = FromExpr->IgnoreParens();
if (isa<UnaryOperator>(E))
E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens();
DeclarationName Name = cast<OverloadExpr>(E)->getName();
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload)
<< (unsigned) FnKind << FnDesc
<< (FromExpr ? FromExpr->getSourceRange() : SourceRange())
<< ToTy << Name << I+1;
return;
}
// Do some hand-waving analysis to see if the non-viability is due
// to a qualifier mismatch.
CanQualType CFromTy = S.Context.getCanonicalType(FromTy);
CanQualType CToTy = S.Context.getCanonicalType(ToTy);
if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>())
CToTy = RT->getPointeeType();
else {
// TODO: detect and diagnose the full richness of const mismatches.
if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>())
if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>())
CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType();
}
if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() &&
!CToTy.isAtLeastAsQualifiedAs(CFromTy)) {
// It is dumb that we have to do this here.
while (isa<ArrayType>(CFromTy))
CFromTy = CFromTy->getAs<ArrayType>()->getElementType();
while (isa<ArrayType>(CToTy))
CToTy = CFromTy->getAs<ArrayType>()->getElementType();
Qualifiers FromQs = CFromTy.getQualifiers();
Qualifiers ToQs = CToTy.getQualifiers();
if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) {
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace)
<< (unsigned) FnKind << FnDesc
<< (FromExpr ? FromExpr->getSourceRange() : SourceRange())
<< FromTy
<< FromQs.getAddressSpace() << ToQs.getAddressSpace()
<< (unsigned) isObjectArgument << I+1;
return;
}
unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers();
assert(CVR && "unexpected qualifiers mismatch");
if (isObjectArgument) {
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this)
<< (unsigned) FnKind << FnDesc
<< (FromExpr ? FromExpr->getSourceRange() : SourceRange())
<< FromTy << (CVR - 1);
} else {
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr)
<< (unsigned) FnKind << FnDesc
<< (FromExpr ? FromExpr->getSourceRange() : SourceRange())
<< FromTy << (CVR - 1) << I+1;
}
return;
}
// Diagnose references or pointers to incomplete types differently,
// since it's far from impossible that the incompleteness triggered
// the failure.
QualType TempFromTy = FromTy.getNonReferenceType();
if (const PointerType *PTy = TempFromTy->getAs<PointerType>())
TempFromTy = PTy->getPointeeType();
if (TempFromTy->isIncompleteType()) {
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete)
<< (unsigned) FnKind << FnDesc
<< (FromExpr ? FromExpr->getSourceRange() : SourceRange())
<< FromTy << ToTy << (unsigned) isObjectArgument << I+1;
return;
}
// TODO: specialize more based on the kind of mismatch
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv)
<< (unsigned) FnKind << FnDesc
<< (FromExpr ? FromExpr->getSourceRange() : SourceRange())
<< FromTy << ToTy << (unsigned) isObjectArgument << I+1;
}
void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand,
unsigned NumFormalArgs) {
// TODO: treat calls to a missing default constructor as a special case
FunctionDecl *Fn = Cand->Function;
const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>();
unsigned MinParams = Fn->getMinRequiredArguments();
// at least / at most / exactly
// FIXME: variadic templates "at most" should account for parameter packs
unsigned mode, modeCount;
if (NumFormalArgs < MinParams) {
assert((Cand->FailureKind == ovl_fail_too_few_arguments) ||
(Cand->FailureKind == ovl_fail_bad_deduction &&
Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments));
if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic())
mode = 0; // "at least"
else
mode = 2; // "exactly"
modeCount = MinParams;
} else {
assert((Cand->FailureKind == ovl_fail_too_many_arguments) ||
(Cand->FailureKind == ovl_fail_bad_deduction &&
Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments));
if (MinParams != FnTy->getNumArgs())
mode = 1; // "at most"
else
mode = 2; // "exactly"
modeCount = FnTy->getNumArgs();
}
std::string Description;
OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description);
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity)
<< (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode
<< modeCount << NumFormalArgs;
}
/// Diagnose a failed template-argument deduction.
void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand,
Expr **Args, unsigned NumArgs) {
FunctionDecl *Fn = Cand->Function; // pattern
TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter();
NamedDecl *ParamD;
(ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) ||
(ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) ||
(ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>());
switch (Cand->DeductionFailure.Result) {
case Sema::TDK_Success:
llvm_unreachable("TDK_success while diagnosing bad deduction");
case Sema::TDK_Incomplete: {
assert(ParamD && "no parameter found for incomplete deduction result");
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction)
<< ParamD->getDeclName();
return;
}
case Sema::TDK_Inconsistent:
case Sema::TDK_InconsistentQuals: {
assert(ParamD && "no parameter found for inconsistent deduction result");
int which = 0;
if (isa<TemplateTypeParmDecl>(ParamD))
which = 0;
else if (isa<NonTypeTemplateParmDecl>(ParamD))
which = 1;
else {
which = 2;
}
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction)
<< which << ParamD->getDeclName()
<< *Cand->DeductionFailure.getFirstArg()
<< *Cand->DeductionFailure.getSecondArg();
return;
}
case Sema::TDK_InvalidExplicitArguments:
assert(ParamD && "no parameter found for invalid explicit arguments");
if (ParamD->getDeclName())
S.Diag(Fn->getLocation(),
diag::note_ovl_candidate_explicit_arg_mismatch_named)
<< ParamD->getDeclName();
else {
int index = 0;
if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD))
index = TTP->getIndex();
else if (NonTypeTemplateParmDecl *NTTP
= dyn_cast<NonTypeTemplateParmDecl>(ParamD))
index = NTTP->getIndex();
else
index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex();
S.Diag(Fn->getLocation(),
diag::note_ovl_candidate_explicit_arg_mismatch_unnamed)
<< (index + 1);
}
return;
case Sema::TDK_TooManyArguments:
case Sema::TDK_TooFewArguments:
DiagnoseArityMismatch(S, Cand, NumArgs);
return;
case Sema::TDK_InstantiationDepth:
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth);
return;
case Sema::TDK_SubstitutionFailure: {
std::string ArgString;
if (TemplateArgumentList *Args
= Cand->DeductionFailure.getTemplateArgumentList())
ArgString = S.getTemplateArgumentBindingsText(
Fn->getDescribedFunctionTemplate()->getTemplateParameters(),
*Args);
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure)
<< ArgString;
return;
}
// TODO: diagnose these individually, then kill off
// note_ovl_candidate_bad_deduction, which is uselessly vague.
case Sema::TDK_NonDeducedMismatch:
case Sema::TDK_FailedOverloadResolution:
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction);
return;
}
}
/// Generates a 'note' diagnostic for an overload candidate. We've
/// already generated a primary error at the call site.
///
/// It really does need to be a single diagnostic with its caret
/// pointed at the candidate declaration. Yes, this creates some
/// major challenges of technical writing. Yes, this makes pointing
/// out problems with specific arguments quite awkward. It's still
/// better than generating twenty screens of text for every failed
/// overload.
///
/// It would be great to be able to express per-candidate problems
/// more richly for those diagnostic clients that cared, but we'd
/// still have to be just as careful with the default diagnostics.
void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand,
Expr **Args, unsigned NumArgs) {
FunctionDecl *Fn = Cand->Function;
// Note deleted candidates, but only if they're viable.
if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) {
std::string FnDesc;
OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc);
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted)
<< FnKind << FnDesc << Fn->isDeleted();
return;
}
// We don't really have anything else to say about viable candidates.
if (Cand->Viable) {
S.NoteOverloadCandidate(Fn);
return;
}
switch (Cand->FailureKind) {
case ovl_fail_too_many_arguments:
case ovl_fail_too_few_arguments:
return DiagnoseArityMismatch(S, Cand, NumArgs);
case ovl_fail_bad_deduction:
return DiagnoseBadDeduction(S, Cand, Args, NumArgs);
case ovl_fail_trivial_conversion:
case ovl_fail_bad_final_conversion:
case ovl_fail_final_conversion_not_exact:
return S.NoteOverloadCandidate(Fn);
case ovl_fail_bad_conversion: {
unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0);
for (unsigned N = Cand->Conversions.size(); I != N; ++I)
if (Cand->Conversions[I].isBad())
return DiagnoseBadConversion(S, Cand, I);
// FIXME: this currently happens when we're called from SemaInit
// when user-conversion overload fails. Figure out how to handle
// those conditions and diagnose them well.
return S.NoteOverloadCandidate(Fn);
}
}
}
void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) {
// Desugar the type of the surrogate down to a function type,
// retaining as many typedefs as possible while still showing
// the function type (and, therefore, its parameter types).
QualType FnType = Cand->Surrogate->getConversionType();
bool isLValueReference = false;
bool isRValueReference = false;
bool isPointer = false;
if (const LValueReferenceType *FnTypeRef =
FnType->getAs<LValueReferenceType>()) {
FnType = FnTypeRef->getPointeeType();
isLValueReference = true;
} else if (const RValueReferenceType *FnTypeRef =
FnType->getAs<RValueReferenceType>()) {
FnType = FnTypeRef->getPointeeType();
isRValueReference = true;
}
if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) {
FnType = FnTypePtr->getPointeeType();
isPointer = true;
}
// Desugar down to a function type.
FnType = QualType(FnType->getAs<FunctionType>(), 0);
// Reconstruct the pointer/reference as appropriate.
if (isPointer) FnType = S.Context.getPointerType(FnType);
if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType);
if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType);
S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand)
<< FnType;
}
void NoteBuiltinOperatorCandidate(Sema &S,
const char *Opc,
SourceLocation OpLoc,
OverloadCandidate *Cand) {
assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary");
std::string TypeStr("operator");
TypeStr += Opc;
TypeStr += "(";
TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString();
if (Cand->Conversions.size() == 1) {
TypeStr += ")";
S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr;
} else {
TypeStr += ", ";
TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString();
TypeStr += ")";
S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr;
}
}
void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc,
OverloadCandidate *Cand) {
unsigned NoOperands = Cand->Conversions.size();
for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) {
const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx];
if (ICS.isBad()) break; // all meaningless after first invalid
if (!ICS.isAmbiguous()) continue;
S.DiagnoseAmbiguousConversion(ICS, OpLoc,
S.PDiag(diag::note_ambiguous_type_conversion));
}
}
SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) {
if (Cand->Function)
return Cand->Function->getLocation();
if (Cand->IsSurrogate)
return Cand->Surrogate->getLocation();
return SourceLocation();
}
struct CompareOverloadCandidatesForDisplay {
Sema &S;
CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {}
bool operator()(const OverloadCandidate *L,
const OverloadCandidate *R) {
// Fast-path this check.
if (L == R) return false;
// Order first by viability.
if (L->Viable) {
if (!R->Viable) return true;
// TODO: introduce a tri-valued comparison for overload
// candidates. Would be more worthwhile if we had a sort
// that could exploit it.
if (S.isBetterOverloadCandidate(*L, *R, SourceLocation())) return true;
if (S.isBetterOverloadCandidate(*R, *L, SourceLocation())) return false;
} else if (R->Viable)
return false;
assert(L->Viable == R->Viable);
// Criteria by which we can sort non-viable candidates:
if (!L->Viable) {
// 1. Arity mismatches come after other candidates.
if (L->FailureKind == ovl_fail_too_many_arguments ||
L->FailureKind == ovl_fail_too_few_arguments)
return false;
if (R->FailureKind == ovl_fail_too_many_arguments ||
R->FailureKind == ovl_fail_too_few_arguments)
return true;
// 2. Bad conversions come first and are ordered by the number
// of bad conversions and quality of good conversions.
if (L->FailureKind == ovl_fail_bad_conversion) {
if (R->FailureKind != ovl_fail_bad_conversion)
return true;
// If there's any ordering between the defined conversions...
// FIXME: this might not be transitive.
assert(L->Conversions.size() == R->Conversions.size());
int leftBetter = 0;
unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument);
for (unsigned E = L->Conversions.size(); I != E; ++I) {
switch (S.CompareImplicitConversionSequences(L->Conversions[I],
R->Conversions[I])) {
case ImplicitConversionSequence::Better:
leftBetter++;
break;
case ImplicitConversionSequence::Worse:
leftBetter--;
break;
case ImplicitConversionSequence::Indistinguishable:
break;
}
}
if (leftBetter > 0) return true;
if (leftBetter < 0) return false;
} else if (R->FailureKind == ovl_fail_bad_conversion)
return false;
// TODO: others?
}
// Sort everything else by location.
SourceLocation LLoc = GetLocationForCandidate(L);
SourceLocation RLoc = GetLocationForCandidate(R);
// Put candidates without locations (e.g. builtins) at the end.
if (LLoc.isInvalid()) return false;
if (RLoc.isInvalid()) return true;
return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc);
}
};
/// CompleteNonViableCandidate - Normally, overload resolution only
/// computes up to the first
void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand,
Expr **Args, unsigned NumArgs) {
assert(!Cand->Viable);
// Don't do anything on failures other than bad conversion.
if (Cand->FailureKind != ovl_fail_bad_conversion) return;
// Skip forward to the first bad conversion.
unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0);
unsigned ConvCount = Cand->Conversions.size();
while (true) {
assert(ConvIdx != ConvCount && "no bad conversion in candidate");
ConvIdx++;
if (Cand->Conversions[ConvIdx - 1].isBad())
break;
}
if (ConvIdx == ConvCount)
return;
assert(!Cand->Conversions[ConvIdx].isInitialized() &&
"remaining conversion is initialized?");
// FIXME: this should probably be preserved from the overload
// operation somehow.
bool SuppressUserConversions = false;
const FunctionProtoType* Proto;
unsigned ArgIdx = ConvIdx;
if (Cand->IsSurrogate) {
QualType ConvType
= Cand->Surrogate->getConversionType().getNonReferenceType();
if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
ConvType = ConvPtrType->getPointeeType();
Proto = ConvType->getAs<FunctionProtoType>();
ArgIdx--;
} else if (Cand->Function) {
Proto = Cand->Function->getType()->getAs<FunctionProtoType>();
if (isa<CXXMethodDecl>(Cand->Function) &&
!isa<CXXConstructorDecl>(Cand->Function))
ArgIdx--;
} else {
// Builtin binary operator with a bad first conversion.
assert(ConvCount <= 3);
for (; ConvIdx != ConvCount; ++ConvIdx)
Cand->Conversions[ConvIdx]
= TryCopyInitialization(S, Args[ConvIdx],
Cand->BuiltinTypes.ParamTypes[ConvIdx],
SuppressUserConversions,
/*InOverloadResolution*/ true);
return;
}
// Fill in the rest of the conversions.
unsigned NumArgsInProto = Proto->getNumArgs();
for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) {
if (ArgIdx < NumArgsInProto)
Cand->Conversions[ConvIdx]
= TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx),
SuppressUserConversions,
/*InOverloadResolution=*/true);
else
Cand->Conversions[ConvIdx].setEllipsis();
}
}
} // end anonymous namespace
/// PrintOverloadCandidates - When overload resolution fails, prints
/// diagnostic messages containing the candidates in the candidate
/// set.
void
Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet,
OverloadCandidateDisplayKind OCD,
Expr **Args, unsigned NumArgs,
const char *Opc,
SourceLocation OpLoc) {
// Sort the candidates by viability and position. Sorting directly would
// be prohibitive, so we make a set of pointers and sort those.
llvm::SmallVector<OverloadCandidate*, 32> Cands;
if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size());
for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(),
LastCand = CandidateSet.end();
Cand != LastCand; ++Cand) {
if (Cand->Viable)
Cands.push_back(Cand);
else if (OCD == OCD_AllCandidates) {
CompleteNonViableCandidate(*this, Cand, Args, NumArgs);
Cands.push_back(Cand);
}
}
std::sort(Cands.begin(), Cands.end(),
CompareOverloadCandidatesForDisplay(*this));
bool ReportedAmbiguousConversions = false;
llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E;
for (I = Cands.begin(), E = Cands.end(); I != E; ++I) {
OverloadCandidate *Cand = *I;
if (Cand->Function)
NoteFunctionCandidate(*this, Cand, Args, NumArgs);
else if (Cand->IsSurrogate)
NoteSurrogateCandidate(*this, Cand);
// This a builtin candidate. We do not, in general, want to list
// every possible builtin candidate.
else if (Cand->Viable) {
// Generally we only see ambiguities including viable builtin
// operators if overload resolution got screwed up by an
// ambiguous user-defined conversion.
//
// FIXME: It's quite possible for different conversions to see
// different ambiguities, though.
if (!ReportedAmbiguousConversions) {
NoteAmbiguousUserConversions(*this, OpLoc, Cand);
ReportedAmbiguousConversions = true;
}
// If this is a viable builtin, print it.
NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand);
}
}
}
static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) {
if (isa<UnresolvedLookupExpr>(E))
return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D);
return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D);
}
/// ResolveAddressOfOverloadedFunction - Try to resolve the address of
/// an overloaded function (C++ [over.over]), where @p From is an
/// expression with overloaded function type and @p ToType is the type
/// we're trying to resolve to. For example:
///
/// @code
/// int f(double);
/// int f(int);
///
/// int (*pfd)(double) = f; // selects f(double)
/// @endcode
///
/// This routine returns the resulting FunctionDecl if it could be
/// resolved, and NULL otherwise. When @p Complain is true, this
/// routine will emit diagnostics if there is an error.
FunctionDecl *
Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType,
bool Complain,
DeclAccessPair &FoundResult) {
QualType FunctionType = ToType;
bool IsMember = false;
if (const PointerType *ToTypePtr = ToType->getAs<PointerType>())
FunctionType = ToTypePtr->getPointeeType();
else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>())
FunctionType = ToTypeRef->getPointeeType();
else if (const MemberPointerType *MemTypePtr =
ToType->getAs<MemberPointerType>()) {
FunctionType = MemTypePtr->getPointeeType();
IsMember = true;
}
// C++ [over.over]p1:
// [...] [Note: any redundant set of parentheses surrounding the
// overloaded function name is ignored (5.1). ]
// C++ [over.over]p1:
// [...] The overloaded function name can be preceded by the &
// operator.
OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer();
TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0;
if (OvlExpr->hasExplicitTemplateArgs()) {
OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer);
ExplicitTemplateArgs = &ETABuffer;
}
// We expect a pointer or reference to function, or a function pointer.
FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType();
if (!FunctionType->isFunctionType()) {
if (Complain)
Diag(From->getLocStart(), diag::err_addr_ovl_not_func_ptrref)
<< OvlExpr->getName() << ToType;
return 0;
}
assert(From->getType() == Context.OverloadTy);
// Look through all of the overloaded functions, searching for one
// whose type matches exactly.
llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches;
llvm::SmallVector<FunctionDecl *, 4> NonMatches;
bool FoundNonTemplateFunction = false;
for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
E = OvlExpr->decls_end(); I != E; ++I) {
// Look through any using declarations to find the underlying function.
NamedDecl *Fn = (*I)->getUnderlyingDecl();
// C++ [over.over]p3:
// Non-member functions and static member functions match
// targets of type "pointer-to-function" or "reference-to-function."
// Nonstatic member functions match targets of
// type "pointer-to-member-function."
// Note that according to DR 247, the containing class does not matter.
if (FunctionTemplateDecl *FunctionTemplate
= dyn_cast<FunctionTemplateDecl>(Fn)) {
if (CXXMethodDecl *Method
= dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) {
// Skip non-static function templates when converting to pointer, and
// static when converting to member pointer.
if (Method->isStatic() == IsMember)
continue;
} else if (IsMember)
continue;
// C++ [over.over]p2:
// If the name is a function template, template argument deduction is
// done (14.8.2.2), and if the argument deduction succeeds, the
// resulting template argument list is used to generate a single
// function template specialization, which is added to the set of
// overloaded functions considered.
// FIXME: We don't really want to build the specialization here, do we?
FunctionDecl *Specialization = 0;
TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc());
if (TemplateDeductionResult Result
= DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs,
FunctionType, Specialization, Info)) {
// FIXME: make a note of the failed deduction for diagnostics.
(void)Result;
} else {
// FIXME: If the match isn't exact, shouldn't we just drop this as
// a candidate? Find a testcase before changing the code.
assert(FunctionType
== Context.getCanonicalType(Specialization->getType()));
Matches.push_back(std::make_pair(I.getPair(),
cast<FunctionDecl>(Specialization->getCanonicalDecl())));
}
continue;
}
if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) {
// Skip non-static functions when converting to pointer, and static
// when converting to member pointer.
if (Method->isStatic() == IsMember)
continue;
// If we have explicit template arguments, skip non-templates.
if (OvlExpr->hasExplicitTemplateArgs())
continue;
} else if (IsMember)
continue;
if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) {
QualType ResultTy;
if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) ||
IsNoReturnConversion(Context, FunDecl->getType(), FunctionType,
ResultTy)) {
Matches.push_back(std::make_pair(I.getPair(),
cast<FunctionDecl>(FunDecl->getCanonicalDecl())));
FoundNonTemplateFunction = true;
}
}
}
// If there were 0 or 1 matches, we're done.
if (Matches.empty()) {
if (Complain) {
Diag(From->getLocStart(), diag::err_addr_ovl_no_viable)
<< OvlExpr->getName() << FunctionType;
for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
E = OvlExpr->decls_end();
I != E; ++I)
if (FunctionDecl *F = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()))
NoteOverloadCandidate(F);
}
return 0;
} else if (Matches.size() == 1) {
FunctionDecl *Result = Matches[0].second;
FoundResult = Matches[0].first;
MarkDeclarationReferenced(From->getLocStart(), Result);
if (Complain)
CheckAddressOfMemberAccess(OvlExpr, Matches[0].first);
return Result;
}
// C++ [over.over]p4:
// If more than one function is selected, [...]
if (!FoundNonTemplateFunction) {
// [...] and any given function template specialization F1 is
// eliminated if the set contains a second function template
// specialization whose function template is more specialized
// than the function template of F1 according to the partial
// ordering rules of 14.5.5.2.
// The algorithm specified above is quadratic. We instead use a
// two-pass algorithm (similar to the one used to identify the
// best viable function in an overload set) that identifies the
// best function template (if it exists).
UnresolvedSet<4> MatchesCopy; // TODO: avoid!
for (unsigned I = 0, E = Matches.size(); I != E; ++I)
MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess());
UnresolvedSetIterator Result =
getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(),
TPOC_Other, From->getLocStart(),
PDiag(),
PDiag(diag::err_addr_ovl_ambiguous)
<< Matches[0].second->getDeclName(),
PDiag(diag::note_ovl_candidate)
<< (unsigned) oc_function_template);
assert(Result != MatchesCopy.end() && "no most-specialized template");
MarkDeclarationReferenced(From->getLocStart(), *Result);
FoundResult = Matches[Result - MatchesCopy.begin()].first;
if (Complain) {
CheckUnresolvedAccess(*this, OvlExpr, FoundResult);
DiagnoseUseOfDecl(FoundResult, OvlExpr->getNameLoc());
}
return cast<FunctionDecl>(*Result);
}
// [...] any function template specializations in the set are
// eliminated if the set also contains a non-template function, [...]
for (unsigned I = 0, N = Matches.size(); I != N; ) {
if (Matches[I].second->getPrimaryTemplate() == 0)
++I;
else {
Matches[I] = Matches[--N];
Matches.set_size(N);
}
}
// [...] After such eliminations, if any, there shall remain exactly one
// selected function.
if (Matches.size() == 1) {
MarkDeclarationReferenced(From->getLocStart(), Matches[0].second);
FoundResult = Matches[0].first;
if (Complain) {
CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first);
DiagnoseUseOfDecl(Matches[0].first, OvlExpr->getNameLoc());
}
return cast<FunctionDecl>(Matches[0].second);
}
// FIXME: We should probably return the same thing that BestViableFunction
// returns (even if we issue the diagnostics here).
Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous)
<< Matches[0].second->getDeclName();
for (unsigned I = 0, E = Matches.size(); I != E; ++I)
NoteOverloadCandidate(Matches[I].second);
return 0;
}
/// \brief Given an expression that refers to an overloaded function, try to
/// resolve that overloaded function expression down to a single function.
///
/// This routine can only resolve template-ids that refer to a single function
/// template, where that template-id refers to a single template whose template
/// arguments are either provided by the template-id or have defaults,
/// as described in C++0x [temp.arg.explicit]p3.
FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) {
// C++ [over.over]p1:
// [...] [Note: any redundant set of parentheses surrounding the
// overloaded function name is ignored (5.1). ]
// C++ [over.over]p1:
// [...] The overloaded function name can be preceded by the &
// operator.
if (From->getType() != Context.OverloadTy)
return 0;
OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer();
// If we didn't actually find any template-ids, we're done.
if (!OvlExpr->hasExplicitTemplateArgs())
return 0;
TemplateArgumentListInfo ExplicitTemplateArgs;
OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs);
// Look through all of the overloaded functions, searching for one
// whose type matches exactly.
FunctionDecl *Matched = 0;
for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
E = OvlExpr->decls_end(); I != E; ++I) {
// C++0x [temp.arg.explicit]p3:
// [...] In contexts where deduction is done and fails, or in contexts
// where deduction is not done, if a template argument list is
// specified and it, along with any default template arguments,
// identifies a single function template specialization, then the
// template-id is an lvalue for the function template specialization.
FunctionTemplateDecl *FunctionTemplate = cast<FunctionTemplateDecl>(*I);
// C++ [over.over]p2:
// If the name is a function template, template argument deduction is
// done (14.8.2.2), and if the argument deduction succeeds, the
// resulting template argument list is used to generate a single
// function template specialization, which is added to the set of
// overloaded functions considered.
FunctionDecl *Specialization = 0;
TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc());
if (TemplateDeductionResult Result
= DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs,
Specialization, Info)) {
// FIXME: make a note of the failed deduction for diagnostics.
(void)Result;
continue;
}
// Multiple matches; we can't resolve to a single declaration.
if (Matched)
return 0;
Matched = Specialization;
}
return Matched;
}
/// \brief Add a single candidate to the overload set.
static void AddOverloadedCallCandidate(Sema &S,
DeclAccessPair FoundDecl,
const TemplateArgumentListInfo *ExplicitTemplateArgs,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet &CandidateSet,
bool PartialOverloading) {
NamedDecl *Callee = FoundDecl.getDecl();
if (isa<UsingShadowDecl>(Callee))
Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl();
if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) {
assert(!ExplicitTemplateArgs && "Explicit template arguments?");
S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet,
false, PartialOverloading);
return;
}
if (FunctionTemplateDecl *FuncTemplate
= dyn_cast<FunctionTemplateDecl>(Callee)) {
S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl,
ExplicitTemplateArgs,
Args, NumArgs, CandidateSet);
return;
}
assert(false && "unhandled case in overloaded call candidate");
// do nothing?
}
/// \brief Add the overload candidates named by callee and/or found by argument
/// dependent lookup to the given overload set.
void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet &CandidateSet,
bool PartialOverloading) {
#ifndef NDEBUG
// Verify that ArgumentDependentLookup is consistent with the rules
// in C++0x [basic.lookup.argdep]p3:
//
// Let X be the lookup set produced by unqualified lookup (3.4.1)
// and let Y be the lookup set produced by argument dependent
// lookup (defined as follows). If X contains
//
// -- a declaration of a class member, or
//
// -- a block-scope function declaration that is not a
// using-declaration, or
//
// -- a declaration that is neither a function or a function
// template
//
// then Y is empty.
if (ULE->requiresADL()) {
for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(),
E = ULE->decls_end(); I != E; ++I) {
assert(!(*I)->getDeclContext()->isRecord());
assert(isa<UsingShadowDecl>(*I) ||
!(*I)->getDeclContext()->isFunctionOrMethod());
assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate());
}
}
#endif
// It would be nice to avoid this copy.
TemplateArgumentListInfo TABuffer;
const TemplateArgumentListInfo *ExplicitTemplateArgs = 0;
if (ULE->hasExplicitTemplateArgs()) {
ULE->copyTemplateArgumentsInto(TABuffer);
ExplicitTemplateArgs = &TABuffer;
}
for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(),
E = ULE->decls_end(); I != E; ++I)
AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs,
Args, NumArgs, CandidateSet,
PartialOverloading);
if (ULE->requiresADL())
AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false,
Args, NumArgs,
ExplicitTemplateArgs,
CandidateSet,
PartialOverloading);
}
static Sema::OwningExprResult Destroy(Sema &SemaRef, Expr *Fn,
Expr **Args, unsigned NumArgs) {
Fn->Destroy(SemaRef.Context);
for (unsigned Arg = 0; Arg < NumArgs; ++Arg)
Args[Arg]->Destroy(SemaRef.Context);
return SemaRef.ExprError();
}
/// Attempts to recover from a call where no functions were found.
///
/// Returns true if new candidates were found.
static Sema::OwningExprResult
BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn,
UnresolvedLookupExpr *ULE,
SourceLocation LParenLoc,
Expr **Args, unsigned NumArgs,
SourceLocation *CommaLocs,
SourceLocation RParenLoc) {
CXXScopeSpec SS;
if (ULE->getQualifier()) {
SS.setScopeRep(ULE->getQualifier());
SS.setRange(ULE->getQualifierRange());
}
TemplateArgumentListInfo TABuffer;
const TemplateArgumentListInfo *ExplicitTemplateArgs = 0;
if (ULE->hasExplicitTemplateArgs()) {
ULE->copyTemplateArgumentsInto(TABuffer);
ExplicitTemplateArgs = &TABuffer;
}
LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(),
Sema::LookupOrdinaryName);
if (SemaRef.DiagnoseEmptyLookup(S, SS, R))
return Destroy(SemaRef, Fn, Args, NumArgs);
assert(!R.empty() && "lookup results empty despite recovery");
// Build an implicit member call if appropriate. Just drop the
// casts and such from the call, we don't really care.
Sema::OwningExprResult NewFn = SemaRef.ExprError();
if ((*R.begin())->isCXXClassMember())
NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs);
else if (ExplicitTemplateArgs)
NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs);
else
NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false);
if (NewFn.isInvalid())
return Destroy(SemaRef, Fn, Args, NumArgs);
Fn->Destroy(SemaRef.Context);
// This shouldn't cause an infinite loop because we're giving it
// an expression with non-empty lookup results, which should never
// end up here.
return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc,
Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs),
CommaLocs, RParenLoc);
}
/// ResolveOverloadedCallFn - Given the call expression that calls Fn
/// (which eventually refers to the declaration Func) and the call
/// arguments Args/NumArgs, attempt to resolve the function call down
/// to a specific function. If overload resolution succeeds, returns
/// the function declaration produced by overload
/// resolution. Otherwise, emits diagnostics, deletes all of the
/// arguments and Fn, and returns NULL.
Sema::OwningExprResult
Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE,
SourceLocation LParenLoc,
Expr **Args, unsigned NumArgs,
SourceLocation *CommaLocs,
SourceLocation RParenLoc) {
#ifndef NDEBUG
if (ULE->requiresADL()) {
// To do ADL, we must have found an unqualified name.
assert(!ULE->getQualifier() && "qualified name with ADL");
// We don't perform ADL for implicit declarations of builtins.
// Verify that this was correctly set up.
FunctionDecl *F;
if (ULE->decls_begin() + 1 == ULE->decls_end() &&
(F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) &&
F->getBuiltinID() && F->isImplicit())
assert(0 && "performing ADL for builtin");
// We don't perform ADL in C.
assert(getLangOptions().CPlusPlus && "ADL enabled in C");
}
#endif
OverloadCandidateSet CandidateSet(Fn->getExprLoc());
// Add the functions denoted by the callee to the set of candidate
// functions, including those from argument-dependent lookup.
AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet);
// If we found nothing, try to recover.
// AddRecoveryCallCandidates diagnoses the error itself, so we just
// bailout out if it fails.
if (CandidateSet.empty())
return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs,
CommaLocs, RParenLoc);
OverloadCandidateSet::iterator Best;
switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) {
case OR_Success: {
FunctionDecl *FDecl = Best->Function;
CheckUnresolvedLookupAccess(ULE, Best->FoundDecl);
DiagnoseUseOfDecl(Best->FoundDecl, ULE->getNameLoc());
Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl);
return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc);
}
case OR_No_Viable_Function:
Diag(Fn->getSourceRange().getBegin(),
diag::err_ovl_no_viable_function_in_call)
<< ULE->getName() << Fn->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs);
break;
case OR_Ambiguous:
Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call)
<< ULE->getName() << Fn->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs);
break;
case OR_Deleted:
Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call)
<< Best->Function->isDeleted()
<< ULE->getName()
<< Fn->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs);
break;
}
// Overload resolution failed. Destroy all of the subexpressions and
// return NULL.
Fn->Destroy(Context);
for (unsigned Arg = 0; Arg < NumArgs; ++Arg)
Args[Arg]->Destroy(Context);
return ExprError();
}
static bool IsOverloaded(const UnresolvedSetImpl &Functions) {
return Functions.size() > 1 ||
(Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin()));
}
/// \brief Create a unary operation that may resolve to an overloaded
/// operator.
///
/// \param OpLoc The location of the operator itself (e.g., '*').
///
/// \param OpcIn The UnaryOperator::Opcode that describes this
/// operator.
///
/// \param Functions The set of non-member functions that will be
/// considered by overload resolution. The caller needs to build this
/// set based on the context using, e.g.,
/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This
/// set should not contain any member functions; those will be added
/// by CreateOverloadedUnaryOp().
///
/// \param input The input argument.
Sema::OwningExprResult
Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn,
const UnresolvedSetImpl &Fns,
ExprArg input) {
UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn);
Expr *Input = (Expr *)input.get();
OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc);
assert(Op != OO_None && "Invalid opcode for overloaded unary operator");
DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
Expr *Args[2] = { Input, 0 };
unsigned NumArgs = 1;
// For post-increment and post-decrement, add the implicit '0' as
// the second argument, so that we know this is a post-increment or
// post-decrement.
if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) {
llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false);
Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy,
SourceLocation());
NumArgs = 2;
}
if (Input->isTypeDependent()) {
CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators
UnresolvedLookupExpr *Fn
= UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass,
0, SourceRange(), OpName, OpLoc,
/*ADL*/ true, IsOverloaded(Fns));
Fn->addDecls(Fns.begin(), Fns.end());
input.release();
return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn,
&Args[0], NumArgs,
Context.DependentTy,
OpLoc));
}
// Build an empty overload set.
OverloadCandidateSet CandidateSet(OpLoc);
// Add the candidates from the given function set.
AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false);
// Add operator candidates that are member functions.
AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet);
// Add candidates from ADL.
AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true,
Args, NumArgs,
/*ExplicitTemplateArgs*/ 0,
CandidateSet);
// Add builtin operator candidates.
AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet);
// Perform overload resolution.
OverloadCandidateSet::iterator Best;
switch (BestViableFunction(CandidateSet, OpLoc, Best)) {
case OR_Success: {
// We found a built-in operator or an overloaded operator.
FunctionDecl *FnDecl = Best->Function;
if (FnDecl) {
// We matched an overloaded operator. Build a call to that
// operator.
// Convert the arguments.
if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) {
CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl);
if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0,
Best->FoundDecl, Method))
return ExprError();
} else {
// Convert the arguments.
OwningExprResult InputInit
= PerformCopyInitialization(InitializedEntity::InitializeParameter(
FnDecl->getParamDecl(0)),
SourceLocation(),
move(input));
if (InputInit.isInvalid())
return ExprError();
input = move(InputInit);
Input = (Expr *)input.get();
}
DiagnoseUseOfDecl(Best->FoundDecl, OpLoc);
// Determine the result type
QualType ResultTy = FnDecl->getResultType().getNonReferenceType();
// Build the actual expression node.
Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(),
SourceLocation());
UsualUnaryConversions(FnExpr);
input.release();
Args[0] = Input;
ExprOwningPtr<CallExpr> TheCall(this,
new (Context) CXXOperatorCallExpr(Context, Op, FnExpr,
Args, NumArgs, ResultTy, OpLoc));
if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(),
FnDecl))
return ExprError();
return MaybeBindToTemporary(TheCall.release());
} else {
// We matched a built-in operator. Convert the arguments, then
// break out so that we will build the appropriate built-in
// operator node.
if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0],
Best->Conversions[0], AA_Passing))
return ExprError();
break;
}
}
case OR_No_Viable_Function:
// No viable function; fall through to handling this as a
// built-in operator, which will produce an error message for us.
break;
case OR_Ambiguous:
Diag(OpLoc, diag::err_ovl_ambiguous_oper)
<< UnaryOperator::getOpcodeStr(Opc)
<< Input->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs,
UnaryOperator::getOpcodeStr(Opc), OpLoc);
return ExprError();
case OR_Deleted:
Diag(OpLoc, diag::err_ovl_deleted_oper)
<< Best->Function->isDeleted()
<< UnaryOperator::getOpcodeStr(Opc)
<< Input->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs);
return ExprError();
}
// Either we found no viable overloaded operator or we matched a
// built-in operator. In either case, fall through to trying to
// build a built-in operation.
input.release();
return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input));
}
/// \brief Create a binary operation that may resolve to an overloaded
/// operator.
///
/// \param OpLoc The location of the operator itself (e.g., '+').
///
/// \param OpcIn The BinaryOperator::Opcode that describes this
/// operator.
///
/// \param Functions The set of non-member functions that will be
/// considered by overload resolution. The caller needs to build this
/// set based on the context using, e.g.,
/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This
/// set should not contain any member functions; those will be added
/// by CreateOverloadedBinOp().
///
/// \param LHS Left-hand argument.
/// \param RHS Right-hand argument.
Sema::OwningExprResult
Sema::CreateOverloadedBinOp(SourceLocation OpLoc,
unsigned OpcIn,
const UnresolvedSetImpl &Fns,
Expr *LHS, Expr *RHS) {
Expr *Args[2] = { LHS, RHS };
LHS=RHS=0; //Please use only Args instead of LHS/RHS couple
BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn);
OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc);
DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
// If either side is type-dependent, create an appropriate dependent
// expression.
if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) {
if (Fns.empty()) {
// If there are no functions to store, just build a dependent
// BinaryOperator or CompoundAssignment.
if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign)
return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc,
Context.DependentTy, OpLoc));
return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc,
Context.DependentTy,
Context.DependentTy,
Context.DependentTy,
OpLoc));
}
// FIXME: save results of ADL from here?
CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators
UnresolvedLookupExpr *Fn
= UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass,
0, SourceRange(), OpName, OpLoc,
/*ADL*/ true, IsOverloaded(Fns));
Fn->addDecls(Fns.begin(), Fns.end());
return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn,
Args, 2,
Context.DependentTy,
OpLoc));
}
// If this is the .* operator, which is not overloadable, just
// create a built-in binary operator.
if (Opc == BinaryOperator::PtrMemD)
return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
// If this is the assignment operator, we only perform overload resolution
// if the left-hand side is a class or enumeration type. This is actually
// a hack. The standard requires that we do overload resolution between the
// various built-in candidates, but as DR507 points out, this can lead to
// problems. So we do it this way, which pretty much follows what GCC does.
// Note that we go the traditional code path for compound assignment forms.
if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType())
return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
// Build an empty overload set.
OverloadCandidateSet CandidateSet(OpLoc);
// Add the candidates from the given function set.
AddFunctionCandidates(Fns, Args, 2, CandidateSet, false);
// Add operator candidates that are member functions.
AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet);
// Add candidates from ADL.
AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true,
Args, 2,
/*ExplicitTemplateArgs*/ 0,
CandidateSet);
// Add builtin operator candidates.
AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet);
// Perform overload resolution.
OverloadCandidateSet::iterator Best;
switch (BestViableFunction(CandidateSet, OpLoc, Best)) {
case OR_Success: {
// We found a built-in operator or an overloaded operator.
FunctionDecl *FnDecl = Best->Function;
if (FnDecl) {
// We matched an overloaded operator. Build a call to that
// operator.
// Convert the arguments.
if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) {
// Best->Access is only meaningful for class members.
CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl);
OwningExprResult Arg1
= PerformCopyInitialization(
InitializedEntity::InitializeParameter(
FnDecl->getParamDecl(0)),
SourceLocation(),
Owned(Args[1]));
if (Arg1.isInvalid())
return ExprError();
if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0,
Best->FoundDecl, Method))
return ExprError();
Args[1] = RHS = Arg1.takeAs<Expr>();
} else {
// Convert the arguments.
OwningExprResult Arg0
= PerformCopyInitialization(
InitializedEntity::InitializeParameter(
FnDecl->getParamDecl(0)),
SourceLocation(),
Owned(Args[0]));
if (Arg0.isInvalid())
return ExprError();
OwningExprResult Arg1
= PerformCopyInitialization(
InitializedEntity::InitializeParameter(
FnDecl->getParamDecl(1)),
SourceLocation(),
Owned(Args[1]));
if (Arg1.isInvalid())
return ExprError();
Args[0] = LHS = Arg0.takeAs<Expr>();
Args[1] = RHS = Arg1.takeAs<Expr>();
}
DiagnoseUseOfDecl(Best->FoundDecl, OpLoc);
// Determine the result type
QualType ResultTy
= FnDecl->getType()->getAs<FunctionType>()->getResultType();
ResultTy = ResultTy.getNonReferenceType();
// Build the actual expression node.
Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(),
OpLoc);
UsualUnaryConversions(FnExpr);
ExprOwningPtr<CXXOperatorCallExpr>
TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr,
Args, 2, ResultTy,
OpLoc));
if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(),
FnDecl))
return ExprError();
return MaybeBindToTemporary(TheCall.release());
} else {
// We matched a built-in operator. Convert the arguments, then
// break out so that we will build the appropriate built-in
// operator node.
if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0],
Best->Conversions[0], AA_Passing) ||
PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1],
Best->Conversions[1], AA_Passing))
return ExprError();
break;
}
}
case OR_No_Viable_Function: {
// C++ [over.match.oper]p9:
// If the operator is the operator , [...] and there are no
// viable functions, then the operator is assumed to be the
// built-in operator and interpreted according to clause 5.
if (Opc == BinaryOperator::Comma)
break;
// For class as left operand for assignment or compound assigment operator
// do not fall through to handling in built-in, but report that no overloaded
// assignment operator found
OwningExprResult Result = ExprError();
if (Args[0]->getType()->isRecordType() &&
Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) {
Diag(OpLoc, diag::err_ovl_no_viable_oper)
<< BinaryOperator::getOpcodeStr(Opc)
<< Args[0]->getSourceRange() << Args[1]->getSourceRange();
} else {
// No viable function; try to create a built-in operation, which will
// produce an error. Then, show the non-viable candidates.
Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
}
assert(Result.isInvalid() &&
"C++ binary operator overloading is missing candidates!");
if (Result.isInvalid())
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2,
BinaryOperator::getOpcodeStr(Opc), OpLoc);
return move(Result);
}
case OR_Ambiguous:
Diag(OpLoc, diag::err_ovl_ambiguous_oper)
<< BinaryOperator::getOpcodeStr(Opc)
<< Args[0]->getSourceRange() << Args[1]->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2,
BinaryOperator::getOpcodeStr(Opc), OpLoc);
return ExprError();
case OR_Deleted:
Diag(OpLoc, diag::err_ovl_deleted_oper)
<< Best->Function->isDeleted()
<< BinaryOperator::getOpcodeStr(Opc)
<< Args[0]->getSourceRange() << Args[1]->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2);
return ExprError();
}
// We matched a built-in operator; build it.
return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
}
Action::OwningExprResult
Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc,
SourceLocation RLoc,
ExprArg Base, ExprArg Idx) {
Expr *Args[2] = { static_cast<Expr*>(Base.get()),
static_cast<Expr*>(Idx.get()) };
DeclarationName OpName =
Context.DeclarationNames.getCXXOperatorName(OO_Subscript);
// If either side is type-dependent, create an appropriate dependent
// expression.
if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) {
CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators
UnresolvedLookupExpr *Fn
= UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass,
0, SourceRange(), OpName, LLoc,
/*ADL*/ true, /*Overloaded*/ false);
// Can't add any actual overloads yet
Base.release();
Idx.release();
return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn,
Args, 2,
Context.DependentTy,
RLoc));
}
// Build an empty overload set.
OverloadCandidateSet CandidateSet(LLoc);
// Subscript can only be overloaded as a member function.
// Add operator candidates that are member functions.
AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet);
// Add builtin operator candidates.
AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet);
// Perform overload resolution.
OverloadCandidateSet::iterator Best;
switch (BestViableFunction(CandidateSet, LLoc, Best)) {
case OR_Success: {
// We found a built-in operator or an overloaded operator.
FunctionDecl *FnDecl = Best->Function;
if (FnDecl) {
// We matched an overloaded operator. Build a call to that
// operator.
CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl);
DiagnoseUseOfDecl(Best->FoundDecl, LLoc);
// Convert the arguments.
CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl);
if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0,
Best->FoundDecl, Method))
return ExprError();
// Convert the arguments.
OwningExprResult InputInit
= PerformCopyInitialization(InitializedEntity::InitializeParameter(
FnDecl->getParamDecl(0)),
SourceLocation(),
Owned(Args[1]));
if (InputInit.isInvalid())
return ExprError();
Args[1] = InputInit.takeAs<Expr>();
// Determine the result type
QualType ResultTy
= FnDecl->getType()->getAs<FunctionType>()->getResultType();
ResultTy = ResultTy.getNonReferenceType();
// Build the actual expression node.
Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(),
LLoc);
UsualUnaryConversions(FnExpr);
Base.release();
Idx.release();
ExprOwningPtr<CXXOperatorCallExpr>
TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript,
FnExpr, Args, 2,
ResultTy, RLoc));
if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(),
FnDecl))
return ExprError();
return MaybeBindToTemporary(TheCall.release());
} else {
// We matched a built-in operator. Convert the arguments, then
// break out so that we will build the appropriate built-in
// operator node.
if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0],
Best->Conversions[0], AA_Passing) ||
PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1],
Best->Conversions[1], AA_Passing))
return ExprError();
break;
}
}
case OR_No_Viable_Function: {
if (CandidateSet.empty())
Diag(LLoc, diag::err_ovl_no_oper)
<< Args[0]->getType() << /*subscript*/ 0
<< Args[0]->getSourceRange() << Args[1]->getSourceRange();
else
Diag(LLoc, diag::err_ovl_no_viable_subscript)
<< Args[0]->getType()
<< Args[0]->getSourceRange() << Args[1]->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2,
"[]", LLoc);
return ExprError();
}
case OR_Ambiguous:
Diag(LLoc, diag::err_ovl_ambiguous_oper)
<< "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2,
"[]", LLoc);
return ExprError();
case OR_Deleted:
Diag(LLoc, diag::err_ovl_deleted_oper)
<< Best->Function->isDeleted() << "[]"
<< Args[0]->getSourceRange() << Args[1]->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2,
"[]", LLoc);
return ExprError();
}
// We matched a built-in operator; build it.
Base.release();
Idx.release();
return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc,
Owned(Args[1]), RLoc);
}
/// BuildCallToMemberFunction - Build a call to a member
/// function. MemExpr is the expression that refers to the member
/// function (and includes the object parameter), Args/NumArgs are the
/// arguments to the function call (not including the object
/// parameter). The caller needs to validate that the member
/// expression refers to a member function or an overloaded member
/// function.
Sema::OwningExprResult
Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE,
SourceLocation LParenLoc, Expr **Args,
unsigned NumArgs, SourceLocation *CommaLocs,
SourceLocation RParenLoc) {
// Dig out the member expression. This holds both the object
// argument and the member function we're referring to.
Expr *NakedMemExpr = MemExprE->IgnoreParens();
MemberExpr *MemExpr;
CXXMethodDecl *Method = 0;
DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public);
NestedNameSpecifier *Qualifier = 0;
if (isa<MemberExpr>(NakedMemExpr)) {
MemExpr = cast<MemberExpr>(NakedMemExpr);
Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl());
FoundDecl = MemExpr->getFoundDecl();
Qualifier = MemExpr->getQualifier();
} else {
UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr);
Qualifier = UnresExpr->getQualifier();
QualType ObjectType = UnresExpr->getBaseType();
// Add overload candidates
OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc());
// FIXME: avoid copy.
TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0;
if (UnresExpr->hasExplicitTemplateArgs()) {
UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer);
TemplateArgs = &TemplateArgsBuffer;
}
for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(),
E = UnresExpr->decls_end(); I != E; ++I) {
NamedDecl *Func = *I;
CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext());
if (isa<UsingShadowDecl>(Func))
Func = cast<UsingShadowDecl>(Func)->getTargetDecl();
if ((Method = dyn_cast<CXXMethodDecl>(Func))) {
// If explicit template arguments were provided, we can't call a
// non-template member function.
if (TemplateArgs)
continue;
AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType,
Args, NumArgs,
CandidateSet, /*SuppressUserConversions=*/false);
} else {
AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func),
I.getPair(), ActingDC, TemplateArgs,
ObjectType, Args, NumArgs,
CandidateSet,
/*SuppressUsedConversions=*/false);
}
}
DeclarationName DeclName = UnresExpr->getMemberName();
OverloadCandidateSet::iterator Best;
switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) {
case OR_Success:
Method = cast<CXXMethodDecl>(Best->Function);
FoundDecl = Best->FoundDecl;
CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl);
DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc());
break;
case OR_No_Viable_Function:
Diag(UnresExpr->getMemberLoc(),
diag::err_ovl_no_viable_member_function_in_call)
<< DeclName << MemExprE->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs);
// FIXME: Leaking incoming expressions!
return ExprError();
case OR_Ambiguous:
Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call)
<< DeclName << MemExprE->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs);
// FIXME: Leaking incoming expressions!
return ExprError();
case OR_Deleted:
Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call)
<< Best->Function->isDeleted()
<< DeclName << MemExprE->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs);
// FIXME: Leaking incoming expressions!
return ExprError();
}
MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method);
// If overload resolution picked a static member, build a
// non-member call based on that function.
if (Method->isStatic()) {
return BuildResolvedCallExpr(MemExprE, Method, LParenLoc,
Args, NumArgs, RParenLoc);
}
MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens());
}
assert(Method && "Member call to something that isn't a method?");
ExprOwningPtr<CXXMemberCallExpr>
TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args,
NumArgs,
Method->getResultType().getNonReferenceType(),
RParenLoc));
// Check for a valid return type.
if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(),
TheCall.get(), Method))
return ExprError();
// Convert the object argument (for a non-static member function call).
// We only need to do this if there was actually an overload; otherwise
// it was done at lookup.
Expr *ObjectArg = MemExpr->getBase();
if (!Method->isStatic() &&
PerformObjectArgumentInitialization(ObjectArg, Qualifier,
FoundDecl, Method))
return ExprError();
MemExpr->setBase(ObjectArg);
// Convert the rest of the arguments
const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>();
if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs,
RParenLoc))
return ExprError();
if (CheckFunctionCall(Method, TheCall.get()))
return ExprError();
return MaybeBindToTemporary(TheCall.release());
}
/// BuildCallToObjectOfClassType - Build a call to an object of class
/// type (C++ [over.call.object]), which can end up invoking an
/// overloaded function call operator (@c operator()) or performing a
/// user-defined conversion on the object argument.
Sema::ExprResult
Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object,
SourceLocation LParenLoc,
Expr **Args, unsigned NumArgs,
SourceLocation *CommaLocs,
SourceLocation RParenLoc) {
assert(Object->getType()->isRecordType() && "Requires object type argument");
const RecordType *Record = Object->getType()->getAs<RecordType>();
// C++ [over.call.object]p1:
// If the primary-expression E in the function call syntax
// evaluates to a class object of type "cv T", then the set of
// candidate functions includes at least the function call
// operators of T. The function call operators of T are obtained by
// ordinary lookup of the name operator() in the context of
// (E).operator().
OverloadCandidateSet CandidateSet(LParenLoc);
DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call);
if (RequireCompleteType(LParenLoc, Object->getType(),
PDiag(diag::err_incomplete_object_call)
<< Object->getSourceRange()))
return true;
LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName);
LookupQualifiedName(R, Record->getDecl());
R.suppressDiagnostics();
for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end();
Oper != OperEnd; ++Oper) {
AddMethodCandidate(Oper.getPair(), Object->getType(),
Args, NumArgs, CandidateSet,
/*SuppressUserConversions=*/ false);
}
// C++ [over.call.object]p2:
// In addition, for each conversion function declared in T of the
// form
//
// operator conversion-type-id () cv-qualifier;
//
// where cv-qualifier is the same cv-qualification as, or a
// greater cv-qualification than, cv, and where conversion-type-id
// denotes the type "pointer to function of (P1,...,Pn) returning
// R", or the type "reference to pointer to function of
// (P1,...,Pn) returning R", or the type "reference to function
// of (P1,...,Pn) returning R", a surrogate call function [...]
// is also considered as a candidate function. Similarly,
// surrogate call functions are added to the set of candidate
// functions for each conversion function declared in an
// accessible base class provided the function is not hidden
// within T by another intervening declaration.
const UnresolvedSetImpl *Conversions
= cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions();
for (UnresolvedSetImpl::iterator I = Conversions->begin(),
E = Conversions->end(); I != E; ++I) {
NamedDecl *D = *I;
CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
if (isa<UsingShadowDecl>(D))
D = cast<UsingShadowDecl>(D)->getTargetDecl();
// Skip over templated conversion functions; they aren't
// surrogates.
if (isa<FunctionTemplateDecl>(D))
continue;
CXXConversionDecl *Conv = cast<CXXConversionDecl>(D);
// Strip the reference type (if any) and then the pointer type (if
// any) to get down to what might be a function type.
QualType ConvType = Conv->getConversionType().getNonReferenceType();
if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
ConvType = ConvPtrType->getPointeeType();
if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>())
AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto,
Object->getType(), Args, NumArgs,
CandidateSet);
}
// Perform overload resolution.
OverloadCandidateSet::iterator Best;
switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) {
case OR_Success:
// Overload resolution succeeded; we'll build the appropriate call
// below.
break;
case OR_No_Viable_Function:
if (CandidateSet.empty())
Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper)
<< Object->getType() << /*call*/ 1
<< Object->getSourceRange();
else
Diag(Object->getSourceRange().getBegin(),
diag::err_ovl_no_viable_object_call)
<< Object->getType() << Object->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs);
break;
case OR_Ambiguous:
Diag(Object->getSourceRange().getBegin(),
diag::err_ovl_ambiguous_object_call)
<< Object->getType() << Object->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs);
break;
case OR_Deleted:
Diag(Object->getSourceRange().getBegin(),
diag::err_ovl_deleted_object_call)
<< Best->Function->isDeleted()
<< Object->getType() << Object->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs);
break;
}
if (Best == CandidateSet.end()) {
// We had an error; delete all of the subexpressions and return
// the error.
Object->Destroy(Context);
for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx)
Args[ArgIdx]->Destroy(Context);
return true;
}
if (Best->Function == 0) {
// Since there is no function declaration, this is one of the
// surrogate candidates. Dig out the conversion function.
CXXConversionDecl *Conv
= cast<CXXConversionDecl>(
Best->Conversions[0].UserDefined.ConversionFunction);
CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl);
DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc);
// We selected one of the surrogate functions that converts the
// object parameter to a function pointer. Perform the conversion
// on the object argument, then let ActOnCallExpr finish the job.
// Create an implicit member expr to refer to the conversion operator.
// and then call it.
CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Best->FoundDecl,
Conv);
return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc,
MultiExprArg(*this, (ExprTy**)Args, NumArgs),
CommaLocs, RParenLoc).result();
}
CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl);
DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc);
// We found an overloaded operator(). Build a CXXOperatorCallExpr
// that calls this method, using Object for the implicit object
// parameter and passing along the remaining arguments.
CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>();
unsigned NumArgsInProto = Proto->getNumArgs();
unsigned NumArgsToCheck = NumArgs;
// Build the full argument list for the method call (the
// implicit object parameter is placed at the beginning of the
// list).
Expr **MethodArgs;
if (NumArgs < NumArgsInProto) {
NumArgsToCheck = NumArgsInProto;
MethodArgs = new Expr*[NumArgsInProto + 1];
} else {
MethodArgs = new Expr*[NumArgs + 1];
}
MethodArgs[0] = Object;
for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx)
MethodArgs[ArgIdx + 1] = Args[ArgIdx];
Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(),
SourceLocation());
UsualUnaryConversions(NewFn);
// Once we've built TheCall, all of the expressions are properly
// owned.
QualType ResultTy = Method->getResultType().getNonReferenceType();
ExprOwningPtr<CXXOperatorCallExpr>
TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn,
MethodArgs, NumArgs + 1,
ResultTy, RParenLoc));
delete [] MethodArgs;
if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(),
Method))
return true;
// We may have default arguments. If so, we need to allocate more
// slots in the call for them.
if (NumArgs < NumArgsInProto)
TheCall->setNumArgs(Context, NumArgsInProto + 1);
else if (NumArgs > NumArgsInProto)
NumArgsToCheck = NumArgsInProto;
bool IsError = false;
// Initialize the implicit object parameter.
IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0,
Best->FoundDecl, Method);
TheCall->setArg(0, Object);
// Check the argument types.
for (unsigned i = 0; i != NumArgsToCheck; i++) {
Expr *Arg;
if (i < NumArgs) {
Arg = Args[i];
// Pass the argument.
2010-01-30 02:43:53 +08:00
OwningExprResult InputInit
= PerformCopyInitialization(InitializedEntity::InitializeParameter(
Method->getParamDecl(i)),
SourceLocation(), Owned(Arg));
IsError |= InputInit.isInvalid();
Arg = InputInit.takeAs<Expr>();
} else {
OwningExprResult DefArg
= BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i));
if (DefArg.isInvalid()) {
IsError = true;
break;
}
Arg = DefArg.takeAs<Expr>();
}
TheCall->setArg(i + 1, Arg);
}
// If this is a variadic call, handle args passed through "...".
if (Proto->isVariadic()) {
// Promote the arguments (C99 6.5.2.2p7).
for (unsigned i = NumArgsInProto; i != NumArgs; i++) {
Expr *Arg = Args[i];
IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod);
TheCall->setArg(i + 1, Arg);
}
}
if (IsError) return true;
if (CheckFunctionCall(Method, TheCall.get()))
return true;
return MaybeBindToTemporary(TheCall.release()).result();
}
/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator->
/// (if one exists), where @c Base is an expression of class type and
/// @c Member is the name of the member we're trying to find.
Sema::OwningExprResult
Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) {
Expr *Base = static_cast<Expr *>(BaseIn.get());
assert(Base->getType()->isRecordType() && "left-hand side must have class type");
SourceLocation Loc = Base->getExprLoc();
// C++ [over.ref]p1:
//
// [...] An expression x->m is interpreted as (x.operator->())->m
// for a class object x of type T if T::operator->() exists and if
// the operator is selected as the best match function by the
// overload resolution mechanism (13.3).
DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow);
OverloadCandidateSet CandidateSet(Loc);
const RecordType *BaseRecord = Base->getType()->getAs<RecordType>();
if (RequireCompleteType(Loc, Base->getType(),
PDiag(diag::err_typecheck_incomplete_tag)
<< Base->getSourceRange()))
return ExprError();
LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName);
LookupQualifiedName(R, BaseRecord->getDecl());
R.suppressDiagnostics();
for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end();
Oper != OperEnd; ++Oper) {
AddMethodCandidate(Oper.getPair(), Base->getType(), 0, 0, CandidateSet,
/*SuppressUserConversions=*/false);
}
// Perform overload resolution.
OverloadCandidateSet::iterator Best;
switch (BestViableFunction(CandidateSet, OpLoc, Best)) {
case OR_Success:
// Overload resolution succeeded; we'll build the call below.
break;
case OR_No_Viable_Function:
if (CandidateSet.empty())
Diag(OpLoc, diag::err_typecheck_member_reference_arrow)
<< Base->getType() << Base->getSourceRange();
else
Diag(OpLoc, diag::err_ovl_no_viable_oper)
<< "operator->" << Base->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1);
return ExprError();
case OR_Ambiguous:
Diag(OpLoc, diag::err_ovl_ambiguous_oper)
<< "->" << Base->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1);
return ExprError();
case OR_Deleted:
Diag(OpLoc, diag::err_ovl_deleted_oper)
<< Best->Function->isDeleted()
<< "->" << Base->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1);
return ExprError();
}
CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl);
DiagnoseUseOfDecl(Best->FoundDecl, OpLoc);
// Convert the object parameter.
CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0,
Best->FoundDecl, Method))
return ExprError();
// No concerns about early exits now.
BaseIn.release();
// Build the operator call.
Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(),
SourceLocation());
UsualUnaryConversions(FnExpr);
QualType ResultTy = Method->getResultType().getNonReferenceType();
ExprOwningPtr<CXXOperatorCallExpr>
TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr,
&Base, 1, ResultTy, OpLoc));
if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(),
Method))
return ExprError();
return move(TheCall);
}
/// FixOverloadedFunctionReference - E is an expression that refers to
/// a C++ overloaded function (possibly with some parentheses and
/// perhaps a '&' around it). We have resolved the overloaded function
/// to the function declaration Fn, so patch up the expression E to
/// refer (possibly indirectly) to Fn. Returns the new expr.
Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found,
FunctionDecl *Fn) {
if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(),
Found, Fn);
if (SubExpr == PE->getSubExpr())
return PE->Retain();
return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr);
}
if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(),
Found, Fn);
assert(Context.hasSameType(ICE->getSubExpr()->getType(),
SubExpr->getType()) &&
"Implicit cast type cannot be determined from overload");
if (SubExpr == ICE->getSubExpr())
return ICE->Retain();
return new (Context) ImplicitCastExpr(ICE->getType(),
ICE->getCastKind(),
SubExpr, CXXBaseSpecifierArray(),
ICE->isLvalueCast());
}
if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) {
assert(UnOp->getOpcode() == UnaryOperator::AddrOf &&
"Can only take the address of an overloaded function");
if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) {
if (Method->isStatic()) {
// Do nothing: static member functions aren't any different
// from non-member functions.
} else {
// Fix the sub expression, which really has to be an
// UnresolvedLookupExpr holding an overloaded member function
// or template.
Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(),
Found, Fn);
if (SubExpr == UnOp->getSubExpr())
return UnOp->Retain();
assert(isa<DeclRefExpr>(SubExpr)
&& "fixed to something other than a decl ref");
assert(cast<DeclRefExpr>(SubExpr)->getQualifier()
&& "fixed to a member ref with no nested name qualifier");
// We have taken the address of a pointer to member
// function. Perform the computation here so that we get the
// appropriate pointer to member type.
QualType ClassType
= Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext()));
QualType MemPtrType
= Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr());
return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf,
MemPtrType, UnOp->getOperatorLoc());
}
}
Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(),
Found, Fn);
if (SubExpr == UnOp->getSubExpr())
return UnOp->Retain();
return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf,
Context.getPointerType(SubExpr->getType()),
UnOp->getOperatorLoc());
}
if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) {
// FIXME: avoid copy.
TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0;
if (ULE->hasExplicitTemplateArgs()) {
ULE->copyTemplateArgumentsInto(TemplateArgsBuffer);
TemplateArgs = &TemplateArgsBuffer;
}
return DeclRefExpr::Create(Context,
ULE->getQualifier(),
ULE->getQualifierRange(),
Fn,
ULE->getNameLoc(),
Fn->getType(),
TemplateArgs);
}
if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) {
// FIXME: avoid copy.
TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0;
if (MemExpr->hasExplicitTemplateArgs()) {
MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer);
TemplateArgs = &TemplateArgsBuffer;
}
Expr *Base;
// If we're filling in
if (MemExpr->isImplicitAccess()) {
if (cast<CXXMethodDecl>(Fn)->isStatic()) {
return DeclRefExpr::Create(Context,
MemExpr->getQualifier(),
MemExpr->getQualifierRange(),
Fn,
MemExpr->getMemberLoc(),
Fn->getType(),
TemplateArgs);
} else {
SourceLocation Loc = MemExpr->getMemberLoc();
if (MemExpr->getQualifier())
Loc = MemExpr->getQualifierRange().getBegin();
Base = new (Context) CXXThisExpr(Loc,
MemExpr->getBaseType(),
/*isImplicit=*/true);
}
} else
Base = MemExpr->getBase()->Retain();
return MemberExpr::Create(Context, Base,
MemExpr->isArrow(),
MemExpr->getQualifier(),
MemExpr->getQualifierRange(),
Fn,
Found,
MemExpr->getMemberLoc(),
TemplateArgs,
Fn->getType());
}
assert(false && "Invalid reference to overloaded function");
return E->Retain();
}
Reimplement reference initialization (C++ [dcl.init.ref]) using the new notion of an "initialization sequence", which encapsulates the computation of the initialization sequence along with diagnostic information and the capability to turn the computed sequence into an expression. At present, I've only switched one CheckReferenceInit callers over to this new mechanism; more will follow. Aside from (hopefully) being much more true to the standard, the diagnostics provided by this reference-initialization code are a bit better than before. Some examples: p5-var.cpp:54:12: error: non-const lvalue reference to type 'struct Derived' cannot bind to a value of unrelated type 'struct Base' Derived &dr2 = b; // expected-error{{non-const lvalue reference to ... ^ ~ p5-var.cpp:55:9: error: binding of reference to type 'struct Base' to a value of type 'struct Base const' drops qualifiers Base &br3 = bc; // expected-error{{drops qualifiers}} ^ ~~ p5-var.cpp:57:15: error: ambiguous conversion from derived class 'struct Diamond' to base class 'struct Base': struct Diamond -> struct Derived -> struct Base struct Diamond -> struct Derived2 -> struct Base Base &br5 = diamond; // expected-error{{ambiguous conversion from ... ^~~~~~~ p5-var.cpp:59:9: error: non-const lvalue reference to type 'long' cannot bind to a value of unrelated type 'int' long &lr = i; // expected-error{{non-const lvalue reference to type ... ^ ~ p5-var.cpp:74:9: error: non-const lvalue reference to type 'struct Base' cannot bind to a temporary of type 'struct Base' Base &br1 = Base(); // expected-error{{non-const lvalue reference to ... ^ ~~~~~~ p5-var.cpp:102:9: error: non-const reference cannot bind to bit-field 'i' int & ir1 = (ib.i); // expected-error{{non-const reference cannot ... ^ ~~~~~~ p5-var.cpp:98:7: note: bit-field is declared here int i : 17; // expected-note{{bit-field is declared here}} ^ llvm-svn: 90992
2009-12-10 07:02:17 +08:00
Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E,
DeclAccessPair Found,
Reimplement reference initialization (C++ [dcl.init.ref]) using the new notion of an "initialization sequence", which encapsulates the computation of the initialization sequence along with diagnostic information and the capability to turn the computed sequence into an expression. At present, I've only switched one CheckReferenceInit callers over to this new mechanism; more will follow. Aside from (hopefully) being much more true to the standard, the diagnostics provided by this reference-initialization code are a bit better than before. Some examples: p5-var.cpp:54:12: error: non-const lvalue reference to type 'struct Derived' cannot bind to a value of unrelated type 'struct Base' Derived &dr2 = b; // expected-error{{non-const lvalue reference to ... ^ ~ p5-var.cpp:55:9: error: binding of reference to type 'struct Base' to a value of type 'struct Base const' drops qualifiers Base &br3 = bc; // expected-error{{drops qualifiers}} ^ ~~ p5-var.cpp:57:15: error: ambiguous conversion from derived class 'struct Diamond' to base class 'struct Base': struct Diamond -> struct Derived -> struct Base struct Diamond -> struct Derived2 -> struct Base Base &br5 = diamond; // expected-error{{ambiguous conversion from ... ^~~~~~~ p5-var.cpp:59:9: error: non-const lvalue reference to type 'long' cannot bind to a value of unrelated type 'int' long &lr = i; // expected-error{{non-const lvalue reference to type ... ^ ~ p5-var.cpp:74:9: error: non-const lvalue reference to type 'struct Base' cannot bind to a temporary of type 'struct Base' Base &br1 = Base(); // expected-error{{non-const lvalue reference to ... ^ ~~~~~~ p5-var.cpp:102:9: error: non-const reference cannot bind to bit-field 'i' int & ir1 = (ib.i); // expected-error{{non-const reference cannot ... ^ ~~~~~~ p5-var.cpp:98:7: note: bit-field is declared here int i : 17; // expected-note{{bit-field is declared here}} ^ llvm-svn: 90992
2009-12-10 07:02:17 +08:00
FunctionDecl *Fn) {
return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn));
Reimplement reference initialization (C++ [dcl.init.ref]) using the new notion of an "initialization sequence", which encapsulates the computation of the initialization sequence along with diagnostic information and the capability to turn the computed sequence into an expression. At present, I've only switched one CheckReferenceInit callers over to this new mechanism; more will follow. Aside from (hopefully) being much more true to the standard, the diagnostics provided by this reference-initialization code are a bit better than before. Some examples: p5-var.cpp:54:12: error: non-const lvalue reference to type 'struct Derived' cannot bind to a value of unrelated type 'struct Base' Derived &dr2 = b; // expected-error{{non-const lvalue reference to ... ^ ~ p5-var.cpp:55:9: error: binding of reference to type 'struct Base' to a value of type 'struct Base const' drops qualifiers Base &br3 = bc; // expected-error{{drops qualifiers}} ^ ~~ p5-var.cpp:57:15: error: ambiguous conversion from derived class 'struct Diamond' to base class 'struct Base': struct Diamond -> struct Derived -> struct Base struct Diamond -> struct Derived2 -> struct Base Base &br5 = diamond; // expected-error{{ambiguous conversion from ... ^~~~~~~ p5-var.cpp:59:9: error: non-const lvalue reference to type 'long' cannot bind to a value of unrelated type 'int' long &lr = i; // expected-error{{non-const lvalue reference to type ... ^ ~ p5-var.cpp:74:9: error: non-const lvalue reference to type 'struct Base' cannot bind to a temporary of type 'struct Base' Base &br1 = Base(); // expected-error{{non-const lvalue reference to ... ^ ~~~~~~ p5-var.cpp:102:9: error: non-const reference cannot bind to bit-field 'i' int & ir1 = (ib.i); // expected-error{{non-const reference cannot ... ^ ~~~~~~ p5-var.cpp:98:7: note: bit-field is declared here int i : 17; // expected-note{{bit-field is declared here}} ^ llvm-svn: 90992
2009-12-10 07:02:17 +08:00
}
} // end namespace clang